Quantum Speedup for Active Learning Agents

Directory of Open Access Journals (Sweden)

Giuseppe Davide Paparo

2014-07-01

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

Preparation and mechanism analysis of an environment-friendly maize seed coating agent.

Science.gov (United States)

Zeng, Defang; Fan, Zhao; Tian, Xu; Wang, Wenjin; Zhou, Mingchun; Li, Haochuan

2018-06-01

Traditional seed coating agents often contain toxic ingredients, which contaminate the environment and threaten human health. This paper expounds a method of preparing a novel environment-friendly seed coating agent for maize and researches its mechanism of action. The natural polysaccharide polymer, which is the main active ingredient of this environment-friendly seed coating agent, has the characteristics of innocuity and harmlessness, and it can replace the toxic ingredients used in traditional seed coating agents. This environment-friendly seed coating agent for maize was mainly made up of the natural polysaccharide polymer and other additives. The field trials results showed that the control efficacy of Helminthosporium maydis came to 93.72%, the anti-feeding rate of cutworms came to 81.29%, and the maize yield was increased by 17.75%. Besides, the LD 50 value (half the lethal dose in rats) of this seed coating agent was 10 times higher than that of the traditional seed coating agents. This seed coating agent could improve the activity of plant protective enzymes (peroxidase, catalase and superoxidase dismutase) and increase the chlorophyll content. This seed coating agent has four characteristics of disease prevention, desinsectization, increasing yield and safety. Results of mechanism analyses showed that this seed coating agent could enhance disease control effectiveness by improving plant protective enzymes activity and increase maize yield by improving chlorophyll content. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Basic MR relaxation mechanisms and contrast agent design.

Science.gov (United States)

De León-Rodríguez, Luis M; Martins, André F; Pinho, Marco C; Rofsky, Neil M; Sherry, A Dean

2015-09-01

The diagnostic capabilities of magnetic resonance imaging (MRI) have undergone continuous and substantial evolution by virtue of hardware and software innovations and the development and implementation of exogenous contrast media. Thirty years since the first MRI contrast agent was approved for clinical use, a reliance on MR contrast media persists, largely to improve image quality with higher contrast resolution and to provide additional functional characterization of normal and abnormal tissues. Further development of MR contrast media is an important component in the quest for continued augmentation of diagnostic capabilities. In this review we detail the many important considerations when pursuing the design and use of MR contrast media. We offer a perspective on the importance of chemical stability, particularly kinetic stability, and how this influences one's thinking about the safety of metal-ligand-based contrast agents. We discuss the mechanisms involved in MR relaxation in the context of probe design strategies. A brief description of currently available contrast agents is accompanied by an in-depth discussion that highlights promising MRI contrast agents in the development of future clinical and research applications. Our intention is to give a diverse audience an improved understanding of the factors involved in developing new types of safe and highly efficient MR contrast agents and, at the same time, provide an appreciation of the insights into physiology and disease that newer types of responsive agents can provide. © 2015 Wiley Periodicals, Inc.

Revealing the Interface Structure and Bonding Mechanism of Coupling Agent Treated WPC

Directory of Open Access Journals (Sweden)

Jiuping Rao

2018-03-01

Full Text Available This paper presents the interfacial optimisation of wood plastic composites (WPC based on recycled wood flour and polyethylene by employing maleated and silane coupling agents. The effect of the incorporation of the coupling agents on the variation of chemical structure of the composites were investigated by Attenuated total reflectance-Fourier Transform Infrared spectroscopy (ATR-FTIR and Solid state 13C Nuclear Magnetic Resonance spectroscopy (NMR analyses. The results revealed the chemical reactions that occurred between the coupling agents and raw materials, which thus contributed to the enhancement of compatibility and interfacial adhesion between the constituents of WPC. NMR results also indicated that there existed the transformation of crystalline cellulose to an amorphous state during the coupling agent treatments, reflecting the inferior resonance of crystalline carbohydrates. Fluorescence Microscope (FM and Scanning Electron Microscope (SEM analyses showed the improvements of wood particle dispersion and wettability, compatibility of the constituents, and resin penetration, and impregnation of the composites after the coupling agent treatments. The optimised interface of the composites was attributed to interdiffusion, electrostatic adhesion, chemical reactions, and mechanical interlocking bonding mechanisms.

Immunotherapeutics in Pediatric Autoimmune Central Nervous System Disease: Agents and Mechanisms.

Science.gov (United States)

Nosadini, Margherita; Sartori, Stefano; Sharma, Suvasini; Dale, Russell C

2017-08-01

Beyond the major advances produced by careful clinical-radiological phenotyping and biomarker development in autoimmune central nervous system disorders, a comprehensive knowledge of the range of available immune therapies and a deeper understanding of their action should benefit therapeutic decision-making. This review discusses the agents used in neuroimmunology and their mechanisms of action. First-line treatments typically include corticosteroids, intravenous immunoglobulin, and plasmapheresis, while for severe disease second-line "induction" agents such as rituximab or cyclophosphamide are used. Steroid-sparing agents such as mycophenolate, azathioprine, or methotrexate are often used in potentially relapsing or corticosteroid-dependent diseases. Lessons from adult neuroimmunology and rheumatology could be translated into pediatric autoimmune central nervous system disease in the future, including the potential utility of monoclonal antibodies targeting lymphocytes, adhesion molecules for lymphocytic migration, cytokines or their receptors, or complement. Finally, many agents used in other fields have multiple mechanisms of action, including immunomodulation, with potential usefulness in neuroimmunology, such as antibiotics, psychotropic drugs, probiotics, gut health, and ketogenic diet. All currently accepted and future potential agents have adverse effects, which can be severe; therefore, a "risk-versus-benefit" determination should guide therapeutic decision-making. Copyright © 2017 Elsevier Inc. All rights reserved.

[Mechanism of action of insulin sensitizer agents in the treatment of polycystic ovarian syndrome].

Science.gov (United States)

Galindo García, Carlos G; Vega Arias, Maria de Jesús; Hernández Marín, Imelda; Ayala, Aquiles R

2007-03-01

Polycystic ovarian disease (PCOD) is the most important endocrine abnormality that affects women in reproductive age. It is characterized by chronic anovulation and hyperandrogenemia probably secondary to insulin resistance. Hence insulin sensitizers agents had been used in PCOD. Metformin is a biguanide used in the treatment of PCOD via decrease of hepatic gluconeogenesis and insulinemia; improvement peripheral glucose utilization, oxidative glucose metabolism, nonoxidative glucose metabolism and intracellular glucose transport. Such effects, when this drug is administered alone during 3 to 6 months, increase sex hormone binding globulin (SHBG), reduce free androgens index and hirsutism, decrease insulin resistance, and regulate menses in 60 to 70% of cases. Thiazolidinodiones are drugs that decrease insulin resistance in the liver with hepatic glucose production. Their mechanism of action is through the peroxisome proliferator-activated receptors gamma (PPAR-gamma), that help to decrease plasmatic concentrations of free fatty acids, pre and postprandial glucose, insulin, triglycerides, increased HDL cholesterol and decreased LDL, menses return to normality, with improvement of ovulation and decreased hirsutism. It seems that by modulation and attenuation of insulin resistance, hypoglucemic agents such as metfomin and thiazolidinodiones can be used effectively to treat anovulation, infertility and hyperandrogenemia.

Modeling Multi-Mobile Agents System Based on Coalition Signature Mechanism Using UML

Institute of Scientific and Technical Information of China (English)

SUNZhixin; HUANGHaiping; WANGRuchuan

2004-01-01

With the development of electronic commerce and agent techniques, multi-mobile agents cooperation can not only improve the efficiency of electronic business trade, but more importantly, it has a comprehensive applicative value in solving the security issues of mobile agent system. This paper firstly describes the mechanism of multi-mobile agents coalition signature aiming at the system security. Subsequently it brings forward a basic architecture of Multi-mobile agents system (MMAS) based on the design pattern of multi-mobile agents. The paper uses the diagrs_rn of UML, such as use case diagram, class diagram and sequence diagram to build the detailed model of the coalition signature and multi-mobile agents cooperation results. Through security analysis, we find that multimobile agents cooperation and interaction can solve some security problems of mobile agents in transfer, and also it can improve the efficiency of business trade. These results indicate that MMAS has a high security performance and can be widely used in E-commerce trade.

Radioprotection: mechanism and radioprotective agents including honeybee venom

Energy Technology Data Exchange (ETDEWEB)

Varanda, E.A.; Tavares, D.C. [UNESP, Araraquara, SP (Brazil). Escola de Ciencias Farmaceuticas. Dept. de Ciencias Biologicas

1998-07-01

Since 1949, a great deal of research has been carried on the radioprotective action of chemical substances. These substances have shown to reduce mortality when administered to animals prior to exposure to a lethal dose of radiation. This fact is of considerable importance since it permits reduction of radiation-induced damage and provides prophylactic treatment for the damaging effects produced by radiotherapy. The following radioprotection mechanisms were proposed: free radical scavenger, repair by hydrogen donation to target molecules formation of mixed disulfides, delay of cellular division and induction of hypoxia in the tissues. Radioprotective agents have been divided into four major groups: the thiol compounds, other sulfur compounds, pharmacological agents (anesthetic drugs, analgesics, tranquilizers, etc.) and other radioprotective agents (WR-1065, WR-2721, vitamins C and E, glutathione, etc.). Several studies revealed the radioprotective action of Apis mellifera honeybee venom as well as that of its components mellitin and histamine. Radioprotective activity of bee venom involves mainly the stimulation of the hematopoietic system. In addition, release of histamine and reduction in oxygen tension also contribute to the radioprotective action of bee venom. (author)

Radioprotection: mechanism and radioprotective agents including honeybee venom

International Nuclear Information System (INIS)

Varanda, E.A.; Tavares, D.C.

1998-01-01

Since 1949, a great deal of research has been carried on the radioprotective action of chemical substances. These substances have shown to reduce mortality when administered to animals prior to exposure to a lethal dose of radiation. This fact is of considerable importance since it permits reduction of radiation-induced damage and provides prophylactic treatment for the damaging effects produced by radiotherapy. The following radioprotection mechanisms were proposed: free radical scavenger, repair by hydrogen donation to target molecules formation of mixed disulfides, delay of cellular division and induction of hypoxia in the tissues. Radioprotective agents have been divided into four major groups: the thiol compounds, other sulfur compounds, pharmacological agents (anesthetic drugs, analgesics, tranquilizers, etc.) and other radioprotective agents (WR-1065, WR-2721, vitamins C and E, glutathione, etc.). Several studies revealed the radioprotective action of Apis mellifera honeybee venom as well as that of its components mellitin and histamine. Radioprotective activity of bee venom involves mainly the stimulation of the hematopoietic system. In addition, release of histamine and reduction in oxygen tension also contribute to the radioprotective action of bee venom. (author)

Influence of Polylactide Modification with Blowing Agents on Selected Mechanical Properties

Directory of Open Access Journals (Sweden)

Aneta Tor-Świątek

2017-12-01

Full Text Available Article presents research of modification of PLA with four types of chemical blowing agents with a different decomposition characteristic. The modification was done both cellular extrusion and injection molding processes. Obtained results shows that dosing blowing agents have the influence on mechanical properties and structure morphology of PLA. The differences in obtained results are also visible and significant between cellular processes.

Mechanisms of self-organization and finite size effects in a minimal agent based model

International Nuclear Information System (INIS)

Alfi, V; Cristelli, M; Pietronero, L; Zaccaria, A

2009-01-01

We present a detailed analysis of the self-organization phenomenon in which the stylized facts originate from finite size effects with respect to the number of agents considered and disappear in the limit of an infinite population. By introducing the possibility that agents can enter or leave the market depending on the behavior of the price, it is possible to show that the system self-organizes in a regime with a finite number of agents which corresponds to the stylized facts. The mechanism for entering or leaving the market is based on the idea that a too stable market is unappealing for traders, while the presence of price movements attracts agents to enter and speculate on the market. We show that this mechanism is also compatible with the idea that agents are scared by a noisy and risky market at shorter timescales. We also show that the mechanism for self-organization is robust with respect to variations of the exit/entry rules and that the attempt to trigger the system to self-organize in a region without stylized facts leads to an unrealistic dynamics. We study the self-organization in a specific agent based model but we believe that the basic ideas should be of general validity

Investigations in physical mechanism of the oxidative desulfurization process assisted simultaneously by phase transfer agent and ultrasound.

Science.gov (United States)

Bhasarkar, Jaykumar B; Chakma, Sankar; Moholkar, Vijayanand S

2015-05-01

This paper attempts to discern the physical mechanism of the oxidative desulfurization process simultaneously assisted by ultrasound and phase transfer agent (PTA). With different experimental protocols, an attempt is made to deduce individual beneficial effects of PTA and ultrasound on the oxidative desulfurization system, and also the synergy between the effects of PTA and ultrasound. Effect of PTA is more marked for mechanically stirred system due to mass transfer limitations, while intense emulsification due to ultrasound helps overcome the mass transfer limitations and reduces the extent of enhancement of oxidation by PTA. Despite application of PTA and ultrasound, the intrinsic factors and properties of the reactants such as polarity (and hence partition coefficient) and diffusivity have a crucial effect on the extent of oxidation. The intrinsic reactivity of the oxidant also plays a vital role, as seen from the extent of oxidation achieved with performic acid and peracetic acid. The interfacial transport of oxidant in the form of oxidant-PTA complex reduces the undesired consumption of oxidant by the reducing species formed during transient cavitation in organic medium, which helps effective utilization of oxidant towards desulfurization. Copyright © 2014 Elsevier B.V. All rights reserved.

Statistical mechanics of competitive resource allocation using agent-based models

Science.gov (United States)

Chakraborti, Anirban; Challet, Damien; Chatterjee, Arnab; Marsili, Matteo; Zhang, Yi-Cheng; Chakrabarti, Bikas K.

2015-01-01

Demand outstrips available resources in most situations, which gives rise to competition, interaction and learning. In this article, we review a broad spectrum of multi-agent models of competition (El Farol Bar problem, Minority Game, Kolkata Paise Restaurant problem, Stable marriage problem, Parking space problem and others) and the methods used to understand them analytically. We emphasize the power of concepts and tools from statistical mechanics to understand and explain fully collective phenomena such as phase transitions and long memory, and the mapping between agent heterogeneity and physical disorder. As these methods can be applied to any large-scale model of competitive resource allocation made up of heterogeneous adaptive agent with non-linear interaction, they provide a prospective unifying paradigm for many scientific disciplines.

Multi-agent Negotiation Mechanisms for Statistical Target Classification in Wireless Multimedia Sensor Networks

Science.gov (United States)

Wang, Xue; Bi, Dao-wei; Ding, Liang; Wang, Sheng

2007-01-01

The recent availability of low cost and miniaturized hardware has allowed wireless sensor networks (WSNs) to retrieve audio and video data in real world applications, which has fostered the development of wireless multimedia sensor networks (WMSNs). Resource constraints and challenging multimedia data volume make development of efficient algorithms to perform in-network processing of multimedia contents imperative. This paper proposes solving problems in the domain of WMSNs from the perspective of multi-agent systems. The multi-agent framework enables flexible network configuration and efficient collaborative in-network processing. The focus is placed on target classification in WMSNs where audio information is retrieved by microphones. To deal with the uncertainties related to audio information retrieval, the statistical approaches of power spectral density estimates, principal component analysis and Gaussian process classification are employed. A multi-agent negotiation mechanism is specially developed to efficiently utilize limited resources and simultaneously enhance classification accuracy and reliability. The negotiation is composed of two phases, where an auction based approach is first exploited to allocate the classification task among the agents and then individual agent decisions are combined by the committee decision mechanism. Simulation experiments with real world data are conducted and the results show that the proposed statistical approaches and negotiation mechanism not only reduce memory and computation requirements in WMSNs but also significantly enhance classification accuracy and reliability. PMID:28903223

On the existence of optimal contract mechanisms for incomplete information principal-agent models

NARCIS (Netherlands)

Balder, E.J.

1997-01-01

Two abstract results are given for the existence of optimal contract selection mechanisms in principal-agent models; by a suitable reformulation of the (almost) incentive compatibility constraint, they deal with both single- and multi-agent models. In particular, it is shown that the existence

Natural agents: cellular and molecular mechanisms of photoprotection.

Science.gov (United States)

Afaq, Farrukh

2011-04-15

The skin is the largest organ of the body that produces a flexible and self-repairing barrier and protects the body from most common potentially harmful physical, environmental, and biological insults. Solar ultraviolet (UV) radiation is one of the major environmental insults to the skin and causes multi-tiered cellular and molecular events eventually leading to skin cancer. The past decade has seen a surge in the incidence of skin cancer due to changes in life style patterns that have led to a significant increase in the amount of UV radiation that people receive. Reducing excessive exposure to UV radiation is desirable; nevertheless this approach is not easy to implement. Therefore, there is an urgent need to develop novel strategies to reduce the adverse biological effects of UV radiation on the skin. A wide variety of natural agents have been reported to possess substantial skin photoprotective effects. Numerous preclinical and clinical studies have elucidated that natural agents act by several cellular and molecular mechanisms to delay or prevent skin cancer. In this review article, we have summarized and discussed some of the selected natural agents for skin photoprotection. Copyright © 2010 Elsevier Inc. All rights reserved.

Multi-agent Negotiation Mechanisms for Statistical Target Classification in Wireless Multimedia Sensor Networks

Directory of Open Access Journals (Sweden)

Sheng Wang

2007-10-01

Full Text Available The recent availability of low cost and miniaturized hardware has allowedwireless sensor networks (WSNs to retrieve audio and video data in real worldapplications, which has fostered the development of wireless multimedia sensor networks(WMSNs. Resource constraints and challenging multimedia data volume makedevelopment of efficient algorithms to perform in-network processing of multimediacontents imperative. This paper proposes solving problems in the domain of WMSNs fromthe perspective of multi-agent systems. The multi-agent framework enables flexible networkconfiguration and efficient collaborative in-network processing. The focus is placed ontarget classification in WMSNs where audio information is retrieved by microphones. Todeal with the uncertainties related to audio information retrieval, the statistical approachesof power spectral density estimates, principal component analysis and Gaussian processclassification are employed. A multi-agent negotiation mechanism is specially developed toefficiently utilize limited resources and simultaneously enhance classification accuracy andreliability. The negotiation is composed of two phases, where an auction based approach isfirst exploited to allocate the classification task among the agents and then individual agentdecisions are combined by the committee decision mechanism. Simulation experiments withreal world data are conducted and the results show that the proposed statistical approachesand negotiation mechanism not only reduce memory and computation requi

A novel biomimetic orthodontic bonding agent helps prevent white spot lesions adjacent to brackets.

Science.gov (United States)

Manfred, Lauren; Covell, David A; Crowe, Jennifer J; Tufekci, Eser; Mitchell, John C

2013-01-01

To compare changes in enamel microhardness adjacent to orthodontic brackets after using bonding agents containing various compositions of bioactive glass compared to a traditional resin adhesive following a simulated caries challenge. Extracted human third molars (n  =  10 per group) had orthodontic brackets bonded using one of four novel bioactive glass (BAG)-containing orthodontic bonding agents (BAG-Bonds) or commercially available Transbond-XT. The four new adhesives contained BAG in varying percentages incorporated into a traditional resin monomer mixture. Teeth were cycled through low-pH demineralizing and physiologic-pH remineralizing solutions once each day over 14 days. Microhardness was measured on longitudinal sections of the teeth 100, 200, and 300 µm from the bracket edge and beneath the brackets, at depths of 25 to 200 µm from the enamel surface. Normalized hardness values were compared using three-way analysis of variance. Significantly less reduction in enamel microhardness was found with the experimental adhesives at depths of 25 and 50 µm at all distances from the bracket edge. In all groups, there were no significant changes in enamel microhardness past 125-µm depth. Results varied with the different BAG-Bonds, with 81BAG-Bond showing the smallest decrease in enamel microhardness. The BAG-Bonds tested in this study showed a reduction in the amount of superficial enamel softening surrounding orthodontic brackets compared to a traditional bonding agent. The results indicate that clinically, BAG-Bonds may aid in maintaining enamel surface hardness, therefore helping prevent white spot lesions adjacent to orthodontic brackets.

Possible targets for the aneugenic activity of alkylating agents

Energy Technology Data Exchange (ETDEWEB)

Pellerano, P. [IST-National Institute for Research on Cancer, Genova (Italy); Abbondandolo, A. [Univ. of Genova (Italy); Bonatti, S.; Simili, M. [CNR Institute of Mutagenesis and Differentiation, Pisa (Italy)

1993-12-31

Alkylating agents have been of invaluable help in mutation research for half a century. In all tested organisms, they have proved able to induce a large variety of genetic effects, including aneuploidy. Credible molecular models exist to explain the ability of alkylating agents to induce gene mutation and to act as initiators in carcinogenesis as a consequence of DNA alkylation at specific sites. On the contrary, neither the mechanism of aneuploidy induction nor the relevant cellular targets are known.

