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Sample records for salting-out agents

  1. Nano-Sized Ultrasound Contrast Agent: Salting-Out Method

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    Margaret A. Wheatley

    2010-03-01

    Full Text Available Tumor imaging by ultrasound is greatly enhanced by the use of ultrasound contrast agents (UCAs, stabilized, gas-filled bodies. They are generally less than 7 μm to pass freely through the capillary bed. Development of a nano-sized agent would enable them to extravasate through the leaky pores of angiogenic vessels. We describe the development of an echogenic, nano-sized polylactic acid UCA by adaptation of a salting-out method. The viscosity of the initial colloidal suspension (concentration and molecular weight of protective colloid [polyvinyl alcohol (PVA] and concentration of polymer was key in determining particle size and polydispersity (increasing viscosity increased both. Addition of the porogens ammonium carbonate and camphor, required to produce hollow echogenic capsules, also increased the size (eg, 5 wt% PVA, mean solid nanocapsule size 386 ± 25 nm, polydispersity index 0.367 ± 0.14, and mean UCA size 640 ± 18 nm, polydispersity index 0.308 ± 0.027. Viscosity had the opposite effect on echogenicity of the resultant nano-UCA, which ranged from 21.69 ± 0.78 dB for 2% PVA to 12.1 ± 0.8 dB for 10% PVA. The UCA prepared with 10% PVA, however, had a longer half-life in the ultrasound beam (t½ > 15 minutes vs t½ < 10 minutes, suggesting a thicker shell. Optimization will require compromise among size, echogenicity, and stability.

  2. Pesticide removal from aqueous solutions by adding salting out agents.

    Science.gov (United States)

    Moscoso, Fátima; Deive, Francisco J; Esperança, José M S S; Rodríguez, Ana

    2013-10-18

    Phase segregation in aqueous biphasic systems (ABS) composed of four hydrophilic ionic liquids (ILs): 1-butyl-3-methylimidazolium methylsulfate and 1-ethyl-3-methylimidazolium methylsulfate (C(n)C₁im C₁SO₄, n = 2 and 4), tributylmethyl phosphonium methylsulfate (P₄₄₄₁ C₁SO₄) and methylpyridinium methylsulfate (C₁Py C₁SO₄) and two high charge density potassium inorganic salts (K₂CO₃ and K₂HPO₄) were determined by the cloud point method at 298.15 K. The influence of the addition of the selected inorganic salts to aqueous mixtures of ILs was discussed in the light of the Hofmeister series and in terms of molar Gibbs free energy of hydration. The effect of the alkyl chain length of the cation on the methylsulfate-based ILs has been investigated. All the solubility data were satisfactorily correlated to several empirical equations. A pesticide (pentachlorophenol, PCP) extraction process based on the inorganic salt providing a greater salting out effect was tackled. The viability of the proposed process was analyzed in terms of partition coefficients and extraction efficiencies.

  3. Pesticide Removal from Aqueous Solutions by Adding Salting Out Agents

    Directory of Open Access Journals (Sweden)

    Fátima Moscoso

    2013-10-01

    Full Text Available Phase segregation in aqueous biphasic systems (ABS composed of four hydrophilic ionic liquids (ILs: 1-butyl-3-methylimidazolium methylsulfate and 1-ethyl-3-methylimidazolium methylsulfate (CnC1im C1SO4, n = 2 and 4, tributylmethyl phosphonium methylsulfate (P4441 C1SO4 and methylpyridinium methylsulfate (C1Py C1SO4 and two high charge density potassium inorganic salts (K2CO3 and K2HPO4 were determined by the cloud point method at 298.15 K. The influence of the addition of the selected inorganic salts to aqueous mixtures of ILs was discussed in the light of the Hofmeister series and in terms of molar Gibbs free energy of hydration. The effect of the alkyl chain length of the cation on the methylsulfate-based ILs has been investigated. All the solubility data were satisfactorily correlated to several empirical equations. A pesticide (pentachlorophenol, PCP extraction process based on the inorganic salt providing a greater salting out effect was tackled. The viability of the proposed process was analyzed in terms of partition coefficients and extraction efficiencies.

  4. Pesticide Removal from Aqueous Solutions by Adding Salting Out Agents

    Science.gov (United States)

    Moscoso, Fátima; Deive, Francisco J.; Esperança, José M. S. S.; Rodríguez, Ana

    2013-01-01

    Phase segregation in aqueous biphasic systems (ABS) composed of four hydrophilic ionic liquids (ILs): 1-butyl-3-methylimidazolium methylsulfate and 1-ethyl-3-methylimidazolium methylsulfate (CnC1im C1SO4, n = 2 and 4), tributylmethyl phosphonium methylsulfate (P4441 C1SO4) and methylpyridinium methylsulfate (C1Py C1SO4) and two high charge density potassium inorganic salts (K2CO3 and K2HPO4) were determined by the cloud point method at 298.15 K. The influence of the addition of the selected inorganic salts to aqueous mixtures of ILs was discussed in the light of the Hofmeister series and in terms of molar Gibbs free energy of hydration. The effect of the alkyl chain length of the cation on the methylsulfate-based ILs has been investigated. All the solubility data were satisfactorily correlated to several empirical equations. A pesticide (pentachlorophenol, PCP) extraction process based on the inorganic salt providing a greater salting out effect was tackled. The viability of the proposed process was analyzed in terms of partition coefficients and extraction efficiencies. PMID:24145747

  5. Effect of temperature and salting-out agents on the sorption of nitrophenols from aqueous solutions

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    E. V. Churilina

    2013-01-01

    Full Text Available Sorption of nitrophenols from aqueous media by сrosslinked N-vinylpyrrolidone-based polymer in static conditions are studied depending on the pH of the solution and the nature of the nitrophenols. It has been established that a temperature and the introduction of salting-out agents influence on the sorption of nitrophenols.

  6. Effects of physicochemical properties of salting-out layer components on drug release.

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    Tasaki, Hiroaki; Yoshida, Takayuki; Maeda, Atsushi; Katsuma, Masataka; Sako, Kazuhiro

    2009-07-06

    A "Salting-out Taste-masking System" generates a long lag time for numbness and bitterness masking, with subsequent immediate drug release to exert pharmacological effects. In this study, the effects of physicochemical properties of salting-out agents and water-soluble polymers in the salting-out layer on the dissolution behaviors of acetaminophen were investigated and predominant factors for lag time generation (Lag time index, hereafter LI) and subsequent drug release (Rapid release index, hereafter RI) were discussed. Each prepared formulation showed a different dissolution profile of acetaminophen with a lag time and subsequent immediate release. Significant correlations between both LI and RI and DeltaCST (the salting-out power of salting-out agents) (r(2)=0.90, 0.67, respectively) and between both LI and RI and CST(1) (the sensitivity of water-soluble polymers to a salting-out effect) (r(2)=0.98, 0.71, respectively) were shown. These results suggest that the components showing a strong salting-out effect inside the beads lead to extended lag times and slow drug releases after the lag times. Results further suggest the use of CST(1) to evaluate suitable combinations of salting-out agents and water-soluble polymers in this system.

  7. Pesticide Removal from Aqueous Solutions by Adding Salting Out Agents

    OpenAIRE

    Fátima Moscoso; Francisco J. Deive; José M. S. S. Esperança; Ana Rodríguez

    2013-01-01

    Phase segregation in aqueous biphasic systems (ABS) composed of four hydrophilic ionic liquids (ILs): 1-butyl-3-methylimidazolium methylsulfate and 1-ethyl-3-methylimidazolium methylsulfate (CnC1im C1SO4, n = 2 and 4), tributylmethyl phosphonium methylsulfate (P4441 C1SO4) and methylpyridinium methylsulfate (C1Py C1SO4) and two high charge density potassium inorganic salts (K2CO3 and K2HPO4) were determined by the cloud point method at 298.15 K. The influence of the addition of the selected i...

  8. Anion bridges drive salting out of a simple amphiphile from aqueous solution

    OpenAIRE

    Bowron, D. T.; Finney, J. L.

    2002-01-01

    Neutron diffraction with isotope substitution has been used to determine the structural changes that occur on the addition of a simple salting-out agent to a dilute aqueous alcohol solution. The striking results obtained demonstrate a relatively simple process occurs in which interamphiphile anionic salt bridges are formed between the polar groups of the alcohol molecules. These ion bridges drive an increase in the exposure of the alcohol molecule nonpolar surface to the solvent water and hen...

  9. Salting Out Effect of Electrolyte Solutions in The Extraction of ...

    African Journals Online (AJOL)

    USER

    ABSTRACT: The salting-out effect of various solutions of electrolyte in the extraction of tantalum and niobium using aqueous biphasic system (ABS) was ... using X-ray fluorescence method. The results show that the percentage ... Liquid/ liquid extraction separates the components of a homogeneous liquid mixture on the ...

  10. Salting-out assisted liquid-liquid extraction for bioanalysis.

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    Tang, Yong Q; Weng, Naidong

    2013-06-01

    Salting-out assisted liquid-liquid extraction (SALLE) applies the salting-out effect to separate water-miscible organic solvent such as acetonitrile from plasma or other aqueous biofluids, and can extract a wide range of drug and metabolites, including many hydrophilic compounds. In most cases, the separated organic phase can be directly injected for bioanalysis, or with a simple dilution. SALLE provides similar simplicity to protein precipitation, but cleaner extracts due to a true phase separation. SALLE is also faster, more environmentally friendly and more cost-efficient than conventional liquid-liquid extraction and SPE. Through 96-well automation, SALLE can be easily integrated into the overall high-throughput LC-MS/MS bioanalysis strategy to increase productivity. This article provides a critical overview of the literatures on SALLE and perspectives of the future bioanalytical application of this often overlooked extraction technique. Important parameters impacting SALLE-LC-MS/MS assays are also discussed.

  11. Amplification of salt-induced polymer diffusiophoresis by increasing salting-out strength.

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    McAfee, Michele S; Zhang, Huixiang; Annunziata, Onofrio

    2014-10-21

    The role of salting-out strength on (1) polymer diffusiophoresis from high to low salt concentration, and (2) salt osmotic diffusion from high to low polymer concentration was investigated. These two cross-diffusion phenomena were experimentally characterized by Rayleigh interferometry at 25 °C. Specifically, we report ternary diffusion coefficients for polyethylene glycol (molecular weight, 20 kg·mol(-1)) in aqueous solutions of several salts (NaCl, KCl, NH4Cl, CaCl2, and Na2SO4) as a function of salt concentration at low polymer concentration (0.5% w/w). We also measured polymer diffusion coefficients by dynamic light scattering in order to discuss the interpretation of these transport coefficients in the presence of cross-diffusion effects. Our cross-diffusion results, primarily those on salt osmotic diffusion, were utilized to extract N(w), the number of water molecules in thermodynamic excess around a macromolecule. This preferential-hydration parameter characterizes the salting-out strength of the employed salt. For chloride salts, changing cation has a small effect on N(w). However, replacing NaCl with Na2SO4 (i.e., changing anion) leads to a 3-fold increase in N(w), in agreement with cation and anion Hofmeister series. Theoretical arguments show that polymer diffusiophoresis is directly proportional to the difference N(w) - n(w), where n(w) is the number of water molecules transported by the migrating macromolecule. Interestingly, the experimental ratio, n(w)/N(w), was found to be approximately the same for all investigated salts. Thus, the magnitude of polymer diffusiophoresis is also proportional to salting-out strength as described by N(w). A basic hydrodynamic model was examined in order to gain physical insight on the role of n(w) in particle diffusiophoresis and explain the observed invariance of n(w)/N(w). Finally, we consider a steady-state diffusion problem to show that concentration gradients of strong salting-out agents such as Na2SO4 can

  12. Arginine increases the solubility of coumarin: comparison with salting-in and salting-out additives.

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    Hirano, Atsushi; Arakawa, Tsutomu; Shiraki, Kentaro

    2008-09-01

    Poor aqueous solubility of low molecular weight drug substances hampers their development as pharmacological agents. Here, we have examined the effects of arginine on the solubility of organic compounds, coumarin, caffeine and benzyl alcohol, in aqueous solution. Arginine increased the solubility of aromatic coumarin, but not non-aromatic caffeine, concentration dependently, suggesting the favourable interaction of arginine with the aromatic structure. Consistent with this, arginine also increased the solubility of aromatic benzyl alcohol. Guanidine hydrochloride, urea and salting-in salts increased both coumarin and caffeine solubilities, while salting-out salts decreased them. These results suggest the specific interaction of arginine with aromatic groups, leading to increased solubility of coumarin. However, the effect of 1 M arginine on coumarin solubility was at most approximately 2-fold, which may limit its applications as a solubility enhancing agent.

  13. Another glimpse over the salting-out assisted liquid-liquid extraction in acetonitrile/water mixtures.

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    Valente, Inês Maria; Gonçalves, Luís Moreira; Rodrigues, José António

    2013-09-20

    The use of the salting-out effect in analytical chemistry is very diverse and can be applied to increase the volatility of the analytes in headspace extractions, to cause the precipitation of proteins in biological samples or to improve the recoveries in liquid-liquid extractions. In the latter, the salting-out process can be used to create a phase separation between water-miscible organic solvents and water. Salting-out assisted liquid-liquid extraction (SALLE) is an advantageous sample preparation technique aiming HPLC-UV analysis when developing analytical methodologies. In fact, some new extraction methodologies like QuEChERS include the SALLE concept. This manuscript discusses another point of view over SALLE with particular emphasis over acetonitrile-water mixtures for HPLC-UV analysis; the influence of the salting-out agents, their concentration and the water-acetonitrile volume ratios were the studied parameters. α-dicarbonyl compounds and beer were used as test analytes and test samples, respectively. The influence of the studied parameters was characterized by the obtained phase separation volume ratio and the fraction of α-dicarbonyls extracted to the acetonitrile phase. Results allowed the distribution of salts within three groups according to the phase separation and their extractability: (1) chlorides and acetates, (2) carbonates and sulfates and (3) magnesium sulfate; of all tested salts, sodium chloride had the highest influence on the α-dicarbonyls fraction extracted. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Salting out the polar polymorph: analysis by alchemical solvent transformation.

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    Duff, Nathan; Dahal, Yuba Raj; Schmit, Jeremy D; Peters, Baron

    2014-01-07

    We computationally examine how adding NaCl to an aqueous solution with α- and γ-glycine nuclei alters the structure and interfacial energy of the nuclei. The polar γ-glycine nucleus in pure aqueous solution develops a melted layer of amorphous glycine around the nucleus. When NaCl is added, a double layer is formed that stabilizes the polar glycine polymorph and eliminates the surface melted layer. In contrast, the non-polar α-glycine nucleus is largely unaffected by the addition of NaCl. To quantify the stabilizing effect of NaCl on γ-glycine nuclei, we alchemically transform the aqueous glycine solution into a brine solution of glycine. The alchemical transformation is performed both with and without a nucleus in solution and for nuclei of α-glycine and γ-glycine polymorphs. The calculations show that adding 80 mg/ml NaCl reduces the interfacial free energy of a γ-glycine nucleus by 7.7 mJ/m(2) and increases the interfacial free energy of an α-glycine nucleus by 3.1 mJ/m(2). Both results are consistent with experimental reports on nucleation rates which suggest: J(α, brine) effect of salt addition. Only the alchemical solvent transformation approach can predict the results for both polar and non-polar polymorphs. The results suggest a general "salting out" strategy for obtaining polar polymorphs and also a general approach to computationally estimate the effects of solvent additives on interfacial free energies for nucleation.

  15. Comparison of DNA isolation using salting-out procedure and automated isolation (MagNA system).

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    Kalousová, Marta; Levová, Kateřina; Kuběna, Aleš A; Jáchymová, Marie; Franková, Věra; Zima, Tomáš

    2017-08-09

    Isolation of genomic DNA is a key step in genetic analysis. The aim of the study was to evaluate the suitability of isolation of DNA from peripheral blood with manual salting-out procedure and automated MagNA system under specific conditions. The impact of storage conditions, type of material (whole blood or blood cells), and method used for DNA extraction were evaluated in terms of DNA yield, its purity, and integrity. Fresh material, and material stored at 2-8°C for 1-4 weeks and frozen at -80°C were tested. For fresh samples, salting-out method gives higher yield than MagNA, irrespectively, on material used. Neither the yield of salting-out method nor its purity decreases during the storage of the samples in the fridge (2-8°C) during 4 weeks. Concerning MagNA, storage of blood cells in the fridge decreases the yield of DNA as well as its purity. For frozen samples, for whole blood, MagNA gives better results while for blood cells, salting-out method seems to be better. For fresh samples, salting-out method is the preferred one, and both whole blood and blood cells can be used. For frozen samples, the preferred method depends on the material.

  16. Using solid phase micro extraction to determine salting-out (Setschenow) constants for hydrophobic organic chemicals.

    NARCIS (Netherlands)

    Jonker, M.T.O.|info:eu-repo/dai/nl/175518793; Muijs, B.|info:eu-repo/dai/nl/194995526

    2010-01-01

    With increasing ionic strength, the aqueous solubility and activity of organic chemicals are altered. This so-called salting-out effect causes the hydrophobicity of the chemicals to be increased and sorption in the marine environment to be more pronounced than in freshwater systems. The process can

  17. Density Fluctuation in Aqueous Solutions and Molecular Origin of Salting-Out Effect for CO2.

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    Ho, Tuan Anh; Ilgen, Anastasia

    2017-12-28

    Using molecular dynamics simulation, we studied the density fluctuations and cavity formation probabilities in aqueous solutions and their effect on the hydration of CO 2 . With increasing salt concentration, we report an increased probability of observing a larger than the average number of species in the probe volume. Our energetic analyses indicate that the van der Waals and electrostatic interactions between CO 2 and aqueous solutions become more favorable with increasing salt concentration, favoring the solubility of CO 2 (salting in). However, due to the decreasing number of cavities forming when salt concentration is increased, the solubility of CO 2 decreases. The formation of cavities was found to be the primary control on the dissolution of gas, and is responsible for the observed CO 2 salting-out effect. Our results provide the fundamental understanding of the density fluctuation in aqueous solutions and the molecular origin of the salting-out effect for real gas.

  18. Salting-in and salting-out of water-soluble polymers in aqueous salt solutions.

    Science.gov (United States)

    Sadeghi, Rahmat; Jahani, Farahnaz

    2012-05-03

    To obtain further experimental evidence for the mechanisms of the salting effect produced by the addition of salting-out or sating-in inducing electrolytes to aqueous solutions of water-soluble polymers, systematic studies on the vapor-liquid equilibria and liquid-liquid equilibria of aqueous solutions of several polymers are performed in the presence of a large series of electrolytes. Polymers are polyethylene glycol 400 (PEG400), polyethylene glycol dimethyl ether 250 (PEGDME250), polyethylene glycol dimethyl ether 2000 (PEGDME2000), and polypropylene glycol 400 (PPG400), and the investigated electrolytes are KCl, NH(4)Cl, MgCl(2), (CH(3))(4)NCl, NaCl, NaNO(3), Na(2)CO(3), Na(2)SO(4), and Na(3)Cit (tri-sodium citrate). Aqueous solutions of PPG400 form aqueous two-phase systems with all the investigated salts; however, other investigated polymers form aqueous two-phase systems only with Na(2)CO(3), Na(2)SO(4), and Na(3)Cit. A relation was found between the salting-out or sating-in effects of electrolyte on the polymer aqueous solutions and the slopes of the constant water activity lines of ternary polymer-salt aqueous solutions, so that, in the case of the salting-out effect, the constant water activity lines had a concave slope, but in the case of the salting-in effects, the constant water activity lines had a convex slope. The effect of temperature, anion of electrolyte, cation of electrolyte, and type and molar mass of polymers were studied and the results interpreted in terms of the solute-water and solute-solute interactions. The salting-out effect results from the formation of ion (specially anion)-water hydration complexes, which, in turn, decreases hydration, and hence, the solubility of the polymer and the salting-in effect results from a direct binding of the cations to the ether oxygens of the polymers.

  19. Salting out of methane by sodium chloride: A scaled particle theory study.

    Science.gov (United States)

    Graziano, Giuseppe

    2008-08-28

    The salting out of methane by adding NaCl to water at 25 degrees C and 1 atm is investigated by calculating the work of cavity creation by means of scaled particle theory and the methane-solvent energy of attraction. The latter quantity changes to little extent on passing from pure water to an aqueous 4M NaCl solution, whereas the magnitude of the work of cavity creation increases significantly, accounting for the salting out effect. There is quantitative agreement between the experimental values of the hydration Gibbs energy and the calculated ones. The behavior of the work of cavity creation is due to the increase in the volume packing density of NaCl solutions, since the average effective molecular diameter does not change, being always 2.80 A. The same approach allows the rationalization of the difference in methane salting out along the alkali chloride series. These results indicate that, fixed the aqueous solution density, the solubility of nonpolar species is mainly determined by the effective diameter of solvent molecules and the corresponding volume packing density. There is no need to take into account the H-bond rearrangement because it is characterized by an almost complete enthalpy-entropy compensation.

  20. The influence of salting out on the sorption of neutral organic compounds in estuaries.

    Science.gov (United States)

    Turner, A; Rawling, M C

    2001-12-01

    The relative (unsaturated) solubility and sorption of 2,2',5,5'-tetrachlorobiphenyl have been studied along an estuarine salinity gradient. The aqueous compound was salted out with increasing salinity and an aqueous salting constant of about 0.0021 g(-1) was derived. Sorption of the compound to estuarine particles increased with increasing salinity for a range of particle concentrations, but the magnitude of this effect (sorption salting constants of about 0.005-0.011 g(-1)) indicated that salting out of the aqueous phase was not solely responsible. It is suggested that the hydrophobicity of sediment organic matter is enhanced by its interaction with seawater ions through a reduction in the charge of the particle surface and, possibly, modification of the structure of the organic matter. Examination of literature data on the sorption of neutral organic compounds to estuarine sediment indicates a general increase in sorption with increasing salinity which can be empirically defined by a salting equation. Although charge reduction of estuarine particles is a general observation, it is not possible to establish the general significance of this effect (or any other form of salting out of sediment organic matter) on the sorption of organic compounds in estuaries because appropriate site- and compound-specific aqueous salting constants are unavailable. Increased sorption at high salinities has obvious implications for the disposal and transport of organic chemicals in estuaries. However, the inverse dependency of sediment-water partitioning on particle concentration is likely to be of at least equal significance in macrotidal environments where sediment resuspension occurs. An empirical model, combining the effects of salinity and particle concentration, is proposed for deriving first-order estimates of the partitioning of neutral organic compounds in estuaries.

  1. Aqueous salting-out effect of inorganic cations and anions on non-electrolytes.

    Science.gov (United States)

    Görgényi, Miklós; Dewulf, Jo; Van Langenhove, Herman; Héberger, Károly

    2006-10-01

    The salting-out effects of 27 lithium, sodium, potassium, ammonium and magnesium salts and HCl on chloroform, benzene, chlorobenzene and anisole were characterized in aqueous solutions at 303 K by measuring the Henry's law constants. The concentration of the salt solutions was 0.5 mol dm(-3), i.e., similar to the salinity of sea water. The solubility change was described in terms of the Setschenow constant, K(S)(salt,solute). The highest salting-out effects were observed for the solutions of salts involving doubly charged anions, and the smallest for NO(-)(3). The individual ionic Setschenow constants, K(S)(cation,solute) and K(S)(anion,solute), were determined by multilinear regression, using the assumption of additivity for the ions. Cl(-) was selected as the reference ion for calculation of the K(S)(ion,solute) values of the other ions. The estimations resulted systematically in significant positive K(S)(cation,solute) values, ranging from 0.13+/-0.026 (NH(+)(4)) to 0.28+/-0.032 (Mg(2+)), which were hardly affected by the accompanying anion in solution, and only slightly affected by the non-electrolytes present. NO(-)(3) resulted in a slight salting-in effect: K(S)(NO(-)(3),solute)=-0.083+/-0.019; the other anions displayed salting-out effect for all of the non-electrolytes studied, with K(S)(anion,solute) ranging between 0.090+/-0.008 (HCO(-)(3)) and 0.21+/-0.035 (CO(2-)(3)).

  2. Recovery of aniline from wastewater by nitrobenzene extraction enhanced with salting-out effect.

    Science.gov (United States)

    Li, Chang-Hai

    2010-06-01

    Nitrobenzene extraction enhanced by salting-out effect was employed to recover aniline from wastewater at 25 degrees C. Batchwise experiments were conducted to elucidate the influence of various operating variables on the extracting performance, including acidity of wastewater, initial aniline concentration, ratios of solvent to wastewater, extraction stages, concentrations and different types of inorganic salts, such as NaCl, KCl, Na(2)SO(4), CaCl(2) and K(2)SO(4). Nitrobenzene with a concentration of 20% and a pH value of 9.1 at the temperature of 25 degrees C together with NaCl of a concentration of 14 wt.% realized nearly 100% aniline recovery at the fifth stage of wastewater treatment. High pH values and volume ratios of nitrobenzene/wastewater are more suitable for recovery of aniline. In addition, recovery of aniline is significantly elevated with increase of the concentration of salts, whose promoting effects are in the following order: NaCl>Na(2)SO(4)>K(2)SO(4)>CaCl(2)>KCl on the weight basis of wastewater. Furthermore, aniline in wastewater can be almost completely recovered by five-stage sequential nitrobenzene extraction, which is promoted continuously by the salting-out effect. Copyright © 2010 The Editorial Board of Biomedical and Environmental Sciences. Published by Elsevier B.V. All rights reserved.

  3. Using solid phase micro extraction to determine salting-out (Setschenow) constants for hydrophobic organic chemicals.

    Science.gov (United States)

    Jonker, Michiel T O; Muijs, Barry

    2010-06-01

    With increasing ionic strength, the aqueous solubility and activity of organic chemicals are altered. This so-called salting-out effect causes the hydrophobicity of the chemicals to be increased and sorption in the marine environment to be more pronounced than in freshwater systems. The process can be described with empirical salting-out or Setschenow constants, which traditionally are determined by comparing aqueous solubilities in freshwater and saline water. Aqueous solubilities of hydrophobic organic chemicals (HOCs) however are difficult to determine, which might partly explain the limited size of the existing data base on Setschenow constants for these chemicals. In this paper, we propose an alternative approach for determining the constants, which is based on the use of solid phase micro extraction (SPME) fibers. Partitioning of polycyclic aromatic hydrocarbons (PAHs) to SPME fibers increased about 1.7 times when going from de-ionized water to seawater. From the log-linear relationship between SPME fiber-water partition coefficients and ionic strength, Setschenow constants were derived, which measured on average 0.35 L mol(-1). These values agreed with literature values existing for some of the investigated PAHs and were independent of solute hydrophobicity or molar volume. Based on the present data, SPME seems to be a convenient and suitable alternative technique to determine Setschenow constants for HOCs. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  4. Recovery of nitrotoluenes from wastewater by solvent extraction enhanced with salting-out effect.

    Science.gov (United States)

    Chen, Wen-Shing; Chiang, Wen-Chih; Wei, Kuo-Ming

    2007-08-17

    Toluene extraction enhanced by salting-out effect was employed to recover dinitrotoluene isomers and 2,4,6-trinitrotoluene (2,4,6-TNT) from wastewater of toluene nitration processes (e.g. dinitration or trinitration). The batchwise experiments were conducted to elucidate the influence of various operating variables on the extracting performance, including concentrations and species of inorganic salts, such as NaCl, KCl, Na(2)SO(4), K(2)SO(4) and MgSO4, acidity of wastewater, volume ratios of solvent versus wastewater and extraction stages in existence of inorganic salts. It was found that recovery of total organic compounds (TOC) was significantly elevated with increasing concentrations of salts, whose promoting effects were in the following order: NaCl>Na(2)SO(4)>K(2)SO(4)>MgSO4>KCl on the weight basis of wastewater. Besides, high volume ratio of toluene/wastewater (ca. 2.0) was more suitable for recovery of TOC from wastewater with or without addition of NaCl, of which extractable priority was as follows: 2,6-DNT>2,4-DNT>2,4,6-TNT. It is remarkable that TOC in wastewater would be almost completely recovered by sequential four stages toluene extraction, promoted continuously by salting-out effect.

  5. Preparation of enteric microsphere of oleanolic acid dihemiphthalate sodium by salting-out action using spherical crystallization technique.

    Science.gov (United States)

    Fan, Yu-ling; Cui, Fu-de; Yang, Ming-shi; Ji, Yu-bin

    2005-03-01

    Enteric microspheres were prepared to prevent the interaction of drug with gastric acid and to improve its bioavailability. The enteric microspheres with a matrix structure were successfully produced using a spherical crystallization technique. Hydroxypropyl methylcellulose phthalate (HP-55), an enteric material, was coprecipitated with the drug by salting-out effect during the preparation process. A mixture of water and ethanol was chosen as a good solvent and dichloromethane was used as a bridging agent while 0.1 mol x L(-1) sodium chloride solution was selected as a poor solvent. It is the first time to prepare microspheres by making the water-soluble drug and water-insoluble excipient coprecipitated. In vivo test demonstrated that the drug absorption from the enteric oleanolic acid dihemiphthalate sodium (OADHPS) microspheres was significantly prolonged compared to that with OADHPS powder after a lag-time. Furthermore, the drug bioavailability was 181.6% greater than that with the OADHPS powder. The microspheres of water soluble drug could be prepared by using water phase replacing organic phase as poor solvent which decrease the quantity of organic solvent and benefit the environment prevention.

  6. Salting-out effects in aqueous ionic liquid solutions: cloud-point temperature shifts.

    Science.gov (United States)

    Trindade, Joana R; Visak, Zoran P; Blesic, Marijana; Marrucho, Isabel M; Coutinho, João A P; Lopes, José N Canongia; Rebelo, Luis P N

    2007-05-10

    The effects of the addition of three inorganic salts, namely, NaCl, Na(2)SO(4), and Na(3)PO(4), on the liquid-liquid (L-L) phase diagram of aqueous solutions containing the model ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate, [bmim][BF(4)], were investigated. All three inorganic salts trigger salting-out effects, leading to significant upward shifts of the L-L demixing temperatures of the systems. The magnitude of the shifts depends on both the water-structuring nature of the salt and its concentration; that is, the effects are correlated with the ionic strength of the solution and the Gibbs free energy of hydration of the inorganic salt. The pH effect and the occurrence of salt precipitation in concentrated solutions are also discussed.

  7. Investigation of the salting out of methane from aqueous electrolyte solutions using computer simulations.

    Science.gov (United States)

    Docherty, H; Galindo, A; Sanz, E; Vega, C

    2007-08-02

    We calculate the excess chemical potential of methane in aqueous electrolyte solutions of NaCl using Monte Carlo computer simulations. In a recent work [Docherty et al. J. Chem. Phys. 2006, 125, 074510], we presented a new potential model for methane in water which is capable of describing accurately the excess chemical potential of methane in pure water over a range of temperatures, a quantity that can be related to the solubility and which is commonly used to study the hydrophobic effect. Here, we use the same potential model for the water-methane interactions and investigate the effect of added salt on the chemical potential of methane in the solution. The methane molecules are modeled as single Lennard-Jones (LJ) interaction sites, and the water molecules are modeled with the TIP4P/2005 model. A correcting factor of chi = 1.07 for the energetic Berthelot (geometric) combining rule of the methane-water interaction is also used, which mimics the polarization of methane in water. We consider NaCl as the salt and treat the ions with the Smith and Dang model (i.e., as charged LJ interaction sites). Ion-water, ion-ion, and ion-methane interactions are treated using Lorentz-Berthelot combining rules. In addition, the Coulombic potential is used to model charge-charge interactions which are calculated using the Ewald sum. We have carried out isobaric-isothermal (NpT) simulations to determine the equilibrium densities of the solutions. The simulation data is in excellent agreement with experimental densities of aqueous NaCl solutions of different concentration. Hydration numbers are also obtained and found to be in agreement with reported data. Canonical (NVT) simulations at the averaged densities are then performed using the Widom test-particle insertion method to obtain the excess chemical potential of methane in the saline solutions. An increase in the chemical potential of methane, corresponding to a salting out effect, is observed when salt is added to the solution

  8. Measuring and modeling the salting-out effect in ammonium sulfate solutions.

    Science.gov (United States)

    Wang, Chen; Lei, Ying Duan; Endo, Satoshi; Wania, Frank

    2014-11-18

    The presence of inorganic salts significantly influences the partitioning behavior of organic compounds between environmentally relevant aqueous phases, such as seawater or aqueous aerosol, and other, nonaqueous phases (gas phase, organic phase, etc.). In this study, salting-out coefficients (or Setschenow constants) (KS [M(-1)]) for 38 diverse neutral compounds in ammonium sulfate ((NH4)2SO4) solutions were measured using a shared headspace passive dosing method and a negligible depletion solid phase microextraction technique. The measured KS were all positive, varied from 0.216 to 0.729, and had standard errors in the range of 0.006-0.060. Compared to KS for sodium chloride (NaCl) in the literature, KS values for (NH4)2SO4 are always higher for the same compound, suggesting a higher salting-out effect of (NH4)2SO4. A polyparameter linear free energy relationship (pp-LFER) for predicting KS in (NH4)2SO4 solutions was generated using the experimental data for calibration. pp-LFER predicted KS agreed well with measured KS reported in the literature. KS for (NH4)2SO4 was also predicted using the quantum-chemical COSMOtherm software and the thermodynamic model AIOMFAC. While COSMOtherm generally overpredicted the experimental KS, predicted and experimental values were correlated. Therefore, a fitting factor needs to be applied when using the current version of COSMOtherm to predict KS. AIOMFAC tends to underpredict the measured KS((NH4)2SO4) but always overpredicts KS(NaCl). The prediction error is generally larger for KS(NaCl) than for KS((NH4)2SO4). AIOMFAC also predicted a dependence of KS on the salt concentrations, which is not observed in the experimental data. In order to demonstrate that the models developed and calibrated in this study can be applied to estimate Setschenow coefficients for atmospherically relevant compounds involved in secondary organic aerosol formation based on chemical structure alone, we predicted and compared KS for selected

  9. Salting-out assisted liquid-liquid extraction and partial least squares regression to assay low molecular weight polycyclic aromatic hydrocarbons leached from soils and sediments

    Science.gov (United States)

    Bressan, Lucas P.; do Nascimento, Paulo Cícero; Schmidt, Marcella E. P.; Faccin, Henrique; de Machado, Leandro Carvalho; Bohrer, Denise

    2017-02-01

    A novel method was developed to determine low molecular weight polycyclic aromatic hydrocarbons in aqueous leachates from soils and sediments using a salting-out assisted liquid-liquid extraction, synchronous fluorescence spectrometry and a multivariate calibration technique. Several experimental parameters were controlled and the optimum conditions were: sodium carbonate as the salting-out agent at concentration of 2 mol L- 1, 3 mL of acetonitrile as extraction solvent, 6 mL of aqueous leachate, vortexing for 5 min and centrifuging at 4000 rpm for 5 min. The partial least squares calibration was optimized to the lowest values of root mean squared error and five latent variables were chosen for each of the targeted compounds. The regression coefficients for the true versus predicted concentrations were higher than 0.99. Figures of merit for the multivariate method were calculated, namely sensitivity, multivariate detection limit and multivariate quantification limit. The selectivity was also evaluated and other polycyclic aromatic hydrocarbons did not interfere in the analysis. Likewise, high performance liquid chromatography was used as a comparative methodology, and the regression analysis between the methods showed no statistical difference (t-test). The proposed methodology was applied to soils and sediments of a Brazilian river and the recoveries ranged from 74.3% to 105.8%. Overall, the proposed methodology was suitable for the targeted compounds, showing that the extraction method can be applied to spectrofluorometric analysis and that the multivariate calibration is also suitable for these compounds in leachates from real samples.

  10. Molecular simulation of the salting out effect in the system H2S-H2O-NaCl.

    Science.gov (United States)

    Vorholz, Johannes; Maurer, Gerd

    2008-12-28

    The reduction of the solubility of a gas due to the presence of ionic species in a solvent is called "salting-out". The "salting-out" of hydrogen sulfide by sodium chloride in water was predicted by Gibbs ensemble Monte Carlo simulation at temperatures between 373 and 423 K and at salt molalities up to 10 mol kg(-1). The intermolecular interactions were modeled by combining Lennard-Jones potentials with Coulomb interactions. Several force fields were examined. The interactions between unlike species were estimated using two common combining rules without any adjustable parameters for the dispersion interaction. The simulations predict the "salting-out" of hydrogen sulfide by sodium chloride in aqueous solutions in an at least qualitative, partly in a quantitative manner.

  11. [Research progress in salting-out extraction of bio-based chemicals].

    Science.gov (United States)

    Dai, Jianying; Liu, Chunjiao; Sun, Yaqin; Xiu, Zhilong

    2013-10-01

    Bio-refinery using cheap biomass focuses mainly on strain improvement and fermentation strategies whereas less effort is made on down-stream processing. Using cheap biomass more impurities are introduced into the fermentation broths than mono-sugar substrate, thus down-stream processing for bio-based chemicals becomes the key problem in industrial production. The technique called salting-out extraction (SOE) was introduced in this review, which is used to separate target products from fermentation broth on the basis of partition difference of chemicals in two phases formed by mixing salts and organic solvents (or amphipathic chemicals) with broth at suitable ratios. The effect of solvents and salts on the formation of two aqueous phases, especially short chain alcohols and inorganic salts, and the application of SOE in recovery of bio-based chemicals, such as lactic acid, 1,3-propanediol, 2,3-butanediol and acetoin were summarized. The bio-chemicals were efficiently recovered from fermentation broth, and most of the impurities (cells and proteins) were removed in the same step. This technique is promising in the separation of bio-based chemicals, especially the recovery of hydrophilic molecules with low molecular weights.

  12. Specific features of the salting-out of oxyethylated nonylphenols using inorganic salts at 25°C

    Science.gov (United States)

    Stankova, A. V.; Elokhov, A. M.; Denisova, S. A.; Kudryashova, O. S.; Lesnov, A. E.

    2017-05-01

    The solubility of oxyethylated nonylphenols (neonol AF 9-12 and neonol AF 9-25) in aqueous solutions of inorganic salts is studied at 25°C. Cation and anion abilities to salt out neonols from aqueous solutions are examined. It is found that anions are able to salt out neonols while cations are able to salt in neonols. The concentration parameters of extraction in water-neonol AF 9-12 (neonol AF 9-25)-(NH4)2SO4 systems are optimized.

  13. Salting-out phenomenon and 1-octanol/water partition coefficient of metalaxyl pesticide.

    Science.gov (United States)

    Saab, J; Bassil, G; Abou Naccoul, R; Stephan, J; Mokbel, I; Jose, J

    2011-02-01

    In this paper, we present the effect of inorganic cations such as Na+, K+, Ca2+, Mg2+ on the salting-out phenomenon of metalaxyl from pure water to aqueous salt solutions. Moreover the 1-octanol/water partition coefficient in pure water is presented. To accomplish this, aqueous solubility of metalaxyl was determined in pure water, in different salt solution (NaCl, KCl, CaCl2 and MgCl2), and at different concentration level ranging from 0.01 to 1.5 M. The 1-octanol/water partition coefficient was determined using the static shake-flask method. Solubility was determined using dynamic saturation method for pure water in the range of 298.15-325.15 K and at 298.15 K for different salt solutions. The solubility value in pure water for studied interval was found constant (m=3.118×10(-2) mol kg(-1)). Solubility values were used to calculate the standard molar Gibbs free energy of dissolution (ΔsolG°) and transfer (ΔtrG°) at 298.15 K. The values of ΔtrG° from pure to all studied aqueous salt solutions did not exceed 2 kJ mol(-1), the value of ΔsolG° of dissolution is 18.5 ±0.72 kJ mol(-1). The 1-octanol/water partition coefficient in pure water log Ko/w is equal to 1.69. The obtained results confirm the classification of the neutral metalaxyl as a slightly hydrophobic molecule. Copyright © 2010. Published by Elsevier Ltd.

  14. On the variability of the salting-out curves of proteins of normal human plasma and serum

    NARCIS (Netherlands)

    Steyn-Parvé, Elizabeth P.; Hout, A.J. van den

    1953-01-01

    Salting-out curves of proteins of normal human plasma reflect the influence of a number of other factors besides the protein composition: the manner of obtaining the blood, the nature of the anti-coagulant used, the non-protein components of the plasma. Diagrams of serum and plasma obtained from

  15. Extraction of chromium(VI) by salting-out with a homogeneous, mixed solvent of water and 2-propanol: a laboratory study.

    Science.gov (United States)

    Samaratunga, Sethsiri S; Nishimoto, Jun; Tabata, Masaaki

    2008-01-01

    Chromium enters into the aquatic environment as a result of effluent discharge from steel works, electroplating, leather tanning industries and chemical industries. As the Cr(VI) is very harmful to living organisms, it should be quickly removed from the environment when it happens to be contaminated. Therefore, the aim of this laboratory research was to develop a rapid, simple and adaptable solvent extraction system to quantitatively remove Cr(VI) from polluted waters. Aqueous salt-solutions containing Cr(VI) as CrO4(2-) at ppm level (4-6 ppm) were prepared. Equal volumes (5 ml) of aqueous and organic (2-PrOH) phases were mixed in a 10 ml centrifuge tube for 15 min, centrifuged and separated. Concentrations of Cr(VI), in both the aqueous and organic phases, were determined by atomic absorption spectrometry. The effects of salt and acid concentrations, and phase-contact time on the extraction of Cr(VI) were investigated. In addition, the extraction of Cr(VI) was assessed in the presence of tetramethylammonium chloride (TMAC) in 2-PrOH phase. Effects of some other metals, (Cd(II), Co(II), Cu(II), Ni(II) and Zn(II)), on the extraction of Cr(VI) were also investigated. The Cr(VI) at ppm level was extracted quantitatively by salting-out the homogeneous system of water and 2-propanol(2-PrOH) using chloride salts, namely CaCl2 or NaCl, under acidic chloride media. The extracted chemical species of Cr(VI) was confirmed to be the CrO3Cl-. The ion-pair complex extracted into the organic phase was rationalized as the solvated ion-pair complex of [2-PrOH2+, CrO3Cl-]. The complex was no longer stable. It implied the reaction between extracted species. Studies revealed that salts and acid directly participated in the formation of the above complex. Use of extracting agents (TMAC) didn't show any significant effect on the extraction of Cr(VI) under high salting-out conditions. There is no significant interference effect on the extraction of Cr(VI) by the presence of other metals

  16. Salting-out in Aqueous Solutions of Ionic Liquids and K3PO4: Aqueous Biphasic Systems and Salt Precipitation

    Directory of Open Access Journals (Sweden)

    Luís P. N. Rebelo

    2007-07-01

    Full Text Available The salting-out effect produced by the addition of potassium phosphate, K3PO4to aqueous solutions of water-miscible ionic liquids, viz. 1-ethyl-3-methylimidazoliumethyl sulfate, 1-butyl-3-methylimidazolium methyl sulfate, or 1-alkyl-3-methylimidazolium chloride (alkyl = butyl, octyl or decyl is investigated. The effects areanalyzed using both the corresponding temperature–composition pseudo-binary andcomposition ternary phase diagrams. Different regions of liquid-liquid and solid-liquidphase demixing are mapped. The phase behavior is interpreted taking into account thecomplex and competing nature of the interactions between the ionic liquid, the inorganicsalt and water. In the case of solutions containing 1-octyl- or 1-decyl-3-methylimidazoliumchloride, the smaller magnitude of the salting-out effects is explained in terms of thepossibility of self-aggregation of the ionic liquid.

  17. Salting-out in Aqueous Solutions of Ionic Liquids and K3PO4: Aqueous Biphasic Systems and Salt Precipitation

    OpenAIRE

    Najdanovic-Visak, Vesna; Canongia Lopes, Jos? N.; Visak, Zoran P.; Trindade, J.; Rebelo, Lu?s P. N.

    2007-01-01

    The salting-out effect produced by the addition of potassium phosphate, K3PO4 to aqueous solutions of water-miscible ionic liquids, viz. 1-ethyl-3-methylimidazolium ethyl sulfate, 1-butyl-3-methylimidazolium methyl sulfate, or 1-alkyl-3-methylimidazolium chloride ( alkyl = butyl, octyl or decyl) is investigated. The effects are analyzed using both the corresponding temperature-composition pseudo-binary and composition ternary phase diagrams. Different regions of liquid-liquid and solid-liquid...

  18. Study on Salting Out-Steam Distillation Extraction Technology and Antibacterial Activities of Essential Oil From Cumin Seeds

    OpenAIRE

    Zhang, Hong; Hu, Qing-Ping

    2014-01-01

    The effects of different factors on the yield of essential oil from were discussed, and the extraction conditions of essential oil from cumin seeds by salting out-steam distillation technology based on single-factor test and orthogonal experiment, as well as its antibacterial activities on several common food spoilage bacteria were studied in this paper. The results showed that, the impact order of the influence factors was liquid/solid ratio > distilling time > NaCl concentration, and optimi...

  19. Salting-out effect in aqueous NaCl solutions: trends with size and polarity of solute molecules.

    Science.gov (United States)

    Endo, Satoshi; Pfennigsdorff, Andrea; Goss, Kai-Uwe

    2012-02-07

    Salting-out in aqueous NaCl solutions is relevant for the environmental behavior of organic contaminants. In this study, Setschenow (or salting-out) coefficients (K(s) [M(-1)]) for 43 diverse neutral compounds in NaCl solutions were measured using a shared headspace passive dosing method and a negligible depletion solid phase microextraction technique. The results were used to calibrate and evaluate estimation models for K(s). The molar volume of the solute correlated only moderately with K(s) (R(2) = 0.49, SD = 0.052). The polyparameter linear free energy relationship (pp-LFER) model that uses five compound descriptors resulted in a more accurate fit to our data (R(2) = 0.83, SD = 0.031). The pp-LFER analysis revealed that Na(+) and Cl(-) in aqueous solutions increase the cavity formation energy cost and the polar interaction energies toward neutral organic solutes. Accordingly, the salting-out effect increases with the size and decreases with the polarity of the solute molecule. COSMO-RS, a quantum mechanics-based fully predictive model, generally overpredicted the experimental K(s), but the predicted values were moderately correlated with the experimental values (R(2) = 0.66, SD = 0.042). Literature data (n = 93) were predicted by the calibrated pp-LFER and COSMO-RS models with root mean squared errors of 0.047 and 0.050, respectively. This study offers prediction models to estimate K(s), allowing implementation of the salting-out effect in contaminant fate models, linkage of various partition coefficients (such as air-water, sediment-water, and extraction phase-water partition coefficients) measured for fresh water and seawater, and estimation of enhancement of extraction efficiency in analytical procedures.

