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Sample records for cariogenic agents

  1. Susceptibility of Enamel Treated with Bleaching Agents to Mineral Loss after Cariogenic Challenge

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    Hüseyin Tezel

    2011-01-01

    Full Text Available Objectives. Controversial reports exist whether bleaching agents cause a susceptibility to demineralization. The aim of this study was to compare the calcium loss of enamel treated with different bleaching agents and activation methods. Method and Materials. The specimens obtained from human premolars were treated in accordance with manufacturer protocols; 10% carbamide peroxide, 38% hydrogen peroxide light-activated, 38% hydrogen peroxide laser-activated, and no treatment (control. After cariogenic challenge calcium concentrations were determined by Inductively Coupled Plasma Mass Spectrometry. Results. No differences were found between the calcium loss of the laser-activated group and 10% carbamide peroxide group (>0.05. However, the differences between laser-activated and control groups were statistically significant (0.05. On the other hand, the light-activated group showed a significantly higher calcium loss compared with the other groups (<0.05. Conclusions. The results show that bleaching agents may cause calcium loss but it seems to be a negligible quantity for clinical aspects.

  2. Halistanol sulfate A and rodriguesines A and B are antimicrobial and antibiofilm agents against the cariogenic bacterium Streptococcus mutans

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    Bruna de A. Lima

    2014-12-01

    Full Text Available In the present investigation we report the antibacterial activity of halistanol sulfate A isolated from the sponge Petromica ciocalyptoides, as well as of rodriguesines A and B isolated from the ascidian Didemnum sp., against the caries etiologic agent Streptococcus mutans. The transcription levels of S. mutans virulence genes gtfB, gtfC and gbpB, as well as of housekeeping genes groEL and 16S, were evaluated by sqRT-PCR analysis of S. mutans planktonic cells. There were no alterations in the expression levels of groEL and 16S after antimicrobial treatment with halistanol sulfate A and with rodriguesines A and B, but the expression of the genes gtfB, gtfC and gbpB was down-regulated. Halistanol sulfate A displayed the most potent antimicrobial effect against S. mutans, with inhibition of biofilm formation and reduction of biofilm-associated gene expression in planktonic cells. Halistanol sulfate A also inhibited the initial oral bacteria colonizers, such as Streptococcus sanguinis, but at much higher concentrations. The results obtained indicate that halistanol sulfate A may be considered a potential scaffold for drug development in Streptococcus mutans antibiofilm therapy, the main etiologic agent of human dental caries.

  3. Non-lethal control of the cariogenic potential of an agent-based model for dental plaque.

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    David A Head

    Full Text Available Dental caries or tooth decay is a prevalent global disease whose causative agent is the oral biofilm known as plaque. According to the ecological plaque hypothesis, this biofilm becomes pathogenic when external challenges drive it towards a state with a high proportion of acid-producing bacteria. Determining which factors control biofilm composition is therefore desirable when developing novel clinical treatments to combat caries, but is also challenging due to the system complexity and the existence of multiple bacterial species performing similar functions. Here we employ agent-based mathematical modelling to simulate a biofilm consisting of two competing, distinct types of bacterial populations, each parameterised by their nutrient uptake and aciduricity, periodically subjected to an acid challenge resulting from the metabolism of dietary carbohydrates. It was found that one population was progressively eliminated from the system to give either a benign or a pathogenic biofilm, with a tipping point between these two fates depending on a multiplicity of factors relating to microbial physiology and biofilm geometry. Parameter sensitivity was quantified by individually varying the model parameters against putative experimental measures, suggesting non-lethal interventions that can favourably modulate biofilm composition. We discuss how the same parameter sensitivity data can be used to guide the design of validation experiments, and argue for the benefits of in silico modelling in providing an additional predictive capability upstream from in vitro experiments.

  4. Non-lethal control of the cariogenic potential of an agent-based model for dental plaque.

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    Head, David A; Marsh, Phil D; Devine, Deirdre A

    2014-01-01

    Dental caries or tooth decay is a prevalent global disease whose causative agent is the oral biofilm known as plaque. According to the ecological plaque hypothesis, this biofilm becomes pathogenic when external challenges drive it towards a state with a high proportion of acid-producing bacteria. Determining which factors control biofilm composition is therefore desirable when developing novel clinical treatments to combat caries, but is also challenging due to the system complexity and the existence of multiple bacterial species performing similar functions. Here we employ agent-based mathematical modelling to simulate a biofilm consisting of two competing, distinct types of bacterial populations, each parameterised by their nutrient uptake and aciduricity, periodically subjected to an acid challenge resulting from the metabolism of dietary carbohydrates. It was found that one population was progressively eliminated from the system to give either a benign or a pathogenic biofilm, with a tipping point between these two fates depending on a multiplicity of factors relating to microbial physiology and biofilm geometry. Parameter sensitivity was quantified by individually varying the model parameters against putative experimental measures, suggesting non-lethal interventions that can favourably modulate biofilm composition. We discuss how the same parameter sensitivity data can be used to guide the design of validation experiments, and argue for the benefits of in silico modelling in providing an additional predictive capability upstream from in vitro experiments.

  5. Zinc Oxide Nanorods-Decorated Graphene Nanoplatelets: A Promising Antimicrobial Agent against the Cariogenic Bacterium Streptococcus mutans

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    Elena Zanni

    2016-09-01

    Full Text Available Nanomaterials are revolutionizing the field of medicine to improve the quality of life due to the myriad of applications stemming from their unique properties, including the antimicrobial activity against pathogens. In this study, the antimicrobial and antibiofilm properties of a novel nanomaterial composed by zinc oxide nanorods-decorated graphene nanoplatelets (ZNGs are investigated. ZNGs were produced by hydrothermal method and characterized through field-emission scanning electron microscopy (FE-SEM, energy-dispersive X-ray spectroscopy (EDX and X-ray diffraction (XRD techniques. The antimicrobial activity of ZNGs was evaluated against Streptococcus mutans, the main bacteriological agent in the etiology of dental caries. Cell viability assay demonstrated that ZNGs exerted a strikingly high killing effect on S. mutans cells in a dose-dependent manner. Moreover, FE-SEM analysis revealed relevant mechanical damages exerted by ZNGs at the cell surface of this dental pathogen rather than reactive oxygen species (ROS generation. In addition, inductively coupled plasma mass spectrometry (ICP-MS measurements showed negligible zinc dissolution, demonstrating that zinc ion release in the suspension is not associated with the high cell mortality rate. Finally, our data indicated that also S. mutans biofilm formation was affected by the presence of graphene-zinc oxide (ZnO based material, as witnessed by the safranin staining and growth curve analysis. Therefore, ZNGs can be a remarkable nanobactericide against one of the main dental pathogens. The potential applications in dental care and therapy are very promising.

  6. The Tea Catechin Epigallocatechin Gallate Suppresses Cariogenic Virulence Factors of Streptococcus mutans▿

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    Xu, Xin; Zhou, Xue D.; Wu, Christine D.

    2010-01-01

    Streptococcus mutans, the primary etiologic agent of dental caries, possesses a series of virulence factors associated with its cariogenicity. Alternatives to traditional antimicrobial treatment, agents selectively inhibiting the virulence factors without necessarily suppressing the resident oral species, are promising. The anticariogenic properties of tea have been suggested in experimental animals and humans. Tea polyphenols, especially epigallocatechin gallate (EGCg), have been shown to in...

  7. Antimicrobial Effects of Garcinia Mangostana on Cariogenic Microorganisms

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    Janardhanan, Sunitha; Girija, A. S. Smiline; Mahendra, Little; Priyadharsini, Vijayashree

    2017-01-01

    Introduction Garcinia mangostana commonly called as Mangosteen fruit has been used as an antibacterial agent since age old times. The mangosteen pericarp has proven to have antibacterial effect, but the effect of the same on cariogenic organisms has not been explored. The present study was an attempt to gain a better understanding of the antibacterial effect of mangosteen pericarp on the cariogenic bacteria, to unravel the therapeutic potential for the same. Aim The aim of the study was to assess the antibacterial efficacy of the crude chloroform extract of mangosteen pericarp against cariogenic bacteria. Materials and Methods The study was done under laboratory settings using an in vitro design. The microorganisms namely Streptococcus mutans, Streptococcus sanguis, Streptococcus salivarius, Streptococcus oralis and Lactobacillus acidophilus were procured from American Type Cell Culture (ATCC) and Microbial Type Culture Collection (MTCC) were revived and lawn cultured. The antibacterial effect of mangosteen pericarp was tested using agar well diffusion method on Trypticase Soy Agar-Blood Agar (TSA-BA) and de Man, Rogosa and Sharpe (MRS) agar media. The standard antiplaque agent chlorhexidine was used as the positive control. This cross-sectional, experimental study was done in Central Research laboratory, Meenakshi Ammal Dental College for period of eight weeks. Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC) values were determined by microbroth dilution method. Statistical analysis was done by calculating the mean of the zones of inhibition on tested microorganisms. Mann-Whitney test was done to compare the zones of inhibition of mangosteen and chlorhexidine. Results The antibacterial bioassay showed the highest activity for Lactobacillus acidophilus (13.6 mm) and Streptococcus sanguis (13.6 mm), whereas, it showed a medium and low activity for Streptococcus oralis (11.3 mm), Streptococcus mutans (10.6 mm) and Streptococcus

  8. Sucrose substitutes affect the cariogenic potential of Streptococcus mutans biofilms.

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    Durso, S C; Vieira, L M; Cruz, J N S; Azevedo, C S; Rodrigues, P H; Simionato, M R L

    2014-01-01

    Streptococcus mutans is considered the primary etiologic agent of dental caries and contributes significantly to the virulence of dental plaque, especially in the presence of sucrose. To avoid the role of sucrose on the virulence factors of S. mutans, sugar substitutes are commonly consumed because they lead to lower or no production of acids and interfere with biofilm formation. This study aimed to investigate the contribution of sugar substitutes in the cariogenic potential of S. mutans biofilms. Thus, in the presence of sucrose, glucose, sucralose and sorbitol, the biofilm mass was quantified up to 96 h, the pH of the spent culture media was measured, the expression of biofilm-related genes was determined, and demineralization challenge experiments were conduct in enamel fragments. The presence of sugars or sugar substitutes profoundly affected the expression of spaP, gtfB, gtfC, gbpB, ftf, vicR and vicX in either biofilm or planktonic cells. The substitution of sucrose induced a down-regulation of most genes involved in sucrose-dependent colonization in biofilm cells. When the ratio between the expression of biofilm and planktonic cells was considered, most of those genes were down-regulated in biofilm cells in the presence of sugars and up-regulated in the presence of sugar substitutes. However, sucralose but not sorbitol fulfilled the purpose of reducing the cariogenic potential of the diet since it induced the biofilm formation with the lowest biomass, did not change the pH of the medium and led to the lowest lesion depth in the cariogenic challenge.

  9. Cariogenic effect of caffeine intake during lactation on first molars of newborn rats.

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    Nakamoto, T; Cheuk, S L; Yoshino, S; Falster, A U; Simmons, W B

    1993-10-01

    Lactating dams with eight suckling pups were fed either a 20% protein diet as a control or experimentally a 20% protein diet supplemented with caffeine (2 mg/100g body weight) from the birth of the pups to day 22. At day 22, the pups from both groups were weaned and fed a cariogenic diet until day 50, when they were killed. Dental caries of the molars were scored from randomized mandibles. The enamel of the first molars in the caffeine group showed significantly higher caries scores than that of the controls. This appears to be the first unequivocal evidence that caffeine is a cariogenic agent when newborns are exposed to it during critical periods of tooth development. Therefore, the widespread human consumption of caffeine could be a threat to the healthy development of teeth.

  10. [Caries preventive effectiveness of Fluor Protector and fluoride lacquer, Duraphat under very cariogenic conditions].

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    De Bruyn, H; Buskes, H

    1988-06-01

    Fluoride varnishes Durpahat and Fluor Protector are commonly used and have proven to be effective as caries preventive agents. In the first part of this paper the features of fluoride varnishes in terms of fluoride uptake, caries prevention and toxicological safety are discussed. The effect of both varnishes under high cariogenic conditions is discussed in the second part. In the presented study, 8 patients carried 3 enamel specimens (Fluor Protector, Duraphat, Control) intra-orally during 4 months. They kept plaque accumulation intact on the specimen and avoided fluoride administration from other sources. After 4 months of substantial cariogenic challenge, the enamel was analysed by microradiography and the degree of caries protection obtained for each varnish type was calculated. The results show that under high-risk caries conditions enamel treated with Fluor Protector was significantly better protected (65%) than enamel treated with Duraphat (3%).

  11. Effect of cariogenic challenge on the stability of dentin bonds

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    Fernanda Blos BORGES

    2014-01-01

    Full Text Available Objective: The oral environment is subject to biofilm accumulation and cariogenic challenge, and few studies exist on the effect of these factors on the bond strength of adhesive systems. The aim of this study was to test if the exposure of adhesive interfaces to cariogenic challenge under biofilm accumulation could promote higher degradation than the exposure to biofilm accumulation alone. Material And Methods: Five molars were ground until exposure of medium dentin and then restored (Single Bond 2 and Z250 3M ESPE. The tooth/resin sets were cut to obtain beam-shaped specimens, which were distributed according to the aging conditions (n=20: water for 24 h (control; biofilm under cariogenic challenge for 3, 5 or 10 days; biofilm without cariogenic challenge for 10 days; and water for 3 months. Microcosm biofilms were formed from human saliva and grown in a saliva analogue medium, supplemented or not with sucrose to promote cariogenic challenge. Specimens were tested for microtensile bond strength, and failure modes were classified using light microscopy. Bond strength data were analyzed using ANOVA and failure modes were analyzed using ANOVA on ranks (α=0.05. Results: No significant differences in bond strength were detected among the aging methods (P=0.248. The aging period was associated with an increase in the frequency of adhesive failures for the groups aged for 10 days or longer (P<0.001. Conclusion: Aging leads to a higher prevalence of interfacial adhesive failures, although this effect is not associated with cariogenic challenge or reduction in bond strengths.

  12. Cariogenic Potential of Sucrose Associated with Maltodextrin on Dental Enamel.

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    Rezende, Gabriela; Arthur, Rodrigo A; Grando, Debora; Hashizume, Lina N

    2017-01-26

    Maltodextrin is a hydrolysate of cornstarch and has been widely used in the food industry associated with sucrose. The addition of starch can increase the cariogenic potential of sucrose; however, there are sparse data regarding the cariogenicity of sucrose associated with maltodextrin. Therefore, the aim of this study was to test in situ if maltodextrin could increase the cariogenic potential of sucrose. This was an in situ, randomized, crossover, split-mouth, and double-blind study. Volunteers wore palatal appliances containing bovine enamel blocks for 2 periods of 14 days. They dripped the following solutions on the enamel blocks 8 times per day: deionized distilled water (DDW), maltodextrin (M), sucrose + maltodextrin (S+M), or sucrose (S). At the end of each experimental period, biofilms were collected and analyzed for microbiological (mutans streptococci, lactobacilli, and total microorganisms counts) and biochemical (calcium, inorganic phosphate, fluoride, and insoluble extracellular polysaccharides concentrations) compositions. The enamel demineralization was assessed by microhardness. Treatments S and S+M resulted in a lower inorganic composition and higher concentration of insoluble extracellular polysaccharides in the biofilms, and higher enamel mineral loss compared to DDW and M. It can be concluded that the cariogenic potential of sucrose is not changed when this carbohydrate is associated with maltodextrin (dextrose equivalent 13-17).

  13. The collagen binding protein Cnm contributes to oral colonization and cariogenicity of Streptococcus mutans OMZ175.

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    Miller, James H; Avilés-Reyes, Alejandro; Scott-Anne, Kathy; Gregoire, Stacy; Watson, Gene E; Sampson, Edith; Progulske-Fox, Ann; Koo, Hyun; Bowen, William H; Lemos, José A; Abranches, Jacqueline

    2015-05-01

    Streptococcus mutans is the etiological agent of dental caries and one of the many bacterial species implicated in infective endocarditis. The expression of the collagen-binding protein Cnm by S. mutans has been associated with extraoral infections, but its relevance for dental caries has only been theorized to date. Due to the collagenous composition of dentinal and root tissues, we hypothesized that Cnm may facilitate the colonization of these surfaces, thereby enhancing the pathogenic potential of S. mutans in advancing carious lesions. As shown for extraoral endothelial cell lines, Cnm mediates the invasion of oral keratinocytes and fibroblasts by S. mutans. In this study, we show that in the Cnm(+) native strain, OMZ175, Cnm mediates stringent adhesion to dentinal and root tissues as well as collagen-coated surfaces and promotes both cariogenicity and carriage in vivo. In vitro, ex vivo, and in vivo experiments revealed that while Cnm is not universally required for S. mutans cariogenicity, it contributes to (i) the invasion of the oral epithelium, (ii) enhanced binding on collagenous surfaces, (iii) implantation of oral biofilms, and (IV) the severity of caries due to a native Cnm(+) isolate. Taken together, our findings reveal that Cnm is a colonization factor that contributes to the pathogenicity of certain S. mutans strains in their native habitat, the oral cavity.

  14. Red fluorescent biofilm: the thick, the old, and the cariogenic

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    Catherine M.C. Volgenant

    2016-04-01

    Full Text Available Background: Some dental plaque fluoresces red. The factors involved in this fluorescence are yet unknown. Objective: The aim of this study was to assess systematically the effect of age, thickness, and cariogenicity on the extent of red fluorescence produced by in vitro microcosm biofilms. Design: The effects of biofilm age and thickness on red fluorescence were tested in a constant depth film fermentor (CDFF by growing biofilms of variable thicknesses that received a constant supply of defined mucin medium (DMM and eight pulses of sucrose/day. The influence of cariogenicity on red fluorescence was tested by growing biofilm on dentin disks receiving DMM, supplemented with three or eight pulses of sucrose/day. The biofilms were analyzed at different time points after inoculation, up to 24 days. Emission spectra were measured using a fluorescence spectrophotometer (λexc405 nm and the biofilms were photographed with a fluorescence camera. The composition of the biofilms was assessed using 454-pyrosequecing of the 16S rDNA gene. Results: From day 7 onward, the biofilms emitted increasing intensities of red fluorescence as evidenced by the combined red fluorescence peaks. The red fluorescence intensity correlated with biofilm thickness but not in a linear way. Biofilm fluorescence also correlated with the imposed cariogenicity, evidenced by the induced dentin mineral loss. Increasing the biofilm age or increasing the sucrose pulsing frequency led to a shift in the microbial composition. These shifts in composition were accompanied by an increase in red fluorescence. Conclusions: The current study shows that a thicker, older, or more cariogenic biofilm results in a higher intensity of red fluorescence.

  15. Red fluorescent biofilm: the thick, the old, and the cariogenic

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    Volgenant, Catherine M.C.; Hoogenkamp, Michel A.; Buijs, Mark J.; Zaura, Egija; ten Cate, Jacob (Bob) M.; van der Veen, Monique H.

    2016-01-01

    Background Some dental plaque fluoresces red. The factors involved in this fluorescence are yet unknown. Objective The aim of this study was to assess systematically the effect of age, thickness, and cariogenicity on the extent of red fluorescence produced by in vitro microcosm biofilms. Design The effects of biofilm age and thickness on red fluorescence were tested in a constant depth film fermentor (CDFF) by growing biofilms of variable thicknesses that received a constant supply of defined mucin medium (DMM) and eight pulses of sucrose/day. The influence of cariogenicity on red fluorescence was tested by growing biofilm on dentin disks receiving DMM, supplemented with three or eight pulses of sucrose/day. The biofilms were analyzed at different time points after inoculation, up to 24 days. Emission spectra were measured using a fluorescence spectrophotometer (λexc405 nm) and the biofilms were photographed with a fluorescence camera. The composition of the biofilms was assessed using 454-pyrosequecing of the 16S rDNA gene. Results From day 7 onward, the biofilms emitted increasing intensities of red fluorescence as evidenced by the combined red fluorescence peaks. The red fluorescence intensity correlated with biofilm thickness but not in a linear way. Biofilm fluorescence also correlated with the imposed cariogenicity, evidenced by the induced dentin mineral loss. Increasing the biofilm age or increasing the sucrose pulsing frequency led to a shift in the microbial composition. These shifts in composition were accompanied by an increase in red fluorescence. Conclusions The current study shows that a thicker, older, or more cariogenic biofilm results in a higher intensity of red fluorescence. PMID:27060056

  16. In vitro antibacterial activity and major bioactive components of Cinnamomum verum essential oils against cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus

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    Okhee Choi

    2016-04-01

    Conclusions: The essential oil of C. verum and its major component cinnamaldehyde possessed considerable in vitro antibacterial activities against cariogenic bacteria, S. mutans and S. sobrinus strains. These results showed that the essential oil of C. verum and its bioactive component, cinnamaldehyde, have potential for application as natural agents for the prevention and treatment of dental caries.

  17. Comparison of Antibacterial Effect of Fluoride and Chlorhexidine on Two Cariogenic Bacteria: An in Vitro Study

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    Poureslami HR

    2014-09-01

    Full Text Available Statement of problem: Dental plaque is the main source for dental caries and there is no proper vaccine that can affect dental plaques. Objectives: Daily use of an efficient anti-plaque product can be very beneficial in plaque control and, thus, prevention of caries. This study aims to evaluate the antibacterial effects of four products of Chlorhexidine and Fluoride on two types of cariogenic bacteria. Materials and Methods: In this in vitro study, the antibacterial effect of Chlorhexidine and Fluoride (gel and solution against Streptococci Sanguis and Sobrinus was evaluated. Chlorhexidine gluconate 1% gel (Corosodyl, France, Chlorhexidine gluconate 2% solution (Consepsis, Ultradent, US, Sodium fluoride 0.2% solution (Oral-B, US and Acidulated Phosphate Fluoride 1.23% gel ( Denti-Care, Canada were used. The disc diffusion method was used for testing bacterial sensitivity. The data were analyzed using paired t-test and Chi-square test. Results: In comparison with the negative control, each of the four gels and solutions showed antibacterial effects but the effects were not statistically significant for fluoride solution (P=0.217. For S. Sobrinus, the mean diameter of inhibition zone around the discs coated with fluoride gel (F g, fluoride solution (F s, Chlorhexidine gel (CHX g and Chlorhexidine solution (CHX s were 19, 9, 21.5 and 27.5mm, respectively. For S. Sanguis, the mean diameter of inhibition zone around the discs coated with F g, F s, CHX g and CHX s were 17, 11, 17 and 25mm, respectively. CHX s had the most effect on both bacteria and F s had the least. CHX g and F g were less effective than CHX s, respectively. Conclusion: The results demonstrated that 2% CHX s and 1.23% F g can be effective on inhibition of the growth of some of cariogenic bacteria. Therefore, these agents can be used in the prevention of Early Childhood Caries.

  18. Antimicrobial activity of different disinfectants against cariogenic microorganisms

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    Esra UZER CELIK

    Full Text Available Abstract The aim of this study was to assess the in vitro antimicrobial effects of chlorhexidine digluconate (CHX, polyhexamethylene biguanide (PHBM, and octenidine dihydrochloride (OCT on cariogenic microorganisms by using their minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC. CHX, PHBM, and OCT were diluted in distilled water to the final test concentrations. Using the in-tube dilution method, Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus rhamnosus, and Actinomyces viscosus were cultivated on blood agar and Mueller–Hinton broth (MHB at 37°C for 48 h. They were read using a spectrophotometer to detect MIC. To determine MBC, samples in the range of the turbidity threshold after 24 h were transferred onto blood agar and evaluated for growth after 24 h. Different MICs and MBCs were observed in all disinfectants against each microorganism. The lowest MIC and MBC against S. mutans (60 mg/L were obtained from PHBM. The lowest values against L. rhamnosus (15 mg/L, 30 mg/L, A. viscosus (30 mg/L, and L. acidophilus (15 mg/L, 30 mg/L were determined by OCT. PHBM and OCT have the potential to be replaced with CHX because they were effective against cariogenic microorganisms.

  19. Plant Polyphenols and Their Anti-Cariogenic Properties: A Review

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    Gabriele Pinto

    2011-02-01

    Full Text Available Polyphenols constitute one of the most common groups of substances in plants. Polyphenolic compounds have been reported to have a wide range of biological activities, many of which are related to their conventional antioxidant action; however, increasing scientific knowledge has highlighted their potential activity in preventing oral disease, including the prevention of tooth decay. The aim of this review is to show the emerging findings on the anti-cariogenic properties of polyphenols, which have been obtained from several in vitro studies investigating the effects of these bioactive molecules against Streptococcus mutans, as well as in vivo studies. The analysis of the literature supports the anti-bacterial role of polyphenols on cariogenic streptococci, suggesting (1 a direct effect against S. mutans; (2 an interaction with microbial membrane proteins inhibiting the adherence of bacterial cells to the tooth surface; and (3 the inhibition of glucosyl transferase and amylase. However, more studies, particularly in vivo and in situ, are necessary to establish conclusive evidence for the effectiveness and the clinical applications of these compounds in the prevention of dental caries. It is essential to better determine the nature and distribution of these compounds in our diet and to identify which of the hundreds of existing polyphenols are likely to provide the greatest effects.

  20. Efficacy of Miswak toothpaste and mouthwash on cariogenic bacteria

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    Al-Dabbagh, Samim A.; Qasim, Huda J.; Al-Derzi, Nadia A.

    2016-01-01

    Objectives: To evaluate the efficacy of Salvadora persica (Miswak) products on cariogenic bacteria in comparison with ordinary toothpaste. Methods: The study was conducted in Zakho city, Kurdistan region, Iraq during the period from October 2013 to January 2014. A randomized controlled clinical trial of 40 students randomly allocated into 4 groups. They were instructed to use Mismark toothpaste, Miswak mouthwash, and ordinary toothpaste with water or with normal saline. Salivary samples were collected at 3-time intervals: before, immediately after use, and after 2 weeks of use. The effect of each method on Streptococcus mutans and Lactobacilli was evaluated by using caries risk test. Results: One-way repeated measure analysis of variance (ANOVA), one-way ANOVA, and least significant difference tests were used. Miswak wash has a significant reduction effect on both bacteria immediately and after 2 weeks of use. Miswak paste has a similar effect on Lactobacilli, while Streptococcus mutans showed a significant decrease only after 2 weeks of use. Ordinary paste showed a non significant effect on both bacteria at both time intervals; while the addition of normal saline showed a significant effect on both bacteria only after 2 weeks of use. Conclusion: Miswak products, especially mouth wash, were more effective in reducing the growth of cariogenic bacteria than ordinary toothpaste. PMID:27570858

  1. Is Stevia rebaudiana Bertoni a Non Cariogenic Sweetener? A Review.

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    Ferrazzano, Gianmaria Fabrizio; Cantile, Tiziana; Alcidi, Brunella; Coda, Marco; Ingenito, Aniello; Zarrelli, Armando; Di Fabio, Giovanni; Pollio, Antonino

    2015-12-26

    Stevia rebaudiana Bertoni is a small perennial shrub of the Asteraceae (Compositae) family that is native to South America, particularly Brazil and Paraguay, where it is known as "stevia" or "honey leaf" for its powerful sweetness. Several studies have suggested that in addition to their sweetness, steviosides and their related compounds, including rebaudioside A and isosteviol, may offer additional therapeutic benefits. These benefits include anti-hyperglycaemic, anti-hypertensive, anti-inflammatory, anti-tumor, anti-diarrheal, diuretic, and immunomodulatory actions. Additionally, critical analysis of the literature supports the anti-bacterial role of steviosides on oral bacteria flora. The aim of this review is to show the emerging results regarding the anti-cariogenic properties of S. rebaudiana Bertoni. Data shown in the present paper provide evidence that stevioside extracts from S. rebaudiana are not cariogenic. Future research should be focused on in vivo studies to evaluate the effects on dental caries of regular consumption of S. rebaudiana extract-based products.

  2. Is Stevia rebaudiana Bertoni a Non Cariogenic Sweetener? A Review

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    Gianmaria Fabrizio Ferrazzano

    2015-12-01

    Full Text Available Stevia rebaudiana Bertoni is a small perennial shrub of the Asteraceae (Compositae family that is native to South America, particularly Brazil and Paraguay, where it is known as “stevia” or “honey leaf” for its powerful sweetness. Several studies have suggested that in addition to their sweetness, steviosides and their related compounds, including rebaudioside A and isosteviol, may offer additional therapeutic benefits. These benefits include anti-hyperglycaemic, anti-hypertensive, anti-inflammatory, anti-tumor, anti-diarrheal, diuretic, and immunomodulatory actions. Additionally, critical analysis of the literature supports the anti-bacterial role of steviosides on oral bacteria flora. The aim of this review is to show the emerging results regarding the anti-cariogenic properties of S. rebaudiana Bertoni. Data shown in the present paper provide evidence that stevioside extracts from S. rebaudiana are not cariogenic. Future research should be focused on in vivo studies to evaluate the effects on dental caries of regular consumption of S. rebaudiana extract-based products.

  3. Functional Relationship between Sucrose and a Cariogenic Biofilm Formation.

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    Jian-Na Cai

    Full Text Available Sucrose is an important dietary factor in cariogenic biofilm formation and subsequent initiation of dental caries. This study investigated the functional relationships between sucrose concentration and Streptococcus mutans adherence and biofilm formation. Changes in morphological characteristics of the biofilms with increasing sucrose concentration were also evaluated. S. mutans biofilms were formed on saliva-coated hydroxyapatite discs in culture medium containing 0, 0.05, 0.1, 0.5, 1, 2, 5, 10, 20, or 40% (w/v sucrose. The adherence (in 4-hour biofilms and biofilm composition (in 46-hour biofilms of the biofilms were analyzed using microbiological, biochemical, laser scanning confocal fluorescence microscopic, and scanning electron microscopic methods. To determine the relationships, 2nd order polynomial curve fitting was performed. In this study, the influence of sucrose on bacterial adhesion, biofilm composition (dry weight, bacterial counts, and water-insoluble extracellular polysaccharide (EPS content, and acidogenicity followed a 2nd order polynomial curve with concentration dependence, and the maximum effective concentrations (MECs of sucrose ranged from 0.45 to 2.4%. The bacterial and EPS bio-volume and thickness in the biofilms also gradually increased and then decreased as sucrose concentration increased. Furthermore, the size and shape of the micro-colonies of the biofilms depended on the sucrose concentration. Around the MECs, the micro-colonies were bigger and more homogeneous than those at 0 and 40%, and were surrounded by enough EPSs to support their structure. These results suggest that the relationship between sucrose concentration and cariogenic biofilm formation in the oral cavity could be described by a functional relationship.

  4. Streptococcus oligofermentans inhibits Streptococcus mutans in biofilms at both neutral pH and cariogenic conditions

    NARCIS (Netherlands)

    Bao, X.; de Soet, J.J.; Tong, H.; Gao, X.; He, L.; van Loveren, C.; Deng, D.M.

    2015-01-01

    Homeostasis of oral microbiota can be maintained through microbial interactions. Previous studies showed that Streptococcus oligofermentans, a non-mutans streptococci frequently isolated from caries-free subjects, inhibited the cariogenic Streptococcus mutans by the production of hydrogen peroxide (

  5. The effect of eugenol on the cariogenic properties of Streptococcus mutans and dental caries development in rats.

    Science.gov (United States)

    Xu, Jing-Shu; Li, Yao; Cao, Xue; Cui, Yun

    2013-06-01

    Eugenol has been widely used in medicine due to its antibacterial, anti-inflammatory, antioxidant, anticancer and analgesic properties. The present study was designed to investigate the effects of eugenol on the cariogenic properties of Streptococcus mutans and dental caries development in rats. Eugenol demonstrated significant inhibitory effects against acid production by S. mutans. The synthesis of water-insoluble glucans by glucosyltransferases was reduced by eugenol. Eugenol also markedly suppressed the adherence of S. mutans to saliva-coated hydroxyapatite beads. Furthermore, topical application of eugenol reduced the incidence and severity of carious lesions in rats. These results suggest that the natural compound eugenol may be a useful therapeutic agent for dental caries.

  6. Evaluation of antibacterial efficiency of chitosan and chitosan nanoparti- cles on cariogenic streptococci: an in vitro study

    Directory of Open Access Journals (Sweden)

    Azam Aliasghari

    2016-05-01

    Full Text Available Background and Objectives: The most prevalent and worldwide oral disease is dental caries that affects a significant pro- portion of the world population. There are some classical approaches for control, prevention and treatment of this pathologic condition; however, the results are still not completely successful. Therefore new methods are needed for better management of this important challenge. Chitosan is a natural and non-toxic polysaccharide with many biological applications, particu- larly as an antimicrobial agent. Chitosan nanoparticle is a bioactive and environment friendly material with unique physico- chemical properties. The aim of the present study was to investigate the antimicrobial effect of chitosan and nano-chitosan on the most important cariogenic streptococci.Materials and Methods: For evaluation of antimicrobial effect of chitosan and nano-chitosan against oral streptococci broth micro-dilution method was carried out for four bacterial species; Streptococcus mutans, Streptococcus sobrinus, Streptococ- cus sanguis and Streptococcus salivarius. Also the effect of these materials on adhesion of above bacteria was evaluated. One-way ANOVA and post hoc Tukey test were used for statistical analysis.Results: The MICs of chitosan for S. mutans, S. sanguis, S. salivarius and S. sobrinus were 1.25, 1.25, 0.625 and 0.625 mg/ mL, respectively. The MIC of chitosan nanoparticle for S. mutans, S. salivarius and S. sobrinus was 0.625 mg/mL and for S. sanguis was 0.312 mg/mL. Chitosan and chitosan nanoparticles at a concentration of 5 mg/mL also reduced biofilm forma- tion of S. mutans up to 92.5% and 93.4%, respectively.Conclusion:  Te results of this study supported the use of chitosan and chitosan nanoparticles as antimicrobial agents against cariogenic Streptococci.

  7. Streptococcus mutans-derived extracellular matrix in cariogenic oral biofilms.

    Science.gov (United States)

    Klein, Marlise I; Hwang, Geelsu; Santos, Paulo H S; Campanella, Osvaldo H; Koo, Hyun

    2015-01-01

    Biofilms are highly structured microbial communities that are enmeshed in a self-produced extracellular matrix. Within the complex oral microbiome, Streptococcus mutans is a major producer of extracellular polymeric substances including exopolysaccharides (EPS), eDNA, and lipoteichoic acid (LTA). EPS produced by S. mutans-derived exoenzymes promote local accumulation of microbes on the teeth, while forming a spatially heterogeneous and diffusion-limiting matrix that protects embedded bacteria. The EPS-rich matrix provides mechanical stability/cohesiveness and facilitates the creation of highly acidic microenvironments, which are critical for the pathogenesis of dental caries. In parallel, S. mutans also releases eDNA and LTA, which can contribute with matrix development. eDNA enhances EPS (glucan) synthesis locally, increasing the adhesion of S. mutans to saliva-coated apatitic surfaces and the assembly of highly cohesive biofilms. eDNA and other extracellular substances, acting in concert with EPS, may impact the functional properties of the matrix and the virulence of cariogenic biofilms. Enhanced understanding about the assembly principles of the matrix may lead to efficacious approaches to control biofilm-related diseases.