Multi-agent simulation of the von Thunen model formation mechanism

Science.gov (United States)

Tao, Haiyan; Li, Xia; Chen, Xiaoxiang; Deng, Chengbin

2008-10-01

This research tries to explain the internal driving forces of circular structure formation in urban geography via the simulation of interaction between individual behavior and market. On the premise of single city center, unchanged scale merit and complete competition, enterprise migration theory as well, an R-D algorithm, that has agents searched the best behavior rules in some given locations, is introduced with agent-based modeling technique. The experiment conducts a simulation on Swarm platform, whose result reflects and replays the formation process of Von Thünen circular structure. Introducing and considering some heterogeneous factors, such as traffic roads, the research verifies several landuse models and discusses the self-adjustment function of price mechanism.

REM sleep pathways and anticholinesterase intoxication: A mechanism for nerve agent-induced, central respiratory failure.

NARCIS (Netherlands)

Kok, A.

1993-01-01

The mechanism of death following exposure to anticholinesterases, such as the highly toxic nerve agents soman and VX, and other organophosphate anticholinesterases such as the insecticide parathion, remains unclear, although evidence from nerve agent research suggests that death occurs by an

Overview of mechanisms of cancer chemopreventive agents

International Nuclear Information System (INIS)

De Flora, Silvio; Ferguson, Lynnette R.

2005-01-01

Epidemiological data provide evidence that it is possible to prevent cancer and other chronic diseases, some of which share common pathogenetic mechanisms, such as DNA damage, oxidative stress, and chronic inflammation. An obvious approach is avoidance of exposure to recognized risk factors. As complementary strategies, it is possible to render the organism more resistant to mutagens/carcinogens and/or to inhibit progression of the disease by administering chemopreventive agents. In a primary prevention setting, addressed to apparently healthy individuals, it is possible to inhibit mutation and cancer initiation by triggering protective mechanisms either in the extracellular environment or inside cells, e.g., by modifying transmembrane transport, modulating metabolism, blocking reactive species, inhibiting cell replication, maintaining DNA structure, modulating DNA metabolism and repair, and controlling gene expression. Tumor promotion can be counteracted by inhibiting genotoxic effects, favoring antioxidant and anti-inflammatory activity, inhibiting proteases and cell proliferation, inducing cell differentiation, modulating apoptosis and signal transduction pathways, and protecting intercellular communications. In a secondary prevention setting, when a premalignant lesion has been detected, it is possible to inhibit tumor progression via the same mechanisms, and in addition by affecting the hormonal status and the immune system in various ways, and by inhibiting tumor angiogenesis. Although tertiary prevention, addressed to cancer patients after therapy, is outside the classical definition of chemoprevention, it exploits similar mechanisms. It is also possible to affect cell-adhesion molecules, to activate antimetastasis genes, and to inhibit proteases involved in basement membrane degradation

Agent autonomy approach to probabilistic physics-of-failure modeling of complex dynamic systems with interacting failure mechanisms

Science.gov (United States)

Gromek, Katherine Emily

A novel computational and inference framework of the physics-of-failure (PoF) reliability modeling for complex dynamic systems has been established in this research. The PoF-based reliability models are used to perform a real time simulation of system failure processes, so that the system level reliability modeling would constitute inferences from checking the status of component level reliability at any given time. The "agent autonomy" concept is applied as a solution method for the system-level probabilistic PoF-based (i.e. PPoF-based) modeling. This concept originated from artificial intelligence (AI) as a leading intelligent computational inference in modeling of multi agents systems (MAS). The concept of agent autonomy in the context of reliability modeling was first proposed by M. Azarkhail [1], where a fundamentally new idea of system representation by autonomous intelligent agents for the purpose of reliability modeling was introduced. Contribution of the current work lies in the further development of the agent anatomy concept, particularly the refined agent classification within the scope of the PoF-based system reliability modeling, new approaches to the learning and the autonomy properties of the intelligent agents, and modeling interacting failure mechanisms within the dynamic engineering system. The autonomous property of intelligent agents is defined as agent's ability to self-activate, deactivate or completely redefine their role in the analysis. This property of agents and the ability to model interacting failure mechanisms of the system elements makes the agent autonomy fundamentally different from all existing methods of probabilistic PoF-based reliability modeling. 1. Azarkhail, M., "Agent Autonomy Approach to Physics-Based Reliability Modeling of Structures and Mechanical Systems", PhD thesis, University of Maryland, College Park, 2007.

Effect Of Coupling Agent On Microstructure And Mechanical Properties Of Polipropene-Flour Maizena Composite

International Nuclear Information System (INIS)

Sudirman; Karo Karo, Aloma; Darwinto, Tri; Teguh, Yulius S.P.P.; Handayani, Ari; Iraman, Dian

2001-01-01

Synthesize of PoIipropilene-flour maizena composite with addition of coupling agent have been done. Polypropylene (PP') which containing of CH 3 functional group was choosen due to its good property of degradable compare to Polyethylene (PE). The experiment carried out by mixing thermoplastic polymer (polypropylene with variation of PP MF2 and PP MFIO) with natural polymer ,flour maizena) varied in the mixing temperature of 180 c . The mixing caused the decreased mechanical properties of the PI' as major component. In addition, PE has better Mechanical properties than PP. Therefore, coupling agent of 3-Aminoprophyl triethoxy silane was added into the composite having function to homogenize the composite, thus the mechanical properties of the composite could increased. The experimental result showed that by adding the coupling agent of 10 phr (per hundred polypmpilene) ioto the PP-Maizena composite (60:40) . of the PP MFIO type could increased a tensile strength from 150.11kg/cm 2 to 226.93 kg/cm 2 , but it decreased the elongation at break from 75.7% to be brittle. Oil the contrary. the addition of coupling agent of 10 phr into PP MF2 could decreased either the tensile strength from 172.05 kg/cm2 to 154.93 kg/cm 2 , or the elongation at break of the composite from 520 % to 425 %

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

Directory of Open Access Journals (Sweden)

Gavin Walker

2012-10-01

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

Multiscale modeling of nerve agent hydrolysis mechanisms: a tale of two Nobel Prizes

Science.gov (United States)

Field, Martin J.; Wymore, Troy W.

2014-10-01

The 2013 Nobel Prize in Chemistry was awarded for the development of multiscale models for complex chemical systems, whereas the 2013 Peace Prize was given to the Organisation for the Prohibition of Chemical Weapons for their efforts to eliminate chemical warfare agents. This review relates the two by introducing the field of multiscale modeling and highlighting its application to the study of the biological mechanisms by which selected chemical weapon agents exert their effects at an atomic level.

Mobile Agent Data Integrity Using Multi-Agent Architecture

National Research Council Canada - National Science Library

McDonald, Jeffrey

2004-01-01

.... Security issues for mobile agents continue to produce research interest, particularly in developing mechanisms that guarantee protection of agent data and agent computations in the presence of malicious hosts...

Influence of additional coupling agent on the mechanical properties of polyester–agave cantala roxb based composites

Energy Technology Data Exchange (ETDEWEB)

Ubaidillah, E-mail: ubaidillah@uns.ac.id [Mechanical Engineering Department, Faculty of Engineering, Sebelas Maret University, Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126 (Indonesia); Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, Kuala Lumpur (Malaysia); Raharjo, Wijang W.; Wibowo, A. [Mechanical Engineering Department, Faculty of Engineering, Sebelas Maret University, Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126 (Indonesia); Harjana [Iwany Acoustic Research Group, Sebelas Maret University, Jl. Ir. Sutami 36A, Kentingan, Surakarta, 57126 (Indonesia); Mazlan, S. A., E-mail: amri.kl@utm.my [Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Jalan Sultan Yahya Petra, Kuala Lumpur (Malaysia)

2016-03-29

The mechanical and morphological properties of the unsaturated polyester resins (UPRs)-agave cantala roxb based composite are investigated in this paper. The cantala fiber woven in 3D angle interlock was utilized as the composite reinforcement. Surface grafting of the cantala fiber through chemical treatment was performed by introducing silane coupling agent to improving the compatibility with the polymer matrix. The fabrication of the composite specimens was conducted using vacuum bagging technique. The effect of additional coupling agent to the morphological appearance of surface fracture was observed using scanning electron microscopy. Meanwhile, the influence of additional silane to the mechanical properties was examined using tensile, bending and impact test. The photograph of surface fracture on the treated specimens showed the residual matrix left on the fibers in which the phenomenon was not found in the untreated specimens. Based on mechanical tests, the treated specimens were successfully increased their mechanical properties by 55%, 9.67%, and 92.4% for tensile strength, flexural strength, and impact strength, respectively, at 1.5% silane coupling agent.

Quantum mechanics implementation in drug-design workflows: does it really help? [Corrigendum

Directory of Open Access Journals (Sweden)

Arodola OA

2017-11-01

Full Text Available Arodola OA, Soliman MES. Quantum mechanics implementation in drug-design workflows: does it really help? Drug Design, Development and Therapy. 2017;11:2551–2564.Figure 3 on page 2557 contains errors. The correct figure is shown.Read the original article

A Mechanism to Avoid Collusion Attacks Based on Code Passing in Mobile Agent Systems

Science.gov (United States)

Jaimez, Marc; Esparza, Oscar; Muñoz, Jose L.; Alins-Delgado, Juan J.; Mata-Díaz, Jorge

Mobile agents are software entities consisting of code, data, state and itinerary that can migrate autonomously from host to host executing their code. Despite its benefits, security issues strongly restrict the use of code mobility. The protection of mobile agents against the attacks of malicious hosts is considered the most difficult security problem to solve in mobile agent systems. In particular, collusion attacks have been barely studied in the literature. This paper presents a mechanism that avoids collusion attacks based on code passing. Our proposal is based on a Multi-Code agent, which contains a different variant of the code for each host. A Trusted Third Party is responsible for providing the information to extract its own variant to the hosts, and for taking trusted timestamps that will be used to verify time coherence.

Neutralization of Aerosolized Bio-Agents by Filled Nanocomposite Materials through Thermal and Chemical Inactivation Mechanisms

Science.gov (United States)

2016-06-01

Bio -agents by Filled Nanocomposite Materials through Thermal and Chemical Inactivation Mechanisms Distribution Statement A. Approved for public...of Cincinnati Project Title: Neutralization of Aerosolized Bio -agents by Filled Nanocomposite Materials through Thermal and Chemical Inactivation...fire ball, where they will not effectively interact with any viable bio -aerosol. 1.1.4. Conclusions Cryo-milling is necessary to achieve a

Non-linear actions of physiological agents: Finite disarrangements elicit fitness benefits.

Science.gov (United States)

Sedlic, Filip; Kovac, Zdenko

2017-10-01

Finite disarrangements of important (vital) physiological agents and nutrients can induce plethora of beneficial effects, exceeding mere attenuation of the specific stress. Such response to disrupted homeostasis appears to be universally conserved among species. The underlying mechanism of improved fitness and longevity, when physiological agents act outside their normal range is similar to hormesis, a phenomenon whereby toxins elicit beneficial effects at low doses. Due to similarity with such non-linear response to toxins described with J-shaped curve, we have coined a new term "mirror J-shaped curves" for non-linear response to finite disarrangement of physiological agents. Examples from the clinical trials and basic research are provided, along with the unifying mechanisms that tie classical non-linear response to toxins with the non-linear response to physiological agents (glucose, oxygen, osmolarity, thermal energy, calcium, body mass, calorie intake and exercise). Reactive oxygen species and cytosolic calcium seem to be common triggers of signaling pathways that result in these beneficial effects. Awareness of such phenomena and exploring underlying mechanisms can help physicians in their everyday practice. It can also benefit researchers when designing studies and interpreting growing number of scientific data showing non-linear responses to physiological agents. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Non-linear actions of physiological agents: Finite disarrangements elicit fitness benefits

Directory of Open Access Journals (Sweden)

Filip Sedlic

2017-10-01

Full Text Available Finite disarrangements of important (vital physiological agents and nutrients can induce plethora of beneficial effects, exceeding mere attenuation of the specific stress. Such response to disrupted homeostasis appears to be universally conserved among species. The underlying mechanism of improved fitness and longevity, when physiological agents act outside their normal range is similar to hormesis, a phenomenon whereby toxins elicit beneficial effects at low doses. Due to similarity with such non-linear response to toxins described with J-shaped curve, we have coined a new term “mirror J-shaped curves” for non-linear response to finite disarrangement of physiological agents. Examples from the clinical trials and basic research are provided, along with the unifying mechanisms that tie classical non-linear response to toxins with the non-linear response to physiological agents (glucose, oxygen, osmolarity, thermal energy, calcium, body mass, calorie intake and exercise. Reactive oxygen species and cytosolic calcium seem to be common triggers of signaling pathways that result in these beneficial effects. Awareness of such phenomena and exploring underlying mechanisms can help physicians in their everyday practice. It can also benefit researchers when designing studies and interpreting growing number of scientific data showing non-linear responses to physiological agents.

Plants-Derived Neuroprotective Agents: Cutting the Cycle of Cell Death through Multiple Mechanisms

Directory of Open Access Journals (Sweden)

Taiwo Olayemi Elufioye

2017-01-01

Full Text Available Neuroprotection is the preservation of the structure and function of neurons from insults arising from cellular injuries induced by a variety of agents or neurodegenerative diseases (NDs. The various NDs including Alzheimer’s, Parkinson’s, and Huntington’s diseases as well as amyotropic lateral sclerosis affect millions of people around the world with the main risk factor being advancing age. Each of these diseases affects specific neurons and/or regions in the brain and involves characteristic pathological and molecular features. Hence, several in vitro and in vivo study models specific to each disease have been employed to study NDs with the aim of understanding their underlying mechanisms and identifying new therapeutic strategies. Of the most prevalent drug development efforts employed in the past few decades, mechanisms implicated in the accumulation of protein-based deposits, oxidative stress, neuroinflammation, and certain neurotransmitter deficits such as acetylcholine and dopamine have been scrutinized in great detail. In this review, we presented classical examples of plant-derived neuroprotective agents by highlighting their structural class and specific mechanisms of action. Many of these natural products that have shown therapeutic efficacies appear to be working through the above-mentioned key multiple mechanisms of action.

Statistical mechanics of socio-economic systems with heterogeneous agents

International Nuclear Information System (INIS)

De Martino, Andrea; Marsili, Matteo

2006-01-01

We review the statistical mechanics approach to the study of the emerging collective behaviour of systems of heterogeneous interacting agents. The general framework is presented through examples in such contexts as ecosystem dynamics and traffic modelling. We then focus on the analysis of the optimal properties of large random resource-allocation problems and on Minority Games and related models of speculative trading in financial markets, discussing a number of extensions including multi-asset models, majority games and models with asymmetric information. Finally, we summarize the main conclusions and outline the major open problems and limitations of the approach. (topical review)

The value of less connected agents in Boolean networks

Science.gov (United States)

Epstein, Daniel; Bazzan, Ana L. C.

2013-11-01

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

Reputation mechanism: From resolution for truthful online auctions to the model of optimal one-gambler problem

Energy Technology Data Exchange (ETDEWEB)

Bradonjic, Milan [Los Alamos National Laboratory

2009-01-01

In this paper we study reputation mechanisms, and show how the notion of reputation can help us in building truthful online auction mechanisms. From the mechanism design prospective, we derive the conditions on and design a truthful online auction mechanism. Moreover, in the case when some agents may lay or cannot have the real knowledge about the other agents reputations, we derive the resolution of the auction, such that the mechanism is truthful. Consequently, we move forward to the optimal one-gambler/one-seller problem, and explain how that problem is refinement of the previously discussed online auction design in the presence of reputation mechanism. In the setting of the optimal one-gambler problem, we naturally rise and solve the specific question: What is an agent's optimal strategy, in order to maximize his revenue? We would like to stress that our analysis goes beyond the scope, which game theory usually discusses under the notion of reputation. We model one-player games, by introducing a new parameter (reputation), which helps us in predicting the agent's behavior, in real-world situations, such as, behavior of a gambler, real-estate dealer, etc.

Agent Based Modeling of Atherosclerosis: A Concrete Help in Personalized Treatments

Science.gov (United States)

Pappalardo, Francesco; Cincotti, Alessandro; Motta, Alfredo; Pennisi, Marzio

Atherosclerosis, a pathology affecting arterial blood vessels, is one of most common diseases of the developed countries. We present studies on the increased atherosclerosis risk using an agent based model of atherogenesis that has been previously validated using clinical data. It is well known that the major risk in atherosclerosis is the persistent high level of low density lipoprotein (LDL) concentration. However, it is not known if short period of high LDL concentration can cause irreversible damage and if reduction of the LDL concentration (either by life style or drug) can drastically or partially reduce the already acquired risk. We simulated four different clinical situations in a large set of virtual patients (200 per clinical scenario). In the first one the patients lifestyle maintains the concentration of LDL in a no risk range. This is the control case simulation. The second case is represented by patients having high level of LDL with a delay to apply appropriate treatments; The third scenario is characterized by patients with high LDL levels treated with specific drugs like statins. Finally we simulated patients that are characterized by several oxidative events (smoke, sedentary life style, assumption of alcoholic drinks and so on so forth) that effective increase the risk of LDL oxidation. Those preliminary results obviously need to be clinically investigated. It is clear, however, that SimAthero has the power to concretely help medical doctors and clinicians in choosing personalized treatments for the prevention of the atherosclerosis damages.

[Alkylating agents].

Science.gov (United States)

Pourquier, Philippe

2011-11-01

With the approval of mechlorethamine by the FDA in 1949 for the treatment of hematologic malignancies, alkylating agents are the oldest class of anticancer agents. Even though their clinical use is far beyond the use of new targeted therapies, they still occupy a major place in specific indications and sometimes represent the unique option for the treatment of refractory diseases. Here, we are reviewing the major classes of alkylating agents and their mechanism of action, with a particular emphasis for the new generations of alkylating agents. As for most of the chemotherapeutic agents used in the clinic, these compounds are derived from natural sources. With a complex but original mechanism of action, they represent new interesting alternatives for the clinicians, especially for tumors that are resistant to conventional DNA damaging agents. We also briefly describe the different strategies that have been or are currently developed to potentiate the use of classical alkylating agents, especially the inhibition of pathways that are involved in the repair of DNA lesions induced by these agents. In this line, the development of PARP inhibitors is a striking example of the recent regain of interest towards the "old" alkylating agents.

SIMULATING AN EVOLUTIONARY MULTI-AGENT BASED MODEL OF THE STOCK MARKET

Directory of Open Access Journals (Sweden)

Diana MARICA

2015-08-01

Full Text Available The paper focuses on artificial stock market simulations using a multi-agent model incorporating 2,000 heterogeneous agents interacting on the artificial market. The agents interaction is due to trading activity on the market through a call auction trading mechanism. The multi-agent model uses evolutionary techniques such as genetic programming in order to generate an adaptive and evolving population of agents. Each artificial agent is endowed with wealth and a genetic programming induced trading strategy. The trading strategy evolves and adapts to the new market conditions through a process called breeding, which implies that at each simulation step, new agents with better trading strategies are generated by the model, from recombining the best performing trading strategies and replacing the agents which have the worst performing trading strategies. The simulation model was build with the help of the simulation software Altreva Adaptive Modeler which offers a suitable platform for financial market simulations of evolutionary agent based models, the S&P500 composite index being used as a benchmark for the simulation results.

Simulation of low temperature combustion mechanism of different combustion-supporting agents in close-coupled DOC and DPF system.

Science.gov (United States)

Jiao, Penghao; Li, Zhijun; Li, Qiang; Zhang, Wen; He, Li; Wu, Yue

2018-07-01

In the coupled Diesel Oxidation Catalyst (DOC) and Diesel Particular Filter (DPF) system, soot cannot be completely removed by only using the passive regeneration. And DPF active regeneration is necessary. The research method in this paper is to spray different kinds of combustion-supporting agents to the DOC in the front of the DPF. Therefore, the low temperature combustion mechanism of different kinds of combustion-supporting agents in DOC was studied, in order to grasp the law of combustion in DOC, and the influence of follow-up emission on DPF removal of soot. During the study, CH 4 H 2 mixture and diesel (n-heptane + toluene) were used as combustion-supporting agents respectively. The simplified mechanisms of two kinds of gas mixtures used as the combustion-supporting agents in DPF have been constructed and testified in the paper. In this paper, the combustion and emission conditions of the two combustion-supporting agents were analyzed so as to meet the practical requirements of different working conditions. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Use of dentifrices to prevent erosive tooth wear: harmful or helpful?

