WorldWideScience

Sample records for gelling agents affect

  1. Selected gelling agents in canned dog food affect nutrient digestibilities and fecal characteristics of ileal cannulated dogs

    NARCIS (Netherlands)

    Karr-Lilienthal, L.K.; Merchen, N.R.; Grieshop, C.M.; Smeets-Petersen, M.J.E.; Fahey, G.C.

    2002-01-01

    Little is known about the effects of gelling agents in canned dog food on nutrient digestibilities and fecal characteristics. Dogs were fed canned diets with either no gelling agent (control) or one of three gelling agents, wheat starch, a guar gum/carrageenan mixture (50:50), and a locust bean meal

  2. Progress in the development of gelling agents for improved culturability of microorganisms

    Directory of Open Access Journals (Sweden)

    Nabajit eDas

    2015-07-01

    Full Text Available Gelling agents are required for formulating both solid and semisolid media, vital for the isolation of microorganisms. Gelatin was the first gelling agent to be discovered but it soon paved the way for agar, which has far superior material qualities. Source depletion, issues with polymerase-chain-reaction and inability to sustain extermophiles etc., necessitate the need of other gelling agents. Many new gelling agents, such as xantham gum, gellan gum, carrageenan, isubgol and guar gum have been formulated, raising the hopes for the growth of previously unculturable microorganisms. We evaluate the progress in the development of gelling agents, with the hope that our synthesis would help accelerate research in the field.

  3. Study and Application of Gelling Water Shutoff and Profile Control Agents

    Institute of Scientific and Technical Information of China (English)

    Wang Hongguan; Yu Liancheng; Tian Hongkun; Xu Yanxing

    1997-01-01

    @@ Oilfield Chemistry Department, Research Institute of Petroleum Exploration and Development, has made great efforts to study and develop oil chemicals since 1976.For many years, the systematic research has been done on the styles of polymers,crosslinking agents and addtional agents, which are primary components of the gelling systems,the chemical reaction process, the physical and chemical performance of final gelling forms,and the compatibility of chemicals with the different strata. The gelling systems adaptable to the different formations have been formed through these studies.

  4. Evaluation of gelling agents on anther culture : response of two soybean cultivars

    OpenAIRE

    Milena Barcelos Cardoso; Maria Helena Bodanese-Zanettini; Elsa Cristina de Mundstock; Eliane Kaltchuk-Santos

    2007-01-01

    Anthers of two soybean cultivars were cultured in B5 long basal culture media gelled with agarose or PhytagelTM. Cytological examinations of the anthers were carried out during the first 45 days of culture to assay the viability and developmental stage of microspores. Frequency of callus formation was recorded at 45 days of culture. The analysis of variance of the microspore viability assay showed significant Cultivar X Gelling Agent X Day of Culture interactions. The frequencies of viable mi...

  5. Evaluation of guar gum derivatives as gelling agents for microbial culture media.

    Science.gov (United States)

    Gangotri, Waikhom; Jain-Raina, Ruchi; Babbar, Shashi B

    2012-05-01

    Guar gum, a galactomannan, has been reported to be an inexpensive substitute of agar for microbial culture media. However, its use is restricted probably because of (1) its highly viscous nature even at high temperatures, making dispensing of the media to Petri plates difficult and (2) lesser clarity of the guar gum gelled media than agar media due to impurities present in guar gum. To overcome these problems, three guar gum derivatives, carboxymethyl guar, carboxymethyl hydroxypropyl guar and hydroxypropyl guar, were tested as gelling agents for microbial growth and differentiation. These were also evaluated for their suitability for other routine microbiological methods, such as, enumeration, use of selective and differential media, and antibiotic sensitivity test. For evaluation purpose, growth and differentiation of eight fungi and eight bacteria grown on the media gelled with agar (1.5%), guar gum (4%) or one of the guar gum derivatives (4%), were compared. All fungi and bacteria exhibited normal growth and differentiation on all these media. Generally, growth of most of the fungi was better on guar gum derivatives gelled medium than on agar medium. The enumeration carried out for Serratia sp. and Pseudomonas aeruginosa by serial dilution and pour plate method yielded similar counts in all the treatments. Likewise, the selective succinate medium, specific for P. aeruginosa, did not allow growth of co-inoculated Bacillus sp. even if gelled with guar gum derivatives. The differential medium, Congo red mannitol agar could not differentiate between Agrobacterium tumefaciens and Rhizobium meliloti on color basis, if gelled with guar gum or any of its derivatives However, for antibiotic sensitivity tests for both Gram-positive and -negative bacteria, guar gum and its derivatives were as effective as agar.

  6. Effect of gelling agents on shoot growth and multiple shoot formation of mangosteen

    Directory of Open Access Journals (Sweden)

    Sompong Te-chato

    2005-12-01

    Full Text Available Apomict seeds of mangosteen were cultured as a whole or half seed on MS medium supplemented with 5 mg/l 6-benzyladenine (BA. The medium was solidified with various gelling agents. After culture for 2 months, multiple shoot formation, morphological and physiological characters of the shoot were investigated. The results revealed that 1.5% agarose gave the highest seed forming shoot (98% and number of shoots per culture seed (20.7. Wounding the seed by sectioning into half promoted higher callus formation (47-88% in all gelling agents. Phytagel (0.17% resulted in the highest callus formation (100% and hyperhydric shoots (11-31%. Those shoots produced translucent, thin and brittle leaves and stems, and malformed stoma. Those leaves had the lowest content of chlorophyll a, b and total chlorophyll.

  7. Stabilization of green bodies via sacrificial gelling agent during electrophoretic deposition

    Science.gov (United States)

    Worsley, Marcus A.; Kuntz, Joshua D.; Rose, Klint A.

    2016-03-22

    In one embodiment, a method for electrophoretic deposition of a three-dimensionally patterned green body includes suspending a first material in a gelling agent above a patterned electrode of an electrophoretic deposition (EPD) chamber, and gelling the suspension while applying a first electric field to the suspension to cause desired patterning of the first material in a resulting gelation. In another embodiment, a ceramic, metal, or cermet includes a plurality of layers, wherein each layer includes a gradient in composition, microstructure, and/or density in an x-y plane oriented parallel to a plane of deposition of the plurality of layers along a predetermined distance in a z-direction perpendicular to the plane of deposition.

  8. Hydroponics gel as a new electrolyte gelling agent for alkaline zinc-air cells

    Science.gov (United States)

    Othman, R.; Basirun, W. J.; Yahaya, A. H.; Arof, A. K.

    The viability of hydroponics gel as a new alkaline electrolyte gelling agent is investigated. Zinc-air cells are fabricated employing 12 wt.% KOH electrolyte immobilised with hydroponics gel. The cells are discharged at constant currents of 5, 50 and 100 mA. XRD and SEM analysis of the anode plates after discharge show that the failure mode is due to the formation of zinc oxide insulating layers and not due to any side reactions between the gel and the plate or the electrolyte.

  9. Evaluation of gelling agents on anther culture: response of two soybean cultivars

    Directory of Open Access Journals (Sweden)

    Milena Barcelos Cardoso

    2007-11-01

    Full Text Available Anthers of two soybean cultivars were cultured in B5 long basal culture media gelled with agarose or PhytagelTM. Cytological examinations of the anthers were carried out during the first 45 days of culture to assay the viability and developmental stage of microspores. Frequency of callus formation was recorded at 45 days of culture. The analysis of variance of the microspore viability assay showed significant Cultivar X Gelling Agent X Day of Culture interactions. The frequencies of viable microspores decreased significantly with time of culture, within each cultivar and gelling agent tested. The interaction Day X Cultivar was significant for the frequencies of binucleate symmetrical grains and multinucleate/multicellular structures. The effect of gelling agents on the frequency of binucleate symmetrical pollens grains and multinucleate/multicellular structures was not significant. About the frequencies of calli and embryogenic calli formed, a significant difference was detected between the cultivars (IAS5= 14.8% and BRS 133=6.6%. Gelling agents showed no effect over these frequencies.Anteras de duas cultivares de soja foram cultivadas em meio de cultura basal B5 longo gelificado com agarose ou Phytagel®. Análises citológicas das anteras foram conduzidas durante os primeiros 45 dias de cultura para avaliar a viabilidade e o estágio de desenvolvimento dos micrósporos. A freqüência de formação de calos foi analisada após 45 dias do início da cultura. A análise da variância da viabilidade do micrósporo mostrou interações significativas de Cultivar X Agente Gelificante X Dias de Cultura. As freqüências de grãos de pólen viáveis diminuíram significativamente com o tempo de cultura, dentro de cada cultivar e agente gelificante testado. A interação Dia X Cultivar foi significante para as freqüências de grãos de pólen binucleados simétricos e estruturas multinucleados/multicelulares. O efeito do agente gelificante na freq

  10. Ensete ventricosum (WELW. CHEESMAN: A CHEAP AND ALTERNATIVE GELLING AGENT FOR PINEAPPLE (Ananas comosus VAR. SMOOTH CAYENNE IN VITRO PROPAGATION

    Directory of Open Access Journals (Sweden)

    Biruk Ayenew

    2012-10-01

    Full Text Available Different mechanisms are tried so far to reduce the production cost of plant tissue culture through increasing multiplication rate and/or substituting expensive components for wider usage of the technology. Subsequently, replacing the most common gelling agent, agar, took an attention since higher proportion of media cost comes from it. Up to now different alternatives were tried though they have drawbacks due to their inherent chemical characteristics. Therefore the search for new alternatives like Enset ventricosum is important. Enset flour, ‘Bulla’, has been tried in this study for the first time to substitute agar and showed no significant difference for shoots number, root number, shoot height, leaf number and an associated fresh weight of the plantlets besides good gelling ability than Agar. Subsequently, ‘Bulla’ at 80g L-1 gelled well and gave 11.8 shoots with 0.95g and 13.33 roots having 1.37 cm length. This rate can also save up to 76 % cost of gelling though significant difference was found for root length of 3.23 cm with Agar, 8 g L-1. This indicates further study on biochemical and/ or hormonal activity and across crop genotypes to use ‘Bulla’ as a cheap alternative commercial gelling agent.

  11. Deformation and fracture of emulsion-filled gels: Effect of gelling agent concentration and oil droplet size

    NARCIS (Netherlands)

    Sala, G.; Vliet, van T.; Cohen Stuart, M.A.; Velde, van de F.; Aken, van G.A.

    2009-01-01

    The effect of the ratio between the modulus of the oil droplets and that of the gel matrix (varied by changing gelling agent concentration and oil droplet size) on the large deformation properties of gelatine, ¿-carrageenan and whey protein isolate (WPI) gels was studied at different compression spe

  12. Successful disinfection protocol for orchid seeds and influence of gelling agent on germination and growth

    Directory of Open Access Journals (Sweden)

    Tomaž JEVŠNIK

    2015-11-01

    Full Text Available Artificial propagation of endangered orchid species is one of the most important actions of conservationists often jeopardized by low numbers of acquired seed, its contamination and viability. Disinfection and chemical composition of media are two of the most important factors contributing to better germination in temperate orchid species. The article deals with three world genera (Epidendrum nocturnum, Prosthechea garciana, Maxillaria rufescens and one commercial hybrid (Zygopetalum and describes an effective method of orchid seed disinfection carried out in a centrifuge. Germination percentages of all three genera and one hybrid were between 60 and 90 % from which we concluded that the risk of physical damage to the seeds by centrifugation is not significant. The time needed for disinfected seeds (E. nocturnum, P. garciana, M. rufescens to swell-form protocorms was 10 days shorter compared to undisinfected seeds (Zygopetalum hybrid - green capsule method and some other studies. Adequate wetting and stratification of the seed is very important for successful germination, which resembles processes in natural environment. Additionally, this method solves the problems of collecting and transferring the seeds after disinfection. It is also important that the time needed for disinfection is shorter, which is desirable for some sensitive species. Our study also focuses on importance of gelling agent, namely Gellan gum and agar, since we noticed an obvious superiority of the former in all phases of in vitro development.

  13. Use of psyllium (isubgol) husk as an alternative gelling agent for the ...

    African Journals Online (AJOL)

    SERVER

    2008-04-17

    Apr 17, 2008 ... microalgae (Cyanobacteria) Chroococcus limneticus and eukaryotic green ... psyllium husk were far lower than 722000 cells mL-1 on agar gelled ..... Evidence for the recognition of a secondary structure of carrageenan.

  14. Cassava starch as an alternative cheap gelling agent for the in vitro ...

    African Journals Online (AJOL)

    SERVER

    2007-07-03

    Jul 3, 2007 ... Potato transplants from the liquid medium and cassava starch gelled medium had .... cant interactions during the three generations of sub- .... biodegradable and poses no threat to the environment on ... provision of potato genotypes and facilities for the ... BSc Dissertation University of Malawi, Bunda.

  15. EFFECT OF PERMEABLE VESSEL CLOSURE AND GELLING AGENT ON REDUCTION OF HYPERHYDRICITY IN IN VITRO CULTURE OF CARNATION

    Directory of Open Access Journals (Sweden)

    B. Winarto

    2016-10-01

    Full Text Available Hyperhydricity, an abnormal morphological appearance and physiologicalfunction, is an important problem in carnation tissue culture. The problem causes premature flowering, high occurrence of abnormal shoots, difficulty in transferring hyperhydric plantlets to soil, and low survival rate of plantlets. High relative humidity and the water potential are considered as the key factors involved in the abnormality. Furthermore, permeable culture vessel and gelling agent were assured to be high potential treatment to eliminate it. Objective of this research was to reduce  hyperhydricity in regenerants of carnation using different permeable vessel closures and gelling agents and to assess the multiplication and  acclimatization abilities of recovered shoots. Experiment was arranged in randomized complete block design with four replications. First factor was different types of closure, i.e. cotton wool, plastic wrap, parafilm and aluminium foil, while second one was gelling agents, i.e. bacto agar, phytagel, swallow agar, and Type 900 agar. The recovered shoots were then multiplied, rooted, and acclimatized. The results showed that hyperhydricity was successfully reduced by applying permeable closure (cotton wool and plastic wrap in combination with Type 900 agar. The combination of plastic wrap and Type 900 agar was the most appropriate treatment in reducing hyperhydricity and producing good quality shoots. The treatment reduced the problem down to 23% of total condition of hyperhydricity (100% and increased leaf chlorophyll content from 0.0883 to 0.1288 mg mg-1. The plastic wrap was easily applied and cheaper material compared to cotton wool. The recovered shoots were able to produce 1-3 healthy axillary shoots and easily rooted on half-strength MS. The recovered plantlets were simply acclimatized with survival rate up to 100% on kossas peat + soil (1:1, v/v and flowered 4-5 months after acclimatization with decreasing in number and size of flower.

  16. Preparation of a Novel Calcium Phosphate Cement Using N-methylene Phosphonic Chitosan as a Gelling Agent

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A modified chitosan ( N-methylene phosphonic Chitosan, NMPC ) was synthesized to improve solubility and ability to bind calcium ion. The properties of the raw material chitosan and its derivative NMPC were characterized using FTIR, 1 H-NMR. The aim of this study was to enhance the compressive CPC by reinforcing with NMPC. A formulation consisting of CPC powder, buffer solution and gelling agent was used for preparation of the CPC. CPC powder consisted of tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous ( DCPA ). NMPC which acted as the gelling agent was dissolved iuto KH2 PO4 -Na2 HPO4 buffer solution. Each specimen in the mold was sandwiched between two fritted glass sides and kept for 24 hours. Compressive strengths were determined, the setting product was identified using X-ray diffraction and scanning electron microscopy was used to investigate the hydroxyapatite particles size and porosity. The experimental results showed that the dominating influence on the compressive strengths of CPC-NMPC was the HA particle size, its uniformity and appropriate porosity.

  17. Influence of 6-Benzyladenine and gelling agent on the reduction of hyperhydricity in Tectona grandis L.

    Directory of Open Access Journals (Sweden)

    Elisa Quiala

    2014-06-01

    Full Text Available Running title: Controlling hyperhydricity in teakInfluencia de la 6-Bencilaminopurina y el agente gelificante en la reducción de la hiperhidricidad en Tectona grandis L. Abstract:  The influence of different factors on shoot proliferation and the occurrence of hyperhydricity in teak (Tectona grandis L. have been studied. Four concentrations of BA (2.22, 4.44, 6.66 and 8.88 µM and a control treatment with 0 BA were examined. Aiming at reducing the costs during commercial propagation by using gelrite in stead of agar, the use of both gelling agent in the proliferation and hyperhydricity was tested. In order to evaluate if hyperhydricity can be reduced by increasing the gelrite concentration in the culture medium, three concentrations (2.0, 2.5 and 3.0 g l-1 were tested in combination with 4.44 µM BA.  The proliferation and occurrence of hyperhydricity during 21 successive subcultures were evaluated. The highest proliferation was achieved in the treatments with 6.66 or 8.88 µM BA. They yielded 5.22 and 5.56 shoots/explant, respectively. But also, the highest percent of hyperhydric shoots was achieved in this treatment. Gelrite resulted in a higher proliferation, but also an almost two times higher hyperhydricity as compared to agar-solidified media. Satisfactory reduction in hyperhydricity (18% was achieved with 3.0 g l-1 gelrite. However, the successive subcultures onto proliferation in this treatment favored hyperhydricity compromising shoot quality and its competence to proliferate. In vitro teak plants were ex vitro rooted and then transferred to greenhouse conditions for acclimatization; ten weeks after transfer they were ready for field plantation.Key words: cytokinin; forestry; micropropagation; morpho-physiological disorder; teakAbbreviations: BA- 6-Benzyladenine, MS- Murashige and Skoog basal medium, IBA- Indole-3-butyric acid, ANA-Naphtalene acetic acidResumen: Se estudió la influencia de diferentes factores en la proliferaci

  18. COMIC AGENTS: FROM A POETIC TO AN ANTHROPOLOGICAL PARADIGM OF COMEDY (ARISTOTLE AND ALFRED GELL

    Directory of Open Access Journals (Sweden)

    ANNA KAWALEC

    2016-05-01

    Full Text Available Aristotle was concerned with the comedy genre as a kind of poetry. Its creators, the comic poets, interested him only marginally. This genological approach to its subject-matter dominated the theory and philosophy of art for subsequent centuries as evidenced by the subsequent elaborations of interpretations of Aristotle’s catharsis. The alternative approach focused instead on subjects as creators of art. As a consequence of the long-term development of anthropocentrism in the humanities, however, this approach took over. The “ performative turn” represents its more recent version. It allows one to interpret Poetics and other classical works not in the context of an object (comedy, but in the context of the acting subject. I claim that social anthropology further explores the concept of comedy and itself presumes it in its conceptual foundations and research approach. I elaborate the argument on the basis of the concept of the “spirit of comedy” coined by Alfred Gell .

  19. Response of Syngonium podophyllum L. ‘White Butterfly’ shoot cultures to alternative media additives and gelling agents, and flow cytometric analysis of regenerants

    Directory of Open Access Journals (Sweden)

    JAIME A. TEIXEIRA DA SILVA

    2015-05-01

    Full Text Available Abstract. Teixeira da Silva JA. 2015. Response of Syngonium podophyllum L. ‘White Butterfly’ shoot cultures to alternative media additives and gelling agents, and flow cytometric analysis of regenerants. Nusantara Bioscience 7: 26-32. Syngonium podophyllum L. (arrowhead vine is a popular leafy indoor pot plant whose tissue culture has been established, primarily through in vitro shoot culture, but several interesting aspects have not yet been explored. In this study, cv. ‘White Butterfly’ was used to investigate the response of shoot formation to alternative gelling agents and media additives. Gellan gum (Gelrite® at 2 g/L resulted in greater leaf production, plantlet fresh weight and higher chlorophyll content (SPAD value than all other gelling agents tested, including agar, Bacto agar, phytagel, oatmeal agar, potato dextrose agar, barley starch and corn starch, when on a basal Hyponex® (NPK = 6.5: 6: 19; 3 g/L medium. Several alternative liquid medium additives tested (low and full fat milk, Coca-Cola®, coffee, Japanese green, Oolong and Darjeeling teas negatively impacted plant growth, stunted roots and decreased chlorophyll content (SPAD value of leaves. Plant growth on medium with refined sucrose or table sugar responded similarly. Poor growth was observed when crude extract from a high rebaudioside-containing stevia (Stevia rebaudiana Bertoni line - an artificial sweetener - was used. Leaf tissue from the control did not show any endopolyploidy but low levels of endopolyploidy (8C were detected in some treatments.

  20. Preparation of demipermanent and semipermanent hair dyes gels from ethanol extract of Caesalpinia sappan L. using carbomer as gelling agent

    Science.gov (United States)

    Indrawati, T.; Syahrin, A.; Irpan

    2017-07-01

    Caesalpinia sappan L. (Cs L) contains of essential oils, saponin, brazilin, brazilein, alkaloids, flavonoids and tannins that have a function as cationic natural dyes. The aim of this research was to prepare the ethanol extract of Cs L wood and to prepare demi-permanent and semi-permanent of hair dye gels by using Carbomer of 2 % and 1.5 % as gelling agent and Cs L extract as cationic dyes. The Extract of Cs L was macerated by using ethanol of 96 % as the solvent, and then thickened. Three formula of demi-permanent hair dye gels were made by using Cs L extract of 3 %, 6% and 9 %. Three formula of semi-permanent hair dye gels were made by using Cs L extract of 2.50 %, 7.00 % and 10.50 %. Those hair dyes gels were prepared by swelling and mixing methods. All products of hair dyes gels were evaluated with organoleptic test, homogeneity test, pH test, consistency test, rheological properties test and dyeing effect test. The demi-permanent hair dye gels products had brown to brown dark black colors, pH of 5.05-5.43, homogeny, specific Cs L odor, and had pseudoplastic thixotropic flow characteristic. The semi-permanent hair dye gels products had red color pH of 6.5-6.25, homogeny, Cs L odor, and have pseudoplastic thixotropic flow characteristics. The optimum formula of demi-permanent was formula gel that contained of 6 % extract of Cs L and the optimum formula of permanent hair dyes gel was formula that contained of 10.50 % extract of Cs L.

  1. Isocyanate-Functionalized Chitin and Chitosan as Gelling Agents of Castor Oil

    Directory of Open Access Journals (Sweden)

    José M. Franco

    2013-06-01

    Full Text Available The main objective of this work was the incorporation of reactive isocyanate groups into chitin and chitosan in order to effectively use the products as reactive thickening agents in castor oil. The resulting gel-like dispersions could be potentially used as biodegradable lubricating greases. Three different NCO–functionalized polymers were obtained: two of them by promoting the reaction of chitosan with 1,6-hexamethylene diisocyanate (HMDI, and the other by using chitin instead of chitosan. These polymers were characterized through 1H-NMR, FTIR and thermogravimetric analysis (TGA. Thermal and rheological behaviours of the oleogels prepared by dispersing these polymers in castor oil were studied by means of TGA and small-amplitude oscillatory shear (SAOS measurements. The evolution and values of the linear viscoelasticity functions with frequency for –NCO–functionalized chitosan- and chitin-based oleogels are quite similar to those found for standard lubricating greases. In relation to long-term stability of these oleogels, no phase separation was observed and the values of viscoelastic functions increase significantly during the first seven days of ageing, and then remain almost constant. TGA analysis showed that the degradation temperature of the resulting oleogels is higher than that found for traditional lubricating greases.

  2. Isocyanate-functionalized chitin and chitosan as gelling agents of castor oil.

    Science.gov (United States)

    Gallego, Rocío; Arteaga, Jesús F; Valencia, Concepción; Franco, José M

    2013-06-03

    The main objective of this work was the incorporation of reactive isocyanate groups into chitin and chitosan in order to effectively use the products as reactive thickening agents in castor oil. The resulting gel-like dispersions could be potentially used as biodegradable lubricating greases. Three different NCO-functionalized polymers were obtained: two of them by promoting the reaction of chitosan with 1,6-hexamethylene diisocyanate (HMDI), and the other by using chitin instead of chitosan. These polymers were characterized through 1H-NMR, FTIR and thermogravimetric analysis (TGA). Thermal and rheological behaviours of the oleogels prepared by dispersing these polymers in castor oil were studied by means of TGA and small-amplitude oscillatory shear (SAOS) measurements. The evolution and values of the linear viscoelasticity functions with frequency for -NCO-functionalized chitosan- and chitin-based oleogels are quite similar to those found for standard lubricating greases. In relation to long-term stability of these oleogels, no phase separation was observed and the values of viscoelastic functions increase significantly during the first seven days of ageing, and then remain almost constant. TGA analysis showed that the degradation temperature of the resulting oleogels is higher than that found for traditional lubricating greases.

  3. Oil-in-water emulsion gels stabilized with chia (Salvia hispanica L.) and cold gelling agents: Technological and infrared spectroscopic characterization.

    Science.gov (United States)

    Pintado, T; Ruiz-Capillas, C; Jiménez-Colmenero, F; Carmona, P; Herrero, A M

    2015-10-15

    This paper reports on the development of olive oil-in-water emulsion gels containing chia (Salvia hispanica L.) (flour or seed) and cold gelling agents (transglutaminase, alginate or gelatin). The technological and structural characteristics of these emulsion gels were evaluated. Both structural and technological changes in emulsion gels resulting from chilled storage were also determined. The color and texture of emulsion gels depend on both the cold gelling agents used and chilled storage. Lipid oxidation increased (p < 0.05) during storage in emulsion gels containing transglutaminase or alginate. Analyses of the half-bandwidth of the 2923 cm(-1) band and the area of the 3220 cm(-1) band suggest that the order/disorder of the oil lipid chain related to lipid interactions and droplet size in the emulsion gels could be decisive in determining their textural properties. The half-bandwidth of 2923 cm(-1) band and area of 3220 cm(-1) band did not show significant differences during chilled storage.

  4. Food gels: gelling process and new applications.

    Science.gov (United States)

    Banerjee, Soumya; Bhattacharya, Suvendu

    2012-01-01

    Food gels are viscoelastic substances and several gelled products are manufactured throughout the world. The gelling agents in foods are usually polysaccharides and proteins. In food gels, the polymer molecules are not cross-linked by covalent bonds with the exception of disulphide bonds in some protein gels. Instead, the molecules are held together by a combination of weak inter-molecular forces like hydrogen bonds, electrostatic forces, Van der Waals forces, and hydrophobic interactions. Polysaccharides including hydrocolloids are strongly hydrated in aqueous medium but they tend to have less ordered structures. The mechanism of gelation depends on the nature of the gelling agent(s) and on the conditions of gel formation like the temperature, the presence of ions, the pH, and the concentration of gelling agents, etc. Characterization of gels can be performed in several ways of which rheological measurements are frequently practiced. Multi-component or mixed gel system is an important area of interest in which two or more gelling components are simultaneously used to achieve certain specific structural and functional characteristics. We here discuss about the different gels and gelling agents, the characterization of gels, and the mechanism of gelation with an emphasis on mixed or multi-component gels that would have significant commercial applications.

  5. Emulsifying and gelling properties of weakfish myofibrillar proteins as affected by squid mantle myofibrillar proteins in a model system

    Directory of Open Access Journals (Sweden)

    Daniela Mariel Suarez

    2014-03-01

    Full Text Available The aim of the present work was to investigate the physicochemical, biochemical and functional characteristics of both the myofibrils (MF and actomyosin (AM of squid mantle (Illex argentinus and weakfish (Cynoscion guatucupa muscles, and evaluate the influence of the addition of myofibrilar proteins from the squid mantle on the physicochemical and functional properties of those of the weakfish. After extraction, purification and characterization of the MF and AM of both species, emulsions of each protein fraction from each muscle were formulated. Mixtures of the MF or AM of both species were also analyzed. The emulsifying properties were monitoring using the Emulsifying Activity Index (EAI and Emulsion Stability (ES. In addition, gel pastes were formulated from the squid mantle, weakfish muscle and the mixture of both species, and the following functional properties of the gels assessed: water holding capacity, colour, textural profile analysis (TPA (hardness, elasticity, cohesiveness, gumminess and gel strength. The EAI values of emulsions formulated with the MF of the mantle were significantly (p<0.05 higher than those formulated from those of weakfish. The incorporation of squid MF in the mixture increased the EAI values. Conversely, the highest ES values were obtained with weakfish MF, and the incorporation of MF weakfish in the mixture increased the ES values. Similar EAI and ES behaviours were observed for the AM of the corresponding species. Irrespective of the thermal treatment, the gel strength of the gelled paste of squid muscle was significantly (p<0.05 lower than that of weakfish muscle and of those obtained with the different mixtures. The behaviours of the expressible moisture (EM from the gelled pastes were similar to those of gel strength. Irrespective of the thermal treatment, the pastes formulated with a high weakfish: mantle ratio showed less water loss. The gelled pastes of squid mantle showed the highest values for whiteness

  6. INFLUENCE OF MEDIA GELLING AGENTS ON ROOT BIOMASS AND IN VITRO VA-MYCORRfflZAL SYMBIOSIS OF CARROT WITH GIGASPORA MARGARITA

    Directory of Open Access Journals (Sweden)

    ANJALI VERMA

    1997-01-01

    Full Text Available An in vitro study with Ri-TDNA transformed roots of carrot (Daucus carota was carried out to evaluate the role of macro-elements contributed as impurities in the gelling agent (phytagel over and above those present in the minimal (M medium. Production of root biomass was taken as a measure to quantify the influence of macro-elements added to the minimal medium. The levels of phosphorus when adjusted to 1.19 mg/1 and 1.09 mg/l, lead to dry root biomass production at par with the control. Attempts made to lower the amount of impurities in phytagel by de-ionization using different alkalies, proved NaOH to give the best results in terms of relatively high amount of root biomass. In an in vitro dual culture system with carrot as host and Gigaspora margarita as the vesicular-arbuscular mycorrhizal fungus, phytagel impurities helped to produce maximum number of infection units and auxiliary cells when phytagel was added to the minimal medium.

  7. Monitoring collagen gelling by elastic scattering spectroscopy (ESS)

    OpenAIRE

    Jawad, H.; Austwick, M.; MacRobert, S.; Kuraishi, A.; Tully, F.; Alkseeva, T.; Brown, R.

    2011-01-01

    Collagen is being used extensively in tissue engineering and on a larger scale in the field of cosmetic surgery. It is either used as a gel or plastically compressed sheet. The fundamental science behind collagen gelling has been studied but little is known about the precise timing of gelling and the variables that affect gelling in the first 30 minutes. Critically, before collagen can be engineered as a predictable functional material we must be able to control fibril aggregation and gel for...

  8. Affective Embodied Conversational Agents for Natural Interaction

    OpenAIRE

    Cerezo, Eva; Baldassarri, Sandra; Hupont, Isabelle; Seron, Francisco J.

    2008-01-01

    This chapter presents a completely automated real-time character-based interface, where a scriptable affective humanoid 3D agent interacts with the user. Special care has been taken in making it possible multimodal natural user-agent interaction: communication is accomplished via text, image and voice (natural language). Our embodied agents are equipped with an emotional state which can be modified throughout the conversation with the user, and depends on the emotional state detected from the...

  9. Aqueous two-phase system cold-set gelation using natural and recombinant probiotic lactic acid bacteria as a gelling agent.

    Science.gov (United States)

    Léonard, Lucie; Husson, Florence; Langella, Philippe; Châtel, Jean-Marc; Saurel, Rémi

    2016-05-01

    The present study aimed to entrap probiotic lactic acid bacteria (LAB) in a sodium alginate and sodium caseinate aqueous two-phase gel system. The natural acidifying properties of two therapeutic probiotic LAB were exploited to liberate calcium ions progressively from calcium carbonate (CaCO3), which caused the gelation of the co-existing phases. Bi-biopolymeric matrix gelation of GDL/CaCO3 or LAB/CaCO3 was monitored by dynamic rheological measurements, and the final gels were characterized by frequency dependence measurements and confocal laser scanning microscopy. Weak to strong gels were formed with an elastic modulus G' from 10 to 1.000Pa, respectively. After cold-set gelation of our system, confocal laser scanning microscopy showed spherical protein microdomains trapped within a calcium alginate network. LAB cells were stained to study their partition in the self-gelling matrices. Our LAB strains showed two different behaviors, which may relate to the exopolysaccharide production: (i) Lactobacillus plantarum CNRZ1997 cells were found mainly in continuous alginate networks, whereas (ii) Lactococcus lactis cells were localized in protein microdomains. This alginate-caseinate phase-separated system that was self-gelled by LAB cells may be an innovative approach for immobilizing and protecting LAB cells.

  10. Biochemical and morpho-anatomical analyses of strawberry vitroplants hyperhydric tissues affected by BA and gelling agents

    Directory of Open Access Journals (Sweden)

    Leticia Mascarenhas Pereira Barbosa

    2013-04-01

    Full Text Available In vitro propagation has become an effective practice for large-scale production of strawberry plants. The objective of this study was to evaluate the hyperhydricity and the multiplication capacity of two strawberry varieties (Fragaria x ananassa Duch. 'Dover' and 'Burkley' propagated in vitro. Plants maintained in MS medium supplemented with 1.0 mg L-1 BA were individualized and transferred to the same medium solidified with Agar (6.5 g L-1 or Phytagel® (2.5 g L-1 and BA at different concentrations (0; 0.5; 1.0; 2.0 and 3.0 mg L-1. Biochemical and anatomical analyses were carried out, as well as the analysis of the morphological hyperhydricity characteristics. The analysis of data showed: a the increase in cytokinin concentration increased hyperhydricity frequency in both varieties; b at concentrations up to 2.0 mg L-1 BA, the replacement of Agar by Phytagel® induced a higher formation of hyperhydric shoots; and c the addition of BA induced oxidative stress, which is characterized by increased antioxidant activity and lipid peroxidation, as well as alterations at the cellular level, such as malformation of stomata and epidermal cells. In conclusion, the culture medium containing 0.5 mg L-1 BA solidified with Agar provided lower hyperhydricity percentages in association with higher rates of shoot proliferation in strawberry.

  11. Gelled Electrolytes For Lithium Batteries

    Science.gov (United States)

    Nagasubramanian, Ganesan; Attia, Alan; Halpert, Gerald

    1993-01-01

    Gelled polymer electrolyte consists of polyacrylonitrile (PAN), LiBF4, and propylene carbonate (PC). Thin films of electrolyte found to exhibit stable bulk conductivities of order of 10 to the negative 3rd power S/cm at room temperature. Used in thinfilm rechargeable lithium batteries having energy densities near 150 W h/kg.

  12. The Peroxidase/H2O2 System as a Free Radical-Generating Agent for Gelling Maize Bran Arabinoxylans: Rheological and Structural Properties

    Directory of Open Access Journals (Sweden)

    Erika Salas-Muñoz

    2011-10-01

    Full Text Available The oxidative gelation of maize bran arabinoxylans (MBAX using a peroxidase/H2O2 system as a free radical-generating agent was investigated. The peroxidase/H2O2 system led to the formation of dimers and trimer of ferulic acid as covalent cross-link structures in the MBAX network. MBAX gels at 4% (w/v presented a storage modulus of 180 Pa. The structural parameters of MBAX gels were calculated from swelling experiments. MBAX gels presented a molecular weight between two cross-links (Mc, a cross-linking density (ρc and a mesh size (x of 49 × 103 g/mol, 30 × 10−6 mol/cm3 and 193 nm, respectively.

  13. Gelled Propellants for Reduced Temperature Operation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is responsive to NASA 2004 SBIR objectives (under Topic X6.05) seeking gelled propellant formulations "for long-duration missions involving low-power...

  14. Effect of mineral salts, vitamins and gelling agents on somatic embryogenesis in Coffea arabica L. ‘Catuai Influência dos sais minerais, vitaminas e agentes gelificantes, na embriogénese somática de Coffea arabica L. ‘Catuai’

    Directory of Open Access Journals (Sweden)

    Maria Cristina Simões-Costa

    2010-12-01

    Full Text Available Somatic embryogenesis was induced in leaf explants of Coffea arabica ‘Catuai’. A two steps procedure was followed: explants were first cultured in a callus induction medium containing 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine and later transferred to an auxin free embryo induction and conversion medium. The influence of three mineral salt formulations: Schenk & Hildebrandt (1972 full salt solution, Murashige & Skoog (1962 full and half salt solutions; two vitamin mixtures: Gamborg et al. (1968 and Schenk & Hildebrandt (1972 and two gelling agents: agar and gelrite, was assessed. Best embryogenic response was obtained in culture medium with Schenk & Hildebrandt (1972 mineral salts, Gamborg et al. (1968 vitamins and agar. In this medium, somatic embryos were observed after 18 weeks of culture and, six weeks later, 85% of the explants presented an average of 18 somatic embryos per explant.Foi induzida embriogénese somática em explantados foliares de Coffea arabica ‘Catuai’. A metodologia seguida incluiu duas fases: os explantados foram cultivados inicialmente em meio de indução de callus, suplementado com ácido 2,4-diclorofenoxiacético e 6-benzilaminopurina, tendo sido depois transferidos para meio sem auxina, com o objectivo de induzir a formação e o desenvolvimento de embriões. Testou-se a influência de três diferentes composições de sais minerais: sais minerais de Schenk & Hildebrandt (1972, sais minerais (concentração completa e ½ concentração de Murashige & Skoog (1962; duas formulações vitamínicas: Gamborg et al. (1968 e Schenk & Hildebrandt (1972 e dois agentes gelificantes: agar e gelrite. A melhor resposta relativamente à embriogénese somática foi registada em meio de cultura com os sais minerais de Schenk & Hildebrandt (1972, as vitaminas de Gamborg et al. (1968 e agar. Neste meio de cultura verificou-se a presença de embriões somáticos após 18 semanas de cultura e, seis semanas mais tarde

  15. Murray Gell-Mann, A Short Appreciation

    CERN Document Server

    Hartle, James B

    2015-01-01

    On September 25, 2014 Murray Gell-Mann was presented with the Helmholz Medal of the Berlin Brandenburg Academy of Sciences and Humanities in a ceremony at the Santa Fe Institute. The author, among others, was asked to speak for fifteen minutes on Murray and his accomplishments. The following is an edited transcription of the author's speaking text.

  16. Gelling nature of aluminum soaps in oils.

    Science.gov (United States)

    Wang, Xiaorong; Rackaitis, Mindaugas

    2009-03-15

    Aluminum soaps are notable for their ability to form soap-hydrocarbon gels of high viscosity. For more than half a century, it has been believed that the gelling mechanism is due to a formation of polymeric chains of aluminum molecules with the aluminum atoms linking along the axis and with the fatty acid chain extended sideways. Here we report results from an investigation using high-resolution electron microscopy and rheology measurements that clearly resolve the ambiguity. Our results reveal that the gelling mechanism stems from the formation of spherical nano-sized micelles from aluminum soap molecules, and those colloidal micelle particles then aggregate into networks of highly fractal and jammed structures. The earlier proposed polymer chain-like structure is definitely incorrect. The discovery of aluminum soap particles could expand application of these materials to new technologies.

  17. Effect of molecular characteristics of Konjac glucomannan on gelling and rheological properties of Tilapia myofibrillar protein.

    Science.gov (United States)

    Jian, Wenjie; Wu, Huayi; Wu, Lanlan; Wu, Yunhui; Jia, Lina; Pang, Jie; Sun, Yuan-Ming

    2016-10-05

    Konjac glucomannan (KGM) is an important gelling agent in composite gels. This study aimed to investigate the effects of KGM molecular characteristics (molecular weight, size and conformation) on gelling properties of Tilapia myofibrillar protein (TMP). In this work, TMP composite gels were prepared under neutral pH with varying KGM (native KGM, 10kGy-KGM, 20kGy-KGM, and 100kGy-KGM) of different molecular characteristics. Native KGM, 10kGy-KGM, and 20kGy-KGM exerted negative effect on gel strength or whiteness of TMP gels. Interestingly 100kGy-KGM improved gelling properties and whiteness of TMP gels. Such effects presented by varying KGM were attributed the physical filling behaviors and the interaction between KGM and TMP. These behaviors or interactions are resulted from different molecular size and conformation. Smaller molecular size (root-mean square radius, Rz 20.2nm) and approximated spherical conformation in 100kGy-KGM enhanced its interaction with TMP and maintained its compact and smooth structure, but the larger molecular size (Rz≥40.2nm) and random coil conformation in other KGMs inhibited part of actins from gelling and deteriorated the network structure. Our study provided principle knowledge to understand the structure-functions relationships of KGM-TMP composite gels. These results can be used to provide theoretical guidance for surimi gel processing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Flow visualization of a rocket injector spray using gelled propellant simulants

    Science.gov (United States)

    Green, James M.; Rapp, Douglas C.; Roncace, James

    1991-01-01

    A study was conducted at NASA-Lewis to compare the atomization characteristics of gelled and nongelled propellant simulants. A gelled propellant simulant composed of water, sodium hydroxide, and an acrylic acid polymer resin (as the gelling agent) was used to simulate the viscosity of an aluminum/PR-1 metallized fuel gel. Water was used as a comparison fluid to isolate the rheological effects of the water-gel and to simulate nongelled RP-1. The water-gel was injected through the central orifice of a triplet injector element and the central post of a coaxial injector element. Nitrogen gas flowed through the outer orifices of the triplet injector element and through the annulus of the coaxial injector element and atomized the gelled and nongelled liquids. Photographs of the water-gel spray patterns at different operating conditions were compared with images obtained using water and nitrogen. A laser light was used for illumination of the sprays. The results of the testing showed that the water sprays produced a finer and more uniform atomization than the water-gel sprays. Rheological analysis of the water-gel showed poor atomization caused by high viscosity of water-gel delaying the transition to turbulence.

  19. In-situ gelling polymers for biomedical applications

    CERN Document Server

    2015-01-01

    This book presents the research involving in situ gelling polymers and can be used as a guidebook for academics, industrialists and postgraduates interested in this area. This work summaries the academic contributions from the top authorities in the field and explore the fundamental principles of in situ gelling polymeric networks, along with examples of their major applications. This book aims to provide an up-to-date resource of in situ gelling polymer research.

  20. Improvising Linguistic Style Social and Affective Bases for Agent Personality

    CERN Document Server

    Walker, M A; Whittaker, S J; Walker, Marilyn A.; Cahn, Janet E.; Whittaker, Stephen J.

    1997-01-01

    This paper introduces Linguistic Style Improvisation, a theory and set of algorithms for improvisation of spoken utterances by artificial agents, with applications to interactive story and dialogue systems. We argue that linguistic style is a key aspect of character, and show how speech act representations common in AI can provide abstract representations from which computer characters can improvise. We show that the mechanisms proposed introduce the possibility of socially oriented agents, meet the requirements that lifelike characters be believable, and satisfy particular criteria for improvisation proposed by Hayes-Roth.

  1. Identification and Development of a Gelled Fuel through the Use of Liquid Gelling Agents

    Science.gov (United States)

    2008-02-01

    polyacrylic acid polymer (solid) that can be used to transform many liquid products into a gel. It is suggested for use as an all-purpose thickener and...Benzene and polystyrene • Aluminum soaps (e.g., aluminum stearate) • Alcohols plus laundry detergent (aluminum soaps) Although all systems above

  2. A Novel Pectin Material: Extraction, Characterization and Gelling Properties

    Directory of Open Access Journals (Sweden)

    Agustin Rascón-Chu

    2010-09-01

    Full Text Available A novel pectin was acid extracted from chickpea husk (CHP. CHP presented a 67% (w/w of galacturonic acid, an intrinsic viscosity of 374 mL/g and a viscosimetric molecular weight of 110 kDa. Fourier transform infrared spectroscopy spectrum of CHP indicated a degree of esterification of about 10%. The CHP-calcium system formed ionic gels with a storage (G’ modulus of 40 Pa and gel set time (G’ > G’’ of 3 min at 1% (w/v, and a G’ of 131 Pa and gel set time of 1 min at 2% (w/v. The G’ of CHP gels was not greatly affected by temperature. The results attained suggest that chickpea husk can be a potential source of a gelling pectin material.

  3. A novel pectin material: extraction, characterization and gelling properties.

    Science.gov (United States)

    Urias-Orona, Vania; Rascón-Chu, Agustin; Lizardi-Mendoza, Jaime; Carvajal-Millán, Elizabeth; Gardea, Alfonso A; Ramírez-Wong, Benjamín

    2010-09-28

    A novel pectin was acid extracted from chickpea husk (CHP). CHP presented a 67% (w/w) of galacturonic acid, an intrinsic viscosity of 374 mL/g and a viscosimetric molecular weight of 110 kDa. Fourier transform infrared spectroscopy spectrum of CHP indicated a degree of esterification of about 10%. The CHP-calcium system formed ionic gels with a storage (G') modulus of 40 Pa and gel set time (G' > G″) of 3 min at 1% (w/v), and a G' of 131 Pa and gel set time of 1 min at 2% (w/v). The G' of CHP gels was not greatly affected by temperature. The results attained suggest that chickpea husk can be a potential source of a gelling pectin material.

  4. Improving reservoir conformance using gelled polymer systems. Annual report, September 15, 1993--September 24, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.; Willhite, G.P.

    1995-07-01

    The objectives of the research program are to (1) identify and develop polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) determine the performance of these systems in bulk and in porous media, and (3) develop methods to predict their performance in field applications. The research focuses on three types of aqueous gel systems - a polysaccharide (KUSP1) that gels as a function of pH, a polyacrylamide-chromium(III) system and a polyacrylamide-aluminum citrate system. This report describes work conducted during the second year of a three-year program. Progress was made in the utilization of KUSP1 as a gelling agent. It was shown that gels can be formed in situ in porous media using CO{sub 2} or ester hydrolysis to lower pH. An ester was identified that could be used in field-scale operations. It was determined that KUSP1 will form strong gels when ortho boric acid is added to the system. It was also determined, in cooperation with Abbott Laboratories, that KUSP1 can be produced on a commercial scale. Rheological studies showed that shear rate significantly affects gelation time and gel strength. The effect of rock-fluid interactions at alkaline conditions was examined experimentally and through mathematical modeling. A model was developed that treats non-equilibrium conditions and this is an improvement over previously published models.

  5. Heather Gell and Music Education in the Community

    Science.gov (United States)

    Nash, Sandra

    2014-01-01

    Kindergartener and Dalcroze teacher, Heather Gell (1896-1988), brought music to thousands of Australian children and adults. The community touched by Gell was vast: it included her classes in studios and teacher training colleges, "listeners in" to her radio programs, viewers of her television programs, Dalcroze trainees, and people in…

  6. Gelled Complex Fluids: Combining Unique Structures with Mechanical Stability.

    Science.gov (United States)

    Stubenrauch, Cosima; Gießelmann, Frank

    2016-03-01

    Gelled complex fluids are soft materials in which the microstructure of the complex fluid is combined with the mechanical stability of a gel. To obtain a gelled complex fluid one either adds a gelator to a complex fluid or replaces the solvent in a gel by a complex fluid. The most prominent example of a "natural" gelled complex fluid is the cell. There are various strategies by which one can form a gelled complex fluid; one such strategy is orthogonal self-assembly, that is, the independent but simultaneous formation of two coexisting self-assembled structures within one system. The aim of this Review is to describe the structure and potential applications of various man-made gelled complex fluids and to clarify whether or not the respective system is formed by orthogonal self-assembly.

  7. An Automatic Evaluation Method for Conversational Agents Based on Affect-as-Information Theory

    OpenAIRE

    Ptaszynski, Michal; Dybala, Pawel; Rzepka, Rafal; Araki, Kenji

    2010-01-01

    This paper presents a method for automatic evaluation of conversational agents. The method consists of several steps. First, an affect analysis system is used to detect users' general emotional engagement in the conversation and classify their specific emotional states. Next, we interpret this data with the use of reasoning based on Affect-as-Information Theory to obtain information about users' general attitudes to the conversational agent and its performance. The affect analysis system was ...

  8. Adaptation gap hypothesis: How differences between users’ expected and perceived agent functions affect their subjective impression

    Directory of Open Access Journals (Sweden)

    Takanori Komatsu

    2011-02-01

    Full Text Available We describe an “adaptation gap” that indicates the differences between the functions of artificial agents that users expect before starting their interactions and the functions they perceive after their interactions. We investigated the effect of this adaptation gap on users’ impressions of artificial agents because any variations in impression before and after the start of an interaction determines whether the user feels that this agent is worth interacting with. The results showed that positive or negative signs of the adaptation gap and subjective impression scores of agents before the experiment significantly affected the users’ final impressions of the agents.

  9. A microbial trigger for gelled polymers

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, S.; Bryant, R.; Zhu, T.

    1995-12-31

    A process using a microbially gelled biopolymer was developed and used to modify permeability in coreflood experiments. Alkaline-soluble curdlan biopolymer was mixed with microbial nutrients and acid-producing alkaliphilic bacteria, and injected into Berea sandstone cores. Concurrent bottle tests with the polymer solution were incubated beside the core. Polymer in the bottle tests formed rigid gel in 2-5 days at 27{degree}C. After 7 days incubation, 25-35 psi fluid pressure was required to begin flow through the cores. Permeability of the cores was decreased from 852 md to 2.99 md and from 904 md to 4.86 md, respectively, giving residual resistance factors of 334 and 186.

  10. Composite resin bond strength to caries-affected dentin contaminated with 3 different hemostatic agents.

    Science.gov (United States)

    Khoroushi, Maryam; Hosseini-Shirazi, Moeen; Farahbod, Foroozan; Keshani, Fatemeh

    2016-01-01

    Bonding of composite resins to sound and caries-affected dentin in cervical areas may necessitate the use of hemostatic agents to control sulcular fluid and hemorrhage. The aim of this in vitro study was to evaluate the bond strengths of a self-etching adhesive system to sound and caries-affected dentin after the use of 3 different hemostatic agents. Composite resin cylinders were bonded to 48 caries-affected and 48 sound dentin surfaces in 8 groups. Groups 1-4 utilized caries-affected dentin: group 1, uncontaminated control; 2, ViscoStat; 3, ViscoStat Clear; and 4, trichloroacetic acid (TCA). Groups 5-8 utilized sound dentin: group 5, uncontaminated control; 6, ViscoStat; 7, ViscoStat Clear; and 8, TCA. The hemostatic agents were applied for 2 minutes and rinsed. After 500 rounds of thermocycling, shear bond strength tests were carried out. Data were analyzed with 1- and 2-way analyses of variance, t test, and post hoc Tukey tests at a significance level of P composite resin to caries-affected dentin was significantly reduced compared to that with sound dentin. Among the studied hemostatic agents, ViscoStat resulted in a greater decrease in dentin bond strength. Contamination of both sound and caries-affected dentin with hemostatic agents decreased composite resin bond strength. Of the 3 hemostatic agents used, ViscoStat Clear appeared to have the least detrimental effect on bond strength.

  11. Design and Characterization of Bioadhesive In-Situ Gelling Ocular Inserts of Gatifloxacin Sesquihydrate

    Directory of Open Access Journals (Sweden)

    Mishra D.N.

    2008-03-01

    Full Text Available Background and purpose of the study: Several polymeric systems have been used to fabricate ocular inserts for better ocular bioavailability and retention to drug of which gelling systems have shown advantages of convenient administration and increased contact time. The purpose of the present study was to develop a bioadhesive in-situe gelling ocular insert of Gatifloxacin using polymeric system of sodium alginate as gelling and chitosan as bioadhesive agent.Materials and methods: Polymeric ocular inserts of Gatifloxacin sesquehydrate (GS were composed using sodium alginate and chitosan with glycerin as plasticizer by solvent casting method. The ocular inserts were investigated for physicochemical properties (thickness, weight variation, folding endurance and surface pH, mechanical strength (tensile strength, elongation at break, swelling index, and bioadhesion parameters. In vitro release studies were carried using a fabricated donor-receptor compartment model. Results: Cumulative drug released from the formulation ranged from 95-99% within 8-12h. The formulation D (2% sodium alginate and 1% chitosan sustained the drug release for the longest period of time (12h. Zero-order release of the drug was from optimized formulation D. A high correlation coefficient (r=0.9845 was recorded between in vitro and in vivo drug release.Conclusion: Gatifloxacin sesquehydrate inserts have appreciable film forming properties and were found to posses good antimicrobial efficacy.

  12. Suitability of various plant derived gelling agents as agar substitute ...

    African Journals Online (AJOL)

    USER

    2012-06-05

    Jun 5, 2012 ... of three test fungi (Trichoderma harzianum, Alternaria alternata and Alternaria solani) as good as agar. Guar gum .... validate the available data and to look for additional cheap and .... A revised medium for rapid growth and.

  13. Gelucire Based In Situ Gelling Emulsions: A Potential Carrier for Sustained Stomach Specific Delivery of Gastric Irritant Drugs

    Directory of Open Access Journals (Sweden)

    Ashwin Saxena

    2013-01-01

    Full Text Available Non steroidal anti-inflammatory drugs (NSAIDs are commonly prescribed medications to the geriatric patients for the treatment of arthritis and other painful disorders. The major side effects of NSAIDs are related to their effects on the stomach and bowels. The present study concerns assessment of the potential of liquid in situ gelling emulsion formulations (emulgels as patient compliant stomach specific sustained release carrier for the delivery of highly gastric irritant drug, Piroxicam. Emulgels were prepared, without using any emulgent, by mixing different concentrations of molten Gelucire 39/01 with low viscosity sodium alginate solution prepared in deionized water at 50°C. CaCO3 was used as buoyancy imparting as well as crosslinking agent. Emulgels so prepared were homogenous, physically stable, and rapidly formed into buoyant gelled mass when exposed to simulated gastric fluid (SGF, pH 1.2. Drug release studies carried out in SGF revealed significant retardation (P<0.05 of Piroxicam release from emulgels compared to conventional in situ gelling formulations prepared without Gelucire 39/01. Pharmacodynamic studies carried out in albino rats revealed significantly increased analgesic/anti-inflammatory response from in situ emulgels compared to conventional in situ gelling formulations. Further, in vivo toxicity studies carried out in albino rats revealed no signs of gastric ulceration upon prolonged dosing.