  8. Streptococcus mutans-derived extracellular matrix in cariogenic oral biofilms

    Directory of Open Access Journals (Sweden)

    Marlise eKlein

    2015-02-01

    Full Text Available Biofilms are highly structured microbial communities that are enmeshed in a self-produced extracellular matrix. Within the complex oral microbiome, Streptococcus mutans is a major producer of extracellular polymeric substances including exopolysaccharides (EPS, eDNA and lipoteichoic acid (LTA. EPS produced by S. mutans-derived exoenzymes promote local accumulation of microbes on the teeth, while forming a spatially heterogeneous and diffusion-limiting matrix that protects embedded bacteria. The EPS-rich matrix provides mechanical stability/cohesiveness and facilitates the creation of highly acidic microenvironments, which are critical for the pathogenesis of dental caries. In parallel, S. mutans also releases eDNA and LTA, which can contribute with matrix development. eDNA enhances EPS (glucan synthesis locally, increasing the adhesion of S. mutans to saliva-coated apatitic surfaces and the assembly of highly cohesive biofilms. eDNA and other extracellular substances, acting in concert with EPS, may impact the functional properties of the matrix and the virulence of cariogenic biofilms. Enhanced understanding about the assembly principles of the matrix may lead to efficacious approaches to control biofilm-related diseases.

  9. STUDY ON ADHERENCE ABILITY OF PERIODONTAL PATHOGENS AND CARIOGENIC BACTERIA TO HYDROXYAPATITE DISKS

    Institute of Scientific and Technical Information of China (English)

    WANG Min-feng; LI De-yi; LI Zong-lin

    2006-01-01

    Objective To study the adherence activity of six representative periodontopathic and cariogenic bacteria to hydroxyapatite disks. Methods Six periodontopathic and cariogenic bacteria of P. gingivalis, A.actinomycetemcomitans, F. nucleatum, S. sanguis, A. viscosus and S. mutans were cultured in modified MD-300 chemostat according to total fifteen experimental groups of single-specie and each pair of periodontal pathogens and cariogenic bacteria, respectively. After 1h attached live bacteria on removable hydroxyapatite disks was analyzed by culture technologies to evaluate the adherence level. Results The adherence activity of periodontopathic and cariogenic bacteria to HA was in the following order: S. sanguis > A. viscosus > S. mutans > A. actinomycetemcomitans > F. nucleatum > P. gingivalis. The number of periodontopathic bacteria to HA was enhanced by S.sanguis and A. viscosus, respectively. When mix-cultivated with S. mutans, the colonization of P. gingivalis was reduced significantly( P<0.001 ). Periodontopathic bacteria had no effect on the adherence activity of S. mutans and A. viscosus, except S. sanguis. Conclusion It was showed that the adherence activity of periodontal pathogens was weaker than that of cariogenic bacteria and emphasized the importance of bacterial adherence in determining the level of bacterial colonization on tooth surfaces. It was suggested that periodontopathic bacteria can utilize initial colonizers to become those predominant bacteria in periodontal ecosystem, which maybe have close relation to the periodontopathic mechanism.

  10. The influence of biosurfactants released by S-mitis BMS on the adhesion of pioneer strains and cariogenic bacteria

    NARCIS (Netherlands)

    Van Hoogmoed, CG; Van der Mei, HC; Busscher, HJ

    2004-01-01

    The influence of Streptococcus mitis BMS biosurfactants on the adhesion of eight pioneer and four cariogenic oral bacterial strains was, for a first screening, examined in a microtiter plate assay. The adhesion to pellicle-coated wells of three cariogenic strains was inhibited >70% by the biosurfact

  11. Cariogenic microbiota of children under chemotherapy: A pilot study

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    Luiz Evaristo Ricci Volpato

    2016-01-01

    Full Text Available Aim: To analyze the cariogenic microbiota of children who are under antineoplastic therapy. Methods: Twenty-seven patients undergoing cancer treatment in the Pediatric Unit of Mato Grosso Cancer Hospital were selected. The inclusion criteria of volunteers were being under chemotherapy in the saliva collection period, age between 2 and 18 years, collaborate with the protocol for clinical examination and saliva collection, and responsible have given their written consent. For the realization of lactobacilli and Streptococcus mutans count in the patients′ saliva, respectively, Dentalcult I and II (LaborClin; kits were used. Statistical Analysis: Kruskal-Wallis and Fisher′s exact tests were used to assess the association of the variables age group, prevalence of lactobacilli and S. mutans, diagnosis of patients, presence and level of decay of patients defined by decayed, filled, and missing teeth (DMFT/dmft indexes with a significance level of 5%. Results: The group of patients consisted of 27 children, 15 males, and 12 females; 44% were aged between 6 and 10 years; 61% had present or past history of caries (dmft/DMFT >0; 48% had low value for Dentalcult I; 59% presented value grade 0 to Dentalcult II; and 63% were diagnosed with acute lymphoid leukemia. Conclusion: There was a high prevalence of dental caries in the study population but low rates of S. mutans and lactobacilli in the saliva of the children. Lactobacilli rate was significantly associated with caries index scores, and the prevalence of caries was directly associated with the age group of the children.

  12. Food expenditures, cariogenic dietary practices and childhood dental caries in southern Brazil.

    Science.gov (United States)

    Feldens, C A; Rodrigues, P H; Rauber, F; Chaffee, B W; Vitolo, M R

    2013-01-01

    Family expenditures on food for children may represent an important barrier to the adoption of healthy feeding practices in populations of low socioeconomic status. The aim of this study was to explore the relationship between cariogenic feeding practices, expenditures on food for children and dental caries. This cross-sectional study included 329 four-year-old children from São Leopoldo in southern Brazil. Cariogenic dietary practices were assessed at 4 years of age using two 24-hour recalls conducted with the children's mothers. Expenditures on food for children were estimated based on all reported food items and the respective amounts ingested. Early childhood caries and severe early childhood caries were assessed by clinical examination at 4 years of age. Cariogenic dietary habits were not associated with lower food expenditures. On the contrary, in multivariable regression analysis, the intake of chocolate (p = 0.007), soft drinks (p = 0.027) and a higher number of meals and snacks per day (p food for children. No statistically significant differences were observed in food expenditures or in the proportion of household income spent on feeding children between caries-free children, those with early childhood caries and those with severe early childhood caries. In conclusion, keeping children free of dental caries does not necessarily increase food expenditures or the proportion of household income spent on feeding children in low-socioeconomic status populations. Some cariogenic dietary practices were associated with greater expenditures on child feeding.

  13. Comparing the cariogenic species Streptococcus sobrinus and S. mutans on whole genome level

    NARCIS (Netherlands)

    Conrads, G.; de Soet, J.J.; Song, L.; Henne, K.; Sztajer, H.; Wagner-Döbler, I.; Zeng, A.P.

    2014-01-01

    Background: Two closely related species of mutans streptococci, namely Streptococcus mutans and Streptococcus sobrinus, are associated with dental caries in humans. Their acidogenic and aciduric capacity is directly associated with the cariogenic potential of these bacteria. To survive acidic and te

  14. Identification of ssDNA aptamers specific to clinical isolates of Streptococcus mutans strains with different cariogenicity.

    Science.gov (United States)

    Cui, Wei; Liu, Jiaojiao; Su, Donghua; Hu, Danyang; Hou, Shuai; Hu, Tongnan; Yang, Jiyong; Luo, Yanping; Xi, Qing; Chu, Bingfeng; Wang, Chenglong

    2016-06-01

    Streptococcus mutans, a Gram-positive facultative anaerobic bacterium, is considered to be a major etiological factor for dental caries. In this study, plaques from dental enamel surfaces of caries-active and caries-free individuals were obtained and cultivated for S. mutans isolation. Morphology examination, biochemical characterization, and polymerase chain reaction were performed to identify S. mutans The cariogenicity of S. mutans strains isolated from clinical specimens was evaluated by testing the acidogenicity, aciduricity, extracellular polysaccharide production, and adhesion ability of the bacteria. Finally, subtractive SELEX (systematic evolution of ligands by exponential enrichment) technology targeting whole intact cells was used to screen for ssDNA aptamers specific to the strains with high cariogenicity. After nine rounds of subtractive SELEX, sufficient pool enrichment was achieved as shown by radioactive isotope analysis. The enriched pool was cloned and sequenced randomly, followed by MEME online and RNA structure software analysis of the sequences. Results from the flow cytometry indicated that aptamers H1, H16, H4, L1, L10, and H19 could discriminate highly cariogenic S. mutans strains from poorly cariogenic strains. Among these, Aptamer H19 had the strongest binding capacity with cariogenic S. mutans strains with a dissociation constant of 69.45 ± 38.53 nM. In conclusion, ssDNA aptamers specific to highly cariogenic clinical S. mutans strains were successfully obtained. These ssDNA aptamers might be used for the early diagnosis and treatment of dental caries.

  15. Pulp response to, and cariogenicity of, a further strain of Streptococcus mutans (NCTC 10832).

    Science.gov (United States)

    Watts, A; Paterson, R C

    1992-05-01

    The pulpal response to and cariogenicity of a third strain of Streptococcus mutans, namely S. mutans (NCTC 10832), was studied in monoinfected gnotobiotic rats of the Fischer strain using the techniques described previously by the present authors. Unlike S. mutans (NCTC 10449 and 10919), S. mutans (NCTC 10832) was associated with the presence of inflammatory cell infiltrates in the coronal pulp of a small number of teeth and extensive periapical inflammation 28 days after the creation of untreated pulpal exposures. S. mutans (NCTC 10832) was associated with the presence of extensive pulpal necrosis and reduced dentine bridge formation. These changes were similar to those noted with the other two strains of S. mutans. S. mutans (NCTC 10832) was non-cariogenic in monoinfected gnotobiotic rats of the Fischer strain.

  16. Anti-cariogenic effects of polyphenols from plant stimulant beverages (cocoa, coffee, tea).

    Science.gov (United States)

    Ferrazzano, Gianmaria F; Amato, Ivana; Ingenito, Aniello; De Natale, Antonino; Pollio, Antonino

    2009-07-01

    Polyphenols occurring in cocoa, coffee and tea can have a role in the prevention of cariogenic processes, due to their antibacterial action. Cocoa polyphenol pentamers significantly reduce biofilm formation and acid production by Streptococcus mutans and S. sanguinis. In the same way, trigonelline, caffeine and chlorogenic acid occurring in green and roasted coffee interfere with S. mutans adsorption to saliva-coated hydroxyapatite beads. Studies carried out on green, oolong and black tea indicate that tea polyphenols exert an anti-caries effect via an anti-microbial mode-of-action, and galloyl esters of (-)-epicatechin, (-)-epigallocatechin and (-)-gallocatechin show increasing antibacterial activities. The anti-cariogenic effects against alpha-haemolytic streptococci showed by polyphenols from cocoa, coffee, and tea suggest further studies to a possible application of these beverages in the prevention of pathogenesis of dental caries.

  17. ANTI-CARIOGENIC EFFECTS OF POLYPHENOL PLANT PRODUCTS-A REVIEW

    Directory of Open Access Journals (Sweden)

    Parashar Kshitiz

    2011-03-01

    Full Text Available Polyphenols occurring in Grape seeds, cocoa, coffee and tea can have a role in the prevention of cariogenic processes, due to their antibacterial action. Cocoa polyphenol pentamers significantly reduce biofilm formation and acid production by Streptococcus mutans and S. sanguinis. In the same way, trigonelline, caffeine and chlorogenic acid occurring in green and roasted coffee interfere with S. mutans adsorption to saliva-coated hydroxyapatite beads. Studies carried out on green oolong tea and black tea indicate that tea polyphenols exert an anti-caries effect via an anti- microbial mode-of-action, and galloyl esters of epicatechin, epigallocatechin and gallocatechin showed increasing antibacterial activities. The anti-cariogenic effects against streptococci showed by polyphenols from cocoa, coffee, and tea suggest further studies to a possible application of these beverages in the prevention of pathogenesis of dental caries.

  18. Evaluation of the cariogenic potential of the intense natural sweeteners stevioside and rebaudioside A.

    Science.gov (United States)

    Das, S; Das, A K; Murphy, R A; Punwani, I C; Nasution, M P; Kinghorn, A D

    1992-01-01

    Stevioside and rebaudioside A, two intense natural sweeteners, that are constituents of the South American plant Stevia rebaudiana, were tested for cariogenicity in albino Sprague-Dawley rats. Sixty rat pups colonized with Streptococcus sobrinus were divided into four groups and fed stevioside, rebaudioside A or sucrose added to basal diet 2000 as follows: group 1, 30% sucrose; group 2, 0.5% stevioside; group 3, 0.5% rebaudioside A, and group 4, no addition. All four groups were sacrificed after 5 weeks. S. sobrinus counts were made and caries was evaluated according to Keyes' technique. There were no differences in food and water intake and weight gains between the four groups. There were significant differences in sulcal caries scores (p rebaudioside A and no-addition groups. It was concluded that neither stevioside nor rebaudioside A is cariogenic under the conditions of this study.

  19. Cariogenicity of a lactate dehydrogenase-deficient mutant of Streptococcus mutans serotype c in gnotobiotic rats.

    Science.gov (United States)

    Fitzgerald, R J; Adams, B O; Sandham, H J; Abhyankar, S

    1989-03-01

    A lactate dehydrogenase-deficient (Ldh-) mutant of a human isolate of Streptococcus mutans serotype c was tested in a gnotobiotic rat caries model. Compared with the wild-type Ldh-positive (Ldh+) strains, it was significantly (alpha less than or equal to 0.005) less cariogenic in experiments with two different sublines of Sprague-Dawley rats. The Ldh- mutant strain 044 colonized the oral cavity of the test animals to the same extent as its parent strain 041, although its initial implantation was slightly but not significantly (P greater than or equal to 0.2) less. Multiple oral or fecal samples plated on 2,3,5-triphenyltetrazolium indicator medium revealed no evidence of back mutation from Ldh- to Ldh+ in vivo. Both Ldh+ strain 041 and Ldh- strain 044 demonstrated bacteriocinlike activity in vitro against a number of human strains of mutans streptococci representing serotype a (S. cricetus) and serotypes c and e (S. mutans). Serotypes b (S. rattus) and f (S. mutans) and strains of S. mitior, S. sanguis, and S. salivarius were not inhibited. Thus, Ldh mutant strain 044 possesses a number of desirable traits that suggest it should be investigated further as a possible effector strain for replacement therapy of dental caries. These traits include its stability and low cariogenicity in the sensitive gnotobiotic rat caries model, its bacteriocinlike activity against certain other cariogenic S. mutans (but not against more inocuous indigenous oral streptococci), and the fact that it is a member of the most prevalent human serotype of cariogenic streptococci.

  20. In vitro antibacterial activity of Camellia sinensis extract against cariogenic microorganisms

    OpenAIRE

    Anita, P.; Sivasamy, Shyam; Madan Kumar, P. D.; Balan, I. Nanda; Ethiraj, Sumathi

    2014-01-01

    Context: Dental caries, a ubiquitous multifactorial infectious disease, is primarily caused by microorganisms like Streptococcus mutans and Lactobacillus acidophilus. Use of antimicrobials is an important strategy to curb cariogenic microorganisms. Aim: The aim was to evaluate the in vitro antimicrobial activity of C. sinensis extract on S. mutans and L. acidophilus. Study Setting and Design: Experimental design, in vitro study, lab setting. Materials and Methods: Aqueous, acetone and ethanol...

  1. Inhibition of Cariogenic Plaque Formation on Root Surface with Polydopamine-Induced-Polyethylene Glycol Coating

    Directory of Open Access Journals (Sweden)

    May Lei Mei

    2016-05-01

    Full Text Available Root caries prevention has been a challenge for clinicians due to its special anatomical location, which favors the accumulation of dental plaque. Researchers are looking for anti-biofouling material to inhibit bacterial growth on exposed root surfaces. This study aimed to develop polydopamine-induced-polyethylene glycol (PEG and to study its anti-biofouling effect against a multi-species cariogenic biofilm on the root dentine surface. Hydroxyapatite disks and human dentine blocks were divided into four groups for experiments. They received polydopamine-induced-PEG, PEG, polydopamine, or water application. Contact angle, quartz crystal microbalance, and Fourier transform infrared spectroscopy were used to study the wetting property, surface affinity, and an infrared spectrum; the results indicated that PEG was induced by polydopamine onto a hydroxyapatite disk. Salivary mucin absorption on hydroxyapatite disks with polydopamine-induced-PEG was confirmed using spectrophotometry. The growth of a multi-species cariogenic biofilm on dentine blocks with polydopamine-induced-PEG was assessed and monitored by colony-forming units, confocal laser scanning microscopy, and scanning electron microscopy. The results showed that dentine with polydopamine-induced-PEG had fewer bacteria than other groups. In conclusion, a novel polydopamine-induced-PEG coating was developed. Its anti-biofouling effect inhibited salivary mucin absorption and cariogenic biofilm formation on dentine surface and thus may be used for the prevention of root dentine caries.

  2. Comparative study of preventive protocols in children at high cariogenic risk.

    Science.gov (United States)

    Martínez, María C; Tolcachir, Betina; Lescano de Ferrer, Alfonsina; Bojanich, María A; Barembaum, Silvina R; Calamari, Silvia E; Azcurra, Ana I

    2012-01-01

    The aim of this study was to compare the efficacy of two preventive protocols -fluoride gel (F) alone or combined with chlorhexidine varnishes (CHX) - on sialochemical, clinical and microbiological parameters in a group of children at high cariogenic risk Two therapeutic-preventive protocols were applied in 73 children at high cariogenic risk (average age 6.2 +/- 1.4 years old) and clinical parameters (simplified oral hygiene index: OHI-S; decayed, missing and filled teeth: dmf index; sugar intake and exposure to fluoride), as well as sialochemical parameters (salivary pH and flow, buffer capacity) and microbiological parameters (CFU/mg of dental biofilm of Streptococcus mutans group) were recorded and correlated before and after the protocols. Association was found between parameters that cause deficient control of dental biofilm: high values of OHIS index, CFU/mg dental biofilm, sugar intake and the d component of dmft index, and lower values of salivary flow rate and buffer capacity. After the protocols, a significant decrease was found in OHI-S and CFU/mg dental biofilm. No significant difference was found with children's gender and age. The association observed between OHI-S and cariogenic bacteria emphasizes the importance of prevention, especially regarding the oral health of the most vulnerable children. The early inclusion of F associated with CHX in the initial step of preventive and therapeutic protocols would provide benefits regarding oral microbe control while children acquire new habits of oral hygiene.

  3. In vitro antibacterial activity and major bioactive components of Cinnamomum verum essential oils against cariogenic bacteria,Streptococcus mutans and Streptococcus sobrinus

    Institute of Scientific and Technical Information of China (English)

    Okhee Choi; Su Kyung Cho; Junheon Kim; Chung Gyoo Park; Jinwoo Kim

    2016-01-01

    Objective:To evaluate the antibacterial activity of Cinnamomum verum(C.verum) from32 different essential oils against cariogenic bacteria,Streptococcus mutans(S.mutans)and Streptococcus sobrinus(S.sobrinus).Methods:The antibacterial activities of each essential oil were individually investigated against S.mutans and S.sobrinus.The essential oil of C.verum was selected for further evaluation against S.mutans and S.sobrinus.Gas chromatography mass spectrometry was used to determine the major constituents of C.verum essential oil.In addition,the minimum inhibitory concentration(MIC) and minimum bactericidal concentration of the most effective constituent was investigated.Results:The essential oil from C.verum exhibited the greatest antibacterial activity.Gas chromatography mass spectrometry analysis revealed that the major components of C.verum essential oil were cinnamaldehyde(56.3%),cinnamyl acetate(7.1%) and bphellandrene(6.3%).The MIC of cinnamaldehyde was measured using broth dilution assays.The MIC of cinnamaldehyde was 0.02%(v/v) against both bacterial strains tested.The minimum bactericidal concentration of cinnamaldehyde against S.mutans and S.sobrinus were 0.2% and 0.1%(v/v),respectively.Conclusions:The essential oil of C.verum and its major component cinnamaldehyde possessed considerable in vitro antibacterial activities against cariogenic bacteria,S.mutans and S.sobrinus strains.These results showed that the essential oil of C.verum and its bioactive component,cinnamaldehyde,have potential for application as natural agents for the prevention and treatment of dental caries.

  4. Study of surface alterations of composite and ionomeric materials submitted to simulation of a high cariogenic challenge

    Directory of Open Access Journals (Sweden)

    VIEIRA Alexandre Rezende

    1999-01-01

    Full Text Available We evaluated the surface of composite resins and glass-ionomer cements in a situation of high cariogenic challenge. Based on seventy-five standard test specimens of one glass-ionomer cement (Chelon Fil - ESPE, one resin-modified glass-ionomer (Vitremer - 3M, two polyacid-modified composite (VariGlass and Dyract - Dentsply and one composite resin (Heliomolar - Vivadent, submitted to fourteen days of demineralization and remineralization cycling to simulate a high cariogenic challenge, the erosive aspects of the surface of the materials were assessed. All of the samples were evaluated by scanning electronic microscope and compared with another five test specimens of each material, prepared in the same way and serving as control. All of the materials studied suffered erosive action by the media, with different characteristics due to the different compositions, after being submitted to in vitro simulation of a high cariogenic challenge.

  5. COAGGREGATION AND COAGGREGATION INHIBITION BETWEEN PERIO-PATHOGENIC AND CARIOGENIC BACTERIA

    Institute of Scientific and Technical Information of China (English)

    FU Rao; LI De-yi

    2005-01-01

    Objective To screen the coaggregating pairs between perio-pathogenic and cariogenic bacteria and to investigate the susceptibility of these coaggregations to inhibitors. Methods 4 strains of perio-pathogenic bacteria, Fusobacterium nuleatum (Fn) ATCC 10953, Actinobacilllus actinomycetem comitans (Aa) Y4, Porphyromonas gingivalis (Pg) ATCC 33277,Prevotella intermedia (Pi) ATCC 25261 and 4 strains of cariogenic bacteria, Streptococcus mutans (Sm) Ingbritt, Streptococcus sanguis (Ss) 34, Actinomyces viscosus (Av) 19246 and Lactobacillus acidophilus (La) ATCC 4356 were used to determine the coaggregating degrees of various combinations of the above bacteria by a visual assay and a turbidimetric assay. Then more than +2(or 20%) coaggregation degrees' pairs were used to investigate the inhibitory effect of lactose and arginine and to identify the minimum of their coaggregation-inhibitory concentration. Results The coaggregation degrees of Fn-Av, Pg-Av, Fn-Sm, Fn-Ss, Fn-La and Pg-Ss pairs were higher than +2(20%). 3.0 ~ 6.0mmol/L of arginine were considerably effective to the above pairs except Fn-Av pair and the disaggregation degrees were 49% ~ 92%. The maximum of their disaggregation degree to Fn-Av pair was just 18%. 120 ~ 300mmol/L of lactose were significantly effective to Pg-Ss pair, the disaggregation degrees were 57% ~ 91%. They partially inhibited Pg-Av pair and were almost ineffective to Fn-G + pairs. Conclusion The coaggregations between perio-pathogenic and cariogenic bacteria are highly specific. Most of them are relatively sensitive to arginine.

  6. Cariogenicity of a lactate dehydrogenase-deficient mutant of Streptococcus mutans serotype c in gnotobiotic rats.

    OpenAIRE

    FitzGerald, R.J.; Adams, B. O.; Sandham, H. J.; Abhyankar, S

    1989-01-01

    A lactate dehydrogenase-deficient (Ldh-) mutant of a human isolate of Streptococcus mutans serotype c was tested in a gnotobiotic rat caries model. Compared with the wild-type Ldh-positive (Ldh+) strains, it was significantly (alpha less than or equal to 0.005) less cariogenic in experiments with two different sublines of Sprague-Dawley rats. The Ldh- mutant strain 044 colonized the oral cavity of the test animals to the same extent as its parent strain 041, although its initial implantation ...

  7. Preventive effect of fluoridated orthodontic resins subjected to high cariogenic challenges

    OpenAIRE

    Passalini,Paula; FIDALGO,Tatiana Kelly da Silva; Caldeira,Erika Machado; Gleiser,Rogerio; Nojima,Matilde da Cunha Gonçalves; Maia, Lucianne Cople

    2010-01-01

    The aim of the present study was to evaluate the in vitro caries preventive effect of fluoridated orthodontic resins under pH cycling with two types of acid demineralizing saliva. Brackets were bonded to 60 bovine incisors, using either Transbond Plus Color Change (n=30) or Orthodontic Fill Magic (n=30) orthodontic resins. Each group of resin was divided into 3 subgroups (n=10): immersion in remineralizing artificial saliva for 14 days, pH cycling with high cariogenic challenge in acid saliva...

  8. Efficacy of chemomechanical caries removal in reducing cariogenic microbiota: a randomized clinical trial

    Directory of Open Access Journals (Sweden)

    Michelle Mikhael AMMARI

    2014-08-01

    Full Text Available The aim of this study was to compare the efficacy of chemochemical methods (Carisolv™ and Papacárie® versus the manual method (excavators in reducing the cariogenic microbiota in dentine caries of primary teeth. Forty-six healthy children (5 to 9 years old having at least one primary tooth with a cavitated dentine carious lesion were included in the study. The teeth presented no clinical or radiographic signs of pulpal involvement. The sample of 74 teeth was randomly divided into three different groups: Papacárie® (n = 25, Carisolv™ (n = 27 and Manual (n = 22. Samples of carious and sound dentine were collected with sterile excavators before and after caries removal in the three groups. The dentine samples were transferred to glass tubes containing a 1mL thioglycollate medium used as a carrier and enriched for microbiological detection of mutans streptococci and Lactobacillus spp, after incubation for 6h at room temperature. The minimum detection value for colony forming units (CFU was 3.3 x 102 CFU/ml, and the results were converted into scores from 0 to 4. A significant difference was observed in relation to the microbiological scores before and after caries removal for all methods (Wilcoxon test; p < 0.001. The use of chemomechanical methods for caries removal did not improve the reduction of cariogenic microorganisms in dentine caries lesions, in comparison with manual excavation.

  9. Comparing the cariogenic species Streptococcus sobrinus and S. mutans on whole genome level

    Directory of Open Access Journals (Sweden)

    Georg Conrads

    2014-12-01

    Full Text Available Background: Two closely related species of mutans streptococci, namely Streptococcus mutans and Streptococcus sobrinus, are associated with dental caries in humans. Their acidogenic and aciduric capacity is directly associated with the cariogenic potential of these bacteria. To survive acidic and temporarily harsh conditions in the human oral cavity with hundreds of other microbial co-colonizers as competitors, both species have developed numerous mechanisms for adaptation. Objectives: The recently published novel genome information for both species is used to elucidate genetic similarities but especially differences and to discuss the impact on cariogenicity of the corresponding phenotypic properties including adhesion, carbohydrate uptake and fermentation, acid tolerance, signaling by two component systems, competence, and oxidative stress resistance. Conclusions: S. sobrinus can down-regulate the SpaA-mediated adherence to the pellicle. It has a smaller number of two-component signaling systems and bacteriocin-related genes than S. mutans, but all or even more immunity proteins. It lacks the central competence genes comC, comS, and comR. There are more genes coding for glucosyltransferases and a novel energy production pathway formed by lactate oxidase, which is not found in S. mutans. Both species show considerable differences in the regulation of fructan catabolism. However, both S. mutans and S. sobrinus share most of these traits and should therefore be considered as equally virulent with regard to dental caries.

  10. Cariogenic effects of probiotic Lactobacillus rhamnosus GG in a dental biofilm model.

    Science.gov (United States)

    Schwendicke, F; Dörfer, C; Kneist, S; Meyer-Lueckel, H; Paris, S

    2014-01-01

    Probiotic bacteria have been suggested to inhibit Streptococcus mutans (SM) and thus prevent dental caries. However, supporting evidence is weak and probiotic species might be cariogenic themselves. Thus, we compared and combined the probiotic Lactobacillus rhamnosus GG (LGG) with SM and analysed the resulting mineral loss (ΔZ) in dental tissues. We simulated three biofilm compositions (SM, LGG, SM × LGG), two lesion sites (smooth enamel, dentin cavity) and two nutrition supply frequencies (twice/day, 6 times/day) in a multi-station, continuous-culture biofilm model. A total of 240 bovine enamel and dentin samples were cut, polished and embedded. All experimental procedures were performed in independent duplicates, with 10 samples being allocated to each group for each experiment (final sample size n = 20/group). Biofilms were cultured on the specimens and supplied with 2% sucrose medium and artificial saliva in consecutive pulses. After 10 days, ΔZ and bacterial numbers were assessed. SM × LGG biofilms caused significantly increased ΔZ compared with SM or LGG biofilms (p biofilms of different species (p > 0.05, ANOVA). Frequent nutrition supply significantly increased bacterial numbers (p Biofilms in dentin cavities compared to smooth enamel harboured significantly more bacteria (p < 0.05). LGG induced mineral loss especially in dentin cavities and under highly cariogenic conditions. LGG did not have inhibitory effects on SM, but rather contributed to the caries process in vitro.

  11. A comparative study of the effect of probiotics on cariogenic biofilm model for preventing dental caries.

    Science.gov (United States)

    Lee, Sung-Hoon; Kim, Young-Jae

    2014-08-01

    Dental caries is induced by oral biofilm containing Streptococcus mutans. Probiotic bacteria were mainly studied for effect on the gastrointestinal tract and have been known to promote human health. However, the information of probiotics for oral health has been lack yet. In this study, we investigated influence of various probiotics on oral bacteria or cariogenic biofilm and evaluated candidate probiotics for dental caries among them. The antimicrobial activity of the spent culture medium of probiotics for oral streptococci was performed. Probiotics were added during the biofilm formation with salivary bacteria including S. mutans. The oral biofilms were stained with a fluorescent dye and observed using the confocal laser scanning microscope. To count bacteria in the biofilm, the bacteria were plated on MSB and BHI agar plates after disrupting the biofilm and cultivated. Glucosyltransferases (gtfs) expression of S. mutans and integration of lactobacilli into the biofilm were evaluated by real-time RT-PCR. Among probiotics, Lactobacillus species strongly inhibited growth of oral streptococci. Moreover, Lactobacillus species strongly inhibited formation of cariogenic biofilm model. The expression of gtfs was significantly reduced by Lactobacillus rhamnosus. The integration of L. rhamnosus into the biofilm model did not exhibit. However, L. acidophilus and L casei integrated into the biofilm model. These results suggest that L. rhamnosus may inhibit oral biofilm formation by decreasing glucan production of S. mutans and antibacterial activity and did not integrate into oral biofilm, which can be a candidate for caries prevention strategy.

  12. Real-time monitoring of cariogenic bacteria via bioluminescent imaging: A biodontic hypothesis

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    Jafar Kolahi

    2016-01-01

    Full Text Available Introduction: Dental caries (tooth decay remains one of the most common chronic infectious disease in the world. Disclosure of camouflaged cariogenic bacteria will be a great motivation for better oral hygiene. The Hypothesis: At present, lux transposon cassette, Tn4001 luxABCDE Kmr, is available that could be used for stable bioluminescent transformation of a wide range of gram-positive bacteria, e.g. Streptococcus mutans and Lactobacillus. After this step, sensitive charge-coupled device (CCD camera could be used to detect the low levels of light emitted from bioluminescent cariogenic bacteria. Living imaging software would be used for analysis and three-dimensional (3D reconstruction of images. Evaluation of the Hypothesis: Entrance of transgenic organisms into the oral cavity should be done with great caution. Ethical consideration is necessary and primary animal studies are required. The main limitation of this technique will be oxygen. As mentioned previously, bioluminescent reactions need oxygen. Hence, bioluminescent imaging cannot be used for anaerobic bacteria, e.g., Streptococcus sobrinus.

  13. Baccharis dracunculifolia-based mouthrinse alters the exopolysaccharide structure in cariogenic biofilms.

    Science.gov (United States)

    Aires, Carolina P; Sassaki, Guilherme L; Santana-Filho, Arquimedes P; Spadaro, Augusto C C; Cury, Jaime A

    2016-03-01

    Baccharis dracunculifolia is a native plant from Brazil with antimicrobial activity. The purpose of this study was to investigate whether a B. dracunculifolia-based mouthrinse (Bd) changes the structure of insoluble exopolysaccharides (IEPS) in Streptococcus mutans UA159 cariogenic biofilm. Biofilms were grown on glass slides and treated with Bd, its vehicle (VC), chlorhexidine digluconate (CHX), or saline solution (NaCl). Among the treatments, only CHX significantly reduced the biofilm biomass and bacterial viability (pIEPS from the four biofilm samples were α- glucans containing different proportions of (1→6) and (1→3) glycosidic linkages. The structural differences among the four IEPS were compared by principal component analysis (PCA). PCA analysis indicated that IEPS from VC- and NaCl-treated biofilms were structurally similar to each other. Compared with the control, IEPS from Bd- and CHX-treated biofilms were structurally different and had distinct chemical profiles. In summary, the fact that Bd changed the IEPS chemical composition indicates that this mouthrinse may affect the cariogenic properties of the S. mutans biofilm formed.

  14. The cariogenic dental biofilm: good, bad or just something to control?

    Science.gov (United States)

    Wolff, Mark Steven; Larson, Charlie

    2009-01-01

    This paper discusses the role of dental biofilm and adjunctive therapies in the management of dental caries. Dental biofilm is a site of bacterial proliferation and growth, in addition to being a location of acid production. It also serves as a reservoir for calcium exchange between the tooth and saliva. The salivary pellicle, a protein-rich biofilm layer, regulates the reaction between tooth surface, saliva and erosive acids. The protective effects of this pellicle on enamel are well established. However, understanding the effects of the pellicle/biofilm interaction in protecting dentin from erosive conditions requires further research. Saliva interacts with the biofilm, and is important in reducing the cariogenic effects of dental plaque as acidogenic bacteria consume fermentable carbohydrates producing acids that may result in tooth demineralization. Adequate supplies of healthy saliva can provide ingredients for successful remineralization. Strategies for managing the cariogenic biofilm are discussed with emphasis on the effectiveness of over-the-counter (OTC) products. However, since many toothpaste components have been altered recently, new clinical trials may be required for true validation of product effectiveness. A new generation of calcium-based remineralizing technologies may offer the ability to reverse the effects of demineralization. Nevertheless, remineralization is a microscopic subsurface phenomenon, and it will not macroscopically replace tooth structure lost in a cavitated lesion. Optimal management of cavitations requires early detection. This, coupled with advances in adhesive restorative materials and microsurgical technique, will allow the tooth to be restored with minimal destruction to nearby healthy tissue.