Directory of Open Access Journals (Sweden)

Ana Carolina Magalhães

2014-01-01

Full Text Available Dental erosion is the loss of dental hard tissues caused by non-bacterial acids. Due to acid contact, the tooth surface becomes softened and more prone to abrasion from toothbrushing. Dentifrices containing different active agents may be helpful in allowing rehardening or in increasing surface resistance to further acidic or mechanical impacts. However, dentifrices are applied together with brushing and, depending on how and when toothbrushing is performed, as well as the type of dentifrice and toothbrush used, may increase wear. This review focuses on the potential harmful and helpful effects associated with the use of dentifrices with regard to erosive wear. While active ingredients like fluorides or agents with special anti-erosive properties were shown to offer some degree of protection against erosion and combined erosion/abrasion, the abrasive effects of dentifrices may increase the surface loss of eroded teeth. However, most evidence to date comes from in vitro and in situ studies, so clinical trials are necessary for a better understanding of the complex interaction of active ingredients and abrasives and their effects on erosive tooth wear.

Effect and Removal Mechanisms of 6 Different Washing Agents for Building Wastes Containing Chromium

Directory of Open Access Journals (Sweden)

Wang Xing-run

2012-01-01

Full Text Available With the building wastes contaminated by chromium in Haibei Chemical Plan in China as objects, we studied the contents of total Cr and Cr (VI of different sizes, analyzed the effect of 6 different washing agents, discussed the removal mechanisms of 6 different washing agents for Cr in various forms, and finally selected applicable washing agent. As per the results, particle size had little impact on the contents of total Cr and Cr (VI; after one washing with water, the removal rate of total Cr and Cr (VI was 75% and 78%, respectively, and after the second washing with 6 agents, the removal rate of citric acid was the highest, above 90% for total Cr and above 99% for hexavalent chromium; the pH of building wastes were reduced by citric acid, and under acid condition, hexavalent chromium was reduced to trivalent chromium spontaneously by organic acid, which led to better removal rate of acid soluble Cr and reducible Cr; due to the complexing action, citric acid had best removal rate for oxidizable trivalent chromium. In conclusion, citric acid is the most applicable second washing agent for building wastes.

New antibiotic agents in the pipeline and how they can help overcome microbial resistance.

Science.gov (United States)

Gould, Ian M; Bal, Abhijit M

2013-02-15

Bacterial resistance is a growing threat and yet few new antibiotics active against multi-resistant bacteria are being explored. A combination of falling profits, regulatory mechanisms and irrational and injudicious use of antibiotics has led to an alarming situation where some infections have no cure. In this article, we summarize the new developments that have been suggested to incentivize the pharmaceutical industries toward the field of infections. We also briefly mention the new compounds on the horizon and some newly approved compounds that might help us tide over this crisis.

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.

Compatibilizing agents influence on mechanical properties of PP/clay nanocomposites

DEFF Research Database (Denmark)

Sanporean, Catalina-Gabriela; Donescu, Dan; Vuluga, Zina

2013-01-01

S-a investigat din punct de vedere mecanic influenţa concentraţiei de argilă şi a utilizării unui sistem cu doi agenţi de compatibilizare. Argila Cloisite –Na a fost modificată organic cu o polietermonoamină, iar, ca agent de compatibilizare secund, s-a adăugat polipropilena maleinizată (MA-PP) s...... in mechanical properties, especially in tensile strength, creep strain and cyclic test, while those with MA-SEBS presented an improvement in neck propagation, as well as an increase in ductility....... la testare ciclică, în timp ce nanocompozitele cu MASEBS au prezentat o îmbunătăţire a curgerii superioare şi o creştere a ductilităţii. The influence of Clay concentration and of two compatibilizers system use was investigated from mechanical point of view. Cloisite-Na Clay was organically modified...

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.

Chitosan-Based Coating with Antimicrobial Agents: Preparation, Property, Mechanism, and Application Effectiveness on Fruits and Vegetables

Directory of Open Access Journals (Sweden)

Yage Xing

2016-01-01

Full Text Available Chitosan coating is beneficial to maintaining the storage quality and prolonging the shelf life of postharvest fruits and vegetables, which is always used as the carrier film for the antimicrobial agents. This review focuses on the preparation, property, mechanism, and application effectiveness on the fruits and vegetables of chitosan-based coating with antimicrobial agents. Chitosan, derived by deacetylation of chitin, is a modified and natural biopolymer as the coating material. In this article, the safety and biocompatible and antimicrobial properties of chitosan were introduced because these attributes are very important for its application. The methods to prepare the chitosan-based coating with antimicrobial agents, such as essential oils, acid, and nanoparticles, were developed by other researchers. Meanwhile, the application of chitosan-based coating is mainly due to its antimicrobial activity and other functional properties, which were investigated, introduced, and analyzed in this review. Furthermore, the surface and mechanical properties were also investigated by researchers and concluded in this article. Finally, the effects of chitosan-based coating on the storage quality, microbial safety, and shelf life of fruits and vegetables were introduced. Their results indicated that chitosan-based coating with different antimicrobial agents would probably have wide prospect in the preservation of fruits and vegetables in the future.

Noise and the statistical mechanics of distributed transport in a colony of interacting agents

Science.gov (United States)

Katifori, Eleni; Graewer, Johannes; Ronellenfitsch, Henrik; Mazza, Marco G.

Inspired by the process of liquid food distribution between individuals in an ant colony, in this work we consider the statistical mechanics of resource dissemination between interacting agents with finite carrying capacity. The agents move inside a confined space (nest), pick up the food at the entrance of the nest and share it with other agents that they encounter. We calculate analytically and via a series of simulations the global food intake rate for the whole colony as well as observables describing how uniformly the food is distributed within the nest. Our model and predictions provide a useful benchmark to assess which strategies can lead to efficient food distribution within the nest and also to what level the observed food uptake rates and efficiency in food distribution are due to stochastic fluctuations or specific food exchange strategies by an actual ant colony.

Photo-crosslinkable cyanoacrylate bioadhesive: shrinkage kinetics, dynamic mechanical properties, and biocompatibility of adhesives containing TMPTMA and POSS nanostructures as crosslinking agents.

Science.gov (United States)

Ghasaban, S; Atai, M; Imani, M; Zandi, M; Shokrgozar, M-A

2011-11-01

The study investigates the photo-polymerization shrinkage behavior, dynamic mechanical properties, and biocompatibility of cyanoacrylate bioadhesives containing POSS nanostructures and TMPTMA as crosslinking agents. Adhesives containing 2-octyl cyanoacrylate (2-OCA) and different percentages of POSS nanostructures and TMPTMA as crosslinking agents were prepared. The 1-phenyl-1, 2-propanedione (PPD) was incorporated as photo-initiator into the adhesive in 1.5, 3, and 4 wt %. The shrinkage strain of the specimens was measured using bonded-disk technique. Shrinkage strain, shrinkage strain rate, maximum and time at maximum shrinkage strain rate were measured and compared. Mechanical properties of the adhesives were also studied using dynamic mechanical thermal analysis (DMTA). Biocompatibility of the adhesives was examined by MTT method. The results showed that shrinkage strain increased with increasing the initiator concentration up to 3 wt % in POSS-containing and 1.5 wt % in TMPTMA-containing specimens and plateaued out at higher concentrations. By increasing the crosslinking agent, shrinkage strain, and shrinkage strain rate increased and the time at maximum shrinkage strain rate decreased. The study indicates that the incorporation of crosslinking agents into the cyanoacrylate adhesives resulted in improved mechanical properties. Preliminary MTT studies also revealed better biocompatibility profile for the adhesives containing crosslinking agents comparing to the neat specimens. Copyright © 2011 Wiley Periodicals, Inc.

Experimental investigations of nonlinearities and destruction mechanisms of an experimental phospholipid-based ultrasound contrast agent.

Science.gov (United States)

Casciaro, Sergio; Palmizio Errico, Rosa; Errico, Rosa Palmizio; Conversano, Francesco; Demitri, Christian; Distante, Alessandro

2007-02-01

We sought to characterize the acoustical behavior of the experimental ultrasound contrast agent BR14 by determining the acoustic pressure threshold above which nonlinear oscillation becomes significant and investigating microbubble destruction mechanisms. We used a custom-designed in vitro setup to conduct broadband attenuation measurements at 3.5 MHz varying acoustic pressure (range, 50-190 kPa). We also performed granulometric analyses on contrast agent solutions to accurately measure microbubble size distribution and to evaluate insonification effects. Attenuation did not depend on acoustic pressure less than 100 kPa, indicating this pressure as the threshold for the appearance of microbubble nonlinear behavior. At the lowest excitation amplitude, attenuation increased during insonification, while, at higher excitation levels, the attenuation decreased over time, indicating microbubble destruction. The destruction rate changed with pressure amplitude suggesting different destruction mechanisms, as it was confirmed by granulometric analysis. Microbubbles showed a linear behavior until 100 kPa, whereas beyond this value significant nonlinearities occurred. Observed destruction phenomena seem to be mainly due to gas diffusion and bubble fragmentation mechanisms.

Action and resistance mechanisms of antibiotics: A guide for clinicians

Directory of Open Access Journals (Sweden)

Garima Kapoor

2017-01-01

Full Text Available Infections account for a major cause of death throughout the developing world. This is mainly due to the emergence of newer infectious agents and more specifically due to the appearance of antimicrobial resistance. With time, the bacteria have become smarter and along with it, massive imprudent usage of antibiotics in clinical practice has resulted in resistance of bacteria to antimicrobial agents. The antimicrobial resistance is recognized as a major problem in the treatment of microbial infections. The biochemical resistance mechanisms used by bacteria include the following: antibiotic inactivation, target modification, altered permeability, and “bypass” of metabolic pathway. Determination of bacterial resistance to antibiotics of all classes (phenotypes and mutations that are responsible for bacterial resistance to antibiotics (genetic analysis are helpful. Better understanding of the mechanisms of antibiotic resistance will help clinicians regarding usage of antibiotics in different situations. This review discusses the mechanism of action and resistance development in commonly used antimicrobials.

Report of National Cancer Institute symposium: comparison of mechanisms of carcinogenesis by radiation and chemical agents. I. Common molecular mechanisms

International Nuclear Information System (INIS)

Borg, D.C.

1984-01-01

Some aspects of molecular mechanisms common to radiation and chemical carcinogenesis are discussed, particularly the DNA damage done by these agents. Emphasis is placed on epidemiological considerations and on dose-response models used in risk assessment to extrapolate from experimental data obtained at high doses to the effects from long-term, low-level exposures. 3 references, 6 figures

Report of National Cancer Institute symposium: comparison of mechanisms of carcinogenesis by radiation and chemical agents. I. Common molecular mechanisms

Energy Technology Data Exchange (ETDEWEB)

Borg, D.C.

1984-01-01

Some aspects of molecular mechanisms common to radiation and chemical carcinogenesis are discussed, particularly the DNA damage done by these agents. Emphasis is placed on epidemiological considerations and on dose-response models used in risk assessment to extrapolate from experimental data obtained at high doses to the effects from long-term, low-level exposures. 3 references, 6 figures. (ACR)

Job satisfaction as a unified mechanism for agent behaviour on a labour market with referral hiring

OpenAIRE

Tarvid, Alexander

2014-01-01

Existing agent-based labour-market models include a very simplistic mechanism of choosing vacancies. This paper proposes to use job satisfaction as a unified mechanism for deciding on both starting to work on a particular job and quitting the current job. An enhanced job satisfaction mechanism consisting of monetary, social, content, and career components is proposed. As an illustrative context, a labour-market model with referral hiring and informal job search through own social networks is ...

Therapeutic efficacy and mechanism of action of ethamsylate, a long-standing hemostatic agent.

Science.gov (United States)

Garay, Ricardo P; Chiavaroli, Carlo; Hannaert, Patrick

2006-01-01

Ethamsylate (2,5-dihydroxy-benzene-sulfonate diethylammonium salt) is a synthetic hemostatic drug indicated in cases of capillary bleeding. This review covers more than 40 years of intensive clinical and fundamental research with ethamsylate. First, we summarize the large medical literature concerning its clinical efficacy. Of these, well-controlled clinical trials clearly showed the therapeutic efficacy of ethamsylate in dysfunctional uterine bleeding, with the magnitude of blood-loss reduction being directly proportional to the severity of the menorrhagia. Other well-controlled clinical trials showed therapeutic efficacy of ethamsylate in periventricular hemorrhage in very low birth weight babies and surgical or postsurgical capillary bleeding. Second, we review the numerous investigations performed to elucidate the mechanism of action of ethamsylate. Ethamsylate acts on the first step of hemostasis by improving platelet adhesiveness and restoring capillary resistance. Recent studies showed that ethamsylate promotes P-selectin-dependent, platelet adhesive mechanisms. Finally, we compare ethamsylate with other recent hemostatic agents. It is suggested that the place of ethamsylate as a hemostatic agent is that of a mild but well-tolerated drug, particularly useful in dysfunctional uterine bleeding when contraception is not needed.

Effect of tooth bleaching agents on protein content and mechanical properties of dental enamel.

Science.gov (United States)

Elfallah, Hunida M; Bertassoni, Luiz E; Charadram, Nattida; Rathsam, Catherine; Swain, Michael V

2015-07-01

This study investigated the effect of two bleaching agents, 16% carbamide peroxide (CP) and 35% hydrogen peroxide (HP), on the mechanical properties and protein content of human enamel from freshly extracted teeth. The protein components of control and treated enamel were extracted and examined on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Marked reduction of the protein matrix and random fragmentation of the enamel proteins after bleaching treatments was found. The mechanical properties were analyzed with Vickers indentations to characterize fracture toughness, and nanoindentation to establish enamel hardness, elastic modulus and creep deformation. Results indicate that the hardness and elastic modulus of enamel were significantly reduced after treatment with CP and HP. After bleaching, the creep deformation at maximum load increased and the recovery upon unloading reduced. Crack lengths of CP and HP treated enamel were increased, while fracture toughness decreased. Additionally, the microstructures of fractured and indented samples were examined with field emission gun scanning electron microscopy (FEG-SEM) showing distinct differences in the fracture surface morphology between pre- and post-bleached enamel. In conclusion, tooth bleaching agents can produce detrimental effects on the mechanical properties of enamel, possibly as a consequence of damaging or denaturing of its protein components. Copyright © 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

An Integrated System for Disabled People Developed with the Agent Platform PANGEA

Directory of Open Access Journals (Sweden)

Carolina ZATO

2013-11-01

Full Text Available New trends in multi-agent systems call for self-adaptation and high dynamics, hence the new model of open MAS or virtual organization of agents. However, as existing agent platforms are not yet equipped to support this behavior, it is necessary to create new systems and mechanisms to facilitate the development of these new architectures. This article presents PANGEA, an agent platform to develop open multi-agent systems, specifically those including organizational aspects such as virtual agent organizations. The platform allows the integral management of organizations and offers tools to the end user. Additionally, it includes a communication protocol based on the IRC standard, which facilitates implementation and remains robust even with a large number of connections. The introduction of a CommunicationAgent and a Sniffer make it possible to offer Web Services for the distributed control of interaction. In order to test PANGEA, an integral system was developed to help the disabled, gathering a set of easily deployable and integrated services under a single architecture.

Silver nanoparticles-loaded activated carbon fibers using chitosan as binding agent: Preparation, mechanism, and their antibacterial activity

Energy Technology Data Exchange (ETDEWEB)

Tang, Chengli, E-mail: tcl-lily@mail.zjxu.edu.cn [College of Mechanical and Electrical Engineering, Jiaxing University, Jiaxing 314001 (China); Hu, Dongmei [College of Mechanical Science and Engineering, Jilin University, Changchun 130022 (China); Cao, Qianqian [College of Mechanical and Electrical Engineering, Jiaxing University, Jiaxing 314001 (China); Yan, Wei [Department of Environmental Science and Engineering, Xi’an Jiaotong University, Xi’an 710049 (China); Xing, Bo [College of Mechanical and Electrical Engineering, Jiaxing University, Jiaxing 314001 (China)

2017-02-01

Highlights: • Chitosan was firstly introduced as binding agent for AgNPs loading on ACF surface. • Molecular dynamics simulation was used to explore the AgNPs loading mechanism. • Loading mechanism was proposed based on the experimental and simulation results. • Antibacterial AgNPs-loaded ACF showed use potential for water disinfection. - Abstract: The effective and strong adherence of silver nanoparticles (AgNPs) to the substrate surface is pivotal to the practical application of those AgNPs-modified materials. In this work, AgNPs were synthesized through a green and facile hydrothermal method. Chitosan was introduced as the binding agent for the effective loading of AgNPs on activated carbon fibers (ACF) surface to fabricate the antibacterial material. Apart from conventional instrumental characterizations, i. e., scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), zeta potential and Brunauer-Emmett-Teller (BET) surface area measurement, molecular dynamics simulation method was also applied to explore the loading mechanism of AgNPs on the ACF surface. The AgNPs-loaded ACF material showed outstanding antibacterial activity for S. aureus and E. coli. The combination of experimental and theoretical calculation results proved chitosan to be a promising binding agent for the fabrication of AgNPs-loaded ACF material with excellent antibacterial activity.

Noncontraceptive use of contraceptive agents.

Science.gov (United States)

Nickles, Monique Collier; Alderman, Elizabeth

2014-06-01

• On the basis of strong research evidence, there are many noncontraceptive advantages to use of hormonal contraceptive agents in adolescent girls. (3) (4)(5)(7)(10)(11)(12)(13)(14). • On the basis of research evidence and consensus, most of these agents are safe with minor adverse effects. (2)(3)(4)(5)(7)(10)(11)(12)(13)(14). • On the basis of research evidence and consensus, through application of evidence-based approaches and proper counseling, pediatricians can use various contraceptive agents to treat several medical conditions and to help alleviate many of the undesired symptoms and complications associated with menstrual periods. (2)(3)(4)(5)(7)(10)(11)(12)(13) (14). • On the basis of research evidence and consensus, these agents may be used in sexually active adolescents to simultaneously help prevent unintended adolescent pregnancies. (2)(3)(4)(5)(7)(10)(11)(12)(13)(14).

Effect of Fluoride Prophylactic Agents on the Mechanical Properties of Nickel-Titanium Wires: An in vitro Study

Directory of Open Access Journals (Sweden)

S R Harish Koushik

2011-01-01

Conclusion : The results suggest that using topical fluoride agents with NiTi wire could decrease the functional unloading mechanical properties of the wire and contribute to prolonged orthodontic treatment.

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.

Influence of complexing agents on the mechanical performances of the cement conditioning matrix

International Nuclear Information System (INIS)

Nicu, M.; Mihai, F.; Turcanu, C.

1998-01-01

The safety of the radioactive waste disposal is a priority demand concerning the protection of the environment and population. For this reason, an engineering multi-barrier system is studied in order to be improved. This study aims to establish the influence of the complexing agents on the mechanical performances of the cement conditioning matrix. Radioactive effluents which contain agents as oxalic and citric acids are generated during the radioactive decontamination operation using chemical methods. The conditioning of these wastes by cementing process imposed the experimental determination of the mechanical performances of the matrix and the upper permissible level of complexing agent concentration. To determine the influence of complexing agents on the mechanical performances of cement conditioning matrix, cubic samples (20 mm x 20 mm x 20 mm) were prepared using commercial Portland cement and solutions of organic complexing acids or salts (citric acid, oxalic acid, tartaric acid, sodium citrate and ammonium oxalate). The complexation concentration varied between 0.25% and 1% in distilled and drinking water, respectively. The selected cement/water ratio was 0.5. The experiments were focused on: - establishing the firmness of the Pa 35 cement pastes and mortars in dependence on the water/cement ratio, by classical methods (Tetmeyer probe for pastes and standard cone for mortars) and by triclinic time through a funnel with 15 mm aperture; - studying the influence of the tartaric, oxalic, citric acids, ammonium oxalate and sodium citrate solution concentrations on water quantities used to obtain pastes with normal firmness and on Pa 35 cement setting; - the influence of oxalic acid, tartaric acid and ammonium oxalate solution concentrations on the strength of compression of the pastes with normal firmness; - for testing, standard test bar cubes with 20 mm sides were used and the strength of compression was tested at 28 days; - establishing the behaviour in time of

Bladder urotoxicity pathophysiology induced by the oxazaphosphorine alkylating agents and its chemoprevention 

Directory of Open Access Journals (Sweden)

Łukasz Dobrek

2012-09-01

Full Text Available The use of oxazaphosphorines (cyclophosphamide, ifosfamide in the treatment of numerous neoplastic disorders is associated with their essential adverse effect in the form of hemorrhagic cystitis, which considerably limits the safety and efficacy of their pharmacotherapy. HC is a complex inflammatory response, induced by toxic oxazaphosphorines metabolite – acrolein with subsequent immunocompetetive cells activation and release of many proinflammatory agents. However, there are some chemoprotectant agents which help reduce the HC exacerbation.The article briefly discuses the mechanism of action of oxazaphosphorines, the pathophysiology of the hemorrhagic cystitis development and currently accepted chemopreventive agents, applied to the objective of urotoxicity amelioration. Moreover, the rationale for some phytopharmaceuticals administration as novel bladder protective compounds accompanying cyclophosphamide or ifosfamide therapy was also mentioned. 