  14. Gelling properties of microparticulated whey proteins.

    Science.gov (United States)

    Dissanayake, Muditha; Kelly, Alan L; Vasiljevic, Todor

    2010-06-09

    Subjecting whey proteins to high-pressure shearing with or without heating, commonly termed microparticulation, results in novel ingredients with modulated functionalities. Gelling properties of microparticulated whey proteins (MWP) were specifically assessed in this study. MWP powders were produced from commercial cheese whey retentate, standardized to 10% (w/w) protein, and subjected to microfluidization (MFZ) at 140 MPa either with or without prior heat-induced denaturation, followed by spray-drying. Gels were created from aqueous MWP dispersions either by heating at 90 degrees C for 20 min or by allowing gels to form at ambient temperature through addition of glucano-delta-lactone and/or NaCl. MWP powders produced from unheated WP dispersions created firm gels upon heating, whereas those produced from denatured WP gave only cold-set gels. Covalent and noncovalent protein-protein interactions were involved during both heat- and cold-induced gelation. Hydrophobic interactions were more pronounced during aggregation of bovine serum albumin. In conclusion, microparticulation of WP resulted in heat- and cold-set gels with different molecular and physical characteristics from those of untreated controls.

  15. Factors affecting in vitro bond strength of bonding agents to human dentin.

    Science.gov (United States)

    Powers, John M; O'Keefe, Kathy L; Pinzon, Lilliam M

    2003-09-01

    Four generations of total-etch (fourth, fifth) and self-etching (sixth, seventh) bonding agents for use with resin composites are commercially available in the United States. Innovations in bonding agents include: filled systems, release of fluoride and other agents, unit dose, self-cured catalyst, option of etching with either phosphoric acid or self-etching primer, and pH indicators. Factors that can affect in vitro bond strength to human dentin include substrate (superficial dentin, deep dentin; permanent versus primary teeth; artificial carious dentin), phosphoric acid versus acidic primers, preparation by air abrasion and laser, moisture, contaminants, desensitizing agents, astringents, and self-cured restorative materials. This article reviews studies conducted at the Houston Biomaterials Research Center from 1993 to 2003. Results show that in vitro bond strengths can be reduced by more than 50% when bonding conditions are not ideal.

  16. I Feel You: The Design and Evaluation of a Domotic Affect-Sensitive Spoken Conversational Agent

    Directory of Open Access Journals (Sweden)

    Juan Manuel Montero

    2013-08-01

    Full Text Available We describe the work on infusion of emotion into a limited-task autonomous spoken conversational agent situated in the domestic environment, using a need-inspired task-independent emotion model (NEMO. In order to demonstrate the generation of affect through the use of the model, we describe the work of integrating it with a natural-language mixed-initiative HiFi-control spoken conversational agent (SCA. NEMO and the host system communicate externally, removing the need for the Dialog Manager to be modified, as is done in most existing dialog systems, in order to be adaptive. The first part of the paper concerns the integration between NEMO and the host agent. The second part summarizes the work on automatic affect prediction, namely, frustration and contentment, from dialog features, a non-conventional source, in the attempt of moving towards a more user-centric approach. The final part reports the evaluation results obtained from a user study, in which both versions of the agent (non-adaptive and emotionally-adaptive were compared. The results provide substantial evidences with respect to the benefits of adding emotion in a spoken conversational agent, especially in mitigating users’ frustrations and, ultimately, improving their satisfaction.

  17. I feel you: the design and evaluation of a domotic affect-sensitive spoken conversational agent.

    Science.gov (United States)

    Lutfi, Syaheerah Lebai; Fernández-Martínez, Fernando; Lorenzo-Trueba, Jaime; Barra-Chicote, Roberto; Montero, Juan Manuel

    2013-08-13

    We describe the work on infusion of emotion into a limited-task autonomous spoken conversational agent situated in the domestic environment, using a need-inspired task-independent emotion model (NEMO). In order to demonstrate the generation of affect through the use of the model, we describe the work of integrating it with a natural-language mixed-initiative HiFi-control spoken conversational agent (SCA). NEMO and the host system communicate externally, removing the need for the Dialog Manager to be modified, as is done in most existing dialog systems, in order to be adaptive. The first part of the paper concerns the integration between NEMO and the host agent. The second part summarizes the work on automatic affect prediction, namely, frustration and contentment, from dialog features, a non-conventional source, in the attempt of moving towards a more user-centric approach. The final part reports the evaluation results obtained from a user study, in which both versions of the agent (non-adaptive and emotionally-adaptive) were compared. The results provide substantial evidences with respect to the benefits of adding emotion in a spoken conversational agent, especially in mitigating users' frustrations and, ultimately, improving their satisfaction.

  18. Dynamics Research on the Gelling Course of Silica Sol

    Institute of Scientific and Technical Information of China (English)

    LUYi-chun; LIZai-geng

    1995-01-01

    Dreipping electrolytes into silica sol ,gelling reaction will occur,The research indicates:this is a complicated physicemistry course,which consists of a pre-reaction and a polymerizaion,The former controls the whole course,and in which electronic layers of the sol's particles be-come more and more thiner,but with incresing of the sol concentration,its control force will be diminished ,till the fast-coagulation ,the gelling couse becomes o-controlled,The latter is an in-finite polymeric chani-reaction.The result of gelatination is to produce a very big plymeric molecule-gel,which involves in all space,includes all water ,and its molecular weight is in-definite big.The researh also indicates:the dy-namic course of the gelling could be described quantitaively by an experience formula:lgt=-nlgc+B,All of the characteristic values have definite physical meaning,Electronic value of the contrary-inos is the biggest influential factor ,the natures of the contrary-ions and the natures of the same-electronic-inos have a few influential forces on the characteristic values,The temperature increasing makes the gelling reaction fast.

  19. Determination of the infectious nature of the agent of acute hepatopancreatic necrosis syndrome affecting penaeid shrimp.

    Science.gov (United States)

    Tran, Loc; Nunan, Linda; Redman, Rita M; Mohney, Leone L; Pantoja, Carlos R; Fitzsimmons, Kevin; Lightner, Donald V

    2013-07-09

    A new emerging disease in shrimp, first reported in 2009, was initially named early mortality syndrome (EMS). In 2011, a more descriptive name for the acute phase of the disease was proposed as acute hepatopancreatic necrosis syndrome (AHPNS). Affecting both Pacific white shrimp Penaeus vannamei and black tiger shrimp P. monodon, the disease has caused significant losses in Southeast Asian shrimp farms. AHPNS was first classified as idiopathic because no specific causative agent had been identified. However, in early 2013, the Aquaculture Pathology Laboratory at the University of Arizona was able to isolate the causative agent of AHPNS in pure culture. Immersion challenge tests were employed for infectivity studies, which induced 100% mortality with typical AHPNS pathology to experimental shrimp exposed to the pathogenic agent. Subsequent histological analyses showed that AHPNS lesions were experimentally induced in the laboratory and were identical to those found in AHPNS-infected shrimp samples collected from the endemic areas. Bacterial isolation from the experimentally infected shrimp enabled recovery of the same bacterial colony type found in field samples. In 3 separate immersion tests, using the recovered isolate from the AHPNS-positive shrimp, the same AHPNS pathology was reproduced in experimental shrimp with consistent results. Hence, AHPNS has a bacterial etiology and Koch's Postulates have been satisfied in laboratory challenge studies with the isolate, which has been identified as a member of the Vibrio harveyi clade, most closely related to V. parahemolyticus.

  20. Use of olive oil-in-water gelled emulsions in model turkey breast emulsions

    Science.gov (United States)

    Serdaroğlu, M.; Öztürk, B.

    2017-09-01

    Today, gelled emulsion systems offer a novel possibility in lipid modification of meat products. In this study, we aimed to investigate the quality characteristics of model turkey emulsions that were prepared with olive oil-in-water gelled emulsion (GE) as partial or total beef fat replacer. The results indicated that while most of the GE treatments showed equivalent emulsion characteristics in terms of emulsion stability, water-holding capacity and cook yield, utilization of 100% GE as the lipid source could increase total expressible fluid of the model turkey emulsion and thus negatively affect the quality. Utilization of GE was effective in total fat reduction, as the model turkey emulsions formulated with more than 50% GE had significantly lower fat content compared to full-beef fat control model emulsion. However, beef fat replacement with GE produced considerable changes in colour parameters. Finally, it was concluded that utilization of GE as a partial beef fat replacer has good potential to enhance stability and reduce total fat in turkey meat emulsion products.

  1. 一种胶体电解液胶凝时间的测定方法%The method measuring the gelling time of gelled electrolyte

    Institute of Scientific and Technical Information of China (English)

    代少振; 王亚斌; 徐丹; 万南红; 刘孝伟

    2015-01-01

    The turbidimetry method measuring the gelling time of gelled electrolyte has been established in this paper. The gelling time of gelled electrolyte can be measured simply, intuitively and accurately by this method, which provides the support of experimental method for development of gelled lead-acid battery.%本文建立了浊度法测定胶体电解液胶凝时间的方法。该方法能简便、直观、准确地测定胶体电解液的胶凝时间,为胶体电池的电解液研制提供实验方法支持。

  2. The agency of Gell in the anthropology of art

    Directory of Open Access Journals (Sweden)

    Caleb Faria Alves

    2008-01-01

    Full Text Available While delineating the parameters for an anthropology of art, Alfred Gell's famous book, Art and Agency, overlooked, for the most part, anthropological tradition. This raises questions as embarrassing as they are ignored: is it possible to produce good theory with no references to achieved knowledge in this particular field? Are the subjects within anthropology so differently pursued that it is not possible to refer to a common way of approaching them? What exactly do we lose with such a self-centered narrative? My point of view is that theory cannot be treated like a list of sentences that can be added to one another, according to their isolated importance. This article proposes an analysis of Alfred Gell's narrative, of how he connects its propositions. I will examine, overall, his readings, the authors he quotes like Peirce, Sally Price and others, and how he fits them along his argumentation. The objective of this exercise is to put in evidence, beyond Gell's definitions, some conceptions about art contained in his formulations, and to enlarge the range of potential references available for an anthropology of art.

  3. Hybridization of an invasive shrub affects tolerance and resistance to defoliation by a biological control agent

    Science.gov (United States)

    Williams, Wyatt I.; Friedman, Jonathan M.; Gaskin, John F.; Norton, Andrew P.

    2014-01-01

    Evolution has contributed to the successful invasion of exotic plant species in their introduced ranges, but how evolution affects particular control strategies is still under evaluation. For instance, classical biological control, a common strategy involving the utilization of highly specific natural enemies to control exotic pests, may be negatively affected by host hybridization because of shifts in plant traits, such as root allocation or chemical constituents. We investigated introgression between two parent species of the invasive shrub tamarisk (Tamarix spp.) in the western United States, and how differences in plant traits affect interactions with a biological control agent. Introgression varied strongly with latitude of origin and was highly correlated with plant performance. Increased levels of T. ramosissima introgression resulted in both higher investment in roots and tolerance to defoliation and less resistance to insect attack. Because tamarisk hybridization occurs predictably on the western U.S. landscape, managers may be able to exploit this information to maximize control efforts. Genetic differentiation in plant traits in this system underpins the importance of plant hybridization and may explain why some biological control releases are more successful than others.

  4. Meta-analysis of Factors Affecting Occupational and Professional Performance of Agricultural Extension Agents

    Directory of Open Access Journals (Sweden)

    Mahshid Bahadori

    2016-03-01

    Full Text Available The purpose of this research is to do a meta-analysis of studies about the results of researches conducted related to the factors affecting the occupational and professionalism performance in the field of agricultural extension agents, in order to integrate the results of research independently carried out to obtain more accurate and more cohesive results. In order to achieve the goal, 177 researches made on the occupational and professional performance (occupational performance, professional performance, professional competence, professional developmentwere collected from sites magiran & sid, and among them, 10 research were selected utilizing tools "check list of technical and methodological research" (including appropriate reliability and validity statistical and sampling correct methodto review and metaanalysis. The results showed that professional features have the greatest impact on the professional and occupational performance of agricultural extension agents. As well, skills and technical competence, the number of field visits, membership of organizations, participation in in-service training courses and access to educational facilities have a high impact on occupational and professional performance. The researchers confirmed these results.

  5. Nanospray technology for an in situ gelling nanoparticulate powder as a wound dressing.

    Science.gov (United States)

    De Cicco, Felicetta; Porta, Amalia; Sansone, Francesca; Aquino, Rita P; Del Gaudio, Pasquale

    2014-10-01

    In the current study the feasibility of the novel nano spray drying technique for the production of stable nanoparticulate dry powder, able to gel when administered locally on a wound, is explored. Gentamicin sulphate (GS) was loaded into alginate/pectin nanoparticles as highly soluble (hygroscopic) model drug with wide range antibacterial agent for wound dressing. The influence of process variables, mainly spray mesh size and feed concentration, on particle size and morphology, powder wound fluid uptake ability and gelling rate, as well as hydrogel water vapour transmission at wound site were studied. Particles morphology was spherical with few exceptions as slightly corrugated particles when the larger nozzle was used. Production of spherical nanoparticles (d50 ∼ 350 nm) in good yield (82-92%) required 4 μm spray mesh whereas 7 μm mesh produced larger wrinkled particles. Nano spray-dried particles showed high encapsulation efficiency (∼ 80%), good flowability, high fluid uptake, fast gel formation (15 min) and proper adhesiveness to fill the wound site and to remove easily the formulation after use. Moreover, moisture transmission of the in situ formed hydrogel was between 95 and 90 g/m(2)/h, an optimum range to avoid wound dehydration or occlusion phenomena. Release of the encapsulated GS, monitored as permeation rate using Franz cells in simulated wound fluid (SWF) was related to particle size and gelling rate. Sustained permeation profiles were obtained achieving total permeation of the drug between 3 and 6 days. However, all nano spray-dried formulations presented a burst effect, suitable to prevent infection spreading at the beginning of the therapy. Antimicrobial tests against Staphylococcus aureus and Pseudomonas aeruginosa showed stronger and prolonged antimicrobial effect of the nanoparticles compared to pure GS both shortly after administration and over time (till 12 days).

  6. FORMULATION AND ASSESSMENT OF GEMIFLOXACIN MESYLATE OCULAR IN SITU GELLING SYSTEM

    Directory of Open Access Journals (Sweden)

    Rajalakshmi R

    2013-10-01

    Full Text Available In situ gels are one of the most successful means of delivering the drug at ocular site with maximum bioavailability, which undergoes gelation upon instillation as drops into the eye due to physicochemical changes inherent to the biological fluids. The main aim of the present investigation was to obtain an ophthalmic drug delivery system with improved mucoadhesive and mechanical properties that could provide extended retention time for the treatment of ocular infections. For this in situ gels of Gemifloxacin Mesylate comprised of the combination of a thermosetting polymer, polaxamer with a mucoadhesive agent chitosan was developed. Fourier Transform Infrared Spectroscopy (FTIR and Differential Scanning Calorimetry techniques (DSC were performed to know the compatibilities between drug and polymer. FTIR spectra and DSC thermograph of Gemifloxacin Mesylate formulations showed that there is no chemical interaction between drug and polymer and confirmed the stability of the drug. The gels were evaluated for pH, Gel strength, Gelling capacity, Rheology, Drug content uniformity and Ocular irritancy studies. In vitro drug release studies reveal that all the formulations showed sustained release of the drug in the range of 70.82 to 76.43 % for a period of 8 h. The optimized formulation was tested for ocular irritation study on male albino rabbit and the result indicated that the formulation was well tolerated, non-irritating and therapeutically efficacious. In conclusion in situ gelling systems containing polaxamer / chitosan solution are viable alternative to enhance bioavailability thus leads to an excellent potential alternative ophthalmic sustained-release formulation of Gemifloxacin Mesylate in ocular infections.

  7. Formulation & Storage Studies on Hydrazine-Based Gelled Propellants.

    Directory of Open Access Journals (Sweden)

    Mohan Verma

    1996-12-01

    Full Text Available The current trend in the area of high energy storable liquid rocket propellant research is to develop gelled/metallized systems and to explore the feasibility of their application in rocket motors. The idea stems from the fact that the conversion of a conventional liquid propellant to a gelled state and its subsequent metallization has the potential to significantly enhance the performance and density specific impulse. However, it is mandatory that the gelation of the liquid propellant be brought about with a minimum concentration of gellant and the gel formed should show a shear-thinning behaviour and good storage life. Keeping this in view, an experimental program to prepare thixotropic gels of hydrazine and its methyl substitutedderivatives like monomethyl hydrazineand unsymmetrical dimethyl hydrazinewas conducted under ambient conditions. The gellants investigated included particulate, chemical and synthetic materials. The gelation of the liquid fuels ..ould be brought about with gellant concentration as low as I wt per cent in some cases. Metallized gels using up to 40 wt per cent of AlIMg metal powders could be formulated. These heterogeneous systems showed a reduction in critical gellant concentration with degree of metallization. Further, less gelation time is observed if the gellant concentration is kept fixed and metal content is increased. The storage studies on gelled systems conducted over a period of three months showed good stability. The metallized systems, however, showed the settling of metal powders in meagre concentration which does not pose a major problem as these gels could be re-homogenized with stirring.

  8. Does Cognitive Style Affect Diagnosis and Intervention Strategies of Change Agents?

    Science.gov (United States)

    Slocum, John W., Jr.

    1978-01-01

    A sample of 152 change agents were given 24 diagnostic questions they might ask the client organization, questions related to the change agents' cognitive styles and the tactics most likely used by the change agents to bring about organizational and/or individual change. Conclusions are compared with previous research findings. (Author)

  9. High Energy, Low Temperature Gelled Bi-Propellant Formulation for Long-Duration In-Space Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of a candidate bi-propellant system consisting of a gelled hydrocarbon fuel coupled with a highly energetic gelled oxidizer suitable for outer planetary...

  10. Rheological properties of reversible thermo-setting in situ gelling solutions with the methylcellulose-polyethylene glycol-citric acid ternary system (2): Effects of various water-soluble polymers and salts on the gelling temperature.

    Science.gov (United States)

    Shimokawa, Ken-ichi; Saegusa, Katsuhiko; Ishii, Fumiyoshi

    2009-11-01

    The influences of various salts and water-soluble polymers on the phase transition temperature of thermo-setting gels prepared by combining methylcellulose (MC)-sodium citrate (SC)-polyethylene glycol (PEG) at appropriate ratios (the MC-SC-PEG system) were investigated. Concerning cations, comparison of the phase transition temperature between SC and tripotassium citrate (PC) showed a rapid increase in the viscosity of SC between 20 degrees C and 25 degrees C and an increase in the viscosity of PC between 30 degrees C and 35 degrees C. Concerning the valency of anions, comparisons among SC, disodium tartrate dihydrate (ST), disodium maleate hemihydrates (SM), and sodium sulfate (SS) showed a rapid increase in the viscosity of trivalent SC between 20 degrees C and 25 degrees C and changes in the viscosity of the three bivalent sodium salts (ST, SM, and SS) at > or =30 degrees C. Thus the phase transition temperature decreased with an increase in the valency of anions. Subsequently, the influences of various water-soluble polymers on the gelling temperature were compared. Using polyvinylpyrrolidone (PVP) instead of PEG, the gelling temperature decreased with an increase in the PVP concentration even without the addition of SC. Unlike PVP, the addition of xanthan gum as a viscosity-increasing polysaccharide did not reduce the gelling temperature irrespective of its concentration. Temperature-associated changes in viscosity were observed at a fixed SC concentration with changes in the concentration of PVP or PEG. The gel phase transition temperature increased from 46 degrees C to 50 degrees C in gels not containing PVP or PEG. The viscosity did not differ between the addition of PVP or PEG at a low concentration and its absence. However, the viscosity clearly changed after the addition of each agent at a high concentration.

  11. How gestures affect students: A comparative experiment using class presentations conducted by an anthropomorphic agent

    Science.gov (United States)

    Shirakawa, Tomohiro; Sato, Hiroshi; Imao, Tomoya

    2017-07-01

    Recently, a variety of user interfaces have been developed based on human-robot and human-agent interaction, and anthropomorphic agents are used as one type of interface. However, the use of anthropomorphic agents is applied mainly to the medical and cognitive sciences, and there are few studies of their application to other fields. Therefore, we used an anthropomorphic agent of MMD in a virtual lecture to analyze the effect of gestures on students and search for ways to apply anthropomorphic agents to the field of educational technology.

  12. Extravascular injection of sclerotic agents does not affect vessels in the rat: experimental implications for percutaneous sclerotherapy of arteriovenous malformations.

    Science.gov (United States)

    Sato, D; Kurita, M; Ozaki, M; Kaji, N; Takushima, A; Harii, K

    2012-07-01

    Sclerotherapy is useful for the treatment of arteriovenous vascular malformations. However, intravascular administration of sclerotic agents into small arteriovenous niduses is often difficult. Extravascular administration of sclerotic agents causes reduction of vascular flow on Doppler echo during clinical sclerotherapy. Therefore, we aimed to investigate whether the extravascular injection of sclerotic agents affects tiny vessels. Animal study. The effect of extravascular injection of sclerotic agents on vessels was investigated using rat femoral and superficial inferior epigastric vessels. After surgical exposure of vessels, absolute ethanol, 5% ethanolamine oleate and 3% polidocanol were injected into perivascular surrounding tissues, and their effect on vessels was evaluated after 14 days using histology and coloured silicone rubber injection. The integrity of the vascular lumen, endothelial cells and vascular patency were not affected by injection of sclerotic agents. Attenuation of vascular flow of an arteriovenous shunt after extravascular injection of sclerotic agents is transient and/or trivial and does not cause disruption of vessels. Therefore, sclerotic agents should be delivered to obtain sufficient destruction of arteriovenous malformation lesions and blood flow. Copyright © 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

  13. A agência de Gell na antropologia da arte

    Directory of Open Access Journals (Sweden)

    Caleb Faria Alves

    2008-06-01

    Full Text Available Ao delinear os parâmetros para uma antropologia da arte, o famigerado livro de Alfred Gell, Art and Agency, deixou de lado boa parte da antropologia, o que coloca algumas questões tão embaraçosas quanto pouco tratadas: pode-se fazer boa teoria sem contar com o acúmulo de conhecimento nessa área? Ou os temas recebem tratamento tão díspar que realmente não faz sentido falar mais em princípios teóricos comuns que podem e devem ser aplicados a qualquer objeto? O que perdemos com uma narrativa tão autocentrada? Partindo do pressuposto de que não é possível tratar teoria enquanto um conjunto de máximas que se somam ou se substituem, ou como um tabuleiro de peças que se acomodam umas às outras segundo sua validade isolada, este artigo procede a um exame da narrativa contida no livro de Gell, das articulações que realiza entre suas proposições. Examinarei, sobretudo, a leitura que faz dos autores que cita, como Peirce, Sally Price, e outros, e como os encaixa na sua argumentação. O objetivo desse exercício é evidenciar, para além de suas próprias definições, certas concepções sobre arte contidas na abordagem que Gell sugere e ampliar as referências para uma antropologia da arte.While delineating the parameters for anthropology of art, the famous Alfred Gell's book, Art and Agency, left apart most of the anthropology authors, what arises some embarrassing and rarely dealt with questions: is it possible to produce good theory with no references to achieved knowledge in this particular field? The subjects within anthropology are so differently undertaken that doesn't make any sense to refer to common ways of approaching them? What exactly we loose which a narrative so self centered? Is my point of view that theory cannot be treated like a list of sentences that can be added to one another according to its isolated importance. This article proposes an analysis of Alfred Gell's narrative, of how he connects its propositions

  14. Difficult to swallow: issues affecting optimal adherence to oral anticancer agents.

    Science.gov (United States)

    Cheung, Winson Y

    2013-01-01

    The number of anticancer drugs currently available in oral formulation has increased dramatically over the past 15 to 20 years, especially with the recent development of new hormonal and targeted therapies. At present, approximately 25% of all cancer drugs are available in oral formulation, with numbers expected to increase exponentially in the coming years. The convenience associated with the self-administration of oral therapy, the requirement of fewer trips to the physician's office, and the lack of infusion reactions are all benefits for patients, allowing them to potentially maintain their relative independence while undergoing active anticancer treatment. On the other hand, there are growing concerns regarding patients' poor adherence to oral therapy as well as the challenges of monitoring patient compliance when treatment administration does not occur in the presence of health care professional (HCPs). More importantly, poor adherence to proven therapies may detrimentally affect the patients' clinical outcomes, such as survival. Thus, there is an urgent need to identify more effective strategies to measure and monitor adherence to oral anticancer agents in an effort to maximize their therapeutic benefits.

  15. Floating drug delivery of a locally acting H2-antagonist: an approach using an in situ gelling liquid formulation.

    Science.gov (United States)

    Rohith, Ganapati; Sridhar, Bhimagoni Keshavamurthy; Srinatha, Anegundha

    2009-09-01

    In the present work, a gastroretentive in situ gelling liquid formulation for controlled delivery of ranitidine was formulated using sodium alginate (low, medium and high viscosity grades), calcium carbonate (source of cations) and ranitidine. Prepared formulations were evaluated for viscosity, buoyancy lag time and buoyancy duration, drug content and in vitro drug release. Formulation variables such as concentration of sodium alginate, calcium carbonate and drug significantly affected the formulation viscosity, floating behavior and in vitro drug release. Analysis of the release pattern showed that the drug release from in situ gel followed a diffusion mechanism.

  16. New formulation of in situ gelling Metolose-based liquid suppository.

    Science.gov (United States)

    Pásztor, E; Makó, A; Csóka, G; Fenyvesi, Zs; Benko, R; Prosszer, M; Marton, S; Antal, I; Klebovich, I

    2011-01-01

    An in situ gelling liquid suppository is liquid at room temperature but forms a gel at body temperature. In our work, Metolose® SM-4000 (methylcellulose) is studied that basically shows thermal gelation at 68°C (2%, w/w). The objective was to study the potency of different factors (concentration, pH, additives) to change the value of thermal gelation temperature (T (t)) for Metolose® to form an in situ gelling liquid suppository. We studied the effect of Metolose® concentration, pH, and salts (sodium chloride, potassium chloride, sodium hydrogen carbonate, and sodium monohydrogen phosphate) on T (t) by viscosimetry. To choose the appropriate compound, in vitro drug release was examined. Rectal safety test was performed on rats in vivo after 12-hour application. Increasing the Metolose® concentrations (0.5-4%, w/w), T (t) can be decreased, but it also altered the consistency of gel. pH does not affect the T (t). The water-soluble salts allowed reducing the gelation temperature to 37°C. Sodium monohydrogen phosphate in 4.5% concentration was found to be the most appropriate. The impact of examined factors on in vitro drug release of piroxicam from the in situ-formed gel was characterized according to Fickian diffusion. Metolose® and the chosen salt did not cause any morphological damage on the rectal tissues. According to our study, Metolose® has the physical and chemical potential to be used as base for liquid suppositories.

  17. Art-matrix theory and cognitive distance: Farago, Preziosi, and Gell on art and enchantment

    Directory of Open Access Journals (Sweden)

    Jakub Stejskal

    2015-12-01

    Full Text Available Theories that treat art objects primarily as agents embedded in a causal nexus of agent–patient relationships, as opposed to studying them as expressions or symbols encoding meanings, tend to identify art’s agency with its power to enchant recipients. I focus on two such approaches, the art-matrix theory of Claire Farago and Donald Preziosi and the art-nexus theory of Alfred Gell. Their authors stress the potential of art to make its enchanting power the topic of our experience with it, that is, to disenchant its own enchantment. This raises the following question: If artworks are to be understood as agents enchanting their recipients, how can they become forces of disenchantment? I argue that the shift in perspective from perceiving art objects as indices of agency within a matrix/nexus to approaching them as possible means of gaining cognitive distance is inadequately addressed by both theories; this is due to features inherent to their respective theoretical outlooks.

  18. On the behaviour of gelled fibre suspensions in steady shear

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Bettina [Unilever Corporate Research, Bedford (United Kingdom); University of Nottingham, Division of Food Sciences, Loughborough (United Kingdom); White, Duncan; Melrose, John R.; Frith, William J. [Unilever Corporate Research, Bedford (United Kingdom)

    2007-03-15

    The shear rheological properties of suspensions of gelled agar fibres in a low viscosity Newtonian matrix fluid were investigated. Two classes of fibres, low aspect ratio fibres and high aspect ratio fibres with an aspect ratio of the order of 10 and 100 respectively were included in the investigations. For all fibre phase volumes investigated, from as low as 0.01 upwards, the flow curves are characterised by an apparent yield stress followed by shear-thinning which was independent of the fibre aspect ratio. Based on our analysis of the flow curves, we conclude that the high aspect ratio fibres behave like flexible threads in contrast to the low aspect ratio fibres whose high shear relative viscosity is successfully described by a relation for long rigid rods. These findings are supported by flow visualisation using an optical shearing stage coupled to a light microscope. (orig.)

  19. Gelled colloidal crystals as tunable optical filters for spectrophotometers

    Science.gov (United States)

    Sugao, Yukihiro; Onda, Sachiko; Toyotama, Akiko; Takiguchi, Yoshihiro; Sawada, Tsutomu; Hara, Shigeo; Nishikawa, Suguru; Yamanaka, Junpei

    2016-08-01

    We examined the performance of charged colloidal crystals immobilized in a polymer gel as tunable optical filters. The colloidal crystals of charged silica particles (particle diameter = 121 nm; particle concentration = 3.5 vol %; and Bragg wavelength λB = 630-720 nm) were produced by unidirectional crystallization under a temperature gradient. Photocurable gelation reagents were dissolved in the sample beforehand; this enabled gel immobilization of the crystals under ultraviolet illumination. The crystals had dimensions of more than 25 mm2 in area and 1 mm in thickness, and spatial λB variations of less than 1%. Upon mechanical compression, λB values shifted linearly and reversibly over almost the entire visible spectrum. Using the gelled crystals as tunable optical filters, we measured the transmittance spectra of various samples and found them to be in close agreement with those determined using a spectrophotometer equipped with optical gratings.

  20. Embodied Agents, E-SQ and Stickiness: Improving Existing Cognitive and Affective Models

    Science.gov (United States)

    de Diesbach, Pablo Brice

    This paper synthesizes results from two previous studies of embodied virtual agents on commercial websites. We analyze and criticize the proposed models and discuss the limits of the experimental findings. Results from other important research in the literature are integrated. We also integrate concepts from profound, more business-related, analysis that deepens on the mechanisms of rhetoric in marketing and communication, and the possible role of E-SQ in man-agent interaction. We finally suggest a refined model for the impacts of these agents on web site users, and limits of the improved model are commented.

  1. In situ gelling systems of ofloxacin: Comparative performance of in vivo precorneal drainage and pharmacokinetic study

    OpenAIRE

    Vrushali S Kashikar; Indrajeet D Gonjari

    2013-01-01

    Our present work describes the formulation and evaluation of an ocular deliver system of ofloxacin based on the concept of temperature-and ion-activated in situ gelling system. A combination of Pluronic F-127 and Pluronic F-68 along with chitosan, (pH-sensitive polymer also acts as a permeation enhancer) was used in temperature and pH-triggered in situ gelling systems while gellan alone was used in ion-activated in situ gelling system. The formulation allows its easy instillation into the eye...

  2. Affect-as-Information Approach to a Sentiment Analysis Based Evaluation of Conversational Agents

    OpenAIRE

    Ptaszynski, Michal; Dybala, Pawel; Higuchi, Shinsuke; Rzepka, Rafal; Araki, Kenji

    2017-01-01

    In this paper we propose a novel method forautomatic evaluation of conversational agents. Themethod is based on analyzing the user’s affectconveyed in utterances. From analyzing: the user’sgeneral emotional engagement in the conversation andthe emotion types conveyed by the user in theconversation, a simple psychological reasoning isderived about the user’s sentiment about the agent’sperformance. The evaluation experiment on twoJapanese-speaking conversational agents showed thesame tendencies...

  3. Identifying and Exploring Factors Affecting Embodied Conversational Agent Social Presence for Interpersonal Skills Training

    Science.gov (United States)

    Chuah, Joon Hao

    2013-01-01

    Embodied conversational agents (ECAs) have been used as virtual conversational partners in interpersonal skills training applications such as medical interviews, military decision making, and cultural training. Ideally, in interpersonal skills training users will perceive and treat the ECAs the same as they would real people. The perception and…

  4. Can focused US with a diagnostic US contrast agent favorably affect renal function?

    Science.gov (United States)

    Sica, Domenic A

    2009-12-01

    Focused ultrasonography (US) with simultaneous administration of a US microbubble contrast agent was used to transiently increase the glomerular filtration rate while altering the sieving properties of glomeruli in normal rabbits. In its current form, this process has very limited application potential to states of abnormal renal function.

  5. Environmental factors affect the activity of biocontrol agents against ochratoxigenic Aspergillus carbonarius on wine grape.

    Science.gov (United States)

    De Curtis, F; de Felice, D V; Ianiri, G; De Cicco, V; Castoria, R

    2012-09-17

    The influence of temperature and relative humidity (RH) on the activity of three biocontrol agents-the yeast Metschnikowia pulcherrima LS16 and two strains of the yeast-like fungus Aureobasidium pullulans LS30 and AU34-2-against infection by A. carbonarius and ochratoxin A (OTA) accumulation in wine grape berries was investigated in lab-scale experiments. The presence of wounds on grape skin dramatically favored infection of berries by A. carbonarius strain A1102, since unwounded berries showed very low levels of infection at all conditions of RH and temperature tested. Artificially wounded berries pre-treated with the biocontrol agents were inoculated with the ochratoxigenic A. carbonarius strain A1102 and were incubated for 5 days at two levels of RH (60% and 100%) and three different temperatures (20, 25 and 30 °C). The three biocontrol agents were able to prevent infections at 60% RH and 20 °C. At 60% RH and 25 °C only strain AU34-2 achieved some protection on day 5, whereas at 30 °C a limited biocontrol efficacy was evident only up to day 2. At 100% RH, LS16, LS30 and AU34-2 showed effective protection of grape berries at 20 °C until the 5th day of incubation. The three biocontrol agents achieved significant protection at higher temperatures only until the 2nd day after the beginning of the experiment: all three strains at 25 °C, and only strain LS16 at 30 °C. After 5 days, the three biocontrol agents were able to significantly reduce the level of OTA in berries at all the conditions tested. This occurred even when protection from infection was not significant, except at 30 °C and 100% of RH for all the three strains, and at 25 °C and 100% of RH for strain LS16. The biocontrol agents displayed a higher rate of colonization on grape berries at 20 and 25 °C than at 30 °C. The higher value of RH (100%) appeared to increase the rate of colonization, in particular at 20 and 25 °C. Taken together, our results emphasize the significant influence of

  6. Chemically Methylated and Reduced Pectins: Preparation and Characterisation by 1H-NMR Spectroscopy, Enzymatic Degradation and Gelling Properties

    DEFF Research Database (Denmark)

    Rosenbohm, Christoph; Lundt, Inge; Christensen, T.M.I.E.;

    2003-01-01

    The gelling properties of pectin are known to be closely related to the degree of methylation (DM) and the distribution of the ester groups. In order to investigate this dependency, a natural citrus pectin (DM=64%) has been methylated to pectins with higher DM’s or saponified to achieve pectins...... than with unmodified pectin. The new reduced pectins exhibit high gelling properties. Keywords: Pectin; Methylation; Deesterification; Reduction; DM and DR by 1H-NMR spectroscopy; Reduced Pectin; Pectinases; Gelling properties....

  7. Linseed oil gelled emulsion: A successful fat replacer in dry fermented sausages.

    Science.gov (United States)

    Alejandre, Marta; Poyato, Candelaria; Ansorena, Diana; Astiasarán, Iciar

    2016-11-01

    Different levels of animal fat replacement by a high omega-3 content carrageenan gelled emulsion in dry fermented sausages were studied in order to improve their fatty acid composition. Percentages of fat replacement were 26.3% (SUB1), 32.8% (SUB2) and 39.5% (SUB3). α-linolenic acid (ALA) content increased up to 1.81, 2.19 and 2.39g/100g (SUB1, SUB2, and SUB3 products) as compared to the Control (0.35g/100g), implying an increment in polyunsaturated fatty acids (PUFA) supply (up to 10.3%) and reductions in omega-6/ omega-3 ratio (75, 82 and 84%, respectively). Peroxides and TBARs values were not affected (P>0.05) by the fat modification and a slight low formation of volatile aldehydes derived from lipid oxidation was detected. Fat replacement did not cause relevant modifications on the instrumental color properties and no sensory differences (P>0.05) were found between Control and SUB2 products (32.8%) for taste and juiciness, pointing out the viability of this formulation for human consumption.

  8. Extraction and Characterization of Highly Gelling Low Methoxy Pectin from Cashew Apple Pomace

    Directory of Open Access Journals (Sweden)

    Beda M. Yapo

    2013-12-01

    Full Text Available Investigation on the pectic substances of cashew (Anacardium occidentale L. apple under different acid-extraction conditions (pH 1.0, 1.5, and 2.0 showed that more than 10%–25% of A. occidentale pectins (AOP could be extracted, depending on the extractant strength. The extracted AOP contained high amounts of galacturonic acid (GalA: 69.9%–84.5% with some neutral sugars of which rhamnose (Rha: 1.3%–2.5%, arabinose (Ara: 2.6%–5.4%, and galactose (Gal: 4.7%–8.6% were the main constituents. The degree of methoxylation (DM was in the range of 28%–46% and was only slightly affected by the extractant strength, thereby indicating isolation of naturally low methoxy pectins (LMP. In terms of gelling capability, AOP yielded firmer Ca2+-mediated LMP gels than commercial citrus LMP with comparable DM. Cashew apple pomace, therefore, appears to be a potentially viable source for possible production of “non-chemically or enzymatically-tailored” LMP.

  9. An agent-based epidemic simulation of social behaviors affecting HIV transmission among Taiwanese homosexuals.

    Science.gov (United States)

    Huang, Chung-Yuan

    2015-01-01

    Computational simulations are currently used to identify epidemic dynamics, to test potential prevention and intervention strategies, and to study the effects of social behaviors on HIV transmission. The author describes an agent-based epidemic simulation model of a network of individuals who participate in high-risk sexual practices, using number of partners, condom usage, and relationship length to distinguish between high- and low-risk populations. Two new concepts-free links and fixed links-are used to indicate tendencies among individuals who either have large numbers of short-term partners or stay in long-term monogamous relationships. An attempt was made to reproduce epidemic curves of reported HIV cases among male homosexuals in Taiwan prior to using the agent-based model to determine the effects of various policies on epidemic dynamics. Results suggest that when suitable adjustments are made based on available social survey statistics, the model accurately simulates real-world behaviors on a large scale.

  10. Soil aggregation and aggregating agents as affected by long term contrasting management of an Anthrosol

    Science.gov (United States)

    Zhang, Shulan; Wang, Renjie; Yang, Xueyun; Sun, Benhua; Li, Qinghui

    2016-12-01

    Soil aggregation was studied in a 21-year experiment conducted on an Anthrosol. The soil management regimes consisted of cropland abandonment, bare fallow without vegetation and cropping system. The cropping system was combined with the following nutrient management treatments: control (CONTROL, no nutrient input); nitrogen, phosphorus and potassium (NPK); straw plus NPK (SNPK); and manure (M) plus NPK (MNPK). Compared with the CONTROL treatment, the abandonment treatment significantly increased the formation of large soil macroaggregates (>2 mm) and consequently improved the stability of aggregates in the surface soil layer due to enhancement of hyphal length and of soil organic matter content. However, in response to long-term bare fallow treatment aggregate stability was low, as were the levels of aggregating agents. Long term fertilization significantly redistributed macroaggregates; this could be mainly ascribed to soil organic matter contributing to the formation of 0.5–2 mm classes of aggregates and a decrease in the formation of the >2 mm class of aggregates, especially in the MNPK treatment. Overall, hyphae represented a major aggregating agent in both of the systems tested, while soil organic compounds played significantly different roles in stabilizing aggregates in Anthrosol when the cropping system and the soil management regimes were compared.

  11. Factors affecting the sensitivity and detection limits of MRI, CT, and SPECT for multimodal diagnostic and therapeutic agents.

    Science.gov (United States)

    Seevinck, Peter R; Seppenwoolde, Jan-Henry; de Wit, Tim C; Nijsen, Johannes F W; Beekman, Freek J; van Het Schip, Alfred D; Bakker, Chris J G

    2007-05-01

    Noninvasive imaging techniques like magnetic resonance imaging (MRI), computed tomography (CT) and single photon emission computed tomography (SPECT) play an increasingly important role in the diagnostic workup and treatment of cancerous disease. In this context, a distinct trend can be observed towards the development of contrast agents and radiopharmaceuticals that open up perspectives on a multimodality imaging approach, involving all three aforementioned techniques. To promote insight into the potentialities of such an approach, we prepared an overview of the strengths and limitations of the various imaging techniques, in particular with regard to their capability to quantify the spatial distribution of a multimodal diagnostic agent. To accomplish this task, we used a two-step approach. In the first step, we examined the situation for a particular therapeutic anti-cancer agent with multimodal imaging opportunities, viz. holmium-loaded microspheres (HoMS). Physical phantom experiments were performed to enable a comparative evaluation of the three modalities assuming the use of standard equipment, standard clinical scan protocols, and signal-known-exactly conditions. These phantom data were then analyzed so as to obtain first order estimates of the sensitivity and detection limits of MRI, CT and SPECT for HoMS. In the second step, the results for HoMS were taken as a starting point for a discussion of the factors affecting the sensitivity and detection limits of MRI, CT and SPECT for multimodal agents in general. In this, emphasis was put on the factors that must be taken into account when extrapolating the findings for HoMS to other diagnostic tasks, other contrast agents, other experimental conditions, and other scan protocols.

  12. Rivastigmine-loaded in situ gelling nanostructured lipid carriers for nose to brain delivery.

    Science.gov (United States)

    Wavikar, Preeti R; Vavia, Pradeep R

    2015-01-01

    In the current research work, rivastigmine (RV)-loaded in situ gelling nanostructured lipid carriers (NLCs) were developed for nose to brain delivery. NLCs were fabricated by ethanol injection method using glyceryl monosterate, Capmul MCM C8, Lecithin and Tween 80. NLCs showed average particle size of 123.2 ± 2.3 nm with entrapment efficiency of 68.34 ± 3.4%. DSC, XRD and IR studies showed complete amorphization and incorporation of the drug into nanoparticles. NLCs were incorporated into an in situ gelling system using 0.8% gellan gum and 15% Lutrol F 127. RV in situ gel showed excellent elasticity, rheology, mucoadhesion and adhesiveness to facilitate its adhesion to the upper nasal mucosa. NLC-based in situ gel showed a 2-fold increase in nasal permeation of the drug over plain RV solution. In situ gelling NLCs showed a 3-fold increase in enzyme inhibition efficacy.

  13. Evaluation of biocompatible stabilised gelled soya bean oil nanoparticles as new hydrophobic reservoirs.

    Science.gov (United States)

    Boudier, Ariane; Kirilov, Plamen; Franceschi-Messant, Sophie; Belkhelfa, Haouaria; Hadioui, Laila; Roques, Christine; Perez, Emile; Rico-Lattes, Isabelle

    2010-01-01

    Based on the organogel concept, in which an oil is trapped in a network of low-molecular-mass organic gelator fibres creating a gel, a formulation of gelled soya bean oil nanoparticles was evaluated for its capacity to form biocompatible hydrophobic reservoirs. The aqueous dispersions of nanoparticles were prepared by hot emulsification (T° > Tgel) and cooling at room temperature in the presence of polyethyleneimine (PEI). The dispersions were stabilised by the electrostatic interactions between the positively charged amino groups of the PEI and the negatively charged carboxylates of the gelator fibres present at the surface of the particles. The aqueous dispersions were highly stable (several months) and the gelled particles were able to entrap a hydrophobic fluorescent model molecule (Nile red), allowing testing in cells. The gelled oil nanoparticles were found to be biocompatible with the tested cells (keratinocytes) and had the ability to become rapidly internalised. Thus, organogel-based nanoparticles are a promising hydrophobic drug delivery system.

  14. Electrospray formation of gelled nano-aluminum microspheres with superior reactivity.

    Science.gov (United States)

    Wang, Haiyang; Jian, Guoqiang; Yan, Shi; DeLisio, Jeffery B; Huang, Chuan; Zachariah, Michael R

    2013-08-14

    Nanometallic fuels with high combustion enthalpy, such as aluminum, have been proposed as a potential fuel replacement for conventional metallic fuel to improve propellant performance in a variety of propulsive systems. Nevertheless, nanometallic fuels suffer from the processing challenges in polymer formulations such as increased viscosity and large agglomeration, which hinder their implementation. In this letter, we employ electrospray as a means to create a gel within a droplet, via a rapid, solvent evaporation-induced aggregation of aluminum nanoparticles, containing a small mass fraction of an energetic binder. The gelled aluminum microspheres were characterized and tested for their burning behavior by rapid wire heating ignition experiments. The gelled aluminum microspheres show enhanced combustion behavior compared to nanoaluminum, which possibly benefits from the nitrocellulose coating and the gelled microstructure, and is far superior to the corresponding dense micrometer-sized aluminum.

  15. Gelling and curing behaviors of benzoxazine/epoxy formulations containing 4,4 Prime -thiodiphenol accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Chow, W.S., E-mail: chowwenshyang@yahoo.com [Institut fuer Verbundwerkstoffe GmbH (Institute for Composite Materials), Kaiserslautern University of Technology, D-67663 Kaiserslautern (Germany); School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, Nibong Tebal 14300, Penang (Malaysia); Grishchuk, S.; Burkhart, T. [Institut fuer Verbundwerkstoffe GmbH (Institute for Composite Materials), Kaiserslautern University of Technology, D-67663 Kaiserslautern (Germany); Karger-Kocsis, J. [Polymer Technology, Faculty of Engineering and the Built Environment, Tshwane University of Technology, Pretoria 0001 (South Africa); Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, H-1111 Budapest (Hungary)

    2012-09-10

    Highlights: Black-Right-Pointing-Pointer Gelling and curing behaviors of benzoxazine/epoxy with accelerator were studied. Black-Right-Pointing-Pointer The activation energy of gelling was assessed by Arrhenius equation. Black-Right-Pointing-Pointer The activation energy of curing was determined from dynamic DSC scans. Black-Right-Pointing-Pointer 4,4 Prime -Thiodiphenol can act as co-reactive accelerator for benzoxazine/epoxy blends. Black-Right-Pointing-Pointer 4,4 Prime -Thiodiphenol markedly reduced the gel time and the activation energy. - Abstract: Benzoxazine (BOX)/diglycidyl ether of bisphenol A (DGEBA) based epoxy resins (BOX/DGEBA = 100/0, 75/25 and 50/50 wt.%) with and without 4,4 Prime -thiodiphenol accelerator (DT300) were prepared. The gelling and curing behaviors of the BOX and BOX/DGEBA mixtures in presence and absence of DT300 (10 parts per hundred resin, phr) were investigated using plate-plate rheometry and differential scanning calorimetry (DSC). The gel time was determined in isothermal scans at three different temperatures (T = 180, 200, and 220 Degree-Sign C). Dynamic DSC scans were registered at four heating rates ({beta} = 5, 10, 15, and 20 Degree-Sign C min{sup -1}, respectively). The activation energy of gelling was assessed by an Arrhenius, whereas that of the curing by the Kissinger and Ozawa methods. Combination of BOX with DGEBA delayed the gel formation and increased the activation energy of both gelling and curing processes compared to neat BOX resin. By contrast, addition of 4,4 Prime -thiodiphenol as co-reactive accelerator markedly reduced the gel time and the activation energy of both gelling and curing of BOX and BOX/DGEBA formulations.

  16. Papaya pulp gelling: is it premature ripening or problems of water accumulation in the apoplast?

    Directory of Open Access Journals (Sweden)

    Jurandi Gonçalves de Oliveira

    Full Text Available Gelled aspect in papaya fruit is typically confused with premature ripening. This research reports the characterization of this physiological disorder in the pulp of papaya fruit by measuring electrolyte leakage, Pi content, lipid peroxidation, pulp firmness, mineral contents (Ca, Mg and K - in pulp and seed tissues, and histological analysis of pulp tissue. The results showed that the gelled aspect of the papaya fruit pulp is not associated with tissue premature ripening. Data indicate a reduction of the vacuole water intake as the principal cause of the loss of cellular turgor; while the waterlogged aspect of the tissue may be due to water accumulation in the apoplast.

  17. Biofilm Matrix Composition Affects the Susceptibility of Food Associated Staphylococci to Cleaning and Disinfection Agents

    Science.gov (United States)

    Fagerlund, Annette; Langsrud, Solveig; Heir, Even; Mikkelsen, Maria I.; Møretrø, Trond

    2016-01-01

    Staphylococci are frequently isolated from food processing environments, and it has been speculated whether survival after cleaning and disinfection with benzalkonium chloride (BC)-containing disinfectants is due to biofilm formation, matrix composition, or BC efflux mechanisms. Out of 35 food associated staphylococci, eight produced biofilm in a microtiter plate assay and were identified as Staphylococcus capitis (2), S. cohnii, S. epidermidis, S. lentus (2), and S. saprophyticus (2). The eight biofilm producing strains were characterized using whole genome sequencing. Three of these strains contained the ica operon responsible for production of a polysaccharide matrix, and formed a biofilm which was detached upon exposure to the polysaccharide degrading enzyme Dispersin B, but not Proteinase K or trypsin. These strains were more tolerant to the lethal effect of BC both in suspension and biofilm than the remaining five biofilm producing strains. The five BC susceptible strains were characterized by lack of the ica operon, and their biofilms were detached by Proteinase K or trypsin, but not Dispersin B, indicating that proteins were major structural components of their biofilm matrix. Several novel cell wall anchored repeat domain proteins with domain structures similar to that of MSCRAMM adhesins were identified in the genomes of these strains, potentially representing novel mechanisms of ica-independent biofilm accumulation. Biofilms from all strains showed similar levels of detachment after exposure to alkaline chlorine, which is used for cleaning in the food industry. Strains with qac genes encoding BC efflux pumps could grow at higher concentrations of BC than strains without these genes, but no differences were observed at biocidal concentrations. In conclusion, the biofilm matrix of food associated staphylococci varies with respect to protein or polysaccharide nature, and this may affect the sensitivity toward a commonly used disinfectant. PMID:27375578

  18. Biofilm matrix composition affects the susceptibility of food associated staphylococci to cleaning and disinfection agents

    Directory of Open Access Journals (Sweden)

    Annette eFagerlund

    2016-06-01

    polysaccharide nature, and this may affect the sensitivity towards a commonly used disinfectant.

  19. Poly(ethylene oxide/propylene oxide) copolymer thermo-reversible gelling system for the enhancement of intranasal zidovudine delivery to the brain.

    Science.gov (United States)

    Ved, Parag M; Kim, Kwonho

    2011-06-15

    The purpose of this study was to investigate the olfactory transfer of zidovudine (ZDV) after intranasal (IN) administration and to assess the effect of thermoreversible gelling system on its absorption and brain uptake. The nasal formulation was prepared by dissolving ZDV in pH 5.5 phosphate buffer solution comprising of 20% polyethylene oxide/propylene oxide (Poloxamer 407, PLX) as thermoreversible gelling agent and 0.1% n-tridecyl-β-D-maltoside (TDM) as permeation enhancer. This formulation exhibited a sufficient stability and an optimum gelation profile at 27-30 °C. The in vitro permeation studies across the freshly excised rabbit nasal mucosa showed a 53% increase in the permeability of ZDV from the formulation. For in vivo evaluation, the drug concentrations in the plasma, cerebrospinal fluid (CSF) and six different regions of the brain tissues, i.e. olfactory bulb (OB), olfactory tract (OT), anterior, middle and posterior segments of cerebrum (CB), and cerebellum (CL) were determined by LC/MS method following IV and IN administration in rabbits at a dose of 1mg/kg. The IN administration of Poloxamer 407 and TDM based formulation showed a systemic bioavailability of 29.4% while exhibiting a 4 times slower absorption process (t(max) = 20 min) than control solution (t(max) = 5 min). The CSF and brain ZDV levels achieved after IN administration of the gelling formulation were approximately 4.7-56 times greater than those attained after IV injection. The pharmacokinetic and brain distribution studies revealed that a polar antiviral compound, ZDV could preferentially transfer into the CSF and brain tissue via an alternative pathway, possibly olfactory route after intranasal administration.

  20. Hyperosmotic Agents and Antibiotics Affect Dissolved Oxygen and pH Concentration Gradients in Staphylococcus aureus Biofilms.