  15. The cariogenic dental biofilm: good, bad or just something to control?

    Directory of Open Access Journals (Sweden)

    Mark Steven Wolff

    2009-06-01

    Full Text Available This paper discusses the role of dental biofilm and adjunctive therapies in the management of dental caries. Dental biofilm is a site of bacterial proliferation and growth, in addition to being a location of acid production. It also serves as a reservoir for calcium exchange between the tooth and saliva. The salivary pellicle, a protein-rich biofilm layer, regulates the reaction between tooth surface, saliva and erosive acids. The protective effects of this pellicle on enamel are well established. However, understanding the effects of the pellicle/biofilm interaction in protecting dentin from erosive conditions requires further research. Saliva interacts with the biofilm, and is important in reducing the cariogenic effects of dental plaque as acidogenic bacteria consume fermentable carbohydrates producing acids that may result in tooth demineralization. Adequate supplies of healthy saliva can provide ingredients for successful remineralization. Strategies for managing the cariogenic biofilm are discussed with emphasis on the effectiveness of over-the-counter (OTC products. However, since many toothpaste components have been altered recently, new clinical trials may be required for true validation of product effectiveness. A new generation of calcium-based remineralizing technologies may offer the ability to reverse the effects of demineralization. Nevertheless, remineralization is a microscopic subsurface phenomenon, and it will not macroscopically replace tooth structure lost in a cavitated lesion. Optimal management of cavitations requires early detection. This, coupled with advances in adhesive restorative materials and microsurgical technique, will allow the tooth to be restored with minimal destruction to nearby healthy tissue.

  16. Is the red fluorescence of dental plaque related to its cariogenicity?

    Science.gov (United States)

    Bittar, Daniela G.; Pontes, Laura Regina A.; Calvo, Ana Flávia B.; Novaes, Tatiane F.; Braga, Mariana M.; Freitas, Patrícia M.; Tabchoury, Cinthia P. M.; Mendes, Fausto M.

    2014-06-01

    It has been speculated that the red fluorescence emitted by dental plaque could be related to its cariogenicity. To test this hypothesis, we designed this crossover in situ study, with two experimental phases of 14 days each. Seventeen volunteers, wearing a palatal appliance with bovine enamel blocks, were instructed to drip a 20% sucrose solution (experimental group) or purified water (control group) onto the enamel blocks eight times daily. The specimens were removed after 4, 7, 10, and 14 days, and the red fluorescence of dental plaque formed on the enamel blocks was assessed using a quantitative light-induced fluorescence device. After the plaque removal, surface and cross-sectional microhardness tests were performed to assess the mineral loss. The comparisons were made by a multilevel linear regression analysis. We observed a significant increase in the red fluorescence of the dental plaque after longer periods of formation, but this trend was verified in both groups. The mineral loss assessed by the microhardness techniques, contrariwise, showed a significant increase only in the experimental group. In conclusion, the red fluorescence emitted by the dental plaque indicates a mature biofilm, but this fact is not necessarily associated with its cariogenicity.

  17. Enterococcus faecium WB2000 Inhibits Biofilm Formation by Oral Cariogenic Streptococci

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    Nao Suzuki

    2011-01-01

    Full Text Available This study investigated the inhibitory effect of probiotic Enterococcus faecium WB2000 on biofilm formation by cariogenic streptococci. The ability of E. faecium WB2000 and JCM5804 and Enterococcus faecalis JCM5803 to inhibit biofilm formation by seven laboratory oral streptococcal strains and 13 clinical mutans streptococcal strains was assayed. The Enterococcal strains inhibited biofilm formation in dual cultures with the mutans streptococcal strains Streptococcus mutans Xc and Streptococcus sobrinus JCM5176 (P<0.05, but not with the noncariogenic streptococcal strains. Enterococcus faecium WB2000 inhibited biofilm formation by 90.0% (9/10 of the clinical S. mutans strains and 100% (3/3 of the clinical S. sobrinus strains. After culturing, the pH did not differ between single and dual cultures. The viable counts of floating mutans streptococci were lower in dual cultures with E. faecium WB2000 than in single cultures. Enterococcus faecium WB2000 acted as a probiotic bacterial inhibitor of cariogenic streptococcal biofilm formation.

  18. Effects of cecropin-XJ on growth and adherence of oral cariogenic bacteria in vitro

    Institute of Scientific and Technical Information of China (English)

    HAO Yu-qing; ZHOU Xue-dong; XIAO Xiao-rong; LU Jun-jun; ZHANG Fu-chun; HU Tao; WU Hong-kun; CHEN Xin-mei

    2005-01-01

    Background Cecropin-XJ belongs to cecropin-B, which is the most potent antibacterial peptide found naturally. The aim of this study was to investigate the effects of cecropin-XJ on growth and adherence of oral cariogenic bacteria.Methods Four oral cariogenic bacteria (Streptococcus mutans, Lactobacillus acidophilus, Actinomyces viscosus and Actinomyces naeslundii) were chosen for this experiment. The minimal inhibitory concentrations (MICs) and reductive percent of bacterial growth were used to assay the antibacterial activity of cecropin-XJ. Mammalian cytotoxicity of cecropin-XJ was tested with human periodontal membrane fibroblasts by tetrazolium (MTT) colorimetric assay. The bacterial morphological changes induced by cecropin-XJ were examined on scanning electron microscope (SEM). The influence of cecropin-XJ on bacterial adhesion to saliva-coated hydroxyapatite (S-HA) was measured by scintillation counting.Results The MICs of cecropin-XJ for inhibition of the growth of four bacteria ranged from 4.0 to 42.8 μmol/L with the highest susceptible to A. Naeslundii and the lowest susceptible to L. Acidophilus. At pH 6.8, 5.5 and 8.2, 1/2 MIC of cecropin-XJ reduced the number of viable bacteria by 40.9%, 67.8% and 32.8% for S. Mutans and by 28.1%, 57.2% and 37.9% for L. Acidophilus. The activities against S.mutans and L. Acidophilus increased at pH 5.5 compared with pH 6.8 (P0.05, respectively), whereas almost no reduction counts were detected in the presence of 20% serum for both bacteria (P>0.05, respectively). Mammalian cytotoxicity of cecropin-XJ from 1.0 to 100 μmol/L exhibited no cytotoxicity against human periodontal membrane fibroblasts (P>0.05). Bacterial morphological changes induced by MIC of cecropin-XJ examined on SEM showed cell surface disruption. Furthermore, the ability of A. Naeslundii adhesion to S-HA decreased significantly with MIC of cecropin-XJ for 10 and 20 minutes (P=0.001 and 0.000, respectively), and S. Mutans, A. Viscosus to S-HA decreased

  19. Cranberry Flavonoids Modulate Cariogenic Properties of Mixed-Species Biofilm through Exopolysaccharides-Matrix Disruption.

    Science.gov (United States)

    Kim, Dongyeop; Hwang, Geelsu; Liu, Yuan; Wang, Yifei; Singh, Ajay P; Vorsa, Nicholi; Koo, Hyun

    2015-01-01

    The exopolysaccharides (EPS) produced by Streptococcus mutans-derived glucosyltransferases (Gtfs) are essential virulence factors associated with the initiation of cariogenic biofilms. EPS forms the core of the biofilm matrix-scaffold, providing mechanical stability while facilitating the creation of localized acidic microenvironments. Cranberry flavonoids, such as A-type proanthocyanidins (PACs) and myricetin, have been shown to inhibit the activity of Gtfs and EPS-mediated bacterial adhesion without killing the organisms. Here, we investigated whether a combination of cranberry flavonoids disrupts EPS accumulation and S. mutans survival using a mixed-species biofilm model under cariogenic conditions. We also assessed the impact of cranberry flavonoids on mechanical stability and the in situ pH at the biofilm-apatite interface. Topical application of an optimized combination of PACs oligomers (100-300 μM) with myricetin (2 mM) twice daily was used to simulate treatment regimen experienced clinically. Treatments with cranberry flavonoids effectively reduced the insoluble EPS content (>80% reduction vs. vehicle-control; pbiofilms. As a result, the 3D architecture of cranberry-treated biofilms was severely compromised, showing a defective EPS-matrix and failure to develop microcolonies on the saliva-coated hydroxyapatite (sHA) surface. Furthermore, topical applications of cranberry flavonoids significantly weaken the mechanical stability of the biofilms; nearly 90% of the biofilm was removed from sHA surface after exposure to a shear stress of 0.449 N/m2 (vs. 36% removal in vehicle-treated biofilms). Importantly, in situ pH measurements in cranberry-treated biofilms showed significantly higher pH values (5.2 ± 0.1) at the biofilm-apatite interface vs. vehicle-treated biofilms (4.6 ± 0.1). Altogether, the data provide important insights on how cranberry flavonoids treatments modulate virulence properties by disrupting the biochemical and ecological changes

  20. Cranberry Flavonoids Modulate Cariogenic Properties of Mixed-Species Biofilm through Exopolysaccharides-Matrix Disruption.

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    Dongyeop Kim

    Full Text Available The exopolysaccharides (EPS produced by Streptococcus mutans-derived glucosyltransferases (Gtfs are essential virulence factors associated with the initiation of cariogenic biofilms. EPS forms the core of the biofilm matrix-scaffold, providing mechanical stability while facilitating the creation of localized acidic microenvironments. Cranberry flavonoids, such as A-type proanthocyanidins (PACs and myricetin, have been shown to inhibit the activity of Gtfs and EPS-mediated bacterial adhesion without killing the organisms. Here, we investigated whether a combination of cranberry flavonoids disrupts EPS accumulation and S. mutans survival using a mixed-species biofilm model under cariogenic conditions. We also assessed the impact of cranberry flavonoids on mechanical stability and the in situ pH at the biofilm-apatite interface. Topical application of an optimized combination of PACs oligomers (100-300 μM with myricetin (2 mM twice daily was used to simulate treatment regimen experienced clinically. Treatments with cranberry flavonoids effectively reduced the insoluble EPS content (>80% reduction vs. vehicle-control; p<0.001, while hindering S. mutans outgrowth within mixed-species biofilms. As a result, the 3D architecture of cranberry-treated biofilms was severely compromised, showing a defective EPS-matrix and failure to develop microcolonies on the saliva-coated hydroxyapatite (sHA surface. Furthermore, topical applications of cranberry flavonoids significantly weaken the mechanical stability of the biofilms; nearly 90% of the biofilm was removed from sHA surface after exposure to a shear stress of 0.449 N/m2 (vs. 36% removal in vehicle-treated biofilms. Importantly, in situ pH measurements in cranberry-treated biofilms showed significantly higher pH values (5.2 ± 0.1 at the biofilm-apatite interface vs. vehicle-treated biofilms (4.6 ± 0.1. Altogether, the data provide important insights on how cranberry flavonoids treatments modulate

  1. THE ADHERENCE OF CARIOGENIC BACTERIA TO PELLICLE FORMED IN VITRO FROM MIXED AND DELIPIDATED SALIVA

    Institute of Scientific and Technical Information of China (English)

    陶洪; 侯铁舟; 阮梅生; 司履生; 王一理

    2002-01-01

    Objective To study the influence of salivary lipids on the adherence of cariogenic bacteria (S.mutans Ingbritt and BF; S.sobrinus OMZ176 and 6715). Methods Mixed saliva was collected from 10 healthy subjects (5 males and 5 females, aged 21~23). The salivary lipids was depleted under nondenatural condition (-10℃, ethanol∶ether 3∶2 V∶V ). The adherence of S.mutans and S.sobrinus to the experimental pellicles formed from mixed saliva or lipids-depleted saliva was investigated with 3H-TdR incorperation assay. Results The amount of S.mutans Ingbritt and BF adhered to lipids-depleted pellicle were significantly increased (PBF>OMZ176>6715. Conclusion Salivary lipids significantly decreased the number of S.mutans adhered to pellicle.

  2. Pulp response to and cariogenicity of Lactobacillus casei in monoinfected gnotobiotic rats.

    Science.gov (United States)

    Paterson, R C; Pountney, S K

    1987-11-01

    The maxillary molar pulps of germ-free rats were mechanically exposed and suspensions of a strain of freshly grown Lactobacillus casei were applied to the pulp wounds. The pulps were left open to the oral environment, and the animals were maintained within the isolator until death. In the majority of teeth, pulp necrosis was evident and apical inflammation was present in 40% of the specimens. The remaining monoinfected animals were bred and the litters were placed on a 46% sucrose diet to determine the cariogenicity of the test strain of L. casei in the mandibular molars. The organism proved to be noncariogenic. The effects of mechanical exposure of the maxillary molars in these animals were similar to those observed in the direct-inoculation study, with the exception of a reduced incidence of apical inflammation.

  3. Inhibitory activity of Aloe vera gel on some clinically isolated cariogenic and periodontopathic bacteria.

    Science.gov (United States)

    Fani, Mohammadmehdi; Kohanteb, Jamshid

    2012-03-01

    Aloe vera is a medicinal plant with anti-inflammatory, antimicrobial, antidiabetic and immune-boosting properties. In the present study we investigated the inhibitory activities of Aloe vera gel on some cariogenic (Streptococcus mutans), periodontopathic (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis) and an opportunistic periodontopathogen (Bacteroides fragilis) isolated from patients with dental caries and periodontal diseases. Twenty isolates of each of these bacteria were investigated for their sensitivity to Aloe vera gel using the disk diffusion and microdilution methods. S. mutans was the species most sensitive to Aloe vera gel with a MIC of 12.5 µg/ml, while A. actinomycetemcomitans, P. gingivalis, and B. fragilis were less sensitive, with a MIC of 25-50 µg/ml (P Aloe vera gel at optimum concentration could be used as an antiseptic for prevention of dental caries and periodontal diseases.

  4. Streptococcus oligofermentans Inhibits Streptococcus mutans in Biofilms at Both Neutral pH and Cariogenic Conditions.

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    Xudong Bao

    Full Text Available Homeostasis of oral microbiota can be maintained through microbial interactions. Previous studies showed that Streptococcus oligofermentans, a non-mutans streptococci frequently isolated from caries-free subjects, inhibited the cariogenic Streptococcus mutans by the production of hydrogen peroxide (HP. Since pH is a critical factor in caries formation, we aimed to study the influence of pH on the competition between S. oligofermentans and S. mutans in biofilms. To this end, S. mutans and S. oligofermentans were inoculated alone or mixed at 1:1 ratio in buffered biofilm medium in a 96-well active attachment model. The single- and dual-species biofilms were grown under either constantly neutral pH or pH-cycling conditions. The latter includes two cycles of 8 h neutral pH and 16 h pH 5.5, used to mimic cariogenic condition. The 48 h biofilms were analysed for the viable cell counts, lactate and HP production. The last two measurements were carried out after incubating the 48 h biofilms in buffers supplemented with 1% glucose (pH 7.0 for 4 h. The results showed that S. oligofermentans inhibited the growth of S. mutans in dual-species biofilms under both tested pH conditions. The lactic acid production of dual-species biofilms was significantly lower than that of single-species S. mutans biofilms. Moreover, dual-species and single-species S. oligofermentans biofilms grown under pH-cycling conditions (with a 16 h low pH period produced a significantly higher amount of HP than those grown under constantly neutral pH. In conclusion, S. oligofermentans inhibited S. mutans in biofilms not only under neutral pH, but also under pH-cycling conditions, likely through HP production. S. oligofermentans may be a compelling probiotic candidate against caries.

  5. Characterization of Recombinant, Ureolytic Streptococcus mutans Demonstrates an Inverse Relationship between Dental Plaque Ureolytic Capacity and Cariogenicity

    OpenAIRE

    Clancy, K. Anne; Pearson, Sylvia; Bowen, William H.; Burne, Robert A.

    2000-01-01

    Dental caries results from prolonged plaque acidification that leads to the establishment of a cariogenic microflora and demineralization of the tooth. Urease enzymes of oral bacteria hydrolyze urea to ammonia, which can neutralize plaque acids. To begin to examine the relationship between plaque ureolytic activity and the incidence of dental caries, recombinant, ureolytic strains of Streptococcus mutans were constructed. Specifically, the ureABCEFGD operon from Streptococcus salivarius 57.I ...

  6. The effect of eugenol on the cariogenic properties of Streptococcus mutans and dental caries development in rats

    OpenAIRE

    XU, JING-SHU; Li, Yao; Cao, Xue; Cui, Yun

    2013-01-01

    Eugenol has been widely used in medicine due to its antibacterial, anti-inflammatory, antioxidant, anticancer and analgesic properties. The present study was designed to investigate the effects of eugenol on the cariogenic properties of Streptococcus mutans and dental caries development in rats. Eugenol demonstrated significant inhibitory effects against acid production by S. mutans. The synthesis of water-insoluble glucans by glucosyltransferases was reduced by eugenol. Eugenol also markedly...

  7. A Comparative Evaluation of the Efficacy of Different Caries Excavation Techniques in reducing the Cariogenic Flora: An in vivo Study

    Science.gov (United States)

    Yadav, Gunjan; Tripathi, Abhay Mani; Mehrotra, Mridul; Saha, Sonali; Garg, Nishita

    2016-01-01

    Background Caries excavation is a noninvasive technique of caries removal with maximum preservation of healthy tooth structure. Aim To compare the efficacy of three different caries excavation techniques in reducing the count of cariogenic flora. Materials and methods Sixty healthy primary molars were selected from 26 healthy children with occlusal carious lesions without pulpal involvement and divided into three groups in which caries excavation was done with the help of (1) carbide bur; (2) polymer bur using slow-speed handpiece; and (3) ultrasonic tip with ultrasonic machine. Samples were collected before and after caries excavation for microbiological analysis with the help of sterile sharp spoon excavator. Samples were inoculated on blood agar plate and incubated at 37°C for 48 hours. After bacterial cultivation, the bacterial count of Streptococcus mutans was obtained. Statistical analysis All statistical analysis was performed using SPSS 13 statistical software version. Kruskal-Wallis analysis of variance, Wilcoxon matched pairs test, and Z test were performed to reveal the statistical significance. Results The decrease in bacterial count of S. mutans before and after caries excavation was significant (p < 0.001) in all the three groups. Conclusion Carbide bur showed most efficient reduction in cariogenic flora, while ultrasonic tip showed almost comparable results, while polymer bur showed least reduction in cariogenic flora after caries excavation. How to cite this article Hassan AF, Yadav G, Tripathi AM, Mehrotra M, Saha S, Garg N. A Comparative Evaluation of the Efficacy of Different Caries Excavation Techniques in reducing the Cariogenic Flora: An in vivo Study. Int J Clin Pediatr Dent 2016;9(3):214-217. PMID:27843252

  8. Lack of Buffering by Composites Promotes Shift to More Cariogenic Bacteria.

    Science.gov (United States)

    Nedeljkovic, I; De Munck, J; Slomka, V; Van Meerbeek, B; Teughels, W; Van Landuyt, K L

    2016-07-01

    Secondary caries (SC) remains a very important problem with composite restorations. The objectives of this study were to test the acid-buffering ability of several restorative materials and to evaluate whether buffering of the restorative material has an impact on the microbial composition of the biofilm. Disk-shaped specimens of conventional composite, composite with surface prereacted glass-ionomer filler particles (so-called giomer), glass-ionomer cement (GIC), amalgam, and hydroxyapatite (HAp) (control) were exposed to aqueous solutions with pH 4, 5, 6, and 7 and to the medium containing bacteria-produced acids, and pH changes were recorded over several days. Next, material specimens were immersed in bacterial growth medium with pH adjusted to 5. After a 24-h incubation, the extracts were collected and inoculated with a cariogenic (Streptococcus mutans) and a noncariogenic (Streptococcus sanguinis) species. The bacterial growth was monitored both in a single-species model by spectrophotometry and in a dual-species model by viability quantitative polymerase chain reaction. Amalgam and HAp showed the strongest acid-buffering ability, followed by the GIC and the giomer, while the conventional composite did not exhibit any buffering capacity. Furthermore, due to the lack of acid-buffering abilities, composite was not able to increase the pH of the medium (pH 5), which, in the absence of antibacterial properties, allowed the growth of S. mutans, while the growth of S. sanguinis, a less aciduric species, was completely inhibited. A similar effect was observed when bacteria were cultured together: there was a higher percentage of S. mutans and lower percentage of S. sanguinis with the conventional composite than with other materials and HAp. In conclusion, conventional composites lack the ability to increase the local pH, which leads to the outgrowth of more acidogenic/aciduric bacteria and higher cariogenicity of the biofilm. Together with lack of antibacterial

  9. Pulp response to, and cariogenicity of, a strain of Streptococcus mutans.

    Science.gov (United States)

    Paterson, R C; Watts, A

    1989-01-01

    Gnotobiotic rats mono-infected with Streptococcus mutans (NCTC 10919) were maintained on a high sucrose diet in an isolator. When they were 8 weeks old the pulps of their maxillary first and second molars were mechanically exposed and left open to the oral environment. The rats were sacrificed in groups after 7 and 28 days. Thirty-seven teeth were available for study in the 7-day group, and 30 teeth in the 28-day group. The test S. mutans was non-cariogenic. After 7 days, necrosis of the superficial layers of the pulp was noted; however, after 28 days pulpal necrosis was much more extensive and calcific repair was observed in only one-third of the teeth examined. The microorganism did not provoke inflammation in the pulp or periapical tissues. This is the second strain of S. mutans tested in this manner. These results are very similar to those reported previously for S. mutans (NCTC 10449) and strengthens the view that organisms of the S. mutans group have a low pathogenicity for the pulp.

  10. Antibacterial Activity of Essential Oils and Their Isolated Constituents against Cariogenic Bacteria: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Irlan Almeida Freires

    2015-04-01

    Full Text Available Dental caries remains the most prevalent and costly oral infectious disease worldwide. Several methods have been employed to prevent this biofilm-dependent disease, including the use of essential oils (EOs. In this systematic review, we discuss the antibacterial activity of EOs and their isolated constituents in view of a potential applicability in novel dental formulations. Seven databases were systematically searched for clinical trials, in situ, in vivo and in vitro studies addressing the topic published up to date. Most of the knowledge in the literature is based on in vitro studies assessing the effects of EOs on caries-related streptococci (mainly Streptococcus mutans and lactobacilli, and on a limited number of clinical trials. The most promising species with antibacterial potential against cariogenic bacteria are: Achillea ligustica, Baccharis dracunculifolia, Croton cajucara, Cryptomeria japonica, Coriandrum sativum, Eugenia caryophyllata, Lippia sidoides, Ocimum americanum, and Rosmarinus officinalis. In some cases, the major phytochemical compounds determine the biological properties of EOs. Menthol and eugenol were considered outstanding compounds demonstrating an antibacterial potential. Only L. sidoides mouthwash (1% has shown clinical antimicrobial effects against oral pathogens thus far. This review suggests avenues for further non-clinical and clinical studies with the most promising EOs and their isolated constituents bioprospected worldwide.

  11. Effect of Punica granatum on the virulence factors of cariogenic bacteria Streptococcus mutans.

    Science.gov (United States)

    Gulube, Zandiswa; Patel, Mrudula

    2016-09-01

    Dental caries is caused by acids produced by biofilm-forming Streptococcus mutans from fermentable carbohydrates and bacterial byproducts. Control of these bacteria is important in the prevention of dental caries. This study investigated the effect of the fruit peel of Punica granatum on biofilm formation, acid and extracellular polysaccharides production (EPS) by S. mutans. Pomegranate fruit peels crude extracts were prepared. The Minimum bactericidal concentrations (MBC) were determined against S. mutans. At 3 sub-bactericidal concentrations, the effect on the acid production, biofilm formation and EPS production was determined. The results were analysed using Kruskal-Wallis and Wilcoxon Rank Sum Tests. The lowest MBC was 6.25 mg/mL. Punica granatum significantly inhibited acid production (p < 0.01). After 6 and 24 h, it significantly reduced biofilm-formation by 91% and 65% respectively (p < 0.01). The plant extract did not inhibit the production of soluble EPS in either the biofilm or the planktonic growth. However, it significantly reduced the insoluble EPS in the biofilm and the plantktonic (p = < 0.01) form of S. mutans. The crude extract of P. granatum killed cariogenic S. mutans at high concentrations. At sub-bactericidal concentrations, it reduced biofilm formation, acid and EPS production. This suggests that P. granatum extract has the potential to prevent dental caries.

  12. Antibacterial Activity of Essential Oils and Their Isolated Constituents against Cariogenic Bacteria: A Systematic Review.

    Science.gov (United States)

    Freires, Irlan Almeida; Denny, Carina; Benso, Bruna; de Alencar, Severino Matias; Rosalen, Pedro Luiz

    2015-04-22

    Dental caries remains the most prevalent and costly oral infectious disease worldwide. Several methods have been employed to prevent this biofilm-dependent disease, including the use of essential oils (EOs). In this systematic review, we discuss the antibacterial activity of EOs and their isolated constituents in view of a potential applicability in novel dental formulations. Seven databases were systematically searched for clinical trials, in situ, in vivo and in vitro studies addressing the topic published up to date. Most of the knowledge in the literature is based on in vitro studies assessing the effects of EOs on caries-related streptococci (mainly Streptococcus mutans) and lactobacilli, and on a limited number of clinical trials. The most promising species with antibacterial potential against cariogenic bacteria are: Achillea ligustica, Baccharis dracunculifolia, Croton cajucara, Cryptomeria japonica, Coriandrum sativum, Eugenia caryophyllata, Lippia sidoides, Ocimum americanum, and Rosmarinus officinalis. In some cases, the major phytochemical compounds determine the biological properties of EOs. Menthol and eugenol were considered outstanding compounds demonstrating an antibacterial potential. Only L. sidoides mouthwash (1%) has shown clinical antimicrobial effects against oral pathogens thus far. This review suggests avenues for further non-clinical and clinical studies with the most promising EOs and their isolated constituents bioprospected worldwide.

  13. Antimicrobial activity of the essential oil of Tetradenia riparia (Hochst. Codd. (Lamiaceae against cariogenic bacteria

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    Nathalya Isabel de Melo

    2015-06-01

    Full Text Available In Brazilian folk medicine, Tetradenia riparia (Hochst. Codd. (Lamiaceae is used to treat toothaches and dental abscesses and diseases induced by worms, bacteria, or fungi. This paper aims to investigate the chemical composition and the antibacterial effects of the essential oil obtained from Tetradenia riparia leaves (TR-EO grown in Southeastern Brazil against a representative panel of oral pathogens. We evaluated the antibacterial activity of TR-EO in terms of the minimal inhibitory concentration (MIC. We identified aromadendrene oxide (14.0%, (E,E-farnesol (13.6%, dronabinol (12.5%, and fenchone (6.2% as the major constituents of TR-EO. TR-EO displayed MIC values between 31.2 and 500 μg/mL, with the lowest MIC value being obtained against Streptococcus mitis (31.2 μg/mL, S. mutans (62.5 μg/mL, S. sobrinus (31.2 μg/mL, and Lactobacillus casei (62.5 μg/mL. In time-kill experiments, TR-EO demonstrated bactericidal activity against S. mutans within the first 12 h, resulting in a curve profile similar to that of chlorhexidine. These results revealed that the essential oil of Tetradenia riparia displays promising activity against most of the selected cariogenic bacteria, including Streptococcus mutans.

  14. An Assessment of the Cariogenicity of Commonly Used Infant Milk Formulae Using Microbiological and Biochemical Methods

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    Shweta Dixit Chaudhary

    2011-01-01

    Full Text Available Dental caries is an important dental public health problem and is the most prevalent oral disease among children in the world. The present study was undertaken to evaluate and comparatively assess the change in plaque and salivary pH after ingestion of various commercially available infant milk formulae, and also to evaluate and comparatively assess plaque and salivary samples for change in colony-forming units of Streptococcus mutans caused due to their ingestion. 36 children in the age group of 1-2 years were fed with infant milk formulae three times a day for 21 days and results quantified. The present study revealed a highly significant increase in the levels of colony-forming units of Streptococcus mutans in both the plaque and salivary samples when assessed at baseline and after a period of 21 days, with the t value being 11.92 for the plaque samples and 11.66 for the salivary samples. It was also observed that all the test samples produced significantly lower plaque pH values than pre-feed pH. Based upon this study, further evaluation of the cariogenicity of infant milk formulae is recommended.

  15. The Effect of Iranian Customary Used Probiotic Yogurt on the Children’s Salivary Cariogenic Microflora

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    Ali Nozari

    2015-06-01

    Full Text Available Statement of the Problem: Dental caries is the most common disease of child-hood. Using probiotics has recently been introduced to reduce the incidence of dental caries.It consists of live microbial food supplements that beneficially affect the host, and hence are considered an alternative way to eradicate the infections. Purpose: The aim of this study is to evaluate the effect of consumption of probi-otic yogurt on the children’s salivary cariogenic microflora. Materials and Method: A double-blind randomized study was performed recruit-ing 2 parallel groups; 24 healthy children in the case and 25 children in the control group. All healthy children were followed- up over 4 periods. Periods 1 and 3 were wash-out periods with duration of 1 and 2 weeks, respectively. During periods 2 and 4 (2weeks duration each, the case group consumed 200g yogurt containing Bifidobacterium lactis (1×106 per gram once daily and the control group consumed normal yogurt. Salivary Streptococci mutans and Lactobacilli were enumerated before and after the yogurt consumption periods. Pre- and post-treatment values within and between regimens were compared using the t-test and paired samples. Results: There was a reduction in Streptococcus mutans and Lactobacillus counts in the control group, but for Streptococcus mutans, the count reduction between phases 1 and 4 was statistically significant (p= 0.009. In the case group, neither the Streptococcus mutans count nor the Lactobacilli count was significantly reduced. Conclusion: Based on the findings of this study, short-term daily consumption of probiotic yogurt containing Bifidobacterium lactis could not reduce the levels of salivary Streptococcus mutans and Lactobacilli in 6 to 12 year-old children, while normal yogurt could reduce the Streptococcus mutans counts significantly.

  16. Genotypic and phenotypic analysis of S. mutans isolated from dental biofilms formed in vivo under high cariogenic conditions.

    Science.gov (United States)

    Arthur, Rodrigo Alex; Cury, Altair Antoninha Del Bel; Graner, Renata Oliveira Mattos; Rosalen, Pedro Luiz; Vale, Gláuber Campos; Paes Leme, Adriana Franco; Cury, Jaime Aparecido; Tabchoury, Cínthia Pereira Machado

    2011-01-01

    The oral cavity harbors several Streptococcus mutans genotypes, which could present distinct virulence properties. However, little is known about the diversity and virulence traits of S. mutans genotypes isolated in vivo under controlled conditions of high cariogenic challenge. This study evaluated the genotypic diversity of S. mutans isolated from dental biofilms formed in vivo under sucrose exposure, as well as their acidogenicity and aciduricity. To form biofilms, subjects rinsed their mouths with distilled water or sucrose solution 8 times/day for 3 days. S. mutans collected from saliva and biofilms were genotyped by arbitrarily-primed PCR. Genotypes identified in the biofilms were evaluated regarding their ability to lower the suspension pH through glycolysis and their acid susceptibility and F-ATPase activity. Most subjects harbored only one genotype in saliva, which was detected in almost all biofilm samples at high proportions. Genotypes isolated only in the presence of sucrose had higher acidogenicity than those isolated only in the presence of water. Genotypes from biofilms formed with sucrose were more aciduric after 30 and 60 min of incubation at pH 2.8 and 5.0, respectively. The present results suggest that biofilms formed under high cariogenic conditions may harbor more aciduric and acidogenic S. mutans genotypes.

  17. Betulin inhibits cariogenic properties of Streptococcus mutans by targeting vicRK and gtf genes.

    Science.gov (United States)

    Viszwapriya, Dharmaprakash; Subramenium, Ganapathy Ashwinkumar; Radhika, Solai; Pandian, Shunmugiah Karutha

    2017-01-01

    Streptococcus mutans, a multivirulent pathogen is considered the primary etiological agent in dental caries. Development of antibiotic resistance in the pathogen has created a need for novel antagonistic agents which can control the virulence of the organism and reduce resistance development. The present study demonstrates the in vitro anti-virulence potential of betulin (lup-20(29)-ene-3β,28-diol), an abundantly available plant triterpenoid against S. mutans UA159. Betulin exhibited significant dose dependent antibiofilm activity without affecting bacterial viability. At 240 µg/ml (biofilm inhibitory concentration), betulin inhibited biofilm formation and adherence to smooth glass surfaces by 93 and 71 % respectively. It reduced water insoluble glucan synthesis by 89 %, in conjunction with down regulation of gtfBC genes. Microscopic analysis confirmed the disruption in biofilm architecture and decreased exopolysaccharide production. Acidogenicity and aciduricity, key virulence factors responsible for carious lesions, were also notably affected. The induced auto-aggregation of cells upon treatment could be due to the down regulation of vicK. Results of gene expression analysis demonstrated significant down-regulation of virulence genes upon betulin treatment. Furthermore, the nontoxic effect of betulin on peripheral blood mononuclear cells even after 72 h treatment makes it a strong candidate for assessing its suitability to be used as a therapeutic agent.

  18. In vitro evaluation of antibacterial activity of hydroalcoholic extract of Salvia officinalis and Pimpinella anisum against cariogenic bacteria

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    Kermanshah H.

    2009-11-01

    Full Text Available "nBackground and Aim: The microbial cause of dental caries has been proved among its multifactorial etiologies. The prevention and control of dental caries is very critical because of high prevalence and cost especially in high risk patient such as xerostomia. Based on the world attraction to traditional treatment and importance of drug extraction of natural materials and plants, in this in vitro study effect of hydroalcoholic extract of Salvia officinalis and Pimpinella anisum which were very useful in traditional treatment of mouth and teeth disease has been determined against cariogenic bacteria. "nMaterials and Methods: In this experimental study, hydroalcoholic extracts have been prepared from Salvia officinalis and Pimpinella anisum with maceration method. Their antibacterial activity against Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces viscosus have been evaluated with broth macrodilution method. Data were analyzed with Mann-Whitney test. "nResults: Minimum Inhibitory Concentration for Salvia officinalis and Pimpinella anisum for streptococcus mutans were respectively 6.25 and 12.5 µg/ml, for Lactobacillus rhamnosus were 1.56 and 12.5 µg/ml and for Actinomyces viscosus were 12.5 and 50 µg/ml. "nConclusion:Both extracts had growth inhibitory effect on all three bacteria. Salvia officinalis had significantly greater effect on inhibition of growth of all three bacteria. Both extracts had bactericidal effect in the range of concentration.

  19. Antimicrobial Effect of Lactobacillus reuteri on Cariogenic Bacteria Streptococcus gordonii, Streptococcus mutans, and Periodontal Diseases Actinomyces naeslundii and Tannerella forsythia.

    Science.gov (United States)

    Baca-Castañón, Magda Lorena; De la Garza-Ramos, Myriam Angélica; Alcázar-Pizaña, Andrea Guadalupe; Grondin, Yohann; Coronado-Mendoza, Anahí; Sánchez-Najera, Rosa Isela; Cárdenas-Estrada, Eloy; Medina-De la Garza, Carlos Eduardo; Escamilla-García, Erandi

    2015-03-01

    Lactic acid bacteria (LAB) are well known for their beneficial effects on human health in the intestine and immune system; however, there are few studies on the impact they can generate in oral health. The aim of this study was to test and compare in vitro antimicrobial activity of L. reuteri on pathogenic bacteria involved in the formation of dental caries: S. mutans, S. gordonii, and periodontal disease: A. naeslundii and T. forsythia. Also, we determined the growth kinetics of each bacterium involved in this study. Before determining the antimicrobial action of L. reuteri on cariogenic bacteria and periodontal disease, the behavior and cell development time of each pathogenic bacterium were studied. Once the conditions for good cell growth of each of selected pathogens were established according to their metabolic requirements, maximum exponential growth was determined, this being the reference point for analyzing the development or inhibition by LAB using the Kirby Bauer method. Chlorhexidine 0.12% was positive control. L. reuteri was shown to have an inhibitory effect against S. mutans, followed by T. forsythia and S. gordonii, and a less significant effect against A. naeslundii. Regarding the effect shown by L. reuteri on the two major pathogens, we consider its potential use as a possible functional food in the prevention or treatment of oral diseases.

