Sample records for coupling agent gamma-aminopropyltriethoxysilane

  1. Infrared analysis of the effect of composition of n-butyltriethoxysilane and gamma-aminopropyltriethoxysilane blends on tertiary amine-catalyzed anhydride-cured epoxy mixtures. Technical report

    SciTech Connect

    Tidrick, S.L.; Ishida, H.; Koenig, J.L.

    1991-05-01

    The enhancement in mechanical properties observed for silane-treated glass-reinforced epoxy materials is highly dependent on the structure of the coupling agent at the interphase. The effect of varying composition of nonhydrolyzed silane coupling agent blends of gamma aminopropyltriethoxysilane (APS) and butyltriethoxysilane (BTS) on the cure of benzyldimethylamine (BDMA)-catalyzed, nadic methyl anhydride (NMA)-cured diglycidyl ether of bisphenol-A epoxy (BDGE) was studied by Fourier transform infrared spectroscopy (FTIR). The silane blends perturbed the kinetics of the alternating anhydride-epoxy copolymerization reaction, with the perturbation being a nonlinear function of the relative amine concentration in the system.

  2. Test of carcinogenicity in mouse skin: Methylenedianiline,. gamma. glycidyloxytrimethyloxysilane,. gamma. aminopropyltriethoxysilane and a mixture of m-phenylenediamine, methylenedianiline, and diglycidylether of bisphenol-A

    SciTech Connect

    Holland, J.M.; Smith, L.H.; Frome, E.; Whitaker, M.J.; Gipson, L.C.; Fry, R.J.M.

    1987-06-01

    Application of graded concentrations of four test substances in acetone to the skin of C3H mice five times a week resulted in the following: ..gamma..aminopropyltriethoxysilane at concentration of 100 and 50 wt/vol % was a severe and mild skin irritant in female C3Hf/Bd respectively and in males a mild skin irritant. Methylenedianiline at a concentration of 10 wt/vol % in methanol killed 4/9 females and 1/9 males. When acetone was the solvent 3/10 females and 3/10 males died within 2 weeks. No mortality or skin damage occurred with ..gamma..glycidyloxytrimethyloxysilane or the mixture of m-phenylenediamine, methylenedianiline and diglycidylether of bisphenol A (MDA). A study of the effects of a two-year, three times a week, topical application of the four test materials revealed no significant increase in skin tumors. The incidence of liver tumors appeared to be increased by exposure to methylenedianiline and with the mixture (MDA). Significant and dose-dependent increases in mortality were found in male mice with MDA and increased mortality at the highest dose (10.8 mg/week) in females. In the case of methylenedianiline excess mortality was found in both sexes. The precise cause of excess mortality from dermal absorption of the materials applied over a two-year period was not established. 5 refs., 12 figs., 12 tabs.

  3. Wood-Fiber/High-Density-Polyethylene Composites: Coupling Agent Performance

    E-print Network

    .interscience.wiley.com). ABSTRACT: The coupling efficiency of seven coupling agents in wood­polymer composites (WPC) was investi structure. As a coupling agent, mal- eated polyethylene (MAPE) had a better performance in WPC than oxidized on the interfacial bonding in WPC. The coupling agents with a high molecular weight, moderate acid number, and low

  4. Development of high temperature resistant graphite fiber coupling agents

    NASA Technical Reports Server (NTRS)

    Griffin, R. N.

    1975-01-01

    Surface treatments were investigated as potential coupling agents to improve the elevated temperature shear strength retention of polyimide/graphite and polyphenylquinoxaline/graphite composites. The potential coupling agents were evaluated by fiber strand tensile tests, fiber and composite weight losses at 533 and 588K, and by interlaminar shear strength retention at 533 and 588K. The two surface treatments selected for more extensive evaluation were a coating of Ventromer T-1, a complex organometallic reaction product of titanium tetrachloride and trimethyl borate, and a polyphenylquinoxaline (PPQ) sizing which was pyrolyzed in nitrogen to form a carbonaceous layer on the fiber. Pyrolyzed polyphenylquinoxaline is a satisfactory coupling agent for polyimide/Thornel 300 graphite fiber composites. During 1000 hours aging at 588K such composites lose a little over half their transverse tensile strength, and suffer a slight loss in flexural modulus. No degradation of flexural strength or interlaminar shear strength occured during 1000 hours aging at 588K. None of the coupling agents examined had a markedly beneficial effect with polyphenylquinoxaline composites.

  5. From One to Many: Planning for Loosely Coupled Multi-Agent Systems Ronen I. Brafman

    E-print Network

    Domshlak, Carmel

    . To cap- ture the level of interaction between agents we define and exploit the agent interaction (diFrom One to Many: Planning for Loosely Coupled Multi-Agent Systems Ronen I. Brafman Dept, Israel Abstract Loosely coupled multi-agent systems are perceived as easier to plan for because

  6. Coherent Pattern Prediction in Swarms of Delay-Coupled Agents

    PubMed Central

    Mier-y-Teran-Romero, Luis; Forgoston, Eric; Schwartz, Ira B.

    2013-01-01

    We consider a general swarm model of self-propelling agents interacting through a pairwise potential in the presence of noise and communication time delay. Previous work has shown that a communication time delay in the swarm induces a pattern bifurcation that depends on the size of the coupling amplitude. We extend these results by completely unfolding the bifurcation structure of the mean field approximation. Our analysis reveals a direct correspondence between the different dynamical behaviors found in different regions of the coupling-time delay plane with the different classes of simulated coherent swarm patterns. We derive the spatiotemporal scales of the swarm structures, as well as demonstrate how the complicated interplay of coupling strength, time delay, noise intensity, and choice of initial conditions can affect the swarm. In particular, our studies show that for sufficiently large values of the coupling strength and/or the time delay, there is a noise intensity threshold that forces a transition of the swarm from a misaligned state into an aligned state. We show that this alignment transition exhibits hysteresis when the noise intensity is taken to be time dependent. PMID:24255625

  7. Regulating Air Traffic Flow with Coupled Agents Adrian Agogino

    E-print Network

    Tumer, Kagan

    .g., different air- lines), limited resources (e.g., air traffic controllers) and very heavy traffic volume (e problems. This paper extends agent-based methods for controlling air traffic flow to more realistic domains an agent control structure that allows agents to control air traffic flow through one of three mechanisms

  8. Further development of high temperature-resistant graphite fiber coupling agents

    NASA Technical Reports Server (NTRS)

    Griffin, R. N.

    1976-01-01

    Potential coupling agents for graphite fibers were screened by their effect on the weight losses of Thornel 300, HMS, and HTS fibers at 588K for 200 and 400 hours. Unidirectional laminates were made from HMS and HTS fibers, untreated, and treated with each of the seven coupling agents. The matrix of all laminates was PMR polyimide (PMR-PR). On the basis of the best overall retention of elevated temperature interlaminar shear strength after 200 hours at 588K, composite weight after 200 hours at 588K, and fiber weight after 400 hours at 588K, ventromer T-1 applied from aqueous solution and pyrolyzed PPQ were selected for further evaluation as coupling agents for HTS fiber while ventromer T-2 and pyrolyzed PPQ were selected as coupling agents for HMS fiber. It was shown that pyrolyzed PPQ as a coupling agent improves the oxidative stability of HTS/PMR-PI composites.

  9. Use of titanate coupling agents in Kevlar (trade name)/phenolic composites

    SciTech Connect

    Menon, N.; Blum, F.D.; Dharani, L.R.

    1994-04-02

    Surface modification of Kevlar(R) fibers with titanate coupling agents for improved adhesion of the fiber and resin in Kevlar(R)/phenolic composites has been attempted to explore the possibility of enhancement in adhesion and bulk properties of composites for friction materials. Titanate coupling agents were used and flexural properties of the Kevlar(R)-fiber reinforced composites determined. A study of different amounts of the coupling agents at the fiber-matrix interface suggested that 2% by weight of fiber was the optimum amount, in terms of improvement in flexural properties. The composite samples with the coupling agents, showed an increase in flexural strength, over the untreated samples with the maximum increase being approx. 18% over the control. Water absorption studies were conducted on Kevlar(R)/phenolic composites treated with organotitanates to determine the effectiveness of these coupling agents in improving resistance to moisture attack. The treated Kevlar(R)/phenolic composite samples exhibited greater resistance to moisture-ingress over the untreated samples. The control samples showed a decrease of 17% in flexural strength. The largest decrease in strength was 14% for the treated samples containing coupling agent tetrakis(2-ethylhexyl)titanate (TYZOR TOT). Recovery in strength on reconditioning, was also greater for treated samples over control. A recovery in strength of ca. 94% was seen for some treated samples. Coupling agents, Composites, Kevlar, Interfaces, Mechanical properties.

  10. Thermal stability of polycarbonate composites reinforced with potassium titanate whiskers: effect of coupling agent addition

    Microsoft Academic Search

    Wei Jiang; S. C. Tjong

    1999-01-01

    Polycarbonate (PC), and PC\\/potassium titanate (K2Ti6O13) whisker composites were extruded in a single extruder. Methyltrimethoxy silane (C4H12O3Si) and tetrabutyl orthotitanate (C16H36O4Ti) were used as coupling agents for these specimens. Differential thermal analysis (DTA) and thermogravimetric (TG) measurements showed that the methyltrimethoxy silane coupling agent had little influence on the thermal stability of PC. On the other hand, the glass transition

  11. Polymer-Supported Siloxane Transfer Agents for Pd-Catalyzed Cross-Coupling Reactions

    PubMed Central

    Nguyen, Minh H.; Smith, Amos B.

    2013-01-01

    The design, synthesis and validation of a ROMP polymer supporting siloxane transfer agents have been achieved that permit efficient palladium-catalyzed cross-coupling reactions. The solubility properties of the polymer not only facilitate product purification, but also recycling without significant loss of cross-coupling activity. PMID:23901881

  12. Rebonding performance of different ceramic brackets conditioned with a new silane coupling agent.

    PubMed

    Falkensammer, Frank; Jonke, Erwin; Bertl, Michael; Freudenthaler, Josef; Bantleon, Hans Peter

    2013-02-01

    The objective of this study was to investigate the rebonding effect of a new silane coupling agent on various ceramic brackets bonded to ceramic specimen. Different ceramic brackets (Fascination 2, Clarity SL, and In-OvationC) were assigned to three groups: rebonding with new silane coupling agent, rebonding with conventional silane coupling agent, or regular bonding as control (n = 16). Bracket adhesion was calculated with a shear test in a universal testing machine. The bracket-composite-ceramic interface was evaluated using the adhesive remnant index score. One-way analysis of variance was applied for inferential statistics. Rebonding with the new silane coupling agent resulted in high shear bond strengths (SBSs; mean values: 37.44-41.24 MPa) and ceramic specimen fractures. Rebonding with the conventional silane coupling agent resulted in significantly (P < 0.001) lower clinically adequate SBS (mean values: 20.20-29.92 MPa) with the least ceramic specimen fractures. Regularly bonded ceramic brackets resulted in clinically adequate to high SBS (mean values: 17.06-41.56 MPa) depending on their bracket base design. Rebonded ceramic brackets showed sufficient SBS to ceramic specimen surfaces. However, increased bracket adhesion was associated with a risk of ceramic specimen surface damage. Therefore, ceramic brackets rebonded with the new silane coupling should be debonded cautiously using alternative debonding methods. PMID:21926314

  13. Recyclable Polystyrene-Supported Siloxane-Transfer Agent for Palladium-Catalyzed Cross-Coupling Reactions

    PubMed Central

    2015-01-01

    The rational design, synthesis, and validation of a significantly improved insoluble polymer-supported siloxane-transfer agent has been achieved that permits efficient palladium-catalyzed cross-coupling reactions. The cross-linked polystyrene support facilitates product purification with excellent siloxane recycling. Drawbacks of a previous polymer-supported siloxane-transfer agent, relating to reaction efficiency and polymer stability after repeated cycles, have been addressed. PMID:24661113

  14. Recyclable polystyrene-supported siloxane-transfer agent for palladium-catalyzed cross-coupling reactions.

    PubMed

    Nguyen, Minh H; Smith, Amos B

    2014-04-01

    The rational design, synthesis, and validation of a significantly improved insoluble polymer-supported siloxane-transfer agent has been achieved that permits efficient palladium-catalyzed cross-coupling reactions. The cross-linked polystyrene support facilitates product purification with excellent siloxane recycling. Drawbacks of a previous polymer-supported siloxane-transfer agent, relating to reaction efficiency and polymer stability after repeated cycles, have been addressed. PMID:24661113

  15. The Interactions of Silane and Zirconate Coupling Agents with Calcium Carbonate

    Microsoft Academic Search

    R. Doufnoune; N. Haddaoui; F. Riahi

    2007-01-01

    The present work deals with the study of the structure and the form of the deposit on calcium carbonate of two types of silane coupling agents and a zirconate one. The structure of the deposited layers as well as their interactions with the filler were investigated by means of Fourier Transform Infra-Red Spectroscopy. The extent of the recovery was determined

  16. Coupled Human and Natural Systems: A Multi-Agent Based Approach

    E-print Network

    Monticino, Michael

    Coupled Human and Natural Systems: A Multi-Agent Based Approach Monticino, Ma , Acevedo M and public policies. Determining conditions on the interactions between human decisions and natural systems decisions and ecosystems, and how the environmental consequences of these decisions influence human values

  17. Effects of silane coupling agents and solutions of different polarity on PMMA bonding to alumina.

    PubMed

    Chaijareenont, Pisaisit; Takahashi, Hidekazu; Nishiyama, Norihiro; Arksornnukit, Mansuang

    2012-01-01

    The objective of this study was to clarify the effects of silane coupling agents and solutions of different polarity on polymethyl methacrylate (PMMA) bonding to alumina. Three silane coupling agents (3-methacryloxypropyltrimethoxysilane (MPS),3-aminopropyltriethoxysilane (APS) and N-2 (aminoethyl) 3-aminopropyltriethoxysilane) and 3 different polar solutions, 70% ethanol, isopropanol and toluene, were selected for silanization. Shear bond strengths were statistically compared with Tukey HSD(?=0.05). The alumina surfaces after silanization and shear bond test were examined with an energy dispersive spectrometer (EDS).The bond strengths of PMMA on the alumina with MPS (15.0 MPa), APS (13.8 MPa) in ethanol were greater than the others in nonthermocyclings. The bond strength decreased after thermocyclings. The ethanol groups were greater than the others. EDS revealed Si remaining on the alumina surface after the shear bond test. The results indicated that the silanization using MPS and APS with ethanol solution was effective. PMID:22864214

  18. Polycaprolactone-starch blends with corn-based coupling agent: physical properties and in vitro analysis.

    PubMed

    Nor, Fethma M; Kurniawan, Denni; Seo, Young-Kwon; Park, Jung-Keug; Lee, Ho Yong; Lim, Joong Yeon

    2012-09-01

    In an attempt to improve properties of polycaprolcatone-starch blend, this study uses zein as coupling agent in preparing the blend through a single-step process. Zein, which has affinity to both polar and non-polar groups, is expected to improve miscibility between the blends' constituents and its overall biocompatibility. Mechanical properties of the blend were tested and further characterizations (Fourier transform infrared spectroscopy, thermal properties) were performed to analyze the effect of zein as an addition to the blend's physical properties. The blend's biocompatibility was examined by indirect methods (contact angle and weight gain after immersion in simulated body fluid) and in vitro analysis. No significant effect on the blend's strength and stiffness was caused by adding zein. Hydrophilicity and cell affinity were improved when zein was added. Zein did not perform as a coupling agent that improved miscibility between polycaprolactone and starch, but its addition improved the blend's biocompatibility. PMID:23025170

  19. Biodegradable polymers\\/bamboo fiber biocomposite with bio-based coupling agent

    Microsoft Academic Search

    Seung-Hwan Lee; Siqun Wang

    2006-01-01

    Effects of lysine-based diisocyanate (LDI) as a coupling agent on the properties of biocomposite from poly (lactic acid) (PLA), poly (butylene succinate) (PBS) and bamboo fiber (BF) were investigated. Tensile properties, water resistance, and interfacial adhesion of both PLA\\/BF and PBS\\/BF composites were improved by the addition of LDI, whereas thermal flow became somewhat difficult due to cross-linking between polymer

  20. Chemical reaction between polyvinyl alcohol and titanate coupling agent with x-ray photoelectron spectroscopy

    Microsoft Academic Search

    Li Bei-xing; Zhang Wen-sheng

    2003-01-01

    The chemical reaction between polyvinyl alcohol (PVA) and tri (dioctylpyrophosphoryloxy) isopropyl titanate (NDZ-201) was studied using X-ray photoelectron spectroscopy (XPS). The results show that some C?OH functional groups of PVA react\\u000a with the titanate coupling agent to form CPVA?O?Ti?O?CPVA bond. The cross-linking of the PVA chains occurs through the formation of CPVA?O?Ti?O?CPVA bonds and produces a three dimensional hydrophobic polymer

  1. Nash Strategies and Adaptation for Decentralized Games Involving Weakly-coupled Agents

    Microsoft Academic Search

    Minyi Huang; R. P. Malhame; Peter E. Caines

    2005-01-01

    We consider dynamic games in large population conditions where the agents evolve according to non-uniform dynamics and are weakly coupled via their individual dynamics and costs. A state aggregation technique is employed to obtain a set of decentralized control laws for the individuals which ensures closed-loop stability and possesses an é-Nash equilibrium property. We then propose a scheme for Nash

  2. Structural Effects on the Interfacial Strength of Silane Coupling Agent Layers

    NASA Astrophysics Data System (ADS)

    Nakamura, Shigeo

    2005-03-01

    The structural effects of silane coupling agent layers on crack growth along a model interface between the natural oxide of [100]Si and an epoxy-hardener mixture consisting of the diglycidyl ether of bisphenol A(DGEBA) and triethylenetetramine (TETA) have been investigated. Previous experiments where (3-glycidoxypropyl)trimethoxysilane (GPS) was the coupling agent revealed network structures that were only loosely cross-linked in the center of the layers. The penetration of epoxy into this swellable layer produced a relatively high fracture energy (Gc) and a threshold energy release rate (Gth), immersed in water, that decreased only modestly between 20 and 80 degrees C. Here we compared these results with Gc and Gth from 10nm thick layers of (3-aminopropyl)trimethoxysilane (APS) and APS combined with [3-(Phenylamino)propyl]trimethoxysilane (PAPS) obtained by spin casting the silane coupling agent solutions composed of 90wt% ethanol and 10wt% water on the silicon oxide interface. These layers, which are closer to those used in typical industrial applications, were characterized by FT-IR, scanning force microscopy and X-ray reflection experiments.

  3. Effects of coupling agents on structure and properties of polyimide\\/Al2O3 nanocomposite films

    Microsoft Academic Search

    L. Z. Liu; L. Weng; Y. X. Song; L. Gao; H. Zhao; Q. Q. Lei

    2011-01-01

    Purpose – The purpose of this paper is to investigate the effects of coupling agents on the structure and properties of the nanocomposite films and clarify their mechanism. Polyimide (PI)\\/Al2O3 nanocomposite films were prepared using different coupling agents. Design\\/methodology\\/approach – Poly(amic acid) (PAA) was firstly synthesised from appropriate pyromellitic diannanocomposite and oxydianiline in N-dimethylacetamide. Calculated amount of nano-Al2O3 particles modified

  4. Surface modification of Fe3O4@SiO2 microsphere by silane coupling agent

    NASA Astrophysics Data System (ADS)

    Ahangaran, Fatemeh; Hassanzadeh, Ali; Nouri, Sirous

    2013-04-01

    In the present study, Fe3O4@SiO2 core-shell microspheres were prepared via two steps. First, Fe3O4 nanoparticles were synthesized by co-precipitation of Fe+3 and Fe+2 as reaction substrates and NaOH as precipitant. Second, the surface of Fe3O4 was coated with silica by hydrolysis of tetraethylorthosilicate as the silica source. Subsequently, in order to reduce the amount of interaction and the agglomeration of Fe3O4@SiO2 microspheres, the silica shell of these particles was modified by vinyltriethoxysilane as the silane coupling agent. The structural properties of the samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy analyses. The results indicated that the average sizes of Fe3O4 and Fe3O4@SiO2 particles were about 50 and 500 nm, respectively. Also, the surface characterization of Fe3O4@SiO2 microspheres showed that the silane coupling agent was covalently coupled with the silica surface.

  5. Development of polypropylene/wood flour ecocomposites. Evaluation of silane as coupling agent

    SciTech Connect

    Bouza, R.; Barral, L.; Abad, M. J.; Montero, B. [Grupo de Polimeros, Dpto. de Fisica, E.U.P. Ferrol, Universidad de A Coruna, Avda. 19 de Febrero s/n, 15405 Ferrol (Spain)

    2010-06-02

    The effects of Pinus Sylvestris wood flour as filler in polypropylene matrix was evaluated. The mechanical properties and the morphology of different wood flour/polypropylene composites (WPC) were studied. The composites materials were prepared with several amounts of wood flour from 10 to 30% wt. Mechanical properties show that the wood flour incorporation increases the rigidity of the composites. Morphological analysis indicates that agglomerates are formed, with amounts exceeding 30% of wood flour. For the silane--treated composites, the dispersion of the filler into the polypropylene (PP) matrix improved. Shore D hardness of the composites is decreased with the addition of the coupling agent.

  6. Development of polypropylene/wood flour ecocomposites. Evaluation of silane as coupling agent

    NASA Astrophysics Data System (ADS)

    Bouza, R.; Barral, L.; Abad, M. J.; Montero, B.

    2010-06-01

    The effects of Pinus Sylvestris wood flour as filler in polypropylene matrix was evaluated. The mechanical properties and the morphology of different wood flour/polypropylene composites (WPC) were studied. The composites materials were prepared with several amounts of wood flour from 10 to 30% wt. Mechanical properties show that the wood flour incorporation increases the rigidity of the composites. Morphological analysis indicates that agglomerates are formed, with amounts exceeding 30% of wood flour. For the silane—treated composites, the dispersion of the filler into the polypropylene (PP) matrix improved. Shore D hardness of the composites is decreased with the addition of the coupling agent.

  7. Effect of a silane coupling agent on the mechanical properties of a microfibrillated cellulose composite.

    PubMed

    Ifuku, Shinsuke; Yano, Hiroyuki

    2015-03-01

    Composite materials reinforced with microfibrillated cellulose (MFC) fibers were prepared and characterized in terms of their mechanical properties. The surface of the MFC fibers was treated with a silane coupling reagent having an NH2 functional group to improve fiber-matrix adhesion. Due to the unique structure of the MFC, which consists of nano-order-scale interconnected fibrils and microfibrils with greatly expanded surface area and submicron pore size compared to conventional cellulose, it was possible to enhance the effect of silane coupling agent and thereby improve the compatibility between the fibers and matrix and also the dispersibility of fibers. The Young's modulus was significantly increased to more than 70%. PMID:25575951

  8. Investigating the use of coupling agents to improve the interfacial properties between a resorbable phosphate glass and polylactic acid matrix.

    PubMed

    Hasan, Muhammad Sami; Ahmed, Ifty; Parsons, Andrew J; Rudd, Chris D; Walker, Gavin S; Scotchford, Colin A

    2013-09-01

    Eight different chemicals were investigated as potential candidate coupling agents for phosphate glass fibre reinforced polylactic acid composites. Evidence of reaction of the coupling agents with phosphate glass and their effect on surface wettability and glass degradation were studied along with their principle role of improving the interface between glass reinforcement and polymer matrix. It was found that, with an optimal amount of coupling agent on the surface of the glass/polymer, interfacial shear strength improved by a factor of 5. Evidence of covalent bonding between agent and glass was found for three of the coupling agents investigated, namely: 3-aminopropyltriethoxysilane; etidronic acid and hexamethylene diisocyanate. These three coupling agents also improved the interfacial shear strength and increased the hydrophobicity of the glass surface. It is expected that this would provide an improvement in the macroscopic properties of full-scale composites fabricated from the same materials which may also help to retain these properties for the desired length of time by retarding the breakdown of the fibre/matrix interface within these composites. PMID:22781920

  9. Cytocompatibility and Mechanical Properties of Short Phosphate Glass Fibre Reinforced Polylactic Acid (PLA) Composites: Effect of Coupling Agent Mediated Interface

    PubMed Central

    Hasan, Muhammad Sami; Ahmed, Ifty; Parsons, Andrew; Walker, Gavin; Scotchford, Colin

    2012-01-01

    In this study three chemical agents Amino-propyl-triethoxy-silane (APS), sorbitol ended PLA oligomer (SPLA) and Hexamethylene diisocyanate (HDI) were identified to be used as coupling agents to react with the phosphate glass fibre (PGF) reinforcement and the polylactic acid (PLA) polymer matrix of the composite. Composites were prepared with short chopped strand fibres (l = 20 mm, ? = 20 µm) in a random arrangement within PLA matrix. Improved, initial composite flexural strength (~20 MPa) was observed for APS treated fibres, which was suggested to be due to enhanced bonding between the fibres and polymer matrix. Both APS and HDI treated fibres were suggested to be covalently linked with the PLA matrix. The hydrophobicity induced by these coupling agents (HDI, APS) helped to resist hydrolysis of the interface and thus retained their mechanical properties for an extended period of time as compared to non-treated control. Approximately 70% of initial strength and 65% of initial modulus was retained by HDI treated fibre composites in contrast to the control, where only ~50% of strength and modulus was retained after 28 days of immersion in PBS at 37 °C. All coupling agent treated and control composites demonstrated good cytocompatibility which was comparable to the tissue culture polystyrene (TCP) control, supporting the use of these materials as coupling agent’s within medical implant devices. PMID:24955744

  10. The effects of corn zein protein coupling agent on mechanical properties of flax fiber reinforced composites

    NASA Astrophysics Data System (ADS)

    Whitacre, Ryan John

    In the field of renewable materials, natural fiber composites demonstrate the capacity to be a viable structural material. When normalized by density, flax fiber mechanical properties are competitive with E-glass fibers. However, the hydrophilic nature of flax fibers reduces the interfacial bond strength with polymer thermosets, limiting composite mechanical properties. Corn zein protein was selected as a natural bio-based coupling agent because of its combination of hydrophobic and hydrophilic properties. Zein was deposited on the surface of flax, which was then processed into unidirectional composite. The mechanical properties of zein treated samples where measured and compared against commonly utilized synthetic treatments sodium hydroxide and silane which incorporate harsh chemicals. Fourier transform infrared spectroscopy, chemical analysis, and scanning electron microscopy were also used to determine analyze zein treatments. Results demonstrate the environmentally friendly zein treatment successfully increased tensile strength 8%, flexural strength 17%, and shear strength 30% compared to untreated samples.

  11. Surface modification of nano-TiN by using silane coupling agent

    NASA Astrophysics Data System (ADS)

    Cheng, Guojun; Luo, Jiaqi; Qian, Jiasheng; Miao, Jibin

    2014-06-01

    Titanium nitride (TiN) nano-particles were subjected to graft modification by silane coupling agent (KH-570) via a direct blending method. The hydroxyl groups on the surface of TiN nano-particles can interact with silanol groups [-Si-OCH3] of KH-570 forming an organic coating layer. The covalent bonds (Ti-O-Si) formation was testified by Fourier transform infrared spectra (FTIR) and X-ray photoelectron spectroscopy (XPS). Through transmission electron micrograph (TEM) observations, it was found that KH-570 could improve the dispersibility of nano-TiN particles in ethyl acetate. Thermo gravimetric analysis (TGA) and contact angle measurements indicated that KH-570 molecules were adsorbed or anchored on the surface of nano-TiN particle and the net efficiency of it was 22.76 %, which facilitated to hinder the aggregation of nano-TiN particles.

  12. Effect of silane coupling agent chemistry on electrical breakdown across hybrid organic-inorganic insulating films.

    PubMed

    Diebold, Roger M; Gordon, Michael J; Clarke, David R

    2014-08-13

    Dielectric breakdown measurements were conducted on self-assembled monolayer (SAM)/native silicon oxide hybrid dielectrics using conductive atomic force microscopy (C-AFM). By depositing silane coupling agents (SCAs) through a diffusional barrier layer, SAM roughness was decoupled from chemistry to compare the chemical effects of exposed R-group functionality on dielectric breakdown. Using Weibull and current-voltage (I-V) analysis, the breakdown strength was observed to be independent of SCA R-group length, and the addition of a SAM was seen to improve the breakdown strength relative to native silicon oxide by up to 158%. Fluorinated SCAs were observed to suppress tunneling leakage and exhibited increased breakdown strength relative to their hydrocarbon analogs. Electron trapping, scattering, or attachment processes inherent to the fluorinated moieties are thought to be the origin of the improved breakdown properties. PMID:25010384

  13. Effect of fibre and coupling agent contents on water absorption and flexural modulus of wood fibre polyethylene composites

    NASA Astrophysics Data System (ADS)

    Tissandier, C.; Zhang, Y.; Rodrigue, D.

    2014-05-01

    In two previous studies, wood fiber-reinforced polymer composites (WPC) were prepared via melt processing. In particular, a response surface strategy of a 20 run optimal design for these three factors was adopted. It was found that for these WPC mixing torque, melt viscosity, Young's modulus and tensile stress at break were related to the type of wood used, as well as wood and coupling agent contents. In addition, thermal properties and strain at break were mainly affected by wood and coupling agent contents. Here, a more complete characterization of these WPC under extreme environmental conditions is performed. In particular, the effect of coupling agent content, wood fibre content and wood fibre type on water absorption and flexural modulus are reported under different water immersion time and temperature. The results show that water absorption is influenced by all the parameters studied, while flexural modulus is mainly influenced by wood content and immersion temperature.

  14. The effect of interstitial pressure on therapeutic agent transport: coupling with the tumor blood and lymphatic vascular systems.

    PubMed

    Wu, Min; Frieboes, Hermann B; Chaplain, Mark A J; McDougall, Steven R; Cristini, Vittorio; Lowengrub, John S

    2014-08-21

    Vascularized tumor growth is characterized by both abnormal interstitial fluid flow and the associated interstitial fluid pressure (IFP). Here, we study the effect that these conditions have on the transport of therapeutic agents during chemotherapy. We apply our recently developed vascular tumor growth model which couples a continuous growth component with a discrete angiogenesis model to show that hypertensive IFP is a physical barrier that may hinder vascular extravasation of agents through transvascular fluid flux convection, which drives the agents away from the tumor. This result is consistent with previous work using simpler models without blood flow or lymphatic drainage. We consider the vascular/interstitial/lymphatic fluid dynamics to show that tumors with larger lymphatic resistance increase the agent concentration more rapidly while also experiencing faster washout. In contrast, tumors with smaller lymphatic resistance accumulate less agents but are able to retain them for a longer time. The agent availability (area-under-the curve, or AUC) increases for less permeable agents as lymphatic resistance increases, and correspondingly decreases for more permeable agents. We also investigate the effect of vascular pathologies on agent transport. We show that elevated vascular hydraulic conductivity contributes to the highest AUC when the agent is less permeable, but to lower AUC when the agent is more permeable. We find that elevated interstitial hydraulic conductivity contributes to low AUC in general regardless of the transvascular agent transport capability. We also couple the agent transport with the tumor dynamics to simulate chemotherapy with the same vascularized tumor under different vascular pathologies. We show that tumors with an elevated interstitial hydraulic conductivity alone require the strongest dosage to shrink. We further show that tumors with elevated vascular hydraulic conductivity are more hypoxic during therapy and that the response slows down as the tumor shrinks due to the heterogeneity and low concentration of agents in the tumor interior compared with the cases where other pathological effects may combine to flatten the IFP and thus reduce the heterogeneity. We conclude that dual normalizations of the micronevironment - both the vasculature and the interstitium - are needed to maximize the effects of chemotherapy, while normalization of only one of these may be insufficient to overcome the physical resistance and may thus lead to sub-optimal outcomes. PMID:24751927

  15. Bonelike apatite formation on ethylene-vinyl alcohol copolymer modified with silane coupling agent and calcium silicate solutions

    Microsoft Academic Search

    Ayako Oyane; Masakazu Kawashita; Kazuki Nakanishi; Tadashi Kokubo; Masahiko Minoda; Takeaki Miyamoto; Takashi Nakamura

    2003-01-01

    An ethylene-vinyl alcohol copolymer (EVOH) was treated with a silane coupling agent and calcium silicate solutions, and then soaked in a simulated body fluid (SBF) with ion concentrations approximately equal to those of human blood plasma. A smooth and uniform bonelike apatite layer was successfully formed on both the EVOH plate and the EVOH-knitted fibers in SBF within 2 days.

  16. Interfacial properties of two-carbon fiber reinforced polycarbonate composites using two-synthesized graft copolymers as coupling agents

    SciTech Connect

    Park, J.M.

    2000-05-15

    Two model coupling agents, water-dispersible (WDGP) and tetrahydrofuran (THF)-soluble graft copolymers (TSGP), were synthesized for carbon fiber/polycarbonate (PC) composites. WDGP contains a long polyacrylamide (PAAm) chain grafted on a PC backbone, whereas TSGP contains a short grafted PAAm Chain. Measurements of the interfacial shear strength (IFSS) and other interfacial properties were evaluated using a fragmentation test for two-fiber composites (TFC) to provide the same loading state. Optimal conditions for the treatment was established as a function of treatment time, temperature, initial concentration, and melting procedure. The amount adsorbed on the carbon fiber was higher for WDGP and TSGP were 54% and 74%, respectively. Mechanisms of energy adsorption for WDGP and intermolecular interaction for TSGP can be considered to contribute differently to IFSS improvement. The improvement in IFSS for both coupling agents may be due to chemical and hydrogen bonding in the interface between functional groups in the carbon fiber and PAAm in the coupling agents and to interdiffusion in the interface between PC in coupling agents and matrix PC.

  17. Bifunctional Coupling Agents for Radiolabeling of Biomolecules and Target-Specific Delivery of Metallic Radionuclides

    PubMed Central

    Liu, Shuang

    2008-01-01

    Receptor-based radiopharmaceuticals are of great current interest in early molecular imaging and radiotherapy of cancers, and provide a unique tool for target-specific delivery of radionuclides to the diseased tissues. In general, a target-specific radiopharmaceutical can be divided into four parts: targeting biomolecule (BM), pharmacokinetic modifying (PKM) linker, bifunctional coupling or chelating agent (BFC), and radionuclide. The targeting biomolecule serves as a “carrier” for specific delivery of the radionuclide. PKM linkers are used to modify radiotracer excretion kinetics. BFC is needed for radiolabeling of biomolecules with a metallic radionuclide. Different radiometals have significant difference in their coordination chemistry, and require BFCs with different donor atoms and chelator frameworks. Since the radiometal chelate can have a significant impact on physical and biological properties of the target-specific radiopharmaceutical, its excretion kinetics can be altered by modifying the coordination environment with various chelators or coligand, if needed. This review will focus on the design of BFCs and their coordination chemistry with technetium, copper, gallium, indium, yttrium and lanthanide radiometals. PMID:18538888

  18. [Luminescence properties of silane coupling agent modified stilbene 3 doped lead-tin-fluorophosphate glass].

    PubMed

    Gu, Mu; Zhao, Zhi-Wei; Liu, Xiao-Lin; Ni, Chen; Huang, Shi-Ming; Liu, Bo; Ouyang, Xiao-Ping

    2010-02-01

    In the present work, the SnF2 powder was modified by silane coupling agent KBM403. The Fourier transform infrared spectrum (FTIR) of the modified powder showed that KBM403 was absorbed on the surface of SnF2 particles through physical absorption besides a weak chemical absorption. Then the SnF2 powder was modified by the solution dissolved with stilbene 3. The modified SnF2 powder could improve the decentralization of stilbene 3 dopant. An organic-inorganic hybrid luminescence glass was prepared by doping the modified SnF2 powder with stilbene 3 into the low melting lead-tin-fluorophosphate (PTFP) glass. The excitation, emission and transmission (absorption) spectra were used to characterize the hybrid glass. The results showed that introducing KBM403 could improve solubility and decentralization of stilbene 3 in PTFP glass, reduce the concentration of stilbene 3 dimers, and increase the transparency and homogeneity of the glass. Meanwhile, the luminescence intensity of stilbene 3 in this hybrid glass increased evidently compared with that of the stilbene 3 doped glass. The effect was assumed to be the reduction of the quenching of luminescence from stilbene 3 dimer and the enhancement of the rigidity of stilbene 3 molecules due to the interaction between KBM403 and stilbene 3. PMID:20384113

  19. Socio-Ecohydrologic Agents And Services: Integrating Human And Natural Components To Address Coupled System Resilience

    NASA Astrophysics Data System (ADS)

    Pavao-zuckerman, M.; Pope, A.; Chan, D.; Curl, K.; Gimblett, H. R.; Hough, M.; House-Peters, L.; Lee, R.; Scott, C. A.

    2012-12-01

    Riparian corridors in arid regions are highly valued for their relative scarcity, and because healthy riparian systems support high levels of biodiversity, can meet human demand for water and water-related resources and functions. Our team is taking a transdiciplinary social-ecological systems approach to assessing riparian corridor resilience in two watersheds (the San Pedro River in USA and Mexico, and the Rio San Miguel in Mexico) through a project funded by the NSF CNH program ("Strengthening Resilience of Arid Region Riparian Corridors"). Multiple perspectives are integrated in the project, including hydrology, ecology, institutional dynamics, and decision making (at the level of both policy and individual choice), as well as the perspectives of various stakeholder groups and individuals in the watersheds. Here we discuss initial findings that center around linking changes in ecohydrology and livelihoods related to decisions in response to climatic, ecological, and social change. The research team is implementing two approaches to integrate the disparate disciplines participating in the research (and the varied perspectives among the stakeholders in this binational riparian context): (1) ecosystem service assessment, and (2) agent based model simulation. We are developing an ecosystem service perspective that provides a bridge between ecological dynamics in the landscape and varied stakeholder perspectives on the implications of ecohydrology for well-being (economic, cultural, ecological). Services are linked on one hand to the spatial patterns of traits of individuals within species (allowing a more predictive application of ecosystem services as they vary with community change in time), and to stakeholder perspectives (facilitating integration of ecosystem services into our understanding of decision making processes) in a case study in the San Pedro River National Conservation Area. The agent- based model (ABM) approach incorporates the influence of human decision-making on spatially-explicit landscapes in a mechanistic way, taking into account social interaction, adaptation, and decision-making at different levels, allowing individual stakeholders to make decisions based on their unique perceptions of their environment, be it economic, social, or ecological awareness. Initial parameterization of the ABM proceeds from a case study centered in the town of Rayón, Sonora, Mexico, where semi-structured interviews were used to elicit perceptions by water resource users of CNH function, change, and solutions relating to livelihood changes in response to several drivers. In both case studies, we see the potential and limitations for an approach to adaptive management and decision support related to water resources that links ecosystem services and agent-based modeling. Methodologically, synthetic approaches such as these may allow coupling of systems for improved assessment and analysis, while at the same time lack a connection to the perspectives of water users and managers on the ground. There is thus potential for a either a loss of system resilience in the face of external change, or an opportunity to increase system resilience by building off perspectives already in place within these coupled socio-ecohydrologic systems.

  20. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Second annual report, October 1993--September 1994

    SciTech Connect

    Pitts, M.J.

    1995-04-01

    {open_quotes}Investigation of Oil Recovery Improvement by Coupling an Interfacial Tension Agent and a Mobility Control Agent in Light Oil Reservoirs{close_quotes} is studying two major areas concerning co-injecting an interfacial tension reduction agent(s) and a mobility control agent. The first area defines the interactions of alkaline agents, surfactants, and polymers on a fluid-fluid and a fluid-rock basis. The second area concerns the economic improvement of the combined technology. This report continues the fluid-fluid interaction evaluations and begins the fluid-rock studies. Fluid-fluid interfacial tension work determined that replacing sodium ion with either potassium or ammonium ion in solutions with interfacial tension reduction up to 19,600 fold was detrimental and had little or no effect on alkali-surfactant solutions with interfacial tension reduction of 100 to 200 fold. Reservoir brine increases interfacial tension between crude oil and alkaline-surfactant solutions. Na{sub 2}CO{sub 3}-surfactant solutions maintained ultra low and low interfacial tension values better than NaOH-surfactant solutions. The initial phase of the fluid-rock investigations was adsorption studies. Surfactant adsorption is reduced when co-dissolved with alkali. Na{sub 2}CO{sub 3} and Na{sub 3}PO{sub 4} are more efficient at reducing surfactant adsorption than NaOH. When polymer is added to the surfactant solution, surfactant adsorption is reduced as well. When both polymer and alkali are added, polymer is the dominate component, reducing the Na{sub 2}CO{sub 3} and NaOH effect on adsorption. Substituting sodium ion with potassium or ammonium ion increased or decreased surfactant adsorption depending on surfactant structure with alkali having a less significant effect. No consistent change of surfactant adsorption with increasing salinity was observed in the presence or absence of alkali or polymer.

  1. LIVING COUPLING REACTION IN LIVING CATIONIC POLYMERIZATION. 4. SYNTHESIS OF TELECHELIC POLYISOBUTYLENES USING BIS-FURANYL DERIVATIVES AS COUPLING AGENTS

    Microsoft Academic Search

    Savvas Hadjikyriacou; Rudolf Faust; Toshio Suzuki

    2000-01-01

    The synthesis of telechelic polyisobutylenes (PIB) by coupling with 2,5-bis-(2-furyl-2-propyl)furan is described. Hydroxyl telechelic PIB with controlled molecular weight was obtained by haloboration-initiation of isobutylene (IB) with a BCl3\\/BBr3 mixture, followed by coupling of the living ends and oxidation of the (CH3O)2B- end groups with H2O2 in alkaline tetrahydrofuran. Vinyl telechelic PIBs were prepared by coupling living PIB obtained using

  2. Influence of silane coupling agents on the interlaminar and thermal properties of woven glass fabric\\/nylon 6 composites

    Microsoft Academic Search

    Donghwan Cho; Suk Hyang Yun; Junkyung Kim; Soonho Lim; Min Park; Sang-Soo Lee; Geon-Woong Lee

    2004-01-01

    In this study, the influence of silane coupling agents, featuring different organo-functional groups on the interlaminar and\\u000a thermal properties of woven glass fabric-reinforced nylon 6 composites, has been by means of shortbeam shear tests, dynamic\\u000a mechanical analysis, scanning electron microscopy, and thermogravimetric analysis. The results indicate that the fiber-matrix\\u000a interfacial characteristics obtained using the different analytical methods agree well with

  3. Interfacial Properties of Two-Carbon Fiber Reinforced Polycarbonate Composites Using Two-Synthesized Graft Copolymers as Coupling Agents

    Microsoft Academic Search

    Joung-Man Park

    2000-01-01

    Two model coupling agents, water-dispersible (WDGP) and tetrahydrofuran (THF)-soluble graft copolymers (TSGP), were synthesized for carbon fiber\\/polycarbonate (PC) composites. WDGP contains a long polyacrylamide (PAAm) chain grafted on a PC backbone, whereas TSGP contains a short grafted PAAm chain. Measurements of the interfacial shear strength (IFSS) and other interfacial properties were evaluated using a fragmentation test for two-fiber composites (TFC)

  4. Improved adhesion between nickel–titanium shape memory alloy and a polymer matrix via silane coupling agents

    Microsoft Academic Search

    N. A. Smith; G. G. Antoun; A. B. Ellis; W. C. Crone

    2004-01-01

    NiTi wires were functionalized with silane coupling agents to improve interfacial adhesion between the inorganic constituent and a host matrix for composite applications. Surface derivatization was characterized by X-ray Photoelectron Spectroscopy, and mechanical pullout tests were performed to quantify the increase in adhesion between the NiTi shape memory alloy wires and polymer matrix. Improvements of roughly 100% in the adhesion

  5. Synthesis of N-arylated oxazolidinones via a palladium catalyzed cross coupling reaction. Application to the synthesis of the antibacterial agent Dup-721

    Microsoft Academic Search

    David J Madar; Hana Kopecka; Daisy Pireh; Jonathan Pease; Marina Pliushchev; Richard J Sciotti; Paul E Wiedeman; Stevan W Djuric

    2001-01-01

    A method for the intermolecular coupling of aryl bromides and oxazolidinones is described. Application to intermediates useful for the preparation of a known class of antibacterial agent and the synthesis of the known antibacterial oxazolidinone Dup-721 are described.

  6. Coupling multi-agent model and GIS to simulate pine wood nematode disease spread in ZheJiang Province, China

    NASA Astrophysics Data System (ADS)

    Huang, Huaguo; Wang, Lei; Zhang, XiaoLi; Luo, YouQing; Zhao, Liqiong

    2008-10-01

    A coupled method based on multi-agent model, remote sensing and GIS is described to simulate the forest disease spread. The coupled model focuses on the temporal dynamics of the Bursaphelenchus xylophilus population at the landscape scale. Each individual is modeled as an autonomous agent who behaves according to a set of rules including spreading in the landscape, feeding on Pinus massoniana, sheltering in forest edges and dying, constrained by terrain, land cover and other variables. The model parameters are derived from remote sensing data and field measurements. Ten factors, including damage degree of Pinus Massoniana, altitude and slope, are helped to build the transfer rules. The main outputs are the dynamic disease distribution maps and survived pine population. Our method is applied and validated in DingHai distinct, Zhou Shan city of Zhejiang Province. Three Landsat TM images from the year 1991 to 2006 are used for the pine information extraction. The extracted pine distribution map is used to compare with the simulated surviving pine map. The results show that the coupled model can produce reasonable results and be used as a virtual experiment tool. However, it is difficult to simulate the human activities to help or prevent disease spread and the long fly behavior of insect vectors. Therefore, there still exists some difference between the simulated results and the real data. At the next step, those factors will be considered.