    Science.gov (United States)

    Kiamco, Mia Mae; Atci, Erhan; Mohamed, Abdelrhman; Call, Douglas R; Beyenal, Haluk

    2017-03-15

    Biofilms on wound surfaces are treated topically with hyperosmotic agents, such as medical-grade honey and cadexomer iodine; in some cases, these treatments are combined with antibiotics. Tissue repair requires oxygen, and a low pH is conducive to oxygen release from red blood cells and epithelialization. We investigated the variation of dissolved oxygen concentration and pH with biofilm depth and the variation in oxygen consumption rates when biofilms are challenged with medical-grade honey or cadexomer iodine combined with vancomycin or ciprofloxacin. Dissolved oxygen and pH depth profiles in Staphylococcus aureus biofilms were measured using microelectrodes. The presence of cadexomer iodine with vancomycin or ciprofloxacin on the surface of the biofilm permitted a measurable concentration of oxygen at greater biofilm depths (101.6 ± 27.3 μm, P = 0.02; and 155.5 ± 27.9 μm, P = 0.016, respectively) than in untreated controls (30.1 μm). Decreases in pH of ∼0.6 and ∼0.4 units were observed in biofilms challenged with medical-grade honey alone and combined with ciprofloxacin, respectively (P dissolved oxygen concentration and penetration depth into the biofilm, while medical-grade honey was associated with a lower pH; not all treatments established a bactericidal effect in the time frame used in the experiments.IMPORTANCE Reports about using hyperosmotic agents and antibiotics against wound biofilms focus mostly on killing bacteria, but the results of these treatments should additionally be considered in the context of how they affect physiologically important parameters, such as oxygen concentration and pH. We confirmed that the combination of a hyperosmotic agent and an antibiotic results in greater dissolved oxygen and reduced pH within an S. aureus biofilm. Copyright © 2017 American Society for Microbiology.

  1. Biochemical and morpho-anatomical analyses of strawberry vitroplants hyperhydric tissues affected by BA and gelling agents Análises bioquímicas e morfo-anatômicas em vitroplantas de morangueiro hiper-hídricas afetadas pelo BA e agentes geleificantes

    Directory of Open Access Journals (Sweden)

    Leticia Mascarenhas Pereira Barbosa

    2013-04-01

    Full Text Available In vitro propagation has become an effective practice for large-scale production of strawberry plants. The objective of this study was to evaluate the hyperhydricity and the multiplication capacity of two strawberry varieties (Fragaria x ananassa Duch. 'Dover' and 'Burkley' propagated in vitro. Plants maintained in MS medium supplemented with 1.0 mg L-1 BA were individualized and transferred to the same medium solidified with Agar (6.5 g L-1 or Phytagel® (2.5 g L-1 and BA at different concentrations (0; 0.5; 1.0; 2.0 and 3.0 mg L-1. Biochemical and anatomical analyses were carried out, as well as the analysis of the morphological hyperhydricity characteristics. The analysis of data showed: a the increase in cytokinin concentration increased hyperhydricity frequency in both varieties; b at concentrations up to 2.0 mg L-1 BA, the replacement of Agar by Phytagel® induced a higher formation of hyperhydric shoots; and c the addition of BA induced oxidative stress, which is characterized by increased antioxidant activity and lipid peroxidation, as well as alterations at the cellular level, such as malformation of stomata and epidermal cells. In conclusion, the culture medium containing 0.5 mg L-1 BA solidified with Agar provided lower hyperhydricity percentages in association with higher rates of shoot proliferation in strawberry.A propagação in vitro tem se destacado como uma técnica efetiva na produção em larga escala de plantas sadias de morangueiro. Neste trabalho estudamos a hiperhidricidade associado a capacidade de multiplicação in vitro na propagação de duas variedades de morangueiro (Fragaria x ananassa Duch. "Dover" e "Burkley". Plantas mantidas em meio de cultura MS, suplementadas com 1.0 mg L-1 de BA fora individualizadas e transferidas para o mesmo meio com Ágar (6.5 g L-1 ou Phytagel® (2,5 g L-1 e BA em diferentes concentrações (0; 0,5; 1,0; 2,0 e 3,0 mg L-1. Foram realizadas análises bioquímica e anatômicas, além da caracterização morfológica do material hiper-hídrico. A análise dos dados mostrou: a o incremento na concentração de citocinina aumentou a freqüência de hiper-hidricidade para ambas as variedades; b concentrações maiores que 2,0 mg L-1 de BA, com a substituição do Ágar pelo Phytagel® induziu a maior formação de ramos hiper-hídricos; e c a adição de BA induziu o estresse oxidativo, caracterizado pelo incremento da atividade antioxidante e peroxidação de lipídeos, bem como alterações a nível celular, como má formação dos estômatos e células epidérmicas. Concluindo, o meio de cultura contendo 0,5 mg L-1 de BA solidificado com Ágar promoveu menor porcentagem de hiper-hidricidade associado com maiores taxas de proliferação de gemas em morangueiro.

  2. Factors affecting the flight capacity of Tetrastichus planipennisi (Hymenoptera: Eulophidae), a classical biological control agent of Agrilus planipennis (Coleoptera: Buprestidae).

    Science.gov (United States)

    Fahrner, Samuel J; Lelito, Jonathan P; Blaedow, Karen; Heimpel, George E; Aukema, Brian H

    2014-12-01

    The dispersal characteristics of a biological control agent can have direct implications on the ability of that agent to control populations of a target host. Tetrastichus planipennisi Yang (Hymenoptera: Eulophidae) is a parasitic wasp native to eastern Asia that has been introduced into the United States as part of a classical biological control program against the emerald ash borer Agrilus planipennis Fairmaire (Coleoptera: Buprestidae). We used computer-monitored flight mills to investigate the role of age, feeding status, mating status, and size on the flight capacity of female T. planipennisi over a 24-h period. We also compared flight capacity between sexes. Flight distance of female T. planipennisi representative of populations released in the biological control program averaged 1.26 km in 24 h with a maximum flight of just over 7 km. Median flight distance, however, was 422 m. The flight capacity of females fed a honey-water solution was 41× that of females provided only water, who flew very little. Larger females were capable of flying farther distances, but age did not affect the flight capacity of females up to 70 d posteclosion. Females dispersed 6× farther than did their smaller, male counterparts. The implications of our findings to host-parasitoid interactions and release protocols for distributing T. planipennisi are discussed.

  3. Effects of plant growth regulator, sugar and gelling agent on protocorm formation of Friederick's Dendrobium Orchid

    Directory of Open Access Journals (Sweden)

    Sanputawong, S.

    2007-05-01

    Full Text Available Shoot tip explants of Friederick's Dendrobium Orchid (Dendrobium friedericksianum Rchb.f were cultured on solidified Murashing and Skoog (MS medium supplemented with various types of sugar, agarand various concentrations of 2,4-dichorophenoxyacetic acid (2,4-D and thidiazuron (TDZ. The pH of medium was adjusted to 5.7 before autoclaving. The medium supplemented with 1 mg/l 2,4-D and 2 mg/lTDZ provided the highest percentage of protocorm-like bodies (PLBs (51%, and PLB-produced shoots (PLB-PS (3%. The combination of 1 mg/l 2,4-D and 1.5 mg/l TDZ gave 47% PLB formation and 2% PLBPS.A 3% sucrose resulted in the highest number of PLBs at 51.21%. Phytagel at concentration of 0.17%gave the highest percentage of PLBs (51.65%

  4. Effect of media composition, including gelling agents, on isolation of previously uncultured rumen bacteria.

    Science.gov (United States)

    Nyonyo, T; Shinkai, T; Tajima, A; Mitsumori, M

    2013-01-01

    The aim of this study was to develop novel anaerobic media using gellan gum for the isolation of previously uncultured rumen bacteria. Four anaerobic media, a basal liquid medium (BM) with agar (A-BM), a modified BM (MBM) with agar (A-MBM), an MBM with phytagel (P-MBM) and an MBM with gelrite (G-MBM) were used for the isolation of rumen bacteria and evaluated for the growth of previously uncultured rumen bacteria. Of the 214 isolates composed of 144 OTUs, 103 isolates (83 OTUs) were previously uncultured rumen bacteria. Most of the previously uncultured strains were obtained from A-MBM, G-MBM and P-MBM, but the predominant cultural members, isolated from each medium, differed. A-MBM and G-MBM showed significantly higher numbers of different OTUs derived from isolates than A-BM (P MBM showed the highest diversity (H' = 3·89) compared with those of G-MBM, P-MBM and A-BM (H' = 3·59, 3·23 and 3·39, respectively). Although previously uncultured rumen bacteria were isolated from all media used, the ratio of previously uncultured bacteria to total isolates was increased in A-MBM, P-MBM and G-MBM.

  5. Gelling ability and crystal morphology of sunflower wax in soybean oil

    Science.gov (United States)

    Plant waxes can effectively form organogels with vegetable oils and these organogels have drawn considerable interests as alternatives to solid fats containing trans fats and saturated fats in margarines and spreads. Among them sunflower wax showed the most pronounced gelling ability. In an attempt ...

  6. Experimental Study on the Combustion and Microexplosion of Freely Falling Gelled Unsymmetrical Dimethylhydrazine (UDMH Fuel Droplets

    Directory of Open Access Journals (Sweden)

    Jianjun Wu

    2012-08-01

    Full Text Available The increasing demand for high energy density fuels and the concern for their safety have propelled research in the field of gelled propellants, where understanding the combustion of single gelled fuel droplets is the first stage to predict the spray combustion characteristics. The experiments utilized single-isolated freely falling gelled unsymmetrical dimethylhydrazine (UDMH droplets instead of the conventional suspended droplet approach, in order to eliminate the perturbation associated with the suspension mechanism. Morphological transformations of the gelled droplet involved in the combustion processes were monitored by employing a high-speed digital camera, while the effects of ambient pressure and oxygen concentration on burning rate constants were also studied. The experimental results show that four main phenomena (droplet deformation, bubble formation and growth, vapor jetting and luminous jetting flame with “horn” shape and three distinct phases were identified in the droplet combustion process; the high yield stress and polymer chain structure of polymer gellant are responsible for the appearance of bubbles with almost the same order of magnitude as the droplets. Increasing the ambient pressure can increase the burning rate, postpone the appearance of microexplosions, and weaken microexplosion intensity; while increasing the ambient oxygen concentration can promote the appearance of microexplosions, strengthen microexplosion intensity and increase the burning rate.

  7. A new approach to model strain change of gelled waxy crude oil under constant stress

    DEFF Research Database (Denmark)

    Hou, Lei; Song, Changyu; Yan, Wei

    2014-01-01

    Deformation of gelled waxy crude oil with loaded stress is worthy of research for the flow assurance of pipelining system. A dispersion parameter was introduced to characterize the disruption degree of wax crystal structure in crude oil with shear action. Based on fractional calculus theory, a rh...

  8. Effect of various gelling cations on the physical properties of "wet" alginate films.

    Science.gov (United States)

    Harper, B Allison; Barbut, Shai; Lim, Loong-Tak; Marcone, Massimo F

    2014-04-01

    In this study, the physical properties of "wet" alginate films gelled with various divalent cations (Ba(2+) , Ca(2+) , Mg(2+) , Sr(2+) , and Zn(2+) ) were explored. Additionally, the effect of adding NaCl to the alginate film-forming solution prior to gelling was evaluated. Aside from Mg(2+) , all of the divalent cations were able to produce workable "wet" alginate films. Films gelled with BaCl2 (without added NaCl) had the highest (P alginate and Sr-alginate films had the highest elongation at break values. Adding NaCl to the alginate film-forming solution increased the viscosity of the solution. Films with added NaCl were less transparent and had lower tensile strength, elongation, and puncture strength than films formed without NaCl in the film-forming solution. ATR-FTIR results showed a slight shift in the asymmetric COO(-) vibrational peak of the alginate when the "wet" alginate films were gelled with Zn(2+) .

  9. In situ gelling systems of ofloxacin: Comparative performance of in vivo precorneal drainage and pharmacokinetic study

    Directory of Open Access Journals (Sweden)

    Vrushali S Kashikar

    2013-01-01

    Full Text Available Our present work describes the formulation and evaluation of an ocular deliver system of ofloxacin based on the concept of temperature-and ion-activated in situ gelling system. A combination of Pluronic F-127 and Pluronic F-68 along with chitosan, (pH-sensitive polymer also acts as a permeation enhancer was used in temperature and pH-triggered in situ gelling systems while gellan alone was used in ion-activated in situ gelling system. The formulation allows its easy instillation into the eye as a liquid (drops, forms transparent gel, and spreads over the corneal surface. At the formulation pH, transcorneal permeation profile of ofloxacin was comparable to that of in vitro release profile. In situ gel-forming ability of the developed systems significantly controls precorneal drainage as studied by gamma scintigraphy. Thus, increased residence time in the eye would help to increase the ocular bioavailability. The formulation was also found to be nonirritant and well tolerable. Cmax of in situ gelling formulation was found to be 1.5 times higher than marketed eye drops solution at the similar Tmax of 1 h.

  10. Strategy to identify and quantify polysaccharide gums in gelled food concentrates

    NARCIS (Netherlands)

    Grün, C.H.; Sanders, P.; Burg, van der M.; Schuurbiers, E.; Adrichem, van L.; Velzen, van E.J.J.; Roo, de N.; Brunt, K.; Westphal, Y.; Schols, H.A.

    2015-01-01

    A strategy for the unambiguous identification and selective quantification of xanthan gum and locust bean gum (LBG) in gelled food concentrates is presented. DNA detection by polymerase chain reaction (PCR) showed to be a fast, sensitive, and selective method that can be used as a first screening to

  11. Understanding the differences in gelling properties between lupin protein isolate and soy protein isolate

    NARCIS (Netherlands)

    Berghout, J.A.M.; Boom, R.M.; Goot, van der A.J.

    2015-01-01

    The gelling properties of lupin protein isolate (LPI) were compared with those of soy protein isolate (SPI). It was found that LPI behaves fundamentally different than SPI, evidenced by the formation of weaker and deformable gels. Further investigation shows that both protein isolates can be conside

  12. Metallized Gelled Propellants: Oxygen/RP-1/Aluminum Rocket Heat Transfer and Combustion Measurements

    Science.gov (United States)

    Palaszewski, Bryan; Zakany, James S.

    1996-01-01

    A series of rocket engine heat transfer experiments using metallized gelled liquid propellants was conducted. These experiments used a small 20- to 40-lb/f thrust engine composed of a modular injector, igniter, chamber and nozzle. The fuels used were traditional liquid RP-1 and gelled RP-1 with 0-, 5-, and 55-percentage by weight loadings of aluminum particles. Gaseous oxygen was used as the oxidizer. Three different injectors were used during the testing: one for the baseline O(2)/RP-1 tests and two for the gelled and metallized gelled fuel firings. Heat transfer measurements were made with a rocket engine calorimeter chamber and nozzle with a total of 31 cooling channels. Each chamber used a water flow to carry heat away from the chamber and the attached thermocouples and flow meters allowed heat flux estimates at each of the 31 stations. The rocket engine Cstar efficiency for the RP-1 fuel was in the 65-69 percent range, while the gelled 0 percent by weight RP-1 and the 5-percent by weight RP-1 exhibited a Cstar efficiency range of 60 to 62% and 65 to 67%, respectively. The 55-percent by weight RP-1 fuel delivered a 42-47% Cstar efficiency. Comparisons of the heat flux and temperature profiles of the RP-1 and the metallized gelled RP-1/A1 fuels show that the peak nozzle heat fluxes with the metallized gelled O2/RP-1/A1 propellants are substantially higher than the baseline O2/RP-1: up to double the flux for the 55 percent by weight RP-1/A1 over the RP-1 fuel. Analyses showed that the heat transfer to the wall was significantly different for the RP-1/A1 at 55-percent by weight versus the RP-1 fuel. Also, a gellant and an aluminum combustion delay was inferred in the 0 percent and 5-percent by weight RP-1/A1 cases from the decrease in heat flux in the first part of the chamber. A large decrease in heat flux in the last half of the chamber was caused by fuel deposition in the chamber and nozzle. The engine combustion occurred well downstream of the injector face

  13. INCREASED OIL RECOVERY FROM MATURE OIL FIELDS USING GELLED POLYMER TREATMENTS

    Energy Technology Data Exchange (ETDEWEB)

    G.P. Willhite; D.W. Green; C.S. McCool

    2003-05-01

    Gelled polymer treatments are applied to oil reservoirs to increase oil production and to reduce water production by altering the fluid movement within the reservoir. This report describes the results of a three-year research program aimed at reducing barriers to the widespread use of gelled polymer treatments by (1) developing methods to predict gel behavior during placement in matrix rock and fractures, (2) determining the persistence of permeability reduction after gel placement, and (3) developing methods to design production well treatments to control water production. The work focused on the gel system composed of polyacrylamide and chromium acetate. The molar mass of the polymer was about six million. Chromium(III) acetate reacted and formed crosslinks between polymer molecules. The crosslinked polymer molecules, or pre-gel aggregates, combine and grow to eventually form a 3-dimensional gel. A fundamental study to characterize the formation and growth of pre-gel aggregates was conducted. Two methods, flow field-flow fractionation (FFFF) and multi-angle laser light scattering (MALLS) were used. Studies using FFFF were inconclusive. Data taken using MALLS showed that at the gel time the average molar mass of gel aggregates increased by a factor of about three while the average size increase was approximately 50%. Increased acetate concentration in the gelant increases the gel time. The in situ performance of an added-acetate system was investigated to determine the applicability for in-depth treatments. Increased acetate concentrations delayed the development of increased flow resistance during gelant injection in short sandpacks. The development of increased flow resistance (in situ gelation) was extended from 2 to 34 days by increasing the acetate-to-chromium ratio from 38 to 153. In situ gelation occurred at a time that was approximately 22% of the bulk gelation time. When carbonate rocks are treated with gel, chromium retention in the rock may limit in

  14. Development of in situ gelling and bio adhesive 5-Fluorouracil enema.

    Science.gov (United States)

    Wang, Lu-Lu; Zheng, Wen-Sheng; Chen, Shao-Hua; Fang, Xia-Qin

    2013-01-01

    In this study, a novel 5-Fluorouracil (5-FU) enema with good bio adhesion and temperature sensitivity was developed using in situ gelling technology. The preparation was formulated as a free-flowing liquid before use, while a layer of gel film was quickly formed when administered in the rectum, with a large contact surface area. It also demonstrated good biocompatibility, appropriate gel strength and bio adhesive force with excellent adhesion to rectal mucosa and prolonged action time, allowing more effective drug absorption and diffusion to surrounding tissues. Poloxamer 407 and poloxamer 188 were applied to adjust the gelling temperature. With the addition of carbopol and polycarbophil (bio adhesive substances), the solubility of 5-FU and gel strength increased, the temperature of gelation and the surface area of drug contact on mucous epithelium decreased. Decreased adhesive force between the preparation and the mucous membrane of the rectum was demonstrated with improving carbopol and polycarbophil's concentration. In vitro release demonstrated that 5-FU in situ gelling enema with different bases had a rapid and almost complete drug release. We used an optimized formulation of P407/P188/polycarbophil/5-FU (17/2.5/0.2/1.0) for animal experiments. The result showed that the drug evenly covered the surface of the rectum and there was no leakage in 6 hours. The in situ gelling enema showed significantly higher rectal tissue levels of 5-FU compared with suppository and intravenous administration, indicating that 5-FU could be well absorbed due to the enlarged releasing area, longer retention time and larger amount of dissolved active ingredients. Systemically, 5-FU levels in the enema group were similar to those in the suppository group and significantly lower than the intravenous group. The enema was not associated with morphological damage to rectal tissue. These results suggest that the bio adhesive and in situ gelling enema could be a more effective rectal

  15. Development of in situ gelling and bio adhesive 5-Fluorouracil enema.

    Directory of Open Access Journals (Sweden)

    Lu-Lu Wang

    Full Text Available In this study, a novel 5-Fluorouracil (5-FU enema with good bio adhesion and temperature sensitivity was developed using in situ gelling technology. The preparation was formulated as a free-flowing liquid before use, while a layer of gel film was quickly formed when administered in the rectum, with a large contact surface area. It also demonstrated good biocompatibility, appropriate gel strength and bio adhesive force with excellent adhesion to rectal mucosa and prolonged action time, allowing more effective drug absorption and diffusion to surrounding tissues. Poloxamer 407 and poloxamer 188 were applied to adjust the gelling temperature. With the addition of carbopol and polycarbophil (bio adhesive substances, the solubility of 5-FU and gel strength increased, the temperature of gelation and the surface area of drug contact on mucous epithelium decreased. Decreased adhesive force between the preparation and the mucous membrane of the rectum was demonstrated with improving carbopol and polycarbophil's concentration. In vitro release demonstrated that 5-FU in situ gelling enema with different bases had a rapid and almost complete drug release. We used an optimized formulation of P407/P188/polycarbophil/5-FU (17/2.5/0.2/1.0 for animal experiments. The result showed that the drug evenly covered the surface of the rectum and there was no leakage in 6 hours. The in situ gelling enema showed significantly higher rectal tissue levels of 5-FU compared with suppository and intravenous administration, indicating that 5-FU could be well absorbed due to the enlarged releasing area, longer retention time and larger amount of dissolved active ingredients. Systemically, 5-FU levels in the enema group were similar to those in the suppository group and significantly lower than the intravenous group. The enema was not associated with morphological damage to rectal tissue. These results suggest that the bio adhesive and in situ gelling enema could be a more

  16. Physicochemical, sensory, and nutritional quality of fresh-cut "Rojo Brillante" persimmon affected by maturity stage and antibrowning agents.

    Science.gov (United States)

    Sanchís, Elena; Mateos, Milagros; Pérez-Gago, María B

    2016-10-01

    To prevent enzymatic browning of fresh-cut 'Rojo Brillante' persimmon, different combinations of ascorbic acid (AA) and citric acid (CA) with calcium chloride (CaCl2) were tested in fruit harvested at two maturity stages (MS1 and MS2). Color, firmness, sensory quality, total vitamin C, radical scavenging activity, total phenolic content, and carotenoids were evaluated over nine days of storage at 5 ℃. Antibrowning dips reduced enzymatic browning if compared with the control samples. Selecting fruits with good firmness and the addition of 10 g/l CaCl2 help prevent loss of firmness of fresh-cut "Rojo Brillante" persimmons treated with acidic solutions as antibrowning agents to control enzymatic browning. The limit of marketability of the persimmon fruit processed at MS1 was significantly reduced by the burst of the disorder known as "flesh browning," and only the samples treated with 10 g/l CA + 10 g/l CaCl2 maintained a limit of marketability close to seven days. At MS2, all the antibrowning solutions allowed a limit of marketability of seven storage days at 5 ℃. Nutritional quality was not affected by either antibrowning dips or cutting processes, but MS at harvest was. © The Author(s) 2016.

  17. Cell proliferation in Allium cepa L. meristems under 8-hydroxyquinoline, a chelating agent that affects DNA and RNA polymerases.

    Science.gov (United States)

    Ferrero, M L; De la Torre, C

    1986-02-01

    8-Hydroxyquinoline (HQ) chelates Mg2+ and Mn2+ and, secondarily, affects the activities of DNA and RNA polymerases. The in vivo effect of HQ has been estimated in Allium cepa L. meristems growing under new growth kinetics in the presence of this agent. HQ (at both 5 X 10(-5) M and 10(-4) M) depressed incorporation of [3H]uridine much more effectively than that of [3H]-thymidine. Cycle kinetics in meristems behaved as if they were independent of the rates of synthesis or accumulation of RNA since, under HQ, cycle time was only moderately modified and the new cycle kinetics achieved could be explained by the new rates of [3H]thymidine incorporation. Lengthened S periods were partially compensated for by shortened G2 phases, suggesting that, in these cells, both the growth cycle and its coupling with the DNA-division cycle were not disturbed by a decreased amount of RNA. Finally, the nucleolar cycle during mitosis, but not the interphase nucleolus, was modified under the new rates of RNA synthesis.

  18. Study of hydroxy propyl guar derivative for its gelling property and it's use in the formulation of tenoxicam gels.

    Science.gov (United States)

    Swamy, N G N; Dharmarajan, T S; Paranjothi, K L K

    2007-01-01

    Gels of tenoxicam 1% w/w were formulated using 2% w/w hydroxy propyl guar derivative and 3% w/w sodium carboxy methyl cellulose as gelling agents. A detailed rheological investigation was carried out to study the influence of preservative, drug and preservative, solvent system and the preservative, drug, solvent system and the preservative on the pseudoplastic behaviour of polymers. Hydroxy propyl guar derivative in 2% w/w strength resulted in gels with a higher pseudoplastic index value of 3.383 in contrast to an index value of 1.797 for a 3% w/w sodium carboxy methyl cellulose gels of a similar composition. The gels were stored at different temperatures and variations in pH values were recorded. Hydroxy propyl guar derivative based gels revealed variations in pH values over a narrow range in contrast to sodium carboxy methyl cellulose gels. The gels were subjected to short term stability studies by storing gels at refrigerated temperature, lab temperature, at 37 degrees C and at 45 degrees C. Gels based on hydroxy propyl guar derivative revealed better drug keeping qualities in contrast to sodium carboxy methyl cellulose stabilized gels. Release studies of tenoxicam from formulations across hairless albino mice skin revealed a zero order drug release pattern from both the formulations.

  19. High Energy, Low Temperature Gelled Bi-Propellant Formulation for Long-Duration In-Space Propulsion Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The use of gelled propellants for deep space planetary missions may enable adoption of high performance (Isp-vac>360 sec) propellant combinations that do not...

  20. Animated pedagogical agents: How the presence and nonverbal communication of a virtual instructor affect perceptions and learning outcomes in a computer-based environment about basic physics concepts

    Science.gov (United States)

    Frechette, M. Casey

    One important but under-researched area of instructional technology concerns the effects of animated pedagogical agents (APAs), or lifelike characters designed to enhance learning in computer-based environments. This research sought to broaden what is currently known about APAs' instructional value by investigating the effects of agents' visual presence and nonverbal communication. A theoretical framework based on APA literature published in the past decade guided the design of the study. This framework sets forth that APAs impact learning through their presence and communication. The communication displayed by an APA involves two distinct kinds of nonverbal cues: cognitive (hand and arm gestures) and affective (facial expressions). It was predicted that the presence of an agent would enhance learning and that nonverbal communication would amplify these effects. The research utilized a between-subjects experimental design. Participants were randomly assigned to treatment conditions in a controlled lab setting, and group means were compared with a MANCOVA. Participants received (1) a non-animated agent, (2) an agent with hand and arm gestures, (3) an agent with facial expressions, or (4) a fully animated agent. The agent appeared in a virtual learning environment focused on Kepler's laws of planetary motion. A control group did not receive the visual presence of an agent. Two effects were studied: participants' perceptions and their learning outcomes. Perceptions were measured with an attitudinal survey with five subscales. Learning outcomes were measured with an open-ended recall test, a multiple choice comprehension test, and an open-ended transfer test. Learners presented with an agent with affective nonverbal communication comprehended less than learners exposed to a non-animated agent. No significant differences were observed when a group exposed to a fully animated agent was compared to a group with a non-animated agent. Adding both nonverbal communication

  1. Layered double hydroxides as an effective additive in polymer gelled electrolyte based dye-sensitized solar cells.

    Science.gov (United States)

    Ho, Hsu-Wen; Cheng, Wei-Yun; Lo, Yu-Chun; Wei, Tzu-Chien; Lu, Shih-Yuan

    2014-10-22

    Layered double hydroxides (LDH), a class of anionic clay materials, were developed as an effective additive for polymer gelled electrolytes for use in dye-sensitized solar cells (DSSC). Carbonate and chloride intercalated Zn-Al LDHs, ZnAl-CO3 LDH, and ZnAl-Cl LDH were prepared with coprecipitation methods. The addition of the two LDHs significantly improved, in terms of power conversion efficiency (PCE), over the plain poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) gelled electrolyte and competed favorably with the liquid electrolyte based DSSCs, 8.13% for the liquid electrolyte, 7.48% for the plain PVDF-HFP gelled electrolyte, 8.11% for the ZnAl-CO3 LDH/PVDF-HFP gelled electrolyte, and 8.00% for the ZnAl-Cl LDH/PVDF-HFP gelled electrolyte based DSSCs. The good performance in PCEs achieved by the LDH-loaded DSSCs came mainly from the significant boost in open circuit voltages (Voc), from 0.74 V for both the liquid electrolyte and PVDF-HFP gelled electrolyte based DSSCs to 0.79 V for both the ZnAl-CO3 LDH/PVDF-HFP and ZnAl-Cl LDH/PVDF-HFP gelled electrolyte based DSSCs. The boost in Voc was contributed mainly by the positive shift in redox potential of the redox couple, I(-)/I3(-), as revealed from cyclic voltammetry analyses. As for the long-term stability, PCE retention rates of 96 and 99% after 504 h were achieved by the ZnAl-CO3 LDH/PVDF-HFP and ZnAl-Cl LDH/PVDF-HFP gelled electrolyte based DSSCs, respectively, appreciably better than 92% achieved by the liquid electrolyte based one after 480 h.

  2. In situ permeability modification using gelled polymer systems. Annual report, April 11, 1997--April 10, 1998

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.; Willhite, G.P.; McCool, C.S.; Heppert, J.A.; Vossoughi, S.; Michnick, M.J.

    1998-09-01

    Results from a research program on the application of gelled polymer technology for in situ permeability modification are presented in this report. The objective of this technology when used with displacement processes such as waterflooding is to reduce the permeability in fractures and/or high permeability matrix zones to improve volumetric sweep efficiency of the displacement process. In production wells, the objective is to reduce water influx. The research program focused on five areas: Gel treatment in fractured systems; Gel treatment in carbonate rocks; In-depth placement of gels; Gel systems for application in carbon dioxide flooding; and Gel treatment in production wells. The research program is primarily an experimental program directed toward improving the understanding of gelled polymer systems and how these systems can be used to increase oil recovery from petroleum reservoirs. A summary of progress for research conducted in the second 12 month period of a 28 month program is described.

  3. In situ permeability modification using gelled polymer systems. Topical report, June 10, 1996--April 10, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.; Willhite, G.P.; McCool, C.S.; Heppert, J.A.; Vossoughi, S.

    1997-10-01

    Results from a research program on the application of gelled polymer technology for in situ permeability modification are presented in this report. The objective of this technology when used with displacement processes such as waterflooding is to reduce the permeability in fractures and/or high permeability matrix zones to improve volumetric sweep efficiency of the displacement process. In production wells, the objective is to reduce water influx. The research program is focused on five areas: gel treatment in fractured systems; gel treatment in carbonate rocks; in-depth placement of gels; gel systems for application in carbon dioxide flooding; and gel treatment in production wells. The research program is primarily an experimental program directed at improving the understanding of gelled polymer systems and how these systems can be used to increase oil recovery from petroleum reservoirs. A summary of progress for research conducted in the first 10 months of a 28 month program is described in the following sections.

  4. Gelling process of sodium alginate with bivalent ions rich microsphere: Nature of bivalent ions

    Science.gov (United States)

    Mauri, Marco; Vicini, Silvia; Castellano, Maila

    2016-05-01

    In the paper we present a new approach for obtaining a controlled gelling process of sodium alginate, based on the quantity of bivalent ions rich alginate micro-beads added as crosslinkers. Typically, calcium ions are used in gelation of alginate solutions. In this study we present different gelling systems realized with alginate microspheres, made by electrospinning methodology, enriched with different bivalent ions (Ca2+, Ba2+ and Mg2+). The microspheres were characterized under the point of view of the morphology by OM and as the ions content. Realized gels were characterized in light of the amount of the ions added to the alginate solution, and in light of the different dimensions of the micro-beads, using rheological measurements to assess the variation in the storage modulus (G'), loss modulus (G″) and complex viscosity (η*).

  5. The flow and spray characteristics of gelled fluids; Die Stroemungs- und Verspruehungseigenschaften gelfoermiger Fluide

    Energy Technology Data Exchange (ETDEWEB)

    Madlener, K.

    2008-07-01

    In the present study gelled fluids are investigated concerning their application as propellants in storable and thrust controllable rocket propulsion systems. The correlations between the non-Newtonian viscosity properties and the flow and spray characteristics are discussed. Based on the proposed viscosity model Herschel-Bulkley-Extended (HBE) the laminar pipe flow is calculated for the investigated propellants. With the introduction of a generalized form of the Reynolds number and the presentation of a possibility to determine the critical values of this number it is possible to calculate the laminar-turbulent transition in a pipe flow. The theoretical results are evaluated with experimental data. The spray characteristics of various gelled fluids are examined using an experimental setup with impinging-jet-injectors. (orig.)

  6. Correlation of the protein structure and gelling properties in dried egg white products.

    Science.gov (United States)

    Handa, A; Hayashi, K; Shidara, H; Kuroda, N

    2001-08-01

    The relationship between protein structure and aggregation, as well as heat-induced gelling properties, of seven dried egg white (DEW) products was investigated. Strong correlations were found between average molecular weight and hydrophobicity plus surface SH groups of DEW-soluble protein aggregate (SPA). This suggests that hydrophobic interactions and disulfide bond formation between protein molecules were involved in the aggregation. The average molecular weight of DEW products with alkaline pHs was relatively higher than those with neutral pHs and the same degree of protein unfolding, probably because of more disulfide bond formation between protein molecules. In addition, strong correlations were found between hydrophobicity, surface SH groups plus average molecular weight of DEW-SPA, and physical properties of the gels from DEW products. These data indicated that controlling the aggregation of DEW proteins in the dry state is crucial to controlling the gelling properties of DEW.

  7. Ligation of pork skin gelatin with glucose moieties affects the junction zones in gelled networks

    NARCIS (Netherlands)

    Baigts Allende, Diana; Jongh, de H.H.J.

    2015-01-01

    This study aims to investigate the role of the ligation of steric moieties on the formation of junction zones during network formation of gelatin gels. The molecular conformational propensities, heat stability and mechanical properties of gradually chemically modified pork skin gelatin have been

  8. Ligation of pork skin gelatin with glucose moieties affects the junction zones in gelled networks

    NARCIS (Netherlands)

    Baigts Allende, Diana; Jongh, de H.H.J.

    2015-01-01

    This study aims to investigate the role of the ligation of steric moieties on the formation of junction zones during network formation of gelatin gels. The molecular conformational propensities, heat stability and mechanical properties of gradually chemically modified pork skin gelatin have been

  9. Rheological profiling of organogels prepared at critical gelling concentrations of natural waxes in a triacylglycerol solvent

    OpenAIRE

    Patel, Ashok; Babaahmadifooladi, Mehrnoosh; Lesaffer, Ans; Dewettinck, Koen

    2015-01-01

    The aim of this study was to use a detailed rheological characterization to gain new insights into the gelation behavior of natural waxes. To make a comprehensive case, six natural waxes (differing in the relative proportion of chemical components: hydrocarbons, fatty alcohols, fatty acids, and wax esters) were selected as organogelators to gel high-oleic sunflower oil. Flow and dynamic rheological properties of organogels prepared at critical gelling concentrations (Cg) of waxes were studied...

  10. Increased Oil Recovery from Mature Oil Fields Using Gelled Polymer Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Willhite, G.P.; Green, D.W.; McCool, C.S.

    2001-01-22

    This report describes the progress of the first year of a three-year research program. This program is aimed at reducing barriers to the widespread use of gelled polymer treatments by (1) developing methods to predict gel behavior during placement in matrix rock and fractures, (2) determining the persistence of permeability reduction after gel placement, and (3) developing methods to design production well treatments to control water production.

  11. Gelled membranes for Li and Li-ion batteries prepared by electrospinning

    Science.gov (United States)

    Bansal, D.; Meyer, B.; Salomon, M.

    Composite polymer gelled membranes have been prepared an electrospinning technique. Electrospinning of polymer fibers or electrospraying of particles is typically accomplished by applying a strong electric field (ca. 1-25 kV cm -1) to a polymer solution or slurry of solids in an appropriate solvent. The fibers are collected as a mat (membrane) on a grounded target such as Al, Cu, Ni, etc. Typical membranes (mats) consist of nanometer size fibers and have porosities of 65-85%. In the present paper, we describe the fabrication of electrospun membranes for use as gelled electrolytes in Li and Li-ion batteries. The electrospun polymer membranes used in this work are based on the polyimides (PIs) Matrimid and Ultem 1000. Pure PI membranes have been prepared, and blends of Matrimid and Ultem with PVdF-HFP and PAN have been studied in 250 mAh and 7 Ah Li-ion cells. Fully imidized polyimides such as Matrimid and Ultem 1000 do not form gels, and are used as a host matrix of high mechanical strength to immobilize the gelling constituents PVdF or PAN.

  12. Gelled membranes for Li and Li-ion batteries prepared by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Bansal, D.; Meyer, B.; Salomon, M. [MaxPower, Inc., 141 Christopher Lane, Harleysville, PA 19438 (United States)

    2008-04-01

    Composite polymer gelled membranes have been prepared an electrospinning technique. Electrospinning of polymer fibers or electrospraying of particles is typically accomplished by applying a strong electric field (ca. 1-25 kV cm{sup -1}) to a polymer solution or slurry of solids in an appropriate solvent. The fibers are collected as a mat (membrane) on a grounded target such as Al, Cu, Ni, etc. Typical membranes (mats) consist of nanometer size fibers and have porosities of 65-85%. In the present paper, we describe the fabrication of electrospun membranes for use as gelled electrolytes in Li and Li-ion batteries. The electrospun polymer membranes used in this work are based on the polyimides (PIs) Matrimid and Ultem 1000. Pure PI membranes have been prepared, and blends of Matrimid and Ultem with PVdF-HFP and PAN have been studied in 250 mAh and 7 Ah Li-ion cells. Fully imidized polyimides such as Matrimid and Ultem 1000 do not form gels, and are used as a host matrix of high mechanical strength to immobilize the gelling constituents PVdF or PAN. (author)

  13. Performance characteristics of a gelled-electrolyte valve-regulated lead-acid battery

    Indian Academy of Sciences (India)

    S K Martha; B Hariprakash; S A Gaffoor; A K Shukla

    2003-08-01

    12 V/25 AH gelled-electrolyte valve-regulated lead-acid batteries have been assembled in-house and their performance studied in relation to the absorptive glass-microfibre valve-regulated and flooded-electrolyte counterparts at various discharge rates and temperatures between –40°C and 40°C. Although the performance of the gelled-electrolyte valve-regulated battery is similar to both the absorptive glass-microfibre valve-regulated and flooded-electrolyte lead-acid batteries at temperatures above 0°C, it is superior to both the flooded-electrolyte and absorptive glass-microfibre valve-regulated lead-acid batteries at temperatures between 0°C and -40°C. The latter characteristic is attractive for expanding the application regime of valve-regulated lead-acid batteries. The corrosion rate for the positive grids in the gelled-electrolyte is also lower than both the flooded-electrolyte and absorptive glass-microfibre configurations.

  14. Temperature-responsive compounds as in situ gelling biomedical materials.

    Science.gov (United States)

    Moon, Hyo Jung; Ko, Du Young; Park, Min Hee; Joo, Min Kyung; Jeong, Byeongmoon

    2012-07-21

    Aqueous solutions that undergo sol-to-gel transition as the temperature increases have been extensively studied during the last decade. The material can be designed by controlling the hydrophilic and hydrophobic balance of the material. Basically, the molecular weight of the hydrophilic block and hydrophobic block of a compound should be fine-tuned from the synthetic point of view. In addition, stereochemistry, microsequence, topology, and nanostructures of the compound also affect the transition temperature, gel window, phase diagram, and modulus of the gel. From a practical point of view, biodegradability, biocompatibility, and interactions between the material and drug or cell should be considered in designing a thermogelling material. The interactions are particularly important in that they control drug release profile and initial burst release of the drug in the drug delivery system, and affect cell proliferation, differentiation, and biomarker expression in three-dimensional cell culture and tissue engineering application. This review provides an in-depth summary of the recent progress of thermogelling systems including polymers, low molecular compounds, and nanoemulsions. Their biomedical applications were also comparatively discussed. In addition, perspectives on future material design of a new thermogelling material and its application are suggested.

  15. Sorption of Cu(II Ions on Chitosan-Zeolite X Composites: Impact of Gelling and Drying Conditions

    Directory of Open Access Journals (Sweden)

    Amal Djelad

    2016-01-01

    Full Text Available Chitosan-zeolite Na-X composite beads with open porosity and different zeolite contents were prepared by an encapsulation method. Preparation conditions had to be optimised in order to stabilize the zeolite network during the polysaccharide gelling process. Composites and pure reference components were characterized using X-ray diffraction (XRD; scanning electron microscopy (SEM; N2 adsorption–desorption; and thermogravimetric analysis (TG. Cu(II sorption was investigated at pH 6. The choice of drying method used for the storage of the adsorbent severely affects the textural properties of the composite and the copper sorption effectiveness. The copper sorption capacity of chitosan hydrogel is about 190 mg·g−1. More than 70% of this capacity is retained when the polysaccharide is stored as an aerogel after supercrititcal CO2 drying, but nearly 90% of the capacity is lost after evaporative drying to a xerogel. Textural data and Cu(II sorption data indicate that the properties of the zeolite-polysaccharide composites are not just the sum of the properties of the individual components. Whereas a chitosan coating impairs the accessibility of the microporosity of the zeolite; the presence of the zeolite improves the stability of the dispersion of chitosan upon supercritical drying and increases the affinity of the composites for Cu(II cations. Chitosan-zeolite aerogels present Cu(II sorption properties.

  16. Formulation and evaluation of microemulsion-based in situ ion-sensitive gelling systems for intranasal administration of curcumin.

    Science.gov (United States)

    Wang, Shuang; Chen, Ping; Zhang, Lin; Yang, Chunfen; Zhai, Guangxi

    2012-12-01

    The purpose of our study was to develop a microemulsion-based in situ ion-sensitive gelling system for intranasal administration of curcumin. A new microemulsion composition for curcumin was optimized with the simple lattice design. And the microemulsion-based in situ ion-sensitive gelling system consisted of Capryol 90 as oil phase, Solutol HS15 as surfactant, Transcutol HP as cosurfactant and 0.3% DGG solution as water phase. The physicochemical properties such as morphology, droplet size distribution, zeta value and the in vitro release were investigated. In addition, the histological section studies on the reaction between the obtained formulation and nasal mucosa showed that the microemulsion-based in situ ion-sensitive gelling system could not produce obvious damage to nasal mucosa. The pharmacokinetics results showed that the absolute bioavailability of curcumin in the microemulsion-based in situ ion-sensitive gelling system was 55.82% by intranasal administration. And the brain targeting index (BTI) was 6.50, and in the tissue distribution experiment, the value of (AUC(brain)/AUC(blood)) following intranasal administration was higher than that following intravenous administration, suggesting that the obvious brain targeting property by nasal delivery be attributed to a direct nose-to-brain drug transport. It can be concluded that the microemulsion-based in situ gelling as an effective and safe vehicle could greatly enhance the in vivo absorption and facilitate the delivery of curcumin to brain by intranasal administration.

  17. Experimental comparative study of doublet and triplet impinging atomization of gelled fuel based on PIV

    Science.gov (United States)

    Yang, Jian-lu; Li, Ning; Weng, Chun-sheng

    2016-10-01

    Gelled propellant is promising for future aerospace application because of its combination of the advantages of solid propellants and liquid propellants. An effort was made to reveal the atomization properties of gelled fuel by particle image velocimetry (PIV) system. The gelled fuel which was formed by gasoline and Nano-silica was atomized using a like-doublet impingement injector and an axisymmetric like-triplet impingement injector. The orifice diameter and length of the nozzle used in this work were of 0.8mm, 4.8mm, respectively. In the impinging spray process, the impingement angles were set at 90° and 120°, and the injection pressures were of 0.50MPa and 1.00MPa. The distance from the exit of the orifice to the impingement point was fixed at 9.6mm. In this study, high-speed visualization and temporal resolution particle image velocimetry techniques were employed to investigate the impingement atomization characteristics. The experimental investigation demonstrated that a long narrow high speed droplets belt formed around the axis of symmetry in the like-doublet impinging atomization area. However, there was no obvious high-speed belt with impingement angle 2θ = 90° and two high-speed belts appeared with impingement angle 2θ = 120° in the like-doublet impingement spray field. The high droplet velocity zone of the like-doublet impingement atomization symmetrically distributed around the central axis, and that of the like-triplet impingement spray deflected to the left of the central axis - opposite of injector. Although the droplets velocity distribution was asymmetry of like-triplet impingement atomization, the injectors were arranged like axisymmetric conical shape, and the cross section of spray area was similar to a circle rather than a narrow rectangle like the like-doublet impingement atomization.

  18. Microcosmos the world of elementary particles : fictional discussions between Einstein, Newton, and Gell-Mann

    CERN Document Server

    Fritzsch, Harald

    2014-01-01

    This book provides a broad introduction into the field of particle physics for the general reader through virtual discussions among prominent physicists, Albert Einstein, Murray Gell-Mann, Issac Newton and a modern physicists. Matter is composed of quarks and electrons. The electrons interact with the atomic nuclei by the exchange of photons. The forces between the quarks are generated by the exchange of gluons, which leads to the confinement of the quarks. The weak bosons provide the weak forces among the leptons and quarks. The book is suitable for non-experts in physics. Readership: General readers, students and researchers in physics.

  19. Increased Oil Recovery from Mature Oil Fields Using Gelled Polymer Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Willhite, G.P.; Green, D.W.; McCool, S.

    2001-03-28

    Gelled polymer treatments were applied to oil reservoirs to increase oil production and to reduce water production by altering the fluid movement within the reservoir. This report is aimed at reducing barriers to the widespread use of these treatments by developing methods to predict gel behavior during placement in matrix rock and fractures, determining the persistence of permeability reduction after gel placement, and by developing methods to design production well treatments to control water production. Procedures were developed to determine the weight-average molecular weight and average size of polyacrylamide samples in aqueous solutions. Sample preparation techniques were key to achieving reproducible results.

  20. Gelling preparation of starting materials for dry and wet syntheses of silicate minerals

    OpenAIRE

    Ikeda, Ko

    1985-01-01

    Gelling technique on the preparation of starting materials of silicates for both dry and wet (hydrothermal) syntheses has been fundamentally reinvestigated on the following components, SiO_2, Al_2O_3, Fe_2O_3, Cr_20_3, MgO, FeO, NiO and CaO by precipitating with excess ammonia water in ethyl alcohol solutions. On the basis of solubilities at each pH for each component, a general procedure for the preparation of starting materials including Na_2O and K_2O has been proposed.

  1. Influence of the concentration of locust bean gum on the gelling ability of whey peptic hydrolysates

    OpenAIRE

    Rocha, Cristina M. R.; Hilliou, L.; Teixeira, J. A.; M. P. Gonçalves

    2008-01-01

    The gelling ability of whey proteins can be changed by limited hydrolysis and by the presence of other components such as polysaccharides; depending on the environmental conditions it can either be improved or impaired. In this work the effect of LBG on the heat-set gelation of aqueous whey protein hydrolysates (10 % w/w) from pepsin was assessed at pH 7.0 by small deformation rheology. Whey protein concentrate (WPC) and hydrolysates with a degree of hydrolysis (DH) of 1.5, ...

  2. Genetic mapping of ada and adc mutations affecting the adaptive response of Escherichia coli to alkylating agents.

    Science.gov (United States)

    Sedgwick, B

    1982-05-01

    The adaptive response to alkylating agents is an inducible repair system which protects Escherichia coli against the mutagenicity and toxicity of these agents. Four mutations, ada-3, ada-5, ada-6, and adc-1, which confer differing phenotypes as regards this response, were shown to be cotransducible with gyrA, and were located at 47 min on the E. coli genetic map. A mutation already shown on the map at 47 min as tag (B. J. Bachmann and K. B. Low, Microbiol. Rev. 44:1--56, 1980; Karran et al., J. Mol. Biol. 140:101--127, 1980) is now known to be an ada mutation (G. Evensen and E. Seeberg, personal communication).

  3. Hot foam for weed control-Do alkyl polyglucoside surfactants used as foaming agents affect the mobility of organic contaminants in soil?

    Science.gov (United States)

    Cederlund, H; Börjesson, E

    2016-08-15

    Use of alkyl polyglucosides (APGs) as a foaming agent during hot water weed control may influence the environmental fate of organic contaminants in soil. We studied the effects of the APG-based foaming agent NCC Spuma (C8-C10) on leaching of diuron, glyphosate, and polycyclic aromatic hydrocarbons (PAHs) in sand columns. We also examined how APG concentration affected the apparent water solubility and adsorption of the herbicides and of the PAHs acenaphthene, acenaphthylene and fluorene. Application of APGs at the recommended concentration of 0.3% did not significantly affect leaching of any of the compounds studied. However, at a concentration of 1.5%, leaching of both diuron and glyphosate was significantly increased. The increased leaching corresponded to an increase in apparent water solubility of diuron and a decrease in glyphosate adsorption to the sand. However, APG addition did not significantly affect the mobility of PAHs even though their apparent water solubility was increased. These results suggest that application of APG-based foam during hot water weed control does not significantly affect the mobility of organic contaminants in soil if used according to recommendations. Moreover, they suggest that APGs could be useful for soil bioremediation purposes if higher concentrations are used.

  4. The Gell-Mann - Okubo Mass Relation among Baryons from Fully-Dynamical, Mixed-Action Lattice QCD

    Energy Technology Data Exchange (ETDEWEB)

    Konstantinos Orginos; Silas Beane; Martin Savage

    2007-10-01

    We explore the Gell-Mann - Okubo mass relation among the octet baryons using fully-dynamical, mixed-action (domain-wall on rooted-staggered) lattice QCD calculations at a lattice spacing of b {approx} 0.125 fm and pion masses of m{sub pi} {approx} 290 MeV, 350 MeV, 490 MeV and 590 MeV. Deviations from the Gell-Mann - Okubo mass relation are found to be small at each quark mass.

  5. Improving reservoir conformance using gelled polymer systems. Eleventh quarterly report, April 1, 1995--June 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.; Willhite, G.P.; Buller, C.; McCool, S.; Vossoughi, S.; Michnick, M.

    1995-07-24

    The general objectives are to (1) to identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) to determine the performance of these systems in bulk and in porous media, and (3) to develop methods to predict the capability of these systems to recover oil from petroleum reservoirs. This work focuses on three types of gel systems -- an aqueous polysaccharide (KUSP1) system that gels as a function of pH, the chromium(III)-polyacrylamide system and the aluminum citrate-polyacrylamide system. Laboratory research is directed at the fundamental understanding of the physics and chemistry of the gelation process in bulk form and in porous media. This knowledge will be used to develop conceptual and mathematical models of the gelation process. Mathematical models will then be extended to predict the performance of gelled polymer treatments in oil reservoirs. Technical progress is described for the following tasks: physical and chemical characterization of gel systems; mechanisms of in situ gelation; and mathematical modelling of the gel systems.

  6. Thiolated poly(aspartic acid) as potential in situ gelling, ocular mucoadhesive drug delivery system.

    Science.gov (United States)

    Horvát, Gabriella; Gyarmati, Benjámin; Berkó, Szilvia; Szabó-Révész, Piroska; Szilágyi, Barnabás Áron; Szilágyi, András; Soós, Judit; Sandri, Giuseppina; Bonferoni, Maria Cristina; Rossi, Silvia; Ferrari, Franca; Caramella, Carla; Csányi, Erzsébet; Budai-Szűcs, Mária

    2015-01-25

    The ophthalmic formulations on the market suffer from poor bioavailability, and it would therefore be useful to design a new formulation which is able to prolong the residence time and reduce the administration frequency. Polymer matrices which exhibit strong mucoadhesion are promising platforms in ocular drug delivery from the aspect of improved bioavailability. In the present study, an in situ gelling, mucoadhesive drug delivery system was fabricated from thiolated poly(aspartic acid) (ThioPASP). The thiol groups of ThioPASP are able to form disulphide linkages with the mucin glycoproteins and prolong the residence time on the eye. The effects of the thiol groups on the structure, swelling behaviour and mucoadhesive character of the gel and on the drug release profile were determined. The gel structure was characterized by means of rheology. The ThioPASP gel was demonstrated by rheology, tensile test and 'wash away' measurements to display strong mucoadhesion. The drug release from the ThioPASP gel was studied on a vertical Franz diffusion cell: a burst release of sodium diclofenac occurred in the first hour, followed by sustained release of the encapsulated drug for up to 24h. The results proved the importance of the presence of the thiol groups and suggested that a ThioPASP formulation can be useful as an in situ gelling, ocular dosage form. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Nanosuspension based in situ gelling nasal spray of carvedilol: development, in vitro and in vivo characterization.

    Science.gov (United States)

    Saindane, Nilesh S; Pagar, Kunal P; Vavia, Pradeep R

    2013-03-01

    The objective of the present investigation was to develop in situ gelling nasal spray formulation of carvedilol (CRV) nanosuspension to improve the bioavailability and therapeutic efficiency. Solvent precipitation-ultrasonication method was opted for the preparation of CRV nanosuspension which further incorporated into the in situ gelling polymer phase. Optimized formulation was extensively characterized for various physical parameters like in situ gelation, rheological properties and in vitro drug release. Formation of in situ gel upon contact with nasal fluid was conferred via the use of ion-activated gellan gum as carrier. In vivo studies in rabbits were performed comparing the nasal bioavailability of CRV after oral, nasal, and intravenous administration. Optimized CRV nanosuspension prepared by combination of poloxamer 407 and oleic acid showed good particle size [d (0.9); 0.19 μm], zeta potential (+10.2 mV) and polydispersity (span; 0.63). The formulation containing 0.5% w/v gellan gum demonstrated good gelation ability and desired sustained drug release over period of 12 h. In vivo pharmacokinetic study revealed that the absolute bioavailability of in situ nasal spray formulation (69.38%) was significantly increased as compared to orally administered CRV (25.96%) with mean residence time 8.65 h. Hence, such in situ gel system containing drug nanosuspension is a promising approach for the intranasal delivery in order to increase nasal mucosal permeability and in vivo residence time which altogether improves drug bioavailability.