  20. A Triple Salting-Out Effect is Required for the Formation of Ionic-Liquid-Based Aqueous Multiphase Systems.

    Science.gov (United States)

    Passos, Helena; Costa, Sara H; Fernandes, Ana M; Freire, Mara G; Rogers, Robin D; Coutinho, João A P

    2017-11-20

    Novel aqueous multiphase systems (MuPSs) formed by quaternary mixtures composed of cholinium-based ionic liquids (ILs), polymers, inorganic salts, and water are reported herein. The influence of several ILs, polymers, and salts was studied, demonstrating that a triple salting-out is a required phenomenon to prepare MuPSs. The respective phase diagrams and "tie-surfaces" were determined, followed by the evaluation of the effect of temperature. Finally, the remarkable ability of IL-based MuPSs to selectively separate mixtures of textile dyes is shown. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Facile reduction of graphene oxide at room temperature by ammonia borane via salting out effect.

    Science.gov (United States)

    Zhuo, Qiqi; Zhang, Yiping; Du, Qingchuan; Yan, Chao

    2015-11-01

    Nascent hydrogen as a strong reducing and environmentally benign agent can be used as the efficient reductant of graphene oxide. The common method is to dissolve metal in acid graphene oxide (GO) solution to generate nascent hydrogen and reduce graphene oxide. However, hydrophobic metal particles cannot contact well with hydrophilic GO. Lots of nascent hydrogen atoms generated surrounding metal particles would quickly form hydrogen instead of reducing GO, which results in low reduction efficiency. In this work, based on the salting effect of GO, we report a facile approach to synthesize graphene by mild reducing of GO using NH3BH3 as the reducing agent and Co3O4 as the catalyst at room temperature. This method exhibited higher nascent hydrogen reduction efficiency and higher C/O atomic ratio of reduced graphene oxide than using Fe, Zn, and Al among others. Also the reaction is conducted under mild conditions (room temperature), resulting in fewer defects. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  2. The effect of solution electrolytes on the uptake of photosensitizers by liposomal membranes: a salting-out effect.

    Science.gov (United States)

    Minnes, Refael; Ytzhak, Shany; Weitman, Hana; Ehrenberg, Benjamin

    2008-09-01

    In this study we investigated, spectroscopically, the effect of electrolytes on the partitioning of hematoporphyrin IX (HP) and hypericin (Hy) into non-charged lipid vesicles. Our aim was to assess the salting-out effect of electrolytes on membrane-partitioning. We titrated aqueous solutions of HP and Hy with lecithin liposomes, at different concentrations of several monovalent and divalent electrolytes in the suspension. The partitioning constant of HP to lecithin liposomes increased from 3.3 (mL/mg) in water containing only 5mM buffer to 8.7 (mL/mg) at 0.36M KCl. KF had a similar effect. NaCl caused a 3-fold increase in the partitioning of Hy to liposomes. MgSO(4) and MgCl(2) also increased the partitioning of HP, by a factor of more than 4 and this occurred already at 0.03M concentration. We analyze the comparative effects of the electrolytes in relation to the Hofmeister series. The salting-out effect could be utilized to enhance the uptake of HP and Hy, and possibly other photosensitizers as well, by artificial and natural membranes.

  3. Cloud point extraction of Cu(II) using a mixture of Triton X-100 and dithizone with a salting-out effect and its application to visual determination.

    Science.gov (United States)

    Sato, Nobuko; Mori, Masanobu; Itabashi, Hideyuki

    2013-12-15

    A method for the separation and concentration of trace copper(II) ion (Cu(II)) via cloud point extraction (CPE) using a nonionic surfactant with a salting-out effect was developed and applied as a technique for the visual determination of Cu(II). Triton X-100 (TX-100), which has a cloud point at 64-67 °C in aqueous solutions, was used as the nonionic surfactant for the CPE of Cu(II). Although CPE with TX-100 requires heating of the solution to separate the surfactant-rich phase from the aqueous phase, the new method achieves phase separation at 15-30 °C owing to the addition of a large amount of salt to the solution, which lowers the cloud point. The compound 1,5-diphenylthiocarbazone (dithizone) was selected as the chelating agent for complexation and transfer of Cu(II) to the surfactant-rich phase. The extractability of Cu(II) (initial concentration: 10 μM) was 96.6±2.1% when Na2SO4 was added to a 20% TX-100/4 μM dithizone solution (pH 2). Using this method, the visual determination of Cu(II) was possible for concentrations ranging from 0.01 to 10 μM. In addition, the extraction system was successfully applied to the visual determination of Cu(II) in a river water sample. © 2013 Elsevier B.V. All rights reserved.

  4. Developing an objective function to characterize the tradeoffs in salting out and the foam and droplet fractionation processes

    Directory of Open Access Journals (Sweden)

    Cherry J.

    2000-01-01

    Full Text Available There are many methods for separating and purifying proteins from dilute solutions, such as salting out/precipitation, adsorption/chromatography, foam fractionation, and droplet fractionation. In order to determine the optimal condition for a selected separation and purification process, an objective function is developed. The objective function consists of three parameters, which are the protein mass recovery, the separation ratio, and the enzymatic activity ratio. In this paper the objective function is determined as a function of the pH of the bulk solution for egg albumin, cellulase, and sporamin (for foam fractionation and invertase ( for droplet fractionation. It is found that the optimal pH for all the systems except for cellulase is near their isoelectric point.

  5. Effect of salting-out on distribution behavior of di(2-ethylhexyl) phthalate and its analogues between water and sediment.

    Science.gov (United States)

    Yuwatini, Erini; Hata, Noriko; Kuramitz, Hideki; Taguchi, Shigeru

    2013-01-01

    A higher enrichment of organic pollutant, di(2-ethylhexyl) phthalate (DEHP) was found in estuary of Oyabe River and Jinzu River, Japan. Based on this, the distribution of DEHP between water and bed sediment was investigated as a model of organic pollutant through both the field investigation and laboratory experiment. The laboratory experiment was performed to examine the effect of seawater, organic matter in sediment and hydrophobicity (log K ow ) of organic pollutants. The result showed that salting-out effect due to the high salinity in seawater and organic matter in sediment contributed towards the increasing of DEHP distribution between water and sediment. Furthermore, the hydrophobicity of organic pollutant also enhances the distribution between water and sediment to a higher magnitude in the presence of seawater.

  6. Separation characteristics of rare earth elements in the TOPO/DTPA - Salting-out reagent solution system

    Energy Technology Data Exchange (ETDEWEB)

    Miyahara, S.; Koma, Yoshikazu; Koyama, Tomozo; Tanaka, Yasumasa [Japan Nuclear Cycle Development Inst., Tokai, Ibaraki (Japan). Tokai Works; Kano, J.

    1998-11-01

    A test of mutual separation of rare earth elements was carried out using an organic phosphorus extraction solvent TOPO (tri-octyl phosphorus oxide). It was found that the distribution ratio monotonously increased with the atomic number and the separation factor of La/Ln was 10{sup 3}. Under the condition that a sufficient quantity of DTPA compared with the amount of rare earth metals and pH > 1.5 in which DTPA easily formed complexes with lanthanides, the following conclusions were obtained; (i) the separation factor was not affected by pH, the kind of salting-out reagent, or the concentration, (ii) the extraction reaction with TOPO and complex formation with DTPA mainly contributed to the separation of lanthanides, and (iii) the separation factor computed by means of the distribution ratio of TOPO extraction and complex formation constant for DTPA more or less agreed with the empirical value. Separation of rare earth elements using TOPO revealed similar characteristics to those of systems with CMPO and TBP. (H. Baba)

  7. Study on Salting out-Steam Distillation Extraction Technology and Antibacterial Activities of Essential Oil from Cumin Seeds

    Directory of Open Access Journals (Sweden)

    Hong Zhang

    2014-11-01

    Full Text Available The effects of different factors on the yield of essential oil from were discussed, and the extraction conditions of essential oil from cumin seeds by salting out-steam distillation technology based on single-factor test and orthogonal experiment, as well as its antibacterial activities on several common food spoilage bacteria were studied in this paper. The results showed that, the impact order of the influence factors was liquid/solid ratio > distilling time > NaCl concentration, and optimized extraction conditions were as follows, liquid to material ratio 15:1, soaking time 1 h, 4% NaCl, steam distilling time 3 h. The yield of essential oil was up to 4.48% under these conditions. The results of antibacterial activity assays showed that the essential oil from cumin seeds exhibited the different antibacterial activities against some food borne pathogens, especially it presented the best inhibitory effect against Bacillus subtilis with the minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC values of 6.25 and 12.5 mg/mL respectively, followed by Staphylococcus albus and Staphylococcus aureus, the lowest for Pseudomonas aeruginosa and Shigella dysenteriae

  8. Salting-out solvent extraction for the off-line preconcentration of benzalkonium chloride in capillary electrophoresis.

    Science.gov (United States)

    So, T S; Huie, C W

    2001-07-01

    The use of salting-out effect for the off-line preconcentration of charged analytes in capillary electrophoresis is demonstrated for the first time. Using benzalkonium chloride (BAK) as model compound, a mixture of cationic surfactants consisting of even-numbered alkylbenzyl quaternary ammonium homologues (C8-C18), the addition of appropriate amounts of sodium chloride and acetonitrile in the sample solution (2 mL sample volume) was found to be capable of providing ca. 40-fold enhancement in detection sensitivity. In addition to affording a preconcentrating effect due to the extraction of BAK in the smaller volume water-miscible organic solvent phase (acetonitrile), the organic solvent also serves to improve the peak area and shape of the longer chain surfactants. Optimal experimental conditions, such as volume of acetonitrile and concentration of sodium chloride, for the preconcentration of BAK with good preconcentration factors and reproducibility were investigated. The usefulness of the present method was demonstrated for the improved determination of BAK present in commercially available industrial and pharmaceutical products.

  9. Salting-out assisted liquid-liquid extraction combined with gas chromatography-mass spectrometry for the determination of pyrethroid insecticides in high salinity and biological samples.

    Science.gov (United States)

    Niu, Zongliang; Yu, Chunwei; He, Xiaowen; Zhang, Jun; Wen, Yingying

    2017-09-05

    A salting-out assisted liquid-liquid extraction (SALLE) combined with gas chromatography-mass spectrometry (GC-MS) method was developed for the determination of four pyrethroid insecticides (PYRs) in high salinity and biological samples. Several parameters including sample pH, salting-out solution volume and salting-out solution pH influencing the extraction efficiency were systematically investigated with the aid of orthogonal design. The optimal extraction conditions of SALLE were: 4mL of salting-out solution with pH=4 and the sample pH=3. Under the optimum extraction and determination conditions, good responses for four PYRs were obtained in a range of 5-5000ng/mL, with linear coefficients greater than 0.998. The recoveries of the four PYRs ranged from 74% to 110%, with standard deviations ranging from 1.8% to 9.8%. The limits of detection based on a signal-to-noise ratio of 3 were between 1.5-60.6ng/mL. The method was applied to the determination of PYRs in urine, seawater and wastewater samples with a satisfactory result. The results demonstrated that this SALLE-GC-MS method was successfully applied to determine PYRs in high salinity and biological samples. SALLE avoided the need for the elimination of salinity and protein in the sample matrix, as well as clean-up of the extractant. Most of all, no centrifugation or any special apparatus are required, make this a promising method for rapid sample preparation procedure. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Salting-out homogeneous liquid-liquid extraction approach applied in sample pre-processing for the quantitative determination of entecavir in human plasma by LC-MS.

    Science.gov (United States)

    Zhao, Feng-Juan; Tang, Hong; Zhang, Qing-Hua; Yang, Jin; Davey, Andrew K; Wang, Ji-Ping

    2012-01-15

    A convenient, robust, economical and selective sample preparation method for the quantitative determination of entecavir in human plasma by LC-MS was developed and validated. Entecavir and the internal standard of acyclovir were extracted from 500 μL of human plasma by a salting-out homogeneous liquid-liquid extraction approach (SHLLE) with acetonitrile as the organic extractant and magnesium sulfate as the salting-out reagent. They were analyzed on a Hanbon® Lichrospher RP C18 HPLC column (150 mm×2.0 mm; 5 μm) with gradient elution. The mobile phase comprised 0.1% acetic acid-0.2 mmol ammonium acetate in water (mobile phase A) and acetonitrile (mobile phase B). The flow rate is 0.2 mL/min. The analytes were detected by a LC-MS 2010 single quadrupole mass spectrometer instrument equipped with an electrospray ionization interface using selective ion monitoring positive mode. A "post cut" column switch technique was incorporated into the method to remove interferences of earlier and later eluting matrix components than entecavir and internal standard, including salting-out reagent used in sample pre-processing. The method was validated over the concentration range of 0.05-20 ng/mL. The intra-day and inter-day precision of the assay, as measured by the coefficient of variation (%CV), was within 3.59%, and the intra-day assay accuracy was found to be within 4.88%. The average recovery of entecavir was about 50% and the ion suppression was approximately 44% over the standard curve. Comparison of matrix effect between SHLLE and SPE by continuous post column infusion showed that these two methods got similar, slight ion suppression. The SHLLE method has been successfully utilized for the analysis of entecavir in post-dose samples from a clinical study. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  11. Determination of atorvastatin in human serum by salting out assisted solvent extraction and reversed-phase high-performance liquid chromatography–UV detection

    OpenAIRE

    Jalal Hassan; Seyed Hamid Bahrani

    2014-01-01

    A simple and rapid technique based on salting out assisted solvent extraction was developed for extraction of atorvastatin from serum sample and high performance liquid chromatography–UV was used for its detection. In the present study, 1.0 mL serum was extracted by 0.5 mL of acetonitrile and some parameters that can affect extraction such as type and volume of extraction solvent, type of salt, and pH were optimized. Under optimized experimental conditions, the calibration curve was found to ...

  12. Salting-in with a salting-out agent: explaining the cation specific effects on the aqueous solubility of amino acids.

    Science.gov (United States)

    Tomé, Luciana I N; Pinho, Simão P; Jorge, Miguel; Gomes, José R B; Coutinho, João A P

    2013-05-23

    Although the understanding of ion specific effects on the aqueous solubilities of biomolecules is crucial for the development of many areas of biochemistry and life sciences, a consensual and well-supported molecular picture of the phenomena has not yet been established. Mostly, the influence of cations and the nature of the molecular interactions responsible for the reversal of the Hofmeister trend in aqueous solutions of amino acids and proteins are still defectively understood. Aiming at contributing to the understanding of the molecular-level mechanisms governing the cation specific effects on the aqueous solubilities of biocompounds, experimental solubility measurements and classical molecular dynamics simulations were performed for aqueous solutions of three amino acids (alanine, valine, and isoleucine), in the presence of a series of inorganic salts. The evidence gathered suggests that the mechanism by which salting-in inducing cations operate in aqueous solutions of amino acids is different from that of anions, and allows for a novel and consistent molecular description of the effect of the cation on the solubility based on specific interactions of the cations with the negatively charged moieties of the biomolecules.

  13. Indirectly suspended droplet microextraction of water-miscible organic solvents by salting-out effect for the determination of polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Daneshfar, Ali; Khezeli, Tahere

    2014-12-01

    A simple and low-cost method that indirectly suspended droplet microextraction of water-miscible organic solvents (ISDME) by salting-out effect before high-performance liquid chromatography and ultraviolet (HPLC-UV) detection was used for the determination of polycyclic aromatic hydrocarbons (PAHs) in different samples. The ISDME is a combination of salting-out extraction of water-miscible organic solvent and directly suspended droplet microextraction (DSDME). Ninety-five microliters water-miscible organic solvent (1-propanol) was added to a 500-µL sample. A homogeneous solution was formed immediately. To produce a steady vortex at the top of the solution, the sample was agitated at 700 rpm using a magnetic stirrer. By the addition of ammonium sulfate (saturated solution) to the homogeneous solution, 1-propanol was separated and collected at the bottom of the steady vortex. Finally, 20 µL 1-propanol was injected into HPLC-UV. The effects of important parameters such as water-miscible organic solvent (type and volume), type of salt, and extraction time were evaluated. Under optimum conditions, the method has a good linear calibration range (0.1 µg/L-300 µg/L), coefficients of determination (R(2) > 0.998), low limits of detection (between 0.02 µg/L and 0.27 µg/L), and acceptable recovery (>85.0%). © 2014 SETAC.

  14. Use of experimentally determined Henry's Law and salting-out constants for ethanol in seawater for determination of the saturation state of ethanol in coastal waters.

    Science.gov (United States)

    Willey, Joan D; Powell, Jacqueline P; Avery, G Brooks; Kieber, Robert J; Mead, Ralph N

    2017-09-01

    The Henry's law constant for ethanol in seawater was experimentally determined to be 221 ± 4 M/atm at 22 °C compared with 247 ± 6 M/atm in pure water. The salting out coefficient for ethanol was 0.13 M(-1). In seawater ln(KH) = -(12.8 ± 0.7) + (5310 ± 197)/T where KH is in M atm(-1) and temperature is in K. This plus the salting out coefficient allow calculation of KH for any estuarine or sea water between 1 and 35 °C. High concentrations of dissolved organic carbon do not affect KH values in fresh or seawater. Nearshore surface waters were usually undersaturated with respect to gas phase ethanol except when air concentrations decreased, whereas surface seawater 40 km from shore was supersaturated. The percent saturation in surface waters is driven primarily by changes in air concentrations because these change quickly (hours) and more extensively than surface water. This study allows calculation of ethanol saturation states from air and surface water concentrations which is a necessary step to define the role of surface oceans in the global biogeochemical cycling of ethanol both now and in the future as use of ethanol biofuel continues to grow. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Salting-out assisted liquid/liquid extraction with acetonitrile: a new high throughput sample preparation technique for good laboratory practice bioanalysis using liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Zhang, Jun; Wu, Huaiqin; Kim, Elaine; El-Shourbagy, Tawakol A

    2009-04-01

    Acetonitrile, an organic solvent miscible with aqueous phase, has seen thousands of publications in the literature as an efficient deproteinization reagent. The use of acetonitrile for liquid-liquid extraction (LLE), however, has seen very limited application due to its miscibility with aqueous phase. The interest in LLE with acetonitrile has been pursued and reported in the literature by significantly lowering the temperature of the mixture or increasing the salt concentration in the mixture of acetonitrile and aqueous phase, resulting in the separation of the acetonitrile phase from aqueous phase, as observed in conventional LLE. However, very limited application of these methods has been reported. The throughput was limited. In this report, we report a new sample preparation technique, salting-out assisted liquid-liquid extraction with acetonitrile, for high-throughput good laboratory practice sample analysis using LCMS, Two compounds from an approved drug, Kaletra, were used to demonstrate the extractability of drugs from human plasma matrix. Magnesium sulfate was used as the salting-out reagent. Extracts were diluted and then injected into a reversed phase LC-MS/MS system directly. One 96-well plate was extracted with this new approach to evaluate multiple parameters of a good laboratory practice analytical method. Results indicate that the method is rapid, reliable and suitable for regulated bioanalysis. With minimal modification, this approach has been used for high-throughput good laboratory practice analysis of a number of compounds under development at Abbott.

  16. Coupling of acetonitrile deproteinization and salting-out extraction with acetonitrile stacking in chiral capillary electrophoresis for the determination of warfarin enantiomers.

    Science.gov (United States)

    Wang, Min; Cai, Zongwei; Xu, Lin

    2011-07-01

    Concurrent sample clean-up and enhancement in detection sensitivity for chiral capillary electrophoresis was demonstrated based on the coupling of salting-out extraction with acetonitrile stacking and the use of dimethyl-beta-cyclodextrin as the chiral selector for the sensitive and enantioselective separation of warfarin enantiomers in urine samples. By optimizing the pH of salting-out extraction, warfarin enantiomers can be efficiently extracted from the aqueous sample solution into a smaller volume organic solvent (acetonitrile) phase. The pressure injection of the enriched acetonitrile phase (containing ca. 1% NaCl) into the CE capillary at 10% capillary volume resulted in additional concentration of the warfarin enantiomers. The limit of detection for both warfarin enantiomers was as low as 1.5 ng/mL in urine sample. Our results show that the novel strategy offers improved sensitivity compared to conventional CE analysis, reaching a combined enrichment factor higher than 1000. Calibration curves of warfarin enantiomers in urine samples were found to be linear between 10 and 1000 ng/mL, and intra- and inter-day precision (N=9) for both warfarin enantiomers in terms of migration time and peak area were found to be within the range of 0.1-0.8% and 1.0-6.7%, respectively. The recovery of warfarin enantiomers from urine was ca. 90%. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Salting-in and salting-out effects of ionic and neutral osmotica on limonene and linalool Henry's law constants and octanol/water partition coefficients.

    Science.gov (United States)

    Copolovici, Lucian; Niinemets, Ulo

    2007-09-01

    Foliar emission rates of plant-generated volatile monoterpenes depend on monoterpene partitioning between air, aqueous and lipid-phases in the leaves. While Henry's law constants (H pc, equilibrium gas/water partition coefficient) and octanol/water partition coefficients (K OW) for pure water have been previously used to simulate monoterpene emissions from the leaves, aqueous phase in plants is a complex solution of electrolytes and neutral osmotica. We studied the effects of dissociated compounds KCl and glycine and sugars glucose, sorbitol and sucrose with concentrations between 0 and 1M on H pc and K OW values for limonene and linalool. Linalool with ca. 1500-fold lower H(pc) (2.62 Pa m(3)mol(-1) for pure water at 30 degrees C) and ca. 30-fold lower K OW (955 mol mol(-1) for pure water at 25 degrees C) is the more hydrophilic compound of the two monoterpenes. H pc of both monoterpenes increased with increasing concentration of both ionic compounds and sorbitol, but decreased with increasing glucose and sucrose concentrations. The salting-out coefficients for H pc (kH) were ca. an order of magnitude larger for more hydrophilic compound linalool than for more hydrophobic limonene. For linalool, co-solutes modified H pc by 30-50% at the highest concentration (1M) tested. The effect of temperature on the salting-out coefficient of KCl was minor. As with H pc, K OW increased with increasing the concentration of KCl, glycine and sorbitol, and decreased with increasing glucose and sucrose concentrations. For limonene, co-solutes modified K OW by 20-50% at the highest concentration used. For linalool, the corresponding range was 10-35%. Salting-out coefficients for H pc and K OW were correlated, but the lipid-solubility was more strongly affected than aqueous solubility in the case of limonene. Overall, these data demonstrate physiologically important effects of co-solutes on H pc and K OW for hydrophilic monoterpenes and on K OW for hydrophobic monoterpenes that should

  18. Salting-out-enhanced ionic liquid microextraction with a dual-role solvent for simultaneous determination of trace pollutants with a wide polarity range in aqueous samples.

    Science.gov (United States)

    Gao, Man; Qu, Jingang; Chen, Kai; Jin, Lide; Dahlgren, Randy Alan; Wang, Huili; Tan, Chengxia; Wang, Xuedong

    2017-11-01

    In real aquatic environments, many occupational pollutants with a wide range of polarities coexist at nanogram to milligram per liter levels. Most reported microextraction methods focus on extracting compounds with similar properties (e.g., polarity or specific functional groups). Herein, we developed a salting-out-enhanced ionic liquid microextraction based on a dual-role solvent (SILM-DS) for simultaneous detection of tetracycline, doxycycline, bisphenol A, triclosan, and methyltriclosan, with log K ow ranging from -1.32 to 5.40 in complex milk and environmental water matrices. The disperser in the ionic-liquid-based dispersive liquid-liquid microextraction was converted to the extraction solvent in the subsequent salting-out-assisted microextraction procedures, and thus a single solvent performed a dual role as both extractant and disperser in the SILM-DS process. Acetonitrile was selected as the dual-role solvent because of its strong affinity for both ionic liquids and water, as well as the extractant in the salting-out step. Optimized experimental conditions were 115 μL [C 8 MIM][PF 6 ] as extractor, 1200 μL acetonitrile as dual-role solvent, pH 2.0, 5.0 min ultrasound extraction time, 3.0 g Na 2 SO 4 , and 3.0 min vortex extraction time. Under optimized conditions, the recoveries of the five pollutants ranged from 74.5 to 106.9%, and their LODs were 0.12-0.75 μg kg -1 in milk samples and 0.11-0.79 μg L -1 in environmental waters. Experimental precision based on relative standard deviation was 1.4-6.4% for intraday and 2.3-6.5% for interday analyses. Compared with previous methods, the prominent advantages of the newly developed method are simultaneous determination of pollutants with a wide range of polarities and a substantially reduced workload for ordinary environmental monitoring and food tests. Therefore, the new method has great application potential for simultaneous determination of trace pollutants with strongly contrasting polarities in several

  19. High-throughput salting-out assisted liquid/liquid extraction and ultrafast LC for same-day delivery of first-in-human bioanalytical data.

    Science.gov (United States)

    Zhang, Jun; Myasein, Francis; Rodila, Ramona; Wu, Huaiqin; El-Shourbagy, Tawakol A

    2009-07-01

    With the need of fast-paced drug development, rapid delivery of bioanalytical data becomes a trend. Here, we present a strategy to demonstrate same-day data delivery. A novel salting-out assisted liquid/liquid extraction (SALLE) with acetonitrile and a MS-friendly salt was used to extract analyte from the first-in-human study plasma samples and the extract was successfully injected into ultrafast chromatography. The strategic combination of SALLE and ultrafast chromatography minimizes the turnaround time and allows the same-day delivery of bioanalytical data. The time saving from both extraction and injection was translated to a fast delivery of bioanalytical data. The first-in-human pharmacokinetic data of an investigational new drug candidate was delivered in approximately 4.5 work h after receiving the samples of each dose group using high-throughput SALLE and ultrafast LC. Incurred sample reassay results proved uncompromised data quality with the high-speed bioanalysis.

  20. Analysis of biogenic amines in wines by salting-out assisted liquid-liquid extraction and high-performance liquid chromatography with fluorimetric detection.

    Science.gov (United States)

    Ramos, Rui Miguel; Valente, Inês Maria; Rodrigues, José António

    2014-06-01

    Biogenic amines are nitrogenous organic compounds of low molecular weight that are either formed or metabolized in cells of living organisms and can be found in several food products, being produced mainly by amino acid decarboxylation. When ingested in high concentrations they can induce several health problems in humans. In alcoholic beverages, and especially in wine, they are formed during the vinification process as a result of the action of microorganisms. In this work it is proposed a new methodology for the determination of biogenic amines in wines, which includes a sample preparation approach based on salting-out assisted liquid-liquid extraction, the use of dansyl chloride for the derivatization and chromatographic separation by high-performance liquid chromatography with fluorimetric detection. The salting-out effect is used to promote phase separation between water and a water-miscible organic solvent, while improving the extraction of organic or inorganic species. Several extraction parameters were optimized, such as the dansyl chloride concentration, pH and the effects caused by the order in which the extraction and derivatization were performed. Extraction of amines, and consequent detection, depends on the presence of dansyl chloride in solution prior to extraction. The results showed the possibility to simultaneously perform the extraction and the derivatization, making sample preparation easier and less time-consuming. The methodology was successfully applied to the determination of biogenic amines in five wines (white, red and rosé). This method has the potential to be a good alternative to existing methods since it is cheaper, easier and simplifies the sample preparation step. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Combination of counter current salting-out homogenous liquid-liquid extraction and dispersive liquid-liquid microextraction as a novel microextraction of drugs in urine samples.

    Science.gov (United States)

    Akramipour, Reza; Fattahi, Nazir; Pirsaheb, Meghdad; Gheini, Simin

    2016-02-15

    The counter current salting-out homogenous liquid-liquid extraction (CCSHLLE) joined with the dispersive liquid-liquid microextraction based on solidification of floating organic drop (DLLME-SFO) has been developed as a high preconcentration technique for the determination of different drugs in urine samples. Amphetamines were employed as model compounds to assess the extraction procedure and were determined by high performance liquid chromatography-ultraviolet detection (HPLC-UV). In this method, initially, NaCl as a separation reagent is filled into a small column and a mixture of urine and acetonitrile is passed through the column. By passing the mixture, NaCl is dissolved and the fine droplets of acetonitrile are formed due to salting-out effect. The produced droplets go up through the remained mixture and collect as a separated layer. Then, the collected acetonitrile is removed with a syringe and mixed with 30.0μL 1-undecanol (extraction solvent). In the second step, the 5.00mLK2CO3 solution (2% w/v) is rapidly injected into the above mixture placed in a test tube for further DLLME-SFO. Under the optimum conditions, calibration curves are linear in the range of 1-3000μgL(-1) and limit of detections (LODs) are in the range of 0.5-2μgL(-1). The extraction recoveries and enrichment factors ranged from 78 to 84% and 157 to 168, respectively. Repeatability (intra-day) and reproducibility (inter-day) of method based on seven replicate measurements of 100μgL(-1) of amphetamines were in the range of 3.5-4.5% and 4-5%, respectively. The method was successfully applied for the determination of amphetamines in the actual urine samples. The relative recoveries of urine samples spiked with amphetamine and methamphetamine are 90-108%. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Quadrupole terms in the Maxwell equations: Debye-Hückel theory in quadrupolarizable solvent and self-salting-out of electrolytes.

    Science.gov (United States)

    Slavchov, Radomir I

    2014-04-28

    If the molecules of a given solvent possess significant quadrupolar moment, the macroscopic Maxwell equations must involve the contribution of the density of the quadrupolar moment to the electric displacement field. This modifies the Poisson-Boltzmann equation and all consequences from it. In this work, the structure of the diffuse atmosphere around an ion dissolved in quadrupolarizable medium is analyzed by solving the quadrupolar variant of the Coulomb-Ampere's law of electrostatics. The results are compared to the classical Debye-Hückel theory. The quadrupolar version of the Debye-Hückel potential of a point charge is finite even in r = 0. The ion-quadrupole interaction yields a significant expansion of the diffuse atmosphere of the ion and, thus, it decreases the Debye-Hückel energy. In addition, since the dielectric permittivity of the electrolyte solutions depends strongly on concentration, the Born energy of the dissolved ions alters with concentration, which has a considerable contribution to the activity coefficient γ± known as the self-salting-out effect. The quadrupolarizability of the medium damps strongly the self-salting-out of the electrolyte, and thus it affects additionally γ±. Comparison with experimental data for γ± for various electrolytes allows for the estimation of the quadrupolar length of water: LQ ≈ 2 Å, in good agreement with previous assessments. The effect of quadrupolarizability is especially important in non-aqueous solutions. Data for the activity of NaBr in methanol is used to determine the quadrupolarizability of methanol with good accuracy.

  3. Antioxidant Activity and Thermal Stability of Oleuropein and Related Phenolic Compounds of Olive Leaf Extract after Separation and Concentration by Salting-Out-Assisted Cloud Point Extraction

    Directory of Open Access Journals (Sweden)

    Konstantinos Stamatopoulos

    2014-04-01

    Full Text Available A fast, clean, energy-saving, non-toxic method for the stabilization of the antioxidant activity and the improvement of the thermal stability of oleuropein and related phenolic compounds separated from olive leaf extract via salting-out-assisted cloud point extraction (CPE was developed using Tween 80. The process was based on the decrease of the solubility of polyphenols and the lowering of the cloud point temperature of Tween 80 due to the presence of elevated amounts of sulfates (salting-out and the separation from the bulk solution with centrifugation. The optimum conditions were chosen based on polyphenols recovery (%, phase volume ratio (Vs/Vw and concentration factor (Fc. The maximum recovery of polyphenols was in total 95.9%; Vs/Vw was 0.075 and Fc was 15 at the following conditions: pH 2.6, ambient temperature (25 °C, 4% Tween 80 (w/v, 35% Na2SO4 (w/v and a settling time of 5 min. The total recovery of oleuropein, hydroxytyrosol, luteolin-7-O-glucoside, verbascoside and apigenin-7-O-glucoside, at optimum conditions, was 99.8%, 93.0%, 87.6%, 99.3% and 100.0%, respectively. Polyphenolic compounds entrapped in the surfactant-rich phase (Vs showed higher thermal stability (activation energy (Ea 23.8 kJ/mol compared to non-entrapped ones (Ea 76.5 kJ/mol. The antioxidant activity of separated polyphenols remained unaffected as determined by the 1,1-diphenyl-2-picrylhydrazyl method.

  4. Salting-out assisted liquid-liquid extraction for the determination of biogenic amines in fruit juices and alcoholic beverages after derivatization with 1-naphthylisothiocyanate and high performance liquid chromatography.

    Science.gov (United States)

    Jain, Archana; Gupta, Manju; Verma, Krishna K

    2015-11-27

    A new method for determining biogenic amines in fruit juices and alcoholic beverages is described involving reaction of biogenic amines with 1-naphthylisothiocyanate followed by extraction of 1-naphthylthiourea derivatives with water-miscible organic solvent acetonitrile when solvents phase separation occurred using ammonium sulphate, a process called salting-out assisted liquid-liquid extraction. The extract was analyzed by high-performance liquid chromatography with UV detection at 254nm. The new reagent avoided many of the inconveniences as observed with existing derivatizing agents, such as dansyl chloride and benzoyl chloride, in regard to their inselectivity, instability, adverse effect of excess reagent, and necessity to remove excess reagent. The procedure has been optimized with respect to reaction time and temperature, water-miscible extraction solvent, and salt for solvents phase separation. Use of reagent as dispersed phase in aqueous medium produced derivatives in high yield. A linear calibration was obtained between the amount of biogenic amines in range 1-1000μgL(-1) and peak areas of corresponding thioureas formed; the correlation coefficient was 0.9965, and the limit of detection and limit of quantification found were 1.1μgL(-1) and 3.2μgL(-1), respectively. The pre-concentration method gave an average enrichment factor of 94. The application of the method has been demonstrated in the determination of biogenic amines in commercial samples of fruit juices and alcoholic beverages. In spiking experiments to real samples, the average recovery found by the present method was 94.5% that agreed well with 95.8% obtained by established comparison methods. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Comparison of salting-out and sugaring-out liquid-liquid extraction methods for the partition of 10-hydroxy-2-decenoic acid in royal jelly and their co-extracted protein content.

    Science.gov (United States)

    Tu, Xijuan; Sun, Fanyi; Wu, Siyuan; Liu, Weiyi; Gao, Zhaosheng; Huang, Shaokang; Chen, Wenbin

    2018-01-15

    Homogeneous liquid-liquid extraction (h-LLE) has been receiving considerable attention as a sample preparation method due to its simple and fast partition of compounds with a wide range of polarities. To better understand the differences between the two h-LLE extraction approaches, salting-out assisted liquid-liquid extraction (SALLE) and sugaring-out assisted liquid-liquid extraction (SULLE), have been compared for the partition of 10-hydroxy-2-decenoic acid (10-HDA) from royal jelly, and for the co-extraction of proteins. Effects of the amount of phase partition agents and the concentration of acetonitrile (ACN) on the h-LLE were discussed. Results showed that partition efficiency of 10-HDA depends on the phase ratio in both SALLE and SULLE. Though the partition triggered by NaCl and glucose is less efficient than MgSO4 in the 50% (v/v) ACN-water mixture, their extraction yields can be improved to be similar with that in MgSO4 SALLE by increasing the initial concentration of ACN in the ACN-water mixture. The content of co-extracted protein was correlated with water concentration in the obtained upper phase. MgSO4 showed the largest protein co-extraction at the low concentration of salt. Glucose exhibited a large protein co-extraction in the high phase ratio condition. Furthermore, NaCl with high initial ACN concentration is recommended because it produced high extraction yield for 10-HDA and the lowest amount of co-extracted protein. These observations would be valuable for the sample preparation of royal jelly. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Thermoresponsive Poly(Ionic Liquid)s in Aqueous Salt Solutions: Salting-Out Effect on Their Phase Behavior and Water Absorption/Desorption Properties.

    Science.gov (United States)

    Okafuji, Akiyoshi; Kohno, Yuki; Ohno, Hiroyuki

    2016-07-01

    Here, a thermoresponsive phase behavior of polymerized ionic liquids (PILs) composed of poly([tri-n-alkyl(vinylbenzyl)phosphonium]chloride) (poly([Pnnn VB ]Cl) is reported, where n (the number of carbon atoms of an alkyl chain) = 4, 5, or 6 after mixing with aqueous sodium chloride solutions. Both monomeric [P555VB ]Cl and the resulting poly([P555VB ]Cl) linear homopolymer show a lower critical solution temperature (LCST)-type phase behavior in aq. NaCl solutions. The phase transition temperature of the PIL shifts to lower value by increasing concentration of NaCl. Also the swelling degree of cross-linked poly([P555VB ]Cl) gel decreases by increasing NaCl concentration, clearly suggesting the "salting-out" effect of NaCl results in a significant dehydration of the poly([P555VB ]Cl) gel. The absorbed water in the PIL gel is desorbed by moderate heating via the LCST behavior, and the absolute absorption/desorption amount is improved by copolymerization of [P555VB ]Cl with more hydrophilic [P444VB ]Cl monomer. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Salting-out assisted liquid-liquid extraction coupled to dispersive liquid-liquid microextraction for the determination of chlorophenols in wine by high-performance liquid chromatography.

    Science.gov (United States)

    Fan, Yingying; Hu, Shibin; Liu, Shuhui

    2014-12-01

    A novel procedure of sample preparation combined with high-performance liquid chromatography with diode array detection is introduced for the analysis of highly chlorinated phenols (trichlorophenols, tetrachlorophenols, and pentachlorophenol) in wine. The main features of the proposed method are (i) low-toxicity diethyl carbonate as extraction solvent to selectively extract the analytes without matrix effect, (ii) the combination of salting-out assisted liquid-liquid extraction and dispersive liquid-liquid microextraction to achieve an enrichment factor of 334-361, and (iii) the extract is analyzed by high-performance liquid chromatography to avoid derivatization. Under the optimum conditions, correlation coefficients (r) were >0.997 for calibration curves in the range 1-80 ng/mL, detection limits and quantification limits ranged from 0.19 to 0.67 and 0.63 to 2.23 ng/mL, respectively, and relative standard deviation was <8%. The method was applied for the determination of chlorophenols in real wines, with recovery rates in the range 82-104%. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Tandem derivatization combined with salting-out assisted liquid-liquid microextraction for determination of biothiols in urine by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Tsai, Chia-Ju; Liao, Fang-Yi; Weng, Jing-Ru; Feng, Chia-Hsien

    2017-11-17

    Detection of polar organic compounds (POCs) using gas chromatography (GC) is not straightforward due to high polarity, hydrophilicity, and low volatility of POCs. In this study, we report a tandem microwave-assisted derivatization method combined with salting-out assisted liquid-liquid microextraction (SALLME) to modify successively the polar groups of POCs in protic and aprotic solvents. Biothiols (cysteine and homocysteine) served as a proof of concept for this method because they possess three polar groups (thiol, amine, and carboxyl); the derivatizing reagent was 3,4,5-trifluorobenzyl bromide (Br-TFB) for alkylation. The solubility of the POCs in the protic or aprotic reaction medium affected the number of TFB molecules attached. Using the tandem derivatization with Br-TFB, the thiol and amine groups of biothiols were alkylated in the protic system, and the carboxylic groups of biothiols were alkylated in the aprotic system. The developed method was then successfully applied to measure biothiols in human urine. Because of the complex urine matrix and the lack of urine samples without endogenous biothiols, the standard addition method was utilized to avoid the matrix effect, check the recovery, and calculate the initial biothiol content in the urine. Regarding the linearity of the standard addition curves, the coefficient of determination was >0.996, and the linear regression showed satisfactory reproducibility with a relative standard deviation effectively increased the sensitivity of GC-MS assays of water-soluble compounds in human urine. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Microextraction by packed sorbent and salting-out-assisted liquid-liquid extraction for the determination of aromatic amines formed from azo dyes in textiles.

    Science.gov (United States)

    Sánchez, Miguel del Nogal; Santos, Patricia Martín; Sappó, Cristina Pérez; Pavón, José Luis Pérez; Cordero, Bernardo Moreno

    2014-02-01

    EU legislation prohibits the use of certain azo dyes which, on reduction, form any of 22 aromatic amines listed in Regulation (EC) 1907/2006 at concentrations above the threshold limit of 30 mg Kg(-1). Two different extraction techniques for the determination of aromatic amines formed from azo dyes in textiles in combination with gas chromatography-mass spectrometry (GC-MS) are described. The first one is based on microextraction by packed sorbent (MEPS) and the other approach involves salting-out-assisted liquid-liquid extraction (SALLE). The influence of several parameters on the efficiency of the extraction using MEPS (sorbent material, sample volume, elution solvent, elution volume and washing steps, among others) and SALLE (extraction volume and amount of salt) were investigated. In addition, chromatographic separation was optimized and quadrupole mass spectrometry was evaluated using the synchronous SIM/scan data acquisition mode. The repeatability (n=8, S/N=3) of the methods, calculated as the relative standard deviation (RSD) was below 15 and 11% for all compounds when MEPS and SALLE were used, respectively. Standard additions procedure was used to quantify the aromatic amines in the textil samples. The detection limits in the samples for both methods were lower than the maximum value allowed by legislation. The results obtained in the analysis of textiles revealed the presence of o-anisidine, p-chloroaniline, 4-chloro-o-toluidine, 2-naphthylamine and 3,3'-dimethoxybenzidine in some of them. © 2013 Elsevier B.V. All rights reserved.

  10. Determination of atorvastatin in human serum by salting out assisted solvent extraction and reversed-phase high-performance liquid chromatography–UV detection

    Directory of Open Access Journals (Sweden)

    Jalal Hassan

    2014-01-01

    Full Text Available A simple and rapid technique based on salting out assisted solvent extraction was developed for extraction of atorvastatin from serum sample and high performance liquid chromatography–UV was used for its detection. In the present study, 1.0 mL serum was extracted by 0.5 mL of acetonitrile and some parameters that can affect extraction such as type and volume of extraction solvent, type of salt, and pH were optimized. Under optimized experimental conditions, the calibration curve was found to be linear in the range of 0.001–10 ng mL−1 in human serum and the correlation coefficient (R2 and the limits of detection were >0.99 and 0.0005 ng mL−1, respectively. The accuracy of the method in terms of average recovery of the compound in spiked serum and water samples was better than 90%.

  11. Salting-out extraction of allicin from garlic (Allium sativum L.) based on ethanol/ammonium sulfate in laboratory and pilot scale.

    Science.gov (United States)

    Li, Fenfang; Li, Qiao; Wu, Shuanggen; Tan, Zhijian

    2017-02-15

    Salting-out extraction (SOE) based on lower molecular organic solvent and inorganic salt was considered as a good substitute for conventional polymers aqueous two-phase extraction (ATPE) used for the extraction of some bioactive compounds from natural plants resources. In this study, the ethanol/ammonium sulfate was screened as the optimal SOE system for the extraction and preliminary purification of allicin from garlic. Response surface methodology (RSM) was developed to optimize the major conditions. The maximum extraction efficiency of 94.17% was obtained at the optimized conditions for routine use: 23% (w/w) ethanol concentration and 24% (w/w) salt concentration, 31g/L loaded sample at 25°C with pH being not adjusted. The extraction efficiency had no obvious decrease after amplification of the extraction. This ethanol/ammonium sulfate SOE is much simpler, cheaper, and effective, which has the potentiality of scale-up production for the extraction and purification of other compounds from plant resources. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Determination of Fusarium toxins in functional vegetable milks applying salting-out-assisted liquid-liquid extraction combined with ultra-high-performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Hamed, Ahmed M; Arroyo-Manzanares, Natalia; García-Campaña, Ana M; Gámiz-Gracia, Laura

    2017-11-01

    Vegetable milks are considered as functional foods due to their physiological benefits. Although the consumption of these products has significantly increased, they have received little attention in legislation with regard to contaminants. However, they may contain mycotoxins resulting from the use of contaminated raw materials. In this work, ultra-high-performance liquid chromatography tandem mass spectrometry has been proposed for the determination of the most relevant Fusarium toxins (fumonisin B1 and B2, HT-2 and T-2 toxins, zearalenone, deoxynivalenol and fusarenon-X) in different functional beverages based on cereals, legumes and seeds. Sample treatment consisted of a simple salting-out-assisted liquid-liquid extraction with no further clean-up. The method provided limits of quantification between 3.2 and 57.7 µg L-1, recoveries above 80% and precision with RSD lower than 12%. The method was also applied for studying the occurrence of these mycotoxins in market samples of vegetable functional beverages and deoxynivalenol was found in three oat-based commercial drinks.

  13. Experimental determination of Henry's law constants of difluoromethane (HFC-32 and the salting-out effects in aqueous salt solutions relevant to seawater

    Directory of Open Access Journals (Sweden)

    S. Kutsuna

    2017-06-01

    Full Text Available Gas-to-water equilibrium coefficients, KeqS (in M atm−1, of difluoromethane (CH2F2, a hydrofluorocarbon refrigerant (HFC-32, in aqueous salt solutions relevant to seawater were determined over a temperature (T range from 276 to 313 K and a salinity (S range up to 51 ‰ by means of an inert-gas stripping method. From the van't Hoff equation, the KeqS value in water, which corresponds to the Henry's law constant (KH, at 298 K was determined to be 0.065 M atm−1. The salinity dependence of KeqS (the salting-out effect, ln(KH∕KeqS, did not obey the Sechenov equation but was proportional to S0. 5. Overall, the KeqS(T value was expressed by ln(KeqS(T  =  −49.71 + (77.70 − 0.134  ×  S0. 5  ×  (100∕T + 19.14  ×  ln(T∕100. By using this equation in a lower-tropospheric semi-hemisphere (30–90 °S of the Advanced Global Atmospheric Gases Experiment (AGAGE 12-box model, we estimated that 1 to 4 % of the atmospheric burden of CH2F2 resided in the ocean mixed layer and that this percentage was at least 4 % in the winter; dissolution of CH2F2 in the ocean may partially influence estimates of CH2F2 emissions from long-term observational data of atmospheric CH2F2 concentrations.

  14. Miniaturized salting-out liquid-liquid extraction in a coupled-syringe system combined with HPLC-UV for extraction and determination of sulfanilamide.