The impact of aerosolized mucolytic agents on the airflow resistance of bacterial filters used in mechanical ventilation

Directory of Open Access Journals (Sweden)

Han-Chung Hu

2015-08-01

Conclusion: This study demonstrated the aerosolized mucolytic agents could increase the pressure drop of the bacterial filters during mechanical ventilation. The pressure drop of the bacterial filters was higher with 10% acetylcysteine. It is critical to continuously monitor the expiration resistance, auto-positive end-expiratory pressure, and ventilator output waveform when aerosolized 10% acetylcysteine was used in mechanical ventilation patients.

A QUANTITATIVE FRAMEWORK FOR EARLY PREDICTION OF COOPERATION IN MULTI-AGENT SYSTEMS

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S. Ajitha

2013-07-01

Full Text Available A Multi-Agent System (MAS is a system composed of multiple interacting intelligent agents. MAS can be used to solve problems that are difficult or impossible for an individual agent to solve. The different characteristics of MAS help in solving highly complex distributed problems. One of the important characteristics of MAS is its cooperative nature. This character helps different agents to interact with each other by exchanging messages. One of the major challenges in MAS is quantifying the cooperation between agents. This paper presents a framework for the quantification of cooperation between agents in MAS. We propose a methodology which helps to quantify the cooperation in the early stages of software development using a UML sequence diagram and a mathematical model. The proposed techniques are illustrated with the help of a case study. The numerical results we got were quite satisfactory.

Principals, agents and research programmes

OpenAIRE

Elizabeth Shove

2003-01-01

Research programmes appear to represent one of the more powerful instruments through which research funders (principals) steer and shape what researchers (agents) do. The fact that agents navigate between different sources and styles of programme funding and that they use programmes to their own ends is readily accommodated within principal-agent theory with the help of concepts such as shirking and defection. Taking a different route, I use three examples of research programming (by the UK, ...

The Effects of Coupling Agents on the Mechanical and Thermal Properties of Eucalyptus Flour/HDPE Composite

Directory of Open Access Journals (Sweden)

Metanawin Siripan

2015-01-01

Full Text Available The aim of this research was to study the effects of the coupling agents, FusabondTM E-528 (polyethylene-grafted maleic anhydride; PE-g-MA, MA and Amino Silane (Si, on the thermal properties, and mechanical properties of Eucalyptus flour-HDPE composite. Variation of the Eucalyptus flour contents in the HDPE resulted in properties of the composite. With increasing in the contents of Eucalyptus flour in polymer matrix, the mechanical properties of the HDPE composite decreased in EU-MA series samples while they were gradually decreased in EU-Si series samples. SEM micrographs showed the fracture surface of the HDPE/Eucalyptus composite at different ratios of Eucalyptus flour. SEM micrograpgh exhibited the dispersion of EU flour in polymer matrix. The samples of both coupling agents showed an increase in interfacial adhesion, observed for the considerable decreased of gaps between the matrix and the dispersed phase. However, the EU-MA sample appeared to be more uniformly than the EU-Si sample.

New Drug Formulary Will Help Expedite Use of Agents in Clinical Trials

Science.gov (United States)

NCI launched the “NCI Formulary” that will enable investigators at NCI-designated Cancer Centers to have quicker access to approved and investigational agents for use in preclinical studies and cancer clinical trials.

Data of thermal degradation and dynamic mechanical properties of starch-glycerol based films with citric acid as crosslinking agent.

Science.gov (United States)

González Seligra, Paula; Medina Jaramillo, Carolina; Famá, Lucía; Goyanes, Silvia

2016-06-01

Interest in biodegradable edible films as packaging or coating has increased because their beneficial effects on foods. In particular, food products are highly dependents on thermal stability, integrity and transition process temperatures of the packaging. The present work describes a complete data of the thermal degradation and dynamic mechanical properties of starch-glycerol based films with citric acid (CA) as crosslinking agent described in the article titled: "Biodegradable and non-retrogradable eco-films based on starch-glycerol with citric acid as crosslinking agent" González Seligra et al. (2016) [1]. Data describes thermogravimetric and dynamical mechanical experiences and provides the figures of weight loss and loss tangent of the films as a function of the temperature.

Agents for navigating virtual reality E-commerce environments

NARCIS (Netherlands)

Nijholt, Anton; van Dijk, Betsy; Sebaaly, Milad Fares

2001-01-01

We report about work in progress on capabilities of navigation agents in virtual environments. These agents may help a user to explore the environment: where to go, where to buy, where to find, etc. The agents may make suggestions based on a user profile, earlier visits and earlier given advice and

Effect of ionizing radiation on mechanical and thermal properties of low-density polyethylene containing pro-degradant agents

International Nuclear Information System (INIS)

Bardi, Marcelo A.G.; Kodama, Yasko; Machado, Luci D.B.; Giovedi, Claudia; Rosa, Derval S.

2009-01-01

The wide use of plastics on packages of short-lifetime products has presented harmful consequences for the environment due to their low degradation rate. By this way, improved results to the bio-assimilation of polyolefins have been achieved by the incorporation of pro-oxidant components. The aim of this work is to evaluate the mechanical and thermal behavior of low-density polyethylene (LDPE) modified by those agents and submitted to ionizing radiation by gamma rays. LDPE was modified using a masterbatch containing calcium stearate (CaSt), or magnesium stearate (MgSt) or Clariant R commercial metallic complex. The final amount of stearate in modified LDPE was 0.2%. The films were obtained by compression molding. Samples were gamma irradiated at absorbed doses of 15 kGy and 100 kGy. Differential scanning calorimetry (DSC) and thermogravimetry (TG) were performed on samples, as well as mechanical analysis by universal testing machine. Thermal properties of samples presenting pro-degradant agents were affected by the ionizing radiation in the dose range studied, and some of the mechanical properties were clearly modified by reducing their values of tensile strength at break and elongation at break. (author)

Effect of ionizing radiation on mechanical and thermal properties of low-density polyethylene containing pro-degradant agents

Energy Technology Data Exchange (ETDEWEB)

Bardi, Marcelo A.G.; Kodama, Yasko; Machado, Luci D.B., E-mail: magbardi@ipen.b, E-mail: ykodama@ipen.b, E-mail: lmachado@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Giovedi, Claudia, E-mail: giovedi@ctmsp.mar.mil.b [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), Sao Paulo, SP (Brazil); Rosa, Derval S., E-mail: derval.rosa@ufabc.edu.b [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

2009-07-01

The wide use of plastics on packages of short-lifetime products has presented harmful consequences for the environment due to their low degradation rate. By this way, improved results to the bio-assimilation of polyolefins have been achieved by the incorporation of pro-oxidant components. The aim of this work is to evaluate the mechanical and thermal behavior of low-density polyethylene (LDPE) modified by those agents and submitted to ionizing radiation by gamma rays. LDPE was modified using a masterbatch containing calcium stearate (CaSt), or magnesium stearate (MgSt) or Clariant{sup R} commercial metallic complex. The final amount of stearate in modified LDPE was 0.2%. The films were obtained by compression molding. Samples were gamma irradiated at absorbed doses of 15 kGy and 100 kGy. Differential scanning calorimetry (DSC) and thermogravimetry (TG) were performed on samples, as well as mechanical analysis by universal testing machine. Thermal properties of samples presenting pro-degradant agents were affected by the ionizing radiation in the dose range studied, and some of the mechanical properties were clearly modified by reducing their values of tensile strength at break and elongation at break. (author)

Preparing Students for Future Learning with Teachable Agents

Science.gov (United States)

Chin, Doris B.; Dohmen, Ilsa M.; Cheng, Britte H.; Oppezzo, Marily A.; Chase, Catherine C.; Schwartz, Daniel L.

2010-01-01

One valuable goal of instructional technologies in K-12 education is to prepare students for future learning. Two classroom studies examined whether Teachable Agents (TA) achieves this goal. TA is an instructional technology that draws on the social metaphor of teaching a computer agent to help students learn. Students teach their agent by…

Ultrasonographic detection of focal liver lesions: increased sensitivity and specificity with microbubble contrast agents

International Nuclear Information System (INIS)

Hohmann, J.; Albrecht, T.; Hoffmann, C.W.; Wolf, K.-J.

2003-01-01

Ultrasonography (US) is the first choice for screening patients with suspected liver lesions. However, due to a lack of contrast agents, US used to be less sensitive and specific compared with computed tomography (CT) and magnet resonance imaging (MRI). The advent of microbubble contrast agents increased both sensitivity and specificity dramatically. Rapid developments of the contrast agents as well as of special imaging techniques were made in recent years. Today numerous different US imaging methods exist which based either on Doppler or on harmonic imaging. They are using the particular behaviour of microbubbles in a sound field which varies depending on the energy of insonation (low/high mechanical index, MI) as well as on the properties of the agent themselves. Apart from just blood pool enhancement some agents have a hepatosplenic specific late phase. US imaging during this late phase using relatively high MI in phase inversion mode (harmonic imaging) or stimulated acoustic emission (SAE; Doppler method) markedly improves the detection of focal liver lesions and is also very helpful for lesion characterisation. With regards to detection, contrast enhanced US performs similarly to CT as shown by recent studies. Early results of studies using low MI imaging and the newer perfluor agents are also showing promising results for lesion detection. Low MI imaging with these agents has the advantage of real time imaging and is particularly helpful for characterisation of focal lesions based on their dynamic contrast behaviour. Apart from the techniques which based on the morphology of liver lesions there were some attempts for the detection of occult metastases or micrometastases by means of liver blood flow changes. Also in this field the use of US contrast agents appears to have advantages over formerly used non contrast-enhanced methods although no conclusive results are available yet

Embodied artificial agents for understanding human social cognition.

Science.gov (United States)

Wykowska, Agnieszka; Chaminade, Thierry; Cheng, Gordon

2016-05-05

In this paper, we propose that experimental protocols involving artificial agents, in particular the embodied humanoid robots, provide insightful information regarding social cognitive mechanisms in the human brain. Using artificial agents allows for manipulation and control of various parameters of behaviour, appearance and expressiveness in one of the interaction partners (the artificial agent), and for examining effect of these parameters on the other interaction partner (the human). At the same time, using artificial agents means introducing the presence of artificial, yet human-like, systems into the human social sphere. This allows for testing in a controlled, but ecologically valid, manner human fundamental mechanisms of social cognition both at the behavioural and at the neural level. This paper will review existing literature that reports studies in which artificial embodied agents have been used to study social cognition and will address the question of whether various mechanisms of social cognition (ranging from lower- to higher-order cognitive processes) are evoked by artificial agents to the same extent as by natural agents, humans in particular. Increasing the understanding of how behavioural and neural mechanisms of social cognition respond to artificial anthropomorphic agents provides empirical answers to the conundrum 'What is a social agent?' © 2016 The Authors.

An agent-based simulation of power generation company behavior in electricity markets under different market-clearing mechanisms

International Nuclear Information System (INIS)

Aliabadi, Danial Esmaeili; Kaya, Murat; Şahin, Güvenç

2017-01-01

Deregulated electricity markets are expected to provide affordable electricity for consumers through promoting competition. Yet, the results do not always fulfill the expectations. The regulator's market-clearing mechanism is a strategic choice that may affect the level of competition in the market. We conceive of the market-clearing mechanism as composed of two components: pricing rules and rationing policies. We investigate the strategic behavior of power generation companies under different market-clearing mechanisms using an agent-based simulation model which integrates a game-theoretical understanding of the auction mechanism in the electricity market and generation companies' learning mechanism. Results of our simulation experiments are presented using various case studies representing different market settings. The market in simulations is observed to converge to a Nash equilibrium of the stage game or to a similar state under most parameter combinations. Compared to pay-as-bid pricing, bid prices are closer to marginal costs on average under uniform pricing while GenCos' total profit is also higher. The random rationing policy of the ISO turns out to be more successful in achieving lower bid prices and lower GenCo profits. In minimizing GenCos' total profit, a combination of pay-as-bid pricing rule and random rationing policy is observed to be the most promising. - Highlights: • An agent-based simulation of generation company behavior in electricity markets is developed. • Learning dynamics of companies is modeled with an extended Q-learning algorithm. • Different market clearing mechanisms of the regulator are compared. • Convergence to Nash equilibria is analyzed under different cases. • The level of competition in the market is studied.

Biological agents and respiratory infections: Causative mechanisms and practice management.

Science.gov (United States)

Takayanagi, Noboru

2015-09-01

Biological agents are increasingly being used to treat patients with immune-mediated inflammatory disease. In Japan, currently approved biological agents for patients with rheumatoid arthritis (RA) include tumor necrosis factor inhibitors, interleukin-6 receptor-blocking monoclonal antibody, and T-cell costimulation inhibitor. Rheumatologists have recognized that safety issues are critical aspects of treatment decisions in RA. Therefore, a wealth of safety data has been gathered from a number of sources, including randomized clinical trials and postmarketing data from large national registries. These data revealed that the most serious adverse events from these drugs are respiratory infections, especially pneumonia, tuberculosis, nontuberculous mycobacteriosis, and Pneumocystis jirovecii pneumonia, and that the most common risk factors associated with these respiratory infections are older age, concomitant corticosteroid use, and underlying respiratory comorbidities. Because of this background, in 2014, the Japanese Respiratory Society published their consensus statement of biological agents and respiratory disorders. This review summarizes this statement and adds recent evidence, especially concerning respiratory infections in RA patients, biological agents and respiratory infections, and practice management of respiratory infections in patients treated with biological agents. To decrease the incidence of infections and reduce mortality, we should know the epidemiology, risk factors, management, and methods of prevention of respiratory infections in patients receiving biological agents. Copyright © 2015 The Japanese Respiratory Society. Published by Elsevier B.V. All rights reserved.

Collaborative Information Agents on the World Wide Web

Science.gov (United States)

Chen, James R.; Mathe, Nathalie; Wolfe, Shawn; Koga, Dennis J. (Technical Monitor)

1998-01-01

In this paper, we present DIAMS, a system of distributed, collaborative information agents which help users access, collect, organize, and exchange information on the World Wide Web. Personal agents provide their owners dynamic displays of well organized information collections, as well as friendly information management utilities. Personal agents exchange information with one another. They also work with other types of information agents such as matchmakers and knowledge experts to facilitate collaboration and communication.

Impact of Carbon Quota Allocation Mechanism on Emissions Trading: An Agent-Based Simulation

Directory of Open Access Journals (Sweden)

Wei Jiang

2016-08-01

Full Text Available This paper establishes an agent-based simulation system of the carbon emissions trading in accordance with the complex feature of the trading process. This system analyzes the impact of the carbon quota allocation mechanism on emissions trading for three different aspects including the amount of emissions reduction, the economic effect on the emitters, and the emissions reduction cost. Based on the data of the carbon emissions of different industries in China, several simulations were made. The results indicate that the emissions trading policy can effectively reduce carbon emissions in a perfectly competitive market. Moreover, by comparing separate quota allocation mechanisms, we obtain the result that the scheme with a small extent quota decrease in a comprehensive allocation mechanism can minimize the unit carbon emission cost. Implementing this scheme can also achieve minimal effects of carbon emissions limitation on the economy on the basis that the environment is not destroyed. However, excessive quota decrease cannot promote the emitters to reduce emission. Taking into account that several developing countries have the dual task of limiting carbon emissions and developing the economy, it is necessary to adopt a comprehensive allocation mechanism of the carbon quota and increase the initial proportion of free allocation.

Developing multimodal conversational agents for an enhanced e-learning experience

Directory of Open Access Journals (Sweden)

David GRIOL

2014-10-01

Full Text Available Conversational agents have become a strong alternative to enhance educational systems with intelligent communicative capabilities, provide motivation and engagement, and increment significant learning and helping in the acquisition of meta-cognitive skills. In this paper, we present Geranium, a multimodal conversational agent that helps children to appreciate and protect their environment. The system, which integrates an interactive chatbot, has been developed by means of a modular and scalable framework that eases building pedagogic conversational agents that can interact with the students using speech and natural language.

Mining Temporal Patterns to Improve Agents Behavior: Two Case Studies

Science.gov (United States)

Fournier-Viger, Philippe; Nkambou, Roger; Faghihi, Usef; Nguifo, Engelbert Mephu

We propose two mechanisms for agent learning based on the idea of mining temporal patterns from agent behavior. The first one consists of extracting temporal patterns from the perceived behavior of other agents accomplishing a task, to learn the task. The second learning mechanism consists in extracting temporal patterns from an agent's own behavior. In this case, the agent then reuses patterns that brought self-satisfaction. In both cases, no assumption is made on how the observed agents' behavior is internally generated. A case study with a real application is presented to illustrate each learning mechanism.

Use of Inotropic Agents in Treatment of Systolic Heart Failure

Directory of Open Access Journals (Sweden)

Sohaib Tariq

2015-12-01

Full Text Available The most common use of inotropes is among hospitalized patients with acute decompensated heart failure, with reduced left ventricular ejection fraction and with signs of end-organ dysfunction in the setting of a low cardiac output. Inotropes can be used in patients with severe systolic heart failure awaiting heart transplant to maintain hemodynamic stability or as a bridge to decision. In cases where patients are unable to be weaned off inotropes, these agents can be used until a definite or escalated supportive therapy is planned, which can include coronary revascularization or mechanical circulatory support (intra-aortic balloon pump, extracorporeal membrane oxygenation, impella, left ventricular assist device, etc.. Use of inotropic drugs is associated with risks and adverse events. This review will discuss the use of the inotropes digoxin, dopamine, dobutamine, norepinephrine, milrinone, levosimendan, and omecamtiv mecarbil. Long-term inotropic therapy should be offered in selected patients. A detailed conversation with the patient and family shall be held, including a discussion on the risks and benefits of use of inotropes. Chronic heart failure patients awaiting heart transplants are candidates for intravenous inotropic support until the donor heart becomes available. This helps to maintain hemodynamic stability and keep the fluid status and pulmonary pressures optimized prior to the surgery. On the other hand, in patients with severe heart failure who are not candidates for advanced heart failure therapies, such as transplant and mechanical circulatory support, inotropic agents can be used for palliative therapy. Inotropes can help reduce frequency of hospitalizations and improve symptoms in these patients.

Use of Inotropic Agents in Treatment of Systolic Heart Failure.

Science.gov (United States)

Tariq, Sohaib; Aronow, Wilbert S

2015-12-04

The most common use of inotropes is among hospitalized patients with acute decompensated heart failure, with reduced left ventricular ejection fraction and with signs of end-organ dysfunction in the setting of a low cardiac output. Inotropes can be used in patients with severe systolic heart failure awaiting heart transplant to maintain hemodynamic stability or as a bridge to decision. In cases where patients are unable to be weaned off inotropes, these agents can be used until a definite or escalated supportive therapy is planned, which can include coronary revascularization or mechanical circulatory support (intra-aortic balloon pump, extracorporeal membrane oxygenation, impella, left ventricular assist device, etc.). Use of inotropic drugs is associated with risks and adverse events. This review will discuss the use of the inotropes digoxin, dopamine, dobutamine, norepinephrine, milrinone, levosimendan, and omecamtiv mecarbil. Long-term inotropic therapy should be offered in selected patients. A detailed conversation with the patient and family shall be held, including a discussion on the risks and benefits of use of inotropes. Chronic heart failure patients awaiting heart transplants are candidates for intravenous inotropic support until the donor heart becomes available. This helps to maintain hemodynamic stability and keep the fluid status and pulmonary pressures optimized prior to the surgery. On the other hand, in patients with severe heart failure who are not candidates for advanced heart failure therapies, such as transplant and mechanical circulatory support, inotropic agents can be used for palliative therapy. Inotropes can help reduce frequency of hospitalizations and improve symptoms in these patients.

Building Agents to Serve Customers

OpenAIRE

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

2004-01-01

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

Intelligent agents for e-commerce applications

Science.gov (United States)

Vuppala, Krishna

1999-12-01

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

Reducing Mortality from Terrorist Releases of Chemical and Biological Agents: I. Filtration for Ventilation Systems in Commercial Building

Energy Technology Data Exchange (ETDEWEB)

Thatcher, Tracy L.; Daisey, Joan M.

1999-09-01

There is growing concern about potential terrorist attacks involving releases of chemical and/or biological (CB) agents, such as sarin or anthrax, in and around buildings. For an external release, the CB agent can enter the building through the air intakes of a building's mechanical ventilation system and by infiltration through the building envelope. For an interior release in a single room, the mechanical ventilation system, which often recirculates some fraction of the air within a building, may distribute the released CB agent throughout the building. For both cases, installing building systems that remove chemical and biological agents may be the most effective way to protect building occupants. Filtration systems installed in the heating, ventilating and air-conditioning (HVAC) systems of buildings can significantly reduce exposures of building occupants in the event of a release, whether the release is outdoors or indoors. Reduced exposures can reduce the number of deaths from a terrorist attack. The purpose of this report is to provide information and examples of the design of filtration systems to help building engineers retrofit HVAC systems. The report also provides background information on the physical nature of CB agents and brief overviews of the basic principles of particle and vapor filtration.