  8. Extraction, characterization and gelling behavior enhancement of pectins from the cladodes of Opuntia ficus indica.

    Science.gov (United States)

    Lefsih, Khalef; Delattre, Cédric; Pierre, Guillaume; Michaud, Philippe; Aminabhavi, Tejraj M; Dahmoune, Farid; Madani, Khodir

    2016-01-01

    Total Pectins Fraction (TPF) was extracted at room temperature from dried cladodes of Opuntia ficus indica. TPF is constituted of three pectic fractions WSP, CSP and ASP, which are made up of 66.6%, 44.3% and 81.1% (w/w) of galacturonic acid, respectively. The antioxidant ability of TPF increased with the concentration increasing. It scavenged hydroxyl radical by 90% and chelated 90% of ferrous ions at 5 g/L. FTIR study was carried out. Strong characteristic absorption peaks at 1,618 cm(-1) assigned to the vibration of COO(-) group of galacturonic acid. In the fingerprint region, we noticed three well-defined peaks at 1054, 1085, and 1,154 cm(-1) characteristic of pectic polysaccharides. TPF are non-gelling pectins. The co-crosslinking of TPF with carrageenan was carried out and the gelling behavior was successfully improved. Thermo-sensitive hydrogel was obtained with 82% of TPF and 18% of carrageenan (w/w).

  9. Do blood contamination and haemostatic agents affect microtensile bond strength of dual cured resin cement to dentin?

    Directory of Open Access Journals (Sweden)

    Kerem KiLiC

    2013-01-01

    Full Text Available Objective The purpose of this study was to evaluate the effects of blood contamination and haemostatic agents such as Ankaferd Blood Stopper (ABS and hydrogen peroxide (H2O2 on the microtensile bond strength between dual cured resin cement-dentin interface. Material and Methods Twelve pressed lithium disilicate glass ceramics were luted to flat occlusal dentin surfaces with Panavia F under the following conditions: Control Group: no contamination, Group Blood: blood contamination, Group ABS: ABS contamination Group H2O2: H2O2 contamination. The specimens were sectioned to the beams and microtensile testing was carried out. Failure modes were classified under stereomicroscope. Two specimens were randomly selected from each group, and SEM analyses were performed. Results There were significant differences in microtensile bond strengths (µTBS between the control and blood-contaminated groups (p0.05. Conclusions Contamination by blood of dentin surface prior to bonding reduced the bond strength between resin cement and the dentin. Ankaferd Blood Stoper and H2O2 could be used safely as blood stopping agents during cementation of all-ceramics to dentin to prevent bond failure due to blood contamination.

  10. Do blood contamination and haemostatic agents affect microtensile bond strength of dual cured resin cement to dentin?

    Science.gov (United States)

    KİLİC, Kerem; ARSLAN, Soley; DEMETOGLU, Goknil Alkan; ZARARSIZ, Gokmen; KESİM, Bulent

    2013-01-01

    Objective: The purpose of this study was to evaluate the effects of blood contamination and haemostatic agents such as Ankaferd Blood Stopper (ABS) and hydrogen peroxide (H2O2) on the microtensile bond strength between dual cured resin cement-dentin interface. Material and Methods: Twelve pressed lithium disilicate glass ceramics were luted to flat occlusal dentin surfaces with Panavia F under the following conditions: Control Group: no contamination, Group Blood: blood contamination, Group ABS: ABS contamination Group H2O2: H2O2 contamination. The specimens were sectioned to the beams and microtensile testing was carried out. Failure modes were classified under stereomicroscope. Two specimens were randomly selected from each group, and SEM analyses were performed. Results: There were significant differences in microtensile bond strengths (µTBS) between the control and blood-contaminated groups (p0.05). Conclusions: Contamination by blood of dentin surface prior to bonding reduced the bond strength between resin cement and the dentin. Ankaferd Blood Stoper and H2O2 could be used safely as blood stopping agents during cementation of all-ceramics to dentin to prevent bond failure due to blood contamination. PMID:23559118

  11. Increased Oil Recovery from Mature Oil Fields Using Gelled Polymer Treatments, Annual Report, June 16,2000-June 15, 2001

    Energy Technology Data Exchange (ETDEWEB)

    Willhite, G.P.; Green, D.W.; McCool, C.S.

    2002-05-22

    This program was aimed at reducing barriers to the widespread use of gelled polymer treatments by (1) developing methods to predict gel behavior during placement in matrix rock and fractures, (2) determining the persistence of permeability reduction after gel placement, and (3) developing methods to design production well treatments to control water production.

  12. A Biogeochemical and Spectral Analysis of Vegetation Affected by External Abiotic Agents: Results of an Investigation from Kitsap County, Washington

    Science.gov (United States)

    1990-12-01

    air spaces developed in the spongy mesophyll of the leaf increase the number of reflecting surfaces with abrupt changes in the index of refraction... mesophyll cells. Although there are several kinds of chlorophylls, chlorophyll a and b are the only important ones in woody plants (Kramer and Kozlowski...with the mesophyll structure. Once the leaf mesophyll is fully developed, small external changes will probably not affect the reflectance. Large

  13. Failure of growth hormone-suppressing agents to affect TSH-releasing hormone- and LH-releasing hormone-induced growth hormone release in acromegaly.

    Science.gov (United States)

    Nakagawa, K; Obara, T

    1977-01-01

    In patients with acromegaly whose basal plasma GH levels were suppressed with 9 mg/day of dexamethasone for 2 days, TRH-(6 cases) and LHRH-(1 case) induced GH release were unaffected when the responses were compared to the basal levels. Phentolamine infusion, 70 mg in 150 min, or hyperglycemia induced by iv infusion of 700 ml of 50% glucose solution also did not suppress TRH-induced GH release in 2 acromegalic patients whose basal GH levels were lowered with these agents alone. These results seem to indicate that dexamethasone does not affect TRH- or LHRH-induced GH release per se, but affects the basal state which determines the absolute level of response. They also support the concept that TRH and LHRH act directly on pituitary tumor cells to release GH in acromegaly.

  14. Applications of Optical Sensors to the Detection of Light Scattered from Gelling Systems

    Science.gov (United States)

    Bulone, Donatella; Manno, Mauro; San Biagio, Pier Luigi; Martorana, Vincenzo

    Visible light, scattered within an angle of few degrees, (Small Angle Light Scattering, SALS) yields information on the spatial correlations and dynamical properties on the scale of the micrometers. In this way a quick and non-invasive characterization of a variety of samples is feasible. Lately the SALS instruments have been built around multielement optical sensors (CCD, CMOS), allowing the simultaneous measurement of the complete structure factor even during fast kinetics. An assessment of some sensor matrices of different technology will be presented. The omolecular assemblies produced by polysaccharides or proteins can be functional or dysfunctional, their properties being either desirable or detrimental. Anyhow, their morphology often depends, in a very delicate way, on the presence of cosolutes, on the thermal history, on the biopolymer concentration etc. We present some applications of low angle dynamic and static light scattering to the study of gelling systems (agarose, pectin, insulin).

  15. Formulation and evaluation of in situ gelling systems for intranasal administration of gastrodin.

    Science.gov (United States)

    Cai, Zheng; Song, Xiangrong; Sun, Feng; Yang, Zhaoxiang; Hou, Shixiang; Liu, Zhongqiu

    2011-12-01

    Gastrodin is the major bioactive constituent of the traditional Chinese drug "Tianma." It is used in the treatment of some nervous system diseases and can be transported to the brain via intranasal administration. In the current paper, the development of a novel ion-activated in situ gelling system for the nasal delivery of gastrodin is discussed. An in situ perfusion model was used to determine the absorption-rate constant of gastrodin through rat nasal mucosa. The optimal formulation was determined by measuring the critical cation concentration, anti-dilution capacity, gel expansion coefficient, water-holding capacity, and adhesive capacity. The best formulation consisted of 10% gastrodin, 0.5% deacetylated gellan gum as the gelatinizer, and 0.03% ethylparaben as the preservative. The rheological properties of gastrodin nasal in situ gels were also investigated. The viscosity and elasticity sharply increased at temperatures below 25°C. When physiological concentrations of cations were added into the preparation, the mixture gelled into a semi-solid. The results of an accelerated stability test show that gastrodin nasal in situ gels can be stable for more than 2 years. Mucociliary toxicity was evaluated using the in situ toad palate model and the rat nasal mucociliary method; both models demonstrated no measurable ciliotoxicity. Pharmacodynamic studies suggest that similar acesodyne and sedative effects were induced following intranasal administration of 50 mg/kg gastrodin nasal in situ gels or oral administration of 100 mg/kg gastrodin solution. The in situ gel preparation is a safe and effective nasal delivery system for gastrodin.

  16. Physical and Antimicrobial Properties of Starch-PVA Blend Films as Affected by the Incorporation of Natural Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Amalia Cano

    2015-12-01

    Full Text Available In this work, active films based on starch and PVA (S:PVA ratio of 2:1 were developed by incorporating neem (NO and oregano essential oils (OEO. First, a screening of the antifungal effectiveness of different natural extracts (echinacea, horsetail extract, liquid smoke and neem seed oil against two fungus (P. expansum and A. niger was carried out. The effect of NO and OEO incorporation on the films’ physical and antimicrobial properties was analyzed. Only composite films containing OEO exhibited antibacterial and antifungal activity. Antibacterial activity occurred at low OEO concentration (6.7%, while antifungal effect required higher doses of OEO in the films. Incorporation of oils did not notably affect the water sorption capacity and water vapor barrier properties of S-PVA films, but reduced their transparency and gloss, especially at the highest concentrations. The mechanical response of the S-PVA films was also negatively affected by oil incorporation but this was only relevant at the highest oil ratio (22%. S-PVA films with 6.7% of OEO exhibited the best physical properties, without significant differences with respect to the S-PVA matrix, while exhibiting antibacterial activity. Thus, the use of OEO as a natural antimicrobial incorporated into starch-PVA films represents a good and novel alternative in food packaging applications.

  17. Physical and Antimicrobial Properties of Starch-PVA Blend Films as Affected by the Incorporation of Natural Antimicrobial Agents

    Science.gov (United States)

    Cano, Amalia; Cháfer, Maite; Chiralt, Amparo; González-Martínez, Chelo

    2015-01-01

    In this work, active films based on starch and PVA (S:PVA ratio of 2:1) were developed by incorporating neem (NO) and oregano essential oils (OEO). First, a screening of the antifungal effectiveness of different natural extracts (echinacea, horsetail extract, liquid smoke and neem seed oil) against two fungus (P. expansum and A. niger) was carried out. The effect of NO and OEO incorporation on the films’ physical and antimicrobial properties was analyzed. Only composite films containing OEO exhibited antibacterial and antifungal activity. Antibacterial activity occurred at low OEO concentration (6.7%), while antifungal effect required higher doses of OEO in the films. Incorporation of oils did not notably affect the water sorption capacity and water vapor barrier properties of S-PVA films, but reduced their transparency and gloss, especially at the highest concentrations. The mechanical response of the S-PVA films was also negatively affected by oil incorporation but this was only relevant at the highest oil ratio (22%). S-PVA films with 6.7% of OEO exhibited the best physical properties, without significant differences with respect to the S-PVA matrix, while exhibiting antibacterial activity. Thus, the use of OEO as a natural antimicrobial incorporated into starch-PVA films represents a good and novel alternative in food packaging applications.

  18. Study on the Gelling Properties of k Carrageenan with Textural Analyzer and Rheometer%质构仪及流变仪研究k-卡拉胶的凝胶特性

    Institute of Scientific and Technical Information of China (English)

    吴伟都; 朱慧; 王雅琼; 李言郡; 李卫群; 赵益臻

    2016-01-01

    本文研究了1.5%k-卡拉胶溶液(质量浓度)的粘度以及水凝胶与钾凝胶的凝胶特性,分别从凝胶强度、弹性模量及动态粘度等指标进行考察。同时,研究了卡拉胶自身含有的离子对粘度以及凝胶特性的影响。实验结果表明k-卡拉胶中K、Na、Ca、Mg含量存在差异性,这些元素含量,特别是K、Ca含量的高低影响卡拉胶溶液的粘度以及水凝胶的凝胶强度、弹性模量值、动态粘度值。水凝胶在凝胶强度测定中出现脆性,增加钾离子明显提高凝胶体的凝胶强度、弹性模量及动态粘度,形成的钾凝胶易析水收缩而未出现脆性。水凝胶耐剪切能力强于钾凝胶,流动时应变高于钾凝胶,应力亦相应低于钾凝胶。另外,水凝胶与钾凝胶的弹性模量基本不随频率增加而增加,而动态粘度却随频率出现明显的剪切稀化现象。%In this paper the viscosity of 1.5%k Carrageenan solution (m/m)as well as the gelling properties of hydro-gel and potassium-gel were studied separately,investigated from the gelling strength,elastic modulus and dynamic viscosity etc. The influences of ion content contained in carrageenan on viscosity and gelling properties were studied. The experimental results showed that there existed the difference on K,Na,Ca and Mg content in k Carrageenan,which would affect the viscosity of carrageenan solution and gelling strength,elastic modulus and dynamic viscosity of hydro-gel especially the content of K and Ca. In the determination of gelling strength of hydro-gel the brittleness occurred. The increase of potassium in the carrageenan solution would significantly improve the gelling strength,elastic modulus and dynamic viscosity of gel which were easy to show syneresis and not brittleness. The hydro-gel was more resistant to shear and the value of strain was higher than that of the potassium-gel on the occurrence of flow while the value of stress was lower

  19. Bone marrow mesenchymal stromal cells affect the cell cycle arrest effect of genotoxic agents on acute lymphocytic leukemia cells via p21 down-regulation.

    Science.gov (United States)

    Zhang, Yiran; Hu, Kaimin; Hu, Yongxian; Liu, Lizhen; Wang, Binsheng; Huang, He

    2014-09-01

    The effect of bone marrow microenvironment on the cell cycle of acute lymphocytic leukemia (ALL) and the underlying mechanism has not been elucidated. In this study, we found that in normal condition, bone marrow mesenchymal stromal cells (BM-MSCs) had no significant effect on the cell cycle and apoptosis of ALL; in the condition when the cell cycle of ALL was blocked by genotoxic agents, BM-MSCs could increase the S-phase cell ratio and decrease the G2/M phase ratio of ALL. Besides, BM-MSCs could protect ALL cells from drug-induced apoptosis. Then, we proved that BM-MSCs affect the cell cycle arrest effect of genotoxic agents on ALL cells via p21 down-regulation. Moreover, our results indicated that activation of Wnt/β-catenin and Erk pathways might be involved in the BM-MSC-induced down-regulation of p21 in ALL cells. Targeting microenvironment-related signaling pathway may therefore be a potential novel approach for ALL therapy.

  20. Do agents' characteristics affect their valuation of 'common pool' resources? A full-preference ranking analysis for the value of sustainable river basin management.

    Science.gov (United States)

    González Dávila, Osiel; Koundouri, Phoebe; Pantelidis, Theologos; Papandreou, Andreas

    2017-01-01

    In this paper we develop a full-preference ranking Choice Experiment (CE) designed to investigate how respondents evaluate a set of proposed improvements towards sustainable river basin management, as per the prescriptions of the European Union-Water Framework Directive (2000). The CE is applied in the Asopos River Basin (ARB) in Greece. Our interest is to test whether residency in the river basin, or otherwise, affects the preferences of the relevant agents. We first estimate a rank-ordered logistic regression based on a full set of choices in order to calculate the willingness to pay (WTP) of respondents for each one of the three attributes considered in the CE (i.e., environmental conditions, impact on the local economy and changes in the potential uses of water). The model is initially estimated for the full sample and then re-estimated twice for two sub-samples: the first one only includes the residents of Athens and the second only includes the residents of Asopos. Afterwards, we examine the effect of various demographic and socio-economic factors (such as income, gender, age, employment and education) on the estimates of our model in order to reveal any differences among respondents with different characteristics, mainly focusing on whether they reside or have personal experience of the RB under valuation. Thus, our analysis simultaneously provides a robustness check on previous findings in the literature and additional information about how various demographic and socio-economic characteristics affect the evaluation of the selected attributes.

  1. How and why affective and reactive virtual agents will bring new insights on social cognitive disorders in schizophrenia? An illustration with a virtual card game paradigm

    Directory of Open Access Journals (Sweden)

    Ali eOker

    2015-03-01

    Full Text Available In recent decades, many studies have shown that schizophrenia is associated with severe social cognitive impairments affecting key components, such as the recognition of emotions, theory of mind, attributional style and metacognition. Most studies investigated each construct separately, precluding analysis of the interactive and immersive nature of real-life situation. Specialized batteries of tests are under investigation to assess social cognition which is thought now as a link between neurocognitive disorders and impaired functioning. However, this link accounts for a limited part of the variance of real life functioning. To fill this gap, advances in virtual reality and affective computing have made it possible to carry out experimental investigations of naturalistic social cognition, in controlled conditions, with good reproducibility. This approach is illustrated with the description of a new paradigm based on an original virtual card game in which subjects interpret emotional displays from a female virtual agent, and decipher her helping intentions. Independent variables concerning emotional expression in terms of valence and intensity were manipulated. We show how several useful dependant variables, ranging from classic experimental psychology data to metacognition or subjective experiences records, may be extracted from a single experiment. Methodological issues about the immersion into a simulated intersubjective situation are considered. The example of this new flexible experimental setting with regards to the many constructs recognized in social neurosciences, constitutes a rationale for focusing on this potential intermediate link between standardized tests and real life functioning, and also for using it as an innovative media for cognitive remediation.

  2. Injectable pectin hydrogels produced by internal gelation: pH dependence of gelling and rheological properties.

    Science.gov (United States)

    Moreira, Helena R; Munarin, Fabiola; Gentilini, Roberta; Visai, Livia; Granja, Pedro L; Tanzi, Maria Cristina; Petrini, Paola

    2014-03-15

    The production of injectable pectin hydrogels by internal gelation with calcium carbonate is proposed. The pH of pectin was increased with NaOH or NaHCO3 to reach physiological values. The determination of the equivalence point provided evidence that the pH can be more precisely modulated with NaHCO3 than with NaOH. Degradation and inability to gel was observed for pectin solutions with pH 5.35 or higher. Therefore, pectin solutions with pH values varying from 3.2 (native pH) to 3.8 were chosen to produce the gels. The increase of the pH for the crosslinked hydrogels, as well as the reduction of the gelling time and their thickening, was dependent upon the amount of calcium carbonate, as confirmed by rheology. Hydrogel extracts were not cytotoxic for L-929 fibroblasts. On the overall, the investigated formulations represent interesting injectable systems providing an adequate microenvironment for cell, drug or bioactive molecules delivery.

  3. Improving reservoir conformance using gelled polymer systems. Annual report, September 25, 1992--September 24, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Green, D.W.; Willhite, G.P.

    1994-08-01

    The general objectives of the research program are to (1) identify and develop gelled polymer systems which have potential to improve reservoir conformance of fluid displacement processes, (2) determine the performance of these systems in bulk and in porous media, and (3) develop methods to predict their performance in field applications. The research focuses on three types of gel systems-an aqueous polysaccharide (KUSPI) that gels as a function of pH, polyacrylamide or xanthan crosslinked by CR(III) and a polyacrylamide-aluminum citrate system. Work to date has focused primarily on development of a database, selection of systems, and work to characterize the gel/polymer physical properties and kinetics. The use of ester hydrolysis to control the rate of pH change of a gel system has been investigated and this approach to gel-time control shows promise. Extensive kinetic data were taken on the uptake of CR(III) oligomers by polyacrylamide. A model was developed which describes very well the monomer uptake rates. The model described the dimer uptake data less well and the trimer uptake data poorly. Studies of the flow and gelation in rock materials have been initiated. A mathematical model of rock-fluid interaction during flow of high pH solutions has been developed.

  4. Structure-property evaluation of thermally and chemically gelling injectable hydrogels for tissue engineering.

    Science.gov (United States)

    Ekenseair, Adam K; Boere, Kristel W M; Tzouanas, Stephanie N; Vo, Tiffany N; Kasper, F Kurtis; Mikos, Antonios G

    2012-09-10

    The impact of synthesis and solution formulation parameters on the swelling and mechanical properties of a novel class of thermally and chemically gelling hydrogels combining poly(N-isopropylacrylamide)-based thermogelling macromers containing pendant epoxy rings with polyamidoamine-based hydrophilic and degradable diamine cross-linking macromers was evaluated. Through variation of network hydrophilicity and capacity for chain rearrangement, the often problematic tendency of thermogelling hydrogels to undergo significant syneresis was addressed. The demonstrated ability to tune postformation dimensional stability easily at both the synthesis and formulation stages represents a significant novel contribution toward efforts to utilize poly(N-isopropylacrylamide)-based polymers as injectable biomaterials. Furthermore, the cytocompatibility of the hydrogel system under relevant conditions was established while demonstrating time- and dose-dependent cytotoxicity at high solution osmolality. Such injectable in situ forming degradable hydrogels with tunable water content are promising candidates for many tissue-engineering applications, particularly for cell delivery to promote rapid tissue regeneration in non-load-bearing defects.

  5. Gelling process for sodium alginate: New technical approach by using calcium rich micro-spheres.

    Science.gov (United States)

    Vicini, Silvia; Castellano, Maila; Mauri, Marco; Marsano, Enrico

    2015-12-10

    Alginate based materials have become an important class of products in many fields from the pharmaceutical industry to tissue engineering, because of their ability to create stimuli responsive hydrogels. We present a new technical approach for obtaining a controlled gelling process, based on the quantities of Ca(2+) rich alginate micro-beads added as crosslinkers. The gels have been evaluated in light of the amount of Ca(2+) added to the alginate solution, and in light of the different dimensions of the micro-beads, using rheological measurements to assess the variation in the storage modulus (G'), loss modulus (G'') and complex viscosity (η(*)) as well as swelling and deswelling tests. The methodology was developed to obtain a material with specific characteristics for application in the field of conservation. The material had to be able to create a stable gel after being applied on the artwork surface and to confine the solvent action at the interface during cleaning operations. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. From short to long distances with Gell-Mann--Low Renormalization group

    Science.gov (United States)

    Dunjko, Vanja; Olshanii, Maxim

    2004-05-01

    Computing correlation functions is an important and formidable problem of many-body physics. For 1D gapless systems, Haldane's theory gives exponents of large distance expansions, model details entering through speed of sound. The prefactors depend on high-energy cutoffs, and it is unclear which model-dependent parameters set them. ..We present a method very well-suited for the approximate computation of the leading order prefactor, with short-distance expansion as an input. Our basis is the Gell-Mann--Low Renormalization Group, and optimism about sufficient analyticity of correlation functions. In the test case of Tonks-Girardeau gas, a rare model where both short and long-distance expansions are known, already the first non-zero subleading term of the short-distance expansion gives the long-distance prefactor to within 15%. ..While Wilson's Renormalization Group makes high energy cutoffs irrelevant, we actually determine them for Haldane model. A byproduct of our method is an interpolation between short and long-distance behaviors, which we use to treat interaction-induced decoherence in atom interferometers.

  7. Enzymatically degradable temperature-sensitive polypeptide as a new in-situ gelling biomaterial.

    Science.gov (United States)

    Jeong, Yuri; Joo, Min Kyung; Bahk, Kyung Hyun; Choi, Yun Young; Kim, Ho-Tae; Kim, Won-Ki; Lee, Hwa Jeong; Sohn, Youn Soo; Jeong, Byeongmoon

    2009-07-01

    We are reporting a poly (ethylene glycol)-block-poly(alanine-co-phenyl alanine) (PEG-PAF) aqueous solution that undergoes sol-to-gel transition as the temperature increases. The sol-to-gel transition was observed at as low a concentration as 3.0-7.0 wt.%. Micellar aggregation accompanying small conformational changes of the peptide from random coils to beta-sheets is suggested as the sol-to-gel transition mechanism of the PEG-PAF aqueous solution. The PEG-PAF is stable in phosphate buffered saline, however, it degraded in the subcutaneous layer of rats. In vitro study showed that proteolytic enzymes such as cathepsin B, cathepsin C, and elastase that are present in the subcutaneous layer of the mammalian tissue might be responsible for the degradation of the polymer in rats. As a feasibility study of this material, a single shot of an aqueous insulin formulation (13.8 mg insulin/kg) showed a hypoglycemic effect over 18 days in rats. The current functional polypeptide may be very promising as an in-situ gelling system for tissue engineering, cell/stem cell therapy, and drug delivery.

  8. Generalized isospin, generalized mass groups, and generalized Gell-Mann--Okubo formalism

    CERN Document Server

    Beaudoin, N; Sandapen, R

    2013-01-01

    The current concepts of isospin and baryon mass groups are only well-adapted to deal with baryon multiplets involving both the u and d quarks, and some other quark k. In this paper, we generalize isospin and mass groups to accommodate baryon multiplets involving quarks of any flavor, and the Gell-Mann--Okubo (GMO) formalism is generalized accordingly. Generalized isospin proves to be a simple and valuable framework when working in non-udk baryon multiplets, and provides new quantum numbers that allows us to distinguish \\Lambda-like baryons from \\Sigma-like baryons in the non-udk multiplets. The generalized GMO formalism allows us to quantify the quality of flavor symmetries seen in baryon multiplets, and also allows us to predict the masses of all observable J^P = 1/2^+ and 3/2^+ baryons with an estimated accuracy on the order of 50 MeV in the worst cases, on mass scales that span anywhere from 1000 MeV to 15000 MeV.

  9. Osteogenic efficiency of in situ gelling poloxamine systems with and without bone morphogenetic protein-2

    Directory of Open Access Journals (Sweden)

    A Rey-Rico

    2011-04-01

    Full Text Available In situ gelling solutions for minimally invasive local application of bone growth factors are attracting increasing attention as efficient and patient-friendly alternative to bone grafts and solid scaffolds for repairing bone defects. Poloxamines, i.e., X-shaped poly(ethylene oxide-poly(propylene oxide block copolymers with an ethylenediamine core (Tetronic®, were evaluated both as an active osteogenic component and as a vehicle for rhBMP-2 injectable implants. After cytotoxicity screening of various poloxamine varieties, Tetronic 908, 1107, 1301 and 1307 solutions were chosen as the most cytocompatible and their sol-to-gel transitions were rheologically characterized. Viscoelastic gels, formed at 37 ºC, sustained protein release under physiological-like conditions. Formulations of rhBMP-2 led to differentiation of mesenchymal stem cells to osteoblasts, quantified as alkaline phosphatase activity with a maximum at day 7, and to mineralized nodules. Interestingly, poloxamine solely gels led to an initial proliferation of the mesenchymal stem cells (first week, followed by differentiation to osteoblasts (second to third week. Histochemical analysis revealed that Tetronic 908 is only osteoinductive; Tetronic 1107 is mostly osteoinductive, although its use leads to a minor differentiation to adipocytes; Tetronic 1307, solely or loaded with rhBMP-2, causes differentiation of both osteoblasts and adipocytes. Enhanced expression levels of CBFA-1 and collagen type I were observed for Tetronic 908, 1107 and 1307, both solely and combined with rhBMP-2. The intrinsic osteogenic activity of poloxamines (not observed for Pluronic F127 offers novel perspectives for bone regeneration using minimally invasive procedures (i.e., injectable scaffolds and overcoming the safety and the cost/effectiveness concerns associated with large scale clinical use of recombinant growth factors.

  10. Rheological profiling of organogels prepared at critical gelling concentrations of natural waxes in a triacylglycerol solvent.

    Science.gov (United States)

    Patel, Ashok R; Babaahmadi, Mehrnoosh; Lesaffer, Ans; Dewettinck, Koen

    2015-05-20

    The aim of this study was to use a detailed rheological characterization to gain new insights into the gelation behavior of natural waxes. To make a comprehensive case, six natural waxes (differing in the relative proportion of chemical components: hydrocarbons, fatty alcohols, fatty acids, and wax esters) were selected as organogelators to gel high-oleic sunflower oil. Flow and dynamic rheological properties of organogels prepared at critical gelling concentrations (Cg) of waxes were studied and compared using drag (stress ramp and steady flow) and oscillatory shear (stress and frequency sweeps) tests. Although, none of the organogels satisfied the rheological definition of a "strong gel" (G″/G' (ω) ≤ 0.1), on comparing the samples, the strongest gel (highest critical stress and dynamic, apparent, and static yield stresses) was obtained not with wax containing the highest proportion of wax esters alone (sunflower wax, SFW) but with wax containing wax esters along with a higher proportion of fatty alcohols (carnauba wax, CRW) although at a comparatively higher Cg (4%wt for latter compared to 0.5%wt for former). As expected, gel formation by waxes containing a high proportion of lower melting fatty acids (berry, BW, and fruit wax, FW) required a comparatively higher Cg (6 and 7%wt, respectively), and in addition, these gels showed the lowest values for plateau elastic modulus (G'LVR) and a prominent crossover point at higher frequency. The gelation temperatures (TG'=G″) for all the studied gels were lower than room temperature, except for SFW and CRW. The yielding-type behavior of gels was evident, with most gels showing strong shear sensitivity and a weak thixotropic recovery. The rheological behavior was combined with the results of thermal analysis and microstructure studies (optical, polarized, and cryo-scanning electron microscopy) to explain the gelation properties of these waxes.

  11. Reasoning about emotional agents

    NARCIS (Netherlands)

    Meyer, J.-J.

    2008-01-01

    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 this f

  12. Banquet Speech at the Singapore Conference in Honour of Murray Gell-Mann on His 80th Birthday

    Science.gov (United States)

    Yang, Chen Ning

    2013-05-01

    It was about 60 years ago in 1951 that I first met in Princeton, at the Institute for Advanced Study, our Honoree tonight, Murray Gell-Mann. In the intervening 60 years, man's understanding of the fundamental structure of matter has made great historic advances. At this wonderful Conference, we have the opportunity to review some of these historic advances. It is a little like looking over an old album of memorable photographs in one's lifetime. In many of these photographs, Murray appears either in the foreground, or as the photographer snapping the picture. We know he is pleased with the album...

  13. Experimental research on characteristic of start-up pressure wave propagation in gelled crude oil by large-scale flow loop

    Institute of Scientific and Technical Information of China (English)

    崔秀国; 艾慕阳; 姜保良; 霍连风; 张立新

    2008-01-01

    In order to research start-up pressure wave propagation mechanism and determine pressure wave speed in gelled crude oil pipelines accurately,experiment of Large-scale flow loop was carried out.In the experiment,start-up pressure wave speeds under various operation conditions were measured,and effects of correlative factors on pressure wave were analyzed.The experimental and theoretical analysis shows that thermal shrinkage and structural properties of gelled crude oils are key factors influencing on start-up pressure wave propagation.The quantitative analysis for these effects can be done by using volume expansion coefficient and structural property parameter of gelled crude oil.A new calculation model of pressure wave speed was developed on the basis of Large-scale flow loop experiment and theoretical analysis.

  14. Total phosphorus recovery in flowback fluids after gelled hydrocarbon fracturing fluid treatments

    Energy Technology Data Exchange (ETDEWEB)

    Fyten, G.; Houle, P.; Taylor, R.S. [Halliburton Energy Services, Calgary, AB (Canada); Stemler, P.S. [Petro-Canada Oil and Gas Inc., Calgary, AB (Canada); Lemieux, A. [Omnicon Consultants Inc., Calgary, AB (Canada)

    2006-07-01

    in the flowback fluid. The total phosphorus introduced by the gelled oil fracturing-fluid treatment could be present in the production fluid for significant periods of time depending on well production rates and hydraulic fracturing fluid treatment volume. Phosphonate ester oil gellants offer a notably lower ratio of volatile phosphorus to total phosphorus than phosphate esters. However, the ratio remains constant for both systems during flowback. The only exception is during initial flowback where a positive mass balance occurs and the ratio of volatile to total phosphorus doubles. 6 refs., 1 tab., 14 figs.

  15. Influence of gelling additives in the green properties of Al{sub 2}O{sub 3} bodies obtained by aqueous gel casting

    Energy Technology Data Exchange (ETDEWEB)

    Millan, A.J. [IUT, Caracas (Venezuela). Dept. Materiales; Baudin, C.; Moreno, R.; Nieto, M.I. [Consejo Nacional de Investigaciones Cientificas, Madrid (Spain). Ist. de Ceramica y Vidrio

    2002-07-01

    The use of gelling additives, as polysaccharides, in colloidal processing provides adequate mechanical properties to the green bodies to be handled. In this work, Al{sub 2}O{sub 3} gel casting is studied by using agar, agarose and carrageenan as gelling additives. The rheological behaviour of the gel casting slurries on cooling is studied. The green characteristics of the gel cast bodies prepared at different conditions are characterised in terms of density, microstructure and mechanical behaviour (bend strength, elastic modulus) at room temperature. A correlation between the obtained results is established and the best compositions and processing conditions are discussed. (orig.)

  16. Development of rectal delivered thermo-reversible gelling film encapsulating a 5-fluorouracil hydroxypropyl-β-cyclodextrin complex.

    Science.gov (United States)

    Wang, Lu-Lu; Zheng, Wen-Sheng; Chen, Shao-Hua; Han, Yan-Xing; Jiang, Jian-Dong

    2016-02-10

    We have developed a novel 5-Fluorouracil (5FU) formulation for rectal application to improve its therapeutic efficiency in colorectal cancer. The results indicated that 5FU formed an inclusion complex with Hydroxypropyl-β-Cyclodextrin (HP-β-CD). The stoichiometry of the complex was 1:1, with apparent stability constant of 100.4M(-1). After investigating physicochemical properties of the 5FU-HP-β-CD complex encapsulated with thermo-reversible gelling film, the optimized formulation P407/P188/HPMC/5FU-HP-β-CD (18.5/2.5/0.2/15%) was selected and evaluated. The result showed that the 5FU-HP-β-CD complex increased the solubility of 5FU, prolonged and enhanced its releasing. As compared to the raw drug, the transport efficiency of the 5FU-HP-β-CD complex itself or entrapped in thermo-reversible gelling film were respectively 7.3- and 6.8-fold increased, and the cellular uptake of 5-FU 4.9- and 5.4-fold elevated. There was no irritation or damage to rectal sites in the 10h treatment period. Therefore, this HP-β-CD based formulation might improve the therapeutic effect of 5FU on colon-rectal cancer.

  17. Thermoresponsive gelling behavior of concentrated alumina suspensions containing poly(acrylic acid) and PEO-PPO-PEO copolymer.

    Science.gov (United States)

    Kondo, Akira; Xu, Hui; Abe, Hiroya; Naito, Makio

    2012-05-01

    Thermoresponsive gelling behavior of concentrated alumina suspensions with poly(acrylic acid) (PAA) and triblock copolymer (PEO(101)-PPO(56)-PEO(101), Pluronic F127) was investigated as a function of PAA concentration (0.4-1.2 mass%) for ceramic solid free forming. The copolymer species assemble into micelles at temperatures above 15°C, yielding aqueous physical gel. In this study, the concentrated alumina aqueous suspensions (φ=35 vol%) were first prepared using the anionic dispersant of PAA, and then the copolymer species (10 mass%) were dissolved at a cooled temperature at 10°C. The addition of the copolymer species had a negligible influence on the adsorption state of PAA onto the alumina surfaces. The PAA concentration needed for the saturation adsorption on the alumina surfaces was ~0.6 mass%. When the PAA concentration was this value or slightly less, the suspension became gel state at 30°C from low viscous state at 10°C. The thermally induced alumina gel had excellent viscoelastic properties, and thereby the three dimensional periodic ceramic structures were successfully fabricated by a direct colloidal printing method that using the gels as "solid" inks at the room temperature. On the other hand, when it exceeded the saturation adsorption limit, the gelling behavior was not observed, indicating that the non-adsorbing PAA species may partly suppress the micellization of the copolymer on the heating.

  18. A novel in-situ-gelling liquid suppository for site-targeting delivery of anti-colorectal cancer drugs.

    Science.gov (United States)

    Lin, Hong-Ru; Tseng, Chao-Chih; Lin, Yiu-Jiuan; Ling, Ming-Hung

    2012-01-01

    In order to avoid anti-cancer drugs undergoing a first-pass effect and reduce their toxicity, and to solve conventional suppositories defects, we developed an in-situ-gelling and injectable Pluronic-poly(acrylic acid) (Pluronic-PAA) liquid suppository, which could gel fast in the physiological state and had suitable gel strength and bioadhesive force. The liquid suppositories were inserted into the rectum of rabbits without difficulty and leakage, and retained in the rectum for at least 6 h and while releasing the drug. The toxicity and cytotoxic tests indicated that Pluronic and PAA were non-toxic materials and could inhibit colon cancer cells when oxaliplatin was incorporated. C max and AUC0→12h values of oxaliplatin after rectal administration of a oxaliplatin suppository were higher than those for an oxaliplatin solution administered orally. These results suggest that an in-situ-gelling and injectable liquid suppository for humans can be further developed as a more convenient and effective rectal dosage form.

  19. 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.

  20. Lax-Phillips evolution as an evolution of Gell-Mann-Hartle-Griffiths histories and emergence of the Schr\\"oedinger equation for a stable history

    CERN Document Server

    Bar, D

    2002-01-01

    Using the Gell-Mann-Hartle-Griffiths formalism in the framework of the Flesia-Piron form of the Lax-Phillips theory we show that the Schr\\"oedinger equation may be derived as a condition of stability of histories. This mechanism is realized in a mathematical structure closely related to the Zeno effect.

  1. Visit of the ATLAS cavern by Prof. Murray Gell-Mann, Physics Nobel 1969. With Dr Peter Jenni and Dr Alison Lister

    CERN Multimedia

    Maximilien Brice

    2012-01-01

    Murray Gell-Mann, well known for proposing the quark model and as a recipient of the Nobel Prize in Physics in 1969, came to CERN on 23 January. During his visit he gave a theoretical physics seminar on decoherent histories in quantum mechanics.

  2. Calculations of influence of electric field on proton magnetic shielding in molecule, by means of Gell-Mann-Feynman theorem

    Energy Technology Data Exchange (ETDEWEB)

    Volodicheva, M.I.; Rebane, T.K.

    1986-01-01

    A method is proposed for calculating the electric-field-linear contribution to the processional magnetic shielding of the nucleus, based on application on the Gell-Mann-Feyman theorem, using the Pade approximant. Calculational formulas have been derived for the first derivatives of the precessional magnetic shielding of the nucleus with respect to the electric field strength, these formulas containing either experimentally determinable characteristics of the molecules or characteristics obtained by interpolation of the observed properties of isoelectronic molecules. No calculations of wavefunctions are required. For hydrogen and hydrogen halide molecules, values have been calculated for the derivatives, with respect to electric field strength, of the precessional sigma/sub H//sup (1)/ prec and total sigma/sub H//sup (1)/ proton magnetic shielding. The results are in good agreement with experimental data.

  3. Restart of circulation of gelled drilling fluids; Estudo do inicio da recirculacao de fluidos de perfuracao gelificados

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Gabriel M. de [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil); Rocha, Leandro L.V. da; Franco, Admilson T.; Negrao, Cezar O.R. [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil). Programa de Pos Graduacao em Engenharia Mecanica e de Materiais; Martins, Andre L. [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)

    2008-07-01

    This paper describes a mathematical model that simulates the start-up flow of gelled drilling fluids in annular spaces with the purpose to predict pressure peaks at the beginning of the flow. The model comprises the one-dimensional conservation equations of mass and momentum, which are discretized by Finite Volume Method. Fully implicit and up-wind discretization schemes are used and the resultant algebraic equations are solved iteratively by developing a FORTRAN algorithm. The model has the potentiality to be easily adapted to a flow inside a tube. Cases studies are conducted to evaluate the temporal variation of velocity and pressure fields inside both the annular space and a tube. One observed that increasing fluid compressibility or viscosity leads to a reduction of the pressure peaks. (author)

  4. Therapeutic potential and critical analysis of trastuzumab and bevacizumab in combination with different chemotherapeutic agents against metastatic breast/colorectal cancer affecting various endpoints.

    Science.gov (United States)

    Wahid, Mohd; Mandal, Raju K; Dar, Sajad A; Jawed, Arshad; Lohani, Mohtashim; Areeshi, Mohammad Y; Akhter, Naseem; Haque, Shafiul

    2016-08-01

    Researchers are working day and night across the globe to eradicate or at least lessen the menace of cancer faced by the mankind. The two very frequently occurring cancers faced by the human beings are metastatic breast cancer and metastatic colorectal cancer. The various chemotherapeutic agents like anthracycline, cyclophosphamide, paclitaxel, irinotecan, fluorouracil and leucovorin etc., have been used impressively for long. But the obstinate character of metastatic breast cancer and metastatic colorectal cancer needs more to tackle the threat. So, the scientists found the use of monoclonal antibodies trastuzumab (Herceptin(®)) and bevacizumab (Avastin(®)) for the same. The current study critically investigates the therapeutic potential of trastuzumab and bevacizumab in combination with various chemotherapeutic agents against metastatic breast cancer and metastatic colorectal cancer. To the best of our knowledge, this is the very first critical analysis showing percent wise increase in various positive endpoints like median time to disease progression, median survival, and progression free survival etc. for the treatment of metastatic breast/colorectal cancer using trastuzumab and bevacizumab in combination with different chemotherapeutic agents and provides the rational for the success and failure of the selected monoclonal antibodies.

  5. Do changes in prescription practice in patients with rheumatoid arthritis treated with biological agents affect treatment response and adherence to therapy? Results from the nationwide Danish DANBIO Registry

    DEFF Research Database (Denmark)

    Hetland, M L; Lindegaard, H M; Hansen, A;

    2008-01-01

    BACKGROUND: Prescription practice for tumour necrosis factor alpha (TNFalpha) inhibitors has changed towards treating patients with lower disease activity. OBJECTIVE: To determine the trend in treatment response in cohorts of patients with rheumatoid arthritis who started TNFalpha inhibitor...... treatment between 2000 and 2005. METHODS: 1813 patients with RA starting treatment with biological agents in 2000-5 were registered prospectively in the nationwide DANBIO Registry. Baseline disease activity and 12 months' treatment responses were determined in cohorts based on start year (2000/1; 2002; 2003...

  6. How much do incentives affect car purchase? Agent-based microsimulation of consumer choice of new cars. Part 2. Forecasting effects of feebates based on energy-efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Haan, Peter de; Mueller, Michel G.; Scholz, Roland W. [ETH Zurich, Institute for Environmental Decisions, Natural and Social Science Interface, Universitaetstr. 22, CHN J73.2, 8092 Zurich (Switzerland)

    2009-03-15

    In this paper, we simulate the car market in order to forecast the effects of feebate systems based on an energy-labeling scheme using categories A to G. Very fuel-efficient (A) cars receive a cash incentive, highly inefficient (G) cars pay additional fees. Consumers have different price elasticities and behavioral options to react to feebates. They can switch to a smaller sized car, but as energy-efficiency varies widely within size segments, they can also stick to the preferred size class and choose a more efficient (smaller) engine. In addition, previously owned cars influence the next car to be chosen. We use an agent-based microsimulation approach particularly suited to predict environmental and market effects of feebates. Heteorogeneous agents choose from a choice set drawn from a detailed fleet of new cars. Incentives of EUR2000 for A-labeled cars induce an additional rated CO{sub 2} emission decrease of new car registrations between 3.4% and 4.3%, with CO{sub 2} abatement costs between EUR6 and EUR13 per ton, and otherwise little undesired market disturbance. The risk of rebound effects is estimated to be low. After adopting the frequencies of consumer segments to a given country, the model presented is applicable to all European car markets. (author)

  7. Enhancing User Experience through Emotional Interaction: Determining Users' Interests in Online Art Collections Using AMARA (Affective Museum of Art Resource Agent)

    Science.gov (United States)

    Park, S. Joon

    2013-01-01

    The need for emotional interaction has already influenced various disciplines and industries, and online museums represent a domain where providing emotional interactions could have a significant impact. Today, online museums lack the appropriate affective and hedonic values necessary to engage art enthusiasts on an emotional level. To address…

  8. Enhancing User Experience through Emotional Interaction: Determining Users' Interests in Online Art Collections Using AMARA (Affective Museum of Art Resource Agent)

    Science.gov (United States)

    Park, S. Joon

    2013-01-01

    The need for emotional interaction has already influenced various disciplines and industries, and online museums represent a domain where providing emotional interactions could have a significant impact. Today, online museums lack the appropriate affective and hedonic values necessary to engage art enthusiasts on an emotional level. To address…

  9. Signal crayfish as zoogeomorphic agents: diel patterns of fine sediment suspension in a crayfish-affected river and the implications for fine sediment fluxes and dynamics

    Science.gov (United States)

    Rice, Stephen; Johnson, Matthew; Reeds, Jake; Longstaff, Holly; Extence, Chris

    2013-04-01

    The signal crayfish (Pacifasticus leniusculus) is a formidable invasive species that has had a deleterious impact on native freshwater fauna across Europe. We contend that the impact of this animal extends beyond ecology into geomorphology and hypothesise that crayfish are significant agents of fine sediment recruitment and mobilisation, with potentially profound impacts on water quality, substrate quality and fine sediment fluxes. Building on pioneering work by colleagues at Queen Mary University, London this poster considers the role of crayfish in fine sediment suspension in a lowland, gravel-bed river. The hypothesis that nocturnal increases in crayfish activity are associated with a greater frequency of sediment suspension events and increases in ambient turbidity, is tested. Strong diel fluctuations in water turbidity were recorded at several sites on the Brampton Arm of the River Nene in England, a river heavily populated by signal crayfish, during August and September 2012. With the exception of three summer flood events, stage measurements during the same period were essentially flat, ruling out a hydraulic cause for overnight rises in turbidity. Water samples collected at midnight and at midday at one site confirm this diel pattern for suspended sediment concentration. Higher mean turbidity values overnight are associated with an increase in the magnitude and frequency of isolated turbidity spikes or events and this is consistent with crayfish nocturnalism. In particular, we suspect that turbidity events are caused by the construction and maintenenance of burrows and by interactions between crayfish and the river bed while foraging, fighting and avoiding each other. Tying the diel SSC signal directly to crayfish activity proved difficult, but several lines of argument presented here suggest that crayfish are the most likely cause of the diel pattern. These results provide substantial support for the idea that signal crayfish are important zoogeomorphic

  10. Optimization of a gelled emulsion intended to supply ω-3 fatty acids into meat products by means of response surface methodology.

    Science.gov (United States)

    Poyato, Candelaria; Ansorena, Diana; Berasategi, Izaskun; Navarro-Blasco, Iñigo; Astiasarán, Iciar

    2014-12-01

    The optimization of a gelled oil-in-water emulsion was performed for use as fat replacer in the formulation of ω-3 PUFA-enriched cooked meat products. The linseed oil content, carrageenan concentration and surfactant-oil ratio were properly combined in a surface response design for maximizing the hardness and minimizing the syneresis of the PUFA delivery system. The optimal formulation resulted in a gelled emulsion containing 40% of oil and 1.5% of carrageenan, keeping a surfactant-oil ratio of 0.003. The gel was applied as a partial fat replacer in a Bologna-type sausage and compared to the use of an O/W emulsion also enriched in ω-3. Both experimental sausages contributed with higher ω-3 PUFA content than the control. No sensory differences were found among formulations. The selected optimized gelled oil-in-water emulsion was demonstrated to be a suitable lipophilic delivery system for ω-3 PUFA compounds and applicable in food formulations as fat replacer.

  11. The dual temperature/pH-sensitive multiphase behavior of poly(N-isopropylacrylamide-co-acrylic acid) microgels for potential application in in situ gelling system.

    Science.gov (United States)

    Xiong, Wei; Gao, Xiang; Zhao, Yanbing; Xu, Huibi; Yang, Xiangliang

    2011-05-01

    Poly(N-isopropylacrylamide-co-acrylic acid) microgels (PNA) may be an excellent formulation for in situ gelling system due to their high sensitivity and fast response rate. Four monodispersed PNA microgels with various contents of acrylic acid (AA) were synthesized by emulsion polymerization in this paper. Their hydrodynamic diameters decreased reversibly with both decreasing pH and increasing temperature. The dual temperature/pH-sensitivity was influenced by many factors such as AA content, cross-link density and ion strength. In addition, high concentration PNA dispersions underwent multiple phase transition according to different temperatures, pHs and concentrations, which were summarized in a 3D sol-gel phase diagram in this study. According to the sol-gel phase transition, 8% PNA-025 dispersion maintained a relatively low viscosity and favorable fluidity at pH 5.0 in the temperature range of 25-40°C, but it rapidly increased in viscosity at pH 7.4 and gelled at 37°C. This feature enabled the dual temperature/pH-sensitive microgels to overcome the troubles in syringing of temperature sensitive materials during the injection. Apart from this, PNA could form gel well in in vitro (e.g., medium and serum) and in in vivo with low cytotoxicity. Therefore, it is promising for PNA to be applied in the in situ gelling system.

  12. How much do incentives affect car purchase? Agent-based microsimulation of consumer choice of new cars. Part 1. Model structure, simulation of bounded rationality, and model validation

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Michel G.; Haan, Peter de [ETH Zurich, Institute for Environmental Decisions, Natural and Social Science Interface, Universitaetstr. 22, CHN J 73.2, 8092 Zurich (Switzerland)

    2009-03-15

    This article presents an agent-based microsimulation capable of forecasting the effects of policy levers that influence individual choices of new passenger cars. The fundamental decision-making units are households distinguished by sociodemographic characteristics and car ownership. A two-stage model of individual decision processes is employed. In the first stage, individual choice sets are constructed using simple, non-compensatory rules that are based on previously owned cars. Second, decision makers evaluate alternatives in their individual choice set using a multi-attributive weighting rule. The attribute weights are based on a multinomial logit model for cross-country policy analysis in European countries. Additionally, prospect theory and the notion of mental accounting are used to model the perception of monetary values. The microsimulation forecasts actual market observations with high accuracy, both on the level of aggregate market characteristics as well as on a highly resolved level of distributions of market shares. The presented approach is useful for the assessment of policies that influence individual purchase decisions of new passenger cars; it allows accounting for a highly resolved car fleet and differentiated consumer segments. As a result, the complexity of incentive schemes can be represented and detailed structural changes can be investigated. (author)

  13. CNS-specific regulatory elements in brain-derived HIV-1 strains affect responses to latency-reversing agents with implications for cure strategies

    Science.gov (United States)

    Gray, L R; Cowley, D; Welsh, C; Lu, H K; Brew, B J; Lewin, S R; Wesselingh, S L; Gorry, P R; Churchill, M J

    2016-01-01

    Latency-reversing agents (LRAs), including histone deacetylase inhibitors (HDACi), are being investigated as a strategy to eliminate latency in HIV-infected patients on suppressive antiretroviral therapy. The effectiveness of LRAs in activating latent infection in HIV strains derived from the central nervous system (CNS) is unknown. Here we show that CNS-derived HIV-1 strains possess polymorphisms within and surrounding the Sp transcription factor motifs in the long terminal repeat (LTR). These polymorphisms result in decreased ability of the transcription factor specificity protein 1 to bind CNS-derived LTRs, reducing the transcriptional activity of CNS-derived viruses. These mutations result in CNS-derived viruses being less responsive to activation by the HDACi panobinostat and romidepsin compared with lymphoid-derived viruses from the same subjects. Our findings suggest that HIV-1 strains residing in the CNS have unique transcriptional regulatory mechanisms, which impact the regulation of latency, the consideration of which is essential for the development of HIV-1 eradication strategies. PMID:26303660

  14. Suppression of calcific fibrous-fatty plaque formation in rabbits by agents not affecting elevated serum cholesterol levels. The effect of thiophene compounds.

    Science.gov (United States)

    Chan, C T; Wells, H; Kramsch, D M

    1978-07-01

    We tested the suppressive effect of antihypercalcemic-hyperphosphatemic agents on atherogenesis. We studied five groups of rabbits for 8 weeks, one control group and four groups on a fibrogenic atherogenic diet. One group received the atherogenic diet alone, and the remaining three atherogenic groups were treated simultaneously with 2-thiophenecarboxylic acid (ThCA), 5-methyl-2-thiophenecarboxylic acid (5-CH3-ThCA), and 5-bromo-2-thiophenecarboxaldehyde (5-Br-ThCA). Rabbits receiving the atherogenic diet alone developed: (1) elevations of serum cholesterol, calcium, and phosphorus; (2) massive fibrous-fatty aortic plaques with excessive accumulation of aortic collagen, elastin, and lipids; (3) marked deposition of calcium and phosphorus in both aortic tissue and elastin; and (4) severe lipid infiltration of the liver. Treatment with all three drugs normalized the elevated serum calcium but not the cholesterol levels, and effectively inhibited all aspects of the atherosclerotic process as determined morphologically and biochemically. The order of effectiveness was: 5-CH3-ThCa greater than 5-Br-ThCA greater than ThCA. No bone resorption occurred in the treated groups. The normalizing effects of the thiophene compounds on serum phosphorus levels were not significant at the dosages used.