    Science.gov (United States)

    Sereshti, Hassan; Khosraviani, Marzieh; Sadegh Amini-Fazl, Mohammad

    2014-04-01

    In salting-out liquid-liquid extraction (SALLE) technique, water-miscible organic solvents are used for extraction of polar analytes from saline solutions. In this study, for the first time, a coupled 1-mL syringes system was utilized to perform a miniaturized SALLE method. Sulfanilamide antibiotic was extracted and determined via the developed method followed by high performance liquid chromatography-ultraviolet detection (HPLC-UV). The extraction process was carried out by rapid shooting of acetonitrile as extraction solvent (syringe B) into saline aqueous sample solution (syringe A), and then the shooting was repeated several times at a rate of 1 cycles(-1). Thereby, an extremely large contact surface area was created between phases and led to a rapid equilibrium and mass transfer. In order to improve the efficiency of the method, the effect of extraction solvent (type and volume), shooting times, salt concentration, and pH on the extraction efficiency was investigated. The best performance of the method was achieved with 250 µL of acetonitrile, salt concentration of 250 mg mL(-1), pH of 7, and shooting times of 5. The linear dynamic range was 0.001-10 µg mL(-1) with the determination coefficient of 0.9999. The relative standard deviation (RSD; n=3, C=5 µg mL(-1)), and the limit of detection (LOD) were 1.55% and 0.3 ng mL(-1), respectively. The developed technique was successfully applied to genuine samples of tea, water, milk, honey, human urine, plasma and blood. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Salting-out-assisted liquid-liquid extraction as a suitable approach for determination of methoxetamine in large sets of tissue samples.

    Science.gov (United States)

    Hajkova, Katerina; Jurasek, Bronislav; Sykora, David; Palenicek, Tomas; Miksatkova, Petra; Kuchar, Martin

    2016-02-01

    A new designer drug, a dissociative anesthetic, and a putative N-methyl-D-aspartate receptor antagonist, methoxetamine (MXE) noted by the EU Early Warning System has been already identified as a cause of several fatalities worldwide. The primary objective of this work was to develop a suitable sample preparation method allowing for isolation of MXE and its main metabolites in high yields from rat brain, liver, and lungs. For the purpose of the project, MXE and five metabolites were synthesized in-house, specifically O-desmethyl-normethoxetamine, O-desmethylmethoxetamine, dihydro-O-desmethylmethoxetamine, normethoxetamine, and dihydromethoxetamine. A sample preparation procedure consisted in the homogenization of the tissue applying salting-out-assisted liquid-liquid extraction (SALLE). A subsequent liquid chromatography-mass spectrometry (LC-MS) analysis was based on reversed-phased chromatography hyphenated with a triple quad MS system in a positive electrospray mode. Multiple reaction monitoring (MRM) was used for qualification and quantification of the analytes. The quantification was based on the application of an isotopically labeled internal standard, normethoxetamine-d3. The matrix-matched calibrations were prepared for each type of matrix with regression coefficients 0.9943-1.0000. The calibration curves were linear in the concentration range of 2.5-250 ng g(-1). Limits of quantification (LOQs) were estimated as 2.5 and 5 ng g(-1), respectively. Recovery (80-117%) and matrix effect (94-110%) at 100 ng g(-1) and intra- and inter-day accuracy and precision at low (2.5 ng g(-1)), middle (25 ng g(-1)), and upper (250 ng g(-1)) concentration levels for all the analytes in all three types of tissues were also determined. The developed analytical method was applied to a set of real samples gathered in toxicological trials on rats and MXE, and its metabolites were determined successfully.

  16. Salting-out assisted extraction method coupled with hydrophilic interaction liquid chromatography for determination of selected β-blockers and their metabolites in human urine.

    Science.gov (United States)

    Magiera, Sylwia; Kolanowska, Anna; Baranowski, Jacek

    2016-06-01

    In this study, a new analytical method was developed and validated for the simultaneous analysis of β-blockers (metoprolol, propranolol, carvedilol) and their metabolites (5'-hydroxycarvedilol, O-desmethylcarvedilol, α-hydroxymetoprolol, O-desmethylmetoprolol, 5-hydroxypropranolol) in human urine. A salting-out assisted liquid-liquid extraction (SALLE) procedure was used for sample preparation. Several parameters affecting the extraction efficiency and method sensitivity including the type and volume of the extraction solvent, the type and quantity of the inorganic salt, extraction time and sample pH were investigated. Hydrophilic interaction liquid chromatography-ultraviolet detection (HILIC-UV) was used for the determination of all analytes. During method development, the effects of mobile phase components (type, pH, concentration of salt, organic modifier type and content, flow rate, column temperature) on the retention and separation of β-blockers and metabolites on the five different HILIC columns were examined. The method was linear for concentrations ranging from 0.1 to 8.0μg/mL, with determination coefficients higher than 0.993 for all analytes. The limits of quantification were in the range from 0.1 to 0.2μg/mL. Intra- and inter-day precision ranged from 0.1 to 8.9%, and accuracy was within±13% interval for all analytes. Under the optimized conditions, extraction efficiency was greater than 83.4% for determined compounds. The validated method was then applied to the measurement of β-blockers and their metabolites in human urine samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. A salting out-acetonitrile homogeneous extraction coupled with gas chromatography-mass spectrometry method for the simultaneous determination of thirteen N-nitrosamines in skin care cosmetics.

    Science.gov (United States)

    Dong, Hao; Guo, Xindong; Xian, Yanping; Luo, Haiying; Wang, Bin; Wu, Yuluan

    2015-11-27

    A sensitive gas chromatography-mass spectrometry method was established for the simultaneous determination of thirteen N-nitrosamines (NAs) in skin care cosmetics. The cosmetics samples were firstly dispersed by water and subsequently extracted and purified using salting out-acetonitrile homogeneous extraction method. Finally, the extracting solution was concentrated by slow nitrogen gas blowing. All of the samples were separated by INNOWAX capillary chromatographic column, and detected by selected ion monitoring (SIM) mode of gas chromatography-mass spectrometry (GC-MS) and quantified by isotope internal standard method. The method was validated for linearity and range, accuracy, precision and sensitivity. Under the optimized condition, the calibration curves were linear over the selected concentration ranges of 2-500μg/L for all the thirteen analytes, with calculated coefficients of determination (R(2)) of greater than 0.996. The limits of detection (LODs) and the limits of quantitation (LOQs) of the method were 3-15μg/kg and 10-50μg/kg, respectively. Recoveries were calculated at three levels of concentration spiked in two kinds of cosmetics (skin care cream and water). The values were found between 93.8% and 121.0% with relative standard deviation (RSD) values of 2.5-7.2% for intra-day precision (n=6) and 3.3-6.7% for inter-day precision (n=5). The method was successfully applied to analyze twenty-two cosmetics samples and N-nitrosodimethylamine (NDMA) was detected in one sample with the concentration of 207μg/kg. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. High-throughput salting-out assisted liquid/liquid extraction with acetonitrile for the simultaneous determination of simvastatin and simvastatin acid in human plasma with liquid chromatography.

    Science.gov (United States)

    Zhang, Jun; Rodila, Ramona; Gage, Eric; Hautman, Mathew; Fan, Leimin; King, Linda L; Wu, Huaiqin; El-Shourbagy, Tawakol A

    2010-02-28

    Simvastatin (SS) is an effective cholesterol-lowering medicine, and is hydrolyzed to simvastatin acid (SSA) after oral administration. Due to SS and SSA inter-conversion and its pH and temperature dependence, SS and SSA quantitation is analytically challenging. Here we report a high-throughput salting-out assisted liquid/liquid extraction (SALLE) method with acetonitrile and mass spectrometry compatible salts for simultaneous LC-MS/MS analysis of SS and SSA. The sample preparation of a 96-well plate using SALLE was completed within 20 min, and the SALLE extract was diluted and injected into an LC-MS/MS system with a cycle time of 2.0 min/sample. The seamless interface of SALLE and LC-MS eliminated drying down step and thus potential sample exposure to room or higher temperature. The stability of SS and SSA in various concentration ratios in plasma was evaluated at room and low (4 degrees C) temperature and the low temperature (4 degrees C) was found necessary to maintain sample integrity. The short sample preparation time along with controlled temperature (2-4 degrees C) and acidity (pH 4.5) throughout sample preparation minimized the conversion of SS-->SSA to SS to 0.00% The method was validated with a lower limit of quantitation (LLOQ) of 0.094 ng mL(-1) for both SS and SSA and a sample volume of 100 microL. The method was used for a bioequivalence study with 4048 samples. Incurred sample reproducibility (ISR) analysis of 362 samples from the study exceeded ISR requirement with 99% re-analysis results within 100+/-20% of the original analysis results. Copyright 2010 Elsevier B.V. All rights reserved.

  19. Experimental determination of Henry's law constants of difluoromethane (HFC-32) and the salting-out effects in aqueous salt solutions relevant to seawater

    Science.gov (United States)

    Kutsuna, Shuzo

    2017-06-01

    Gas-to-water equilibrium coefficients, KeqS (in M atm-1), of difluoromethane (CH2F2), a hydrofluorocarbon refrigerant (HFC-32), in aqueous salt solutions relevant to seawater were determined over a temperature (T) range from 276 to 313 K and a salinity (S) range up to 51 ‰ by means of an inert-gas stripping method. From the van't Hoff equation, the KeqS value in water, which corresponds to the Henry's law constant (KH), at 298 K was determined to be 0.065 M atm-1. The salinity dependence of KeqS (the salting-out effect), ln(KH/KeqS), did not obey the Sechenov equation but was proportional to S0. 5. Overall, the KeqS(T) value was expressed by ln(KeqS(T)) = -49.71 + (77.70 - 0.134 × S0. 5) × (100/T) + 19.14 × ln(T/100). By using this equation in a lower-tropospheric semi-hemisphere (30-90 °S) of the Advanced Global Atmospheric Gases Experiment (AGAGE) 12-box model, we estimated that 1 to 4 % of the atmospheric burden of CH2F2 resided in the ocean mixed layer and that this percentage was at least 4 % in the winter; dissolution of CH2F2 in the ocean may partially influence estimates of CH2F2 emissions from long-term observational data of atmospheric CH2F2 concentrations.

  20. Assessing the Salting-Out Behavior of 2,4-Dinitrobenzaldehyde and 2,6-Dinitrobenzaldehyde from Solubility Values in Pure Water and Seawater at Temperatures between (280 and 313) K

    Science.gov (United States)

    2011-05-12

    Assessing the Salting-out Behavior of Nitrobenzene, 2- Nitrotoluene , and 3- Nitrotoluene from Solubility Values in Pure Water and Seawater at...Temperatures Between (277 and 314)K. J. Chem. Eng. Data 2009, 54, 1231–1235. (17) Sada, E.; Kito, S.; Ito, Y. Solubility of Toluene in Aqueous Salt Solutions

  1. Salting-out assisted liquid-liquid extraction with the aid of experimental design for determination of benzimidazole fungicides in high salinity samples by high-performance liquid chromatography.

    Science.gov (United States)

    Wen, Yingying; Li, Jinhua; Yang, Fangfang; Zhang, Weiwei; Li, Weiran; Liao, Chunyang; Chen, Lingxin

    2013-03-15

    A novel method for the simultaneous separation and determination of four benzimidazole fungicides (i.e., carbendazim, fuberidazole, thiophanate-methyl and thiophanate) in high salinity samples was developed by using salting-out assisted liquid-liquid extraction (SALLE) via water-miscible acetonitrile as the extractant coupled with high-performance liquid chromatography. Box-Behnken design and response surface were employed to assist the optimization of SALLE conditions, including volume of salting-out solvent, the pH of sample solution and salting-out solvent as variable factors. The optimal salting-out parameters were obtained as follows: 2 mL of acetonitrile was added to 2 mL of sample solution with pH=4 and then 2 mL salting-out solvent containing 5 mol L(-1) sodium chloride at a pH of 7 was added to the solution for extraction. This procedure afforded a convenient and cost-saving operation with good cleanup ability for the benzimidazole fungicides, such as good linear relationships (R>0.996) between peak area and concentration from 2.5 ng mL(-1) to 500 ng mL(-1), low limits of detection between 0.14 ng mL(-1) and 0.38 ng mL(-1) and the intra-day precisions of retention time below 1.0%. The method recoveries obtained at fortified three concentrations for three seawater samples ranged from 60.4% to 99.1%. The simple, rapid and eco-benign SALLE based method proved potentially applicable for trace benzimidazole fungicides analysis in high salinity samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  2. Toward an understanding of the salting-out effects in aqueous ionic liquid solutions: vapor-liquid equilibria, liquid-liquid equilibria, volumetric, compressibility, and conductivity behavior.

    Science.gov (United States)

    Sadeghi, Rahmat; Mostafa, Bahar; Parsi, Elham; Shahebrahimi, Yasaman

    2010-12-16

    The action of particular electrolytes in altering the solution properties of ionic liquids is well documented, although the origin of this effect is not clearly defined. In order to clarify this point, the aim of this work is to obtain further evidence about the salting-out effect produced by the addition of different salts to aqueous solutions of water miscible ionic liquids by evaluating the effect of a large series of salts on the vapor-liquid equilibria, liquid-liquid phase diagram, volumetric, compressibility, and conductometric properties of ionic liquids 1-alkyl-3-methylimidazolium halide ([C(n)mim][X]). In the first part of this work, the experimental measurements of water activity at 298.15 and 308.15 K for aqueous binary and ternary solutions containing 1-alkyl-3-methylimidazolium bromide ([Rmim][Br], R = butyl (C(4)), heptyl (C(7)), and octyl (C(8))), sodium dihydrogen citrate (NaH(2)Cit), disodium hydrogen citrate (Na(2)HCit), and trisodium citrate (Na(3)Cit) are taken using both vapor pressure osmometry (VPO) and improved isopiestic methods. The effect of temperature, charge on the anion of sodium citrate salts, and alkyl chain length of ionic liquids on the vapor-liquid equilibria properties of the investigated systems are studied. The constant water activity lines of all the ternary systems show large negative deviation from the linear isopiestic relation (Zdanovskii-Stokes-Robinson rule) derived using the semi-ideal hydration model, and the vapor pressure depression for a ternary solution is much larger than the sum of those for the corresponding binary solutions with the same molality of the ternary solution. The results have been interpreted in terms of the solute-water and solute-solute interactions. In the second part of this work, the effects of the addition of (NH(4))(3)Cit, K(3)Cit, Na(3)Cit, (NH(4))(2)HPO(4), and (NH(4))(3)PO(4) on the liquid-liquid phase diagram, apparent molar volume, isentropic compressibility, and conductivity of aqueous

  3. Development of a new extraction method based on counter current salting-out homogenous liquid-liquid extraction followed by dispersive liquid-liquid microextraction: Application for the extraction and preconcentration of widely used pesticides from fruit juices.

    Science.gov (United States)

    Farajzadeh, Mir Ali; Feriduni, Behruz; Mogaddam, Mohammad Reza Afshar

    2016-01-01

    In this paper, a new extraction method based on counter current salting-out homogenous liquid-liquid extraction (CCSHLLE) followed by dispersive liquid-liquid microextraction (DLLME) has been developed for the extraction and preconcentration of widely used pesticides in fruit juice samples prior to their analysis by gas chromatography-flame ionization detection (GC-FID). In this method, initially, sodium chloride as a separation reagent is filled into a small column and a mixture of water (or fruit juice) and acetonitrile is passed through the column. By passing the mixture sodium chloride is dissolved and the fine droplets of acetonitrile are formed due to salting-out effect. The produced droplets go up through the remained mixture and collect as a separated layer. Then, the collected organic phase (acetonitrile) is removed with a syringe and mixed with 1,1,2,2-tetrachloroethane (extraction solvent at µL level). In the second step, for further enrichment of the analytes the above mixture is injected into 5 mL de-ionized water placed in a test tube with conical bottom in order to dissolve acetonitrile into water and to achieve a sedimented phase at µL-level volume containing the enriched analytes. Under the optimal extraction conditions (extraction solvent, 1.5 mL acetonitrile; pH, 7; flow rate, 0.5 mL min(-1); preconcentration solvent, 20 µL 1,1,2,2-tetrachloroethane; NaCl concentration; 5%, w/w; and centrifugation rate and time, 5000 rpm and 5 min, respectively), the extraction recoveries and enrichment factors ranged from 87% to 96% and 544 to 600, respectively. Repeatability of the proposed method, expressed as relative standard deviations, ranged from 2% to 6% for intra-day (n=6, C=250 or 500 µg L(-1)) and inter-days (n=4, C=250 or 500 µg L(-1)) precisions. Limits of detection are obtained between 2 and 12 µg L(-1). Finally, the proposed method is applied for the determination of the target pesticide residues in the juice samples. Copyright © 2015

  4. Salting-out assisted liquid-liquid extraction coupled to ultra-high performance liquid chromatography-tandem mass spectrometry for the determination of tetracycline residues in infant foods.

    Science.gov (United States)

    Moreno-González, David; García-Campaña, Ana M

    2017-04-15

    The use of salting-out assisted liquid-liquid extraction (SALLE) combined with ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) has been evaluated for the determination of tetracyclines in infant foods based on meat and vegetables or in milk. To obtain satisfactory extraction efficiencies for the studied analytes, several parameters affecting the SALLE procedure were optimized. Analytical performances of the method were satisfactory, obtaining limits of quantification lower than 0.48μgkg -1 in all cases. The precision, expressed as relative standard deviation (%, RSD) was below 11.3%. The extraction efficiency for fortified samples ranged from 89.2 to 96.8%, with RSDs lower than 7.3%. Matrix effect was evaluated for all samples studied, being lower than |21|% in all cases. In relation to the low solvent consumption, the proposed methodology could be considered rapid, cheap and environmentally friendly. Its applicability has been successfully tested in a wide range of infant foods. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Development and application of salting-out assisted liquid/liquid extraction for multi-mycotoxin biomarkers analysis in pig urine with high performance liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Song, Suquan; Ediage, Emmanuel Njumbe; Wu, Aibo; De Saeger, Sarah

    2013-05-31

    Direct determination of urinary mycotoxins is a better approach to assess individual's exposure than the indirect estimation from average dietary intakes. In this study, a new analytical method was developed and validated for simultaneous analysis of aflatoxin B1, deoxynivalenol, fumonisin B1, ochratoxin A, zearalenone and T2 toxin and their metabolites in pig urine. In total 12 analytes were selected. A salting-out assisted liquid-liquid extraction procedure was used for sample preparation. High performance liquid chromatography/tandem mass spectrometry was used for the separation and detection of all the analytes. The extraction recoveries were in a range of 70-108%, with the intra-day relative standard deviation and inter-day relative standard deviation lower than 25% for most of the compounds at 3 different concentration levels. Meanwhile the method bias for all the analytes did not exceed 20%. The limits of quantification ranged from 0.07ngmL(-1) for ochratoxin A to 3.3ngmL(-1) for deoxynivalenol. Matrix effect was evaluated in this study and matrix-matched calibration was used for quantification. The developed method was also validated for human urine as an extension of its application. Finally, the developed method was applied in a pilot study to analyze 28 pig urine samples. Deoxynivalenol, aflatoxin B1, fumonisin B1 and ochratoxin A were detected in these samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Determination of sulfonamides in swine muscle after salting-out assisted liquid extraction with acetonitrile coupled with back-extraction by a water/acetonitrile/dichloromethane ternary component system prior to high-performance liquid chromatography.

    Science.gov (United States)

    Tsai, Wen-Hsien; Huang, Tzou-Chi; Chen, Ho-Hsien; Wu, Yuh-Wern; Huang, Joh-Jong; Chuang, Hung-Yi

    2010-01-15

    A salting-out assisted liquid extraction coupled with back-extraction by a water/acetonitrile/dichloromethane ternary component system combined with high-performance liquid chromatography with diode-array detection (HPLC-DAD) was developed for the extraction and determination of sulfonamides in solid tissue samples. After the homogenization of the swine muscle with acetonitrile and salt-promoted partitioning, an aliquot of 1 mL of the acetonitrile extract containing a small amount of dichloromethane (250-400 microL) was alkalinized with diethylamine. The clear organic extract obtained by centrifugation was used as a donor phase and then a small amount of water (40-55 microL) could be used as an acceptor phase to back-extract the analytes in the water/acetonitrile/dichloromethane ternary component system. In the back-extraction procedure, after mixing and centrifuging, the sedimented phase would be water and could be withdrawn easily into a microsyringe and directly injected into the HPLC system. Under the optimal conditions, recoveries were determined for swine muscle fortified at 10 ng/g and quantification was achieved by matrix-matched calibration. The calibration curves of five sulfonamides showed linearity with the coefficient of estimation above 0.998. Relative recoveries for the analytes were all from 96.5 to 109.2% with relative standard deviation of 2.7-4.0%. Preconcentration factors ranged from 16.8 to 30.6 for 1 mL of the acetonitrile extract. Limits of detection ranged from 0.2 to 1.0 ng/g. 2009 Elsevier B.V. All rights reserved.

  7. Salting Out Effect of Electrolyte Solutions in The Extraction of ...

    African Journals Online (AJOL)

    USER

    form aqueous biphasic are: PEG-Sodium carbonate or. PEG and phosphates, citrates or sulphates. ... of liquid-liquid extraction and also has a number of unique advantages due, in large part, to their aqueous nature. ... (wt/wt) sodium carbonate (Na2CO3) at PEG/salt ratio of. 1:1 (El Hussein, 2004) was also prepared. Equal.

  8. FRAKSINASI ENZIM LIPASE DARI ENDOSPERM KELAPA DENGAN METODE SALTING OUT (Lipase fractionation of Coconut Endosperm by Salting out Method

    Directory of Open Access Journals (Sweden)

    Moh. Su'i

    2014-02-01

    Full Text Available This research learns about fractionation of lipases activity from coconut endosperm by using ammonium sulphate of 0–15%; 15-30 %, 30–45 %, 45–60 %, 60–75 % and 75–90 %. The results showed that the fractions of 0–15% ; 30–45 %, 45–60 % and 60–75 % have lipase activity. Meanwhile, the highest activity was fractions of 60-75%. fractions of 15-30% and 75-90%  have no lipase enzym activity. Molecule weigh of lipase enzyme was 72 kDa. Keywords: Lipases, endosperm, coconut, fractionation, ammonium sulphate   ABSTRAK Penelitian ini mempelajari fraksinasi enzim lipase dari endosperm kelapa menggunakan ammonium sulfat. fraksinasi dilakukan dengan variasi konsentrasi ammonium sulfat 0–15% ; 15-30%; 30–45 %, 45–60 %, 60–75 % dan 75–90 %. Hasil penelitian menunjukkan bahwa enzim lipase terdapat pada fraksi 0–15% ; 30–45 %, 45–60 % dan fraksi 60–75 % dengan aktivitas enzim tertinggi pada fraksi 60-75%. Sedangkan fraksi 15-30% dan 75-90% tidak ada enzim lipase. Berat molekul enzim lipase pada semua fraksi 72 kDa. Kata kunci: Lipase, endosperm, fraksinasi, ammonium sulfat

  9. Trading Agents

    CERN Document Server

    Wellman, Michael

    2011-01-01

    Automated trading in electronic markets is one of the most common and consequential applications of autonomous software agents. Design of effective trading strategies requires thorough understanding of how market mechanisms operate, and appreciation of strategic issues that commonly manifest in trading scenarios. Drawing on research in auction theory and artificial intelligence, this book presents core principles of strategic reasoning that apply to market situations. The author illustrates trading strategy choices through examples of concrete market environments, such as eBay, as well as abst

  10. Radioprotective Agents

    Directory of Open Access Journals (Sweden)

    Ilker Kelle

    2008-01-01

    Full Text Available Since1949, a great deal of research has been carried out on the radioprotective activity of various chemical substances. Thiol compounds, compounds which contain –SH radical, different classes of pharmacological agents and other compounds such as vitamine C and WR-2721 have been shown to reduce mortality when administered prior to exposure to a lethal dose of radiation. Recently, honey bee venom as well as that of its components melittin and histamine have shown to be valuable in reduction of radiation-induced damage and also provide prophylactic alternative treatment for serious side effects related with radiotherapy. It has been suggested that the radioprotective activity of bee venom components is related with the stimulation of the hematopoetic system.

  11. Agent Building Software

    Science.gov (United States)

    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.

  12. Agility: Agent - Ility Architecture

    National Research Council Canada - National Science Library

    Thompson, Craig

    2002-01-01

    ...., object and web technologies). The objective of the Agility project is to develop an open agent grid architecture populated with scalable, deployable, industrial strength agent grid components, targeting the theme 'agents for the masses...

  13. Riot Control Agents

    Science.gov (United States)

    ... Submit What's this? Submit Button Facts About Riot Control Agents Interim document Recommend on Facebook Tweet Share Compartir FACT SHEET What riot control agents are Riot control agents (sometimes referred to ...

  14. Interacting agents in finance

    NARCIS (Netherlands)

    Hommes, C.; Durlauf, S.N.; Blume, L.E.

    2008-01-01

    Interacting agents in finance represent a behavioural, agent-based approach in which financial markets are viewed as complex adaptive systems consisting of many boundedly rational agents interacting through simple heterogeneous investment strategies, constantly adapting their behaviour in response

  15. Taskable Reactive Agent Communities

    National Research Council Canada - National Science Library

    Myers, Karen

    2002-01-01

    The focus of Taskable Reactive Agent Communities (TRAC) project was to develop mixed-initiative technology to enable humans to supervise and manage teams of agents as they perform tasks in dynamic environments...

  16. Mobile Agents Applications.

    Science.gov (United States)

    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…

  17. Users, Bystanders and Agents

    DEFF Research Database (Denmark)

    Krummheuer, Antonia Lina

    2015-01-01

    Human-agent interaction (HAI), especially in the field of embodied conversational agents (ECA), is mainly construed as dyadic communication between a human user and a virtual agent. This is despite the fact that many application scenarios for future ECAs involve the presence of others. This paper...

  18. Reasoning about emotional agents

    NARCIS (Netherlands)

    Meyer, J.-J.

    In this paper we discuss the role of emotions in artificial agent design, and the use of logic in reasoning about the emotional or affective states an agent can reside in. We do so by extending the KARO framework for reasoning about rational agents appropriately. In particular we formalize in

  19. Culturally Aware Agent Communication

    DEFF Research Database (Denmark)

    Rehm, Matthias; Nakano, Yukiko; Koda, Tomoko

    2012-01-01

    Agent based interaction in the form of Embodied Conversational Agents (ECAs) has matured over the last decade and agents have become more and more sophisticated in terms of their verbal and nonverbal behavior like facial expressions or gestures. Having such “natural” communication channels...

  20. Agents modeling agents in information economies

    Energy Technology Data Exchange (ETDEWEB)

    Vidal, J.M.; Durfee, E.H. [Univ. of Michigan, Ann Arbor, MI (United States)

    1996-12-31

    Our goal is to design and build agents that act intelligently when placed in an agent-based information economy, where agents buy and sell services (e.g. thesaurus, search, task planning services, etc.). The economy we are working in is the University of Michigan Digital Library (UMDL), a large scale multidisciplinary effort to build an infrastructure for the delivery of library services. In contrast with a typical economy, an information economy deals in goods and services that are often derived from unique sources (authors, analysts, etc.), so that many goods and services are not interchangeable. Also, the cost of replicating and transporting goods is usually negligible, and the quality of goods and services is difficult to measure objectively: even two sources with essentially the same information might appeal to different audiences. Thus, each agent has its own assessment of the quality of goods and services delivered.

  1. Moral actor, selfish agent.

    Science.gov (United States)

    Frimer, Jeremy A; Schaefer, Nicola K; Oakes, Harrison

    2014-05-01

    People are motivated to behave selfishly while appearing moral. This tension gives rise to 2 divergently motivated selves. The actor-the watched self-tends to be moral; the agent-the self as executor-tends to be selfish. Three studies present direct evidence of the actor's and agent's distinct motives. To recruit the self-as-actor, we asked people to rate the importance of various goals. To recruit the self-as-agent, we asked people to describe their goals verbally. In Study 1, actors claimed their goals were equally about helping the self and others (viz., moral); agents claimed their goals were primarily about helping the self (viz., selfish). This disparity was evident in both individualist and collectivist cultures, attesting to the universality of the selfish agent. Study 2 compared actors' and agents' motives to those of people role-playing highly prosocial or selfish exemplars. In content (Study 2a) and in the impressions they made on an outside observer (Study 2b), actors' motives were similar to those of the prosocial role-players, whereas agents' motives were similar to those of the selfish role-players. Study 3 accounted for the difference between the actor and agent: Participants claimed that their agent's motives were the more realistic and that their actor's motives were the more idealistic. The selfish agent/moral actor duality may account for why implicit and explicit measures of the same construct diverge, and why feeling watched brings out the better angels of human nature.

  2. Formalizing Properties of Agents

    Science.gov (United States)

    1993-05-01

    of any possible agent. For example, consider the task of getting a particular star to go supernova at a particular time. The star either will go... supernova or not, independent of what the agent does. 45 We define an independent task to be a task where if one agent succeeds in a given set of initial...Scott Reilly, Lonnie Chrisman. Siegfried Bocionek and David Zabowski for their comments. 48 A Z primer This appendix contains a short introduction to the

  3. Representation in dynamical agents.

    Science.gov (United States)

    Ward, Ronnie; Ward, Robert

    2009-04-01

    This paper extends experiments by Beer [Beer, R. D. (1996). Toward the evolution of dynamical neural networks for minimally cognitive behavior. In P. Maes, M. Mataric, J. Meyer, J. Pollack, & S. Wilson (Eds.), From animals to animats 4: Proceedings of the fourth international conference on simulation of adaptive behavior (pp. 421-429). MIT Press; Beer, R. D. (2003). The dynamics of active categorical perception in an evolved model agent (with commentary and response). Adaptive Behavior, 11 (4), 209-243] with an evolved, dynamical agent to further explore the question of representation in cognitive systems. Beer's environmentally-situated visual agent was controlled by a continuous-time recurrent neural network, and evolved to perform a categorical perception task, discriminating circles from diamonds. Despite the agent's high levels of discrimination performance, Beer found no evidence of internal representation in the best-evolved agent's nervous system. Here we examine the generality of this result. We evolved an agent for shape discrimination, and performed extensive behavioral analyses to test for representation. In this case we find that agents developed to discriminate equal-width shapes exhibit what Clark [Clark, A. (1997). The dynamical challenge. Cognitive Science, 21 (4), 461-481] calls "weak-substantive representation". The agent had internal configurations that (1) were understandably related to the object in the environment, and (2) were functionally used in a task relevant way when the target was not visible to the agent.

  4. Decontamination Data - Blister Agents

    Data.gov (United States)

    U.S. Environmental Protection Agency — Decontamination efficacy data for blister agents on various building materials using various decontamination solutions. This dataset is associated with the following...

  5. NMR-based localization of ions involved in salting out of hen egg white lysozyme.

    Science.gov (United States)

    Poznański, Jarosław

    2006-01-01

    NaCl-induced aggregation of hen egg white lysozyme (HEWL) was monitored by NMR spectroscopy. Small, but significant, changes induced by salt addition in TOCSY spectra were attributed to the effect of local reorganization of protein backbone upon ion binding. Salt-induced variations in HN and H alpha chemical shifts were mapped on the HEWL 3D structure which allowed the construction of a scheme of the spatial localization of potential ion binding sites. It was found that in a 0.5 M NaCl solution six chloride anions and at least one sodium cation are bound to preferred sites on the HEWL surface.

  6. PRODUCTION OF 5-HYDROXYMETHYLFURFURAL (HMF VIA FRUCTOSE DEHYDRATION: EFFECT OF SOLVENT AND SALTING-OUT

    Directory of Open Access Journals (Sweden)

    F. N. D. C. Gomes

    2015-03-01

    Full Text Available Abstract 5-Hydroxymethylfurfural (HMF is a key renewable platform compound for production of fuels and chemical intermediates. The production of 5-hydroxymethylfurfural (HMF from fructose dehydration was studied using H3PO4 as catalyst, in organic/water system with different solvents (acetone, 2-butanol and ethyl ether. The effect of fructose concentration, temperature and acid concentration was investigated in acetone/water medium. The increase in fructose concentration favors the formation of condensation products and rehydration products are favored at high acid concentration. The solvents exhibited similar performance when the volume ratio of organic to aqueous phase was 1:1, but when this ratio increases to 2:1, the HMF yield obtained with ether was much lower. NaCl addition to the aqueous phase promoted the extraction of HMF to the organic phase, with an HMF yield of 80% in the case of 2:1 acetone/water medium.

  7. PRODUCTION OF 5-HYDROXYMETHYLFURFURAL (HMF) VIA FRUCTOSE DEHYDRATION: EFFECT OF SOLVENT AND SALTING-OUT

    OpenAIRE

    F. N. D. C. Gomes; L. R. Pereira; N. F. P. Ribeiro; M. M. V. M. Souza

    2015-01-01

    Abstract 5-Hydroxymethylfurfural (HMF) is a key renewable platform compound for production of fuels and chemical intermediates. The production of 5-hydroxymethylfurfural (HMF) from fructose dehydration was studied using H3PO4 as catalyst, in organic/water system with different solvents (acetone, 2-butanol and ethyl ether). The effect of fructose concentration, temperature and acid concentration was investigated in acetone/water medium. The increase in fructose concentration favors the formati...

  8. Salting-out of methane in the aqueous solutions of urea and sarcosine

    Indian Academy of Sciences (India)

    bltembe-1

    Serial No. Atom name, Partial charge /(|e|), where e is the electronic charge. 1, N, 0.038907. 2, H, 0.231172. 3, C, -0.358527. 4, C, 0.890129. 5, H, 0.146003. 6, H, 0.140616. 7, O, -0.749174. 8, O, -0.720346. 9, C, -0.248899. 10, H, 0.161962. 11, H, 0.111890. 12, H, 0.114049. 13, H, 0.242217 ...

  9. Salting-out of methane in the aqueous solutions of urea and sarcosine

    Indian Academy of Sciences (India)

    Withers P C and Guppy M 1996 J. Exp. Biol. 199. 1809. 12. Holthauzen L M F and Bolen D W 2007 Protein Sci. 16. 293. 13. Venkatesu P, Lee Ming-Jer and Lin Ho-mu 2009 J. Phys. Chem. B 113 5327. 14. Chandler D and Pratt R 1997 J. Chem. Phys. 67 3683. 15. Berne B J, Rao M and Pangali C 1979 J. Chem. Phys.

  10. "Salting-out" concentration of phytoplankton pigment extracts previous to their analysis by HPLC

    Directory of Open Access Journals (Sweden)

    José Luis Garrido

    2014-04-01

    The recoveries of different pigments varied depending on their chemical nature and the degree of enrichment of the extract. Carotenoids and non-polar chlorophylls were recovered above 85 % with 5M saline solutions, while the recovery of acidic clorophylls (c3 and c2 decreased with enrichment factors.

  11. Teaching Tourism Change Agents

    DEFF Research Database (Denmark)

    Stilling Blichfeldt, Bodil; Kvistgaard, Hans-Peter; Hird, John

    2017-01-01

    course that is part of a Tourism Master’s program, where a major challenge is not only to teach students about change and change agents, but to teach them how change feels and ho w to become change agents. The c hange management course contains an experiment inspired by experiential teaching literature...... change in tourism in the future....

  12. Agents in domestic environments

    NARCIS (Netherlands)

    Glenn Meerstra; Wouter Langerak; Leo van Moergestel; Niels van Nieuwenburg; John-Jules Meyer; Ing. Erik Puik; Franc Pape; Daniël Telgen

    2013-01-01

    Athor supplied : "This paper describes an agent-based architecture for domotics. This architecture is based on requirements about expandability and hardware independence. The heart of the system is a multi-agent system. This system is distributed over several platforms to open the possibility to

  13. Change Agent Survival Guide

    Science.gov (United States)

    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…

  14. Biological warfare agents

    Directory of Open Access Journals (Sweden)

    Duraipandian Thavaselvam

    2010-01-01

    Full Text Available 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.

  15. Agent-Based Optimization

    CERN Document Server

    Jędrzejowicz, Piotr; Kacprzyk, Janusz

    2013-01-01

    This volume presents a collection of original research works by leading specialists focusing on novel and promising approaches in which the multi-agent system paradigm is used to support, enhance or replace traditional approaches to solving difficult optimization problems. The editors have invited several well-known specialists to present their solutions, tools, and models falling under the common denominator of the agent-based optimization. The book consists of eight chapters covering examples of application of the multi-agent paradigm and respective customized tools to solve  difficult optimization problems arising in different areas such as machine learning, scheduling, transportation and, more generally, distributed and cooperative problem solving.

  16. Delta agent (Hepatitis D)

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000216.htm Hepatitis D (Delta agent) To use the sharing features on this page, please enable JavaScript. Hepatitis D is a viral infection caused by the ...

  17. Agent Standards Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The innovation of the work herein proposed is the development of standards for software autonomous agents. These standards are essential to achieve software...

  18. Developing effective change agents.

    Science.gov (United States)

    Daniels, L A

    1986-01-01

    With small/rural hospitals employing a multitude of professionals it becomes imperative that trainers explore ways to develop "self-help" or "change agent" groups if training departments are to persist ... indeed exist. The approach described here concentrates not only on developing the training director's skills but also on developing the skills of department managers and supervisors in facilitating change and becoming change agents. It also illustrates the importance of cooperation between department heads and the education and training staff.

  19. Agent amplified communication

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Agents unleashed a public domain look at agent technology

    CERN Document Server

    Wayner, Peter

    1995-01-01

    Agents Unleashed: A Public Domain Look at Agent Technology covers details of building a secure agent realm. The book discusses the technology for creating seamlessly integrated networks that allow programs to move from machine to machine without leaving a trail of havoc; as well as the technical details of how an agent will move through the network, prove its identity, and execute its code without endangering the host. The text also describes the organization of the host's work processing an agent; error messages, bad agent expulsion, and errors in XLISP-agents; and the simulators of errors, f

  1. The need for agents

    DEFF Research Database (Denmark)

    Abolfazlian, Ali Reza Kian

    1996-01-01

    I denne artikel arbejder vi med begrebet Intelligent Software Agents (ISAs), som autonomous, social, reactive, proactive og subservient computer systemer. Baseret på socialt psykologiske argumenter viser jeg endvidere, hvordan både den menneskelige natur og det teknologiske stadium, som mennesket...... befinder sig i, forårsager behovet for disse ISAs. Der gives eksempler på ISAs, samt de områder, hvor man har særlige behov for disse agenter, og hvordan nogle af disse ISAs allerede er blevet taget i brug for at løse problemerne i disse områder....

  2. Announcements to Attentive Agents

    DEFF Research Database (Denmark)

    Bolander, Thomas; van Ditmarsch, Hans; Herzig, Andreas

    2016-01-01

    In public announcement logic it is assumed that all agents pay attention to the announcement. Weaker observational conditions can be modelled in action model logic. In this work, we propose a version of public announcement logic wherein it is encoded in the states of the epistemic model which...... agents pay attention to the announcement. This logic is called attention-based announcement logic. We give an axiomatization of the logic and prove that complexity of satisfiability is the same as that of public announcement logic, and therefore lower than that of action model logic. An attention...

  3. From autistic to social agents

    NARCIS (Netherlands)

    Dignum, F.; Hofstede, G.J.; Prada, R.

    2014-01-01

    The theory, models and architectures of intelligent agents are based loosely on the theory of intentions from Bratman resulting in the so-called BDI agents. Although this func- tions well for single agents it has been long recognized that this approach falls short for multi-agent systems. It lacks

  4. Agent Persuasion Mechanism of Acquaintance

    Science.gov (United States)

    Jinghua, Wu; Wenguang, Lu; Hailiang, Meng

    Agent persuasion can improve negotiation efficiency in dynamic environment based on its initiative and autonomy, and etc., which is being affected much more by acquaintance. Classification of acquaintance on agent persuasion is illustrated, and the agent persuasion model of acquaintance is also illustrated. Then the concept of agent persuasion degree of acquaintance is given. Finally, relative interactive mechanism is elaborated.

  5. Software Agent Techniques in Design

    DEFF Research Database (Denmark)

    Hartvig, Susanne C

    1998-01-01

    This paper briefly presents studies of software agent techniques and outline aspects of these which can be applied in design agents in integrated civil engineering design environments.......This paper briefly presents studies of software agent techniques and outline aspects of these which can be applied in design agents in integrated civil engineering design environments....

  6. Forest Service special agents, assistant special agents in charge, senior special agents, and supervisory special agents report: nationwide study

    Science.gov (United States)

    Deborah J. Chavez; Joanne F. Tynon

    2007-01-01

    This is the fourth in a series of studies to evaluate perceptions of U.S. Department of Agriculture Forest Service law enforcement personnel of the roles, responsibilities, and issues related to their jobs. An e-mail survey was administered to the 89 Forest Service special agents, assistant special agents in charge, senior special agents, and supervisory special agents...

  7. Programming multi-agent systems

    NARCIS (Netherlands)

    Dastani, Mehdi

    2015-01-01

    With the significant advances in the area of autonomous agents and multi-agent systems in the last decade, promising technologies for the development and engineering of multi-agent systems have emerged. The result is a variety of agent-oriented programming languages, development frameworks,

  8. SECOND BUYING AGENT

    CERN Multimedia

    SPL - SERVICES ACHATS

    2000-01-01

    Last year the buying agent LOGITRADE started operations on the CERN site, processing purchasing requests for well-defined families of products up to a certain value. It was planned from the outset that a second buying agent would be brought in to handle the remaining product families. So, according to that plan, the company CHARLES KENDALL will be commencing operations at CERN on 8 May 2000 in Building 73, 1st floor, offices 31 and 35 (phone and fax numbers to be announced).Each buying agent will have its own specific list of product families and will handle purchasing requests up to 10'000 CHF.Whenever possible they will provide the requested supplies at a price (including the cost of their own services) which must be equivalent to or lower than the price mentioned on the purchasing request, changing the supplier if necessary. If a lower price cannot be obtained, agents will provide the necessary administrative support free of charge.To ensure that all orders are processed in the best possible conditions, us...

  9. Infectious Agents and Cancer

    African Journals Online (AJOL)

    Hepatocellular carcinoma. Cervical cancer, other anogenital ... The expression of the E6 and E7 open reading frames (ORFs) from high .... protein CagA [3 5]. They also elaborate urease, alcohol dehydrogenase and mucolytic factors. All these agents contribute to the development of cancer following H. pylori infection.

  10. Developing Enculturated Agents

    DEFF Research Database (Denmark)

    Rehm, Matthias

    2010-01-01

    on our cultural profiles that provide us with heuristics of behavior and interpretation. Thus, integrating cultural aspects of communicative behaviors in virtual agents and thus enculturating such systems seems to be inevitable. But culture is a multi-defined domain and thus a number of pitfalls arise...

  11. Socially Intelligent Tutor Agents

    NARCIS (Netherlands)

    Heylen, Dirk K.J.; Nijholt, Antinus; op den Akker, Hendrikus J.A.; Vissers, M.; Aylett, R.; Ballin, D.; Rist, T.

    2003-01-01

    Emotions and personality have received quite a lot of attention the last few years in research on embodied conversational agents. Attention is also increasingly being paid to matters of social psychology and interpersonal aspects, for work of our group). Given the nature of an embodied

  12. Biomimetic Emotional Learning Agents

    OpenAIRE

    Kenyon, Samuel H.

    2005-01-01

    This extended abstract proposes a type of AI agent comprised of: an autonomous real-time control system, low-level emotional learning (including a simple knowledge base that links homeostatic/innate drives to sensory perception states), and a novel sliding-priority drive motivation mechanism. Learning occurs in both phylogenetic and ontogenetic training.

  13. Soundless Chemical Demolition Agents

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    The traditional approach to demolishing concrete structures or reducing the size of large rocks or boulders has typically included the use of explosives. The resulting explosions are associated with the obvious risks posed by shock waves and fly rock. Soundless chemical demolition agents (SCDAs) have proven to be viable substitutes for the use of explosives. SCDAs are powdery materials that will expand considerably when mixed with water.

  14. Constructing Secure Mobile Agent Systems Using the Agent Operating System

    NARCIS (Netherlands)

    van t Noordende, G.J.; Overeinder, B.J.; Timmer, R.J.; Brazier, F.M.; Tanenbaum, A.S.

    2009-01-01

    Designing a secure and reliable mobile agent system is a difficult task. The agent operating system (AOS) is a building block that simplifies this task. AOS provides common primitives required by most mobile agent middleware systems, such as primitives for secure communication, secure and

  15. Organizations as Socially Constructed Agents in the Agent Oriented Paradigm

    NARCIS (Netherlands)

    G. Boella (Guido); L.W.N. van der Torre (Leon)

    2005-01-01

    htmlabstractIn this paper we propose a new role for the agent metaphor in the definition of the organizational structure of multiagent systems. The agent metaphor is extended to consider as agents also social entities like organizations, groups and normative systems, so that mental attitudes can

  16. The Power Trading Agent Competition

    NARCIS (Netherlands)

    W. Ketter (Wolfgang); J. Collins (John); P. Reddy (Prashant); C. Flath (Christoph)

    2011-01-01

    textabstractThis is the specification for the Power Trading Agent Competition for 2011 (Power TAC 2011). Agents are simulations of electrical power brokers, who must compete with each other for both power production and consumption, and manage their portfolios.

  17. Collaborating with Autonomous Agents

    Science.gov (United States)

    Trujillo, Anna C.; Cross, Charles D.; Fan, Henry; Hempley, Lucas E.; Motter, Mark A.; Neilan, James H.; Qualls, Garry D.; Rothhaar, Paul M.; Tran, Loc D.; Allen, B. Danette

    2015-01-01

    With the anticipated increase of small unmanned aircraft systems (sUAS) entering into the National Airspace System, it is highly likely that vehicle operators will be teaming with fleets of small autonomous vehicles. The small vehicles may consist of sUAS, which are 55 pounds or less that typically will y at altitudes 400 feet and below, and small ground vehicles typically operating in buildings or defined small campuses. Typically, the vehicle operators are not concerned with manual control of the vehicle; instead they are concerned with the overall mission. In order for this vision of high-level mission operators working with fleets of vehicles to come to fruition, many human factors related challenges must be investigated and solved. First, the interface between the human operator and the autonomous agent must be at a level that the operator needs and the agents can understand. This paper details the natural language human factors e orts that NASA Langley's Autonomy Incubator is focusing on. In particular these e orts focus on allowing the operator to interact with the system using speech and gestures rather than a mouse and keyboard. With this ability of the system to understand both speech and gestures, operators not familiar with the vehicle dynamics will be able to easily plan, initiate, and change missions using a language familiar to them rather than having to learn and converse in the vehicle's language. This will foster better teaming between the operator and the autonomous agent which will help lower workload, increase situation awareness, and improve performance of the system as a whole.