  7. Attaching Biological Probes to Silica Optical Biosensors Using Silane Coupling Agents

    PubMed Central

    Soteropulos, Carol E.; Hunt, Heather K.

    2012-01-01

    In order to interface with biological environments, biosensor platforms, such as the popular Biacore system (based on the Surface Plasmon Resonance (SPR) technique), make use of various surface modification techniques, that can, for example, prevent surface fouling, tune the hydrophobicity / hydrophilicity of the surface, adapt to a variety of electronic environments, and most frequently, induce specificity towards a target of interest.1-5 These techniques extend the functionality of otherwise highly sensitive biosensors to real-world applications in complex environments, such as blood, urine, and wastewater analysis.2,6-7 While commercial biosensing platforms, such as Biacore, have well-understood, standard techniques for performing such surface modifications, these techniques have not been translated in a standardized fashion to other label-free biosensing platforms, such as Whispering Gallery Mode (WGM) optical resonators.8-9 WGM optical resonators represent a promising technology for performing label-free detection of a wide variety of species at ultra-low concentrations.6,10-12 The high sensitivity of these platforms is a result of their unique geometric optics: WGM optical resonators confine circulating light at specific, integral resonance frequencies.13 Like the SPR platforms, the optical field is not totally confined to the sensor device, but evanesces; this "evanescent tail" can then interact with species in the surrounding environment. This interaction causes the effective refractive index of the optical field to change, resulting in a slight, but detectable, shift in the resonance frequency of the device. Because the optical field circulates, it can interact many times with the environment, resulting in an inherent amplification of the signal, and very high sensitivities to minor changes in the environment.2,14-15 To perform targeted detection in complex environments, these platforms must be paired with a probe molecule (usually one half of a binding pair, e.g. antibodies / antigens) through surface modification.2 Although WGM optical resonators can be fabricated in several geometries from a variety of material systems, the silica microsphere is the most common. These microspheres are generally fabricated on the end of an optical fiber, which provides a "stem" by which the microspheres can be handled during functionalization and detection experiments. Silica surface chemistries may be applied to attach probe molecules to their surfaces; however, traditional techniques generated for planar substrates are often not adequate for these three-dimensional structures, as any changes to the surface of the microspheres (dust, contamination, surface defects, and uneven coatings) can have severe, negative consequences on their detection capabilities. Here, we demonstrate a facile approach for the surface functionalization of silica microsphere WGM optical resonators using silane coupling agents to bridge the inorganic surface and the biological environment, by attaching biotin to the silica surface.8,16 Although we use silica microsphere WGM resonators as the sensor system in this report, the protocols are general and can be used to functionalize the surface of any silica device with biotin. PMID:22588224

  8. Synthesis of silica-coated ZnO nanocomposite: the resonance structure of polyvinyl pyrrolidone (PVP) as a coupling agent

    Microsoft Academic Search

    Jinfeng Wang; Takuya Tsuzuki; Bin Tang; Pavel Cizek; Lu Sun; Xungai Wang

    2010-01-01

    The preparation of silica-coated ZnO nanocomposite using polyvinyl pyrrolidone (PVP) as a coupling agent was investigated.\\u000a Transmission electron microscopy analysis revealed that silica has been deposited on the surface of PVP-capped ZnO nanoparticles\\u000a as a continuous thin layer. Two-dimensional correlation analysis based on the time-dependent UV–vis spectra was introduced\\u000a to study the interaction governing the deposition of silica on to

  9. Coupled human and natural systems: A multi-agent-based approach Michael Monticino*, Miguel Acevedo, Baird Callicott, Travis Cogdill, Christopher Lindquist

    E-print Network

    Monticino, Michael

    Coupled human and natural systems: A multi-agent-based approach Michael Monticino*, Miguel Acevedo between human decisions and natural systems that lead to long-term sustainability of forest ecosystems growth management strategies. The main focus here is on the human system component of the coupled model

  10. Monomolecular layers and thin films of silane coupling agents by vapor-phase adsorption on oxidized aluminum

    SciTech Connect

    Kurth, D.G.; Bein, T. [Purdue Univ., West Lafayette, IN (United States)

    1992-08-06

    Thin films of tetraethoxysilane [TEOS], (3-bromopropyl)trimethoxysilane [BPS], trimethoxyvinylsilane [VS], and 3-(trimethoxysilyl) propyl methacrylate [TPM] on oxidized aluminum surfaces have been investigated by reflection-absorption FTIR spectroscopy, ellipsometry, contact angle, and quartz crystal microbalance (QCM) measurements. Gravimetric measurements with the QCM can reveal quantitative aspects of adsorption and film formation, even for films as thin as monolayers. Adsorption of these silane coupling agents from solution typically produces multilayer films. Vapor-phase adsorption of TEOS and TPM at room temperature results in monomolecular layers. The coupling agents VS and BPS require additional heating after the vapor-phase adsorption to initiate the hydrolysis and condensation reactions necessary for the surface attachment, which produces one to three layers. For vapor adsorbed films a packing density of 4-7 molecules/nm{sup 2} was found. The data strongly suggest that the organic moieties in several of these films have a preferential orientation on the surface; they can be viewed as two-dimensional, oligomeric siloxane networks with oriented organic chains. Subsequent heating of TPM films results in structural rearrangements; heating of TEOS results in complete condensation to SiO{sub 2} films. 43 refs., 6 figs., 4 tabs.

  11. Iminodibenzyl as a novel coupling agent for the spectrophotometric determination of sulfonamide derivatives

    Microsoft Academic Search

    Padmarjaiah Nagaraja; Kallanchira R Sunitha; Ramanathapura A Vasantha; Hemmige S Yathirajan

    2002-01-01

    A rapid, selective and simple spectrophotometric method for the determination of sulfa-drugs is described. The method is based on the formation of violet colored azo product by the diazotization of sulfonamides, viz. sulfathiazole (SFT), sulfadiazine (SFD), sulfacetamide (SFA), sulfamethoxazole (SFMx), sulfamerazine (SFMr), sulfaguanidine (SFG) and sulfadimidine (SFDd) followed by a coupling reaction with iminodibenzyl in alcohol medium. Absorbance of the

  12. 3Aminophenol as a novel coupling agent for the spectrophotometric determination of sulfonamide derivatives

    Microsoft Academic Search

    P. Nagaraja; H. S. Yathirajan; C. R. Raju; R. A. Vasantha; P. Nagendra; M. S. Hemantha Kumar

    2003-01-01

    A rapid, simple and sensitive spectrophotometric method for the determination of some sulfa drugs is described. The method is based on the formation of orange yellow colored azo product by the diazotization of sulfonamides, viz., dapsone (DAP), sulfathiazole (SFT), sulfadiazine (SFD), sulfacetamide (SFA), sulfamethoxazole (SFMx), sulfamerazine (SFMr), sulfaguanidine (SFG) and sulfadimidine (SFDd) followed by a coupling reaction with 3-aminophenol in

  13. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Final report

    SciTech Connect

    Pitts, M.

    1995-12-01

    This research studied the oil recovery potential of flooding light oil reservoirs by combining interfacial tension reducing agent(s) with a mobility control agent. The specific objectives were: To define the mechanisms and limitations of co-injecting interfacial tension reduction agent(s) and a mobility control agent to recover incremental oil. Specifically, the study focused on the fluid-fluid and fluid-rock interactions. To evaluate the economics of the combination technology and investigate methods to make the process more profitable. Specific areas of study were to evaluate different chemical concentration tapers and the volume of chemical injection required to give optimal oil recovery.

  14. Metal chelators coupled with nanoparticles as potential therapeutic agents for Alzheimer's disease

    PubMed Central

    Liu, Gang; Men, Ping; Perry, George; Smith, Mark A.

    2009-01-01

    Alzheimer's disease (AD) is a devastating neuro-degenerative disorder characterized by the progressive and irreversible loss of memory followed by complete dementia. Despite the disease's high prevalence and great economic and social burden, an explicative etiology or viable cure is not available. Great effort has been made to better understand the disease's pathogenesis, and to develop more effective therapeutic agents. However, success is greatly hampered by the presence of the blood-brain barrier that limits a large number of potential therapeutics from entering the brain. Nanoparticle-mediated drug delivery is one of the few valuable tools for overcoming this impediment and its application as a potential AD treatment shows promise. In this review, the current studies on nanoparticle delivery of chelation agents as possible therapeutics for AD are discussed because several metals are found excessive in the AD brain and may play a role in the disease development. Specifically, a novel approach involving transport of iron chelation agents into and out of the brain by nanoparticles is highlighted. This approach may provide a safer and more effective means of simultaneously reducing several toxic metals in the AD brain. It may also provide insights into the mechanisms of AD pathophysiology, and prove useful in treating other iron-associated neurodegenerative diseases such as Friedreich's ataxia, Parkinson's disease, Huntington's disease and Hallervorden-Spatz Syndrome. It is important to note that the use of nanoparticle-mediated transport to facilitate toxicant excretion from diseased sites in the body may advance nanoparticle technology, which is currently focused on targeted drug delivery for disease prevention and treatment. The application of nanoparticle-mediated drug transport in the treatment of AD is at its very early stages of development and, therefore, more studies are warranted. PMID:19936278

  15. The influence of coupling agents on mechanical property retention and long-term cytocompatibility of phosphate glass fibre reinforced PLA composites.

    PubMed

    Hasan, M S; Ahmed, I; Parsons, A J; Walker, G S; Scotchford, C A

    2013-12-01

    Completely resorbable composites are an attractive alternative for metallic bone-fracture fixation devices. However, failure of their interfacial integrity within aqueous environments, which can lead to a rapid loss of overall mechanical properties, has been reported in the literature. In this study coupling agents were investigated for phosphate glass fibre reinforced poly(lactic acid) composites. Three coupling agents with varying wettability were employed to improve initial mechanical properties and their retention in vitro via improvement of the interfacial bond between polymer matrix and fibres. Coupling agents were grafted onto the glass fibres by dip-coating in coupling agent solution at optimised concentrations. Three-aminopropyltriethoxy silane and sorbitol ended PLA oligomer treatments improved the initial flexural properties (27% strength with APS and 17% modulus via SPLA treatment) of the composites and 3-aminopropyltriethoxy silane and hexamethylene diisocyanate (HDI) treatments also decreased the loss of flexural strength and modulus during degradation. HDI treated samples retained 57.2% and 64.7% of their initial strength and modulus, respectively compared to control where only 34% of initial strength and 52% of initial modulus was retained after 28 days of degradation in PBS solution. Initial improvements in flexural properties were associated with improved shear bond strength at the interface due to covalent bonding between the glass fibres and polymer matrix provided by the coupling agents. Delay in mechanical property loss with degradation was suggested to be due to the hydrophobicity at the interface, which could have hindered the interfacial integrity loss and consequently loss of mechanical integrity of the composites. All coupling agent treated and control composites were tested for cytocompatibility using a primary human osteoblast cell line. A comparable response to the control, in terms of cell adhesion, proliferation and differentiation was observed supporting the use of these agents within implantable devices. PMID:23959231

  16. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Summary annual report, October 1994September 1995

    Microsoft Academic Search

    Pitts

    1995-01-01

    The study will investigate two major areas concerning co-injecting an interfacial tension reduction agent(s) and a mobility control agent into petroleum reservoirs. The first will consist of defining the mechanisms of interaction of an alkaline agent, a surfactant, and a polymer on a fluid-fluid and a fluid-rock basis. The second is the improvement of the economics of the combined technology.

  17. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Technical progress report, January--March 1994

    SciTech Connect

    Pitts, M.J.

    1994-12-31

    The study will investigate two major areas concerning co-injecting an interfacial tension reduction agent(s) and a mobility control agent into petroleum reservoirs. The first will consist of defining the mechanisms of interaction of an alkaline agent, a surfactant, and a polymer on a fluid-fluid and a fluid-rock basis. The second is the improvement of the economics of the combined technology. This report examines the adsorption of alkali, surfactant, and polymer onto crushed Berea sandstone.

  18. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Technical progress report, September--December 1993

    SciTech Connect

    Pitts, M.J.

    1993-12-31

    The study will investigate two major areas concerning co-injecting an interfacial tension reduction agent(s) and a mobility control agent into petroleum reservoirs. The first will consist of defining the mechanisms of interaction of an alkaline agent, a surfactant, and a polymer on a fluid-fluid and a fluid-rock basis. The second is the improvement of the economics of the combined technology. This report examines the adsorption of alkali, surfactant, and polymer onto crushed Berea sandstone.

  19. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Technical progress report, April--June 1993

    SciTech Connect

    Pitts, M.J.

    1993-10-01

    The study will investigate two major areas concerning co-injecting on interfacial tension reduction agent(s) and a mobility control agent into petroleum reservoirs. The first will consist of defining the mechanisms of interaction of an alkaline agent, a surfactant, and a polymer on a fluid-fluid and fluid-rock basis. The second is the improvement of the economic of the combined technology. This report examines the effect of polymer addition to different combinations of alkaline agents and surfactants. Xanthan gum and polyacrylamide polymers were evaluated. In addition, the effect of alkali and polymer on the critical micelle concentration of different surfactant types was investigated.

  20. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Technical progress report, July--September 1993

    SciTech Connect

    Pitts, M.J.

    1993-12-01

    The study will investigate two major areas concerning co-injecting an interfacial tension reduction agent(s) and a mobility control agent into petroleum reservoirs. The first will consist of defining the mechanisms of interaction of an alkaline agent, a surfactant, and a polymer on a fluid-fluid and a fluid-rock basis. The second is the improvement of the economics of the combined technology. This report examines the effect of polymer addition to different combinations of alkaline agents and surfactants. Xanthan gum and polyacrylamide polymers were evaluated. In addition, the effect of alkali and polymer on the critical micelle concentration of different surfactant types was investigated.

  1. Synthesis of Dithio-Diphosphine (P2S2COOH)Based Bifunctional Chelating Agent. Its Coupling Reactions with Peptide Analogs and Steroids

    Microsoft Academic Search

    Hariprasad Gali; Srinivasa R. Karra; Sreenivasa V. Reedy; Roger Schilbli; Wynn A. Volkert; Kattesh V. Katti

    1999-01-01

    Bifunctional chelating agents are important in the development of site-specific radiopharmaceuticals for diagnosis and therapy of cancer. Recently. our Laboratory has developed a new dithio-diphosphine (P2S2COOH)-based bifunctional chelating agent [1]. Its coupling to biologically important molecules such as peptide analogs and steroids have been investigated in detail (Scheme I). The intermediate compound P2S2 phosphine hydride 3 was synthesized as described

  2. 3-Aminophenol as a novel coupling agent for the spectrophotometric determination of sulfonamide derivatives.

    PubMed

    Nagaraja, P; Yathirajan, H S; Raju, C R; Vasantha, R A; Nagendra, P; Hemantha Kumar, M S

    2003-12-01

    A rapid, simple and sensitive spectrophotometric method for the determination of some sulfa drugs is described. The method is based on the formation of orange yellow colored azo product by the diazotization of sulfonamides, viz., dapsone (DAP), sulfathiazole (SFT), sulfadiazine (SFD), sulfacetamide (SFA), sulfamethoxazole (SFMx), sulfamerazine (SFMr), sulfaguanidine (SFG) and sulfadimidine (SFDd) followed by a coupling reaction with 3-aminophenol in aqueous medium. Absorbance of the resulting orange yellow product is measured at 460 nm and is stable for 6 days at 27 degrees C. Beer's law is obeyed in the concentration range of 0.05-8.0 microg/ml at the wavelength of maximum absorption. The method is successfully employed for the determination of sulfonamides in various pharmaceutical preparations and common excipients used as additives in pharmaceuticals do not interfere in the proposed method. Plausible reaction mechanism is proposed for the formation of the azo product. PMID:14630242

  3. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Technical progress report, October--December 1994

    SciTech Connect

    Pitts, M.J.

    1994-01-01

    The study will investigate two major areas concerning co-injecting an interfacial tension reduction agent(s) and a mobility control agent into petroleum reservoirs. The first will consist of defining the mechanisms of interaction of an alkaline agent, a surfactant, and a polymer on a fluid-fluid and a fluid-rock basis. The second is the improvement of the economics of the combined technology. This report examines effect of rock type on oil recovery by an alkaline-surfactant-polymer solutions. This report also begins a series of evaluations to improve the economics of alkaline-surfactant-polymer oil recovery.

  4. Iminodibenzyl as a novel coupling agent for the spectrophotometric determination of sulfonamide derivatives.

    PubMed

    Nagaraja, Padmarjaiah; Sunitha, Kallanchira R; Vasantha, Ramanathapura A; Yathirajan, Hemmige S

    2002-03-01

    A rapid, selective and simple spectrophotometric method for the determination of sulfa-drugs is described. The method is based on the formation of violet colored azo product by the diazotization of sulfonamides, viz. sulfathiazole (SFT), sulfadiazine (SFD), sulfacetamide (SFA), sulfamethoxazole (SFMx), sulfamerazine (SFMr), sulfaguanidine (SFG) and sulfadimidine (SFDd) followed by a coupling reaction with iminodibenzyl in alcohol medium. Absorbance of the resulting violet azo product is measured at 570-580 nm and is stable for 24 h at 27 degrees C. Beer's law is obeyed in the concentration range of 0.05-6.0 microg ml(-1) at the wavelength of maximum absorption. The method is successfully employed for the determination of sulfonamides in various pharmaceutical preparations and common excipients used as additives in pharmaceuticals do not interfere in the proposed method. The method offers the advantages of simplicity, rapidity and sensitivity without the need for extraction or heating. A reaction mechanism is proposed for the formation of the violet azo product. PMID:11880002

  5. Exfoliated graphite nanoplatelet-filled impact modified polypropylene nanocomposites: influence of particle diameter, filler loading, and coupling agent on the mechanical properties

    NASA Astrophysics Data System (ADS)

    Duguay, Alex J.; Nader, Jacques W.; Kiziltas, Alper; Gardner, Douglas J.; Dagher, Habib J.

    2014-03-01

    Exfoliated graphite nanoplatelets (xGnP)-filled impact-modified polypropylene (IMPP) composites were prepared at 2, 4, 6, and 8 wt % xGnP with and without the addition of a coupling agent and manufactured using melt mixing followed by injection molding. The coupling agent used in this study was polypropylene-graft-maleic anhydride (PP-g-MA). The nanoparticles used were xGnP with three different sizes: xGnP5 has an average thickness of 10 nm, and an average platelet diameter of 5 ?m, whereas xGnP15 and xGnP25 have the same thickness but average diameters are 15 and 25 ?m, respectively. Test results show that nanocomposites with smaller xGnP diameter exhibited better flexural and tensile properties for both neat and compatibilized composites. For composites containing a coupling agent, tensile and flexural modulus and strength increased with the addition of xGnP. In the case of neat composites, both tensile and flexural modulus and strength decreased at higher filler loading levels. Increasing xGnP loading resulted in reduction of elongation at break for both neat and composites containing coupling agent. Explanation of this brittle behavior in a nanoplatelet-filled IMPP is presented using scanning electron microscopy and transmission electron microscopy.

  6. Grafting of a functionalized side-chain liquid crystal polymer on carbon fiber surfaces: Novel coupling agents for fiber\\/polymer matrix composites

    Microsoft Academic Search

    Vassoudevane Le Bonheur; Samuel I. Stupp

    1993-01-01

    The authors studied covalent grafting to functionalized carbon fibers of a specially designed liquid crystalline monomer and its corresponding side-chain liquid crystalline polymer containing pendant chemical functions on their mesogenic groups. From a materials point of view these liquid crystalline compounds could act as coupling agents at fiber\\/polymer matrix interfaces, offering a mechanism to control composite properties not only through

  7. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Technical progress report, July 1995--September 1995

    SciTech Connect

    Pitts, M.J.

    1995-10-01

    This study will investigate two major areas concerning co-injection and interfacial tension reduction agents and a mobility control agent into petroleum reservoirs. The first will consist of defining the mechanisms of interaction of an alkaline agent, a surfactant, and a polymer on a fluid-fluid and a fluid-rock basis. The second is the improvement of the economics of the combined technology. This report examines altering the concentration of alkali and polymer on the oil recovery economics of alkaline-surfactant-polymer solution.

  8. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Technical progress report, April--June 1994

    SciTech Connect

    Pitts, M.J.; Casteel, J.

    1994-09-01

    The study will investigate two major areas concerning co-injecting an interfacial tension reduction agent(s) and a mobility control agent into petroleum reservoirs. The first will consist of defining the mechanisms of interaction of an alkaline agent, a surfactant, and a polymer on a fluid-fluid and a fluid-rock basis. The second is the improvement of the economics of the combined technology. This report examines the changes in the relative permeability characteristics with addition of alkali, surfactant, and polymer to the injected solution, the effect of matrix type on relative permeability characteristics with alkali-surfactant-polymer and the effect of different polymer concentrations on oil recovery by an alkaline-surfactant-polymer solution.

  9. A high efficient method for introducing reactive amines onto carbon fiber surfaces using hexachlorocyclophosphazene as a new coupling agent

    NASA Astrophysics Data System (ADS)

    Xu, Haibing; Zhang, Xiaoqing; Liu, Dong; Chun, Yan; Fan, Xinyu

    2014-11-01

    To improve the interfacial properties of carbon fiber (CF) reinforced composites, an innovative and simple functionalized strategy has been proposed by grafting 4,4?-oxydianiline (ODA) onto carbon fiber surface using hexachlorocyclophosphazene (HCCP) as a novel coupling agent at mild reaction conditions. The chemical composition of the CF surface was confirmed by X-ray photoelectron spectra (XPS). The surface topography and surface energy of CF were examined by atomic force microscope (AFM) and dynamic contact angle tests (DCA), respectively. The interfacial shear strength (IFSS) of CF reinforced composites was studied by microbond test. The tensile strength of CF was measured by single filament tensile test. After functionalization treatment, the grafted amine groups on the fiber surface enhanced the surface wettability of modified CF and formed strong chemical bonding between fiber and matrix, improving the interfacial adhesion strength of composites. The interfacial shear strength of modified CF reinforced composites increased by 71.2% compared with that of desized CF. The interfacial enhancement mechanism was also discussed in detail. Moreover, the modified CF almost kept the original mechanical properties after functionalization.

  10. The surface modification of TiN nano-particles using macromolecular coupling agents, and their resulting dispersibility

    NASA Astrophysics Data System (ADS)

    Cheng, Guojun; Qian, Jiasheng; Miao, Jibin; Yang, Bin; Xia, Ru; Chen, Peng

    2014-05-01

    Titanium nitride (TiN) nano-particles were modified by the grafting of a random copolymerization functionalized macromolecular coupling agent (F-MCA) via a direct blending method. The hydroxyl groups on the surface of the nano-TiN particles interact with the silanol groups [SiOCH3] of the F-MCA to form an organic coating layer. The formation of covalent bonds [TiOSi] was verified using Fourier transform infrared spectroscopy. An X-ray diffraction analysis suggests that the presence of the F-MCA inhibited the growth of the crystal plane but did not change the crystal structure of the TiN. Thermogravimetric analysis and contact angle measurement indicated that the F-MCA molecules were adsorbed or anchored to the surface of the nano-TiN particles, which hindered their aggregation. Pristine nano-TiN particles are poorly dispersed in ethyl acetate. Compared with the pristine TiN particles, the modified TiN particles show good dispersibility and form a stable colloidal dispersion in ethyl acetate. The surface hydrophobicity of the modified TiN increases, and the F-MCA molecules are anchored on the surface of the TiN particles. TiN particles modified by a F-MCA can be used in polymer blends, thermoplastic elastomers and polymer nanocomposites that have a better performance and longer life cycle.

  11. Investigation of oil recovery improvement by coupling an interfacial tension agent and a mobility control agent in light oil reservoirs. Summary annual report, October 1994--September 1995

    SciTech Connect

    Pitts, M.J.

    1995-12-31

    The study will investigate two major areas concerning co-injecting an interfacial tension reduction agent(s) and a mobility control agent into petroleum reservoirs. The first will consist of defining the mechanisms of interaction of an alkaline agent, a surfactant, and a polymer on a fluid-fluid and a fluid-rock basis. The second is the improvement of the economics of the combined technology. The third year of the study finished the oil recovery coreflood studies and evaluated different techniques to improve alkaline-surfactant-polymer solution economics. The final series of corefloods compared the oil recovery efficiency of the alkali gradient in Berea sandstone and J Sand sandstone. Oil recovery efficiency was essentially the same in both types of core, 13 to 15% PV of oil. Cost of chemical per incremental barrel of oil with 30% pore volume of alkaline-surfactant- polymer solution injected were $3.20 for the Na{sub 2}CO{sub 3}- Petrostep B-100-Flopaam 3330S solution in both types of core.

  12. Improve the Strength of PLA/HA Composite Through the Use of Surface Initiated Polymerization and Phosphonic Acid Coupling Agent

    PubMed Central

    Wang, Tongxin; Chow, Laurence C.; Frukhtbeyn, Stanislav A.; Ting, Andy Hai; Dong, Quanxiao; Yang, Mingshu; Mitchell, James W.

    2012-01-01

    Bioresorbable composite made from degradable polymers, e.g., polylactide (PLA), and bioactive calcium phosphates, e.g., hydroxyapatite (HA), are clinically desirable for bone fixation, repair and tissue engineering because they do not need to be removed by surgery after the bone heals. However, preparation of PLA/HA composite from non-modified HA usually results in mechanical strength reductions due to a weak interface between PLA and HA. In this study, a calcium-phosphate/phosphonate hybrid shell was developed to introduce a greater amount of reactive hydroxyl groups onto the HA particles. Then, PLA was successfully grafted on HA by surface-initiated polymerization through the non-ionic surface hydroxyl groups. Thermogravimetric analysis indiated that the amount of grafted PLA on HA can be up to 7 %, which is about 50 % greater than that from the literature. PLA grafted HA shows significantly different pH dependent ?-potential and particle size profiles from those of uncoated HA. By combining the phosphonic acid coupling agent and surface initiated polymerization, PLA could directly link to HA through covalent bond so that the interfacial interaction in the PLA/HA composite can be significantly improved. The diametral tensile strength of PLA/HA composite prepared from PLA-grafted HA was found to be over twice that of the composite prepared from the non-modified HA. Moreover, the tensile strength of the improved composite was 23 % higher than that of PLA alone. By varying additional variables, this approach has the potential to produce bioresorbable composites with improved mechanical properties that are in the range of natural bones, and can have wide applications for bone fixation and repair in load-bearing areas. PMID:22399838

  13. Dynamic mechanical properties of multi-functional epoxy resin cured with diamine and filled with pitch-based carbon short fibers treated with coupling agents

    Microsoft Academic Search

    Katsutoshi Tanaka; Muneaki Yamaguchi

    1995-01-01

    We have been conducting research on the development of heat-resistant composite materials filled with functional short fibers in multi-functional epoxy resin. As part of such effort, the filling effects of pitch-based carbon short fibers were investigated. In addition, the effects of treatment of coupling agents were studied by filling treated fibers into matrices cured with acid anhydride taking the large

  14. Enhanced heat transfer through filler-polymer interface by surface-coupling agent in heat-dissipation material: A non-equilibrium molecular dynamics study

    NASA Astrophysics Data System (ADS)

    Tanaka, Kouichi; Ogata, Shuji; Kobayashi, Ryo; Tamura, Tomoyuki; Kitsunezuka, Masashi; Shinma, Atsushi

    2013-11-01

    Developing a composite material of polymers and micrometer-sized fillers with higher heat conductance is crucial to realize modular packaging of electronic components at higher densities. Enhancement mechanisms of the heat conductance of the polymer-filler interfaces by adding the surface-coupling agent in such a polymer composite material are investigated through the non-equilibrium molecular dynamics (MD) simulation. A simulation system is composed of ?-alumina as the filler, bisphenol-A epoxy molecules as the polymers, and model molecules for the surface-coupling agent. The inter-atomic potential between the ?-alumina and surface-coupling molecule, which is essential in the present MD simulation, is constructed to reproduce the calculated energies with the electronic density-functional theory. Through the non-equilibrium MD simulation runs, we find that the thermal resistance at the interface decreases significantly by increasing either number or lengths of the surface-coupling molecules and that the effective thermal conductivity of the system approaches to the theoretical value corresponding to zero thermal-resistance at the interface. Detailed analyses about the atomic configurations and local temperatures around the interface are performed to identify heat-transfer routes through the interface.

  15. Enhanced heat transfer through filler-polymer interface by surface-coupling agent in heat-dissipation material: A non-equilibrium molecular dynamics study

    SciTech Connect

    Tanaka, Kouichi [DENSO CORPORATION, Kariya, Aichi 448-8661 (Japan); Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Ogata, Shuji; Kobayashi, Ryo; Tamura, Tomoyuki [Graduate School of Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Kitsunezuka, Masashi; Shinma, Atsushi [DENSO CORPORATION, Kariya, Aichi 448-8661 (Japan)

    2013-11-21

    Developing a composite material of polymers and micrometer-sized fillers with higher heat conductance is crucial to realize modular packaging of electronic components at higher densities. Enhancement mechanisms of the heat conductance of the polymer-filler interfaces by adding the surface-coupling agent in such a polymer composite material are investigated through the non-equilibrium molecular dynamics (MD) simulation. A simulation system is composed of ?-alumina as the filler, bisphenol-A epoxy molecules as the polymers, and model molecules for the surface-coupling agent. The inter-atomic potential between the ?-alumina and surface-coupling molecule, which is essential in the present MD simulation, is constructed to reproduce the calculated energies with the electronic density-functional theory. Through the non-equilibrium MD simulation runs, we find that the thermal resistance at the interface decreases significantly by increasing either number or lengths of the surface-coupling molecules and that the effective thermal conductivity of the system approaches to the theoretical value corresponding to zero thermal-resistance at the interface. Detailed analyses about the atomic configurations and local temperatures around the interface are performed to identify heat-transfer routes through the interface.

  16. Analysis of Gadolinium-based contrast agents in tap water with a new hydrophilic interaction chromatography (ZIC-cHILIC) hyphenated with inductively coupled plasma mass spectrometry.

    PubMed

    Lindner, Uwe; Lingott, Jana; Richter, Silke; Jiang, Wen; Jakubowski, Norbert; Panne, Ulrich

    2014-12-01

    Hydrophilic interaction chromatography (HILIC) coupled with inductively coupled plasma mass spectrometry (ICP-MS) were optimised for the direct determination of gadolinium-based contrast agents in tap water. In comparison to our previous work, a new developed zwitterionic HILIC column (ZIC-cHILIC) was used for speciation of Gd-containing contrast agents. The limit of quantification (LOQ) for the five contrast agents Gd-BOPTA, Gd-DPTA-BMA, Gd-BT-DO3A, Gd-DOTA and Gd-DTPA are in the range of 5-12 ng Gd per litre. Additionally, a new internal standard, Pr-DOTA, was investigated to correct intensity drifts, minor and major changes in the sample volumes and possible matrix effects. With the speciation method described, tap water samples from the area of Berlin were analysed and for the first time, three Gd species, Gd-BT-DO3A, Gd-DOTA and Gd-BOPTA, were found in tap water samples at concentrations of about 10-20 ng Gd per litre. These are the same Gd species which have been previously detected predominantly in surface waters of the Berlin area. PMID:25486924

  17. Novel One-pot Fabrication of Lab-on-a-Bubble@Ag Substrate without Coupling-agent for Surface Enhanced Raman Scattering

    PubMed Central

    Jiang, Jizhou; Ou-Yang, Lei; Zhu, Lihua; Zou, Jing; Tang, Heqing

    2014-01-01

    Through in-situ reduction of silver nitrate without using any coupling-agent, a substrate for surface-enhanced Raman scattering (SERS) was prepared by coating silver on hollow buoyant silica microspheres as a lab on a bubble (LoB). The silver coated LoBs (LoBs@Ag) floated on surface of a solution could provide a very convenient platform for the detection of target molecules in the solution. The LoBs@Ag substrate not only immobilized well-distributed Ag nanoparticles on the surface LoBs, but excluded the interference of coupling agents. This yielded high-resolution SERS spectra with excellent reproducibility. The adsorption of crystal violet (CV) on the LoBs@Ag substrate was investigated by means of SERS combined with density functional theory (DFT) calculations. The LoBs@Ag substrate exhibited a remarkable Raman enhancement effect for CV with an enhancement factor of 6.9 × 108 and wide adaptability from dye, pesticide to bio-molecules. On the basis of this substrate, a simple and sensitive SERS method was proposed for the determination of trace organic pollutants or bio-molecules. PMID:24487575

  18. X-ray photoelectron spectroscopy studies of bond structure between polyvinyl alcohol and a titanate cross-coupling agent

    Microsoft Academic Search

    M. A. Guelguen; Oludele O. Popoola; Waltraud M. Kriven

    1995-01-01

    Chemical interactions between polyvinyl alcohol (PVA) and triethanol amine titanate chelate were studied using x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The titanate chelate cross coupled the PVA solution and produced a viscous gel. The gel had a three- dimensional network structure containing --C{sub PVA}--O--Ti--O--C{sub PVA}--organic complexes. A new C(1{ital s}) signature at 285.7 eV and an O(1{ital

  19. Quinoline-8-ol and its derivatives as preconcentration agents in flow injection analysis coupled to atomic and molecular spectrometric techniques.

    PubMed

    Rao, T Prasada; Gladis, J Mary

    2002-05-01

    Quinoline-8-ol, one of the most popular and versatile organic reagents, is known to react with several metals, because it has both a basic nitrogen and a phenolic group. Hence, quinoline-8-ol and its derivatives have been widely used as chelating and/or sorbent extraction agents in on-line flow injection analysis (FIA) along with a suitable detection technique. The state of the art for using quinoline-8-ol and its derivatives in FIA was studied in terms of the selectivity, sensitivity and precision. Emphasis was placed on validating these procedures by analyzing certified reference materials and applying these analytical methodologies to real samples for the determination of inorganics. PMID:12036117

  20. An IETS study of a silane coupling agent; the interaction of 3-(trimethoxysilyl)propanethiol with aluminium oxide and silver surfaces

    NASA Astrophysics Data System (ADS)

    Van Velzen, Peter N. T.

    1984-05-01

    The inelastic electron tunnelling spectrum of a silane coupling agent, 3-(trimethoxysilyl)propanethiol, is presented. Approximately monolayer quantities of this silane are present on the barrier oxide of an aluminium-aluminium oxide-metal tunnelling junction, in which the counter electrode is either lead or silver. It is deduced from the IETS spectra that the alkoxy groups of this silane condense with the surface hydroxyl groups. No interaction with the lead is observed but the silver layer clearly reacts with the thiol group of the silane molecule, since the thiol stretching vibration is absent in the spectra, and probably forms the corresponding silver thiolate. The influence of this reaction on the conformation of the bound silane is discussed.

  1. Portable Solid Phase Micro-Extraction Coupled with Ion Mobility Spectrometry System for On-Site Analysis of Chemical Warfare Agents and Simulants in Water Samples

    PubMed Central

    Yang, Liu; Han, Qiang; Cao, Shuya; Yang, Jie; Yang, Junchao; Ding, Mingyu

    2014-01-01

    On-site analysis is an efficient approach to facilitate analysis at the location of the system under investigation as it can result in more accurate, more precise and quickly available analytical data. In our work, a novel self-made thermal desorption based interface was fabricated to couple solid-phase microextraction with ion mobility spectrometry for on-site water analysis. The portable interface can be connected with the front-end of an ion mobility spectrometer directly without other modifications. The analytical performance was evaluated via the extraction of chemical warfare agents and simulants in water samples. Several parameters including ionic strength and extraction time have been investigated in detail. The application of the developed method afforded satisfactory recoveries ranging from 72.9% to 114.4% when applied to the analysis of real water samples. PMID:25384006

  2. Portable solid phase micro-extraction coupled with ion mobility spectrometry system for on-site analysis of chemical warfare agents and simulants in water samples.

    PubMed

    Yang, Liu; Han, Qiang; Cao, Shuya; Yang, Jie; Yang, Junchao; Ding, Mingyu

    2014-01-01

    On-site analysis is an efficient approach to facilitate analysis at the location of the system under investigation as it can result in more accurate, more precise and quickly available analytical data. In our work, a novel self-made thermal desorption based interface was fabricated to couple solid-phase microextraction with ion mobility spectrometry for on-site water analysis. The portable interface can be connected with the front-end of an ion mobility spectrometer directly without other modifications. The analytical performance was evaluated via the extraction of chemical warfare agents and simulants in water samples. Several parameters including ionic strength and extraction time have been investigated in detail. The application of the developed method afforded satisfactory recoveries ranging from 72.9% to 114.4% when applied to the analysis of real water samples. PMID:25384006

  3. X-ray photoelectron spectroscopy studies of bond structure between polyvinyl alcohol and a titanate cross-coupling agent

    SciTech Connect

    Guelguen, M.A.; Popoola, O.O.; Kriven, W.M. [Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, 105 S. Goodwin Avenue, Urbana, Illinois 61801 (United States)

    1995-06-01

    Chemical interactions between polyvinyl alcohol (PVA) and triethanol amine titanate chelate were studied using x-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The titanate chelate cross coupled the PVA solution and produced a viscous gel. The gel had a three- dimensional network structure containing --C{sub PVA}--O--Ti--O--C{sub PVA}--organic complexes. A new C(1{ital s}) signature at 285.7 eV and an O(1{ital s}) signature at 531.25 eV were associated with the formation of these complexes. The water of the PVA solution was physically retained in the gelled structure and was readily available for chemical reactions. The removal of this entrapped water was irreversible and lead to a collapsed film of Ti-cross-linked PVA.

  4. Infrared analysis of the effect of composition of silane blends of amino and alkyl silane blends in tertiary amine-catalyzed anhydride-cured epoxy mixtures. Technical report

    SciTech Connect

    Tidrick, S.L.; Ishida, H.; Koenig, J.L.

    1991-05-01

    The property enhancement caused by silane coupling agents in glass-reinforced epoxy matrices is a function of the structure and composition of the silane. The effect of hydrolyzed and nonhydrolyzed of various compositions of silane coupling agent blends of gamma aminopropyltriethoxysilane (APS) and either butyltriethoxysilane (BTS) or ethyltriethoxysilane (ETS) on the cure of a benzyldimethylamine (BDMA)-catalyzed, nadic methyl anhydride (NMA) cured diglycidyl ether of bisphenol-A type epoxy were investigated by Fourier transform infrared spectroscopy (FTIR). The presence of the amine group perturbs the alternating copolymerization of the anhydride and epoxy groups by initiating and catalyzing the reaction. Hydrolysis also promoted the reaction rate. Samples containing ETS cured more rapidly than those containing BTS at the same composition. Imide formation was not significant in the presence of the alkyl-ended silanes. A very simple mathematical simulation was invoked to justify assumptions made during data analysis.

  5. New use of cyanosilane coupling agent for direct binding of antibodies to silica supports. Physicochemical characterization of molecularly bioengineered layers.

    PubMed

    Falipou, S; Chovelon, J M; Martelet, C; Margonari, J; Cathignol, D

    1999-01-01

    A simple protocol to fix biological species to silica-based surfaces (silica microbeads and glass slides), using a bifunctional silane reagent (3-cyanopropyl dimethyl chlorosilane), is presented. This silane reagent was used without further derivatization. This system led to strong, but not covalent, linkage of antibodies through their glycosylated regions (OH groups) to solid supports. The use of a microsized sample revealed that the coupling process depends not only on physicochemical interactions but also on steric phenomena, and in this case, it was shown that a molecule acting as a spacer was required for more efficient cell fixation. Here, monoclonal mouse antibodies against the CD45 molecule expressed on rat lymphocytes (MAR anti CD45 Ab) were linked to lymphocytes, and as spacers, sheep anti-mouse antibodies (SAM Ab) were immobilized on silica surfaces, allowing the cells to stick to the floating hollow silica microbeads by simple incubation. Under such conditions, a single microbead can fix several cells. The potential of this hollow, low-density support is in ultrasound applications, for the destruction by cavitation phenomena of cells selectively fixed onto such a support. Such a study can serve as a basic model for various microbiosystems involving cell manipulation. PMID:10346863

  6. Merging concepts - coupling an agent-based model of hematopoietic stem cells with an ODE model of granulopoiesis

    PubMed Central

    2013-01-01

    Background Hematopoiesis is a complex process involving different cell types and feedback mechanisms mediated by cytokines. This complexity stimulated various models with different scopes and applications. A combination of complementary models promises to provide their mutual confirmation and to explain a broader range of scenarios. Here we propose a combination of an ordinary differential equation (ODE) model of human granulopoiesis and an agent-based model (ABM) of hematopoietic stem cell (HSC) organization. The first describes the dynamics of bone marrow cell stages and circulating cells under various perturbations such as G-CSF treatment or chemotherapy. In contrast to the ODE model describing cell numbers, our ABM focuses on the organization of individual cells in the stem population. Results We combined the two models by replacing the HSC compartment of the ODE model by a difference equation formulation of the ABM. In this hybrid model, regulatory mechanisms and parameters of the original models were kept unchanged except for a few specific improvements: (i) Effect of chemotherapy was restricted to proliferating HSC and (ii) HSC regulation in the ODE model was replaced by the intrinsic regulation of the ABM. Model simulations of bleeding, chronic irradiation and stem cell transplantation revealed that the dynamics of hybrid and ODE model differ markedly in scenarios with stem cell damage. Despite these differences in response to stem cell damage, both models explain clinical data of leukocyte dynamics under four chemotherapy regimens. Conclusions ABM and ODE model proved to be compatible and were combined without altering the structure of both models. The new hybrid model introduces model improvements by considering the proliferative state of stem cells and enabling a cell cycle-dependent effect of chemotherapy. We demonstrated that it is able to explain and predict granulopoietic dynamics for a large variety of scenarios such as irradiation, bone marrow transplantation, chemotherapy and growth factor applications. Therefore, it promises to serve as a valuable tool for studies in a broader range of clinical applications, in particular where stem cell activation and proliferation are involved. PMID:24180697

  7. Grafting of a functionalized side-chain liquid crystal polymer on carbon fiber surfaces: Novel coupling agents for fiber/polymer matrix composites

    SciTech Connect

    Le Bonheur, V.; Stupp, S.I. (Univ. of Illinois, Urbana, IL (United States))

    1993-09-01

    The authors studied covalent grafting to functionalized carbon fibers of a specially designed liquid crystalline monomer and its corresponding side-chain liquid crystalline polymer containing pendant chemical functions on their mesogenic groups. From a materials point of view these liquid crystalline compounds could act as coupling agents at fiber/polymer matrix interfaces, offering a mechanism to control composite properties not only through bonding but also through their [open quotes]spontaneous[close quotes] molecular orientation in interfacial regions. The grafting methodology for both monomer and polymer to fiber surfaces involved esterification through carbodiimide chemistry in solution. Carboxylic acid groups found on functionalized carbon fiber surfaces were esterified to phenolic functions in the side chains of the experimental polymer. Following grafting procedures the fibers were analyzed by scanning electron microscopy (SEM) and by contact angle measurements. SEM micrographs of fibers grafted with polymer revealed the presence of strongly attached polymeric material on the graphitic surface after rigorous extraction with polymer solvent. Contact angle measurements and polar/dispersive free energy analysis indicated also a smaller polar component of the surface free energy of fibers possibly due to the hydrophobic polymer backbone grafted on the carbon surfaces. On the basis of results, it is concluded that the esterification reaction grafted the polyphenolic liquid-crystal polymer on graphite fiber surfaces. 24 refs., 8 figs., 4 tabs.

  8. The Effects of Short Glass Fibre (SGF) Loading and a Silane Coupling Agent on Properties of Polypropylene\\/Waste Tyre Dust\\/Short Glass Fibre (PP\\/WTD\\/SGF) Composites

    Microsoft Academic Search

    Z. Zainal; H. Ismail

    2011-01-01

    The properties of polypropylene\\/waste tyre dust\\/short glass fibre (PP\\/WTD\\/SGF) composites at 0 to 20 php SGF loading, with and without a silane coupling agent, ?-aminopropyltrimethoxysilane (?-APS) were studied. The results reveal that the equilibrium torque and Young's modulus increased while tensile strength and elongation at break decreased as SGF loading increased. SEM micrographs show poor adhesion of SGF-PP\\/WTD while FTIR analysis

  9. Biological Agents

    MedlinePLUS

    ... Statistics Training Publications Newsroom Small Business Anti-Retaliation Biological Agents Safety and Health Topics A-Z Index What's New Biological agents include bacteria, viruses, fungi, other microorganisms and ...

  10. Agent Orange

    MedlinePLUS

    ... ZIP code here Enter ZIP code here Agent Orange American Heart Month Exposed to herbicides during service ... U.S. military sprayed millions of gallons of Agent Orange and other herbicides on trees and vegetation during ...

  11. Enantioselective total synthesis of the potent antitumor agent (-)-mucocin using a temporary silicon-tethered ring-closing metathesis cross-coupling reaction.