  20. Systematic screening of plant extracts from the Brazilian Pantanal with antimicrobial activity against bacteria with cariogenic relevance.

    Science.gov (United States)

    Brighenti, F L; Salvador, M J; Delbem, Alberto Carlos Botazzo; Delbem, Ádina Cleia Bottazzo; Oliveira, M A C; Soares, C P; Freitas, L S F; Koga-Ito, C Y

    2014-01-01

    This study proposes a bioprospection methodology regarding the antimicrobial potential of plant extracts against bacteria with cariogenic relevance. Sixty extracts were obtained from ten plants--(1) Jatropha weddelliana, (2) Attalea phalerata, (3) Buchenavia tomentosa, (4) Croton doctoris, (5) Mouriri elliptica, (6) Mascagnia benthamiana, (7) Senna aculeata, (8) Unonopsis guatterioides, (9) Allagoptera leucocalyx and (10) Bactris glaucescens--using different extraction methods - (A) 70° ethanol 72 h/25°C, (B) water 5 min/100°C, (C) water 1 h/55°C, (D) water 72 h/25°C, (E) hexane 72 h/25°C and (F) 90° ethanol 72 h/25°C. The plants were screened for antibacterial activity at 50 mg/ml using the agar well diffusion test against Actinomyces naeslundii ATCC 19039, Lactobacillus acidophilus ATCC 4356, Streptococcus gordonii ATCC 10558, Streptococcus mutans ATCC 35688, Streptococcus sanguinis ATCC 10556, Streptococcus sobrinus ATCC 33478 and Streptococcus mitis ATCC 9811. The active extracts were tested to determine their minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), cytotoxicity and chemical characterization. Forty-seven extracts (78%) were active against at least one microorganism. Extract 4A demonstrated the lowest MIC and MBC for all microorganisms except S. gordonii and the extract at MIC concentration was non-cytotoxic. The concentrated extracts were slightly cytotoxic. Electrospray ionization with tandem mass spectrometry analyses demonstrated that the extract constituents coincided with the mass of the terpenoids and phenolics. Overall, the best results were obtained for extraction methods A, B and C. The present work proved the antimicrobial activity of several plants. Particularly, extracts from C. doctoris were the most active against bacteria involved in dental caries disease.

  1. Chemical and botanical characterization of Chilean propolis and biological activity on cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus

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    Leticia Barrientos

    2013-01-01

    Full Text Available Propolis is a non-toxic natural substance with multiple pharmacological properties including anticancer, antioxidant, fungicidal, antibacterial, antiviral, and anti-inflammatory among others. The aim of this study was to determine the chemical and botanical characterization of Chilean propolis samples and to evaluate their biological activity against the cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus. Twenty propolis samples were obtained from beekeeping producers from the central and southern regions of Chile. The botanical profile was determined by palynological analysis. Total phenolic contents were determined using colorimetric assays. Reverse phase HPLC and HPLC-MS were used to determine the chemical composition. The minimum inhibitory concentration (MIC was determined on S. mutans and S. sobrinus. All propolis samples were dominated by structures from native plant species. The characterization by HPLC/MS, evidenced the presence of quercetin, myricetin, kaempferol, rutine, pinocembrin, coumaric acid, caffeic acid and caffeic acid phenethyl ester, that have already been described in these propolis with conventional HPLC. Although all propolis samples inhibited the mutans streptococci growth, it was observed a wide spectrum of action (MIC 0.90 to 8.22 µgmL-1. Given that results it becomes increasingly evident the need of standardization procedures, where we combine both the determination of botanical and the chemical characterization of the extracts. Research conducted to date, describes a promising effectiveness of propolis in the prevention of caries and other diseases of the oral cavity, making it necessary to develop studies to identify and understand the therapeutic targets or mechanisms of molecular action of the various compounds present on them.

  2. Chemical and botanical characterization of Chilean propolis and biological activity on cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus.

    Science.gov (United States)

    Barrientos, Leticia; Herrera, Christian L; Montenegro, Gloria; Ortega, Ximena; Veloz, Jorge; Alvear, Marysol; Cuevas, Alejandro; Saavedra, Nicolás; Salazar, Luis A

    2013-01-01

    Propolis is a non-toxic natural substance with multiple pharmacological properties including anti-cancer, antioxidant, fungicidal, antibacterial, antiviral, and anti-inflammatory among others. The aim of this study was to determine the chemical and botanical characterization of Chilean propolis samples and to evaluate their biological activity against the cariogenic bacteria Streptococcus mutans and Streptococcus sobrinus. Twenty propolis samples were obtained from beekeeping producers from the central and southern regions of Chile. The botanical profile was determined by palynological analysis. Total phenolic contents were determined using colorimetric assays. Reverse phase HPLC and HPLC-MS were used to determine the chemical composition. The minimum inhibitory concentration (MIC) was determined on S. mutans and S. sobrinus. All propolis samples were dominated by structures from native plant species. The characterization by HPLC/MS, evidenced the presence of quercetin, myricetin, kaempferol, rutine, pinocembrin, coumaric acid, caffeic acid and caffeic acid phenethyl ester, that have already been described in these propolis with conventional HPLC. Although all propolis samples inhibited the mutans streptococci growth, it was observed a wide spectrum of action (MIC 0.90 to 8.22 μg mL(-1)). Given that results it becomes increasingly evident the need of standardization procedures, where we combine both the determination of botanical and the chemical characterization of the extracts. Research conducted to date, describes a promising effectiveness of propolis in the prevention of caries and other diseases of the oral cavity, making it necessary to develop studies to identify and understand the therapeutic targets or mechanisms of molecular action of the various compounds present on them.

  3. Synthesis and antibacterial activities of 4-hydroxy-o-phenylphenol and 3,6-diallyl-4-hydroxy-o-phenylphenol against a cariogenic bacterium Streptococcus mutans OMZ 176.

    Science.gov (United States)

    Bae, K H; Koo, S H; Seo, W J

    1991-03-01

    For the purpose of survey of the antibacterial activity against a cariogenic bacterium Streptococcus mutans OMZ 176 with the introduction of hydroxyl and allyl groups to o-phenylphenol (Fig. 2, 1), 4-hydroxy-o-phenylphenol (2), and 3,6-diallyl-4-hydroxy-o-phenylphenol (4) were synthesized, successively. The synthesized compounds, 2 and 4 showed more potent antibacterial activity than the starting material, 1. The hydroxyl group was supposed to the essential element for the antibacterial activity and the introduction of allyl group to phenolic ring to be another element to increase the activity.

  4. A mathematical model of the influence of salivary urea on the pH of fasted dental plaque and on the changes occurring during a cariogenic challenge.

    Science.gov (United States)

    Dibdin, G H; Dawes, C

    1998-01-01

    Urea diffusing from saliva into dental plaque is converted to ammonia and carbon dioxide by bacterial ureases. The influence of normal salivary urea levels on the pH of fasted plaque and on the depth and duration of a Stephan curve is uncertain. A numerical model which simulates a cariogenic challenge (a 10% sucrose rinse alone or one followed by use of chewing-gum with or without sugar) was modified to include salivary urea levels from 0 to 30 mmol/l. It incorporated: site-dependent exchange between bulk saliva and plaque surfaces via a salivary film; sugar and urea diffusion into plaque; pH-dependent rates of acid formation and urea breakdown; diffusion and dissociation of end-products and other buffers (acetate, lactate, phosphate, ammonia and carbonate); diffusion of protons and other ions; equilibration with fixed and mobile buffers; and charge-coupling between ionic flows. The Km (2.12 mmol/l) and Vmax (0.11 micromol urea/min/mg dry weight) values for urease activity and the pH dependence of Vmax were taken from the literature. From the results, it is predicted that urea concentrations normally present in saliva (3-5 mmol/l) will increase the pH at the base of a 0.5-mm-thick fasted plaque by up to 1 pH unit, and raise the pH minimum after a sucrose rinse or sugar-containing chewing-gum by at least half a pH unit. The results suggest that plaque cariogenicity may be inversely related to salivary urea concentrations, not only when the latter are elevated because of disease, but even when they are in the normal range.

  5. 变异链球菌耐氟菌株的致龋能力%Cariogenicity of fluoride-resistant strains of Streptococcus mutans

    Institute of Scientific and Technical Information of China (English)

    许华(综述); 刘英群(审校)

    2013-01-01

    长期应用氟化物会导致变异链球菌耐氟菌株的产生,此变异是否导致其致龋能力发生变化,并且对于氟化物防龋是否出现新的影响,国内外学者进行了大量的研究。本文就变异链球菌耐氟菌株的产酸能力、脱矿能力、耐酸能力、黏附能力和糖酵解能力等研究进展作一综述。%Long-term?application?of?fluoride?results?in?the?generation?of?fluoride-resistant?strains?of?Streptococcus mutans.?Several?studies?have?been?conducted?worldwide?to?confirm?whether?or?not?changes?in?cariogenic?ability?are?induced?by?this?mutation?and?investigate?the?effectiveness?of?various?fluoride?methods?in?preventing?dental?caries.?This?article?discusses?research?progress?on?the?aciduricity,?demineralization,?acidogenecity,?adherence,?and?glycolytic?capacity?of?fluoride-resistant?strains?of?Streptococcus mutans.

  6. [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.

  7. Antibiotic Agents

    Science.gov (United States)

    ... Superbugs and Drugs" Home | Contact Us General Background: Antibiotic Agents What is an antibacterial and how are ... with the growth and reproduction of bacteria. While antibiotics and antibacterials both attack bacteria, these terms have ...

  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. Overview of the Cariogenic Characteristics of Carie-related Microorganisms%龋病相关微生物的致龋性研究概况

    Institute of Scientific and Technical Information of China (English)

    杨健康; 董文刚; 方舟

    2011-01-01

    龋病是慢性感染性疾病,是口腔内多种微生物共同作用的结果.龋病相关微生物在龋病病理变化中的作用,主要取决于三大生物学特性:产酸与耐酸力、产糖能力和黏附能力.随着近年来龋病研究的日益深入,龋病相关分子机制逐渐引起学者们的重视,越来越多的微生物也被认为与龋病相关.现对主要龋病相关微生物的致龋性进行综述,以期对龋病的深入研究提供参考.%Dental caries are chronic infectious diseases and the consequence of oral etiological disequilibrium. Carie-related microorganisms have three important biological characteristics: the capabilities of acid production and acid tolerance, the capability to adhere the dental surface and the ability to synthesize amylose, which play an important role on the pathological progress of dental caries. Following the improvement of the shudy about caries, people has paid close attention on the molecular mechanism of caries. Meanwhile,more and more microorganisms has been proved to relate to caries. The cariogenicities of carie-related microorganisms are summarized in this paper,in order to provide some reference for further shudy about caries.

  11. 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

  12. Effect of Menthol compound decoction on the growth and metabolism of cariogenic bacteria in vitro%薄荷复方煎液对致龋菌生长代谢的体外研究

    Institute of Scientific and Technical Information of China (English)

    丘创华; 李卓成; 孙墅

    2016-01-01

    目的:研究薄荷复方煎液对致龋菌生长及产酸的影响,明确薄荷复方煎液的抗菌机制。方法选择变形链球菌、血链球菌和牙龈卟啉单胞菌作为实验菌株,用纸片扩散法测定薄荷复方煎液对菌株的抑制作用,同时测量不同质量浓度薄荷复方煎液对菌株产酸的影响。结果薄荷复方煎液能有效抑制血链球菌和牙龈卟啉单胞菌的生长,同时有效抑制各实验菌株的产酸能力,只是在药物质量浓度上有一定差异。结论薄荷复方煎液对致龋菌的生长和酸代谢具有一定的抑制作用。%Objective To investigate the effect of menthol compound decoction on the growth and acid metabolism of cariogenic bacteria and to find out the anticariogenic mechanism of Menthol compound decoction .Methods Streptococcus mutans ,Streptococ‐cus sanguinis and Porphyromonas gingivalis were chosen as the experimental bacteria .Firstly ,slip diffusion method was used to ex‐amine the inhibitory effect of menthol compound decoction on cariogenic bacteria .Secondly ,observing the effect of menthol com‐pound decoction of different concentration on acid metabolism .Results Menthol compound decoction could inhibit the growth of Streptococcus sanguinis and Porphyromonas gingivalis .And it also inhibited the acid production of cariogenic bacteria ,but the con‐centration of menthol compound decoction were different .Conclusion Menthol compound decoction may have an inhibitory effect on the growth and acid metabolism of cariogenic bacteria .

  13. Phytochemical and antibacterial activity of the extracts of Fagara zanthoxyloides on selected cariogenic and enteric bacterial isolates

    Directory of Open Access Journals (Sweden)

    Martins Ajibade Adefisoye

    2012-02-01

    Methods: Crude extracts were obtained by cold extraction method of the powdered stem in methanol-water mixture (MW in ratio 3:2 and phosphate buffer saline (PBS. Filtrates obtained were concentrated in a rotary evaporator and lyophilized. Antimicrobial activity of the extracts, at a concentration of 25 mg/ml was tested against four bacterial isolates using agar well diffusion method. Phytochemical analysis of the plant extract for the presence of tannins, saponins, alkaloids and flavanoids was based on chemical examination. Results and discussions: Extracts from methanol-water mixture showed some antimicrobial activity against Lactobacillus brevis (NCIMB 4617, L. plantarum (NCDO 1752 and Escherichia coli and Proteus vulgaris. The minimum inhibitory concentration (MIC of extracts ranged between 1.57 and 12.5 mg/ml except in E. coli with value greater than 12.5.mg/ml. The phytochemical screening indicated that the extract tested positive for tannin, saponin, flavonoids and alkaloids. Results showed that F. zanthoxyloides would be valuable in the treatment of microbial diseases particularly those of the oral cavity. The considerable antibacterial activities exhibited by the extract of the plant thus justify the use as a teeth cleansing agent in the local setting. The problem of antibiotics resistance to synthetic drugs is also expected to be mitigated with the use of natural drugs. [J Intercult Ethnopharmacol 2012; 1(1.000: 1-6

  14. 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.

  15. Development of transcriptional regulators of Streptococcus mutans in cariogenic virulence%变异链球菌毒力相关转录调节因子的研究进展

    Institute of Scientific and Technical Information of China (English)

    李蓝; 张博文; 李继遥

    2016-01-01

    研究发现众多转录调节因子参与调节变异链球菌耐酸性等关键致龋毒力因子的表达,虽然仍有许多转录调节因子的作用靶点和调控机制尚不明确,但已有学者针对变异链球菌个别宏观转录调控因子进行单基因突变研究.本文就已发现的影响变异链球菌致龋毒力因子表达的调节因子及其功能和可能的作用机制进行综述.%Some transcriptional regulators contribute to the expression ofStreptococcus mutans (S. mutans) cariogenic virulence factors. Although the target sequence transcriptional regulators anchored on the cell wall and the molecular mecha-nism of the regulation ofS. mutans are yet to be clarified, certain global regulators potentially associated with the cariogenicity ofS. mutans have been identified. This review is about these related transcriptional regulators, their function, and possible mechanisms.

  16. Inhibited biofilm formation and improved antibacterial activity of a novel nanoemulsion against cariogenic Streptococcus mutans in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Li YF

    2015-01-01

    . CNE treatment at a concentration of 0.2 µg/mL inhibited biofilm formation more effectively than CHX, as indicated by the crystal violet staining method, scanning electron microscopy, and atomic force microscopy. The cell membrane of S. mutans was also severely disrupted by 0.2 µg/mL CNE, as indicated by transmission electron microscopy. These results demonstrated that CNE greatly improved the solubility and antimicrobial activity of this agent against S. mutans both in vitro and in vivo. This novel nanoemulsion is a promising medicine for preventing and curing dental caries. Keywords: nanoemulsion, chlorhexidine acetate, Streptococcus mutans, antibacterial

  17. 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

  18. Inhibitory effect of photodynamic therapy on cariogenicity in rats%光动力疗法防龋效果的动物实验研究

    Institute of Scientific and Technical Information of China (English)

    孙继军; 王爱芹; 王栋; 李言君

    2012-01-01

    Objective: To investigate the anticarious effect of photodynamic therapy(PDT) in rats. Methods: Dental caries models were established in 45 Wistar rats by cariogenic diet 2000# and by infection with streptococcus mutans. Then the animals were devided into 3 groups: Control group, NaF group and PDT group. The treatments were continued for 60 d. The general biological characteristics and pathological changes of periodontal tissue of the animals were observed. The effects of PDT on caries development were observed by Keyes scoring method. Results: In PDT group, there was no abnormal change in periodontal tissues. According to Keyes score, E, Ds, Dm and Dx levels in PDT group were significantly lower than those in control group ( P < 0. 01 ) and NaF group( P < 0. 05 ) . Conclusion ; PDT can inhibit the development of caries and is more effective than NaF.%目的:探讨光动力疗法对龋病发生发展的抑制作用.方法:用45只Wistar大鼠建立人工龋大鼠模型,随机分为对照组、氟化钠组和光动力组3组,观察各组实验动物一般生物学特征和牙周组织病理变化;通过Keyes龋齿评分,观察各组龋病发生、发展情况.结果:光动力组大鼠牙周组织无损害,Keyes记分结果显示,光动力组窝沟釉质龋、牙本质浅龋和牙本质深龋的龋齿计分均显著低于对照组(P<0.01)和氟化钠组(P<0.05).结论:光动力疗法可有效抑制大鼠龋齿的发生发展,其效果优于氟化钠,对牙周组织无损害.

  19. Identification of linoleic acid, a main component of the n-hexane fraction from Dryopteris crassirhizoma, as an anti-Streptococcus mutans biofilm agent.

    Science.gov (United States)

    Jung, Ji-Eun; Pandit, Santosh; Jeon, Jae-Gyu

    2014-01-01

    Dryopteris crassirhizoma is a semi-evergreen plant. Previous studies have shown the potential of this plant as an agent for the control of cariogenic biofilms. In this study, the main antibacterial components of the plant were identified by correlating gas chromatography-mass spectrometry data with the antibacterial activity of chloroform and n-hexane fractions and then evaluating the activity of the most potent antibacterial component against Streptococcus mutans UA159 biofilms. The most potent antibacterial component was linoleic acid, a main component of the n-hexane fraction. Linoleic acid reduced viability in a dose dependent manner and reduced biofilm accumulation during initial and mature biofilm formation. Furthermore, when the biofilms were briefly treated with linoleic acid (10 min/treatment, a total of six times), the dry weight of the biofilms was significantly diminished. In addition, the anti-biofilm activity of the n-hexane fraction was similar to that of linoleic acid. These results suggest that the n-hexane fraction of D. crassirhizoma and linoleic acid may be useful for controlling cariogenic biofilms.

  20. 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

  1. 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, ...

  2. 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

  3. 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 ...

  4. 变异链球菌致龋性及酸性压力对其HtrA表达情况的影响%Influence of HtrA Expression on the Cariogenicity and the Acid Stress of Streptococcus Mutans

    Institute of Scientific and Technical Information of China (English)

    杨铁崎; 聂庆东; 郑鹏

    2013-01-01

    目的:探讨变异链球菌株HtrA的表达与其致龋性和耐酸性的关系.方法:收集了不同龋敏感性儿童口腔分离的变异链球菌共36株(高、低、无龋各12株),通过RT-PCR的方法对所有菌株HtrA的mRNA的表达水平进行了检测;此外,还检测了在分别含有10、20 mmol/L乳酸的培养基中生长的变异链球菌UA159菌株HtrAmRNA的表达变化.结果:高龋、低龋及无龋儿童口腔变异链球菌临床分离株HtrA mRNA表达存在差异,高龋组>低龋组>无龋组,差异具有统计学意义(P<0.01);酸性环境下变异链球菌中HtrA mRNA的表达水平也发生了明显上调(P<0.01).结论:HtrA基因的表达与变异链球菌的致龋性和耐酸性有着一定的相关性.%Objective: To explore the relationship between the HtrA expression of Streptococcus mutans and its cariogenicity and acid resistance.Methods: A totally of 36 isolates of Streptococcus mutans were obtained from children with different degree of dental caries (High- , low- and free - caries are 12 strains, respectively) , and the expression of HtrA mRNA of all strains were detected by RT- PCR method.Additional, the HtrA mRNA expression of S.mutans UA159 under lactic acid conditions were observed.Results: There was a difference among the HtrA mRNA expression in S.mutans isolates form Children with different degree of dental caries, High - caries group>low-caries group>free - caries group, and the difference was statistically significance (P<0.01).The HtrA mRNA expression level of S.mutans were up-regulated under acid conditions (P<0.01).Conclusion: The HtrA expression of S.mutans was related to its cariogenicity and acid resistance.

  5. 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.

  6. Study on the Influence and Mechanism of Photodynamic Therapy on the Cariogenic Bacteria in Dental Plaque Biofilms%光动力疗法对牙菌斑生物膜内致龋菌的影响及作用机制的研究

    Institute of Scientific and Technical Information of China (English)

    常秀明; 邹朝晖; 阴慧娟

    2012-01-01

    Objective: To study the killing effects and mechanism of photodynamic therapy using hematoporphyrin monomethylether as photosensitizer on the cariogenic bacteria in dental plaque biofilms. Methods: S. mutans. S. sangius. L. acidophilus. A. viscosus had been chosen as the experimental bacteria to establish dental plaque biofilms model. Divide them into four groups; HMME-PDT group,HMME-PDT+ sodium azide group, cetylpyridinium chloride group, normal saline group. The influence of the cariogenic bacteria in plaque biofilms was observed according to plate counting of bacteria method. A pH reflect the acid production of cariogenic bacteria of the different treatments. Results: Compared to normal saline group, HMME-PDT and cetylpyridinium chloride made the number of cariogenic bacteria (CFU/mL) in plaque biofilms significantly reduced(Pcariogenic bacteria in plaque biofilms of HMME + sodium azide group was not significant different, with the bactericidal rate only 9. 47%.⊿ pH of the records showed that, HMME-PDT group could prevent the acid production of cariogenic bacteria in plaque biofilms in a certain time range (0-24h). Conclusion: PDT is an effective method in eliminating cariogenic bacteria of dental plaque biofilms and inhibiting the acid production,while singlet oxygen plays an important role in the sterile process of PDT.%目的:探讨以血卟啉单甲醚( hematoporphyrin monomethylether,HMME)为光敏剂的光动力疗法(photodynamic therapy,PDT)对牙菌斑生物膜内致龋菌的杀灭作用及机制.方法:以变形链球菌、血链球菌、嗜酸性乳杆菌和粘性放线菌为实验菌株,建立牙菌斑生物膜模型.实验分为4组:HMME- PDT组、HMME- PDT加叠氮钠组、西吡氯铵处理组、生理盐水处理组.平板菌落计数观察牙菌斑内致龋菌的活力,并测定不同处理前后pH的变化值(△pH)观察其对致龋菌产酸能力的影响.结

  7. 黄芪浸出液对致龋菌的体外抑菌实验%In vitro antibiotic effect of the leaching solution of astragalus on cariogenic bacteria

    Institute of Scientific and Technical Information of China (English)

    张金婷; 邓旎; 车团结; 康妍丽; 何祥一

    2009-01-01

    选择甘肃产黄芪为原料,制成水浸出液,研究其对口腔常见致龋菌的抑制效果,并与国外致龋菌抑菌产品(MI)进行比较.以变形链球菌、乳酸杆菌为实验菌株,用选择性培养基进行液体培养,在培养基中添加不等量的药物,测培养24 h后菌液的A值、pH值;用SPSS 13.0对数据进行统计分析.黄芪浸出液对变形链球菌、乳酸杆菌的生长、产酸均有抑制效果,抗菌效果与MI相当.%Astragalus produced in Gansu were chosen as the raw material to leachate. Studied the antibiotic effects of the leaching solution on the cariogenic bacteria and compared with the imported bacteriostatic product MI. Streptococcus mutans and Lactobacilli were cultured in the medium for 24 h. The PH and A600 values were measured. Statistical analysis was conducted by using SPSS 13.0. The leaching solution of astragalus has the same inhibitory effects on the growth and acid production of streptococcus mutans and lactobacilli as MI.

  8. 柠檬提取物对口腔致龋菌生长影响的研究%Effect of Lemon Peel Extracts on the Growth of Cariogenic Bacteria

    Institute of Scientific and Technical Information of China (English)

    韩慧; 张向宇; 杨丽杰; 马金爽; 郭卯丁

    2012-01-01

    目的:检测柠檬提取物的生物安全性,研究柠檬提取物对主要致龋菌生长的影响,为进一步机制研究提供依据.方法:柠檬提取物ICR小鼠急性毒性试验(LD50试验):实验分两组,实验组柠檬水提浓缩液按0.05 ml/10g· bw灌胃,空白对照组室温、阳光等饲养条件与实验组相同.饲养14 d观察动物反应,第15天处死,解剖检查脏器情况;采用琼脂稀释法研究柠檬提取物对5种主要致龋菌(变异链球菌、血链球菌、内氏放线菌、远缘链球菌、嗜酸乳杆菌)生长的抑制作用,并采用菌落计数法检测柠檬提取物对5种细菌生长的影响.结果:ICR小鼠在14 d观察期中未发现死亡现象,处死后检查各脏器无异常现象.柠檬提取物对变异链球菌、血链球菌、远缘链球菌的最小抑菌浓度MIC(minimum inhibitory concentration)为4.5 g/L,对嗜酸乳杆菌和内氏放线菌的MIC为2.25 g/L.5种致龋菌在柠檬提取物作用下,其生长曲线均在第6小时左右出现明显的转折点,实验组与阴性组的细菌菌量均有显著性差异(P<0.05).结论:柠檬提取物样品LD50大于5000 mg/kg· bw,属于实际无毒物质;柠檬提取物对口腔致龋菌的生长有抑制作用.%Objective: To test the biological safety of lemon peel extract, find effect of lemon peel extracts on the growth of cariogenic bacteria and provide a basis for further study of mechanism. Methods; Acute toxicity test of lemon peel extracts on ICR mice (LD50 test): This experiment was divided into two groups. The experimental group was fed by lemonade concentrate with concentration of 0. 05ml/10g · bw. The room temperature, sunlight and other breeding conditions of control group were same with experimental group. 14-day's observation of animal response to feeding was conducted. These mice were killed and dissected to check the organs on the 15th day. The effect of lemon peel extracts on the growth of L. Acidophilus, A. Naeslundii, S

  9. 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

  10. 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)

  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. 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...

  13. Inhibitory efficacy of cyclo(L-leucyl-L-prolyl) from mangrove rhizosphere bacterium-Bacillus amyloliquefaciens (MMS-50) toward cariogenic properties of Streptococcus mutans.

    Science.gov (United States)

    Gowrishankar, Shanmugaraj; Poornima, Balan; Pandian, Shunmugiah Karutha

    2014-05-01

    Since Streptococcus mutans is the principal etiologic agent causing dental caries, by encompassing an array of unique virulence traits, emerging treatment strategies that specifically target the virulence of this pathogen may be promising as alternative approaches compared to conventional antibiotic therapy. In this perspective, we investigated chloroform extract of cell-free culture supernatant from mangrove rhizosphere bacterium Bacillus amyloliquefaciens (MMS-50) in terms of anticariogenic properties of S. mutans, without suppressing its viability. Crude chloroform extract of MMS-50 was subjected to column and high performance liquid chromatographic techniques to obtain the active fraction (AF), and MMS-50 AF was used for all further assays. GC-MS and FT-IR were carried out to identify the major components present in MMS-50 AF. Comparative gene expression analysis of some biofilm-forming and virulence genes (vicR, comDE, gtfC, and gbpB) was done by real-time PCR. Cyclo(L-leucyl-L-prolyl) was found to be the chief compound in MMS-50 AF responsible for bioactivity. The minimum and maximum inhibitory concentrations of MMS-50 AF against S. mutans were found to be 100 and 250 μg/mL, respectively. Anti-virulence assays performed using below-sub-MIC levels of MMS-50 AF (30 μg/mL) resulted in significant reduction in adherence (68%), acid production, acid tolerance, glucan synthesis (32%), biofilm formation (53.5%) and cell surface hydrophobicity, all devoid of affecting its viability. The micrographs of CLSM and SEM further confirmed the antibiofilm and anti-virulence efficacies of MMS-50 AF. Expression data showed significant reduction in expression of all studied virulence genes. Thus, the current study unveils the anticariogenic potential of cyclo(L-leucyl-L-prolyl) from B. amyloliquefaciens, as well as its suitability as a novel and alternative anticariogenic agent against dental caries.

  14. The study on anti-cariogenicity of rubrus suarissimus S. Lee saponin to streptococcus mutans%甜茶皂甙对变形链*球菌抑龋性的研究

    Institute of Scientific and Technical Information of China (English)

    李莉; 王玉波; 陈岱韻; 李俊福

    2014-01-01

    Objective:To study the inhibition of rubrus suavissimus S. Lee on the cariogenicity of streptococcus mutans . Methods:0. 1 ml streptococcus mutans solution was mixed with rubrus suavissimus S. Lee saponin of different concentra-tion,but the negative control group without rubrus suavissimus S. Lee saponin,and the glass rod was put in for 48 hours, then Each group was measured the OD of the streptococcus mutans on the glass rod. Results:When the concentration of rubrus suarissimus S. Lee Saponin was higher than 0. 625g/ml,the adhering glass rod of Streptococcus Mutans was lower than the negative control group. Conclusion:Rubrus suarissimus S. Lee Saponin could inhibit the streptococcus mutans.%目的:研究甜茶皂甙对变形链球菌致龋性的抑制作用。方法将0.1 ml变形链球菌悬液加入不同浓度的甜茶皂甙溶液的实验组,和无甜茶皂甙的基础液对照组,将玻棒分别插入各支试管培养48 h,将玻棒上黏附的菌细胞洗脱下来,测OD值。结果甜茶皂甙的浓度≥0.625 g/100 ml时,变形链球菌对玻璃棒的黏附低于无甜茶皂甙的对照组。结论甜茶皂甙对变形链球菌黏附抑制作用。

  15. 薄荷复方煎液对龋病及牙周病致病菌生理活性的影响%Effect of Menthol compound decoction on the physiological activity of cariogenic and periodontopathic bacteria

    Institute of Scientific and Technical Information of China (English)

    孙墅; 丘创华; 王舞妮

    2015-01-01

    Objective:The purpose of this study was to investigate the role of Menthol compound decoction on the metaboliam of glycose metabolism and acid metabolism of cariogenic bacteria and to find out the mechanism of anticario-genic of Menthol compound decoction. Method:Streptococcus sanguinis (ATCC 10556) and Porphyromonas gingivalis (ATCC 33277) were chosen as the experimental bacterias,observing the change of glycose metabolism and acid metabolism on the effect of Menthol compound decoction. Result:Menthol compound decoction had an inhibitory effect to the acid and the WIG of Streptococcus sanguinis (ATCC 10556) and Porphyromonas gingivalis (ATCC 33277). Conclusion: Menthol compound decoction had an inhibitory effect to the glycol metabolism and acid metabolism.%目的:研究薄荷复方煎液对龋病及牙周病致病菌产酸及合成细胞外多糖的影响,明确薄荷复方煎液的抗菌机制. 方法:选取血链球菌和牙龈卟啉单胞菌作为实验菌株,研究薄荷复方煎液对口腔细菌产酸及合成水不溶性胞外多糖能力的影响. 结果:薄荷复方煎液使血链球菌和牙龈卟啉单胞菌的产酸量和合成不溶性葡聚糖含量明显减少.结论:薄荷复方煎液对口腔细菌的酸代谢和糖代谢有一定的抑制作用.

  16. 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.

  17. 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...

  18. 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.

  19. 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.

  20. 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...

  1. 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…

  2. 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

  3. 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: ...

  4. 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.

  5. Analysis of the sterilization effects of Menthol compound decoction on the cariogenic and periodontopathic bacteria%薄荷复方煎液对龋病、牙周病致病菌杀菌作用的研究

    Institute of Scientific and Technical Information of China (English)

    孙墅; 丘创华; 王舞妮

    2015-01-01

    目的:研究薄荷复方煎液对龋病、牙周病致病菌的抑制和杀灭作用。方法:致龋菌血链球菌、变形链球菌和牙周病致病菌牙龈卟啉单胞菌分离培养,将薄荷复方煎液配成不同浓度,分别对4种细菌做药敏试验,记录各自的最小抑菌浓度(MIC)和最小杀菌浓度(MBC)。结果:血链球菌MIC1:32,变形链球菌MIC1:4,牙龈卟啉单胞菌MIC1:32;血链球菌MBC1:16,变形链球菌MBC1:1,牙龈卟啉单胞菌MBC1:8。结论:薄荷复方煎液对龋病、牙周病致病菌有抑制和杀灭作用。%Objective:TO examine the inhibitory and killing effects of Menthol compound decoction on the cariogenic and periodontopathic bacteria,providing the basis for drugs that treat dental caries and periodontal disease. Method:The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of Menthol compound decoction a-gainst S. sanguinis (ATCC 10556),S.mutans (ATCC 25175) and P. gingivalis (ATCC 33277)were measured. Result:The MIC of Menthol compound decoction on S. sanguinis was 1:32,the MBC was 1:16;the MIC of it on S.mutans was 1:4,the MBC was 1:1;the MIC of it on P. gingivalis was 1:32,the MBC was 1:8. Conclusion:Menthol compound decoction has in-hibition and bactericidal effects on oral pathogens.

  6. Culturally Aware Agent Communication

    DEFF Research Database (Denmark)

    Rehm, Matthias; Nakano, Yukiko; Koda, Tomoko

    2012-01-01

    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......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...

  7. 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.

  8. 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

  9. 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...

  10. 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.

  11. 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.

  12. 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

  13. 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...

  14. Hydroxychalcone inhibitors of Streptococcus mutans glucosyl transferases and biofilms as potential anticaries agents.

    Science.gov (United States)

    Nijampatnam, Bhavitavya; Casals, Luke; Zheng, Ruowen; Wu, Hui; Velu, Sadanandan E

    2016-08-01

    Streptococcus mutans has been implicated as the major etiological agent in the initiation and the development of dental caries due to its robust capacity to form tenacious biofilms. Ideal therapeutics for this disease will aim to selectively inhibit the biofilm formation process while preserving the natural bacterial flora of the mouth. Several studies have demonstrated the efficacies of flavonols on S. mutans biofilms and have suggested the mechanism of action through their effect on S. mutans glucosyltransferases (Gtfs). These enzymes metabolize sucrose into water insoluble and soluble glucans, which are an integral measure of the dental caries pathogenesis. Numerous studies have shown that flavonols and polyphenols can inhibit Gtf and biofilm formation at millimolar concentrations. We have screened a group of 14 hydroxychalcones, synthetic precursors of flavonols, in an S. mutans biofilm assay. Several of these compounds emerged to be biofilm inhibitors at low micro-molar concentrations. Chalcones that contained a 3-OH group on ring A exhibited selectivity for biofilm inhibition. Moreover, we synthesized 6 additional analogs of the lead compound and evaluated their potential activity and selectivity against S. mutans biofilms. The most active compound identified from these studies had an IC50 value of 44μM against biofilm and MIC50 value of 468μM against growth displaying >10-fold selectivity inhibition towards biofilm. The lead compound displayed a dose dependent inhibition of S. mutans Gtfs. The lead compound also did not affect the growth of two commensal species (Streptococcus sanguinis and Streptococcus gordonii) at least up to 200μM, indicating that it can selectively inhibit cariogenic biofilms, while leaving commensal and/or beneficial microbes intact. Thus non-toxic compounds have the potential utility in public oral health regimes.