  18. Agentes selladores en endodoncia

    OpenAIRE

    Racciatti, Gabriela

    2003-01-01

    Recibido: Noviembre 2002 Aceptado: Enero 2003 La gutapercha sigue siendo uno de los materiales predilectos, pero debido a su falta de adhesión a las paredes dentinarias, debe estar siempre combinada con un sellador que actúe como interfase entre la masa de gutapercha y la estructura dentaria. El uso de un agente sellador para obturar los conductos radiculares es esencial para el éxito del proceso de obturación. Un buen sellador debe ser biocompatible y bien tolerado por los tejid...

  19. Chemical warfare agents

    Directory of Open Access Journals (Sweden)

    Vijayaraghavan R

    2010-01-01

    Full Text Available 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.

  20. Teaching tourism change agents

    OpenAIRE

    Stilling Blichfeldt, Bodil; Kvistgaard, Hans-Peter; Hird, John

    2017-01-01

    This article discuss es know ledge, competencies and skills Master’s students should obtain during their academic studies and particularly, the differences between teaching about a topic and teaching to do. This is ex emplified by experiential learning theory and the case of a change management course that is part of a Tourism Master’s program, where a major challenge is not only to teach students about change and change agents, but to teach them how change feels and ho w to become change age...

  1. Toxorhynchites as biocontrol agents.

    Science.gov (United States)

    Focks, Dana A

    2007-01-01

    Toxorhynchites is an unusual and interesting genus of large, non-biting mosquitoes. In spite of their size, they are--like many species of mosquitoes--completely harmless to man. The larvae are predaceous on other mosquitoes and aquatic organisms that inhabit both natural and artificial containers. Because this habitat is the source of several medically important species of mosquitoes, there is warrant for evaluating the potential of Toxorhynchites as a biological control agent under various conditions. Toxorhynchites is not seen as a panacea for the control of all container-inhabiting mosquitoes. However, it has demonstrated practical potential in certain restricted but important situations.

  2. A Characterization of Sapient Agents

    NARCIS (Netherlands)

    van Otterlo, M.; Wiering, Marco; Dastani, Mehdi; Meyer, John-Jules; Hexmoor, H.

    2003-01-01

    This paper presents a proposal to characterize Sapient Agents in terms of cognitive concepts and abilities. In particular, a sapient agent is considered as a cognitive agent the learns its cognitive state and capabilities through experience. This characterization is based on formal concepts such as

  3. Motivating agents in software tutorials

    NARCIS (Netherlands)

    van der Meij, Hans

    2013-01-01

    Pedagogical agents can provide important support for the user in human–computer interaction systems. This paper examines whether a supplementary, motivating agent in a print tutorial can enhance student motivation and learning in software training. The agent served the role of motivator, attending

  4. Cultural Differentiation of Negotiating Agents

    NARCIS (Netherlands)

    Hofstede, G.J.; Jonker, C.M.; Verwaart, D.

    2012-01-01

    Negotiations proceed differently across cultures. For realistic modeling of agents in multicultural negotiations, the agents must display culturally differentiated behavior. This paper presents an agent-based simulation model that tackles these challenges, based on Hofstede’s model of national

  5. Cultural differentiation of negotiating agents

    NARCIS (Netherlands)

    Hofstede, G.J.; Jonker, C.M.; Verwaart, T.

    2010-01-01

    Negotiations proceed differently across cultures. For realistic modeling of agents in multicultural negotiations, the agents must display culturally differentiated behavior. This paper presents an agent-based simulation model that tackles these challenges, based on Hofstede’s model of national

  6. A logic for agent organizations

    NARCIS (Netherlands)

    Dignum, M.V.; Dignum, F.P.M.

    2007-01-01

    Organization concepts and models are increasingly being adopted for the design and specification of multi-agent systems. Agent organizations can be seen as mechanisms of social order, created to achieve common goals for more or less autonomous agents. In order to develop a theory on the relation

  7. Amphoteric surface active agents

    Directory of Open Access Journals (Sweden)

    Eissa, A.M. F.

    1995-10-01

    Full Text Available 2-[trimethyl ammonium, triethyl ammonium, pyridinium and 2-amino pyridinium] alkanoates, four series of surface active agents containing carbon chain C12, C14, C16 and C18carbon atoms, were prepared. Their structures were characterized by microanalysis, infrared (IR and nuclear magnetic resonance (NMR. Surface and interfacial tension, Krafft point, wetting time, emulsification power, foaming height and critical micelle concentration (cmc were determined and a comparative study was made between their chemical structure and surface active properties. Antimicrobial activity of these surfactants was also determined.

    Se prepararon cuatro series de agentes tensioactivos del tipo 2-[trimetil amonio, trietil amonio, piridinio y 2-amino piridinio] alcanoatos, que contienen cadenas carbonadas con C12, C14, C16 y C18 átomos de carbono.
    Se determinaron la tensión superficial e interfacial, el punto de Krafft, el tiempo humectante, el poder de emulsionamiento, la altura espumante y la concentración critica de miscela (cmc y se hizo un estudio comparativo entre la estructura química y sus propiedades tensioactivas. Se determinó también la actividad antimicrobiana de estos tensioactivos. Estas estructuras se caracterizaron por microanálisis, infrarrojo (IR y resonancia magnética nuclear (RMN.

  8. Holograms as Teaching Agents

    Science.gov (United States)

    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.

  9. Learning models of intelligent agents

    Energy Technology Data Exchange (ETDEWEB)

    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. Flexible, secure agent development framework

    Science.gov (United States)

    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.

  11. New antifungal agents.

    Science.gov (United States)

    Gupta, Aditya K; Tomas, Elizabeth

    2003-07-01

    Currently, use of standard antifungal therapies can be limited because of toxicity, low efficacy rates, and drug resistance. New formulations are being prepared to improve absorption and efficacy of some of these standard therapies. Various new antifungals have demonstrated therapeutic potential. These new agents may provide additional options for the treatment of superficial fungal infections and they may help to overcome the limitations of current treatments. Liposomal formulations of AmB have a broad spectrum of activity against invasive fungi, such as Candida spp., C. neoformans, and Aspergillus spp., but not dermatophyte fungi. The liposomal AmB is associated with significantly less toxicity and good rates of efficacy, which compare or exceed that of standard AmB. These factors may provide enough of an advantage to patients to overcome the increased costs of these formulations. Three new azole drugs have been developed, and may be of use in both systemic and superficial fungal infections. Voriconazole, ravuconazole, and posaconazole are triazoles, with broad-spectrum activity. Voriconazole has a high bioavailability, and has been used with success in immunocompromised patients with invasive fungal infections. Ravuconazole has shown efficacy in candidiasis in immunocompromised patients, and onychomycosis in healthy patients. Preliminary in vivo studies with posaconazole indicated potential use in a variety of invasive fungal infections including oropharyngeal candidiasis. Echinocandins and pneumocandins are a new class of antifungals, which act as fungal cell wall beta-(1,3)-D-glucan synthase enzyme complex inhibitors. Caspofungin (MK-0991) is the first of the echinocandins to receive Food and Drug Administration approval for patients with invasive aspergillosis not responding or intolerant to other antifungal therapies, and has been effective in patients with oropharyngeal and esophageal candidiasis. Standardization of MIC value determination has improved the

  12. Mushrooms as therapeutic agents

    Directory of Open Access Journals (Sweden)

    Sushila Rathee

    2012-04-01

    Full Text Available Mushrooms have been known for their nutritional and culinary values and used as medicines and tonics by humans for ages. In modern terms, they can be considered as functional foods which can provide health benefits beyond the traditional nutrients. There are monographs that cover the medicinal and healing properties of some individual traditional mushrooms. There has been a recent upsurge of interest in mushrooms not only as a health food which is rich in protein but also as a source of biologically active compounds of medicinal value which include complementary medicine/dietary supplements for anticancer, antiviral, hepatoprotective, immunopotentiating and hypocholesterolemic agents. However the mechanisms of the various health benefits of mushrooms to humans still require intensive investigation, especially given the emergence of new evidence of their health benefits. In the present paper the medicinal potential of mushrooms is being discussed.

  13. [Chemotherapeutic agents under study].

    Science.gov (United States)

    Kawahara, S

    1998-12-01

    The development of new drugs with strong antituberculous activity and fewer side effects which are not cross-resistant to conventional antituberculosis drugs is urgently desired now. The chemotherapeutic agents under study which are considered a candidate for a new antituberculosis drug are listed below. 1) Rifamycin derivatives: rifabutin, rifapentin, KRM-1648, FCE-22250, 22807, CGP-7040, 27557, 29035, 29861, P-DEA, SPA-S-565, R-76-1. 2) New quinolones: ofloxacin, ciprofloxacin, levofloxacin, sparfloxacin, gatifloxacin, CS-940, Du-6859a. 3) Phenazines: clofazimine, B746, B4101, B4154, B4157. 4) Pyrazinamide derivatives: N-hydroxy pyrazinamide, N-hydroxy pyrazinamide-4-oxide. 5) Nitroimidazole derivatives: metronidazole et al.

  14. Odor Classification using Agent Technology

    Directory of Open Access Journals (Sweden)

    Sigeru OMATU

    2014-03-01

    Full Text Available In order to measure and classify odors, Quartz Crystal Microbalance (QCM can be used. In the present study, seven QCM sensors and three different odors are used. The system has been developed as a virtual organization of agents using an agent platform called PANGEA (Platform for Automatic coNstruction of orGanizations of intElligent Agents. This is a platform for developing open multi-agent systems, specifically those including organizational aspects. The main reason for the use of agents is the scalability of the platform, i.e. the way in which it models the services. The system models functionalities as services inside the agents, or as Service Oriented Approach (SOA architecture compliant services using Web Services. This way the adaptation of the odor classification systems with new algorithms, tools and classification techniques is allowed.

  15. Anticancer agents from medicinal plants

    Directory of Open Access Journals (Sweden)

    Mohammad Shoeb

    2006-06-01

    Full Text Available Cancer is a major public health burden in both developed and developing countries. Plant derived agents are being used for the treatment of cancer. Several anticancer agents including taxol, vinblastine, vincristine, the camptothecin derivatives, topotecan and irinotecan, and etoposide derived from epipodophyllotoxin are in clinical use all over the world. A number of promising agents such as flavopiridol, roscovitine, combretastatin A-4, betulinic acid and silvestrol are in clinical or preclinical development.

  16. Anticancer agents from medicinal plants

    Directory of Open Access Journals (Sweden)

    Mohammad Shoeb

    2006-12-01

    Full Text Available Cancer is a major public health burden in both developed and developing countries. Plant derived agents are being used for the treatment of cancer. Several anticancer agents including taxol, vinblas-tine, vincristine, the camptothecin derivatives, topotecan and irinotecan, and etoposide derived from epipodophyllotoxin are in clinical use all over the world. A number of promising agents such as flavopiridol, roscovitine, combretastatin A-4, betulinic acid and silvestrol are in clinical or preclinical development.

  17. Firefighting Agent Research, Phase I

    National Research Council Canada - National Science Library

    Dierdorf, Douglas S; Enlow, Mark A; Stern, Seymour; Carr, Virgil J

    2007-01-01

    .... Such physical characteristics as equilibrium surface tension, dynamic interfacial tension, and surface pressure have been examined in order to determine agent/surfactant behavior during the extinguishment process...

  18. Business Intelligence using Software Agents

    Directory of Open Access Journals (Sweden)

    Ana-Ramona BOLOGA

    2011-12-01

    Full Text Available This paper presents some ideas about business intelligence today and the importance of developing real time business solutions. The authors make an exploration of links between business intelligence and artificial intelligence and focuses specifically on the implementation of software agents-based systems in business intelligence. There are briefly presented some of the few solutions proposed so far that use software agents properties for the benefit of business intelligence. The authors then propose some basic ideas for developing real-time agent-based software system for business intelligence in supply chain management, using Case Base Reasoning Agents.

  19. Agent Mediated Electronic Commerce: Designing Trading Agents and Mechanisms

    NARCIS (Netherlands)

    J.A. La Poutré (Han); N.M. Sadeh; S. Janson

    2006-01-01

    htmlabstractThis book constitutes the thoroughly refereed post-proceedings of the 7th International Workshop on Agent-Mediated Electronic Commerce, AMEC VII 2005, held in Utrecht, Netherlands in July 2005, as part of AAMAS 2005, and the third Workshop on Trading Agent Design and Analysis, TADA 2005,

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

    Science.gov (United States)

    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.

  1. Deliberate evolution in multi-agent systems

    NARCIS (Netherlands)

    F.M.T. Brazier; C.M. Jonker (Catholijn); J. Treur; N.J.E. Wijngaards

    1998-01-01

    textabstract This paper presents an architecture for an agent capable of deliberation about the creation of new agents, and of actually creating a new agent in the multi-agent system, on the basis of this deliberation. After its creation the new agent participates fully in the running multi-agent

  2. Players' agents worldwide: legal aspects

    NARCIS (Netherlands)

    Siekmann, R.C.R.; Parrish, R.; Branco Martins, R.; Soek, J.W.

    2007-01-01

    Publicly, at least, there appears to be a strong collective will within football to clean up the game, to make the work of players’ agents more transparent and to allow a greater share of the game’s profits to stay within the game. Privately, there seems to be unease that current agent regulation is

  3. Social Agents: the first generations

    NARCIS (Netherlands)

    Heylen, Dirk K.J.; Theune, Mariet; op den Akker, Hendrikus J.A.; Nijholt, Antinus; Pantic, Maja; Vinciarello, A.

    2009-01-01

    Embodied Conversational Agents can be viewed as spoken dialogue systems with a graphical representation of a human body. But the embodiment is not the only difference. Whereas Spoken Dialogue Systems are mostly focused on computing the linguistic dimensions of communication, conversational agents

  4. Modelling Reasoning and Acting Agents

    NARCIS (Netherlands)

    Dunin-Keplicz, B.M.; Treur, J.

    1995-01-01

    This paper addresses the issue of the use of formal modelling languages in multi-agent domains. As a main question we evaluate in what respect the formal modelling language DESIRE fulfills the requirements imposed by these domains. To get an answer we studied two examples of multi-agent tasks and

  5. 13 CFR 108.1620 - Functions of agents, including Central Registration Agent, Selling Agent and Fiscal Agent.

    Science.gov (United States)

    2010-01-01

    ... appoint a Fiscal Agent to: (i) Establish performance criteria for Poolers. (ii) Monitor and evaluate the... Assistance for NMVC Companies (Leverage) Funding Leverage by Use of Sba Guaranteed Trust Certificates (âtcsâ... Debenture, SBA may cause each NMVC Company to appoint a Selling Agent to perform functions that include, but...

  6. 13 CFR 107.1620 - Functions of agents, including Central Registration Agent, Selling Agent and Fiscal Agent.

    Science.gov (United States)

    2010-01-01

    ... Fiscal Agent to: (i) Establish performance criteria for Poolers. (ii) Monitor and evaluate the financial... Assistance SMALL BUSINESS ADMINISTRATION SMALL BUSINESS INVESTMENT COMPANIES SBA Financial Assistance for... Participating Securities. (iii) Monitor the performance of the Selling Agent, Poolers, CRA, and the Trustee. (iv...

  7. Relational agents: A critical review

    DEFF Research Database (Denmark)

    Campbell, Robert H.; Grimshaw, Mark Nicholas; Green, Gill

    2009-01-01

    Relationships between people who meet in virtual worlds are common and these relationships can be long term, in some cases lasting a life-time. Although relationships formed in virtual worlds have invited a lot of recent interest, surprisingly little work has been done on developing computer agents...... and non-player characters that can actively participate in such relationships. The focus of this review is relational agents, agents that can build long term socioemotional relationships with users. In virtual worlds, such agents are just starting to emerge; they are more common in other environments...... but remain few and far between. This review critically assesses the progress of relational agent development and research since their inception in 2005, proposes new areas of research and considers the potential for their exploitation in virtual worlds....

  8. Agent Communications using Distributed Metaobjects

    Energy Technology Data Exchange (ETDEWEB)

    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.

  9. Nuclear magnetic resonance contrast agents

    Science.gov (United States)

    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.

  10. An Introduction to Software Agents

    Science.gov (United States)

    2008-02-01

    détruire une unité de valeur élevée »). Le fait d’avoir des forces rouges ayant des comportements réalistes est essentiel au succès d’une expérience...agent, but more likely it will consist of multiple agents. The following attributes are only applicable in a multi-agent system: 9. Social ...communication ( social ability) and cooperation. The final two characteristics that will be mentioned here are more related to the capability of the

  11. Antisense Treatments for Biothreat Agents

    National Research Council Canada - National Science Library

    Warfield, Kelly L; Panchal, Rekha G; Aman, M J; Bavari, Sina

    2006-01-01

    ... a variety of pathogens in cell culture studies and nonhuman primate models of infection. For these reasons, antisense technologies are being pursued as treatments against biothreat agents such as Ebola virus, dengue virus and Bacillus anthracis...

  12. Building Agents to Serve Customers

    OpenAIRE

    Barbuceanu, Mihai; Fox, Mark S; Hong, Lei; Lallement, Yannick; Zhang, Zhongdong

    2004-01-01

    AI agents combining natural language interaction, task planning, and business ontologies can help companies provide better-quality and more costeffective customer service. Our customer-service agents use natural language to interact with customers, enabling customers to state their intentions directly instead of searching for the places on the Web site that may address their concern. We use planning methods to search systematically for the solution to the customer's problem, ensuring that a r...

  13. Believable Social and Emotional Agents.

    Science.gov (United States)

    1996-05-01

    AGENTS v Acknowledgements I would like the thank my advisors, Joe and Jaime. When you get to CMU as a first year graduate student , you’re told that...failure traits is “ depressed .” A depressed agent, according to this theory, will often respond to failures by being more like- ly to abandon the plan and...forms of distress expression, like frowning, crying, and moving slowly. Below that type might be subtypes, such as grief, homesick - ness, and

  14. Business Intelligence using Software Agents

    OpenAIRE

    Ana-Ramona BOLOGA; Razvan BOLOGA

    2011-01-01

    This paper presents some ideas about business intelligence today and the importance of developing real time business solutions. The authors make an exploration of links between business intelligence and artificial intelligence and focuses specifically on the implementation of software agents-based systems in business intelligence. There are briefly presented some of the few solutions proposed so far that use software agents properties for the benefit of business intelligence. The authors then...

  15. Natural products as antimitotic agents.

    Science.gov (United States)

    Dall'Acqua, Stefano

    2014-01-01

    Natural products still play an important role in the medicinal chemistry, especially in some therapeutic areas. As example more than 60% of currently-used anticancer agents are derives from natural sources including plants, marine organisms or micro-organism. Thus natural products (NP) are an high-impact source of new "lead compounds" or new potential therapeutic agents despite the large development of biotechnology and combinatorial chemistry in the drug discovery and development. Many examples of anticancer drugs as paclitaxel, combretastatin, bryostatin and discodermolide have shown the importance of NP in the anticancer chemotherapy through many years. Many organisms have been studied as sources of drugs namely plants, micro-organisms and marine organisms and the obtained NP can be considered a group of "privileged chemical structures" evolved in nature to interact with other organisms. For this reason NP are a good starting points for pharmaceutical research and also for library design. Tubulin and microtubules are one of the most studied targets for the search of anticancer compounds. Microtubule targeting agents (MTA) also named antimitotic agents are compounds that are able to perturb mitosis but are also able to arrest cell growing during interphase. The anticancer drugs, taxanes and vinca alkaloids have established tubulin as important target in cancer therapy. More recently the vascular disrupting agents (VDA) combretastatin analogues were studied for their antimitotics properties. This review will consider the anti mitotic NP and their potential impact in the development of new therapeutic agents.

  16. Mobile Objects and Agents (MOA)

    Science.gov (United States)

    Milojicic, Dejan S.; LaForge, William; Chauhan, Deepika

    1998-12-01

    This paper describes the design and implementation of the Mobile Objects and Agents (MOA) project at the Open Group Research Institute. MOA was designed to support migration, communication and control of agents. It was implemented on top of the Java Virtual Machine, without any modifications to it. The initial project goals were to support communication across agent migration, as a means for collaborative work; and to provide extensive resource control, as a basic support for countering denial of service attacks. In the course of the project we added two further goals: compliance with the Java Beans component model, which provides for additional configurability and customization of agent system and agent applications; and interoperability, which allows cooperation with other agent systems. This paper analyses the architecture of MOA, in particular the support for mobility, naming and locating, communication, and resource management. Object and component models of MOA are discussed and some implementation details described. We summarize the lessons learned while developing and implementing MOA and compare it with related work.

  17. What makes virtual agents believable?

    Science.gov (United States)

    Bogdanovych, Anton; Trescak, Tomas; Simoff, Simeon

    2016-01-01

    In this paper we investigate the concept of believability and make an attempt to isolate individual characteristics (features) that contribute to making virtual characters believable. As the result of this investigation we have produced a formalisation of believability and based on this formalisation built a computational framework focused on simulation of believable virtual agents that possess the identified features. In order to test whether the identified features are, in fact, responsible for agents being perceived as more believable, we have conducted a user study. In this study we tested user reactions towards the virtual characters that were created for a simulation of aboriginal inhabitants of a particular area of Sydney, Australia in 1770 A.D. The participants of our user study were exposed to short simulated scenes, in which virtual agents performed some behaviour in two different ways (while possessing a certain aspect of believability vs. not possessing it). The results of the study indicate that virtual agents that appear resource bounded, are aware of their environment, own interaction capabilities and their state in the world, agents that can adapt to changes in the environment and exist in correct social context are those that are being perceived as more believable. Further in the paper we discuss these and other believability features and provide a quantitative analysis of the level of contribution for each such feature to the overall perceived believability of a virtual agent.

  18. Glutamic acid as anticancer agent: An overview

    National Research Council Canada - National Science Library

    Dutta, Satyajit; Ray, Supratim; Nagarajan, K

    2013-01-01

    The objective of the article is to highlight various roles of glutamic acid like endogenic anticancer agent, conjugates to anticancer agents, and derivatives of glutamic acid as possible anticancer agents...

  19. Inaccessibility in Multi-Agent Systems

    Science.gov (United States)

    2004-03-08

    Agent Manager takes care of creation, execution and removal of agents. – Service Manager . The Service Manager takes care of starting and stopping the...in Multi-Agent Systems 34 Agents Services Agent Manager Service Manager Container Core Message Transport Receiving Thread Incoming Queue Incoming Queue...the AgentContainer class contains public final variable TIMER (java.util.Timer). 6.5.6. Service Manager The Service Manager takes care of services

  20. Community Health Agents and the meanings of "being an agent"

    OpenAIRE

    Viviane Milan Pupin; Cármen Lúcia Cardoso

    2008-01-01

    O Programa Saúde da Família constitui-se enquanto estratégia de mudança do modelo assistencial. O artigo apresenta os resultados de uma pesquisa qualitativa sobre os sentidos de "ser agente" produzidos, por meio de entrevistas abertas, com Agentes Comunitários de Saúde que trabalham nos cinco Núcleos de Saúde da Família da cidade de Ribeirão Preto - São Paulo, vinculados à Faculdade de Medicina de Ribeirão Preto - USP. As entrevistas foram gravadas e transcritas na íntegra e analisadas segund...

  1. Agent Based Individual Traffic Guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen

    This thesis investigates the possibilities in applying Operations Research (OR) to autonomous vehicular traffic. The explicit difference to most other research today is that we presume that an agent is present in every vehicle - hence Agent Based Individual Traffic guidance (ABIT). The next...... evolutionary step for the in-vehicle route planners is the introduction of two-way communication. We presume that the agent is capable of exactly this. Based on this presumption we discuss the possibilities and define a taxonomy and use this to discuss the ABIT system. Based on a set of scenarios we conclude...... of the project were not previously considered. We define a special inseparable cost function and develop a solution complex capable of using this cost function. In relation to calibration and estimation of statistical models used for dynamic route guidance we worked with generating random number sequences...

  2. Agent review phase one report.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Children as digital rights agents

    DEFF Research Database (Denmark)

    Stald, Gitte Bang

    2016-01-01

    This paper looks at children’s involvement and contribution to internet safety policy. In many respects, the research perspective on children and young people has also seen a shift towards the child as agent, as citizen (Livingstone 2002, 2009; Dahlgren 2007). With increasing attention given...... to children’s communication rights there is an acknowledgement that children’s voices should be heard in all matters that affect them (Hamelink 2008). We still, however, primarily discuss how adults could and should take responsibility in guarding children and young people from risk and harm, and what...... 2007). The paper presents a model for analyzing the intersecting levels of children as agents in relation to digital risks and rights: Children as peer-to-peer agents. Children provide mutual practical guidance; experience sharing; advice. re. to risk and harm. Children as advocates/ politicians...

  4. Dopamine agents for hepatic encephalopathy

    DEFF Research Database (Denmark)

    Junker, Anders Ellekær; Als-Nielsen, Bodil; Gluud, Christian

    2014-01-01

    BACKGROUND: Patients with hepatic encephalopathy may present with extrapyramidal symptoms and changes in basal ganglia. These changes are similar to those seen in patients with Parkinson's disease. Dopamine agents (such as bromocriptine and levodopa, used for patients with Parkinson's disease) have...... therefore been assessed as a potential treatment for patients with hepatic encephalopathy. OBJECTIVES: To evaluate the beneficial and harmful effects of dopamine agents versus placebo or no intervention for patients with hepatic encephalopathy. SEARCH METHODS: Trials were identified through the Cochrane...... of the trials followed participants after the end of treatment. Only one trial reported adequate bias control; the remaining four trials were considered to have high risk of bias. Random-effects model meta-analyses showed that dopamine agents had no beneficial or detrimental effect on hepatic encephalopathy...

  5. Learning Agents in Automated Negotiations

    Science.gov (United States)

    Chandrashekhar, Hemalatha; Bhasker, Bharat

    In bilateral multi-issue negotiations involving two-sided information uncertainty, selfish agents participating in a distributed search of the solution space need to learn the opponent’s preferences from the on-going negotiation interactions and utilize such knowledge to construct future proposals in order to hope to arrive at efficient outcomes. Besides, negotiation support systems that inhibit strategic misrepresentation of information need to be in place in order to assist the protagonists to obtain truly efficient solutions. To this end, this work suggests an automated negotiation procedure that while protecting the information privacy of the participating agents encourages truthful revelation of information through successive proposals. Further we present an algorithm for proposal construction in the case of two continuous issues. When both the negotiating agents implement the algorithm the negotiation trace shall be confined to the Pareto frontier. The Pareto-optimal deal close to the Nash solution shall be located whenever such a deal exists.

  6. Agent based simulations in healthcare.

    Science.gov (United States)

    Bilge, Ugur; Saka, Osman

    2006-01-01

    Agent Based Simulations (ABS) is a relatively recent computer paradigm. As opposed to "top down" conventional computer simulations, the ABS approach is a "bottom-up" modelling technique where a medium to high number of independent agents is modelled. These agents' interactions sometimes cause unexpected "emergent" system behaviour. ABS is particularly suitable in the social context such as healthcare where a large number of human agents interact and co-operate for common goals. Today ABS in the social context is often used together with the recently introduced network analysis techniques and network visualization tools for modelling and simulating social agents within organisations. At Akdeniz University we are starting a number of projects for applying ABS technology in healthcare. In this paper we present two of the ongoing projects in this field. Firstly we have developed a prototype simulator for the long term monitoring of Chronic Obstructive Pulmonary Disease (COPD) as a major public health problem. We present the COPD simulator, its agents, parameters and working principles. Secondly we want to apply ABS and the network analysis techniques to visualise and explore informal social networks amongst staff at the Akdeniz University Hospital to assess and evaluate properties of the organisation in terms of its ability to innovate and share knowledge. In our applications, we primarily aim to use ABS in a web-based platform to create a virtual environment for discussion, visualising and running what-if scenarios to test out various options for managing healthcare, as well as sharing information and creating a virtual community.

  7. Intelligent agent software for medicine.

    Science.gov (United States)

    Lieberman, Henry; Mason, Cindy

    2002-01-01

    An important trend for the future of health technology will be the increasing use of intelligent agent software for medical applications. As the complexity of situations faced by both patients and health care providers grows, conventional interfaces that rely on users to manually transfer data and manually perform each problem-solving step, won't be able to keep up. This article describes how software agents that incorporate learning, personalization, proactivity, context-sensitivity and collaboration will lead to a new generation of medical applications that will streamline user interfaces and enable more sophisticated communication and problem-solving.

  8. 13 CFR 120.952 - Fiscal agent.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Fiscal agent. 120.952 Section 120... Loan Program (504) Debenture Sales and Service Agents § 120.952 Fiscal agent. SBA shall appoint a Fiscal Agent to assess the financial markets, minimize the cost of sales, arrange for the production of...

  9. Dialogs with BDP agents in virtual environments

    NARCIS (Netherlands)

    Egges, A.; Nijholt, Antinus; op den Akker, Hendrikus J.A.; Jokinen, K.

    2001-01-01

    In this paper we discuss a multi-modal agent platform, based on the BDI paradigm. We now have environments where more than one agent is available and where there is a need for uniformity in agent design and agent interaction. This requires a more general and uniform approach to developing

  10. Building Multi-Agent Systems Using Jason

    DEFF Research Database (Denmark)

    Boss, Niklas Skamriis; Jensen, Andreas Schmidt; Villadsen, Jørgen

    2010-01-01

    on the Technical University of Denmark (DTU). A part of this course was a short introduction to the multi-agent framework Jason, which is an interpreter for AgentSpeak, an agent-oriented programming language. As the final project in this course a solution to the Multi-Agent Programming Contest from 2007, the Gold...

  11. Clustering recommendations to compute agent reputation

    Science.gov (United States)

    Bedi, Punam; Kaur, Harmeet

    2005-03-01

    Traditional centralized approaches to security are difficult to apply to multi-agent systems which are used nowadays in e-commerce applications. Developing a notion of trust that is based on the reputation of an agent can provide a softer notion of security that is sufficient for many multi-agent applications. Our paper proposes a mechanism for computing reputation of the trustee agent for use by the trustier agent. The trustier agent computes the reputation based on its own experience as well as the experience the peer agents have with the trustee agents. The trustier agents intentionally interact with the peer agents to get their experience information in the form of recommendations. We have also considered the case of unintentional encounters between the referee agents and the trustee agent, which can be directly between them or indirectly through a set of interacting agents. The clustering is done to filter off the noise in the recommendations in the form of outliers. The trustier agent clusters the recommendations received from referee agents on the basis of the distances between recommendations using the hierarchical agglomerative method. The dendogram hence obtained is cut at the required similarity level which restricts the maximum distance between any two recommendations within a cluster. The cluster with maximum number of elements denotes the views of the majority of recommenders. The center of this cluster represents the reputation of the trustee agent which can be computed using c-means algorithm.

  12. 2APL: a practical agent programming language

    NARCIS (Netherlands)

    Dastani, M.M.

    2008-01-01

    This article presents a BDI-based agent-oriented programming language, called 2APL (A Practical Agent Programming Language). This programming language facilitates the implementation ofmulti-agent systems consisting of individual agents thatmay share and access external environments. It realizes

  13. Kriitikute lemmikfilm on "Agent Sinikael"

    Index Scriptorium Estoniae

    2003-01-01

    Eesti Filmiajakirjanike Ühing andis kümnendat korda välja auhinda Aasta film 2002. Parimaks filmiks tunnistati mängufilm "Agent Sinikael" : režissöör Marko Raat. Viimane sai preemiaks Neitsi Maali kuju ja 12 000 krooni

  14. Ultrasound Contrast Agent Microbubble Dynamics

    NARCIS (Netherlands)

    Overvelde, M.L.J.; Vos, Henk; de Jong, N.; Versluis, Andreas Michel; Paradossi, Gaio; Pellegretti, Paolo; Trucco, Andrea

    2010-01-01

    Ultrasound contrast agents are traditionally used in ultrasound-assisted organ perfusion imaging. Recently the use of coated microbubbles has been proposed for molecular imaging applications where the bubbles are covered with a layer of targeting ligands to bind specifically to their target cells.

  15. Infectious Agents in Childhood Leukemia.

    Science.gov (United States)

    Arellano-Galindo, José; Barrera, Alberto Parra; Jiménez-Hernández, Elva; Zavala-Vega, Sergio; Campos-Valdéz, Guillermina; Xicohtencatl-Cortes, Juan; Ochoa, Sara A; Cruz-Córdova, Ariadnna; Crisóstomo-Vázquez, María Del Pilar; Fernández-Macías, Juan Carlos; Mejía-Aranguré, Juan Manuel

    2017-05-01

    Acute leukemia is the most common pediatric cancer, representing one-third of all cancers that occurs in under 15 year olds, with a varied incidence worldwide. Although a number of advances have increased the knowledge of leukemia pathophysiology, its etiology remains less well understood. The role of infectious agents, such as viruses, bacteria, or parasites, in the pathogenesis of leukemia has been discussed. To date, several cellular mechanisms involving infectious agents have been proposed to cause leukemia following infections. However, although leukemia can be triggered by contact with such agents, they can also be beneficial in developing immune stimulation and protection despite the risk of leukemic clones. In this review, we analyze the proposed hypotheses concerning how infectious agents may play a role in the origin and development of leukemia, as well as in a possible mechanism of protection following infections. We review reported clinical observations associated with vaccination or breastfeeding, that support hypotheses such as early life exposure and the resulting early immune stimulation that lead to protection. Copyright © 2017 IMSS. Published by Elsevier Inc. All rights reserved.

  16. The Power Trading Agent Competition

    NARCIS (Netherlands)

    W. Ketter (Wolfgang); J. Collins (John); P. Reddy (Prashant); C. Flath (Christoph); M.M. de Weerdt (Mathijs)

    2011-01-01

    textabstractThis is the specification for the Power Trading Agent Competition for 2012 (Power TAC 2012). Power TAC is a competitive simulation that models a “liberalized” retail electrical energy market, where competing business entities or “brokers” offer energy services to customers through tariff

  17. The Power Trading Agent Competition

    NARCIS (Netherlands)

    Ketter, W.; Collins, J.; Reddy, P.; Flath, C.; De Weerdt, M.M.

    2011-01-01

    This is the specification for the Power Trading Agent Competition for 2012 (Power TAC 2012). Power TAC is a competitive simulation that models a “liberalized” retail electrical energy market, where competing business entities or “brokers” offer energy services to customers through tariff contracts,

  18. Humor and Embodied Conversational Agents

    NARCIS (Netherlands)

    Nijholt, Antinus

    This report surveys the role of humor in human-to-human interaction and the possible role of humor in human-computer interaction. The aim is to see whether it is useful for embodied conversational agents to integrate humor capabilities in their internal model of intelligence, emotions and

  19. 7 CFR 4290.1620 - Functions of agents, including Central Registration Agent, Selling Agent and Fiscal Agent.

    Science.gov (United States)

    2010-01-01

    ... to: (i) Establish performance criteria for Poolers. (ii) Monitor and evaluate the financial markets..., DEPARTMENT OF AGRICULTURE RURAL BUSINESS INVESTMENT COMPANY (âRBICâ) PROGRAM Financial Assistance for RBICs... the performance of the Selling Agent, Poolers, CRA, and the Trustee. (iv) Perform such other functions...

  20. Enhancing products by embedding agents

    NARCIS (Netherlands)

    Hendrik Folmer; Daniël Telgen; Leo van Moergestel; Ing. Erik Puik; Hielke Veringa; Matthijs Grünbauer; Robbert Proost; John-Jules Meyer

    2014-01-01

    Author provided: Monitoring of computernetworks, complex technical systems like aeroplanes is common practice. In this article the use of a monitoring agent in an arbitrary product is discussed. The product itself could be any product with sucient hardware capabilities. The focus is on the

  1. Raspberry Pi for secret agents

    CERN Document Server

    Sjogelid, Stefan

    2015-01-01

    This book is an easy-to-follow guide with practical examples in each chapter. Suitable for the novice and expert alike, each topic provides a fast and easy way to get started with exciting applications and also guides you through setting up the Raspberry Pi as a secret agent toolbox.

  2. Institutional Researchers as Change Agents

    Science.gov (United States)

    Swing, Randy L.

    2009-01-01

    The future challenge and opportunity for institutional researchers is to serve as change agents with involvement in initiating, implementing, and evaluating campus work. Institutional researchers are poised to excel at doing so because of the array of technical skills they routinely apply to existing institutional research roles. Their work…

  3. SEM: A Cultural Change Agent

    Science.gov (United States)

    Barnes, Bradley; Bourke, Brian

    2015-01-01

    The authors advance the concept that institutional culture is a purposeful framework by which to view SEM's utility, particularly as a cultural change agent. Through the connection of seemingly independent functions of performance and behavior, implications emerge that deepen the understanding of the influence of culture on performance outcomes…

  4. Biocontrol agents in signalling resistance

    NARCIS (Netherlands)

    Loon, L.C. van; Pieterse, C.M.J.

    2002-01-01

    The mechanisms by which biological control agents suppress disease comprise competition for nutrients, notably iron, production of antibiotics, and secretion of lytic enzymes, as well as inducing resistance in the plant. The former three mechanisms act primarily on the pathogen by decreasing its

  5. Agent-Based Automated Algorithm Generator

    Science.gov (United States)

    2010-01-12

    capabilities for vehicles and subsystems. In Lee et al’s recent paper [2] on the modeling and simulation of vehicle electric power, the battery and generator...proposed A2G framework; Section 3 describes the SRS design; Section 4 reports the light-weight D/P algorithms in A2G; Section 5 presents simulation ...Detection and Isolation Agent (FDIA), Prognostic Agent (PA), Fusion Agent (FA), and Maintenance Mining Agent (MMA). FDI agents perform diagnostics

  6. MRI contrast agents: Classification and application (Review).

    Science.gov (United States)

    Xiao, Yu-Dong; Paudel, Ramchandra; Liu, Jun; Ma, Cong; Zhang, Zi-Shu; Zhou, Shun-Ke

    2016-11-01

    Magnetic resonance imaging (MRI) contrast agents are categorised according to the following specific features: chemical composition including the presence or absence of metal atoms, route of administration, magnetic properties, effect on the magnetic resonance image, biodistribution and imaging applications. The majority of these agents are either paramagnetic ion complexes or superparamagnetic magnetite particles and contain lanthanide elements such as gadolinium (Gd3+) or transition metal manganese (Mn2+). These elements shorten the T1 or T2 relaxation time, thereby causing increased signal intensity on T1-weighted images or reduced signal intensity on T2-weighted images. Most paramagnetic contrast agents are positive agents. These agents shorten the T1, so the enhanced parts appear bright on T1-weighted images. Dysprosium, superparamagnetic agents and ferromagnetic agents are negative contrast agents. The enhanced parts appear darker on T2-weighted images. MRI contrast agents incorporating chelating agents reduces storage in the human body, enhances excretion and reduces toxicity. MRI contrast agents may be administered orally or intravenously. According to biodistribution and applications, MRI contrast agents may be categorised into three types: extracellular fluid, blood pool and target/organ-specific agents. A number of contrast agents have been developed to selectively distinguish liver pathologies. Some agents are also capable of targeting other organs, inflammation as well as specific tumors.

  7. 75 FR 76940 - User Fees Relating to Enrolled Agents and Enrolled Retirement Plan Agents

    Science.gov (United States)

    2010-12-10

    ... Internal Revenue Service 26 CFR Part 300 RIN 1545-BJ65 User Fees Relating to Enrolled Agents and Enrolled... regulations relating to the imposition of user fees for enrolled agents and enrolled retirement plan agents. The proposed regulations separate the enrolled retirement plan agent user fees from the enrolled agent...

  8. 31 CFR 10.4 - Eligibility for enrollment as enrolled agent or enrolled retirement plan agent.

    Science.gov (United States)

    2010-07-01

    ... enrolled agent or enrolled retirement plan agent. 10.4 Section 10.4 Money and Finance: Treasury Office of... to Practice § 10.4 Eligibility for enrollment as enrolled agent or enrolled retirement plan agent. (a) Enrollment as an enrolled agent upon examination. The Director of the Office of Professional Responsibility...

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

    Science.gov (United States)

    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

  10. Injectable agents affecting subcutaneous fats.

    Science.gov (United States)

    Chen, David Lk; Cohen, Joel L; Green, Jeremy B

    2015-09-01

    Mesotherapy is an intradermal or subcutaneous injection of therapeutic agents to induce local effects, and was pioneered in Europe during the 1950s. For the past 2 decades, there has been significant interest in the use of mesotherapy for minimally invasive local fat contouring. Based on the theorized lipolytic effects of the agent phosphatidylcholine, initial attempts involved its injection into subcutaneous tissue. With further studies, however, it became apparent that the activity attributed to phosphatidylcholine mesotherapy was due to the adipolytic effects of deoxycholate, a detergent used to solubilize phosphatidylcholine. Since then, clinical trials have surfaced that demonstrate the efficacy of a proprietary formulation of deoxycholate for local fat contouring. Current trials on mesotherapy with salmeterol, a b-adrenergic agonist and lipolysis stimulator, are underway-with promising preliminary results as well. ©2015 Frontline Medical Communications.

  11. Chaotic neurodynamics for autonomous agents.

    Science.gov (United States)

    Harter, Derek; Kozma, Robert

    2005-05-01

    Mesoscopic level neurodynamics study the collective dynamical behavior of neural populations. Such models are becoming increasingly important in understanding large-scale brain processes. Brains exhibit aperiodic oscillations with a much more rich dynamical behavior than fixed-point and limit-cycle approximation allow. Here we present a discretized model inspired by Freeman's K-set mesoscopic level population model. We show that this version is capable of replicating the important principles of aperiodic/chaotic neurodynamics while being fast enough for use in real-time autonomous agent applications. This simplification of the K model provides many advantages not only in terms of efficiency but in simplicity and its ability to be analyzed in terms of its dynamical properties. We study the discrete version using a multilayer, highly recurrent model of the neural architecture of perceptual brain areas. We use this architecture to develop example action selection mechanisms in an autonomous agent.

  12. Toxicity of weight loss agents.

    Science.gov (United States)

    Yen, May; Ewald, Michele Burns

    2012-06-01

    With the rise of the obesity epidemic in the United States over the last several decades and the medical complications seen with it, weight loss and dieting have become a national public health concern. Because of their increased use and availability through internet sales, several different dieting agents were reviewed for potential toxicity. These included: syrup of ipecac, cathartics, human chorionic gonadotropin hormone, 2,4 Dinitrophenol, guar gum, phenylpropanolamine, ma huang/ ephedra, caffeine, clenbuterol, fenfluramine, sibutramine, thyroid hormone, orlistat and cannabinoid antagonists. With the internet making even banned products readily accessible, healthcare providers need to be aware of the potential toxicities of a wide range of weight loss agents. Our review covered topics we thought to be most historically significant as well as pertinent to the practice of medical toxicology today.

  13. Logical Theories for Agent Introspection

    DEFF Research Database (Denmark)

    Bolander, Thomas

    2004-01-01

    several such logical theories which we prove to be consistent. These theories are all based on first-order predicate logic. To prove our consistency results, we develop a general mathematical framework, suitable for proving a large number of consistency results concerning logical theories involving...... by developments within semantics for logic programming within computational logic and formal theories of truth within philosophical logic. The thesis provides a number of examples showing how the developed theories can be used as reasoning frameworks for agents with introspective abilities. In Danish...... by self-reference. In the standard approach taken in artificial intelligence, the model that an agent has of its environment is represented as a set of beliefs. These beliefs are expressed as logical formulas within a formal, logical theory. When the logical theory is expressive enough to allow...

  14. Software agents in molecular computational biology.

    Science.gov (United States)

    Keele, John W; Wray, James E

    2005-12-01

    Progress made in applying agent systems to molecular computational biology is reviewed and strategies by which to exploit agent technology to greater advantage are investigated. Communities of software agents could play an important role in helping genome scientists design reagents for future research. The advent of genome sequencing in cattle and swine increases the complexity of data analysis required to conduct research in livestock genomics. Databases are always expanding and semantic differences among data are common. Agent platforms have been developed to deal with generic issues such as agent communication, life cycle management and advertisement of services (white and yellow pages). This frees computational biologists from the drudgery of having to re-invent the wheel on these common chores, giving them more time to focus on biology and bioinformatics. Agent platforms that comply with the Foundation for Intelligent Physical Agents (FIPA) standards are able to interoperate. In other words, agents developed on different platforms can communicate and cooperate with one another if domain-specific higher-level communication protocol details are agreed upon between different agent developers. Many software agent platforms are peer-to-peer, which means that even if some of the agents and data repositories are temporarily unavailable, a subset of the goals of the system can still be met. Past use of software agents in bioinformatics indicates that an agent approach should prove fruitful. Examination of current problems in bioinformatics indicates that existing agent platforms should be adaptable to novel situations.

  15. Optimal Taxation with Behavioral Agents

    OpenAIRE

    Emmanuel Farhi; Xavier Gabaix

    2015-01-01

    This paper develops a theory of optimal taxation with behavioral agents. We use a general behavioral framework that encompasses a wide range of behavioral biases such as misperceptions, internalities and mental accounting. We revisit the three pillars of optimal taxation: Ramsey (linear commodity taxation to raise revenues and redistribute), Pigou (linear commodity taxation to correct externalities) and Mirrlees (nonlinear income taxation). We show how the canonical optimal tax formulas are m...

  16. Selective anti-herpesvirus agents.

    Science.gov (United States)

    De Clercq, Erik

    2013-01-23

    This review article focuses on the anti-herpesvirus agents effective against herpes simplex virus, varicella-zoster virus and cytomegalovirus, which have either been licensed for clinical use (idoxuridine, trifluridine, brivudin, acyclovir, valaciclovir, valganciclovir, famciclovir and foscarnet) or are under clinical development (CMX001 [the hexadecyloxypropyl prodrug of cidofovir], the helicase-primase inhibitor BAY 57-1293 [now referred to as AIC316], FV-100 [the valine ester of Cf 1743] and the terminase inhibitor letermovir [AIC246]).

  17. Controlled Blasting with Demolition Agent

    OpenAIRE

    Dambov, Risto; Stefanovska Karanakova, Radmila; Dambov, Ilija

    2009-01-01

    Over the last decades of last century and this years the interest in using nonexplosive demolition has increased again. Several companies started producing various agents with various names and similar characteristics, but with the same conditions of use. Unlike demolition by blasting, this method is environmentally friendly. The operation takes place quietly, with no seismic affects, dust, gases and no flying rocks. Rock cutting is done as needed and in the desired scale, with-out affecti...