A Neural Path Integration Mechanism for Adaptive Vector Navigation in Autonomous Agents

DEFF Research Database (Denmark)

Goldschmidt, Dennis; Dasgupta, Sakyasingha; Wörgötter, Florentin

2015-01-01

Animals show remarkable capabilities in navigating their habitat in a fully autonomous and energy-efficient way. In many species, these capabilities rely on a process called path integration, which enables them to estimate their current location and to find their way back home after long-distance...... of autonomous agent navigation, but it also reproduces various aspects of animal navigation. Finally, we discuss how the proposed path integration mechanism may be used as a scaffold for spatial learning in terms of vector navigation.......Animals show remarkable capabilities in navigating their habitat in a fully autonomous and energy-efficient way. In many species, these capabilities rely on a process called path integration, which enables them to estimate their current location and to find their way back home after long...

Chemical characterization and ecotoxicity of three soil foaming agents used in mechanized tunneling

Energy Technology Data Exchange (ETDEWEB)

Baderna, Diego, E-mail: diego.baderna@marionegri.it [Laboratory of Environmental Chemistry and Toxicology, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy); Lomazzi, Eleonora [Laboratory of Environmental Chemistry and Toxicology, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy); Passoni, Alice [Unit of Analytical Instrumentation, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy); Pogliaghi, Alberto; Petoumenou, Maria Ifigeneia [Laboratory of Environmental Chemistry and Toxicology, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy); Bagnati, Renzo [Unit of Analytical Instrumentation, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy); Lodi, Marco [Laboratory of Environmental Chemistry and Toxicology, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy); Viarengo, Aldo; Sforzini, Susanna [Department of Sciences and Technological Innovation (DiSIT), University of Piemonte Orientale “A. Avogadro”, 15121 Alessandria (Italy); Benfenati, Emilio [Laboratory of Environmental Chemistry and Toxicology, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy); Fanelli, Roberto [Department of Environmental Health Sciences, IRCCS – Istituto di Ricerche Farmacologiche Mario Negri, Via Giuseppe La Masa 19, 20156 Milan (Italy)

2015-10-15

Highlights: • An integrated approach was applied to study three foaming agents. • Several compounds not reported on the safety data sheets were identified by HRMS. • Environmental impacts were investigated with a battery of biological assays. • An ecotoxicological ranking of the products was obtained. - Abstract: The construction of tunnels and rocks with mechanized drills produces several tons of rocky debris that are today recycled as construction material or as soil replacement for covering rocky areas. The lack of accurate information about the environmental impact of these excavated rocks and foaming agents added during the excavation process has aroused increasing concern for ecosystems and human health. The present study proposes an integrated approach to the assessment of the potential environmental impact of three foaming agents containing different anionic surfactants and other polymers currently on the market and used in tunnel boring machines. The strategy includes chemical characterization with high resolution mass spectrometry techniques to identify the components of each product, the use of in silico tools to perform a similarity comparison among these compounds and some pollutants already listed in regulatory frameworks to identify possible threshold concentrations of contamination, and the application of a battery of ecotoxicological assays to investigate the impact of each foaming mixture on model organisms of soil (higher plants and Eisenia andrei) and water communities (Daphnia magna). The study identified eleven compounds not listed on the material safety data sheets for which we have identified possible concentrations of contamination based on existing regulatory references. The bioassays allowed us to determine the no effect concentrations (NOAECs) of the three mixtures, which were subsequently used as threshold concentration for the product in its entirety. The technical mixtures used in this study have a different degree of toxicity

Chemical characterization and ecotoxicity of three soil foaming agents used in mechanized tunneling

International Nuclear Information System (INIS)

Baderna, Diego; Lomazzi, Eleonora; Passoni, Alice; Pogliaghi, Alberto; Petoumenou, Maria Ifigeneia; Bagnati, Renzo; Lodi, Marco; Viarengo, Aldo; Sforzini, Susanna; Benfenati, Emilio; Fanelli, Roberto

2015-01-01

Highlights: • An integrated approach was applied to study three foaming agents. • Several compounds not reported on the safety data sheets were identified by HRMS. • Environmental impacts were investigated with a battery of biological assays. • An ecotoxicological ranking of the products was obtained. - Abstract: The construction of tunnels and rocks with mechanized drills produces several tons of rocky debris that are today recycled as construction material or as soil replacement for covering rocky areas. The lack of accurate information about the environmental impact of these excavated rocks and foaming agents added during the excavation process has aroused increasing concern for ecosystems and human health. The present study proposes an integrated approach to the assessment of the potential environmental impact of three foaming agents containing different anionic surfactants and other polymers currently on the market and used in tunnel boring machines. The strategy includes chemical characterization with high resolution mass spectrometry techniques to identify the components of each product, the use of in silico tools to perform a similarity comparison among these compounds and some pollutants already listed in regulatory frameworks to identify possible threshold concentrations of contamination, and the application of a battery of ecotoxicological assays to investigate the impact of each foaming mixture on model organisms of soil (higher plants and Eisenia andrei) and water communities (Daphnia magna). The study identified eleven compounds not listed on the material safety data sheets for which we have identified possible concentrations of contamination based on existing regulatory references. The bioassays allowed us to determine the no effect concentrations (NOAECs) of the three mixtures, which were subsequently used as threshold concentration for the product in its entirety. The technical mixtures used in this study have a different degree of toxicity

Effect of Silane Coupling Agent on the Creep Behavior and Mechanical Properties of Carbon Fibers/Acrylonitrile Butadiene Rubber Composites.

Science.gov (United States)

Choi, Woong-Ki; Park, Gil-Young; Kim, Byoung-Shuk; Seo, Min-Kang

2018-09-01

In this study, we investigated the effect of the silane coupling agent on the relationship between the surface free energy of carbon fibers (CFs) and the mechanical strength of CFs/acrylonitrile butadiene rubber (NBR) composites. Moreover, the creep behavior of the CF/NBR composites at surface energetic point of view were studied. The specific component of the surface free energy of the carbon fibers was found to increase upon grafting of the silane coupling agent, resulting in an increase in the tensile strength of the CF/NBR composites. On the other hand, the compressive creep strength was found to follow a slightly different trend. These results indicate the possible formation of a complex interpenetrating polymer network depending on the molecular size of the organic functional groups of the silane coupling agent.

Effect of carboxylic acids as compatibilizer agent on mechanical properties of thermoplastic starch and polypropylene blends.

Science.gov (United States)

Martins, Andréa Bercini; Santana, Ruth Marlene Campomanes

2016-01-01

In this work, polypropylene/thermoplastic starch (PP/TPS) blends were prepared as an alternative material to use in disposable packaging, reducing the negative polymeric environmental impact. Unfortunately, this material displays morphological characteristics typical of immiscible polymer blends and a compatibilizer agent is needed. Three different carboxyl acids: myristic (C14), palmitic (C16) and stearic acids (C18) were used as natural compatibilizer agent (NCA). The effects of NCA on the mechanical, physical, thermal and morphological properties of PP/TPS blends were investigated and compared against PP/TPS with and without PP-grafted maleic anhydride (PPgMA). When compared to PP/TPS, blends with C18, PPgMA and C14 presented an improvement of 25, 22 and 17% in tensile strength at break and of 180, 194 and 259% in elongation at break, respectively. The highest increase, 54%, in the impact strength was achieved with C14 incorporation. Improvements could be seen, through scanning electron microscopy (SEM) images, in the compatibility between the immiscible components by acids incorporation. These results showed that carboxylic acids, specifically C14, could be used as compatibilizer agent and could substitute PPgMA. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reducing Interaction Costs for Self-interested Agents

Science.gov (United States)

Zhang, Yunqi; Larson, Kate

In many multiagent systems, agents are not able to freely interact with each other or with a centralized mechanism. They may be limited in their interactions by cost or by the inherent structure of the system. Using a combinatorial auction application as motivation, we study the impact of interaction costs and structure on the strategic behaviour of self-interested agents. We present a particular model of costly agent-interaction, and argue that self-interested agents may wish to coordinate their actions with their neighbours so as to reduce their individual costs. We highlight the issues that arise in such a setting, propose a cost-sharing mechanism that agents can use, and discuss group coordination procedures. Experimental work validates our model.

Influence of some crosslinking agents on thermal and mechanical properties of electron beam irradiated polylactide

Energy Technology Data Exchange (ETDEWEB)

Rytlewski, Piotr, E-mail: prytlewski@ukw.edu.p [Department of Materials Engineering, Kazimierz Wielki University, ul. Chodkiewicza 30, 85-064 Bydgoszcz (Poland); Malinowski, RafaL [Institute for Engineering of Polymer Materials and Dyes, ul. M. SkLodowskiej-Curie 55, 87-100 Torun (Poland); Moraczewski, Krzysztof [Department of Materials Engineering, Kazimierz Wielki University, ul. Chodkiewicza 30, 85-064 Bydgoszcz (Poland); Zenkiewicz, Marian [Institute for Engineering of Polymer Materials and Dyes, ul. M. SkLodowskiej-Curie 55, 87-100 Torun (Poland)

2010-10-15

The aim of this article was to determine and compare the influence of trimethylopropane trimethacylate (TMPTA) and trially isocyanurate (TAIC) crosslinking agents on thermal and mechanical properties of electron beam irradiated polylactide (PLA). The blends were made of PLA mixed with 3 wt% of TMPTA (PLA/TMPTA), and PLA mixed with 3 wt% of TAIC (PLA/TAIC). Injection moulded samples were irradiated with the use of high energy (10 MeV) electron beam at various radiation doses to crosslinking PLA macromolecules. Thermal and mechanical properties were investigated by means of differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), tensile strength, and impact strength measurements. The samples were also characterized by Fourier transform infrared spectroscopy (FTIR). It was found that under the influence of electron irradiation PLA/TMPTA samples underwent degradation while PLA/TAIC samples became crosslinked. Tensile and impact strengths of PLA/TMPTA samples decreased with increasing radiation dose while an enhancement of these properties for PLA/TAIC samples was observed.

Influence of some crosslinking agents on thermal and mechanical properties of electron beam irradiated polylactide

International Nuclear Information System (INIS)

Rytlewski, Piotr; Malinowski, RafaL; Moraczewski, Krzysztof; Zenkiewicz, Marian

2010-01-01

The aim of this article was to determine and compare the influence of trimethylopropane trimethacylate (TMPTA) and trially isocyanurate (TAIC) crosslinking agents on thermal and mechanical properties of electron beam irradiated polylactide (PLA). The blends were made of PLA mixed with 3 wt% of TMPTA (PLA/TMPTA), and PLA mixed with 3 wt% of TAIC (PLA/TAIC). Injection moulded samples were irradiated with the use of high energy (10 MeV) electron beam at various radiation doses to crosslinking PLA macromolecules. Thermal and mechanical properties were investigated by means of differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), tensile strength, and impact strength measurements. The samples were also characterized by Fourier transform infrared spectroscopy (FTIR). It was found that under the influence of electron irradiation PLA/TMPTA samples underwent degradation while PLA/TAIC samples became crosslinked. Tensile and impact strengths of PLA/TMPTA samples decreased with increasing radiation dose while an enhancement of these properties for PLA/TAIC samples was observed.

Gastroduodenal mucosal defence mechanisms and the action of non-steroidal anti-inflammatory agents.

Science.gov (United States)

Garner, A; Allen, A; Rowe, P H

1987-01-01

This review summarises gastroduodenal protective mechanisms, the actions of non-steroidal anti-inflammatory (NSAI) agents on mucus and HCO3 secretions, and the basis of gastric mucosal injury induced by acetylsalicylic and salicylic acids (ASA and SA). Resistance to autodigestion by acid and pepsin present in gastric juice is multifactorial involving pre-epithelial (mucus-bicarbonate barrier) and post-epithelial (blood flow, acid-base balance) factors in addition to properties of the surface cell layer per se. The latter includes mucosal re-epithelialisation, a property which appears particularly important with respect to recovery from acute injury. A range of NSAI agents (ASA, fenclofenac, ibuprofen and indomethacin) inhibit gastric HCO3 transport in isolated mucosal preparations. Inhibition of duodenal HCO3 transport has been demonstrated in response to indomethacin in vitro and in vivo. These effects on secretion can be antagonised by exogenous prostaglandins of the E series. The layer of secreted mucus gel overlying the epithelial surface is not affected by NSAI drugs in the short term. However a number of these agents have been shown to inhibit glycoprotein biosynthesis by the epithelial cells. Thus loss of this protective coat could be anticipated during chronic drug exposure since erosion of adherent mucus by luminal shear and proteolysis would not be compensated by continued secretion. Detailed analysis of the gastric mucosal injury induced by salicylates both in vitro and in vivo reveals that much of the damage previously attributed to ASA is in fact due to the metabolic product SA. In this respect it is concluded that mucosal injury caused by ASA is due to a combination of two factors.(ABSTRACT TRUNCATED AT 250 WORDS)

Limonene and tetrahydrofurfuryl alcohol cleaning agent

Science.gov (United States)

Bohnert, George W.; Carter, Richard D.; Hand, Thomas E.; Powers, Michael T.

1996-05-07

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

Limonene and tetrahydrofurfurly alcohol cleaning agent

Science.gov (United States)

Bohnert, George W.; Carter, Richard D.; Hand, Thomas E.; Powers, Michael T.

1997-10-21

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

Nanocomposite scaffolds with tunable mechanical and degradation capabilities: co-delivery of bioactive agents for bone tissue engineering.

Science.gov (United States)

Cattalini, Juan P; Roether, Judith; Hoppe, Alexander; Pishbin, Fatemeh; Haro Durand, Luis; Gorustovich, Alejandro; Boccaccini, Aldo R; Lucangioli, Silvia; Mouriño, Viviana

2016-10-21

Novel multifunctional nanocomposite scaffolds made of nanobioactive glass and alginate crosslinked with therapeutic ions such as calcium and copper were developed for delivering therapeutic agents, in a highly controlled and sustainable manner, for bone tissue engineering. Alendronate, a well-known antiresorptive agent, was formulated into microspheres under optimized conditions and effectively loaded within the novel multifunctional scaffolds with a high encapsulation percentage. The size of the cation used for the alginate crosslinking impacted directly on porosity and viscoelastic properties, and thus, on the degradation rate and the release profile of copper, calcium and alendronate. According to this, even though highly porous structures were created with suitable pore sizes for cell ingrowth and vascularization in both cases, copper-crosslinked scaffolds showed higher values of porosity, elastic modulus, degradation rate and the amount of copper and alendronate released, when compared with calcium-crosslinked scaffolds. In addition, in all cases, the scaffolds showed bioactivity and mechanical properties close to the endogenous trabecular bone tissue in terms of viscoelasticity. Furthermore, the scaffolds showed osteogenic and angiogenic properties on bone and endothelial cells, respectively, and the extracts of the biomaterials used promoted the formation of blood vessels in an ex vivo model. These new bioactive nanocomposite scaffolds represent an exciting new class of therapeutic cell delivery carrier with tunable mechanical and degradation properties; potentially useful in the controlled and sustainable delivery of therapeutic agents with active roles in bone formation and angiogenesis, as well as in the support of cell proliferation and osteogenesis for bone tissue engineering.

Radiation protective agents possessing anti-oxidative properties

Energy Technology Data Exchange (ETDEWEB)

Anzai, Kazunori; Ueno, Emi; Yoshida, Akira; Furuse, Masako; Ikota, Nobuo [National Inst. of Radiological Sciences, Research Center for Radiation Safety, Chiba, Chiba (Japan)

2005-11-15

The purpose of studies is to see mechanisms of radiation protection of agents possessing anti-oxidative properties because the initial step resulting in radiation hazard is the formation of radicals by water radiolysis. Agents were commercially available or synthesized proxyl derivatives (spin prove agents), commercially available spin-trapping agents, edaravone and TMG (a tocopherol glycoside). Mice and cultured cells were X-irradiated by Shimadzu Pantak HF-320 or 320S. Survivals of cells were determined by colony assay and of mice, to which the agents were given intraperitoneally before or after X-irradiation, within 30 days post irradiation. Plasma and marrow concentrations of proxyls were estimated by electron spin resonance (ESR) spectrometry. Mechanisms of their radiation protective effects were shown different from agent to agent. TMG was found effective even post irradiation, which suggests a possibility for a new drug development. Some (spin trapping agents and TMG), virtually ineffective at the cell level, were found effective in the whole body, suggesting the necessity of studies on their disposition and metabolism. (S.I.)

Radiation protective agents possessing anti-oxidative properties

International Nuclear Information System (INIS)

Anzai, Kazunori; Ueno, Emi; Yoshida, Akira; Furuse, Masako; Ikota, Nobuo

2005-01-01

The purpose of studies is to see mechanisms of radiation protection of agents possessing anti-oxidative properties because the initial step resulting in radiation hazard is the formation of radicals by water radiolysis. Agents were commercially available or synthesized proxyl derivatives (spin prove agents), commercially available spin-trapping agents, edaravone and TMG (a tocopherol glycoside). Mice and cultured cells were X-irradiated by Shimadzu Pantak HF-320 or 320S. Survivals of cells were determined by colony assay and of mice, to which the agents were given intraperitoneally before or after X-irradiation, within 30 days post irradiation. Plasma and marrow concentrations of proxyls were estimated by electron spin resonance (ESR) spectrometry. Mechanisms of their radiation protective effects were shown different from agent to agent. TMG was found effective even post irradiation, which suggests a possibility for a new drug development. Some (spin trapping agents and TMG), virtually ineffective at the cell level, were found effective in the whole body, suggesting the necessity of studies on their disposition and metabolism. (S.I.)

Influence of corn flour as pore forming agent on porous ceramic material based mullite: Morphology and mechanical properties

Directory of Open Access Journals (Sweden)

Ayala-Landeros J.G.

2016-01-01

Full Text Available Porous material was processed by the mixing, molding and pressing the ceramic material, afterward burnout and sintering; through the forming porous, using corn flour at different concentration (10, 15 and 20 wt.% as a pore forming agent; in order to determinate the influence of porous on the mechanical, morphological and structural properties. The effect of the volume fraction of corn flour in the mullite matrix, at various sintering temperature from 1100, 1200, 1300 and 1500°C were tested by Diffraction X ray, showing changes in crystalline phases of mullite (3Al2O3-2SiO2, as result of sintered temperatures. Presence of talcum powder in formula, also cause the formation of the cordierite and cristobalite crystalline phases, giving stability and adhesion to the structure of ceramic material. When sintering at temperatures between 1300 to 1500°C, and it was used the concentration of corn flour 15-20 wt.% as forming agent porous, it was found the better mechanical properties. The scanning electron microscopy analysis shows the presence of open porosity and anisotropy.

Conversational agents for academically productive talk: a comparison of directed and undirected agent interventions

DEFF Research Database (Denmark)

Tegos, Stergios; Demetriadis, Stavros N.; Papadopoulos, Pantelis M.

2016-01-01

Conversational agents that draw on the framework of academically productive talk (APT) have been lately shown to be effective in helping learners sustain productive forms of peer dialogue in diverse learning settings. Yet, literature suggests that more research is required on how learners respond...

A Distributed Multi-Agent System for Collaborative Information Management and Learning

Science.gov (United States)

Chen, James R.; Wolfe, Shawn R.; Wragg, Stephen D.; Koga, Dennis (Technical Monitor)

2000-01-01

In this paper, we present DIAMS, a system of distributed, collaborative agents to help users access, manage, share and exchange information. A DIAMS personal agent helps its owner find information most relevant to current needs. It provides tools and utilities for users to manage their information repositories with dynamic organization and virtual views. Flexible hierarchical display is integrated with indexed query search-to support effective information access. Automatic indexing methods are employed to support user queries and communication between agents. Contents of a repository are kept in object-oriented storage to facilitate information sharing. Collaboration between users is aided by easy sharing utilities as well as automated information exchange. Matchmaker agents are designed to establish connections between users with similar interests and expertise. DIAMS agents provide needed services for users to share and learn information from one another on the World Wide Web.

Entrepreneurial Attitudes and Behaviors that Can Help Prepare Successful Change-Agents in Education

Science.gov (United States)

Borasi, Raffaella; Finnigan, Kara

2010-01-01

This article explores how the preparation of educators committed to improving education can capitalize on entrepreneurship when broadly defined as "transforming ideas into enterprises that generate economic, intellectual and/or social value." The article reports on the case-studies of six educators who have been successful change-agents in a…

Monolithic Controlled Delivery Systems: Part I. Basic Characteristics and Mechanisms

Directory of Open Access Journals (Sweden)

Rumiana Blagoeva

2006-04-01

Full Text Available The article considers contemporary systems for controlled delivery of active agents, such as drugs, agricultural chemicals, pollutants and additives in the environment. A useful classification of the available controlled release systems (CRS is proposed according to the type of control (passive, active or self-preprogrammed and according to the main controlling mechanism (diffusion, swelling, dissolution or erosion. Special attention is given to some of the most used CRS - polymer monoliths. The structural and physical-chemical characteristics of CRS as well as the basic approaches to their production are examined. The basic mechanisms of controlled agent release are reviewed in detail and factors influencing the release kinetics are classified according to their importance. The present study can be helpful for understanding and applying the available mathematical models and for developing more comprehensive ones intended for design of new controlled delivery systems.