  15. 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.

  16. 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....

  17. 高果糖玉米糖浆致龋性的动物实验研究%Cariogenicity of high fructose corn syrup: an experimental study on rats

    Institute of Scientific and Technical Information of China (English)

    肖天鸣; 夏文薇

    2013-01-01

    目的:通过观察大鼠进食含高果糖玉米糖浆(high fructose corn syrups,HFCS)饲料后牙齿的患龋情况,评价HFCS的致龋性.方法:选择适龄SPF级远交群大鼠(Spraque-Dawley,SD)30只,抑制口腔固有菌群后接种变异链球菌UA159,并随机分为3组,分别用不含糖饲料、含蔗糖饲料和含HFCS饲料喂养3个月.3个月后截取上下颌骨,体视显微镜观察磨牙颊舌面龋损;制作磨牙纵磨片,荧光染色后用荧光显微镜观察(牙合)面和邻面龋损情况,并根据Keyes评分法评价龋损程度.结果:3组大鼠的患龋率均为100%.HFCS组与蔗糖组的龋损程度无统计学差异(P>0.05);蔗糖组各牙面的龋齿记分均显著高于不含糖饲料组(P<0.05);HFCS组中,窝沟龋全层、平滑面龋釉质和牙本质外层1/4的龋齿记分均明显高于不含糖饲料组(P<0.05),而平滑面龋损深度超过牙本质厚度1/4的龋齿记分与不含糖饲料组比较无统计学差异(P>0.05).结论:含HFCS的饮食能导致SD大鼠发生龋病,其龋损程度与蔗糖相近.%AIM:To evaluate the cariogenicity of high fructose corn syrup (HFCS).METHODS:30 SPF Sprague-Dawley(SD) rats inoculated orally with Streptococcus mutans UA159 were randomly divided into 3 groups and were respectively provided with non-sugar,sucrose-containing and HFCS-containing diets.After 3 months,the Jaw bones were removed.A binocular microscope was used to examine the teeth for buccal and lingual caries.Grinding sections were then prepared,stained with Rhodamine B,and examined for proximal and fissure caries by fluorescence microscope.The caries lesions were assessed by Keyes method.RESULTS:The prevalence of dental caries was 100% in all 3 groups.Keyes caries scores in sucrose group were similar to those in HFCS group(P > 0.05) and significantly higher than in non-sugar group(P < 0.05).While no significant difference was observed in the levels of lesions extending into the inner 3/4 of dentine on smooth

  18. Influence of apigenin on the cariogenicity of Streptococcus mutans%芹菜素对变异链球菌致龋力影响的实验研究

    Institute of Scientific and Technical Information of China (English)

    李蓓蕾; 岳阳丽; 刘瑶; 刘学军

    2014-01-01

    目的:研究芹菜素(apigenin)对变异链球菌致龋力的影响。方法:用含20 g/L蔗糖的TPY液体培养基,以二倍体稀释法将芹菜素配制成12.5、25、50、100、200、400μg/mL 的含药培养基,并与变异链球菌ATCC25175(血清C型)共同培养;分别观察不同浓度芹菜素对变异链球菌增殖及其产酸能力、粘附能力、葡聚糖转移酶(GTF )活力和水不溶性胞外多糖生成能力的影响。结果:与空白对照组相比,不同浓度芹菜素对变异链球菌的增殖和产酸均无明显影响(P>0.05);但可明显抑制变异链球菌的粘附能力、GTF的活性以及水不溶性胞外多糖的生成量(P<0.05);且随着芹菜素浓度的增加,其抑制作用逐渐增强,各浓度组相比,除200μg/mL与400μg/mL组间无统计学差异(P>0.05)外,其他各浓度组间差异均有统计学意义(P<0.05)。结论:芹菜素对变异链球菌的生长、产酸无影响,但对其粘附、GTF活性和水不溶性胞外多糖的生成具有抑制作用。%AIM:To study the effects of apigenin on the cariogenicity of Streptoccous mutans (S.mutans). METHODS:S.mutans ATCC25175 cells were treated by apigenin at the concentration (μg/mL)of 12.5,25,50, 100,200 and 400 respectively,and TPY liquid medium was used as the control.Bacteriostatic experiment was conduc-ted by disc diffusion method.PH value drop quantity,adhesion inhibition rate,glucanotransferase (GTF)vitality and the content of insoluble exopolysaccharides were measured in every groups.RESULTS:Apigenin solution at the vari-ous concentrations showed no effect on the proliferation and anaerobic acidogenesis of the bacteria.With the increase of apigenin concentration the adhesion inhibition rate of S.mutans increased,while GTF vitality and insoluble exopolysac-charides content decreased(P<0.05).CONCLUSION:Apigenin has no inhibition effect on the proliferation and acid production of S

  19. 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...

  20. 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...

  1. 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

  2. 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.

  3. 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...

  4. Non-digestible oligosaccharides used as prebiotic agents: mode of production and beneficial effects on animal and human health.

    Science.gov (United States)

    Grizard, D; Barthomeuf, C

    1999-01-01

    Prebiotic agents are food ingredients that are potentially beneficial to the health of consumers. The main commercial prebiotic agents consist of oligosaccharides and dietary fibres (mainly inulin). They are essentially obtained by one of three processes: 1) the direct extraction of natural polysaccharides from plants; 2) the controlled hydrolysis of such natural polysaccharides; 3) enzymatic synthesis, using hydrolases and/or glycosyl transferases. Both of these enzyme types catalyse transglycosylation reactions, allowing synthesis of small molecular weight synthetic oligosaccharides from mono- and disaccharides. Presently, in Europe, inulin-type fructans, characterised by the presence of fructosyl units bound to the beta-2,1 position of sucrose, are considered as one of the carbohydrate prebiotic references. Prebiotics escape enzymatic digestion in the upper gastrointestinal tract and enter the caecum without change to their structure. None are excreted in the stools, indicating that they are fermented by colonic flora so as to give a mixture of short-chain fatty acids (acetate, propionate and butyrate), L-lactate, carbon dioxide and hydrogen. By stimulating bifidobacteria, they may have the following implications for health: 1) potential protective effects against colorectal cancer and infectious bowel diseases by inhibiting putrefactive bacteria (Clostridium perfringens ) and pathogen bacteria (Escherichia coli, Salmonella, Listeria and Shigella ), respectively; 2) improvement of glucid and lipid metabolisms; 3) fibre-like properties by decreasing the renal nitrogen excretion; 4) improvement in the bioavailability of essential minerals; and 5) low cariogenic factor. These potential beneficial effects have been largely studied in animals but have not really been proven in humans. The development of a second generation of oligosaccharides and the putative implication of a complex bacterial trophic chain in the intestinal prebiotic fermentation process are also

  5. 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...

  6. 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.

  7. [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.

  8. [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.

  9. 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

  10. 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...

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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...

  16. 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.

  17. 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...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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...

  14. 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.

  15. 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...

  16. 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

  17. Effect of Sucrose Concentration on Cariogenicity of Streptococcus mutans in Dental Plaque of S-ECC%蔗糖浓度对重症婴幼儿龋菌斑中变型链球菌致龋性的影响

    Institute of Scientific and Technical Information of China (English)

    赵玮; 李文卿; 卢佳璇; 余东升

    2011-01-01

    [Objective] To determine the effect of sucrose concentration on cariogenicity of Streptococcus mutans in dental plaque of S-ECC. [Methods] Plaque samples were collected from 67 children aged from 3 to 5. Strains of Streptococcus mutans were identified, purified and then cultured in PYC medium with 1%, 5%, 10%, and 20% sucrose. The pH value of supernatant was measured to evaluate acidogencity of Streptococcus mutans, and OD600 to evaluate the propagating status. The quantities of water insoluble glucans (WIG) were measured by anthrone method. Turbidimetry was used to measure the adhesive ability. [Results] Acidogenicity, propagation, WIG synthesis, and adhesion ratio of Streptococcus mutans from S-ECC group were statistically higher than caries free group. The cariogenicity of Streptococcus mutans enhanced with the increase of sucrose concentration. In 5% sucrose group, pH decreased to critical pH5.5. Propagation, WIG synthesis and adhesion ratio increased a lot, especially in S-ECC group. When sucrose concentration was above 5%, ApH, OD600, WIG and adhesion ratio still increased, however, the growth rate became slow down. [Conclusion] The cariogenicity of Streptococcus mutans was dose-dependent with sucrose levels, and the concentration of which exceeded 5% is considered to be more cariogenic and important for S-ECC prevention.%摘要:[目的]探讨不同蔗糖浓度对重症婴幼儿龋(S-ECC)菌斑中变形链球菌致龋性的影响.[方法]采集67名3~5岁S-ECC及无龋儿童牙面菌斑,获取纯化的变链菌株,接种至蔗糖浓度分别为1%、5%、10%及20%的PYG液体培养基,采用精密pH计测变链菌产酸能力;分光光度仪测定OD600值,评价其生长情况;蒽酮法测定水不溶性葡聚糖(WIG)的量;比浊法测定变链菌的黏附比值,对比分析变形链球菌不同临床菌株的致龋性.[结果]随蔗糖浓度升高,S-ECC及无龋组变形链球菌临床分离菌株产酸、合成胞外多糖及粘附能力均

  18. 细菌外排泵抑制剂对光动力疗法抑制牙菌斑生物膜内主要致龋菌作用的影响%Impact of Efflux Pump-Inhibitors on Inhibition of Cariogenic Bacteria in Dental Plaque Biofilms with Photodynamic Therapy

    Institute of Scientific and Technical Information of China (English)

    陶亚东; 邹朝晖; 孙盼盼; 郭鹏; 阴慧娟

    2012-01-01

    To Study the impact of the efflux pump-inhibitor, verapamil, on the cariogenic bacteria in dental plaque biofilms in the photodynamic therapy using hematoporphyrin monomethylether as photosensitizer.The dental plaque biofilm models were established with streptococcus mutans, streptococcus sanguis, eosinophilic lactoba- cillus and actinomyces viscosus. By the order to add verapamil and photosensitizer in the PDT process, five groups were created; Group A, in which cells were incubated with photosensitizer and verapamil simultaneously; Group B, in which cells were incubated with verapamil before photosensitizer, Group C, in which cells were incubated with photosensitizer before verapamil; Group D, in which cells were given only PDT; and Group E, the saline-treated group. After the laser irradiation, plate count of bacteria was obtained to evaluate the vitality of the dental plaque bacteria after the PDT. Results The reduction of living cariogenic bacteria (CFU/mL) in plaque biofilms was much more distinctive (P <0.05 ) in the sole PDT group than in the saline-treatment group, showing a bactericidal rate up to 94.92% . The comparison between Group B and Group D indicated a significant upward trend in the number of living cariogenic bacteria (P < 0. 05), and the sterilizationrate of the latter was 80.92%. Conclusions HMME-PDT inhibits effectively the growth of cariogenic bacteria and bacterial efflux pump plays an extremely important role in the process.%目的 探讨细菌外排泵抑制剂(microbial efflux pump Inhibitor,EPI)——维拉帕米对以血卟啉单甲醚(hematoporphyrin monomethylether,HMME)为光敏剂的光动力疗法(photodynamic therapy,PDT)抵抗牙菌斑生物膜内主要致龋菌作用的影响.方法 以变形链球菌、血链球菌、嗜酸性乳杆菌和粘性放线菌为实验菌株,建立牙菌斑生物膜模型.以维拉帕米作为细菌外排泵抑制剂,根据在PDT过程中加入维拉帕米和光敏剂的先后顺序,实验分为5

  19. 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.

  20. Agent Based Individual Traffic Guidance

    DEFF Research Database (Denmark)

    Wanscher, Jørgen

    This thesis investigates the possibilities in applying Operations Research (OR) to autonomous vehicular traffic. The explicit difference to most other research today is that we presume that an agent is present in every vehicle - hence Agent Based Individual Traffic guidance (ABIT). The next...... evolutionary step for the in-vehicle route planners is the introduction of two-way communication. We presume that the agent is capable of exactly this. Based on this presumption we discuss the possibilities and define a taxonomy and use this to discuss the ABIT system. Based on a set of scenarios we conclude...

  1. 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.

  2. 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.

  3. 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

  4. Anti-Clotting Agents Explained

    Science.gov (United States)

    ... or may require special dosage adjustments. Anticoagulants While antiplatelets keep clots from forming by inhibiting the production of thromboxane, anticoagulants target clotting factors, which are other agents that are crucial to the blood-clotting process. ...

  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. 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. 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.

  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. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Study of the effective of efflux pump inhibitors in photodynamic therapy inhibition the cariogenic bacteria in dental plaque biofilms%激光共聚焦显微镜观察维拉帕米对HMME-PDT抑制混合菌菌斑生物膜作用的影响

    Institute of Scientific and Technical Information of China (English)

    邹朝晖; 陶亚东; 孙盼盼; 阴慧娟; 李迎新

    2013-01-01

    Objective To Study the effect of efflux pump-inhibitors(EPI)-Verapamil in photodynamic therapy (PDT) using hematoporphyrin monomethylether (HMME) as photosensitizer on the cariogenic bacteria in dental plaque biofilms.Methods According to the administrator order of the verapamil and photosensitizer in PDT,streptococcus mutans,streptococcus sanguis,eosinophilic lactobacillus and actinomyces viscosus were used to establish the dental plaque biofilm model.The experiment was divided into five groups,group A was incubated with the photosensitizer and verapamil group,group B using verapamil before incubated the photosensitize,group C suing photosensitizer before incubated verapamil,group D with PDT only,group E was control group.After laser treatment,the influence of the dental plaque biofilms was observed by confocal laser scanning microscope.Results As saline-treated group is a group of normal the dental plaque biofilms.In PDT only group,compared with the saline group,red fluorescence increased significantly,the bacteria lose accumulation capacity,and were isolated and scattered in dispersed state.In PDT plus verapamil group,compared with only PDT group,green staining increased,bacterial activity increased.In group B,cells were incubated with verapamil before incubated the photosensitizer group,green staining increased significantly,red fluorescence reduced,indicating live bacteria increased,and bacteria activity was significantly increased.Conclusion PDT is an effective method in eliminating cariogenic bacteria of dental plaque biofilms.Bacterial efflux pump inhibitors can lower HMME-PDT inhibition cariogenic bacteria in dental plaque biofilm,and pre-verapamil administration could significantly inhibit the effect of PDT treatment of dental caries.%目的 探讨细菌外排泵抑制剂(EPI)——维拉帕米对以血卟啉单甲醚(HMME)为光敏剂的光动力疗法(PDT)抵抗牙菌斑生物膜内主要致龋菌作用的影响.方法 以变形链球菌、血链球菌

  15. 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...

  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. [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.

  19. 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.

  20. 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.

  1. Agent communication and artificial institutions

    OpenAIRE

    Fornara, Nicoletta; Viganò, Francesco; Colombetti, Marco

    2011-01-01

    In this paper we propose an application-independent model for the definition of artificial institutions that can be used to define open multi-agent systems. Such a model of institutional reality makes us able also to define an objective and external semantics of a commitment-based Agent Communication Language (ACL). In particular we propose to regard an ACL as a set of conventions to act on a fragment of institutional reality, defined in the context of an artificial institution. Another c...

  2. 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...

  3. 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.

  4. 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...

  5. 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.

  6. 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

  7. 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

  8. 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,

  9. 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.

  10. 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

  11. 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…

  12. An Introduction to Software Agents

    Science.gov (United States)

    2008-02-01

    applicable to modelling red force entities for VMSA. This paper provides an overview of software agents and represents the first step in the...ordinateur, et que la simulation en cours modélise leurs capteurs , leurs armes et leurs caractéristiques matérielles. vi DRDC Atlantic TM...34 9 Sample Applications

  13. 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...

  14. 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

  15. 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

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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...

  4. 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...... 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...... by developments within semantics for logic programming within computational logic and formal theories of truth within philosophical logic. The thesis provides a number of examples showing how the developed theories can be used as reasoning frameworks for agents with introspective abilities. In Danish...

  5. 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.

  6. 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...

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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- ...

  12. 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]....

  13. 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...

  14. 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...

  15. 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.

  16. 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 ...

  17. Presença de Streptococcus mutans e Streptococcus mutans associado a Streptococcus sobrinus em escolares de diferentes classes sócio-econômicas e sua relação com a atividade cariogênica dessas populações Association between Streptococcus mutans/Streptococcus sobrinus in students of different social levels and their relationship with the cariogenic activity in these populations

    Directory of Open Access Journals (Sweden)

    José Francisco HÖFLING

    1999-04-01

    Full Text Available As espécies de estreptococos do grupo mutans mais predominantemente isoladas de amostras salivares têm sido S. mutans e S. sobrinus. A detecção desses microrganismos em escolares de diferentes classes sócio-econômicas e sua relação com a atividade cariogênica dessas populações foi estudada, em correlação com os parâmetros clínicos CPOD, CPOS, ceo e ceos. Duzentos (200 escolares pertencentes a cinco categorias sócio-econômicas foram separados em subgrupos de acordo com as espécies de microrganismos identificadas em suas amostras salivares. Do total de crianças analisadas, 103 (51,0% apresentaram apenas S. mutans na saliva, 33 (17,0% a associação S. mutans/S. sobrinus, e o restante, 64 (32,0%, outras espécies do grupo mutans (individualmente ou em associação. Nos subgrupos S. mutans e S. mutans/S. sobrinus 79,0% (81 e 76,0% (25, respectivamente, apresentavam cárie dentária, sugerindo um alto índice cariogênico. Para os indivíduos colonizados por S. mutans/S. sobrinus e apenas S. mutans, obtiveram-se valores médios de 9,40 e 6,70, respectivamente, para o índice de ceos, sugerindo que a associação S. mutans/S. sobrinus é potencialmente mais cariogênica que a colonização apenas por S. mutans.The group mutans streptococci, more predominantly isolated of salivary samples, have been the S. mutans and S. mutans/S. sobrinus. The detection of these microorganisms in students of different socio-economic levels and their relationship with the cariogenic activity of these populations was studied, correlating them with the clinical parameters DMFT, DMFS, dmf and dmfs. Two hundred (200 students belonging to five socio-economic levels were distributed in sub-groups, according to the species of microorganisms identified in their salivaries samples. Of all children analysed, 103 (51.0% presented only S. mutans in the saliva, 33 (17.0% the association S. mutans/S. sobrinus, and 64 (32.0%, other group mutans species (individually

  18. 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.

  19. Percepções e atitudes de responsáveis por crianças frente ao uso de medicamentos infantis e sua relação com cárie e erosão dentária Perceptions and attitudes among parents and guardians on the use of pediatric medicines and their cariogenic and erosive potential

    Directory of Open Access Journals (Sweden)

    Beatriz Gonçalves Neves

    2007-10-01

    Full Text Available Este estudo avaliou as percepções e atitudes de responsáveis por crianças sobre os potenciais cariogênico e erosivo de medicamentos infantis. Foram realizadas entrevistas sobre a associação do uso de medicamentos infantis com cárie e erosão dentária, bem como os cuidados com a higiene bucal após sua ingestão. Do total de responsáveis com entrevista completa (n=86, 24 (27,9% consideraram os medicamentos infantis ácidos, 51 (59,3% amargos e 56 (65,1% doces; porém, apenas 16 (28,6% destes últimos realizavam higiene bucal das crianças após utilização (Exato de Fisher; p>0,05. Além disso, apenas 18 (20,9% responsáveis realizavam esta prática, dos quais 8 (44,4% haviam recebido orientação prévia sobre higiene bucal (Exato de Fisher; pThe study assesses the perceptions of parents/guardians on the use of pediatric medicines and their cariogenic/erosive potential, interviewing them on the relationship between the use of pediatric medicines and cavities/dental erosion, as well as oral hygiene procedures after the medication. Among the interviewed parents/guardians (n=86, 24 (27.9% mentioned the sour taste of pediatric medication, 51 (59.3% the bitter taste, and 56 (65.1% considered them sweet, although only 16 (28.6% of these parents/guardians brushed their children's teeth after the medication (Fisher's Exact; p>0.05. Moreover, only 18 (20.9% of the parents/guardians performed oral hygiene practices after the medication, of whom 8 (44.4% received previous instructions (Fisher's Exact; p<0.05. The association between taking medications and dental caries or structural dental defects was mentioned by 61 (70.9% of the parents/guardians, with 24 (39.3% of them justifying this association through the presence of sugar in the formulations. Although parents/guardians consider medicines to be sweet substances and relate their use to dental caries and tooth structure flaws, most of them do not brush their children's teeth after taking

  20. A Framework for Multi-Agent Planning

    NARCIS (Netherlands)

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

    2000-01-01

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

  1. 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.

  2. 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 ...

  3. Security Measures to Protect Mobile Agents

    Science.gov (United States)

    Dadhich, Piyanka; Govil, M. C.; Dutta, Kamlesh

    2010-11-01

    The security issues of mobile agent systems have embarrassed its widespread implementation. Mobile agents that move around the network are not safe because the remote hosts that accommodate the agents initiates all kinds of attacks. These hosts try to analyze the agent's decision logic and their accumulated data. So, mobile agent security is the most challenging unsolved problems. The paper analyzes various security measures deeply. Security especially the attacks performed by hosts to the visiting mobile agent (the malicious hosts problem) is a major obstacle that prevents mobile agent technology from being widely adopted. Being the running environment for mobile agent, the host has full control over them and could easily perform many kinds of attacks against them.

  4. 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.

  5. Agent Communication Channel Based on BACnet

    Institute of Scientific and Technical Information of China (English)

    Jiang Wen-bin; Zhou Man-li

    2004-01-01

    We analyze the common shortcoming in the existing agent MTPs (message transport protocols). With employing the File object and related service AtomicWriteFile of BACnet (a data communication protocol building automation and control networks), a new method of agent message transport is proposed and implemented. Every agent platform (AP) has one specified File object and agents in another AP can communicate with agents in the AP by using AtomicWriteFile service. Agent messages can be in a variety of formats. In implementation, BACnet/IP and Ethernet are applied as the BACnet data link layers respectively. The experiment results show that the BACnet can provide perfect support for agent communication like other conventional protocols such as hypertext transfer protocol(HTTP), remote method invocation (RMI) etc. and has broken through the restriction of TCP/IP. By this approach, the agent technology is introduced into the building automation control network system.

  6. Integration of Agent System with Legacy Software

    Institute of Scientific and Technical Information of China (English)

    SHEN Qi; ZHAO Yan-hong; YIN Zhao-lin

    2003-01-01

    Agent technique is a new method that can analyze, design and realize a distributed open system. It has been used in almost every field. But if act for the real practical words in technique, it must integrate with legacy software, such as database system etc, and control them. This paper introduces the specification of agent software integration, ontology, instances database as implementing agent software integration with CORBA technique and takes XML, ACL as language communicating among agents.

  7. Kansei Evaluation in Agent Rearing Game

    OpenAIRE

    野路, 浩一朗; 西野, 順二; 小高, 知宏; 小倉, 久和; NOJI, Koichiro; NISHINO, Junji; ODAKA, Tomohiro; OGURA, Hisakazu

    1999-01-01

    In this paper, We have studied the Kansei evaluation of the agent rearing game. The agent rearing game is a game by which the characters who are the agents are brouht up. The Kansei evaluation is an evaluation by Kansei engineering like the sensibility and feelings, etc. to treat technological1y. In this research, We produced the agent rearing game. We propose the method of the interesting the game using the technique of Kansei engineering for the evaluation.

  8. Sports Agent Industry Emerges in China

    Institute of Scientific and Technical Information of China (English)

    HeiZiand; YiYou

    2003-01-01

    The agent profession is not new to Chinese. First appearing in the Western Zhou Dynasty, agents were called "Zhi Ren" then and "Ya Ren" from the Tang Dynasty onwards. In the Ming Dynasty, a certain amount of property and a license were required if one wanted to become an agent. In the late Qing Dynasty, Mai Ban (Chinese executives working in foreign firms), also a sort of agents, began to emerge in major cities of China.

  9. Honey - A Novel Antidiabetic Agent

    Directory of Open Access Journals (Sweden)

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

    2012-01-01

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

  10. Pathogenic agents in freshwater resources

    Science.gov (United States)

    Geldreich, Edwin E.

    1996-02-01

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

  11. Preferences of Agents in Defeasible Logic

    NARCIS (Netherlands)

    Dastani, M.; Governatori, G.; Rotolo, A.; Torre, L.W.N. van der

    2005-01-01

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

  12. Stability of Evolving Multi-Agent Systems

    CERN Document Server

    De Wilde, Philippe; 10.1109/TSMCB.2011.2110642

    2011-01-01

    A Multi-Agent System is a distributed system where the agents or nodes perform complex functions that cannot be written down in analytic form. Multi-Agent Systems are highly connected, and the information they contain is mostly stored in the connections. When agents update their state, they take into account the state of the other agents, and they have access to those states via the connections. There is also external, user-generated input into the Multi-Agent System. As so much information is stored in the connections, agents are often memory-less. This memory-less property, together with the randomness of the external input, has allowed us to model Multi-Agent Systems using Markov chains. In this paper, we look at Multi-Agent Systems that evolve, i.e. the number of agents varies according to the fitness of the individual agents. We extend our Markov chain model, and define stability. This is the start of a methodology to control Multi-Agent Systems. We then build upon this to construct an entropy-based defi...

  13. Do pedagogical agents enhance software training?

    NARCIS (Netherlands)

    Meij, van der Hans

    2013-01-01

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

  14. Properties of Ettringite Type Expansive Agent

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    By employing different forms and amounts of materials,many kinds of ettringite type expansive agents had been prepared.The relationship between the compositions and properties of expansive agents was analyzed.The design methods of expansive agent have been put forward according to the property requirement of expansive concrete.

  15. A principal-agent model of corruption

    NARCIS (Netherlands)

    Groenendijk, Nico

    1997-01-01

    One of the new avenues in the study of political corruption is that of neo-institutional economics, of which the principal-agent theory is a part. In this article a principal-agent model of corruption is presented, in which there are two principals (one of which is corrupting), and one agent (who is

  16. 31 CFR 332.12 - Fiscal agents.

    Science.gov (United States)

    2010-07-01

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

  17. 31 CFR 339.6 - Fiscal agents.

    Science.gov (United States)

    2010-07-01

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

  18. 31 CFR 352.13 - Fiscal agents.

    Science.gov (United States)

    2010-07-01

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

  19. 31 CFR 316.12 - Fiscal agents.

    Science.gov (United States)

    2010-07-01

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

  20. Touching virtual agents: embodiment and mind

    NARCIS (Netherlands)

    Huisman, Gijs; Bruijnes, Merijn; Kolkmeier, Jan; Jung, Merel; Darriba Frederiks, Aduén; Rybarczyk, Yves

    2014-01-01

    In this paper we outline the design and development of an embodied conversational agent setup that incorporates an augmented reality screen and tactile sleeve. With this setup the agent can visually and physically touch the user. We provide a literature overview of embodied conversational agents, as

  1. Agents and Lattice-valued Logic

    Institute of Scientific and Technical Information of China (English)

    Germanno Resconi

    2006-01-01

    In fuzzy set theory, instead of the underlying membership set being a two -valued set it is a multi-valued set that generally has the structure of a lattice L with a minimal element O and the maximal element I. Furthermore if ∧, ∨, → and (「) are defined in the set L, then we can use these operations to define, as in the ordinary set theory, operations on fuzzy subsets. In this paper we give a model of the Lattice-Valued Logic with set of agents.Any agents know the logic value of a sentence p. The logic value is compatible with all of the accessible conceptual models or worlds of p inside the agent. Agent can be rational or irrational in the use of the logic operation.Every agent of n agents can have the same set of conceptual models for p and know the same logic for p in this case the agents form a consistent group of agents.When agents have different conceptual models for p,different subgroup of agents know different logic value for p. In this case the n agents are inconsistent in the expression of the logic value for p. The valuation structure of set of agents can be used as a semantic model for the Lattice-valued Logic and fuzzy logic.

  2. Multi-Agent Planning with Planning Graph

    NARCIS (Netherlands)

    Bui, The Duy; Jamroga, Wojciech

    2003-01-01

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

  3. Embedded Automation in Human-Agent Environment

    CERN Document Server

    Tweedale, Jeffrey W

    2012-01-01

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

  4. Deliberative evolution in multi-agent systems

    NARCIS (Netherlands)

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

    2001-01-01

    Evolution of automated systems, in particular evolution of automated agents based on agent deliberation, is the topic of this paper. Evolution is not a merely material process, it requires interaction within and between individuals, their environments and societies of agents. An architecture for an

  5. Compositional Design of a Generic Design Agent

    NARCIS (Netherlands)

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

    2001-01-01

    This paper presents a generic architecture for a design agent, to be used in an Internet environment. The design agent is based on an existing generic agent model, and includes a refinement of a generic model for design, in which strategic reasoning

  6. A theoretical framework for explaining agent behavior

    NARCIS (Netherlands)

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

    2011-01-01

    To understand emergent processes in multi-agent-based simulations it is important to study the global processes in a simulation as well as the processes on the agent level. The behavior of individual agents is easier to understand when they are able to explain their own behavior. In this paper, a th

  7. Mobile Agents in Networking and Distributed Computing

    CERN Document Server

    Cao, Jiannong

    2012-01-01

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

  8. Animated BDP agents in virtual environments

    NARCIS (Netherlands)

    Nijholt, A.; Egges, A.; Akker, op den H.J.A.; Zwiers, J.; Krose, B.; de Rijke, M.; Schreiber, G.; van Someren, M.

    2001-01-01

    We introduce a Believes, Desires and Plans (BDP) agent that acts in a virtual environment using multi-modal interaction with the user. The environment is our virtual theatre environment. In this environment different agents have been introduced. In order to obtain a more uniform framework for agent

  9. Multi agent gathering waste system

    Directory of Open Access Journals (Sweden)

    Álvaro LOZANO MURCIEGO

    2016-07-01

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

  10. Social communication with virtual agents

    DEFF Research Database (Denmark)

    Marschner, Linda; Pannasch, Sebastian; Schulz, Johannes

    2015-01-01

    In social communication, the gaze direction of other persons provides important information to perceive and interpret their emotional response. Previous research investigated the influence of gaze by manipulating mutual eye contact. Therefore, gaze and body direction has been changed as a whole...... response, and emotional experience to agents of different gender and facial expressions were investigated. Eye movement data revealed longer fixation durations, i.e. a stronger allocation of attention, when gaze and body direction were not congruent with each other or when both were directed towards...

  11. Multi agent gathering waste system

    OpenAIRE

    Lozano Murciego, Álvaro; Gabriel VILLARRUBIA GONZÁLEZ; Alberto LÓPEZ BARRIUSO; Daniel HERNÁNDEZ DE LA IGLESIA; Jorge REVUELTA HERRERO

    2015-01-01

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

  12. [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.

  13. Social Robots as Persuasive Agents

    DEFF Research Database (Denmark)

    Vlachos, Evgenios; Schärfe, Henrik

    2014-01-01

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

  14. Triazole: A Promising Antitubercular Agent.

    Science.gov (United States)

    Keri, Rangappa S; Patil, Siddappa A; Budagumpi, Srinivasa; Nagaraja, Bhari Mallanna

    2015-10-01

    Tuberculosis is a contagious disease with comparatively high mortality worldwide. The statistics shows that around three million people throughout the world die annually from tuberculosis and there are around eight million new cases each year, of which developing countries showed major share. Therefore, the discovery and development of effective antituberculosis drugs with novel mechanism of action have become an insistent task for infectious diseases research programs. The literature reveals that, heterocyclic moieties have drawn attention of the chemists, pharmacologists, microbiologists, and other researchers owing to its indomitable biological potential as anti-infective agents. Among heterocyclic compounds, triazole (1,2,3-triazole/1,2,4-triazole) nucleus is one of the most important and well-known heterocycles, which is a common and integral feature of a variety of natural products and medicinal agents. Triazole core is considered as a privileged structure in medicinal chemistry and is widely used as 'parental' compounds to synthesize molecules with medical benefits, especially with infection-related activities. In the present review, we have collated published reports on this versatile core to provide an insight so that its complete therapeutic potential can be utilized for the treatment of tuberculosis. This review also explores triazole as a potential targeted core moiety against tuberculosis and various research ongoing worldwide. It is hoped that this review will be helpful for new thoughts in the quest for rational designs of more active and less toxic triazole-based antituberculosis drugs.

  15. A Review of Luting Agents

    Directory of Open Access Journals (Sweden)

    Cornelis H. Pameijer

    2012-01-01

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

  16. Surfactants as blackbird stressing agents

    Science.gov (United States)

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

    1970-01-01

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

  17. An Agent-Based Distributed Manufacturing System

    Institute of Scientific and Technical Information of China (English)

    J.Li; J.Y.H.Fuh; Y.F.Zhang; A.Y.C.Nee

    2006-01-01

    Agent theories have shown their promising capability in solving distributed complex system ever since its development. In this paper, one multi-agent based distributed product design and manufacturing planning system is presented. The objective of the research is to develop a distributed collaborative design environment for supporting cooperation among the existing engineering functions. In the system, the functional agents for design, manufacturability evaluation,process planning and scheduling are efficiently integrated with a facilitator agent. This paper firstly gives an introduction to the system structure, and the definitions for each executive agent are then described and a prototype of the proposed is also included at the end part.

  18. A framework for organization-aware agents

    DEFF Research Database (Denmark)

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

    2016-01-01

    ’ behavior space and describe the expected behavior of the agents. Assuming an open environment, where agents are developed independently of the Organizational structures, agents need to be able to reason about the structure, so that they can deliberate about their actions and act within the expected...... boundaries and work towards the objectives of the organization. In this paper, we present the AORTA reasoning framework and show how it can be integrated into typical BDI-agents. We provide operational semantics that enables agents to make organizational decisions in order to coordinate and cooperate without...

  19. Building Multi-Agent Systems Using Jason

    DEFF Research Database (Denmark)

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

    2010-01-01

    We provide a detailed description of the Jason-DTU system, including the used methodology, tools as well as team strategy. We also discuss the experience gathered in the contest. In spring 2009 the course “Artificial Intelligence and Multi- Agent Systems” was held for the first time...... on the Technical University of Denmark (DTU). A part of this course was a short introduction to the multi-agent framework Jason, which is an interpreter for AgentSpeak, an agent-oriented programming language. As the final project in this course a solution to the Multi-Agent Programming Contest from 2007, the Gold...

  20. 75 FR 56489 - Separation Distances of Ammonium Nitrate and Blasting Agents From Explosives or Blasting Agents...