    PubMed

    Evans, P Andrew; Cui, Jian; Gharpure, Santosh J; Polosukhin, Alexei; Zhang, Hai-Ren

    2003-12-01

    The enantioselective total synthesis of the annonaceous acetogenin (-)-mucocin (1) was accomplished using a triply convergent 12-step sequence (longest linear sequence) in 13.6% overall yield. This represents the first application of the temporary silicon-tethered (TST) ring-closing metathesis (RCM) cross-coupling reaction and the enantioselective alkyne/aldehyde addition to the synthesis of a complex annonaceous acetogenin. Moreover, all three fragments required for the coupling reactions are conveniently prepared in 5-6 steps from two readily available enantiomerically enriched epoxides. Finally, this synthesis stimulated the development of a new approach for the construction of 3-hydroxy-2,6-disubstituted tetrahydropyrans, using the bismuth tribromide-mediated reductive etherification reaction, which represents a motif that is prevalent in a wide range of pharmacologically significant natural products. PMID:14640634

  12. Software agents

    Microsoft Academic Search

    Michael R. Genesereth; Steven P. Ketchpel

    1994-01-01

    this paper, we discuss these questions and describe someemerging technologies that provide answers. In the final section, we mention some additionalissues and summarize the key points of the paper. (For more information onagent-based software engineering, see [Genesereth 1989] and [Genesereth 1992]. See also[Shoham 1993] for a description of a variation of agent-based software engineering knownas "agent-oriented programming".)2. Agent Communication Language

  13. Surface modification of ZrO2 nanoparticles with styrene coupling agent and its effect on the corrosion behaviour of epoxy coating

    NASA Astrophysics Data System (ADS)

    Zhao, Xia; Liu, Shuan; Wang, Xiutong; Hou, Baorong

    2014-09-01

    The surface of ZrO2 nanoparticles was modified by styrene coupling grafting method to improve the dispersion and interaction of the nanoparticles with the epoxy coating in which the modified ZrO2 nanoparticles were used as an additive. The grafting performance and microstructure of the nano-ZrO2/epoxy coating were analyzed by Fourier transformation infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The corrosion behavior of the nano-ZrO2/epoxy coating on mild steel was evaluated in neutral 3.5 wt% NaCl solution using electrochemical impedance spectroscopy (EIS). Both the coating capacitance and coating resistance fitted by the equivalent circuit from EIS were used to evaluate the protective performance of the coating towards the mild steel. The results show a superior stability and efficient corrosion protection by the modified ZrO2 nanoparticles. The epoxy coating containing 2 wt% modified ZrO2 nanoparticles exhibited the best corrosion performance among all the coating specimens. This research may provide an insight into the protection of mild steel using modified epoxy coatings.

  14. Sunscreening Agents

    PubMed Central

    Martis, Jacintha; Shobha, V; Sham Shinde, Rutuja; Bangera, Sudhakar; Krishnankutty, Binny; Bellary, Shantala; Varughese, Sunoj; Rao, Prabhakar; Naveen Kumar, B.R.

    2013-01-01

    The increasing incidence of skin cancers and photodamaging effects caused by ultraviolet radiation has increased the use of sunscreening agents, which have shown beneficial effects in reducing the symptoms and reoccurrence of these problems. Many sunscreen compounds are in use, but their safety and efficacy are still in question. Efficacy is measured through indices, such as sun protection factor, persistent pigment darkening protection factor, and COLIPA guidelines. The United States Food and Drug Administration and European Union have incorporated changes in their guidelines to help consumers select products based on their sun protection factor and protection against ultraviolet radiation, whereas the Indian regulatory agency has not yet issued any special guidance on sunscreening agents, as they are classified under cosmetics. In this article, the authors discuss the pharmacological actions of sunscreening agents as well as the available formulations, their benefits, possible health hazards, safety, challenges, and proper application technique. New technologies and scope for the development of sunscreening agents are also discussed as well as the role of the physician in patient education about the use of these agents. PMID:23320122

  15. Design of a new, multi-purpose, light-curing adhesive comprising a silane coupling agent, acidic adhesive monomers and dithiooctanoate monomers for bonding to varied metal and dental ceramic materials.

    PubMed

    Ikemura, Kunio; Tanaka, Hisaki; Fujii, Toshihide; Deguchi, Mikito; Negoro, Noriyuki; Endo, Takeshi; Kadoma, Yoshinori

    2011-01-01

    A newly designed, light-curing adhesive was investigated for its bonding effectiveness to porcelain, alumina, zirconia, Au, Au alloy, Ag alloy, Au-Ag-Pd alloy, and Ni-Cr alloy. Four experimental adhesives were prepared using varying contents of the following: a silane coupling agent [3-methacryloyloxypropyltriethoxysilane (3-MPTES)], acidic adhesive monomers [6-methacryloyloxyhexyl phosphonoacetate(6-MHPA),6-methacryloyloxyhexyl3-phosphonopropionate(6-MHPP)and 4-methacryloyloxyethoxycarbonylphthalic acid (4-MET)], and dithiooctanoate monomers [6-methacryloyloxyhexyl 6,8-dithiooctanoate (6-MHDT) and 10-methacryloyloxydecyl 6,8-dithiooctanoate (10-MDDT)]. After all adherend surfaces were sandblasted and applied with an experimental adhesive, shear bond strengths (SBSs) of a light-curing resin composite (Beautifil II, Shofu Inc., Kyoto, Japan) to the adherend materials after 2,000 times of thermal cycling were measured. For the experimental adhesive which contained 3-MPTES (30.0 wt%), 6-MHPA (1.0 wt%), 6-MHPP (1.0 wt%), 4-MET (1.0 wt%), 6-MHDT (0.5 wt%) and 10-MDDT (0.5 wt%), it consistently yielded the highest SBS for all adherend surfaces in the range of 20.8 (4.8)-30.3 (7.9) MPa, with no significant differences among all the adherend materials (p>0.05). Therefore, the newly designed, multi-purpose, light-curing adhesive was able to deliver high SBS to all the adherend materials tested. PMID:21778601

  16. Application of high performance liquid chromatography coupled to on-line solid-phase extraction-nuclear magnetic resonance spectroscopy for the analysis of degradation products of V-class nerve agents and nitrogen mustard.

    PubMed

    Mazumder, Avik; Kumar, Ajeet; Purohit, Ajay K; Dubey, Devendra K

    2010-04-23

    The detection and identification of the degradation products of nitrogen mustard and nerve agent VX by high performance liquid chromatography coupled to on-line solid-phase extraction-nuclear magnetic resonance spectroscopy (HPLC-UV-SPE-NMR) were demonstrated. The analytes selected for the study were N,N-dimethylaminoethanol (DMAE), N,N-diethylaminoethanol (DEAE), N,N-diisopropylaminoethanol (DIAE) and triethanolamine (TEA). Offline solid-phase extraction (SPE) followed by derivatization was applied to eliminate the interferents and make the analytes amenable for UV detection. Thereafter, chromatographically separated derivatives were trapped on on-line SPE cartridges. They were subsequently eluted and 1H NMR and COSY spectra were obtained. The overall detection limits of the LC-UV-SPE-NMR method for the mentioned analytes were found to be 18, 23, 25, and 32 mg/L respectively. Applicability of the method to real samples was demonstrated by the analysis of samples provided during the 22nd OPCW official proficiency test. The method gave reproducible NMR spectra devoid of intense background signals. PMID:20303089

  17. Antidiabetic Agents.

    ERIC Educational Resources Information Center

    Plummer, Nancy; Michael, Nancy, Ed.

    This module on antidiabetic agents is intended for use in inservice or continuing education programs for persons who administer medications in long-term care facilities. Instructor information, including teaching suggestions, and a listing of recommended audiovisual materials and their sources appear first. The module goal and objectives are then…

  18. Silane coupling agents for corrosion protection

    NASA Astrophysics Data System (ADS)

    Subramanian, Vijay

    2000-10-01

    Organofunctional silanes have retained special attention of the adhesion world for a long time. The current work attempts to expand the areas of application of silanes into corrosion control of metals and alloys. Studies of selected functional and non-functional silane films formed on iron substrates showed that there is interaction between the amine functional group of gamma-aminopropyl trimethoxysilane (gamma-APS) and the iron substrate, the result of which is no improvement in corrosion protection. A non-functional silane, Bis-triethoxysilyl ethane (BTSE), on the other hand, formed more number of oxane bonds with the substrate, when applied from acidic pH range. This results in improved corrosion protection. A two-step silane treatment consisting of a non-functional first silane layer and a functional silane second layer is proposed, which can provide corrosion protection and adhesion enhancement. Several alloy systems and bis-silanes are investigated and the two step silane treatment is shown to improve both adhesion and corrosion performance. The selection of the silane application pH is shown to be related to the stability of the metal or oxide surface present. The roles of the first and second layer of the silane are corrosion protection and adhesion improvement with the top-coat respectively. Concentration of BTSE in the coating solution is shown to affect the properties of the protective film formed on AL 2024. The thickness of the silane film increases proportional to the concentration. Thinner films of BTSE reduce only the cathodic reaction rates at the metal surface, whereas thicker films substantially reduce both anodic and cathodic reaction rates. These results also match several performance tests including ASTM B-117 salt spray. On Al 1050, the oxide layer on the surface is shown to have little effect on the electrical properties of the BTSE film formed. Preheating the surface and curing of the deposited film strongly influence the electrical properties. The condensation reaction occurring during the curing process results in a hydrophobic silane film. This results in the emergence of a second relaxation in the impedance behavior, which is directly related to the resistance offered by the silane film towards corrosive attack.

  19. Dynamic Agents of Magnetosphere-Ionosphere Coupling

    NASA Technical Reports Server (NTRS)

    Khazanov, George V.; Rowland, Douglas E.; Moore, Thomas E.; Collier, Michael

    2011-01-01

    VISIONS sounding rocket mission (VISualizing Ion Outflow via Neutral atom imaging during a Substorm) has been awarded to NASA/GSFC (PI Rowland) in order to provide the first combined remote sensing and in situ measurements of the regions where ion acceleration to above 5 e V is occurring, and of the sources of free energy and acceleration mechanisms that accelerate the ions. The key science question of VISIONS is how, when, and where, are ions accelerated to escape velocities in the auroral zone below 1000 km, following substorm onset? Sources of free energy that power this ion acceleration process include (but not limited) electron precipitation, field-aligned currents, velocity shears, and Alfvenic Poynting flux. The combine effect of all these processes on ionospheric ion outflows will be investigated in a framework of the kinetic model that has been developed by Khazanov et al. in order to study the polar wind transport in the presence of photoelectrons.

  20. Agent Exoplanet

    NSDL National Science Digital Library

    2014-05-14

    Astronomers at Las Cumbres Observatory are investigating exoplanets - planets which orbit stars other than our Sun - and you can too. Joining Agent Exoplanet you will study known exoplanets using images taken by LCOGT’s telescopes. You'll measure the brightness of a star while a planet moves between it and our viewpoint. You can examine as many images, from as many exoplanet transit events, as you like and contribute to understanding the properties of each exoplanet.

  1. Magnetized silane-coupling agent KH-570 based solid-phase extraction followed by gas chromatography-flame ionization detection to determine venlafaxine in human hair and aqueous environmental samples.

    PubMed

    Ebrahimi, Mahmoud; Ebrahimitalab, Abdolhossein; Es'haghi, Zarrin; Mohammadinejad, Arash

    2015-02-01

    In the present study, a novel adsorbent, Fe3O4 magnetic nanoparticles (MNPs) functionalized by silane-coupling agent KH-570, was successfully synthesized. The prepared MNPs were characterized by Fourier-transform infrared spectroscopy and transmission electron microscopy. It was applied as functionalized magnetic nano-adsorbent for magnetic solid-phase extraction of trace levels of venlafaxine using gas chromatography with flame ionization detector. This method was developed and optimized for use in analysis of venlafaxine in human hair and aqueous environmental samples. The main factors influencing the extraction efficiency including pH of sample, amount of the MNPs, adsorption time, volume of sample, and desorption conditions such as volume of solvent and desorption time were studied and optimized. Under the optimized experimental conditions, good linearity was observed in the range of 1-1,000 µg L(-1) for aqueous environmental samples with correlation coefficients (R (2)) 0.996. The limits of detection and quantification were 0.1 and 0.5 ?g L(-1), respectively. Good reproducibility with the relative standard deviations (n = 5) 3.21 % was obtained. The developed method was successfully applied to the extraction of venlafaxine from spiked human hair, river water, and surface water samples and the relative recoveries of 89.36, 93.43, and 94.99 % were obtained, respectively. The results indicated that Fe3O4/KH-570 MNPs have a satisfying extraction efficiency and can be served as a sensitive, inexpensive, and reliable method for analysis of antidepressant drugs such as venlafaxine in biological and aqueous environmental samples. PMID:25367213

  2. KGB agents

    NASA Astrophysics Data System (ADS)

    Gaina, Alex

    A short story is reported in which the activity of Communist Party of the USSR and secret KGB agents, which were payed by the State, in view of controlling of the conscience of population. The story reffers to the Physics Department of the Moscow University, Planing Institute of the Gosplan of Moldavian S.S.R. and Chishinau Technical University (actually: Technical University of Moldova), where the author has worked during Soviet times. Almost every 6-th citizen in the USSR was engaged in this activity, while actually the former communists rule in the Republic of Moldova.

  3. Agent Building Software

    NASA Technical Reports Server (NTRS)

    2000-01-01

    AgentBuilder is a software component developed under an SBIR contract between Reticular Systems, Inc., and Goddard Space Flight Center. AgentBuilder allows software developers without experience in intelligent agent technologies to easily build software applications using intelligent agents. Agents are components of software that will perform tasks automatically, with no intervention or command from a user. AgentBuilder reduces the time and cost of developing agent systems and provides a simple mechanism for implementing high-performance agent systems.

  4. The Rights of Agents

    Microsoft Academic Search

    Christen Krogh

    1995-01-01

    Abstract Many agents are conceived to achieve certain goals on behalf of their owners by interacting with other agents In order to make these agents behave so as not to violate other agent's rights (or, more uncontroversially: the rights of the owners of other agents), we have to build into agents an attitude about such rights To do this, we

  5. Open Multi-Agent Systems: Agent

    E-print Network

    Utrecht, Universiteit

    that facilitate the communication process in a multi-agent system. These agents, referred to with terms like facilitators, routers, mediators, bro- kers and so on (cf. [8]) act as intermediaries between communicatingOpen Multi-Agent Systems: Agent Communication and Integration Rogier M. van Eijk, Frank S. de Boer

  6. Agents on the Web Making Agents

    E-print Network

    Huhns, Michael N.

    around for ages. In the 16th century, for instance, Venetian mer- chants used poison and bribery to gain itself to the JADE (Java Agent Development Framework) agent platform in Italy, killing all of the agents it found there. Although not as serious as it might appear -- because the agents in Italy were

  7. Agents on the Web Making Agents

    E-print Network

    Farkas, Csilla

    for ages. In the 16th century, for instance, Venetian merchants used poison and bribery to gain market itself to the JADE (Java Agent Development Framework) agent platform in Italy, killing all of the agents it found there. Although not as serious as it might appear -- because the agents in Italy were

  8. UMBC AgentWeb: Intelligent Software Agents

    NSDL National Science Digital Library

    This site, sponsored and maintained by the University of Maryland Baltimore County (UMBC) Laboratory for Advanced Information Technology (LAIT), focuses on intelligent agents, known alternatively as software agents, knowbots, infobots or intentional agents. The site is divided into several parts, some of which are annotated and some of which contain only links to resources. Annotated resources include a bibliography titled Introduction to Agents (under Introductory Material), a list of research projects involving agent technology, and abstracts of and links to articles on a variety of topics such as Agents and Security and Agents in Manufacturing.

  9. 7 CFR 4290.1620 - Functions of agents, including Central Registration Agent, Selling Agent and Fiscal Agent.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...false Functions of agents, including Central Registration Agent, Selling Agent and...1620 Functions of agents, including Central Registration Agent, Selling Agent and...time to time, may prescribe. (3) Central Registration Agent. Pursuant...

  10. 13 CFR 107.1620 - Functions of agents, including Central Registration Agent, Selling Agent and Fiscal Agent.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...false Functions of agents, including Central Registration Agent, Selling Agent and...1620 Functions of agents, including Central Registration Agent, Selling Agent and...time to time, may prescribe. (3) Central Registration Agent. Pursuant...

  11. Detecting agents.

    PubMed Central

    Johnson, Susan C

    2003-01-01

    This paper reviews a recent set of behavioural studies that examine the scope and nature of the representational system underlying theory-of-mind development. Studies with typically developing infants, adults and children with autism all converge on the claim that there is a specialized input system that uses not only morphological cues, but also behavioural cues to categorize novel objects as agents. Evidence is reviewed in which 12- to 15-month-old infants treat certain non-human objects as if they have perceptual/attentional abilities, communicative abilities and goal-directed behaviour. They will follow the attentional orientation of an amorphously shaped novel object if it interacts contingently with them or with another person. They also seem to use a novel object's environmentally directed behaviour to determine its perceptual/attentional orientation and object-oriented goals. Results from adults and children with autism are strikingly similar, despite adults' contradictory beliefs about the objects in question and the failure of children with autism to ultimately develop more advanced theory-of-mind reasoning. The implications for a general theory-of-mind development are discussed. PMID:12689380

  12. Mobile Agents White Paper

    Microsoft Academic Search

    Jim White

    1996-01-01

    this paper.IntroductionNew productsNew applicationsNew networksAbout "Mobile Agents"Enabling mobile agentsMobile agent paradigmMobile agent conceptsMobile agent technologyProgramming mobile agentsProgramming a placeProgramming an agentUsing mobile agentsMonitoring changing conditionsDoing time-consuming legworkUsing services in combinationThe user experienceHow agents provide the experienceVariations on the themeAcknowledgmentsRelated workReferencesIntroduction

  13. Intelligence artificielle Agents intelligents

    E-print Network

    Bonzon, Elise

    Intelligence artificielle Agents intelligents Elise Bonzon http://web.mi.parisdescartes.fr/ bonzon´e Paris Descartes 1 / 21 Intelligence artificielle #12;Agents intelligents Agents intelligents Agents et environnement Rationalit´e PEAS Types d'environnement Structure des agents Conclusion 2 / 21 Intelligence

  14. Agent-user etiquette

    Microsoft Academic Search

    S. Schiaffino; A. Amandi

    2006-01-01

    This paper describes the agent-user etiquette. The areas of personal agents and human-computer interaction are the two main contributions. First, it increases understanding of personalization in user-agent interaction. Second, our approach enhances a personal agent's capabilities since it enables developers to build personal agents that will certainly gain higher acceptance among users than traditional personal agents because they take into

  15. On Programming KARO Agents

    Microsoft Academic Search

    John-jules Ch. Meyer; Frank S. De Boer; Rogier M. Van Eijk; Koen V. Hindriks; Wiebe Van Der Hoek

    2001-01-01

    After having dened the KARO logic for specifying intelligent agents (an amalgam of various modal logics to reason about both informational and motivational attitudes of agents) in earlier work we now turn to the question how to realise agents specied in the KARO framework. To this end we look at agent programming languages that we have dened, and investigate how

  16. Software agents: an overview

    Microsoft Academic Search

    Hyacinth S. Nwana

    1996-01-01

    Agent software is a rapidly developing area of research. However, the overuse of the word 'agent' has tended to mask the fact that, in reality, there is a truly heterogeneous body of research being carried out under this banner. This overview paper presents a typology of agents. Next, it places agents in context, defines them and then goes on, inter

  17. Spacecraft sanitation agent development

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The development of an effective sanitizing agent that is compatible with the spacecraft environment and the human occupant is discussed. Experimental results show that two sanitation agents must be used to satisfy mission requirements: one agent for personal hygiene and one for equipment maintenance. It was also recommended that a water rinse be used with the agents for best results, and that consideration be given to using the agents pressure packed or in aerosol formulations.

  18. Securing Agent Based Architectures

    Microsoft Academic Search

    Michael Maxim; Ashish Venugopal

    2002-01-01

    Agent based architectures provide significant flexibility and extensibility to software systems that attempt to model complex\\u000a real world interactions between human users and functional agents. Such systems allow agents to be seamlessly published into\\u000a the system providing services to human agent consumers. Securing agent based architectures in permissions based environments\\u000a while still maintaining extensibility involves establishing a pathway of trust

  19. Agents Recognizing Emergence

    E-print Network

    Agents that recognize self organizing systems and their emergent properties have a competitive advantage. In this paper we introduce a classication of self-organizing systems based on phase transitions, macroscopic dynamic structures, evolution, self-regulation, and ultra-stability. Sometimes the agent can recognize the type of self-organizing system by observing its internal mechanisms such as feedback mechanisms or essential variables, but in general he has to interpret the system's behavior and in particular its relation with the environment. The agent therefore uses besides theories of self-organization also theories of cybernetics. 1 Introduction Autonomous agents and multi agent systems are active research areas in arti- cial intelligence. We are interested in cognitive agents that use models of their environment, including models of other agents. In agent-based software engineering it has been recognized that the major drawback of the agent perspective is that in exc...

  20. Relational Agents Page 1 Relational Agents for

    E-print Network

    Bickmore, Timothy

    -updated multiple-choice menu (Fig 1). These agents have been tested in two randomized trials for physical activity effectiveness over standard-of-care control conditions. These trials were conducted on home desktop computers goals were met and problem-solving to overcome obstacles when they weren't. In addition, the agent

  1. Synchronization of mobile chaotic agents on connected networks

    NASA Astrophysics Data System (ADS)

    Bu, Shou-Liang; Wen, Jian-Ping; Zhong, Qing-Hu; Yi, Xue-Hua

    2013-12-01

    This work studies the synchronization of a number of mobile agents on a substrate network. Each agent carries a chaotic map and randomly walks on a connected network. The collection of agents consists of another time-varying network derived from the substrate network. It is found that the synchronization conditions of this agent network depend on the average degree of the substrate network’s connectivity, the coupling strength between interacting agents, and the agent density in the network. Synchronization of the agent network on scale-free and ER networks is considered here, and it is found that the scale-free topology is more applicable to synchronize mobile chaotic agents. To get analytical insights, the star graph is taken and considered as a substrate network.

  2. Designing Intelligent Agents Tutorial 1: Java Agent Package

    E-print Network

    Logan, Brian

    G54DIA: Designing Intelligent Agents Tutorial 1: Java Agent Package Brian Logan School of Computer package(s) · agent toolkits · uk.ac.nott.cs.g54dia Java agent packages ­library package ­demo package © Brian Logan 2013 G54DIA Tutorial 1: Java Agent Package 2 #12;Implementing your agent · many agent

  3. AgentSheets

    NSDL National Science Digital Library

    Alex Reppening

    From personal and information Agents to interactive demos, modifiable simulations to virtual game worlds, AgentSheets' unique user interface captivates people and draws them into a new relationship with technology.

  4. Agent Oriented Programming

    Microsoft Academic Search

    Yoav Shoham

    1992-01-01

    Shoham, Y., Agent-oriented programming, Artificial Intelligence 60 (1993) 51-92. A new computational framework is presented, called agent-oriented programming (AOP), which can be viewed as a specialization of object-oriented programming. The state of an agent consists of components such as beliefs, decisions, capabilities, and obligations; for this reason the state of an agent is called its mental state. The mental state

  5. Biological warfare agents

    Microsoft Academic Search

    Miroslav Pohanka; Kamil Ku?a

    \\u000a Biological warfare agents are a group of pathogens and toxins of biological origin that can be potentially misused for military\\u000a or criminal purposes. The present review attempts to summarize necessary knowledge about biological warfare agents. The historical\\u000a aspects, examples of applications of these agents such as anthrax letters, biological weapons impact, a summary of biological\\u000a warfare agents and epidemiology of

  6. Intelligent Agents: A Primer.

    ERIC Educational Resources Information Center

    Yu, Edmund; Feldman, Susan

    1999-01-01

    Provides an in-depth introduction to the various technologies that are bringing intelligent agents into the forefront of information technology, explaining how such agents work, the standards involved, and how agent-based applications can be developed. (Author/AEF)

  7. APP: AGENT PLANNING PACKAGE

    Microsoft Academic Search

    S RADOVANOVI ´ C

    C† Abstract. Nowadays, a large number of planning systems exist. The majority of them are either applicable only to specific domains (domain dependent) or support only plan generation, but not plan execution and supervision. This paper presents Agent Planning Package (APP), a new domain independent planner which facilitates the creation of intelligent agents. Through the use of APP, agents can

  8. Mobile Agents Applications.

    ERIC Educational Resources Information Center

    Martins, Rosane Maria; Chaves, Magali Ribeiro; Pirmez, Luci; Rust da Costa Carmo, Luiz Fernando

    2001-01-01

    Discussion of the need to filter and retrieval relevant information from the Internet focuses on the use of mobile agents, specific software components which are based on distributed artificial intelligence and integrated systems. Surveys agent technology and discusses the agent building package used to develop two applications using IBM's Aglet…

  9. MOBILE AGENTS AND SECURITY

    Microsoft Academic Search

    W. A. Jansen

    1999-01-01

    Mobile agent technology offers a new computing paradigm in which a software agent can suspend its execution on a host computer, transfer itself to another agent-enabled host on the network, and resume execution on the new host. The use of mobile code has a long history dating back to the use of remote job entry systems in the 1960's. Today's

  10. Normative KGP agents

    Microsoft Academic Search

    Fariba Sadri; Kostas Stathis; Francesca Toni

    2006-01-01

    We extend the logical model of agency known as the KGP model, to support agents with normative concepts, based on the roles an agent plays and the obligations and prohibitions that result from playing these roles. The proposed framework illustrates how the resulting normative concepts, including the roles, can evolve dynamically during the lifetime of the agent. Furthermore, we illustrate

  11. Declarative Agent Control

    Microsoft Academic Search

    Antonis C. Kakas; Paolo Mancarella; Fariba Sadri; Kostas Stathis; Francesca Toni

    2004-01-01

    In this work, we extend the architecture of agents (and robots) based upon fixed, one-size-fits-all cycles of operation, by providing a framework of declarative specification of agent control. Control is given in terms of cycle the- ories, which define in a declarative way the possible alternative behaviours of agents, depending on the particular circumstances of the (perceived) external en- vironment

  12. Cooperative Interface Agents

    Microsoft Academic Search

    Sebastiano Pizzutilo; Berardina De Carolis; Fiorella de Rosis

    Animated agents are endowed with personality and emotions, with the aim of increasing their believability and of establishing an “empathetic” relationship with the user. In this chapter, we claim that, to endow agents with social intelligence, the communication traits described in the Five Factor Model should be integrated with some cooperation attitudes. We describe our experience in building an agent

  13. Agent-enhanced Workflow

    Microsoft Academic Search

    Donald Judge; Brian Odgers; John Shepherdson; Zhan Cui

    1998-01-01

    In agent-enhanced workflow, a community of intelligent, distributed and autonomous software agents is used to improve the management of business processes under the control of a workflow management system. These improvements are achieved by allowing the software agents to negotiate with each other to establish contracts that govern the distribution of work across a number of processing centres. Furthermore, the

  14. Proceedings of the Agent 2002 Conference on Social Agents : Ecology, Exchange, and Evolution

    SciTech Connect

    Macal, C., ed.; Sallach, D., ed.

    2003-04-10

    Welcome to the ''Proceedings'' of the third in a series of agent simulation conferences cosponsored by Argonne National Laboratory and The University of Chicago. The theme of this year's conference, ''Social Agents: Ecology, Exchange and Evolution'', was selected to foster the exchange of ideas on some of the most important social processes addressed by agent simulation models, namely: (1) The translation of ecology and ecological constraints into social dynamics; (2) The role of exchange processes, including the peer dependencies they create; and (3) The dynamics by which, and the attractor states toward which, social processes evolve. As stated in the ''Call for Papers'', throughout the social sciences, the simulation of social agents has emerged as an innovative and powerful research methodology. The promise of this approach, however, is accompanied by many challenges. First, modeling complexity in agents, environments, and interactions is non-trivial, and these representations must be explored and assessed systematically. Second, strategies used to represent complexities are differentially applicable to any particular problem space. Finally, to achieve sufficient generality, the design and experimentation inherent in agent simulation must be coupled with social and behavioral theory. Agent 2002 provides a forum for reviewing the current state of agent simulation scholarship, including research designed to address such outstanding issues. This year's conference introduces an extensive range of domains, models, and issues--from pre-literacy to future projections, from ecology to oligopolistic markets, and from design to validation. Four invited speakers highlighted major themes emerging from social agent simulation.

  15. Intelligent Agents What is an Agent?

    E-print Network

    Dyer, Charles R.

    and news from stock market and produces buy/sell trades as actions · Medicine ­ Diagnostic agent takes test's sensors give it access to the complete state of the environment at any point in time · If all aspects

  16. Multi-agent autonomous system

    NASA Technical Reports Server (NTRS)

    Fink, Wolfgang (Inventor); Dohm, James (Inventor); Tarbell, Mark A. (Inventor)

    2010-01-01

    A multi-agent autonomous system for exploration of hazardous or inaccessible locations. The multi-agent autonomous system includes simple surface-based agents or craft controlled by an airborne tracking and command system. The airborne tracking and command system includes an instrument suite used to image an operational area and any craft deployed within the operational area. The image data is used to identify the craft, targets for exploration, and obstacles in the operational area. The tracking and command system determines paths for the surface-based craft using the identified targets and obstacles and commands the craft using simple movement commands to move through the operational area to the targets while avoiding the obstacles. Each craft includes its own instrument suite to collect information about the operational area that is transmitted back to the tracking and command system. The tracking and command system may be further coupled to a satellite system to provide additional image information about the operational area and provide operational and location commands to the tracking and command system.

  17. IM Free Agent Sign Up 1 Wanted! Intramurals Free Agents!

    E-print Network

    Hemmers, Oliver

    IM Free Agent Sign Up 1 Wanted! Intramurals Free Agents! Individuals who do not have a full team a "Free Agent". Within the UNLV Intramural Sports program there are multiple ways to improve a Free Agent will not force any team to accept a Free Agent participant. History and research has shown that Free Agents

  18. Helix coupling

    DOEpatents

    Ginell, W.S.

    1982-03-17

    A coupling for connecting helix members in series, which consists of a pair of U-shaped elements, one of which is attached to each helix end with the U sections of the elements interlocked. The coupling is particularly beneficial for interconnecting helical Nitinol elements utilized in thermal actuators or engines. Each coupling half is attached to the associated helix at two points, thereby providing axial load while being easily removed from the helix, and reusable.

  19. Helix coupling

    DOEpatents

    Ginell, W.S.

    1989-04-25

    A coupling for connecting helix members in series, which consists of a pair of U-shaped elements, one of which is attached to each helix end with the "U" sections of the elements interlocked. The coupling is particularly beneficial for interconnecting helical Nitinol elements utilized in thermal actuators or engines. Each coupling half is attached to the associated helix at two points, thereby providing axial load while being easily removed from the helix, and reusable.

  20. Agent Architectures for Compliance

    NASA Astrophysics Data System (ADS)

    Burgemeestre, Brigitte; Hulstijn, Joris; Tan, Yao-Hua

    A Normative Multi-Agent System consists of autonomous agents who must comply with social norms. Different kinds of norms make different assumptions about the cognitive architecture of the agents. For example, a principle-based norm assumes that agents can reflect upon the consequences of their actions; a rule-based formulation only assumes that agents can avoid violations. In this paper we present several cognitive agent architectures for self-monitoring and compliance. We show how different assumptions about the cognitive architecture lead to different information needs when assessing compliance. The approach is validated with a case study of horizontal monitoring, an approach to corporate tax auditing recently introduced by the Dutch Customs and Tax Authority.

  1. Extending UML for Agents

    Microsoft Academic Search

    James Odell; H. Van Dyke Parunak; Bernhard Bauer

    2000-01-01

    Gaining wide acceptance for the use of agents in industry requires both relating it to the nearest antecedent technology (object-oriented software development) and using artifacts to support the development environment throughout the full system lifecycle. We address both of these requirements in this paper by describing some of the most common requirements for modeling agents and agent-based systems—using a set

  2. DCTD — Featured Agents

    Cancer.gov

    DNA damaging agents are among the most successful treatments for cancer. The enzyme Poly(ADP-ribose)polymerase (abbreviated PARP) can facilitate repair of DNA damage caused by insult from chemotherapeutic agents and radiation. Increased PARP activity is associated with survival of some cancer cells. ABT-888, an orally bioavailable PARP-inhibitor developed by Abbott Laboratories, significantly enhanced the antitumor activity of DNA-damaging agents and radiation in preclinical models. Further development of this compound is ongoing.

  3. DCTD — Featured Agents

    Cancer.gov

    The “Featured Agents” portion of the DCTD Website provides information for researchers involved in drug discovery and development. Any public preclinical and clinical data that DCTD has on a particular agent are presented here. New agents will be added periodically to the current list. DCTD Website visitors may subscribe to the Listserv on this page to be notified when additions to the list are made.

  4. Interactive agent generated architecture

    E-print Network

    Krause, Jeffrey Charles Stanley

    1996-01-01

    The thesis explores architectural form generation through two behavior based artificial intelligence approaches: the communication of agents in an unpredictable simulation system, and the codification of information within ...

  5. Joint chemical agent detector (JCAD): the future of chemical agent detection

    NASA Astrophysics Data System (ADS)

    Laljer, Charles E.

    2003-08-01

    The Joint Chemical Agent Detector (JCAD) has continued development through 2002. The JCAD has completed Contractor Validation Testing (CVT) that included chemical warfare agent testing, environmental testing, electromagnetic interferent testing, and platform integration validation. The JCAD provides state of the art chemical warfare agent detection capability to military and homeland security operators. Intelligence sources estimate that over twenty countries have active chemical weapons programs. The spread of weapons of mass destruction (and the industrial capability for manufacture of these weapons) to third world nations and terrorist organizations has greatly increased the chemical agent threat to U.S. interests. Coupled with the potential for U.S. involvement in localized conflicts in an operational or support capacity, increases the probability that the military Joint Services may encounter chemical agents anywhere in the world. The JCAD is a small (45 in3), lightweight (2 lb.) chemical agent detector for vehicle interiors, aircraft, individual personnel, shipboard, and fixed site locations. The system provides a common detection component across multi-service platforms. This common detector system will allow the Joint Services to use the same operational and support concept for more efficient utilization of resources. The JCAD detects, identifies, quantifies, and warns of the presence of chemical agents prior to onset of miosis. Upon detection of chemical agents, the detector provides local and remote audible and visual alarms to the operators. Advance warning will provide the vehicle crew and other personnel in the local area with the time necessary to protect themselves from the lethal effects of chemical agents. The JCAD is capable of being upgraded to protect against future chemical agent threats. The JCAD provides the operator with the warning necessary to survive and fight in a chemical warfare agent threat environment.

  6. Mobile Agents and Java Mobile Agents Toolkits

    Microsoft Academic Search

    Damir Horvat; Dragana Cvetkovi?; Veljko Milutinovi?; Petar Ko?ovi?; Vlada Kova?evi?

    2001-01-01

    This paper gives an overview of what the mobile agents are, what they should do and how they can be implemented in Java. Why Java? The choice to concentrate on Java is evoked by many existing solutions in Java that handles architectural heterogeneity between communicating machines on the net. It seems to be the best available language for making mobile

  7. Agents on the Web Ontologies for Agents

    E-print Network

    Huhns, Michael N.

    When we need to find the cheapest airfare, we call our travel agent, Betsi, at Prestige Travel. We of discourse (e.g., classes, relations, functions, or other objects) with human-readable text describing what. The semantic relationships provide users with an abstract view of an information space for their domain

  8. Change Agent Survival Guide

    ERIC Educational Resources Information Center

    Dunbar, Folwell L.

    2011-01-01

    Consulting is a rough racket. Only a tarantula hair above IRS agents, meter maids and used car sales people, the profession is a prickly burr for slings and arrows. Throw in education, focus on dysfunctional schools and call oneself a "change agent," and this bad rap all but disappears. Unfortunately, though, consulting/coaching/mentoring in…

  9. DCTD — Featured Agents

    Cancer.gov

    Skip to Content Click here to view the Site Map Home | Sitemap | Contact DCTD Search this site Featured Agents Agents NCI Experimental Therapeutics (NExT) Program Drug Development Primer FDA-Approved Cancer Drugs DCTD Programs Cancer Diagnosis Program Cancer

  10. Chemical warfare agents

    Microsoft Academic Search

    Rohit Shenoi

    2002-01-01

    There is an increased risk that civilian populations will be targets of domestic terrorism. Release of chemical warfare agents in these populations can cause a large number of casualties, with children being disproportionately affected. Chemical agents pose a significant risk to unprepared medical providers. Emergency medical personnel must be able to diagnose and manage victims of toxic exposures. This article

  11. Agent Server Architecture for the Ajanta MobileAgent System

    E-print Network

    Minnesota, University of

    Agent Server Architecture for the Ajanta Mobile­Agent System Neeran M. Karnik and Anand R. Tripathi an overview of Ajanta, a Java­based mobile­agent system, and focuses in par­ ticular on the architecture. Keywords: Mobile agents, Distributed computing, Java, Security 1 Introduction Mobile agent

  12. Agents as web service providers: single agents or MAS?

    Microsoft Academic Search

    Michael Sonntag

    2006-01-01

    Agents are good tools for providing Web services. They are usually either single agents, where one agent provides one or multiple services, or multiple individual agents that are discovered using UDDI. But then also a singular recipient is determined for fulfilling actual requests. This is well suited for smaller services, which are provided by a single, but perhaps complex, agent

  13. Open MultiAgent Systems: Agent Communication and Integration

    E-print Network

    Utrecht, Universiteit

    have been proposed that facilitate the communication process in a multi­agent system. These agentsOpen Multi­Agent Systems: Agent Communication and Integration Rogier M. van Eijk, Frank S. de Boer is on the issues of agent communication and integration. We define an abstract programming lan­ guage for open

  14. How do agents represent?

    NASA Astrophysics Data System (ADS)

    Ryan, Alex

    Representation is inherent to the concept of an agent, but its importance in complex systems has not yet been widely recognised. In this paper I introduce Peirce's theory of signs, which facilitates a definition of representation in general. In summary, representation means that for some agent, a model is used to stand in for another entity in a way that shapes the behaviour of the agent with respect to that entity. Representation in general is then related to the theories of representation that have developed within different disciplines. I compare theories of representation from metaphysics, military theory and systems theory. Additional complications arise in explaining the special case of mental representations, which is the focus of cognitive science. I consider the dominant theory of cognition — that the brain is a representational device — as well as the sceptical anti-representational response. Finally, I argue that representation distinguishes agents from non-representational objects: agents are objects capable of representation.

  15. Pediatric Antifungal Agents

    PubMed Central

    Cohen-Wolkowiez, Michael; Moran, Cassandra; Benjamin, Daniel K.; Smith, P Brian

    2009-01-01

    Purpose of review In immunocompromised hosts, invasive fungal infections are common and fatal. In the past decade, the antifungal armamentarium against invasive mycoses has expanded greatly. The purpose of this report is to review the most recent literature addressing the use of antifungal agents in children. Recent findings Most studies evaluating the safety and efficacy of antifungal agents are limited to adults. However, important progress has been made in describing the pharmacokinetics and safety of newer antifungal agents in children, including the echinocandins. Summary Dosage guidelines for newer antifungal agents are currently based on adult and limited pediatric data. Because important developmental pharmacology changes occur throughout childhood impacting the pharmacokinetics of these agents, antifungal studies specifically designed for children are necessary. PMID:19741525

  16. Fluorescence imaging agents in cancerology

    PubMed Central

    Paganin-Gioanni, Aurélie; Bellard, Elisabeth; Paquereau, Laurent; Ecochard, Vincent; Golzio, Muriel; Teissié, Justin

    2010-01-01

    Background One of the major challenges in cancer therapy is to improve early detection and prevention using novel targeted cancer diagnostics. Detection requests specific recognition. Tumor markers have to be ideally present on the surface of cancer cells. Their targeting with ligands coupled to imaging agents make them visible/detectable. Conclusions Fluorescence imaging is a newly emerging technology which is becoming a complementary medical method for cancer diagnosis. It allows detection with a high spatio-temporal resolution of tumor markers in small animals and in clinical studies. In this review, we focus on the recent outcome of basic studies in the design of new approaches (probes and devices) used to detect tumor cells by fluorescence imaging. PMID:22933906

  17. Autonomous Interface Agents Henry Lieberman

    E-print Network

    the user and the agent "take turns" acting. Autonomous interface agents lead to a somewhat different design "agents" that are gaining currency are interface agents, software that actively assists a user in operating an interactive interface, and autonomous agents, software that takes action without user

  18. Biological warfare agents

    PubMed Central

    Thavaselvam, Duraipandian; Vijayaraghavan, Rajagopalan

    2010-01-01

    The recent bioterrorist attacks using anthrax spores have emphasized the need to detect and decontaminate critical facilities in the shortest possible time. There has been a remarkable progress in the detection, protection and decontamination of biological warfare agents as many instrumentation platforms and detection methodologies are developed and commissioned. Even then the threat of biological warfare agents and their use in bioterrorist attacks still remain a leading cause of global concern. Furthermore in the past decade there have been threats due to the emerging new diseases and also the re-emergence of old diseases and development of antimicrobial resistance and spread to new geographical regions. The preparedness against these agents need complete knowledge about the disease, better research and training facilities, diagnostic facilities and improved public health system. This review on the biological warfare agents will provide information on the biological warfare agents, their mode of transmission and spread and also the detection systems available to detect them. In addition the current information on the availability of commercially available and developing technologies against biological warfare agents has also been discussed. The risk that arise due to the use of these agents in warfare or bioterrorism related scenario can be mitigated with the availability of improved detection technologies. PMID:21829313

  19. Agent oriented programming

    NASA Technical Reports Server (NTRS)

    Shoham, Yoav

    1994-01-01

    The goal of our research is a methodology for creating robust software in distributed and dynamic environments. The approach taken is to endow software objects with explicit information about one another, to have them interact through a commitment mechanism, and to equip them with a speech-acty communication language. System-level applications include software interoperation and compositionality. A government application of specific interest is an infrastructure for coordination among multiple planners. Daily activity applications include personal software assistants, such as programmable email, scheduling, and new group agents. Research topics include definition of mental state of agents, design of agent languages as well as interpreters for those languages, and mechanisms for coordination within agent societies such as artificial social laws and conventions.

  20. Healthcare Agents: Being One

    MedlinePLUS

    ... Preparing Your Advance Directives Storing Your Advance Directives Healthcare Agents: Being One Advocating for your loved one ... will be to communicate with your loved ones healthcare providers to ensure your loved ones' wishes are ...

  1. Prosthesis coupling

    NASA Technical Reports Server (NTRS)

    Reswick, J. B.; Mooney, V.; Bright, C. W.; Owens, L. J. (inventors)

    1979-01-01

    A coupling for use in an apparatus for connecting a prosthesis to the bone of a stump of an amputated limb is described which permits a bio-compatible carbon sleeve forming a part of the prosthesis connector to float so as to prevent disturbing the skin seal around the carbon sleeve. The coupling includes a flexible member interposed between a socket that is inserted within an intermedullary cavity of the bone and the sleeve. A lock pin is carried by the prosthesis and has a stem portion which is adapted to be coaxially disposed and slideably within the tubular female socket for securing the prosthesis to the stump. The skin around the percutaneous carbon sleeve is able to move as a result of the flexing coupling so as to reduce stresses caused by changes in the stump shape and/or movement between the bone and the flesh portion of the stump.

  2. Chemopreventive Agent Development

    Cancer.gov

    This group promotes and supports research on early chemopreventive agent development, from preclinical studies to phase I clinical trials. The focus is to identify and develop agents with the potential to help detect, block, reverse, or delay early stages of cancer. Preclinical studies evaluate potential new drugs and combinations in model systems using emergent knowledge of genetic and biochemical mechanisms, while early phase trials emphasize pharmacokinetics, efficacy, and safety.

  3. Agent amplified communication

    SciTech Connect

    Kautz, H.; Selman, B.; Milewski, A. [AT& T Laboratories, Murray Hill, NJ (United States)

    1996-12-31

    We propose an agent-based framework for assisting and simplifying person-to-person communication for information gathering tasks. As an example, we focus on locating experts for any specified topic. In our approach, the informal person-to-person networks that exist within an organization are used to {open_quotes}referral chain{close_quotes} requests for expertise. User-agents help automate this process. The agents generate referrals by analyzing records of e-mail communication patterns. Simulation results show that the higher responsiveness of an agent-based system can be effectively traded for the higher accuracy of a completely manual approach. Furthermore, preliminary experience with a group of users on a prototype system has shown that useful automatic referrals can be found in practice. Our experience with actual users has also shown that privacy concerns are central to the successful deployment of personal agents: an advanced agent-based system will therefore need to reason about issues involving trust and authority.

  4. Agents & ALifeAgents & ALife Artificial LifeArtificial Life

    E-print Network

    Hawick, Ken

    -state phase space systems thatCannot (?) pre-state phase space systems that include life?include life? HowAgents & ALifeAgents & ALife Artificial LifeArtificial Life Thumbing its Nose atThumbing its NoseMassey University #12;Agents & ALifeAgents & ALife QuestionsQuestions Philosophy and Life - what is it

  5. Agent Server Architecture for the Ajanta Mobile-Agent System

    Microsoft Academic Search

    Neeran M. Karnik; Anand R. Tripathi

    1998-01-01

    This paper provides an overview of Ajanta, aJava-based mobile-agent system, and focuses in particularon the architecture of the agent server --the process which hosts agents and enables them toaccess resources, communicate, migrate etc. Theagent server's main components include an agentexecution environment, an agent transfer protocol,a resource access protocol, and an agent monitoringservice. Security is a major concern in the designof

  6. Observational heterarchy enhancing active coupling

    NASA Astrophysics Data System (ADS)

    Gunji, Yukio-Pegio; Kamiura, Moto

    2004-11-01

    Heterarchy and the agent of self-organization are ones of most challengeable topics in complex systems. When the notion of heterarchy is generalized and dilated to general phenomena and is replaced by observational heterarchy, the agent of self-organization (i.e., internal observer carrying measurement) is found even in non-hierarchical system. A usual dynamics in the sense of complex system is articulated into two kinds of dynamics, Intent and Extent dynamics, and the interaction between them, where Intent corresponds to an attribute to a given phenomenon and Extent corresponds to a collection of objects satisfying the phenomenon. We formalize observational heterarchy by introducing pre-equivalence (pre-adjunction) between Intent and Extent, and apply it to a coupled map system. Since the model inherits evoluvability of dynamics, we call it active coupling to distinguish usual (passive) coupling from it. We show that perturbation can modify the dynamics itself and enhance robust behavior opened to emergence in the system of active coupling, and discuss the significance of observational heterarchy in complex systems.