  15. Structural optimization and evaluation of butenolides as potent antifouling agents: modification of the side chain affects the biological activities of compounds

    KAUST Repository

    Li, Yongxin

    2012-09-01

    A recent global ban on the use of organotin compounds as antifouling agents has increased the need for safe and effective antifouling compounds. In this study, a series of new butenolide derivatives with various amine side chains was synthesized and evaluated for their anti-larval settlement activities in the barnacle, Balanus amphitrite. Side chain modification of butenolide resulted in butenolides 3c-3d, which possessed desirable physico-chemical properties and demonstrated highly effective non-toxic anti-larval settlement efficacy. A structure-activity relationship analysis revealed that varying the alkyl side chain had a notable effect on anti-larval settlement activity and that seven to eight carbon alkyl side chains with a tert-butyloxycarbonyl (Boc) substituent on an amine terminal were optimal in terms of bioactivity. Analysis of the physico-chemical profile of butenolide analogues indicated that lipophilicity is a very important physico-chemical parameter contributing to bioactivity. © 2012 Copyright Taylor and Francis Group, LLC.

  16. Tropheryma whipplei, the agent of Whipple's disease, affects the early to late phagosome transition and survives in a Rab5- and Rab7-positive compartment.

    Directory of Open Access Journals (Sweden)

    Giovanna Mottola

    Full Text Available Tropheryma whipplei, the agent of Whipple's disease, inhibits phago-lysosome biogenesis to create a suitable niche for its survival and replication in macrophages. To understand the mechanism by which it subverts phagosome maturation, we used biochemical and cell biological approaches to purify and characterise the intracellular compartment where Tropheryma whipplei resides using mouse bone-marrow-derived macrophages. We showed that in addition to Lamp-1, the Tropheryma whipplei phagosome is positive for Rab5 and Rab7, two GTPases required for the early to late phagosome transition. Unlike other pathogens, inhibition of PI(3P production was not the mechanism for Rab5 stabilisation at the phagosome. Overexpression of the inactive, GDP-bound form of Rab5 bypassed the pathogen-induced blockade of phago-lysosome biogenesis. This suggests that Tropheryma whipplei blocks the switch from Rab5 to Rab7 by acting on the Rab5 GTPase cycle. A bio-informatic analysis of the Tropheryma whipplei genome revealed a glyceraldehyde-3-phosphate dehydrogenase (GAPDH homologous with the GAPDH of Listeria monocytogenes, and this may be the bacterial protein responsible for blocking Rab5 activity. To our knowledge, Tropheryma whipplei is the first pathogen described to induce a "chimeric" phagosome stably expressing both Rab5 and Rab7, suggesting a novel and specific mechanism for subverting phagosome maturation.

  17. Thermosensitive and pH induced in situ ophthalmic gelling system for ciprofloxacin hydrochloride: hydroxypropyl-beta-cyclodextrin complex.

    Science.gov (United States)

    Başaran, Berrin; Bozkir, Asuman

    2012-01-01

    The prolonged residence of drug formulation in the ocular cavity is important for ocular drug delivery. The purpose of the present study was to develop ophthalmic in situ gelling systems of ciprofloxacin hydrochloride with reduced pre-corneal elimination in order to improve the bioavailability and therapeutic response. Hydroxypropyl-beta-cyclodextrin was used in order to increase the stability of ciprofloxacin hydrochloride. In situ gels were prepared based on the concept of thermosensitive and pH induced in situ gelation. The inclusion complex of ciprofloxacin hydrochloride with hydroxypropyl-beta-cyclodextrin was prepared at a 1:1 molar ratio. The complex formation was thoroughly confirmed using various techniques, including (1)H NMR spectroscopy, FTIR spectrophotometry and differential scanning calorimetry. Both pure ciprofloxacin HCI and the inclusion complex were individually used in the formulations. Formulations were successfully prepared which were liquid at room temperature and exhibited viscosity increase and gelation at ophthalmic temperature. As a result of antimicrobial efficacy and in vitro release experiments, the developed formulations were found therapeutically efficient and provided sustained release of the drug over an 8 h period. These systems can be more advantageous than conventional eye drops.

  18. Moxifloxacin-Gelrite in situ ophthalmic gelling system against photodynamic therapy for treatment of bacterial corneal inflammation.

    Science.gov (United States)

    El-Laithy, Hanan M; Nesseem, Demiana I; El-Adly, Amira A; Shoukry, Meriana

    2011-10-01

    In this study, six in situ gelling formulations based on Gelrite were prepared and evaluated for the retained ophthalmic delivery of Moxifloxacin (Mox). The effectiveness of the best developed formula G5 was compared with photodynamic therapy (PDT), the recent expanding approach for the treatment of ophthalmologic disorders after the assessment of optimum photodynamic inactivation parameters that permit efficient pathogens eradication. It was found that, Staphylococcus aureus (S. aureus) (Gram-positive) was more susceptible to effective lethal photosensitization that reaches 93.5% reduction in viable count than Escherichia coli (E. coli) (Gramnegative) of 76.1% using 3 mg/mL Hematoporphyrin (HP), illuminated by 630 nm Light Emitting Diode (LED) at 9 J/cm(2) and incubated for 15 min. Following topical instillation of G5 to rabbits corneas, higher amount of Mox was retained in the aqueous humor up to 24 h with significant 6-fold increase in the C(max) and AUC((0-∞)) compared to vigamox commercial eye drops. After post corneal infection with S. aureus, both approaches were effectively treating the infection without causing ocular irritation or collateral damage to corneal tissue where G5 showed remarkable improvement after four days compared to seven days of PDT treatment.

  19. Improvement in the in situ gelling properties of deacetylated gellan gum by the immobilization of thiol groups.

    Science.gov (United States)

    Krauland, Alexander H; Leitner, Verena M; Bernkop-Schnürch, Andreas

    2003-06-01

    The rheological properties of an in situ crosslinking thiolated deacetylated gellan gum were examined in vitro. Mediated by a carbodiimide, L-cysteine was covalently bound to deacetylated gellan gum (DGG). The deacetylated gellan gum-cysteine (DGG-Cys) conjugate displayed 216.53 +/- 59.54 micromol thiol groups per gram polymer (means +/- SD, n = 3). The thiolated polymer was capable of forming inter- and/or intramolecular disulfide bonds in aqueous solution (1.5%; m/m) at pH 7. After 6 h of incubation at room temperature, storage modulus, loss modulus, and complex viscosity increased 300-, 6.4-, and 26.6-fold, respectively, relative to the unthiolated polymer. Loss tangent of DGG-Cys was gel, whereas the corresponding unmodified polymer had a loss tangent of >1, indicating a fluid. Frequency sweep measurements demonstrated an increase in crosslinking of the thiolated polymer as a function of time. DGG-Cys appeared to be superior to the unmodified polymer also in the presence of physiological cation concentrations found (e.g., in tear fluid and nasal secretion), which is referred to rheological properties. The polymer generated within this study represents a promising novel excipient for various drug delivery systems in which in situ gelling properties are favorable.

  20. In situ gelling, bioadhesive nasal inserts for extended drug delivery: in vitro characterization of a new nasal dosage form.

    Science.gov (United States)

    Bertram, Ulrike; Bodmeier, Roland

    2006-01-01

    The purpose of this study was the preparation and characterization of sponge-like, in situ gelling inserts based on bioadhesive polymers. Hydrophilic polymers (carrageenan, Carbopol, chitosan, hydroxypropyl methylcellulose (HPMC) K15M and E5, sodium alginate, sodium carboxy methylcellulose (NaCMC), polyvinyl pyrrolidone (PVP) 90, xanthan gum) were dissolved with/without the model drug oxymetazoline HCl in demineralized water and lyophilized into small inserts. The drug release, water uptake, mechanical properties, X-ray diffraction and bioadhesion potential of the nasal inserts were investigated. A sponge-like structure of nasal inserts was formed with amorphous, but not with crystalline polymers during the freeze-drying process. The insert hardness increased with the glass transition temperature of the polymer (PVP25HPMC E5, Na-alginate, PVP90). The drug release from inserts prepared from high molecular weight polymers (carrageenan, Carbopol, chitosan, HPMC K15M, NaCMC, xanthan gum) was a complex interplay of osmotic forces, water uptake and electrostatic interactions between drug and polymer. The drug release decreased with higher polymer content and increased drug loading of the insert. Bioadhesive nasal inserts have a high potential as new nasal dosage form for extended drug delivery.

  1. Evaluation of biodiesel as bioremediation agent for the treatment of the shore affected by the heavy oil spill of the Prestige.

    Science.gov (United States)

    Fernández-Alvarez, P; Vila, J; Garrido, J M; Grifoll, M; Feijoo, G; Lema, J M

    2007-08-25

    The efficiency of different bioremediation products (nutrients, microorganisms and biodiesel) was tested using tiles located in both the supra-littoral and intertidal zones of a beach that was affected by the heavy oil spill of the Prestige. Neither nutrients nor microorganisms meant an improvement with respect to the natural processes. The addition of biodiesel improved the appearance of the treated tiles and apparently accelerated the degradation of the aliphatic and aromatic fractions of the residual fuel oil. Nevertheless, PAHs degradation was similar and very high in all the treatments (80-85% after 60 days). On the other hand, the evolution with time of the amount of vanadium was similar to that of 17alpha(H),21beta(H)-hopane, so it was concluded that vanadium could also be used to estimate the extent of oil degradation in the field. These results also suggested that the residual fuel oil mineralization was very low throughout 1 year in all the treatments. Moreover, the increase of the oxygen content of the residual oil from around 1% till 4-8% indicated that the partial oxidation of hydrocarbons took place, and that the hydrocarbon oxidation products accumulated in the polar fractions. In general, the results pointed out that bioremediation techniques were not suitable for the recovery of shores affected by heavy oil spills.

  2. Studies on rheology and microbiological evaluation of hydrotropically gelled starch as topical vehicle for terbinafine hydrochloride

    Directory of Open Access Journals (Sweden)

    Rao Kovur

    2008-01-01

    Full Text Available The present study was aimed for the development and evaluation of hydrotropic starch gels of terbinafine hydrochloride which is an allylamine derivative of antifungal agent was formulated by using corn starch and sodium salicylate as hydrotropic salt. The gels were prepared in presence and absence of propylene glycol. The prepared gels were evaluated for in vitro drug release, rheological behavior and microbial studies. The degree of increase in the drug diffusion was found to be in order corn starch gel with propylene glycol was greater than corn starch gel without propylene glycol. The microbial studies were carried out in soya bean casein digest medium with Candida albicans as test organisms and were found to be 22.86 ± 0.58 and 20.22 ± 0.65 mm for TCSG (IV and TCS (III, respectively. All the gels exhibited shear thinning. The rheogram indicated that the gel systems are pseudoplastic and exhibited thixotropy. The added propylene glycol has not appreciably altered the apparent viscosity values.

  3. Short-term prolactin administration causes expressible galactorrhea but does not affect bone turnover: pilot data for a new lactation agent

    Directory of Open Access Journals (Sweden)

    Smith Patricia C

    2007-07-01

    Full Text Available Abstract Background Medications used to augment lactation increase prolactin secretion but can have intolerable side effects. We examined the biological activity of recombinant human prolactin (r-hPRL as preliminary data for its use to augment lactation. Methods Healthy, non-postpartum women (n = 21 with regular menstrual cycles underwent a seven day randomized, double-blind, placebo-controlled trial of r-hPRL. Expressible galactorrhea, markers of bone turnover, calcium homeostasis and gonadal function were measured and side effects recorded. Results Prolactin levels increased during r-hPRL administration (20.0 ± 2.8 to 231.7 ± 48.9 μg/L at 6 hours; p Conclusion In summary, r-hPRL can cause expressible galactorrhea. Seven days of r-hPRL administration does not adversely affect bone turnover or menstrual cyclicity. Thus, r-hPRL may be a viable option for short-term lactation augmentation. Trial registration Clinical Trials.gov NCT00438490

  4. Intranasal delivery of Norwalk virus-like particles formulated in an in situ gelling, dry powder vaccine.

    Science.gov (United States)

    Velasquez, Lissette S; Shira, Samantha; Berta, Alice N; Kilbourne, Jacquelyn; Medi, Babu M; Tizard, Ian; Ni, Yawei; Arntzen, Charles J; Herbst-Kralovetz, Melissa M

    2011-07-18

    The development of a vaccine to prevent norovirus infections has been focused on immunization at a mucosal surface, but has been limited by the low immunogenicity of self-assembling Norwalk virus-like particles (NV VLPs) delivered enterically or at nasal surfaces. Nasal immunization, which offers the advantage of ease of immunization, faces obstacles imposed by the normal process of mucociliary clearance, which limits residence time of applied antigens. Herein, we describe the use of a dry powder formulation (GelVac) of an inert in situ gelling polysaccharide (GelSite) extracted from Aloe vera for nasal delivery of NV VLP antigen. Powder formulations, with or without NV VLP antigen, were similar in structure in dry form or when rehydrated in simulated nasal fluids. Immunogenicity of the dry powder VLP formulation was compared to equivalent antigen/adjuvant liquid formulations in animals. For the GelVac powder, we observed superior NV-specific serum and mucosal (aerodigestive and reproductive tracts) antibody responses relative to liquid formulations. Incorporation of the TLR7 agonist gardiquimod in dry powder formulations did not enhance antibody responses, although its inclusion in liquid formulations did enhance VLP immunogenicity irrespective of the presence or absence of GelSite. We interpret these data as showing that GelSite-based dry powder formulations (1) stabilize the immunogenic structural properties of VLPs and (2) induce systemic and mucosal antibody titers which are equal or greater than those achieved by VLPs plus adjuvant in a liquid formulation. We conclude that in situ gelation of the GelVac dry powder formulation at nasal mucosal surfaces delays mucociliary clearance and thereby prolongs VLP antigen exposure to immune effector sites.

  5. In vitro-in vivo evaluation of in situ gelling and thermosensitive ketoprofen liquid suppositories.

    Science.gov (United States)

    Ozgüney, Işık; Kardhiqi, Anita; Yıldız, Gülbeyaz; Ertan, Gökhan

    2014-12-01

    The main objective of this study was to investigate the release and pharmacokinetic profiles of ketoprofen (KP) from developed thermosensitive and mucoadhesive liquid suppositories. Thermosensitive liquid suppositories were prepared using KP, poloxamer 407 (P 407), poloxamer 188 (P 188) and various amounts of different mucoadhesive polymers. In vitro release studies was monitored by the USP XXVI paddle method. The results thus obtained were evaluated kinetically and mechanism of release was analyzed. Identification of poloxamer gel localization in vivo was conducted using white male rabbits by adding 1 % methylene blue. For in vivo studies, twenty-four white male rabbits were randomly divided into three groups. The rabbits in each group were administered with liquid suppository F1 [P407/P188/KP (4/20/2.5 %)], F5 [P407/P188/KP/C (4/20/2.5/0.8 %)] or conventional suppository (F-C) into the rectum. The plasma concentration of KP was analyzed by high performance liquid chromatography (HPLC). C max, AUC, MRT and T max were evaluated. The release of KP was variously affected by the mucoadhesive polymers. In vitro release studies showed that Carbopol 934 P(C) has significant effect on release rate among the mucoadhesive polymers. When the formulations were evaluated kinetically, different kinetic models were obtained. Formulation F6 [P407/P188/KP/C (4/20/2.5/1.6 %)] which contains the highest C concentration and very high viscosity, shows a significantly better fit with Higuchi kinetic model. n value of this formulation was also found approximately 0.5. n exponent results of the other formulations showed that KP might be released from the suppositories by non-Fickian diffusion. Identification of poloxamer gel localization in vivo showed that the suppositories remain in the rectum without leakage after administration. With regard to the results of in vivo studies, the AUC6→14 values of KP in liquid suppository containing C are significantly higher than those in

  6. Supramolecular synthons in designing low molecular mass gelling agents: L-amino acid methyl ester cinnamate salts and their anti-solvent-induced instant gelation.

    Science.gov (United States)

    Sahoo, Pathik; Kumar, D Krishna; Raghavan, Srinivasa R; Dastidar, Parthasarathi

    2011-04-04

    Easy access to a class of chiral gelators has been achieved by exploiting primary ammonium monocarboxylate (PAM), a supramolecular synthon. A combinatorial library comprising of 16 salts, derived from 5 L-amino acid methyl esters and 4 cinnamic acid derivatives, has been prepared and scanned for gelation. Remarkably, 14 out of 16 salts prepared (87.5 % of the salts) show moderate to good gelation abilities with various solvents, including commercial fuels, such as petrol. Anti-solvent induced instant gelation at room temperature has been achieved in all the gelator salts, indicating that the gelation process is indeed an aborted crystallization phenomenon. Rheology, optical and scanning electron microscopy, small angle neutron scattering, and X-ray powder diffraction have been used to characterize the gels. A structure-property correlation has been attempted, based on these data, in addition to the single-crystal structures of 5 gelator salts. Analysis of the FT-IR and (1)H NMR spectroscopy data reveals that some of these salts can be used as supramolecular containers for the slow release of certain pest sex pheromones. The present study clearly demonstrates the merit of crystal engineering and the supramolecular synthon approach in designing new materials with multiple properties.

  7. [Uricosuric agent].

    Science.gov (United States)

    Ohno, Iwao

    2008-04-01

    Urate lowering treatment is indicated in patients with recurrent acute attacks, tophi, gouty arthropathy, radiographic changes of gout, multiple joint involvement, or associated uric acid nephrolithiasis. Uricosuric agents like benzbromarone and probenecid are very useful to treat hyperuricemia as well as allopurinol (xanthine oxidase inhibitor). Uricosuric agents act the urate lowering effect through blocking the URAT1, an urate transporter, in brush border of renal proximal tubular cells. In order to avoid the nephrotoxicity and urolithiasis due to increasing of urinary urate excretion by using uricosuric agents, the proper urinary tract management (enough urine volume and correction of aciduria) should be performed.

  8. Vasoactive Agents

    OpenAIRE

    Husedzinovic, Ino; Bradic, Nikola; Goranovic, Tanja

    2006-01-01

    This article is a short review of vasoactive drugs which are in use in todays clinical practice. In the past century, development of vasoactive drugs went through several phases. All of these drugs are today divided into several groups, depending on their place of action, pharmacological pathways and/or effects on target organ or organ system. Hence, many different agents are today in clinical practice, we have shown comparison between them. These agents provide new directions in the treatmen...

  9. [Inotropic agents].

    Science.gov (United States)

    Sasayama, Shigetake

    2003-05-01

    Depression of myocardial contractility plays an important role in the development of heart failure and many inotropic agents were developed to improve the contractile function of the failing heart. Agents that increase cyclic AMP, either by increasing its synthesis or reducing its degradation, exerted dramatic short-term hemodynamic benefits, but these acute effects were not extrapolated into long-term improvement of the clinical outcome of heart failure patients. Administration of these agents to an energy starved failing heart would be expected to increase myocardial energy use and could accelerate disease progression. The role of digitalis in the management of heart failure has been controversial, however, the recent large scale clinical trial has ironically proved that digoxin reduced the rate of hospitalization both overall and for worsening heart failure. More recently, attention was paid to other inotropic agents that have a complex and diversified mechanism. These agents have some phosphodiesterase-inhibitory action but also possess additional effects, including cytokine inhibitors, immunomodulators, or calcium sensitizers. In the Western Societies these agents were again shown to increase mortality of patients with severe heart failure in a dose dependent manner with the long-term administration. However, it may not be the case in the Japanese population in whom mortality is relatively low. Chronic treatment with inotropic agent may be justified in Japanese, as it allows optimal care in the context of relief of symptoms and an improved quality of life. Therefore, each racial group should obtain specific evidence aimed at developing its own guidelines for therapy rather than translating major guidelines developed for other populations.

  10. Research and development of 6-DZMJ-12 gelled lead-acid battery%6-DZMJ-12全胶体铅酸蓄电池的研发

    Institute of Scientific and Technical Information of China (English)

    李桂发; 郭志刚; 刘玉; 邓成智; 周文渭

    2016-01-01

    本文围绕电动自行车用全胶体铅酸蓄电池的研发,从电池内部结构设计、生极板预处理工艺、胶体配方和分散方式及充电化成工艺四个方面进行了研究。实验结果表明:全胶体电池可以满足电动自行车的使用需求,能够很大程度上解决酸分层等问题,进而延长电池的循环使用寿命。%The 6-DZMJ-12 gelled lead-acid batteries for E-bikes were studied from the aspects of internal structure design, plate pretreatment process, gel formula, dispersion, and charging of the formation process. Experimental results showed that the gelled batteries could fully meet the demands of electric bicycle power batteries, because stratiifcation of sulfuric acid electrolyte and other problems were solved largely to extend the life of battery.

  11. 大豆素火腿加工的凝胶工艺研究%Gelling technology of soybean vegetarian ham

    Institute of Scientific and Technical Information of China (English)

    邓源喜; 马龙; 李妍; 许晖; 徐世晶

    2011-01-01

    凝胶过程是决定素火腿品质的关键工序.采用单因素试验、正交试验,研究了素火腿加工的凝胶工艺,并对关键参数进行了优化.结果表明,选择浓度为0.25mol/L的CaSO4及浓度为2.0mol/L的卤水作为凝固剂,凝固温度为85℃,大豆蛋白含量为14%,此时形成的蛋白凝胶硬度为351g,加工的素火腿有很好的咀嚼性和粘弹性.%Gelling was considered as the key processing stage in the production of vegetarian ham.A new gelling technology of vegetarian ham was studied and optimized by single factor and orthogonal tests.The results showed that when 0.25mol/L CaSO4 and 2.0mol/L Lushui were used as coagulants, the coagulation temperature was 85℃ and the soybean protein content was 14%, the firmness of the protein gel was 351g, and the vegetarian ham was chewy and viscoelastic.

  12. Comparison of ion-activated in situ gelling systems for ocular drug delivery. Part 1: physicochemical characterisation and in vitro release.

    Science.gov (United States)

    Rupenthal, Ilva D; Green, Colin R; Alany, Raid G

    2011-06-15

    Conventional eye drops can result in poor drug bioavailability due to the unique ocular anatomy and physiology. Ion-activated in situ gelling systems are able to crosslink with cations present in the tear fluid, therefore forming a gel on the ocular surface, which results in prolonged corneal contact time. The present study compared a number of anionic polysaccharides (gellan gum, xanthan gum, carrageenan and alginate) to an uncharged (HPMC) and a positively charged (chitosan) polymer system with emphasis on the gelling behaviour, rheological and textural properties, gel microstructure, contact angle and in vitro release characteristics. All systems exhibited physically entangled polymer networks that were able to disentangle upon shear stress and significantly prolonged the in vitro release of a model hydrophilic drug compared to a solution. While systems based on HPMC and chitosan showed no structural changes upon addition of cations, formulations based on gellan gum and carrageenan demonstrated a remarkable increase in viscosity, pseudoplasticity and hardness upon addition of Ca(2+) and K(+) respectively. This renders them favourable for ocular use as they would gel once in contact with the cations of the tear fluid, thus reducing nasolacrimal drainage, but would thin upon shearing, preventing ocular irritation and therefore induced lacrimation.

  13. Comparative study of polymer matrices for gelled electrolytes of lithium batteries; Etude comparative de matrices polymeres pour electrolytes gelifies de batteries au lithium

    Energy Technology Data Exchange (ETDEWEB)

    Du Pasquier, A.; Sarrazin, C.; Fauvarque, J.F. [CNAM, 75 - Paris (France); Andrieu, X. [Alcatel Alsthom Recherche, 91 - Marcoussis (France)

    1996-12-31

    A solid electrolyte for lithium batteries requires several properties: a good ionic conductivity of about 10{sup -3} S/cm at 298 deg. K, a high cationic transport number (greater than 0.5), a redox stability window higher than 4.5 V, a good stability of the interface with the lithium electrode, and a sufficient mechanical stability. The family of gelled or hybrid electrolytes seems to meet all these requirements. Thus, a systematic study of the gelling of an ethylene carbonate and lithium bistrifluorosulfonimide (LiTFSI) based electrolyte has been carried out. The polymers used for gel or pseudo-gel synthesis are POE, PMMA and PAN which represent 3 different cases of interaction with the electrolyte. All the properties mentioned above have been studied according to the nature of the polymer and to the concentration of lithium salt, showing the advantages and drawbacks of each polymer. The possibility of using some of these gels in lithium-ion batteries has been tested by lithium intercalation tests in UF2 graphite at the C/10 regime and by the cycling of LiCoO{sub 2}/UF{sub 2} batteries at the C/5 regime. Interesting performances have been obtained on Li/PPy batteries which can operate at the 7.5 C regime. (J.S.)

  14. Sunscreening Agents

    Science.gov (United States)

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

    2013-01-01

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

  15. Modulating rheological and degradation properties of temperature-responsive gelling systems composed of blends of PCLA-PEG-PCLA triblock copolymers and their fully hexanoyl-capped derivatives.

    Science.gov (United States)

    Petit, Audrey; Müller, Benno; Bruin, Peter; Meyboom, Ronald; Piest, Martin; Kroon-Batenburg, Loes M J; de Leede, Leo G J; Hennink, Wim E; Vermonden, Tina

    2012-12-01

    In this study, the ability to modulate rheological and degradation properties of temperature-responsive gelling systems composed of aqueous blends of poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide) (PCLA-PEG-PCLA) triblock copolymers (i.e. uncapped) and their fully capped derivatives was investigated. Uncapped and capped PCLA-PEG-PCLA triblock copolymers, abbreviated as degree of modification 0 and 2 (DM0 and DM2, respectively), were composed of identical PCLA and PEG blocks but different end groups: namely hydroxyl and hexanoyl end groups. DM0 was synthesized by ring opening polymerization of l-lactide and ε-caprolactone in toluene using PEG as initiator and tin(II) 2-ethylhexanoate as the catalyst. A portion of DM0 was subsequently reacted with an excess of hexanoyl chloride in solution to yield DM2. The cloud point and phase behaviour of DM0 and DM2 in buffer as well as that of their blends were determined by light scattering in a diluted state and by vial tilting and rheological measurements in a concentrated state. Degradation/dissolution properties of temperature-responsive gelling systems were studied in vitro at pH 7.4 and 37°C. The cloud points of DM0/DM2 blends were ratio-dependent and could be tailored from 15 to 40°C for blends containing 15 to 100wt.% DM0. Vial tilting and rheological experiments showed that, with solid contents between 20 and 30wt.%, DM0/DM2 blends (15/85 to 25/75w/w) had a sol-to-gel transition temperature at 10-20°C, whereas blends with less than 15wt.% DM0 formed gels below 4°C and the ones with more than 25wt.% DM0 did not show a sol-to-gel transition up to 50°C. Complete degradation of temperature-responsive gelling systems took ∼100days, independent of the DM0 fraction and the initial solid content. Analysis of residual gels in time by GPC and (1)H-NMR showed no chemical polymer degradation, but indicated gel degradation by dissolution. Preferential dissolution of lactoyl

  16. Mobile Agents

    Science.gov (United States)

    Satoh, Ichiro

    Mobile agents are autonomous programs that can travel from computer to computer in a network, at times and to places of their own choosing. The state of the running program is saved, by being transmitted to the destination. The program is resumed at the destination continuing its processing with the saved state. They can provide a convenient, efficient, and robust framework for implementing distributed applications and smart environments for several reasons, including improvements to the latency and bandwidth of client-server applications and reducing vulnerability to network disconnection. In fact, mobile agents have several advantages in the development of various services in smart environments in addition to distributed applications.

  17. Antibiotic Agents

    Science.gov (United States)

    ... agents. A recent survey reported that 76% of liquid soaps from 10 states in the US contained triclosan ... regulated depends upon its intended use and its effectiveness. The US Food and Drug Administration (FDA) regulates antibacterial soaps and antibacterial substances that will either be used ...

  18. 蛋白氧化对大豆蛋白凝胶和乳化特性影响的研究进展%Research Progress of the Effect of Oxidation on Emulsifying and Gelling Properties of Soybean Protein

    Institute of Scientific and Technical Information of China (English)

    卢岩; 于飞; 刘骞; 孔保华; 韩建春

    2014-01-01

    大豆蛋白是一种重要的食品基料,由于某些功能特性的限制而影响了其在食品加工中的应用。由于大豆中含有丰富的多不饱和脂肪酸及脂肪氧化酶,因此在大豆蛋白的加工、应用和贮藏过程中会导致其氧化,并最终影响大豆蛋白的功能特性。本文介绍了蛋白氧化对大豆蛋白结构以及功能特性的影响,并展望了通过适度氧化等方法对大豆蛋白凝胶性和乳化性的促进和改善,对于发掘和拓宽大豆蛋白改性技术具有重要的意义。%Soy protein is an important food material, owing to some restrictions of functional properties, its application in food industry is limited. Soybean is rich in polyunsaturated fatty acids and lipoxygenase ,so soybean protein will be oxidated in the processing, application and storage, ultimately the functional properties of soy protein can also be affected. This article introduced the effect of protein oxidation on structure and functional properties of soybean protein. In addition, oxidation modification methods in the improvement of the gelling and emulsifying property of SPI were expounded. By moderate oxidating of soybean protein, could broaden the scope of its applications in food industry and had the vital significance.

  19. Radioprotective Agents

    Science.gov (United States)

    1982-01-01

    claimed to be effective are gallic acid derivatives, eg, sodium gallate 12053-21-61 (295-297) and propyl gallate 1121-79-91 (298). p...inhibition of a-adrenergic receptors can be achieved through the use of the antiradiation agents 2-(5-aminopentylamino)ethanephos- phorothioic acid ...tissue was ap- preciated immediately as a potential medical set, and they were put to use en- thusiastically. Early workers did notice an erythematous

  20. The Behaviors Decision of Agent in Multi-agent System%多agent系统中agent的行为决策

    Institute of Scientific and Technical Information of China (English)

    毛新军; 王怀民; 楚蓓蓓; 王逸欣

    2003-01-01

    The behavior decision of agent in multi-agent system is dependent on the task of individual agent ,the cooperation with other agents,and the multi-agent system' constraints. The paper presents three abstract concept models of achievement intention,joint intention and maintenance intention representing the factors that affect agent's behaviors respectively,to investigate autonomous agent's behaviors decision in support of agent-oriented software development. The paper discusses and analyzes how they will affect agent's behavior decision and the relationship among them,defines their formal and rigorous semantics,finally specifies and proves a number of important properties.

  1. Summation of divergent series of perturbation theory in the limit of strong bind. Function of Gell-Mann-Low theory psi sup 4

    CERN Document Server

    Suslov, I M

    2001-01-01

    Algorithm for ascertaining the asymptotics of a series sum in the perturbation theory in the strong bond limit according to preset values of its coefficients was suggested. The algorithm was illustrated using test examples, methods of error estimation and optimization procedure were developed. Application of the algorithm to theory psi sup 4 provides behavior beta(g) approx = 7.4g sup 0 sup . sup 9 sup 6 at high g for its Gell-Mann-Low function. The index similarity to unity can be interpreted as manifestation of logarithmic branching of the beta(g) approx g(lng) sup - supgamma type with gamma approx = 0.14, independent arguments in favor of the assumption being available. In any case, theory psi sup 4 is intrinsically consistent. The procedure of summation of series of the perturbation theory at random values of expansion parameters is discussed

  2. Technical note: PaGELL v.1.5: A flexible parametric program for the Bayesian analysis of longevity data within the context of animal breeding.

    Science.gov (United States)

    Casellas, J; Brito, L C

    2017-10-01

    This technical note presents the program PaGELL v.1.5 (Parametric Genetic Evaluation of Lifespan in Livestock), a flexible software program to analyze (right-censored) longevity data in livestock populations, with a special emphasis on the genetic evaluation of the breeding stock. This software relies on a parametric generalization of the proportional hazard model; more specifically, the baseline hazard function follows a Weibull process and flexibility is gained by including an additional time-dependent effect with the number of change points defined by the user. The program can accommodate 3 different sources of variation (i.e., systematic, permanent environmental, and additive genetic effects) and both fixed and time-dependent patterns (only for systematic and permanent environmental effects). Analyses are performed within a Bayesian context by sampling from the joint posterior distribution of the model, and model fit can be easily determined by the calculation of the deviance information criterion. Although this software has already been used on field data sets, its performance has been double-checked on simulated data set, and results are presented in this technical note. PaGELL v.1.5 was written in Fortran 95 language and, after compiling with the GNU Fortran Compiler v.4.7 and later, it has been tested in Windows, Linux, and MacOS operating systems (both 32- and 64-bit platforms). This program is available at http://www.casellas.info/files/pageII.zip. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. 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

  4. Study on High Temperature Tolerant and Solids Free Weak Gelling Drilling Fluid%抗高温无固相弱凝胶钻井液体系研究

    Institute of Scientific and Technical Information of China (English)

    许明标; 马双政; 韩金芳; 艾关林; 朱胜

    2012-01-01

    抗高温无固相弱凝胶钻井液配方为:海水+0.5%NaOH+0.5%Na2C03+1%VIS-H+0.5%抗高温稳定剂SPD+3%KCl+1%聚胺UHIB+30k聚合醇JLX-C+3%降滤失剂RS.1+5%酸溶性储层保护剂JQWY,甲酸钠加重至钻井液密度为1.2g/cm3。性能评价结果表明,钻井液高温稳定性良好;160℃热滚16h后的低剪切速率黏度为34095mPa·s(0.3r/min),悬浮性优异;900C黏附系数为0.083,滚动回收率为90.28%,防膨率为90.59%,润滑性和抑制性较好。储层保护剂JQWY可大大减小钻井液对储层的损害,中压滤失量降至2.6mL。裸眼完井时,通过破胶剂JPC-LV易清除滤饼,岩心渗透率恢复值为97.80k,满足了高温水平井油气层开发的需要。图1表4参7%The formula of high temperature tolerant and solids free weak gelling drilling fluid was: seawater, 0.5% NaOH, 0.5% Na2CO3, 1% VIS-H, 0.5% high temperature stabilizer SPD, 3% KCl, 1% polyamine UHIB, 3% polymerization alcohols JLX-C, 3% fluid loss agent RS-1 and 5% acid-soluble reservoir protection agent JQWY. The density of drilling fluid was aggravated to 1.2 g/cm3 by sodium formate. The results of property evaluation showed that the high temperature stability of drilling fluid was good and the viscosity was of 34095 mPa.s with low rotate speed 0.3 r/min after rolling 16 h at 160℃. The lubricity and inhibitory of drilling fluid wasgood with 0. 083 adhesion coefficient'at 90℃, 90.28% rolling recovery rate and 90.59% anti-clay-swelling rate. The damage of drilling fluid to reservoir greatly reduced after reservoir protective agent JQWY added and API fotration decreased to 2.6 mL. The filter cake could be easily removed by breaking gel agent JPC-LV on completion and the core recovery of permeability reached 97.8% which met the requirements of hydrocarbon reservoir development in high temperature horizontal well.

  5. Analysis and Optimization for Mobile Agent Communication

    Institute of Scientific and Technical Information of China (English)

    YANGBo; LIUDayou

    2005-01-01

    Communication performance is one of the most important factors affecting the efficiency of mobile agent system. Only traditional optimization techniques for communication performance are not enough, especially in large-scale intelligent mobile agent system, so more intelligent optimization techniques are needed. In the background, the paper studies communication of mobile agent system from the viewpoint of performance. The paper makes qualitative and quantitative analysis of four important factors that will affect the communication performance of mobile agent system and presents the communication performance optimization model. The model hasthree primary functions. First, the model provides a formalism method to describe the communication task and process of mobile agent. Second, the model provides a means to make quantitative analysis of the performance of mobile agent system. Third, the model can plan out an optimal communication scheme for mobile agent to minimize the cost of whole communication. The model could thus be a building block for the optimization of the communication behavior of mobile agent.

  6. Humor and embodied conversational agents

    OpenAIRE

    Nijholt, A.

    2003-01-01

    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 interaction (verbal and nonverbal) capabilities. A current state of the art of research in embodied conversational agents, affective computing and verbal and nonverbal interaction is presented. The report ad...

  7. Transient characteristics for working process of pulse detonation engine with aluminized gelled fuels%含铝凝胶燃料脉冲爆轰发动机工作过程瞬态特性

    Institute of Scientific and Technical Information of China (English)

    胡洪波; 翁春生

    2016-01-01

    In order to understand the transient mechanism of pulse detonation engine with gelled fuels during the working process,the mathematical and physical model of pulse detonation engine with aluminized gelled fuels was established.The flow field of a single cycle pulse detonation engine with aluminized gelled fuels was simulated numerically by using the conservation element and solution element method,and the transient characteristics during the detonation reaction and impulse generation processes were analyzed.The calculation results show that the strip of the aluminized gelled fuels droplet under the detonation wave is predominant. The aluminum particles scatter into the detonation tube accompanying with the strip of droplets,and participate in reaction,so the a⁃luminum quantity accumulated in the final stage is small.And the process of the gelled fuels'detonation exhaust can be divided into three typical stages,which are expansion stage attached to detonation,gas"choked" expansion stage and weaken expansion stage in sequence.The results have some significant references for application research on pulse detonation engine with gelled fuels.%为了解含铝凝胶燃料脉冲爆轰发动机工作过程的瞬态机理,建立了含铝凝胶燃料脉冲爆轰发动机数学物理模型。采用守恒元与求解元数值计算方法,对单循环含铝凝胶燃料脉冲爆轰发动机流场进行了数值仿真,分析了其爆轰反应过程与冲量产生过程的瞬态特征。计算结果表明,爆轰波作用下,凝胶燃料液滴变化以剥离破碎为主,燃料液滴中铝颗粒随液滴剥离弥散于爆轰管内并参与反应,累积在最后阶段反应的铝颗粒较少。凝胶燃料爆轰燃气排放过程可划分为爆轰附着膨胀、燃气“壅塞”膨胀和膨胀减弱等3个典型特征阶段。研究结果对凝胶燃料脉冲爆轰发动机的应用研究具有参考意义。

  8. Influence of drying in the gelling and emulsifying properties of the fractions 7S and 11S protein from soybean

    OpenAIRE

    2012-01-01

    Resumo: Dietas a base de vegetais e suas proteínas têm se tornado cada vez mais populares visando saúde e bem-estar. Dentre as proteínas vegetais, a de soja é a mais utilizada como ingrediente na indústria de alimentos, atuando inclusive como estabilizante de emulsões e agente gelificante. As globulinas 7S (ß ¿ conglicinina) e 11S (glicinina) são as principais frações protéicas da soja, sendo que a primeira possui boa capacidade emulsificante e a segunda tem alto poder gelificante. Em função ...

  9. Effect of polymer composition on rheological and degradation properties of temperature-responsive gelling systems composed of acyl-capped PCLA-PEG-PCLA.

    Science.gov (United States)

    Petit, Audrey; Müller, Benno; Meijboom, Ronald; Bruin, Peter; van de Manakker, Frank; Versluijs-Helder, Marjan; de Leede, Leo G J; Doornbos, Albert; Landin, Mariana; Hennink, Wim E; Vermonden, Tina

    2013-09-09

    In this study, the ability to modulate the rheological and degradation properties of temperature-responsive gelling systems composed of acyl-capped poly(ε-caprolactone-co-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-lactide) (PCLA-PEG-PCLA) triblock copolymers was investigated. Eight polymers with varying molecular weight of PCLA, caproyl/lactoyl ratio (CL/LA) and capped with either acetyl- or propionyl-groups were synthesized by ring-opening polymerization of L-lactide and ε-caprolactone in toluene using PEG as initiator and tin(II) 2-ethylhexanoate as catalyst, and subsequently reacted in solution with an excess of acyl chloride to yield fully acyl-capped PCLA-PEG-PCLA. The microstructure of the polymers was determined by (1)H NMR, and the thermal properties and crystallinity of the polymers in dry state and in 25 wt % aqueous systems were studied by differential scanning calorimetry and X-ray diffraction. Rheological and degradation/dissolution properties of aqueous systems composed of the polymers in 25 wt % aqueous systems were studied. (1)H NMR analysis revealed that the monomer sequence in the PCLA blocks was not fully random, resulting in relatively long CL sequences, even though transesterification was demonstrated by the enrichment with lactoyl units and the presence of PEG-OH end groups. Except the most hydrophilic polymer composed of acetyl-capped PCLA1400-PEG1500-PCLA1400 having a CL/LA molar ratio of 2.5, the polymers at 25 wt % in buffer were sols below room temperature and transformed into gels between room temperature and 37 °C, which makes them suitable as temperature-responsive gelling systems for drug delivery. Over a period of weeks at 37 °C, the systems containing polymers with long CL sequences (~8 CL) and propionyl end-groups became semicrystalline as shown by X-ray diffraction analysis. Degradation of the gels by dissolution at 37 °C took 100-150 days for the amorphous gels and 250-300 days for the semicrystalline gels

  10. MOBILE AGENT: EMERGING TECHNOLOGY

    OpenAIRE

    RAJGURU P. V. DR. DESHMUKH S. D

    2011-01-01

    Mobile agent technology has been promoted as an emerging technology that makes it much easier to design, implement, and maintain distributed systems, introduction to basic concepts of mobile agents like agent mobility, agent types and places and agent communication. Then benefits of the usage of mobile agents are summarized and illustrated by selected applications. The next section lists requirements and desirable properties for mobile agent languages and systems. We study the main features, ...

  11. Physically Gelled Room-Temperature Ionic Liquid-Based Composite Membranes for CO2/N-2 Separation: Effect of Composition and Thickness on Membrane Properties and Performance

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, PT; Voss, BA; Wiesenauer, EF; Gin, DL; Nobe, RD

    2013-07-03

    An aspartame-based, low molecular-weight organic gelator (LMOG) was used to form melt-infused and composite membranes with two different imidazolium-based room-temperature ionic liquids (RTILs) for CO2 separation from N-2. Previous work demonstrated that LMOGs can gel RTILs at low, loading levels, and this aspartame-based LMOG was selected because it has been reported to gel a large number of RTILs. The imidazolium-based RTILs were used because of their inherent good properties for CO2/light gas separations. Analysis of the resulting bulk RTIL/LMOG physical gels showed that these materials have high sol-gel transition temperatures (ca. 135 degrees C) suitable for flue gas applications. Gas permeabilities and burst pressure measurements of thick, melt infused membranes revealed a trade-off between high CO2 permeabilities and good mechanical stability as a function of the LMOG loading. Defect-free, composite membranes of the gelled RTILs were successfully fabricated by choosing an appropriate porous membrane support (hydrophobic PTFE) using a suitable coating technique (roller coating). The thicknesses of the applied composite gel layers ranged from 10.3 to 20.7 mu m, which represents an order of magnitude decrease in active layer thickness, compared to the original melt-infused gel RTIL membranes.

  12. La antropología, el arte y la vida de las cosas. Una aproximación desde "Art and Agency" de Alfred Gell

    Directory of Open Access Journals (Sweden)

    Sergio Martínez Luna

    2012-05-01

    Full Text Available El arte ha sido un concepto controvertido para la teoría antropológica desde sus inicios. La Antropología se situó a menudo entre el reconocimiento de la singularidad cultural de objetos y prácticas a los que no se podía calificar como artísticos sin caer en el etnocentrismo y el esfuerzo por componer marcos comparativos tan amplios como para incluir una variedad de prácticas humanas relativas a la experiencia estética. Para salir del espacio definido por esos dos discursos, Alfred Gell sugirió que la experiencia del arte tiene que ver con una especial forma de atribución de agencia a los objetos y las imágenes. Considerar este fenómeno puede ser el punto de partida para elaborar una genuina teoría antropológica del arte, construida sobre la especificidad de la disciplina y sus herramientas conceptuales. Tal enfoque plantea cuestiones acerca de la definición de los conceptos de agencia, personalidad y materialidad que comprometen a otras versiones del análisis y la crítica cultural.

  13. Gelling characteristics of whey protein concentrate partially hydrolyzed by alcalase%碱性蛋白酶限制性酶解乳清浓缩蛋白成胶特性的研究

    Institute of Scientific and Technical Information of China (English)

    熊星星; 毛学英; 谷俊男; 任发政

    2012-01-01

    The effect of partial hydrolysis of whey protein concentrate (WPC) by alcalase on the gelling characteristics,gelling temperature, the particle size, and degradation of whey protein was investigated.Results showed that the gelling characteristics, especially elastic property improved.The hydrolysate obtained at 70min with hydrolysis degree of 7.22% possessed the best gelling properties.The gelling temperature of all the WPC hydrolysates obtained at different hydrolysis time was 80℃.Compared with unhydrolyzed whey protein,the particle size reduced by more than 90%.Part of β-lactoglobulin and rarely part of bovine serum albumin were degraded after partial hydrolysis by Alcalase,while almost all of α-lactalbumin was hydrolyzed.%研究了利用碱性蛋白酶限制性酶解乳清蛋白对其凝胶特性、成胶温度、凝胶粒径和蛋白组分水解情况的影响,结果表明,酶解可以提高乳清蛋白的凝胶特性,在酶解70min时达到最大值,此时乳清蛋白的水解度为7.22%,当酶解时间超过70min后随着水解时间的延长凝胶特性略有下降;各水解时间点乳清蛋白成胶温度均为80℃;酶解后乳清蛋白凝胶的粒径值下降了90%以上,且酶解30min后形成的凝胶粒径值都在50um以内;在碱性蛋白酶的限制性酶解作用下,仅部分β-乳球蛋白和很少部分牛血清白蛋白被酶解,而大部分α-乳白蛋白被酶解。

  14. Method for testing porosity of gelled cement slurry based on soil science%基于土壤学的胶凝态水泥浆孔隙度测试方法

    Institute of Scientific and Technical Information of China (English)

    李早元; 李进; 刘健; 董广超; 张凯; 郭小阳

    2015-01-01

    The porosity of gelled cement slurry is one of the important parameters in evaluating the gelling performance in the process of cement slurry gelling. This article compared and analyzed the gelled cement slurry and soil in macro and micro scales by means of qualitative analysis and experimental demonstration, and the result shows that these two have similar‘framework-pore structure’, both showing certain porosity and permeability. Therefore, by introducing the method of soil porosity testing in soil science, and combining the hydration properties of gelled cement slurry, the drying method in the soil porosity test principle is changed to freeze drying by liquid nitrogen, vacuum negative pressure drying or heated and dried after hydration is terminated by soaking in absolute ethyl alcohol which can inhibit hydration. And research was conducted on the porosity of slurry at speciifc hydration time, which provides reference for detection of porosity of cement slurry.%胶凝态水泥浆孔隙度是水泥浆凝结过程中评价胶凝态性能的重要参数之一。通过定性分析、实验验证的方法,对胶凝态水泥浆和土壤进行了宏观及微观等对比分析,两者具有相类似的“骨架-孔隙结构”,均表现出一定的孔隙性和渗透性。因此,引入土壤学中土壤孔隙度测试方法,同时结合胶凝态水泥浆的水化特性,将土壤孔隙度测试原理中烘干方式改进为液氮冷冻干燥、真空负压干燥或用无水乙醇浸泡终止水化后再升温干燥等可抑制水化反应的烘干方式。应用该方法对特定水化时间下的浆体开展了孔隙度探索实验,为检测水泥浆体的孔隙度提供了可借鉴的方法。

  15. Evaluation of methods for assessing toxicity of oil spill treating agents

    Energy Technology Data Exchange (ETDEWEB)

    Lumley, T.C.; Hollebone, B.P. [Environment Canada, Ottawa, ON (Canada); Harrison, S. [SAIC Canada, Ottawa, ON (Canada)

    2007-07-01

    The first counter-measure considered during an oil spill is the mechanical removal of the spilled oil, but this rarely collects more than 20 per cent of the spilled oil. When mechanical means are insufficient, it is advisable to use spill treating agents (STAs). The potential impact of STAs on the environment is estimated by assessing their in-vitro toxicity to sensitive or sentinel organisms. The typical endpoint in animal exposure models is acute lethality LC{sub 50}, which is the concentration that will be fatal to 50 per cent of the test population. The range of STAs include dispersants; shoreline washing agents; de-emulsifiers or emulsion inhibitors; herding agents; recovery agents; solidifiers or gelling agents; biodegradation agents; and, sinking agents. However, a thorough understanding of the overall toxicity of the agent to the environment must be determined along with the net environmental benefit. The agents must undergo rigorous toxicity evaluations to meet the requirements of the New Substances Notification or Significant New Activity Notification sections of the Canadian Environmental Protection Act of 1999. Environment Canada's guidelines for the use and acceptability of dispersants also address toxicity issues. In particular, emphasis has been on evaluating toxicity by the 96-hour rainbow trout lethality test. This paper presented challenges to the current test protocols and recommended that Environment Canada's guidelines for the use of oil STAs should be modified to include a broader definition of toxicity. The toxicity of a dispersant should be less than the toxicity of the water soluble fraction of an oil slick. However, sublethal effects of dispersant exposure, such as endocrine disruption, organ toxicity, mutagenicity and geotoxicity must be better understood. It was argued that testing on one fish species in an enclosed system does not adequately address a diverse marine environment. It was recommended that testing procedures

  16. Assessment of the capability of a gelling complex made of tara gum and the exopolysaccharides produced by the microorganism Streptococcus thermophilus ST10 to prospectively restore the gut physiological barrier: a pilot study.

    Science.gov (United States)

    Del Piano, Mario; Balzarini, Marco; Carmagnola, Stefania; Pagliarulo, Michela; Tari, Roberto; Nicola, Stefania; Deidda, Francesca; Pane, Marco

    2014-01-01

    Leaky gut, or intestinal permeability, is the phenomenon of the gut wall exhibiting increased absorbency. It is pretty well recognised that an altered or damaged bowel lining or gut wall may result from unbalanced diet, parasites, infection, or medications and that this allows substances such as toxins, microbes, undigested food, or waste to leak through. As a natural consequence, this prompts the body to initiate an immune reaction leading to potentially severe health conditions. Different strategies may be used to improve, at least temporarily, the physiological intestinal barrier. The use of specific beneficial microorganisms, such as lactobacilli and bifidobacteria, has been suggested as an innovative tool to counteract an improper level of intestinal permeability. The association of bacteria with specific gelling agents, such as gums, may represent an improvement since these molecules are able to form hydrophilic gels that distribute uniformly over the inner intestinal surface. This pilot study was undertaken to evaluate intestinal permeability in subjects treated with a gelling complex, an association of tara gum and the microorganism Streptococcus thermophilus ST10 (DSM 25246), which has a well-demonstrated in vitro ability to synthesise and secrete exopolysaccharides (EPSs). Twenty-five healthy subjects were enrolled in this human intervention, double-blind, placebo-controlled, pilot trial (age between 21 and 57 y, mean 37.7±11.2). Subjects were then randomised into 2 groups: group A (13 subjects) was given an active formulation containing 250 mg of tara gum and 1 billion viable cells of S. thermophilus ST10, whereas group B (12 subjects) was given a placebo formulation. All the subjects participating in the study were directed to take 1 dose per day for 30 consecutive days. The presence and concentration of exopolysaccharides (EPSs) in the faeces was determined at time 0 (d0), after 30 days of treatment (d30), and at the end of the 2-week follow-up period

  17. In situ gelling pH- and temperature-sensitive biodegradable block copolymer hydrogels for drug delivery.

    Science.gov (United States)

    Singh, Narendra K; Lee, Doo Sung

    2014-11-10

    Stimuli-sensitive injectable polymeric hydrogels have been extensively investigated during the past decade as bioactive agent delivery vehicles and for tissue engineering applications. An aqueous solution of these polymers undergoes a sol-to-gel phase transition in response to external stimuli such as pH, temperature, salt, light, biomolecules, electromagnetic field, etc. Bioactive molecules or cells can be mixed into the low-viscosity state of the polymer solution and injected into the body at a target site, forming an in situ hydrogel depot, which can then serve as bioactive-molecule-releasing carriers or a cell-growing microenvironment. This review systematically summarizes the recent progress in biodegradable and injectable block copolymer hydrogels, giving special attention to the novel and promising pH- and temperature-sensitive injectable block copolymer hydrogels for biomedical applications. The gelation mechanism, formation of ionic complexes, and biodegradation are highlighted as key factors responsible for controlled protein/drug delivery. The advantages and perspectives of pH- and temperature-sensitive injectable block copolymer hydrogels are also highlighted.

  18. Experiment Test on Expanding Agent Affected to Mechanics Performances of Fly Ash Shotcrete%粉煤灰膨胀剂对喷射混凝土力学性能影响试验

    Institute of Scientific and Technical Information of China (English)

    申文萍; 马芹永; 李伏虎

    2012-01-01

    Under the certain accelerating agent mixed, a study was conducted on the mechanics performanees of the shotcrete under the effect of the different quantity fly ash and swelling agent mixed. The study results showed that when the mixed value of the swelling agent was 6%, the shrinking compensated shotcrete with a single swelling agent mixed would have good compressive and splitting tensile strength performances. As for the shot fly ash concrete with single fly ash mixed, the compressive and splitting tensile strength would be reduced with the fly ash mixed value increased. When the swelling agent mixed value was 6% and the fly ash mixed value was 10% , the effect of the shot shrinking compensated fly ash concrete will be the best and the compressive and splitting tensile strength would be in- creased with 4. 5% and 6.6% higher than the plain concrete individually.%基于一定掺量速凝剂条件下,对喷射混凝土掺不同量的粉煤灰与膨胀剂下的力学性能进行了研究。结果表明,单掺膨胀剂的喷射补偿收缩混凝土在膨胀剂掺量为6%时,抗压、劈裂抗拉强度较好;单掺粉煤灰的喷射粉煤灰混凝土,抗压、劈裂抗拉强度随粉煤灰掺量增加而下降;粉煤灰混凝土在膨胀剂掺量为6%、粉煤灰掺量为10%时效果最佳,抗压、劈裂抗拉强度相对于素混凝土分别增加了4.5%、6.6%。

  19. 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 ...