    Science.gov (United States)

    2010-09-16

    ... Ammonium Nitrate and Blasting Agents From Explosives or Blasting Agents (2002R-226P) AGENCY: Bureau of... CFR 555.220 set forth a table of separation distances of ammonium nitrate and blasting agents from explosives or blasting agents followed by six explanatory notes. Note three (3) states that the...

  1. Introduction to Agent Mining Interaction and Integration

    Science.gov (United States)

    Cao, Longbing

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

  2. An Agent Framework of Tourism Recommender System

    Directory of Open Access Journals (Sweden)

    Jia Zhi Yang

    2016-01-01

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

  3. Model Based Testing for Agent Systems

    Science.gov (United States)

    Zhang, Zhiyong; Thangarajah, John; Padgham, Lin

    Although agent technology is gaining world wide popularity, a hindrance to its uptake is the lack of proper testing mechanisms for agent based systems. While many traditional software testing methods can be generalized to agent systems, there are many aspects that are different and which require an understanding of the underlying agent paradigm. In this paper we present certain aspects of a testing framework that we have developed for agent based systems. The testing framework is a model based approach using the design models of the Prometheus agent development methodology. In this paper we focus on model based unit testing and identify the appropriate units, present mechanisms for generating suitable test cases and for determining the order in which the units are to be tested, present a brief overview of the unit testing process and an example. Although we use the design artefacts from Prometheus the approach is suitable for any plan and event based agent system.

  4. Knowledge Management in Role Based Agents

    Science.gov (United States)

    Kır, Hüseyin; Ekinci, Erdem Eser; Dikenelli, Oguz

    In multi-agent system literature, the role concept is getting increasingly researched to provide an abstraction to scope beliefs, norms, goals of agents and to shape relationships of the agents in the organization. In this research, we propose a knowledgebase architecture to increase applicability of roles in MAS domain by drawing inspiration from the self concept in the role theory of sociology. The proposed knowledgebase architecture has granulated structure that is dynamically organized according to the agent's identification in a social environment. Thanks to this dynamic structure, agents are enabled to work on consistent knowledge in spite of inevitable conflicts between roles and the agent. The knowledgebase architecture is also implemented and incorporated into the SEAGENT multi-agent system development framework.

  5. Agent-Oriented Probabilistic Logic Programming

    Institute of Scientific and Technical Information of China (English)

    Jie Wang; Shi-Er Ju; Chun-Nian Liu

    2006-01-01

    Currently, agent-based computing is an active research area, and great efforts have been made towards the agent-oriented programming both from a theoretical and practical view. However, most of them assume that there is no uncertainty in agents' mental state and their environment. In other words, under this assumption agent developers are just allowed to specify how his agent acts when the agent is 100% sure about what is true/false. In this paper, this unrealistic assumption is removed and a new agent-oriented probabilistic logic programming language is proposed, which can deal with uncertain information about the world. The programming language is based on a combination of features of probabilistic logic programming and imperative programming.

  6. Multi-agent for manufacturing systems optimization

    Science.gov (United States)

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

    2016-08-01

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

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

    CERN Document Server

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

    2012-01-01

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

  8. Survey of agent for intelligent information retrieval; Chiteki kensaku no tame no agent no chosa

    Energy Technology Data Exchange (ETDEWEB)

    Yazawa, T. [Central Research Institute of Electric Power Industry, Tokyo (Japan)

    1996-09-01

    Development of agent systems has been surveyed, to classify and arrange characteristic functions of the agents, and to grasp the realization situation of these agents in their development. In addition, prospective functions of information retrieval systems using the agents at maximum and functions to be developed among these in the future are clarified. The agents are characterized by the expression function, communication function, planning function, adaptive function, and learning function. The agents are desired to be classified into interface agents whose works are to respond to individual workers, coordinator agents which conduct works with high pervasion, such as assignment of works and their control, and task agents which conduct specialized works for individual examples. Thus, design and configuration of the agent system, and improvement and expansion of system functions can be effectively and easily conducted. 52 refs., 5 figs., 3 tabs.

  9. Opinion evolution influenced by informed agents

    Science.gov (United States)

    Fan, Kangqi; Pedrycz, Witold

    2016-11-01

    Guiding public opinions toward a pre-set target by informed agents can be a strategy adopted in some practical applications. The informed agents are common agents who are employed or chosen to spread the pre-set opinion. In this work, we propose a social judgment based opinion (SJBO) dynamics model to explore the opinion evolution under the influence of informed agents. The SJBO model distinguishes between inner opinions and observable choices, and incorporates both the compromise between similar opinions and the repulsion between dissimilar opinions. Three choices (support, opposition, and remaining undecided) are considered in the SJBO model. Using the SJBO model, both the inner opinions and the observable choices can be tracked during the opinion evolution process. The simulation results indicate that if the exchanges of inner opinions among agents are not available, the effect of informed agents is mainly dependent on the characteristics of regular agents, including the assimilation threshold, decay threshold, and initial opinions. Increasing the assimilation threshold and decay threshold can improve the guiding effectiveness of informed agents. Moreover, if the initial opinions of regular agents are close to null, the full and unanimous consensus at the pre-set opinion can be realized, indicating that, to maximize the influence of informed agents, the guidance should be started when regular agents have little knowledge about a subject under consideration. If the regular agents have had clear opinions, the full and unanimous consensus at the pre-set opinion cannot be achieved. However, the introduction of informed agents can make the majority of agents choose the pre-set opinion.

  10. Fault Tolerance Mobile Agent System Using Witness Agent in 2-Dimensional Mesh Network

    Directory of Open Access Journals (Sweden)

    Ahmad Rostami

    2010-09-01

    Full Text Available Mobile agents are computer programs that act autonomously on behalf of a user or its owner and travel through a network of heterogeneous machines. Fault tolerance is important in their itinerary. In this paper, existent methods of fault tolerance in mobile agents are described which they are considered in linear network topology. In the methods three agents are used to fault tolerance by cooperating to each others for detecting and recovering server and agent failure. Three types of agents are: actual agent which performs programs for its owner, witness agent which monitors the actual agent and the witness agent after itself, probe which is sent for recovery the actual agent or the witness agent on the side of the witness agent. Communication mechanism in the methods is message passing between these agents. The methods are considered in linear network. We introduce our witness agent approach for fault tolerance mobile agent systems in Two Dimensional Mesh (2D-Mesh Network. Indeed Our approach minimizes Witness-Dependency in this network and then represents its algorithm.

  11. 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.

  12. Host modulation by therapeutic agents

    Directory of Open Access Journals (Sweden)

    Sugumari Elavarasu

    2012-01-01

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

  13. [Risk assessment of chemical agents].

    Science.gov (United States)

    Cottica, Danilo; Grignani, Elena; Bartolucci, Giovanni Battista

    2011-01-01

    The risk assessment of chemical agents is a well known and applied process carried out by Industrial Hygienists and Occupational Physicians based on exposure evaluation. The application of REACH (CE 1907/2006), CLP (CE 1272/2008) and SDS (UE 453/2010) introduces some changes and instruments to carry out the occupational exposure assessment, like new classification of substances, Exposure Scenario, suggested control measures that the Industrial Hygienist and the Occupational Physician must evaluate. If there is not a similar Exposure Scenario to apply a new risk assessment must carried out also by recommended software (ECETOC Targeted Risk Assessment; Easy to use workplace EMKG; Stoffenmanager). Looking at the relevance of the control measures and evaluation of Exposure Scenario we report the flowchart of risk assessment and management by the Method of Organisational Congruencies carried out with the Prevention and Protection Service and Occupational Physician Office of the Health Service of the Azienda Provinciale of Trento.

  14. [Fiber as a carcinogenic agent].

    Science.gov (United States)

    Pott, F

    1987-04-01

    According to the findings that long, thin, and durable fibres have a high carcinogenic potency after intrapleural and intraperitoneal administration, the elongated shape of a particle represents a carcinogenic agent; this physical phenomenon is a special cause of cancer. It induces a biological process which can lead to cancer by several as yet unknown steps. However, the properties of the material the fibres are made of determine the carcinogenic potency of a fibre in a secondary way although they do not seem to be responsible for the true carcinogenic agent. For example, these properties determine the degree of solubility and flexibility. The persistence of fibres in the tissue is a very important property with regard to their carcinogenic effect because the formation of a tumour takes many years or some decades. It can be assumed that a fibre has to remain by the bronchial or serosa tissue until the induction of tumour cells occurs. If this hypothesis is correct, there could be a "durability threshold value" for fibres whose length and diameter would otherwise indicate a high carcinogenic potency. There are indications that other fibre properties apart from length, diameter and durability are important for tumour induction, however, at present, they cannot be included in a definition of carcinogenic fibres. It is proposed to classify all natural and man-made mineral fibres with an aspect ratio of greater than 5:1 as carcinogenic when they are longer than 3 microns, thinner than 1 micron (or can split into such fine fibres) and when they can persist in the tissue for more than 3 years.

  15. Agent Reward Shaping for Alleviating Traffic Congestion

    Science.gov (United States)

    Tumer, Kagan; Agogino, Adrian

    2006-01-01

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

  16. Agent Grid技术研究初探%Initial Research on Agent Grid

    Institute of Scientific and Technical Information of China (English)

    张英朝; 张维明; 肖卫东; 沙基昌

    2003-01-01

    The term "Grid" is increasingly appearing in computer literature, generally referring to some form of system framework into which hardware, software, or information resources can be plugged, and which permits easy configuration and creation of new functionality from existing resources. In this article, first, we introduce the concepts of Grid and Agent Grid based on our own understanding. Then we compare Agent Grid with the traditional Multi-Agent System to make the concept and characters of Agent Grid much clearer. Next, the key techniques of Agent Grid, such as Agent Grid System Architecture, System Models, Intelligent Agents and Agent-Based System Resource Management, are thoroughly illustrated. Finally, we briefly discusse the future applications of Agent Grid.

  17. MATRIX-AGENT FRAMEWORK:A VIRTUAL PLATFORM FOR MULTI-AGENTS

    Institute of Scientific and Technical Information of China (English)

    Hao Lan ZHANG; Clement H.C. LEUNG; Gitesh K. RAIKUNDALIA

    2006-01-01

    Multi-agent technology has been applied extensively to many areas, including Decision Support Systems (DSS). However, the applications of multi-agent technology in DSS are still very preliminary.Most of the current agent frameworks, such as middle-agent-based or agent-facilitator-based frameworks, are basically agent-to-agent model. These agent-based frameworks often neglect the living environment for agents and they suffer from: (i) inability to adapt to the environment, (ii)inability to self-upgrade, and (iii) inefficiency in information acquisition. Here, we introduce a recently proposed multi-agent framework, namely Agent-based Open Connectivity for Decision Support Systems (AOCD). In this new framework, the communication and cooperation between agents are through a key component, the Matrix, which provides a virtual platform for agents. We use a unified Matrices framework to solve the bottleneck problem in the AOCD framework. Our experimental results based on different agent network topologies indicate that the hybrid topology presents superior performance compared with the centralised and decentralised topologies.

  18. Persuasive Conversational Agent with Persuasion Tactics

    Science.gov (United States)

    Narita, Tatsuya; Kitamura, Yasuhiko

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

  19. Diuretic Agents in Treatment of Sudden Deafness

    Institute of Scientific and Technical Information of China (English)

    JI Chang-you; LI Hong-tao; ZHOU Ding-rong; CHEN Ji-chuan; WANG Yi-nan; GUAN Li-qian; ZHANG Min

    2008-01-01

    Objective To study the role of diuretic agents in treating sudden deafness (SD) and explore the possibility of endolymphatic hydrops as a potential cause of SD. Methods Twenty-eight SD cases were reviewed. In 23 cases, treatment was initiated with routine agents. Diuretic agents were later added in 8 of these cases that failed to respond to routine treatment agents. Diuretic agents were included in the initial treatment in the rest 5 cases. In total, 13 cases received diuretics in addition to routine treatment agents and 15 cases received conventional treatment only. Results In the 8 cases who received diuretics after failed conventional treatments, 4 showed hearing improvement, whereas all 5 cases in which diuretics were included in the initial treatment demonstrated hearing improvement. Conclusion These results suggest a possible role of endolymphatic hydrops in the pathophysiologic course of SD. Diuretics should be considered when clear indications exist with no conflicts to other medical conditions.

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

    Science.gov (United States)

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

    2003-01-01

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

  1. Cariogenic bacteria degrade dental resin composites and adhesives.

    Science.gov (United States)

    Bourbia, M; Ma, D; Cvitkovitch, D G; Santerre, J P; Finer, Y

    2013-11-01

    A major reason for dental resin composite restoration replacement is related to secondary caries promoted by acid production from bacteria including Streptococcus mutans (S. mutans). We hypothesized that S. mutans has esterase activities that degrade dental resin composites and adhesives. Standardized specimens of resin composite (Z250), total-etch (Scotchbond Multipurpose, SB), and self-etch (Easybond, EB) adhesives were incubated with S. mutans UA159 or uninoculated culture medium (control) for up to 30 days. Quantification of the BisGMA-derived biodegradation by-product, bishydroxy-propoxy-phenyl-propane (BisHPPP), was performed by high-performance liquid chromatography. Surface analysis of the specimens was performed by scanning electron microscopy (SEM). S. mutans was shown to have esterase activities in levels comparable with those found in human saliva. A trend of increasing BisHPPP release throughout the incubation period was observed for all materials and was more elevated in the presence of bacteria vs. control medium for EB and Z250, but not for SB (p < .05). SEM confirmed the increased degradation of all materials with S. mutans UA159 vs. control. S. mutans has esterase activities at levels that degrade resin composites and adhesives; degree of degradation was dependent on the material's chemical formulation. This finding suggests that the resin-dentin interface could be compromised by oral bacteria that contribute to the progression of secondary caries.

  2. Massive Multi-Agent Systems Control

    Science.gov (United States)

    Campagne, Jean-Charles; Gardon, Alain; Collomb, Etienne; Nishida, Toyoaki

    2004-01-01

    In order to build massive multi-agent systems, considered as complex and dynamic systems, one needs a method to analyze and control the system. We suggest an approach using morphology to represent and control the state of large organizations composed of a great number of light software agents. Morphology is understood as representing the state of the multi-agent system as shapes in an abstract geometrical space, this notion is close to the notion of phase space in physics.

  3. Web-Based Computing Resource Agent Publishing

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Web-based Computing Resource Publishing is a efficient way to provide additional computing capacity for users who need more computing resources than that they themselves could afford by making use of idle computing resources in the Web.Extensibility and reliability are crucial for agent publishing. The parent-child agent framework and primary-slave agent framework were proposed respectively and discussed in detail.

  4. Intelligent Agents in E-Commerce

    Directory of Open Access Journals (Sweden)

    Valentin LITOIU

    2006-01-01

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

  5. Deaths due to Unknown Foodborne Agents

    OpenAIRE

    2004-01-01

    This study reviews the available evidence on unknown pathogenic agents transmitted in food and examines the methods that have been used to estimate that such agents cause 3,400 deaths per year in the United States. The estimate of deaths was derived from hospital discharge and death certificate data on deaths attributed to gastroenteritis of unknown cause. Fatal illnesses due to unknown foodborne agents do not always involve gastroenteritis, and gastroenteritis may not be accurately diagnosed...

  6. Resource Adaptive Agents in Interactive Theorem Proving

    CERN Document Server

    Benzmueller, Christoph

    2009-01-01

    We introduce a resource adaptive agent mechanism which supports the user in interactive theorem proving. The mechanism uses a two layered architecture of agent societies to suggest appropriate commands together with possible command argument instantiations. Experiments with this approach show that its effectiveness can be further improved by introducing a resource concept. In this paper we provide an abstract view on the overall mechanism, motivate the necessity of an appropriate resource concept and discuss its realization within the agent architecture.

  7. 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...

  8. Decentralized network management based on mobile agent

    Institute of Scientific and Technical Information of China (English)

    李锋; 冯珊

    2004-01-01

    The mobile agent technology can be employed effectively for the decentralized management of complex networks. We show how the integration of mobile agent with legacy management protocol, such as simple network management protocol (SNMP), leads to decentralized management architecture. HostWatcher is a framework that allows mobile agents to roam network, collect and process data, and perform certain adaptive actions. A prototype system is built and a quantitative analysis underlines the benefits in respect to reducing network load.

  9. Glaucoma: role of neuroprotective agents

    Directory of Open Access Journals (Sweden)

    Achyut N. Pandey

    2014-10-01

    Full Text Available Glaucoma is an optic neuropathy, considered as the second leading cause of blindness worldwide. Glaucoma is characterized by selective death of retinal ganglion cells (RGC and a progressive loss of vision. Elevated intraocular pressure (IOP is one of the most important risk factors for developing glaucoma and hence we mainly focus on lowering IOP to arrest the progression of glaucoma. However, many patients continue to demonstrate a clinically downhill course despite the control of initially raised IOP. In fact, some patients develop what is called normal tension glaucoma, not associated to an increased IOP. This emphasizes that several pressure-independent mechanisms are responsible for the development and progression of glaucomatous neuropathy and that high IOP and vascular insufficiency in the optic nerve head are only risk factors for the development of glaucoma, and are not the only target for the treatment of glaucoma. The reason is that the process of RGC death is thought to be biphasic, and the primary injury is followed by a slower secondary degeneration related to a noxious environment surrounding the apoptotic cells. This environment is characterized by changes in the extra-cellular ionic concentrations, increased amounts of free radicals, neurotrophins (NT depletion and increased glutamate-induced excitotoxicity due to high extra-cellular glutamate levels, which binds to N-methyl-D-aspartate (NMDA receptors leading to an abnormally high intracellular Ca2+ concentration. Neuroprotection is a process that attempts to preserve the remaining cells that are still vulnerable to damage, and the main aim of neuroprotective therapy is to employ pharmacologic or other means to attenuate the hostility of the environment surrounding the degenerating cells, or to supply the cells with the tools to deal with this aggression, providing resilience to the insult. Several agents have been reported neuroprotective in glaucoma, both in clinical assays

  10. Multi-agent systems simulation and applications

    CERN Document Server

    Uhrmacher, Adelinde M

    2009-01-01

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

  11. Agent-Based Health Monitoring System Project

    Data.gov (United States)

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

  12. Active evacuation guidance using sensor agent robot

    Science.gov (United States)

    Ise, Daiki; Mita, Akira

    2012-04-01

    Evacuation systems for buildings are designed based on event scenarios, so they are not prepared for unexpected events that are not included in the scenarios. In this paper, we propose a new active evacuation guidance system using sensor agent robots. We first introduce a Structural Health Monitoring (SHM) system to be used in conjunction with sensor agent robots for active evacuation guidance. Then the role of sensor agent robots is explained. An algorithm to immediately access the safety of the building after a large earthquake is also proposed using only the information taken by a sensor agent robot.

  13. Multi-agent and complex systems

    CERN Document Server

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

    2017-01-01

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

  14. The Research on Mobile-agent Security

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Mobile agent technology offers a new computing paradigm in which a program, in the form of a software agent, can suspend its execution in a host computer, transfer itself to another agent-enabled host in the network, and resume execution of the new host. As the sophistication of mobile software has increased with the time, so have the associated threats to security. This paper provides an overview of the range of threats facing the designers of mobile agent. The paper also identifies generic security objectives, and a range of measures for countering the identified threats.

  15. Integrating Interaction Framework for Agent Negotiation

    Institute of Scientific and Technical Information of China (English)

    肖正光; 王振杰; 徐良贤

    2003-01-01

    Agent negotiation has become increasingly important since the advent of electronic commerce.There are two kinds of interactions in the process of agent negotiation.One is the interaction between different agents,and the other is the interaction between the agent and the human user.In this paper,firstly,we introduce Q language,a scenario description language for designing interactions between agents and human users.Then we propose an integrating interaction framework for agent negotiation,in which both kinds of interactions are described by Q scenario.Our framework can make the interaction process open and easy to be understood by the users.Users can understand how the negotiation process goes and what is happening in the system including some erroneous or inappropriate actions caused by the negotiation agent.This gives the users a chance to terminate or change the behavior of negotiation agent in time to avoid unfavorable negotiation outcome.In addition,users can customize the agent's behaviors through visible interactions with it.

  16. Confocal laser scanning microscopy for observing difference in synthesizing exopolysaccharide by highly cariogenic clinical and standard strains of biofilm Streptococcus mutans%激光共聚焦扫描显微镜观察变异链球菌高致龋力临床株与标准株合成胞外多糖能力差异

    Institute of Scientific and Technical Information of China (English)

    黄晓晶; 江山; 陈帅

    2011-01-01

    exopolysaccharides during formation of biofilm increases with time in both clinical and standard strains of S. mutans. However, the stronger synthesizing ability of strain 593 in the early biofilm formation stage (3-16 h) may be the reason for its higher cariogenic ability, indicating that the clinical isolates may be more sensitive in studying the mechanism of caries pathogenesis.

  17. Direct anti-HCV agents

    Directory of Open Access Journals (Sweden)

    Xingquan Zhang

    2016-01-01

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

  18. Dronedarone: a new antiarrhythmic agent.

    Science.gov (United States)

    Oyetayo, Ola O; Rogers, Carrie E; Hofmann, Prudence O

    2010-09-01

    Dronedarone is an antiarrhythmic agent recently approved by the United States Food and Drug Administration for the reduction of cardiovascular-related hospitalizations in patients with paroxysmal or persistent atrial fibrillation or atrial flutter. The drug is a derivative of amiodarone and has been modified to reduce the organ toxicities frequently encountered with amiodarone. Dronedarone exerts its antiarrhythmic effects through multichannel blockade of the sodium, potassium, and calcium channels and also possesses antiadrenergic activity, thereby exhibiting pharmacologic effects of all four Vaughan Williams classes of antiarrhythmics. The efficacy of dronedarone for the maintenance of sinus rhythm, ventricular rate control, and reduction in cardiovascular-related hospitalizations has been demonstrated in several randomized, placebo-controlled trials. Although a high rate of gastrointestinal events (e.g., nausea, vomiting, and diarrhea) has been associated with dronedarone, more serious adverse events such as thyroid, liver, or pulmonary toxicities have not been observed. Because of a possible increase in mortality, dronedarone should be avoided in patients with New York Heart Association class IV or II-III heart failure with a recent decompensation. Given the efficacy and safety data currently available, dronedarone represents a reasonable alternative for maintenance of sinus rhythm in appropriately selected patients.

  19. 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

  20. Copper complexes as therapeutic agents.

    Science.gov (United States)

    Duncan, Clare; White, Anthony R

    2012-02-01

    The importance of transition metals in biological processes has been well established. Copper (Cu) is a transition metal that can exist in oxidised and reduced states. This allows it to participate in redox and catalytic chemistry, making it a suitable cofactor for a diverse range of enzymes and molecules. Cu deficiency or toxicity is implicated in a variety of pathological conditions; therefore inorganic complexes of Cu have been investigated for their therapeutic and diagnostic potential. These Cu complexes have been shown to be effective in cancer treatment due to their cytotoxic action on tumour cells. Alternatively, Cu complexes can also modulate Cu homeostasis in the brain, resulting in protective effects in several models of neurodegeneration. In other diseases such as coronary heart disease and skin disease, the success of Cu complexes as potential therapeutics will most likely be due to their ability to increase SOD activity, leading to relief of oxidative stress. This review seeks to provide a broad insight into some of the diverse actions of Cu complexes and demonstrate the strong future for these compounds as potential therapeutic agents.

  1. Application Framework with Abstractions for Protocol and Agent Role

    DEFF Research Database (Denmark)

    Kristensen, Bent Bruun

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Fujimura, Kikuo.

    1990-01-01

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

  3. Group Behavior Learning in Multi-Agent Systems Based on Social Interaction Among Agents

    OpenAIRE

    Zhang, Kun; Maeda, Yoichiro; Takahashi, Yasutake

    2011-01-01

    Research on multi-agent systems, in which autonomous agents are able to learn cooperative behavior, has been the subject of rising expectations in recent years. We have aimed at the group behavior generation of the multi-agents who have high levelsof autonomous learning ability, like that of human beings, through social interaction between agents to acquire cooperative behavior. The sharing of environmentstates can improve cooperative ability, andthe changing state of the environment in the i...

  4. Practice among Novice Change Agents in Schools

    Science.gov (United States)

    Blossing, Ulf

    2016-01-01

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

  5. Security of Mobile Agents on the Internet.

    Science.gov (United States)

    Corradi, Antonio; Montanari, Rebecca; Stefanelli, Cesare

    2001-01-01

    Discussion of the Internet focuses on new programming paradigms based on mobile agents. Considers the security issues associated with mobile agents and proposes a security architecture composed of a wide set of services and components capable of adapting to a variety of applications, particularly electronic commerce. (Author/LRW)

  6. Agent Based Reasoning in Multilevel Flow Modeling

    DEFF Research Database (Denmark)

    Lind, Morten; Zhang, Xinxin

    2012-01-01

    to launch the MFM Workbench into an agent based environment, which can complement disadvantages of the original software. The agent-based MFM Workbench is centered on a concept called “Blackboard System” and use an event based mechanism to arrange the reasoning tasks. This design will support the new...

  7. Modelling cooperative agents in infrastructure networks

    NARCIS (Netherlands)

    Ligtvoet, A.; Chappin, E.J.L.; Stikkelman, R.M.

    2010-01-01

    This paper describes the translation of concepts of cooperation into an agent-based model of an industrial network. It first addresses the concept of cooperation and how this could be captured as heuristical rules within agents. Then it describes tests using these heuristics in an abstract model of

  8. Freeze conditioning agents ease winter railcar unloading

    Energy Technology Data Exchange (ETDEWEB)

    Olson, G.E.

    1982-02-01

    A US midwest utility's freeze control programme is described. All coal is treated with a glycol-based freeze control agent. Some rail wagons were treated with a side release agent which stops coal sticking to the metal wagon. The use of calcium chloride or heat to thaw frozen coal is also discussed.

  9. Cognitive agent programming : A semantic approach

    NARCIS (Netherlands)

    Riemsdijk, M.B. van

    2006-01-01

    In this thesis we are concerned with the design and investigation of dedicated programming languages for programming agents. We focus in particular on programming languages for rational agents, i.e., flexibly behaving computing entities that are able to make "good" decisions about what to do. An imp

  10. Tennessee Extension Agents' Perceptions of Performance Appraisal

    Science.gov (United States)

    Donaldson, Joseph L.; French, Russell L.

    2013-01-01

    Performance appraisal is necessary for summative decisions about employees, such as merit pay and promotion. The research reported here describes Extension agent perceptions of their performance appraisal system. The population studied consisted of all Tennessee Extension agents (N = 312). Surveys were completed by 218 respondents, for a completed…

  11. On conversational agents with mental states

    NARCIS (Netherlands)

    Bosse, T.; Provoost, S.

    2015-01-01

    Embodied conversational agents (ECAs) have been put forward as a promising means for the training of social skills. The traditional approach to drive the behaviour of ECAs during human-agent dialogues is to use conversation trees. Although this approach is easy to use and very transparent, an import

  12. Towards Emergent Energy Synchronization using Agents

    NARCIS (Netherlands)

    Pournaras, E.; Warnier, M.E.; Brazier, F.M.T.

    2010-01-01

    Synchronization of energy consumption is a key determinant for the stabilization of smart energy grids. This paper proposes software agents that locally synchronize the energy usage of appliances to minimize the oscillations in global energy consumption. Agents can manage demand-side devices with pe

  13. Modeling of Agent Behavior Using Behavioral Specifications

    NARCIS (Netherlands)

    Sharpanskykh, A.; Treur, J.

    2006-01-01

    The behavioral dynamics of a cognitive agent can be considered both from an external and an internal perspective. From the external perspective, behavior is described by specifying (temporal) correlations between input and output states of the agent. From the internal perspective the agent’s dynamic

  14. Marine natural products as prototype agrochemical agents.

    Science.gov (United States)

    Peng, Jiangnan; Shen, Xiaoyu; El Sayed, Khalid A; Dunbar, D Charles; Perry, Tony L; Wilkins, Scott P; Hamann, Mark T; Bobzin, Steve; Huesing, Joseph; Camp, Robin; Prinsen, Mike; Krupa, Dan; Wideman, Margaret A

    2003-04-09

    In the interest of identifying new leads that could serve as prototype agrochemical agents, 18 structurally diverse marine-derived compounds were examined for insecticidal, herbicidal, and fungicidal activities. Several new classes of compounds have been shown to be insecticidal, herbicidal, and fungicidal, which suggests that marine natural products represent an intriguing source for the discovery of new agrochemical agents.

  15. Marine Natural Products as Prototype Agrochemical Agents

    OpenAIRE

    Peng, Jiangnan; Shen, Xiaoyu; Khalid A. El Sayed; Dunbar, D. C Harles; Perry, Tony L.; Wilkins, Scott P.; Hamann, Mark T.; Bobzin, Steve; Huesing, Joseph; Camp, Robin; Prinsen, Mike; Krupa, Dan; Wideman, Margaret A.

    2003-01-01

    In the interest of identifying new leads that could serve as prototype agrochemical agents, 18 structurally diverse marine-derived compounds were examined for insecticidal, herbicidal, and fungicidal activities. Several new classes of compounds have been shown to be insecticidal, herbicidal, and fungicidal, which suggests that marine natural products represent an intriguing source for the discovery of new agrochemical agents.

  16. Biological agents in polyarticular juvenile idiopathic arthritis

    DEFF Research Database (Denmark)

    Amarilyo, Gil; Tarp, Simon; Foeldvari, Ivan

    2016-01-01

    BACKGROUND AND OBJECTIVE: Although various biological agents are in use for polyarticular juvenile idiopathic arthritis (pJIA), head-to-head trials comparing the efficacy and safety among them are lacking. We aimed to compare the efficacy and safety of biological agents in pJIA using all currentl...

  17. Modelling social agents: Communication as actions

    NARCIS (Netherlands)

    Dignum, F.P.M.; Linder, B. van; M. Wooldridge J. Muller and N. Jennings

    1997-01-01

    In this paper we present a formal framework for social agents. The social agents consist of four components: the information component (containing knowledge and belief), the action component, the motivational component (where goals, intentions, etc. play arole) and the social component (containing a

  18. 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...

  19. Agent programming languages: programming with mental models

    NARCIS (Netherlands)

    Hindriks, K.V.

    2001-01-01

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

  20. Agent based computational model of trust

    NARCIS (Netherlands)

    A. Gorobets (Alexander); B. Nooteboom (Bart)

    2004-01-01

    textabstractThis paper employs the methodology of Agent-Based Computational Economics (ACE) to investigate under what conditions trust can be viable in markets. The emergence and breakdown of trust is modeled in a context of multiple buyers and suppliers. Agents adapt their trust in a partner, the w

  1. PU Sizing Agent Sector Starts Reform

    Institute of Scientific and Technical Information of China (English)

    Wang Lei

    2007-01-01

    @@ Polyurethane (PU) sizing agent is a thermoplastic PU elastomer extensively used in synthetic leather, artificial deerskin and electrostatic flocking sectors. The drastic production and demand increase of synthetic leather in China in recent years has promoted rapid consumption growth of PU sizing agent.

  2. Designing Negotiating Agent for Automated Negotiations

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Traditional research in automated negotiation is focused on negotiation protocol and strategy.This paper studies automated negotiation from a new point of view, proposes a novel concept, namely negotiating agent, and discusses its significance in construction of automated negotiation system, with an abstract model formally described and the architecture designed, which supports both goal-directed reasoning and reactive response. A communication model was proposed to construct interaction mechanism used by negotiating agents, in which the negotiation language used by agents is defined.The communication model and the language are defined in a way general enough to support a wide variety of market mechanisms, thus being particularly suitable for flexible applications such as electronic business. The design and expression of the negotiation ontology is also discussed. On the base of the theoretical model of negotiating agent, negotiating agent architecture and negotiating agent communication model (NACM) are explicit and formal specifications for the agents negotiating in an E-business environment; especially, NACM defines the negotiation language template shared among all agents formally and explicitly. The novelty of the communication model is twofold.

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

    CERN Document Server

    Müller, Jörg; Rodríguez, Juan; Pérez, Javier

    2012-01-01

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

  4. Econophysics of agent-based models

    CERN Document Server

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

    2014-01-01

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

  5. Fault Reconnaissance Agent for Sensor Networks

    Directory of Open Access Journals (Sweden)

    Elhadi M. Shakshuki

    2010-01-01

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

  6. Development of Soda Residue Concrete Expansion Agent

    Institute of Scientific and Technical Information of China (English)

    WANG Bao-min; WANG Li-jiu; M F Mohd Zain; F C Lai

    2003-01-01

    A new type of concrete expansion agent has been successfully developed for the first time in the world by utilizing an industrial waste residue-soda residue and an industrial wasteliquor.Adding 3%-6% of the agent into Portland cement enables a shrinkage-compensating concrete to be prepared.Mortar and concrete containing this expansion agent have better shrinkage-compensating and mechanical properties.The raw materials component,production process,technical properties,micro-analysis of mortar made with this expansion agent,mechanism of expansion and research results are described in this article.The experimental results show that the new type of concrete expansion agent accords with the standard and its main mineral component is xCaO-ySO3-zAl2O3.

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

    CERN Document Server

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

    2012-01-01

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

  8. Automated Agent Ontology Creation for Distributed Databases

    Science.gov (United States)

    2004-03-01

    Query Agent ..……………………………………………………47 3.3 Database Agent Implementation…………………………………………………..48 3.3.1 Leader Election Procedure...algorithm. Section 3.3.1 details the leader election process, Section 3.3.2 discusses the Jaro method, and Section 3.3.3 details the ontology creation...Receives new number Receives new number from Agent2 from Agent2 Figure 3-2. Agent leader communication 49 3.3.1 Leader Election Procedure Figure

  9. Agent-oriented modeling of the dynamics of complex biological processes I: single agent models

    NARCIS (Netherlands)

    Jonker, C.M.; Treur, J.