  7. Agent independent task planning

    NASA Technical Reports Server (NTRS)

    Davis, William S.

    1990-01-01

    Agent-Independent Planning is a technique that allows the construction of activity plans without regard to the agent that will perform them. Once generated, a plan is then validated and translated into instructions for a particular agent, whether a robot, crewmember, or software-based control system. Because Space Station Freedom (SSF) is planned for orbital operations for approximately thirty years, it will almost certainly experience numerous enhancements and upgrades, including upgrades in robotic manipulators. Agent-Independent Planning provides the capability to construct plans for SSF operations, independent of specific robotic systems, by combining techniques of object oriented modeling, nonlinear planning and temporal logic. Since a plan is validated using the physical and functional models of a particular agent, new robotic systems can be developed and integrated with existing operations in a robust manner. This technique also provides the capability to generate plans for crewmembers with varying skill levels, and later apply these same plans to more sophisticated robotic manipulators made available by evolutions in technology.

  8. Sensor networks with mobile agents

    Microsoft Academic Search

    Lang Tong; Qing Zhao; Srihari Adireddy

    2003-01-01

    Architecture for large scale low power sensor network is proposed. Referred to as sensor networks with mobile agents (SENMA), SENMA exploit node redundancies by introducing mobile agents that communicate opportunistically with a large field of sensors. The addition of mobile agents shifts computationally intensive tasks away from primitive sensors to more powerful mobile agents, which enables energy efficient operations under

  9. Inactivation of the BSE agent

    Microsoft Academic Search

    David Taylor

    2002-01-01

    In the studies carried out so far, the BSE agent has proved to be just as resistant as other TSE agents to inactivation by procedures such as autoclaving or exposure to sodium hydroxide that are effective with conventional microorganisms. However, in common with other TSE agents, the BSE agent appears to be effectively inactivated by exposure to sodium hypochlorite solutions

  10. On the limit of large couplings and weighted averaged dynamics

    E-print Network

    Selten, Frank

    earlier reported supermodeling results. Further- more, we explore the behavior in partially coupled crickets, fir- ing neurons and applauding audiences [10]. Similar phenomena occur in multi-agent systems

  11. Surface reactions on thin layers of silane coupling agents

    SciTech Connect

    Kurth, D.G.; Bein, T. (Purdue Univ., West Lafayette, IN (United States))

    1993-11-01

    The reactivity of immobilized functional groups in thin layers of (3-aminopropyl)triethoxysilane (APS), (3-mercaptopropyl)trimethoxysilane, (3-bromopropyl)trimethoxysilane, and (8-bromooctyl)trimethoxysilane on oxidized aluminum substrates was studied with reflection-adsorption infrared spectroscopy (RAIR), optical ellipsometry and contact-angle measurements. Mass changes on the surface associated with the surface-confined reactions were measured with the quartz crystal microbalance (QCM). Single layers of (3-aminopropyl)triethoxysilane on oxidized aluminum react with chlorodimethylsilane to give [(-O)[sub 3]Si(CH[sub 2])[sub 3]NH[sub 2][sup +]SiMe[sub 2]H]Cl[sup [minus

  12. Novel Phenylethynyl Imide Silanes as Coupling Agents for Titanium Alloy

    NASA Technical Reports Server (NTRS)

    Park, C.; Lowther, S. E.; Smith, J. G., Jr.; Conell, J. W.; Hergenrother, P. M.; SaintClair, T. L.

    2004-01-01

    The durability of titanium (Ti) alloys bonded with high temperature adhesives such as polyimides has failed to attain the level of performance required for many applications. The problem to a large part is attributed to the instability of the surface treatment on the Ti substrate. Although Ti alloy adhesive specimens with surface treatments such as chromic acid anodization, Pasa-Jell, Turco, etc. have provided high initial mechanical properties, these properties have decreased as a function of aging at ambient temperature and faster, when aged at elevated temperatures or in a hot-wet environment. As part of the High Speed Civil Transport program where Ti honeycomb sandwich structure must perform for 60,000 hours at 177 C, work was directed to the development of environmentally safe, durable Ti alloy surface treatments.

  13. Space Travel Agent

    NSDL National Science Digital Library

    Ms. Williams

    2010-11-29

    You are in charge of creating a travel brochure to a planet in our solar system. Travel Agent for the Solar System Introduction You are in charge of the new ?Travel the Solar System? account at Universe Travel Agency.

  14. E-Learning Agents

    ERIC Educational Resources Information Center

    Gregg, Dawn G.

    2007-01-01

    Purpose: The purpose of this paper is to illustrate the advantages of using intelligent agents to facilitate the location and customization of appropriate e-learning resources and to foster collaboration in e-learning environments. Design/methodology/approach: This paper proposes an e-learning environment that can be used to provide customized…

  15. Mobility control agent

    SciTech Connect

    Argabright, P.A.; Phillips, B.L.; Rhudy, J.S.

    1983-05-17

    Polymer mobility control agents useful in supplemental oil recovery processes, which give improved reciprocal relative mobilities, are prepared by initiating the polymerization of a monomer containing a vinyl group with a catalyst comprising a persulfate and ferrous ammonium sulfate. The vinyl monomer is an acrylyl, a vinyl cyanide, a styryl and water soluble salts thereof.

  16. Can agents close contracts?

    Microsoft Academic Search

    Frances Brazier; Anja Oskamp; Maurice Schellekens; Niek Wijngaards

    2003-01-01

    One of the tasks of software agents on the Internet will be to close contracts on behalf of their owner. The closing of a contract is subject to liabilities. In this, there is no distinction between the real world and the virtual world. Like in the real world, within the virtual world a distinction has to be made between the

  17. Embodied mobile agents

    Microsoft Academic Search

    Bill Tomlinson; Man Lok Yau; Eric Baumer

    2006-01-01

    The move in many societies toward individuals having multiple networked computational devices - workstations, notebooks computers, mobile phones, PDAs - radically changes the ways in which people engage those devices. However, we lack interaction paradigms that enable a coherent experience across these technologies. One possible approach to this problem involves the use of embodied mobile agents (EMAs), that is, graphically

  18. New antitumor agent — Spirobromin

    Microsoft Academic Search

    T. S. Safonova; V. A. Chernov; S. M. Minakova; M. I. Dorokhova; L. G. Levkovskaya; T. A. Andreyanova; L. A. Serochkina; I. E. Mamaeva

    1983-01-01

    piperazinium dichloride (Ia) with the acid chloride of B-bromopropionic acid. Reaction was effected in aqueous medium or a medium of wa~er and ether with basic agents such as LiOH or NaHCO3 used as acceptors to bind the hydrogen chloride formed in the reaction process. N,N'\\

  19. Remote Agent Experiment

    NASA Technical Reports Server (NTRS)

    Benard, Doug; Dorais, Gregory A.; Gamble, Ed; Kanefsky, Bob; Kurien, James; Millar, William; Muscettola, Nicola; Nayak, Pandu; Rouquette, Nicolas; Rajan, Kanna; Norvig, Peter (Technical Monitor)

    2000-01-01

    Remote Agent (RA) is a model-based, reusable artificial intelligence (At) software system that enables goal-based spacecraft commanding and robust fault recovery. RA was flight validated during an experiment on board of DS1 between May 17th and May 21th, 1999.

  20. Agents of Infection

    NSDL National Science Digital Library

    Michelle Ferro

    2012-06-15

    This is a collaborative lesson design by Lori Kern and Dawn Barone. This lesson focuses on infectious agents (fungus, bacteria, virus and parasites). Students will be able experience a hands-on activity to reinforce the concepts addressed in this benchmark.

  1. Tubular Coupling

    NASA Technical Reports Server (NTRS)

    Rosenbaum, Bernard J. (Inventor)

    2000-01-01

    A system for coupling a vascular overflow graft or cannula to a heart pump. A pump pipe outlet is provided with an external tapered surface which receives the end of a compressible connula. An annular compression ring with a tapered internal bore surface is arranged about the cannula with the tapered internal surface in a facing relationship to the external tapered surface. The angle of inclination of the tapered surfaces is converging such that the spacing between the tapered surfaces decreases from one end of the external tapered surface to the other end thereby providing a clamping action of the tapered surface on a cannula which increases as a function of the length of cannula segment between the tapered surfaces. The annular compression ring is disposed within a tubular locking nut which threadedly couples to the pump and provides a compression force for urging the annular ring onto the cannula between the tapered surfaces. The nut has a threaded connection to the pump body. The threaded coupling to the pump body provides a compression force for the annular ring. The annular ring has an annular enclosure space in which excess cannula material from the compression between the tapered surfaces to "bunch up" in the space and serve as an enlarged annular ring segment to assist holding the cannula in place. The clamped cannula provides a seamless joint connection to the pump pipe outlet where the clamping force is uniformly applied to the cannula because of self alignment of the tapered surfaces. The nut can be easily disconnected to replace the pump if necessary.

  2. Validating the Autonomous Science Agent

    NASA Technical Reports Server (NTRS)

    Chien, Steve; Cichy, Benjamin; Schaffer, Steve; Tran, Danny; Rabideau, Gregg; Sherwood, Rob; Bote, Robert; Mandl, Dan; Frye, Stu; Shulman, Seth; Van Gaasbeck, Jim; Boyer, Darrell

    2003-01-01

    This paper describes the validation process for the Autonomous Science Agent, a software agent that will fly onboard the EO-1 spacecraft from 2003-2004. This agent will recognize science events, retarget the spacecraft to respond to the science events, and reduce data downlink to only the highest value science data. The autonomous science agent has been designed using a layered architectural approach with specific redundant safeguards to reduce the risk of an agent malfunction to the EO-1 spacecraft. This 'safe' design is also in the process of being thoroughly validated by informal validation methods and extensive testing. This paper describes the analysis used to define agent safety, elements of the design that increase the safety of the agent, and the process being used to validate agent safety prior to the agent software controlling the spacecraft.

  3. REMOTE BIOSENSOR FOR IN SITU MONITORING OF ORGANOPHOSPHATE NERVE AGENTS. (R823663)

    EPA Science Inventory

    A remote electrochemical biosensor for field monitoring of organophosphate nerve agents is described. The new sensor relies on the coupling of the effective biocatalytic action of organophosphorus hydrolase (OPH) with a submersible amperometric probe design. This combination resu...

  4. Agent-based Simulation Platforms Agent-based Simulation Platforms

    E-print Network

    Boone, Randall B.

    Agent-based Simulation Platforms Agent-based Simulation Platforms: Review and Development 1081 Fritz Ave. McKinleyville, CA 95519, USA Five software platforms for scientific agent-based models documentation. It is designed primarily for ABMs of mobile individuals with local interactions in a grid space

  5. HYBRID AGENT & COMPONENT-BASED MANAGEMENT OF BACKCHANNELS

    E-print Network

    Hammerton, James

    -Oriented Software Engineering (AOSE) is viewed as a general-purpose paradigm advocating the engineering of complex distributed software applica- tions as Multi Agent Systems (MASs), i.e. loosely- coupled, autonomous, situated to ground RETSINA-style spec- ifications by providing a set of concrete operators and by defining a simple

  6. Oral hypoglycemic agent update.

    PubMed

    Krall, L P; Chabot, V A

    1978-07-01

    The treatment of diabetes is still a problem more than a half-century after the discovery of insulin. Patients are now living significantly longer but until the development of oral hypoglycemic agents, the only direct treatment modalities were exercise, diet, and insulin. Before evaluating the effectiveness of treatment, a therapeutic goal must be determined. While there are no absolutely "hard" facts proving that "good control" is beneficial in preventing chronic complications of diabetes, increasing accumulation of "soft" data strongly suggests that normal blood glucose levels are most desirable, when possible, but not at the cost of severe or disabling hypoglycemic reactions. The development of the oral agents was a great public health advance in that many persons with early diabetes, but fearful of insulin injections, had less dread of "the pills" and sought treatment. The oral agents simplified care but this very simplification process often undermined the need for proper diet and good fundamental care. This often led to mediocre diabetes care. While useful, the oral agents have marked limitations and in some are effective only temporarily. The presently available oral agents are sulfonylureas and require a viable beta-cell system for success. This limits the number of diabetics responsive to such treatment. The general indications for tolbutamide, chlorpropamide, acetohexamide and tolazamide are in maturity-onset diabetics, generally beyond the age of 40 with diabetes of less than 10 years. They are contraindicated in juvenile-onset diabetics, in pregnant women, and usually in patients undergoing major surgery, and can become ineffective during periods of extreme stress or during severe infection. They can lower blood glucose levels if used in proper doses in properly selected patients. Contrary to several decades of documentation, it has become popular to suggest that the oral agents are not effective. They can be effective but for many reasons apparently were not in their use by the U.G.D.P. researchers. This might not be the fault of the oral agent used. If ineffective, they should be discontinued. Many, but not all, patients may respond to diet therapy, which is then the treatment of choice. Obviously insulin, though difficult to use for many persons and in itself able to induce several severe reactions if not used properly, is the only treatment (with diet) for the severe diabetic. There is a large spectrum of patients inbetween in whom the oral agents may be useful. The use of phenformin (phenethyl-biguanide) has been effectively curtailed because of many reported cases of lactic acidosis, and while it is doubtful that phenformin alone, in the absence of complicating factors, is the causative factor, it is capable of being an augmenting influence when other conditions, such as decreased kidney function, prevail... PMID:98675

  7. Dark coupling

    SciTech Connect

    Gavela, M.B.; Hernández, D.; Honorez, L. Lopez [Departamento de Física Teórica and Instituto de Física Teórica, Universidad Autónoma de Madrid, 28049 Cantoblanco, Madrid (Spain); Mena, O. [Instituto de Física Corpuscular, IFIC, CSIC and Universidad de Valencia, Valencia (Spain); Rigolin, S., E-mail: belen.gavela@uam.es, E-mail: d.hernandez@uam.es, E-mail: laura.lopez@uam.es, E-mail: omena@ific.uv.es, E-mail: stefano.rigolin@pd.infn.it [Dipartimento d Fisica ''Galileo Galilei'', Universitá di Padova, via Marzolo 8, I-35131 Padova (Italy)

    2009-07-01

    The two dark sectors of the universe—dark matter and dark energy—may interact with each other. Background and linear density perturbation evolution equations are developed for a generic coupling. We then establish the general conditions necessary to obtain models free from non-adiabatic instabilities. As an application, we consider a viable universe in which the interaction strength is proportional to the dark energy density. The scenario does not exhibit ''phantom crossing'' and is free from instabilities, including early ones. A sizeable interaction strength is compatible with combined WMAP, HST, SN, LSS and H(z) data. Neutrino mass and/or cosmic curvature are allowed to be larger than in non-interacting models. Our analysis sheds light as well on unstable scenarios previously proposed.

  8. Thermoacoustic couple

    DOEpatents

    Wheatley, J.C.; Swift, G.W.; Migliori, A.

    1983-10-04

    An apparatus and method for determining acoustic power density level and its direction in a fluid using a single sensor are disclosed. The preferred embodiment of the apparatus, which is termed a thermoacoustic couple, consists of a stack of thin, spaced apart polymeric plates, selected ones of which include multiple bimetallic thermocouple junctions positioned along opposite end edges thereof. The thermocouple junctions are connected in series in the nature of a thermopile, and are arranged so as to be responsive to small temperature differences between the opposite edges of the plates. The magnitude of the temperature difference, as represented by the magnitude of the electrical potential difference generated by the thermopile, is found to be directly related to the level of acoustic power density in the gas.

  9. Attentive Presentation Agents

    Microsoft Academic Search

    Tobias Eichner; Helmut Prendinger; Elisabeth André; Mitsuru Ishizuka

    2007-01-01

    The paper describes an infotainment application where life- like characters present two MP3 players in a virtual showroom. The key feature of the system is that the presenter agents analyze the user's gaze-behavior in real-time and may thus adapt the presentation flow ac- cordingly. In particular, a user's (non-)interest in interface objects and also preference in decision situations is estimated

  10. Rigid bifunctional chelating agents

    DOEpatents

    Sweet, M.P.; Mease, R.C.; Srivastava, S.C.

    1998-07-21

    Bicyclo[2.2.2] octane-2,3 diamine-N,N,N`,N`-tetraacetic acids (BODTA) and bicyclo[2.2.1] heptane-2,3 diamine-N,N,N`,N`-tetraacetic acid (BHDTA) are chelating agents useful in forming detectably labeled bioconjugate compounds for diagnostic and therapeutic purposes. New compounds and processes of forming BODTA and BHDTA are disclosed. Radioimmunoconjugates of the present invention show high and prolonged tumor uptake with low normal tissue uptakes.

  11. Rigid bifunctional chelating agents

    DOEpatents

    Sweet, Mark P. (Coram, NY); Mease, Ronnie C. (Fairfax, VA); Srivastava, Suresh C. (Setauket, NY)

    2000-02-08

    Bicyclo[2.2.2]octane-2,3 diamine-N,N,N',N'-tetraacetic acids (BODTA) and bicyclo[2.2.1]heptane-2,3 diamine-N,N,N',N'-tetraacetic acid (BHDTA) are chelating agents useful in forming detectably labeled bioconjugate compounds for diagnostic and therapeutic purposes. New compounds and processes of forming BODTA and BHDTA are disclosed. Radioimmunoconjugates of the present invention show high and prolonged tumor uptake with low normal tissue uptakes.

  12. Rigid bifunctional chelating agents

    DOEpatents

    Sweet, Mark P. (Coram, NY); Mease, Ronnie C. (Fairfax, VA); Srivastava, Suresh C. (Setauket, NY)

    1998-07-21

    Bicyclo›2.2.2! octane-2,3 diamine-N,N,N',N'-tetraacetic acids (BODTA) and bicyclo›2.2.1! heptane-2,3 diamine-N,N,N',N'-tetraacetic acid (BHDTA) are chelating agents useful in forming detectably labeled bioconjugate compounds for diagnostic and therapeutic purposes. New compounds and processes of forming BODTA and BHDTA are disclosed. Radioimmunoconjugates of the present invention show high and prolonged tumor uptake with low normal tissue uptakes.

  13. Agents for Traffic Simulation

    Microsoft Academic Search

    Arne Kesting; Martin Treiber; Dirk Helbing

    2008-01-01

    Vehicular traffic is a classical example of a multi-agent system in which autonomous drivers operate in a shared environment. The article provides an overview of the state-of-the-art in microscopic traffic modeling and the implications for simulation techniques. We focus on the short-time dynamics of car-following models which describe continuous feedback control tasks (acceleration and braking) and models for discrete-choice tasks

  14. Peripheral Neuropathy and Agent Orange

    MedlinePLUS

    ... Enter ZIP code here Peripheral Neuropathy and Agent Orange VA presumes Veterans' early-onset peripheral neuropathy is related to their exposure to Agent Orange or other herbicides during service when the disease ...

  15. Newer antifungal agents.

    PubMed

    Türel, Ozden

    2011-03-01

    The frequency and spectrum of fungal infections have been increasing steadily over the last several decades. The reason for this increase may be explained by the increase in the number of immunocompromised patients due to malignancies, AIDS, invasive surgical procedures and transplantation. In parallel with this increase, several therapeutic options have become available but problems such as intrinsic or acquired antifungal resistance have led researchers to develop new antifungal drugs with expanded effectiveness. Reduced toxicity, enhancement of bioavailability and counteraction of resistance are features desired by clinicians. The aim of this article is to summarize the studies involving isavuconazole, ravuconazole, albaconazole, aminocandin and some other investigational antifungal agents. Most data on the clinical use of ravuconazole, isavuconazole and albaconazole are mainly available as meeting abstracts or limited to animal studies or Phase I/II studies in humans. These new antifungal agents in development offer extended half-lives, possibly reduced drug interaction profiles and good tolerance. In addition to activity against Candida and Aspergillus spp., they have a broad spectrum of activity including activity against resistant and emerging pathogens. The real possibilities of these agents will only be fully understood after adequate randomized clinical trials. PMID:21417872

  16. Dual targeting improves microbubble contrast agent adhesion to VCAM-1 and P-selectin under flow

    Microsoft Academic Search

    E. A. Ferrante; J. E. Pickard; J. Rychak; A. Klibanov; K. Ley

    2009-01-01

    To improve ultrasound contrast agents targeted to the adhesion molecules P-selectin and VCAM-1 for the purpose of molecular imaging of atherosclerotic plaques, perfluorocarbon-filled phospholipid microbubble contrast agents were coupled by a polyethylene glycol–biotin–streptavidin bridge with mAb MVCAM.A(429), a sialyl Lewisx polymer (PAA-sLex), or both (dual). Approximately three hundred thousand antibody molecules were coupled to the surface of each microbubble. Recombinant

  17. Liability for Autonomous Agent Design

    Microsoft Academic Search

    Carey Heckman; Jacob O. Wobbrock

    1999-01-01

    Though exciting scientifically, autonomous agent design can result in legal liability. This paper surveys those legal concerns, focusing on issues arising from the unique qualities of agents not found in conventional software. Informed designers can more effectively reduce their liability exposure and influence emerging agent liability law and policies.

  18. Liability for autonomous agent design

    Microsoft Academic Search

    Carey Heckman; Jacob O. Wobbrock

    1998-01-01

    Though exciting scientifically, autonomous agent design can result in legal liability. This paper surveys those legal concerns, focusing on issues arising from the unique qualities of agents not found in conventional software. Informed designers can more effectively reduce their liability exposure and influence emerging agent liability law and policies.

  19. Mobile Agents for Mobile Computing

    Microsoft Academic Search

    Daniela Rus; David Kotz; George Cybenko; Robert Gray; Saurab Nog

    1996-01-01

    Mobile agents are programs that can move through a network under their own control, migratingfrom host to host and interacting with other agents and resources on each. We argue thatthese mobile, autonomous agents have the potential to provide a convenient, efficient and robustprogramming paradigm for distributed applications, particularly when partially connected computersare involved. Partially connected computers include mobile computers such

  20. Countermeasures for mobile agent security

    Microsoft Academic Search

    Wayne A. Jansen

    2000-01-01

    Security is an important issue for the widespread deployment of applications based on software agent technology. It is generally agreed that without the proper countermeasures in place, use of agent-based applications will be severely impeded. However, not all applications require the same set of countermeasures, nor can they depend entirely on the agent system to provide them. Instead, countermeasures are

  1. Software Agent Technology: An Overview

    Microsoft Academic Search

    Chrysanthi E. Georgakarakou; Anastasios A. Economides

    This chapter provides an overview of the rapidly evolving area of software agents and presents the basic aspects of applying the agent technology to virtual enterprises (VE). As the field of software agents can appear chaotic, this chapter briefly introduces the key issues rather than present an in-depth analysis and critique of the field. In addition to, this chapter investigates

  2. Hydroxypyridonate and hydroxypyrimidinone chelating agents

    DOEpatents

    Raymond, Kenneth N.; Doble, Daniel M.; Sunderland, Christopher J.; Thompson, Marlon

    2005-01-25

    The present invention provides hydroxypyridinone and hydroxypyrimidone chelating agents. Also provides are Gd(III) complexes of these agents, which are useful as contrast enhancing agents for magnetic resonance imaging. The invention also provides methods of preparing the compounds of the invention, as well as methods of using the compounds in magnetic resonance imaging applications.

  3. Launch commit criteria monitoring agent

    Microsoft Academic Search

    Glenn S. Semmel; Steven R. Davis; Kurt W. Leucht; Daniel A. Rowe; Andrew O. Kelly; Ladislau Bölöni

    2005-01-01

    The Spaceport Processing Systems Branch at NASA Kennedy Space Center has developed and deployed a software agent to monitor the Space Shuttle's ground processing telemetry stream. The application, the Launch Commit Criteria Monitoring Agent, increases situational awareness for system and hardware engineers during Shuttle launch countdown. The agent provides autonomous monitoring of the telemetry stream, automatically alerts system engineers when

  4. Decision making soft computing agents

    Microsoft Academic Search

    Dimitar Vassilev Lakov; Mariana Vassileva Vassileva

    2005-01-01

    The paper describes a soft computing agent approach to intelligent control of remote learning. It presents a special type of decision making soft computing agent applied to the selection of appropriate groups for definition of individual remote learning purposes. Soft computing agents are used to perform two tasks: optimal partitioning of distributed data bases in accordance with a grade of

  5. Multi-Agent Planning Introduction

    E-print Network

    Moraitis, Pavlos

    Multi-Agent Planning Introduction Pavlos Moraitis #12;Introductory Comments · Multi-Agent (MAS) planning is the problem of finding a plan of action for a set of agents in order to reach a set of goals as Distributed Planning to emphasize the distributed nature of the problem · MAS planning is not only reasoning

  6. CATS-based Air Traffic Controller Agents

    NASA Technical Reports Server (NTRS)

    Callantine, Todd J.

    2002-01-01

    This report describes intelligent agents that function as air traffic controllers. Each agent controls traffic in a single sector in real time; agents controlling traffic in adjoining sectors can coordinate to manage an arrival flow across a given meter fix. The purpose of this research is threefold. First, it seeks to study the design of agents for controlling complex systems. In particular, it investigates agent planning and reactive control functionality in a dynamic environment in which a variety perceptual and decision making skills play a central role. It examines how heuristic rules can be applied to model planning and decision making skills, rather than attempting to apply optimization methods. Thus, the research attempts to develop intelligent agents that provide an approximation of human air traffic controller behavior that, while not based on an explicit cognitive model, does produce task performance consistent with the way human air traffic controllers operate. Second, this research sought to extend previous research on using the Crew Activity Tracking System (CATS) as the basis for intelligent agents. The agents use a high-level model of air traffic controller activities to structure the control task. To execute an activity in the CATS model, according to the current task context, the agents reference a 'skill library' and 'control rules' that in turn execute the pattern recognition, planning, and decision-making required to perform the activity. Applying the skills enables the agents to modify their representation of the current control situation (i.e., the 'flick' or 'picture'). The updated representation supports the next activity in a cycle of action that, taken as a whole, simulates air traffic controller behavior. A third, practical motivation for this research is to use intelligent agents to support evaluation of new air traffic control (ATC) methods to support new Air Traffic Management (ATM) concepts. Current approaches that use large, human-in-the-loop simulations are unquestionably valuable for this purpose, but pose considerable logistical, fiscal, and experimental control problems. First, data analysis is extremely complicated, owing simply to the large number of participants and data sources in such simulations. In addition, experienced human air traffic controllers working adjacent sectors tend to flexibly adapt to the evolving control problem - potentially shifting to other strategies than those under investigation. In addition, their performance is tightly coupled to the control interface, which in the development phase may support some concepts and supporting strategies better than others. A simple shift in strategy by one controller can change the character of a particular traffic scenario dramatically, which makes experimental comparison of ATC performance under different traffic scenarios difficult. Training a given team of controllers on operations under a new ATM concept for a sufficient period of time could avert such difficulties, but instituting an adequate training program is expensive and logistically difficult.

  7. The value of less connected agents in Boolean networks

    NASA Astrophysics Data System (ADS)

    Epstein, Daniel; Bazzan, Ana L. C.

    2013-11-01

    In multiagent systems, agents often face binary decisions where one seeks to take either the minority or the majority side. Examples are minority and congestion games in general, i.e., situations that require coordination among the agents in order to depict efficient decisions. In minority games such as the El Farol Bar Problem, previous works have shown that agents may reach appropriate levels of coordination, mostly by looking at the history of past decisions. Not many works consider any kind of structure of the social network, i.e., how agents are connected. Moreover, when structure is indeed considered, it assumes some kind of random network with a given, fixed connectivity degree. The present paper departs from the conventional approach in some ways. First, it considers more realistic network topologies, based on preferential attachments. This is especially useful in social networks. Second, the formalism of random Boolean networks is used to help agents to make decisions given their attachments (for example acquaintances). This is coupled with a reinforcement learning mechanism that allows agents to select strategies that are locally and globally efficient. Third, we use agent-based modeling and simulation, a microscopic approach, which allows us to draw conclusions about individuals and/or classes of individuals. Finally, for the sake of illustration we use two different scenarios, namely the El Farol Bar Problem and a binary route choice scenario. With this approach we target systems that adapt dynamically to changes in the environment, including other adaptive decision-makers. Our results using preferential attachments and random Boolean networks are threefold. First we show that an efficient equilibrium can be achieved, provided agents do experimentation. Second, microscopic analysis show that influential agents tend to consider few inputs in their Boolean functions. Third, we have also conducted measurements related to network clustering and centrality that help to see how agents are organized.

  8. Intelligent agents: Theory and practice

    E-print Network

    Michael Wooldridge; Nicholas R. Jennings

    1995-01-01

    The concept of an agent has become important in both Artificial Intelligence (AI) and mainstream computer science. Our aim in this paper is to point the reader at what we perceive to be the most important theoretical and practical issues associated with the design and construction of intelligent agents. For convenience, we divide these issues into three areas (though as the reader will see, the divisions are at times somewhat arbitrary). Agent theory is concerned with the question of what an agent is, and the use of mathematical formalisms for representing and reasoning about the properties of agents. Agent architectures can be thought of as software engineering models of agents; researchers in this area are primarily concerned with the problem of designing software or hardware systems that will satisfy the prop-erties specified by agent theorists. Finally, agent languages are software systems for programming and experimenting with agents; these languages may embody principles proposed by theorists. The paper is not intended to serve as a tutorial introduction to all the issues mentioned; we hope instead simply to identify the most important issues, and point to work that elaborates on them. The article includes a short review of current and potential applications of agent technology.

  9. Learning models of intelligent agents

    SciTech Connect

    Carmel, D.; Markovitch, S. [Computer Science Dept., Haifa (Israel)

    1996-12-31

    Agents that operate in a multi-agent system need an efficient strategy to handle their encounters with other agents involved. Searching for an optimal interactive strategy is a hard problem because it depends mostly on the behavior of the others. In this work, interaction among agents is represented as a repeated two-player game, where the agents` objective is to look for a strategy that maximizes their expected sum of rewards in the game. We assume that agents` strategies can be modeled as finite automata. A model-based approach is presented as a possible method for learning an effective interactive strategy. First, we describe how an agent should find an optimal strategy against a given model. Second, we present an unsupervised algorithm that infers a model of the opponent`s automaton from its input/output behavior. A set of experiments that show the potential merit of the algorithm is reported as well.

  10. An Introduction to Software Agents

    E-print Network

    Jeffrey M. Bradshaw

    1997-01-01

    ion and delegation: Agents can be made extensible and composable in ways that common iconic interface objects cannot. Because we can "communicate" with them, they can share our goals, rather than simply process our commands. They can show us how to do things and tell us what went wrong (Miller and Neches 1987). . Flexibility and opportunism: Because they can be instructed at the level of 16 BRADSHAW goals and strategies, agents can find ways to "work around" unforeseen problems and exploit new opportunities as they help solve problems. . Task orientation: Agents can be designed to take the context of the person's tasks and situation into account as they present information and take action. . Adaptivity: Agents can use learning algorithms to continually improve their behavior by noticing recurrent patterns of actions and events. Toward Agent-Enabled System Architectures In the future, assistant agents at the user interface and resource-managing agents behind the scenes will increas...

  11. Flexible, secure agent development framework

    DOEpatents

    Goldsmith; Steven Y. (Rochester, MN)

    2009-04-07

    While an agent generator is generating an intelligent agent, it can also evaluate the data processing platform on which it is executing, in order to assess a risk factor associated with operation of the agent generator on the data processing platform. The agent generator can retrieve from a location external to the data processing platform an open site that is configurable by the user, and load the open site into an agent substrate, thereby creating a development agent with code development capabilities. While an intelligent agent is executing a functional program on a data processing platform, it can also evaluate the data processing platform to assess a risk factor associated with performing the data processing function on the data processing platform.

  12. Humans as Geomorphic Agents

    NSDL National Science Digital Library

    Catherine Riihimaki

    1) The students read an article from the literature on humans as geomorphic agents as an introduction to order-of-magnitude calculations. 2) The class discusses the article in a 50-minute class 3) The students complete a problem set that introduces them to dimensional analysis, walks them through a comparison of the article's results to natural geomorphic rates, and explores how the author derived the article's final numbers. 4) Once the students are done with the problem set, the class discusses the results and implications as a group.

  13. DCTD — Featured Agents

    Cancer.gov

    Tandutinib (MLN518), previously known as CT53518, is a small-molecule inhibitor of the type III receptor tyrosine kinases, including the Fms-like tyrosine kinase 3 receptor (FLT3), platelet-derived growth factor receptor (PDGFR), and c-Kit receptor tyrosine kinase. Tandutinib is relatively selective, having no appreciable activity against EGFR, FGFR, KDR, or several non-receptor kinases. FLT3, c-Kit, and ßPDGFR are equally inhibited by tandutinib, while the agent is much less active against CSF-1R (in vitro IC50 of 3.4 µM).

  14. Chemical warfare agents

    PubMed Central

    Ganesan, K.; Raza, S. K.; Vijayaraghavan, R.

    2010-01-01

    Among the Weapons of Mass Destruction, chemical warfare (CW) is probably one of the most brutal created by mankind in comparison with biological and nuclear warfare. Chemical weapons are inexpensive and are relatively easy to produce, even by small terrorist groups, to create mass casualties with small quantities. The characteristics of various CW agents, general information relevant to current physical as well as medical protection methods, detection equipment available and decontamination techniques are discussed in this review article. A brief note on Chemical Weapons Convention is also provided. PMID:21829312

  15. Chemical warfare agents.

    PubMed

    Ganesan, K; Raza, S K; Vijayaraghavan, R

    2010-07-01

    Among the Weapons of Mass Destruction, chemical warfare (CW) is probably one of the most brutal created by mankind in comparison with biological and nuclear warfare. Chemical weapons are inexpensive and are relatively easy to produce, even by small terrorist groups, to create mass casualties with small quantities. The characteristics of various CW agents, general information relevant to current physical as well as medical protection methods, detection equipment available and decontamination techniques are discussed in this review article. A brief note on Chemical Weapons Convention is also provided. PMID:21829312

  16. Diastereoselective pinacol coupling of alkyl aryl ketones with rare earth metals in the presence of chlorosilanes

    Microsoft Academic Search

    Akiya Ogawa; Hiroki Takeuchi; Toshikazu Hirao

    1999-01-01

    Rare earth metals (Ln) are found to act as useful reducing agents for the pinacol coupling reaction of alkyl aryl ketones in the presence of chlorosilanes. Although the hitherto known pinacol coupling reaction using rare earth reducing agents generally exhibits very low diastereoselectivities, the present pinacol coupling by use of a LnR3SiCl system usually indicates higher diastereoselectivities. In particular, a

  17. Holograms as Teaching Agents

    NASA Astrophysics Data System (ADS)

    Walker, Robin A.

    2013-02-01

    Hungarian physicist Dennis Gabor won the Pulitzer Prize for his 1947 introduction of basic holographic principles, but it was not until the invention of the laser in 1960 that research scientists, physicians, technologists and the general public began to seriously consider the interdisciplinary potentiality of holography. Questions around whether and when Three-Dimensional (3-D) images and systems would impact American entertainment and the arts would be answered before educators, instructional designers and students would discover how much Three-Dimensional Hologram Technology (3DHT) would affect teaching practices and learning environments. In the following International Symposium on Display Holograms (ISDH) poster presentation, the author features a traditional board game as well as a reflection hologram to illustrate conventional and evolving Three-Dimensional representations and technology for education. Using elements from the American children's toy Operation® (Hasbro, 2005) as well as a reflection hologram of a human brain (Ko, 1998), this poster design highlights the pedagogical effects of 3-D images, games and systems on learning science. As teaching agents, holograms can be considered substitutes for real objects, (human beings, organs, and animated characters) as well as agents (pedagogical, avatars, reflective) in various learning environments using many systems (direct, emergent, augmented reality) and electronic tools (cellphones, computers, tablets, television). In order to understand the particular importance of utilizing holography in school, clinical and public settings, the author identifies advantages and benefits of using 3-D images and technology as instructional tools.

  18. Lipid-lowering agents.

    PubMed

    Ewang-Emukowhate, Mfon; Wierzbicki, Anthony S

    2013-09-01

    The role of lipid lowering in reducing the risk of mortality and morbidity from cardiovascular disease (CVD) is well established. Treatment particularly aimed at decreasing low-density lipoprotein cholesterol (LDL-C) is effective in reducing the risk of death from coronary heart disease and stroke. Statins form the cornerstone of treatment. However, in some individuals with a high risk of CVD who are unable to achieve their target LDL-C due to either intolerance or lack of efficacy, there is the need for alternative therapies. This review provides an overview of the different classes of currently available lipid-lowering medications including statins, fibrates, bile acid sequestrants (resins), and omega-3 fatty acids. Data are presented on their indications, pharmacology, and the relevant end point clinical trial data with these drugs. It also discusses the human trial data on some novel therapeutic agents that are being developed including those for homozygous familial hypercholesterolemia--the antisense oligonucleotide mipomersen and the microsomal transfer protein inhibitor lomitapide. Data are presented on phase II and III trials on agents with potentially wider applications, cholesterol ester transfer protein inhibitors and proprotein convertase subtilisin kexin 9 inhibitors. The data on a licensed gene therapy for lipoprotein lipase deficiency are also presented. PMID:23811423

  19. Evaluating Competing Agent Strategies for a Voice Email Agent

    Microsoft Academic Search

    Marilyn A. Walker; Donald Hindle; Jeanne Fromer; Giuseppe Di Fabbrizio; Craig Mestel

    1997-01-01

    This paper reports experimental results comparing a mixed-initiative to a system-initiative dialog strategy i n the context of a personal voice email agent. To independently test the effects of dialog strategy and user expertise, user s in- teract with either the system-initiative or the mixed-init iative agent to perform three successive tasks which are identical for both agents. We report

  20. Desferrithiocin Analogue Uranium Decorporation Agents

    PubMed Central

    Bergeron, Raymond J.; Wiegand, Jan; Singh, Shailendra

    2010-01-01

    Purpose Previous systematic structure-activity studies of the desferrithiocin (DFT) platform have allowed the design and synthesis of analogues and derivatives of DFT that retain the exceptional iron-clearing activity of the parent, while eliminating its adverse effects. We hypothesized that a similar approach could be adopted to identify DFT-related analogues that could effectively decorporate uranium. Materials and Methods The decorporation properties of nine DFT-related analogues were determined in a bile duct-cannulated rat model. Diethylenetriaminepentaacetic acid (DTPA) served as a positive control. Selected ligands also underwent multiple and delayed dosing regimens. Uranium excretion in urine and bile or stool was determined by inductively coupled plasma mass spectroscopy (ICP-MS); tissue levels of uranium were also assessed. Results The two best clinical candidates are (S)-4,5-dihydro-2-[2-hydroxy-4-(3,6,9-trioxadecyloxy)phenyl]-4-methyl-4-thiazolecarboxylic acid [(S)-4'-(HO)-DADFT-PE (9)], with a 57% reduction in kidney uranium levels on oral (p.o.) administration and (S)-4,5-dihydro-2-[2-hydroxy-3-(3,6,9-trioxadecyloxy)phenyl]-4-methyl-4-thiazolecarboxylic acid [(S)-3'-(HO)-DADFT-PE (10)], with a 62% renal reduction on p.o. administration. The majority of the metal excretion promoted by these analogues is in the bile, thus further reducing kidney actinide exposure. Conclusions While 9 administered p.o. or subcutaneously (s.c.) immediately post-metal is an effective decorporation agent, withholding the dose (s.c.) until 4 h reduced the activity of the compound. Conversion of 9 to its isopropyl ester may circumvent this issue. PMID:19399680

  1. Crafting the mind of PROSOCS agents

    Microsoft Academic Search

    Andrea Bracciali; Ulle Endriss; Neophytos Demetriou; Antonis C. Kakas; Wenjin Lu; Kostas Stathis

    2006-01-01

    prosocs agents are software agents that are built according to the kgp model of agency. kgp is used as a model for the mind of the agent, so that the agent can act autonomously using a collection of logic theories, providing the mind's reasoning functionalities. The behaviour of the agent is controlled by a cycle theory that specifies the agent's

  2. Fluoroquinolone antimicrobial agents.

    PubMed Central

    Wolfson, J S; Hooper, D C

    1989-01-01

    The fluoroquinolones, a new class of potent orally absorbed antimicrobial agents, are reviewed, considering structure, mechanisms of action and resistance, spectrum, variables affecting activity in vitro, pharmacokinetic properties, clinical efficacy, emergence of resistance, and tolerability. The primary bacterial target is the enzyme deoxyribonucleic acid gyrase. Bacterial resistance occurs by chromosomal mutations altering deoxyribonucleic acid gyrase and decreasing drug permeation. The drugs are bactericidal and potent in vitro against members of the family Enterobacteriaceae, Haemophilus spp., and Neisseria spp., have good activity against Pseudomonas aeruginosa and staphylococci, and (with several exceptions) are less potent against streptococci and have fair to poor activity against anaerobic species. Potency in vitro decreases in the presence of low pH, magnesium ions, or urine but is little affected by different media, increased inoculum, or serum. The effects of the drugs in combination with a beta-lactam or aminoglycoside are often additive, occasionally synergistic, and rarely antagonistic. The agents are orally absorbed, require at most twice-daily dosing, and achieve high concentrations in urine, feces, and kidney and good concentrations in lung, bone, prostate, and other tissues. The drugs are efficacious in treatment of a variety of bacterial infections, including uncomplicated and complicated urinary tract infections, bacterial gastroenteritis, and gonorrhea, and show promise for therapy of prostatitis, respiratory tract infections, osteomyelitis, and cutaneous infections, particularly when caused by aerobic gram-negative bacilli. Fluoroquinolones have also proved to be efficacious for prophylaxis against travelers' diarrhea and infection with gram-negative bacilli in neutropenic patients. The drugs are effective in eliminating carriage of Neisseria meningitidis. Patient tolerability appears acceptable, with gastrointestinal or central nervous system toxicities occurring most commonly, but only rarely necessitating discontinuance of therapy. In 17 of 18 prospective, randomized, double-blind comparisons with another agent or placebo, fluoroquinolones were tolerated as well as or better than the comparison regimen. Bacterial resistance has been uncommonly documented but occurs, most notably with P. aeruginosa and Staphylococcus aureus and occasionally other species for which the therapeutic ratio is less favorable. Fluoroquinolones offer an efficacious, well-tolerated, and cost-effective alternative to parenteral therapies of selected infections. PMID:2680058

  3. Agent-based enterprise integration

    SciTech Connect

    N. M. Berry; C. M. Pancerella

    1998-12-01

    The authors are developing and deploying software agents in an enterprise information architecture such that the agents manage enterprise resources and facilitate user interaction with these resources. The enterprise agents are built on top of a robust software architecture for data exchange and tool integration across heterogeneous hardware and software. The resulting distributed multi-agent system serves as a method of enhancing enterprises in the following ways: providing users with knowledge about enterprise resources and applications; accessing the dynamically changing enterprise; locating enterprise applications and services; and improving search capabilities for applications and data. Furthermore, agents can access non-agents (i.e., databases and tools) through the enterprise framework. The ultimate target of the effort is the user; they are attempting to increase user productivity in the enterprise. This paper describes their design and early implementation and discusses the planned future work.

  4. Collaborating Fuzzy Reinforcement Learning Agents

    NASA Technical Reports Server (NTRS)

    Berenji, Hamid R.

    1997-01-01

    Earlier, we introduced GARIC-Q, a new method for doing incremental Dynamic Programming using a society of intelligent agents which are controlled at the top level by Fuzzy Relearning and at the local level, each agent learns and operates based on ANTARCTIC, a technique for fuzzy reinforcement learning. In this paper, we show that it is possible for these agents to compete in order to affect the selected control policy but at the same time, they can collaborate while investigating the state space. In this model, the evaluator or the critic learns by observing all the agents behaviors but the control policy changes only based on the behavior of the winning agent also known as the super agent.

  5. Ambient Intelligence Using KGP Agents

    Microsoft Academic Search

    Kostas Stathis; Francesca Toni

    2004-01-01

    \\u000a We investigate the application of a logical model of agency, known as the KGP model, to develop agents for ambient intelligence\\u000a applications. Using a concrete scenario, we illustrate how the logical formalism employed by a KGP agent allows a person to\\u000a access the surrounding ambient through the agent in a transparent manner. We evaluate our claims by implementing the resulting

  6. Specifying recursive agents with GDTs

    Microsoft Academic Search

    Bruno Mermet; Gaële Simon

    2011-01-01

    The purpose of this article is to formalise the notion of recursive agent by extending the Goal Decomposition Tree formalism (GDT). A formal semantics of this decomposition is given, as well as the\\u000a definition of operators to introduce various ways of recursively defining agents. Design patterns, that show various use cases\\u000a for recursive agents, are also presented. Finally, to preserve

  7. [Unconventional antidiabetic agents].