  20. Interacting agents in finance

    NARCIS (Netherlands)

    C. Hommes

    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 t

  1. 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

  2. 12 CFR 725.4 - Agent membership.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Agent membership. 725.4 Section 725.4 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS NATIONAL CREDIT UNION ADMINISTRATION CENTRAL LIQUIDITY FACILITY § 725.4 Agent membership. (a) A central credit union or a group...

  3. How much do incentives affect car purchase? Agent-based microsimulation of consumer choice of new cars-Part II: Forecasting effects of feebates based on energy-efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Haan, Peter de [ETH Zurich, Institute for Environmental Decisions, Natural and Social Science Interface, Universitaetstr. 22, CHN J73.2, 8092 Zurich (Switzerland)], E-mail: dehaan@env.ethz.ch; Mueller, Michel G.; Scholz, Roland W. [ETH Zurich, Institute for Environmental Decisions, Natural and Social Science Interface, Universitaetstr. 22, CHN J73.2, 8092 Zurich (Switzerland)

    2009-03-15

    In this paper, we simulate the car market in order to forecast the effects of feebate systems based on an energy-labeling scheme using categories A to G. Very fuel-efficient (A) cars receive a cash incentive, highly inefficient (G) cars pay additional fees. Consumers have different price elasticities and behavioral options to react to feebates. They can switch to a smaller sized car, but as energy-efficiency varies widely within size segments, they can also stick to the preferred size class and choose a more efficient (smaller) engine. In addition, previously owned cars influence the next car to be chosen. We use an agent-based microsimulation approach particularly suited to predict environmental and market effects of feebates. Heteorogenous agents choose from a choice set drawn from a detailed fleet of new cars. Incentives of Euro 2000 for A-labeled cars induce an additional rated CO{sub 2} emission decrease of new car registrations between 3.4% and 4.3%, with CO{sub 2} abatement costs between Euro 6 and Euro 13 per ton, and otherwise little undesired market disturbance. The risk of rebound effects is estimated to be low. After adopting the frequencies of consumer segments to a given country, the model presented is applicable to all European car markets.

  4. Investigation of in situ gelling alginate formulations as a sustained release vehicle for co-precipitates of dextromethrophan and Eudragit S 100

    Directory of Open Access Journals (Sweden)

    Maghraby Gamal Mohamed El

    2014-03-01

    Full Text Available Alginate vehicles are capable of forming a gel matrix in situ when they come into contact with gastric medium in the presence of calcium ions. However, the gel structure is pH dependent and can break after gastric emptying, leading to dose dumping. The aim of this work was to develop modified in situ gelling alginate formulations capable of sustaining dextromethorphan release throughout the gastrointestinal tract. Alginate solution (2 %, m/m was used as a vehicle for the tested formulations. Solid matrix of the drug and Eudragit S 100 was prepared by dissolving the drug and polymer in acetone. The organic solvent was then evaporated and the deposited solid matrix was micronized, sieved and dispersed in alginate solution to obtain candidate formulations. The release behavior of dextromethorphan was monitored and evaluated in a medium simulating the gastric and intestinal pH. Drug-polymer compatibility and possible solid-state interactions suggested physical interaction through hydrogen bonding between the drug and the polymer. A significant decrease in the rate and extent of dextromethorphan release was observed with increasing Eudragit S 100 concentration in the prepared particles. Most formulations showed sustained release profiles similar to that of a commercial sustained-release liquid based on ion exchange resin. The release pattern indicated strict control of drug release both under gastric and intestinal conditions, suggesting the potential advantage of using a solid dispersion of drug-Eudragit S 100 to overcome the problem of dose dumping after the rupture of the pH dependent alginate gels

  5. Investigation of in situ gelling alginate formulations as a sustained release vehicle for co-precipitates of dextromethrophan and Eudragit S 100.

    Science.gov (United States)

    El Maghraby, Gamal Mohamed; Elzayat, Ehab Mostafa; Alanazi, Fars Kaed

    2014-03-01

    Alginate vehicles are capable of forming a gel matrix in situ when they come into contact with gastric medium in the presence of calcium ions. However, the gel structure is pH dependent and can break after gastric emptying, leading to dose dumping. The aim of this work was to develop modified in situ gelling alginate formulations capable of sustaining dextromethorphan release throughout the gastrointestinal tract. Alginate solution (2 %, m/m) was used as a vehicle for the tested formulations. Solid matrix of the drug and Eudragit S 100 was prepared by dissolving the drug and polymer in acetone. The organic solvent was then evaporated and the deposited solid matrix was micronized, sieved and dispersed in alginate solution to obtain candidate formulations. The release behavior of dextromethorphan was monitored and evaluated in a medium simulating the gastric and intestinal pH. Drug-polymer compatibility and possible solid-state interactions suggested physical interaction through hydrogen bonding between the drug and the polymer. A significant decrease in the rate and extent of dextromethorphan release was observed with increasing Eudragit S 100 concentration in the prepared particles. Most formulations showed sustained release profiles similar to that of a commercial sustained-release liquid based on ion exchange resin. The release pattern indicated strict control of drug release both under gastric and intestinal conditions, suggesting the potential advantage of using a solid dispersion of drug-Eudragit S 100 to overcome the problem of dose dumping after the rupture of the pH dependent alginate gels.

  6. Performance of a new gelled nested PCR test for the diagnosis of imported malaria: comparison with microscopy, rapid diagnostic test, and real-time PCR.

    Science.gov (United States)

    Iglesias, Nuria; Subirats, Mercedes; Trevisi, Patricia; Ramírez-Olivencia, Germán; Castán, Pablo; Puente, Sabino; Toro, Carlos

    2014-07-01

    Microscopy and rapid diagnostic tests (RDTs) are the techniques commonly used for malaria diagnosis but they are usually insensitive at very low levels of parasitemia. Nested PCR is commonly used as a reference technique in the diagnosis of malaria due to its high sensitivity and specificity. However, it is a cumbersome assay only available in reference centers. We evaluated a new nested PCR-based assay, BIOMALAR kit (Biotools B&M Labs, Madrid, Spain) which employs ready-to-use gelled reagents and allows the identification of the main four species of Plasmodium. Blood samples were obtained from patients with clinical suspicion of malaria. A total of 94 subjects were studied. Fifty-two (55.3%) of them were malaria-infected subjects corresponding to 48 cases of Plasmodium falciparum, 1 Plasmodium malariae, 2 Plasmodium vivax, and 1 Plasmodium ovale. The performance of the BIOMALAR test was compared with microscopy, rapid diagnostic test (RDT) (BinaxNOW® Malaria) and real-time quantitative PCR (qPCR). The BIOMALAR test showed a sensitivity of 98.1% (95% confidence interval [CI], 89.7-100), superior to microscopy (82.7% [95% CI, 69.7-91.8]) and RDT (94.2% [95% CI, 84.1-98.8]) and similar to qPCR (100% [95% CI, 93.2-100]). In terms of specificity, the BIOMALAR assay showed the same value as microscopy and qPCR (100% [95% CI, 93.2-100]). Nine subjects were submicroscopic carriers of malaria. The BIOMALAR test identified almost all of them (8/9) in comparison with RDT (6/9) and microscopy (0/9). In conclusion, the BIOMALAR is a PCR-based assay easy to use with an excellent performance and especially useful for diagnosis submicroscopic malaria.

  7. 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.

  8. Sanitary diagnosis in different snail breeding places in Colombia: main pathogen agents affecting the snail Helix aspersa (O.F. Muller, 1774 in every phase of its biological process

    Directory of Open Access Journals (Sweden)

    Felipe A. Moncada Reyes

    2007-12-01

    Full Text Available The snail culture is an activity that requires of investigative processes for his optimal development. In Colombia the advances documented on the subject are almost inexistent. Therefore, it is responsibility of the veterinary doctor to create studies that generate a real knowledge on topics as the disease prevention within the snail breeding place. This investigation tries to make a sanitary diagnosis in each phase of the biological cycle of the snail Helix aspersa (O.F. Muller, 1774 bred in captivity. It also determines how different environmental factors (temperature, humidity, altitude above sea level, etc., and different forms of handling can be or no implied in the presentation of any disease. Thus, it identifies and classifies the main pathogenic agents of the land Helix snails in different environmental conditions of regions appropriate for the snail culture in Colombia. This study also makes an analysis of nonparametric observations studies, by observing particular pathological cases, exposed or not, to different risk factors. They measure the prevalence of every disease after applying a survey epidemiologist of risks, determining the pathologies related to the presented symptomatology and carrying out a microbiological isolation of the main contained pathogenic agents in each snail breeding place. The most significant pathologies will be documented inside the snail breeding place, based on the analysis of results through associations, and the rates of incidence for each disease, the presented relative risk, and the main factors of risk will be determined. Finally, with suitable breeding practices established after this study, we can foresee the presence of these alterations in the production of the snail in Colombia.

  9. Biological warfare agents.

    Science.gov (United States)

    Pohanka, Miroslav; Kuca, Kamil

    2010-01-01

    Biological warfare agents are a group of pathogens and toxins of biological origin that can be potentially misused for military or criminal purposes. The present review attempts to summarize necessary knowledge about biological warfare agents. The historical aspects, examples of applications of these agents such as anthrax letters, biological weapons impact, a summary of biological warfare agents and epidemiology of infections are described. The last section tries to estimate future trends in research on biological warfare agents.

  10. Thyroid Dysfunction from Antineoplastic Agents

    Science.gov (United States)

    Larsen, P. Reed; Marqusee, Ellen

    2011-01-01

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

  11. Thyroid dysfunction from antineoplastic agents.

    Science.gov (United States)

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

    2011-11-02

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

  12. How much do incentives affect car purchase? Agent-based microsimulation of consumer choice of new cars-Part I: Model structure, simulation of bounded rationality, and model validation

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Michel G. [ETH Zurich, Institute for Environmental Decisions, Natural and Social Science Interface, Universitaetstr. 22, CHN J 73.2, 8092 Zurich (Switzerland); Haan, Peter de [ETH Zurich, Institute for Environmental Decisions, Natural and Social Science Interface, Universitaetstr. 22, CHN J 73.2, 8092 Zurich (Switzerland)], E-mail: peter.dehaan@env.ethz.ch

    2009-03-15

    This article presents an agent-based microsimulation capable of forecasting the effects of policy levers that influence individual choices of new passenger cars. The fundamental decision-making units are households distinguished by sociodemographic characteristics and car ownership. A two-stage model of individual decision processes is employed. In the first stage, individual choice sets are constructed using simple, non-compensatory rules that are based on previously owned cars. Second, decision makers evaluate alternatives in their individual choice set using a multi-attributive weighting rule. The attribute weights are based on a multinomial logit model for cross-country policy analysis in European countries. Additionally, prospect theory and the notion of mental accounting are used to model the perception of monetary values. The microsimulation forecasts actual market observations with high accuracy, both on the level of aggregate market characteristics as well as on a highly resolved level of distributions of market shares. The presented approach is useful for the assessment of policies that influence individual purchase decisions of new passenger cars; it allows accounting for a highly resolved car fleet and differentiated consumer segments. As a result, the complexity of incentive schemes can be represented and detailed structural changes can be investigated.

  13. Early developmental 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure decreases chick embryo heart chronotropic response to isoproterenol but not to agents affecting signals downstream of the beta-adrenergic receptor.

    Science.gov (United States)

    Sommer, Rebecca J; Hume, Adam J; Ciak, Jessica M; Vannostrand, John J; Friggens, Megan; Walker, Mary K

    2005-02-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) causes cardiovascular toxicity in laboratory animals, including alteration in several processes in which beta-adrenergic receptor (beta-AR) signaling plays important roles. Thus, our laboratory investigated the effects of TCDD on beta-AR expression and signal transduction. Fertile chicken eggs were injected with vehicle (corn oil), 0.24 or 0.3 pmol TCDD/g egg on incubation day 0 (D0) or D5. On D10, heart function was assessed by ECG in ovo. Exposure to TCDD increased the incidence of arrhythmias and decreased the positive chronotropic responsiveness of the heart to isoproterenol. The reduced beta-AR responsiveness was, in part, independent of any overt morphological changes in the heart as chick embryos exposed to TCDD on D5 displayed an intermediate responsiveness to beta-AR agonist in the absence of the dilated cardiomyopathy observed in chick embryos exposed to TCDD on D0. TCDD did not decrease the chronotropic response of the heart to agents that stimulate signals downstream of the beta-AR. In fact, TCDD-exposed embryos were more sensitive than controls to forskolin, increasing heart rates (HR) 21.8 +/- 3.5 beats per min (bpm) above baseline versus control values at 6.3 +/- 2.7 bpm above baseline. TCDD exposure also augmented the negative chronotropic response of the heart to verapamil, decreasing HR -23.2 +/- 7.4 bpm relative to baseline versus control embryos at -12.7 +/- 5.9 bpm below baseline. Finally, the mean cardiac beta1-AR mRNA expression in D10 embryos was not significantly altered by exposure to TCDD on D0. These findings establish that a functional end point of the developing chick heart is sensitive to TCDD exposure and that the TCDD-induced reduction in beta-AR responsiveness may result from alterations in signal transduction upstream of adenylyl cyclase.

  14. Infectious Agents and Cancer

    African Journals Online (AJOL)

    these agents on subsequent risk of cancer. There are currently ... tween genetic and environmental factors (that include infectious agents) .... opment of gastric adenocarcinoma and gastric lym- phoma. However .... Lung cancer i. Skin cancers ...

  15. Biodegradable in situ gelling delivery systems containing pilocarpine as new antiglaucoma formulations: effect of a mercaptoacetic acid/N-isopropylacrylamide molar ratio

    Directory of Open Access Journals (Sweden)

    Lai JY

    2013-10-01

    Full Text Available Jui-Yang Lai Institute of Biochemical and Biomedical Engineering, Biomedical Engineering Research Center, Molecular Medicine Research Center, Chang Gung University, Taoyuan, Taiwan Abstract: Ocular drug delivery is one of the most commonly used treatment modalities in the management of glaucoma. We have recently proposed the use of gelatin and poly(N-isopropylacrylamide (PNIPAAm graft copolymers as biodegradable in situ forming delivery systems for the intracameral administration of antiglaucoma medications. In this study, we further investigated the influence of carrier characteristics on drug delivery performance. The carboxyl-terminated PNIPAAm samples with different molecular weights were synthesized by varying the molar ratio of mercaptoacetic acid (MAA/N-isopropylacrylamide (NIPAAm from 0.05 to 1.25, and were determined by end-group titration. The preparation of gelatin-g-PNIPAAm (GN copolymers from these thermoresponsive polymers was achieved using carbodiimide chemistry. Our results showed that the carboxylic end-capped PNIPAAm of high molecular weight may lead to the lower thermal phase transition temperature and slower degradation rate of GN vehicles than its low molecular weight counterparts. With a decreasing MAA/NIPAAm molar ratio, the drug encapsulation efficiency of copolymers was increased due to fast temperature-triggered capture of pilocarpine nitrate. The degradation of the gelatin network could greatly affect the drug release profiles. All of the GN copolymeric carriers demonstrated good corneal endothelial cell and tissue compatibility. It is concluded that different types of GN-based delivery systems exhibit noticeably distinct intraocular pressure-lowering effect and miosis action, thereby reflecting the potential value of a MAA/NIPAAm molar ratio in the development of new antiglaucoma formulations. Keywords: gelatin, poly(N-isopropylacrylamide, glaucoma, chain transfer agent, ocular drug delivery

  16. Animal Capture Agents

    Science.gov (United States)

    1990-01-01

    agents and delivery systems reviewed . Questionnaires were sent to 137 Air Force bases to obtain information about the chemical agents and delivery systems...used by animal control personnel. A literature review included chemical agents, delivery methods, toxicity information and emergency procedures from...34-like agent. Users should familiarize themselves with catatonia in general and particularly that its successful use as an immobilizer doesn’t necessarily

  17. Intelligent Agents: A Primer.

    Science.gov (United States)

    Yu, Edmund; Feldman, Susan

    1999-01-01

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

  18. 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...

  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. Dialogue posthume avec Alfred Gell

    Directory of Open Access Journals (Sweden)

    Natalie Heinich

    2012-05-01

    Full Text Available Presented as an imaginary dialogue with the author of Art and Agency, this paper displays a number of methodological shared positions: the contextualist nature of his epistemology, his focus on relations rather than on objects, his sense of pragmatism, his proximity with the notion of “person-objects” such as developed by the author of the present paper, his attention to the meso-social level and, eventually, his neutral standing in front of research objects. In spite of a few disagreements, all these properties bring to light a convergence between Gell’s anthropological approach and the kind of sociological methodology presently practiced in certain trends of French sociology.

  1. Experiment of detonation characteristics of gelled gasolines in pulse detonation engine%凝胶汽油在脉冲爆轰发动机中的爆轰特性实验

    Institute of Scientific and Technical Information of China (English)

    胡洪波; 翁春生; 白桥栋; 杨建鲁

    2014-01-01

    An experimental system of pulse detonation rocket engine using gelled fuels was established to explore the feasibility of application of gelled fuels on pulse detonation engines.The hot state tests were accomplished on multi-cycle pulse detonation rock-et engine at different oxygen concentration and supply conditions of gelled fuels.The influences of oxygen concentration and fuel sup-ply conditions on pressure and wave propagation velocity of detonation wave were analyzed. The experimental results indicate that pulse detonation rocket engine can work stably with gelled fuels.With 42% oxygen in filling gases and injection pressure coefficients of fuel and atomizing air at 2.5 and 1,the average value of detonation pressure and wave velocity were 2.02 MPa and 1 124 m/s re-spectively.The pressure and wave velocity of detonation increase with oxygen addition under the same fuel supply conditions.The re-sults have some significant references for application investigation on gelled fuels and pulse detonation engines.%为探索凝胶燃料在脉冲爆轰发动机中应用的可行性,设计了凝胶汽油脉冲爆轰火箭发动机实验系统。对不同氧含量和凝胶汽油供给工况下的多循环脉冲爆轰发动机进行了热态实验,分析了氧含量和燃料供给工况对爆轰段爆轰压力和波传播速度的影响。实验结果表明,使用凝胶汽油的脉冲爆轰火箭发动机能稳定工作;在氧气质量百分比为42%、凝胶汽油/雾化空气喷射压力系数为2.5/1工况下,距离发动机点火位置770 mm处的爆轰压力均值为2.02 MPa,爆轰波速度均值为1124 m/s。在相同凝胶汽油供给条件下,增加氧含量能够获得更大的爆轰压力和爆轰波速度。研究结果对凝胶燃料和脉冲爆轰发动机应用研究具有参考意义。

  2. Affective Urbanism

    DEFF Research Database (Denmark)

    Samson, Kristine

    Urban design and architecture are increasingly used as material and affective strategies for setting the scene, for manipulation and the production of urban life: The orchestration of atmospheres, the framing and staging of urban actions, the programming for contemplation, involvement, play, expe...... affects can be choreographed and designed intentionally or whether it arises from unpredictable circumstances within urbanity itself....

  3. Affective Maps

    DEFF Research Database (Denmark)

    Salovaara-Moring, Inka

    of environmental knowledge production. It uses InfoAmazonia, the databased platform on Amazon rainforests, as an example of affective geo-visualization within information mapping that enhances embodiment in the experience of the information. Amazonia is defined as a digitally created affective (map)space within...

  4. An Agent for the Prospect Presentation Problem

    Science.gov (United States)

    2014-05-01

    example is a medical system which assists a doc- tor or patient in deciding whether to use a certain medica - tion. The medication is associated with one...affects the users’ interaction with the agent. We chose the pie charts (combined and separate) in order to enhance com- prehension of the proposed...Z. Rabinovich, S. Kraus, C. V. Goldman, and Y. Gal. Strategic advice provision in repeated human-agent interactions . In AAAI, 2012. [5] A. Azaria, Z

  5. 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.

  6. 鸡蛋品质与蛋白凝胶性的相关性研究%Correlation between Quality of Hen Egg and Gelling Properties of Albumin

    Institute of Scientific and Technical Information of China (English)

    于滨; 王喜波

    2012-01-01

    Studies were conducted to evaluate the correlation between hen egg quality and gelling properties of albumin. Hen eggs were stored to investigate the weight loss, the Haugh unit, the content of dense albumin and the pH of albumin. The texture characteristic and the microstructure of gel from albumin were also tested during storage. The results showed that hen egg quality decreased with storage time, especially for higher temperature. The texture characteristic of gel from albumin increased with storage temperature. There was a significant correlation between hen egg quality and texture characteristic of gel from albumin, which had positive correlation to weight loss and pH of albumin, and negative correlation to the Haugh unit and the content of dense albumin. The microstructure of gel from albumin suggested variation of intermolecular force of proteins induced by decreasement of quality of hen egg changed the microstructure of gel from albumin and texture characteristic. The quality parameters could be used to indicate the change of the texture characteristic of gel from albumin during storage.%为探索贮藏过程中鸡蛋品质与蛋白凝胶质构性质的关系,试验研究了不同贮藏条件下,鸡蛋失重率、哈夫单位、浓蛋白含量、蛋白pH等品质变化及其对蛋白凝胶的质构性质、微观结构的影响。结果表明鸡蛋品质与贮藏时间呈负相关,且温度越高,品质下降速度越快,蛋白凝胶质构性质与贮藏时间呈正相关。鸡蛋品质与蛋白凝胶质构性质之间有显著的相关性:失重率和pHL5凝胶质构性质呈正相关,哈夫单位和浓蛋白含量与凝胶质构性质呈负相关。由蛋白凝胶的微结构变化推断,鸡蛋品质变化引起蛋白质分子问作用力的变化,改变了蛋白凝胶的微观结构和质构性质。鸡蛋贮藏过程中可以使用品质指标表征蛋白凝胶的质构性质变化规律。

  7. THE INTEGRATED AGENT IN MULTI-AGENT SYSTEMS

    OpenAIRE

    Maleković, Mirko; Čubrilo, Mirko

    2000-01-01

    [n this paper, we characterize the integrated agent in multi-agent systems. The following result is proved: if a multi-agent system is reflexive (symmetric, transitive, Euclidean) then the integrated agent of the multi-agent system is reflexive (symmetric, transitive, Euclidean), respectively. We also prove that the analogous result does not hold for multi-agent system's serial ness. A knowledge relationship between the integrated agent and agents in a multiagent system is presented.

  8. Mobile agent security using proxy-agents and trusted domains

    OpenAIRE

    Mitrovic, Nikola; Arronategui Arribalzaga, Unai

    2009-01-01

    Commercial or wide-network deployment of Mobile Agent Systems is not possible without satisfying security architecture. In this paper we propose architecture for secure Mobile Agent Systems, using Trusted Domains and Proxy agents. Existing approaches are based on security services at the level of an agent system, library or specific objects. Our concept uses proxy agents to enable transparent security services both to security-aware mobile agents and legacy agents. Per-agent and domain-level...

  9. Agent Architectures for Compliance

    Science.gov (United States)

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

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

  10. Adaptive auctioneer agents

    OpenAIRE

    2011-01-01

    M.Sc. This dissertation investigates how auctioneer agents can maximise the revenue of an auction. Auctions are an effective solution to agent negotiation because of their simplicity. They are therefore the most widely used approach to agent negotiation. A review of auction theory proves that auction revenue is influenced by factors such as the auction format and the auction parameters. The optimal auction format and parameters are dependent on the bidders and the auction environment. A st...

  11. 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...... available for expressing not only task-relevant but also socially and psychologically relevant information makes it necessary to take influences into account that are not readily implemented like emotions or cultural heuristics. These influences have a huge impact on the success of an interaction...... the expression of multimodal behavior in agents....

  12. 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...

  13. [Antiangiogenic agents in ARMD treatment].

    Science.gov (United States)

    Coroi, Mihaela-Cristiana; Demea, Sorina; Todor, Meda; Apopei, Emmanuela

    2012-01-01

    The aim of antiangiogenic agents in the treatment of age related senile macular degeneration is to destroy coroidian neoformation vessels by minimally affecting the central vision. We present a case of important central vision recovery after 3 intravitreal injections of Avastin. The therapeutic decision and patient monitoring have been made using imaging studies, such as OCT and AFG. A modern therapeutic approach of neovascular forms of age related macular degeneration, backed up by AFG and OCT is a modern treatment method of this disabling illness which brings patients optimal functional and structural improvement.

  14. How feeling betrayed affects cooperation.

    Directory of Open Access Journals (Sweden)

    Pouria Ramazi

    Full Text Available For a population of interacting self-interested agents, we study how the average cooperation level is affected by some individuals' feelings of being betrayed and guilt. We quantify these feelings as adjusted payoffs in asymmetric games, where for different emotions, the payoff matrix takes the structure of that of either a prisoner's dilemma or a snowdrift game. Then we analyze the evolution of cooperation in a well-mixed population of agents, each of whom is associated with such a payoff matrix. At each time-step, an agent is randomly chosen from the population to update her strategy based on the myopic best-response update rule. According to the simulations, decreasing the feeling of being betrayed in a portion of agents does not necessarily increase the level of cooperation in the population. However, this resistance of the population against low-betrayal-level agents is effective only up to some extend that is explicitly determined by the payoff matrices and the number of agents associated with these matrices. Two other models are also considered where the betrayal factor of an agent fluctuates as a function of the number of cooperators and defectors that she encounters. Unstable behaviors are observed for the level of cooperation in these cases; however, we show that one can tune the parameters in the function to make the whole population become cooperative or defective.

  15. 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…

  16. Agents in domestic environments

    NARCIS (Netherlands)

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

    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 ti

  17. 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

  18. Asimovian Adaptive Agents

    CERN Document Server

    Gordon, D F

    2011-01-01

    The goal of this research is to develop agents that are adaptive and predictable and timely. At first blush, these three requirements seem contradictory. For example, adaptation risks introducing undesirable side effects, thereby making agents' behavior less predictable. Furthermore, although formal verification can assist in ensuring behavioral predictability, it is known to be time-consuming. Our solution to the challenge of satisfying all three requirements is the following. Agents have finite-state automaton plans, which are adapted online via evolutionary learning (perturbation) operators. To ensure that critical behavioral constraints are always satisfied, agents' plans are first formally verified. They are then reverified after every adaptation. If reverification concludes that constraints are violated, the plans are repaired. The main objective of this paper is to improve the efficiency of reverification after learning, so that agents have a sufficiently rapid response time. We present two solutions: ...

  19. 基于SPH方法的凝胶推进剂一次雾化仿真研究%Simulation research on first atomization characteristics of gelled propellant based on SPH method

    Institute of Scientific and Technical Information of China (English)

    强洪夫; 刘虎; 韩亚伟; 陈福振

    2013-01-01

    As the free surface and large deformation problem in first atomization were both challenges to traditional grid based method,the first atomization characteristics of gelled propellant using Smoothed Particle Hydrodynamics (SPH) method was investigated. The computational models were simplified from the doublet like-on-like impinging jet injector. The particle number of each computational model was controlled at level of 105. As the shear rate during the impinging process was high,gelled propellant was treated as high viscous Newtonian fluid. The influences of velocity, impinging angle and viscosity were investigated. The simulation results show an agreement with analysis and experiment, which proves that SPH is an efficient method to solve the first atomization problem.%一次雾化中存在传统网格法难以解决的自由表面、大变形等问题,本文将光滑粒子流体动力学(SPH)方法探索性地应用于凝胶推进剂一次雾化仿真研究.模型粒子数保持在105左右,在高剪切速率下,将凝胶推进剂看作高粘度牛顿流体,研究了撞击速度、撞击角度以及凝胶推进剂物性参数对雾化效果的影响,仿真结果与实验结论基本一致.

  20. Affect Regulation

    DEFF Research Database (Denmark)

    Pedersen, Signe Holm; Poulsen, Stig Bernt; Lunn, Susanne

    2014-01-01

    Gergely and colleagues’ state that their Social Biofeedback Theory of Parental Affect Mirroring” can be seen as a kind of operationalization of the classical psychoanalytic concepts of holding, containing and mirroring. This article examines to what extent the social biofeedback theory of parental...

  1. Non-verbal persuasion and communication in an affective agent

    NARCIS (Netherlands)

    André, Elisabeth; Bevacqua, Elisabetta; Heylen, Dirk; Niewiadomski, Radoslaw; Pelachaud, Catherine; Peters, Christopher; Poggi, Isabella; Rehm, Matthias; Cowie, Roddy; Pelachaud, Catherine; Petta, Paolo

    2011-01-01

    This chapter deals with the communication of persuasion. Only a small percentage of communication involves words: as the old saying goes, “it’s not what you say, it’s how you say it”. While this likely underestimates the importance of good verbal persuasion techniques, it is accurate in underlining

  2. Environmental factors affecting autoimmune thyroid disease

    Energy Technology Data Exchange (ETDEWEB)

    Safran, M.; Paul, T.L.; Roti, E.; Braverman, L.E.

    1987-06-01

    A number of environmental factors affect the incidence and progression of autoimmune thyroid disease. Exposure to excess iodine, certain drugs, infectious agents and pollutants, and stress have all been implicated.

  3. 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.

  4. Affective Networks

    Directory of Open Access Journals (Sweden)

    Jodi Dean

    2010-02-01

    Full Text Available This article sets out the idea of affective networks as a constitutive feature of communicative capitalism. It explores the circulation of intensities in contemporary information and communication networks, arguing that this circulation should be theorized in terms of the psychoanalytic notion of the drive. The article includes critical engagements with theorists such as Guy Debord, Jacques Lacan, Tiziana Terranova, and Slavoj Zizek.

  5. Physicochemical and thermal properties of taro (Colocasia esculenta sp) powders as affected by state of maturity and drying method.

    Science.gov (United States)

    Himeda, M; Njintang, Y N; Gaiani, C; Nguimbou, R M; Scher, J; Facho, B; Mbofung, C M F

    2014-09-01

    The study was aimed at determining the effect of harvesting time and drying method on the thermal and physicochemical properties of taro powder, Sosso ecotype. A 5 × 2 factorial experiment with 5 harvesting times (6, 7, 8, 9 and 10 months after planting) and 2 drying methods (sun and electric oven drying) was used for this purpose. The variance component analysis revealed harvesting time as the most important factor affecting all the variables measured. In particular the proteins and available sugar contents of the powders increased significantly with increase in harvesting time. The same was true of the gelling property and water absorption capacity of the powders. It was equally observed that the temperatures (start, peak and end) and enthalpy of gelatinization of the powders increased with harvesting time. It is concluded that harvesting sosso-taro at full maturity (10 months after planting) and sun-drying produces food powders with excellent gelling properties among others.

  6. 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.

  7. Health care agents

    Science.gov (United States)

    ... make decisions during a stressful time. Your agent's duty is to see that your wishes are followed. ... Philadelphia, PA: Elsevier; 2016:chap 5. Zorowitz RA. Ethics. In: Ham RJ Jr, Sloane PD, Warshaw GA, ...

  8. 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...

  9. Steroidal neuromuscular blocking agents

    NARCIS (Netherlands)

    Wierda, JMKH; Mori, K; Ohmura, A; Toyooka, H; Hatano, Y; Shingu, K; Fukuda, K

    1998-01-01

    Since 1964 approximately 20 steroidal neuromuscular blocking agents have been evaluated clinically. Pancuronium, a bisquaternary compound designed on the drawingboard, was the first steroidal relaxant introduced into clinical practice worldwide in the 1970's. Although a major improvement, pancuroniu

  10. 基于对策论的MAS-BDI主体模型%Modeling MAS-BDI Agent in Game Theory

    Institute of Scientific and Technical Information of China (English)

    吴朝晖; 忻栋; 潘云鹤

    2001-01-01

    BDI Agent will choose the intention, which has minimal penalty and maximal income, to achieve its goal. While in multi-Agent system,it is hard for the Agent to find the best intention,not only because of the lack of information,but also the high complexity ot computation. The factors ,which will affect the Agents' decision-making,are the cooperation state of Agents ,the Agents' reasoning process,etc. In this paper,we introduce a new model of MAS-BDI Agent based on game theory,and propose the intention selection strategy for a single BDI Agent, (cooperated)multi-Agent and(uncooperated)multiAgent.

  11. A porous poly(vinylidene fluoride) gel electrolyte for lithium ion batteries prepared by using salicylic acid as a foaming agent

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.P. [Department of Material Science, Fudan University, Shanghai 200433 (China); Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433 (China); Zhang, P.; Li, G.C.; Wu, Y.P. [Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433 (China); Sun, D.L. [Department of Material Science, Fudan University, Shanghai 200433 (China)

    2009-04-01

    A porous gel polymer electrolyte based on poly(vinylidene fluoride) (PVDF) was for the first time prepared via a foaming technology using salicylic acid as a foaming agent. The pores are evenly distributed with an average diameter of about 400 nm. The results from TG/DTA, XRD and FT-IR show that there are no vesicant residues after the PVDF film was heat-treated at 200 C to get the porous structure. When the film is gelled with liquid electrolyte, the ion conductivity can be up to 4.8 x 10{sup -3} S cm{sup -1} at room temperature and the activation energy for ionic transfer is 10.2 kJ mol{sup -1}. LiCoO{sub 2} cathode also presents good cycling performance. These primary results show great promise for this simple method to prepare porous gel polymer electrolytes for practical application in lithium ion batteries. (author)

  12. Development and in-vitro characterization of fish oil oleogels containing benzoyl peroxide and salicylic acid as keratolytic agents.

    Science.gov (United States)

    Rehman, K; Tan, C M; Zulfakar, M H

    2014-03-01

    Topical keratolytic agents such as benzoyl peroxide (BP) and salicylic acid (SA) are one of the common treatments for inflammatory skin diseases. However, the amount of drug delivery through the skin is limited due to the stratum corneum. The purposes of this study were to investigate the ability of fish oil to act as penetration enhancer for topical keratolytic agents and to determine the suitable gelator for formulating stable fish oil oleogels. 2 types of gelling agents, beeswax and sorbitan monostearate (Span 60), were used to formulate oleogels. To investigate the efficacy of fish oil oleogel permeation, commercial hydrogels of benzoyl peroxide (BP) and salicylic acid (SA) were used as control, and comparative analysis was performed using Franz diffusion cell. Stability of oleogels was determined by physical assessments at 20°C and 40°C storage. Benzoyl peroxide (BP) fish oil oleogels containing beeswax were considered as better formulations in terms of drug permeation and cumulative drug release. All the results were found to be statistically significant (pskin and stability.

  13. Effects of Sodium Ligninsulfonate as Gelled-electrolyte Additive on the Performance of Gel Valve-regulated Lead-acid Battery%木质素磺酸钠对铅酸蓄电池胶体性能的影响

    Institute of Scientific and Technical Information of China (English)

    李核; 黄贤伟; 刘何萍; 陈红雨; 王德喜

    2011-01-01

    采用不同比例的木质素磺酸钠作为胶体电解质添加剂,探讨其添加前后胶体电解质的物理和电化学性能的变化.粘度测试、老化析水量测试以及循环伏安和交流阻抗分析表明,添加剂能影响胶体粘度,减少老化析水量,提高胶体电化学性能和减少胶体电池内阻.确定添加剂最佳添加量的质量分数为0.005%~0.01%,胶体电解质中气相二氧化硅的适宜质量分数为3.0%.采用UV-Vis、FT-IR光谱、TEM和SEM对添加剂和胶体电解质的结构和形貌变化进行了表征.结果表明,添加木质素磺酸钠的胶体电解质形成更为疏松多孔的结构,更有利于离子的传导和电解液的储存.%In order to improve the performance of a gelled electrolyte and decrease its internal resistance, sodium ligninsulfonate was used as an additive to the gelled electrolyte. The properties and electrochemistry of the gelled electrolytes with and without additives were studied by viscosity test, aging test, cyclic voltammetry (CV), and electrochemical impedance spectroscopy(EIS). The data indicated that when the mass fraction of SiO2 was 3.0% , the viscosity of the gel electrolyte with 0.01% additives is increased by 6 times comparing with the gel electrolyte without additives. The volume of precipitated water and the internal resistance of gelled electrolyte decrease as the additive is added. The optimum conditions are obtained. The dosage ( mass fraction) of additives is 0.005% ~0.01% , and the fumed silica is 3.0 %. UV-Vis, FT-IR, SEM and TEM were used to characterize the gelled electrolyte with and without additives. The results show that the microstructure of gelled electrolyte is more porous with improved ion conduction, and the sulphuric acid solution can therefore be stored more easily with addition of sodium liginsulfonate.

  14. [Affective dependency].

    Science.gov (United States)

    Scantamburlo, G; Pitchot, W; Ansseau, M

    2013-01-01

    Affective dependency is characterized by emotional distress (insecure attachment) and dependency to another person with a low self-esteem and reassurance need. The paper proposes a reflection on the definition of emotional dependency and the confusion caused by various denominations. Overprotective and authoritarian parenting, cultural and socio-environmental factors may contribute to the development of dependent personality. Psychological epigenetic factors, such as early socio-emotional trauma could on neuronal circuits in prefronto-limbic regions that are essential for emotional behaviour.We also focus on the interrelations between dependent personality, domestic violence and addictions. The objective for the clinician is to propose a restoration of self-esteem and therapeutic strategies focused on autonomy.

  15. Biological Warfare Agents

    Directory of Open Access Journals (Sweden)

    Dev Vrat Kamboj

    2006-10-01

    Full Text Available There is a long historic record of use of biological warfare (BW agents by warring countriesagainst their enemies. However, the frequency of their use has increased since the beginningof the twentieth century. World war I witnessed the use of anthrax agent against human beingsand animals by Germans, followed by large-scale field trials by Japanese against war prisonersand Chinese population during world war II. Ironically, research and development in biologicalwarfare agents increased tremendously after the Geneva Protocol, signed in 1925, because ofits drawbacks which were overcome by Biological and Toxin Weapons Convention (BTWC in1972. Biological warfare programme took back seat after the 1972 convention but biologicalagents regained their importance after the bioterrorist attacks of anthrax powder in 2001. In thelight of these attacks, many of which turned out to be hoax, general awareness is required aboutbiological warfare agents that can be used against them. This review has been written highlightingimportant biological warfare agents, diseases caused by them, possible therapies and otherprotection measures.

  16. Effect of acidic agents on surface roughness of dental ceramics

    Directory of Open Access Journals (Sweden)

    Boonlert Kukiattrakoon

    2011-01-01

    Conclusion: Acidic agents used in this study negatively affected the surface of ceramic materials. This should be considered when restoring the eroded tooth with ceramic restorations in patients who have a high risk of erosive conditions.

  17. Agent Oriented Programming进展%Advances in Agent Oriented Programming

    Institute of Scientific and Technical Information of China (English)

    王一川; 石纯一

    2002-01-01

    Agent-oriented programming (AOP) is a framework to develop agents, and it aims to link the gap betweentheory and practical in agent research. The core of an AOP framework is its language and semantics. In this paper,we propose the necessary properties which agents should have, and then give a summary and analysis about differentAOP languages based on these properties.

  18. Teaching Tourism Change Agents

    DEFF Research Database (Denmark)

    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 agents. The c hange management course contains an experiment inspired by experiential teaching literature...... and methods. The experiment seeks to make students not only hear/learn about change agency and management, but to make them feel cha nge, hereby enabling them to develop the skills and competencies necessary for them to take on the role as change agent s and thus enable them to play key role s in implementing...

  19. 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

  20. Developing Enculturated Agents

    DEFF Research Database (Denmark)

    Rehm, Matthias

    2010-01-01

    Embodied Conversational Agents (ECAs) are complex multimodal systems with rich verbal and nonverbal repertoires. There human-like appearance raises severe expectations regarding natural communicative behaviors on the side of the user. But what is regarded as “natural” is to a large degree dependent...... 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...

  1. 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.

  2. 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....

  3. Programming Agents with Emotions

    NARCIS (Netherlands)

    Dastani, Mehdi; Floor, Chr.; Meyer, John-Jules Charles

    2014-01-01

    In this paper we show how a cognitive agent programming language can be endowed with ways to program emotions. In particular we show how the programming language 2APL can be augmented so that it can work together with the computational emotion model ALMA to deal with appraisal, emotion/mood generati

  4. 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...

  5. 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

  6. 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...

  7. Remote Agent Experiment

    Science.gov (United States)

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

    2000-01-01

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

  8. Learning Sequences of Actions in Collectives of Autonomous Agents

    Science.gov (United States)

    Turner, Kagan; Agogino, Adrian K.; Wolpert, David H.; Clancy, Daniel (Technical Monitor)

    2001-01-01

    In this paper we focus on the problem of designing a collective of autonomous agents that individually learn sequences of actions such that the resultant sequence of joint actions achieves a predetermined global objective. We are particularly interested in instances of this problem where centralized control is either impossible or impractical. For single agent systems in similar domains, machine learning methods (e.g., reinforcement learners) have been successfully used. However, applying such solutions directly to multi-agent systems often proves problematic, as agents may work at cross-purposes, or have difficulty in evaluating their contribution to achievement of the global objective, or both. Accordingly, the crucial design step in multiagent systems centers on determining the private objectives of each agent so that as the agents strive for those objectives, the system reaches a good global solution. In this work we consider a version of this problem involving multiple autonomous agents in a grid world. We use concepts from collective intelligence to design goals for the agents that are 'aligned' with the global goal, and are 'learnable' in that agents can readily see how their behavior affects their utility. We show that reinforcement learning agents using those goals outperform both 'natural' extensions of single agent algorithms and global reinforcement, learning solutions based on 'team games'.

  9. Agent-Based Cloud Computing

    OpenAIRE

    Sim, Kwang Mong

    2012-01-01

    Agent-based cloud computing is concerned with the design and development of software agents for bolstering cloud service\\ud discovery, service negotiation, and service composition. The significance of this work is introducing an agent-based paradigm for\\ud constructing software tools and testbeds for cloud resource management. The novel contributions of this work include: 1) developing\\ud Cloudle: an agent-based search engine for cloud service discovery, 2) showing that agent-based negotiatio...

  10. 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.

  11. The Physicochemical Evaluation and Applicability of Landolphia owariensis latex as a Release Modulating Agent in its Admixture with Carbosil® in Ibuprofen-loaded Self-Emulsifying Oil Formulations

    Directory of Open Access Journals (Sweden)

    N C Obitte

    2009-12-01

    Full Text Available Summary: The need to address the problematic gastric irritation side effects and inconsistent bioavailability of most poorly soluble drugs has drawn the attention of researchers to self emulsifying drug delivery system as one of the possible solutions to these problems. Secondly self emulsifying oil formulations good as they may be could be associated with leakage from their hard gelatin capsules. This further motivated the introduction of gelling agents to address this problem. The objective of this work was to investigate some preliminary properties of Landolphia owariensis latex, including its applicability as a release modulating agent when admixed with Carbosil®, a gelling agent in Ibuprofen-loaded Palm Kernel oil (PKO-based self-emulsifying oil formulations (SEOFs. Purification and precipitation were carried out on the oil and the latex respectively. Some physicochemical properties of the latex were also determined. SEOFs were formulated using varying concentrations of PKO, Tween 80 and Span 85 and thereafter tested for isotropicity. Drug-loaded SEOFs with or without Landolphia owariensis latex (LOL and Carbosil-LOL admixture respectively were evaluated for stability, emulsification time, drug release, aqueous dilution, freeze thaw and drug precipitation tests. Results showed that LOL contained some phytocostituents, had a reasonable adhesive strength, and could retard aqueous permeation. Three out of nine batches of the SEOFs passed the isotropicity test, witnessed no phase separation when emulsified and diluted, and could resist drug precipitation after dilution. LOL did not at all delay drug release from SEOFs unlike LOL-Carbosil admixture. LOL-Carbosil admixture significantly (p<0.05 reduced emulsification time. There was no consistent trend in the dynamic viscosity result. Stability of the SEOFs was maintained at refrigeration temperature of 20C. The above results indicated that LOL, an oil-soluble latex possesses excipient

  12. [Decontamination of chemical and biological warfare agents].

    Science.gov (United States)

    Seto, Yasuo

    2009-01-01

    Chemical and biological warfare agents (CBWA's) are diverse in nature; volatile acute low-molecular-weight toxic compounds, chemical warfare agents (CWA's, gaseous choking and blood agents, volatile nerve gases and blister agents, nonvolatile vomit agents and lacrymators), biological toxins (nonvolatile low-molecular-weight toxins, proteinous toxins) and microbes (bacteria, viruses, rickettsiae). In the consequence management against chemical and biological terrorism, speedy decontamination of victims, facilities and equipment is required for the minimization of the damage. In the present situation, washing victims and contaminated materials with large volumes of water is the basic way, and additionally hypochlorite salt solution is used for decomposition of CWA's. However, it still remains unsolved how to dispose large volumes of waste water, and the decontamination reagents have serious limitation of high toxicity, despoiling nature against the environments, long finishing time and non-durability in effective decontamination. Namely, the existing decontamination system is not effective, nonspecifically affecting the surrounding non-target materials. Therefore, it is the urgent matter to build up the usable decontamination system surpassing the present technologies. The symposiast presents the on-going joint project of research and development of the novel decontamination system against CBWA's, in the purpose of realizing nontoxic, fast, specific, effective and economical terrorism on-site decontamination. The projects consists of (1) establishment of the decontamination evaluation methods and verification of the existing technologies and adaptation of bacterial organophosphorus hydrolase, (2) development of adsorptive elimination technologies using molecular recognition tools, and (4) development of deactivation technologies using photocatalysis.

  13. Use of antimicrobial agents in livestock.

    Science.gov (United States)

    Pagel, S W; Gautier, P

    2012-04-01

    Antimicrobial agents, especially antibacterial agents, are used throughout the world, across a diverse array of extensive and intensive livestock production systems, to protect the health and welfare of livestock and to improve their performance. While some agents that are used in livestock belong to classes that have no counterpart in human medicine, this is not the case for the most widely used agents: the tetracyclines, penicillins, macrolides and sulphonamides. Many bacterial diseases of livestock cause devastating losses of animal life and productivity. As a result, their keepers can lose their livelihoods and see a dramatic reduction in income, so there is often a great sense of urgency to treat affected animals early. However, there are a large number of bacterial pathogens that cause disease and it is frequently difficult to reach a conclusive diagnosis prior to instituting treatment. There are many ways in which existing uses of antimicrobial agents can be improved, amongst the most important are increased utilisation of veterinary professional services, the introduction of enhanced infection control measures, improved point-of-care diagnostic tests, and the application of physiologically based population pharmacokinetic-pharmacodynamic modelling.

  14. Effect of DNA damage caused by cryopreservation of spermatozoa using a modified Single cell gell electrophoresis in the freshwater catfish Pangasianodon hypophthalmus (Fowler, 1936)

    OpenAIRE

    Kuppusamy Umaa Rani; Natesan Munuswamy

    2014-01-01

    Objective: To detect the integrity of sperm DNA in the catfish Pangasianodon hypophthalmus cryopreserved with Hanks balanced salt solution, 5%-30% dimethyl acetamide (DMA) using the single-cell gel electrophoresis in order to test how sperm cryopreservation affected nuclear DNA stability. Methods: Electrophoresis was conducted for 60 min at 130 mA and 15 V. The comet images were analyzed using software CometScore 1.5, and parameters such as comet length, tail length an...

  15. [Pharmacology of inotropic agents].

    Science.gov (United States)

    Pastelín Hernández, Gustavo

    2002-01-01

    High-risk patients, during anesthesia and after surgery present changes in pharmacokinetics (biotransformation reactions, renal clearance, drug interactions, etc.) modifying the usefulness of most drugs, cardiac inotropics included. This group of substances is formed by adrenergic agents, phospodiesterase inhibitors and digitalis compounds. Adrenergic agents are the catecholamines, adrenaline (A), noradrenaline (NA) and dopamine (D), plus dopaminergic agonists as dobutamine and pirbuterol. Phosphodiesterase inhibitors, as amrinone and milrinone, produce their inotropic action by preserving cyclic adenosine monophosphate (AMPc) from its intracellular catabolism. Recent studies on the utility of digitalis compounds demonstrated the valuable applicability of digoxin in chronic and acute heart failure. Another group of substances whose mechanism of action differs from that of the inotropics, offers future utility in high risk patients, they include: inhibitors of nitric oxide sintases, natriuretic atrial peptide inhibitors, Q-10 coenzyme, endothelin antagonists, and anti-tumoral necrosis factor.

  16. 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......-based announcement can also be described as an action model. We extend our logic by integrating attention change. Finally, we add the notion of common belief to the language, we exploit this to formalize the concept of joint attention, that has been widely discussed in the philosophical and cognitive science...

  17. [The antiretroviral agent Fullevir].

    Science.gov (United States)

    Nosik, D N; Lialina, I K; Kalnina, L B; Lobach, O A; Chataeva, M S; Rasnetsov, L D

    2009-01-01

    The antiretroviral properties of Fullevir (sodium salt of fullerenepolyhydropolyaminocaproic acid) manufactured by IntelFarm Co.) were studied in the human cell culture infected with human immunodeficiency virus (HIV). The agent was ascertained to be able to protect the cell from the cytopathic action of HIV. The 90% effective concentration (EF90) was 5 microg/ml. The 50% average toxic concentration was 400 microg/ml. Testing of different (preventive and therapeutic) Fullevir dosage regimens has shown that the drug is effective when used both an hour before and an hour after infection and when administered simultaneously with cell infection. The longer contact time for the agent with the cells increased the degree of antiviral defense. Co-administration of Fullevir and the HIV reverse transcriptase inhibitor Retrovir (azidothymidine) showed a synergistic antiretroviral effect. Thus, Fullevir may be regarded as a new promising antiretroviral drug for the treatment of HIV infection.

  18. Pharmacology of antiplatelet agents.

    Science.gov (United States)

    Kalra, Kiran; Franzese, Christopher J; Gesheff, Martin G; Lev, Eli I; Pandya, Shachi; Bliden, Kevin P; Tantry, Udaya S; Gurbel, Paul A

    2013-12-01

    Pharmacotherapies with agents that inhibit platelet function have proven to be effective in the treatment of acute coronary syndromes, and in the prevention of complications during and after percutaneous coronary intervention. Because of multiple synergetic pathways of platelet activation and their close interplay with coagulation, current treatment strategies are based not only on platelet inhibition, but also on the attenuation of procoagulant activity, inhibition of thrombin generation, and enhancement of clot dissolution. Current strategies can be broadly categorized as anticoagulants, antiplatelet agents, and fibrinolytics. This review focuses on the pharmacology of current antiplatelet therapy primarily targeting the inhibition of the enzyme cyclooxygenase 1, the P2Y12 receptor, the glycoprotein IIb/IIIa receptor, and protease-activated receptor 1.

  19. Sunscreening Agents: A Review

    OpenAIRE

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

    2013-01-01

    The increasing incidence of skin cancers and photodamaging effects caused by ultraviolet radiation has increased the use of sunscreening agents, which have shown beneficial effects in reducing the symptoms and reoccurrence of these problems. Many sunscreen compounds are in use, but their safety and efficacy are still in question. Efficacy is measured through indices, such as sun protection factor, persistent pigment darkening protection factor, and COLIPA guidelines. The United States Food an...

  20. Intelligent Agent Integration Technology

    Science.gov (United States)

    1998-04-01

    The DARPA knowledge sharing effort: Progress report. In B. Nebel , C. Rich, and W. Swartout, editors, Principles of Knowledge Representation and...and Automation, pages 2,785-2,788. IEEE CS Press. [18] Carl Hewitt. Offices are open systems. Communications of the ACM, 4(3):271-287, July 1986...19] Carl Hewitt and Jeff Inman. DAI betwixt and be- tween: From "intelligent agents" to open systems sci- ence. IEEE Transactions on Systems, Man

  1. NOVEL ATYPICAL ANTIPSYCHOTIC AGENTS

    Directory of Open Access Journals (Sweden)

    Vijay Vinay

    2011-05-01

    Full Text Available Antipsychotics are a group of drugs commonly but not exclusively used to treat psychosis. Antipsychotic agents are grouped in two categories: Typical and Atypical antipsychotics. The first antipsychotic was chlorpromazine, which was developed as a surgical anesthetic. The first atypical anti-psychotic medication, clozapine, was discovered in the 1950s, and introduced in clinical practice in the 1970s. Both typical and atypical antipsychotics are effective in reducing positive and negative symptoms of schizophrenia. Blockade of D2 receptor in mesolimbic pathway is responsible for antipsychotic action. Typical antipsychotics are not particularly selective and also block Dopamine receptors in the mesocortical pathway, tuberoinfundibular pathway, and the nigrostriatal pathway. Blocking D2 receptors in these other pathways is thought to produce some of the unwanted side effects. Atypical antipsychotics differ from typical psychotics in their "limbic-specific" dopamine type 2 (D2-receptor binding and high ratio of serotonin type 2 (5-HT2-receptor binding to D2. Atypical antipsychotics are associated with a decreased capacity to cause EPSs, TD, narcoleptic malignant syndrome, and hyperprolactinemia. Atypical antipsychotic agents were developed in response to problems with typical agents, including lack of efficacy in some patients, lack of improvement in negative symptoms, and troublesome adverse effects, especially extrapyramidal symptoms (EPSs and tardive dyskinesia (TD.