  18. Synthesis of New Antimalarial Agents.

    Science.gov (United States)

    1985-05-01

    1) Chinese workers reported the isolation and characterization of a new 1,2schizonticidal agent, qinghaosu (1). Qinghaosu is a sesquiterpene lactone ...trimethylbenzyl- ammonium hydroxide. Subsequent base hydrolysis gave 60% of the keto-acid 14a. Lactonization was effected by treatment with acetic anhydride and...for the enolic double bond confirmed the presence of the enol lactone function. Allylic bromination and dehydrobromination proceeded smoothly to provide

  19. Needs, Pains, and Motivations in Autonomous Agents.

    Science.gov (United States)

    Starzyk, Janusz A; Graham, James; Puzio, Leszek

    This paper presents the development of a motivated learning (ML) agent with symbolic I/O. Our earlier work on the ML agent was enhanced, giving it autonomy for interaction with other agents. Specifically, we equipped the agent with drives and pains that establish its motivations to learn how to respond to desired and undesired events and create related abstract goals. The purpose of this paper is to explore the autonomous development of motivations and memory in agents within a simulated environment. The ML agent has been implemented in a virtual environment created within the NeoAxis game engine. Additionally, to illustrate the benefits of an ML-based agent, we compared the performance of our algorithm against various reinforcement learning (RL) algorithms in a dynamic test scenario, and demonstrated that our ML agent learns better than any of the tested RL agents.This paper presents the development of a motivated learning (ML) agent with symbolic I/O. Our earlier work on the ML agent was enhanced, giving it autonomy for interaction with other agents. Specifically, we equipped the agent with drives and pains that establish its motivations to learn how to respond to desired and undesired events and create related abstract goals. The purpose of this paper is to explore the autonomous development of motivations and memory in agents within a simulated environment. The ML agent has been implemented in a virtual environment created within the NeoAxis game engine. Additionally, to illustrate the benefits of an ML-based agent, we compared the performance of our algorithm against various reinforcement learning (RL) algorithms in a dynamic test scenario, and demonstrated that our ML agent learns better than any of the tested RL agents.

  20. New agents in HSC mobilization.

    Science.gov (United States)

    Domingues, Mélanie J; Nilsson, Susan K; Cao, Benjamin

    2017-02-01

    Mobilized peripheral blood (PB) is the most common source of hematopoietic stem cells (HSC) for autologous transplantation. Granulocyte colony stimulating factor (G-CSF) is the most commonly used mobilization agent, yet despite its widespread use, a considerable number of patients still fail to mobilize. Recently, a greater understanding of the interactions that regulate HSC homeostasis in the bone marrow (BM) microenvironment has enabled the development of new molecules that mobilize HSC through specific inhibition, modulation or perturbation of these interactions. AMD3100 (plerixafor), a small molecule that selectively inhibits the chemokine receptor CXCR4 is approved for mobilization in combination with G-CSF in patients with Non-Hodgkin's lymphoma and multiple myeloma. Nevertheless, identifying mobilization strategies that not only enhance HSC number, but are rapid and generate an optimal "mobilized product" for improved transplant outcomes remains an area of clinical importance. In recent times, new agents based on recombinant proteins, peptides and small molecules have been identified as potential candidates for therapeutic HSC mobilization. In this review, we describe the most recent developments in HSC mobilization agents and their potential impact in HSC transplantation.

  1. Multi-agent autonomous system

    Science.gov (United States)

    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.

  2. Pharmacologic Agents for Chronic Diarrhea

    Science.gov (United States)

    2015-01-01

    Chronic diarrhea is usually associated with a number of non-infectious causes. When definitive treatment is unavailable, symptomatic drug therapy is indicated. Pharmacologic agents for chronic diarrhea include loperamide, 5-hydroxytryptamine type 3 (5-HT3) receptor antagonists, diosmectite, cholestyramine, probiotics, antispasmodics, rifaximin, and anti-inflammatory agents. Loperamide, a synthetic opiate agonist, decreases peristaltic activity and inhibits secretion, resulting in the reduction of fluid and electrolyte loss and an increase in stool consistency. Cholestyramine is a bile acid sequestrant that is generally considered as the first-line treatment for bile acid diarrhea. 5-HT3 receptor antagonists have significant benefits in patients with irritable bowel syndrome (IBS) with diarrhea. Ramosetron improves stool consistency as well as global IBS symptoms. Probiotics may have a role in the prevention of antibiotic-associated diarrhea. However, data on the role of probiotics in the treatment of chronic diarrhea are lacking. Diosmectite, an absorbent, can be used for the treatment of chronic functional diarrhea, radiation-induced diarrhea, and chemotherapy-induced diarrhea. Antispasmodics including alverine citrate, mebeverine, otilonium bromide, and pinaverium bromide are used for relieving diarrheal symptoms and abdominal pain. Rifaximin can be effective for chronic diarrhea associated with IBS and small intestinal bacterial overgrowth. Budesonide is effective in both lymphocytic colitis and collagenous colitis. The efficacy of mesalazine in microscopic colitis is weak or remains uncertain. Considering their mechanisms of action, these agents should be prescribed properly. PMID:26576135

  3. Unusual but potential agents of terrorists.

    Science.gov (United States)

    Holstege, Christopher P; Bechtel, Laura K; Reilly, Tracey H; Wispelwey, Bram P; Dobmeier, Stephen G

    2007-05-01

    Emergency personnel are tasked with the daunting job of being the first to evaluate and manage victims of a terrorist attack. Numerous potential chemical agents could be used by terrorists. The challenge for first responders and local hospital emergency personnel is to prepare for a terrorist event that might use one or more of these agents. As part of that preparation, emergency physicians should have a basic understanding of potential chemical terrorist agents. It is beyond the scope of this article to review all potential terrorist agents. Rather, four potential agents have been chosen for review: sodium monofluoroacetate, trichothecene mycotoxins, vomiting agents, and saxitoxin.

  4. 14th International Conference on Practical Applications of Agents and Multi-Agent Systems : Special Sessions

    CERN Document Server

    Escalona, María; Corchuelo, Rafael; Mathieu, Philippe; Vale, Zita; Campbell, Andrew; Rossi, Silvia; Adam, Emmanuel; Jiménez-López, María; Navarro, Elena; Moreno, María

    2016-01-01

    PAAMS, the International Conference on Practical Applications of Agents and Multi-Agent Systems is an evolution of the International Workshop on Practical Applications of Agents and Multi-Agent Systems. PAAMS is an international yearly tribune to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development of Agents and Multi-Agent Systems. This volume presents the papers that have been accepted for the 2016 in the special sessions: Agents Behaviours and Artificial Markets (ABAM); Advances on Demand Response and Renewable Energy Sources in Agent Based Smart Grids (ADRESS); Agents and Mobile Devices (AM); Agent Methodologies for Intelligent Robotics Applications (AMIRA); Learning, Agents and Formal Languages (LAFLang); Multi-Agent Systems and Ambient Intelligence (MASMAI); Web Mining and ...

  5. Learning other agents` preferences in multiagent negotiation

    Energy Technology Data Exchange (ETDEWEB)

    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).

  6. A Framework for Multi-Agent Planning

    NARCIS (Netherlands)

    Bos, A.; Tonino, J.F.M.; De Weerdt, M.M.; Witteveen, C.

    2000-01-01

    We introduce a computational framework, consisting of resources, skills, goals and services to represent the plans of individual agents and to develop models and algorithms for cooperation processes between a collection of agents.

  7. Youth Development Agents' Needs: Challenges for Extension ...

    African Journals Online (AJOL)

    ... the areas of competencies. Regular training was therefore recommended for youth development agents to enable them update, improve and learn new strategies in the application of their competencies for extension service delivery. Keywords: Youth, Development, Agents' needs, Volunteer management, Competencies.

  8. Surface modification agents for lithium batteries

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zonghai; Amine, Khalil; Belharouak, Ilias

    2017-11-21

    An active material for an electrochemical device wherein a surface of the active material is modified by a surface modification agent, wherein the surface modification agent is an organometallic compound.

  9. Comparison of Communication Models for Mobile Agents

    Directory of Open Access Journals (Sweden)

    Xining Li

    2003-04-01

    Full Text Available An agent is a self-contained process being acting on behalf of a user. A Mobile Agent is an agent roaming the internet to access data and services, and carry out its assigned task remotely. This paper will focus on the communication models for Mobile Agents. Generally speaking, communication models concern with problems of how to name Mobile Agents, how to establish communication relationships, how to trace moving agents, and how to guarantee reliable communication. Some existing MA systems are purely based on RPC-style communication, whereas some adopts asynchronous message passing, or event registration/handling. Different communication concepts suitable for Mobile Agents are well discussed in [1]. However, we will investigate these concepts and existing models from a different point view: how to track down agents and deliver messages in a dynamic, changing world.

  10. INTERACTION MANAGMENT BETWEEN SOCIAL AGENTS AND HUMAN

    OpenAIRE

    Pruski, Alain; Moussaoui, Abdelhak

    2012-01-01

    International audience; In this paper we address the problem of managing social interactions between a human user and a set of social agents in structured environments. These agents have to regulate a measurable characteristic of the user. Our study focuses mainly therapeutic, caring for elderly people and assessment applications. The agent concept considered in this study is suitable for multi-robot systems (physical, service, mobile or not), but also to virtual agents (avatars) in a virtual...

  11. AAAI-96 Workshop on Agent Modeling

    OpenAIRE

    Tambe, Milind; Gmytrasiewicz, Piotr

    1997-01-01

    Agent modeling -- the ability to model and reason other agents' knowledge, beliefs, goals, and actions -- is central to intelligent interaction. The Workshop on Agent Modeling, held as part of the Thirteenth National Conference on Artificial Intelligence, was organized to bring together researchers working in these areas to assess the state of the art and discuss the common issues in representation and reasoning with models of agents.

  12. Intelligent supply chain agents using ADE

    OpenAIRE

    Mehra, Anshu; Nissen, Mark

    1998-01-01

    From: Proceedings of the Artificial Intelligence and Manufacturing Workshop. This paper reviews extant agent applications and describes the Agent Development Environment (ADE) toolkit. ADE is the integrated development environment to design, develop, debug, simulate and deploy agents. ADE supports the development of multi-agent applications capable of running on a single machine or on a distributed network. ADE has been used to build commercial applications in the area of: (i) manufacturin...

  13. Interactive teaching strategies for agent training

    OpenAIRE

    Amir, Ofra; Kamar, Ece; Kolobov, Andrey; Grosz, Barbara J.

    2016-01-01

    Agents learning how to act in new environments can benefit from input from more experienced agents or humans. This paper studies interactive teaching strategies for identifying when a student can benefit from teacher-advice in a reinforcement learning framework. In student-teacher learning, a teacher agent can advise the student on which action to take. Prior work has considered heuristics for the teacher to choose advising opportunities. While these approaches effectively accelerate agent tr...

  14. Self-Adapting Reactive Autonomous Agents

    Science.gov (United States)

    Andrecut, M.; Ali, M. K.

    This paper describes a new self-adapting control algorithm for reactive autonomous agents. The architecture of the autonomous agents integrates the reactive behavior with reinforcement learning. We show how these components perform on-line adaptation of the autonomous agents to various complex navigation situations by constructing an internal model of the environment. Also, a discussion on cooperation and coordination of teams of agents is presented.

  15. Pathogenic agents in freshwater resources

    Science.gov (United States)

    Geldreich, Edwin E.

    1996-02-01

    Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen.As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology.Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

  16. Honey - A Novel Antidiabetic Agent

    Science.gov (United States)

    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

  17. Agent Based Individual Traffic guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen Bundgaard

    2004-01-01

    When working with traffic planning or guidance it is common practice to view the vehicles as a combined mass. >From this models are employed to specify the vehicle supply and demand for each region. As the models are complex and the calculations are equally demanding the regions and the detail...... of the road network is aggregated. As a result the calculations reveal only what the mass of vehicles are doing and not what a single vehicle is doing. This is the crucial difference to ABIT (Agent Based Individual Trafficguidance). ABIT is based on the fact that information on the destination of each vehicle...

  18. Towards Agents for Policy Making

    OpenAIRE

    Dignum, F.P.M.; Dignum, V; Jonker, C.M.

    2008-01-01

    The process of introducing new public policies is a complex one in the sense that the behavior of society at the macro-level depends directly on the individual behavior of the people in that society and ongoing dynamics of the environment. It is at the micro-level that change is initiated, that policies effectively change the behavior of individuals. Since macro-models do not suffice, science has turned to develop and study agent-based simulations, i.e., micro-level models. In correspondence ...

  19. Multi agent gathering waste system

    Directory of Open Access Journals (Sweden)

    Álvaro LOZANO MURCIEGO

    2016-07-01

    Full Text Available Along this paper, we present a new multi agent-based system to gather waste on cities and villages. We have developed a low cost wireless sensor prototype to measure the volume level of the containers. Furthermore a route system is developed to optimize the routes of the trucks and a mobile application has been developed to help drivers in their working days. In order to evaluate and validate the proposed system a practical case study in a real city environment is modeled using open data available and with the purpose of identifying limitations of the system.

  20. Social Robots as Persuasive Agents

    DEFF Research Database (Denmark)

    Vlachos, Evgenios; Schärfe, Henrik

    2014-01-01

    Robots are more and more used in a social context, and in this paper we try to formulate a research agenda concerning ethical issues around social HRI in order to be prepared for future scenarios where robots may be a naturally integrated part of human society. We outline different paradigms...... to describe the role of social robots in communication processes with humans, and connect HRI with the topic of persuasive technology in health care, to critically reflect the potential benefits of using social robots as persuasive agents....

  1. 31 CFR 352.13 - Fiscal agents.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Fiscal agents. 352.13 Section 352.13 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE....13 Fiscal agents. (a) Federal Reserve Banks and Branches, referred to below, as fiscal agents of the...

  2. 31 CFR 332.12 - Fiscal agents.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Fiscal agents. 332.12 Section 332.12 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE....12 Fiscal agents. (a) Federal Reserve Banks and Branches referred to below, as fiscal agents of the...

  3. 31 CFR 339.6 - Fiscal agents.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Fiscal agents. 339.6 Section 339.6 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE... H § 339.6 Fiscal agents. Federal Reserve Banks and Branches, as fiscal agents of the United States...

  4. 31 CFR 316.12 - Fiscal agents.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Fiscal agents. 316.12 Section 316.12 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE....12 Fiscal agents. (a) Federal Reserve Banks and Branches referred to below, as fiscal agents of the...

  5. On Programming Organization-Aware Agents

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt

    2013-01-01

    Since it is difficult (or even impossible) to assume anything about the agents’ behavior and goals in an open multi-agent system, it is often suggested that an organization is imposed upon the agents, whichhich, by abstracting away from the agents, specifies boundaries and objectives that the age...

  6. Do pedagogical agents enhance software training?

    NARCIS (Netherlands)

    van der Meij, Hans

    2013-01-01

    This study investigates whether a tutorial for software training can be enhanced by adding a pedagogical agent, and whether the type of agent matters (i.e., cognitive, motivational, or mixed). The cognitive agent was designed to stimulate students to process their experiences actively. The

  7. Cooperative heuristic multi-agent planning

    NARCIS (Netherlands)

    De Weerdt, M.M.; Tonino, J.F.M.; Witteveen, C.

    2001-01-01

    In this paper we will use the framework to study cooperative heuristic multi-agent planning. During the construction of their plans, the agents use a heuristic function inspired by the FF planner (l3l). At any time in the process of planning the agents may exchange available resources, or they may

  8. A Framework for Organization-Aware Agents

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt; Dignum, Virginia; Villadsen, Jørgen

    2016-01-01

    This short paper introduces and summarizes the AORTA reasoning framework that can be integrated into BDI-agents to enable organizational decision-making. This work has recently been published in the Journal of Autonomous Agents and Multi-Agent Systems (JAAMAS), as [3]....

  9. Embedded Automation in Human-Agent Environment

    CERN Document Server

    Tweedale, Jeffrey W

    2012-01-01

    This research book proposes a general conceptual framework for the development of automation in human-agents environments that will allow human- agent teams to work effectively and efficiently. We examine various schemes to implement artificial intelligence techniques in agents.  The text is directed to the scientists, application engineers, professors and students of all disciplines, interested in the agency methodology and applications.

  10. Mobile Agents in Networking and Distributed Computing

    CERN Document Server

    Cao, Jiannong

    2012-01-01

    The book focuses on mobile agents, which are computer programs that can autonomously migrate between network sites. This text introduces the concepts and principles of mobile agents, provides an overview of mobile agent technology, and focuses on applications in networking and distributed computing.

  11. Agent modelling in METATEM and DESIRE

    NARCIS (Netherlands)

    Mulder, Marco; Treur, Jan; Fisher, Michael

    1998-01-01

    In spite of the rapid spread of agent technology, there is, as yet, little evidence of an engineering approach to the development of multi-agent systems. For example, both development methods and verification techniques for multi-agent systems are rare. In this paper, we describe a case study aimed

  12. Programming Cognitive Agents in Defeasible Logic

    NARCIS (Netherlands)

    M. Dastani; G. Governatori; A. Rotolo; L.W.N. van der Torre (Leon)

    2005-01-01

    htmlabstractDefeasible Logic is extended to programming languages for cognitive agents with preferences and actions for planning. We define rule-based agent theories that contain preferences and actions, together with inference procedures. We discuss patterns of agent types in this setting. Finally,

  13. Preferences of Agents in Defeasible Logic

    NARCIS (Netherlands)

    M. Dastani; G. Governatori; A. Rotolo; L.W.N. van der Torre (Leon)

    2005-01-01

    htmlabstractDefeasible Logic is extended to programming languages for cognitive agents with preferences and actions for planning. We define rule-based agent theories that contain preferences and actions, together with inference procedures. We discuss patterns of agent types in this setting. Finally,

  14. Construction and Evaluation of Animated Teachable Agents

    Science.gov (United States)

    Bodenheimer, Bobby; Williams, Betsy; Kramer, Mattie Ruth; Viswanath, Karun; Balachandran, Ramya; Belynne, Kadira; Biswas, Gautam

    2009-01-01

    This article describes the design decisions, technical approach, and evaluation of the animation and interface components for an agent-based system that allows learners to learn by teaching. Students learn by teaching an animated agent using a visual representation. The agent can answer questions about what she has been taught and take quizzes.…

  15. Multi-Agent Planning with Planning Graph

    NARCIS (Netherlands)

    Bui, T.D.; Jamroga, W.J.

    2003-01-01

    In this paper, we consider planning for multi-agents situations in STRIPS-like domains with planning graph. Three possible relationships between agents' goals are considered in order to evaluate plans: the agents may be collaborative, adversarial or indifferent entities. We propose algorithms to

  16. Nanoparticle-based theranostic agents

    Science.gov (United States)

    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

  17. Surfactants as blackbird stressing agents

    Science.gov (United States)

    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.

  18. Electric power market agent design

    Science.gov (United States)

    Oh, Hyungseon

    The electric power industry in many countries has been restructured in the hope of a more economically efficient system. In the restructured system, traditional operating and planning tools based on true marginal cost do not perform well since information required is strictly confidential. For developing a new tool, it is necessary to understand offer behavior. The main objective of this study is to create a new tool for power system planning. For the purpose, this dissertation develops models for a market and market participants. A new model is developed in this work for explaining a supply-side offer curve, and several variables are introduced to characterize the curve. Demand is estimated using a neural network, and a numerical optimization process is used to determine the values of the variables that maximize the profit of the agent. The amount of data required for the optimization is chosen with the aid of nonlinear dynamics. To suggest an optimal demand-side bidding function, two optimization problems are constructed and solved for maximizing consumer satisfaction based on the properties of two different types of demands: price-based demand and must-be-served demand. Several different simulations are performed to test how an agent reacts in various situations. The offer behavior depends on locational benefit as well as the offer strategies of competitors.

  19. Animal venoms as antimicrobial agents.

    Science.gov (United States)

    Perumal Samy, Ramar; Stiles, Bradley G; Franco, Octavio L; Sethi, Gautam; Lim, Lina H K

    2017-06-15

    Hospitals are breeding grounds for many life-threatening bacteria worldwide. Clinically associated gram-positive bacteria such as Staphylococcus aureus/methicillin-resistant S. aureus and many others increase the risk of severe mortality and morbidity. The failure of antibiotics to kill various pathogens due to bacterial resistance highlights the urgent need to develop novel, potent, and less toxic agents from natural sources against various infectious agents. Currently, several promising classes of natural molecules from snake (terrestrial and sea), scorpion, spider, honey bee and wasp venoms hold promise as rich sources of chemotherapeutics against infectious pathogens. Interestingly, snake venom-derived synthetic peptide/snake cathelicidin not only has potent antimicrobial and wound-repair activity but is highly stable and safe. Such molecules are promising candidates for novel venom-based drugs against S. aureus infections. The structure of animal venom proteins/peptides (cysteine rich) consists of hydrophobic α-helices or β-sheets that produce lethal pores and membrane-damaging effects on bacteria. All these antimicrobial peptides are under early experimental or pre-clinical stages of development. It is therefore important to employ novel tools for the design and the development of new antibiotics from the untapped animal venoms of snake, scorpion, and spider for treating resistant pathogens. To date, snail venom toxins have shown little antibiotic potency against human pathogens. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Product Conceptual Design Based on Agent Federation

    Science.gov (United States)

    Yuan, Minghai; Wang, Song; Huang, Jinting

    2017-10-01

    A cooperative Agent Federation was used in the complicated products conceptual design after studying the characteristics of the conceptual design. Each Agent Federation designed products cooperatively under the control of the chief Agent Federation. Thus, the mapping of ‘function-behaviour-structure’ was achieved, and the whole process of the conceptual design was accomplished. The functions, communications, cooperation and the theories about running of the key Agent Federation were discussed, and the frame of the conceptual design based on cooperative Agent Federation and work group was established in this paper.

  1. Anchor Toolkit - a secure mobile agent system

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Introduction to Agent Mining Interaction and Integration

    Science.gov (United States)

    Cao, Longbing

    In recent years, more and more researchers have been involved in research on both agent technology and data mining. A clear disciplinary effort has been activated toward removing the boundary between them, that is the interaction and integration between agent technology and data mining. We refer this to agent mining as a new area. The marriage of agents and data mining is driven by challenges faced by both communities, and the need of developing more advanced intelligence, information processing and systems. This chapter presents an overall picture of agent mining from the perspective of positioning it as an emerging area. We summarize the main driving forces, complementary essence, disciplinary framework, applications, case studies, and trends and directions, as well as brief observation on agent-driven data mining, data mining-driven agents, and mutual issues in agent mining. Arguably, we draw the following conclusions: (1) agent mining emerges as a new area in the scientific family, (2) both agent technology and data mining can greatly benefit from agent mining, (3) it is very promising to result in additional advancement in intelligent information processing and systems. However, as a new open area, there are many issues waiting for research and development from theoretical, technological and practical perspectives.

  3. Variations on agent-oriented programming

    Directory of Open Access Journals (Sweden)

    Dalia Baziukė

    2017-12-01

    Full Text Available Occurrence of the agent paradigm and its further applications have stimulated the emergence of new concepts and methodologies in computer science. Today terms like multi-agent system, agent-oriented methodology, and agent-oriented programming (AOP are widely used. The aim of this paper is to clarify the validity of usage of the terms AOP and AOP language. This is disclosed in two phases of an analysis process. Determining to which concepts, terms like agent, programming, object-oriented analysis and design, object-oriented programming, and agent-oriented analysis and design correspond is accomplished in the first phase. Analysis of several known agent system engineering methodologies in terms of key concepts used, final resulting artifacts, and their relationship with known programming paradigms and modern tools for agent system development is performed in the second phase. The research shows that in most cases in the final phase of agent system design and in the coding stage, the main artifact is an object, defined according to the rules of the object-oriented paradigm. Hence, we say that the computing society still does not have AOP owing to the lack of an AOP language. Thus, the term AOP is very often incorrectly assigned to agent system development frameworks that in most cases, transform agents into objects.DOI: 10.15181/csat.v5i1.1361

  4. A Framework for Organization-Aware Agents

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt; Dignum, Virginia; Villadsen, Jørgen

    2017-01-01

    boundaries and work towards the objectives of the organization. In this paper, we present the AORTA reasoning framework and show how it can be integrated into typical BDI-agents. We provide operational semantics that enables agents to make organizational decisions in order to coordinate and cooperate without...... explicit coordination mechanisms within the agents. The organizational model is independent of that of the agents, and the approach is not tied to a specific organizational model, but uses an organizational metamodel. We show how AORTA helps agents work together in a system with an organization......Open systems are characterized by the presence of a diversity of heterogeneous and autonomous agents that act according to private goals. Organizations, such as those used in real-life to structure human activities such as task allocation, coordination and supervision, can regulate the agents...

  5. An Agent Framework of Tourism Recommender System

    Directory of Open Access Journals (Sweden)

    Jia Zhi Yang

    2016-01-01

    Full Text Available This paper proposes the development of an Agent framework for tourism recommender system. The recommender system can be featured as an online web application which is capable of generating a personalized list of preference attractions for tourists. Traditional technologies of classical recommender system application domains, such as collaborative filtering, content-based filtering and content-based filtering are effectively adopted in the framework. In the framework they are constructed as Agents that can generate recommendations respectively. Recommender Agent can generate recommender information by integrating the recommendations of Content-based Agent, collaborative filtering-based Agent and constraint-based Agent. In order to make the performance more effective, linear combination method of data fusion is applied. User interface is provided by the tourist Agent in form of webpages and mobile app.

  6. Multi-agent for manufacturing systems optimization

    Science.gov (United States)

    Ciortea, E. M.; Tulbure, A.; Huţanu, C.-tin

    2016-08-01

    The paper is meant to be a dynamic approach to optimize manufacturing systems based on multi-agent systems. Multi-agent systems are semiautonomous decision makers and cooperate to optimize the manufacturing process. Increasing production the capacity is achieved by developing, implementing efficient and effective systems from control based on current manufacturing process. The model multi-agent proposed in this paper is based on communication between agents who, based on their mechanisms drive to autonomous decision making. Methods based on multi-agent programming are applied between flexible manufacturing processes and cooperation with agents. Based on multi-agent technology and architecture of intelligent manufacturing can lead to development of strategies for control and optimization of scheduled production resulting from the simulation.

  7. 10th International Conference on Practical Applications of Agents and Multi-Agent Systems

    CERN Document Server

    Pérez, Javier; Golinska, Paulina; Giroux, Sylvain; Corchuelo, Rafael; Trends in Practical Applications of Agents and Multiagent Systems

    2012-01-01

    PAAMS, the International Conference on Practical Applications of Agents and Multi-Agent Systems is an evolution of the International Workshop on Practical Applications of Agents and Multi-Agent Systems. PAAMS is an international yearly tribune to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development of Agents and Multi-Agent Systems.   This volume presents the papers that have been accepted for the 2012 in the workshops: Workshop on Agents for Ambient Assisted Living, Workshop on Agent-Based Solutions for Manufacturing and Supply Chain and Workshop on Agents and Multi-agent systems for Enterprise Integration.

  8. Bioprotective agents in safety control

    Directory of Open Access Journals (Sweden)

    Dimitrijević-Branković Suzana I.

    2003-01-01

    Full Text Available Food poisoning is the one of the main health hazards even today. More than 200 known diseases are transmitted through food. The causes of foodborne illness include viruses, bacteria, parasites, toxins, metals, and prions and the symptoms of foodborne illness range from mild gastroenteritis to life-threatening neurological, hepatic and renal syndromes.The prevention of food poisonings represents very serious task for food manufacturers. Beside food control according to the concept "from the farm to the table" there is increased need for the development of new technology for longer shelf lifes of food. Food fermented by lactic acid bacteria (LAB and traditionally considered to be safe. There are many substances produced by LAB that affect the shelf life of fermented food, by active suppression of poisoning microorganisms growth. Because of that, the LAB is recently considered as bioprotective agents that have important role in food safety.

  9. Xenon as an anesthetic agent.

    Science.gov (United States)

    Jordan, Bryan D; Wright, Elizabeth Laura

    2010-10-01

    Discovered in 1898 by British chemists, xenon is a rare gas belonging to the noble gases of the periodic table. Xenon is used in many different ways, from high-intensity lamps to jet propellant, and in 1939, its anesthetic properties were discovered. Xenon exerts its anesthetic properties, in part, through the noncompetitive inhibition of N-methyl-D-aspartate receptors. Currently, xenon is being used primarily throughout Europe; however, the high price of manufacturing and scavenging the noble gas has discouraged more widespread use. As technology in anesthetic delivery improves, xenon is being investigated further as a possible replacement for nitrous oxide as an inhalational agent. This article reviews the anesthetic properties of xenon and current and potential research about the gas.

  10. Blasting agents and initiation systems

    Energy Technology Data Exchange (ETDEWEB)

    Fiscor, S.

    2000-01-01

    Although blasting differs between and within each industry, as a whole, the mines and quarries are making a shift from a purely ammonium nitrate/fuel oil (ANFO) mixture to a blend of emulsion and ANFO on a straight emulsion. Non-electric (shock tube) initiation systems have provided a viable alternative to the electric detonator (blasting cap). Explosives manufacturers are seeing their roles changes to being blasting contractors or consultants rather than just suppliers. The article discusses these trends and gives examples of typical blasting techniques and amounts of blasting agent used at large USA surface coal mines. Electric caps are still used in blasting underground coal. The Ensign Bickford Co. (EBCo) is developing electronic detonators and has been field testing an electronic initiator, the DIGIDET detonator, for the last four years. When commercially available, electronic detonators will be accurate but will come with a hefty price tag. 2 photos.

  11. Host modulation by therapeutic agents

    Directory of Open Access Journals (Sweden)

    Sugumari Elavarasu

    2012-01-01

    Full Text Available Periodontal disease susceptible group present advanced periodontal breakdown even though they achieve a high standard of oral hygiene. Various destructive enzymes and inflammatory mediators are involved in destruction. These are elevated in case of periodontal destruction. Host modulation aims at bringing these enzymes and mediators to normal level. Doxycycline, nonsteroidal anti-inflammatory drugs (NSAIDs, bisphosphonates, nitrous oxide (NO synthase inhibitors, recombinant human interleukin-11 (rhIL-11, omega-3 fatty acid, mouse anti-human interleukin-6 receptor antibody (MRA, mitogen-activated protein kinase (MAPK inhibitors, nuclear factor-kappa B (NF-kb inhibitors, osteoprotegerin, and tumor necrosis factor antagonist (TNF-α are some of the therapeutic agents that have host modulation properties.

  12. Fluorescence imaging agents in cancerology.

    Science.gov (United States)

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

    2010-09-01

    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. 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.

  13. Agent Reward Shaping for Alleviating Traffic Congestion

    Science.gov (United States)

    Tumer, Kagan; Agogino, Adrian

    2006-01-01

    Traffic congestion problems provide a unique environment to study how multi-agent systems promote desired system level behavior. What is particularly interesting in this class of problems is that no individual action is intrinsically "bad" for the system but that combinations of actions among agents lead to undesirable outcomes, As a consequence, agents need to learn how to coordinate their actions with those of other agents, rather than learn a particular set of "good" actions. This problem is ubiquitous in various traffic problems, including selecting departure times for commuters, routes for airlines, and paths for data routers. In this paper we present a multi-agent approach to two traffic problems, where far each driver, an agent selects the most suitable action using reinforcement learning. The agent rewards are based on concepts from collectives and aim to provide the agents with rewards that are both easy to learn and that if learned, lead to good system level behavior. In the first problem, we study how agents learn the best departure times of drivers in a daily commuting environment and how following those departure times alleviates congestion. In the second problem, we study how agents learn to select desirable routes to improve traffic flow and minimize delays for. all drivers.. In both sets of experiments,. agents using collective-based rewards produced near optimal performance (93-96% of optimal) whereas agents using system rewards (63-68%) barely outperformed random action selection (62-64%) and agents using local rewards (48-72%) performed worse than random in some instances.

  14. Persuasive Conversational Agent with Persuasion Tactics

    Science.gov (United States)

    Narita, Tatsuya; Kitamura, Yasuhiko

    Persuasive conversational agents persuade people to change their attitudes or behaviors through conversation, and are expected to be applied as virtual sales clerks in e-shopping sites. As an approach to create such an agent, we have developed a learning agent with the Wizard of Oz method in which a person called Wizard talks to the user pretending to be the agent. The agent observes the conversations between the Wizard and the user, and learns how to persuade people. In this method, the Wizard has to reply to most of the user's inputs at the beginning, but the burden gradually falls because the agent learns how to reply as the conversation model grows.

  15. An Important Chemical Weapon Group: Nerve Agents

    Directory of Open Access Journals (Sweden)

    Hakan Yaren

    2007-12-01

    Full Text Available As a result of developing modern chemistry, nerve agents, which are one of the most important group of efficient chemical warfare agents, were developed just before Second World War. They generate toxic and clinical effects via inhibiting acetylcholinesterase irreversibly and causing excessive amounts of acetylcholine at cholinergic synapses in the body. Clinical symptoms are occurred as a result of affected muscarinic (stimulation of secretuar glands, miosis, breathing problems etc., nicotinic (stimulation of skeletal muscles, paralyse, tremors etc. and central nerve system (convulsions, loss of consciousness, coma etc. areas. In case of a nerve agent exposure, treatment includes the steps of ventilation, decontamination, antidotal treatment (atropine, oximes, diazepam and pyridostigmine bromide and supportive theraphy. Because of arising possibility of using chemical warfare agents due to current conjuncture of the world, medical staff should know about nerve agents, their effects and how to treat the casualties exposured to nerve agents. [TAF Prev Med Bull. 2007; 6(6: 491-500

  16. An Important Chemical Weapon Group: Nerve Agents

    Directory of Open Access Journals (Sweden)

    Hakan Yaren

    2007-12-01

    Full Text Available As a result of developing modern chemistry, nerve agents, which are one of the most important group of efficient chemical warfare agents, were developed just before Second World War. They generate toxic and clinical effects via inhibiting acetylcholinesterase irreversibly and causing excessive amounts of acetylcholine at cholinergic synapses in the body. Clinical symptoms are occurred as a result of affected muscarinic (stimulation of secretuar glands, miosis, breathing problems etc., nicotinic (stimulation of skeletal muscles, paralyse, tremors etc. and central nerve system (convulsions, loss of consciousness, coma etc. areas. In case of a nerve agent exposure, treatment includes the steps of ventilation, decontamination, antidotal treatment (atropine, oximes, diazepam and pyridostigmine bromide and supportive theraphy. Because of arising possibility of using chemical warfare agents due to current conjuncture of the world, medical staff should know about nerve agents, their effects and how to treat the casualties exposured to nerve agents. [TAF Prev Med Bull 2007; 6(6.000: 491-500

  17. Different Views of Software Agent Paradigm

    OpenAIRE

    Anand Kumar Pandey; Rashmi Pandey

    2012-01-01

    Agent modelling in software engineering is a relatively young area, and there are, as yet, no standard methodologies, development tools, or software architectures. Although our work is emphasized on to represent the agent specifications using different views, they are not oriented for software engineering in terms of providing a modeling notation that directly supports software development. There are, however, some software frameworks using different views of software agents, that are beginni...

  18. Migration Dynamics in Artificial Agent Societies

    OpenAIRE

    Harjot Kaur; Karanjeet Singh Kahlon; Rajinder Singh Virk

    2014-01-01

    An Artificial Agent Society can be defined as a collection of agents interacting with each other for some purpose and/or inhabiting a specific locality, possibly in accordance to some common norms/rules. These societies are analogous to human and ecological societies, and are an expanding and emerging field in research about social systems. Social networks, electronic markets and disaster management organizations can be viewed as such artificial (open) agent societies and can be best understo...

  19. Massive Multi-Agent Systems Control

    Science.gov (United States)

    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.

  20. Rule Value Reinforcement Learning for Cognitive Agents

    OpenAIRE

    Child, C. H. T.; Stathis, K.

    2006-01-01

    RVRL (Rule Value Reinforcement Learning) is a new algorithm which extends an existing learning framework that models the environment of a situated agent using a probabilistic rule representation. The algorithm attaches values to learned rules by adapting reinforcement learning. Structure captured by the rules is used to form a policy. The resulting rule values represent the utility of taking an action if the rule`s conditions are present in the agent`s current percept. Advantages of the new f...

  1. Intelligent Agents in E-Commerce

    Directory of Open Access Journals (Sweden)

    Valentin LITOIU

    2006-01-01

    Full Text Available This paper emphasizes the importance of intelligent agents in e-commerce, with a particular focus on the B2C and B2B context. From the consumer buying behaviour perspective, agents can be used to assist the following stages: need identification, product brokering, buyer coalition formation, merchant brokering and negotiation. Related to B2B commerce, intelligent agents are involved in partnership formation, brokering and negotiation.

  2. Foodborne illness acquired in the United States--unspecified agents

    National Research Council Canada - National Science Library

    Scallan, Elaine; Griffin, Patricia M; Angulo, Frederick J; Tauxe, Robert V; Hoekstra, Robert M

    2011-01-01

    ... 9.4 million episodes of foodborne illness. Additional episodes of illness were caused by unspecified agents, including known agents with insufficient data to estimate agent-specific illness, known agents not yet recognized as causing...

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

    Science.gov (United States)

    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…

  4. Agent-Based Health Monitoring System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose combination of software intelligent agents to achieve decentralized reasoning, with fault detection and diagnosis using PCA, neural nets, and maximum...

  5. Multi-agent and complex systems

    CERN Document Server

    Ren, Fenghui; Fujita, Katsuhide; Zhang, Minjie; Ito, Takayuki

    2017-01-01

    This book provides a description of advanced multi-agent and artificial intelligence technologies for the modeling and simulation of complex systems, as well as an overview of the latest scientific efforts in this field. A complex system features a large number of interacting components, whose aggregate activities are nonlinear and self-organized. A multi-agent system is a group or society of agents which interact with others cooperatively and/or competitively in order to reach their individual or common goals. Multi-agent systems are suitable for modeling and simulation of complex systems, which is difficult to accomplish using traditional computational approaches.

  6. Improving Multi-Agent Systems Using Jason

    DEFF Research Database (Denmark)

    Vester, Steen; Boss, Niklas Skamriis; Jensen, Andreas Schmidt

    2011-01-01

    used the implementation from 2009 as a foundation and therefore much of the work done this year was on improving that implementation. We present a description which includes design and analysis of the system as well as the main features of our agent team strategy. In addition we discuss......We describe the approach used to develop the multi-agent system of herders that competed as the Jason-DTU team at the Multi-Agent Programming Contest 2010. We also participated in 2009 with a system developed in the agentoriented programming language Jason which is an extension of AgentSpeak. We...

  7. Conversational Agents in E-Learning

    Science.gov (United States)

    Kerry, Alice; Ellis, Richard; Bull, Susan

    This paper discusses the use of natural language or 'conversational' agents in e-learning environments. We describe and contrast the various applications of conversational agent technology represented in the e-learning literature, including tutors, learning companions, language practice and systems to encourage reflection. We offer two more detailed examples of conversational agents, one which provides learning support, and the other support for self-assessment. Issues and challenges for developers of conversational agent systems for e-learning are identified and discussed.

  8. Agent-Based Negotiation in Uncertain Environments

    Science.gov (United States)

    Debenham, John; Sierra, Carles

    An agent aims to secure his projected needs by attempting to build a set of (business) relationships with other agents. A relationship is built by exchanging private information, and is characterised by its intimacy — degree of closeness — and balance — degree of fairness. Each argumentative interaction between two agents then has two goals: to satisfy some immediate need, and to do so in a way that develops the relationship in a desired direction. An agent's desire to develop each relationship in a particular way then places constraints on the argumentative utterances. The form of negotiation described is argumentative interaction constrained by a desire to develop such relationships.

  9. Multi-agent systems simulation and applications

    CERN Document Server

    Uhrmacher, Adelinde M

    2009-01-01

    Methodological Guidelines for Modeling and Developing MAS-Based SimulationsThe intersection of agents, modeling, simulation, and application domains has been the subject of active research for over two decades. Although agents and simulation have been used effectively in a variety of application domains, much of the supporting research remains scattered in the literature, too often leaving scientists to develop multi-agent system (MAS) models and simulations from scratch. Multi-Agent Systems: Simulation and Applications provides an overdue review of the wide ranging facets of MAS simulation, i

  10. Agent fabrication and its implementation for agent-based electronic commerce

    OpenAIRE

    Guan, SU; Zhu, F

    2002-01-01

    In the last decade, agent-based e-commerce has emerged as a potential role for the next generation of e-commerce. How to create agents for e-commerce applications has become a serious consideration in this field. This paper proposes a new scheme named agent fabrication and elaborates its implementation in multi-agent systems based on the SAFER (Secure Agent Fabrication, Evolution & Roaming) architecture. First, a conceptual structure is proposed for software agents carrying out e-commerce act...

  11. Licopeno como agente antioxidante Lycopene as an antioxidant agent

    Directory of Open Access Journals (Sweden)

    Najua Juma Ismail Esh Shami

    2004-06-01

    Full Text Available Este trabalho constitui uma revisão de dados científicos sobre o consumo de licopeno e sua ação como fator antioxidante. O licopeno é considerado o carotenóide que possui a maior capacidade seqüestrante do oxigênio singlete. Radicais livres agem continuamente no organismo, podendo desencadear danos celulares e serem os responsáveis pelo desenvolvimento de câncer e certas doenças crônicas. Estudos mostram que o licopeno protege moléculas de lipídios, lipoproteínas de baixa densidade, proteínas e DNA contra o ataque dos radicais, tendo um papel essencial na proteção de doenças. Como prevenção, preconiza-se o consumo de dietas ricas em alimentos fontes de licopeno: tomates e seus produtos (purê, pasta, catchup, mamão, pitanga e goiaba; que aportem cerca de 35mg de licopeno ao dia.This paper is a review of scientific data about lycopene as an antioxidant agent. Lycopene is considered the carotenoid that has the highest capacity of capturing the singlet oxygen. Free radicals are continuously acting on the organism, being capable of promoting cellular damage and development of cancer among other chronic diseases. Studies show that lycopene protects lipid molecules, low-density lipoproteins, proteins and DNA against the attack of free radicals. They have an essential function in the protection against diseases. As a precaution, one should eat foods that are a source of lycopene: tomatoes and tomato-products (purée, pasta, ketchup, papaya, pitanga and guava; to provide approximately 35mg of lycopene a day.

  12. Toddlers Selectively Help Fair Agents

    Directory of Open Access Journals (Sweden)

    Luca Surian

    2017-06-01

    Full Text Available Previous research showed that infants and toddlers are inclined to help prosocial agents and assign a positive valence to fair distributions. Also, they expect that positive and negative actions directed toward distributors will conform to reciprocity principles. This study investigates whether toddlers are selective in helping others, as a function of others’ previous distributive actions. Toddlers were presented with real-life events in which two actresses distributed resources either equally or unequally between two puppets. Then, they played together with a ball that accidentally fell to the ground and asked participants to help them to retrieve it. Participants preferred to help the actress who performed equal distributions. This finding suggests that by the second year children’s prosocial actions are modulated by their emerging sense of fairness.HighlightsToddlers (mean age = 25 months are selective in helping distributors.Toddlers prefer helping a fair rather than an unfair distributor.Toddlers’ selective helping provides evidence for an early sense of fairness.

  13. Novel Methylselenoesters as Antiproliferative Agents

    Directory of Open Access Journals (Sweden)

    Nuria Díaz-Argelich

    2017-08-01

    Full Text Available Selenium (Se compounds are potential therapeutic agents in cancer. Importantly, the biological effects of Se compounds are exerted by their metabolites, with methylselenol (CH3SeH being one of the key executors. In this study, we developed a new series of methylselenoesters with different scaffolds aiming to modulate the release of CH3SeH. The fifteen compounds follow Lipinski’s Rule of Five and with exception of compounds 1 and 14, present better drug-likeness values than the positive control methylseleninic acid. The compounds were evaluated to determine their radical scavenging activity. Compound 11 reduced both DPPH and ABTS radicals. The cytotoxicity of the compounds was evaluated in a panel of five cancer cell lines (prostate, colon and lung carcinoma, mammary adenocarcinoma and chronic myelogenous leukemia and two non-malignant (lung and mammary epithelial cell lines. Ten compounds had GI50 values below 10 μM at 72 h in four cancer cell lines. Compounds 5 and 15 were chosen for further characterization of their mechanism of action in the mammary adenocarcinoma cell line due to their similarity with methylseleninic acid. Both compounds induced G2/M arrest whereas cell death was partially executed by caspases. The reduction and metabolism were also investigated, and both compounds were shown to be substrates for redox active enzyme thioredoxin reductase.

  14. Departments as Agents of Change

    Science.gov (United States)

    Lagowski, J. J.

    1996-07-01

    Higher education is changing because it has no choice. And, for the most part, outside influences are dictating the processes of change. The more fortunate institutions have had a flat budget during this period, but most have been forced to deal with a declining revenue stream as well. Legislators seem bent on micromanaging state-supported institutions, even as they cut their support. Regulators demand greater institutional accountability. Students and their parents expect more service at lower prices and increased flexibility. Technological advances have dramatically affected the availability and accessibility of extant knowledge. It is no longer a question of whether institutions will change, but rather, who will control the change. Most institutions possess long-standing academic traditions, but these are placed at risk in an increasingly competitive market that holds little sympathy for such traditions and may even see them as obstacles or barriers. As a result, the change agents will undoubtedly have a profound effect on the very nature of academic institutions. From the academic point of view, it would seem prudent to attempt to manage the changes that will inevitably occur. A number of concerned observers, notably the Pew Higher Education Roundtable and the American Association for Higher Education, argue persuasively that the academic department is the logical focus for responding to the current winds of change. Using a marketing metaphor, the academic department has been likened to a "producers' cooperative" of services that consumers seek. Thus, the department should be held accountable for the quality of teaching delivered by its members, for the coherence of its major, for its contributions to the general education curriculum, and for supervising and rewarding its individual faculty members. If departments are to be held accountable, it is surely in their best interest to act in such a way that they are accountable. Expecting academic departments to be

  15. Direct anti-HCV agents

    Directory of Open Access Journals (Sweden)

    Xingquan Zhang

    2016-01-01

    Full Text Available Unlike human immunodeficiency virus (HIV and hepatitis B virus (HBV, hepatitis C virus (HCV infection is a curable disease. Current direct antiviral agent (DAA targets are focused on HCV NS3/4A protein (protease, NS5B protein (polymerase and NS5A protein. The first generation of DAAs includes boceprevir and telaprevir, which are protease inhibitors and were approved for clinical use in 2011. The cure rate for genotype 1 patients increased from 45% to 70% when boceprevir or telaprevir was added to standard PEG-IFN/ribavirin. More effective and less toxic second generation DAAs supplanted these drugs by 2013. The second generation of DAAs includes sofosbuvir (Sovaldi, simeprevir (Olysio, and fixed combination medicines Harvoni and Viekira Pak. These drugs increase cure rates to over 90% without the need for interferon and effectively treat all HCV genotypes. With these drugs the “cure HCV” goal has become a reality. Concerns remain about drug resistance mutations and the high cost of these drugs. The investigation of new HCV drugs is progressing rapidly; fixed dose combination medicines in phase III clinical trials include Viekirax, asunaprevir+daclatasvir+beclabuvir, grazoprevir+elbasvir and others.