Interactions of ionic and nonionic contrast agents with thrombolytic agents

International Nuclear Information System (INIS)

Fareed, J.; Moncada, R.; Scanlon, P.; Hoppensteadt, D.; Huan, X.; Walenga, J.M.

1987-01-01

Both the ionic and nonionic intravascular contrast media have been used before and after the administration of thrombolytic agents to evaluate clot lysis during angioplasty and the treatment of myocardial infarction. In experimental animal models, the authors found that the clot lytic efficacy of streptokinase, streptokinase-plasminogen complex, and tissue plasminogen activator (t-PA) is markedly augmented if these agents are administered within 1 hour after the angiographic producers. Furthermore, contrast agents injected after the administration of t-Pa exhibit a synergistic action. In stimulated models administration of one ionic contrast medium (Angiovist, Berlex, Wayne, NJ) and two nonionic contrast agents (Isovue-370, Squibb Diagnostics, New Brunswick, NJ; Omnipaque-350, Winthrop, NY) 15 minutes before the administration of t-PA resulted in marked enhancement of the lytic activity. Although the mechanism of this interaction is unknown at this time, it should be taken into consideration in the treatment of patients with myocardial infarction, in whom contrast agents are continually used to evaluate the therapeutic lysis. Furthermore, this interaction may be partly related to the therapeutic efficacy and/or hemorrhagic actions observed

Chemical characterization and ecotoxicity of three soil foaming agents used in mechanized tunneling.

Science.gov (United States)

Baderna, Diego; Lomazzi, Eleonora; Passoni, Alice; Pogliaghi, Alberto; Petoumenou, Maria Ifigeneia; Bagnati, Renzo; Lodi, Marco; Viarengo, Aldo; Sforzini, Susanna; Benfenati, Emilio; Fanelli, Roberto

2015-10-15

The construction of tunnels and rocks with mechanized drills produces several tons of rocky debris that are today recycled as construction material or as soil replacement for covering rocky areas. The lack of accurate information about the environmental impact of these excavated rocks and foaming agents added during the excavation process has aroused increasing concern for ecosystems and human health. The present study proposes an integrated approach to the assessment of the potential environmental impact of three foaming agents containing different anionic surfactants and other polymers currently on the market and used in tunnel boring machines. The strategy includes chemical characterization with high resolution mass spectrometry techniques to identify the components of each product, the use of in silico tools to perform a similarity comparison among these compounds and some pollutants already listed in regulatory frameworks to identify possible threshold concentrations of contamination, and the application of a battery of ecotoxicological assays to investigate the impact of each foaming mixture on model organisms of soil (higher plants and Eisenia andrei) and water communities (Daphnia magna). The study identified eleven compounds not listed on the material safety data sheets for which we have identified possible concentrations of contamination based on existing regulatory references. The bioassays allowed us to determine the no effect concentrations (NOAECs) of the three mixtures, which were subsequently used as threshold concentration for the product in its entirety. The technical mixtures used in this study have a different degree of toxicity and the predicted environmental concentrations based on the conditions of use are lower than the NOAEC for soils but higher than the NOAEC for water, posing a potential risk to the waters due to the levels of foaming agents in the muck. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of compatibilizing agents on the interface and mechanical behaviour of polypropylene/hemp bast fiber biocomposites

Science.gov (United States)

Boruvka, M.; Lenfeld, P.; Brdlik, P.; Behalek, L.

2015-07-01

During the last years automotive industry has given a lot of attention to the biobased polymers that are sustainable and eco-friendly. Nevertheless fully green composites are currently too expensive for most applications. A viable solution and logical starting point at this material revolution lies in reinforced synthetic thermoplastics based on plant derived biodegradable fibers. Plant fibers (PF's) have potential to reduce weight of composite vehicle parts up to 40% compared with the main automotive composites filler, glass fibers (GF's). Production of GF's composites is much more energy intensive and polluting compared with growing, harvesting and preparing of PF's. The main disadvantage of PF's lies in combination of non-polar hydrophobic polymer matrix and polar hydrophilic fibers. This combination creates poor interface with low adhesion of both components. That implies poor wettability of fibres by polymer matrix and low mechanical properties of biocomposites. Therefore specific compatibilizing agents (Struktol SA1012, Fusabond P353, Smart + Luperox) were used in order to enhance compatibility between reinforcement and matrix. In this paper sets of biocomposite compounds were prepared by twin screw extrusion considering different type and weight percentage (wt. %) of compatibilizing agents, hemp bast fibres (HBF's) within ratio 20 (wt. %) and polypropylene (PP) THERMOFIL PP E020M matrix. Resulting compounds were than injection molded and tested samples were characterized by means of scanning electron microscopy (SEM) and mechanical testing.

Study on the application of sensitizing and protective agent in the process of radiation chemistry

International Nuclear Information System (INIS)

Kamal, Z.

1976-01-01

The role of sensitizing agent and protective agent in the process of radiation chemistry is studied. Direct and indirect radiation effects on bio molecules, molecular and sensitizing agent mechanism, electron activities as the basis for sensitizing agent mechanism, protective agent mechanism on irradiated macro molecules, and kinds of protective and sensitizing agents, are discussed. (RUW)

Chemical warfare agents. Classes and targets.

Science.gov (United States)

Schwenk, Michael

2018-09-01

Synthetic toxic chemicals (toxicants) and biological poisons (toxins) have been developed as chemical warfare agents in the last century. At the time of their initial consideration as chemical weapon, only restricted knowledge existed about their mechanisms of action. There exist two different types of acute toxic action: nonspecific cytotoxic mechanisms with multiple chemo-biological interactions versus specific mechanisms that tend to have just a single or a few target biomolecules. TRPV1- and TRPA-receptors are often involved as chemosensors that induce neurogenic inflammation. The present work briefly surveys classes and toxicologically relevant features of chemical warfare agents and describes mechanisms of toxic action. Copyright © 2017 Elsevier B.V. All rights reserved.

Mechanism of action of direct-acting antiviral agents in treatment of chronic hepatitis C

Directory of Open Access Journals (Sweden)

WEN Xiaoyu

2016-09-01

Full Text Available With the development and launch of direct-acting antiviral agents (DAAs in the world in recent years, therapeutic regimens for chronic hepatitis C are constantly evolving. DAAs will also be launched in China in the near future. DAAs mainly target at the non-structural proteins of HCV and can inhibit HCV RNA replication. This article introduces the targets, mechanism of action, and resistance characteristics of different DAAs, as well as their current research and development in China and the results of phase Ⅲ clinical studies, in order to provide a reference for combined therapeutic strategies with DAAs in the treatment for chronic hepatitis C.

Key considerations on nebulization of antimicrobial agents to mechanically ventilated patients.

Science.gov (United States)

Rello, J; Rouby, J J; Sole-Lleonart, C; Chastre, J; Blot, S; Luyt, C E; Riera, J; Vos, M C; Monsel, A; Dhanani, J; Roberts, J A

2017-09-01

Nebulized antibiotics have an established role in patients with cystic fibrosis or bronchiectasis. Their potential benefit to treat respiratory infections in mechanically ventilated patients is receiving increasing interest. In this consensus statement of the European Society of Clinical Microbiology and Infectious Diseases, the body of evidence of the therapeutic utility of aerosolized antibiotics in mechanically ventilated patients was reviewed and resulted in the following recommendations: Vibrating-mesh nebulizers should be preferred to jet or ultrasonic nebulizers. To decrease turbulence and limit circuit and tracheobronchial deposition, we recommend: (a) the use of specifically designed respiratory circuits avoiding sharp angles and characterized by smooth inner surfaces, (b) the use of specific ventilator settings during nebulization including use of a volume controlled mode using constant inspiratory flow, tidal volume 8 mL/kg, respiratory frequency 12 to 15 bpm, inspiratory:expiratory ratio 50%, inspiratory pause 20% and positive end-expiratory pressure 5 to 10 cm H 2 O and (c) the administration of a short-acting sedative agent if coordination between the patient and the ventilator is not obtained, to avoid patient's flow triggering and episodes of peak decelerating inspiratory flow. A filter should be inserted on the expiratory limb to protect the ventilator flow device and changed between each nebulization to avoid expiratory flow obstruction. A heat and moisture exchanger and/or conventional heated humidifier should be stopped during the nebulization period to avoid a massive loss of aerosolized particles through trapping and condensation. If these technical requirements are not followed, there is a high risk of treatment failure and adverse events in mechanically ventilated patients receiving nebulized antibiotics for pneumonia. Copyright © 2017 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights

Mechanisms of Resilience in Common-pool Resource Management Systems: an Agent-based Model of Water Use in a River Basin

Directory of Open Access Journals (Sweden)

Maja Schlüter

2007-12-01

scenarios of information on water availability. Under the given conditions of a regularly fluctuating inflow and compliance of agents with orders from a national authority, the centralized system performs better as long as irrigation is the only type of water use. Diversification of resource use, e.g., irrigation and fishing, increases the performance of the decentralized regime and the resilience of both. Systematic analysis of the performance of different system structures will help to identify properties and mechanisms of resilience. This understanding will be valuable for the identification, development, and evaluation of management interventions in specific river basins.

Metareasoning and Social Evaluations in Cognitive Agents

Science.gov (United States)

Pinyol, Isaac; Sabater-Mir, Jordi

Reputation mechanisms have been recognized one of the key technologies when designing multi-agent systems. They are specially relevant in complex open environments, becoming a non-centralized mechanism to control interactions among agents. Cognitive agents tackling such complex societies must use reputation information not only for selecting partners to interact with, but also in metareasoning processes to change reasoning rules. This is the focus of this paper. We argue about the necessity to allow, as a cognitive systems designers, certain degree of freedom in the reasoning rules of the agents. We also describes cognitive approaches of agency that support this idea. Furthermore, taking as a base the computational reputation model Repage, and its integration in a BDI architecture, we use the previous ideas to specify metarules and processes to modify at run-time the reasoning paths of the agent. In concrete we propose a metarule to update the link between Repage and the belief base, and a metarule and a process to update an axiom incorporated in the belief logic of the agent. Regarding this last issue we also provide empirical results that show the evolution of agents that use it.

Combating Principal-Agent Relationship Problems: Use of the Truth Revealing Incentive Mechanism

National Research Council Canada - National Science Library

Gates, Daniel R; Yoder, E. C; Coughlan, Peter J

2007-01-01

.... This report describes the principal-agent theory, identifies principal-agent problems in the current DoD contracting environment, discusses how the TRIM addresses these problems more effectively...

Non-radiological contrast agents (MRI)

International Nuclear Information System (INIS)

Bonnemain, B.; Lautrou, J.; Meyer, D.; Doucet, D.

1987-01-01

Over the past few years, extensive research has been carried out in an attempt to develop contrast agents that could help improve both the performance (acquisition times) and the diagnostic efficacy of Magnetic Resonance Imaging (MRI) techniques. On the basis of physicochemical and pharmacological criteria discussed in this presentation, a few efficacious, well-tolerated compounds could be developed. Two of them, the gadolinium complexes Gd-DOTA and Gd-DTPA, are currently being tried in man. This first generation of contrast agents, which are aspecific markers of the intravascular space, has been shown to have good diagnostic potential in conventional MRI procedures. The diagnostic contribution of these contrast agents will probably be a most essential factor in new MRI techniques using low field strengh or fast imaging sequences [fr

Towards Culturally-Aware Virtual Agent Systems

DEFF Research Database (Denmark)

Endrass, Birgit; André, Elisabeth; Rehm, Matthias

2010-01-01

Globalization leads to an increase in intercultural encounters with a risk of misunderstandings due to different patterns of behavior and understanding. Learning applications have been proposed that employ virtual agents as their primary tool. Through their embodiment, learning can be done...... in a game-like environment in a more interesting way than for example learning with a textbook. The authors support the idea that virtual agents are a great opportunity for teaching cultural awareness. Realizing this, the concept of culture needs to be translated into computational models and the advantages...... of different systems using virtual agents need to be considered. Therefore, the authors reflect in this chapter on how virtual agents can help to learn about culture, scan definitions of culture from the social sciences, give an overview on how multiagent systems developed over time and classify the state...

Investigating the impacts of recommendation agents on impulsive purchase behaviour

NARCIS (Netherlands)

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

2015-01-01

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

PPARC: Grid technology helps astronomers keep pace with the Universe

CERN Multimedia

2003-01-01

"Intelligent Agent" computer programs are roaming the Internet and watching the skies. These programs, using Grid computing technology, will help astronomers detect some of the most dramatic events in the universe, such as massive supernova explosions (1 page).

Review of the systems biology of the immune system using agent-based models.

Science.gov (United States)

Shinde, Snehal B; Kurhekar, Manish P

2018-06-01

The immune system is an inherent protection system in vertebrate animals including human beings that exhibit properties such as self-organisation, self-adaptation, learning, and recognition. It interacts with the other allied systems such as the gut and lymph nodes. There is a need for immune system modelling to know about its complex internal mechanism, to understand how it maintains the homoeostasis, and how it interacts with the other systems. There are two types of modelling techniques used for the simulation of features of the immune system: equation-based modelling (EBM) and agent-based modelling. Owing to certain shortcomings of the EBM, agent-based modelling techniques are being widely used. This technique provides various predictions for disease causes and treatments; it also helps in hypothesis verification. This study presents a review of agent-based modelling of the immune system and its interactions with the gut and lymph nodes. The authors also review the modelling of immune system interactions during tuberculosis and cancer. In addition, they also outline the future research directions for the immune system simulation through agent-based techniques such as the effects of stress on the immune system, evolution of the immune system, and identification of the parameters for a healthy immune system.

Design and properties of a novel nucleating agent for isotactic polypropylene

International Nuclear Information System (INIS)

Lv, Zhiping; Yang, Yunfei; Wu, Ran; Tong, Yuchao

2012-01-01

Highlights: ► Three new nucleating agents which is structurally similar to Al-PTBBA were prepared. ► These three nucleating agents were very effective in increasing T c and X c of iPP. ► Great improvement of mechanical properties of nucleated iPP was also obtained. ► Nucleating agent TSD was the most effective nucleating agent for iPP. -- Abstract: Three new nucleating agents TB, TD and TSD (titanate of benzoate or 4-tert-Butylbenzoate) were prepared. Isotactic polypropylene (iPP) nucleated were studied by using thermogravimetry analysis (TGA), X-ray diffraction analysis (XRD), differential scanning calorimetry (DSC) and polarized light microscopy (PLM). The mechanical properties and Vicat softening temperature (VST) of iPP were also tested. The results indicated that these three nucleating agents were very effective in increasing the crystallization temperature (T c ) and crystallinity (X c ) of iPP. Mechanical properties of nucleated iPP were improved remarkably, especially nucleating agent TSD.

A Conversation Model Enabling Intelligent Agents to Give Emotional Support

NARCIS (Netherlands)

Van der Zwaan, J.M.; Dignum, V.; Jonker, C.M.

2012-01-01

In everyday life, people frequently talk to others to help them deal with negative emotions. To some extent, everybody is capable of comforting other people, but so far conversational agents are unable to deal with this type of situation. To provide intelligent agents with the capability to give

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...

L-β-N-methylamino-l-alanine (BMAA) nitrosation generates a cytotoxic DNA damaging alkylating agent: An unexplored mechanism for neurodegenerative disease.

Science.gov (United States)

Potjewyd, G; Day, P J; Shangula, S; Margison, G P; Povey, A C

2017-03-01

L-β-N-methylamino-l-alanine (BMAA) is a non-proteinic amino acid, that is neurotoxic in vitro and in animals, and is implicated in the causation of amyotrophic lateral sclerosis and parkinsonism-dementia complex (ALS-PDC) on Guam. Given that natural amino acids can be N-nitrosated to form toxic alkylating agents and the structural similarity of BMAA to other amino acids, our hypothesis was that N-nitrosation of BMAA might result in a toxic alkylating agent, providing a novel mechanistic hypothesis for BMAA action. We have chemically nitrosated BMAA with sodium nitrite to produce nitrosated BMAA (N-BMAA) which was shown to react with the alkyl-trapping agent, 4-(p-nitrobenzyl)pyridine, cause DNA strand breaks in vitro and was toxic to the human neuroblastoma cell line SH-SY5Y under conditions in which BMAA itself was minimally toxic. Our results indicate that N-BMAA is an alkylating agent and toxin suggesting a plausible and previously unrecognised mechanism for the neurotoxic effects of BMAA. Copyright © 2017 Elsevier B.V. All rights reserved.

Deploying Affect-Inspired Mechanisms to Enhance Agent Decision-Making and Communication

OpenAIRE

Antos, Dimitrios

2012-01-01

Computer agents are required to make appropriate decisions quickly and efficiently. As the environments in which they act become increasingly complex, efficient decision-making becomes significantly more challenging. This thesis examines the positive ways in which human emotions influence people’s ability to make good decisions in complex, uncertain contexts, and develops computational analogues of these beneficial functions, demonstrating their usefulness in agent decision-making and communi...

Evaluation of the onset of failure under mechanical and thermal stresses on luting agent for metal-ceramic and metal crowns by finite element analysis

Directory of Open Access Journals (Sweden)

Hema Agnihotri

2010-01-01

Full Text Available Long-term clinical failures of cemented prosthesis depend, to a large extent, on the integrity of the luting agent. The causative factors that lead to microfracture and, hence, failure of the luting agents are the stresses acting inside the oral cavity. Therefore, the present study was designed to develop an understanding of the relationship between stresses in the tooth and the failure potential of the luting agent. Two-dimensional finite element stress analysis was performed on the mandibular second premolar. The behavior of zinc-phosphate and glass-ionomer were studied under different crowns (metal-ceramic and metal crown and loading conditions (mechanical force of 450 N acting vertically over the occlusal surface, thermal loads of 60° and 0°C. It was observed from the study that failure threshold of the luting agent was influenced both by the elastic modulus of the luting agent and by the type of the crown.

pH Dependent Antimicrobial Peptides and Proteins, Their Mechanisms of Action and Potential as Therapeutic Agents

Directory of Open Access Journals (Sweden)

Erum Malik

2016-11-01

and hydrogel delivery systems. Nonetheless, many pH dependent AMPs and antimicrobial proteins have yet to be fully characterized and these molecules, as a whole, represent an untapped source of novel biologically active agents that could aid fulfillment of the urgent need for alternatives to conventional antibiotics, helping to avert a return to the pre-antibiotic era.

Quantum mechanics implementation in drug-design workflows: does it really help?

Science.gov (United States)

Arodola, Olayide A; Soliman, Mahmoud Es

2017-01-01

The pharmaceutical industry is progressively operating in an era where development costs are constantly under pressure, higher percentages of drugs are demanded, and the drug-discovery process is a trial-and-error run. The profit that flows in with the discovery of new drugs has always been the motivation for the industry to keep up the pace and keep abreast with the endless demand for medicines. The process of finding a molecule that binds to the target protein using in silico tools has made computational chemistry a valuable tool in drug discovery in both academic research and pharmaceutical industry. However, the complexity of many protein-ligand interactions challenges the accuracy and efficiency of the commonly used empirical methods. The usefulness of quantum mechanics (QM) in drug-protein interaction cannot be overemphasized; however, this approach has little significance in some empirical methods. In this review, we discuss recent developments in, and application of, QM to medically relevant biomolecules. We critically discuss the different types of QM-based methods and their proposed application to incorporating them into drug-design and -discovery workflows while trying to answer a critical question: are QM-based methods of real help in drug-design and -discovery research and industry?

Next frontier in agent-based complex automated negotiation

CERN Document Server

Ito, Takayuki; Zhang, Minjie; Robu, Valentin

2015-01-01

This book focuses on automated negotiations based on multi-agent systems. It is intended for researchers and students in various fields involving autonomous agents and multi-agent systems, such as e-commerce tools, decision-making and negotiation support systems, and collaboration tools. The contents will help them to understand the concept of automated negotiations, negotiation protocols, negotiating agents’ strategies, and the applications of those strategies. In this book, some negotiation protocols focusing on the multiple interdependent issues in negotiations are presented, making it possible to find high-quality solutions for the complex agents’ utility functions. This book is a compilation of the extended versions of the very best papers selected from the many that were presented at the International Workshop on Agent-Based Complex Automated Negotiations.