  2. Software agents and the route to the information economy.

    Science.gov (United States)

    Kephart, Jeffrey O

    2002-05-14

    Humans are on the verge of losing their status as the sole economic species on the planet. In private laboratories and in the Internet laboratory, researchers and developers are creating a variety of autonomous economically motivated software agents endowed with algorithms for maximizing profit or utility. Many economic software agents will function as miniature businesses, purchasing information inputs from other agents, combining and refining them into information goods and services, and selling them to humans or other agents. Their mutual interactions will form the information economy: a complex economic web of information goods and services that will adapt to the ever-changing needs of people and agents. The information economy will be the largest multiagent system ever conceived and an integral part of the world's economy. I discuss a possible route toward this vision, beginning with present-day Internet trends suggesting that agents will charge one another for information goods and services. Then, to establish that agents can be competent price setters, I describe some laboratory experiments pitting software bidding agents against human bidders. The agents' superior performance suggests they will be used on a broad scale, which in turn suggests that interactions among agents will become frequent and significant. How will this affect macroscopic economic behavior? I describe some interesting phenomena that my colleagues and I have observed in simulations of large populations of automated buyers and sellers, such as price war cycles. I conclude by discussing fundamental scientific challenges that remain to be addressed as we journey toward the information economy.

  3. Ultrasound-assisted degradation of a new bacterial ...

    African Journals Online (AJOL)

    user

    2012-05-14

    May 14, 2012 ... cable as a gelling agent at high temperature when other gelling agents ... distinguish it from thermal or photochemical degradation. (Price and Smith ... S64 spindle. Monosaccharide analysis ..... power ultrasound. Ultrason ...

  4. Multi-agent reinforcement learning with cooperation based on eligibility traces

    Institute of Scientific and Technical Information of China (English)

    杨玉君; 程君实; 陈佳品

    2004-01-01

    The application of reinforcement learning is widely used by multi-agent systems in recent years. An agent uses a multi-agent system to cooperate with other agents to accomplish the given task, and one agent's be-havior usually affects the others' behaviors. In traditional reinforcement learning, one agent takes the others lo-cation, so it is difficult to consider the others' behavior, which decreases the learning efficiency. This paper proposes multi-agent reinforcement learning with cooperation based on eligibility traces, i.e. one agent esti-mates the other agent's behavior with the other agent's eligibility traces. The results of this simulation prove the validity of the proposed learning method.

  5. Agents Play Mix-game

    CERN Document Server

    Gou, C

    2005-01-01

    In mix-game which is an extension of minority game, there are two groups of agents; group1 plays the majority game, but the group2 plays the minority game. This paper studies the change of the average winnings of agents and volatilities vs. the change of mixture of agents in mix-game model. It finds that the correlations between the average winnings of agents and the mean of local volatilities are different with different combinations of agent memory length when the proportion of agents in group 1 increases. This study result suggests that memory length of agents in group1 be smaller than that of agent in group2 when mix-game model is used to simulate the financial markets.

  6. Product and Agent

    DEFF Research Database (Denmark)

    Montecino, Alex; Valero, Paola

    2015-01-01

    In this paper we will explore how the “mathematics teacher” becomes a subject and, at the same time, is subjected as part of diverse dispositive of power. We argue that the mathematics teacher becomes both a product and a social agent, which has been set, within current societies, from the ideas...... of globalization, social progress, and competitive logic. For our approximation, we use the concepts societies of control, dispositive, and discourses from a Foucault–Deleuze toolbox. Our purpose is to cast light on the social and cultural constitution of the ways of thinking about the mathematics teacher. Hence...

  7. Agentes selladores en endodoncia

    OpenAIRE

    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...

  8. Secure Mobile Trade Agent

    Directory of Open Access Journals (Sweden)

    Musbah M. Aqe

    2007-01-01

    Full Text Available E-commerce on the internet has the ability to produce millions of transactions and a great number of merchants whose supply merchandise over the internet. As a result, it is difficult for entities to roam over every site on the internet and choose the best merchandise to trade. So, in this paper we introduced a mobile trade agent that visit the sites to gather and evaluate the information from merchant servers and decide to trade goods on behalf of the user. We observed that the combination of public key cryptosystem with distributed object technology make this proposed scheme more secure and efficient than the already existed schemes.

  9. Product and Agent

    DEFF Research Database (Denmark)

    Montecino, Alex; Valero, Paola

    2015-01-01

    In this paper we will explore how the “mathematics teacher” becomes a subject and, at the same time, is subjected as part of diverse dispositive of power. We argue that the mathematics teacher becomes both a product and a social agent, which has been set, within current societies, from the ideas...... of globalization, social progress, and competitive logic. For our approximation, we use the concepts societies of control, dispositive, and discourses from a Foucault–Deleuze toolbox. Our purpose is to cast light on the social and cultural constitution of the ways of thinking about the mathematics teacher. Hence...

  10. Antineoplastic agents and thrombotic microangiopathy.

    Science.gov (United States)

    Garcia, Gwenalyn; Atallah, Jean Paul

    2017-03-01

    Thrombotic microangiopathy is an uncommon but reported adverse effect of a variety of antineoplastic drugs, including chemotherapy agents such as mitomycin C and gemcitabine, and newer targeted agents such as the vascular endothelial growth factor inhibitors. We present a review of thrombotic microangiopathy associated with antineoplastic agents and its implications in current cancer therapy.

  11. 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 cultu

  12. 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 cultu

  13. Implementing an Agent Trade Server

    OpenAIRE

    Boman, Magnus; Sandin, Anna

    2003-01-01

    An experimental server for stock trading autonomous agents is presented and made available, together with an agent shell for swift development. The server, written in Java, was implemented as proof-of-concept for an agent trade server for a real financial exchange.

  14. Assigning agents to a line

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Moreno-Ternero, Juan D.; Østerdal, Lars Peter Raahave

    2014-01-01

    We consider the problem of assigning agents to slots on a line, where only one agent can be served at a slot and each agent prefers to be served as close as possible to his target. Our focus is on aggregate gap minimizing methods, i.e., those that minimize the total gap between targets and assigned...

  15. Agentes de información Information Agents

    Directory of Open Access Journals (Sweden)

    Alfonso López Yepes

    2005-12-01

    Full Text Available Este artículo realiza un repaso sobre las tipologías de agentes de información y describe aspectos como movilidad, racionalidad y adaptatividad, y el ajuste final de estos conceptos a entornos distribuidos como Internet, donde este tipo de agentes tienen un amplio grado de aplicación. Asimismo, se propone una arquitectura de agentes para un sistema multiagente de recuperación de información donde se aplica un paradigma documental basado en el concepto de ciclo documental.This article summarizes the main information agent types reflecting on issues such as mobility, rationality, adaptability and the final adjustment of this concepts to distributed environments such as the Internet, where this kind of agents has wide range application. Likewise, an information agent architecture is proposed to create a multi-agent information retrieval system in which a documentary paradigm based on the documentary cycle is developed.

  16. [New agents for hypercholesterolemia].

    Science.gov (United States)

    Pintó, Xavier; García Gómez, María Carmen

    2016-02-19

    An elevated proportion of high cardiovascular risk patients do not achieve the therapeutic c-LDL goals. This owes to physicians' inappropriate or insufficient use of cholesterol lowering medications or to patients' bad tolerance or therapeutic compliance. Another cause is an insufficient efficacy of current cholesterol lowering drugs including statins and ezetimibe. In addition, proprotein convertase subtilisin kexin type 9 inhibitors are a new cholesterol lowering medications showing safety and high efficacy to reduce c-LDL in numerous already performed or underway clinical trials, potentially allowing an optimal control of hypercholesterolemia in most patients. Agents inhibiting apolipoprotein B synthesis and microsomal transfer protein are also providing a new potential to decrease cholesterol in patients with severe hypercholesterolemia and in particular in homozygote familial hypercholesterolemia. Last, cholesteryl ester transfer protein inhibitors have shown powerful effects on c-HDL and c-LDL, although their efficacy in cardiovascular prevention and safety has not been demonstrated yet. We provide in this article an overview of the main characteristics of therapeutic agents for hypercholesterolemia, which have been recently approved or in an advanced research stage. Copyright © 2015 Elsevier España, S.L.U. All rights reserved.

  17. 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.

  18. 原位胶原凝胶对大鼠脊髓损伤后功能恢复的影响%Effect of in situ gelling collagen on restoration of function after spinal cord injury in rats

    Institute of Scientific and Technical Information of China (English)

    李长文; 郑启新; 吴永超; 郭晓东; 李景峰

    2009-01-01

    Objective To explore the effects of in situ gelling collagen on restoration of neuron function after spinal cord injury in rats. Methods Fifteen healthy female SD rats were randomly divided into collagen group, control group and sham operation group. Contusive spinal cord injury models were made by improved Allen's weight drop method. In collagen group and control group, collagen and PBS solutions were respectively injected into epicenter using micro-syringes, and allowed for gel formation in situ at body temperature. BBB loco-motion scores were tested once per week for 6 weeks. After 6 weeks, immunohistochemistry was carried out to as-sess glial scar formation and axon regeneration. Results BBB scores of collagen group were significantly higher than that of control group from 5th week. Fewer glial scars were found in injured area in collagen group and more axons regenerated into injured area than that of control group. Conclusion In situ gelling collagen can inhibit the formation of glial scars in injured area and promote axon regeneration into injured area. Collagen might be a promising injectable material for the repairing of spinal cord injury.%目的:研究脊髓损伤后原位形成胶原凝胶对神经功能恢复的影响.方法:15只健康雌性SD大鼠随机分为胶原组、对照组和假手术组,Allen撞击法制作脊髓损伤模型.用微量注射器将胶原溶液注入损伤部位,在体温作用下让其原位形成凝胶,对照组注入PBS溶液,每周进行运动评分,6周后取脊髓组织进行免疫荧光染色,观察损伤部位的胶质瘢痕和轴突生长情况.结果:胶原组大鼠第5周起BBB评分显著高于对照组,免疫荧光显示损伤部位胶质瘢痕少于对照组,且长入损伤部位的轴突也多于对照组.结论:原位形成的胶原凝胶能抑制损伤部位胶质瘢痕的形成,并能促进轴突再生长入损伤部位.证明胶原是一种较好的能用于修复脊髓损伤的可注射材料.

  19. Agent-oriented Software Engineering

    Institute of Scientific and Technical Information of China (English)

    GUAN Xu; CHENG Ming; LIU Bao

    2001-01-01

    An increasing number of computer systems are being viewed in terms of autonomous agents.Most people believe that agent-oriented approach is well suited to design and build complex systems. Yet. todate, little effort had been devoted to discuss the advantages of agent-oriented approach as a mainstreamsoftware engineering paradigm. Here both of this issues and the relation between object-oriented and agent-oriented will be argued. we describe an agent-oriented methodology and provide a quote for designing anauction system.

  20. 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.

  1. Effect of DNA damage caused by cryopreservation of spermatozoa using a modified Single cell gell electrophoresis in the freshwater catfish Pangasianodon hypophthalmus (Fowler, 1936

    Directory of Open Access Journals (Sweden)

    Kuppusamy Umaa Rani

    2014-07-01

    Full Text Available Objective: To detect the integrity of sperm DNA in the catfish Pangasianodon hypophthalmus cryopreserved with Hanks balanced salt solution, 5%-30% dimethyl acetamide (DMA using the single-cell gel electrophoresis in order to test how sperm cryopreservation affected nuclear DNA stability. Methods: Electrophoresis was conducted for 60 min at 130 mA and 15 V. The comet images were analyzed using software CometScore 1.5, and parameters such as comet length, tail length and percentage DNA in the tail were obtained. Then the comet rate and damage coefficient were calculated. Results: There were no significant differences in motility, comet rate and damage coefficient between fresh sperm and cryopreserved sperm stored in 5%, 10%, 15% and 20% DMA, while the sperm cryopreserved with 25% and 30% DMA had lower motility, higher comet length and damage coefficients than those of fresh sperm. Conclusions: There was a positive correlation between comet rate of cryopreserved sperm and the concentration of DMA. The toxicity of cryoprotectant is the main factor for DNA damage in cryopreserved sperm.

  2. 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.

  3. THE AGENT-BASED MODEL OF REGULATION OF RETAIL PRICES ON THE MARKET OF PETROLEUM PRODUCTS

    OpenAIRE

    Leonid Galchynsky; Andrij Svydenko; Iryna Veremenko

    2011-01-01

    This article provides model of the retail gasoline market as multi-agent systems. The main factors, which affecting on the retail price of gasoline were determined. The authors found that using the agent approach, which takes into consideration the coalitions in the market, in particular, tacit collusion, it is possible to describe the behaviour of players correctly. An description of agent behaviour models and algorithms specific agent were done.

  4. MORBIDITY AGENTS: A REVIEW

    Directory of Open Access Journals (Sweden)

    Shrivastava Neelesh

    2011-09-01

    Full Text Available This paper discuss on clinical representation of morbid jealousy which often termed delusional jealousy or ‘Othello Syndrome’ is a psychiatric condition where a lover believes against all reason and their beloved is being sexually unfaithful. Patients will be preoccupied with their partner’s perceived lack of sexual fidelity and will often behave in an unacceptable or extreme way as they endeavor to prove their ideas. Misuse of any psychomotor is an important association cause morbidity jealousy agents, like CNS stimulants that release the catecholamine, particularly dopamine, from pre synaptic terminals substance should be treated as a priority. Where higher levels of violence are reported Sildenafil may be useful as a diagnostic as well as therapeutic test in such cases .Many studies have shown an association between high alcohol consumption and developing morbid jealousy. Amphetamine-induced psychosis has been extensively studied because of its close resemblance to schizophrenia.

  5. An Emotional Agent Model Based on Granular Computing

    Directory of Open Access Journals (Sweden)

    Jun Hu

    2012-01-01

    Full Text Available Affective computing has a very important significance for fulfilling intelligent information processing and harmonious communication between human being and computers. A new model for emotional agent is proposed in this paper to make agent have the ability of handling emotions, based on the granular computing theory and the traditional BDI agent model. Firstly, a new emotion knowledge base based on granular computing for emotion expression is presented in the model. Secondly, a new emotional reasoning algorithm based on granular computing is proposed. Thirdly, a new emotional agent model based on granular computing is presented. Finally, based on the model, an emotional agent for patient assistant in hospital is realized, experiment results show that it is efficient to handle simple emotions.

  6. UTBot: A Virtual Agent Platform for Teaching Agent System Design

    Directory of Open Access Journals (Sweden)

    In-Cheol Kim

    2007-02-01

    Full Text Available We introduce UTBot, a virtual agent platform for teaching agent system design. UTBot implements a client for the Unreal Tournament game server and Gamebots system. It provides students with the basic functionality required to start developing their own intelligent virtual agents to play autonomously UT games. UTBot includes a generic agent architecture, CAA (Context-sensitive Agent Architecture, a domain-specific world model, a visualization tool, several basic strategies (represented by internal modes and internal behaviors, and skills (represented by external behaviors. The CAA architecture can support complex long-term behaviors as well as reactive short-term behaviors. It also realizes high context-sensitivity of behaviors. We also discuss our experience using UTBot as a pedagogical tool for teaching agent system design in undergraduate Artificial Intelligence course.

  7. Do Embodied Conversational Agents Know When to Smile?

    OpenAIRE

    Nijholt, Anton; Chiaro, D.

    2002-01-01

    We survey the role of humor in particular domains of human-to-human interaction with the aim of seeing whether it is useful for embodied conversational agents to integrate humor capabilities in their models of intelligence, emotions and interaction (verbal and nonverbal) Therefore we first look at the current state of the art of research in embodied conversational agents, affective computing and verbal and nonverbal interaction. We adhere to the 'Computers Are Social Actors' paradigm to assum...

  8. Embodied Agents: A New Impetus to Humor Research

    OpenAIRE

    Stock, O.; Strapparava, C.; Nijholt, A.

    2002-01-01

    In this paper we survey the role of humor in human-to-human interaction with the aim to see whether it is useful for embodied conversational agents to integrate humor capabilities in their internal model of intelligence, emotions and interaction (verbal and nonverbal) capabilities. For that reason we shortly survey the current state of the art of research in embodied conversational agents, affective computing and verbal and nonverbal interaction. We adhere to the ‘Computers Are Social Actors’...

  9. Modeling Ambiguity in a Multi-Agent System

    OpenAIRE

    Monz, Christof

    2000-01-01

    This paper investigates the formal pragmatics of ambiguous expressions by modeling ambiguity in a multi-agent system. Such a framework allows us to give a more refined notion of the kind of information that is conveyed by ambiguous expressions. We analyze how ambiguity affects the knowledge of the dialog participants and, especially, what they know about each other after an ambiguous sentence has been uttered. The agents communicate with each other by means of a TELL-function, whose applicati...

  10. Pharmacogenomics of antimicrobial agents.

    Science.gov (United States)

    Aung, Ar Kar; Haas, David W; Hulgan, Todd; Phillips, Elizabeth J

    2014-01-01

    Antimicrobial efficacy and toxicity varies between individuals owing to multiple factors. Genetic variants that affect drug-metabolizing enzymes may influence antimicrobial pharmacokinetics and pharmacodynamics, thereby determining efficacy and/or toxicity. In addition, many severe immune-mediated reactions have been associated with HLA class I and class II genes. In the last two decades, understanding of pharmacogenomic factors that influence antimicrobial efficacy and toxicity has rapidly evolved, leading to translational success such as the routine use of HLA-B*57:01 screening to prevent abacavir hypersensitivity reactions. This article examines recent advances in the field of antimicrobial pharmacogenomics that potentially affect treatment efficacy and toxicity, and challenges that exist between pharmacogenomic discovery and translation into clinical use.

  11. 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.

  12. Agent-based enterprise integration

    Energy Technology Data Exchange (ETDEWEB)

    N. M. Berry; C. M. Pancerella

    1998-12-01

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

  13. Agent-based enterprise integration

    Energy Technology Data Exchange (ETDEWEB)

    N. M. Berry; C. M. Pancerella

    1998-12-01

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

  14. 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.

  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. Research on Negotiating Agent Development

    Institute of Scientific and Technical Information of China (English)

    WEI Ding-guo; PENG Hong

    2004-01-01

    The paper presents a flexible and effective method of development of negotiating agents.A strategy specification, which is specified by a state chart and defeasible rules, can be dynamically inserted into an agent shell incorporating a state chart interpreter and a defeasible logic inference engine, in order to yield a desirable agent.The set of desirable criteria and rules is required to be justified with different context of the application.

  17. Agent 与Multi-Agent System 技术研究%The Research on Agent and Multi-Agent System

    Institute of Scientific and Technical Information of China (English)

    党建武; 韩泉叶; 崔文华

    2002-01-01

    分析了Multi-Agent System 涉及的相关问题,在普通的Multi-Agent System的组织结构的基础上提出了管理服务机构,中介服务机构和主控流动服务机构的Multi-Agent System,并对不同组织结构的Agent之间的协同进行了讨论.

  18. Broad-spectrum antiviral agents

    Directory of Open Access Journals (Sweden)

    Jun-Da eZhu

    2015-05-01

    Full Text Available Development of highly effective, broad-spectrum antiviral agents is the major objective shared by the fields of virology and pharmaceutics. Antiviral drug development has focused on targeting viral entry and replication, as well as modulating cellular defense system. High throughput screening of molecules, genetic engineering of peptides, and functional screening of agents have identified promising candidates for development of optimal broad-spectrum antiviral agents to intervene in viral infection and control viral epidemics. This review discusses current knowledge, prospective applications, opportunities, and challenges in the development of broad-spectrum antiviral agents.

  19. 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.

  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. An Agent Based Model for Social Class Emergence

    Science.gov (United States)

    Yang, Xiaoxiang; Rodriguez Segura, Daniel; Lin, Fei; Mazilu, Irina

    We present an open system agent-based model to analyze the effects of education and the society-specific wealth transactions on the emergence of social classes. Building on previous studies, we use realistic functions to model how years of education affect the income level. Numerical simulations show that the fraction of an individual's total transactions that is invested rather than consumed can cause wealth gaps between different income brackets in the long run. In an attempt to incorporate the network effects, we also explore how the probability of interactions among agents depending on the spread of their income brackets affects wealth distribution.

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

    Science.gov (United States)

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

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

  3. How does real affect affect affect recognition in speech?

    NARCIS (Netherlands)

    Truong, Khiet Phuong

    2009-01-01

    The automatic analysis of affect is a relatively new and challenging multidisciplinary research area that has gained a lot of interest over the past few years. The research and development of affect recognition systems has opened many opportunities for improving the interaction between man and

  4. Deliberate evolution in multi-agent systems

    NARCIS (Netherlands)

    Brazier, F.M.T.; Jonker, C.M.; Treur, J.; Wijngaards, N.J.E.

    1998-01-01

    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 system. The age

  5. Formulación de una Pasta Gelificada a Partir del Descarte de Arándanos (Vaccinium corymbosum Formulation of a Gelling Paste from the remainders of blueberry (Vaccinium corymbosum

    Directory of Open Access Journals (Sweden)

    Rosemarie Stückrath

    2007-01-01

    Full Text Available Se efectuó un estudio para formular una pasta gelificada de bajas calorías que permita aumentar su valor añadido de descartes de arándanos. Se realizaron ocho formulaciones después de efectuar la caracterización del fruto, la que muestra una adecuada relación entre calcio y pectina, de gran importancia en el mecanismo de gelificación. Los resultados muestran tres formulaciones sin diferencias significativas en su vida útil de alrededor de 40 días. De ellas se eligió la formulación 8 (pH 4.3, 1 g/kg de sorbato de potasio y 2% de glicerol, que presenta la mejor condición de pH para la gelificación de los iones calcio. Esta formulación presenta una curva típica en el análisis de perfil de textura (TPA con una elevada dureza. Además presenta un contenido calorífico de 26.04 kcal/100g que indica características hipocalóricas. El estudio muestra que es posible obtener formulaciones con una razonable vida útil y distinta consistencia que permite su uso en diversas preparaciones alimentarias según los requerimientos.A study was developed to formulate a low calorie gelling paste that allows giving aggregate value to discarding blueberries. Eight formulations were done after the characterization of the fruit that shows a high proportion of calcium/pectin, of great importance in the gelation capacity. The results show three formulations without significant differences in their shelf life of around forty days, From them, the formulation 8 (pH 4.3, 1 g/kg of potassium sorbate and 2% of glycerol presents the best condition of pH for calcium gelation. This formulation presents a typical curve of the texture profile analysis (TPA with a high hardness and a caloric content of 26.04 kcal/100g that indicates that its hypocaloric characteristics. The study shows that it is possible to obtain formulations with a reasonable shelf life and different consistency to be used in diverse alimentary preparations according to requirements.

  6. Effects of Ultra-high Pressure and Carrageenan on Gelling Properties of Surimi from Silver Carp, Hypophthalmichthys molitrix%卡拉胶和超高压对鱼糜凝胶性质的影响

    Institute of Scientific and Technical Information of China (English)

    陆剑锋; 邵明栓; 林琳; 叶应旺; 陈从贵; 姜绍通

    2011-01-01

    以白鲢鱼糜为研究对象,将卡拉胶添加其中,经超高压处理后,再经二段加热处理形成鱼糜凝胶,测定其凝胶强度、白度值、pH值,研究压力、保压时间和卡拉胶质量分数对白鲢鱼糜凝胶性质的影响.单因素实验表明,当压力大于300 MPa时凝胶强度显著下降;保压时间大于10 min,卡拉胶质量分数大于0.8%时凝胶强度变化不显著.通过正交实验确定了优化工艺条件为:压力300 MPa、保压时间10 min、卡拉胶质量分数0.8%.各因素对白鲢鱼糜凝胶强度影响程度由大至小依次为压力、保压时间、卡拉胶质量分数.研究结果表明,超高压处理协同添加卡拉胶能够促进白鲢鱼糜形成良好的凝胶.%Surimi gel added with carrageenan from silver carp ( Hypophthalmichthys molitrix) processed by ultra-high pressure (UHP) and a two-stage heat treatment was formed. The gel strength, whiteness and pH values were measured, respectively. The effects of pressure, time and carrageenan addition (mass percentage) on the gelling properties of silver carp surimi were studied. The single-factor experiments showed that gel strength decreased significantly when pressure was more than 300 Mpa, while there was no significant change in gel strength when time and carrageenan addition were more than 10 min and 0. 8% , respectively. The optimum conditions were optimized with orthogonal experiments as follows: pressure of 300 Mpa, time of 10 min and carrageenan addition of 0. 8% . UHP treatment conditions had an effect on gel strength in an order of pressure, time, carrageenan addition. This study indicated that UHP treatment with carrageenan addition could well modify the effect on the formation of silver carp surimi gel.

  7. An Introduction to Software Agents

    Science.gov (United States)

    2008-02-01

    Tropos .......................................................................................................................... 34 8.3 Gaia...32 DRDC Atlantic TM 2007-221 Each of these methodologies (Prometheus, Tropos and Gaia) guide the user to develop a specification for agents...specific agents required. While Prometheus and Tropos cover similar portions of the overall design process (from requirements to implementation

  8. 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...

  9. Topical agents in burn care

    Directory of Open Access Journals (Sweden)

    Momčilović Dragan

    2002-01-01

    Full Text Available Introduction Understanding of fluid shifts and recognition of the importance of early and appropriate fluid replacement therapy have significantly reduced mortality in the early post burn period. After the bum patient successfully passes the resuscitation period, the burn wound represents the greatest threat to survival. History Since the dawn of civilization, man has been trying to find an agent which would help burn wounds heal, and at the same time, not harm general condition of the injured. It was not until the XX century, after the discovery of antibiotics, when this condition was fulfilled. In 1968, combining silver and sulfadiazine, fox made silver-sulfadiazine, which is a 1% hydro-soluble cream and a superior agent in topical treatment of burns today. Current topical agents None of the topical antimicrobial agents available today, alone or combined, have the characteristics of ideal prophylactic agents, but they eliminate colonization of burn wound, and invasive infections are infrequent. With an excellent spectrum of activity, low toxicity, and ease of application with minimal pain, silver-sulfadiazine is still the most frequently used topical agent. Conclusion The incidence of invasive infections and overall mortality have been significantly reduced after introduction of topical burn wound antimicrobial agents into practice. In most burn patients the drug of choice for prophylaxis is silver sulfadiazine. Other agents may be useful in certain clinical situations.

  10. Multimodal nanoparticulate bioimaging contrast agents.

    Science.gov (United States)

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

    2010-01-01

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

  11. Implementing Lego Agents Using Jason

    CERN Document Server

    Jensen, Andreas Schmidt

    2010-01-01

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

  12. Activity Recognition for Agent Teams

    Science.gov (United States)

    2007-07-01

    seek to use in the upcoming confrontation. There is not a simple mapping between a character capabilities and this policy; an effective team role must...additional research challenges, specific to the team role assumed by the agent. Agents that support individual human team members face the following chal

  13. Pharmacologic Agents for Chronic Diarrhea

    OpenAIRE

    Lee, Kwang Jae

    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 reductio...

  14. Organogel formation of soybean oil with waxes

    Science.gov (United States)

    Many waxes including plant waxes and animal waxes were evaluated for the gelation ability toward soybean oil (SBO) and compared with hydrogenated vegetable oils, petroleum waxes and commercial non-edible gelling agents to understand factors affecting the gelation ability of a gelator. Sunflower wax...

  15. Experiencing affective interactive art

    NARCIS (Netherlands)

    Bialoskorski, Leticia S.S.; Westerink, Joyce H.D.M.; Broek, van den Egon L.

    2010-01-01

    The progress in the field of affective computing enables the realization of affective art. This paper describes the affective interactive art system Mood Swings, which interprets and visualizes affect expressed by a person. Mood Swings is founded on the integration of a framework for affective move

  16. Technical-Technological Dimension of Facebook: towards a Collective Affectivity

    Directory of Open Access Journals (Sweden)

    Yeraldine Aldana Gutiérrez

    2014-06-01

    Full Text Available Social and particularly, affective relationships and practices seem to shape and be reshaped at once by technical-technological devices, such as Facebook. The principal aim of this article is to account for the technical technological processes that transform Facebook members’ affectivity. Twelve ninth graders’ Communicational Practices in Facebook and their perceptions were collected and qualitatively studied. Findings suggest that ninth graders as Affective agents seem to construct a virtualized affective reality, exchanging their emotions and affections by three different operations namely; the grammatical operation, the dialectical operation and the rhetorical operation. Furthermore, Facebook members might not only be users, but also Affective Agents who assess and negotiate their affection Hyper-discourses. In so doing, they are able to build up a Collective Affectivity within the emerging Facebook cyber-field.

  17. Bufo toxin: A new testing prospect for the screening of anti-convulsant agents. A review

    Directory of Open Access Journals (Sweden)

    David Arome

    2014-07-01

    Full Text Available Epilepsy is a common neurological disorder with diverse aetiology, affecting approximately 1 % of the entire population. Epilepsy present wide range of clinical manifestations, that affect the way a person feels and acts for a short time. Previous scientific investigations have indicated bufo toxin as a potential convulsant candidate that produced similar effects as other known convulsant agents. Bufo toxin has been shown to mimic or exhibit similar action as other known convulsant agent. Its biochemical components are formed as a result of the binding of bufo-fagin and a molecule arginina. There exist wide array of convulsant agents used in the screening of anti-convulsant agents. The commonly used one are: bicuculline, picrotoxin, pentylene tetrazole, isonizid etc. However, these agents are expensive, not easily available and affordable. This challenge prompted the search of other alternative convulsant agents that is easily accessible for use in the screening of anti-convulsant agents. The principal objective of this review paper is to suggest the possible use of bufo toxin which mimics the action of existing convulsant agents. This new testing convulsant agent (bufo toxin is inexpensive, affordable and easy to use when compared to other known convulsant agents. The experimental procedure is easy and it gives a broad spectrum in comparing the action of bufo toxin to other chemical convulsant agents. It also offers researchers broader view or options in exploring the anti-convulsant activity of test agents and the understanding of their possible mechanism of action.

  18. Time to first fracture affects sweetness of gels

    NARCIS (Netherlands)

    Sala, G.; Stieger, M.A.

    2013-01-01

    The aim of this study was to investigate the influence of the breakdown behaviour on sweetness intensity of gelled model foods. Emulsion-filled gelatine/agar gels varying mainly in fracture strain (eF) were used. The fracture strain was modified by changing either the ratio between gelatine and agar

  19. Emotional Belief-Desire-Intention Agent Model: Previous Work And Proposed Architecture

    Directory of Open Access Journals (Sweden)

    Mihaela- Alexandra Puica

    2013-02-01

    Full Text Available Research in affective computing shows that agents cannot be truly intelligent, nor believable or realistic without emotions. In this paper, we present a model of emotional agents that is based on a BDI architecture. We show how we can integrate emotions, resources and personality features into an artificial intelligent agent so as to obtain a human-like behavior of this agent. We place our work in the general context of existing research in emotional agents, with emphasis on BDI emotional models.

  20. Quantized Dissensus in Networks of Agents subject to Death and Duplication

    CERN Document Server

    Bauso, D; Pesenti, R

    2009-01-01

    Dissensus is a modeling framework for networks of dynamic agents in competition for scarce resources. Originally inspired by biological cells behaviors, it fits also marketing, finance and many other application areas. Competition is often unstable in the sense that strong agents, those having access to large resources, gain more and more resources at the expense of weak agents. Thus, strong agents duplicate when reaching a critical amount of resources, whereas weak agents die when loosing all their resources. To capture all these phenomena we introduce systems with a discrete time gossip and unstable state dynamics interrupted by discrete events affecting the network topology. Invariancy of states and topologies and network connectivity are explored.

  1. Loaded Gelled Bipropellants for Optimized Performance Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposal is responsive to NASA 2003 SBIR Topic E2.05, ?On-Board Propulsion," addressing Thruster Technology and in particular "Suitability of propellant...

  2. Loaded Gelled Bipropellants for Optimized Performance Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The focus of this program is the development and validation of formulations, and development methodologies, for optimizing high-performance particulate-loaded...

  3. Spray and Combustion of Gelled Hypergolic Propellants

    Science.gov (United States)

    2014-10-20

    extension to cell-centered finite-volume variables, (09 2010) C. Lopez- Rivera , P. Sojka. Secondary Breakup of Inelastic Non-Newtonian Liquid Drops...Injector Flow Characteristics for Gel Propellants”, AIAA-2011-5707, 47th AIAA Joint Propulsion Conference, San Diego , California, July 31 - Aug. 3, 2011...PRO 15112, Reaction Design: San Diego , 2011. 70. Lawver, B. R., and Breen, B. P. "Hypergolic Stream Impingement Phenomena-Nitrogen Tetroxide/Hydrazine

  4. 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

  5. Mobile agent driven by aspect

    Directory of Open Access Journals (Sweden)

    Youssef Hannad

    2010-11-01

    Full Text Available Domain application of mobile agents is quite large. They are used for network management and the monitoring of complex architecture. Mobile agent is also essential into specific software architecture such that adaptable grid architecture. Even if the concept of mobile agent seems to be obvious, the development is always complex because it needs to understand network features but also security features and negotiation algorithms. We present a work about an application of aspects dedicated to mobile agent development over a local network. At this level, the underlying protocol is called jini and allows managing several essential concepts such that short transaction and permission management. Three subsets of aspects are defined in this work. A part is for the description of agent host and its security level, accessible resource, etc. A second part is about mobile agent and their collaboration. This means how they can operate on an agent host with the respect of the execution context. All the results are illustrated through a distributed monitoring application called DMA. Its main objective is the observation of component servers.

  6. 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

  7. Using Mobile Agents and Overlay Networks to Secure Electrical Networks

    Energy Technology Data Exchange (ETDEWEB)

    Dawes, Neal A.; Prosser, Bryan J.; Fulp, Errin W.; McKinnon, Archibald D.

    2013-02-11

    ABSTRACT The use of wandering, mobile agents can provide a robust approach for managing, monitoring, and securing electrical distribution networks. However, the topological structure of electrical networks can affect system performance. For example, if the multi-agent system relies on a regular inspection rate (on average, points of interest are inspected with equal frequency), then locations that are not well connected will on average be inspected less frequently. This paper discusses creation and use of overlay networks that create a virtual grid graph can provide faster coverage and a more uniform average agent sampling rate. Using overlays agents wander a virtual neighborhood consisting of only points of interest that are interconnected in a regular fashion (each point has the same number of neighbors). Experimental results will show that an overlay can often provide better network coverage and a more uniform inspection rate, which can improve cyber security by providing a faster detection of threats.

  8. Using Mobile Agents and Overlay Networks to Secure Electrical Netoworks

    Energy Technology Data Exchange (ETDEWEB)

    Dawes, Neal A.; Prosser, Bryan J.; Fulp, Errin W.; McKinnon, Archibald D.

    2013-04-01

    ABSTRACT The use of wandering, mobile agents can provide a robust approach for managing, monitoring, and securing electrical distribution networks. However, the topological structure of electrical networks can affect system performance. For example, if the multi-agent system relies on a regular inspection rate (on average, points of interest are inspected with equal frequency), then locations that are not well connected will on average be inspected less frequently. This paper discusses creation and use of overlay networks that create a virtual grid graph can provide faster coverage and a more uniform average agent sampling rate. Using overlays agents wander a virtual neighborhood consisting of only points of interest that are interconnected in a regular fashion (each point has the same number of neighbors). Experimental results will show that an overlay can often provide better network coverage and a more uniform inspection rate, which can improve cyber security by providing a faster detection of threats

  9. Oral anticancer agent medication adherence by outpatients.

    Science.gov (United States)

    Kimura, Michio; Usami, Eiseki; Iwai, Mina; Nakao, Toshiya; Yoshimura, Tomoaki; Mori, Hiromi; Sugiyama, Tadashi; Teramachi, Hitomi

    2014-11-01

    In the present study, medication adherence and factors affecting adherence were examined in patients taking oral anticancer agents. In June 2013, 172 outpatients who had been prescribed oral anticancer agents by Ogaki Municipal Hospital (Ogaki, Gifu, Japan) completed a questionnaire survey, with answers rated on a five-point Likert scale. The factors that affect medication adherence were evaluated using a customer satisfaction (CS) analysis. For patients with good and insufficient adherence to medication, the median ages were 66 years (range, 21-85 years) and 73 years (range, 30-90 years), respectively (P=0.0004), while the median dosing time was 131 days (range, 3-3,585 days) and 219 days (24-3,465 days), respectively (P=0.0447). In 36.0% (62 out of 172) of the cases, there was insufficient medication adherence; 64.5% of those cases (40 out of 62) showed good medication compliance (4-5 point rating score). However, these patients did not fully understand the effects or side-effects of the drugs, giving a score of three points or less. The percentage of patients with good medication compliance was 87.2% (150 out of 172). Through the CS analysis, three items, the interest in the drug, the desire to consult about the drug and the condition of the patient, were extracted as items for improvement. Overall, the medication compliance of the patients taking the oral anticancer agents was good, but the medication adherence was insufficient. To improve medication adherence, a better understanding of the effectiveness and necessity of drugs and their side-effects is required. In addition, the interest of patients in their medication should be encouraged and intervention should be tailored to the condition of the patient. These steps should lead to improved medication adherence.

  10. Therapeutic potential of chalcones as cardiovascular agents.

    Science.gov (United States)

    Mahapatra, Debarshi Kar; Bharti, Sanjay Kumar

    2016-03-01

    Cardiovascular diseases are the leading cause of death affecting 17.3 million people across the globe and are estimated to affect 23.3 million people by year 2030. In recent years, about 7.3 million people died due to coronary heart disease, 9.4 million deaths due to high blood pressure and 6.2 million due to stroke, where obesity and atherosclerotic progression remain the chief pathological factors. The search for newer and better cardiovascular agents is the foremost need to manage cardiac patient population across the world. Several natural and (semi) synthetic chalcones deserve the credit of being potential candidates to inhibit various cardiovascular, hematological and anti-obesity targets like angiotensin converting enzyme (ACE), cholesteryl ester transfer protein (CETP), diacylglycerol acyltransferase (DGAT), acyl-coenzyme A: cholesterol acyltransferase (ACAT), pancreatic lipase (PL), lipoprotein lipase (LPL), calcium (Ca(2+))/potassium (K(+)) channel, COX-1, TXA2 and TXB2. In this review, a comprehensive study of chalcones, their therapeutic targets, structure activity relationships (SARs), mechanisms of actions (MOAs) have been discussed. Chemically diverse chalcone scaffolds, their derivatives including structural manipulation of both aryl rings, replacement with heteroaryl scaffold(s) and hybridization through conjugation with other pharmacologically active scaffold have been highlighted. Chalcones which showed promising activity and have a well-defined MOAs, SARs must be considered as prototype for the design and development of potential anti-hypertensive, anti-anginal, anti-arrhythmic and cardioprotective agents. With the knowledge of these molecular targets, structural insights and SARs, this review may be helpful for (medicinal) chemists to design more potent, safe, selective and cost effective chalcone derivatives as potential cardiovascular agents.

  11. Antibacterial agents in the cinema.

    Science.gov (United States)

    García Sánchez, J E; García Sánchez, E; Merino Marcos, M L

    2006-12-01

    Numerous procedures used as antibacterial therapy are present in many films and include strategies ranging from different antimicrobial drugs to surgery and supporting measures. Films also explore the correct use and misuse of antimicrobial agents. Side effects and other aspects related to antibacterial therapy have also been reflected in some films. This article refers to the presence of antibacterial agents in different popular movies. There are movies in which antibacterial agents form part of the central plot, while in others it is merely an important part of the plot. In still others, its presence is isolated, and in these it plays an ambient or anecdotal role.

  12. Agent Based Multiviews Requirements Model

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Based on the current researches of viewpoints oriented requirements engineering and intelligent agent, we present the concept of viewpoint agent and its abstract model based on a meta-language for multiviews requirements engineering. It provided a basis for consistency checking and integration of different viewpoint requirements, at the same time, these checking and integration works can automatically realized in virtue of intelligent agent's autonomy, proactiveness and social ability. Finally, we introduce the practical application of the model by the case study of data flow diagram.

  13. Decision Facilitator for Launch Operations using Intelligent Agents

    Science.gov (United States)

    Thirumalainambi, Rajkumar; Bardina, Jorge

    2005-01-01

    Launch operations require millions of micro-decisions which contribute to the macro decision of 'Go/No-Go' for a launch. Knowledge workers"(such as managers and technical professionals) need information in a timely precise manner as it can greatly affect mission success. The intelligent agent (web search agent) uses the words of a hypertext markup language document which is connected through the internet. The intelligent agent's actions are to determine if its goal of seeking a website containing a specified target (e.g., keyword or phrase), has been met. There are few parameters that should be defined for the keyword search like "Go" and "No-Go". Instead of visiting launch and range decision making servers individually, the decision facilitator constantly connects to all servers, accumulating decisions so the final decision can be decided in a timely manner. The facilitator agent uses the singleton design pattern, which ensures that only a single instance of the facilitator agent exists at one time. Negotiations could proceed between many agents resulting in a final decision. This paper describes details of intelligent agents and their interaction to derive an unified decision support system.

  14. Evolutionary game theory using agent-based methods.

    Science.gov (United States)

    Adami, Christoph; Schossau, Jory; Hintze, Arend

    2016-12-01

    Evolutionary game theory is a successful mathematical framework geared towards understanding the selective pressures that affect the evolution of the strategies of agents engaged in interactions with potential conflicts. While a mathematical treatment of the costs and benefits of decisions can predict the optimal strategy in simple settings, more realistic settings such as finite populations, non-vanishing mutations rates, stochastic decisions, communication between agents, and spatial interactions, require agent-based methods where each agent is modeled as an individual, carries its own genes that determine its decisions, and where the evolutionary outcome can only be ascertained by evolving the population of agents forward in time. While highlighting standard mathematical results, we compare those to agent-based methods that can go beyond the limitations of equations and simulate the complexity of heterogeneous populations and an ever-changing set of interactors. We conclude that agent-based methods can predict evolutionary outcomes where purely mathematical treatments cannot tread (for example in the weak selection-strong mutation limit), but that mathematics is crucial to validate the computational simulations.

  15. THE EFFECTS OF ANIMATED AGENTS ON STUDENTS’ ACHIEVEMENT AND ATTITUDES

    Directory of Open Access Journals (Sweden)

    Figen UNAL-COLAK

    2012-04-01

    Full Text Available Animated agents are electronic agents that interact with learners through voice, visuals or text and that carry human-like characteristics such as gestures and facial expressions with the purpose of creating a social learning environment, and provide information and guidance and when required feedback and motivation to students during their learning experience. The aim of this study is to analyze the effect of the use of pedagogical agents in learning materials designed in multimedia on the achievement and attitudes of students. A general evaluation of the research findings indicate that the use of multimedia software developed by using pedagogical agents positively affects student achievement and attitude. The achievement of the students who worked with the software significantly increased, but no significant difference in terms of different pedagogical agents was observed. The comparison of the student’s attitudes revealed no significant difference in terms of different pedagogical agents, yet the attitudes regarding “bearing human features” showed positively significant difference for the software with body shot of a real person. As it is seen in the unstructured interviews with the participants conducted during and after the experimental process, it should be stated that the students had positive attitudes towards the software and the use of pedagogical agent and expressed their liking.

  16. Water relations in culture media influence maturation of avocado somatic embryos.

    Science.gov (United States)

    Márquez-Martín, Belén; Sesmero, Rafael; Quesada, Miguel A; Pliego-Alfaro, Fernando; Sánchez-Romero, Carolina

    2011-11-15

    Application of transformation and other biotechnological tools in avocado (Persea americana Mill.) is hampered by difficulties in obtaining mature somatic embryos capable of germination at an acceptable rate. In this work, we evaluated the effect of different compounds affecting medium water relations on maturation of avocado somatic embryos. Culture media were characterized with respect to gel strength, water potential and osmotic potential. Improved production of mature somatic embryos was achieved with gelling agent concentrations higher than those considered standard. The osmotic agents such as sorbitol and PEG did not have positive effects on embryo maturation. The number of w-o mature somatic embryos per culture was positively correlated with medium gel strength. Gel strength was significantly affected by gelling agent type as well as by gelling agent and PEG concentration. Medium water potential was influenced by sorbitol concentration; incorporation of PEG to a culture medium did not affect medium water potential. The highest maturation results were achieved on a medium gelled with 10 gl(-1) agar. Moreover, these somatic embryos had improved germination rates. These results corroborate the role of water restriction as a key factor controlling maturation of somatic embryos.

  17. Agent-Based Crowd Simulation Considering Emotion Contagion for Emergency Evacuation Problem

    Science.gov (United States)

    Faroqi, H.; Mesgari, M.-S.

    2015-12-01

    During emergencies, emotions greatly affect human behaviour. For more realistic multi-agent systems in simulations of emergency evacuations, it is important to incorporate emotions and their effects on the agents. In few words, emotional contagion is a process in which a person or group influences the emotions or behavior of another person or group through the conscious or unconscious induction of emotion states and behavioral attitudes. In this study, we simulate an emergency situation in an open square area with three exits considering Adults and Children agents with different behavior. Also, Security agents are considered in order to guide Adults and Children for finding the exits and be calm. Six levels of emotion levels are considered for each agent in different scenarios and situations. The agent-based simulated model initialize with the random scattering of agent populations and then when an alarm occurs, each agent react to the situation based on its and neighbors current circumstances. The main goal of each agent is firstly to find the exit, and then help other agents to find their ways. Numbers of exited agents along with their emotion levels and damaged agents are compared in different scenarios with different initialization in order to evaluate the achieved results of the simulated model. NetLogo 5.2 is used as the multi-agent simulation framework with R language as the developing language.

  18. AGENT-BASED CROWD SIMULATION CONSIDERING EMOTION CONTAGION FOR EMERGENCY EVACUATION PROBLEM

    Directory of Open Access Journals (Sweden)

    H. Faroqi

    2015-12-01

    Full Text Available During emergencies, emotions greatly affect human behaviour. For more realistic multi-agent systems in simulations of emergency evacuations, it is important to incorporate emotions and their effects on the agents. In few words, emotional contagion is a process in which a person or group influences the emotions or behavior of another person or group through the conscious or unconscious induction of emotion states and behavioral attitudes. In this study, we simulate an emergency situation in an open square area with three exits considering Adults and Children agents with different behavior. Also, Security agents are considered in order to guide Adults and Children for finding the exits and be calm. Six levels of emotion levels are considered for each agent in different scenarios and situations. The agent-based simulated model initialize with the random scattering of agent populations and then when an alarm occurs, each agent react to the situation based on its and neighbors current circumstances. The main goal of each agent is firstly to find the exit, and then help other agents to find their ways. Numbers of exited agents along with their emotion levels and damaged agents are compared in different scenarios with different initialization in order to evaluate the achieved results of the simulated model. NetLogo 5.2 is used as the multi-agent simulation framework with R language as the developing language.

  19. Novel anticaries and remineralizing agents: prospects for the future

    NARCIS (Netherlands)

    ten Cate, J.M.

    2012-01-01

    Although the use of fluorides has been successful in reducing dental caries, the need remains to develop and evaluate new approaches and promising products for caries prevention. Comprehensive caries-prevention protocols should encompass fluoride and other agents affecting the de-/remineralization b

  20. Investigating the impacts of recommendation agents on impulsive purchase behaviour

    NARCIS (Netherlands)

    Zhu, H.; Yang, Z.; Ou, Carol; Liu, H.W.; Davison, R.M.

    2015-01-01

    The usage of recommendation agents (RAs) in the online marketplace can help consumers to locate their desired products. RAs can help consumers effectively obtain comprehensive product information and compare their candidate target products. As a result, RAs have affected consumers’ shopping behaviou

  1. Social Importance Dynamics: A Model for Culturally-Adaptive Agents

    NARCIS (Netherlands)

    Mascarenhas, S.; Prada, R.; Paiva, A.; Hofstede, G.J.

    2013-01-01

    The unwritten rules of human cultures greatly affect social behaviour and as such should be considered in the development of socially intelligent agents. So far, there has been a large focus on modeling cultural aspects related to non-verbal behaviour such as gaze or body posture. However, culture a

  2. Group Project Support Agents for Helping Students Work Online.

    Science.gov (United States)

    Whatley, Janice; Staniford, Geof; Beer, Martin; Scown, Phil

    1999-01-01

    Discusses group projects in distance learning, describes factors affecting the successful completion of group projects, and considers whether agent technology (self-contained, concurrently executing software processes that encapsulate the current state in terms of knowledge) is able to support students doing group projects. (LRW)

  3. Investigating the impacts of recommendation agents on impulsive purchase behaviour

    NARCIS (Netherlands)

    Zhu, H.; Yang, Z.; Ou, Carol; Liu, H.W.; Davison, R.M.

    2015-01-01

    The usage of recommendation agents (RAs) in the online marketplace can help consumers to locate their desired products. RAs can help consumers effectively obtain comprehensive product information and compare their candidate target products. As a result, RAs have affected consumers’ shopping

  4. Deliberate Evolution in Multi-Agent Systems

    NARCIS (Netherlands)

    Brazier, F.M.T.; Jonker, C.M.; Treur, J.; Wijngaards, N.J.E.

    2000-01-01

    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. The agent architecture is based on an existing

  5. Computational Environment of Software Agents

    Directory of Open Access Journals (Sweden)

    Martin Tomášek

    2008-05-01

    Full Text Available Presented process calculus for software agent communication and mobility canbe used to express distributed computational environment and mobile code applications ingeneral. Agents are abstraction of the functional part of the system architecture and theyare modeled as process terms. Agent actions model interactions within the distributedenvironment: local/remote communication and mobility. Places are abstraction of thesingle computational environment where the agents are evaluated and where interactionstake place. Distributed environment is modeled as a parallel composition of places whereeach place is evolving asynchronously. Operational semantics defines rules to describebehavior within the distributed environment and provides a guideline for implementations.Via a series of examples we show that mobile code applications can be naturally modeled.

  6. Infectious Agents Trigger Trophic Cascades.

    Science.gov (United States)

    Buck, Julia C; Ripple, William J

    2017-09-01

    Most demonstrated trophic cascades originate with predators, but infectious agents can also cause top-down indirect effects in ecosystems. Here we synthesize the literature on trophic cascades initiated by infectious agents including parasitoids, pathogens, parasitic castrators, macroparasites, and trophically transmitted parasites. Like predators, infectious agents can cause density-mediated and trait-mediated indirect effects through their direct consumptive and nonconsumptive effects respectively. Unlike most predators, however, infectious agents are not fully and immediately lethal to their victims, so their consumptive effects can also trigger trait-mediated indirect effects. We find that the frequency of trophic cascades reported for different consumer types scales with consumer lethality. Furthermore, we emphasize the value of uniting predator-prey and parasite-host theory under a general consumer-resource framework. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Bacteriocins as Potential Anticancer Agents

    National Research Council Canada - National Science Library

    Kaur, Sumanpreet; Kaur, Sukhraj

    2015-01-01

    .... Thus, the demand for novel anti-cancer agents is increasing day by day. Some of the experimental studies have reported the therapeutic potential of bacteriocins against various types of cancer cell lines...

  8. 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...

  9. Antimicrobials for bacterial bioterrorism agents.

    Science.gov (United States)

    Sarkar-Tyson, Mitali; Atkins, Helen S

    2011-06-01

    The limitations of current antimicrobials for highly virulent pathogens considered as potential bioterrorism agents drives the requirement for new antimicrobials that are suitable for use in populations in the event of a deliberate release. Strategies targeting bacterial virulence offer the potential for new countermeasures to combat bacterial bioterrorism agents, including those active against a broad spectrum of pathogens. Although early in the development of antivirulence approaches, inhibitors of bacterial type III secretion systems and cell division mechanisms show promise for the future.

  10. 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...

  11. Drugs affecting the eye.

    Science.gov (United States)

    Taylor, F

    1985-08-01

    This discussion reviews drugs that affect the eye, including antihyperglycemic agents; corticosteroids; antirheumatic drugs (quinolines, indomethacin, and allopurinol); psychiatric drugs (phenothiazine, thioridazine, and chlorpromazine); drugs used in cardiology (practolol, amiodarone, and digitalis gylcosides); drugs implicated in optic neuritis and atrophy, drugs with an anticholinergic action; oral contraceptives (OCs); and topical drugs and systemic effects. Refractive changes, either myopic or hypermetropic, can occur as a result of hyperglycemia, and variation in vision is sometimes a presenting symptom in diabetes mellitus. If it causes a change in the refraction, treatment of hyperglycemia almost always produces a temporary hypermetropia. A return to the original refractive state often takes weeks, sometimes months. There is some evidence that patients adequately treated with insulin improve more rapidly than those taking oral medication. Such patients always should be referred for opthalmological evaluation as other factors might be responsible, but it might not be possible to order the appropriate spectacle correction for some time. The most important ocular side effect of the systemic adiministration of corticosteroids is the formation of a posterior subcapsular cataract. Glaucoma also can result from corticosteroids, most often when they are applied topically. Corticosteroids have been implicated in the production of benign intracranial hypertension, which is paradoxical because they also are used in its treatment. The most important side effect of drugs such as chloroquine and hydroxychloroquine is an almost always irreversible maculopathy with resultant loss of central vision. Corneal and retinal changes similar to those caused by the quinolines have been reported with indomethacin, but there is some question about a cause and effect relationship. The National Registry of Drug Induced Ocular Side Effects in the US published 30 case histories of

  12. 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.