  16. Application Framework with Abstractions for Protocol and Agent Role

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun

    2016-01-01

    In multi-agent systems, agents interact by sending and receiving messages and the actual sequences of message form interaction structures between agents. Protocols and agents organized internally by agent roles support these interaction structures. Description and use of protocols based on agent...

  17. Ultrasound contrast agents: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Cosgrove, David [Imaging Sciences Department, Imperial College, Hammersmith Hospital, London (United Kingdom)]. E-mail: d.cosgrove@csc.mrc.ac.uk

    2006-12-15

    With the introduction of microbubble contrast agents, diagnostic ultrasound has entered a new era that allows the dynamic detection of tissue flow of both the macro and microvasculature. Underpinning this development is the fact that gases are compressible, and thus the microbubbles expand and contract in the alternating pressure waves of the ultrasound beam, while tissue is almost incompressible. Special software using multiple pulse sequences separates these signals from those of tissue and displays them as an overlay or on a split screen. This can be done at low acoustic pressures (MI < 0.3) so that the microbubbles are not destroyed and scanning can continue in real time. The clinical roles of contrast enhanced ultrasound scanning are expanding rapidly. They are established in echocardiography to improve endocardial border detection and are being developed for myocardial perfusion. In radiology, the most important application is the liver, especially for focal disease. The approach parallels that of dynamic CT or MRI but ultrasound has the advantages of high spatial and temporal resolution. Thus, small lesions that can be indeterminate on CT can often be studied with ultrasound, and situations where the flow is very rapid (e.g., focal nodular hyperplasia where the first few seconds of arterial perfusion may be critical to making the diagnosis) are readily studied. Microbubbles linger in the extensive sinusoidal space of normal liver for several minutes whereas they wash out rapidly from metastases, which have a low vascular volume and thus appear as filling defects. The method has been shown to be as sensitive as three-phase CT. Microbubbles have clinical uses in many other applications where knowledge of the microcirculation is important (the macrocirculation can usually be assessed adequately using conventional Doppler though there are a few important situations where the signal boost given by microbubbles is useful, e.g., transcranial Doppler for evaluating

  18. Evolution of hemostatic agents in surgical practice

    Directory of Open Access Journals (Sweden)

    Chandru P Sundaram

    2010-01-01

    Conclusions : A review of the evolution of topical hemostatic agents highlights opportunities for potential novel research. Fibrin sealants may have the most opportunity for advancement, and understanding the history of these products is useful. With the drive in urology for minimally invasive surgical techniques, adaptation of topical hemostatic agents to this surgical approach would be valuable and offers an opportunity for novel contributions.

  19. 31 CFR 330.9 - Fiscal agents.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Fiscal agents. 330.9 Section 330.9 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE... OF UNITED STATES SAVINGS BONDS AND UNITED STATES SAVINGS NOTES (FREEDOM SHARES) § 330.9 Fiscal agents...

  20. Ultrasound contrast agents : dynamics of coated bubbles

    NARCIS (Netherlands)

    Overvelde, M.L.J.

    2010-01-01

    Contrast-enhanced ultrasound imaging relies on the nonlinear scattering of microbubbles suspended in an ultrasound contrast agent. The bubble dynamics is described by a Rayleigh-Plesset-type equation, and the success of harmonic imaging using contrast agents has always been attributed to the

  1. Extravasation of antineoplastic agents: prevention and treatments.

    Science.gov (United States)

    Boschi, Rita; Rostagno, Elena

    2012-07-31

    The extravasation of antineoplastic agents is an unwanted and distressing situation that can easily occur. It may cause severe and irreversible local injuries. Left untreated, vesicant chemotherapy extravasation can potentially cause tissue necrosis, functional impairment and permanent disfigurement. This article provides a review of current literature regarding recommendations on the prevention and treatment of extravasation of antineoplastic agents.

  2. Extravasation of antineoplastic agents: prevention and treatments

    Directory of Open Access Journals (Sweden)

    Rita Boschi

    2012-08-01

    Full Text Available The extravasation of antineoplastic agents is an unwanted and distressing situation that can easily occur. It may cause severe and irreversible local injuries. Left untreated, vesicant chemotherapy extravasation can potentially cause tissue necrosis, functional impairment and permanent disfigurement. This article provides a review of current literature regarding recommendations on the prevention and treatment of extravasation of antineoplastic agents.

  3. Agent programming languages: programming with mental models

    NARCIS (Netherlands)

    Hindriks, K.V.

    2001-01-01

    Intelligent Agents are personal assistants which can provide proactive support to users by executing routine activities like searching on the Internet, the scheduling of meetings, etc. The concept of an Intelligent Agent has its roots in Artificial Intelligence and provides a basis for the

  4. The Change Agent's Guide. Second Edition.

    Science.gov (United States)

    Havelock, Ronald G.; Zlotolow, Steve

    This guidebook describes how successful change happens and how change agents can organize their work to make it happen. It is designed to help change agents in various organizational settings understand the dimensions of the problem and the social situation; organize a plan for change; know what to look for and what to avoid in one's self, team,…

  5. Training and the Change Agent Role Model

    Science.gov (United States)

    Leach, Wesley B.; Owens, Vyrle W.

    1973-01-01

    The authors discuss the qualities possessed by a model change agent and roles played by him as resident technical participant: analyst, advisor, advocate, systems linker, innovator, and trainer. Besides presenting the teaching plan for change agents, the authors call upon their Peace Corps experiences to provide specific examples of what is…

  6. Ultrasound contrast agents: bubbles, drops and particles

    NARCIS (Netherlands)

    Lajoinie, Guillaume Pierre Rene

    2015-01-01

    The research on the medical use of microbubbles has coontinuously provided fascinating results for half a century. Investigating new agents or new uses of existing agents requires both innovative physics and ideas and extensive testing in-vitro and in vivo. The translation from the lab to the clinic

  7. Mechanisms of bacterial resistance to antimicrobial agents.

    NARCIS (Netherlands)

    van Duijkeren, Engeline; Schink, Anne-Kathrin; Roberts, Marilyn C; Wang, Yang; Schwarz, Stefan

    During the past decades resistance to virtually all antimicrobial agents has been observed in bacteria of animal origin. This chapter describes in detail the mechanisms so far encountered for the various classes of antimicrobial agents. The main mechanisms include enzymatic inactivation by either

  8. AORTA: Adding Organizational Reasoning to Agents

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt; Dignum, Virginia

    2014-01-01

    the expected behavior of the agents. Agents need to be able to reason about the regulations, so that they can act within the expected boundaries and work towards the objectives of the organization. This extended abstract introduces AORTA, a component that can be integrated into agents’ reasoning mechanism...

  9. Cognitive impact of cytotoxic agents in mice

    NARCIS (Netherlands)

    Seigers, R.; Loos, M.; van Tellingen, O.; Boogerd, W.; Smit, A.B.; Schagen, S.B.

    2015-01-01

    Rationale and objectives: Adjuvant chemotherapy is associated with changes in cognition in a subgroup of cancer patients. Chemotherapy is generally given as a combination of cytotoxic agents, which makes it hard to define the agent responsible for these observed changes. Literature on animal

  10. Terpyridyl Complexes as Antimalarial Agents | Paraskevopoulos ...

    African Journals Online (AJOL)

    The data indicate that efficacy could be a result of several mechanisms and that speciation of the metal complex and the manner in which the agents are added to the parasitic broth have a profound effect on the activity of the agents. We believe that our study offers a template by which other researchers should approach ...

  11. Dynamics of three-agent games

    Energy Technology Data Exchange (ETDEWEB)

    Mungan, Muhittin [Department of Physics, Bogazici University, Bebek 34342, Istanbul (Turkey); Rador, Tonguc [Department of Physics, Bogazici University, Bebek 34342, Istanbul (Turkey)

    2008-02-08

    We study the dynamics and resulting score distribution of three-agent games where after each competition a single agent wins and scores a point. A single competition is described by a triplet of numbers p, t and q denoting the probabilities that the team with the highest, middle or lowest accumulated score wins. The three-agent game can be regarded as a social model where a player can be favored or disfavored for advancement, based on his/her accumulated score. We study the full family of solutions in the regime, where the number of agents and competitions is large, which can be regarded as a hydrodynamic limit. Depending on the parameter values (p, q, t), we find six qualitatively different asymptotic score distributions and we provide a qualitative explanation of these results. We also compare our analytical results against numerical simulations of the microscopic model and find these to be in excellent agreement. It is possible to decide the outcome of a three-agent game through a mini-tournament of two-agent competitions among the participating players and it turns out that the resulting possible score distributions are a subset of those obtained for the general three-agent games. We discuss how one can add a steady and democratic decline rate to the model and present a simple geometric construction that allows one to obtain the score evolution equations for n-agent games.

  12. Moral conflicts between groups of agents

    NARCIS (Netherlands)

    Kooi, Barteld; Tamminga, A.

    Two groups of agents, G1 and G2, face a *moral conflict* if G1 has a moral obligation and G2 has a moral obligation, such that these obligations cannot both be fulfilled. We study moral conflicts using a multi-agent deontic logic devised to represent reasoning about sentences like 'In the interest

  13. New ultrasound contrast agents and technological innovations.

    Science.gov (United States)

    de Jong, N; Ten Cate, F J

    1996-06-01

    Further development of clinical diagnostic procedures, as well as new diagnostic techniques, requires ultrasound specific contrast agents as well as technological innovations. This paper reviews contrast agents developed in the last decade, which are all based on free gas or encapsulated gas bubbles.

  14. Practice among Novice Change Agents in Schools

    Science.gov (United States)

    Blossing, Ulf

    2016-01-01

    The aim of the article is to understand practice as negotiation of meaning among novice and internal change agents in school organisations. The research question is as follows: What themes of participation and reification/management occur among the change agents? The study was qualitative in design using the social learning theory of community of…

  15. assessment of extension agents' communication methods

    African Journals Online (AJOL)

    USER

    ABSTRACT. The need to improve aquaculture production through enhanced technology transfer necessitated this study to assess extension agents' use of communication methods and its impact on linkage. A structured questionnaire was administered to 44 extension agents who were randomly selected from Lagos State ...

  16. Advanced Agent Methods in Adversarial Environment

    Science.gov (United States)

    2005-11-30

    A. Ortega- Ruiz . An implementation of self-protected mobile agents. In ECBS, pages 544–549, 2004. 5. R. Axelrod. The evolution of strategies in the...Bradshaw, Maggie R. Breedy, Thomas B. Cowin, Paul T. Groth, Raul Saavedra, and Andrzej Uszok. Enforcement of communications policies in software agent

  17. AGENT: Awareness Game Environment for Natural Training

    NARCIS (Netherlands)

    Linssen, Johannes Maria; de Groot, Thomas

    We propose AGENT, the Awareness Game Environment for Natural Training, as a virtual environment in which serious games can be enacted. AGENT combines research on interactive storytelling, game design, turn-taking and social signal processing with a multi-modal UI in a modular fashion. Current work

  18. A Successful Broker Agent for Power TAC

    NARCIS (Netherlands)

    B.J. Liefers (Bart); J. Hoogland (Jasper); J.A. La Poutré (Han)

    2014-01-01

    htmlabstractThe Power TAC simulates a smart grid energy market. In this simulation, broker agents compete for customers on a tariff market and trade energy on a wholesale market. It provides a platform for testing strategies of broker agents against other strategies. In this paper we describe the

  19. 31 CFR 10.5 - Application for enrollment as an enrolled agent or enrolled retirement plan agent.

    Science.gov (United States)

    2010-07-01

    ... enrolled agent or enrolled retirement plan agent. 10.5 Section 10.5 Money and Finance: Treasury Office of... to Practice § 10.5 Application for enrollment as an enrolled agent or enrolled retirement plan agent. (a) Form; address. An applicant for enrollment as an enrolled agent or enrolled retirement plan agent...

  20. Safe motion planning for mobile agents: A model of reactive planning for multiple mobile agents

    Energy Technology Data Exchange (ETDEWEB)

    Fujimura, Kikuo.

    1990-01-01

    The problem of motion planning for multiple mobile agents is studied. Each planning agent independently plans its own action based on its map which contains a limited information about the environment. In an environment where more than one mobile agent interacts, the motions of the robots are uncertain and dynamic. A model for reactive agents is described and simulation results are presented to show their behavior patterns. 18 refs., 2 figs.

  1. Agent-based models of cellular systems.

    Science.gov (United States)

    Cannata, Nicola; Corradini, Flavio; Merelli, Emanuela; Tesei, Luca

    2013-01-01

    Software agents are particularly suitable for engineering models and simulations of cellular systems. In a very natural and intuitive manner, individual software components are therein delegated to reproduce "in silico" the behavior of individual components of alive systems at a given level of resolution. Individuals' actions and interactions among individuals allow complex collective behavior to emerge. In this chapter we first introduce the readers to software agents and multi-agent systems, reviewing the evolution of agent-based modeling of biomolecular systems in the last decade. We then describe the main tools, platforms, and methodologies available for programming societies of agents, possibly profiting also of toolkits that do not require advanced programming skills.

  2. Biological agents in polyarticular juvenile idiopathic arthritis

    DEFF Research Database (Denmark)

    Amarilyo, Gil; Tarp, Simon; Foeldvari, Ivan

    2016-01-01

    available randomized withdrawal trials (wRCTs). METHODS: A systematic search of MEDLINE, EMBASE, CENTRAL, and clinicaltrials.gov was performed. Eligible wRCTs: patients with pJIA where a biological agent was compared with another biological agent or placebo. Efficacy was evaluated using disease flare......BACKGROUND AND OBJECTIVE: Although various biological agents are in use for polyarticular juvenile idiopathic arthritis (pJIA), head-to-head trials comparing the efficacy and safety among them are lacking. We aimed to compare the efficacy and safety of biological agents in pJIA using all currently...... as a measure. Adverse events (AEs) and serious AEs were evaluated. Network meta-analysis compared biological agents based on a (empirical Bayes) mixed-effects logistic regression model that combines statistical inference from both direct and indirect comparisons of the treatment effects between biological...

  3. Highlights on Practical Applications of Agents and Multi-Agent Systems 10th International Conference on Practical Applications of Agents and Multi-Agent Systems

    CERN Document Server

    Sánchez, Miguel; Mathieu, Philippe; Rodríguez, Juan; Adam, Emmanuel; Ortega, Alfonso; Moreno, María; Navarro, Elena; Hirsch, Benjamin; Lopes-Cardoso, Henrique; Julián, Vicente

    2012-01-01

    Research on Agents and Multi-Agent Systems has matured during the last decade and many effective applications of this technology are now deployed. PAAMS provides an international forum to present and discuss the latest scientific developments and their effective applications, to assess the impact of the approach, and to facilitate technology transfer. PAAMS started as a local initiative, but has since grown to become THE international yearly platform to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development and deployment of Agents and Multi-Agent Systems. PAAMS intends to bring together researchers and developers from industry and the academic world to report on the latest scientific and technical advances on the application of multi-agent systems, to discuss and debate the major ...

  4. Advances on Practical Applications of Agents and Multi-Agent Systems 10th International Conference on Practical Applications of Agents and Multi-Agent Systems

    CERN Document Server

    Müller, Jörg; Rodríguez, Juan; Pérez, Javier

    2012-01-01

    Research on Agents and Multi-Agent Systems has matured during the last decade and many effective applications of this technology are now deployed. PAAMS provides an international forum to present and discuss the latest scientific developments and their effective applications, to assess the impact of the approach, and to facilitate technology transfer. PAAMS started as a local initiative, but has since grown to become THE international yearly platform to present, to discuss, and to disseminate the latest developments and the most important outcomes related to real-world applications. It provides a unique opportunity to bring multi-disciplinary experts, academics and practitioners together to exchange their experience in the development and deployment of Agents and Multi-Agent Systems. PAAMS intends to bring together researchers and developers from industry and the academic world to report on the latest scientific and technical advances on the application of multi-agent systems, to discuss and debate the major ...

  5. Fault Reconnaissance Agent for Sensor Networks

    Directory of Open Access Journals (Sweden)

    Elhadi M. Shakshuki

    2010-01-01

    Full Text Available One of the key prerequisite for a scalable, effective and efficient sensor network is the utilization of low-cost, low-overhead and high-resilient fault-inference techniques. To this end, we propose an intelligent agent system with a problem solving capability to address the issue of fault inference in sensor network environments. The intelligent agent system is designed and implemented at base-station side. The core of the agent system – problem solver – implements a fault-detection inference engine which harnesses Expectation Maximization (EM algorithm to estimate fault probabilities of sensor nodes. To validate the correctness and effectiveness of the intelligent agent system, a set of experiments in a wireless sensor testbed are conducted. The experimental results show that our intelligent agent system is able to precisely estimate the fault probability of sensor nodes.

  6. Econophysics of agent-based models

    CERN Document Server

    Aoyama, Hideaki; Chakrabarti, Bikas; Chakraborti, Anirban; Ghosh, Asim

    2014-01-01

    The primary goal of this book is to present the research findings and conclusions of physicists, economists, mathematicians and financial engineers working in the field of "Econophysics" who have undertaken agent-based modelling, comparison with empirical studies and related investigations. Most standard economic models assume the existence of the representative agent, who is “perfectly rational” and applies the utility maximization principle when taking action. One reason for this is the desire to keep models mathematically tractable: no tools are available to economists for solving non-linear models of heterogeneous adaptive agents without explicit optimization. In contrast, multi-agent models, which originated from statistical physics considerations, allow us to go beyond the prototype theories of traditional economics involving the representative agent. This book is based on the Econophys-Kolkata VII Workshop, at which many such modelling efforts were presented. In the book, leading researchers in the...

  7. 9th KES Conference on Agent and Multi-Agent Systems : Technologies and Applications

    CERN Document Server

    Howlett, Robert; Jain, Lakhmi

    2015-01-01

    Agents and multi-agent systems are related to a modern software paradigm which has long been recognized as a promising technology for constructing autonomous, complex and intelligent systems. The topics covered in this volume include agent-oriented software engineering, agent co-operation, co-ordination, negotiation, organization and communication, distributed problem solving, specification of agent communication languages, agent privacy, safety and security, formalization of ontologies and conversational agents. The volume highlights new trends and challenges in agent and multi-agent research and includes 38 papers classified in the following specific topics: learning paradigms, agent-based modeling and simulation, business model innovation and disruptive technologies, anthropic-oriented computing, serious games and business intelligence, design and implementation of intelligent agents and multi-agent systems, digital economy, and advances in networked virtual enterprises. Published p...

  8. 76 FR 21805 - User Fees Relating to Enrolled Agents and Enrolled Retirement Plan Agents

    Science.gov (United States)

    2011-04-19

    ... Service 26 CFR Part 300 RIN 1545-BJ65 User Fees Relating to Enrolled Agents and Enrolled Retirement Plan... 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...

  9. 76 FR 2617 - User Fees Relating to Enrolled Agents and Enrolled Retirement Plan Agents; Hearing Cancellation

    Science.gov (United States)

    2011-01-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE TREASURY Internal Revenue Service 26 CFR Part 300 RIN 1545-BJ65 User Fees Relating to Enrolled Agents and Enrolled... enrolled agents and enrolled retirement plan agents. DATES: The public hearing, originally scheduled for...

  10. Human-agent experience sharing : Creating social agents for elderly people with dementia

    NARCIS (Netherlands)

    Peeters, M.M.M.; Neerincx, M.A.

    2016-01-01

    As intelligent technology steadily becomes a part of modern societies, people collaborate with agents more frequently, and so agents need to be socially intelligent, i.e. personalised and context-sensitive. This paper introduces a context-sensitive personalisation framework for social agents that

  11. For whom will the Bayesian agents vote?

    Science.gov (United States)

    Caticha, Nestor; Cesar, Jonatas; Vicente, Renato

    2015-04-01

    Within an agent-based model where moral classifications are socially learned, we ask if a population of agents behaves in a way that may be compared with conservative or liberal positions in the real political spectrum. We assume that agents first experience a formative period, in which they adjust their learning style acting as supervised Bayesian adaptive learners. The formative phase is followed by a period of social influence by reinforcement learning. By comparing data generated by the agents with data from a sample of 15000 Moral Foundation questionnaires we found the following. 1. The number of information exchanges in the formative phase correlates positively with statistics identifying liberals in the social influence phase. This is consistent with recent evidence that connects the dopamine receptor D4-7R gene, political orientation and early age social clique size. 2. The learning algorithms that result from the formative phase vary in the way they treat novelty and corroborative information with more conservative-like agents treating it more equally than liberal-like agents. This is consistent with the correlation between political affiliation and the Openness personality trait reported in the literature. 3. Under the increase of a model parameter interpreted as an external pressure, the statistics of liberal agents resemble more those of conservative agents, consistent with reports on the consequences of external threats on measures of conservatism. We also show that in the social influence phase liberal-like agents readapt much faster than conservative-like agents when subjected to changes on the relevant set of moral issues. This suggests a verifiable dynamical criterium for attaching liberal or conservative labels to groups.

  12. Multi-Agent Systems for E-Commerce

    OpenAIRE

    Solodukha, T. V.; Sosnovskiy, O. A.; Zhelezko, B. A.

    2009-01-01

    The article focuses on multi-agent systems (MAS) and domains that can benefit from multi-agent technology. In the last few years, the agent based modeling (ABM) community has developed several practical agent based modeling toolkits that enable individuals to develop agent-based applications. The comparison of agent-based modeling toolkits is given. Multi-agent systems are designed to handle changing and dynamic business processes. Any organization with complex and distributed busine...

  13. Chemical Warfare Agent Decontaminant Solution Using Quaternary Ammonium Complexes

    Science.gov (United States)

    1997-12-11

    warfare agents, which include a variety of organophosphorus and organosulfur compounds, are known in the art. 15 However, these known methods use...chemical warfare agents, and works particularly well for neutralization of organosulfur agents such as mustard gas (HD), and organophosphorus agents such...detoxifying/neutralizing a variety of chemical warfare agents, including organosulfur agents such as mustard gas (HD), and organophosphorus agents such as

  14. Persistent agents in Axelrod's social dynamics model

    Science.gov (United States)

    Reia, Sandro M.; Neves, Ubiraci P. C.

    2016-01-01

    Axelrod's model of social dynamics has been studied under the effect of external media. Here we study the formation of cultural domains in the model by introducing persistent agents. These are agents whose cultural traits are not allowed to change but may be spread through local neighborhood. In the absence of persistent agents, the system is known to present a transition from a monocultural to a multicultural regime at some critical Q (number of traits). Our results reveal a dependence of critical Q on the occupation probability p of persistent agents and we obtain the phase diagram of the model in the (p,Q) -plane. The critical locus is explained by the competition of two opposite forces named here barrier and bonding effects. Such forces are verified to be caused by non-persistent agents which adhere (adherent agents) to the set of traits of persistent ones. The adherence (concentration of adherent agents) as a function of p is found to decay for constant Q. Furthermore, adherence as a function of Q is found to decay as a power law with constant p.

  15. Continuum deformation of multi-agent systems

    CERN Document Server

    Rastgoftar, Hossein

    2016-01-01

    This monograph presents new algorithms for formation control of multi-agent systems (MAS) based on principles of continuum mechanics. Beginning with an overview of traditional methods, the author then introduces an innovative new approach whereby agents of an MAS are considered as particles in a continuum evolving in ℝn whose desired configuration is required to satisfy an admissible deformation function. The necessary theory and its validation on a mobile-agent-based swarm test bed are considered for two primary tasks: homogeneous transformation of the MAS and deployment of a random distribution of agents on a desired configuration. The framework for this model is based on homogeneous transformations for the evolution of an MAS under no inter-agent communication, local inter-agent communication, and intelligent perception by agents. Different communication protocols for MAS evolution, the robustness of tracking of a desired motion by an MAS evolving in ℝn, and the effect of communication delays in an MAS...

  16. Dynamic Channel Allocation Management Using Agents Technology

    Directory of Open Access Journals (Sweden)

    Ion BOGDAN

    2009-07-01

    Full Text Available Channel allocation schemes are management techniques meant to solve the radio access problem in the telecommunications area. There are several known schemes namely: static, dynamic, hybrid and flexible channel allocation schemes. In our work we developed the channel allocation scheme using a decentralized structure, based on software agents. In order to create such a structure, some functions must be carried out by some specialized functional entities. Each functional entity is implemented with an agent, having a specific role. Using this manner of implementation, different functions of the system can be implemented at different sites, located apart and also the structure can be modularized. In our work we have created the agents structure and the communications between agents, on the use of Multiagent Systems Engineering Technology. We also involved the AgentTool platform to automate the creation of the agents structure and the code resulted was in Java. In order to realize the test of our system we considered a shape of 21 radio areas, each including a number of users. Each wireless user can initiate a number of calls per hour and each call last a holding time. The communications between agents were realized for the TCP/IP protocol, based on socket connections.

  17. Relay tracking control for second-order multi-agent systems with damaged agents.

    Science.gov (United States)

    Dong, Lijing; Li, Jing; Liu, Qin

    2017-07-07

    This paper investigates a situation where smart agents capable of sensory and mobility are deployed to monitor a designated area. A preset number of agents start tracking when a target intrudes this area. Some of the tracking agents are possible to be out of order over the tracking course. Thus, we propose a cooperative relay tracking strategy to ensure the successful tracking with existence of damaged agents. Relay means that, when a tracking agent quits tracking due to malfunction, one of the near deployed agents replaces it to continue the tracking task. This results in jump of tracking errors and dynamic switching of topology of the multi-agent system. Switched system technique is employed to solve this specific problem. Finally, the effectiveness of proposed tracking strategy and validity of the theoretical results are verified by conducting a numerical simulation. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  18. Agent and multi-Agent systems in distributed systems digital economy and e-commerce

    CERN Document Server

    Hartung, Ronald

    2013-01-01

    Information and communication technology, in particular artificial intelligence, can be used to support economy and commerce using digital means. This book is about agents and multi-agent distributed systems applied to digital economy and e-commerce to meet, improve, and overcome challenges in the digital economy and e-commerce sphere. Agent and multi-agent solutions are applied in implementing real-life, exciting developments associated with the need to eliminate problems of distributed systems.   The book presents solutions for both technology and applications, illustrating the possible uses of agents in the enterprise domain, covering design and analytic methods, needed to provide a solid foundation required for practical systems. More specifically, the book provides solutions for the digital economy, e-sourcing clusters in network economy, and knowledge exchange between agents applicable to online trading agents, and security solutions to both digital economy and e-commerce. Furthermore, it offers soluti...

  19. Multi-Agent Pathfinding with n Agents on Graphs with n Vertices

    DEFF Research Database (Denmark)

    Förster, Klaus-Tycho; Groner, Linus; Hoefler, Torsten

    2017-01-01

    We investigate the multi-agent pathfinding (MAPF) problem with $n$ agents on graphs with $n$ vertices: Each agent has a unique start and goal vertex, with the objective of moving all agents in parallel movements to their goal s.t.~each vertex and each edge may only be used by one agent at a time....... We give a combinatorial classification of all graphs where this problem is solvable in general, including cases where the solvability depends on the initial agent placement. Furthermore, we present an algorithm solving the MAPF problem in our setting, requiring O(n²) rounds, or O(n³) moves...... of individual agents. Complementing these results, we show that there are graphs where Omega(n²) rounds and Omega(n³) moves are required for any algorithm....

  20. Historical Perspective of Imaging Contrast Agents.

    Science.gov (United States)

    Zamora, Carlos A; Castillo, Mauricio

    2017-11-01

    Contrast agents were introduced early in the history of medical imaging. Iodine-based intravascular agents became the radiographic compounds of choice and refinements of their chemical structures led to the highly tolerated low-osmolarity agents in use today. Gadolinium became the most popular compound for MR imaging; however, recognition of nephrogenic systemic fibrosis and in vivo dechelation intensified research on their safety profile. Ultrasonography contrast media evolved from manual injections of air through agitated saline solutions to microbubbles with different gases. Research has concentrated on bubble stabilization and development of small but sufficiently echogenic particles. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Dendrimers as high relaxivity MR contrast agents.

    Science.gov (United States)

    Longmire, Michelle R; Ogawa, Mikako; Choyke, Peter L; Kobayashi, Hisataka

    2014-01-01

    Dendrimers are versatile macromolecules with tremendous potential as magnetic resonance imaging (MRI) contrast agents. Dendrimer-based agents provide distinct advantages over low-molecular-weight gadolinium chelates, including enhanced r1 relaxivity due to slow rotational dynamics, tunable pharmacokinetics that can be adapted for blood pool, liver, kidney, and lymphatic imaging, the ability to be a drug carrier, and flexibility for labeling due to their inherent multivalency. Clinical applications are increasingly being developed, particularly in lymphatic imaging. Herein we present a broad overview of dendrimer-based MRI contrast agents with attention to the unique chemistry and physical properties as well as emerging clinical applications. © 2013 Wiley Periodicals, Inc.

  2. Topical antimicrobial agents in ophthalmology. A review

    Directory of Open Access Journals (Sweden)

    E. V. Dovgan’

    2014-01-01

    Full Text Available The data on different antimicrobial agents (fluoroquinolones, minoglycosides, macrolides, fusidic acid, chloramphenicol and their activity against various microorganisms are reviewed. The findings from different researchers are analyzed. Considerable attention is devoted to the problem of antimicrobial resistance in ophthalmology. Pharmacokinetics of topical antimicrobial agents applied in ophthalmology, their safety and tolerability are described. The indications for topical antimicrobial agents use in ophthalmology approved in Russian Federation are presented. With regard for pharmacokinetics and pharmacodynamics, safety profile and good tolerability, it is concluded that fluoroquinolones are medication of choice for empirical antimicrobial treatment in ophthalmology.

  3. Pharmacologic agents for mucus clearance in bronchiectasis.

    Science.gov (United States)

    Nair, Girish B; Ilowite, Jonathan S

    2012-06-01

    There are no approved pharmacologic agents to enhance mucus clearance in non-cystic fibrosis (CF) bronchiectasis. Evidence supports the use of hyperosmolar agents in CF, and studies with inhaled mannitol and hypertonic saline are ongoing in bronchiectasis. N-acetylcysteine may act more as an antioxidant than a mucolytic in other lung diseases. Dornase α is beneficial to patients with CF, but is not useful in patients with non-CF bronchiectasis. Mucokinetic agents such as β-agonists have the potential to improve mucociliary clearance in normals and many disease states, but have not been adequately studied in patients with bronchiectasis. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Internet resources for agent-based modelling.

    Science.gov (United States)

    Devillers, J; Devillers, H; Decourtye, A; Aupinel, P

    2010-04-01

    The use of agent-based models (ABMs) is steadily increasing in all the disciplines including environmental chemistry and toxicology. This growth is mainly driven by their ability to address problems that conventional modelling techniques cannot, such as the change of scale or the emergence of unanticipated phenomena resulting from interactions between their constitutive goal-directed agents. After a brief introduction on the basic principles of agent-based modelling and the presentation of selected case studies, the main software resources available on the Internet are presented. An attempt is made to estimate the complexity of these tools versus their potentialities and flexibility.

  5. Designing Agent Utilities for Coordinated, Scalable and Robust Multi-Agent Systems

    Science.gov (United States)

    Tumer, Kagan

    2005-01-01

    Coordinating the behavior of a large number of agents to achieve a system level goal poses unique design challenges. In particular, problems of scaling (number of agents in the thousands to tens of thousands), observability (agents have limited sensing capabilities), and robustness (the agents are unreliable) make it impossible to simply apply methods developed for small multi-agent systems composed of reliable agents. To address these problems, we present an approach based on deriving agent goals that are aligned with the overall system goal, and can be computed using information readily available to the agents. Then, each agent uses a simple reinforcement learning algorithm to pursue its own goals. Because of the way in which those goals are derived, there is no need to use difficult to scale external mechanisms to force collaboration or coordination among the agents, or to ensure that agents actively attempt to appropriate the tasks of agents that suffered failures. To present these results in a concrete setting, we focus on the problem of finding the sub-set of a set of imperfect devices that results in the best aggregate device. This is a large distributed agent coordination problem where each agent (e.g., device) needs to determine whether to be part of the aggregate device. Our results show that the approach proposed in this work provides improvements of over an order of magnitude over both traditional search methods and traditional multi-agent methods. Furthermore, the results show that even in extreme cases of agent failures (i.e., half the agents failed midway through the simulation) the system's performance degrades gracefully and still outperforms a failure-free and centralized search algorithm. The results also show that the gains increase as the size of the system (e.g., number of agents) increases. This latter result is particularly encouraging and suggests that this method is ideally suited for domains where the number of agents is currently in the

  6. Contrast Agent in Magnetic Resonance Imaging

    DEFF Research Database (Denmark)

    Vu-Quang, Hieu

    2015-01-01

    Nanoparticles have been employed as contrast agent in magnetic resonance imaging (MRI) in order to improve sensitivity and accuracy in diagnosis. In addition, these contrast agents are potentially combined with other therapeutic compounds or near infrared bio-imaging (NIR) fluorophores to obtain...... theranostic or dual imaging purposes, respectively. There were two main types of MRI contrast agent that were synthesized during this PhD project including fluorine containing nanoparticles and magnetic nanoparticles. In regard of fluorine containing nanoparticles, there were two types contrast agent...... that were synthesized in project I and II. In project I, Poly (lactic-co-glycolic acid)-block-poly (ethylene glycol)-Folate Pefluorooctyl Bromide/Indocyanine green/ Doxorubicin (PLGA-PEG-Folate PFOB/ICG/Dox) has been formulated for the dual imaging NIR and 19F MRI as well as in the combination of Dox...

  7. AORTA: Adding Organizational Reasoning to Agents

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt; Dignum, Virginia

    2014-01-01

    the expected behavior of the agents. Agents need to be able to reason about the regulations, so that they can act within the expected boundaries and work towards the objectives of the organization. This extended abstract introduces AORTA, a component that can be integrated into agents’ reasoning mechanism......Open systems are characterized by a diversity of heterogeneous and autonomous agents that act according to private goals, and with a behavior that is hard to predict. They can be regulated through organizations similar to human organizations, which regulate the agents’ behavior space and describe......, allowing them to reason about (and act upon) regulations specified by an organizational model using simple reasoning rules. The added value is that the organizational model is independent of that of the agents, and that the approach is not tied to a specific organizational model....

  8. Agent-based modeling of sustainable behaviors

    CERN Document Server

    Sánchez-Maroño, Noelia; Fontenla-Romero, Oscar; Polhill, J; Craig, Tony; Bajo, Javier; Corchado, Juan

    2017-01-01

    Using the O.D.D. (Overview, Design concepts, Detail) protocol, this title explores the role of agent-based modeling in predicting the feasibility of various approaches to sustainability. The chapters incorporated in this volume consist of real case studies to illustrate the utility of agent-based modeling and complexity theory in discovering a path to more efficient and sustainable lifestyles. The topics covered within include: households' attitudes toward recycling, designing decision trees for representing sustainable behaviors, negotiation-based parking allocation, auction-based traffic signal control, and others. This selection of papers will be of interest to social scientists who wish to learn more about agent-based modeling as well as experts in the field of agent-based modeling.

  9. Nominaliseeritud protsessi agent meediauudistes / Reet Kasik

    Index Scriptorium Estoniae

    Kasik, Reet, 1946-

    2006-01-01

    Ajalehe "Postimees" 2005. aasta materjalile toetudes vaadeldakse, mis tüüpi on nominalisatsioonides representeeritavad protsessid ja mis kujul on esitatud protsessi agent ehk tegija. Aluseks on võetud funktsionaalse grammatika põhimõtted.

  10. BDI agent architecture for a POMDP planner

    CSIR Research Space (South Africa)

    Rens, G

    2009-06-01

    Full Text Available Traditionally, agent architectures based on the Belief-Desire-Intention (BDI) model make use of precompiled plans, or if they do generate plans, the plans do not involve stochastic actions nor probabilistic observations. Plans that do involve...

  11. Spatial interactions in agent-based modeling

    CERN Document Server

    Ausloos, Marcel; Merlone, Ugo

    2014-01-01

    Agent Based Modeling (ABM) has become a widespread approach to model complex interactions. In this chapter after briefly summarizing some features of ABM the different approaches in modeling spatial interactions are discussed. It is stressed that agents can interact either indirectly through a shared environment and/or directly with each other. In such an approach, higher-order variables such as commodity prices, population dynamics or even institutions, are not exogenously specified but instead are seen as the results of interactions. It is highlighted in the chapter that the understanding of patterns emerging from such spatial interaction between agents is a key problem as much as their description through analytical or simulation means. The chapter reviews different approaches for modeling agents' behavior, taking into account either explicit spatial (lattice based) structures or networks. Some emphasis is placed on recent ABM as applied to the description of the dynamics of the geographical distribution o...

  12. Enriching project organizations with formal change agents

    DEFF Research Database (Denmark)

    Eskerod, Pernille; Justesen, Just Bendix; Sjøgaard, Gisela

    2017-01-01

    an internal change project that enhanced physical activity at the workplace and in leisure time. Change agents in the form of peer health ambassadors were selected by middle management and hereafter trained by the project representatives. Findings: The findings suggest that the selection of change agents...... and middle and top management support are major determinants of success within change projects. To select change agents that the employees respect and can identify with, combined with top management prioritization, is important in order for the project organization to benefit from the additional role....... Practical implications: Selecting the “wrong” change agents can jeopardize a change project, even when the project is supported by top management and the target group members at the starting point are highly motivated to change. Originality/value: The research contributes to the understanding of project...

  13. Fairness emergence from zero-intelligence agents.

    Science.gov (United States)

    Duan, Wen-Qi; Stanley, H Eugene

    2010-02-01

    Fairness plays a key role in explaining the emergence and maintenance of cooperation. Opponent-oriented social utility models were often proposed to explain the origins of fairness preferences in which agents take into account not only their own outcomes but are also concerned with the outcomes of their opponents. Here, we propose a payoff-oriented mechanism in which agents update their beliefs only based on the payoff signals of the previous ultimatum game, regardless of the behaviors and outcomes of the opponents themselves. Employing adaptive ultimatum game, we show that (1) fairness behaviors can emerge out even under such minimalist assumptions, provided that agents are capable of responding to their payoff signals, (2) the average game payoff per agent per round decreases with the increasing discrepancy rate between the average giving rate and the average asking rate, and (3) the belief update process will lead to 50%-50% fair split provided that there is no mutation in the evolutionary dynamics.

  14. Intelligent agents in data-intensive computing

    CERN Document Server

    Correia, Luís; Molina, José

    2016-01-01

    This book presents new approaches that advance research in all aspects of agent-based models, technologies, simulations and implementations for data intensive applications. The nine chapters contain a review of recent cross-disciplinary approaches in cloud environments and multi-agent systems, and important formulations of data intensive problems in distributed computational environments together with the presentation of new agent-based tools to handle those problems and Big Data in general. This volume can serve as a reference for students, researchers and industry practitioners working in or interested in joining interdisciplinary work in the areas of data intensive computing and Big Data systems using emergent large-scale distributed computing paradigms. It will also allow newcomers to grasp key concepts and potential solutions on advanced topics of theory, models, technologies, system architectures and implementation of applications in Multi-Agent systems and data intensive computing. .

  15. Nanosilver: Potent antimicrobial agent and its biosynthesis

    African Journals Online (AJOL)

    VIKAS

    2014-01-22

    Jan 22, 2014 ... Department of Biotechnology, Deenbandhu Chotu Ram University of Science ... plants in the synthesis of nanosilver and their potent application as antimicrobial agent. ... solute molecules that are formed during a chemical.

  16. New agents in renal cell carcinoma.

    Science.gov (United States)

    Dabney, Raetasha; Devine, Ryan; Sein, Nancy; George, Benjamin

    2014-09-01

    Prior to 2005, the treatment options for metastatic renal cell carcinoma (mRCC) were limited. There has been a proliferation of agents since the introduction of sorafenib, sunitinib, and becavicumab for clinical use in advanced renal cell carcinoma. Recently, four new agents have been approved by the US Food and Drug Administration (FDA) for use in mRCC. These agents come from two unique targeted pathways for RCC, tyrosine kinase inhibitors (TKIs) of vascular endothelial growth factor (VEGF) and mammalian target of rapamycin (mTOR) inhibitors. This review examines the investigational evolution, phases of development, adverse event profiles, and future directions of pazopanib, axitinib, everolimus, and temsirolimus as well as new novel agents being explored in clinical trials for these targeted pathways.

  17. Simulation of Conditioning Mechanisms in Agents

    NARCIS (Netherlands)

    Bosse, T.; Jonker, C.M.; Treur, J.; Bento, C.; Cardoso, A.; Dias, G.

    2005-01-01

    In order to create adaptive Agent Systems with abilities matching those of their biological counterparts, a natural approach is to incorporate classical conditioning mechanisms into such systems. However, existing models for classical conditioning are usually based on differential equations. Since

  18. Microscopic agents programmed by DNA circuits

    Science.gov (United States)

    Gines, G.; Zadorin, A. S.; Galas, J.-C.; Fujii, T.; Estevez-Torres, A.; Rondelez, Y.

    2017-05-01

    Information stored in synthetic nucleic acids sequences can be used in vitro to create complex reaction networks with precisely programmed chemical dynamics. Here, we scale up this approach to program networks of microscopic particles (agents) dispersed in an enzymatic solution. Agents may possess multiple stable states, thus maintaining a memory and communicate by emitting various orthogonal chemical signals, while also sensing the behaviour of neighbouring agents. Using this approach, we can produce collective behaviours involving thousands of agents, for example retrieving information over long distances or creating spatial patterns. Our systems recapitulate some fundamental mechanisms of distributed decision making and morphogenesis among living organisms and could find applications in cases where many individual clues need to be combined to reach a decision, for example in molecular diagnostics.

  19. Reactive Oxygen Species as Agents of Fatigue

    National Research Council Canada - National Science Library

    REID, MICHAEL B

    2016-01-01

    ...) generated in exercising muscle and the potential role that ROS may play in fatigue. METHODSReports in the peer-reviewed literature were analyzed and published findings integrated to synthesize an overview of ROS as agents of fatigue...

  20. Paramecium tetraurelia: prescreen for hazardous agents

    Energy Technology Data Exchange (ETDEWEB)

    Smith-Sonneborn, J.; Herr, C.; VanKirk, E.

    1979-01-01

    The ciliated protozoan, paramecia, is proposed as a eukaryote model system for use in short-term screening assays for detection of mutagenic/carcinogenic and hazardous agents. The approach utilizes two assays: the mutagenic and photodynamic systems.

  1. Panel: Methodologies for multi-agent systems

    NARCIS (Netherlands)

    Kinny, David; Treur, Jan; Gasser, Les; Clark, Steve; Müller, Jörg

    1998-01-01

    Multi-Agent Systems technologies are migrating from research labs to software engineering centres. If these technologies are to realize their potential, it will become increasingly important to develop and employ methodologies, accessible to software engineers, for specifying, analysing, designing,

  2. Agentes de software móviles

    Directory of Open Access Journals (Sweden)

    Crisman Martínez Barrera

    2001-10-01

    Full Text Available Los agentes móviles son programas de software inteligentes que realizan un objetivo que involucran desarrollos soportados en técnicas de Inteligencia Artificial, los cuales pretenden facilitar la interoperabilidad de sistemas. Este artículo define las disciplinas, plataformas y herramientas necesarias para el desarrollo de agentes móviles, sus características principales y las arquitecturas predominantes de éstas; presenta además una evaluación de sus perspectivas futuras.Mobile agents are intelligent software programs that can obtain an objective that involucrates developments supported in Artificial Intelligence techniques. These pretend to facilitate the interoperability of systems. This article defines disciplines, platforms and tools necessary for the development of mobile agents, their principal characteristics and the predominant architectures of these. A final evaluation and future perspectives are offered.

  3. Competing intelligent search agents in global optimization

    Energy Technology Data Exchange (ETDEWEB)

    Streltsov, S.; Vakili, P. [Boston Univ., MA (United States); Muchnik, I. [Rutgers Univ., Piscataway, NJ (United States)

    1996-12-31

    In this paper we present a new search methodology that we view as a development of intelligent agent approach to the analysis of complex system. The main idea is to consider search process as a competition mechanism between concurrent adaptive intelligent agents. Agents cooperate in achieving a common search goal and at the same time compete with each other for computational resources. We propose a statistical selection approach to resource allocation between agents that leads to simple and efficient on average index allocation policies. We use global optimization as the most general setting that encompasses many types of search problems, and show how proposed selection policies can be used to improve and combine various global optimization methods.

  4. Disease-modifying agents in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Coyle P

    2009-01-01

    Full Text Available Since 1993, six disease-modifying therapies for multiple sclerosis (MS have been proven to be of benefit in rigorous phase III clinical trials. Other agents are also available and are used to treat MS, but definitive data on their efficacy is lacking. Currently, disease-modifying therapy is used for relapsing forms of MS. This includes clinically isolated syndrome/first-attack high-risk patients, relapsing patients, secondary progressive patients who are still experiencing relapses, and progressive relapsing patients. The choice of agent depends upon drug factors (including affordability, availability, convenience, efficacy, and side effects, disease factors (including clinical and neuroimaging prognostic indicators, and patient factors (including comorbidities, lifestyle, and personal preference. This review will discuss the disease-modifying agents used currently in MS, as well as available alternative agents.

  5. Towards Culturally-Aware Virtual Agent Systems

    DEFF Research Database (Denmark)

    Endrass, Birgit; André, Elisabeth; Rehm, Matthias

    2010-01-01

    in a game-like environment in a more interesting way than for example learning with a textbook. The authors support the idea that virtual agents are a great opportunity for teaching cultural awareness. Realizing this, the concept of culture needs to be translated into computational models and the advantages...... of different systems using virtual agents need to be considered. Therefore, the authors reflect in this chapter on how virtual agents can help to learn about culture, scan definitions of culture from the social sciences, give an overview on how multiagent systems developed over time and classify the state...... of the art that integrates culture in multiagent systems. In addition, an approach of simulating culture-specific behavior using such a multiagent system is introduced and future trends in enculturating virtual agent systems are outlined....