An Immune Agent for Web-Based AI Course

Science.gov (United States)

Gong, Tao; Cai, Zixing

2006-01-01

To overcome weakness and faults of a web-based e-learning course such as Artificial Intelligence (AI), an immune agent was proposed, simulating a natural immune mechanism against a virus. The immune agent was built on the multi-dimension education agent model and immune algorithm. The web-based AI course was comprised of many files, such as HTML…

A framework to protect mobile agents by using reference states

OpenAIRE

Hohl, Fritz

2000-01-01

To protect mobile agents from attacks by their execution environments, or hosts, one class of protection mechanisms uses 'reference states' to detect modification attacks. Reference states are agent states that have been produced by non-attacking, or reference hosts. This paper examines this class of mechanisms and present the bandwidth of the achieved protection. First, a new general definition of attacks against mobile agents is presented. As this general definition does not lead to a pract...

Protecting software agents from malicious hosts using quantum computing

Science.gov (United States)

Reisner, John; Donkor, Eric

2000-07-01

We evaluate how quantum computing can be applied to security problems for software agents. Agent-based computing, which merges technological advances in artificial intelligence and mobile computing, is a rapidly growing domain, especially in applications such as electronic commerce, network management, information retrieval, and mission planning. System security is one of the more eminent research areas in agent-based computing, and the specific problem of protecting a mobile agent from a potentially hostile host is one of the most difficult of these challenges. In this work, we describe our agent model, and discuss the capabilities and limitations of classical solutions to the malicious host problem. Quantum computing may be extremely helpful in addressing the limitations of classical solutions to this problem. This paper highlights some of the areas where quantum computing could be applied to agent security.

Trust Level and Routing Selection for Mobile Agents in a Smart Home

NARCIS (Netherlands)

Nasution, Sandy; Hartel, Pieter H.; Suryana, Nanna; Azman, Nur; Shahib, Shahrin

The central security concern for systems where agents roam is how to establish trust in the agent. We present a Fuzzy Logic mechanism to calculate a level of trust and an optimal route for a mobile agent system in a smart home. The mechanism consists of two parts. The first part calculates a trust

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...

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...

Agent-Based Models and Optimal Control in Biology: A Discrete Approach

Science.gov (United States)

2012-01-01

alive. Thus, the rules are reminiscent of a population whose survival is affected by under- and overpopulation . If we now initialize this “Game” by...helpful in models consisting of many agents of the same type, or many agents that follow the same set of rules. In modeling seasonal animal migration

A BDI Dialogue Agent for Social Support : Specification and Evaluation Method

NARCIS (Netherlands)

Van der Zwaan, J.M.; Dignum, V.; Jonker, C.M.

2012-01-01

An important task for empathic agents is to provide social support, that is, to help people increase their well-being and decrease the perceived burden of their problems. The contributions of this paper are 1) the specifcation of speech acts for a social support dialogue agent, and 2) an evaluation

Clustering recommendations to compute agent reputation

Science.gov (United States)

Bedi, Punam; Kaur, Harmeet

2005-03-01

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

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....

Overview of shoreline cleaning agents

International Nuclear Information System (INIS)

Clayton, J.

1992-01-01

Chemical cleaning agents may be used to promote release of stranded oil from shorelines for reasons including biological sensitivity of indigenous fauna and flora to the oil, amenity considerations of the shoreline, or concern about refloating of the oil and subsequent stranding on adjacent shorelines. While use of chemical cleaning agents may be appropriate under proper toxic responses in circumstances, certain limitations should be recognized. The potential for toxic responses in indigenous fauna and flora to the cleaning agents must be considered. Enhanced penetration of oil into permeable shorelines following treatment with chemical cleaning agents also is not desirable. However, if conditions related to toxicity and substrate permeability are determined to be acceptable, the use of chemical cleaning agents for treatment of stranded oil can be considered. Chemical agents for cleaning oiled shorelines can be grouped into three categories: (1) non-surfactant-based solvents, (2) chemical dispersants, and (3) formulations especially designed to release stranded oil from shoreline substrates (i.e., shoreline-cleaning-agents). Depending on the specific circumstances present on an oiled shoreline, it is generally desirable that chemical agents used for cleaning will release oil from shoreline substrate(s) to surface waters. Recovery of the oil can then be accomplished by mechanical procedures such as booming and skimming operations

Novel Antitumor Platinum(II) Conjugates Containing the Nonsteroidal Anti-inflammatory Agent Diclofenac: Synthesis and Dual Mechanisms of Antiproliferative Effects.

Science.gov (United States)

Intini, Francesco Paolo; Zajac, Juraj; Novohradsky, Vojtech; Saltarella, Teresa; Pacifico, Concetta; Brabec, Viktor; Natile, Giovanni; Kasparkova, Jana

2017-02-06

One concept how to improve anticancer effects of conventional metallodrugs consists in conjugation of these compounds with other biologically (antitumor) active agents, acting by a different mechanism. Here, we present synthesis, biological effects, and mechanisms of action of new Pt(II) derivatives containing one or two nonsteroidal anti-inflammatory diclofenac (DCF) ligands also known for their antitumor effects. The antiproliferative properties of these metallic conjugates show that these compounds are potent and cancer cell selective cytotoxic agents exhibiting activity in cisplatin resistant and the COX-2 positive tumor cell lines. One of these compounds, compound 3, in which DCF molecules are coordinated to Pt(II) through their carboxylic group, is more potent than parental conventional Pt(II) drug cisplatin, free DCF and the congeners of 3 in which DCF ligands are conjugated to Pt(II) via a diamine. The potency of 3 is due to several factors including enhanced internalization that correlates with enhanced DNA binding and cytotoxicity. Mechanistic studies show that 3 combines multiple effects. After its accumulation in cells, it releases Pt(II) drug capable of binding/damaging DNA and DCF ligands, which affect distribution of cells in individual phases of the cell cycle, inhibit glycolysis and lactate transport, collapse mitochondrial membrane potential, and suppress the cellular properties characteristic of metastatic progression.

Socially rational agents in spatial land use planning: a heuristic proposal based negotiation mechanism

NARCIS (Netherlands)

Ghavami, S.M.; Taleai, M.; Arentze, T.A.

2016-01-01

This paper introduces a novel heuristic based negotiation model for urban land use planning by using multi-agent systems. The model features two kinds of agents: facilitator and advocate. Facilitator agent runs the negotiation according to a certain protocol that defines the procedure. Two roles are

Preparation of carbon black masterbatch for PET using polymeric dispersing agents

Energy Technology Data Exchange (ETDEWEB)

Oh, D.H. [Kyungpook National University, Taegu (Korea, Republic of); Lim, J.C. [Pukyong National University, Pusan (Korea, Republic of); Seo, K.H. [Yeungnam College of Science and Technology, Taegu (Korea, Republic of)

1999-03-01

Three kinds of copolyesters, dispersing agents, were synthesized from the polycondensation reaction of dimethylterephthalate (DMT), dimethylisophthalate (DMI), sebacic acid (SA), and 1,4-butanediol (BD). Carbon black masterbatches were prepared by mixing carbon black into the dispersing agents (1 : 1.3 weight ratio) in a Brabender Plasticorder Using single screw extruder, masterbatches were compounded with poly(ethylene terephthalate) in 3 wt% concentration and mechanical properties of the compounds were investigated Gel permeation chromatography data implied that thermal degradation of polymeric dispersing agents was not significant through dispersion. Capillary rheometer test showed that PBTI has the highest viscosity and shear sensitivity among the there dispersing agents. Volume resistivities of masterbatch and transmission electron micrographs showed that dispersity of carbon black was improved with increasing melt viscosity of dispersing agent. The ultimate performance and mechanical characteristics of carbon black filled PET compounds depended directly on dispersion quality of the carbon black in masterbatch. Mechanical properties of compounds were improved with increasing dispersity of carbon black and with increasing content of rigid aromatic group in the copolyester dispersing agent. 30 refs., 9 figs., 5 tabs.

Bridging humans via agent networks

International Nuclear Information System (INIS)

Ishida, Toru

1994-01-01

Recent drastic advance in telecommunication networks enabled the human organization of new class, teleorganization, which differ from any existing organization in that the organization which is easy to create by using telecommunication networks is virtual and remote, that people can join multiple organizations simultaneously, and that the organization can involve people who may not know each other. In order to enjoy the recent advance in telecommunication, the agent networks to help people organize themselves are needed. In this paper, an architecture of agent networks, in which each agent learns the preference or the utility functioin of the owner, and acts on behalf of the owner in maintaining the organization, is proposed. When an agent networks supports a human organization, the conventional human interface is divided into personal and social interfaces. The functionalities of the social interface in teleconferencing and telelearning were investigated. In both cases, the existence of B-ISDN is assumed, and the extension to the business meeting scheduling using personal handy phone (PHS) networks with personal digital assistant (PDA) terminals is expected. These circumstances are described. Mutual selection protocols (MSP) and their dynamic properties are explained. (K.I.)

The Effect of Silane Coupling Agents on a Composite Polyamide-6/Talc

Directory of Open Access Journals (Sweden)

H. Wiebeck

1998-12-01

Full Text Available This paper evaluates the effect of the addition of silane agents on the mechanical properties (tensile strength, hardness and flexibility of the composite polyamide-6/talc. For this purpose, 30% and 40% of a talc with and without the addition of silane agents were incorporated into polyamide-6. Three kinds of silane agents were used, resulting in nine formulations. Comparing the experimental results, it is concluded that the silane agents improve the mechanical properties of the composite material.

Internet-enabled collaborative agent-based supply chains

Science.gov (United States)

Shen, Weiming; Kremer, Rob; Norrie, Douglas H.

2000-12-01

This paper presents some results of our recent research work related to the development of a new Collaborative Agent System Architecture (CASA) and an Infrastructure for Collaborative Agent Systems (ICAS). Initially being proposed as a general architecture for Internet based collaborative agent systems (particularly complex industrial collaborative agent systems), the proposed architecture is very suitable for managing the Internet enabled complex supply chain for a large manufacturing enterprise. The general collaborative agent system architecture with the basic communication and cooperation services, domain independent components, prototypes and mechanisms are described. Benefits of implementing Internet enabled supply chains with the proposed infrastructure are discussed. A case study on Internet enabled supply chain management is presented.

Effects and Mechanisms of Checkpoint Inhibitors (CTLA-4, PD-1 and PD-L1 Inhibitors as New Immunotherapeutic Agents for Bladder Cancer

Directory of Open Access Journals (Sweden)

Serdar Çelik

2018-04-01

Full Text Available Since intravesical Bacillus Calmette-Guerin (BCG began to be used for bladder cancer, our understanding of the importance of immune mechanisms in bladder cancer has steadily grown. With developments in immunotherapy in recent years, the use of new immunotherapeutic agents for bladder cancer, especially chemotherapy-resistant invasive and metastatic cancers, has opened the way for research in this area. Of these new therapeutic agents, this article reviews studies published on PubMed or listed on the ClinicalTrials.gov website as of December 2017 regarding the effects and mechanisms of action of checkpoint inhibitors [cytotoxic t-lymphocyte associated protein-4, programmed cell death 1 receptor (PD-1 and PD-1 ligand inhibitors] on bladder cancer. Because checkpoint inhibitors were first used for chemotherapy-resistant bladder cancer after identification of positive expression in tumor cells and especially in tumor-infiltrating mononuclear cells, significant objective response rates and survival advantages have been reported. Research continues regarding the use of these agents as first- and second-line treatment for metastatic disease in combination with chemotherapy; their efficacy in neoadjuvant, adjuvant, and bladder-preserving approaches to muscle-invasive bladder cancer (MIBC disease, and their use in non-muscle-invasize bladder cancer (NMIBC, especially BCG-refractory disease. Depending on the results of these ongoing studies, immunotherapy may direct the treatment of bladder cancer in the future.

Special Agents Can Promote Cooperation in the Population

Science.gov (United States)

Wang, Xin; Han, Jing; Han, Huawei

2011-01-01

Cooperation is ubiquitous in our real life but everyone would like to maximize her own profits. How does cooperation occur in the group of self-interested agents without centralized control? Furthermore, in a hostile scenario, for example, cooperation is unlikely to emerge. Is there any mechanism to promote cooperation if populations are given and play rules are not allowed to change? In this paper, numerical experiments show that complete population interaction is unfriendly to cooperation in the finite but end-unknown Repeated Prisoner's Dilemma (RPD). Then a mechanism called soft control is proposed to promote cooperation. According to the basic idea of soft control, a number of special agents are introduced to intervene in the evolution of cooperation. They comply with play rules in the original group so that they are always treated as normal agents. For our purpose, these special agents have their own strategies and share knowledge. The capability of the mechanism is studied under different settings. We find that soft control can promote cooperation and is robust to noise. Meanwhile simulation results demonstrate the applicability of the mechanism in other scenarios. Besides, the analytical proof also illustrates the effectiveness of soft control and validates simulation results. As a way of intervention in collective behaviors, soft control provides a possible direction for the study of reciprocal behaviors. PMID:22216202

Immune mechanisms regulating pharmacokinetics and pharmacodynamics of PEGylated liposomal anticancer agents

Science.gov (United States)

Song, Gina

integrated approaches, we were able to identify the immunological mechanisms at the molecular, tissue, and clinical levels that may contribute to inter-individual variability in PK and PD of PLD. This dissertation research has a potential to make an impact on development of future NP-based anticancer therapeutics as well as on clinical use of PLD (DoxilRTM) and other PEGylated liposomal anticancer agents.

Sustainable Society Formed by Unselfish Agents

Science.gov (United States)

Kikuchi, Toshiko

It has been pointed out that if the social configuration of the three relations (market, communal and obligatory relations) is not balanced, a market based society as a total system fails. Using multi-agent simulations, this paper shows that a sustainable society is formed when all three relations are integrated and function respectively. When agent trades are based on the market mechanism (i.e., agents act in their own interest and thus only market relations exist), weak agents who cannot perform transactions die. If a compulsory tax is imposed to enable all weak agents to survive (i.e., obligatory relations exist), then the fiscal deficit increases. On the other hand, if agents who have excess income undertake the unselfish action of distributing their surplus to the weak agents (i.e., communal relations exist), then trade volume increases. It is shown that the existence of unselfish agents is necessary for the realization of a sustainable society. However, the survival of all agents is difficult in a communal society. In an artificial society, for all agents survive and fiscal balance to be maintained, all three social relations need to be fully integrated. These results show that adjusting the balance of the three social relations well lead to the realization of a sustainable society.

Antimicrobial Agents Used in Endodontic Treatment

Directory of Open Access Journals (Sweden)

Marina George Kudiyirickal

2008-01-01

Full Text Available Biomechanical preparation alone does not completely eradicate microorganisms from the root canal, hence the next logical step is to perform root canal procedures in conjunction with antimicrobials. The use of an antimicrobial agent improves the efficacy and prognosis of endodontic treatment. This review enumerates the most widely used antimicrobial agents, their mechanism of action and their potential use in reducing the microbial load.

Dialogues for Embodied Agents in Virtual Environments

NARCIS (Netherlands)

op den Akker, Hendrikus J.A.; Nijholt, Antinus; Christodoulakis, D.N.

2000-01-01

This paper is a progress report on our research, design, and implementation of a virtual reality environment where users (visitors, customers) can interact with agents that help them to obtain information, to perform certain transactions and to collaborate with them in order to get some tasks done.

Magnetic nanoparticles as contrast agents for molecular imaging in medicine

Science.gov (United States)

O'Donnell, Matthew

2018-05-01

For over twenty years, superparamagnetic nanoparticles have been developed for a number of medical applications ranging from bioseparations, magnetic drug targeting, hyperthermia and imaging. Recent studies have shown that they can be functionalized for in vivo biological targeting, potentially enabling nanoagents for molecular imaging and site-localized drug delivery. Here we review several imaging technologies developed using functionalized superparamagnetic iron oxide nanoparticles (SPIONs) as targeted molecular agents. Several imaging modalities have exploited the large induced magnetic moment of SPIONs to create local mechanical force. Magnetic force microscopy can probe nanoparticle uptake in single cells. For in vivo applications, magnetomotive modulation of primary images in ultrasound (US), photoacoustics (PA), and optical coherence tomography (OCT) can help identify very small concentrations of nanoagents while simultaneously suppressing intrinsic background signals from tissue.

Fundamentals of Agent Perception and Attention Modelling

DEFF Research Database (Denmark)

Peters, Christopher; Castellano, Ginevra; Rehm, Matthias

2011-01-01

Perception and attention mechanisms are of great importance for entities situated within complex dynamic environments. With roles extending greatly beyond passive information services about the external environment, such mechanisms actively prioritise, augment and expedite information to ensure t...... agents can achieve a more substantial connection with their environment for the purposes of reacting, planning, decision making and, ultimately, behaving.......Perception and attention mechanisms are of great importance for entities situated within complex dynamic environments. With roles extending greatly beyond passive information services about the external environment, such mechanisms actively prioritise, augment and expedite information to ensure...... that the potentially relevant is made available so appropriate action can take place. Here, we describe the rationale behind endowing artificial entities, or virtual agents, with real-time perception and attention systems. We cover the fundamentals of designing and building such systems. Once equipped, the resulting...

A technology path to tactical agent-based modeling

Science.gov (United States)

James, Alex; Hanratty, Timothy P.

2017-05-01

Wargaming is a process of thinking through and visualizing events that could occur during a possible course of action. Over the past 200 years, wargaming has matured into a set of formalized processes. One area of growing interest is the application of agent-based modeling. Agent-based modeling and its additional supporting technologies has potential to introduce a third-generation wargaming capability to the Army, creating a positive overmatch decision-making capability. In its simplest form, agent-based modeling is a computational technique that helps the modeler understand and simulate how the "whole of a system" responds to change over time. It provides a decentralized method of looking at situations where individual agents are instantiated within an environment, interact with each other, and empowered to make their own decisions. However, this technology is not without its own risks and limitations. This paper explores a technology roadmap, identifying research topics that could realize agent-based modeling within a tactical wargaming context.

Common Agents used in parasuicide in Buffalo City

Directory of Open Access Journals (Sweden)

Kiran Sukeri

2009-10-01

Full Text Available Background. Parasuicide is a serious public health concern. Understanding the methods used will help in developing preventive strategies. Objective. To investigate the agent(s used in parasuicide attempts by individuals aged 10 - 20 years in Buffalo City (which includes the municipalities of East London, King William’s Town and Bhisho in the Eastern Cape. Method. All referrals for parasuicide to the East London Mental Health Unit, the only mental health facility servicing Buffalo City, for the period January 2006 to December 2008 were analysed with regard to age, agent(s, number of attempts and psychiatric disorder. Results. Of 1 169 patients referred after parasuicide by ingestion of substances, 360 (31% were between the ages of 10 and 20 years. Eighty-three per cent were female and 17% male. Cattle dip was the commonest agent used, followed by amitriptyline. Conclusion. The study showed that organophosphates were the commonest agent used in parasuicide in Buffalo City and that the incidence of parasuicide was higher in females than in males.

Anti-Infectious Agents against MRSA

Directory of Open Access Journals (Sweden)

Nobuhiro Koyama

2012-12-01

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

Putting Ethics on the Agenda for Real Estate Agents

OpenAIRE

Brinkmann, Johannes

2009-01-01

A post-print of an article originally published in Journal of Business Ethics: http://www.springer.com/philosophy/ethics/journal/10551 This article uses sociological role theory to help understand ethical challenges faced by Norwegian real estate agents. The article begins with an introductory case, and then briefly examines the strengths and limitations of using legal definitions and rules for understanding real estate agency and real estate agent ethics. It goes on to a...

Online self-help forums on cannabis: A content assessment.

Science.gov (United States)

Greiner, Christian; Chatton, Anne; Khazaal, Yasser

2017-10-01

To investigate online self-help forums related to cannabis users who were searching for help on the Internet. We analyzed the content of 717 postings by 328 users in three online forums in terms of fields of interest and self-help mechanisms. Only English-language forums that were free of charge and without registration were investigated. The main self-help mechanisms were disclosure and symptoms, with relatively few posts concerning legal issues and social perceptions. The forums differed significantly in all fields of interest and self-help mechanisms except for social network and financial and vocational issues. Highly involved users more commonly posted on topics related to diagnosis, etiology/research, and provision of information and less commonly on those related to gratitude. Correlation analysis showed a moderate negative correlation between emotional support and illness-related aspects and between emotional support and exchange of information. Cannabis forums share similarities with other mental health forums. Posts differ according to user involvement and the specific orientation of the forum. The Internet offers a viable source of self-help and social support for cannabis users, which has potential clinical implications in terms of referring clients to specific forums. Copyright © 2017 Elsevier B.V. All rights reserved.

Benzotriazole as a passivating agent during chemical mechanical planarization of Ni–P alloy substrates

International Nuclear Information System (INIS)

Mu, Yan; Zhong, Mingjie; Rushing, Kenneth J.; Li, Yuzhuo; Shipp, Devon A.