    PubMed

    Rustenbeck, Ingo

    2007-04-01

    The current pharmacological therapy of type 2 diabetes reduces the risk of diabetic complications, but is not able to achieve a long-lasting normalization of the metabolic disorder. Thus diabetic patients in increasing numbers are taking dietary supplements and herbs from which they expect additional health benefits. These unconventional antidiabetic agents consist mainly in trace metals like chromium, vanadium and zinc and a heterogeneous group of traditionally used antidiabetic herbs (e. g. Momordica charantia, Gymnema sylvestre, Trigonella foenum-graecum) often derived from the ayurvedic medicine. In this overview the current evidence for the antidiabetic effect is presented. The trace elements chromium and vanadium have a number of potentially antidiabetic actions in vitro, however, the results obtained with diabetic patients are not convincing so far. Similarly, the available data on the therapeutic use of herbs suggest that in principle a number of them possess a blood glucose-lowering effect, but at present no firm conclusions as to their efficacy and safety can be made. To set up reliable dose-effect relationships requires the identification of the relevant antidiabetic molecules as was apparently achieved by isolating 4-hydroxyisoleucine from the seeds of T. foenum-graecum. This requirement is also valid in the case of the antidiabetic action of cinnamon. Coffee and a moderate alcohol consumption were found to be surprisingly effective in lowering the risk of type 2 diabetes manifestation, their effect being roughly equal to that of conventional drugs used in diabetes prevention trials. Diabetic patients should inform their physician about the use of unconventional agents and should be warned against uncontrolled starting or stopping their use. PMID:17484443

  8. Stability of Coupling Algorithms

    E-print Network

    Akkasale, Abhineeth

    2012-07-16

    , to obtain the coupled response. A popular coupling algorithm widely employed in numerical simulations of such coupled problems is the conventional staggered scheme (CSS). However, there is no systematic study on the stability characteristics of the CSS...

  9. Agent based process management: applying intelligent agents to workflow

    Microsoft Academic Search

    P. D. O'BRIEN; W. E. Wiegand

    1998-01-01

    This paper presents an Agent-based Process Management System (APMS) architecture that combines recent developments in autonomous agent technology and distributed computing platforms. It argues that a service-oriented view is required in order to meet the requirements of open distributed enterprises, now and in the future. This approach embraces and fully supports the decentralisation of responsibility and local autonomy, within and

  10. Investigating Interactions Between Agent Conversations and Agent Control Components \\Lambday

    E-print Network

    Massachusetts at Amherst, University of

    for the purpose of coordinating \\Lambda Effort sponsored by the Defense Advanced Research Projects Agency (DARPA, either expressed or implied, of the Defense Advanced Research Projects Agency (DARPA), Air Force Research agent conversation in the context of fine­grained agent coordination research has raised several

  11. Agent Tcl: A flexible and secure mobile-agent system

    Microsoft Academic Search

    Robert S. Gray

    1997-01-01

    A mobile agent is an autonomous program that can migrate under its own control from machine to machine in a heterogeneous network. In other words, the program can suspend its execution at an arbitrary point, transport itself to another machine, and then resume execution from the point of suspension. Mobile agents have the potential to provide a single, general framework

  12. Agents as Resource Brokers in Grids - Forming Agent Teams

    Microsoft Academic Search

    Wojciech Kuranowski; Marcin Paprzycki; Maria Ganzha; Maciej Gawinecki; Ivan Lirkov; Svetozar Margenov

    2007-01-01

    Recently we have proposed an approach to utilizing agent teams as resource brokers and managers in the Grid. Thus far we have discussed the general overview of the proposed system, how to efficiently implement matchmaking services, as well as proposed a way by which agents select a team that will execute their job. In this paper we focus our attention

  13. Concept features in Re:Agent, an intelligent Email agent

    Microsoft Academic Search

    Gary Boone

    1998-01-01

    An important issue in the application of machine learningtechniques to information management tasks is the natureof features extracted from textual information. We have createdan intelligent email agent that can learn actions suchas filtering, prioritizing, downloading to palmtops, and forwardingemail to voicemail using automatic feature extraction.Our agent's new feature extraction approach is basedon first learning concepts present within the mail, then

  14. An Afiective Agent Framework Towards Believable Agents for Digital Entertainment

    Microsoft Academic Search

    Rogerio E. da Silva; Amilcar Cardoso; Luis Macedo

    Digital entertainment industry uses multi-agents techniques based on several difierent approaches to establish autonomous characters that behave the most believable way as possible. This article presents a preliminary version of an agent architecture based on psychological and neurobiological theories. We expect that this architecture could facili- tate implementation of synthetic believable characters by providing ways of deflning difierent personalities for

  15. Incorporating BDI Agents into Human-Agent Decision Making Research

    NASA Astrophysics Data System (ADS)

    Kamphorst, Bart; van Wissen, Arlette; Dignum, Virginia

    Artificial agents, people, institutes and societies all have the ability to make decisions. Decision making as a research area therefore involves a broad spectrum of sciences, ranging from Artificial Intelligence to economics to psychology. The Colored Trails (CT) framework is designed to aid researchers in all fields in examining decision making processes. It is developed both to study interaction between multiple actors (humans or software agents) in a dynamic environment, and to study and model the decision making of these actors. However, agents in the current implementation of CT lack the explanatory power to help understand the reasoning processes involved in decision making. The BDI paradigm that has been proposed in the agent research area to describe rational agents, enables the specification of agents that reason in abstract concepts such as beliefs, goals, plans and events. In this paper, we present CTAPL: an extension to CT that allows BDI software agents that are written in the practical agent programming language 2APL to reason about and interact with a CT environment.

  16. TACtic- A Multi Behavioral Agent for Trading Agent Competition

    NASA Astrophysics Data System (ADS)

    Khosravi, Hassan; Shiri, Mohammad E.; Khosravi, Hamid; Iranmanesh, Ehsan; Davoodi, Alireza

    Software agents are increasingly being used to represent humans in online auctions. Such agents have the advantages of being able to systematically monitor a wide variety of auctions and then make rapid decisions about what bids to place in what auctions. They can do this continuously and repetitively without losing concentration. To provide a means of evaluating and comparing (benchmarking) research methods in this area the trading agent competition (TAC) was established. This paper describes the design, of TACtic. Our agent uses multi behavioral techniques at the heart of its decision making to make bidding decisions in the face of uncertainty, to make predictions about the likely outcomes of auctions, and to alter the agent's bidding strategy in response to the prevailing market conditions.

  17. Agent Model Development for Assessing Climate-Induced Geopolitical Instability.

    SciTech Connect

    Boslough, Mark B.; Backus, George A.

    2005-12-01

    We present the initial stages of development of new agent-based computational methods to generate and test hypotheses about linkages between environmental change and international instability. This report summarizes the first year's effort of an originally proposed three-year Laboratory Directed Research and Development (LDRD) project. The preliminary work focused on a set of simple agent-based models and benefited from lessons learned in previous related projects and case studies of human response to climate change and environmental scarcity. Our approach was to define a qualitative model using extremely simple cellular agent models akin to Lovelock's Daisyworld and Schelling's segregation model. Such models do not require significant computing resources, and users can modify behavior rules to gain insights. One of the difficulties in agent-based modeling is finding the right balance between model simplicity and real-world representation. Our approach was to keep agent behaviors as simple as possible during the development stage (described herein) and to ground them with a realistic geospatial Earth system model in subsequent years. This work is directed toward incorporating projected climate data--including various C02 scenarios from the Intergovernmental Panel on Climate Change (IPCC) Third Assessment Report--and ultimately toward coupling a useful agent-based model to a general circulation model.3

  18. Neuromuscular blocking agents.

    PubMed

    Lingle, C J; Steinbach, J H

    1988-01-01

    Clearly, many aspects of the action of neuromuscular blockers remain poorly understood at the molecular level. In the case of competitive blockers, blockade of EPPs by competitive binding to the ACh receptor site accounts for the most clinically important aspect of blockade. Although train-of-four fade produced by curare and some other competitive agents probably represents a presynaptic action, the molecular mechanisms underlying this effect have not been addressed. Depolarizing blockade is inherently more complicated than competitive blockade. Simple depolarization and inactivation of the mechanism for generation of the action potential probably account for the major clinical effect seen in phase I block. Furthermore, the relative balance between activation of channels and desensitization may also provide a qualitative explanation for phase II block and tachyphylaxis. However, effects that are more likely to be explained by presynaptic actions of depolarizing blockers have also been described, and it is not yet possible to assess quantitatively whether the rates of onset of the different postsynaptic actions can account for most aspects of depolarizing block. This discussion has raised several issues which need to be addressed in future studies. 1. What are the presynaptic effects of cholinergic drugs? Do these drugs act through a specific receptor or, on other ion channels in the terminal membrane, or do they operate by mechanisms distinct from effects on membrane conductance? Can any of the observations be explained by indirect effects mediated through postsynaptic ACh receptors, e.g., K+ release? 2. What are the factors that influence variability in sensitivity to neuromuscular blockers among species, muscles within species, and during development? Many of the potential factors, e.g., differences in safety factor, resting conductances, ACh receptor type, and differences in the presence and absence of presynaptic receptors, have been outlined, but definitive tests of the contribution of any particular mechanisms are lacking. 3. Does modulation of desensitization play a role in any components of neuromuscular blockade? 4. Can trapping of blocking agents in ion channels in some cases account for slowly reversible components of blockade? 5. Can closed-channel block provide an effective mechanism of neuromuscular block? PMID:2848776

  19. Implementing Lego Agents Using Jason

    E-print Network

    Jensen, Andreas Schmidt

    2010-01-01

    Since many of the currently available multi-agent frameworks are generally mostly intended for research, it can be difficult to built multi-agent systems using physical robots. In this report I describe a way to combine the multi-agent framework Jason, an extended version of the agent-oriented programming language AgentSpeak, with Lego robots to address this problem. By extending parts of the Jason reasoning cycle I show how Lego robots are able to complete tasks such as following lines on a floor and communicating to be able to avoid obstacles with minimal amount of coding. The final implementation is a functional extension that is able to built multi-agent systems using Lego agents, however there are some issues that have not been addressed. If the agents are highly dependent on percepts from their sensors, they are required to move quite slowly, because there currently is a high delay in the reasoning cycle, when it is combined with a robot. Overall the system is quite robust and can be used to make simple...

  20. Microsphere contrast agents for OCT

    E-print Network

    Suslick, Kenneth S.

    409 CHAPTER 29 Microsphere contrast agents for OCT Stephen A Boppart Kenneth S Suslick INTRODUCTION in achieving this goal for OCT15 , with the development of contrast agents such as microspheres16 describes the fabrication, characterization and application of a new class of engineered protein microsphere

  1. Agents Capable of Dynamic Negotiations

    Microsoft Academic Search

    Garima Parakh; Sandhya Rani; Marcin Paprzycki; Ajith Abraham; Johnson Thomas

    Support for negotiation is one of the more important research issues when developing agent systems utilized in e-commerce. While, depending on the type of the transaction, different negotiation procedures need to be utilized, only very few proposed frameworks are generic and flexible enough to handle multiple scenarios. This note presents negotiating agents, which can change their negotiation strategy depending on

  2. Self-Protected Mobile Agents

    Microsoft Academic Search

    Joan Ametller; Sergi Robles; Jose A. Ortega-Ruiz

    2004-01-01

    In this paper, we present a new solution for the implementation of flexible protection mechanisms in the context of mobile agent systems, where security problems are currently a major issue. In our scheme, agents protect their code and data by carrying their own protection mechanisms. This approach improves traditional solutions, where protection was managed by the platform. The implementation is

  3. Gelled Anti-icing Agents

    NASA Technical Reports Server (NTRS)

    Markles, O. F.; Sperber, H. H.

    1983-01-01

    Pectin added to antifreeze/water mixture. Formulations include water with dimethyl sulfoxide (DMSO) as deicer and pectin as gel former. Without gelling agent, deicer runs off vertical surfaces. Without pectin solution will completely evaporate in far less time. Agents developed have wide potential for ice prevention on runways, highways, bridges and sidewalks.

  4. Itinerant agents for mobile computing

    Microsoft Academic Search

    David Chess; Benjamin Grosof; Colin Harrison; David Levine; Colin Parris; Gene Tsudik

    1995-01-01

    Describes a framework for itinerant agents that can be used to implement secure, remote applications in large, public networks such as the Internet or the IBM Global Network. Itinerant agents are programs, dispatched from a source computer, that roam among a set of networked servers until they accomplish their task. This is an extension to the client\\/server model in which

  5. Language Support for Mobile Agents

    Microsoft Academic Search

    Frederick Colville Knabe

    1995-01-01

    Mobile agents are code-containing objects that may be transmitted between communicatingparticipants in a distributed system. As opposed to systems that onlyallow the exchange of nonexecutable data, systems incorporating mobile agentscan achieve significant gains in performance and functionality.A programming language for mobile agents must be able to express theirconstruction, transmission, receipt, and subsequent execution. Its implementationmust handle architectural heterogeneity...

  6. Situating Cognitive Agents in GOLEM

    Microsoft Academic Search

    Stefano Bromuri; Kostas Stathis

    2007-01-01

    We investigate the application of a logic-based framework representing an agent environment as a composite structure that evolves over time. Such a complex structure contains the interaction between two main classes of entities: agents and objects. Interactions between these entities are specified in term of events whose occurrence is governed by a set of physical laws specifying the possible evolutions

  7. Multimodal communication between synthetic agents

    Microsoft Academic Search

    Catherine Pelachaud; Isabella Poggi

    1998-01-01

    Dialoging with a synthetic agent is a vast research topic to enhance user-interface friendliness. We present in this paper an on-going project on the simulation of a dialog situation between two synthetic agents. More particularly we focus our interest on finding the appropriate facial expressions of a speaker addressing to different types of listeners (tourist, employee, child, and so on)

  8. Contrast agents for NMR imaging

    SciTech Connect

    Gamble, R.C.; Schmidt, P.G.

    1988-03-01

    Magnetic resonance imaging contrast agents for scanning tissue are described comprising bilayer vesicles with paramagnetic material encapsulated therein. The vesicles are formulated with an agent to promote vesicle stability for a sufficient time to allow biodistribution of the vesicles for scanning of the tissue and formulated to permit adequate water proton exchange across the vesicle bilayer to provide contrast for scanning the tissue.

  9. A Simple Shill Bidding Agent

    Microsoft Academic Search

    Jarrod Trevathan; Wayne Read

    2007-01-01

    Shill bidding is where fake bids are introduced into an auction to drive up the final price for the seller, thereby defrauding legitimate bidders. Although shill bidding is strictly forbidden in online auctions such as eBay, it is still a major problem. This paper presents a software bidding agent that follows a shill bidding strategy. The malicious bidding agent was

  10. Multimodal nanoparticulate bioimaging contrast agents.

    PubMed

    Sharma, Parvesh; Singh, Amit; Brown, Scott C; Bengtsson, Niclas; Walter, Glenn A; Grobmyer, Stephen R; Iwakuma, Nobutaka; Santra, Swadeshmukul; Scott, Edward W; Moudgil, Brij M

    2010-01-01

    A wide variety of bioimaging techniques (e.g., ultrasound, computed X-ray tomography, magnetic resonance imaging (MRI), and positron emission tomography) are commonly employed for clinical diagnostics and scientific research. While all of these methods use a characteristic "energy-matter" interaction to provide specific details about biological processes, each modality differs from another in terms of spatial and temporal resolution, anatomical and molecular details, imaging depth, as well as the desirable material properties of contrast agents needed for augmented imaging. On many occasions, it is advantageous to apply multiple complimentary imaging modalities for faster and more accurate prognosis. Since most imaging modalities employ exogenous contrast agents to improve the signal-to-noise ratio, the development and use of multimodal contrast agents is considered to be highly advantageous for obtaining improved imagery from sought-after imaging modalities. Multimodal contrast agents offer improvements in patient care, and at the same time can reduce costs and enhance safety by limiting the number of contrast agent administrations required for imaging purposes. Herein, we describe the synthesis and characterization of nanoparticulate-based multimodal contrast agent for noninvasive bioimaging using MRI, optical, and photoacoustic tomography (PAT)-imaging modalities. The synthesis of these agents is described using microemulsions, which enable facile integration of the desired diversity of contrast agents and material components into a single entity. PMID:20217589

  11. COOPERATIVE INFORMATION AGENTS AND COMMUNICATION

    E-print Network

    Dignum, Frank

    Information Agents. We describe an architecture for these CIA's in which the relations of a CIA with other CIA manager can also negotiate a contract with other CIA's. The contracts (which may include communication or transaction protocols) between agents are handled by the contract manager of the CIA responsible

  12. Multi-agent smart environments

    Microsoft Academic Search

    Diane J. Cook

    2009-01-01

    Research in pervasive computing and ambient intelligence has catapulted smart environments to the forefront of many research labs. While tremendous strides have been made toward realizing the dream of designing environments that act as intelligent agents, the size of the problem creates issues that still need to be addressed by researchers. One such issue is the role of multi-agent systems

  13. Empathic Touch by Relational Agents

    Microsoft Academic Search

    Timothy W. Bickmore; Rukmal Fernando; Lazlo Ring; Daniel Schulman

    2010-01-01

    We describe a series of experiments with an agent designed to model human conversational touch-capable of physically touching users in synchrony with speech and other nonverbal communicative behavior-and its use in expressing empathy to users in distress. The agent is composed of an animated human face that is displayed on a monitor affixed to the top of a human mannequin,

  14. Intelligent Agents: Theory and Practice

    Microsoft Academic Search

    Michael Wooldridge; Nicholas R. Jennings

    1995-01-01

    The concept of an agent has become important in both Artificial Intelligence (AI) and mainstream computer science. Our aim in this paper is to point the reader at what we perceive to be the most important theoretical and practical issues associated with the design and construction of intelligent agents. For convenience, we divide these issues into three areas (though as

  15. Cooperating Air Traffic Control Agents

    Microsoft Academic Search

    Geoff Nitschke

    2001-01-01

    The key aim of cooperating air traffic control agents (CAT CA) was to comparatively analyze and evaluate the success of a multiagent system (MAS) and a single agent system (SAS) at addressing a given set of goals in a problem domain amenable to the utilization of either a MAS or SAS. The problem domain selected was air traffic control (AT

  16. Transdermal delivery of therapeutic agent

    NASA Technical Reports Server (NTRS)

    Kwiatkowski, Krzysztof C. (Inventor); Hayes, Ryan T. (Inventor); Magnuson, James W. (Inventor); Giletto, Anthony (Inventor)

    2008-01-01

    A device for the transdermal delivery of a therapeutic agent to a biological subject that includes a first electrode comprising a first array of electrically conductive microprojections for providing electrical communication through a skin portion of the subject to a second electrode comprising a second array of electrically conductive microprojections. Additionally, a reservoir for holding the therapeutic agent surrounding the first electrode and a pulse generator for providing an exponential decay pulse between the first and second electrodes may be provided. A method includes the steps of piercing a stratum corneum layer of skin with two arrays of conductive microprojections, encapsulating the therapeutic agent into biocompatible charged carriers, surrounding the conductive microprojections with the therapeutic agent, generating an exponential decay pulse between the two arrays of conductive microprojections to create a non-uniform electrical field and electrokinetically driving the therapeutic agent through the stratum corneum layer of skin.

  17. Markov Tracking for Agent Coordination

    NASA Technical Reports Server (NTRS)

    Washington, Richard; Lau, Sonie (Technical Monitor)

    1998-01-01

    Partially observable Markov decision processes (POMDPs) axe an attractive representation for representing agent behavior, since they capture uncertainty in both the agent's state and its actions. However, finding an optimal policy for POMDPs in general is computationally difficult. In this paper we present Markov Tracking, a restricted problem of coordinating actions with an agent or process represented as a POMDP Because the actions coordinate with the agent rather than influence its behavior, the optimal solution to this problem can be computed locally and quickly. We also demonstrate the use of the technique on sequential POMDPs, which can be used to model a behavior that follows a linear, acyclic trajectory through a series of states. By imposing a "windowing" restriction that restricts the number of possible alternatives considered at any moment to a fixed size, a coordinating action can be calculated in constant time, making this amenable to coordination with complex agents.

  18. Phytonutrients as therapeutic agents.

    PubMed

    Gupta, Charu; Prakash, Dhan

    2014-09-01

    Nutrients present in various foods plays an important role in maintaining the normal functions of the human body. The major nutrients present in foods include carbohydrates, proteins, lipids, vitamins, and minerals. Besides these, there are some bioactive food components known as "phytonutrients" that play an important role in human health. They have tremendous impact on the health care system and may provide medical health benefits including the prevention and/or treatment of disease and various physiological disorders. Phytonutrients play a positive role by maintaining and modulating immune function to prevent specific diseases. Being natural products, they hold a great promise in clinical therapy as they possess no side effects that are usually associated with chemotherapy or radiotherapy. They are also comparatively cheap and thus significantly reduce health care cost. Phytonutrients are the plant nutrients with specific biological activities that support human health. Some of the important bioactive phytonutrients include polyphenols, terpenoids, resveratrol, flavonoids, isoflavonoids, carotenoids, limonoids, glucosinolates, phytoestrogens, phytosterols, anthocyanins, ?-3 fatty acids, and probiotics. They play specific pharmacological effects in human health such as anti-microbial, anti-oxidants, anti-inflammatory, antiallergic, anti-spasmodic, anti-cancer, anti-aging, hepatoprotective, hypolipidemic, neuroprotective, hypotensive, diabetes, osteoporosis, CNS stimulant, analgesic, protection from UVB-induced carcinogenesis, immuno-modulator, and carminative. This mini-review attempts to summarize the major important types of phytonutrients and their role in promoting human health and as therapeutic agents along with the current market trend and commercialization. PMID:25051278

  19. Plasmids encoding therapeutic agents

    DOEpatents

    Keener, William K. (Idaho Falls, ID)

    2007-08-07

    Plasmids encoding anti-HIV and anti-anthrax therapeutic agents are disclosed. Plasmid pWKK-500 encodes a fusion protein containing DP178 as a targeting moiety, the ricin A chain, an HIV protease cleavable linker, and a truncated ricin B chain. N-terminal extensions of the fusion protein include the maltose binding protein and a Factor Xa protease site. C-terminal extensions include a hydrophobic linker, an L domain motif peptide, a KDEL ER retention signal, another Factor Xa protease site, an out-of-frame buforin II coding sequence, the lacZ.alpha. peptide, and a polyhistidine tag. More than twenty derivatives of plasmid pWKK-500 are described. Plasmids pWKK-700 and pWKK-800 are similar to pWKK-500 wherein the DP178-encoding sequence is substituted by RANTES- and SDF-1-encoding sequences, respectively. Plasmid pWKK-900 is similar to pWKK-500 wherein the HIV protease cleavable linker is substituted by a lethal factor (LF) peptide-cleavable linker.

  20. Knowledge focus via software agents

    NASA Astrophysics Data System (ADS)

    Henager, Donald E.

    2001-09-01

    The essence of military Command and Control (C2) is making knowledge intensive decisions in a limited amount of time using uncertain, incorrect, or outdated information. It is essential to provide tools to decision-makers that provide: * Management of friendly forces by treating the "friendly resources as a system". * Rapid assessment of effects of military actions againt the "enemy as a system". * Assessment of how an enemy should, can, and could react to friendly military activities. Software agents in the form of mission agents, target agents, maintenance agents, and logistics agents can meet this information challenge. The role of each agent is to know all the details about its assigned mission, target, maintenance, or logistics entity. The Mission Agent would fight for mission resources based on the mission priority and analyze the effect that a proposed mission's results would have on the enemy. The Target Agent (TA) communicates with other targets to determine its role in the system of targets. A system of TAs would be able to inform a planner or analyst of the status of a system of targets, the effect of that status, adn the effect of attacks on that system. The system of TAs would also be able to analyze possible enemy reactions to attack by determining ways to minimize the effect of attack, such as rerouting traffic or using deception. The Maintenance Agent would scheudle maintenance events and notify the maintenance unit. The Logistics Agent would manage shipment and delivery of supplies to maintain appropriate levels of weapons, fuel and spare parts. The central idea underlying this case of software agents is knowledge focus. Software agents are createad automatically to focus their attention on individual real-world entities (e.g., missions, targets) and view the world from that entities perspective. The agent autonomously monitors the entity, identifies problems/opportunities, formulates solutions, and informs the decision-maker. The agent must be able to communicate to receive and disseminate information and provide the decision-maker with assistance via focused knowledge. THe agent must also be able to monitor the state of its own environment and make decisions necessary to carry out its delegated tasks. Agents bring three elements to the C2 domain that offer to improve decision-making. First, they provide higher-quality feedback and provide it more often. In doing so, the feedback loop becomes nearly continuous, reducing or eliminating delays in situation updates to decision-makers. Working with the most current information possible improves the control process, thus enabling effects based operations. Second, the agents accept delegation of actions and perform those actions following an established process. Agents' consistent actions reduce the variability of human input and stabilize the control process. Third, through the delegation of actions, agents ensure 100 percent consideration of plan details.

  1. Emergent Behavior and Mobile Agents Bernard Pagurek

    E-print Network

    White, Tony

    Emergent Behavior and Mobile Agents Tony White Bernard Pagurek ({tony,bernie}@sce.carleton.ca) http, we discuss mobile agents and how they represent a novel problem solving paradigm that can exploit in the communications domain. Keywords: mobile agents, agent coordination, agent collaboration, swarm intelligence 1

  2. Curious agents and situated design evaluations

    Microsoft Academic Search

    Rob Saunders; John S. Gero

    2004-01-01

    This paper presents a possible future direction for agent- based simulation using complex agents that can learn from experience and report their individual evaluations. Adding learning to the agent model permits the simulation of potentially important agent behaviour such as curiosity. The agents can then report evaluations of a design that are situated in their individual experience. The paper describes

  3. Interacting Agent Based Systems Dean Petters

    E-print Network

    Bullinaria, John

    . Emailing agents 4. Computer games 5. Robotics 6. Sociological simulations 7. Psychological simulations #12 is or is not an agent. This talk takes the view that agents are not just: distributed/concurrent systems such as java threads Agents are: autonomous, for example synchronisation occurs at run time and agents are self

  4. Matchmaking among Heterogeneous Agents on the Internet

    Microsoft Academic Search

    Katia Sycara; Matthias Klusch; Seth Widoff; Jianguo Lu

    1999-01-01

    The Internet not only provides data for users to browse, but also databases to query, and software agents to run. Due to the exponential increase of deployed agents on the Internet, automating the search and selection of relevant agents is essential for both users and collaboration among different software agents. This paper first describes the agent capability description language LARKS.

  5. Surface preparation and coupling in plastic scintillator dosimetry.

    PubMed

    Ayotte, Guylaine; Archambault, Louis; Gingras, Luc; Lacroix, Frédéric; Beddar, A Sam; Beaulieu, Luc

    2006-09-01

    One way to improve the performance of scintillation dosimeters is to increase the light-collection efficiency at the coupling interfaces of the detector system. We performed a detailed study of surface preparation of scintillating fibers and their coupling with clear optical fibers to minimize light loss and increase the amount of light collected. We analyzed fiber-surface polishing with aluminum oxide sheets, coating fibers with magnesium oxide, and the use of eight different coupling agents (air, three optical gels, an optical curing agent, ultraviolet light, cyanoacrylate glue, and acetone). We prepared 10 scintillating fiber and clear optical fiber light guide samples to test different coupling methods. To test the coupling, we first cut both the scintillating fiber and the clear optical fiber. Then, we cleaned and polished both ends of both fibers. Finally, we coupled the scintillating fiber with the clear optical fiber in either a polyethylene jacket or a V-grooved support depending on the coupling agent used. To produce more light, we used an ultraviolet lamp to stimulate scintillation. A typical series of similar couplings showed a standard deviation in light-collection efficiency of 10%. This can be explained by differences in the surface preparation quality and alignment of the scintillating fiber with the clear optical fiber. Absence of surface polishing reduced the light collection by approximately 40%, and application of magnesium oxide on the proximal end of the scintillating fiber increased the amount of light collected from the optical fiber by approximately 39%. Of the coupling agents, we obtained the best results using one of the optical gels. Because a large amount of the light produced inside a scintillator is usually lost, better light-collection efficiency will result in improved sensitivity. PMID:17022248

  6. Surface preparation and coupling in plastic scintillator dosimetry

    SciTech Connect

    Ayotte, Guylaine; Archambault, Louis; Gingras, Luc; Lacroix, Frederic; Beddar, A. Sam; Beaulieu, Luc [Departement de physique, de genie physique et d'optique, Universite Laval, Quebec City, Quebec, G1K7P4 (Canada) and Departement de Radio-Oncologie, Hotel Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec City, Quebec, G1R2J6 (Canada); Departement de physique, de genie physique et d'optique, Universite Laval, Quebec City, Quebec, G1K7P4 (Canada) and Department de Radio-Oncologie, Hotel Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec City, Quebec, G1R2J6 (Canada) and Department of Radiation Physics, Division of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030 (United States); Department de physique, de genie physique et d'optique, Universite Laval, Quebec City, Quebec, G1K7P4 (Canada) and Department de Radio-Oncologie, Hotel Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec City, Quebec, G1R2J6 (Canada); Department of Radiation Physics, Division of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030 (United States); Department de physique, de genie physique et d'optique, Universite Laval, Quebec City, Quebec, G1K7P4 (Canada) and Department de Radio-Oncologie, Hotel Dieu de Quebec, Centre Hospitalier Universitaire de Quebec, Quebec City, Quebec, G1R2J6 (Canada)

    2006-09-15

    One way to improve the performance of scintillation dosimeters is to increase the light-collection efficiency at the coupling interfaces of the detector system. We performed a detailed study of surface preparation of scintillating fibers and their coupling with clear optical fibers to minimize light loss and increase the amount of light collected. We analyzed fiber-surface polishing with aluminum oxide sheets, coating fibers with magnesium oxide, and the use of eight different coupling agents (air, three optical gels, an optical curing agent, ultraviolet light, cyanoacrylate glue, and acetone). We prepared 10 scintillating fiber and clear optical fiber light guide samples to test different coupling methods. To test the coupling, we first cut both the scintillating fiber and the clear optical fiber. Then, we cleaned and polished both ends of both fibers. Finally, we coupled the scintillating fiber with the clear optical fiber in either a polyethylene jacket or a V-grooved support depending on the coupling agent used. To produce more light, we used an ultraviolet lamp to stimulate scintillation. A typical series of similar couplings showed a standard deviation in light-collection efficiency of 10%. This can be explained by differences in the surface preparation quality and alignment of the scintillating fiber with the clear optical fiber. Absence of surface polishing reduced the light collection by approximately 40%, and application of magnesium oxide on the proximal end of the scintillating fiber increased the amount of light collected from the optical fiber by approximately 39%. Of the coupling agents, we obtained the best results using one of the optical gels. Because a large amount of the light produced inside a scintillator is usually lost, better light-collection efficiency will result in improved sensitivity.

  7. Agent Communications using Distributed Metaobjects

    SciTech Connect

    Goldsmith, Steven Y.; Spires, Shannon V.

    1999-06-10

    There are currently two proposed standards for agent communication languages, namely, KQML (Finin, Lobrou, and Mayfield 1994) and the FIPA ACL. Neither standard has yet achieved primacy, and neither has been evaluated extensively in an open environment such as the Internet. It seems prudent therefore to design a general-purpose agent communications facility for new agent architectures that is flexible yet provides an architecture that accepts many different specializations. In this paper we exhibit the salient features of an agent communications architecture based on distributed metaobjects. This architecture captures design commitments at a metaobject level, leaving the base-level design and implementation up to the agent developer. The scope of the metamodel is broad enough to accommodate many different communication protocols, interaction protocols, and knowledge sharing regimes through extensions to the metaobject framework. We conclude that with a powerful distributed object substrate that supports metaobject communications, a general framework can be developed that will effectively enable different approaches to agent communications in the same agent system. We have implemented a KQML-based communications protocol and have several special-purpose interaction protocols under development.

  8. JACK Intelligent Agents - Components for Intelligent Agents in Java

    Microsoft Academic Search

    Paolo Busetta; Ralph Rönnquist; Andrew Hodgson; Andrew Lucas

    1999-01-01

    This paper is organised as follows.Section 2 introduces JACK IntelligentAgents, presenting the approach taken byAOS to its design and outlining its majorengineering characteristics. The BDImodel is discussed briefly in Section 3.Section 4 gives an outline of how to buildan application with JACK IntelligentAgents. Finally, in Section 5 we discusshow the use of this framework can bebeneficial to both engineers and

  9. Nuclear magnetic resonance contrast agents

    DOEpatents

    Smith, Paul H. (Los Alamos, NM); Brainard, James R. (Los Alamos, NM); Jarvinen, Gordon D. (Los Alamos, NM); Ryan, Robert R. (Los Alamos, NM)

    1997-01-01

    A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC.sub.16 H.sub.14 N.sub.6. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques.

  10. Nuclear magnetic resonance contrast agents

    DOEpatents

    Smith, P.H.; Brainard, J.R.; Jarvinen, G.D.; Ryan, R.R.

    1997-12-30

    A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC{sub 16}H{sub 14}N{sub 6}. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques. 10 figs.

  11. Requirements Modeling with Agent Programming

    NASA Astrophysics Data System (ADS)

    Dasgupta, Aniruddha; Krishna, Aneesh; Ghose, Aditya K.

    Agent-oriented conceptual modeling notations are highly effective in representing requirements from an intentional stance and answering questions such as what goals exist, how key actors depend on each other, and what alternatives must be considered. In this chapter, we review an approach to executing i* models by translating these into set of interacting agents implemented in the CASO language and suggest how we can perform reasoning with requirements modeled (both functional and non-functional) using i* models. In this chapter we particularly incorporate deliberation into the agent design. This allows us to benefit from the complementary representational capabilities of the two frameworks.

  12. 75 FR 81332 - Health Outcomes Not Associated With Exposure to Certain Herbicide Agents; Veterans and Agent...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ...Herbicide Agents; Veterans and Agent Orange: Update 2008 ACTION: Notice...Affairs, under the authority of the Agent Orange Act of 1991, Public Law 102-4 (codified...report entitled ``Veterans and Agent Orange: Update 2008'' (Update 2008),...

  13. Optimal agent cooperation with local information

    E-print Network

    De Mot, Jan

    2005-01-01

    Multi-agent systems are in general believed to be more efficient, robust, and versatile than their single-agent equivalents. However, it is not an easy task to design strategies that fully exploit the multi-agent benefits, ...

  14. Launch Commit Criteria Monitoring Agent

    NASA Technical Reports Server (NTRS)

    Semmel, Glenn S.; Davis, Steven R.; Leucht, Kurt W.; Rowe, Dan A.; Kelly, Andrew O.; Boeloeni, Ladislau

    2005-01-01

    The Spaceport Processing Systems Branch at NASA Kennedy Space Center has developed and deployed a software agent to monitor the Space Shuttle's ground processing telemetry stream. The application, the Launch Commit Criteria Monitoring Agent, increases situational awareness for system and hardware engineers during Shuttle launch countdown. The agent provides autonomous monitoring of the telemetry stream, automatically alerts system engineers when predefined criteria have been met, identifies limit warnings and violations of launch commit criteria, aids Shuttle engineers through troubleshooting procedures, and provides additional insight to verify appropriate troubleshooting of problems by contractors. The agent has successfully detected launch commit criteria warnings and violations on a simulated playback data stream. Efficiency and safety are improved through increased automation.

  15. Agentes Intencionales BDI Capitulo 3

    E-print Network

    Guerra Hernández, Alejandro

    los seres humanos como agentes racionales con creencias, deseos, intenciones y otros atributos m mundo. Si tengo una creencia, debe ser una creencia que tal y tal es el caso; si deseo algo debe ser el

  16. Tissue Penetration of Antifungal Agents

    PubMed Central

    Felton, Timothy; Troke, Peter F.

    2014-01-01

    SUMMARY Understanding the tissue penetration of systemically administered antifungal agents is critical for a proper appreciation of their antifungal efficacy in animals and humans. Both the time course of an antifungal drug and its absolute concentrations within tissues may differ significantly from those observed in the bloodstream. In addition, tissue concentrations must also be interpreted within the context of the pathogenesis of the various invasive fungal infections, which differ significantly. There are major technical obstacles to the estimation of concentrations of antifungal agents in various tissue subcompartments, yet these agents, even those within the same class, may exhibit markedly different tissue distributions. This review explores these issues and provides a summary of tissue concentrations of 11 currently licensed systemic antifungal agents. It also explores the therapeutic implications of their distribution at various sites of infection. PMID:24396137

  17. Triggered pore-forming agents

    DOEpatents

    Bayley, Hagan (Grafton, MA); Walker, Barbara J. (Auburn, MA); Chang, Chung-yu (Worcester, MA); Niblack, Brett (Nashville, TN); Panchal, Rekha (Shrewsbury, MA)

    1998-01-01

    An inactive pore-forming agent which is activated to lytic function by a condition such as pH, light, heat, reducing potential, or metal ion concentration, or substance such as a protease, at the surface of a cell.

  18. Chemical Agents: Facts about Evacuation

    MedlinePLUS

    ... Public Health Matters What's New A - Z Index Chemical Agents: Facts About Evacuation Language: English Español (Spanish) ... on Facebook Tweet Share Compartir Some kinds of chemical accidents or attacks, such as a train derailment ...

  19. Agent-based forward analysis

    SciTech Connect

    Kerekes, Ryan A [ORNL; Jiao, Yu [ORNL; Shankar, Mallikarjun [ORNL; Potok, Thomas E [ORNL; Lusk, Rick M [ORNL

    2008-01-01

    We propose software agent-based "forward analysis" for efficient information retrieval in a network of sensing devices. In our approach, processing is pushed to the data at the edge of the network via intelligent software agents rather than pulling data to a central facility for processing. The agents are deployed with a specific query and perform varying levels of analysis of the data, communicating with each other and sending only relevant information back across the network. We demonstrate our concept in the context of face recognition using a wireless test bed comprised of PDA cell phones and laptops. We show that agent-based forward analysis can provide a significant increase in retrieval speed while decreasing bandwidth usage and information overload at the central facility. n

  20. Communication Efficiency in Multi-agent Systems

    Microsoft Academic Search

    Mary Berna-koes; Illah R. Nourbakhsh; Katia P. Sycara

    2004-01-01

    ó Despite the growing number of multi-agent software systems, relatively few physical systems have adopted multi-agent systems technology. Agents that interact with a dynamic physical environment have requirements not shared by virtual agents, including the need to transfer information about the world and their interaction with it. The agent communication languages proven successful in software based multi-agent systems incur overheads

  1. 76 FR 21805 - User Fees Relating to Enrolled Agents and Enrolled Retirement Plan Agents

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-19

    This document contains amendments to the regulations relating to the imposition of user fees for enrolled agents and enrolled retirement plan agents. The final regulations lower the initial enrollment and renewal of enrollment user fees for enrolled agents and enrolled retirement plan agents and separate the enrolled retirement plan agent user fees from the enrolled agent user fees. The final......

  2. 06/29/01 Computer Science Dept., UIC 1 Mobile AgentsMobile Agents

    E-print Network

    Xu, Haiping

    1 06/29/01 Computer Science Dept., UIC 1 Mobile AgentsMobile Agents Haiping Xu Computer Science agents. ­ Collaborate and cooperate in an intelligent manner. · Mobile agents (MA) ­ Model agent mobility., UIC 5 Evolution of the Mobile Agent Paradigm Client Server Client Server Server-1 Client Server-2

  3. The Interoperability Problem: Bringing together Mobile Agents and Agent Communication Languages

    E-print Network

    Finin, Tim

    The Interoperability Problem: Bringing together Mobile Agents and Agent Communication Languages is a central issue for both the mobile agents community and the wider agents community. Unfor- tunately is an issue that has been addressed in a limited man- ner by the mobile agents community. Agent communication

  4. The Interoperability Problem: Bringing together Mobile Agents and Agent Communication Languages

    E-print Network

    Peng, Yun

    The Interoperability Problem: Bringing together Mobile Agents and Agent Communication Languages is a central issue for both the mobile agents community and the wider agents community. Unfor­ tunately is an issue that has been addressed in a limited man­ ner by the mobile agents community. Agent communication

  5. The agent environment in multi-agent systems: A middleware perspective

    Microsoft Academic Search

    Danny Weyns; Alexander Helleboogh; Tom Holvoet; Michael Schumacher

    Interaction is at the core of multi-agent systems. We use agent environment as a general term to denote the medium for agent interaction. Over the last years, the agent environment has been subject of active research. In this paper, we reflect on the role of the agent environment in multi-agent systems from a middleware perspective. Our study yields the following

  6. Nonsteroid immunosuppressive agents and bone

    Microsoft Academic Search

    Solomon Epstein; Angela M. Inzerillo

    2004-01-01

    The immunosuppressive agents introduced to enhance the action of glucocorticoids and to prevent organ rejection had a dramatic\\u000a impact on reducing the incidence of organ rejection, enhancing donor organ, and hence patient survival following transplantation.\\u000a However, these agents, cyclosporine and tacrolimus, termed calcineurin inhibitors (CIs) also have side effects, including the promotion of rapid and severe bone loss in vivo

  7. The Agentis Agent Interaction Model

    Microsoft Academic Search

    David Kinny

    1998-01-01

    Agentis is a framework for the implementation of commercial, interactive, process-driven application systems, and is based\\u000a upon an underlying agent technology (presently dMARS) that provides core agent functionality. These systems are intended to\\u000a be programmed by the business process owner - application functionality is defined by a set of procedure and data definitions in an abstract process description language\\u000a called

  8. Expanding indications for biotechnology agents.

    PubMed

    Piascik, P

    1995-04-01

    Many biotechnology products currently on the market were initially approved for indications affecting only a small number of patients. However, pharmaceutical manufacturers have continued to study these agents for potential new therapeutic uses. The result is that several of these products are now approved for multiple uses involving large patient populations. In many cases, the biotechnology agents are being used in patients for whom no effective therapy was previously available. PMID:7754973

  9. Handling of injectable antineoplastic agents.

    PubMed Central

    Knowles, R S; Virden, J E

    1980-01-01

    Although the clinical toxicity of antineoplastic drugs has been well documented there is little or no information on the problems that may arise on the handling and mishandling of such agents. This paper attempts to highlight the importance of taking precautions to prevent adverse effects resulting from contact with cytotoxic drugs during handling and to suggest a practical guide for the handling of such agents. PMID:7427382

  10. Intelligent agents: theory and practice

    Microsoft Academic Search

    M. Woolridge; N. Jennings

    1995-01-01

    Abstract The concept of an agent has become,important in both Artificial Intelligence (AI) and mainstream,computer,science. Our aim in this paper is to point the reader at what we perceive to be the most important theoretical and practical issues as sociated with the design and construction of intelligent agents. For convenience, we divide these issues into three areas (though as the

  11. Game Couplings: Learning Dynamics and Applications Maria-Florina Balcan ninamf@cc.gatech.edu

    E-print Network

    Shamma, Jeff S.

    Game Couplings: Learning Dynamics and Applications Maria-Florina Balcan ninamf, Georgia Institute of Technology, Atlanta, GA 30332 Abstract Games encode complex strategic interactions involving numerous agents. Specific game properties, such as the existence of a potential function (Monderer

  12. A amphoteric copolymer profile modification agent

    SciTech Connect

    Wang HongGuan; Yu LianCheng; Tian HongKun [Scientific Research Inst. of Petroleum Exploration and Development, Beijing (China)

    1995-11-01

    This report provides a new gel profile modification agent prepared by an amphoteric copolymer (FT-213) and a novel crosslinking agent (BY), and introduces the preparations of the amphoteric polymer, the crosslinking agent and the profile modification agent, the action mechanism, the test conditions and the evaluations of the performance of the agent. The 45 well treatments in oilfields demonstrate that the agent can be prepared conveniently, the agent has better compatibility and application performances, and the treatment life is longer with the use of the agent. 80,000 tons incremental oil and 60,000 m{sup 3} decreasing water production have been achieved.

  13. Formalization of Embodied Sensorimotor Coupling System

    NASA Astrophysics Data System (ADS)

    Nakajima, Kohei

    2008-10-01

    Theoretical conception of an active behavior of the system is one of the most challengeable topics in complex systems research. Recently, especially in the fields of robotics and artificial intelligence, there broadly exists the study to understand the interface between the system and its environment by creating an autonomous agent that carries a sensorimotor coupling. In this paper, an embodied sensorimotor coupling system is discussed. Applying a generative pointer, the system is formalized to contain an intrinsic discrepancy induced by heterarichical duality in a flow construction by using category theory. In the system, the body plays a positive role as a dynamical mediator, or interface, between two conflicting layers, a relational layers and a constituent layers. As a result, it induces a structural change of the system itself. Implementing the construction to a Braitenberg type vehicle, we observed dynamical changes of system parameters and its behavior revealed various motion patterns compared with the conventional sensorimotor coupling system.

  14. Separation and analysis of lanthanides by isotachophoresis coupled with inductively coupled plasma mass spectrometry.