  6. Spions as nano-theranostics agents

    CERN Document Server

    Zarepour, Atefeh; Khosravi, Arezoo

    2017-01-01

    This Brief introduces SuperParamagnetic Iron Oxide Nanoparticles (SPIONs), the different synthesis approaches, their applications in the field of diagnostics and treatment and finally as theranostic agents in cancer.

  7. Organizations as agents of social change

    National Research Council Canada - National Science Library

    D'Souza, Keith C

    1984-01-01

    Organizations have an important role to play as agents of social change and developement, particularly in developing countries in which changes in social conditions are often prerequisites for growth...

  8. Argumentation and Multi-Agent Decision Making

    OpenAIRE

    Parsons, S; Jennings, NR

    1998-01-01

    This paper summarises our on-going work on mixed- initiative decision making which extends both classical decision theory and a symbolic theory of decision making based on argumentation to a multi-agent domain.

  9. Learning-by-Teaching: Designing Teachable Agents with Intrinsic Motivation

    Science.gov (United States)

    Zhao, Guopeng; Ailiya; Shen, Zhiqi

    2012-01-01

    Teachable agent is a type of pedagogical agent which instantiates Learning-by-Teaching theory through simulating a "naive" learner in order to motivate students to teach it. This paper discusses the limitation of existing teachable agents and incorporates intrinsic motivation to the agent model to enable teachable agents with initiative…

  10. Influence-based autonomy levels in agent Decision-making

    NARCIS (Netherlands)

    Vecht, B. van der; Meyer, A.P.; Neef, R.M.; Dignum, F.; Meyer, J.J.C.

    2007-01-01

    Autonomy is a crucial and powerful feature of agents and it is the subject of much research in the agent field. Controlling the autonomy of agents is a way to coordinate the behavior of groups of agents. Our approach is to look at it as a design problem for agents. We analyze the autonomy of an

  11. Influence-Based Autonomy Levels in Agent Decision-Making

    NARCIS (Netherlands)

    Vecht, B. van der; Meyer, A.P.; Neef, R.M.; Dignum, F.; Meyer, J.J.C.

    2006-01-01

    Autonomy is a crucial and powerful feature of agents and it is the subject of much research in the agent field. Controlling the autonomy of agents is a way to coordinate the behavior of groups of agents. Our approach is to look at it as a design problem for agents. We analyze the autonomy of an

  12. inventory management, VMI, software agents, MDV model

    Directory of Open Access Journals (Sweden)

    Waldemar Wieczerzycki

    2012-03-01

    Full Text Available Background: As it is well know, the implementation of instruments of logistics management is only possible with the use of the latest information technology. So-called agent technology is one of the most promising solutions in this area. Its essence consists in an entirely new way of software distribution on the computer network platform, in which computer exchange among themselves not only data, but also software modules, called just agents. The first aim is to propose the alternative method of the implementation of the concept of the inventory management by the supplier with the use of intelligent software agents, which are able not only to transfer the information but also to make the autonomous decisions based on the privileges given to them. The second aim of this research was to propose a new model of a software agent, which will be both of a high mobility and a high intelligence. Methods: After a brief discussion of the nature of agent technology, the most important benefits of using it to build platforms to support business are given. Then the original model of polymorphic software agent, called Multi-Dimensionally Versioned Software Agent (MDV is presented, which is oriented on the specificity of IT applications in business. MDV agent is polymorphic, which allows the transmission through the network only the most relevant parts of its code, and only when necessary. Consequently, the network nodes exchange small amounts of software code, which ensures high mobility of software agents, and thus highly efficient operation of IT platforms built on the proposed model. Next, the adaptation of MDV software agents to implementation of well-known logistics management instrument - VMI (Vendor Managed Inventory is illustrated. Results: The key benefits of this approach are identified, among which one can distinguish: reduced costs, higher flexibility and efficiency, new functionality - especially addressed to business negotiation, full automation

  13. A multi-agent based cell controller

    OpenAIRE

    Paulo Leitão; Francisco José de Oliveira Restivo; Goran Putnik

    2001-01-01

    This paper discusses the opportunity to use multi-agents technology in automation and distributed manufacturing systems and the expected improvements. To support the discussion, it is described a manufacturing cell control application developed using the multi-agent technology, and the results are compared with other control application developed in the past by some of the authors, using a traditional approach, for the same flexible manufacturing cell.

  14. Pythagoras: An Agent-Based Simulation Environment

    OpenAIRE

    Henscheid, Zoe; Middleton, Donna; Bitinas, Edmund

    2006-01-01

    from Scythe : Proceedings and Bulletin of the International Data Farming Community, Issue 1 Workshop 13 NetLogo is a freely available agent-based modeling environment being developed by Northwestern University’s Center for Connected Learning (ccl.northwestern.edu/ netlogø). NetLogo is an excellent environment for creating simpler or smaller-scale agent-based models or prototyping more complex models. NetLogo’s strengths include using a very easy to learn and flexible ...

  15. Institutions, Behavior of Agents and Efficiency

    Directory of Open Access Journals (Sweden)

    Sukharev Oleg, S.

    2016-03-01

    Full Text Available We study the efficiency criterion, describing the behavior and choices of agents, the influence of moral norms on the model of behavior, as well as the criterion of efficiency as an institution to assess the behavior and development of the economic system. Curve proposed institutional compromise that allows to determine the possibility of changes in the welfare of interacting agents and their compliance with ethical standards when welfare increases due to violation or compliance with these standards. For the purposes of this demonstration of the influence of the model of chart-based dilemmas Holmes-Moriarty. Incentives in determining the agents behaviors play a key role in their formation due to the moral principles of behavior. However, in economics there are situations when moral principles are derived certain behaviors or interactions agents. Holmes and Moriarty there is an alternative interaction, which they can not take advantage of, and there is a full range of alternatives that actually programs the strategic outcomes of interactions that reflect the curves of "institutional compromise." Choosing an agent of moral standards as a potential model determines its behavior and, most importantly, interaction with other agents, adhering to certain moral principles. Assess the condition and the possibility of using a static criterion of Pareto efficiency for the analysis of situations where it is important to measure the economic efficiency. Showing institutional aspects that must be considered in the application or formulation of new performance criteria. It is proved that there is a connection microeconomic efficiency / inefficiency and parameters of behavior of agents that actualizes the need to impact on the behavior of agents incentives to solve the task of changing the structure.

  16. Agent-Based Models of Organizations

    OpenAIRE

    Chang, Myong-Hun; Joseph E. Harrington

    2004-01-01

    An organization is a collection of agents that interact and produce some form of output. Formal organizations - such as corporations and governments - are typically constructed for an explicit purpose though this purpose needn’t be shared by all organizational members. An entrepreneur who creates a firm may do so in order to generate personal wealth but the worker she hires may have very different goals. As opposed to more amorphous collections of agents such as friendship networks and societ...

  17. New Safety rule for Chemical Agents

    CERN Multimedia

    Safety Commission

    2010-01-01

    The following Safety rule has been issued on 08-01-2010: Safety Regulation SR-C Chemical Agents This document applies to all persons under the Director General’s authority. It sets out the minimal requirements for the protection of persons from risks to their safety and health arising, or likely to arise, from the effects of hazardous chemical agents used in any CERN activity. All Safety rules are available on the web pages.

  18. Corticosteroid-sparing agents: conventional systemic immunosuppressants.

    Science.gov (United States)

    Kruh, Jonathan; Foster, C Stephen

    2012-01-01

    The introduction of corticosteroids in the mid-20th century to control inflammatory eye disease revolutionized treatment practices. As long-term use of corticosteroids became the backbone of immunosuppressive therapy, it soon became evident that it was associated with significant morbidity to the patient. For this reason, other immunosuppressant agents were sought. Thereafter, the first generation of immunosuppressive agents were born. The main action of all such agents involves the inhibition of lymphoid proliferation. The agents can be further subdivided into the following categories based on their specific mechanism of action: alkylating (cyclophosphamide and chlorambucil), antimetabolite (methotrexate, mycophenolate mofetil and azathioprine), and antibiotic/calcineurin inhibitor (cyclosporine, tacrolimus and sirolimus). These immunomodulating agents serve as the foundation to modern corticosteroid-sparing immunosuppressive therapy. Many times, these agents are now even indicated as first-line therapy for the treatment of systemic inflammatory diseases with destructive ocular sequela, e.g. Behçet's disease and granulomatosis with polyangiitis (Wegener's). Choosing the most appropriate immunomodulatory agent to initiate therapy can often be difficult; a multifactorial approach in the decision-making process is essential. Special attention must be given to the patient's medical history, type and severity of inflammatory disease, social history, compliance, age, and sex. Oftentimes, it takes a joint effort between the ophthalmologist and multiple sub-specialists (rheumatology, oncology, and hematology) to administer and monitor these therapies. Even though each of these systemic immunosuppressive agents has its own array of potential side effects, with careful monitoring and titration of dosages, such potential side effects can be minimized or avoided altogether. Ultimately, these patients are afforded a much more favorable long-term outcome, free of the

  19. A review of imaging agent development.

    Science.gov (United States)

    Agdeppa, Eric D; Spilker, Mary E

    2009-06-01

    This educational review highlights the processes, opportunities, and challenges encountered in the discovery and development of imaging agents, mainly positron emission tomography and single-photon emission computed tomography tracers. While the development of imaging agents parallels the drug development process, unique criteria are needed to identify opportunities for new agents. Imaging agent development has the flexibility to pursue functional or nonfunctional targets as long as they play a role in the specific disease or mechanism of interest and meet imageability requirements. However, their innovation is tempered by relatively small markets for diagnostic imaging agents, intellectual property challenges, radiolabeling constraints, and adequate target concentrations for imaging. At the same time, preclinical imaging is becoming a key translational tool for proof of mechanism and concept studies. Pharmaceutical and imaging industries face a common bottleneck in the form of the limited number of trials one company can possibly perform. However, microdosing and theranostics are evidence that partnerships between pharmaceutical and imaging companies can accelerate clinical translation of tracers and therapeutic interventions. This manuscript will comment on these aspects to provide an educational review of the discovery and development processes for imaging agents.

  20. Reaching High Interactive Levels with Situated Agents

    Directory of Open Access Journals (Sweden)

    Guzmán-Obando J.

    2013-01-01

    Full Text Available El documento presenta un proceso coordinado a través del cual los agentes situados son capaces de trabajar en forma conjunta con el conocimiento de sus habilidades para interactuar con otras entidades similares. Una buena coordinación se deriva de que cada agente situado es capaz de representar sus tasas de idoneidad para llevar a cabo cualquier acción de una manera eficaz. Además de utilizar dichas tasas, un agente puede coordinar sus acciones con otros agentes. En este sentido, cada agente situado trata de seleccionar y realizar sólo las acciones con los mayores índices de ejecución. Algunos experimentos en un verdadero fútbol robótico banco de pruebas están diseñadas para poner en práctica el enfoque coordinado propuesto. Observaciones finales concluir la eficacia y las ventajas de la obra presentada con el fin de aumentar el rendimiento de un equipo integrado por agentes situados cuando tienen que resolver tareas complejas en un escenario dinámico, competitivo e impredecible.

  1. Current clinical use of depigmenting agents

    Directory of Open Access Journals (Sweden)

    Jung Won Shin

    2014-12-01

    Full Text Available A variety of topical depigmenting agents have been used clinically, with varying degrees of success. To date, the most effective topical treatment is a triple-combination agent containing hydroquinone (HQ, tretinoin, and fluocinolone acetonide. However, its use is associated with relatively high frequencies of adverse reactions, and therefore there is a necessity to produce effective topical depigmenting agents with fewer adverse effects. Several processes can be targeted for the treatment of hyperpigmentation; specifically, regulation of melanogenesis by inhibiting tyrosinase activity, a key enzyme in melanin synthesis, represents a major therapeutic target. Another option is regulation of melanosomes by manipulation of their formation or transfer. In addition, depigmenting agents can act through antioxidant or anti-inflammatory activities. We compared the tyrosinase inhibitory activity and cytotoxicity of HQ with those of other cosmetic ingredients. The results showed that although HQ was a strong tyrosinase inhibitor, it was cytotoxic at high concentrations. By contrast, 4-n-butylresorcinol effectively controlled tyrosinase activity without showing toxicity at high concentrations. These findings indicated that 4-n-butylresorcinol had the potential to act as an effective depigmenting agent, while producing less irritation than the currently available agents.

  2. Using Cognitive Agents to Train Negotiation Skills

    Directory of Open Access Journals (Sweden)

    Christopher A. Stevens

    2018-02-01

    Full Text Available Training negotiation is difficult because it is a complex, dynamic activity that involves multiple parties. It is often not clear how to create situations in which students can practice negotiation or how to measure students' progress. Some have begun to address these issues by creating artificial software agents with which students can train. These agents have the advantage that they can be “reset,” and played against multiple times. This allows students to learn from their mistakes and try different strategies. However, these agents are often based on normative theories of how negotiators should conduct themselves, not necessarily how people actually behave in negotiations. Here, we take a step toward addressing this gap by developing an agent grounded in a cognitive architecture, ACT-R. This agent contains a model of theory-of-mind, the ability of humans to reason about the mental states of others. It uses this model to try to infer the strategy of the opponent and respond accordingly. In a series of experiments, we show that this agent replicates some aspects of human performance, is plausible to human negotiators, and can lead to learning gains in a small-scale negotiation task.

  3. Agent-based modeling and network dynamics

    CERN Document Server

    Namatame, Akira

    2016-01-01

    The book integrates agent-based modeling and network science. It is divided into three parts, namely, foundations, primary dynamics on and of social networks, and applications. The book begins with the network origin of agent-based models, known as cellular automata, and introduce a number of classic models, such as Schelling’s segregation model and Axelrod’s spatial game. The essence of the foundation part is the network-based agent-based models in which agents follow network-based decision rules. Under the influence of the substantial progress in network science in late 1990s, these models have been extended from using lattices into using small-world networks, scale-free networks, etc. The book also shows that the modern network science mainly driven by game-theorists and sociophysicists has inspired agent-based social scientists to develop alternative formation algorithms, known as agent-based social networks. The book reviews a number of pioneering and representative models in this family. Upon the gi...

  4. Unibot, a Universal Agent Architecture for Robots

    Directory of Open Access Journals (Sweden)

    Saša Mladenović

    2017-01-01

    Full Text Available Today there are numerous robots in different applications domains despite the fact that they still have limitations in perception, actuation and decision process. Consequently, robots usually have limited autonomy, they are domain specific or have difficulty to adapt on new environments. Learning is the property that makes an agent intelligent and the crucial property that a robot should have to proliferate into the human society. Embedding the learning ability into the robot may simplify the development of the robot control mechanism. The motivation for this research is to develop the agent architecture of the universal robot – Unibot. In our approach the agent is the robot i.e. Unibot that acts in the physical world and is capable of learning. The Unibot conducts several simultaneous simulations of a problem of interest like path-finding. The novelty in our approach is the Multi-Agent Decision Support System which is developed and integrated into the Unibot agent architecture in order to execute simultaneous simulations. Furthermore, the Unibot calculates and evaluates between multiple solutions, decides which action should be performed and performs the action. The prototype of the Unibot agent architecture is described and evaluated in the experiment supported by the Lego Mindstorms robot and the NetLogo.

  5. CHI: A General Agent Communication Framework

    Energy Technology Data Exchange (ETDEWEB)

    Goldsmith, S.Y.; Phillips, L.R.; Spires, S.V.

    1998-12-17

    We have completed and exercised a communication framework called CHI (CLOS to HTML Interface) by which agents can communicate with humans. CHI follows HTTP (HyperText Transfer Protocol) and produces HTML (HyperText Markup Language) for use by WWW (World-Wide Web) browsers. CHI enables the rapid and dynamic construction of interface mechanisms. The essence of CHI is automatic registration of dynamically generated interface elements to named objects in the agent's internal environment. The agent can access information in these objects at will. State is preserved, so an agent can pursue branching interaction sequences, activate failure recovery behaviors, and otherwise act opportunistically to maintain a conversation. The CHI mechanism remains transparent in multi-agent, multi-user environments because of automatically generated unique identifiers built into the CHI mechanism. In this paper we discuss design, language, implementation, and extension issues, and, by way of illustration, examine the use of the general CHI/HCHI mechanism in a specific international electronic commerce system. We conclude that the CHI mechanism is an effective, efficient, and extensible means of the agent/human communication.

  6. History of chemical and biological warfare agents.

    Science.gov (United States)

    Szinicz, L

    2005-10-30

    Chemical and biological warfare agents constitute a low-probability, but high-impact risk both to the military and to the civilian population. The use of hazardous materials of chemical or biological origin as weapons and for homicide has been documented since ancient times. The first use of chemicals in terms of weapons of mass destruction goes back to World War I, when on April 22, 1915 large amounts of chlorine were released by German military forces at Ypres, Belgium. Until around the 1970s of the 20th century, the awareness of the threat by chemical and biological agents had been mainly confined to the military sector. In the following time, the development of increasing range delivery systems by chemical and biological agents possessors sensitised public attention to the threat emanating from these agents. Their proliferation to the terrorists field during the 1990s with the expanding scale and globalisation of terrorist attacks suggested that these agents are becoming an increasing threat to the whole world community. The following article gives a condensed overview on the history of use and development of the more prominent chemical and biological warfare agents.

  7. Intelligent agents for e-commerce applications

    Science.gov (United States)

    Vuppala, Krishna

    1999-12-01

    This thesis focuses on development of intelligent agent solutions for e-commerce applications. E-Commerce has several complexities like: lack of information about the players, learning the nature of one's business partners/competitors, finding the right business partner to do business with, using the right strategy to get best profit out of the negotiations etc. The agent models developed can be used in any agent solution for e-commerce. Concepts and techniques from Game Theory and Artificial Intelligence are used. The developed models have several advantages over the existing ones as: the models assume the non-availability of information about other players in the market, the models of players get updated over the time as and when new information comes about the players, the negotiation model incorporates the patience levels of the players and expectations from other players in the market. Power industry has been chosen as the application area for the demonstration of the capabilities and usage of the developed agent models. Two e-commerce scenarios where sellers and buyers can go through the power exchanges to bid in auctions, or make bilateral deals outside of the exchange are addressed. In the first scenario agent helps market participants in coordinating strategies with other participants, bidding in auctions by analyzing and understanding the behavior of other participants. In the second scenario, called "Power Traders Assistant" agent helps power trader, who buys and sells power through bilateral negotiations, in negotiating deals with his customers.

  8. Transfection Agent Induced Nanoparticle Cell Loading

    Directory of Open Access Journals (Sweden)

    Karin Montet-Abou

    2005-07-01

    Full Text Available Loading cells with magnetic nanoparticles, and tracking their fate in vivo by high resolution MRI, is an attractive approach for enhancing the efficacy of cell-based therapies including those utilizing hematopoietic stem cells, neuroprogenitor cells, and T cells. The transfection agent (internalization agent assisted loading with the Feridex IV® nanoparticle is an attractive method of loading because of the low cost of materials, and possible low regulatory barriers for eventual clinical use. We therefore explored the interaction between Feridex IV® and three internalization agents protamine (PRO, polylysine (PLL, and lipofectamine (LFA. Feridex reacted with internalization agents to form aggregates, except when either the internalization agent or Feridex was present in large excess. When Jurkat T cells were incubated with Feridex/LFA or Feridex/PRO mixtures, and washed by centrifugation, nanoparticle aggregates co-purified with cells. With C17.2 cells large iron oxide particles adhered to the cell surface. At 30 μg/mL Feridex and 3 μg/mL LFA, internalization was largely mediated by LFA and was largely cytoplasmic. However, we found that the conditions used to label cells with Feridex and transfection agents need to be carefully selected to avoid the problems of surface adsorption and nanoparticle precipitation.

  9. Scolicidal Agents in Hydatid Cyst Surgery

    Directory of Open Access Journals (Sweden)

    H. Besim

    1998-01-01

    Full Text Available Injecting scolicidal solutions into the hydatid cyst and packing the operative field with sponges soaked in scolicidal agents have been used to avoid dissemination of the parasite during surgery. In the first part of this invitro study, we tried to determine the scolicidal property of various agents in different concentrations and exposure times. In the second part, we tested whether sponges soaked in different type and concentrations of scolicidal agents have any role beyond being a mechanical barrier. 20% saline, 3% hydrogen peroxide, 1.5% cetrimide-0.15% chlorhexidine (10% Savlon®, 95% ethyl alcohol, 10% polyvinylpirrolidone-iodine (Betadine® and their further dilutions were used in this study. Protoscoleces were obtained from the cyst containing livers of the sheep and viability was determined with dye-uptake (0.1% Eosin and flame cell activity. Savlon® was found to be the least concentration dependent scolicidal agent among those studied. Scoleces sprayed on sponges soaked in 20% saline, 95% ethyl alcohol, Betadine® and 3% hydrogen peroxide were killed after 15 minutes. 3% and 10% saline and normal saline were ineffective. Sponges work not only as a mechanical barrier but also as a chemical one if the agent is chosen correctly. In purely cystic hydatid liver disease, the risk of dissemination of the cyst contents can be avoided by injection of a potent scolicidal agent such as Savlon®.

  10. Algebraic Model for Agent Explicit Knowledge in Multi-agent Systems

    OpenAIRE

    Sabri, Khair Eddin; Khedri, Ridha; Jaskolka, Jason

    2009-01-01

    In this chapter, we present a structure to specify agent explicit knowledge based on information algebra. We define in the context of agent knowledge the combining, marginalizing, and labelling operators. Also, we define remove and frame substitution operator. These operators are all what is needed to express operations on agent explicit knowledge. We also define a set of frames to be associated with information. Then, we prove that our structure is an information algebra which links our work...

  11. Drug-Based Optical Agents : Infiltrating Clinics at Lower Risk

    NARCIS (Netherlands)

    Scheuer, Werner; van Dam, Gooitzen M.; Dobosz, Michael; Schwaiger, Markus; Ntziachristos, Vasilis

    2012-01-01

    Fluorescent agents with specificity to cellular and subcellular moieties present promise for enhancing diagnostics and theranostics, yet challenges associated with regulatory approvals of experimental agents stifle the clinical translation. As a result, targeted fluorescent agents have remained

  12. Cancer chemotherapeutic agents as human teratogens.

    Science.gov (United States)

    Selig, Brady P; Furr, James R; Huey, Ryan W; Moran, Colin; Alluri, Vinod N; Medders, Gregory R; Mumm, Christina D; Hallford, H Gene; Mulvihill, John J

    2012-08-01

    Cancer is the second leading cause of death among women of reproductive age. Although the coincidence of pregnancy and cancer is rare and treatment may sometimes be safely delayed, the use of chemotherapeutic agents in pregnancy is sometimes unavoidable or inadvertent. We review the literature for the use of antineoplastic agents in single-agent and combination therapy from 1951 through June 2012. We also summarize the evidence relating to teratogenicity of disorder-specific combination chemotherapy treatments for those malignancies frequently encountered in women of childbearing age. Major endpoints were called "adverse pregnancy outcomes" (APOs), to include structural anomalies (congenital malformations), functional defects, blood or electrolyte abnormalities, stillbirths, spontaneous abortions (miscarriages), and fetal, neonatal, or maternal deaths. The registry totals 863 cases. Rates of APOs (and congenital malformations) after any exposure were 33% (16%), 27% (8%), and 25% (6%), for first, second, and third trimesters. Among the groups of cancer drugs, antimetabolites and alkylating agents have the highest rates of APOs. Mitotic inhibitors and antibiotics seem more benign. Mixed results were observed from single-agent exposure, often because of small numbers of exposures. As a whole, the alkylating agents and antimetabolites are more harmful when given as a single agent rather than as part of a regimen. First-trimester exposure poses a more permanent risk to the fetus. Systematic ascertainment of women early in pregnancy, preferably in a population base, is needed for assessment of true risks. Long-term follow-up is needed to rule out neurobehavioral effects. Copyright © 2012 Wiley Periodicals, Inc.

  13. In vitro penetration of bleaching agents into the pulp chamber

    DEFF Research Database (Denmark)

    Benetti, Ana Raquel; Valera, M C; Mancini, M N G

    2004-01-01

    To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures.......To investigate pulp chamber penetration of bleaching agents in teeth following restorative procedures....

  14. Environmental Agents Service (EAS) Registry System of Records

    Data.gov (United States)

    Department of Veterans Affairs — The Environmental Agent Service (EAS) Registries is the information system encompassing the Ionizing Radiation Registry (IRR), the Agent Orange Registry (AOR), and...

  15. 2015 Special Sessions of the 13th International Conference on Practical Applications of Agents and Multi-Agent Systems

    CERN Document Server

    Hernández, Josefa; Mathieu, Philippe; Campbell, Andrew; Fernández-Caballero, Antonio; Moreno, María; Julián, Vicente; Alonso-Betanzos, Amparo; Jiménez-López, María; Botti, Vicente; Trends in Practical Applications of Agents, Multi-Agent Systems and Sustainability : the PAAMS Collection

    2015-01-01

    This volume presents the papers that have been accepted for the 2015 special sessions of the 13th International Conference on Practical Applications of Agents and Multi-Agent Systems, held at University of Salamanca, Spain, at 3rd-5th June, 2015: Agents Behaviours and Artificial Markets (ABAM); Agents and Mobile Devices (AM); Multi-Agent Systems and Ambient Intelligence (MASMAI); Web Mining and Recommender systems (WebMiRes); Learning, Agents and Formal Languages (LAFLang); Agent-based Modeling of Sustainable Behavior and Green Economies (AMSBGE); Emotional Software Agents (SSESA) and Intelligent Educational Systems (SSIES). The volume also includes the paper accepted for the Doctoral Consortium in PAAMS 2015. PAAMS, the International Conference on Practical Applications of Agents and Multi-Agent Systems is an evolution of the International Workshop on Practical Applications of Agents and Multi-Agent Systems. PAAMS is an international yearly tribune to present, to discuss, and to disseminate the latest develo...

  16. Agent Based Modeling Applications for Geosciences

    Science.gov (United States)

    Stein, J. S.

    2004-12-01

    Agent-based modeling techniques have successfully been applied to systems in which complex behaviors or outcomes arise from varied interactions between individuals in the system. Each individual interacts with its environment, as well as with other individuals, by following a set of relatively simple rules. Traditionally this "bottom-up" modeling approach has been applied to problems in the fields of economics and sociology, but more recently has been introduced to various disciplines in the geosciences. This technique can help explain the origin of complex processes from a relatively simple set of rules, incorporate large and detailed datasets when they exist, and simulate the effects of extreme events on system-wide behavior. Some of the challenges associated with this modeling method include: significant computational requirements in order to keep track of thousands to millions of agents, methods and strategies of model validation are lacking, as is a formal methodology for evaluating model uncertainty. Challenges specific to the geosciences, include how to define agents that control water, contaminant fluxes, climate forcing and other physical processes and how to link these "geo-agents" into larger agent-based simulations that include social systems such as demographics economics and regulations. Effective management of limited natural resources (such as water, hydrocarbons, or land) requires an understanding of what factors influence the demand for these resources on a regional and temporal scale. Agent-based models can be used to simulate this demand across a variety of sectors under a range of conditions and determine effective and robust management policies and monitoring strategies. The recent focus on the role of biological processes in the geosciences is another example of an area that could benefit from agent-based applications. A typical approach to modeling the effect of biological processes in geologic media has been to represent these processes in

  17. Electrospun biodegradable polymers loaded with bactericide agents

    Directory of Open Access Journals (Sweden)

    Ramaz Katsarava

    2016-03-01

    Full Text Available Development of materials with an antimicrobial activity is fundamental for different sectors, including medicine and health care, water and air treatment, and food packaging. Electrospinning is a versatile and economic technique that allows the incorporation of different natural, industrial, and clinical agents into a wide variety of polymers and blends in the form of micro/nanofibers. Furthermore, the technique is versatile since different constructs (e.g. those derived from single electrospinning, co-electrospinning, coaxial electrospinning, and miniemulsion electrospinning can be obtained to influence the ability to load agents with different characteristics and stability and to modify the release behaviour. Furthermore, antimicrobial agents can be loaded during the electrospinning process or by a subsequent coating process. In order to the mitigate burst release effect, it is possible to encapsulate the selected drug into inorganic nanotubes and nanoparticles, as well as in organic cyclodextrine polysaccharides. In the same way, processes that involve covalent linkage of bactericide agents during surface treatment of electrospun samples may also be considered. The present review is focused on more recent works concerning the electrospinning of antimicrobial polymers. These include chitosan and common biodegradable polymers with activity caused by the specific load of agents such as metal and metal oxide particles, quaternary ammonium compounds, hydantoin compounds, antibiotics, common organic bactericides, and bacteriophages.

  18. Smell Detection Agent Based Optimization Algorithm

    Science.gov (United States)

    Vinod Chandra, S. S.

    2016-09-01

    In this paper, a novel nature-inspired optimization algorithm has been employed and the trained behaviour of dogs in detecting smell trails is adapted into computational agents for problem solving. The algorithm involves creation of a surface with smell trails and subsequent iteration of the agents in resolving a path. This algorithm can be applied in different computational constraints that incorporate path-based problems. Implementation of the algorithm can be treated as a shortest path problem for a variety of datasets. The simulated agents have been used to evolve the shortest path between two nodes in a graph. This algorithm is useful to solve NP-hard problems that are related to path discovery. This algorithm is also useful to solve many practical optimization problems. The extensive derivation of the algorithm can be enabled to solve shortest path problems.

  19. Kampus Islam Sebagai Agent Of Change

    Directory of Open Access Journals (Sweden)

    M. Fahim Tharaba

    2013-09-01

    Full Text Available A man is Abdullah and Khalifatullah, he must understand, internalize, apply, and adopt Islamic values in his believe. Therefore, it requires two comitment, firstly, a comitment to Allah (habl min Allah and comitment to other human (habl min an-nas and habl min al-alam. The Islamic campus not only has a role as an “agent of concervation” but also producer of an “agent of change”. These agents should be equipped by the universal and objective values (nilai Ilahiyah which live in our tradition. These values should be configured and adapted through the time, condition, and place. Similarly, local values and subjectif values (nilai insaniyah should be modified and dynimicaly changed to meet the present needs of the sosiety. The campus (education gives should preserve and sustain values in the right position and place.

  20. Autonomous Formations of Multi-Agent Systems

    Science.gov (United States)

    Dhali, Sanjana; Joshi, Suresh M.

    2013-01-01

    Autonomous formation control of multi-agent dynamic systems has a number of applications that include ground-based and aerial robots and satellite formations. For air vehicles, formation flight ("flocking") has the potential to significantly increase airspace utilization as well as fuel efficiency. This presentation addresses two main problems in multi-agent formations: optimal role assignment to minimize the total cost (e.g., combined distance traveled by all agents); and maintaining formation geometry during flock motion. The Kuhn-Munkres ("Hungarian") algorithm is used for optimal assignment, and consensus-based leader-follower type control architecture is used to maintain formation shape despite the leader s independent movements. The methods are demonstrated by animated simulations.

  1. Anti-Infectious Agents against MRSA

    Directory of Open Access Journals (Sweden)

    Nobuhiro Koyama

    2012-12-01

    Full Text Available Clinically useful antibiotics, β-lactams and vancomycin, are known to inhibit bacterial cell wall peptidoglycan synthesis. Methicillin-resistant Staphylococcus aureus (MRSA has a unique cell wall structure consisting of peptidoglycan and wall teichoic acid. In recent years, new anti-infectious agents (spirohexaline, tripropeptin C, DMPI, CDFI, cyslabdan, 1835F03, and BPH-652 targeting MRSA cell wall biosynthesis have been discovered using unique screening methods. These agents were found to inhibit important enzymes involved in cell wall biosynthesis such as undecaprenyl pyrophosphate (UPP synthase, FemA, flippase, or UPP phosphatase. In this review, the discovery, the mechanism of action, and the future of these anti-infectious agents are described.

  2. Network Management using Multi-Agents System

    Directory of Open Access Journals (Sweden)

    Nestor DUQUE

    2013-07-01

    Full Text Available This paper aims to present a multiagent system for network management. The models developed for the proposed system defines certain intelligent agents interact to achieve the objectives and requirements of the multiagent organization.These agents have the property of being adaptive, acquire knowledge and skills to make decisions according to the actual state of the network that is represented in the information base, MIB, SNMP devices. The ideal state of the network policy is defined by the end user entered, which contain the value that should have performance variables and other parameters such as the frequency with which these variables should be monitored.. An agent based architecture increase the integration, adaptability, cooperation, autonomy and the efficient operation in heterogeneous environment in the network supervision. 

  3. Network Management using Multi-Agents System

    Directory of Open Access Journals (Sweden)

    Gustavo ISAZA

    2012-12-01

    Full Text Available This paper aims to present a multiagent system for network management. The models developed for the proposed system defines certain intelligent agents interact to achieve the objectives and requirements of the multiagent organization.These agents have the property of being adaptive, acquire knowledge and skills to make decisions according to the actual state of the network that is represented in the information base, MIB, SNMP devices. The ideal state of the network policy is defined by the end user entered, which contain the value that should have performance variables and other parameters such as the frequency with which these variables should be monitored.. An agent based architecture increase the integration, adaptability, cooperation, autonomy and the efficient operation in heterogeneous environment in the network supervision. 

  4. Planning of Autonomous Multi-agent Intersection

    Directory of Open Access Journals (Sweden)

    Viksnin Ilya I.

    2016-01-01

    Full Text Available In this paper, we propose a traffic management system with agents acting on behalf autonomous vehicle at the crossroads. Alternatively to existing solutions based on usage of semiautonomous control systems with the control unit, proposed in this paper algorithm apply the principles of decentralized multi-agent control. Agents during their collaboration generate intersection plan and determinate the optimal order of road intersection for a given criterion based on the exchange of information about them and their environment. The paper contains optimization criteria for possible routes selection and experiments that perform in order to estimate the proposed model. Experiment results show that this model can significantly reduce traffic density compared to the traditional traffic management systems. Moreover, the proposed algorithm efficiency increases with road traffic density. Furthermore, the availability of control unit in the system significantly reduces the negative impact of possible failures and hacker attacks.

  5. Glutamic acid as anticancer agent: An overview.

    Science.gov (United States)

    Dutta, Satyajit; Ray, Supratim; Nagarajan, K

    2013-10-01

    The objective of the article is to highlight various roles of glutamic acid like endogenic anticancer agent, conjugates to anticancer agents, and derivatives of glutamic acid as possible anticancer agents. Besides these emphases are given especially for two endogenous derivatives of glutamic acid such as glutamine and glutamate. Glutamine is a derivative of glutamic acid and is formed in the body from glutamic acid and ammonia in an energy requiring reaction catalyzed by glutamine synthase. It also possesses anticancer activity. So the transportation and metabolism of glutamine are also discussed for better understanding the role of glutamic acid. Glutamates are the carboxylate anions and salts of glutamic acid. Here the roles of various enzymes required for the metabolism of glutamates are also discussed.

  6. PRODUCTION OPTIMIZATION USING AGENT-BASED SYSTEM

    Directory of Open Access Journals (Sweden)

    Aleksandar Vujovic

    2016-03-01

    Full Text Available Production systems suffer frequent changes due to the growing demand and need for providing market competitiveness. Therefore, the application of intelligent systems can greatly increase the level of flexibility and efficiency, but also reduce the overall costs. On example of system for the production of irregular and variable shaped parts by cutting the wooden flat surfaces, it is discussed the possibility of applying intelligent agent-based system. In order to implement it in the production process, it was necessary to firstly performed an analysis and assessment of the initial situation. Then, we spotted a weak points and gave some suggestions to improve process by application of agents. The obtained solution has reduced the number of engaged workers, reduced the scope of their duties, made faster flow of materials, improved its utilization and we finally introduced the scheme of the new agent-based manufacturing process that achieves the foregoing benefits.

  7. Agents That Negotiate Proficiently with People

    Science.gov (United States)

    Kraus, Sarit

    Negotiation is a process by which interested parties confer with the aim of reaching agreements. The dissemination of technologies such as the Internet has created opportunities for computer agents to negotiate with people, despite being distributed geographically and in time. The inclusion of people presents novel problems for the design of autonomous agent negotiation strategies. People do not adhere to the optimal, monolithic strategies that can be derived analytically, as is the case in settings comprising computer agents alone. Their negotiation behavior is affected by a multitude of social and psychological factors, such as social attributes that influence negotiation deals (e.g., social welfare, inequity aversion) and traits of individual negotiators (e.g., altruism, trustworthiness, helpfulness). Furthermore, culture plays an important role in their decision making and people of varying cultures differ in the way they make offers and fulfill their commitments in negotiation.

  8. ECONOMÍA COMPUTACIONAL BASADA EN AGENTES

    Directory of Open Access Journals (Sweden)

    FABIÁN ANDRÉS GIRALDO GIRALDO

    2012-12-01

    Full Text Available El artículo tiene como objetivo mostrarvarios trabajos de investigación sobre un enfoque desimulación denominado Economía computacional basadaen agentes, el cual rechaza las asunciones delos enfoques de estudio tradicionales que indican quela economía es un sistema cerrado que eventualmentelogra un estado de equilibrio, en el que deben realizarsesupuestos de racionalidad perfecta e inversioneshomogéneas para que los modelos sean tratadosanalíticamente. En su lugar, ve a la economía comoun sistema complejo, adaptativo y dinámico. Estenuevo enfoque permite usar la simulación basada enagentes para comprender que varios agentes económicos(firmas, grupos económicos con sus propiasreglas y objetivos, son capaces de interactuar entresí y con su entorno para obtener comportamientosemergentes que no son explicables directamente delas propiedades de los agentes individuales.

  9. Quantum Speedup for Active Learning Agents

    Directory of Open Access Journals (Sweden)

    Giuseppe Davide Paparo

    2014-07-01

    Full Text Available Can quantum mechanics help us build intelligent learning agents? A defining signature of intelligent behavior is the capacity to learn from experience. However, a major bottleneck for agents to learn in real-life situations is the size and complexity of the corresponding task environment. Even in a moderately realistic environment, it may simply take too long to rationally respond to a given situation. If the environment is impatient, allowing only a certain time for a response, an agent may then be unable to cope with the situation and to learn at all. Here, we show that quantum physics can help and provide a quadratic speedup for active learning as a genuine problem of artificial intelligence. This result will be particularly relevant for applications involving complex task environments.

  10. FIPA agent based network distributed control system

    Energy Technology Data Exchange (ETDEWEB)

    D. Abbott; V. Gyurjyan; G. Heyes; E. Jastrzembski; C. Timmer; E. Wolin

    2003-03-01

    A control system with the capabilities to combine heterogeneous control systems or processes into a uniform homogeneous environment is discussed. This dynamically extensible system is an example of the software system at the agent level of abstraction. This level of abstraction considers agents as atomic entities that communicate to implement the functionality of the control system. Agents' engineering aspects are addressed by adopting the domain independent software standard, formulated by FIPA. Jade core Java classes are used as a FIPA specification implementation. A special, lightweight, XML RDFS based, control oriented, ontology markup language is developed to standardize the description of the arbitrary control system data processor. Control processes, described in this language, are integrated into the global system at runtime, without actual programming. Fault tolerance and recovery issues are also addressed.

  11. Animated Pedagogical Agents: A Review of Agent Technology Software in Electronic Learning Environments

    Science.gov (United States)

    Govindasamy, Malliga K.

    2014-01-01

    Agent technology has become one of the dynamic and most interesting areas of computer science in recent years. The dynamism of this technology has resulted in computer generated characters, known as pedagogical agent, entering the digital learning environments in increasing numbers. Commonly deployed in implementing tutoring strategies, these…

  12. An Interactive Tool for Creating Multi-Agent Systems and Interactive Agent-based Games

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Pagliarini, Luigi

    2011-01-01

    . The modular and physical property of the tiles provides students with hands-on experience in exploring the theoretical aspects underlying multi-agent systems which often appear as challenging to students. By changing the representation of the cognitive challenging aspects of multi-agent systems education...

  13. Nondestructive Intervention to Multi-Agent Systems through an Intelligent Agent

    Science.gov (United States)

    Han, Jing; Wang, Lin

    2013-01-01

    For a given multi-agent system where the local interaction rule of the existing agents can not be re-designed, one way to intervene the collective behavior of the system is to add one or a few special agents into the group which are still treated as normal agents by the existing ones. We study how to lead a Vicsek-like flocking model to reach synchronization by adding special agents. A popular method is to add some simple leaders (fixed-headings agents). However, we add one intelligent agent, called ‘shill’, which uses online feedback information of the group to decide the shill's moving direction at each step. A novel strategy for the shill to coordinate the group is proposed. It is strictly proved that a shill with this strategy and a limited speed can synchronize every agent in the group. The computer simulations show the effectiveness of this strategy in different scenarios, including different group sizes, shill speed, and with or without noise. Compared to the method of adding some fixed-heading leaders, our method can guarantee synchronization for any initial configuration in the deterministic scenario and improve the synchronization level significantly in low density groups, or model with noise. This suggests the advantage and power of feedback information in intervention of collective behavior. PMID:23658695

  14. Nondestructive intervention to multi-agent systems through an intelligent agent.

    Science.gov (United States)

    Han, Jing; Wang, Lin

    2013-01-01

    For a given multi-agent system where the local interaction rule of the existing agents can not be re-designed, one way to intervene the collective behavior of the system is to add one or a few special agents into the group which are still treated as normal agents by the existing ones. We study how to lead a Vicsek-like flocking model to reach synchronization by adding special agents. A popular method is to add some simple leaders (fixed-headings agents). However, we add one intelligent agent, called 'shill', which uses online feedback information of the group to decide the shill's moving direction at each step. A novel strategy for the shill to coordinate the group is proposed. It is strictly proved that a shill with this strategy and a limited speed can synchronize every agent in the group. The computer simulations show the effectiveness of this strategy in different scenarios, including different group sizes, shill speed, and with or without noise. Compared to the method of adding some fixed-heading leaders, our method can guarantee synchronization for any initial configuration in the deterministic scenario and improve the synchronization level significantly in low density groups, or model with noise. This suggests the advantage and power of feedback information in intervention of collective behavior.

  15. Intelligent Software Agents: Sensor Integration and Response

    Energy Technology Data Exchange (ETDEWEB)

    Kulesz, James J [ORNL; Lee, Ronald W [ORNL

    2013-01-01

    Abstract In a post Macondo world the buzzwords are Integrity Management and Incident Response Management. The twin processes are not new but the opportunity to link the two is novel. Intelligent software agents can be used with sensor networks in distributed and centralized computing systems to enhance real-time monitoring of system integrity as well as manage the follow-on incident response to changing, and potentially hazardous, environmental conditions. The software components are embedded at the sensor network nodes in surveillance systems used for monitoring unusual events. When an event occurs, the software agents establish a new concept of operation at the sensing node, post the event status to a blackboard for software agents at other nodes to see , and then react quickly and efficiently to monitor the scale of the event. The technology addresses a current challenge in sensor networks that prevents a rapid and efficient response when a sensor measurement indicates that an event has occurred. By using intelligent software agents - which can be stationary or mobile, interact socially, and adapt to changing situations - the technology offers features that are particularly important when systems need to adapt to active circumstances. For example, when a release is detected, the local software agent collaborates with other agents at the node to exercise the appropriate operation, such as: targeted detection, increased detection frequency, decreased detection frequency for other non-alarming sensors, and determination of environmental conditions so that adjacent nodes can be informed that an event is occurring and when it will arrive. The software agents at the nodes can also post the data in a targeted manner, so that agents at other nodes and the command center can exercise appropriate operations to recalibrate the overall sensor network and associated intelligence systems. The paper describes the concepts and provides examples of real-world implementations

  16. Agent Based Reasoning in Multilevel Flow Modeling

    DEFF Research Database (Denmark)

    Lind, Morten; Zhang, Xinxin

    2012-01-01

    to launch the MFM Workbench into an agent based environment, which can complement disadvantages of the original software. The agent-based MFM Workbench is centered on a concept called “Blackboard System” and use an event based mechanism to arrange the reasoning tasks. This design will support the new......Multilevel Flow Modeling (MFM) is a modeling method used for modeling complex industrial plant. Currently, MFM is supported with a standalone software tool called MFM Workbench, which is equipped with causal-relation analysis and other functionalities. The aim of this paper is to offer a new design...

  17. Liposomal Drug Delivery of Anticancer Agents

    DEFF Research Database (Denmark)

    Pedersen, Palle Jacob

    In the first part of the thesis the work towards a new generation of liposomal drug delivery systems for anticancer agents is described. The drug delivery system takes advantage of the elevated level of secretory phospholipase A2 (sPLA2) IIA in many tumors and the enhanced permeability...... and retention (EPR) effect. The liposomes consists of sPLA2 IIA sensitive phospholipids having anticancer drugs covalently attached to the sn-2 position of the glycerol backbone in the phospholipids, hence drug leakage is avoided from the carrier system. Various known anticancer agents, like chlorambucil, all...

  18. Software agents in surgery: an update.

    Science.gov (United States)

    Mohr, Markus T J

    2003-01-01

    Intelligent and, thus, autonomously reacting software programs are capable of handling a lot of different tasks as has been realized in economics and network administration. The same so-called software agents can be used for a variety of organizational tasks in medicine. Some software agents already manage an individual patient's health care record from documentation to ambulant or stationary admission, surgical planning, and many other tasks which currently consume more than half of a physician's daily working time. Hence, not only a large potential of time, but also of economical savings result to the physicians' new disposition.

  19. Novel anti-inflammatory agents in COPD

    DEFF Research Database (Denmark)

    Loukides, Stelios; Bartziokas, Konstantinos; Vestbo, Jørgen

    2013-01-01

    Inflammation plays a central role in chronic obstructive pulmonary disease (COPD). COPD related inflammation is less responsive to inhaled steroids compared to asthma. There are three major novel anti-inflammatory approaches to the management of COPD. The first approach is phosphodiesterase...... on these strategies exist at the moment. A third potential approach involves novel agents whose mechanism of action is closely related to COPD mechanisms and pathophysiology. Such novel treatments are of great interest since they may treat both COPD and co-morbidities. Several novel agents are currently under...

  20. Psoriatic arthritis: treatment strategies using biologic agents

    Directory of Open Access Journals (Sweden)

    C. Palazzi

    2012-06-01

    Full Text Available The traditional management of psoriatic arthritis (PsA includes NSAIDs, corticosteroids and DMARDs. Advancement in the knowledge of the immunopathogenesis of PsA has been associated with the development of biologic agents which have revolutionized the management of the disease. Among biologics drugs, there are the 4 currently availablee anti-TNFα blocking agents (etanercept, infliximab, adalimumab and golimumab which are more effective than traditional DMARDs on symptoms/signs of inflammation, quality of life, function, and in inhibiting the progression of the structural joint damage. Despite of the high cost, TNF inhibitors are costeffective on both the musculoskeletal and skin manifestations of psoriatic disease.