  13. 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.

  14. 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...

  15. Gallium a unique anti-resorptive agent in bone: Preclinical studies on its mechanisms of action

    Energy Technology Data Exchange (ETDEWEB)

    Bockman, R.; Adelman, R.; Donnelly, R.; Brody, L.; Warrell, R. (Hospital for Special Surgery, New York, NY (USA)); Jones, K.W. (Brookhaven National Lab., Upton, NY (USA))

    1990-01-01

    The discovery of gallium as a new and unique agent for the treatment of metabolic bone disorders was in part fortuitous. Gallium is an exciting new therapeutic agent for the treatment of pathologic states characterized by accelerated bone resorption. Compared to other therapeutic metal compounds containing platinum or germanium, gallium affects its antiresorptive action without any evidence of a cytotoxic effect on bone cells. Gallium is unique amongst all therapeutically available antiresorptive agents in that it favors bone formation. 18 refs., 1 fig.

  16. Geo-Agents: Design and Implement

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Geo-Agents, a multi-agent system that processes distr ib utedgeospatial information and geospatial service was presented. Firstly, the requirement for distributed geographical information process was discussed, and the architecture of Geo-Agents was introduced. Then in-depth discussions were r aised on agent system implementation, such as the basic agent, agent advertising , message passing, and collaborating. An example was also given to explain the p roblem solving process.

  17. Colitis associated with biological agents

    Institute of Scientific and Technical Information of China (English)

    Hugh James Freeman

    2012-01-01

    In the past,there has been considerable focus on a host of drugs and chemicals that may produce colonic toxicity.Now,a variety of new biological monoclonal antibody agents,usually administered by infusion,have appeared in the clinical realm over the last decade or so to treat different chronic inflammatory or malignant disorders.For some of these agents,adverse effects have been documented,including apparently new forms of immune-mediated inflammatory bowel disease.In some,only limited symptoms have been recorded,but in others,severe colitis with serious complications,such as bowel perforation has been recorded.In others,adverse effects may have a direct vascular or ischemic basis,while other intestinal effects may be related to a superimposed infection.Some new onset cases of ulcerative colitis or Crohn's disease may also be attributed to the same agents used to treat these diseases,or be responsible for disease exacerbation.Dramatic and well documented side effects have been observed with ipilimumab,a humanized monoclonal antibody developed to reduce and overcome cytotoxic T-lymphocyte antigen 4,a key negative feedback regulator of the T-cell anti-tumor response.This agent has frequently been used in the treatment of different malignancies,notably,malignant melanoma.Side effects with this agent occur in up to 40% and these are believed to be largely immune-mediated.One of these is a form of enterocolitis that may be severe,and occasionally,fatal.Other agents include rituximab (an antiCD20 monoclonal antibody),bevacizumab (a monoclonal antibody against the vascular endothelial growth factor) and anti-tumor necrosis factor agents,including infliximab,adalimumab and etanercept.

  18. Can Human-Like Bots Control Collective Mood: Agent-Based Simulations of Online Chats

    CERN Document Server

    Tadic, Bosiljka

    2013-01-01

    Using agent-based modeling approach, in this paper, we study self-organized dynamics of interacting agents in the presence of chat Bots. Different Bots with tunable ``human-like'' attributes, which exchange emotional messages with agents, are considered, and collective emotional behavior of agents is quantitatively analysed. In particular, using detrended fractal analysis we determine persistent fluctuations and temporal correlations in time series of agent's activity and statistics of avalanches carrying emotional messages of agents when Bots favoring positive/negative affects are active. We determine the impact of Bots and identify parameters that can modulate it. Our analysis suggests that, by these measures, the emotional Bots induce collective emotion among interacting agents by suitably altering the fractal characteristics of the underlying stochastic process.Positive-emotion Bots are slightly more effective than the negative ones. Moreover, the Bots which are periodically alternating between positive a...

  19. A multi-agent architecture for geosimulation of moving agents

    Science.gov (United States)

    Vahidnia, Mohammad H.; Alesheikh, Ali A.; Alavipanah, Seyed Kazem

    2015-10-01

    In this paper, a novel architecture is proposed in which an axiomatic derivation system in the form of first-order logic facilitates declarative explanation and spatial reasoning. Simulation of environmental perception and interaction between autonomous agents is designed with a geographic belief-desire-intention and a request-inform-query model. The architecture has a complementary quantitative component that supports collaborative planning based on the concept of equilibrium and game theory. This new architecture presents a departure from current best practices geographic agent-based modelling. Implementation tasks are discussed in some detail, as well as scenarios for fleet management and disaster management.

  20. The Cost of Performance? Students' Learning about Acting as Change Agents in Their Schools

    Science.gov (United States)

    Kehoe, Ian

    2015-01-01

    This paper explores how performance culture could affect students' learning about, and disposition towards, acting as organisational change agents in schools. This is based on findings from an initiative aimed to enable students to experience acting as change agents on an aspect of the school's culture that concerned them. The initiative was…

  1. The Cost of Performance? Students' Learning about Acting as Change Agents in Their Schools

    Science.gov (United States)

    Kehoe, Ian

    2015-01-01

    This paper explores how performance culture could affect students' learning about, and disposition towards, acting as organisational change agents in schools. This is based on findings from an initiative aimed to enable students to experience acting as change agents on an aspect of the school's culture that concerned them. The initiative…

  2. Multi-dimensional information diffusion and balancing market supply: an agent-based approach

    NARCIS (Netherlands)

    Osinga, S.A.; Kramer, M.R.; Hofstede, G.J.; Beulens, A.J.M.

    2013-01-01

    This agent-based information management model is designed to explore how multi-dimensional information, spreading through a population of agents (for example farmers) affects market supply. Farmers make quality decisions that must be aligned with available markets. Markets distinguish themselves by

  3. Comprehension and engagement in survey interviews with virtual agents.

    Science.gov (United States)

    Conrad, Frederick G; Schober, Michael F; Jans, Matt; Orlowski, Rachel A; Nielsen, Daniel; Levenstein, Rachel

    2015-01-01

    This study investigates how an onscreen virtual agent's dialog capability and facial animation affect survey respondents' comprehension and engagement in "face-to-face" interviews, using questions from US government surveys whose results have far-reaching impact on national policies. In the study, 73 laboratory participants were randomly assigned to respond in one of four interviewing conditions, in which the virtual agent had either high or low dialog capability (implemented through Wizard of Oz) and high or low facial animation, based on motion capture from a human interviewer. Respondents, whose faces were visible to the Wizard (and videorecorded) during the interviews, answered 12 questions about housing, employment, and purchases on the basis of fictional scenarios designed to allow measurement of comprehension accuracy, defined as the fit between responses and US government definitions. Respondents answered more accurately with the high-dialog-capability agents, requesting clarification more often particularly for ambiguous scenarios; and they generally treated the high-dialog-capability interviewers more socially, looking at the interviewer more and judging high-dialog-capability agents as more personal and less distant. Greater interviewer facial animation did not affect response accuracy, but it led to more displays of engagement-acknowledgments (verbal and visual) and smiles-and to the virtual interviewer's being rated as less natural. The pattern of results suggests that a virtual agent's dialog capability and facial animation differently affect survey respondents' experience of interviews, behavioral displays, and comprehension, and thus the accuracy of their responses. The pattern of results also suggests design considerations for building survey interviewing agents, which may differ depending on the kinds of survey questions (sensitive or not) that are asked.

  4. Human-Agent Decision-making: Combining Theory and Practice

    Directory of Open Access Journals (Sweden)

    Sarit Kraus

    2016-06-01

    Full Text Available Extensive work has been conducted both in game theory and logic to model strategic interaction. An important question is whether we can use these theories to design agents for interacting with people? On the one hand, they provide a formal design specification for agent strategies. On the other hand, people do not necessarily adhere to playing in accordance with these strategies, and their behavior is affected by a multitude of social and psychological factors. In this paper we will consider the question of whether strategies implied by theories of strategic behavior can be used by automated agents that interact proficiently with people. We will focus on automated agents that we built that need to interact with people in two negotiation settings: bargaining and deliberation. For bargaining we will study game-theory based equilibrium agents and for argumentation we will discuss logic-based argumentation theory. We will also consider security games and persuasion games and will discuss the benefits of using equilibrium based agents.

  5. Reinforcement learning agents providing advice in complex video games

    Science.gov (United States)

    Taylor, Matthew E.; Carboni, Nicholas; Fachantidis, Anestis; Vlahavas, Ioannis; Torrey, Lisa

    2014-01-01

    This article introduces a teacher-student framework for reinforcement learning, synthesising and extending material that appeared in conference proceedings [Torrey, L., & Taylor, M. E. (2013)]. Teaching on a budget: Agents advising agents in reinforcement learning. {Proceedings of the international conference on autonomous agents and multiagent systems}] and in a non-archival workshop paper [Carboni, N., &Taylor, M. E. (2013, May)]. Preliminary results for 1 vs. 1 tactics in StarCraft. {Proceedings of the adaptive and learning agents workshop (at AAMAS-13)}]. In this framework, a teacher agent instructs a student agent by suggesting actions the student should take as it learns. However, the teacher may only give such advice a limited number of times. We present several novel algorithms that teachers can use to budget their advice effectively, and we evaluate them in two complex video games: StarCraft and Pac-Man. Our results show that the same amount of advice, given at different moments, can have different effects on student learning, and that teachers can significantly affect student learning even when students use different learning methods and state representations.

  6. Wealth distribution across communities of adaptive financial agents

    Science.gov (United States)

    DeLellis, Pietro; Garofalo, Franco; Lo Iudice, Francesco; Napoletano, Elena

    2015-08-01

    This paper studies the trading volumes and wealth distribution of a novel agent-based model of an artificial financial market. In this model, heterogeneous agents, behaving according to the Von Neumann and Morgenstern utility theory, may mutually interact. A Tobin-like tax (TT) on successful investments and a flat tax are compared to assess the effects on the agents’ wealth distribution. We carry out extensive numerical simulations in two alternative scenarios: (i) a reference scenario, where the agents keep their utility function fixed, and (ii) a focal scenario, where the agents are adaptive and self-organize in communities, emulating their neighbours by updating their own utility function. Specifically, the interactions among the agents are modelled through a directed scale-free network to account for the presence of community leaders, and the herding-like effect is tested against the reference scenario. We observe that our model is capable of replicating the benefits and drawbacks of the two taxation systems and that the interactions among the agents strongly affect the wealth distribution across the communities. Remarkably, the communities benefit from the presence of leaders with successful trading strategies, and are more likely to increase their average wealth. Moreover, this emulation mechanism mitigates the decrease in trading volumes, which is a typical drawback of TTs.

  7. Agents that act luminally to treat diarrhoea and constipation.

    Science.gov (United States)

    Menees, Stacy; Saad, Richard; Chey, William D

    2012-11-01

    Diarrhoea and constipation are common clinical complaints that negatively affect quality of life, reduce work productivity and lead to considerable health-care expenditure. A variety of therapies have been used to treat these conditions. Unlike drugs that require systemic absorption to exert their effects, luminally acting agents improve diarrhoea and constipation by altering intestinal and/or colonic motility, as well as mucosal absorption and secretion, through a variety of mechanisms. Examples of luminally acting agents for diarrhoea include peripherally acting opiate analogues, enkephalinase inhibitors, bile-acid binding agents, nonabsorbed antibiotics, probiotics, bismuth-containing compounds, berberine and agents with possible effects on intestinal secretion or permeability. Luminally acting drugs for constipation include bulking agents, surfactants, osmotics, stimulants, chloride-channel activators, probiotics, drugs that increase delivery of bile acids to the colon and natural therapies such as prunes and hemp seed extract. As the physiological effects of luminally acting drugs are largely confined to the gastrointestinal tract, these agents are unlikely to cause adverse effects outside of the gastrointestinal tract.

  8. Impact of the antifouling agent Irgarol 1051 on marine phytoplankton species

    NARCIS (Netherlands)

    Buma, Anita G. J.; Sjollema, Sascha B.; van de Poll, Willem H.; Klamer, Hans J. C.; Bakker, Joop F.

    2009-01-01

    In the present study we tested the hypothesis that environmental concentrations of the antifouling agent Irgarol 1051, as measured in coastal Western European waters, affect marine phytoplankton performance. The impact of Irgarol was investigated in the phytoplankton species Thalassiosira weissflogi

  9. Environmental fate of TCDD and Agent Orange and bioavailability to troops in Vietnam

    Energy Technology Data Exchange (ETDEWEB)

    Karch, N.J.; Watkins, D.K.; Ginevan, M.E. [Exponent, Inc., Washington, DC (United States); Young, A.L. [Oklahoma Univ., Norman, OK (United States)

    2004-09-15

    This paper reviews the environmental fate of Agent Orange and the contaminant, 2,3,7,8- tetrachlorodibenzo-p-dioxin (TCDD), and discusses how this affects the bioavailability of TCDD for ground troops in Vietnam.

  10. Why technical trading may be successful? A lesson from the agent-based modeling

    Science.gov (United States)

    Schmidt, Anatoly B.

    2002-01-01

    It is shown using a simple agent-based market dynamics model that if the technical traders are able to affect the market liquidity, their concerted actions can move the market price in the direction favorable to their strategy.

  11. Affects and assemblages

    DEFF Research Database (Denmark)

    Samson, Kristine

    affects and assemblages produce subjective feelings and emotions (Pile 2009) Recently, urban experience designs and events aim at evoking affects through affects and assemblages. A Danish example is the Carlsberg city in Copenhagen another is The High line in Chelsea, New York (Samson 2011). Thus...

  12. Therapeutic options for herpes labialis, I: Oral agents.

    Science.gov (United States)

    Elish, Diana; Singh, Fiza; Weinberg, Jeffrey M

    2004-07-01

    Given the prevalence of herpes labialis, effective therapy has the potential to affect the lives of many and presents a challenge for clinicians. Over the last several years, most of the focus of herpes research has been on the treatment of genital herpes. Recently, however, several studies have been published examining the efficacy of therapies specifically for herpes labialis. Several therapeutic agents, both prescription and over-the-counter, are available for controlling and managing the disease. In this series of articles, we review oral and topical therapeutic agents that are available in the treatment of herpes labialis and its associated symptoms. This article will review oral treatment options.

  13. 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.

  14. 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...

  15. [Anti-influenza virus agent].

    Science.gov (United States)

    Nakamura, Shigeki; Kohno, Shigeru

    2012-04-01

    The necessity of newly anti-influenza agents is increasing rapidly after the prevalence of pandemic influenza A (H1N1) 2009. In addition to the existing anti-influenza drugs, novel neuraminidase inhibitors such as peramivir (a first intravenous anti-influenza agent) and laninamivir (long acting inhaled anti-influenza agent) can be available. Moreover favipiravir, which shows a novel anti-influenza mechanism acting as RNA polymerase inhibitor, has been developing. These drugs are expected to improve the prognosis of severe cases caused by not only seasonal influenza but pandemic influenza A (H1N1) 2009 virus and H5N1 avian influenza, and also treat oseltamivir-resistant influenza effectively.

  16. Dual Rationality and Deliberative Agents

    Science.gov (United States)

    Debenham, John; Sierra, Carles

    Human agents deliberate using models based on reason for only a minute proportion of the decisions that they make. In stark contrast, the deliberation of artificial agents is heavily dominated by formal models based on reason such as game theory, decision theory and logic—despite that fact that formal reasoning will not necessarily lead to superior real-world decisions. Further the Nobel Laureate Friedrich Hayek warns us of the ‘fatal conceit’ in controlling deliberative systems using models based on reason as the particular model chosen will then shape the system’s future and either impede, or eventually destroy, the subtle evolutionary processes that are an integral part of human systems and institutions, and are crucial to their evolution and long-term survival. We describe an architecture for artificial agents that is founded on Hayek’s two rationalities and supports the two forms of deliberation used by mankind.

  17. Relational agents in clinical psychiatry.

    Science.gov (United States)

    Bickmore, Timothy; Gruber, Amanda

    2010-01-01

    Relational agents are computational artifacts, such as animated, screen-based characters or social robots, that are designed to establish a sense of rapport, trust, and even therapeutic alliance with patients, using ideal therapeutic relationships between human counselors and patients as role models. We describe the development and evaluation of several such agents designed for health counseling and behavioral-change interventions, in which a therapeutic alliance is established with patients in order to enhance the efficacy of the intervention. We also discuss the promise of using such agents as adjuncts to clinical psychiatry, a range of possible applications, and some of the challenges and ethical issues in developing and fielding them in psychiatric interventions.

  18. Autonomous sensor manager agents (ASMA)

    Science.gov (United States)

    Osadciw, Lisa A.

    2004-04-01

    Autonomous sensor manager agents are presented as an algorithm to perform sensor management within a multisensor fusion network. The design of the hybrid ant system/particle swarm agents is described in detail with some insight into their performance. Although the algorithm is designed for the general sensor management problem, a simulation example involving 2 radar systems is presented. Algorithmic parameters are determined by the size of the region covered by the sensor network, the number of sensors, and the number of parameters to be selected. With straight forward modifications, this algorithm can be adapted for most sensor management problems.

  19. Agentes infecciosos y enfermedades autoinmunes

    OpenAIRE

    Carlos Riebeling; Vicente Madrid; Beatriz Elena Camarena; Oscar Peralta; Raúl Barrera

    1992-01-01

    En este trabajo se describen los aspectos molecidares de la relación entre agentes infecciosos y enfermedades autoinrnitnes; los mecanismos de respuesta inmune a los agentes infecciosos, y las Iiiyótesis más recientes de la causa de las enfermedades autoinmunes. Los antígenos son procesados y seleccionados por su inmitnogenicidad, ypresentadospor lasmolécitlasde HLA a los receptores de antígeno de los linfocitos T. Aunque existen rnuclias hipótesk sobre el origen de las enfermedades arrtoinmu...

  20. Multi-agent Water Resources Management

    Science.gov (United States)

    Castelletti, A.; Giuliani, M.

    2011-12-01

    Increasing environmental awareness and emerging trends such as water trading, energy market, deregulation and democratization of water-related services are challenging integrated water resources planning and management worldwide. The traditional approach to water management design based on sector-by-sector optimization has to be reshaped to account for multiple interrelated decision-makers and many stakeholders with increasing decision power. Centralized management, though interesting from a conceptual point of view, is unfeasible in most of the modern social and institutional contexts, and often economically inefficient. Coordinated management, where different actors interact within a full open trust exchange paradigm under some institutional supervision is a promising alternative to the ideal centralized solution and the actual uncoordinated practices. This is a significant issue in most of the Southern Alps regulated lakes, where upstream hydropower reservoirs maximize their benefit independently form downstream users; it becomes even more relevant in the case of transboundary systems, where water management upstream affects water availability downstream (e.g. the River Zambesi flowing through Zambia, Zimbabwe and Mozambique or the Red River flowing from South-Western China through Northern Vietnam. In this study we apply Multi-Agent Systems (MAS) theory to design an optimal management in a decentralized way, considering a set of multiple autonomous agents acting in the same environment and taking into account the pay-off of individual water users, which are inherently distributed along the river and need to coordinate to jointly reach their objectives. In this way each real-world actor, representing the decision-making entity (e.g. the operator of a reservoir or a diversion dam) can be represented one-to-one by a computer agent, defined as a computer system that is situated in some environment and that is capable of autonomous action in this environment in

  1. Radiation sensitivity modification by chemotherapeutic agents

    Energy Technology Data Exchange (ETDEWEB)

    Hetzel, F.W.; Brown, M.; Kaufman, N.; Bicher, H.I.

    1981-01-01

    Three chemotherapeutic agents, chlorambucil, mustargen, and BCNU-409962, being investigated for their possible clinical use in conjunction with radiation therapy have been shown in vitro to dramatically affect the characteristics of standard radiation survival curves (in V79 cells and spheroids). The agent mustargen, at a concentration of 0.25 microgram/ml administered 1 hour prior to 9-MeV-electron exposure, had a significant effect in reducing D0. The 165-rad D0 observed in control curves was reduced to 105 rads in the presence of drug. One hour preincubation with BCNU (prior to radiation exposure) at a concentration of 3.0 microgram/ml was found to dramatically reduce the initial shoulder region with n number values for drug curves approximately one-half those seen for controls. No effect is seen when chlorambucil is combined with radiation in exponential or confluent cultures but an enhancement ratio of 1.8 is found when intact spheroids are pretreated with this drug.

  2. Agrobacterium-mediated transformation of apple (Malus x domestica Borkh.): an assessment of factors affecting regeneration of transgenic plants.

    Science.gov (United States)

    De Bondt, A; Eggermont, K; Penninckx, I; Goderis, I; Broekaert, W F

    1996-03-01

    We have previously developed a protocol for efficient gene transfer and regeneration of transgenic calli following cocultivation of apple (cv. Jonagold) explants with Agrobacterium tumefaciens (De Bondt et al. 1994, Plant Cell Reports 13: 587-593). Now we report on the optimization of postcultivation conditions for efficient and reproducible regeneration of transgenic shoots from the apple cultivar Jonagold. Factors which were found to be essential for efficient shoot regeneration were the use of gelrite as a gelling agent and the use of the cytokinin-mimicing thidiazuron in the selective postcultivation medium. Improved transformation efficiencies were obtained by combining the hormones thidiazuron and zeatin and by using leaf explants from in vitro grown shoots not older than 4 weeks after multiplication. Attempts to use phosphinothricin acetyl transferase as a selectable marker were not successful. Using selection on kanamycin under optimal postcultivation conditions, about 2% of the leaf explants developed transgenic shoots or shoot clusters. The presence and expression of the transferred genes was verified by β-glucuronidase assays and Southern analysis. The transformation procedure has also been succesfully applied to several other apple cultivars.

  3. NICA: Natural Interaction with a Caring Agent

    Science.gov (United States)

    de Carolis, Berardina; Mazzotta, Irene; Novielli, Nicole

    Ambient Intelligence solutions may provide a great opportunity for elderly people to live longer at home. Assistance and care are delegated to the intelligence embedded in the environment. However, besides considering service-oriented response to the user needs, the assistance has to take into account the establishment of social relations. We propose the use of a robot NICA (as the name of the project Natural Interaction with a Caring Agent) acting as a caring assistant that provides a social interface with the smart home services. In this paper, we introduce the general architecture of the robot's "mind" and then we focus on the need to properly react to affective and socially oriented situations.

  4. Affect in Tutoring Dialogues

    NARCIS (Netherlands)

    Heylen, Dirk K.J.; Nijholt, Antinus; op den Akker, Hendrikus J.A.

    2005-01-01

    This paper is about INES, an intelligent, multimodal tutoring environment, and how we build a tutor agent in the environment that tries to be sensitive to the mental state of the student that interacts with it. The environment was primarily designed to help students practice nursing tasks. For

  5. 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...

  6. 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…

  7. 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.

  8. Multi-Agent Transport Planning

    NARCIS (Netherlands)

    Zutt, J.; Witteveen, C.

    2005-01-01

    We discuss a distributed transport planning problem with competitive autonomous actors that carry out time-constrained pick-up delivery orders from customers. The agents have to find conflict-free routes to execute a series of orders they have accepted. Hatzack and Nebel [2] were the first to sugges

  9. 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

  10. 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,

  11. Humor and embodied conversational agents

    NARCIS (Netherlands)

    Nijholt, A.

    2003-01-01

    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 interactio

  12. 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

  13. Biotech drugs : biological therapeutic agents

    OpenAIRE

    Grech, Godfrey; Fenech, Anthony

    2009-01-01

    The recent years has seen significant growth in a new therapeutic approach to the management of disease. Biological therapeutic agents, constitute a broad category of drugs, usually generated by recombinant techniques from living organisms. These therapies revolutionise the traditional approaches to drug design and development, and regulatory agencies have been swift in developing the necessary structures to ensure their optimal use.

  14. 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...

  15. 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

  16. Identity Management in Agent Systems

    NARCIS (Netherlands)

    Brazier, F.M.T.; Groot, de D.R.A.

    2006-01-01

    If agent-based applications are to be used in large scale, open environments, security is a main issue; digital identity management (DIDM) an essential element. DIDM is needed to be able to determine the rights and obligations of the four main

  17. 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

  18. [Application of organic agents in remediation of heavy metals- contaminated soil].

    Science.gov (United States)

    Sun, Xiaofeng; Wu, Longhua; Luo, Yongming

    2006-06-01

    Organic agents play an important role in the remediation of heavy metals - contaminated soil, and their introduction into practice is a promising strategy to develop an efficient solution for this remediation. This paper summarized the research advances in the application of organic agents to the remediation of heavy metals- polluted soil, including their action mechanisms, advantages and disadvantages, and factors affecting their efficiency. The commonly used organic agents, such as aminopolycarboxylic acid, organic acid, humic acid, biosurfactants, etc., were introduced, and the prospects of organic agents' application were discussed.

  19. Multi-agent-based Approach for Determination of Time-quota in Integrated Environment

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Time-quota is one of important factors in producti on system. It is affected by various factors. time-quota is studied in CAPP and p roduction schedule integration environment in this paper. An agent-based time- quota method is put forward and the structure model is established by means of i ntelligent agent in integrated environment. The method can map the influencing t ime-quota factors into part agent related to process state and machine method a gent, resorting to the function of agent rule-based reaso...

  20. High-Relaxivity MRI Contrast Agents: Where Coordination Chemistry Meets Medical Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Werner, Eric J.; Datta, Ankona; Jocher, Christoph J.; Raymond, Kenneth N.

    2008-01-15

    The desire to improve and expand the scope of clinical magnetic resonance imaging (MRI) has prompted the search for contrast agents of higher efficiency. The development of better agents requires consideration of the fundamental coordination chemistry of the gadolinium(III) ion and the parameters that affect its efficacy as a proton relaxation agent. In optimizing each parameter, other practical issues such as solubility and in vivo toxicity must also be addressed, making the attainment of safe, high-relaxivity agents a challenging goal. Here we present recent advances in the field, with an emphasis on the hydroxypyridinone family of Gd{sup III} chelates.

  1. Halide test agent replacement study

    Energy Technology Data Exchange (ETDEWEB)

    Banks, E.M.; Freeman, W.P.; Kovach, B.J. [and others

    1995-02-01

    The intended phaseout of the chlorofluorocarbons (CFCs) from commercial use required the evaluation of substitute materials for the testing for leak paths through both individual adsorbers and installed adsorbent banks. The American Society of Mechanical Engineers (ASME) Committee on Nuclear Air and Gas Treatment (CONAGT) is in charge of maintaining the standards and codes specifying adsorbent leak test methods for the nuclear safety related air cleaning systems. The currently published standards and codes cite the use of R-11, R-12 and R-112 for leak path test agents. All of these compounds are CFCs. There are other agencies and organizations (USDOE, USDOD and USNRC) also specifying testing for leak paths or in some cases for special life tests using the above compounds. The CONAGT has recently developed criteria for the suitability evaluation of substitute test agents. On the basis of these criteria, several compounds were evaluated for their acceptability as adsorbent bed leak and life test agents. The ASME CONAGT Test Agent Qualification Criteria. The test agent qualification is based on the following parameters: (1) Similar retention times on activated carbons at the same concentration levels as one of the following: R-11, R-12, R-112 or R-112a. (2) Similar lower detection limit sensitivity and precision in the concentration range of use as R-11, R-12, R-112 and R-112a. (3) Gives the same in-place leak test results as R-11, R-12, R-112, or R-112a. (4) Chemical and radiological stability under the use conditions. (5) Causes no degradation of the carbon and its impregnant or of the other NATS components under the use conditions. (6) Is listed in the USEPA Toxic Substances Control Act (TSCA) inventory for commercial use.

  2. Persuasive Teachable Agent for Intergenerational Learning

    OpenAIRE

    Lim, Su Fang

    2016-01-01

    Teachable agents are computer agents based on the pedagogical concept of learning-by-teaching. During the tutoring process, where students take on the role of the tutor to teach a computer agent tutee, learners have been observed to gain deeper understanding of the subject matter. Teachable agents are commonly used in the areas of science and mathematics learning where learners are able to learn complex concepts and deep reasoning by teaching the teachable agent through graphic representation...

  3. [Incorporation of controlling dengue by community health agent].

    Science.gov (United States)

    Cazola, Luiza Helena de Oliveira; Tamaki, Edson Mamoru; Pontes, Elenir Rose Jardim Cury

    2014-01-01

    The purpose of this study was to identify self-perceived differences in the work processes of community health agents (CHA) in two counties of Mato Grosso do Sul, regarding dengue control and Family Health Strategy (FHS) activities. Structured interviews were applied to 57 CHA. The subjects had similar sociodemographic characteristics. Agents in Rio Verde de Mato Grosso county, who performed only FHS tasks, failed to complete essential data of the Form A. In São Gabriel do Oeste county, CHA currently perform tasks pertaining to dengue fever control, previously conducted by Endemic Disease Control Agents (now abolished), while in Rio Verde de Mato Grosso county, dengue control remained assigned to the latter group. In São Gabriel do Oeste county, CHA did not view the double workload of two programs as affecting their professional productivity. The pooling of tasks from the two programs proved to be feasible, with no detrimental effects on performance.

  4. Affectivity and race

    DEFF Research Database (Denmark)

    of the Nordic countries, Affectivity and Race draws on a variety of sources, including television programmes, news media, fictional literature, interviews, ethnographic observations, teaching curricula and policy documents, to explore the ways in which ideas about affectivity and emotion afford new insights...... into the experience of racial difference and the unfolding of political discourses on race in various social spheres. Organised around the themes of the politicisation of race through affect, the way that race produces affect and the affective experience of race, this interdisciplinary collection sheds light...... on the role of feelings in the formation of subjectivities, how race and whiteness are affectively circulated in public life and the ways in which emotions contribute to regimes of inclusion and exclusion. As such it will appeal to scholars across the social sciences, with interests in sociology, anthropology...

  5. Migration Dynamics in Artificial Agent Societies

    Directory of Open Access Journals (Sweden)

    Harjot Kaur

    2014-02-01

    Full Text Available 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 understood as computational societies. Members of such artificial agent societies are heterogeneous intelligent software agents which are operating locally and cooperating and coordinating with each other in order to achieve goals of an agent society. These artificial agent societies have some kind of dynamics existing in them in terms of dynamics of Agent Migration, Role-Assignment, Norm- Emergence, Security and Agent-Interaction. In this paper, we have described the dynamics of agent migration process, starting from the various types of agent migration, causes or reasons for agent migration, consequences of agent migration, and an agent migration framework to model the its behavior for migration of agents between societies.

  6. Comprehension and Engagement in Survey Interviews with Virtual Agents

    Directory of Open Access Journals (Sweden)

    Frederick eConrad

    2015-10-01

    Full Text Available This study investigates how an onscreen virtual agent's dialog capability and facial animation affect survey respondents' comprehension and engagement in face-to-face interviews, using questions from US government surveys whose results have far-reaching impact on national policies. In the study, 73 laboratory participants were randomly assigned to respond in one of four interviewing conditions, in which the virtual agent had either high or low dialog capability (implemented through Wizard of Oz and high or low facial animation, based on motion capture from a human interviewer. Respondents, whose faces were visible to the Wizard (and videorecorded during the interviews, answered 12 questions about housing, employment, and purchases on the basis of fictional scenarios designed to allow measurement of comprehension accuracy, defined as the fit between responses and US government definitions. Respondents answered more accurately with the high-dialog-capability agents, requesting clarification more often particularly for ambiguous scenarios; and they generally treated the high-dialog-capability interviewers more socially, looking at the interviewer more and judging high-dialog-capability agents as more personal and less distant. Greater interviewer facial animation did not affect response accuracy, but it led to more displays of engagement—acknowledgements (verbal and visual and smiles—and to the virtual interviewer's being rated as less natural. The pattern of results suggests that a virtual agent’s dialog capability and facial animation differently affect survey respondents' experience of interviews, behavioral displays, and comprehension, and thus the accuracy of their responses. The pattern of results also suggests design considerations for building survey interviewing agents, which may differ depending on the kinds of survey questions (sensitive or not that are asked.

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

    Science.gov (United States)

    Baker, Lauri M.; Hadley, Gregg

    2014-01-01

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

  8. Gd-HOPO Based High Relaxivity MRI Contrast Agents

    Energy Technology Data Exchange (ETDEWEB)

    Datta, Ankona; Raymond, Kenneth

    2008-11-06

    Tris-bidentate HOPO-based ligands developed in our laboratory were designed to complement the coordination preferences of Gd{sup 3+}, especially its oxophilicity. The HOPO ligands provide a hexadentate coordination environment for Gd{sup 3+} in which all he donor atoms are oxygen. Because Gd{sup 3+} favors eight or nine coordination, this design provides two to three open sites for inner-sphere water molecules. These water molecules rapidly exchange with bulk solution, hence affecting the relaxation rates of bulk water olecules. The parameters affecting the efficiency of these contrast agents have been tuned to improve contrast while still maintaining a high thermodynamic stability for Gd{sup 3+} binding. The Gd- HOPO-based contrast agents surpass current commercially available agents ecause of a higher number of inner-sphere water molecules, rapid exchange of inner-sphere water molecules via an associative mechanism, and a long electronic relaxation time. The contrast enhancement provided by these agents is at least twice that of commercial contrast gents, which are based on polyaminocarboxylate ligands.

  9. Assessing Student Affect

    Science.gov (United States)

    Popham, W. James

    2009-01-01

    Student affect--the attitudes, interests, and values that students exhibit and acquire in school--can play a profoundly important role in students' postschool lives, possibly an even more significant role than that played by students' cognitive achievements. If student affect is so crucial, then why don't teachers assess it? One deterrent is that…

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

    Science.gov (United States)

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

    2016-08-17

    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.

  11. CATS-based Agents That Err

    Science.gov (United States)

    Callantine, Todd J.

    2002-01-01

    This report describes preliminary research on intelligent agents that make errors. Such agents are crucial to the development of novel agent-based techniques for assessing system safety. The agents extend an agent architecture derived from the Crew Activity Tracking System that has been used as the basis for air traffic controller agents. The report first reviews several error taxonomies. Next, it presents an overview of the air traffic controller agents, then details several mechanisms for causing the agents to err in realistic ways. The report presents a performance assessment of the error-generating agents, and identifies directions for further research. The research was supported by the System-Wide Accident Prevention element of the FAA/NASA Aviation Safety Program.

  12. 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.

  13. Logical Theories for Agent Introspection

    DEFF Research Database (Denmark)

    Bolander, Thomas

    2004-01-01

    Artificial intelligence systems (agents) generally have models of the environments they inhabit which they use for representing facts, for reasoning about these facts and for planning actions. Much intelligent behaviour seems to involve an ability to model not only one's external environment...... 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...... introspective reasoning, the presence of self-reference causes the theory to be prone to inconsistency. The challenge therefore becomes to construct logical theories supporting introspective reasoning while at the same time ensuring that consistency is retained. In the thesis, we meet this challenge by devising...

  14. Extension agents and conflict narratives

    DEFF Research Database (Denmark)

    Bond, Jennifer Lauren

    2016-01-01

    conflict. Originality: This work contributes to a growing body of literature interested in the role of extension agents in conflict management. By applying Q methodology, this work has shown that while extension agents are involved in conflict management, their perceptions of these conflicts are subjective......Purpose: This work investigated the narratives of development extensionists in relation to natural resource conflict, in order to understand the competing discourses surrounding the wicked problems of natural resource management in Laikipia County, Kenya. Methodology: Q methodology was used...... to elicit the conflict narratives present among extension professionals. A concourse of 221 statements were devised from interviews and group discussions with key informants and a final sample of 49 statements was used for the sorting. Thirteen Q-sorts were undertaken with among rural extension...

  15. Bacteriocins as potential anticancer agents

    Directory of Open Access Journals (Sweden)

    Sukhraj eKaur

    2015-11-01

    Full Text Available Cancer remains one of the leading causes of deaths worldwide, despite advances in its treatment and detection. The conventional chemotherapeutic agents used for the treatment of cancer have nonspecific toxicity towards normal body cells that cause various side effects. Secondly, cancer cells are known to develop chemotherapy resistance in due course of treatment. Thus, the demand for novel anti-cancer agents is increasing day by day. Some of the experimental studies have reported the therapeutic potential of bacteriocins against various types of cancer cell lines. Bacteriocins are ribosomally-synthesized cationic peptides secreted by almost all groups of bacteria. Some bacteriocins have shown selective cytotoxicity towards cancer cells as compared to normal cells. This makes them promising candidates for further investigation and clinical trials. In this review article, we present the overview of the various cancer cell-specific cytotoxic bacteriocins, their mode of action and efficacies.

  16. Subharmonic imaging of contrast agents.

    Science.gov (United States)

    Forsberg, F; Shi, W T; Goldberg, B B

    2000-03-01

    Ultrasound contrast agents promise to improve the sensitivity and specificity of diagnostic ultrasound imaging. It is of great importance to adapt ultrasound equipment for optimal use with contrast agents e.g., by exploiting the nonlinear properties of the contrast microbubbles. Harmonic imaging is one technique that has been extensively studied and is commercially available. However, harmonic imaging is associated with problems, due to second harmonic generation and accumulation within the tissue itself. Given the lack of subharmonic generation in tissue, one alternative is the creation of subharmonic images by transmitting at the fundamental frequency (fo) and receiving at the subharmonic (fo/2). Subharmonic imaging should have a much better lateral resolution and may be suitable for scanning deep-lying structures owing to the higher transmit frequency and the much smaller attenuation of scattered subharmonic signals. In this paper, we will review different aspects of subharmonic imaging including implementation, in-vitro gray-scale imaging and subharmonic aided pressure estimation.

  17. Logical Theories for Agent Introspection

    DEFF Research Database (Denmark)

    Bolander, Thomas

    2004-01-01

    Artificial intelligence systems (agents) generally have models of the environments they inhabit which they use for representing facts, for reasoning about these facts and for planning actions. Much intelligent behaviour seems to involve an ability to model not only one's external environment...... 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...... introspective reasoning, the presence of self-reference causes the theory to be prone to inconsistency. The challenge therefore becomes to construct logical theories supporting introspective reasoning while at the same time ensuring that consistency is retained. In the thesis, we meet this challenge by devising...

  18. Heterogeneous Agents, Distribution and Growth

    OpenAIRE

    Paquin, Lloyd

    1999-01-01

    We modify the Uzawa-Lucas representative agent model of endogenous economic growth to allow for a variety of differences among households: differences in their tastes, in their human capital production technologies, and in their initial endowments. Some differences are incompatible with the existence of a steady- state equilibrium, while others have no effect upon the steady-state growth rate. However, a variety of differences give rise to inequalities in the distribution of income and to var...

  19. Direct Vasodilators and Sympatholytic Agents.

    Science.gov (United States)

    McComb, Meghan N; Chao, James Y; Ng, Tien M H

    2016-01-01

    Direct vasodilators and sympatholytic agents were some of the first antihypertensive medications discovered and utilized in the past century. However, side effect profiles and the advent of newer antihypertensive drug classes have reduced the use of these agents in recent decades. Outcome data and large randomized trials supporting the efficacy of these medications are limited; however, in general the blood pressure-lowering effect of these agents has repeatedly been shown to be comparable to other more contemporary drug classes. Nevertheless, a landmark hypertension trial found a negative outcome with a doxazosin-based regimen compared to a chlorthalidone-based regimen, leading to the removal of α-1 adrenergic receptor blockers as first-line monotherapy from the hypertension guidelines. In contemporary practice, direct vasodilators and sympatholytic agents, particularly hydralazine and clonidine, are often utilized in refractory hypertension. Hydralazine and minoxidil may also be useful alternatives for patients with renal dysfunction, and both hydralazine and methyldopa are considered first line for the treatment of hypertension in pregnancy. Hydralazine has also found widespread use for the treatment of systolic heart failure in combination with isosorbide dinitrate (ISDN). The data to support use of this combination in African Americans with heart failure are particularly robust. Hydralazine with ISDN may also serve as an alternative for patients with an intolerance to angiotensin antagonists. Given these niche indications, vasodilators and sympatholytics are still useful in clinical practice; therefore, it is prudent to understand the existing data regarding efficacy and the safe use of these medications. © The Author(s) 2015.

  20. Identification of novel and improved antimitotic agents derived from noscapine.

    Science.gov (United States)

    Anderson, James T; Ting, Anthony E; Boozer, Sherry; Brunden, Kurt R; Crumrine, Chris; Danzig, Joel; Dent, Tom; Faga, Laurel; Harrington, John J; Hodnick, William F; Murphy, Steven M; Pawlowski, Gary; Perry, Robert; Raber, Amy; Rundlett, Stephen E; Stricker-Krongrad, Alain; Wang, Jianmin; Bennani, Youssef L

    2005-11-17

    Analogues of the natural product noscapine were synthesized and their potential as antitumor agents evaluated. The discovery of a novel regioselective O-demethylation facilitated the synthesis of the potent aniline 6, which arrests mammalian cells in the G2/M phase of the cell cycle at 0.1 microM and also affects tubulin polymerization. Aniline 6 is orally bioavailable and is 250-fold more potent than noscapine in reducing cell proliferation in rapidly dividing cells.

  1. Thrombotic microangiopathies and antineoplastic agents.

    Science.gov (United States)

    Grangé, Steven; Coppo, Paul

    2017-04-01

    Thrombotic microangiopathy is a well-described complication of cancer treatment. Its incidence has increased these last decades, as a result of a better awareness of this complication in cancer patients in one hand, but also of a larger array of therapeutic compounds including anti-vascular endothelium growth factor (VEGF) drugs. It is therefore mandatory to recognize these conditions since they have a significant impact in thrombotic microangiopathies management and prognosis. Practitioners should be aware of the more classical antineoplastic agents associated with thrombotic microangiopathies, the mechanisms by which they induce them, and the resulting management and prognosis. Since malignancy itself can induce thrombotic microangiopathies, it is also mandatory to know how to distinguish rapidly those caused by antineoplastic agents from those associated with cancer, for an adapted management. Thrombotic microangiopathies associated with chemotherapy remain of dismal prognosis. A better understanding of pathophysiology in these forms of thrombotic microangiopathies, in association with a more empirical approach through the use of new therapeutic agents that can also help in the understanding on new mechanisms a posteriori, should improve their prognosis. The preliminary encouraging results reported with complement blockers in this field could represent a convincing example. Copyright © 2017 Société francophone de néphrologie, dialyse et transplantation. Published by Elsevier Masson SAS. All rights reserved.

  2. Chemotherapy and Dietary Phytochemical Agents

    Directory of Open Access Journals (Sweden)

    Katrin Sak

    2012-01-01

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

  3. Preponderant agent, what is that?

    Directory of Open Access Journals (Sweden)

    Clara Luz Álvarez

    2015-05-01

    Full Text Available Purpose – Preponderant agent is a new instrument for preventing and reverting adverse impact in competition due to highly concentrated markets. Therefore, this paper's objective is to present and analyze the preponderant agent concept in Mexico with emphasis on the broadcast sector, the telecommunication regulator decisions and the courts' interpretation. Methodology/approach/design – The objectives were achieved by researching and analyzing the main legal documents, the Congress reports and debates, the regulator's decisions and other relevant regulator's documents, as well as final decisions by the courts in connection with broadcast sector. Findings – Among the findings are that certain topics were not duly addressed by the Mexican regulator, or by the Congress, whereas the courts were more willing to hold decisions in favor of public interest based on constitutional intent and deference to the regulator's decision. Originality/value – This paper will be valuable for persons interested in telecommunications, broadcast and antitrust. Although the preponderant agent concept created in Mexico is not necessarily a “best practice”, it does provide an alternative instrument in antitrust. Moreover, the courts decisions also provide criteria regarding regulatory deference for the regulator.

  4. Pharmacologic Agents for Chronic Diarrhea.

    Science.gov (United States)

    Lee, Kwang Jae

    2015-10-01

    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.

  5. 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.

  6. 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.

  7. An Agent Based Classification Model

    CERN Document Server

    Gu, Feng; Greensmith, Julie

    2009-01-01

    The major function of this model is to access the UCI Wisconsin Breast Can- cer data-set[1] and classify the data items into two categories, which are normal and anomalous. This kind of classifi cation can be referred as anomaly detection, which discriminates anomalous behaviour from normal behaviour in computer systems. One popular solution for anomaly detection is Artifi cial Immune Sys- tems (AIS). AIS are adaptive systems inspired by theoretical immunology and observed immune functions, principles and models which are applied to prob- lem solving. The Dendritic Cell Algorithm (DCA)[2] is an AIS algorithm that is developed specifi cally for anomaly detection. It has been successfully applied to intrusion detection in computer security. It is believed that agent-based mod- elling is an ideal approach for implementing AIS, as intelligent agents could be the perfect representations of immune entities in AIS. This model evaluates the feasibility of re-implementing the DCA in an agent-based simulation environ- ...

  8. Antagonistic formation motion of cooperative agents

    Institute of Scientific and Technical Information of China (English)

    卢婉婷; 代明香; 薛方正

    2015-01-01

    This paper investigates a new formation motion problem of a class of first-order multi-agent systems with antagonis-tic interactions. A distributed formation control algorithm is proposed for each agent to realize the antagonistic formation motion. A sufficient condition is derived to ensure that all agents make an antagonistic formation motion in a distributed manner. It is shown that all agents can be spontaneously divided into several groups, and agents in the same group collab-orate while agents in different groups compete. Finally, a numerical simulation is included to demonstrate our theoretical results.

  9. 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......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...

  10. 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].......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]....

  11. FUZZY LOGIC MULTI-AGENT SYSTEM

    OpenAIRE

    Atef GHARBI; Ben Ahmed, Samir

    2014-01-01

    The paper deals with distributed planning in a Multi-Agent System (MAS) constituted by several intelligent agents each one has to interact with the other autonomous agents. The problem faced is how to ensure a distributed planning through the cooperation in our multi-agent system. To do so, we propose the use of fuzzy logic to represent the response of the agent in case of interaction with the other. Finally, we use JADE platform to create agents and ensure the communication be...

  12. 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 ...

  13. An embodiment effect in computer-based learning with animated pedagogical agents.

    Science.gov (United States)

    Mayer, Richard E; DaPra, C Scott

    2012-09-01

    How do social cues such as gesturing, facial expression, eye gaze, and human-like movement affect multimedia learning with onscreen agents? To help address this question, students were asked to twice view a 4-min narrated presentation on how solar cells work in which the screen showed an animated pedagogical agent standing to the left of 11 successive slides. Across three experiments, learners performed better on a transfer test when a human-voiced agent displayed human-like gestures, facial expression, eye gaze, and body movement than when the agent did not, yielding an embodiment effect. In Experiment 2 the embodiment effect was found when the agent spoke in a human voice but not in a machine voice. In Experiment 3, the embodiment effect was found both when students were told the onscreen agent was consistent with their choice of agent characteristics and when inconsistent. Students who viewed a highly embodied agent also rated the social attributes of the agent more positively than did students who viewed a nongesturing agent. The results are explained by social agency theory, in which social cues in a multimedia message prime a feeling of social partnership in the learner, which leads to deeper cognitive processing during learning, and results in a more meaningful learning outcome as reflected in transfer test performance.

  14. Borrelioses, agentes e vetores Borrelioses, agents and vectors: a review

    Directory of Open Access Journals (Sweden)

    Cleber O. Soares

    2000-03-01

    Full Text Available As borrelioses são enfermidades infecciosas determinadas por espiroquetas do gênero Borrelia, agentes transmissíveis, principalmente, por carrapatos aos animais e/ou ao homem. Nesta revisão são apresentadas e discutidas as enfermidades determinadas por borrélias, bem como as características gerais das espiroquetas, os aspectos relacionados a transmissão por artrópodes, as enfermidades nos animais domésticos e silvestres, quanto aos aspectos biológicos e patológicos, a doença de Lyme como principal zoonose do grupo, a associação de borrélia com outros agentes hematozoários e os métodos diagnósticos e a epidemiologia comparativa entre dados obtidos no Brasil com os de outros países. Estas borrelioses possuem características patológicas, clínicas e epidemiológicas variadas de acordo à região fisiográfica, devido à existência de distintas espécies, genoespécies e cepas; estes aspectos variam ainda em função dos artrópodes vetores, da interação vetor-patógeno e dos ecossistemas distintos.Borrelioses are infectous diseases caused by spirochaetes of the genus Borrelia. They are born mainly through ticks at animals and/or human beings. In this review are shown and discussed five groups of diseases determined by borrelia, general characteristics of the spirochaetes, aspects related to transmission by arthropods, biological and pathological aspects of the diseases in domestic and wild animals, Lyme disease as an important zoonosis, the association of borrelia with other hematozoa agents, the diagnostic methods and the comparative epidemiology with data obtained from Brazil and other countries. The borrelioses have pathological, clinical and epidemiological characteristics which vary according to physiographic regions due to the existence of different species, genospecies and strains of borrelia, of arthropod vectors, vector-agent relationship and of different ecocystems.

  15. A Teachable-Agent-Based Game Affording Collaboration and Competition: Evaluating Math Comprehension and Motivation

    Science.gov (United States)

    Pareto, Lena; Haake, Magnus; Lindstrom, Paulina; Sjoden, Bjorn; Gulz, Agneta

    2012-01-01

    This paper presents an educational game in mathematics based on an apprenticeship model using a teachable agent, as well as an evaluative study of how the game affects (1) conceptual understanding and (2) attitudes towards mathematics. In addition, we discuss how collaborative and competitive affordances of the game may affect understanding and…

  16. Antipsychotic agents: efficacy and safety in schizophrenia

    Directory of Open Access Journals (Sweden)

    de Araújo AN

    2012-11-01

    Full Text Available Arão Nogueira de Araújo,1 Eduardo Pondé de Sena,1,2 Irismar Reis de Oliveira,1,3 Mario F Juruena41Postgraduation Program in Interactive Processes of Organs and Systems, 2Department of Pharmacology, Institute of Health Sciences, 3Department of Neurosciences and Mental Health, School of Medicine, Federal University of Bahia, Salvador, Brazil; 4Stress and Affective Disorders Program, Department of Neuroscience and Behavior, Faculty of Medicine of Ribeirao Preto, University of Sao Paulo, Sao Paulo, BrazilAbstract: Antipsychotics have provided a great improvement in the management of people with schizophrenia. The first generation antipsychotics could establish the possibility of managing many psychotic subjects in an outpatient setting. With the advent of the second (SGA and third generation antipsychotics (TGA, other psychiatric disorders such as bipolar depression, bipolar mania, autism, and major depressive disorder have now been approved for the use of these drugs for their treatment. Also, the administration of more specific assessment tools has allowed for better delineation of the repercussions of these drugs on symptoms and the quality of life of patients who use antipsychotic agents. In general, the SGA share similar mechanisms of action to achieve these results: dopamine-2 receptor antagonism plus serotonin-2A receptor antagonism. The TGA (eg, aripiprazole have partial agonist activity at the dopamine-2 receptor site, and are also called dopaminergic stabilizers. The pharmacological profile of SGA and TGA may provide better efficacy against negative symptoms, and are less likely to produce extrapyramidal symptoms; however, the SGA and TGA are associated with many other adverse events. The clinician has to balance the risks and benefits of these medications when choosing an antipsychotic for an individual patient.Keywords: antipsychotic agents, schizophrenia, pharmacology, safety

  17. Colors Can Affect Us!

    Institute of Scientific and Technical Information of China (English)

    张俊斌

    2006-01-01

    Different colors affect us differently.The following will show us how they work. Experiment proves that math problems worked on yellow paper have fewer mistakes than problems written on other colors of paper.

  18. Pain, Affect, and Attachment

    Directory of Open Access Journals (Sweden)

    Carl Eduard Scheidt

    2015-03-01

    Full Text Available Various psychodynamic processes may underlie the development of psychogenic pain disorder such as conversion, the displacement of affect, or narcissistic defenses. However, many of the processes suggested are related to a disorder of affect regulation. The term affect regulation in psychoanalytic literature refers to phenomena which are often described by the concept of alexithymia. Empirical observations suggest that alexithymia is correlated to insecure attachment, especially an insecure dismissing representation of attachment. Psychodynamic psychotherapy in psychogenic pain disorder should focus on the reintegration of split-off affects which may provoke intensive counter-transference and which in order to be used therapeutically must be linked to attachment experiences within and outside of the therapeutic relationship.

  19. Preoperative management of anticoagulation and antiplatelet agents.

    Science.gov (United States)

    Gleason, Lauren Jan; Friedman, Susan M

    2014-05-01

    This article describes current literature and treatment plans for managing anticoagulation and antiplatelet agents in patients presenting with hip fractures. Indications for anticoagulation and antiplatelet agents are discussed, and management techniques for when patients present with hip fractures are reviewed.

  20. What Are Anticoagulants and Antiplatelet Agents?

    Science.gov (United States)

    ... by heart Treatments + Tests What Are Anticoagulants and Antiplatelet Agents? Anticoagulants and antiplatelet agents are medicines that reduce blood clotting in an artery, a vein or the heart. Blood clots can block the ...