    PubMed

    Vio, Laurent; Crétier, Gérard; Chartier, Frédéric; Geertsen, Valérie; Gourgiotis, Alkiviadis; Isnard, Hélène; Rocca, Jean-Louis

    2012-09-15

    This study is a large project initiated by the French Nuclear Agency, and concerns the development of a new electrolyte system for the separation of lanthanides by isotachophoresis. This new system is based on a leading electrolyte that incorporates 2-hydroxy-2-methylbutyric acid as complexing agent. The optimization of separation conditions (complexing agent concentration, pH, capillary dimensions, injection conditions, and current intensity) performed by experiments on a commercial capillary instrument with contactless conductivity detection, which allows to improve the separation of 13 lanthanides (La to Lu, except Pm and Ho). We have also directly coupled the isotachophoresis to an inductively coupled plasma mass spectrometer to visualize the mono-elementary elution bands and demonstrate the potentiality of the method for isotope ratio measurements. The application to a simulated solution representative of a fraction of fission products present in a MOX spent fuel is presented in this paper to demonstrate the possible application in future on nuclear fuel samples. PMID:22967598

  15. Asymmetric interpersonal coupling in a cyclic sports-related movement task.

    PubMed

    Meerhoff, L Rens A; De Poel, Harjo J

    2014-06-01

    In interactive sports, teammates and/or opponents mutually tune their behavior. Expert performance thus implies certain interactive abilities, which critically depend on perceptual coupling. To illustrate this assertion, we examined the coordination dynamics with asymmetric interaction of dyads performing a sports-related cyclical movement task. In pairs, basketball players performed lateral defensive slides in in-phase, until a cue prompted them to switch to antiphase coordination. We assessed how these switches were mediated by phase adaptations of each agent under bidirectional (i.e., agents facing one another) and unidirectional (i.e., one agent facing the back of the other) visual interaction conditions. This imposed asymmetry in visual coupling exemplified an imbalance in the interaction (or 'interact-ability') between two agents. The results concurred the asymmetric coupling: during the switch the agent facing the other adapted his phasing more than the other agent. Furthermore, also in the bidirectional condition the coupling revealed dyad-intrinsic asymmetries (e.g., related to implicit follower-leader strategies). Together, this illustrates that interpersonal coordination is characterized by asymmetric coupling between the agents, and highlights how mutual perception of pertinent information mediates interpersonal coordination. This study offered a first step towards analyzing interpersonal coordination dynamics in relation to 'interact-ability'. PMID:24835161

  16. Applet: Coupled Oscillators

    NSDL National Science Digital Library

    Bauer, W. (Wolfgang), 1959-

    This website from Dr. Wolfgang Bauer at the University of Michigan contains a java applet which allows the user to change certain parameters while observing simulated coupled oscillators. In the process of coupled oscillations, energy is transferred between the individual oscillators. This is how waves propagate. Here you can study this with the most simple example of two coupled spring oscillators.

  17. Next Generation Remote Agent Planner

    NASA Technical Reports Server (NTRS)

    Jonsson, Ari K.; Muscettola, Nicola; Morris, Paul H.; Rajan, Kanna

    1999-01-01

    In May 1999, as part of a unique technology validation experiment onboard the Deep Space One spacecraft, the Remote Agent became the first complete autonomous spacecraft control architecture to run as flight software onboard an active spacecraft. As one of the three components of the architecture, the Remote Agent Planner had the task of laying out the course of action to be taken, which included activities such as turning, thrusting, data gathering, and communicating. Building on the successful approach developed for the Remote Agent Planner, the Next Generation Remote Agent Planner is a completely redesigned and reimplemented version of the planner. The new system provides all the key capabilities of the original planner, while adding functionality, improving performance and providing a modular and extendible implementation. The goal of this ongoing project is to develop a system that provides both a basis for future applications and a framework for further research in the area of autonomous planning for spacecraft. In this article, we present an introductory overview of the Next Generation Remote Agent Planner. We present a new and simplified definition of the planning problem, describe the basics of the planning process, lay out the new system design and examine the functionality of the core reasoning module.

  18. Investigational Antimicrobial Agents of 2013

    PubMed Central

    Pucci, Michael J.

    2013-01-01

    SUMMARY New antimicrobial agents are always needed to counteract the resistant pathogens that continue to be selected by current therapeutic regimens. This review provides a survey of known antimicrobial agents that were currently in clinical development in the fall of 2012 and spring of 2013. Data were collected from published literature primarily from 2010 to 2012, meeting abstracts (2011 to 2012), government websites, and company websites when appropriate. Compared to what was reported in previous surveys, a surprising number of new agents are currently in company pipelines, particularly in phase 3 clinical development. Familiar antibacterial classes of the quinolones, tetracyclines, oxazolidinones, glycopeptides, and cephalosporins are represented by entities with enhanced antimicrobial or pharmacological properties. More importantly, compounds of novel chemical structures targeting bacterial pathways not previously exploited are under development. Some of the most promising compounds include novel ?-lactamase inhibitor combinations that target many multidrug-resistant Gram-negative bacteria, a critical medical need. Although new antimicrobial agents will continue to be needed to address increasing antibiotic resistance, there are novel agents in development to tackle at least some of the more worrisome pathogens in the current nosocomial setting. PMID:24092856

  19. Spatial process and data models : toward integration of agent-based models and GIS.

    SciTech Connect

    Brown, D. G.; North, M. J.; Robinson, D. T.; Riolo, R.; Rand, W.; Decision and Information Sciences; Univ. of Michigan

    2007-10-01

    The use of object-orientation for both spatial data and spatial process models facilitates their integration, which can allow exploration and explanation of spatial-temporal phenomena. In order to better understand how tight coupling might proceed and to evaluate the possible functional and efficiency gains from such a tight coupling, we identify four key relationships affecting how geographic data (fields and objects) and agent-based process models can interact: identity, causal, temporal and topological. We discuss approaches to implementing tight integration, focusing on a middleware approach that links existing GIS and ABM development platforms, and illustrate the need and approaches with example agent-based models.

  20. D'Agents: Security in a Multiple-Language, Mobile-Agent System

    Microsoft Academic Search

    Robert S. Gray; David Kotz; George Cybenko; Daniela Rus

    1998-01-01

    Mobile-agent systems must address three security issues: pro- tecting an individual machine, protecting a group of machines, and pro- tecting an agent. In this chapter, we discuss these three issues in the context of D'Agents, a mobile-agent system whose agents can be writ- ten in Tcl, Java and Scheme. (D'Agents was formerly known as Agent Tcl.) First we discuss mechanisms

  1. Simulating Instructional Roles through Pedagogical Agents

    Microsoft Academic Search

    Amy L. Baylor; Yanghee Kim

    2005-01-01

    This paper describes the design and empirical validation of three distinct pedagogical agent roles (Expert, Motivator, and Mentor) for college students within the MIMIC (Multiple Intelligent Mentors Instructing Collaboratively) agent-based research environment. The pedagogical agent roles were operationalized by image, animation, affect, voice and script, and were developed in Poser 4 and implemented via Microsoft Agent. Two controlled experiments validated

  2. Preemptive mobile code protection using spy agents

    E-print Network

    Sheldon, Nathan D.

    Preemptive mobile code protection using spy agents Georgios Kalogridis Information Security Group in remote hosts in mobile code scenarios. In this security paradigm, a spy agent, i.e. a mobile agent which: 2 #12;Abstract This thesis introduces `spy agents' as a new security paradigm for evaluating trust

  3. Mobile Agents for Network Management Andrzej Bieszczad

    E-print Network

    White, Tony

    Mobile Agents for Network Management Andrzej Bieszczad (andrzej@sce.carleton.ca) Bernard Pagurek the potential uses of mobile agents in Network Management. We define software agents and a navigation model, which determines agent mobility. We list a number of potential advantages and disadvantages of mobile

  4. Mole – Concepts of a mobile agent system

    Microsoft Academic Search

    J. Baumann; F. Hohl; K. Rothermel; M. Straßer

    1998-01-01

    Due to its salient properties, mobile agent technology has received a rapidly growing attention over the last few years. Many developments of mobile agent systems are under way in both academic and industrial environments. In addition, there are already various efforts to standardize mobile agent facilities and architectures. Mole is the first mobile agent system that has been developed in

  5. Design issues in mobile agent programming systems

    Microsoft Academic Search

    Neeran M. Karnik; Anand R. Tripathi

    1998-01-01

    The article discusses system-level issues and agent programming requirements that arise in the design of mobile agent systems. The authors describe several mobile agent systems to illustrate different approaches designers have taken in addressing these challenges. The following areas are discussed: agent mobility, naming, security issues, privacy and integrity, authentication, authorization and access control, metering and charging mechanisms, programming primitives,

  6. Connection Management using Adaptive Mobile Agents

    Microsoft Academic Search

    Tony White; Bernard Pagurek; Franz Oppacher

    1998-01-01

    This paper describes how adaptive mobile agents can be used to solve connection management problems in Telecommunications using a parallel, distributed process. These agents have behavior that is inspired by the foraging activities of ants, with each agent capable of simple actions. Problem solving is distributed and arises as a consequence of the self-organization of a collection of agents, or

  7. Intelligent Task Composition and Allocation through Agents

    Microsoft Academic Search

    Alessandro Negri; Agostino Poggi; Michele Tomaiuolo

    2005-01-01

    In this paper we present GAIN (grid agent infrastructure), a multi-agent system that can be used for the development and deployment of flexible agent-based grid systems. Through the use of the agents jointly with the workflow and Web service technologies, we are able to support the users in the development and execution of grid applications. In particular, the GAIN system

  8. Extending JADE for Agent Grid Applications

    Microsoft Academic Search

    Agostino Poggi; Michele Tomaiuolo; Paola Turci

    2004-01-01

    This paper presents an extension of the JADE agent development framework that may be the basis for the realization of flexible agent-based grid systems. In particular, JADE framework has been enriched with two new types of agents that, on the one hand simplify the distribution of tasks inside a grid of agent platforms, and, on the other hand, facilitate the

  9. Open protocol in multi-agent systems

    Microsoft Academic Search

    Gerard A. W. Vreeswijk

    1995-01-01

    Protocols for intelligent agents are difficult to write. This is partially because intelligent agents accommodate their interaction to the situation that arises. As a result, the interaction among intelligent agents cannot be governed by a fixed protocol. In this paper I describe an open protocol paradigm for reasoning in a multi-agent system with decentralized control. An open protocol is a

  10. Modeling Virtual Gardens by Autonomous Procedural Agents

    Microsoft Academic Search

    Bedrich Benes; Javier Abdul Cordóba; Juan Miguel Soto

    2003-01-01

    A cultivated virtual plant ecosystems modeling by means of simple memoryless procedural agents is presented. The ecosystem growth is a dynamic process with a tendency to chaos. An agent can move in the ecosystem and perform certain actions defined by users in the agent description file. Agents can seed new plants, pull out weeds, water plants, and communicate by message

  11. Agent Communication Languages: The Current Landscape

    Microsoft Academic Search

    Yannis Labrou; Tim Finin; Yun Peng

    1999-01-01

    this article---suggest a paradigm for software developmentthat emphasizes autonomy both at design timeand runtime, adaptivity, and cooperation. Thisapproach seems appealing in a world of distributed,heterogeneous systems. Languagesfor communicating agents promise to play therole that natural languages played for theirhuman counterparts. An agent communicationlanguage that allows agents to interactwhile hiding the details of their internal workingswill result in agent communities...

  12. Agent Program Planning Information Balancing Food & Play

    E-print Network

    for body mass index [BMI] by age/sex). In Texas, 23 percent of fourth-grade children are obese (95th by county agents will generate results for agent use. Agent Training Check the Agent Training CalendarLife Extension Service are open to all people without regard to race, color, sex, disability, religion, age

  13. Agents That Reason and Negotiate by Arguing

    Microsoft Academic Search

    Simon Parsons; Carles Sierra; Nicholas R. Jennings

    1998-01-01

    The need for negotiation in multi-agent systems stems from the requirement for agents to solve the problems posed by their interdependence upon one another. Negotiation provides a solution to these problems by giving the agents the means to resolve their conflicting objectives, correct inconsistencies in their knowledge of other agents' world views, and coordinate a joint approach to domain tasks

  14. BDI Agents: From Theory to Practice

    Microsoft Academic Search

    Anand S. Rao; Michael P. Georgeff

    1995-01-01

    The study of computational agents capable of rational behaviour has received a great deal of attention in recent years. Theoretical formal- izations of such agents and their implementa- tions have proceeded in parallel with little or no connection between them. Tkis paper ex- plores a particular type of rational agent, a Belief- Desire-Intention (BDI) agent. The primary aim of this

  15. An efficient preparation of polyanionic affinity agent and its evaluation for the measurement of glycated hemoglobin.

    PubMed

    Reddy, Rajarathnam E; Pan, You; Johnson, Donald D; Chen, Yon-Yih; Datwyler, Saul A; Hauptman, Michelle S; Thottathil, John K

    2005-05-16

    An efficient method was developed for the preparation of polyanionic affinity agent (3), a key component in the measurement of glycated hemoglobin (GHb). Glycated hemoglobin is an important clinical marker for diagnosis of patients with diabetes and useful to monitor the management of disease. The affinity agent (3) was prepared based on coupling reaction between poly(acrylic acid) (1) and 3-aminophenylboronic acid (2) in water. The critical features of this polymeric affinity agent (3), such as size, boronic acid incorporation ratio and concentration, on the measurement of glycated hemoglobin were evaluated. It was found that the agent (3) prepared using poly(acrylic acid) (1) with 225 kDa molecular weight gave optimal GHb measurement. The performance test results demonstrated that the boronic acid incorporation ratio and concentration of affinity agent (3) play a critical role in the assay and determines the precision of glycated hemoglobin measurement. PMID:15848760

  16. Agent review phase one report.

    SciTech Connect

    Zubelewicz, Alex Tadeusz; Davis, Christopher Edward; Bauer, Travis LaDell

    2009-12-01

    This report summarizes the findings for phase one of the agent review and discusses the review methods and results. The phase one review identified a short list of agent systems that would prove most useful in the service architecture of an information management, analysis, and retrieval system. Reviewers evaluated open-source and commercial multi-agent systems and scored them based upon viability, uniqueness, ease of development, ease of deployment, and ease of integration with other products. Based on these criteria, reviewers identified the ten most appropriate systems. The report also mentions several systems that reviewers deemed noteworthy for the ideas they implement, even if those systems are not the best choices for information management purposes.

  17. Haloprogin: a Topical Antifungal Agent

    PubMed Central

    Harrison, E. F.; Zwadyk, P.; Bequette, R. J.; Hamlow, E. E.; Tavormina, P. A.; Zygmunt, W. A.

    1970-01-01

    Haloprogin was shown to be a highly effective agent for the treatment of experimentally induced topical mycotic infections in guinea pigs. Its in vitro spectrum of activity also includes yeasts, yeastlike fungi (Candida species), and certain gram-positive bacteria. The in vitro and in vivo antifungal activity of haloprogin against dermatophytes was equal to that observed with tolnaftate. The striking differences between the two agents were the marked antimonilial and selective antibacterial activities shown by haloprogin, contrasted with the negligible activities found with tolnaftate. Addition of serum decreased the in vitro antifungal activity of haloprogin to a greater extent than that of tolnaftate; however, diminished antifungal activity was not observed when haloprogin was applied topically to experimental dermatophytic infections. Based on its broad spectrum of antimicrobial activity, haloprogin may prove to be a superior topical agent in the treatment of dermatophytic and monilial infections in man. PMID:5422306

  18. Coupled Fano resonators.

    PubMed

    Tu, Xiaoguang; Mario, Landobasa Y; Mei, Ting

    2010-08-30

    We theoretically investigate coupled Fano structures which combine the characteristics of both directly coupled Fabry-Perot cavities (DCFPC) and a side-coupled integrated spaced sequence of resonators (SCISSOR). Asymmetric and symmetric Fano resonances in a single and doubly-coupled Fano unit are analytically derived based on Fabry-Perot approach. It is found that doubly-coupled Fano units show a special asymmetric EIT-like lineshape. This structure shows an index changing sensitivity of 10(-6), about two orders higher than that of the single Fano resonator, which is promising for index sensor application. A unique frequency detuning method of EIT like lineshape is also found in the doubly-coupled Fano units. The multiple coupled Fano unit structure demonstrates potentials for applications of tunable optical filter and slow light, whereas for the latter it shows much higher group delay than that of SCISSORS and DCFPC with the same parameters. PMID:20940775

  19. Thyroid dysfunction from antineoplastic agents.

    PubMed

    Hamnvik, Ole-Petter Riksfjord; Larsen, P Reed; Marqusee, Ellen

    2011-11-01

    Unlike cytotoxic agents that indiscriminately affect rapidly dividing cells, newer antineoplastic agents such as targeted therapies and immunotherapies are associated with thyroid dysfunction. These include tyrosine kinase inhibitors, bexarotene, radioiodine-based cancer therapies, denileukin diftitox, alemtuzumab, interferon-?, interleukin-2, ipilimumab, tremelimumab, thalidomide, and lenalidomide. Primary hypothyroidism is the most common side effect, although thyrotoxicosis and effects on thyroid-stimulating hormone secretion and thyroid hormone metabolism have also been described. Most agents cause thyroid dysfunction in 20%-50% of patients, although some have even higher rates. Despite this, physicians may overlook drug-induced thyroid dysfunction because of the complexity of the clinical picture in the cancer patient. Symptoms of hypothyroidism, such as fatigue, weakness, depression, memory loss, cold intolerance, and cardiovascular effects, may be incorrectly attributed to the primary disease or to the antineoplastic agent. Underdiagnosis of thyroid dysfunction can have important consequences for cancer patient management. At a minimum, the symptoms will adversely affect the patient's quality of life. Alternatively, such symptoms can lead to dose reductions of potentially life-saving therapies. Hypothyroidism can also alter the kinetics and clearance of medications, which may lead to undesirable side effects. Thyrotoxicosis can be mistaken for sepsis or a nonendocrinologic drug side effect. In some patients, thyroid disease may indicate a higher likelihood of tumor response to the agent. Both hypothyroidism and thyrotoxicosis are easily diagnosed with inexpensive and specific tests. In many patients, particularly those with hypothyroidism, the treatment is straightforward. We therefore recommend routine testing for thyroid abnormalities in patients receiving these antineoplastic agents. PMID:22010182

  20. Investigating Interactions Between Agent Conversations and Agent Control Components y

    E-print Network

    Massachusetts at Amherst, University of

    for the purpose of coordinating E ort sponsored by the Defense Advanced Research Projects Agency (DARPA) and Air, either expressed or implied, of the Defense Advanced Research Projects Agency (DARPA), Air Force Research conversation in the context of ne-grained agent coordination research has raised several intellectual questions

  1. Programacin de Agentes y Sistemas Multi-Agentes

    E-print Network

    Guerra Hernández, Alejandro

    . Compare la propuesta de Yoav Shoham (1993) expuesta en su artículo en Artificial Intelligence 60-Hernández Departamento de Inteligencia Artificial Universidad Veracruzana Facultad de Física e Inteligencia Artificial:51­92 "Agent Oriented Programming" con las con- ceptos básicos introducidos en clase. Señale claramente

  2. The Information Agent: An Infrastructure Agent Supporting Collaborative Enterprise Architectures

    E-print Network

    Fox, Mark S.

    that need it. · Automatic retrieval, processing and integration of infor- mation that is relevant to agents language as the underlying representational and inferential substrate. Second, it extends this substrate, it integrates in this environment recent languages including KQML [7] for the high level communi- cation

  3. Some thoughts on agent trust and delegation

    Microsoft Academic Search

    Yuh-Jong Hu

    2001-01-01

    In this paper, we are going to show how to build up agent-oriented Public Key Infrastructure(PKI) from SPKI\\/SDSI and X.509 standards. A variety of delegation mechanisms for agents will be demonstrated under this agent-oriented PKI. The mechanisms include: chain-ruled, threshold, and conditional. The lack of agent security management standards did not allow us to do the agent trust and delegation

  4. Agents in bioinformatics, computational and systems biology

    Microsoft Academic Search

    Emanuela Merelli; Giuliano Armano; Nicola Cannata; Flavio Corradini; Mark D'inverno; Andreas Doms; Phillip W. Lord; Andrew Martin; Luciano Milanesi; Steffen Möller; Michael Schroeder; Michael Luck

    2007-01-01

    The adoption of agent technologies and multi-agent systems constitutes an emerging area in bioinformatics. In this article, we report on the activity of the Working Group on Agents in Bioinformatics (BIOAGENTS) founded during the first AgentLink III Technical Forum meeting on the 2nd of July, 2004, in Rome. The meeting provided an opportunity for seeding collaborations between the agent and

  5. Limonene and tetrahydrofurfuryl alcohol cleaning agent

    DOEpatents

    Bohnert, G.W.; Carter, R.D.; Hand, T.E.; Powers, M.T.

    1997-10-21

    The present invention is a tetrahydrofurfuryl alcohol and limonene cleaning agent and method for formulating and/or using the cleaning agent. This cleaning agent effectively removes both polar and nonpolar contaminants from various electrical and mechanical parts and is readily used without surfactants, thereby reducing the need for additional cleaning operations. The cleaning agent is warm water rinsable without the use of surfactants. The cleaning agent can be azeotropic, enhancing ease of use in cleaning operations and ease of recycling.

  6. Middle-Agents for the Internet

    Microsoft Academic Search

    Keith Decker; Katia P. Sycara; Mike Williamson

    1997-01-01

    Like middle-men in physical commerce, middle-agents support the flow of information in electronic commerce, assisting in locating and connecting the ultimate information provider with the ultimate information requester. Many different types of middle-agents will be useful in realistic, large, distributed, open multi-agent problem solving systems. These include matchmakers or yellow page agents that process advertisements, blackboard agents that collect requests,

  7. Effect of application rates of assistant agents on properties of nano SiO 2 \\/NR composites

    Microsoft Academic Search

    Tongjian Zhao; Yun Xu; Jiang Wang; Xin Fu

    2009-01-01

    Nano SiO2\\/NR composites were prepared through blending nano SiO2 emulsion with natural rubber latex and then concreting with acetic acid. The emulsion nano SiO2 was prepared with Na2SiO3·9H2O and hydrochloric acid under the reaction of the assistant agents. The was analyzed effect of the application rates of assistant\\u000a agents such as silane coupling agent, surfactant, nucleating agent and dispersant on

  8. Is it an Agent, or Just a Program?: A Taxonomy for Autonomous Agents

    Microsoft Academic Search

    Stan Franklin; Arthur C. Graesser

    1996-01-01

    The advent of software agents gave rise to much discussion of just what such an agent is, and of how they differ from programs in general. Here we propose a formal definition of an autonomous agent which clearly distinguishes a software agent from just any program. We also offer the beginnings of a natural kinds taxonomy of autonomous agents, and

  9. Does an Agent Matter? The Effects of Animated Pedagogical Agents on Multimedia Environments.

    ERIC Educational Resources Information Center

    Craig, Scotty D.; Gholson, Barry

    Data are presented on the effects of Animated Agents on multimedia learning environments with specific concerns of split attention and modality effects. The study was a 3 (agent properties: agent only, agent with gestures, no agent) x 3 (picture features: static picture, sudden onset, animation) factorial design with outcome measures of mental…

  10. Lazy Agent Replication and Asynchronous Consensus for the FaultTolerant Mobile Agent System

    E-print Network

    Yeom, Heon Young

    Lazy Agent Replication and Asynchronous Consensus for the Fault­Tolerant Mobile Agent System,widepisg@sejong.ac.kr yeom@arirang.snu.ac.kr ABSTRACT Fault­tolerant execution of a mobile agent is an important design issue to build a reliable mobile agent system. Agent replication is a fault­tolerant scheme, which tolerates up

  11. Is it an agent or just a program?: A taxonomy for autonomous agents

    Microsoft Academic Search

    Stan Franklin

    1997-01-01

    Abstract The advent of software agents gave rise to much discussion of just what such an agent is, and of how they differ from programs in general. Here we propose a formal definition of an autonomous agent which clearly distinguishes a software agent from just any program. We also offer the beginnings of a natural kinds taxonomyo f autonomous agents,

  12. The New Agent: A Qualitative Study to Strategically Adapt New Agent Professional Development

    ERIC Educational Resources Information Center

    Baker, Lauri M.; Hadley, Gregg

    2014-01-01

    The qualitative study reported here assessed the needs of agents related to new agent professional development to improve the current model. Agents who participated in new agent professional development within the last 5 years were selected to participate in focus groups to determine concerns and continued needs. Agents enjoyed networking and…

  13. Theoretical Evaluation of Ring-Based Architectural Model for Middle Agents in Agent-Based System

    E-print Network

    Cao, Longbing

    ]. Cernuzzi et al. proposed a framework for evaluating methodologies, so that agent-based system designersTheoretical Evaluation of Ring-Based Architectural Model for Middle Agents in Agent-Based System and solve the matching problem between service provider agents and requester agents. We evaluate the ring

  14. ADK: An Agent Development Kit Based on a Formal Design Model for Multi-Agent Systems

    Microsoft Academic Search

    Haiping Xu; Sol M. Shatz

    2003-01-01

    The advent of multi-agent systems has brought us opportunities for the development of complex software that will serve as the infrastructure for advanced distributed applications. During the past decade, there have been many agent architectures proposed for implementing agent-based systems, and also a few efforts to formally specify agent behaviors. However, research on narrowing the gap between agent formal models

  15. Model-Based Development of Intelligent Communicating Agents for Multi-Agent Systems1

    E-print Network

    Xu, Haiping

    as both a specification and a high-level design for the tool kit called ADK (Agent Development Kit built on ADK, we present an air-ticket trading example. Keywords: agent-oriented G-net model, intelligent communicating agent, multi-agent system, agent development kit (ADK), model-based development. 1

  16. Software for Automation of Real-Time Agents, Version 2

    NASA Technical Reports Server (NTRS)

    Fisher, Forest; Estlin, Tara; Gaines, Daniel; Schaffer, Steve; Chouinard, Caroline; Engelhardt, Barbara; Wilklow, Colette; Mutz, Darren; Knight, Russell; Rabideau, Gregg; Chien, Steve; Simmons, Reid; Apfelbaum, David

    2005-01-01

    Version 2 of Closed Loop Execution and Recovery (CLEaR) has been developed. CLEaR is an artificial intelligence computer program for use in planning and execution of actions of autonomous agents, including, for example, Deep Space Network (DSN) antenna ground stations, robotic exploratory ground vehicles (rovers), robotic aircraft (UAVs), and robotic spacecraft. CLEaR automates the generation and execution of command sequences, monitoring the sequence execution, and modifying the command sequence in response to execution deviations and failures as well as new goals for the agent to achieve. The development of CLEaR has focused on the unification of planning and execution to increase the ability of the autonomous agent to perform under tight resource and time constraints coupled with uncertainty in how much of resources and time will be required to perform a task. This unification is realized by extending the traditional three-tier robotic control architecture by increasing the interaction between the software components that perform deliberation and reactive functions. The increase in interaction reduces the need to replan, enables earlier detection of the need to replan, and enables replanning to occur before an agent enters a state of failure.

  17. Nucleotide cleaving agents and method

    DOEpatents

    Que, Jr., Lawrence (Roseville, MN); Hanson, Richard S. (Falcon Heights, MN); Schnaith, Leah M. T. (Redwing, MN)

    2000-01-01

    The present invention provides a unique series of nucleotide cleaving agents and a method for cleaving a nucleotide sequence, whether single-stranded or double-stranded DNA or RNA, using and a cationic metal complex having at least one polydentate ligand to cleave the nucleotide sequence phosphate backbone to yield a hydroxyl end and a phosphate end.

  18. IMPLEMENTING AGENTS FOR INTRUSION DETECTION

    Microsoft Academic Search

    Ioan Alfred Letia; Dan Alexandru Marian

    2010-01-01

    Many advanced techniques have been developed recently to help fight against intrusion. Significant power in this direction can be gained by better taking advantage of the patterns available in the data passing through the network. We have conceived various software agents, distributed over a network, that are able to collect and filter the data and also consider the firewall rules.

  19. Other Viruses and Viruslike Agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The diseases reported under 'Virus and Virus-like Agents' in the first volume of this compendium, with the exception of Cherry rasp leaf virus and Rubus chinese seed-borne virus, should be considered oddities since there are no known type isolates available for these reported viruses. Without a po...

  20. Agents and the Semantic Web

    Microsoft Academic Search

    James A. Hendler

    2001-01-01

    This article offers a few pointers to this emerging area and shows how the ontology languages of the Semantic Web can lead directly to more powerful agent-based approaches---that is, to the realization of my colleague's "science fiction " vision.

  1. Travel Agent. Occupational Simulation Kit.

    ERIC Educational Resources Information Center

    Peterson, Wayne

    This career exploration instructional booklet on the travel agent's occupation is one of several resulting from the rural southwestern Colorado CEPAC Project (Career Education Process of Attitude Change). Based on a job analysis and utilizing a programed instructional format, the following content is included: A brief description of what a travel…

  2. Triggered pore-forming agents

    DOEpatents

    Bayley, H.; Walker, B.J.; Chang, C.Y.; Niblack, B.; Panchal, R.

    1998-07-07

    An inactive pore-forming agent is revealed which is activated to lytic function by a condition such as pH, light, heat, reducing potential, or metal ion concentration, or substance such as a protease, at the surface of a cell. 30 figs.

  3. An Introduction to Software Agents

    Microsoft Academic Search

    Jeffrey M. Bradshaw

    1997-01-01

    ince the beginning of recorded history, people have been fascinated with the idea of non-human agencies.1 Popular notions about androids, hu- manoids, robots, cyborgs, and science fiction creatures permeate our cul- ture, forming the unconscious backdrop against which software agents are per- ceived. The word \\

  4. Gaze-based infotainment agents

    Microsoft Academic Search

    Helmut Prendinger; Tobias Eichner; Elisabeth André; Mitsuru Ishizuka

    2007-01-01

    We propose an infotainment presentation system that relies on eye gaze as an intuitive and unobtrusive input modal- ity. The system analyzes eye movements in real-time to in- fer users' attention, visual interest, and preference regarding interface objects. The application consists of a virtual show- room where a team of two highly realistic 3D agents presents product items in an

  5. RNA viruses as virotherapy agents

    Microsoft Academic Search

    Stephen J Russell

    2002-01-01

    RNA viruses are rapidly emerging as extraordinarily promising agents for oncolytic virotherapy. Integral to the lifecycles of all RNA viruses is the formation of double-stranded RNA, which activates a spectrum of cellular defense mechanisms including the activation of PKR and the release of interferon. Tumors are frequently defective in their PKR signaling and interferon response pathways, and therefore provide a

  6. Communicating Virtual Agents Nicole Krmer

    E-print Network

    Moeller, Ralf

    conversational actions · Four basic models employed Personality Emotion Performatives Conversational function Kopp & Krämer KI3: Communicating virtual agents Models of personality · Personality: Consistent and enduring patterns of thought, behavior, and emotion in individuals · Five major dimensions account

  7. Cooperating Agents for Information Retrieval

    Microsoft Academic Search

    Craig A. Knoblock; Yigal Arens; Chun-nan Hsu

    1994-01-01

    With the vast number of information resourcesavailable today, a critical problem is how to locate,retrieve and process information. It wouldbe impractical to build a single unified systemthat combines all of these information resources.A more promising approach is to build specializedinformation retrieval agents that provide accessto a subset of the information resourcesand can send requests to other information retrievalagents when appropriate.

  8. Agent-based substation automation

    Microsoft Academic Search

    D. P. Buse; P. Sun; Q. H. Wu; J. Fitch

    2003-01-01

    Agent technology is one of the most interesting developments in the field of distributed artificial intelligence. It has a wide range of applications, with information management, intelligent user interfaces, personal assistants, and Internet commerce among the most popular. This article defines a generic architecture that applies the multiagent systems methodology to the field of substation automation, describes the design of

  9. Agents and the Semantic Web

    E-print Network

    James Hendler

    2001-01-01

    Many challenges of bringing communicating multiagent systems to the Web require ontologies. The integration of agent technology and ontologies could significantly affect the use of Web services and the ability to extend programs to perform tasks for users more efficiently and with less human

  10. Natural products as antibacterial agents

    Microsoft Academic Search

    Gail B. Mahady; Yue Huang; Brian J. Doyle; Tracie Locklear

    2008-01-01

    For thousands of years medicinal plants have played a significant role in the treatment of a wide range of medical conditions, including infectious diseases. Some naturally occurring chemical compounds serve as models for a large percentage clinically proven drugs, and many are now being re-assessed as antimicrobial agents. The primary reason for this renaissance is the fact that infectious disease

  11. Novel Investigational Agents & Clinical Trials

    E-print Network

    Kay, Mark A.

    Bexarotene, denileukin diftitox, IFN vorinostat, romidepsin (single or combination) Single-agent chemotherapy overall clinical benefit RCTs are strongly recommended #12;Era of targeted therapies Huge impact.g., CD4, CD25, CD30, CD40, CD52, CD158k, CCR4) Tumor proliferation, metabolism, survival, progression

  12. Agentes moviles en Computacion Ubicua

    Microsoft Academic Search

    Ma Celeste; Campo Vazquez

    Resumen. La computacion ubicua segun la vision de Weiser, presenta entornos saturados de dis- positivos con capacidades de computacion y comunicacion que le proporcionan a los usuarios ser- vicios ocultando la complejidad tecnologica subyacente. Nuestra l´inea de investigacion pretende potenciar el uso de la tecnolog´ia de agentes moviles en computacion ubicua para facilitar este obje- tivo. El trabajo que estamos

  13. Chicken anaemia agent: A review

    Microsoft Academic Search

    M. S. McNulty

    1991-01-01

    Chicken anaemia agent (CAA) is a small, unclassified, icosahedral DNA virus with a single?stranded, circular genome. It seems to have a worldwide distribution. Only one serotype of CAA has been found, and all isolates investigated so far are pathogenic for young chicks.CAA causes a syndrome in chickens characterised by increased mortality, anaemia associated with atrophy of the haematopoietic tissues in

  14. Endophytic Actinomycetes: Attractive Biocontrol Agents

    Microsoft Academic Search

    Hitoshi KUNOH

    2002-01-01

    In modern agriculture, application of agrochemicals is still an invaluable and effective method to control plant diseases. However, since use of agrochemicals has been fallen into disfavor because of environmental pollution and detrimental effects on a variety of nontarget organisms, potential use of microbe-based biocontrol agents as replacements or supplements for agrochemicals has increased in agricultural importance. The success of

  15. Agent-Mediated Internet Advertising

    Microsoft Academic Search

    David Siew; Xun Yi

    2000-01-01

    After fewer than three years as an industry, Internet advertising has grown rapidly and is expected to command an even larger portion of advertisers' media budgets with the next decade. From the points of view of Internet advertisers, it will be very advantageous if Internet advertising can be automatically carried out. Software agent technology offers a new paradigm for advertising

  16. Reliable slip-on vacuum coupling for low-temperature apparatus

    NASA Astrophysics Data System (ADS)

    Stasiak, J. W.; Guernsey, R. W., Jr.

    1984-09-01

    A reliable slip-on vacuum coupling scheme for low-temperature applications is described. The novel aspect of this concept is the use of silicone fluid as the sealing agent. The stem and coupling joint described has performed without failure at room temperature, immersed in normal 4He and in superfluid 4He.

  17. Impact of hypoglycemic agents on myocardial ischemic preconditioning

    PubMed Central

    Rahmi Garcia, Rosa Maria; Rezende, Paulo Cury; Hueb, Whady

    2014-01-01

    Murry et al in 1986 discovered the intrinsic mechanism of profound protection called ischemic preconditioning. The complex cellular signaling cascades underlying this phenomenon remain controversial and are only partially understood. However, evidence suggests that adenosine, released during the initial ischemic insult, activates a variety of G protein-coupled agonists, such as opioids, bradykinin, and catecholamines, resulting in the activation of protein kinases, especially protein kinase C (PKC). This leads to the translocation of PKC from the cytoplasm to the sarcolemma, where it stimulates the opening of the ATP-sensitive K+ channel, which confers resistance to ischemia. It is known that a range of different hypoglycemic agents that activate the same signaling cascades at various cellular levels can interfere with protection from ischemic preconditioning. This review examines the effects of several hypoglycemic agents on myocardial ischemic preconditioning in animal studies and clinical trials. PMID:24936247

  18. Agent-based models in translational systems biology

    PubMed Central

    An, Gary; Mi, Qi; Dutta-Moscato, Joyeeta; Vodovotz, Yoram

    2013-01-01

    Effective translational methodologies for knowledge representation are needed in order to make strides against the constellation of diseases that affect the world today. These diseases are defined by their mechanistic complexity, redundancy, and nonlinearity. Translational systems biology aims to harness the power of computational simulation to streamline drug/device design, simulate clinical trials, and eventually to predict the effects of drugs on individuals. The ability of agent-based modeling to encompass multiple scales of biological process as well as spatial considerations, coupled with an intuitive modeling paradigm, suggests that this modeling framework is well suited for translational systems biology. This review describes agent-based modeling and gives examples of its translational applications in the context of acute inflammation and wound healing. PMID:20835989

  19. Swarm autonomic agents with self-destruct capability

    NASA Technical Reports Server (NTRS)

    Hinchey, Michael G. (Inventor); Sterritt, Roy (Inventor)

    2009-01-01

    Systems, methods and apparatus are provided through which in some embodiments an autonomic entity manages a system by generating one or more stay alive signals based on the functioning status and operating state of the system. In some embodiments, an evolvable synthetic neural system is operably coupled to one or more evolvable synthetic neural systems in a hierarchy. The evolvable neural interface receives and generates heartbeat monitor signals and pulse monitor signals that are used to generate a stay alive signal that is used to manage the operations of the synthetic neural system. In another embodiment an asynchronous Alice signal (Autonomic license) requiring valid credentials of an anonymous autonomous agent is initiated. An unsatisfactory Alice exchange may lead to self-destruction of the anonymous autonomous agent for self-protection.

  20. Swarm autonomic agents with self-destruct capability

    NASA Technical Reports Server (NTRS)

    Hinchey, Michael G. (Inventor); Sterritt, Roy (Inventor)

    2011-01-01

    Systems, methods and apparatus are provided through which in some embodiments an autonomic entity manages a system by generating one or more stay alive signals based on the functioning status and operating state of the system. In some embodiments, an evolvable synthetic neural system is operably coupled to one or more evolvable synthetic neural systems in a hierarchy. The evolvable neural interface receives and generates heartbeat monitor signals and pulse monitor signals that are used to generate a stay alive signal that is used to manage the operations of the synthetic neural system. In another embodiment an asynchronous Alice signal (Autonomic license) requiring valid credentials of an anonymous autonomous agent is initiated. An unsatisfactory Alice exchange may lead to self-destruction of the anonymous autonomous agent for self-protection.

  1. From actors to agents in socio-ecological systems models

    PubMed Central

    Rounsevell, M. D. A.; Robinson, D. T.; Murray-Rust, D.

    2012-01-01

    The ecosystem service concept has emphasized the role of people within socio-ecological systems (SESs). In this paper, we review and discuss alternative ways of representing people, their behaviour and decision-making processes in SES models using an agent-based modelling (ABM) approach. We also explore how ABM can be empirically grounded using information from social survey. The capacity for ABM to be generalized beyond case studies represents a crucial next step in modelling SESs, although this comes with considerable intellectual challenges. We propose the notion of human functional types, as an analogy of plant functional types, to support the expansion (scaling) of ABM to larger areas. The expansion of scope also implies the need to represent institutional agents in SES models in order to account for alternative governance structures and policy feedbacks. Further development in the coupling of human-environment systems would contribute considerably to better application and use of the ecosystem service concept. PMID:22144388

  2. Agent Ludens: Games for Agent Dialogues Peter McBurney and Simon Parsons

    E-print Network

    Parsons, Simon

    Agent Ludens: Games for Agent Dialogues Peter McBurney and Simon Parsons Department of Computer proposed for mod- eling agent interactions, for example by Parsons and Jen- nings (Parsons & Jennings 1996

  3. Agent Ludens: Games for Agent Dialogues Peter McBurney and Simon Parsons

    E-print Network

    McBurney, Peter

    Agent Ludens: Games for Agent Dialogues Peter McBurney and Simon Parsons Department of Computer proposed for mod­ eling agent interactions, for example by Parsons and Jen­ nings (Parsons & Jennings 1996

  4. Agent planning in AgScala

    NASA Astrophysics Data System (ADS)

    Toši?, Saša; Mitrovi?, Dejan; Ivanovi?, Mirjana

    2013-10-01

    Agent-oriented programming languages are designed to simplify the development of software agents, especially those that exhibit complex, intelligent behavior. This paper presents recent improvements of AgScala, an agent-oriented programming language based on Scala. AgScala includes declarative constructs for managing beliefs, actions and goals of intelligent agents. Combined with object-oriented and functional programming paradigms offered by Scala, it aims to be an efficient framework for developing both purely reactive, and more complex, deliberate agents. Instead of the Prolog back-end used initially, the new version of AgScala relies on Agent Planning Package, a more advanced system for automated planning and reasoning.

  5. Intgration d'un agent mobile dans un Systme multi-agent hirarchique

    E-print Network

    Paris-Sud XI, Université de

    Intégration d'un agent mobile dans un Système multi-agent hiérarchique Maghri D1 , Amara N2 1'intégration d'un agent mobile à base de composants dans un Système Multi-Agents (SMA) à structure hiérarchique mobile, système multi-agents hiérarchique, intégration. 1 INTRODUCTION De nos jours, les agents mobiles

  6. Electromagnetic coupling in aperture-coupled and proximity-coupled microstrip antenna structures

    Microsoft Academic Search

    Lee Geun Yoonx; Ji Hwan Ko

    2001-01-01

    The problems of electromagnetic coupling in aperture-coupled and proximity-coupled microstrip antenna structures are considered focusing on two kinds of radiative coupling mechanisms, cavity-type and parasitic-type

  7. Peptide-based protein capture agents with high affinity, selectivity, and stability as antibody replacements in biodetection assays

    NASA Astrophysics Data System (ADS)

    Coppock, Matthew B.; Farrow, Blake; Warner, Candice; Finch, Amethist S.; Lai, Bert; Sarkes, Deborah A.; Heath, James R.; Stratis-Cullum, Dimitra

    2014-05-01

    Current biodetection assays that employ monoclonal antibodies as primary capture agents exhibit limited fieldability, shelf life, and performance due to batch-to-batch production variability and restricted thermal stability. In order to improve upon the detection of biological threats in fieldable assays and systems for the Army, we are investigating protein catalyzed capture (PCC) agents as drop-in replacements for the existing antibody technology through iterative in situ click chemistry. The PCC agent oligopeptides are developed against known protein epitopes and can be mass produced using robotic methods. In this work, a PCC agent under development will be discussed. The performance, including affinity, selectivity, and stability of the capture agent technology, is analyzed by immunoprecipitation, western blotting, and ELISA experiments. The oligopeptide demonstrates superb selectivity coupled with high affinity through multi-ligand design, and improved thermal, chemical, and biochemical stability due to non-natural amino acid PCC agent design.

  8. Neuroprotective "agents" in surgery. Secret "agent" man, or common "agent" machine?

    NASA Technical Reports Server (NTRS)

    Andrews, R. J.

    1999-01-01

    The search for clinically-effective neuroprotective agents has received enormous support in recent years--an estimated $200 million by pharmaceutical companies on clinical trials for traumatic brain injury alone. At the same time, the pathophysiology of brain injury has proved increasingly complex, rendering the likelihood of a single agent "magic bullet" even more remote. On the other hand, great progress continues with technology that makes surgery less invasive and less risky. One example is the application of endovascular techniques to treat coronary artery stenosis, where both the invasiveness of sternotomy and the significant neurological complication rate (due to microemboli showering the cerebral vasculature) can be eliminated. In this paper we review aspects of intraoperative neuroprotection both present and future. Explanations for the slow progress on pharmacologic neuroprotection during surgery are presented. Examples of technical advances that have had great impact on neuroprotection during surgery are given both from coronary artery stenosis surgery and from surgery for Parkinson's disease. To date, the progress in neuroprotection resulting from such technical advances is an order of magnitude greater than that resulting from pharmacologic agents used during surgery. The progress over the last 20 years in guidance during surgery (CT and MRI image-guidance) and in surgical access (endoscopic and endovascular techniques) will soon be complemented by advances in our ability to evaluate biological tissue intraoperatively in real-time. As an example of such technology, the NASA Smart Probe project is considered. In the long run (i.e., in 10 years or more), pharmacologic "agents" aimed at the complex pathophysiology of nervous system injury in man will be the key to true intraoperative neuroprotection. In the near term, however, it is more likely that mundane "agents" based on computers, microsensors, and microeffectors will be the major impetus to improved intraoperative neuroprotection.