  1. Agentes Comunitários de Saúde e os sentidos de "ser agente" Community Health Agents and the meanings of "being an agent"

    Directory of Open Access Journals (Sweden)

    Viviane Milan Pupin

    2008-08-01

    Full Text Available O Programa Saúde da Família constitui-se enquanto estratégia de mudança do modelo assistencial. O artigo apresenta os resultados de uma pesquisa qualitativa sobre os sentidos de "ser agente" produzidos, por meio de entrevistas abertas, com Agentes Comunitários de Saúde que trabalham nos cinco Núcleos de Saúde da Família da cidade de Ribeirão Preto - São Paulo, vinculados à Faculdade de Medicina de Ribeirão Preto - USP. As entrevistas foram gravadas e transcritas na íntegra e analisadas segundo princípios da análise de conteúdo. A análise permitiu a descrição de sentidos acerca de ser agente subdivididos em: Sentidos produzidos na relação com a comunidade e Sentidos produzidos na relação com a equipe. A análise dos sentidos de ser agente possibilitou construir um diálogo sobre as tensões relacionadas a um fazer em saúde ora permeado por concepções atreladas ao modelo biomédico, ora atrelado aos novos paradigmas em saúde.The Family Health Program consists of a strategy to change the health care model. This article presents the results from a qualitative study about the meanings of "being an agent" obtained through open interviews with Community Health Agents who work in five Family Health Centers of the Ribeirão Preto School of Medicine (University of São Paulo, located in Ribeirão Preto, São Paulo. Interviews were tape recorded, fully transcribed, and then content analyzed. The analysis allowed for descriptions of meanings toward "being an agent", subdivided into: Meanings produced by relationships with the community, and Meanings produced by relationships with the team. Analyzing the meanings of being an agent provided the establishment of a dialogue about the tensions related to a health practice that is at times influenced by conceptions associated with the biomedical method, and at other times with the new health paradigm.

  2. Organophosphate Nerve Agent Detection with Europium Complexes

    Directory of Open Access Journals (Sweden)

    Jake R. Schwierking

    2004-01-01

    Full Text Available We explore the detection of paraoxon, a model compound for nonvolatile organophosphate nerve agents such as VX. The detection utilizes europium complexes with 1,10 phenanthroline and thenoyltrifluoroacetone as sensitizing ligands. Both europium luminescence quenching and luminescence enhancement modalities are involved in the detection, which is simple, rapid, and sensitive. It is adaptable as well to the more volatile fluorophosphate nerve agents. It involves nothing more than visual luminescence observation under sample illumination by an ordinary hand-held ultraviolet lamp.

  3. AGENTES DE SOFTWARE MÓVILES

    Directory of Open Access Journals (Sweden)

    Crisman Martínez Barrera

    2001-01-01

    Full Text Available Los agentes móviles son programas de software inteligentes que realizan un objetivo que involucran desarrollos soportados en técnicas de Inteligencia Artificial, los cuales pretenden facilitar la interoperabilidad de sistemas. Este artículo define las disciplinas, plataformas y herramientas necesarias para el desarrollo de agentes móviles, sus características principales y las arquitecturas predominantes de éstas; presenta además una evaluación de sus perspectivas futuras.

  4. Agentes en bases de datos distribuidas

    OpenAIRE

    Miaton, Ivana Carla; Pesado, Patricia Mabel; Bertone, Rodolfo Alfredo; De Giusti, Armando Eduardo

    2003-01-01

    El paradigma de agentes móviles permite acceder, recolectar o actualizar información desde cualquier estación de trabajo dentro de una red heterogénea de computadoras. De esta forma, el código ejecutable de un agente móvil puede migrar entre los puestos de trabajo. Mantener una BD distribuida actualizada en todos los puntos de un sistema distribuido y en todo momento mediante transacciones, tiene difervas dificultades (inestabilidad) debido a la carga de trabajo que varía de acuerdo a la u...

  5. A Diversified Investment Strategy Using Autonomous Agents

    Science.gov (United States)

    Barbosa, Rui Pedro; Belo, Orlando

    In a previously published article, we presented an architecture for implementing agents with the ability to trade autonomously in the Forex market. At the core of this architecture is an ensemble of classification and regression models that is used to predict the direction of the price of a currency pair. In this paper, we will describe a diversified investment strategy consisting of five agents which were implemented using that architecture. By simulating trades with 18 months of out-of-sample data, we will demonstrate that data mining models can produce profitable predictions, and that the trading risk can be diminished through investment diversification.

  6. Developing Agent-Oriented Video Surveillance System through Agent-Oriented Methodology (AOM

    Directory of Open Access Journals (Sweden)

    Cheah Wai Shiang

    2016-12-01

    Full Text Available Agent-oriented methodology (AOM is a comprehensive and unified agent methodology for agent-oriented software development. Although AOM is claimed to be able to cope with a complex system development, it is still not yet determined up to what extent this may be true. Therefore, it is vital to conduct an investigation to validate this methodology. This paper presents the adoption of AOM in developing an agent-oriented video surveillance system (VSS. An intruder handling scenario is designed and implemented through AOM. AOM provides an alternative method to engineer a distributed security system in a systematic manner. It presents the security system at a holistic view; provides a better conceptualization of agent-oriented security system and supports rapid prototyping as well as simulation of video surveillance system.

  7. 10th KES Conference on Agent and Multi-Agent Systems : Technologies and Applications

    CERN Document Server

    Chen-Burger, Yun-Heh; Howlett, Robert; Jain, Lakhmi

    2016-01-01

    The modern economy is driven by technologies and knowledge. Digital technologies can free, shift and multiply choices, often intruding on the space of other industries, by providing new ways of conducting business operations and creating values for customers and companies. The topics covered in this volume include software agents, multi-agent systems, agent modelling, mobile and cloud computing, big data analysis, business intelligence, artificial intelligence, social systems, computer embedded systems and nature inspired manufacturing, etc. that contribute to the modern Digital Economy. This volume highlights new trends and challenges in agent, new digital and knowledge economy research and includes 28 papers classified in the following specific topics: business process management, agent-based modeling and simulation, anthropic-oriented computing, learning paradigms, business informatics and gaming, digital economy, and advances in networked virtual enterprises. Published papers were selected for presentatio...

  8. Human Carboxylesterase 1 Stereoselectively Binds the Nerve Agent Cyclosarin and Spontaneously Hydrolyzes the Nerve Agent Sarin

    Energy Technology Data Exchange (ETDEWEB)

    Hemmert, Andrew C.; Otto, Tamara C.; Wierdl, Monika; Edwards, Carol C.; Fleming, Christopher D.; MacDonald, Mary; Cashman, John R.; Potter, Philip M.; Cerasoli, Douglas M.; Redinbo, Matthew R. (UNC); (USARL); (SJCH)

    2010-10-28

    Organophosphorus (OP) nerve agents are potent toxins that inhibit cholinesterases and produce a rapid and lethal cholinergic crisis. Development of protein-based therapeutics is being pursued with the goal of preventing nerve agent toxicity and protecting against the long-term side effects of these agents. The drug-metabolizing enzyme human carboxylesterase 1 (hCE1) is a candidate protein-based therapeutic because of its similarity in structure and function to the cholinesterase targets of nerve agent poisoning. However, the ability of wild-type hCE1 to process the G-type nerve agents sarin and cyclosarin has not been determined. We report the crystal structure of hCE1 in complex with the nerve agent cyclosarin. We further use stereoselective nerve agent analogs to establish that hCE1 exhibits a 1700- and 2900-fold preference for the P{sub R} enantiomers of analogs of soman and cyclosarin, respectively, and a 5-fold preference for the P{sub S} isomer of a sarin analog. Finally, we show that for enzyme inhibited by racemic mixtures of bona fide nerve agents, hCE1 spontaneously reactivates in the presence of sarin but not soman or cyclosarin. The addition of the neutral oxime 2,3-butanedione monoxime increases the rate of reactivation of hCE1 from sarin inhibition by more than 60-fold but has no effect on reactivation with the other agents examined. Taken together, these data demonstrate that hCE1 is only reactivated after inhibition with the more toxic P{sub S} isomer of sarin. These results provide important insights toward the long-term goal of designing novel forms of hCE1 to act as protein-based therapeutics for nerve agent detoxification.

  9. CATS-based Air Traffic Controller Agents

    Science.gov (United States)

    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

  10. 49 CFR 375.205 - May I have agents?

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false May I have agents? 375.205 Section 375.205... General Responsibilities § 375.205 May I have agents? (a) You may have agents provided you comply with... performs such services only on an emergency or temporary basis. (b) If you have agents, you must have...

  11. 42 CFR 434.10 - Contracts with fiscal agents.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 4 2010-10-01 2010-10-01 false Contracts with fiscal agents. 434.10 Section 434.10... (CONTINUED) MEDICAL ASSISTANCE PROGRAMS CONTRACTS Contracts with Fiscal Agents and Private Nonmedical Institutions § 434.10 Contracts with fiscal agents. Contracts with fiscal agents must— (a) Meet the...

  12. Schools as Agents of Social Exclusion and Inclusion

    Science.gov (United States)

    Razer, Michal; Friedman, Victor J.; Warshofsky, Boaz

    2013-01-01

    Although schools are usually regarded as important agents for social inclusion, research has shown that they may also function as agents of exclusion itself. The goal of this paper is to deepen our understanding of how schools function as agents of exclusion and how they can become more effective agents of inclusion. It is based on action research…

  13. 49 CFR 1312.15 - Change of carrier or agent.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Change of carrier or agent. 1312.15 Section 1312... NONCONTIGUOUS DOMESTIC TRADE § 1312.15 Change of carrier or agent. (a) Change in carrier. When a carrier's name... by this paragraph is the date the event occurs. (b) Change of agent. When a new agent is appointed to...

  14. An improved 2-agent kidney exchange mechanism

    DEFF Research Database (Denmark)

    Caragiannis, Ioannis; Filos-Ratsikas, Aris; Procaccia, Ariel D.

    2015-01-01

    We study a mechanism design version of matching computation in graphs that models the game played by hospitals participating in pairwise kidney exchange programs. We present a new randomized matching mechanism for two agents which is truthful in expectation and has an approximation ratio of 3...

  15. Emerging therapeutic agents for lung cancer

    Directory of Open Access Journals (Sweden)

    Bhagirathbhai Dholaria

    2016-12-01

    Full Text Available Abstract Lung cancer continues to be the most common cause of cancer-related mortality worldwide. Recent advances in molecular diagnostics and immunotherapeutics have propelled the rapid development of novel treatment agents across all cancer subtypes, including lung cancer. Additionally, more pharmaceutical therapies for lung cancer have been approved by the US Food and Drug Administration in the last 5 years than in previous two decades. These drugs have ushered in a new era of lung cancer managements that have promising efficacy and safety and also provide treatment opportunities to patients who otherwise would have no conventional chemotherapy available. In this review, we summarize recent advances in lung cancer therapeutics with a specific focus on first in-human or early-phase I/II clinical trials. These drugs either offer better alternatives to drugs in their class or are a completely new class of drugs with novel mechanisms of action. We have divided our discussion into targeted agents, immunotherapies, and antibody drug conjugates for small cell lung cancer (SCLC and non-small-cell lung cancer (NSCLC. We briefly review the emerging agents and ongoing clinical studies. We have attempted to provide the most current review on emerging therapeutic agents on horizon for lung cancer.

  16. Self-explaining agents in virtual training

    NARCIS (Netherlands)

    Harbers, M.; Bosch, K. van den; Meyer, J.J.C.

    2008-01-01

    Virtual training systems are increasingly used for the training of complex, dynamic tasks. To give trainees the opportunity to train autonomously, intelligent agents are used to generate the behavior of the virtual players in the training scenario. For effective training however, trainees should be

  17. Behavioural domain knowledge transfer for autonomous agents

    CSIR Research Space (South Africa)

    Rosman, Benjamin S

    2014-11-01

    Full Text Available task independent behaviour model based on the underlying structure of a domain which is common across multiple tasks presented to an autonomous agent. Our approach involves learning action priors: a behavioural model which encodes a notion of local...

  18. Job satisfaction of extension agents towards innovation ...

    African Journals Online (AJOL)

    The study assessed job satisfaction of extension agents towards innovation dissemination to fish farmers in Lagos State, Nigeria. A simple random sampling technique was used to select 44 extension officers from which data were collected. A structured questionnaire consisting of 6 personal characteristics, 23 management ...

  19. 31 CFR 342.9 - Fiscal agents.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Fiscal agents. 342.9 Section 342.9 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE, DEPARTMENT OF THE TREASURY BUREAU OF THE PUBLIC DEBT OFFERING OF UNITED STATES SAVINGS NOTES § 342.9 Fiscal...

  20. The Use and Efficacy of Mucolytic Agents

    African Journals Online (AJOL)

    1971-08-28

    Aug 28, 1971 ... propylene glycol or saline diluent with the addition of. Mg-+. Propylene glycol is preferred as it provides a sooth- ing effect on the tracheobronchial tree and eases the mobili- zation of respiratory secretion. In the abovementioned investigations dornase proved to be an effective mucolytic agent for the ...

  1. An analysis of multi-agent diagnosis

    NARCIS (Netherlands)

    Roos, Nico; Ten Teije, Annette; Bos, André; Witteveen, Cees; Castelfranchi, C.; Johnson, W.L.

    2002-01-01

    This paper analyzes the use of a Multi-Agent System for Model-Based Diagnosis. In a large dynamical system, it is often infeasible or even impossible to maintain a model of the whole system. Instead, several incomplete models of the system have to be used to establish a diagnosis and to detect

  2. Agent-based simulation of animal behaviour

    NARCIS (Netherlands)

    C.M. Jonker (Catholijn); J. Treur

    1998-01-01

    textabstract In this paper it is shown how animal behaviour can be simulated in an agent-based manner. Different models are shown for different types of behaviour, varying from purely reactive behaviour to pro-active, social and adaptive behaviour. The compositional development method for

  3. The Hybrid Ethical Reasoning Agent IMMANUEL

    DEFF Research Database (Denmark)

    Bentzen, Martin Mose; Linder, Felix

    We introduce a novel software library that supportsthe implementation of hybrid ethical reasoning agents (HERA).The objective is to make moral principles available to robotprogramming. At its current stage, HERA can assess the moralpermissibility of actions using the principle of double effect...

  4. Supporting a Learner Community with Software Agents

    Science.gov (United States)

    Taurisson, Neil; Tchounikine, Pierre

    2004-01-01

    This paper describes a multi-agent approach that aims at supporting learners involved in a collective activity. We consider pedagogical situations where students have to explicitly define the articulation of their collective work and then achieve the different tasks they have defined. Our objective is to support these students by taking some of…

  5. Layered Learning in Multi-Agent Systems

    Science.gov (United States)

    1998-12-15

    Andhill󈨦 NEC, Japan 8-0 ISIS Information Sciences Institute (USC), USA 12-0 Rolling Brains Johannes Gutenberg -University Mainz, Germany 13-0 Windmill...other situations in which homogeneous agents might switch roles, the cost to the team in terms of possible discontinuities of roles being filled and in

  6. Parents as change agents: a psychodynamic model.

    Science.gov (United States)

    Zacker, J

    1978-10-01

    A treatment model is described by which psychodynamic clinicians can guide parents to become the primary change agents when their child is the identified patient. Three cases are presented where brief treatment, in which guided clinical interventions were largely carried out by the parents, led to sustained improvement in the child. Advantages of the approach and clinical issues regarding tis application are discussed.

  7. Agent Sinikael ja Neitsi Maali / Jaan Ruus

    Index Scriptorium Estoniae

    Ruus, Jaan, 1938-2017

    2003-01-01

    Eesti Filmiajakirjanike Ühing andis kümnendat korda välja auhinda Aasta film. 2002.a. parimaks filmiks tunnistati mängufilm "Agent Sinikael" : režissöör Marko Raat, produtsendid Peeter Urbla ja Veiko Õunpuu. Ära toodud ka varasemad "aastafilmid"

  8. "Agent Sinikael" aasta parim film / Ivar Sild

    Index Scriptorium Estoniae

    Sild, Ivar

    2003-01-01

    Eesti Filmiajakirjanike Ühing andis kümnendat korda välja auhinda Aasta film 2002. Parimaks filmiks tunnistati mängufilm "Agent Sinikael" : režissöör Marko Raat. Viimane sai preemiaks Neitsi Maali kuju ja 12 000 krooni

  9. Neitsi Maali "Agent Sinikaelale" / Tarmo Teder

    Index Scriptorium Estoniae

    Teder, Tarmo, 1958-

    2003-01-01

    Eesti Filmiajakirjanike Ühing andis kümnendat korda välja auhinda Aasta film 2002. Parimaks filmiks tunnistati mängufilm "Agent Sinikael" : režissöör Marko Raat. Viimane sai preemiaks Neitsi Maali kuju ja 12 000 krooni

  10. Agent Sinikael asub tegutsema / Tiit Tuumalu

    Index Scriptorium Estoniae

    Tuumalu, Tiit, 1971-

    2001-01-01

    Marko Raat alustab järgmisel nädalal uue eesti mängufilmi "Agent Sinikael" võtteid. Režissöör on kirjutanud stsenaariumi koos Andres Maimikuga. Tootjaks on Suhkurfilm koostöös Exitfilmi ja Taani kuulsa firmaga Zentropa. Ka osatäitjatest

  11. Controlling the Gaze of Conversational Agents

    NARCIS (Netherlands)

    Heylen, Dirk K.J.; van Es, I.; van Dijk, Elisabeth M.A.G.; Nijholt, Antinus; van Kuppevelt, J.; Dybkjaer, L.; Bernsen, N.O.

    2005-01-01

    We report on a pilot experiment that investigated the effects of different eye gaze behaviours of a cartoon-like talking face on the quality of human-agent dialogues. We compared a version of the talking face that roughly implements some patterns of human-like behaviour with two other versions. In

  12. Learning in engineered multi-agent systems

    Science.gov (United States)

    Menon, Anup

    Consider the problem of maximizing the total power produced by a wind farm. Due to aerodynamic interactions between wind turbines, each turbine maximizing its individual power---as is the case in present-day wind farms---does not lead to optimal farm-level power capture. Further, there are no good models to capture the said aerodynamic interactions, rendering model based optimization techniques ineffective. Thus, model-free distributed algorithms are needed that help turbines adapt their power production on-line so as to maximize farm-level power capture. Motivated by such problems, the main focus of this dissertation is a distributed model-free optimization problem in the context of multi-agent systems. The set-up comprises of a fixed number of agents, each of which can pick an action and observe the value of its individual utility function. An individual's utility function may depend on the collective action taken by all agents. The exact functional form (or model) of the agent utility functions, however, are unknown; an agent can only measure the numeric value of its utility. The objective of the multi-agent system is to optimize the welfare function (i.e. sum of the individual utility functions). Such a collaborative task requires communications between agents and we allow for the possibility of such inter-agent communications. We also pay attention to the role played by the pattern of such information exchange on certain aspects of performance. We develop two algorithms to solve this problem. The first one, engineered Interactive Trial and Error Learning (eITEL) algorithm, is based on a line of work in the Learning in Games literature and applies when agent actions are drawn from finite sets. While in a model-free setting, we introduce a novel qualitative graph-theoretic framework to encode known directed interactions of the form "which agents' action affect which others' payoff" (interaction graph). We encode explicit inter-agent communications in a directed

  13. Chemical Warfare Agent Degradation and Decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Talmage, Sylvia Smith [ORNL; Watson, Annetta Paule [ORNL; Hauschild, Veronique [U.S. Environmental Protection Agency; Munro, Nancy B [ORNL; King, J. [U.S. Army Environmental Center

    2007-02-01

    The decontamination of chemical warfare agents (CWA) from structures, environmental media, and even personnel has become an area of particular interest in recent years due to increased homeland security concerns. In addition to terrorist attacks, scenarios such as accidental releases of CWA from U.S. stockpile sites or from historic, buried munitions are also subjects for response planning. To facilitate rapid identification of practical and effective decontamination approaches, this paper reviews pathways of CWA degradation by natural means as well as those resulting from deliberately applied solutions and technologies; these pathways and technologies are compared and contrasted. We then review various technologies, both traditional and recent, with some emphasis on decontamination materials used for surfaces that are difficult to clean. Discussion is limited to the major threat CWA, namely sulfur mustard (HD, bis(2-chloroethyl)sulfide), VX (O-ethyl S-(2-diisopropylaminoethyl) methylphosphonothioate), and the G-series nerve agents. The principal G-agents are GA (tabun, ethyl N,N-dimethylphosphoramidocyanidate), GB (sarin, isopropyl methylphosphonofluoridate), and GD (soman, pinacolyl methylphosphonofluoridate). The chemical decontamination pathways of each agent are outlined, with some discussion of intermediate and final degradation product toxicity. In all cases, and regardless of the CWA degradation pathway chosen for decontamination, it will be necessary to collect and analyze pertinent environmental samples during the treatment phase to confirm attainment of clearance levels.

  14. Quitina y carboximetilquitosana como agentes desintegrantes

    Directory of Open Access Journals (Sweden)

    Sol A Fernández Monagas

    1998-08-01

    Full Text Available Se realizó un estudio comparativo de la quitina y la carboximetilquitosana como agentes desintegrantes, y se evaluó la influencia ejercida por el método empleado en la elaboración de las tabletas sobre la actividad desintegrante de ambos polímeros. La quitina presentó buenas características como agente desintegrante independientemente del método utilizado en la elaboración de las tabletas, mientras que la actividad desintegrante de la carboximetilquitosana fue afectada por el proceso de granulación.A comparative study of chitin and carboxymethylchitosan as disintegrating agents was wade made. The influence exerted bu tje method used in the preparation of the tablets on the disintegrating activity of both polymers was evaluated. Chitin proved to have good characteristics as a disintegrating agent independently of the method used to make tablets. The disintegrating activity of carboxymethylchitosan was affected by the granulation process.

  15. What Are Anticoagulants and Antiplatelet Agents?

    Science.gov (United States)

    ... find bruises or blood blisters. •You have an accident of any kind. What should I know about antiplatelet agents? Antiplatelet medicines keep blood clots from forming by preventing blood platelets from sticking together. Many heart attack and stroke patients — and people seeking to avoid these events — ...

  16. Trusted intermediating agents in electronic trade networks

    NARCIS (Netherlands)

    T.B. Klos (Tomas); F. Alkemade (Floortje)

    2005-01-01

    htmlabstract Electronic commerce and trading of information goods significantly impact the role of intermediaries: consumers can bypass intermediating agents by forming direct links to producers. One reason that traditional intermediaries can still make a profit, is that they have more knowledge of

  17. Agent Based Modelling for Social Simulation

    NARCIS (Netherlands)

    Smit, S.K.; Ubink, E.M.; Vecht, B. van der; Langley, D.J.

    2013-01-01

    This document is the result of an exploratory project looking into the status of, and opportunities for Agent Based Modelling (ABM) at TNO. The project focussed on ABM applications containing social interactions and human factors, which we termed ABM for social simulation (ABM4SS). During the course

  18. High Framerate Imaging of Ultrasound Contrast Agents

    NARCIS (Netherlands)

    J. Viti (Jacopo)

    2016-01-01

    markdownabstractUltrasound contrast agents (UCAs) consists of a suspension of tiny gas bubbles that is injected into a patient's bloodstream to enhance the visualization of blood in ultrasound images. As UCAs respond differently to ultrasound pulses compared to the surrounding soft tissues and

  19. Socialization Agents and Activities of Young Adolescents

    Science.gov (United States)

    Arnon, Sara; Shamai, Shmuel; Ilatov, Zinaida

    2008-01-01

    Research examined the relative importance of peer groups for young adolescents as compared with diverse adult socialization agents--family, school, and community. The factors involved were teenagers' activities, preferences, feelings, and thoughts as to how they spend their leisure time, their preferences for help providers, and their sense of…

  20. Saponins from Chinese Medicines as Anticancer Agents

    OpenAIRE

    Xiao-Huang Xu; Ting Li; Chi Man Vivienne Fong; Xiuping Chen; Xiao-Jia Chen; Yi-Tao Wang; Ming-Qing Huang; Jin-Jian Lu

    2016-01-01

    Saponins are glycosides with triterpenoid or spirostane aglycones that demonstrate various pharmacological effects against mammalian diseases. To promote the research and development of anticancer agents from saponins, this review focuses on the anticancer properties of several typical naturally derived triterpenoid saponins (ginsenosides and saikosaponins) and steroid saponins (dioscin, polyphyllin, and timosaponin) isolated from Chinese medicines. These saponins exhibit in vitro and in vivo...

  1. Disappearing computers, social actors and embodied agents

    NARCIS (Netherlands)

    Nijholt, Antinus; Kunii, T.L.; Hock Soon, S.; Sourin, A.

    2003-01-01

    Presently, there are user interfaces that allow multimodal interactions. Many existing research and prototype systems introduced embodied agents, assuming that they allow a more natural conversation or dialogue between user and computer. Here we will first take a look at how in general people react

  2. Visual Stereotypes and Virtual Pedagogical Agents

    Science.gov (United States)

    Haake, Magnus; Gulz, Agneta

    2008-01-01

    The paper deals with the use of visual stereotypes in virtual pedagogical agents and its potential impact in digital learning environments. An analysis of the concept of visual stereotypes is followed by a discussion of affordances and drawbacks as to their use in the context of traditional media. Next, the paper explores whether virtual…

  3. Newspapers' agricultural agenda setting and extension agents ...

    African Journals Online (AJOL)

    Newspapers content were analyzed from January to June 2002 for agricultural issues raised in them. Data were analyzed using frequencies, percentages, and Spearman rho correlation coefficient. The results revealed that extension agents ranked storage problems as most important (4.24) and investment in agriculture ...

  4. Representation for Reciprocal Agent-Environment Interaction

    NARCIS (Netherlands)

    Bosse, T.; Jonker, C.M.; Treur, J.

    2009-01-01

    Declarative modelling approaches in principle assume a notion of representation or representational content for the modelling concepts. The notion of representational content as discussed in literature in cognitive science and philosophy of mind shows complications as soon as agent and environment

  5. The 2013 Power Trading Agent Competition

    NARCIS (Netherlands)

    W. Ketter (Wolfgang); J. Collins (John); P. Reddy (Prashant); M.M. de Weerdt (Mathijs)

    2013-01-01

    textabstractThis is the specification for the Power Trading Agent Competition for 2013 (Power TAC 2013). Power TAC is a competitive simulation that models a “liberalized” retail electrical energy market, where competing business entities or “brokers” offer energy services to customers through tariff

  6. The 2015 Power Trading Agent Competition

    NARCIS (Netherlands)

    W. Ketter (Wolfgang); J. Collins (John); P. Reddy (Prashant); M.M. de Weerdt (Mathijs)

    2015-01-01

    markdownabstractThis is the specification for the Power Trading Agent Competition for 2015 (Power TAC 2015). Power TAC is a competitive simulation that models a “liberalized” retail electrical energy market, where competing business entities or “brokers” offer energy services to customers through

  7. The 2018 Power Trading Agent Competition

    NARCIS (Netherlands)

    W. Ketter (Wolfgang); J. Collins (John); M.M. de Weerdt (Mathijs)

    2017-01-01

    markdownabstractThis is the specification for the Power Trading Agent Competition for 2018 (Power TAC 2018). Power TAC is a competitive simulation that models a “liberalized” retail electrical energy market, where competing business entities or “brokers” offer energy services to customers through

  8. The 2014 Power Trading Agent Competition

    NARCIS (Netherlands)

    W. Ketter (Wolfgang); J. Collins (John); P. Reddy (Prashant); M.M. de Weerdt (Mathijs)

    2014-01-01

    textabstractThis is the specification for the Power Trading Agent Competition for 2014 (Power TAC 2014). Power TAC is a competitive simulation that models a “liberalized” retail electrical energy market, where competing business entities or “brokers” offer energy services to customers through tariff

  9. The 2017 Power Trading Agent Competition

    NARCIS (Netherlands)

    W. Ketter (Wolfgang); J. Collins (John); M.M. de Weerdt (Mathijs)

    2017-01-01

    markdownabstractThis is the specification for the Power Trading Agent Competition for 2017 (Power TAC 2017). Power TAC is a competitive simulation that models a “liberalized” retail electrical energy market, where competing business entities or “brokers” offer energy services to customers through

  10. The 2012 Power Trading Agent Competition

    NARCIS (Netherlands)

    W. Ketter (Wolfgang); J. Collins (John); P. Reddy (Prashant); M.M. de Weerdt (Mathijs)

    2012-01-01

    textabstractThis is the specification for the Power Trading Agent Competition for 2012 (Power TAC 2012). Power TAC is a competitive simulation that models a “liberalized” retail electrical energy market, where competing business entities or “brokers” offer energy services to customers through tariff

  11. The 2016 Power Trading Agent Competition

    NARCIS (Netherlands)

    W. Ketter (Wolfgang); J. Collins (John); M.M. de Weerdt (Mathijs)

    2016-01-01

    markdownabstractThis is the specification for the Power Trading Agent Competition for 2016 (Power TAC 2016). Power TAC is a competitive simulation that models a “liberalized” retail electrical energy market, where competing business entities or “brokers” offer energy services to customers through

  12. Multi-Agent Systems Design for Novices

    Science.gov (United States)

    Lynch, Simon; Rajendran, Keerthi

    2005-01-01

    Advanced approaches to the construction of software systems can present difficulties to learners. This is true for multi-agent systems (MAS) which exhibit concurrency, non-determinacy of structure and composition and sometimes emergent behavior characteristics. Additional barriers exist for learners because mainstream MAS technology is young and…

  13. GRASP agents: social first, intelligent later

    NARCIS (Netherlands)

    Hofstede, G.J.

    2017-01-01

    This paper urges that if we wish to give social intelligence to our agents, it pays to look at how we acquired our social intelligence ourselves. We are born with drives and motives that are innate and deeply social. Next, as children we are socialized to acquire norms and values and to understand

  14. Raising agents: sources of human social intelligence

    NARCIS (Netherlands)

    Hofstede, G.J.

    2014-01-01

    This paper urges that if we wish to give social intelligence to our agents, it pays to look at how we acquired our social intelligence ourselves. Our drives and motives are innate and deeply social. Next, as children we are social-ized to acquire norms and values. This motivational and group-based

  15. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

    Augustijn-Beckers, Petronella; Doldersum, Tom; Useya, Juliana; Augustijn, Dionysius C.M.

    2016-01-01

    This paper introduces a spatially explicit agent-based simulation model for micro-scale cholera diffusion. The model simulates both an environmental reservoir of naturally occurring V.cholerae bacteria and hyperinfectious V. cholerae. Objective of the research is to test if runoff from open refuse

  16. Constructing Careers: Actor, Agent, and Author

    Science.gov (United States)

    Savickas, Mark L.

    2011-01-01

    When individuals seek career counseling, they have stories to tell about their working lives. The aim of career construction theory is to be comprehensive in encouraging employment counselors to listen for a client's career story from the perspectives of actor, agent, and author. Taking multiple perspectives on career stories enables counselors to…

  17. Beyond Needs Assessments: Marketing as Change Agent.

    Science.gov (United States)

    Piland, William E.

    1984-01-01

    Views marketing techniques as agents of change providing valuable assistance to community college decision makers. Discusses the importance of a balance among the four P's of marketing (i.e., promotion, price, place, and product); and seven procedural steps in developing a sound marketing strategy. (DMM)

  18. QUANTITATIVE RISK ASSESSMENT FOR MICROBIAL AGENTS

    Science.gov (United States)

    Compared to chemical risk assessment, the process for microbial agents and infectious disease is more complex because of host factors and the variety of settings in which disease transmission can occur. While the National Academy of Science has established a paradigm for performi...

  19. 21 CFR 178.3860 - Release agents.

    Science.gov (United States)

    2010-04-01

    ... agent, applied on the internal parts of reactors employed in the production of polyvinyl chloride and... per million. N,N′-Dioleoylethylenediamine For use only in polyvinyl chloride films in amounts such... limitations prescribed for hydrogenated polybutene under § 178.3740(b). Poly(vinyl acetate/vinyl N...

  20. Professionalism as an Agent of Legitimation.

    Science.gov (United States)

    Tuchman, Gaye

    1978-01-01

    Criticizes Elihu Katz's understanding of professionalism in media journalism as used in his report to the British Broadcasting Corporation (on social research on broadcasting), on the grounds that reporting the news should not be the agent for legitimizing the event. (JMF)

  1. Characteristics of Teachers as Change Agents

    Science.gov (United States)

    van der Heijden, H. R. M. A.; Geldens, J. J. M.; Beijaard, D.; Popeijus, H. L.

    2015-01-01

    Teachers play a key role in realizing successful changes in education. Among them are real "change agents" at both classroom and school level. To obtain insights into what characterizes these teachers, an exploratory study has been conducted by interviewing external experts, principals, and teachers (n = 20). An analysis of data resulted…

  2. Artists and designers as agents of change

    NARCIS (Netherlands)

    dr. Anne Nigten; Dr. Michel van Dartel; Bart Barnard; Nathalie Beekman; Klaas Pieter Lindeman

    2015-01-01

    This paper will focus on the role of artists and designers as agents of change in sustainability innovation. We will analyse the characteristics of this role on the basis of a review of literature that discusses various concepts, methodologies and strategies applied by artists and designers in

  3. Children as Change Agents for Family Health

    Science.gov (United States)

    Burrows, Lisette

    2017-01-01

    Purpose: The purpose of this paper is to explore ways in which children and young people are being positioned as change agents for families through school health promotion initiatives in New Zealand. Design/methodology/approach: The paper maps and describes the kinds of policies and initiatives that directly or indirectly regard children as…

  4. A Verification Framework for Agent Communication

    NARCIS (Netherlands)

    Eijk, R.M. van; Boer, F.S. de; Hoek, W. van der; Meyer, J-J.Ch.

    2003-01-01

    In this paper, we introduce a verification method for the correctness of multiagent systems as described in the framework of acpl (Agent Communication Programming Language). The computational model of acpl consists of an integration of the two different paradigms of ccp (Concurrent Constraint

  5. Thoracic duct lymphography by subcutaneous contrast agent ...

    African Journals Online (AJOL)

    A 4-year-old male Japanese Shiba Inu presented with recurrent chylothorax. The thoracic duct was successfully imaged using computed tomography after the injection of an iodine contrast agent into the subcutaneous tissue surrounding the anus. The thoracic duct was successfully ligated and pericardectomy performed via ...

  6. Process for preparation of MR contrast agents

    DEFF Research Database (Denmark)

    2002-01-01

    The present invention provides a process for the preparation of an MR contrast agent, said process comprising: i) obtaining a solution in a solvent of a hydrogenatable, unsaturated substrate compound and a catalyst for the hydrogenation of said substrate compound; ii) introducing said solution...

  7. Games and Agents: Designing Intelligent Gameplay

    Directory of Open Access Journals (Sweden)

    F. Dignum

    2009-01-01

    Full Text Available There is an attention shift within the gaming industry toward more natural (long-term behavior of nonplaying characters (NPCs. Multiagent system research offers a promising technology to implement cognitive intelligent NPCs. However, the technologies used in game engines and multiagent platforms are not readily compatible due to some inherent differences of concerns. Where game engines focus on real-time aspects and thus propagate efficiency and central control, multiagent platforms assume autonomy of the agents. Increased autonomy and intelligence may offer benefits for a more compelling gameplay and may even be necessary for serious games. However, it raises problems when current game design techniques are used to incorporate state-of-the-art multiagent system technology. In this paper, we will focus on three specific problem areas that arise from this difference of view: synchronization, information representation, and communication. We argue that the current attempts for integration still fall short on some of these aspects. We show that to fully integrate intelligent agents in games, one should not only use a technical solution, but also a design methodology that is amenable to agents. The game design should be adjusted to incorporate the possibilities of agents early on in the process.

  8. CAUSATIVE AGENTS OF KERATOMYCOSIS IN IBADAN: REVIEW ...

    African Journals Online (AJOL)

    boaz

    Introduction: Fungi are responsible for less than 2.0 % of corneal infection around the globe. Trauma to the cornea is the leading cause of fungal keratitis especially with history of corneal trauma with vegetable or organic matter. Because of the dearth of data on the aetiological agents of Keratomycosis in this hospital, this ...

  9. Design and evaluation of explainable BDI agents

    NARCIS (Netherlands)

    Harbers, M.; Bosch, K. van den; Meyer, J.J.C.

    2010-01-01

    It is widely acknowledged that providing explanations is an important capability of intelligent systems. Explanation capabilities are useful, for example, in scenario-based training systems with intelligent virtual agents. Trainees learn more from scenario-based training when they understand why the

  10. Microbial aetiologic agents associated with pneumonia in ...

    African Journals Online (AJOL)

    Pulmonary infections are a major cause of morbidity and mortality in the immunosuppressed patients. The aim of this study was to determine the etiologic agents and predisposing factors associated with pneumonia infections in immunocompromised patients. Cross-sectional survey of 100 immunocompromised patients due ...

  11. Beta-blocking agents and electroconvulsive therapy

    NARCIS (Netherlands)

    W.W. van den Broek (Walter); T.H.N. Groenland (Theo); P.G.H. Mulder (Paul); A. Kusuma (Ari); T.K. Birkenhäger (Tom); E.M. Pluijms (Esther); J.A. Bruijn (Jan)

    2007-01-01

    textabstractIn this review we want to summarize the results of the placebo-controlled randomized clinical trials with betablocking adrenergic agents during electroconvulsive therapy (ECT), and review the effect on seizure duration and cardiovascular variables. We searched for studies in the

  12. Conversational Agents in Virtual Worlds: Bridging Disciplines

    Science.gov (United States)

    Veletsianos, George; Heller, Robert; Overmyer, Scott; Procter, Mike

    2010-01-01

    This paper examines the effective deployment of conversational agents in virtual worlds from the perspective of researchers/practitioners in cognitive psychology, computing science, learning technologies and engineering. From a cognitive perspective, the major challenge lies in the coordination and management of the various channels of information…

  13. Ultrasonic characterization of ultrasound contrast agents

    NARCIS (Netherlands)

    N. de Jong (Nico); M. Emmer (Marcia); A. van Wamel (Annemieke); M. Versluis (Michel)

    2009-01-01

    textabstractThe main constituent of an ultrasound contrast agent (UCA) is gas-filled microbubbles. An average UCA contains billions per ml. These microbubbles are excellent ultrasound scatterers due to their high compressibility. In an ultrasound field they act as resonant systems, resulting in

  14. Applications of Multi-Agent Technology to Power Systems

    Science.gov (United States)

    Nagata, Takeshi

    Currently, agents are focus of intense on many sub-fields of computer science and artificial intelligence. Agents are being used in an increasingly wide variety of applications. Many important computing applications such as planning, process control, communication networks and concurrent systems will benefit from using multi-agent system approach. A multi-agent system is a structure given by an environment together with a set of artificial agents capable to act on this environment. Multi-agent models are oriented towards interactions, collaborative phenomena, and autonomy. This article presents the applications of multi-agent technology to the power systems.

  15. Instructable autonomous agents. Ph.D. Thesis

    Science.gov (United States)

    Huffman, Scott Bradley

    1994-01-01

    In contrast to current intelligent systems, which must be laboriously programmed for each task they are meant to perform, instructable agents can be taught new tasks and associated knowledge. This thesis presents a general theory of learning from tutorial instruction and its use to produce an instructable agent. Tutorial instruction is a particularly powerful form of instruction, because it allows the instructor to communicate whatever kind of knowledge a student needs at whatever point it is needed. To exploit this broad flexibility, however, a tutorable agent must support a full range of interaction with its instructor to learn a full range of knowledge. Thus, unlike most machine learning tasks, which target deep learning of a single kind of knowledge from a single kind of input, tutorability requires a breadth of learning from a broad range of instructional interactions. The theory of learning from tutorial instruction presented here has two parts. First, a computational model of an intelligent agent, the problem space computational model, indicates the types of knowledge that determine an agent's performance, and thus, that should be acquirable via instruction. Second, a learning technique, called situated explanation specifies how the agent learns general knowledge from instruction. The theory is embodied by an implemented agent, Instructo-Soar, built within the Soar architecture. Instructo-Soar is able to learn hierarchies of completely new tasks, to extend task knowledge to apply in new situations, and in fact to acquire every type of knowledge it uses during task performance - control knowledge, knowledge of operators' effects, state inferences, etc. - from interactive natural language instructions. This variety of learning occurs by applying the situated explanation technique to a variety of instructional interactions involving a variety of types of instructions (commands, statements, conditionals, etc.). By taking seriously the requirements of flexible

  16. Security Framework for Agent-Based Cloud Computing

    Directory of Open Access Journals (Sweden)

    K Venkateshwaran

    2015-06-01

    Full Text Available Agent can play a key role in bringing suitable cloud services to the customer based on their requirements. In agent based cloud computing, agent does negotiation, coordination, cooperation and collaboration on behalf of the customer to make the decisions in efficient manner. However the agent based cloud computing have some security issues like (a. addition of malicious agent in the cloud environment which could demolish the process by attacking other agents, (b. denial of service by creating flooding attacks on other involved agents. (c. Some of the exceptions in the agent interaction protocol such as Not-Understood and Cancel_Meta protocol can be misused and may lead to terminating the connection of all the other agents participating in the negotiating services. Also, this paper proposes algorithms to solve these issues to ensure that there will be no intervention of any malicious activities during the agent interaction.

  17. Multimodal nanoparticle imaging agents: design and applications

    Science.gov (United States)

    Burke, Benjamin P.; Cawthorne, Christopher; Archibald, Stephen J.

    2017-10-01

    Molecular imaging, where the location of molecules or nanoscale constructs can be tracked in the body to report on disease or biochemical processes, is rapidly expanding to include combined modality or multimodal imaging. No single imaging technique can offer the optimum combination of properties (e.g. resolution, sensitivity, cost, availability). The rapid technological advances in hardware to scan patients, and software to process and fuse images, are pushing the boundaries of novel medical imaging approaches, and hand-in-hand with this is the requirement for advanced and specific multimodal imaging agents. These agents can be detected using a selection from radioisotope, magnetic resonance and optical imaging, among others. Nanoparticles offer great scope in this area as they lend themselves, via facile modification procedures, to act as multifunctional constructs. They have relevance as therapeutics and drug delivery agents that can be tracked by molecular imaging techniques with the particular development of applications in optically guided surgery and as radiosensitizers. There has been a huge amount of research work to produce nanoconstructs for imaging, and the parameters for successful clinical translation and validation of therapeutic applications are now becoming much better understood. It is an exciting time of progress for these agents as their potential is closer to being realized with translation into the clinic. The coming 5-10 years will be critical, as we will see if the predicted improvement in clinical outcomes becomes a reality. Some of the latest advances in combination modality agents are selected and the progression pathway to clinical trials analysed. This article is part of the themed issue 'Challenges for chemistry in molecular imaging'.

  18. AgPi: Agents on Raspberry Pi

    Directory of Open Access Journals (Sweden)

    Tushar Semwal

    2016-10-01

    Full Text Available The Raspberry Pi and its variants have brought with them an aura of change in the world of embedded systems. With their impressive computation and communication capabilities and low footprint, these devices have thrown open the possibility of realizing a network of things in a very cost-effective manner. While such networks offer good solutions to prominent issues, they are indeed a long way from being smart or intelligent. Most of the currently available implementations of such a network of devices involve a centralized cloud-based server that contributes to making the necessary intelligent decisions, leaving these devices fairly underutilized. Though this paradigm provides for an easy and rapid solution, they have limited scalability, are less robust and at times prove to be expensive. In this paper, we introduce the concept of Agents on Raspberry Pi (AgPi as a cyber solution to enhance the smartness and flexibility of such embedded networks of physical devices in a decentralized manner. The use of a Multi-Agent System (MAS running on Raspberry Pis aids agents, both static and mobile, to govern the various activities within the network. Agents can act autonomously or on behalf of a human user and can collaborate, learn, adapt and act, thus contributing to embedded intelligence. This paper describes how Tartarus, a multi-agent platform, embedded on Raspberry Pis that constitute a network, can bring the best out of the system. To reveal the versatility of the concept of AgPi, an application for a Location-Aware and Tracking Service (LATS is presented. The results obtained from a comparison of data transfer cost between the conventional cloud-based approach with AgPi have also been included.

  19. Measuring the Pro-Activity of Software Agents

    OpenAIRE

    Alonso Amo, Fernando; Fuertes Castro, José Luis; Martínez Normand, Loïc

    2010-01-01

    Despite having well-defined characteristics, software agents do not have a developed set of measures defining their quality. Attempts at evaluating software agent quality have focused on some agent aspects, like the development process, whereas others focusing on the agent as a software product have basically adopted measures associated with other software paradigms, like procedural and object-oriented concepts. Here we propose a set of measures for evaluating software agent pro-activity, the...

  20. OVULATION INDUCTION AGENTS AND OVARIAN CANCER

    Directory of Open Access Journals (Sweden)

    Barbara Požlep

    2001-10-01

    Full Text Available Background. Ovarian cancer is the most frequentcause of death among gynecologic malignancies. Epidemiologicaldata show that environmental, hormonal and geneticfactors are etiologically significant. Beside the already knownrisk factors, ovulation induction agents have been reported asrisk factors in literature since 1986. Over the last two decades,ovulation induction agents have been widely used in variousassisted reproduction techniques (ART. This study focusedon the question whether in patients receiving ovulation inductionagents the risk for developing pathologic processes onthe ovaries was higher than in those not receiving them, andwhether they were related to the dose and type of ovulationinduction agent.Methods. In a prospective study 380 subjects were enrolled.The study group consisted of 280 women who had undergonean ART procedure three or more times. The control group consistedof 120 infertile women, never included in an ART procedure.All the enrolled subjects underwent the same examinations:a detailed gynecological history was taken, pelvic examinationand vaginal ultrasound were performed, and a bloodsample for tumour marker CA 125 determination was taken.Statistical analysis was done using Chi-square test, t test andlogistic regression.Results. Ultrasound examination revealed pathology on thegenital tract in 136 women in the study group and in 60 womenin the control group. Differences in the incidence of ovarian,tubal and uterine pathology were not statistically significant.The analysis of the medical records showed that the incidenceof ovarian pathology was significantly higher in thestudy than in the control group (p < 0.05. We found no correlationbetween the incidence of ovarian pathology and typeor dose of ovulation induction agent. Increased CA 125 levelswere found in 12 women. In none of the women neither malignantnor borderline malignant disease was found.Conclusions. Although the analysis of the data from medicalhistory showed