    2008-01-01

    In the pair of papers of which this is Part I, the agent-oriented modeling perspective to cope with biological complexity is discussed. Three levels of dynamics are distinguished and related to each other: dynamics of externally observable agent behavior, dynamics of internal agent processes, and dy

  10. 9th KES Conference on Agent and Multi-Agent Systems : Technologies and Applications

    CERN Document Server

    Howlett, Robert; Jain, Lakhmi

    2015-01-01

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

  11. For whom will the Bayesian agents vote?

    Science.gov (United States)

    Caticha, Nestor; Cesar, Jonatas; Vicente, Renato

    2015-04-01

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

  12. Polyphenols as cancer chemopreventive agents.

    Science.gov (United States)

    Stoner, G D; Mukhtar, H

    1995-01-01

    This article summarizes available data on the chemopreventive efficacies of tea polyphenols, curcumin and ellagic acid in various model systems. Emphasis is placed upon the anticarcinogenic activity of these polyphenols and their proposed mechanism(s) of action. Tea is grown in about 30 countries and, next to water, is the most widely consumed beverage in the world. Tea is manufactured as either green, black, or oolong; black tea represents approximately 80% of tea products. Epidemiological studies, though inconclusive, suggest a protective effect of tea consumption on human cancer. Experimental studies of the antimutagenic and anticarcinogenic effects of tea have been conducted principally with green tea polyphenols (GTPs). GTPs exhibit antimutagenic activity in vitro, and they inhibit carcinogen-induced skin, lung, forestomach, esophagus, duodenum and colon tumors in rodents. In addition, GTPs inhibit TPA-induced skin tumor promotion in mice. Although several GTPs possess anticarcinogenic activity, the most active is (-)-epigallocatechin-3-gallate (EGCG), the major constituent in the GTP fraction. Several mechanisms appear to be responsible for the tumor-inhibitory properties of GTPs, including enhancement of antioxidant (glutathione peroxidase, catalase and quinone reductase) and phase II (glutathione-S-transferase) enzyme activities; inhibition of chemically induced lipid peroxidation; inhibition of irradiation- and TPA-induced epidermal ornithine decarboxylase (ODC) and cyclooxygenase activities; inhibition of protein kinase C and cellular proliferation; antiinflammatory activity; and enhancement of gap junction intercellular communication. Curcumin is the yellow coloring agent in the spice tumeric. It exhibits antimutagenic activity in the Ames Salmonella test and has anticarcinogenic activity, inhibiting chemically induced preneoplastic lesions in the breast and colon and neoplastic lesions in the skin, forestomach, duodenum and colon of rodents. In addition

  13. An Application of Mobile Agent System in Network Management

    Institute of Scientific and Technical Information of China (English)

    YANGChen-xiang; DUJun-ping; YINYi-xin

    2004-01-01

    This paper describes an application of a reusable mobile agent system in network management. A mobile agent reusable system is constructed to realize a new method in forming mobile agent systems. By using this method, an agent can change its route dynamically without making any change to its specific behavior. By classifying mobile agents into two categories, the task agent can be reusable in different networks. In this way, a mobile agent system can easily carry out network management tasks.

  14. Dynamic Channel Allocation Management Using Agents Technology

    Directory of Open Access Journals (Sweden)

    Ion BOGDAN

    2009-07-01

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

  15. Agent-Supported Mission Operations Teamwork

    Science.gov (United States)

    Malin, Jane T.

    2003-01-01

    This slide presentation reviews the development of software agents to support of mission operations teamwork. The goals of the work was to make automation by agents easy to use, supervise and direct, manage information and communication to decrease distraction, interruptions, workload and errors, reduce mission impact of off-nominal situations and increase morale and decrease turnover. The accomplishments or the project are: 1. Collaborative agents - mixed initiative and creation of instructions for mediating agent 2. Methods for prototyping, evaluating and evolving socio-technical systems 3. Technology infusion: teamwork tools in mISSIons 4. Demonstrations in simulation testbed An example of the use of agent is given, the use of an agent to monitor a N2 tank leak. An incomplete instruction to the agent is handled with mediating assistants, or Intelligent Briefing and Response Assistant (IBRA). The IBRA Engine also watches data stream for triggers and executes Act-Whenever actions. There is also a Briefing and Response Instruction (BRI) which is easy for a discipline specialist to create through a BRI editor.

  16. Continuum deformation of multi-agent systems

    CERN Document Server

    Rastgoftar, Hossein

    2016-01-01

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

  17. Brahms Mobile Agents: Architecture and Field Tests

    Science.gov (United States)

    Clancey, William J.; Sierhuis, Maarten; Kaskiris, Charis; vanHoof, Ron

    2002-01-01

    We have developed a model-based, distributed architecture that integrates diverse components in a system designed for lunar and planetary surface operations: an astronaut's space suit, cameras, rover/All-Terrain Vehicle (ATV), robotic assistant, other personnel in a local habitat, and a remote mission support team (with time delay). Software processes, called agents, implemented in the Brahms language, run on multiple, mobile platforms. These mobile agents interpret and transform available data to help people and robotic systems coordinate their actions to make operations more safe and efficient. The Brahms-based mobile agent architecture (MAA) uses a novel combination of agent types so the software agents may understand and facilitate communications between people and between system components. A state-of-the-art spoken dialogue interface is integrated with Brahms models, supporting a speech-driven field observation record and rover command system (e.g., return here later and bring this back to the habitat ). This combination of agents, rover, and model-based spoken dialogue interface constitutes a personal assistant. An important aspect of the methodology involves first simulating the entire system in Brahms, then configuring the agents into a run-time system.

  18. Agents described in the Molecular Imaging and Contrast Agent Database for imaging carbonic anhydrase IX expression.

    Science.gov (United States)

    Sneddon, Deborah; Poulsen, Sally-Ann

    2014-10-01

    Carbonic anhydrase IX (CA IX) is selectively expressed in a range of hypoxic tumours and is a validated endogenous hypoxia marker with prognostic significance; hence, CA IX is of great interest as a molecular imaging target in oncology. In this review, we present an overview of the different imaging agents and imaging modalities that have been applied for the in vivo detection of CA IX. The imaging agents reviewed are all entries in the Molecular Imaging and Contrast Agent Database (MICAD) and comprise antibody, antibody fragments and small molecule imaging agents. The effectiveness of these agents for imaging CA IX in vivo gave variable performance; however, a number of agents proved very capable. As molecular imaging has become indispensable in current medical practice we anticipate that the clinical significance of CA IX will see continued development and improvements in imaging agents for targeting this enzyme.

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

    CERN Document Server

    Hartung, Ronald

    2013-01-01

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

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

    Science.gov (United States)

    Tumer, Kagan

    2005-01-01

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

  1. Steganographic Routing in Multi Agent System Environment

    CERN Document Server

    Szczypiorski, Krzysztof; Mazurczyk, Wojciech

    2008-01-01

    In this paper we present an idea of trusted communication platform for Multi-Agent Systems (MAS) called TrustMAS. Based on analysis of routing protocols suitable for MAS we have designed a new proactive hidden routing. Proposed steg-agents discovery procedure, as well as further routes updates and hidden communication, are cryptographically independent. Steganographic exchange can cover heterogeneous and geographically outlying environments using available cross-layer covert channels. Finally we have specified rules that agents have to follow to benefit the TrustMAS distributed router platform.

  2. Software agents for distributed load balancing

    Energy Technology Data Exchange (ETDEWEB)

    Wernstedt, F.; Davidsson, P. [Department of Systems and Software Engineering, School of Engineering, Blekinge Institute of Technology, Ronneby (Sweden)

    2004-07-01

    We present results from experiments where the effects of flow control at a single substation are compared to distributed flow control at multiple substations. The latter approach is made possible by equipping individual substations with some computing power and integrating them into a communications network. Software agents, who cooperate with other software agents (substations) and invoke time limited reductions to consumption, are embedded in each substation. The experiments show that it is possible to automatically load balance a small district heating network using agent technology, e.g., to perform automatic peak clipping and load shifting. (orig.)

  3. AORTA: Adding Organizational Reasoning to Agents

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt; Dignum, Virginia

    2014-01-01

    the expected behavior of the agents. Agents need to be able to reason about the regulations, so that they can act within the expected boundaries and work towards the objectives of the organization. This extended abstract introduces AORTA, a component that can be integrated into agents’ reasoning mechanism......, allowing them to reason about (and act upon) regulations specified by an organizational model using simple reasoning rules. The added value is that the organizational model is independent of that of the agents, and that the approach is not tied to a specific organizational model....

  4. Pharmacologic agents for mucus clearance in bronchiectasis.

    Science.gov (United States)

    Nair, Girish B; Ilowite, Jonathan S

    2012-06-01

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

  5. Agent Based Processing of Global Evaluation Function

    CERN Document Server

    Hossain, M Shahriar; Joarder, Md Mahbubul Alam

    2011-01-01

    Load balancing across a networked environment is a monotonous job. Moreover, if the job to be distributed is a constraint satisfying one, the distribution of load demands core intelligence. This paper proposes parallel processing through Global Evaluation Function by means of randomly initialized agents for solving Constraint Satisfaction Problems. A potential issue about the number of agents in a machine under the invocation of distribution is discussed here for securing the maximum benefit from Global Evaluation and parallel processing. The proposed system is compared with typical solution that shows an exclusive outcome supporting the nobility of parallel implementation of Global Evaluation Function with certain number of agents in each invoked machine.

  6. Towards Culturally-Aware Virtual Agent Systems

    DEFF Research Database (Denmark)

    Endrass, Birgit; André, Elisabeth; Rehm, Matthias

    2010-01-01

    of different systems using virtual agents need to be considered. Therefore, the authors reflect in this chapter on how virtual agents can help to learn about culture, scan definitions of culture from the social sciences, give an overview on how multiagent systems developed over time and classify the state...... of the art that integrates culture in multiagent systems. In addition, an approach of simulating culture-specific behavior using such a multiagent system is introduced and future trends in enculturating virtual agent systems are outlined....

  7. Information Service Model with Mobile Agent Supported

    Institute of Scientific and Technical Information of China (English)

    邹涛; 王继成; 张福炎

    2000-01-01

    Mobile Agent is a kind of novel agent technology characterized by mobile, intelligent, parallel and asynchronous computing. In this paper, a new information service model that adopts mobile agent technology is introduced first,and then an experimental system DOLTRIA system that is implemented based on the model is described. The DOLTRIA system implemented by WWW framework and Java can search for relevant HTML documents on a set of Web servers. The result of experiments shows that performance improvement can be achieved by this model, and both the elapsed time and network traffic are reduced significantly.

  8. RESEARCH ON A SOCCER SERVER TEAM WITH ENVIRONMENTAL-AGENTS

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper proposed a new agent model, which applies the agent-oriented paradigm to represent multiple objects. This agent model consists of three types of agents as follows: (a) an upperagent which describes an autonomous and dynamic object; (b) a lower-agent which describes a reactive and static object; and (c) an environ-mental-agent which describes the environment of the other agents. As an example, it considered soccer players (a kind of multiple objects) in environmental-agent. Three kinds of soccer agents were constructed with different powers. With soccer server the soccer games were simulated to confirm the effectiveness of our model.

  9. Multi-target pursuit formation of multi-agent systems

    Institute of Scientific and Technical Information of China (English)

    Yan Jing; Guan Xin-Ping; Luo Xiao-Yuan

    2011-01-01

    The main goal of this paper is to design a team of agents that can accomplish multi-target pursuit formation using a developed leader-follower strategy. It is supposed that every target can accept a certain number of agents. First, each agent can automatically choose its target based on the distance from the agent to the target and the number of agents

  10. Continuous Explanation Generation in a Multi-Agent Domain

    Science.gov (United States)

    2015-01-01

    International Conference on Autonomous Agents and Multi - Agent Systems (pp. 989-996). Valencia, Spain: IFAAMAS. Molineaux, M., Klenk, M., & Aha, D.W. (2010...Continuous Explanation Generation in a Multi - Agent Domain Matthew Molineaux MATTHEW.MOLINEAUX@KNEXUSRESEARCH.COM Knexus Research Corporation, 9120...Abstract An agent operating in a dynamic, multi - agent environment with partial observability should continuously generate and maintain an explanation

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

    Science.gov (United States)

    Zhao, Guopeng; Ailiya; Shen, Zhiqi

    2012-01-01

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

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

    Science.gov (United States)

    Zhao, Guopeng; Ailiya; Shen, Zhiqi

    2012-01-01

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

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

    NARCIS (Netherlands)

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

    2007-01-01

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

  14. Bisimulation for Single-Agent Plausibility Models

    DEFF Research Database (Denmark)

    Andersen, Mikkel Birkegaard; Bolander, Thomas; van Ditmarsch, H.;

    2013-01-01

    Epistemic plausibility models are Kripke models agents use to reason about the knowledge and beliefs of themselves and each other. Restricting ourselves to the single-agent case, we determine when such models are indistinguishable in the logical language containing conditional belief, i.e., we...... define a proper notion of bisimulation, and prove that bisimulation corresponds to logical equivalence on image-finite models. We relate our results to other epistemic notions, such as safe belief and degrees of belief. Our results imply that there are only finitely many non-bisimilar single......-agent epistemic plausibility models on a finite set of propositions. This gives decidability for single-agent epistemic plausibility planning....

  15. Multi-Agent System for Resource Reliability

    Science.gov (United States)

    2007-11-02

    1 research and development of a prototype for network resource reliability has laid the groundwork for the Phase 2 implementation of MASRR, a Multi - Agent System for Resource Reliability, and its eventual commercialization.

  16. Autonomic Management for Multi-agent Systems

    CERN Document Server

    Salih, Nadir K; Viju, PG K; Mohamed, Abdelmotalib A

    2011-01-01

    Autonomic computing is a computing system that can manage itself by self-configuration, self-healing, self-optimizing and self-protection. Researchers have been emphasizing the strong role that multi agent systems can play progressively towards the design and implementation of complex autonomic systems. The important of autonomic computing is to create computing systems capable of managing themselves to a far greater extent than they do today. With the nature of autonomy, reactivity, sociality and pro-activity, software agents are promising to make autonomic computing system a reality. This paper mixed multi-agent system with autonomic feature that completely hides its complexity from users/services. Mentioned Java Application Development Framework as platform example of this environment, could applied to web services as front end to users. With multi agent support it also provides adaptability, intelligence, collaboration, goal oriented interactions, flexibility, mobility and persistence in software systems

  17. A Highly Secure Mobile Agent System Architecture

    Science.gov (United States)

    Okataku, Yasukuni; Okutomi, Hidetoshi; Yoshioka, Nobukazu; Ohgishi, Nobuyuki; Honiden, Shinichi

    We propose a system architecture for mobile agents to improve their security in the environments of insecure networks and non-sophisticated terminals such as PDAs. As mobile agents freely migrate onto their favorite terminals through insecure networks or terminals, it is not appropriate for them to store some secret information for authentication and encryption/decryption. We introduce one and more secure nodes(OASIS NODE) for securely generating and verifying authentication codes. The each agent’s data are encrypted by a pseudo-chaos cipher mechanism which doesn’t need any floating processing co-processor. We’ve constructed a prototype system on a Java mobile agent framework, “Bee-gent" which implements the proposed authentication and cipher mechanisms, and evaluated their performances and their applicability to business fields such as an auction system by mobile agents.

  18. Competing intelligent search agents in global optimization

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  19. Empowerment for Continuous Agent-Environment Systems

    CERN Document Server

    Jung, Tobias; Stone, Peter

    2012-01-01

    This paper develops generalizations of empowerment to continuous states. Empowerment is a recently introduced information-theoretic quantity motivated by hypotheses about the efficiency of the sensorimotor loop in biological organisms, but also from considerations stemming from curiosity-driven learning. Empowemerment measures, for agent-environment systems with stochastic transitions, how much influence an agent has on its environment, but only that influence that can be sensed by the agent sensors. It is an information-theoretic generalization of joint controllability (influence on environment) and observability (measurement by sensors) of the environment by the agent, both controllability and observability being usually defined in control theory as the dimensionality of the control/observation spaces. Earlier work has shown that empowerment has various interesting and relevant properties, e.g., it allows us to identify salient states using only the dynamics, and it can act as intrinsic reward without requi...

  20. Penetratin and derivatives acting as antifungal agents

    NARCIS (Netherlands)

    Masman, Marcelo F.; Rodriguez, Ana M.; Raimondi, Marcela; Zacchino, Susana A.; Luiten, Paul G. M.; Somlai, Csaba; Kortvelyesi, Tamas; Penke, Botond; Enriz, Ricardo D.

    2009-01-01

    The synthesis, in vitro evaluation, and conformational study of RQIKTWFQNRRMKWKK-NH(2) (penetratin) and related derivatives acting as antifungal agents are reported. Penetratin and some of its derivatives displayed antifungal activity against the human opportunistic pathogenic standardized ATCC stra

  1. Spions as nano-theranostics agents

    CERN Document Server

    Zarepour, Atefeh; Khosravi, Arezoo

    2017-01-01

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

  2. For whom will the Bayesian agents vote?

    CERN Document Server

    Caticha, Nestor; Vicente, Renato

    2015-01-01

    Within an agent-based model where moral classifications are socially learned, we ask if a population of agents behaves in a way that may be compared with conservative or liberal positions in the real political spectrum. We assume that agents first experience a formative period, in which they adjust their learning style acting as supervised Bayesian adaptive learners. The formative phase is followed by a period of social influence by reinforcement learning. By comparing data generated by the agents with data from a sample of 15000 Moral Foundation questionnaires we found the following. 1. The number of information exchanges in the formative phase correlates positively with statistics identifying liberals in the social influence phase. This is consistent with recent evidence that connects the dopamine receptor D4-7R gene, political orientation and early age social clique size. 2. The learning algorithms that result from the formative phase vary in the way they treat novelty and corroborative information with mo...

  3. NETWORK MANAGEMENT WITH SECURED MOBILE AGENT

    Institute of Scientific and Technical Information of China (English)

    迈克尔; 徐良贤

    2002-01-01

    Network management scheme must consider security challenges for the Mobile Agent paradigm to be accepted in the Internet computing world. Techniques to provide security solutions have been proposed and some have achieved good results. For example, it is possible to launch a code with a guarantee that it cannot attack the hosting sites. The main problem remaining, however, is protecting the mobile code against malicious service providers, the host problem. This paper proposed a Mobile Agent management scheme in a hierarchical level that provides to user a reliable and flexible global access to internet/network information services. We further described a protection mechanism to Mobile Agents against malicious hosts. As an effort to address host problems we first identify the kinds of attack that may be performed by malicious hosts, and propose a mechanism to prevent these attacks. At each agent host we introduce a trusted third party entity on each server called Secure Service Station (SSS) to carry out security actions.

  4. Agentes de software móviles

    Directory of Open Access Journals (Sweden)

    Crisman Martínez Barrera

    2001-10-01

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

  5. Agent-based modeling of sustainable behaviors

    CERN Document Server

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

    2017-01-01

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

  6. Behavior-based dual dynamic agent architecture

    Institute of Scientific and Technical Information of China (English)

    仵博; 吴敏; 曹卫华

    2003-01-01

    The objective of the architecture is to make agent promptly and adaptively accomplish tasks in the real-time and dynamic environment. The architecture is composed of elementary level behavior layer and high level be-havior layer. In the elementary level behavior layer, the reactive architecture is introduced to make agent promptlyreact to events; in the high level behavior layer, the deliberation architecture is used to enhance the intelligence ofthe agent. A confidence degree concept is proposed to combine the two layers of the architecture. An agent decisionmaking process is also presented, which is based on the architecture. The results of experiment in RoboSoccer simu-lation team show that the proposed architecture and the decision process are successful.

  7. Spatial interactions in agent-based modeling

    CERN Document Server

    Ausloos, Marcel; Merlone, Ugo

    2014-01-01

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

  8. Neuromodulators: available agents, physiology, and anatomy.

    Science.gov (United States)

    Nettar, Kartik; Maas, Corey

    2011-12-01

    Neuromodulators have risen to the forefront of aesthetic medicine. By reversibly relaxing target muscles, neuromodulators exhibit their effect by softening hyperfunctional lines. An understanding of their physiology, relevant facial anatomy, and current agents is imperative for a successful aesthetic practice.

  9. Improving Multi-Agent Systems Using Jason

    DEFF Research Database (Denmark)

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

    2011-01-01

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

  10. Disease-modifying agents in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Coyle P

    2009-01-01

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

  11. Empirically Based, Agent-based models

    Directory of Open Access Journals (Sweden)

    Elinor Ostrom

    2006-12-01

    Full Text Available There is an increasing drive to combine agent-based models with empirical methods. An overview is provided of the various empirical methods that are used for different kinds of questions. Four categories of empirical approaches are identified in which agent-based models have been empirically tested: case studies, stylized facts, role-playing games, and laboratory experiments. We discuss how these different types of empirical studies can be combined. The various ways empirical techniques are used illustrate the main challenges of contemporary social sciences: (1 how to develop models that are generalizable and still applicable in specific cases, and (2 how to scale up the processes of interactions of a few agents to interactions among many agents.

  12. Intelligent agents in data-intensive computing

    CERN Document Server

    Correia, Luís; Molina, José

    2016-01-01

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

  13. Nominaliseeritud protsessi agent meediauudistes / Reet Kasik

    Index Scriptorium Estoniae

    Kasik, Reet, 1946-

    2006-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Waldemar Wieczerzycki

    2012-03-01

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

  15. Creating Real-Time Embodied Autonomous Agents

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@ A challenging research area for computer graphics and virtual environments (VE) is training interpersonal interactions. In such a system, at least one person is the VE participant, while several more virtual human agents (represented by human-like, embodied models) are engaged in activities in the same virtual space. The participants, whether live or virtual, should interact as if all were real. This means that the virtual agents must have several characteristics afforded to real people, including the following:

  16. Research on Virtual Agent Perception Model

    Institute of Scientific and Technical Information of China (English)

    FENG Xiu-fang; GAO Bao-lu

    2006-01-01

    An intelligent virtual environment is described for training users in the operation of complex engineering systems. After analyzing the original model of virtual environment, a virtual agent perception model was put forward. The information layer was inserted into original virtual environment. The model classifies all kinds of information and offers a way for knowledge description of virtual environment, and contributes to set up feeling model for the Virtual Agent within virtual environment.

  17. 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

  18. Agent-oriented commonsense knowledge base

    Institute of Scientific and Technical Information of China (English)

    陆汝钤; 石纯一; 张松懋; 毛希平; 徐晋晖; 杨萍; 范路

    2000-01-01

    Common sense processing has been the key difficulty in Al community. Through analyzing various research methods on common sense, a large-scale agent-oriented commonsense knowledge base is described in this paper. We propose a new type of agent——CBS agent, specify common sense oriented semantic network descriptive language-Csnet, augment Prolog for common sense, analyze the ontology structure, and give the execution mechanism of the knowledge base.

  19. Coordinating Learning Agents for Active Information Collection

    Science.gov (United States)

    2011-06-30

    ranging from robocup soccer [26, 27], to rover coordination [19], to trading agents [25, 43], to air traffic management [32]. What makes this problem...Bazzan, A. and Ossowski, S. (eds.), Applications of Agent Technology in Traffic and Transportation ( Springer , 2005). [19] Mataric, M. J., Coordination...of Complex Systems ( Springer , 2004). September 16, 2009 16:40 WSPC/169-ACS 00230 472 K. Tumer and N. Khani [24] Pynadath, D. and Tambe, M., The

  20. Inaccessibility in Multi-Agent Systems

    Science.gov (United States)

    2007-11-02

    reliable. Software agents may need to migrate e.g. in the situations where the information needs to be transformed between two mutually inaccessible...integrate the software prototype from the MRinMAS project in a timely fashion. An important development period of this project has been devoted to...footprint and message sending speed). For selected agent platforms - JADE, FIPA-OS, ZEUS, JACK, GRASSHOPPER and A–globe - the results of benchmarking are

  1. A Estreptozootocina Como Agente Diabetogênico

    OpenAIRE

    Furlan,Maria Montserrat Diaz Pedrosa

    2008-01-01

    Os quadros experimentais de diabetes mellitus permitem observar as diversas variáveis envolvidas na fisiopatologia desta doença sob condições controladas. Entretanto, conhecer as características do agente químico usado na indução do diabetes é importante para uma análise coerente dos resultados obtidos. Esta revisão apresenta aspectos relacionados à estreptozootocina, um agente diabetogênico amplamente u...

  2. Solving Integer Programming by Evolutionary Soft Agent

    Institute of Scientific and Technical Information of China (English)

    Yin Jian

    2003-01-01

    Many practical problems in commerce and industry involve finding the best way to allocate scarce resources a mong competing activities. This paper focuses on the problem of integer programming, and describes an evolutionary soft agent model to solve it. In proposed model, agent is composed of three components: goal, environment and behavior. Experirnental shows thne model has the characters of parallel computing and goal driving.

  3. New Safety rule for Chemical Agents

    CERN Multimedia

    Safety Commission

    2010-01-01

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

  4. Innovative Design and Synthesis of Antiparasite Agents

    Science.gov (United States)

    1997-06-01

    chalcones (including 2’,3’,4’-trihydroxychalcone) for inhibition of heme polymerization. None of these compounds exhibited activity at concentrations as high...artemisinin analogs in vitro. Antimicrobial Agents and Chemotherapy 38:1813-9. 87. Winter, R., M. Ignatushchenko, 0. Ogundahunsi, K. Cornell, A. Oduola...D. Hinrichs, and M. Riscoe. 1997. Potentiation of an antimalarial oxidant drug. Antimicrobial Agents and Chemotherapy 41: in press (July issue). 88

  5. Perpetual Self-Aware Cognitive Agents

    OpenAIRE

    2007-01-01

    To construct a perpetual self-aware cognitive agent that can continuously operate with independence, an introspective machine must be produced. To assemble such an agent, it is necessary to perform a full integration of cognition (planning, understanding, and learning) and metacognition (control and monitoring of cognition) with intelligent behaviors. The failure to do this completely is why similar, more limited efforts have not succeeded in the past. I outline some key computational require...

  6. Scheduling Activity in an Agent Architecture

    OpenAIRE

    Soto, Ignacio

    2000-01-01

    Agents for applications in dynamic environments require artificial intelligence techniques to solve problems to achieve their objectives. For example, they must develop plans of actions to carry out missions in their environment, in other words, to achieve some state in the world. But also, the agents must fulfill real-time requirements that arise because the characteristics of the applications and the dynamism of the environment. In this paper we analyze the use of a schedule of activity in ...

  7. Towards Emergent Energy Synchronization using Agents

    OpenAIRE

    Pournaras, E.; Warnier, M.E.; Brazier, F.M.T.

    2010-01-01

    Synchronization of energy consumption is a key determinant for the stabilization of smart energy grids. This paper proposes software agents that locally synchronize the energy usage of appliances to minimize the oscillations in global energy consumption. Agents can manage demand-side devices with periodic operation and synchronize their consumption locally resulting in an emerging global stability of energy consumption. The benefits and challenges of such an approach are discussed in this paper.

  8. Bacteriophages as recognition and identification agents

    Energy Technology Data Exchange (ETDEWEB)

    Teodorescu, M.C.; Gaspar, A.

    1987-04-23

    Bacteriophages are employed as agents for recognition and identification of molecules and cellular materials, using their ability to recognize their bacterial host, by coating them with antibodies or by selecting them to perform in a manner analogous to antibodies. Visibility for identification is effected by incorporating a fluorescent agent, a radioisotope, a metal, an enzyme, or other staining material. The method of this invention may be utilized in selected clinical procedures, and is adaptable to use in an assay kit.

  9. Pyridinium Oxime Compounds as Antimicrobial Agents

    Science.gov (United States)

    2007-08-01

    incident combinant les agents neurotoxiques et biologiques ne serait probablement pas efficace contre l’agent biologique, surtout s’il s’agit du charbon ...Nelson, K., and Beverley, S. M. (1993). Evolution of the nuclear ribosomal RNAs in kinetoplastid protozoa: perspectives on the age and origins of...indexing annotation must be entered when the overall document is classified) ORIGINATOR (The name and address of the organization preparing the document

  10. Robust Multi-Agent Sensor Network Systems

    Science.gov (United States)

    2012-05-08

    Decision and Control December 15-17, 2010 Hilton Atlanta Hotel , Atlanta, GA, USA 978-1-4244-7744-9/10/$26.00 ©2010 IEEE 402 II. PRELIMINARIES We will...interference caused by other simultaneously active transmissions. • We derived analytical expression for the capacity of the above network. • Considering...which are robust against the loss of multiple agents. A formation is said to be rigid if by actively maintaining a designated set of inter-agent

  11. Knowledge Representation for Decision Making Agents

    Science.gov (United States)

    2013-07-15

    Knowledge Representation for Decision Making Agents MAJ Peter Nesbitt Dr. Tom Anderson LTC Jonathan Alt Mr. David Ohmen Mr. Kyle Quinnell Mr. Mario...Torres TRADOC Analysis Center - Monterey 700 Dyer Road Monterey, California 93943 PREPARED BY: APPROVED BY: Peter A. Nesbitt Jonathan K. Alt MAJ, AR LTC...Include area code) 07/15/2013 Technical Report APR 2013 - JUN 2013 Knowledge Representation for Decision Making Agents MAJ Peter Nesbitt Dr Tom Anderson

  12. Organophosphate Nerve Agent Detection with Europium Complexes

    OpenAIRE

    Schwierking, Jake R.; Laird W. Menzel; E. Roland Menzel

    2004-01-01

    We explore the detection of paraoxon, a model compound for nonvolatile organophosphate nerve agents such as VX. The detection utilizes europium complexes with 1,10 phenanthroline and thenoyltrifluoroacetone as sensitizing ligands. Both europium luminescence quenching and luminescence enhancement modalities are involved in the detection, which is simple, rapid, and sensitive. It is adaptable as well to the more volatile fluorophosphate nerve agents. It involves nothing more than visual lumines...

  13. Agent-based simulation of animal behaviour

    OpenAIRE

    Jonker, C.M.; Treur, J.

    1998-01-01

    In this paper it is shown how animal behaviour can be simulated in an agent-based manner. Different models are shown for different types of behaviour, varying from purely reactive behaviour to pro-active, social and adaptive behaviour. The compositional development method for multi-agent systems DESIRE and its software environment supports the conceptual and detailed design, and execution of these models. Experiments reported in the literature on animal behaviour have been simulated for a num...

  14. 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.

  15. CHI: A General Agent Communication Framework

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-17

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

  16. Multi Agent system Randomized in Road Traffic

    Directory of Open Access Journals (Sweden)

    Gouiouez Mounir,

    2013-02-01

    Full Text Available In recent years, the rapid growth of road traffic density in theworld generates a rising request for tools that can be used toanalyze and control the traffic networks. Microscopic trafficsimulation[1,2,3] has proven to be one of the most useful toolsfor analysis of various traffic systems. Thus microscopic trafficsimulation has become an ever increasing field of research anddevelopment. In this paper we present a new model formicroscopic traffic simulation; Traditional traffic simulationmodels neglect some real-life factors that need to be considered,such as the effect of random distribution in the entry of lanehence ,this paper presents the development of a concept and anassociated architecture called the MAS2RT (Multi Agentsystem Randomized in Road Traffic, which is based on thecombination of Multi-Agent Systems (MAS [4,5], Poissondistribution in urban Traffic and a stochastic model [6,7] tocapture the randomness of individual agent. The secondcontribution of this paper is about the internal structure ofmobile agents[8], initially reacts according to the instructions ofthe Main agent (MA and in the case of a lack of dynamicinformation, the mobile agents take decisions based on theirexperiences accumulated during previous interactions.The obtained results illustrate that using the randomness in thereaction of agent enhanced greatly the performance ofsimulation.

  17. Agent-based modeling and network dynamics

    CERN Document Server

    Namatame, Akira

    2016-01-01

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

  18. Scolicidal Agents in Hydatid Cyst Surgery

    Directory of Open Access Journals (Sweden)

    H. Besim

    1998-01-01

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

  19. A Comparison of Organization-Centered and Agent-Centered Multi-Agent Systems

    DEFF Research Database (Denmark)

    Jensen, Andreas Schmidt; Villadsen, Jørgen

    2013-01-01

    Whereas most classical multi-agent systems have the agent in center, there has recently been a development towards focusing more on the organization of the system, thereby allowing the designer to focus on what the system goals are, without considering how the goals should be fulfilled. We have d...... that the agent-oriented approach has a number of advantages when it comes to game-like scenarios with just a few different character types....... developed and evaluated two teams of agents for a variant of the well-known Bomberman computer game. One team is based on the basic Jason system, which is an implementation in Java of an extension of the logic-based agent-oriented programming language AgentSpeak. The other team is based...

  20. Intelligent Agent-Based System for Digital Library Information Retrieval

    Institute of Scientific and Technical Information of China (English)

    师雪霖; 牛振东; 宋瀚涛; 宋丽哲

    2003-01-01

    A new information search model is reported and the design and implementation of a system based on intelligent agent is presented. The system is an assistant information retrieval system which helps users to search what they need. The system consists of four main components: interface agent, information retrieval agent, broker agent and learning agent. They collaborate to implement system functions. The agents apply learning mechanisms based on an improved ID3 algorithm.

  1. Research and Application of Multi-Agent Technology

    Institute of Scientific and Technical Information of China (English)

    Li Wei; Zhang Fengming

    2006-01-01

    This paper firstly introduces the background and conception of Agent and Multi-Agent technology and compares the frameworks of Agent system and MAS. Analyzing the framework of Agent secondly. Then explaining the communication language used in the Multi-Agent society where knowledge communication plays a key role among Agents. Finally, some applications are enumerated and the future direction of this technology is prospected.

  2. The Agent Modeling Language AML A Comprehensive Approach to Modeling Multi-agent Systems

    CERN Document Server

    Cervenka, Radovan

    2007-01-01

    Multi-agent systems are already a focus of studies for more than 25 years. Despite substantial effort of an active research community, modeling of multi-agent systems still lacks complete and proper definition, general acceptance, and practical application. Due to the vast potential of these systems e.g., to improve the practice in software and to extent the applications that can feasibly be tackled, this book tries to provide a comprehensive modeling language - the Agent Modeling Language (AML) - as an extension of UML 2.0, concentrating on multi-agent systems and applications.

  3. Mobile Agent Based on Internet%基于Internet的移动Agent

    Institute of Scientific and Technical Information of China (English)

    徐练; 周龙骧; 王翰虎

    2001-01-01

    Mobile Agent is a hybrid of Internet technology and Artificial Intelligence. Today there are tremendous amount of information resources distributing among Internet ,but it's very difficult to find the wanted-thing. Internet has increasingly become a vital compute platform for electron commercial which has highly popular through the world. Developing new Internet-based application programs such as shopping online,e-business,search engine etc pose new task. Mobile Agent proffers new clue and technology. Considering Internet,this thesis conducts a research on architecture,mobile mechanism in mobile Agent system. Based on the Agent theory research and engineering ,the thesis focuses point at researching Mobile Agents,which have the ability to rove through the network. Using OMG's "Mobile Agent Facility Specification" for reference,we design a model architecture of Mobile Agent System. Based on the architecture ,the article analyzes the key technology and gives methods to resolving them ,emphases on mobility mechanism of Agent and implementing it. At last a model of java-based Mobile Agent System is given.

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

    DEFF Research Database (Denmark)

    Lund, Henrik Hautop; Pagliarini, Luigi

    2011-01-01

    Utilizing principles from parallel and distributed processing combined with inspiration from modular robotics, we developed the modular interactive tiles. As an educational tool, the modular interactive tiles facilitate the learning of multi-agent systems and interactive agent-based games....... The modular and physical property of the tiles provides students with hands-on experience in exploring the theoretical aspects underlying multi-agent systems which often appear as challenging to students. By changing the representation of the cognitive challenging aspects of multi-agent systems education...