  9. A gas chromatography–mass spectrometric method to determine skin-whitening agents in cosmetic products

    Microsoft Academic Search

    Alberto Chisvert; Judit Sisternes; Ángel Balaguer; Amparo Salvador

    2010-01-01

    An analytical method is proposed here to determine three allowed (kojic acid, azelaic acid and arbutin) and two forbidden (resorcinol and hydroquinone) skin-whitening agents in cosmetics. The method is based on gas chromatography coupled with mass spectrometric detection, which allows the two prohibited target compounds to be identified unequivocally by means of their mass spectra acquired in full-scan mode at

  10. Prebiotic condensation reactions in an aqueous medium: A review of condensing agents

    Microsoft Academic Search

    Josée Hulshof; Cyril Ponnamperuma

    1976-01-01

    Biopolymers are formed by dehydration-type condensation reactions. In aqueous solutions dehydration reactions are very unlikely to happen spontaneously. However, coupling of dehydration-condensation to the hydrolysis of condensing agents could facilitate the synthesis of biopolymers in an aqueous solution. The literature shows that the peptides, nucleosides, nucleotides and oligonucleotides can be formed in this way. A careful study of the literature

  11. Chromatographic and electrophoretic techniques used in the analysis of triazole antifungal agents—a review

    Microsoft Academic Search

    R. J. Ekiert; J. Krzek; P. Talik

    2010-01-01

    Systematic review of literature coupled with integrative research of published data for triazole antifungal agents was done. The investigated literature covered chromatographic and electrophoretic methods developed in the last 10 years (2000–2009). The aim of this review was to compare different methodologies, assess preferences in the selection of analytical methods and to find still existing analytical problems. Last decade is

  12. Agile assembly architecture: an agent based approach to modular precision assembly systems

    Microsoft Academic Search

    Alfred A. Rizzi; Jay Gowdy; Ralph L. Hollis

    1997-01-01

    This paper presents our initial thoughts on the design of an architecture for highly flexible, modular, and distributed precision assembly systems. Through the use of a unified design, simulation, programming, and monitoring environment coupled with self-representing cooperative agents, this architecture will significantly simplify the process of factory design and deployment. Our demonstration of this architecture takes the form of a

  13. Modeling and Visualizing Flow of Chemical Agents Across Complex Terrain

    NASA Technical Reports Server (NTRS)

    Kao, David; Kramer, Marc; Chaderjian, Neal

    2005-01-01

    Release of chemical agents across complex terrain presents a real threat to homeland security. Modeling and visualization tools are being developed that capture flow fluid terrain interaction as well as point dispersal downstream flow paths. These analytic tools when coupled with UAV atmospheric observations provide predictive capabilities to allow for rapid emergency response as well as developing a comprehensive preemptive counter-threat evacuation plan. The visualization tools involve high-end computing and massive parallel processing combined with texture mapping. We demonstrate our approach across a mountainous portion of North California under two contrasting meteorological conditions. Animations depicting flow over this geographical location provide immediate assistance in decision support and crisis management.

  14. Coevolutionary networks of reinforcement-learning agents

    NASA Astrophysics Data System (ADS)

    Kianercy, Ardeshir; Galstyan, Aram

    2013-07-01

    This paper presents a model of network formation in repeated games where the players adapt their strategies and network ties simultaneously using a simple reinforcement-learning scheme. It is demonstrated that the coevolutionary dynamics of such systems can be described via coupled replicator equations. We provide a comprehensive analysis for three-player two-action games, which is the minimum system size with nontrivial structural dynamics. In particular, we characterize the Nash equilibria (NE) in such games and examine the local stability of the rest points corresponding to those equilibria. We also study general n-player networks via both simulations and analytical methods and find that, in the absence of exploration, the stable equilibria consist of star motifs as the main building blocks of the network. Furthermore, in all stable equilibria the agents play pure strategies, even when the game allows mixed NE. Finally, we study the impact of exploration on learning outcomes and observe that there is a critical exploration rate above which the symmetric and uniformly connected network topology becomes stable.

  15. Translation-coupling systems

    DOEpatents

    Pfleger, Brian; Mendez-Perez, Daniel

    2013-11-05

    Disclosed are systems and methods for coupling translation of a target gene to a detectable response gene. A version of the invention includes a translation-coupling cassette. The translation-coupling cassette includes a target gene, a response gene, a response-gene translation control element, and a secondary structure-forming sequence that reversibly forms a secondary structure masking the response-gene translation control element. Masking of the response-gene translation control element inhibits translation of the response gene. Full translation of the target gene results in unfolding of the secondary structure and consequent translation of the response gene. Translation of the target gene is determined by detecting presence of the response-gene protein product. The invention further includes RNA transcripts of the translation-coupling cassettes, vectors comprising the translation-coupling cassettes, hosts comprising the translation-coupling cassettes, methods of using the translation-coupling cassettes, and gene products produced with the translation-coupling cassettes.

  16. Biologic agents in islet transplantation.

    PubMed

    Gala-Lopez, Boris; Pepper, Andrew R; Shapiro, A M James

    2013-10-01

    Islet transplantation is today an accepted modality for treating selected patients with frequent hypoglycemic events or severe glycemic lability. Despite tremendous progress in islet isolation, culture, and preservation, clinical use is still restricted to a limited subset, and lifelong immunosuppression is required. Issues surrounding limited islet revascularization and immune destruction remain. One of the major challenges is to prevent alloreactivity and recurrence of autoimmunity against ?-cells. These two hurdles can be effectively reduced by immunosuppressive therapy combining induction and maintenance treatments. The introduction of highly potent and selective biologic agents has significantly reduced the frequency of acute rejection and has prolonged graft survival, while minimizing the complications of this therapeutic scheme. This review will address the most important biological agents used in islet transplantation. We provide a historical perspective of their introduction into clinical practice and their role in current clinical protocols, aiming at improved engraftment efficiency, increased long-term survival, and better overall results of clinical islet transplantation. PMID:23918618

  17. Epidemic Thresholds with External Agents

    E-print Network

    Banerjee, Siddhartha; Shakkottai, Sanjay

    2013-01-01

    We study the effect of external infection sources on phase transitions in epidemic processes. In particular, we consider an epidemic spreading on a network via the SIS/SIR dynamics, which in addition is aided by external agents - sources unconstrained by the graph, but possessing a limited infection rate or virulence. Such a model captures many existing models of externally aided epidemics, and finds use in many settings - epidemiology, marketing and advertising, network robustness, etc. We provide a detailed characterization of the impact of external agents on epidemic thresholds. In particular, for the SIS model, we show that any external infection strategy with constant virulence either fails to significantly affect the lifetime of an epidemic, or at best, sustains the epidemic for a lifetime which is polynomial in the number of nodes. On the other hand, a random external-infection strategy, with rate increasing linearly in the number of infected nodes, succeeds under some conditions to sustain an exponent...

  18. The model coupling toolkit.

    SciTech Connect

    Larson, J. W.; Jacob, R. L.; Foster, I.; Guo, J.

    2001-04-13

    The advent of coupled earth system models has raised an important question in parallel computing: What is the most effective method for coupling many parallel models to form a high-performance coupled modeling system? We present our solution to this problem--The Model Coupling Toolkit (MCT). We explain how our effort to construct the Next-Generation Coupler for NCAR Community Climate System Model motivated us to create this toolkit. We describe in detail the conceptual design of the MCT and explain its usage in constructing parallel coupled models. We present preliminary performance results for the toolkit's parallel data transfer facilities. Finally, we outline an agenda for future development of the MCT.

  19. MULTI-AGENT REINFORCEMENT LEARNING

    E-print Network

    Steels, Luc

    · the reward function of agent k s(t) s(t+1) a1(t) a2(t) ... an(t) r1(t+1) r2(t+1) ... rn(t+1) ...s(t+2) r1(t+2) r2(t+2) ... rn(t+2) a1(t+1) a2(t+1) ... an(t+1) a1(t+2) a2(t+2) ... an(t+2) 9 n S = s1, . . . , s

  20. Antirheumatic agents and leukocyte recruitment

    Microsoft Academic Search

    Michael J Parnham

    1999-01-01

    Most anti-inflammatory agents used in the treatment of joint diseases exert inhibitory effects on leukocyte infiltration. Methotrexate, a disease-modifying drug, and corticosteroids also inhibit leukocyte accumulation during inflammation. However, the mechanisms of action of these different compounds on leukocytes vary and in the case of non-steroidal anti-inflammatory drugs (NSAIDs) the mechanism(s) may be indirect. No current drug for inflammatory or

  1. Intelligent Agent Architectures: Reactive Planning Testbed

    NASA Technical Reports Server (NTRS)

    Rosenschein, Stanley J.; Kahn, Philip

    1993-01-01

    An Integrated Agent Architecture (IAA) is a framework or paradigm for constructing intelligent agents. Intelligent agents are collections of sensors, computers, and effectors that interact with their environments in real time in goal-directed ways. Because of the complexity involved in designing intelligent agents, it has been found useful to approach the construction of agents with some organizing principle, theory, or paradigm that gives shape to the agent's components and structures their relationships. Given the wide variety of approaches being taken in the field, the question naturally arises: Is there a way to compare and evaluate these approaches? The purpose of the present work is to develop common benchmark tasks and evaluation metrics to which intelligent agents, including complex robotic agents, constructed using various architectural approaches can be subjected.

  2. Agent Program Planning Information Master of Memory

    E-print Network

    are increased by factors such as inattention, anxiety, or depression. Living alone, stress, illness, adapting conditions, and exercise for the body and mind. Agent Training Check the Agent Training Calendar

  3. Learning other agents` preferences in multiagent negotiation

    SciTech Connect

    Bui, H.H.; Kieronska, D.; Venkatesh, S. [Curtin Univ. of Technology, Perth, WA (Australia)

    1996-12-31

    In multiagent systems, an agent does not usually have complete information about the preferences and decision making processes of other agents. This might prevent the agents from making coordinated choices, purely due to their ignorance of what others want. This paper describes the integration of a learning module into a communication-intensive negotiating agent architecture. The learning module gives the agents the ability to learn about other agents` preferences via past interactions. Over time, the agents can incrementally update their models of other agents` preferences and use them to make better coordinated decisions. Combining both communication and learning, as two complement knowledge acquisition methods, helps to reduce the amount of communication needed on average, and is justified in situations where communication is computationally costly or simply not desirable (e.g. to preserve the individual privacy).

  4. Intelligent Agents as Cognitive Tools for Education.

    ERIC Educational Resources Information Center

    Baylor, Amy

    1999-01-01

    Examines the educational potential for intelligent agents as cognitive tools. Discusses the role of intelligent agents: managing large amounts of information (information overload), serving as a pedagogical expert, and creating programming environments for the learner. (AEF)

  5. Patterns of intelligent and mobile agents

    Microsoft Academic Search

    Elizabeth A. Kendall; P. V. Murali Krishna; Chirag V. Pathak; C. B. Suresh

    1998-01-01

    1. ABSTRACT Agent systems must have a strong foundation; one approach that has been successfully applied to other kinds of software is patterns. This paper presents a collection of patterns for agents.

  6. Porphyria Cutanea Tarda and Agent Orange

    MedlinePLUS

    ... ZIP code here Porphyria Cutanea Tarda and Agent Orange VA presumes porphyria cutanea tarda (PCT) is related to Veterans' exposure to Agent Orange or other herbicides during military service when the ...

  7. Soft Tissue Sarcomas and Agent Orange

    MedlinePLUS

    ... ZIP code here Soft Tissue Sarcomas and Agent Orange VA presumes some soft tissue sarcomas in Veterans are related to their exposure to Agent Orange or other herbicides during military service. The soft ...

  8. Intraperitoneal contrast agents for computed tomography

    SciTech Connect

    Stork, J.

    1985-08-01

    Intraperitoneal contrast agents have been used to diagnose mass lesions, adhesions, and hernias using conventional radiographic techniques. The use of intraperitoneal contrast agents in conjunction with computed tomography (CT) has been limited and is the subject of this report.

  9. Agent-based Modeling Adam Getchell

    E-print Network

    Tesfatsion, Leigh

    @ucdavis.edu June 9, 2008 Abstract The theory and practice of agent-based modeling is reviewed, and agent simulation, a 3D collision and gravity system, the chaotic Gray Scott diffusion reaction, a sophisticated

  10. Interactions of Fluoroquinolone Antibacterial Agents with Aqueous

    E-print Network

    Huang, Ching-Hua

    , including E. coli and common Aeromonas and Pseudomonas strains (14). Continuous exposure of bacterialInteractions of Fluoroquinolone Antibacterial Agents with Aqueous Chlorine: Reaction Kinetics extensively investigated to elucidate the behavior of fluoroquinolone antibacterial agents during water

  11. Mortality among agricultural extension agents.

    PubMed

    Alavanja, M C; Blair, A; Merkle, S; Teske, J; Eaton, B

    1988-01-01

    The mortality experience of agricultural extension agents in the Cooperative Extension Service (CES) of the U.S. Department of Agriculture who died during the period January 1, 1970-December 31, 1979 (n = 1,495 white males) was evaluated in proportionate-mortality and case-control studies. The proportionate-mortality analysis was used to identify cancers that might be elevated in this occupational group compared with the U.S. white male population. All cancers with a significantly elevated proportionate-mortality ratio were more thoroughly evaluated in the case-control study, where there is presumably less of a selection bias in the comparison. In the case-control study, leukemia demonstrated a statistically significant linear trend with duration of employment as an extension agent. Smaller, but nonsignificant, trends were seen for non-Hodgkin's lymphoma, multiple myeloma, and brain cancer. The odds ratio for Hodgkin's disease and cancers of the colon, prostate, and kidney did not vary with the number of years on the job. These patterns resemble cancer risks seen among farmers, suggesting that agricultural factors may also play a role in the origin of these tumors among extension agents. PMID:3207102

  12. Chemotherapy and Dietary Phytochemical Agents

    PubMed Central

    Sak, Katrin

    2012-01-01

    Chemotherapy has been used for cancer treatment already for almost 70 years by targeting the proliferation potential and metastasising ability of tumour cells. Despite the progress made in the development of potent chemotherapy drugs, their toxicity to normal tissues and adverse side effects in multiple organ systems as well as drug resistance have remained the major obstacles for the successful clinical use. Cytotoxic agents decrease considerably the quality of life of cancer patients manifesting as acute complaints and impacting the life of survivors also for years after the treatment. Toxicity often limits the usefulness of anticancer agents being also the reason why many patients discontinue the treatment. The nutritional approach may be the means of helping to raise cancer therapy to a new level of success as supplementing or supporting the body with natural phytochemicals cannot only reduce adverse side effects but improve also the effectiveness of chemotherapeutics. Various plant-derived compounds improve the efficiency of cytotoxic agents, decrease their resistance, lower and alleviate toxic side effects, reduce the risk of tumour lysis syndrome, and detoxify the body of chemotherapeutics. The personalised approach using various phytochemicals provides thus a new dimension to the standard cancer therapy for improving its outcome in a complex and complementary way. PMID:23320169

  13. Investigating biocomplexity through the agent-based paradigm

    PubMed Central

    Kaul, Himanshu

    2015-01-01

    Capturing the dynamism that pervades biological systems requires a computational approach that can accommodate both the continuous features of the system environment as well as the flexible and heterogeneous nature of component interactions. This presents a serious challenge for the more traditional mathematical approaches that assume component homogeneity to relate system observables using mathematical equations. While the homogeneity condition does not lead to loss of accuracy while simulating various continua, it fails to offer detailed solutions when applied to systems with dynamically interacting heterogeneous components. As the functionality and architecture of most biological systems is a product of multi-faceted individual interactions at the sub-system level, continuum models rarely offer much beyond qualitative similarity. Agent-based modelling is a class of algorithmic computational approaches that rely on interactions between Turing-complete finite-state machines—or agents—to simulate, from the bottom-up, macroscopic properties of a system. In recognizing the heterogeneity condition, they offer suitable ontologies to the system components being modelled, thereby succeeding where their continuum counterparts tend to struggle. Furthermore, being inherently hierarchical, they are quite amenable to coupling with other computational paradigms. The integration of any agent-based framework with continuum models is arguably the most elegant and precise way of representing biological systems. Although in its nascence, agent-based modelling has been utilized to model biological complexity across a broad range of biological scales (from cells to societies). In this article, we explore the reasons that make agent-based modelling the most precise approach to model biological systems that tend to be non-linear and complex. PMID:24227161

  14. Depression: The Differing Narratives of Couples in Couple Therapy

    ERIC Educational Resources Information Center

    Rautiainen, Eija-Liisa; Aaltonen, Jukka

    2010-01-01

    How does the spouse of a person with depression take part in constructing narratives of depression in couple therapy? In this study we examined couples' ways of co-constructing narratives of depression in couple therapy. Three couple therapy processes were chosen for the study, one spouse in each couple having been referred to an outpatient clinic…

  15. Intelligent agents for an artificial market system

    Microsoft Academic Search

    Nikos I. Karacapilidis; Pavlos Moraïtis

    2001-01-01

    This paper describes an agent- based artificial market system whose underlying interaction protocols provide advanced features. Using the system, actors (i. e., customers and merchants) can delegate a variety of tasks to personal intelligent agents that act as their artificial employees. Contrary to other approaches, where a new agent is launched when their associated actors intend to perform a buying

  16. Poaching and Distraction in Asynchronous Agent Activities

    Microsoft Academic Search

    Mike H. Chia; Daniel E. Neiman; Victor R. Lesser

    1998-01-01

    We investigate coordination issues in a distributed jobshop scheduling system in which agents schedule potentially contentious activities asynchronously in parallel. Agents in such a system will in general have a limited view of the global state of resources and must exchange appropriate state information with other agents in order to schedule effectively. However, even given perfect instantaneous knowledge of other

  17. Using Intelligent Agents To Assist Educators.

    ERIC Educational Resources Information Center

    Knode, Steve; Knode, Jon-David W.

    This paper begins with background on intelligent agents (software programs built to perform certain specific tasks for the user). A taxonomy that categorizes intelligent agents by the degree of intelligence embedded in the software is presented. Applications of today's intelligent agents are discussed, including specific examples of the following:…

  18. Beyond Butlers: Intelligent Agents as Mentors.

    ERIC Educational Resources Information Center

    Baylor, Amy

    2000-01-01

    Discusses pedagogical issues for intelligent agents to successfully serve as mentors for educational purposes. Examines broader issues about the nature or persona necessary for an intelligent agent as mentor, incorporating usability and human-computer interaction issues such as the anthropomorphic qualities of the agent and the social relationship…

  19. Randomization for Multi-agent Constraint Optimization

    Microsoft Academic Search

    Quang Huy Nguyen; Boi V. Faltings

    2005-01-01

    Many practical applications require solving an optimization problem for multiple agents where each agent has its own preferences in the problem solution. Examples include resource allocation, scheduling, planning, configuration, voting and many others. Two major challenges when solving such problems are the complexity of finding optimal solution and the incentive compatibility for participating agents. First, these problems are often NP-hard

  20. Diplomarbeit Modeling Agent Interaction Protocols with

    E-print Network

    Hamburg.Universit�¤t

    are forming a society of agents called a multi-agent system. As a reference architecture Mulan, a Petri net to certain elements and constellations of elements, is to achieve a modeling technique for Mulan-based agent interaction protocols that is consistent and helps the developers in the development process of Mulan

  1. Letizia: An Agent That Assists Web Browsing

    Microsoft Academic Search

    Henry Lieberman

    1995-01-01

    Letizia is a user interface agent that assists a user browsing the World Wide Web. As the user operates a conventional Web browser such as Netscape, the agent tracks user behavior and attempts to anticipate items of interest by doing concurrent, autonomous exploration of links from the user's current position. The agent automates a browsing strategy consisting of a best-first

  2. Towards Socially Intelligent Agent-Building

    Microsoft Academic Search

    Phoebe Sengers

    1997-01-01

    If agents are going to interact socially with humans, they can not be simply correct; they must also be comprehensible. This article describes my thesis work-in-progress, which fo- cuses on designing agents that can effectively expressto users the goals and activities their designer has chosen for them. In order to build agents that express clearly the intentions of their designers,

  3. Distributed Collaborations using Network Mobile Agents ?

    E-print Network

    Tripathi, Anand

    Distributed Collaborations using Network Mobile Agents ? Anand Tripathi, Tanvir Ahmed, Vineet Science University of Minnesota, Minneapolis MN 55455 Abstract. This paper describes a mobile agent the Ajanta mobile agent system. 1 Introduction The focus of this paper is on building distributed

  4. A Performance Model for Mobile Agent Systems

    Microsoft Academic Search

    Markus Straßer; Markus Schwehm

    1997-01-01

    A performance model for the interaction of agents in mobile agent systems is presented. Two inter- action models, namely the remote procedure call and the agent migration are considered. Performance mod- els for a single interaction are introduced, which are then used to derive a performance model for a sequence of interactions. This performance model can be used to evaluate

  5. Mobile Agents: An Introduction Gian Pietro Picco

    E-print Network

    Picco, Gian Pietro

    1 Mobile Agents: An Introduction Gian Pietro Picco Dipartimento di Elettronica e Informazione, Politecnico di Milano, Italy picco@elet.polimi.it Abstract| Mobile agents are enjoying a lot of popularity to the related research #12;eld by showing evidence of the bene#12;ts mobile agents can potentially achieve

  6. TransactionBased Coordination of Software Agents ?

    E-print Network

    Pitoura, Evaggelia

    methods for enforcing them in the context of mobile object systems. 1 Introduction Mobile agents, this new model of distributed computing has attracted much attention. The mobile agent model provides the interchanged messages. In addition, mobile agents support intermittent connectivity, slow networks, and light

  7. Mobile Agent Security Issues Ramya Prabhu

    E-print Network

    1 Mobile Agent Security Issues Ramya Prabhu Department Of Computer Science Oregon State University prabhu@cs.orst.edu Abstract: Mobile Agent technology offers a new computing paradigm in which a program the strengths and weaknesses of the techniques involved. #12;2 Security Threats: Threats to mobile agents

  8. SMASH: Modular Security for Mobile Agents

    E-print Network

    Julien, Christine

    SMASH: Modular Security for Mobile Agents TR-UTEDGE-2006-007 Adam Pridgen Christine Julien © Copyright 2006 The University of Texas at Austin #12;SMASH: Modular Security for Mobile Agents Adam Pridgen and Computer Engineering The University of Texas at Austin {atpridgen, c.julien}@mail.utexas.edu Mobile agent

  9. Mobile Agent Abstractions: Formulation and Implementation

    E-print Network

    Joshi, Rushikesh K.

    Mobile Agent Abstractions: Formulation and Implementation Rushikesh K. Joshi, Harikrishnan C. R., M, Mumbai-400076, India. Email := {rkj, harikcr, ansari}@cse.iitb.ac.in Abstract We present mobile agent, and mobility and disconnection of host machines. Combining these primitives leads to different agent

  10. Measurement and Evaluation of Embodied Conversational Agents

    Microsoft Academic Search

    Gregory A. Sanders; Jean Scholtz

    conversational agents are both types of conversational systems, and explain that embodied conversation is nevertheless different from speech-only interaction. Third, we then present a detailed formative evaluation that we proposed for a speech-based agent interface: the DARPA Communicator program. Fourth, we correspondingly then discuss the ways that the process of measurement and evaluation of embodied conversational agents is very much

  11. Vivid Agents: Theory, Architecture, and Applications

    Microsoft Academic Search

    Michael Schroeder; Gerd Wagner

    2000-01-01

    Vivid agents (48) are software-controlled systems whose state comprises the mental components of knowledge, perceptions, tasks, and intentions, and whose behaviour is represented by means of action and reaction rules .W e present an execution model for vivid agents which is based on an archi- tecture for concurrent action and planning (CAP). We evaluate the concept of vivid agents and

  12. Agent-mediated electronic commerce: a survey

    Microsoft Academic Search

    ROBERT H. GUTTMAN; ALEXANDROS G. MOUKAS; PATTIE MAES

    1998-01-01

    Software agents help automate a variety of tasks including those involved in buying and selling products over the Internet. This paper surveys several of these agent- mediated electronic commerce systems by describing their roles in the context of a Consumer Buying Behavior (CBB) model. The CBB model we present augments traditional marketing models with concepts from Software Agents research to

  13. Laboratory Analysis of Toothpastes Containing Anticaries Agents

    Microsoft Academic Search

    JOHN J. HEFFERREN

    are described and discussed. Toothpaste formulations containing anticaries agents should have all the characteristics, such as cleansing action, feel, and flavor, desired in a toothpaste which has good consumer acceptability. In ad- dition, the abrasive and other agents present in the formulation and the tube must be compatible with the anticaries agent. In order to achieve these aims, knowledge of

  14. STUDIES OF WATERBORNE AGENTS OF VIRAL GASTROENTERITIS

    EPA Science Inventory

    The etiologic agent of a large outbreak of waterborne viral gastroenteritis was detected employing immune electron microscopy (IEM) and a newly developed solid phase radioimmunoassay (RIA). This agent, referred to as the Snow Mountain Agent (SMA), is 27-32 nm. in diameter, has cu...

  15. ACRE: Agent Conversation Reasoning Engine David Lillis

    E-print Network

    Hammerton, James

    , communication by means of Agent Communication Languages has a key role to play in the co-operation, co programming languages. ACRE (Agent Communication Reasoning Engine) aims to complement the existing logical interaction protocols in order to facilitate conversations between agents. This paper outlines the aims

  16. Hydroxypyridonate chelating agents and synthesis thereof

    DOEpatents

    Raymond, K.N.; Scarrow, R.C.; White, D.L.

    1985-11-12

    Chelating agents having 1-hydroxy-2-pyridinone (HOPO) and related moieties incorporated within their structures, including polydentate HOPO-substituted polyamines such as spermidine and spermine, and HOPO-substituted desferrioxamine. The chelating agents are useful in selectively removing certain cations from solution, and are particularly useful as ferric ion and actinide chelators. Novel syntheses of the chelating agents are provided. 4 tabs.

  17. Agent Autonomy: Social Integrity and Social Independence

    Microsoft Academic Search

    Marcus J. Huber

    2007-01-01

    As interactions between agents become more common, it will become very important to be able to characterize and perhaps even guarantee an agent's level of autonomy. We will both want agents to perform tasks on their own while at the same time both remaining controllable by ourselves and secure from control and manipulation by others. Most intuitions of autonomy seem

  18. Agent-based modeling of complex infrastructures

    SciTech Connect

    North, M. J.

    2001-06-01

    Complex Adaptive Systems (CAS) can be applied to investigate complex infrastructures and infrastructure interdependencies. The CAS model agents within the Spot Market Agent Research Tool (SMART) and Flexible Agent Simulation Toolkit (FAST) allow investigation of the electric power infrastructure, the natural gas infrastructure and their interdependencies.

  19. Learning by Knowledge Exchange in Logical Agents

    Microsoft Academic Search

    Stefania Costantini; Arianna Tocchio

    2005-01-01

    In this paper we introduce a form of cooperation among agents based on exchanging sets of rules. In principle, the approach extends to agent societies a feature which is proper of human societies, i.e., the cultural transmission of abilities. However, acquiring knowledge from untrustworthy agents should be avoided, and the new knowledge should be evaluated according to its usefulness. After

  20. Degree of Satisfaction in Agent Negotiation

    Microsoft Academic Search

    Kuo-ming Chao; Muhammad Younas; Rachid Anane; Chen-fang Tsai; Von-wun Soo

    2003-01-01

    Agent negotiation over multiple issues is often seen as the process of searching for a solution in a complex and large space. Depending on the negotiation mechanism such search space can be dynamic wherein agents may be cooperative or non-cooperative. In a realistic negotiation, agents are unwilling to reveal their utility functions to their opponents or collaborators. These important characteristics

  1. 46 CFR 153.1106 - Cleaning agents.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 5 2010-10-01 2010-10-01 false Cleaning agents. 153.1106 Section 153.1106 Shipping...and D Cargo and Nls Residue § 153.1106 Cleaning agents. No tank cleaning agent other than water or steam may be used to...

  2. Infants Attribute to Agents Goals and Dispositions

    ERIC Educational Resources Information Center

    Luo, Yuyan; Choi, You-jung

    2012-01-01

    This commentary article is to be published alongside: Hernik, M., & Southgate, V. (2012). What do infants know about agents' goals? The authors see this issue consisting of two closely related questions. First, what is an agent to infants? Second, how do infants attribute goals to agents? Hernik and Southgage (H&S) focused on the second question.…

  3. THREE-DIMENSIONAL MODELING OF THE DYNAMICS OF THERAPEUTIC ULTRASOUND CONTRAST AGENTS

    PubMed Central

    Hsiao, Chao-Tsung; Lu, Xiaozhen; Chahine, Georges

    2010-01-01

    A 3-D thick-shell contrast agent dynamics model was developed by coupling a finite volume Navier-Stokes solver and a potential boundary element method flow solver to simulate the dynamics of thick-shelled contrast agents subjected to pressure waves. The 3-D model was validated using a spherical thick-shell model validated by experimental observations. We then used this model to study shell break-up during nonspherical deformations resulting from multiple contrast agent interaction or the presence of a nearby solid wall. Our simulations indicate that the thick viscous shell resists the contrast agent from forming a re-entrant jet, as normally observed for an air bubble oscillating near a solid wall. Instead, the shell thickness varies significantly from location to location during the dynamics, and this could lead to shell break-up caused by local shell thinning and stretching. PMID:20950929

  4. Mobile agent location in distributed environments

    NASA Astrophysics Data System (ADS)

    Fountoukis, S. G.; Argyropoulos, I. P.

    2012-12-01

    An agent is a small program acting on behalf of a user or an application which plays the role of a user. Artificial intelligence can be encapsulated in agents so that they can be capable of both behaving autonomously and showing an elementary decision ability regarding movement and some specific actions. Therefore they are often called autonomous mobile agents. In a distributed system, they can move themselves from one processing node to another through the interconnecting network infrastructure. Their purpose is to collect useful information and to carry it back to their user. Also, agents are used to start, monitor and stop processes running on the individual interconnected processing nodes of computer cluster systems. An agent has a unique id to discriminate itself from other agents and a current position. The position can be expressed as the address of the processing node which currently hosts the agent. Very often, it is necessary for a user, a processing node or another agent to know the current position of an agent in a distributed system. Several procedures and algorithms have been proposed for the purpose of position location of mobile agents. The most basic of all employs a fixed computing node, which acts as agent position repository, receiving messages from all the moving agents and keeping records of their current positions. The fixed node, responds to position queries and informs users, other nodes and other agents about the position of an agent. Herein, a model is proposed that considers pairs and triples of agents instead of single ones. A location method, which is investigated in this paper, attempts to exploit this model.

  5. Multifield coupled quintessence

    NASA Astrophysics Data System (ADS)

    Amendola, Luca; Barreiro, Tiago; Nunes, Nelson J.

    2014-10-01

    We study models of quintessence consisting of a number of scalar fields coupled to several dark matter components. In the case of exponential potentials the scaling solutions can be described in terms of a single field. The corresponding effective logarithmic slope and effective coupling can be written in a simple form in terms of the individual slopes and couplings of the original fields. We also investigate solutions where the scalar potential is negligible, in particular those leading to transient matter dominated solutions. Finally, we compute the evolution equations for the linear perturbations which will allow these models to be tested against current and future observational data.

  6. AgentSys: a mobile agent system for digital media access and interaction on an Internet

    Microsoft Academic Search

    Benjamin Falchuk; Ahmed Karmouch

    1997-01-01

    Mobile agents have emerged as a new computing alternative and are proving to be more flexible and dynamic than the classical client-server model. In the mobile agent model the program is sent to and runs on the remote site, thereby operating closer to and more interactively with the remote document resource. AgentSys is a mobile agent system that implements the

  7. Financial Advisor Agent in a Multi-Agent Financial Trading System

    Microsoft Academic Search

    Vikrant Pandey; Wee-Keong Ng; Ee-peng Lim

    2000-01-01

    Agent based technology has gained a lot of importance over recent years as is evident from the rapidly growing number of Web sites using agents. In the future, the level of automation would be such that work delegated to an agent could be accomplished by collaborating with other agents. Conventional financial trading systems alert the user based on the analysis

  8. A Multi-Agent Model for Emotion Contagion Spirals Integrated within a Supporting Ambient Agent Model

    E-print Network

    Treur, Jan

    1 A Multi-Agent Model for Emotion Contagion Spirals Integrated within a Supporting Ambient Agent emotion contagion spirals within groups. The computational multi-agent model is integrated within an intelligent ambient agent to monitor and predict group emotion levels over time and propose group support

  9. Macro-level Attention to Mobile Agent Security: Introducing the Mobile Agent Secure Hub Infrastructure Concept

    E-print Network

    Roth, Volker

    Macro-level Attention to Mobile Agent Security: Introducing the Mobile Agent Secure Hub}@isrc.qut.edu.au, vroth@igd.fhg.de Abstract. The autonomous capabilities of Internet mobile agents are one of their great an infrastructural strategy that allows mobile agent users to delegate responsibility to a trusted third party

  10. MDE and Mobile agents: another reflection on the agent migration Tahar GHERBI

    E-print Network

    Paris-Sud XI, Université de

    MDE and Mobile agents: another reflection on the agent migration Tahar GHERBI Computer science code. Mobile agents are a very interesting technology to develop applications for mobile and distributed environments. A mobile agent is essentially a computer program that acts autonomously on behalf

  11. Towards an MDE Methodology to Develop Multi-Agents Systems Including Mobile Agents

    E-print Network

    Boyer, Edmond

    Towards an MDE Methodology to Develop Multi-Agents Systems Including Mobile Agents Tahar GHERBI1.borne}@univ-ubs.fr, meslati_djamel@yahoo.com Keywords: Mobile Agent, MAS, MaSE, m-GAIA, AALAADIN, PIM, MDE. Abstract of mobile-agents systems. For this reason, we have presented in a previous work, our meta-model to design

  12. Motivation and Requirements for the AgentSpace: A Framework for Developing Agent Programming Systems

    E-print Network

    da Silva, Alberto Rodrigues

    of all its potential when there are multiple agents co-existing in what we will call an agent community systems that can support this kind of application, as well as to design other agent-based applications System design support build Figure 1. From Framework to Agent-based Applications The motivation

  13. Modelling Agent-Environment Interaction in Multi-Agent Simulations with Affordances

    E-print Network

    Pearce, Adrian

    approaches to the design of the interaction mechanism between agents and the environments in which is on the interaction between the agent and the environment that has the potential for more situated agent behaviour in a manner which allows for flexibility in the design of the multi-agent simulation. The model captures

  14. Agent-based health care management An Agent-based Approach to Health Care Management

    E-print Network

    Mascardi, Viviana

    Agent-based health care management 1 An Agent-based Approach to Health Care Management Jun Huang1, London WC2A 3PX, UK. Abbreviated title: Agent-based health care management Complete Mailing Address. London E1 4NS UK #12;Agent-based health care management 2 Abstract The provision of medical care

  15. Anchor Toolkit - a secure mobile agent system

    SciTech Connect

    Mudumbai, Srilekha S.; Johnston, William; Essiari, Abdelilah

    1999-05-19

    Mobile agent technology facilitates intelligent operation insoftware systems with less human interaction. Major challenge todeployment of mobile agents include secure transmission of agents andpreventing unauthorized access to resources between interacting systems,as either hosts, or agents, or both can act maliciously. The Anchortoolkit, designed by LBNL, handles the transmission and secure managementof mobile agents in a heterogeneous distributed computing environment. Itprovides users with the option of incorporating their security managers.This paper concentrates on the architecture, features, access control anddeployment of Anchor toolkit. Application of this toolkit in a securedistributed CVS environment is discussed as a case study.

  16. Coupling in the Tevatron

    SciTech Connect

    Gelfand, N.M.

    1994-12-01

    The performance of the Fermilab Tevatron Collider at the commencement of run Ib was far below expectations. After a frustrating period of several months, a low-{beta} quad downstream of the interaction point at B0 was found to be rolled. This rolled quadrupole coupled the horizontal and vertical motion of the Tevatron beams. It also made matching the beam from the Main Ring to the Tevatron impossible, resulting in emittance blow up on injection. The net result of the roll was a significant reduction in the Tevatron luminosity. When the roll in the quadrupole was corrected the performance of the Tevatron improved dramatically. This note will discuss the experimental data indicating the presence of coupling and subsequent calculations which show how coupling an affect the luminosity. It is not intended to exhaust a discussion of coupling, which hopefully will be understood well enough to be discussed in a subsequent note.

  17. Do Couples Assortatively Mate? 

    E-print Network

    Mistry, Navin

    2010-06-30

    This study investigated the role of intelligence, conservatism, personal values, and Openness in assortative mating. A sample of 32 couples was given questionnaires, which measured self-rated intelligence and partner-rated Openness, conservatism...

  18. Coherently coupled exciton lasing

    E-print Network

    Bulovic, Vladimir

    Lowest reported threshold organic semiconductor VCSEL (4.9 muJ/cm[superscript 2]) is achieved when excitons coherently couple, upon sub-picosecond non-resonant optical excitation. Temperature dependence of lambda/2 n device, ...

  19. Honey - A Novel Antidiabetic Agent

    PubMed Central

    Erejuwa, Omotayo O.; Sulaiman, Siti A.; Wahab, Mohd S. Ab

    2012-01-01

    Diabetes mellitus remains a burden worldwide in spite of the availability of numerous antidiabetic drugs. Honey is a natural substance produced by bees from nectar. Several evidence-based health benefits have been ascribed to honey in the recent years. In this review article, we highlight findings which demonstrate the beneficial or potential effects of honey in the gastrointestinal tract (GIT), on the gut microbiota, in the liver, in the pancreas and how these effects could improve glycemic control and metabolic derangements. In healthy subjects or patients with impaired glucose tolerance or diabetes mellitus, various studies revealed that honey reduced blood glucose or was more tolerable than most common sugars or sweeteners. Pre-clinical studies provided more convincing evidence in support of honey as a potential antidiabetic agent than clinical studies did. The not-too-impressive clinical data could mainly be attributed to poor study designs or due to the fact that the clinical studies were preliminary. Based on the key constituents of honey, the possible mechanisms of action of antidiabetic effect of honey are proposed. The paper also highlights the potential impacts and future perspectives on the use of honey as an antidiabetic agent. It makes recommendations for further clinical studies on the potential antidiabetic effect of honey. This review provides insight on the potential use of honey, especially as a complementary agent, in the management of diabetes mellitus. Hence, it is very important to have well-designed, randomized controlled clinical trials that investigate the reproducibility (or otherwise) of these experimental data in diabetic human subjects. PMID:22811614

  20. Dynamics of coupled human-landscape systems

    NASA Astrophysics Data System (ADS)

    Werner, B. T.; McNamara, D. E.

    2007-11-01

    A preliminary dynamical analysis of landscapes and humans as hierarchical complex systems suggests that strong coupling between the two that spreads to become regionally or globally pervasive should be focused at multi-year to decadal time scales. At these scales, landscape dynamics is dominated by water, sediment and biological routing mediated by fluvial, oceanic, atmospheric processes and human dynamics is dominated by simplifying, profit-maximizing market forces and political action based on projection of economic effect. Also at these scales, landscapes impact humans through patterns of natural disasters and trends such as sea level rise; humans impact landscapes by the effect of economic activity and changes meant to mitigate natural disasters and longer term trends. Based on this analysis, human-landscape coupled systems can be modeled using heterogeneous agents employing prediction models to determine actions to represent the nonlinear behavior of economic and political systems and rule-based routing algorithms to represent landscape processes. A cellular model for the development of New Orleans illustrates this approach, with routing algorithms for river and hurricane-storm surge determining flood extent, five markets (home, labor, hotel, tourism and port services) connecting seven types of economic agents (home buyers/laborers, home developers, hotel owners/ employers, hotel developers, tourists, port services developer and port services owners/employers), building of levees or a river spillway by political agents and damage to homes, hotels or port services within cells determined by the passage or depth of flood waters. The model reproduces historical aspects of New Orleans economic development and levee construction and the filtering of frequent small-scale floods at the expense of large disasters.

  1. EVOLUTION OF SOFTWARE AGENT-BASED E-COMMERCE: BASED ON AGENT COMPETITION MODEL

    Microsoft Academic Search

    Dongsu Jin

    Many changes have been expected to occur in existing e-commerce paradigm by the emergence of agent-based e-business. In this paper, to find these changes we establish agent-based e- commerce framework consisting of five actors, which are agent-based e-business, existing e- business, user, other agent and external entities. We also propose a simple agent competition model, which can be used to

  2. Well servicing agents and processes

    SciTech Connect

    Messenger, J.U.

    1986-04-01

    This patent describes a well servicing agents and processes contained in the servicing of a well penetrating a subterranean formation in the earth's crust wherein a well servicing liquid is circulated into the well in contact with the formation. The improvement consists of incorporating within the servicing liquid a particulate material formed of a thermoplastic polymer in a flexible, elongated, laminar form in which the length of the laminar particles is substantially greater than their width to provide a ratio of length to width of at least 6. The width of the laminar particles is substantially greater than their thickness to provide a ratio of width to thickness of at least 20.

  3. Anabolic Agents and Bone Quality

    Microsoft Academic Search

    Tarek Sibai; Elise F. Morgan; Thomas A. Einhorn

    Background  The definition of bone quality is evolving particularly from the perspective of anabolic agents that can enhance not only\\u000a bone mineral density but also bone microarchitecture, composition, morphology, amount of microdamage, and remodeling dynamics.\\u000a \\u000a \\u000a \\u000a \\u000a Questions\\/purposes  This review summarizes the molecular pathways and physiologic effects of current and potential anabolic drugs.\\u000a \\u000a \\u000a \\u000a Methods  From a MEDLINE search (1996–2010), articles were identified by the search

  4. Anticancer agents from marine sponges.

    PubMed

    Ye, Jianjun; Zhou, Feng; Al-Kareef, Ammar M Q; Wang, Hong

    2015-01-01

    Marine sponges are currently one of the richest sources of anticancer active compounds found in the marine ecosystems. More than 5300 different known metabolites are from sponges and their associated microorganisms. To survive in the complicated marine environment, most of the sponge species have evolved chemical means to defend against predation. Such chemical adaptation produces many biologically active secondary metabolites including anticancer agents. This review highlights novel secondary metabolites in sponges which inhibited diverse cancer species in the recent 5 years. These natural products of marine sponges are categorized based on various chemical characteristics. PMID:25402340

  5. Diarrhea caused by circulating agents.

    PubMed

    Fabian, Elisabeth; Kump, Patrizia; Krejs, Guenter J

    2012-09-01

    Circulating agents cause intestinal secretion or changes in motility with decreased intestinal transit time, resulting in secretory-type diarrhea. Secretory diarrhea as opposed to osmotic diarrhea is characterized by large-volume, watery stools, often more than 1 L per day; by persistence of diarrhea when patients fast; and by the fact that on analysis of stool-water, measured osmolarity is identical to that calculated from the electrolytes present. Although sodium plays the main role in water and electrolyte absorption, chloride is the major ion involved in secretion. PMID:22917166

  6. Method For Detecting Biological Agents

    DOEpatents

    Chen, Liaohai (Los Alamos, NM); McBranch, Duncan W. (Santa Fe, NM); Wang, Hsing-Lin (Los Alamos, NM); Whitten, David G. (Santa Fe, NM)

    2005-12-27

    A sensor is provided including a polymer capable of having an alterable measurable property from the group of luminescence and electrical conductivity, the polymer having an intermediate combination of a recognition element, a tethering element and a property-altering element bound thereto and capable of altering the measurable property, the intermediate combination adapted for subsequent separation from the polymer upon exposure to an agent having an affinity for binding to the recognition element whereupon the separation of the intermediate combination from the polymer results in a detectable change in the alterable measurable property, and, detecting said detectable change in the alterable measurable property.

  7. Analysis of commercial plastination agents.

    PubMed

    Chaynes, P; Mingotaud, A-F

    2004-06-01

    S3, S6 and S10 are the most commonly used agents for tissue plastination. Surprisingly, their chemical structures are not known. We therefore decided to fully characterize these products by standard analytical methods: multinucleus magnetic resonance, infrared spectroscopy and size exclusion chromatography. These experiments have shown that Biodur S10 is a polydimethylsiloxane with a molecular weight of 27,200 and silanol functionalities, Biodur S6 is tetraethoxysilane, and Biodur S3 is a mixture the main component of which is dibutyltindilaurate. PMID:15098138

  8. Coupled transverse motion

    SciTech Connect

    Teng, L.C.

    1989-01-01

    The magnetic field in an accelerator or a storage ring is usually so designed that the horizontal (x) and the vertical (y) motions of an ion are uncoupled. However, because of imperfections in construction and alignment, some small coupling is unavoidable. In this lecture, we discuss in a general way what is known about the behaviors of coupled motions in two degrees-of-freedom. 11 refs., 6 figs.

  9. Negative-coupling resonances in pump-coupled lasers

    E-print Network

    T. W. Carr; M. L. Taylor; I. B. Schwartz

    2005-10-28

    We consider coupled lasers, where the intensity deviations from the steady state, modulate the pump of the other lasers. Most of our results are for two lasers where the coupling constants are of opposite sign. This leads to a Hopf bifurcation to periodic output for weak coupling. As the magnitude of the coupling constants is increased (negatively) we observe novel amplitude effects such as a weak coupling resonance peak and, strong coupling subharmonic resonances and chaos. In the weak coupling regime the output is predicted by a set of slow evolution amplitude equations. Pulsating solutions in the strong coupling limit are described by discrete map derived from the original model.

  10. Recent developments in antiviral agents against enterovirus 71 infection

    PubMed Central

    2014-01-01

    Enterovirus 71 (EV-71) is the main etiological agent of hand, foot and mouth disease (HFMD). Recent EV-71 outbreaks in Asia-Pacific were not limited to mild HFMD, but were associated with severe neurological complications such as aseptic meningitis and brainstem encephalitis, which may lead to cardiopulmonary failure and death. The absence of licensed therapeutics for clinical use has intensified research into anti-EV-71 development. This review highlights the potential antiviral agents targeting EV-71 attachment, entry, uncoating, translation, polyprotein processing, virus-induced formation of membranous RNA replication complexes, and RNA-dependent RNA polymerase. The strategies for antiviral development include target-based synthetic compounds, anti-rhinovirus and poliovirus libraries screening, and natural compound libraries screening. Growing knowledge of the EV-71 life cycle will lead to successful development of antivirals. The continued effort to develop antiviral agents for treatment is crucial in the absence of a vaccine. The coupling of antivirals with an effective vaccine will accelerate eradication of the disease. PMID:24521134

  11. An agent-based microsimulation of critical infrastructure systems

    SciTech Connect

    BARTON,DIANNE C.; STAMBER,KEVIN L.

    2000-03-29

    US infrastructures provide essential services that support the economic prosperity and quality of life. Today, the latest threat to these infrastructures is the increasing complexity and interconnectedness of the system. On balance, added connectivity will improve economic efficiency; however, increased coupling could also result in situations where a disturbance in an isolated infrastructure unexpectedly cascades across diverse infrastructures. An understanding of the behavior of complex systems can be critical to understanding and predicting infrastructure responses to unexpected perturbation. Sandia National Laboratories has developed an agent-based model of critical US infrastructures using time-dependent Monte Carlo methods and a genetic algorithm learning classifier system to control decision making. The model is currently under development and contains agents that represent the several areas within the interconnected infrastructures, including electric power and fuel supply. Previous work shows that agent-based simulations models have the potential to improve the accuracy of complex system forecasting and to provide new insights into the factors that are the primary drivers of emergent behaviors in interdependent systems. Simulation results can be examined both computationally and analytically, offering new ways of theorizing about the impact of perturbations to an infrastructure network.

  12. Multi-Agent Information Classification Using Dynamic Acquaintance Lists.

    ERIC Educational Resources Information Center

    Mukhopadhyay, Snehasis; Peng, Shengquan; Raje, Rajeev; Palakal, Mathew; Mostafa, Javed

    2003-01-01

    Discussion of automated information services focuses on information classification and collaborative agents, i.e. intelligent computer programs. Highlights include multi-agent systems; distributed artificial intelligence; thesauri; document representation and classification; agent modeling; acquaintances, or remote agents discovered through…

  13. Evolving object oriented agent programs in Robocup Domain

    E-print Network

    Fernandez, Thomas

    , Design, Languages Keywords Genetic Algorithms, Genetic Programming, Agent programs. 1. INTRODUCTIONEvolving object oriented agent programs in Robocup Domain David E. Suárez Student Universidad generation of agents under the Object Oriented Paradigm. To generate the agent programs code, we evolve

  14. Metamaterial enchanced coupling

    NASA Astrophysics Data System (ADS)

    Strikwerda, Andrew C.

    In the past decade interest in metamaterials has risen dramatically. This is due, in large part, to metamaterials' ability to exhibit electromagnetic behavior not normally found in nature. This is because these artificial structures display a strong electromagnetic response as a result of their geometry, as opposed to their chemistry, and that response typically dominates that of the substrate they are placed on. As a result, metamaterials can couple free space radiation in previously unheard of ways, and in this thesis I examine several of these coupling mechanisms. After an appropriate discussion of theoretical and experimental tools required for metamaterial study, the thesis turns to the metamaterial substrate and explores the coupling effects of the metamaterial and the substrate itself. We discuss the theory and experimentally demonstrate that the metamaterial and substrate composite can couple free space radiation for use in enhanced dielectric sensing, perfect absorption, and even mechanical deflection for electromagnetic detection. In addition to coupling with dielectric materials, the near field response of a metamaterial can also couple with another metamaterial. Subsequently, this thesis investigates the coupling between a pair of identical split ring resonators, and develops a general framework for evaluating the mode hybridization that results from their near field interaction. In fact, we find that the near field coupling is extremely sensitive to the relative orientation of the two metamaterials, and results in mode splitting between the two resonators. By manipulating their lateral displacement, the coupling, and the mode splitting, can be altered. In this way, an unprecedented modulation of the metamaterial response is demonstrated. Finally, we turn our attention to the effects that metamaterial behavior has on the far field response. Specifically, we focus on the symmetry, or lack thereof, of the unit cell and show that it manifests itself as a birefringence in the far field. As a result, metamaterials can be used as wave retarders to couple between polarization states. Herein we analyze this behavior and experimentally demonstrate functioning metamaterial based terahertz waveplates that are highly efficient at a previously unachieved sub wavelength size.

  15. Nanoparticle-based theranostic agents

    PubMed Central

    Xie, Jin; Lee, Seulki; Chen, Xiaoyuan

    2010-01-01

    Theranostic nanomedicine is emerging as a promising therapeutic paradigm. It takes advantage of the high capacity of nanoplatforms to ferry cargo and loads onto them both imaging and therapeutic functions. The resulting nanosystems, capable of diagnosis, drug delivery and monitoring of therapeutic response, are expected to play a significant role in the dawning era of personalized medicine, and much research effort has been devoted toward that goal. A convenience in constructing such function-integrated agents is that many nanoplatforms are already, themselves, imaging agents. Their well developed surface chemistry makes it easy to load them with pharmaceutics and promote them to be theranostic nanosystems. Iron oxide nanoparticles, quantum dots, carbon nanotubes, gold nanoparticles and silica nanoparticles, have been previously well investigated in the imaging setting and are candidate nanoplatforms for building up nanoparticle-based theranostics. In the current article, we will outline the progress along this line, organized by the category of the core materials. We will focus on construction strategies and will discuss the challenges and opportunities associated with this emerging technology. PMID:20691229

  16. A Review of Luting Agents

    PubMed Central

    Pameijer, Cornelis H.

    2012-01-01

    Due to the availability of a large number of luting agents (dental cements) proper selection can be a daunting task and is usually based on a practitioner's reliance on experience and preference and less on in depth knowledge of materials that are used for the restoration and luting agent properties. This review aims at presenting an overview of current cements and discusses physical properties, biocompatibility and other properties that make a particular cement the preferred choice depending on the clinical indication. Tables are provided that outline the different properties of the generic classification of cements. It should be noted that no recommendations are made to use a particular commercial cement for a hypothetical clinical situation. The choice is solely the responsibility of the practitioner. The appendix is intended as a guide for the practitioner towards a recommended choice under commonly encountered clinical scenarios. Again, no commercial brands are recommended although the author recognizes that some have better properties than others. Please note that this flowchart strictly presents the author's opinion and is based on research, clinical experience and the literature. PMID:22505909

  17. Ruthenium complexes as antimicrobial agents.

    PubMed

    Li, Fangfei; Collins, J Grant; Keene, F Richard

    2015-04-10

    One of the major advances in medical science has been the development of antimicrobials; however, a consequence of their widespread use has been the emergence of drug-resistant populations of microorganisms. There is clearly a need for the development of new antimicrobials - but more importantly, there is the need for the development of new classes of antimicrobials, rather than drugs based upon analogues of known scaffolds. Due to the success of the platinum anticancer agents, there has been considerable interest in the development of therapeutic agents based upon other transition metals - and in particular ruthenium(ii/iii) complexes, due to their well known interaction with DNA. There have been many studies of the anticancer properties and cellular localisation of a range of ruthenium complexes in eukaryotic cells over the last decade. However, only very recently has there been significant interest in their antimicrobial properties. This review highlights the types of ruthenium complexes that have exhibited significant antimicrobial activity and discusses the relationship between chemical structure and biological processing - including site(s) of intracellular accumulation - of the ruthenium complexes in both bacterial and eukaryotic cells. PMID:25724019

  18. Surfactants as blackbird stressing agents

    USGS Publications Warehouse

    Lefebvre, P.W.; Seubert, J.L.

    1970-01-01

    Applications of wetting-agent solutions produce mortality in birds. The exact cause of death is undetermined but it is believed that destruction of the insulating qualities of the plumage permits ambient cold temperatures and evaporation to lower the body temperature to a lethal level. The original concept of using these materials as bird-control tools was developed in 1958 at the Patuxent Wildlife Research Center, Bureau of Sport Fisheries and Wildlife Laurel, Maryland. Early field trials by personnel of the Division of Wildlife Services and the Denver Wildlife Research Center indicated that ground-application techniques had promise but limitations of the equipment precluded successful large-scale roost treatments. In 1966, Patuxent Center personnel began using tanker-type aircraft to evaluate high-volume aerial applications of wetting agents. The success of these tests led to the use of small aircraft to make low-volume, high-concentration aerial applications just prior to expected rainfall. Recent trials of the low-volume method show that, with some limitations, it is effective, inexpensive, and safe to the environment. Current research emphasizes the screening of new candidate materials for efficacy, biodegradability, and toxicity to plants and non-target animals, as well as basic investigations of the avian physiological mechanisms involved. Field trials to develop more effective application techniques will continue.

  19. Control Architecture for Robotic Agent Command and Sensing

    NASA Technical Reports Server (NTRS)

    Huntsberger, Terrance; Aghazarian, Hrand; Estlin, Tara; Gaines, Daniel

    2008-01-01

    Control Architecture for Robotic Agent Command and Sensing (CARACaS) is a recent product of a continuing effort to develop architectures for controlling either a single autonomous robotic vehicle or multiple cooperating but otherwise autonomous robotic vehicles. CARACaS is potentially applicable to diverse robotic systems that could include aircraft, spacecraft, ground vehicles, surface water vessels, and/or underwater vessels. CARACaS incudes an integral combination of three coupled agents: a dynamic planning engine, a behavior engine, and a perception engine. The perception and dynamic planning en - gines are also coupled with a memory in the form of a world model. CARACaS is intended to satisfy the need for two major capabilities essential for proper functioning of an autonomous robotic system: a capability for deterministic reaction to unanticipated occurrences and a capability for re-planning in the face of changing goals, conditions, or resources. The behavior engine incorporates the multi-agent control architecture, called CAMPOUT, described in An Architecture for Controlling Multiple Robots (NPO-30345), NASA Tech Briefs, Vol. 28, No. 11 (November 2004), page 65. CAMPOUT is used to develop behavior-composition and -coordination mechanisms. Real-time process algebra operators are used to compose a behavior network for any given mission scenario. These operators afford a capability for producing a formally correct kernel of behaviors that guarantee predictable performance. By use of a method based on multi-objective decision theory (MODT), recommendations from multiple behaviors are combined to form a set of control actions that represents their consensus. In this approach, all behaviors contribute simultaneously to the control of the robotic system in a cooperative rather than a competitive manner. This approach guarantees a solution that is good enough with respect to resolution of complex, possibly conflicting goals within the constraints of the mission to be accomplished by the vehicle(s).

  20. Emergent Behavior of Coupled Barrier Island - Resort Systems

    NASA Astrophysics Data System (ADS)

    McNamara, D. E.; Werner, B. T.

    2004-12-01

    Barrier islands are attractive sites for resorts. Natural barrier islands experience beach erosion and island overwash during storms, beach accretion and dune building during inter-storm periods, and migration up the continental shelf as sea level rises. Beach replenishment, artificial dune building, seawalls, jetties and groins have been somewhat effective in protecting resorts against erosion and overwash during storms, but it is unknown how the coupled system will respond to long-term sea level rise. We investigate coupled barrier island - resort systems using an agent-based model with three components: natural barrier islands divided into a series of alongshore cells; resorts controlled by markets for tourism and hotel purchases; and coupling via storm damage to resorts and resort protection by government agents. Modeled barrier islands change by beach erosion, island overwash and inlet cutting during storms, and beach accretion, tidal delta growth and dune and vegetation growth between storms. In the resort hotel market, developer agents build hotels and hotel owning agents purchase them using predictions of future revenue and property appreciation, with the goal of maximizing discounted utility. In the tourism market, hotel owning agents set room rental prices to maximize profit and tourist agents choose vacation destinations maximizing a utility based on beach width, price and word-of-mouth. Government agents build seawalls, groins and jetties, and widen the beach and build up dunes by adding sand to protect resorts from storms, enhance beach quality, and maximize resort revenue. Results indicate that barrier islands and resorts evolve in a coupled manner to resort size saturation, with resorts protected against small-to-intermediate-scale storms under fairly stable sea level. Under extended, rapidly rising sea level, protection measures enhance the effect of large storms, leading to emergent behavior in the form of limit cycles or barrier submergence, depending on the relative rates of resort recovery from storms and sea level rise. The model is applied to Ocean City, Maryland and neighboring undeveloped Assateague Island National Seashore. Supported by the National Science Foundation, Geology and Paleontology Program, and the Andrew W. Mellon Foundation

  1. Serotonin Regulates Electrical Coupling via Modulation of Extrajunctional Conductance: H-current

    PubMed Central

    Szabo, Theresa M.; Caplan, Jonathan S.; Zoran, Mark J.

    2010-01-01

    Synaptic strength can be highly variable from animal to animal within a species or over time within an individual. The process of synaptic plasticity induced by neuromodulatory agents might be unpredictable when the underlying circuits subject to modulation are themselves inherently variable. Serotonin (5-hydroxytryptomine; 5HT) and serotonergic signaling pathways are important regulators of animal behavior and are pharmacological targets in a wide range of neurological disorders. We have examined the effect of 5HT on electrical synapses possessing variable coupling strengths. While 5HT decreased electrical coupling at synapses with weak electrical connectivity, synapses with strong electrical coupling were less affected by 5HT treatment, as follows from the equations used for calculating coupling coefficients. The fact that the modulatory effect of 5HT on electrical connections was negatively correlated with the strength of electrical coupling suggests that the degree of electrical coupling within a neural network impacts subsequent neuromodulation of those synapses. Biophysical studies indicated that these effects were primarily due to 5HT-induced modulation of membrane currents that indirectly affect junctional coupling at synaptic contacts. In support of these experimental analyses, we created a simple model of coupled neurons to demonstrate that modulation of electrical coupling could be due solely to 5HT effects on H-channel conductance. Therefore, variability in the strength of electrical coupling in neural circuits can determine the pharmacological effect of this neuromodulatory agent. PMID:20599836

  2. Serotonin regulates electrical coupling via modulation of extrajunctional conductance: H-current.

    PubMed

    Szabo, Theresa M; Caplan, Jonathan S; Zoran, Mark J

    2010-08-19

    Synaptic strength can be highly variable from animal to animal within a species or over time within an individual. The process of synaptic plasticity induced by neuromodulatory agents might be unpredictable when the underlying circuits subject to modulation are themselves inherently variable. Serotonin (5-hydroxytryptomine; 5HT) and serotonergic signaling pathways are important regulators of animal behavior and are pharmacological targets in a wide range of neurological disorders. We have examined the effect of 5HT on electrical synapses possessing variable coupling strengths. While 5HT decreased electrical coupling at synapses with weak electrical connectivity, synapses with strong electrical coupling were less affected by 5HT treatment, as follows from the equations used for calculating coupling coefficients. The fact that the modulatory effect of 5HT on electrical connections was negatively correlated with the strength of electrical coupling suggests that the degree of electrical coupling within a neural network impacts subsequent neuromodulation of those synapses. Biophysical studies indicated that these effects were primarily due to 5HT-induced modulation of membrane currents that indirectly affect junctional coupling at synaptic contacts. In support of these experimental analyses, we created a simple model of coupled neurons to demonstrate that modulation of electrical coupling could be due solely to 5HT effects on H-channel conductance. Therefore, variability in the strength of electrical coupling in neural circuits can determine the pharmacological effect of this neuromodulatory agent. PMID:20599836

  3. Mobile Software-Agents Workshop at Schloss Dagstuhl

    E-print Network

    Mobile Software-Agents Workshop at Schloss Dagstuhl Oct 13-17, 1997 organized by Friedemann Mattern Darmstadt, Kurt Rothermel Stuttgart, Fred B. Schneider Cornell, Brent Welch Mountain View Mobile agents state. Agents can communicate with other mobile agents or with stationary server agents. Agents may

  4. Persuading users through counseling dialogue with a conversational agent

    Microsoft Academic Search

    Daniel Schulman; Timothy W. Bickmore

    2009-01-01

    We present an empirical study of the effect of a computer agent designed to engage a user in a persuasive counseling dialogue on attitudes towards regular exercise. We used two manipulations: (1) how closely the agent simulated human conversation, using either an embodied conversational agent (ECA) or a text-only agent, and (2) whether the agent attempted to build a user-agent

  5. An intelligent fuzzy agent for meeting scheduling decision support system

    Microsoft Academic Search

    Chang-shing Lee; Chen-yu Pan

    2004-01-01

    An Intelligent Fuzzy Agent for Meeting Scheduling Decision Support System is proposed in this paper. The proposed Intelligent Fuzzy Agent including Meeting Negotiation Agent, Fuzzy Inference Agent and Genetic Learning Agent can search and decide the suitable meeting time for the specified meeting in an organization. When a meeting host requests a meeting, the Meeting Negotiation Agent immediately sends the

  6. Coupled adaptive complex networks

    NASA Astrophysics Data System (ADS)

    Shai, S.; Dobson, S.

    2013-04-01

    Adaptive networks, which combine topological evolution of the network with dynamics on the network, are ubiquitous across disciplines. Examples include technical distribution networks such as road networks and the internet, natural and biological networks, and social science networks. These networks often interact with or depend upon other networks, resulting in coupled adaptive networks. In this paper we study susceptible-infected-susceptible (SIS) epidemic dynamics on coupled adaptive networks, where susceptible nodes are able to avoid contact with infected nodes by rewiring their intranetwork connections. However, infected nodes can pass the disease through internetwork connections, which do not change with time: The dependencies between the coupled networks remain constant. We develop an analytical formalism for these systems and validate it using extensive numerical simulation. We find that stability is increased by increasing the number of internetwork links, in the sense that the range of parameters over which both endemic and healthy states coexist (both states are reachable depending on the initial conditions) becomes smaller. Finally, we find a new stable state that does not appear in the case of a single adaptive network but only in the case of weakly coupled networks, in which the infection is endemic in one network but neither becomes endemic nor dies out in the other. Instead, it persists only at the nodes that are coupled to nodes in the other network through internetwork links. We speculate on the implications of these findings.

  7. Coupled quantized mechanical oscillators

    E-print Network

    K. R. Brown; C. Ospelkaus; Y. Colombe; A. C. Wilson; D. Leibfried; D. J. Wineland

    2011-11-14

    The harmonic oscillator is one of the simplest physical systems but also one of the most fundamental. It is ubiquitous in nature, often serving as an approximation for a more complicated system or as a building block in larger models. Realizations of harmonic oscillators in the quantum regime include electromagnetic fields in a cavity [1-3] and the mechanical modes of a trapped atom [4] or macroscopic solid [5]. Quantized interaction between two motional modes of an individual trapped ion has been achieved by coupling through optical fields [6], and entangled motion of two ions in separate locations has been accomplished indirectly through their internal states [7]. However, direct controllable coupling between quantized mechanical oscillators held in separate locations has not been realized previously. Here we implement such coupling through the mutual Coulomb interaction of two ions held in trapping potentials separated by 40 um (similar work is reported in a related paper [8]). By tuning the confining wells into resonance, energy is exchanged between the ions at the quantum level, establishing that direct coherent motional coupling is possible for separately trapped ions. The system demonstrates a building block for quantum information processing and quantum simulation. More broadly, this work is a natural precursor to experiments in hybrid quantum systems, such as coupling a trapped ion to a quantized macroscopic mechanical or electrical oscillator [9-13].

  8. Considerations in detecting CDC select agents under field conditions

    NASA Astrophysics Data System (ADS)

    Spinelli, Charles; Soelberg, Scott; Swanson, Nathaneal; Furlong, Clement; Baker, Paul

    2008-04-01

    Surface Plasmon Resonance (SPR) has become a widely accepted technique for real-time detection of interactions between receptor molecules and ligands. Antibody may serve as receptor and can be attached to the gold surface of the SPR device, while candidate analyte fluids contact the detecting antibody. Minute, but detectable, changes in refractive indices (RI) indicate that analyte has bound to the antibody. A decade ago, an inexpensive, robust, miniature and fully integrated SPR chip, called SPREETA, was developed. University of Washington (UW) researchers subsequently developed a portable, temperature-regulated instrument, called SPIRIT, to simultaneously use eight of these three-channel SPREETA chips. A SPIRIT prototype instrument was tested in the field, coupled to a remote reporting system on a surrogate unmanned aerial vehicle (UAV). Two target protein analytes were released sequentially as aerosols with low analyte concentration during each of three flights and were successfully detected and verified. Laboratory experimentation with a more advanced SPIRIT instrument demonstrated detection of very low levels of several select biological agents that might be employed by bioterrorists. Agent detection under field-like conditions is more challenging, especially as analyte concentrations are reduced and complex matricies are introduced. Two different sample preconditioning protocols have been developed for select agents in complex matrices. Use of these preconditioning techniques has allowed laboratory detection in spiked heavy mud of Francisella tularensis at 10 3 CFU/ml, Bacillus anthracis spores at 10 3 CFU/ml, Staphylococcal enterotoxin B (SEB) at 1 ng/ml, and Vaccinia virus (a smallpox simulant) at 10 5 PFU/ml. Ongoing experiments are aimed at simultaneous detection of multiple agents in spiked heavy mud, using a multiplex preconditioning protocol.

  9. Evolutionary algorithms and multi-agent systems

    NASA Astrophysics Data System (ADS)

    Oh, Jae C.

    2006-05-01

    This paper discusses how evolutionary algorithms are related to multi-agent systems and the possibility of military applications using the two disciplines. In particular, we present a game theoretic model for multi-agent resource distribution and allocation where agents in the environment must help each other to survive. Each agent maintains a set of variables representing actual friendship and perceived friendship. The model directly addresses problems in reputation management schemes in multi-agent systems and Peer-to-Peer distributed systems. We present algorithms based on evolutionary game process for maintaining the friendship values as well as a utility equation used in each agent's decision making. For an application problem, we adapted our formal model to the military coalition support problem in peace-keeping missions. Simulation results show that efficient resource allocation and sharing with minimum communication cost is achieved without centralized control.

  10. Antagonistic formation motion of cooperative agents

    NASA Astrophysics Data System (ADS)

    Lu, Wan-Ting; Dai, Ming-Xiang; Xue, Fang-Zheng

    2015-02-01

    This paper investigates a new formation motion problem of a class of first-order multi-agent systems with antagonistic interactions. A distributed formation control algorithm is proposed for each agent to realize the antagonistic formation motion. A sufficient condition is derived to ensure that all of the agents make an antagonistic formation motion in a distributed manner. It is shown that all of the agents can be spontaneously divided into several groups and that agents in the same group collaborate while agents in different groups compete. Finally, a numerical simulation is included to demonstrate our theoretical results. Project supported by the National Natural Science Foundation of China (Grant Nos. 61203080 and 61473051) and the Natural Science Foundation of Chongqing City (Grant No. CSTC 2011BB0081).

  11. Systemic use of non-biologic agents in orofacial diseases: other immunomodulatory agents.

    PubMed

    Georgakopoulou, Ea; Scully, C

    2013-08-12

    Systemic non-biologic agents have long been in clinical use in medicine - often with considerable efficacy, albeit with some adverse effects - as with all medications. With the advent of biologic agents, all of which currently are restricted to systemic use, there is a growing need to ensure which agents have the better therapeutic ratio. The non-biologic agents (NBAs) include a range of agents, most importantly the corticosteroids (steroids). Previous articles by us in this series have discussed systemic use of corticosteroids and purine synthesis inhibitors; the other immunomodulating agents (calcineurin inhibitors, thalidomide, dapsone, colchicine and cyclophosphamide) are reviewed in this final article. PMID:24028818

  12. 3DGIS-Based Multi-Agent Geosimulation and Visualization of Building Evacuation Using GAMA Platform

    NASA Astrophysics Data System (ADS)

    Macatulad, E. G.; Blanco, A. C.

    2014-11-01

    Recent GIS applications have already extended analyses from the traditional 2-2.5D environment (x,y,attributes) to 3D space (x,y,z,attributes). Coupled with agent-based modeling (ABM), available 3DGIS data can be used to develop simulation models for improved analysis of spatial data and spatial processes. One such application is on building evacuation for which ABM is integrated with 3D indoor spatial data to model human behavior during evacuation events and simulate evacuation scenarios visualized in 3D. The research presented in this paper develops a multi-agent geosimulation model for building evacuation, integrating 3DGIS dataset of the case study building as input in ABM using the GAMA simulation platform. This model is intended to complement and improve traditional approaches in building evacuation planning and management such as earthquake and fire drills. The initial model developed includes PEOPLE agents to model the building occupants, and FLOORS, ROOMS, INDOOR_PATHS and EXIT_POINTS agents, which are modeled from the 3DGIS layers. The INDOOR_PATHS and EXIT_POINTS agents influence the movement of PEOPLE agents. Test simulations were performed involving PEOPLE agents placed in rooms of the building based on potential number of occupants computed based from the floor area of each room. The PEOPLE agents are programmed to find the shortest path along the INDOOR_PATHS towards the EXIT_POINTS instance designated for each room of the building. The simulation computes for the total time it takes for all PEOPLE agents to exit the building.

  13. Tachyon Couplings to Fermion

    E-print Network

    Mohammad R. Garousi

    2008-11-22

    By fixing the internal CP factor of tachyon and massless Ramond vertex operators in different pictures, we have shown that the internal CP factor of the disk level S-matrix elements of two fermions and odd number of tachyon vertex operators in the world volume of non-BPS D-branes/D-brane-anti-D-brane is zero. We have calculated the S-matrix element of two fermions and two tachyons which has non vanishing internal CP factor, and found the momentum expansion of this amplitude. In the abelian case, we have compared the two-fermion-two-tachyon coupling at low energy with the corresponding coupling in the gauge-fixed supersymmetric tachyon DBI action. The couplings in the two cases are exactly the same.

  14. Fucoidans: pro- or antiangiogenic agents?

    PubMed

    Ustyuzhanina, Nadezhda E; Bilan, Maria I; Ushakova, Natalia A; Usov, Anatolii I; Kiselevskiy, Mikhail V; Nifantiev, Nikolay E

    2014-12-01

    Sulfated polysaccharides of brown algae (fucoidans) attract great attention due to their high and strongly diversified biological activity. This review summarizes recent data on the structural variability of these polysaccharides and reports their anti- and proangiogenic properties. Recent publications have revealed that fucoidans isolated from different algal species may differ considerably in the structures of their backbones and branches, in both monosaccharide composition and sulfate content. It was found that the degree of sulfation significantly influences the biological properties of fucoidans. Additionally, fucoidan action in angiogenesis is highly dependent on molecular weight: antiangiogenic activity is connected with the high-molecular weight of polysaccharide molecules, whereas the low-molecular-weight fractions may act as proangiogenic agents. The influence of other fine structural details of fucoidans on angiogenesis remains to be established. PMID:24973252

  15. Building Dynamic Agent Organizations in Cyberspace

    Microsoft Academic Search

    Milind Tambe; David V. Pynadath; Nicolas Chauvat

    2000-01-01

    With the promise of agent-based systems, a variety of research\\/industrial groups are developing autonomous, heterogeneous agents, that are distributed over a variety of platforms and environments in cyberspace. Rapid integration of such distributed, heterogeneous agents would enable software to be rapidly developed to address large-scale problems of interest. Unfortunately, rapid and robust integration remains a difficult challenge. To address this

  16. Bottoms up: improvisational micro-agents

    Microsoft Academic Search

    Brian Magerko; Casey Fiesler; Allan Baumer; Daniel Fuller

    2010-01-01

    This paper describes our current approach in implementing computational improvisational micro-agents, agents that perform one specific aspect of our findings from the Digital Improv Project. This approach is intended to foster bottom-up research to better understand how to build more complex agent behaviors in a theatrical improvisational setting. The Digital Improv Project is a multi-year study at the Georgia Institute

  17. A Roadmap of Agent Research and Development

    E-print Network

    Nicholas R. Jennings; Katia Sycara

    1998-01-01

    This paper provides an overview of research and development activities in the field of autonomous agents and multi-agent systems. It aims to identify key concepts and applications, and to indicate how they relate to one-another. Some historical context to the field of agent-based computing is given, and contemporary research directions are presented. Finally, a range of open issues and future challenges are highlighted.

  18. An Ontology Support for Semantic Aware Agents

    Microsoft Academic Search

    Michele Tomaiuolo; Paola Turci; Federico Bergenti; Agostino Poggi

    2005-01-01

    \\u000a The work presented in this paper is an attempt to bridge two co-existing realties: Semantic Web and Multi-Agent Systems. Semantic\\u000a aware agents will be able to interoperate in a semantic way as well as to produce and consume semantically annotated information\\u000a and services. Agents should be enhanced with tools and mechanisms in order to autonomously achieve these strategic and ambitious

  19. Agent-Based Health Care Systems

    Microsoft Academic Search

    John L. Nealon; Antonio Moreno

    In this paper we introduce the main issues related to the deployment of agent-based systems in health care. First, we comment on the characteristics of health care problems and we argue that multi-agent systems are a good choice to tackle problems with these features. This belief is supported with a number of exemplar applications of agent-based systems in medical domains.

  20. Agent-Based Applications in Health Care

    Microsoft Academic Search

    John Nealon; Antonio Moreno

    2003-01-01

    In this paper we introduce the main issues related to the deployment of agent-based systems in health care. First, we comment on the characteristics of health care problems and we argue that multi-agent systems are a good choice to tackle problems with these features. This be- lief is supported with a number of exemplar applications of agent-based systems in medical

  1. Massive Multi-Agent Systems Control

    NASA Technical Reports Server (NTRS)

    Campagne, Jean-Charles; Gardon, Alain; Collomb, Etienne; Nishida, Toyoaki

    2004-01-01

    In order to build massive multi-agent systems, considered as complex and dynamic systems, one needs a method to analyze and control the system. We suggest an approach using morphology to represent and control the state of large organizations composed of a great number of light software agents. Morphology is understood as representing the state of the multi-agent system as shapes in an abstract geometrical space, this notion is close to the notion of phase space in physics.

  2. Multi-agent-based agile scheduling

    Microsoft Academic Search

    Ricardo J. Rabelo; Luis M. Camarinha-matos; Hamideh Afsarmanesh

    1999-01-01

    The multi-agent systems paradigm represents one of the most promising approaches to the development of agile scheduling systems in manufacturing. Innovative and balanced perspectives of multi-agent approaches to agile scheduling are discussed in this paper, and several achieved results and current developments are described. The description of the multi-agent framework emphasizes the use of negotiation mechanism to improve the scheduling

  3. The EO-1 Autonomous Science Agent Architecture

    NASA Technical Reports Server (NTRS)

    Chien, Steve; Sherwood, Rob; Tran, Daniel; Cichy, Benjamin; Rabideau, Gregg; Castano, Rebecca; Davies, Ashley; Lee, Rachel; Mandl, Dan; Frye, Stuart; Trout, Bruce; Hengemihle, Jerry; D'Agostino, Jeff; Shulman, Seth; Ungar, Stephen; Brakke, Thomas; Boyer, Darrell; Van Gaasbeck, Jim; Greeley, Ronald; Doggett, Thomas; Baker, Victor; Dohm, James; Ip, Felipe

    2004-01-01

    An Autonomous Science Agent is currently flying onboard the Earth Observing One Spacecraft. This software enables the spacecraft to autonomously detect and respond to science events occurring on the Earth. The package includes software systems that perform science data analysis, deliberative planning, and run-time robust execution. Because of the deployment to a remote spacecraft, this Autonomous Science Agent has stringent constraints of autonomy, reliability, and limited computing resources. We describe these constraints and how they are reflected in our agent architecture.

  4. Do infants bind mental states to agents?

    PubMed

    Kampis, Dora; Somogyi, Eszter; Itakura, Shoji; Király, Ildikó

    2013-11-01

    Recent findings suggest that infants understand others' preferential choice and can use the perspectives and beliefs of others to interpret their actions. The standard interpretation in the field is that infants understand preferential choice as a dispositional state of the agent. It is possible, however, that these social situations trigger the acquisition of more general, not person-specific knowledge. In a looking-time study we showed an Agent A demonstrating a choice, that only could have been interpreted as preferential based on the perspective (and thus the belief) of the agent, not the observer. Then we introduced a new agent (Agent B), who chose consistently or inconsistently with Agent A; also varying whether Agent B was an adult or a child. Results show that infants expected Agent B (both the adult and the child) to choose as Agent A, but only in the condition where according to Agent A's knowledge two objects were present in familiarization(confirming previous evidence on the importance of contrastive choice). We interpret these results in the following way: (1) infants do not encode the perspectives of other agents as person-specific sources of knowledge and (2) they learn about the object, rather than the agent's disposition towards that object. We propose that early theory of mind processes lack the binding of belief content to the belief holder. However, such limitation may in fact serve an important function, allowing infants to acquire information through the perspectives of others in the form of universal access to general information. PMID:23942349

  5. Does Android Dream with Intelligent Agents?

    Microsoft Academic Search

    Jorge Agüero; Miguel Rebollo; Carlos Carrascosa; Vicente Julián

    2008-01-01

    In this paper, a new agent model “specially” designed for the recent Android Google SDK is presented, where the Android mobile\\u000a phone can be considered agent software. This agent model has an approach more practical than theoretical because it uses abstractions\\u000a which allow to implement it on various systems. The appearance of Android as an open system based on Linux

  6. On Agent-Mediated Electronic Commerce

    Microsoft Academic Search

    Minghua He; Nicholas R. Jennings; Ho-fung Leung

    2003-01-01

    This paper surveys and analyses the state of the art of agent-mediated electronic commerce (e-commerce),concentrating particularly on the business-to-consumer (B2C) and business-to-business (B2B) aspects.From the consumer buying behaviour perspective, agents are being used in the following activities: needidentification, product brokering, buyer coalition formation, merchant brokering and negotiation. Theroles of agents in B2B e-commerce are discussed through the business-to-business...

  7. Agents with Faces: A Study on the Effects of Personification of Software Agents 23 CHAPTER 2 Related Work in

    E-print Network

    Agents with Faces: A Study on the Effects of Personification of Software Agents Apple Knowledge NavigatorAgents with Faces: A Study on the Effects of Personification of Software Agents 23 CHAPTER 2 interface, believable agents, and software agents. The second half of this chapter describes psychological

  8. Adaptive tracking-type games for coupled large population ARMAX systems

    Microsoft Academic Search

    Qiang Zhang; Ji-Feng Zhang

    2010-01-01

    Distributed adaptive tracking-type games is investigated for large population stochastic multi-agent systems. The dynamics of each agent is described by ARMAX model with unknown structure parameters and unknown coupled terms. The performance index has an unknown population state average (PSA) term. In order to deal with the uncertainties, the extended least-squares algorithm is used to estimate the unknown parameters, and

  9. Reinforcement Learning Multi-Agent Modeling of Decision-Making Agents for the Study of Transboundary Surface Water Conflicts with Application to the Syr Darya River Basin

    NASA Astrophysics Data System (ADS)

    Riegels, N.; Siegfried, T.; Pereira Cardenal, S. J.; Jensen, R. A.; Bauer-Gottwein, P.

    2008-12-01

    In most economics--driven approaches to optimizing water use at the river basin scale, the system is modelled deterministically with the goal of maximizing overall benefits. However, actual operation and allocation decisions must be made under hydrologic and economic uncertainty. In addition, river basins often cross political boundaries, and different states may not be motivated to cooperate so as to maximize basin- scale benefits. Even within states, competing agents such as irrigation districts, municipal water agencies, and large industrial users may not have incentives to cooperate to realize efficiency gains identified in basin- level studies. More traditional simulation--optimization approaches assume pre-commitment by individual agents and stakeholders and unconditional compliance on each side. While this can help determine attainable gains and tradeoffs from efficient management, such hardwired policies do not account for dynamic feedback between agents themselves or between agents and their environments (e.g. due to climate change etc.). In reality however, we are dealing with an out-of-equilibrium multi-agent system, where there is neither global knowledge nor global control, but rather continuous strategic interaction between decision making agents. Based on the theory of stochastic games, we present a computational framework that allows for studying the dynamic feedback between decision--making agents themselves and an inherently uncertain environment in a spatially and temporally distributed manner. Agents with decision-making control over water allocation such as countries, irrigation districts, and municipalities are represented by reinforcement learning agents and coupled to a detailed hydrologic--economic model. This approach emphasizes learning by agents from their continuous interaction with other agents and the environment. It provides a convenient framework for the solution of the problem of dynamic decision-making in a mixed cooperative / non-cooperative environment with which different institutional setups and incentive systems can be studied so to identify reasonable ways to reach desirable, Pareto--optimal allocation outcomes. Preliminary results from an application to the Syr Darya river basin in Central Asia will be presented and discussed. The Syr Darya River is a classic example of a transboundary river basin in which basin-wide efficiency gains identified in optimization studies have not been sufficient to induce cooperative management of the river by the riparian states.

  10. Coupling gravitons to matter.

    PubMed

    Bern, Z; De Freitas, A; Wong, H L

    2000-04-17

    Using relationships between open and closed strings, we present a construction of tree-level scattering amplitudes for gravitons minimally coupled to matter in terms of gauge theory partial amplitudes. In particular, we present examples of amplitudes with gravitons coupled to vectors or to a single fermion pair. We also present two examples with massive graviton exchange, as would arise in the presence of large compact dimensions. The gauge charges are represented by flavors of dynamical scalars or fermions. This also leads to an unconventional decomposition of color and kinematics in gauge theories. PMID:11019138

  11. Coupled Transport Protein Systems

    NSDL National Science Digital Library

    Jack D. Thatcher (Lewisburg; West Virginia School of Osteopathic Medicine REV)

    2013-04-16

    This set of animated lessons provides examples of how transport proteins interact in coupled systems to produce physiologic effects. The gastric pumps animation depicts the secretion of hydrochloric acid into the gastric lumen. The animation called glucose absorption depicts glucose absorption by intestinal epithelial cells. The CFTR animation explains how the cystic fibrosis conductance transmembrane regulator (CFTR) functions as a key component of a coupled system of transport proteins that clears the pulmonary system of mucus and inhaled particulates. These animations serve as valuable resources for any collegiate-level course that describes these processes. Courses that might use them include introductory biology, biochemistry, biophysics, cell biology, pharmacology, and physiology.

  12. Characterization of chemical agent transport in paints.

    PubMed

    Willis, Matthew P; Gordon, Wesley; Lalain, Teri; Mantooth, Brent

    2013-09-15

    A combination of vacuum-based vapor emission measurements with a mass transport model was employed to determine the interaction of chemical warfare agents with various materials, including transport parameters of agents in paints. Accurate determination of mass transport parameters enables the simulation of the chemical agent distribution in a material for decontaminant performance modeling. The evaluation was performed with the chemical warfare agents bis(2-chloroethyl) sulfide (distilled mustard, known as the chemical warfare blister agent HD) and O-ethyl S-[2-(diisopropylamino)ethyl] methylphosphonothioate (VX), an organophosphate nerve agent, deposited on to two different types of polyurethane paint coatings. The results demonstrated alignment between the experimentally measured vapor emission flux and the predicted vapor flux. Mass transport modeling demonstrated rapid transport of VX into the coatings; VX penetrated through the aliphatic polyurethane-based coating (100 ?m) within approximately 107 min. By comparison, while HD was more soluble in the coatings, the penetration depth in the coatings was approximately 2× lower than VX. Applications of mass transport parameters include the ability to predict agent uptake, and subsequent long-term vapor emission or contact transfer where the agent could present exposure risks. Additionally, these parameters and model enable the ability to perform decontamination modeling to predict how decontaminants remove agent from these materials. PMID:23872337

  13. Decidability Classes for Mobile Agents Computing

    E-print Network

    Fraigniaud, Pierre

    2010-01-01

    We establish a classification of decision problems that are to be solved by mobile agents operating in unlabeled graphs, using a deterministic protocol. The classification is with respect to the ability of a team of agents to solve the problem, possibly with the aid of additional information. In particular, our focus is on studying differences between the decidability of a decision problem by agents and its verifiability when a certificate for a positive answer is provided to the agents. We show that the class MAV of mobile agents verifiable problems is much wider than the class MAD of mobile agents decidable problems. Our main result shows that there exist natural MAV-complete problems: the most difficult problems in this class, to which all problems in MAV are reducible. Our construction of a MAV-complete problem involves two main ingredients in mobile agents computability: the topology of the quotient graph and the number of operating agents. Beyond the class MAV we show that, for a single agent, three nat...

  14. Active evacuation guidance using sensor agent robot

    NASA Astrophysics Data System (ADS)

    Ise, Daiki; Mita, Akira

    2012-04-01

    Evacuation systems for buildings are designed based on event scenarios, so they are not prepared for unexpected events that are not included in the scenarios. In this paper, we propose a new active evacuation guidance system using sensor agent robots. We first introduce a Structural Health Monitoring (SHM) system to be used in conjunction with sensor agent robots for active evacuation guidance. Then the role of sensor agent robots is explained. An algorithm to immediately access the safety of the building after a large earthquake is also proposed using only the information taken by a sensor agent robot.

  15. Design considerations for targeted optical contrast agents

    PubMed Central

    Lee, Jeong Heon; Park, Gwangli; Hong, Gloria H.; Choi, Jungmun

    2012-01-01

    Optical fluorescence imaging with the right combination of imaging modality and targeted contrast agents offers tremendous improvement in intraoperative imaging and clinical output (i.e., image-guided cancer surgery). Therefore, it is of paramount importance to gain an in-depth knowledge in the design of targeted contrast agents to meet clinical requirements. Currently, there are several clinically approved contrast agents available; however, none perform optimally in vivo by providing optimum sensitivity, stability, specificity, and safety for target imaging, diagnosis, and therapy. In this review, we discuss basic design considerations for targeted contrast agents in terms of optical and physicochemical properties, biological and physiological interactions, and biodistribution and targeting. PMID:23289086

  16. Tightly Coupled Geodynamic Systems

    E-print Network

    Brown, Jed

    evolution Ridge 2D Porosity Driven Stokes Solitary Waves Isoviscous McKenzie Eqns. Specific Physical · Effective solution methods for studying dynamical systems described by very viscous, creeping flow, i.e. 5 linear and nonlinear problems to be obtained. · If the coupled problem is nonlinear, we need: · A method

  17. Coupled Resonant Pendulums

    NSDL National Science Digital Library

    The Exploratorium

    2012-01-30

    In this activity, learners discover that two pendulums suspended from a common support will swing back and forth in intriguing patterns, if the support allows the motion of one pendulum to influence the motion of the other. Learners are encouraged to experiment with different wire lengths and string tensions to produce stronger or weaker interdependent coupled pendulums.

  18. Coupling Gammasphere and ORRUBA

    SciTech Connect

    Ratkiewicz, A.; Cizewski, J. A.; Manning, B. [Department of Physics and Astronomy, Rutgers University, New Brunswick, NJ 08903 (United States); Pain, S. D.; Bardayan, D. W. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Blackmon, J. C.; Matos, M. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Chipps, K. A. [Department of Physics, Colorado School of Mines, Golden, CO 80401 (United States); Hardy, S.; Shand, C. [Department of Physics and Astronomy, Rutgers University, New Brunswick, NJ 08903 and Department of Physics, University of Surrey, Guildford, Surrey, GU2 7XH (United Kingdom); Jones, K. L. [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States); Kozub, R. L. [Physics Department, Tennessee Technological University, Cookeville, TN 38505 (United States); Lister, C. J. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 and Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA 01854 (United States); Peters, W. A. [Oak Ridge Associated Universities, Oak Ridge, TN 37830 (United States); Seweryniak, D. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2013-04-19

    The coincident detection of particles and gamma rays allows the study of the structure of exotic nuclei via inverse kinematics reactions using radioactive ion beams and thick targets. We report on the status of the project to couple the highresolution charged-particle detector ORRUBA to Gammasphere, a high-efficiency, high-resolution gamma ray detector.

  19. Generic flux coupling analysis.

    PubMed

    Reimers, Arne C; Goldstein, Yaron; Bockmayr, Alexander

    2015-04-01

    Flux coupling analysis (FCA) has become a useful tool for aiding metabolic reconstructions and guiding genetic manipulations. Originally, it was introduced for constraint-based models of metabolic networks that are based on the steady-state assumption. Recently, we have shown that the steady-state assumption can be replaced by a weaker lattice-theoretic property related to the supports of metabolic fluxes. In this paper, we further extend our approach and develop an efficient algorithm for generic flux coupling analysis that works with any kind of qualitative pathway model. We illustrate our method by thermodynamic flux coupling analysis (tFCA), which allows studying steady-state metabolic models with loop-law thermodynamic constraints. These models do not satisfy the lattice-theoretic properties required in our previous work. For a selection of genome-scale metabolic network reconstructions, we discuss both theoretically and practically, how thermodynamic constraints strengthen the coupling results that can be obtained with classical FCA. A prototype implementation of tFCA is available at http://hoverboard.io/L4FC. PMID:25619608

  20. Valorization of titanium metal wastes as tanning agent used in leather industry.

    PubMed

    Crudu, Marian; Deselnicu, Viorica; Deselnicu, Dana Corina; Albu, Luminita

    2014-10-01

    The development of new tanning agents and new technologies in the leather sector is required to cope with the increasingly higher environmental pressure on the current tanning materials and processes such as tanning with chromium salts. In this paper, the use of titanium wastes (cuttings) resulting from the process of obtaining highly pure titanium (ingots), for the synthesis of new tanning agent and tanning bovine hides with new tanning agent, as alternative to tanning with chromium salts are investigated. For this purpose, Ti waste and Ti-based tanning agent were characterized for metal content by inductively coupled plasma mass spectrometry (ICP-MS) and chemical analysis; the tanned leather (wet white leather) was characterized by Scanning Electron Microscope/Energy Dispersive Using X-ray (Analysis). SEM/EDX analysis for metal content; Differential scanning calorimetric (DSC), Micro-Hot-Table and standard shrinkage temperature showing a hydrothermal stability (ranged from 75.3 to 77°C) and chemical analysis showing the leather is tanned and can be processed through the subsequent mechanical operations (splitting, shaving). On the other hand, an analysis of major minor trace substances from Ti-end waste (especially vanadium content) in new tanning agent and wet white leather (not detected) and residue stream was performed and showed that leachability of vanadium is acceptable. The results obtained show that new tanning agent obtained from Ti end waste can be used for tanning bovine hides, as eco-friendly alternative for chrome tanning. PMID:24507977