  5. Challenges of agent banking experiences in Kenya

    Directory of Open Access Journals (Sweden)

    Fred Gichana Atandi

    2013-08-01

    Full Text Available More than ever before there is a global concern to entrench financial deepening access to previously ignored areas due to some areas considered economically unviable where majority of the MSEs operate their businesses. There is an increasing need to promote technological and institutional innovation as a means to expand financial system access and usage, including addressing infrastructure weaknesses and empowering business enterprises by developing financial literacy and financial capability programs to bring all people on board and all to participate in economic development of a country, perhaps agent banking will offer a solution to slow pace of individuals enterprise development especially from the rural areas. The uptake of agent banking in Kenya has not been well appreciated by the target beneficiaries who include among others the micro and small enterprises in the rural areas in Kenya who were expected to benefit from this technologically innovative service. In as much as it has been witnessed that there is an increase in penetration of agent banking services clients have not fully made use of the available agents at their localities to cut down on transaction costs occasioned by travelling to traditional branches and also time wasted on queuing for services . It can also be noted that, the banks have not fully taken advantage of agent banking to explore all market segments at a low operating costs. The researcher also identified some of the factors hindering the well functioning of agent banking despite mounting financial literacy training to Equity bank clients. Lack of mobile network services and float, lack of capital, issues of insecurity and fear of robbery. The paper is based on a study conducted to reveal the challenges which are hindering the rural people of Kenya from benefiting from agent banking.

  6. Growth of the Pittsburgh Pneumonia Agent in Animal Cell Cultures

    OpenAIRE

    Rinaldo, Charles R.; Pasculle, A. William; Myerowitz, Richard L.; Gress, Francis M.; Dowling, John N.

    1981-01-01

    Pittsburgh pneumonia agent (Legionella micdadei) grew in monkey, chicken, and human cell cultures. Pittsburgh pneumonia agent grew predominantly in the cytoplasm, resulting in a nonfocal, mild cytopathic effect.

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

    Data.gov (United States)

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

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

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  9. 2015 Special Sessions of the 13th International Conference on Practical Applications of Agents and Multi-Agent Systems

    CERN Document Server

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

    2015-01-01

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

  10. Agent Based Modeling Applications for Geosciences

    Science.gov (United States)

    Stein, J. S.

    2004-12-01

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

  11. Electrospun biodegradable polymers loaded with bactericide agents

    Directory of Open Access Journals (Sweden)

    Ramaz Katsarava

    2016-03-01

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

  12. Cyclosarin-An Organophosphate Nerve Agent

    Directory of Open Access Journals (Sweden)

    G. Krejcova

    2005-04-01

    Full Text Available Organophosphorus compounds ascribed to as nerve agents (sarin, soman, tabun, cyclosarin are highly toxic, and are considered to be the most dangerous chemical compounds. All apparently share a common mechanism of cholinesterase inhibition and can cause similar sv.m .ot oms. The standard therapy, in the case of organophosphorus poisoning, has the prophylactic use of reversibly acting AChE inhibitors and antidotal administration of AChE reactivators-oximes. Unfortunately, none of these oximes can be regarded as a broad spectrum antidote, ie, effective against all nerve agents. While the presently available oximes (pralidoxime, ohidoxime are not considered to be sufficiently effective against nerve agents, especially in the case of soman poisoning, the H oximes (HI-6, HLo7 appear to,be very promising antidotes against nerve agents because these are able to protect the experimental animals from toxic effects and improve survival of animals poisoned with supralethal doses. A lot of research has been pursued on the treatment of sarin, soman, and tabun, but cyclosarin was not considered for such a study for a long time. Recently, attention of researchers has also turned to cyclosarin because of its potential use as a chemical warfare agent. Cyclosarin is highly toxic organophosphorus compound which is resistant to conventional oxime therapy. This paper reviews the latest positionof cyclosarin in standpoint of medical treatment by various reactivators considering the ability of various oximes, HI-6, HS-6, BI-6, and KO33 of their reactivation potency.

  13. [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.

  14. Dispatching mobile Agents for DDM applicationss

    Institute of Scientific and Technical Information of China (English)

    LI Xi-ning; Guillaume Autran

    2008-01-01

    Techniques for mining information from distributed data sources accessible over the Internet are a growing area of research. The mobile Agent paradigm opens a new door for distributed data mining and knowledge discovery applications. In this paper we present the design of a mobile agent system which couples service discovery, using a logical language based application programming interface, and database access. Combining mobility with database access provides a means to create more efficient data mining applications. The processing of data is moved to network wide data locations instead of the traditional approach of bringing huge amount of data to the processing location. Our proposal aims at implementing system tools that will enable intelligent mobile Agents to roam the Internet searching for distributed data services. Agents access the data, discover patterns, extract useful information from facts recorded in the databases, then communicate local results back to the user. The user then generates a global data model through the aggregation of results provided by all Agents. This overcomes barriers posed by network congestion, poor security, and unreliability.

  15. 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.

  16. A Multi-Agent Approach for Solving Traveling Salesman Problem

    Institute of Scientific and Technical Information of China (English)

    ZHOU Tiejun; TAN Yihong; XING Lining

    2006-01-01

    The traveling salesman problem (TSP) is a classical optimization problem and it is one of a class of NP-Problem. This paper presents a new method named multi-agent approach based genetic algorithm and ant colony system to solve the TSP. Three kinds of agents with different function were designed in the multi-agent architecture proposed by this paper. The first kind of agent is ant colony optimization agent and its function is generating the new solution continuously. The second kind of agent is selection agent, crossover agent and mutation agent, their function is optimizing the current solutions group. The third kind of agent is fast local searching agent and its function is optimizing the best solution from the beginning of the trial. At the end of this paper, the experimental results have shown that the proposed hybrid approach has good performance with respect to the quality of solution and the speed of computation.

  17. Advances in Magnetic Resonance Imaging Contrast Agents for Biomarker Detection

    Science.gov (United States)

    Sinharay, Sanhita; Pagel, Mark D.

    2016-06-01

    Recent advances in magnetic resonance imaging (MRI) contrast agents have provided new capabilities for biomarker detection through molecular imaging. MRI contrast agents based on the T2 exchange mechanism have more recently expanded the armamentarium of agents for molecular imaging. Compared with T1 and T2* agents, T2 exchange agents have a slower chemical exchange rate, which improves the ability to design these MRI contrast agents with greater specificity for detecting the intended biomarker. MRI contrast agents that are detected through chemical exchange saturation transfer (CEST) have even slower chemical exchange rates. Another emerging class of MRI contrast agents uses hyperpolarized 13C to detect the agent with outstanding sensitivity. These hyperpolarized 13C agents can be used to track metabolism and monitor characteristics of the tissue microenvironment. Together, these various MRI contrast agents provide excellent opportunities to develop molecular imaging for biomarker detection.

  18. Price Prediction in a Trading Agent Competition

    CERN Document Server

    Lochner, K M; Vorobeychik, Y; Wellman, M P; 10.1613/jair.1333

    2011-01-01

    The 2002 Trading Agent Competition (TAC) presented a challenging market game in the domain of travel shopping. One of the pivotal issues in this domain is uncertainty about hotel prices, which have a significant influence on the relative cost of alternative trip schedules. Thus, virtually all participants employ some method for predicting hotel prices. We survey approaches employed in the tournament, finding that agents apply an interesting diversity of techniques, taking into account differing sources of evidence bearing on prices. Based on data provided by entrants on their agents' actual predictions in the TAC-02 finals and semifinals, we analyze the relative efficacy of these approaches. The results show that taking into account game-specific information about flight prices is a major distinguishing factor. Machine learning methods effectively induce the relationship between flight and hotel prices from game data, and a purely analytical approach based on competitive equilibrium analysis achieves equal ac...

  19. Toward Agent Programs with Circuit Semantics

    Science.gov (United States)

    Nilsson, Nils J.

    1992-01-01

    New ideas are presented for computing and organizing actions for autonomous agents in dynamic environments-environments in which the agent's current situation cannot always be accurately discerned and in which the effects of actions cannot always be reliably predicted. The notion of 'circuit semantics' for programs based on 'teleo-reactive trees' is introduced. Program execution builds a combinational circuit which receives sensory inputs and controls actions. These formalisms embody a high degree of inherent conditionality and thus yield programs that are suitably reactive to their environments. At the same time, the actions computed by the programs are guided by the overall goals of the agent. The paper also speculates about how programs using these ideas could be automatically generated by artificial intelligence planning systems and adapted by learning methods.

  20. Autonomous Formations of Multi-Agent Systems

    Science.gov (United States)

    Dhali, Sanjana; Joshi, Suresh M.

    2013-01-01

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

  1. Multi-Agent Simulation and Management Practices

    CERN Document Server

    Siebers, Peer-Olaf; Celia, Helen; Clegg, Chris

    2010-01-01

    Intelligent agents offer a new and exciting way of understanding the world of work. Agent-Based Simulation (ABS), one way of using intelligent agents, carries great potential for progressing our understanding of management practices and how they link to retail performance. We have developed simulation models based on research by a multi-disciplinary team of economists, work psychologists and computer scientists. We will discuss our experiences of implementing these concepts working with a well-known retail department store. There is no doubt that management practices are linked to the performance of an organisation (Reynolds et al., 2005; Wall & Wood, 2005). Best practices have been developed, but when it comes down to the actual application of these guidelines considerable ambiguity remains regarding their effectiveness within particular contexts (Siebers et al., forthcoming a). Most Operational Research (OR) methods can only be used as analysis tools once management practices have been implemented. Ofte...

  2. Heterocyclic chalcone analogues as potential anticancer agents.

    Science.gov (United States)

    Sharma, Vikas; Kumar, Vipin; Kumar, Pradeep

    2013-03-01

    Chalcones, aromatic ketones and enones acting as the precursor for flavonoids such as Quercetin, are known for their anticancer effects. Although, parent chalcones consist of two aromatic rings joined by a three-carbon α,β-unsaturated carbonyl system, various synthetic compounds possessing heterocyclic rings like pyrazole, indole etc. are well known and proved to be effective anticancer agents. In addition to their use as anticancer agents in cancer cell lines, heterocyclic analogues are reported to be effective even against resistant cell lines. In this connection, we hereby highlight the potential of various heterocyclic chalcone analogues as anticancer agents with a brief summary about therapeutic potential of chalcones, mechanism of anticancer action of various chalcone analogues, and current and future prospects related to the chalcones-derived anticancer research. Furthermore, some key points regarding chalcone analogues have been reviewed by analyzing their medicinal properties.

  3. Antiseptic skin agents for percutaneous procedures.

    Science.gov (United States)

    Lepor, Norman E; Madyoon, Hooman

    2009-01-01

    Infections associated with percutaneously implanted devices, such as pacemakers, internal cardiac defibrillators, and endovascular prostheses, create difficult and complex clinical scenarios because management can entail complete device removal, antibiotic therapy, and prolonged hospitalization. A source for pathogens is often thought to be the skin surface, making skin preparation at the time of the procedure a critical part of minimizing implantation of infected devices and prostheses. The most common skin preparation agents used today include products containing iodophors or chlorhexidine gluconate. Agents are further classified by whether they are aqueous-based or alcoholbased solutions. Traditional aqueous-based iodophors, such as povidone-iodine, are one of the few products that can be safely used on mucous membrane surfaces. Alcohol-based solutions are quick, sustained, and durable, with broader spectrum antimicrobial activity. These agents seem ideal for percutaneous procedures associated with prosthesis implantation, when it is critical to minimize skin colony counts to prevent hardware infection.

  4. FIPA agent based network distributed control system

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-03-01

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

  5. Animals as sentinels of bioterrorism agents.

    Science.gov (United States)

    Rabinowitz, Peter; Gordon, Zimra; Chudnov, Daniel; Wilcox, Matthew; Odofin, Lynda; Liu, Ann; Dein, Joshua

    2006-04-01

    We conducted a systematic review of the scientific literature from 1966 to 2005 to determine whether animals could provide early warning of a bioterrorism attack, serve as markers for ongoing exposure risk, and amplify or propagate a bioterrorism outbreak. We found evidence that, for certain bioterrorism agents, pets, wildlife, or livestock could provide early warning and that for other agents, humans would likely manifest symptoms before illness could be detected in animals. After an acute attack, active surveillance of wild or domestic animal populations could help identify many ongoing exposure risks. If certain bioterrorism agents found their way into animal populations, they could spread widely through animal-to-animal transmission and prove difficult to control. The public health infrastructure must look beyond passive surveillance of acute animal disease events to build capacity for active surveillance and intervention efforts to detect and control ongoing outbreaks of disease in domestic and wild animal populations.

  6. Existence of Multiagent Equilibria with Limited Agents

    CERN Document Server

    Bowling, M; 10.1613/jair.1332

    2011-01-01

    Multiagent learning is a necessary yet challenging problem as multiagent systems become more prevalent and environments become more dynamic. Much of the groundbreaking work in this area draws on notable results from game theory, in particular, the concept of Nash equilibria. Learners that directly learn an equilibrium obviously rely on their existence. Learners that instead seek to play optimally with respect to the other players also depend upon equilibria since equilibria are fixed points for learning. From another perspective, agents with limitations are real and common. These may be undesired physical limitations as well as self-imposed rational limitations, such as abstraction and approximation techniques, used to make learning tractable. This article explores the interactions of these two important concepts: equilibria and limitations in learning. We introduce the question of whether equilibria continue to exist when agents have limitations. We look at the general effects limitations can have on agent b...

  7. Intelligent Virtual Agents Architecture in Unknown Environment

    Directory of Open Access Journals (Sweden)

    Jiangfan Feng

    2012-11-01

    Full Text Available As the contemporary performing behavior in the reciprocity of virtual agents is glazed excessively and can't satisfy complex unknown environment, the research of Intelligent Virtual Agents (IVA with active learning and local apperception must be accelerated. In this paper, we design and implement a new IVA system architecture, for which active learning and local apperceive interaction were approached. Active learning using knowledge acquisition and knowledge evolution improved the self-regulation of behavior mechanism significantly, while local apperceive interaction could sense disturbances of the simulated environment and interactively communicate with other simulated agents within perception dimension effectively. Ultimately, the experimental result provides effectiveness and practicability of the performance in our prototype IVA system.

  8. NATURAL AGENTS FOR INFLAMMATORY BOWEL DISEASE

    Directory of Open Access Journals (Sweden)

    Darji Vinay Chhanalal

    2011-02-01

    Full Text Available Inflammatory bowel disease (IBD is a chronic inflammatory disease of gastrointestinal tract. It comprises the two conditions, Crohn’s disease and ulcerative colitis, characterized by chronic recurrent ulceration of the bowel. Conventional drugs for colitis treatment include aminosalicylate, corticosteroids,antibiotics & immunomodulators. 5- Amino salicylic acid having side effects in 30% of the patients. Systemic corticosteroids producing incidence of complication is 4.3%. Antibiotic therapy is beneficial in 70% of the patients & Immunomodulators having 50 to 70% beneficial effects. This report shows that there is no any appropriate treatment available to treat IBD without side effects. A natural agent with reduced or no toxicity is therefore essential. In nature there are so many types of natural agents which are used as protective agents in IBD. This article emphasizes many natural products obtained from plant & other sources, which possess potent activity against experimentally induced IBD.

  9. Network Management using Multi-Agents System

    Directory of Open Access Journals (Sweden)

    Nestor DUQUE

    2013-07-01

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

  10. Network Management using Multi-Agents System

    Directory of Open Access Journals (Sweden)

    Gustavo ISAZA

    2012-12-01

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

  11. Learning Pet -- Intelligent Agents for WBE

    Institute of Scientific and Technical Information of China (English)

    戴玮; 俞方桦

    2001-01-01

    An intelligent agent is any program that can be considered by the user to be acting as an assistant or helper, rather than as a tool in the manner of a conventional direct-manipulation interface. An agent should as well display some, but perhaps not all, of the characteristics that are associated with human intelligence: learning, inference, adaptability,independence, creativity, etc.. In order to make webbased education (WBE) more vividly and instructionally with learner's independence at the same time, the intelligent agent can act as a learning pet, which is affiliated with learner's score or grades and will grow up with learner's achievement. And during the course of study, the learning pet can provides any information required by the learner, gives hints if necessary when the learner doing his/her assignment, offers instructional guide for further study etc..

  12. Planning of Autonomous Multi-agent Intersection

    Directory of Open Access Journals (Sweden)

    Viksnin Ilya I.

    2016-01-01

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

  13. Glutamic acid as anticancer agent: An overview.

    Science.gov (United States)

    Dutta, Satyajit; Ray, Supratim; Nagarajan, K

    2013-10-01

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

  14. Microbial biofilms: biosurfactants as antibiofilm agents.

    Science.gov (United States)

    Banat, Ibrahim M; De Rienzo, Mayri A Díaz; Quinn, Gerry A

    2014-12-01

    Current microbial inhibition strategies based on planktonic bacterial physiology have been known to have limited efficacy on the growth of biofilm communities. This problem can be exacerbated by the emergence of increasingly resistant clinical strains. All aspects of biofilm measurement, monitoring, dispersal, control, and inhibition are becoming issues of increasing importance. Biosurfactants have merited renewed interest in both clinical and hygienic sectors due to their potential to disperse microbial biofilms in addition to many other advantages. The dispersal properties of biosurfactants have been shown to rival those of conventional inhibitory agents against bacterial and yeast biofilms. This makes them suitable candidates for use in new generations of microbial dispersal agents and for use as adjuvants for existing microbial suppression or eradication strategies. In this review, we explore aspects of biofilm characteristics and examine the contribution of biologically derived surface-active agents (biosurfactants) to the disruption or inhibition of microbial biofilms.

  15. A Multi Agent System for MS Windows using Matlab-enabled Agents

    NARCIS (Netherlands)

    Hupkens, Th.M.; Thaens, R.

    2005-01-01

    A method is described to program the properties of agents of a multi agent system by using Matlab instructions or Matlab m-files. Apart from the obvious advantage that all Matlab functionality is immediately available, there is the added advantage that all debugging capabilities that Matlab provides

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

    Science.gov (United States)

    Han, Jing; Wang, Lin

    2013-01-01

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

  17. Agent Behavior alignment : A mechanism to overcome problems in agent interactions during runtime

    NARCIS (Netherlands)

    Meyer, Gerben G.; Szirbik, Nick B.; Klusch, M; Hindriks, K; Papazoglou, MP; Strerling, L

    2007-01-01

    When two or more agents interacting, their behaviors are not necessarily matching. Automated ways to overcome conflicts in the behavior of agents can make the execution of interactions more reliable. Such an alignment mechanism will reduce the necessary human intervention. This paper shows how to de

  18. Research of Communication Mechanism of the Multi-agent in Multi-agent Robot Systems

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The cooperation of multi-robot that is based on the multi-agent system (MAS) theory of distributed artificial intelligence has become a hotspot in the robotics R&D. In the research the multi-robot is regarded as multi-agent. So the communication and cooperation of multi-agent become the key problem for gaining the dynamic running information of cooperating robots. In this paper the authors introduce the communication modes for agent and provide a common strategy which aims at the communication resources of multi-agent model-the CSMA/CD (Carrier Sense Multiple Access with Collision Detection) protocol which is based on the transmittal medium. It supports the cable-communication of multi-robot and the experiments prove its validity.

  19. 10th KES Conference on Agent and Multi-Agent Systems : Technologies and Applications

    CERN Document Server

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

    2016-01-01

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

  20. Novel anti-inflammatory agents in COPD

    DEFF Research Database (Denmark)

    Loukides, Stelios; Bartziokas, Konstantinos; Vestbo, Jørgen

    2013-01-01

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

  1. Traffic Signal Using Smart Agent System

    Directory of Open Access Journals (Sweden)

    Cheonshik Kim

    2008-01-01

    Full Text Available In this research, we propose an electro-sensitive traffic light using the smart agent algorithm to reduce traffic congestion and traffic accidents. The multi-agent system approach can provide a new and preferable solution. The proposed method adaptively controls the cycle of traffic signals even though the traffic volume varies. Consequently, we reduce the car waiting time and start-up delay time using fuzzy control of feedback data. In particular, we have designed and implemented a system to create optimum traffic signals in congested conditions. The effectiveness of this method was shown through simulation of multiple intersections.

  2. Integrating Reactive and Deliberative Planning for Agents

    Science.gov (United States)

    1993-05-01

    eff’ectivelv. \\Ve integrate these two systems so as to retain the strengths of each by giving primary control of the agent to Hlap . Hap keeps the tree of...predefined subset of the agent’s goals. Because Hap and Prodigy have somewhat different notions of what goals are, not all Hlap goals are expressible as...for executing these subgoals in the dynamic world. Hap is able to fill in the dynamic details that Prodigy’ did not plan for. Also, Hlap will often

  3. Detection of electrophilic and nucleophilic chemical agents

    Energy Technology Data Exchange (ETDEWEB)

    McElhanon, James R.; Shepodd, Timothy J.

    2014-08-12

    A "real time" method for detecting chemical agents generally and particularly electrophilic and nucleophilic species by employing tunable, precursor sensor materials that mimic the physiological interaction of these agents to form highly florescent berberine-type alkaloids that can be easily and rapidly detected. These novel precursor sensor materials can be tuned for reaction with both electrophilic (chemical species, toxins) and nucleophilic (proteins and other biological molecules) species. By bonding or otherwise attaching these precursor molecules to a surface or substrate they can be used in numerous applications.

  4. Psoriatic arthritis: treatment strategies using biologic agents

    Directory of Open Access Journals (Sweden)

    C. Palazzi

    2012-06-01

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

  5. New agents: great expectations not realized.

    Science.gov (United States)

    Lancet, Jeffrey E

    2013-09-01

    A number of new agents in acute myeloid leukemia (AML) have held much promise in recent years, but most have failed to change the therapeutic landscape. Indeed, with the exception of gemtuzumab ozogamicin (which was subsequently voluntarily withdrawn from the commercial market), no new agent has been approved for acute myeloid leukemia (AML) beyond the 7 + 3 regimen, which was has been in use for over 40 years. This review touches upon the potential reasons for these failures and explores the newer therapeutic approaches being pursued in AML.

  6. Agendas for Multi-Agent Learning

    Science.gov (United States)

    2006-12-01

    for our agents to learn to achieve high rewards. 2 Unfortunately, the current state of the art for testing whether we have done a good job is to hand...our model to some learning agents and see how much reward they can earn. This sort of test isn’t a good way to draw general con- clusions: if the... Barany . Fair distribution protocols or how the players replace fortune. Mathematics of Operations Research, 17(2):327–340, 1992. [32] Yevgeniy Dodis

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

    Directory of Open Access Journals (Sweden)

    Viviane Milan Pupin

    2008-08-01

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

  8. A Diversified Investment Strategy Using Autonomous Agents

    Science.gov (United States)

    Barbosa, Rui Pedro; Belo, Orlando

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

  9. Liposome imaging agents in personalized medicine

    DEFF Research Database (Denmark)

    Petersen, Anncatrine Luisa; Hansen, Anders Elias; Gabizon, Alberto;

    2012-01-01

    that selectively localize in tumor tissue can transport both drugs and imaging agents, which allows for a theranostic approach with great potential in personalized medicine. Radiolabeling of liposomes have for many years been used in preclinical studies for evaluating liposome in vivo performance and has been...... start to consider how to use imaging for patient selection and treatment monitoring in connection to nanocarrier based medicines. Nanocarrier imaging agents could furthermore have interesting properties for disease diagnostics and staging. Here, we review the major advances in the development...... of radiolabeled liposomes for imaging as a tool in personalized medicine....

  10. Organophosphate Nerve Agent Detection with Europium Complexes

    Directory of Open Access Journals (Sweden)

    Jake R. Schwierking

    2004-01-01

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

  11. Intrathecal chemotherapy. Selection of cytostatic agents.

    Science.gov (United States)

    Hayakawa, T; Yamada, R; Kanai, N; Kuroda, R; Ushio, Y; Higashi, H; Mogami, H

    1970-09-01

    Selection of cytostatic agents for intrathecal administration is the subject of this paper.Both the toxic side effects-destruction of blood-brain barrier and change of body weight-and the cytostatic effects on intracranially transplanted Yoshida ascites sarcoma were investigated of intrathecal administration of various cytostatic agents. As a result, it may be concluded that Methotrexate and Endoxan and lower dose of mitomycin C are suitable drugs for intrathecal chemotherapy.Based on these findings, clinical cases of malignant brain tumours were treated with intrathecal chemotherapy.Grateful acknowledgement is made to Professor Dennosuke Jinnai for his constant interest and guidance in this investigation.

  12. CATS-based Air Traffic Controller Agents

    Science.gov (United States)

    Callantine, Todd J.

    2002-01-01

    This report describes intelligent agents that function as air traffic controllers. Each agent controls traffic in a single sector in real time; agents controlling traffic in adjoining sectors can coordinate to manage an arrival flow across a given meter fix. The purpose of this research is threefold. First, it seeks to study the design of agents for controlling complex systems. In particular, it investigates agent planning and reactive control functionality in a dynamic environment in which a variety perceptual and decision making skills play a central role. It examines how heuristic rules can be applied to model planning and decision making skills, rather than attempting to apply optimization methods. Thus, the research attempts to develop intelligent agents that provide an approximation of human air traffic controller behavior that, while not based on an explicit cognitive model, does produce task performance consistent with the way human air traffic controllers operate. Second, this research sought to extend previous research on using the Crew Activity Tracking System (CATS) as the basis for intelligent agents. The agents use a high-level model of air traffic controller activities to structure the control task. To execute an activity in the CATS model, according to the current task context, the agents reference a 'skill library' and 'control rules' that in turn execute the pattern recognition, planning, and decision-making required to perform the activity. Applying the skills enables the agents to modify their representation of the current control situation (i.e., the 'flick' or 'picture'). The updated representation supports the next activity in a cycle of action that, taken as a whole, simulates air traffic controller behavior. A third, practical motivation for this research is to use intelligent agents to support evaluation of new air traffic control (ATC) methods to support new Air Traffic Management (ATM) concepts. Current approaches that use large, human

  13. A dialogue agent for navigation support in virtual reality

    NARCIS (Netherlands)

    Luin, van J.; Akker, op den H.J.A.; Nijholt, A.; Jacko, J.; Sears, A.

    2001-01-01

    We describe our work on designing a natural language accessible navigation agent for a virtual reality (VR) environment. The agent is part of an agent framework, which means that it can communicate with other agents. Its navigation task consists of guiding the visitors in the environment and to answ

  14. Current multiple myeloma treatment strategies with novel agents

    DEFF Research Database (Denmark)

    Ludwig, Heinz; Beksac, Meral; Bladé, Joan;

    2010-01-01

    The treatment of multiple myeloma (MM) has undergone significant developments in recent years. The availability of the novel agents thalidomide, bortezomib, and lenalidomide has expanded treatment options and has improved the outcome of patients with MM. Following the introduction of these agents...... presents an overview of the most recent data with these novel agents and summarizes European treatment practices incorporating the novel agents....

  15. A Multi-Agent Immunology Model for Security Computer

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents a computer immunology model for computersecurity , whose main components are defined as idea of Multi-Agent. It introduces the n at ural immune system on the principle, discusses the idea and characteristics of Mu lti-Agent. It gives a system model, and describes the structure and function of each agent. Also, the communication method between agents is described.

  16. Do you get it? User-evaluated explainable BDI agents

    NARCIS (Netherlands)

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

    2010-01-01

    In this paper we focus on explaining to humans the behavior of autonomous agents, i.e., explainable agents. Explainable agents are useful for many reasons including scenario-based training (e.g. disaster training), tutor and pedagogical systems, agent development and debugging, gaming, and interacti

  17. Agent-Based Computing in Distributed Adversarial Planning

    Science.gov (United States)

    2010-08-09

    agents, P3 represents games with 3 agents; value of BF represents the branching factors for the agents in fixed order (each digit for one agent...and M. Wooldridge. Cooperation, knowledge, and time: Alternating-time temporal epistemic logic and its applications. Studia Logica , 75(1):125–157

  18. Schools as Agents of Social Exclusion and Inclusion

    Science.gov (United States)

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

    2013-01-01

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

  19. 49 CFR 375.205 - May I have agents?

    Science.gov (United States)

    2010-10-01

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

  20. A Forward Integrity and Itinerary Secrecy Protocol for Mobile Agents

    Institute of Scientific and Technical Information of China (English)

    GUAN Huanmei; MENG Xuejun; ZHANG Huanguo

    2006-01-01

    The security problem of mobile agents is widely being discussed. The problem which protects mobile agents from malicious hosts is difficult to solve, because a host has access to the complete internal state of an agent. Forward integrity in mobile agents guarantees that offers contained in a mobile agent from previously visited host can not be modified by a malicious host. Itinerary secrecy can prevent mobile agent from being passively attack. This paper proposes a new forward integrity and itinerary secrecy protocol for mobile agent. The protocol can also resist collusion truncation attack.

  1. Repatriates as Knowlege-transfer Agents

    DEFF Research Database (Denmark)

    Lemmergaard, Jeanette; Sanchez Vidal, Ma Eugenia

    Expatriates are increasingly recognized for their central role as knowledge-transfer agents. Traditionally expatriates were only sent out to control and coordinate activities, but in the knowledge economy international assignments are seen as a way of obtaining knowledge-transfer between organiza...

  2. Acoustic properties of ultrasound contrast agents

    NARCIS (Netherlands)

    N. de Jong (Nico)

    1993-01-01

    textabstractSafety of contrast agents is reported in the years after. Both the intracoronary use of sonicated Renografin as well as intravenous use of commercial product as Albunex and Lechovist has been investigated. Thereafter more pathophysiologic studies were performed. Ten Cate described the po

  3. Advanced detection strategies for ultrasound contrast agents

    NARCIS (Netherlands)

    J.M.G. Borsboom (Jerome)

    2005-01-01

    markdownabstract__Abstract__ Ultrasound contrast agent was discovered serendipitously by Gramiak and Shah in I968 when they injected indocyanine green dye into the heart and observed increased echogenicity of the blood containing the dye. Small cavitation bubbles that were formed upon injection of

  4. 7 CFR 930.87 - Agents.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Agents. 930.87 Section 930.87 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE TART CHERRIES GROWN IN THE STATES...

  5. Dynamic agent hierarchies for design prototypes

    NARCIS (Netherlands)

    Szirbik, Nick; Stuit, Marco; Meyer, Gerben; Reddy, S.

    2009-01-01

    Introducing dynamic aspects in diagrams that capture the aggregate structure of composite agents represents a promising notion, which can help to express in a straightforward manner how an entity is changing its placement during its evolution in time. This paper focuses on the novel concept of a dyn

  6. Multi-Agent Systems Design for Novices

    Science.gov (United States)

    Lynch, Simon; Rajendran, Keerthi

    2005-01-01

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

  7. Targeted Agents for Imaging and Therapy

    NARCIS (Netherlands)

    Grüll, H.; Robillard, M.S.

    2005-01-01

    Molecular Imaging allows the visualization of biological processesin vivo, offering new chances for healthcare with respect to early diagnosis and improved therapy. The new field of molecular imaging isboosted by more sensitive imaging systems and the emergence of targeted imaging agents that hom

  8. Constructing Careers: Actor, Agent, and Author

    Science.gov (United States)

    Savickas, Mark L.

    2011-01-01

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

  9. Agents adopting agriculture : Modeling the agricultural transition

    NARCIS (Netherlands)

    van der Vaart, Elske; de Boer, Bart; Hankel, Albert; Verheij, Bart; Nolfi, S; Baldassarre, G; Calabretta, R; Hallam, JCT; Marocco, D; Meyer, JA; Miglino, O; Parisi, D

    2006-01-01

    The question "What drove foragers to farm?" has drawn answers from many different disciplines, often in the form of verbal models. Here, we take one such model, that of the ideal free distribution, and implement it as an agent-based computer simulation. Populations distribute themselves according to

  10. Games and Agents: Designing Intelligent Gameplay

    Directory of Open Access Journals (Sweden)

    F. Dignum

    2009-01-01

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

  11. Sexual dysfunction with antihypertensive and antipsychotic agents.

    Science.gov (United States)

    Smith, P J; Talbert, R L

    1986-05-01

    The physiology of the normal sexual response, epidemiology of sexual dysfunction, and the pharmacologic mechanisms involved in antihypertensive- and antipsychotic-induced problems with sexual function are discussed, with recommendations for patient management. The physiologic mechanisms involved in the normal sexual response include neurogenic, psychogenic, vascular, and hormonal factors that are coordinated by centers in the hypothalamus, limbic system, and cerebral cortex. Sexual dysfunction is frequently attributed to antihypertensive and antipsychotic agents and is a cause of noncompliance. Drug-induced effects include diminished libido, delayed orgasm, ejaculatory disturbances, gynecomastia, impotence, and priapism. The pharmacologic mechanisms proposed to account for these adverse effects include adrenergic inhibition, adrenergic-receptor blockade, anticholinergic properties, and endocrine and sedative effects. The most frequently reported adverse effect on sexual function with the antihypertensive agents is impotence. It is seen most often with methyldopa, guanethidine, clonidine, and propranolol. In contrast, the most common adverse effect on sexual function with the antipsychotic agents involves ejaculatory disturbances. Thioridazine, with its potent anticholinergic and alpha-blocking properties, is cited most often. Drug-induced sexual dysfunction may be alleviated by switching to agents with dissimilar mechanisms to alter the observed adverse effect while maintaining adequate control of the patient's disease state.

  12. Smart Questions To Ask Your Insurance Agent.

    Science.gov (United States)

    Cohen, Abby J.

    1997-01-01

    Provides advice on insurance coverage for child care centers. Suggests that before purchasing insurance you inquire about the agent's qualifications, company's financial stability, and corporate ratings; and obtain written answers to questions about specific coverage issues such as volunteers, legal defense costs, special events, and…

  13. Een navigatie-agent in virtual reality

    NARCIS (Netherlands)

    Nijholt, A.; Luin, van J.; Akker, op den H.J.A.

    2002-01-01

    We geven een korte beschrijving van ons werk gericht op het ontwerpen van een navigatie-agent voor een virtuele werled die met natuurlijke taal aangesproken kan worden. Het project is gestart als afstudeerwerk van de tweede auteur. Dit artikel beschrijft voornamelijk zijn werk. Het werk wordt op dit

  14. Collaborative learning agents supporting service network management

    NARCIS (Netherlands)

    Mulder, W.; Meijer, G.R.; Adriaans, P.W.

    2008-01-01

    Service oriented systems need to be maintained to keep the requested level of service. This is challenge in large grid- and saas based networks that are managed by numerous entities. This paper is about supporting multi agent systems that operate in the network and support its management by learning

  15. Agent Turnovers in Ohio State University Extension.

    Science.gov (United States)

    Rousan, Laith M.; Henderson, Janet L.

    1996-01-01

    Responses from 61 of 67 Ohio State University extension agents who left between 1990-94 showed they were primarily female (66%), white (90%), and untenured (98%). They were most likely to leave due to other priorities, insufficient pay, family obligations, too many work responsibilities, or the opportunity to make more money elsewhere. (SK)

  16. Kw-1 Agent Used in Steam Injection

    Institute of Scientific and Technical Information of China (English)

    Yang Deyuan

    1997-01-01

    @@ The main function of Kw-1 agent is to reduce the interfacial tension between the interfaces of oil and water, and oil and rock (See Fig. 1).Its action mechanism is peeling off,emulsion breaking, changing the relative permeability and enlarging the sweeping volume.

  17. The 2014 Power Trading Agent Competition

    NARCIS (Netherlands)

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

    2014-01-01

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

  18. The 2017 Power Trading Agent Competition

    NARCIS (Netherlands)

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

    2017-01-01

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

  19. The 2015 Power Trading Agent Competition

    NARCIS (Netherlands)

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

    2015-01-01

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

  20. The 2012 Power Trading Agent Competition

    NARCIS (Netherlands)

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

    2012-01-01

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