2014-01-01

Highlights: • Benzotriazole (BTA) is used to passivate the Chemical Mechanical Planarization of Ni-P alloys. • BTA significantly decreases the average R a of the polished surfaces at low concentrations. • XPS, AFM and electrochemical studies are used to probe passivation effects of BTA on Ni–P surfaces. • Findings potentially impact hard disk drive manufacturing processes. - Abstract: With the rapid increase of data storage density on computer hard disk drives (HDDs), the operation distance between read/write head and disk surface has fallen to just a few nanometers. Chemical mechanical planarization (CMP) has been selected as the best process to produce high quality surface finish during the manufacturing of Ni–P alloy substrates for HDD applications. Herein we report, for the first time, the use of benzotriazole (BTA) as a passivating agent in CMP slurries to decrease the surface roughness (R a ). Results show that the average R a of the polished surfaces is decreased to 0.2 nm in a 5 μm × 5 μm scan area with the adding of 2 mM BTA. X-ray photoelectron spectroscopy (XPS) and electrochemical studies results further prove the interaction between BTA and Ni–P surface and the formation of an effective passivating layer on Cu in CMP slurries containing BTA

Assurance in Agent-Based Systems

Energy Technology Data Exchange (ETDEWEB)

Gilliom, Laura R.; Goldsmith, Steven Y.

1999-05-10

Our vision of the future of information systems is one that includes engineered collectives of software agents which are situated in an environment over years and which increasingly improve the performance of the overall system of which they are a part. At a minimum, the movement of agent and multi-agent technology into National Security applications, including their use in information assurance, is apparent today. The use of deliberative, autonomous agents in high-consequence/high-security applications will require a commensurate level of protection and confidence in the predictability of system-level behavior. At Sandia National Laboratories, we have defined and are addressing a research agenda that integrates the surety (safety, security, and reliability) into agent-based systems at a deep level. Surety is addressed at multiple levels: The integrity of individual agents must be protected by addressing potential failure modes and vulnerabilities to malevolent threats. Providing for the surety of the collective requires attention to communications surety issues and mechanisms for identifying and working with trusted collaborators. At the highest level, using agent-based collectives within a large-scale distributed system requires the development of principled design methods to deliver the desired emergent performance or surety characteristics. This position paper will outline the research directions underway at Sandia, will discuss relevant work being performed elsewhere, and will report progress to date toward assurance in agent-based systems.

Assurance in Agent-Based Systems

International Nuclear Information System (INIS)

Gilliom, Laura R.; Goldsmith, Steven Y.

1999-01-01

Our vision of the future of information systems is one that includes engineered collectives of software agents which are situated in an environment over years and which increasingly improve the performance of the overall system of which they are a part. At a minimum, the movement of agent and multi-agent technology into National Security applications, including their use in information assurance, is apparent today. The use of deliberative, autonomous agents in high-consequence/high-security applications will require a commensurate level of protection and confidence in the predictability of system-level behavior. At Sandia National Laboratories, we have defined and are addressing a research agenda that integrates the surety (safety, security, and reliability) into agent-based systems at a deep level. Surety is addressed at multiple levels: The integrity of individual agents must be protected by addressing potential failure modes and vulnerabilities to malevolent threats. Providing for the surety of the collective requires attention to communications surety issues and mechanisms for identifying and working with trusted collaborators. At the highest level, using agent-based collectives within a large-scale distributed system requires the development of principled design methods to deliver the desired emergent performance or surety characteristics. This position paper will outline the research directions underway at Sandia, will discuss relevant work being performed elsewhere, and will report progress to date toward assurance in agent-based systems

The use of monoamine pharmacological agents in the treatment of sexual dysfunction: evidence in the literature.

Science.gov (United States)

Moll, Jennifer L; Brown, Candace S

2011-04-01

The monoamine neurotransmitters serotonin, dopamine, and norepinephrine play an important role in many medical and psychological conditions, including sexual responsiveness and behavior. Pharmacological agents that modulate monoamines may help alleviate sexual dysfunction. To provide an overview of pharmacological agents that modulate monoamines and their use in the treatment of sexual dysfunction. EMBASE and PubMed search for articles published between 1950 and 2010 using key words "sexual dysfunction,"monoamines,"monoaminergic receptors," and "generic names for pharmacological agents." To assess the literature evaluating the efficacy of monoamine pharmacologic agents used in the treatment of sexual dysfunction. The literature primarily cites the use of monoaminergic agents to treat sexual side effects from serotonergic reuptake inhibitors (SSRIs), with bupropion, buspirone and ropinirole providing the most convincing evidence. Controlled trials have shown that bupropion improves overall sexual dysfunction, but not frequency of sexual activity in depressed and nondepressed patients. Nefazodone and apomorphine have been used to treat sexual dysfunction, but their use is limited by significant side effect and safety profiles. New research on pharmacologic agents with subtype selectivity at dopaminergic and serotonergic receptors and those that possess dual mechanisms of action are being investigated. There has been tremendous progress over the past 50 years in understanding the role of monoamines in sexual function and the effect of pharmacologic agents which stimulate or antagonize monoaminergic receptors on sexual dysfunction. Nevertheless, large, double-blind, placebo-controlled studies evaluating the efficacy of currently available agents in populations without comorbid disorders are limited, preventing adequate interpretation of data. Continued research on sexual function and specific receptor subtypes will result in the development of more selective

Military chemical warfare agent human subjects testing: part 2--long-term health effects among participants of U.S. military chemical warfare agent testing.

Science.gov (United States)

Brown, Mark

2009-10-01

Military chemical warfare agent testing from World War I to 1975 produced thousands of veterans with concerns about how their participation affected their health. A companion article describes the history of these experiments, and how the lack of clinical data hampers evaluation of long-term health consequences. Conversely, much information is available about specific agents tested and their long-term health effects in other populations, which may be invaluable for helping clinicians respond effectively to the health care and other needs of affected veterans. The following review describes tested agents and their known long-term health consequences. Although hundreds of chemicals were tested, they fall into only about a half-dozen pharmaceutical classes, including common pharmaceuticals; anticholinesterase agents including military nerve agents and pesticides; anticholinergic glycolic acid esters such as atropine; acetylcholine reactivators such as 2-PAM; psychoactive compounds including cannabinoids, phencyclidine, and LSD; and irritants including tear gas and riot control agents.

Socialization Agents and Activities of Young Adolescents

Science.gov (United States)

Arnon, Sara; Shamai, Shmuel; Ilatov, Zinaida

2008-01-01

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

A Neurocomputational Model of Goal-Directed Navigation in Insect-Inspired Artificial Agents

DEFF Research Database (Denmark)

Goldschmidt, Dennis; Manoonpong, Poramate; Dasgupta, Sakyasingha

2017-01-01

in artificial agents. The model consists of a path integration mechanism, reward-modulated global learning, random search, and action selection. The path integration mechanism integrates compass and odometric cues to compute a vectorial representation of the agent's current location as neural activity patterns...

Agents That Negotiate Proficiently with People

Science.gov (United States)

Kraus, Sarit

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

Cyber-support: an analysis of online self-help forums (online self-help forums in bipolar disorder).

Science.gov (United States)

Bauer, Rita; Bauer, Michael; Spiessl, Hermann; Kagerbauer, Tanja

2013-06-01

The Internet is becoming increasingly important in psychiatry and psychotherapy. The objective of this study was to evaluate if and how online self-help forums are used by patients with bipolar disorders, their relatives and treating professionals. A total of 2400 postings in two online forums were analysed qualitatively and quantitatively. "Disclosure", "friendship" and "online-group cohesion" were the main self-help mechanisms. The topics most discussed were "social network", "symptoms of the illness" and "medication". Factor analyses revealed three factors concerning self-help mechanisms: "group cohesion", "emotional support" and "exchange of information", as well as three factors concerning fields of interest: "illness-related aspects", "social aspects" and "financial and legal issues". We infer that the main interest in participating in online forums for patients with bipolar disorders and their relatives is to share emotions and to discuss their daily struggles with the illness. Our study also reveals that social networking is very important for patients coping with bipolar disorders. Psycho-educative programmes should focus on those aspects.

Multi-Agent Market Modeling of Foreign Exchange Rates

Science.gov (United States)

Zimmermann, Georg; Neuneier, Ralph; Grothmann, Ralph

A market mechanism is basically driven by a superposition of decisions of many agents optimizing their profit. The oeconomic price dynamic is a consequence of the cumulated excess demand/supply created on this micro level. The behavior analysis of a small number of agents is well understood through the game theory. In case of a large number of agents one may use the limiting case that an individual agent does not have an influence on the market, which allows the aggregation of agents by statistic methods. In contrast to this restriction, we can omit the assumption of an atomic market structure, if we model the market through a multi-agent approach. The contribution of the mathematical theory of neural networks to the market price formation is mostly seen on the econometric side: neural networks allow the fitting of high dimensional nonlinear dynamic models. Furthermore, in our opinion, there is a close relationship between economics and the modeling ability of neural networks because a neuron can be interpreted as a simple model of decision making. With this in mind, a neural network models the interaction of many decisions and, hence, can be interpreted as the price formation mechanism of a market.

Effect of Amount of 3-Methacryloxy Propyl Thrimethoxysilane Coupling Agent and Nano Filling Structure on Physic-Mechanical Properties of Dental Resin Composite

Directory of Open Access Journals (Sweden)

Farbod Tondnevis

2017-07-01

Full Text Available Many researchers in the field of dental polymeric base nano composite investigated the effect filling morphology and filling material content on mechanical and physical properties of construction after setting reaction. Our present study concentrated on the effect of ϒ metacryloxy propyloxt tri metoxy silane (ϒ MPS content as coupling agent (orgnic material on physical and mechanical performance of nano composite material. It was shown that despite of contraction after setting reaction, all this properties improved and efficient silanization can efficiently affect structural integrity of dental filling nano composite

Organic Colouring Agents in the Pharmaceutical Industry

Directory of Open Access Journals (Sweden)

Šuleková M.

2017-09-01

Full Text Available Food dyes are largely used in the process of manufacturing pharmaceutical products. The aim of such a procedure is not only to increase the attractiveness of products, but also to help patients distinguish between pharmaceuticals. Various dyes, especially organic colouring agents, may in some cases have a negative impact on the human body. They are incorporated into pharmaceutical products including tablets, hard gelatine capsules or soft gelatine capsules, lozenges, syrups, etc. This article provides an overview of the most widely used colouring agents in pharmaceuticals, their characteristics and the EU legislation which regulates their use.

Organized dentistry as an agent for helping others: the leadership of Donna J. Rumberger.

Science.gov (United States)

Rule, James T; Bebeau, Muriel J

2003-09-01

Dr Donna Rumberger graduated from New York University College of Dentistry in 1980 and has practiced dentistry in Manhattan ever since. Even before her graduation, she was active in organized dentistry, always viewing it as a conduit for helping other people. Working with the American Association of Women Dentists, she was cofounder of the Smiles for Success Foundation, a program started in New York City that helps women advance from welfare into the workforce with restored, healthy smiles. That program now has expanded to 14 other cities. Working with organized dentistry in New York City, she has been instrumental in initiating and running the Skate Safe program, which provides mouthguards and oral home care education for inner city children in Harlem. In addition, she has worked with the dentistry merit badge program for the Boy Scouts of America Jamborees, helped coalesce women's dental organizations in New York City, and led her dental society to collaborate with Columbia University in a program to improve access to dental care. As further evidence of her ability to get things done, she also has served as president of the American Association of Women Dentists, the Midtown Dental Society, and the New York County Dental Society--one of the largest dental societies in the country.

Gadolinium-based contrast agent toxicity: a review of known and proposed mechanisms.

Science.gov (United States)

Rogosnitzky, Moshe; Branch, Stacy

2016-06-01

Gadolinium chelates are widely used as contrast media for magnetic resonance imaging. The approved gadolinium-based contrast agents (GBCAs) have historically been considered safe and well tolerated when used at recommended dosing levels. However, for nearly a decade, an association between GBCA administration and the development of nephrogenic systemic fibrosis (NSF) has been recognized in patients with severe renal impairment. This has led to modifications in clinical practices aimed at reducing the potential and incidence of NSF development. Newer reports have emerged regarding the accumulation of gadolinium in various tissues of patients who do not have renal impairment, including bone, brain, and kidneys. Despite the observations of gadolinium accumulation in tissues regardless of renal function, very limited clinical data regarding the potential for and mechanisms of toxicity is available. This significant gap in knowledge warrants retrospective cohort study efforts, as well as prospective studies that involve gadolinium ion (Gd(3+)) testing in patients exposed to GBCA. This review examines the potential biochemical and molecular basis of gadolinium toxicity, possible clinical significance of gadolinium tissue retention and accumulation, and methods that can limit gadolinium body burden.

Synthesis, Biological Evaluation, and Autophagy Mechanism of 12N-Substituted Sophoridinamines as Novel Anticancer Agents.

Science.gov (United States)

Bi, Chongwen; Zhang, Na; Yang, Peng; Ye, Cheng; Wang, Yanxiang; Fan, Tianyun; Shao, Rongguang; Deng, Hongbin; Song, Danqing

2017-02-09

A series of 12 N -substituted sophoridinamine derivatives were synthesized and evaluated for their cytotoxic activities in human HepG2 hepatoma cells. Structure-activity relationship revealed that introduction of a suitable arylidene or arylethyl at the N '-end could greatly enhance antiproliferation potency. Among them, compound 6b possessing a N '-trimethoxyphenyl methylene exhibited potent antiproliferation effect against three human tumor cell lines including HepG2, leukemia (K562), and breast cancer (HMLE), with IC 50 between 0.55 and 1.7 μM. The underlying mechanism of 6b against tumor cells is to block autophagic flux, mainly through neutralizing lysosomal acidity. Our results indicated that compound 6b is a potent lysosomal deacidification agent and is accordingly able to block autophagic flux and inhibit tumor cell growth.

Properties of realgar bioleaching using an extremely acidophilic bacterium and its antitumor mechanism as an anticancer agent.

Science.gov (United States)

Chen, Peng; Xu, Ruixiang; Yan, Lei; Wu, Zhengrong; Wei, Yan; Zhao, Wenbin; Wang, Xin; Xie, Qinjian; Li, Hongyu

2017-05-22

Realgar is a naturally occurring arsenic sulfide (or Xionghuang, in Chinese). It contains over 90% tetra-arsenic tetra-sulfide (As 4 S 4 ). Currently, realgar has been confirmed the antitumor activities, both in vitro and in vivo, of realgar extracted using Acidithiobacillus ferrooxidans (A. ferrooxidans). Bioleaching, a new technology to greatly improve the use rate of arsenic extraction from realgar using bacteria, is a novel methodology that addressed a limitation of the traditional method for realgar preparation. The present systematic review reports on the research progress in realgar bioleaching and its antitumor mechanism as an anticancer agent. A total of 93 research articles that report on the biological activity of extracts from realgar using bacteria and its preparation were presented in this review. The realgar bioleaching solution (RBS) works by inducing apoptosis when it is used to treat tumor cells in vitro and in vivo. When it is used to treat animal model organisms in vivo, such as mice and Caenorhabditis elegans, tumor tissues grew more slowly, with mass necrosis. Meanwhile, the agent also showed obvious inhibition of tumor cell growth. Bioleaching technology greatly improves the utilization of realgar and is a novel methodology to improve the traditional method.

Trust Level and Routing Selection for Mobile Agents in a Smart Home (Extended version)

NARCIS (Netherlands)

Nasution, S.; Hartel, Pieter H.; Suryana, N.; Azman, N.; Shahib, S.

The central security concern for systems where agents roam is how to establish trust in the agent. We present a Fuzzy Logic mechanism to calculate a level of trust and an optimal route for a mobile agent system in a smart home. The mechanism consists of two parts. The first part calculates a trust

Multi-agent grid system Agent-GRID with dynamic load balancing of cluster nodes

Science.gov (United States)

Satymbekov, M. N.; Pak, I. T.; Naizabayeva, L.; Nurzhanov, Ch. A.

2017-12-01

In this study the work presents the system designed for automated load balancing of the contributor by analysing the load of compute nodes and the subsequent migration of virtual machines from loaded nodes to less loaded ones. This system increases the performance of cluster nodes and helps in the timely processing of data. A grid system balances the work of cluster nodes the relevance of the system is the award of multi-agent balancing for the solution of such problems.

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.

Help to perpetuate traditional gender roles: Benevolent sexism increases engagement in dependency-oriented cross-gender helping.

Science.gov (United States)

Shnabel, Nurit; Bar-Anan, Yoav; Kende, Anna; Bareket, Orly; Lazar, Yael

2016-01-01

Based on theorizing that helping relations may serve as a subtle mechanism to reinforce intergroup inequality, the present research (N = 1,315) examined the relation between benevolent sexism (i.e., a chivalrous yet subtly oppressive view of women) and helping. In cross-gender interactions, the endorsement of (Studies 1, 3, and 4) or exposure to (Study 2) benevolent sexism predicted (a) men's preference to provide women with dependency-oriented help (i.e., direct assistance) rather than tools for autonomous coping, and (b) women's preference to seek dependency-oriented help rather than tools for autonomous coping. Benevolent sexism did not predict men's and women's engagement in dependency-oriented helping relations in same-gender interactions. Studies 1 and 2 examined behavioral intentions in response to a series of hypothetical scenarios; Studies 3 and 4 examined actual behavior in tests of mathematical and logical ability, and pointed to assumed partner's expectations as a potential mediator. The converging evidence supports the hypothesis that benevolent sexism encourages engagement in cross-gender helping relations that perpetuate traditional gender roles. (c) 2016 APA, all rights reserved).

Xanthone and Flavone Derivatives as Dual Agents with Acetylcholinesterase Inhibition and Antioxidant Activity as Potential Anti-Alzheimer Agents

Directory of Open Access Journals (Sweden)

Inês Cruz

2017-01-01

Full Text Available Alzheimer’s disease (AD is a multifactorial neurodegenerative disorder that is associated with the elderly. The current therapy that is used to treat AD is based mainly on the administration of acetylcholinesterase (AChE inhibitors. Due to their low efficacy there is a considerable need for other therapeutic strategies. Considering that the malfunctions of different, but interconnected, biochemical complex pathways play an important role in the pathogenesis of this disease, a promising therapy may consist in administration of drugs that act on more than a target on biochemical scenery of AD. In this work, the synthesis and evaluation of xanthone and flavone derivatives as antioxidants with AChE inhibitory activity were accomplished. Among the obtained compounds, Mannich bases 3 and 14 showed capacity to inhibit AChE and antioxidant property, exerting dual activity. Moreover, for the most promising AChE inhibitors, docking studies on the target have been performed aiming to predict the binding mechanism. The results presented here may help to identify new xanthone and flavone derivatives as dual anti-Alzheimer agents with AChE inhibitory and antioxidant activities.

Recent advances in agent-based complex automated negotiation

CERN Document Server

Ito, Takayuki; Zhang, Minjie; Fujita, Katsuhide; Robu, Valentin

2016-01-01

This book covers recent advances in Complex Automated Negotiations as a widely studied emerging area in the field of Autonomous Agents and Multi-Agent Systems. The book includes selected revised and extended papers from the 7th International Workshop on Agent-Based Complex Automated Negotiation (ACAN2014), which was held in Paris, France, in May 2014. The book also includes brief introductions about Agent-based Complex Automated Negotiation which are based on tutorials provided in the workshop, and brief summaries and descriptions about the ANAC'14 (Automated Negotiating Agents Competition) competition, where authors of selected finalist agents explain the strategies and the ideas used by them. The book is targeted to academic and industrial researchers in various communities of autonomous agents and multi-agent systems, such as agreement technology, mechanism design, electronic commerce, related areas, as well as graduate, undergraduate, and PhD students working in those areas or having interest in them.

Quantum entanglement helps in improving economic efficiency

International Nuclear Information System (INIS)

Du Jiangfeng; Ju Chenyong; Li Hui

2005-01-01

We propose an economic regulation approach based on quantum game theory for the government to reduce the abuses of oligopolistic competition. Theoretical analysis shows that this approach can help government improve the economic efficiency of the oligopolistic market, and help prevent monopoly due to incorrect information. These advantages are completely attributed to the quantum entanglement, a unique quantum mechanical character

Quantum entanglement helps in improving economic efficiency

Science.gov (United States)

Du, Jiangfeng; Ju, Chenyong; Li, Hui

2005-02-01

We propose an economic regulation approach based on quantum game theory for the government to reduce the abuses of oligopolistic competition. Theoretical analysis shows that this approach can help government improve the economic efficiency of the oligopolistic market, and help prevent monopoly due to incorrect information. These advantages are completely attributed to the quantum entanglement, a unique quantum mechanical character.

Smart Contrast Agents for Magnetic Resonance Imaging.

Science.gov (United States)

Bonnet, Célia S; Tóth, Éva

2016-01-01

By visualizing bioactive molecules or biological parameters in vivo, molecular imaging is searching for information at the molecular level in living organisms. In addition to contributing to earlier and more personalized diagnosis in medicine, it also helps understand and rationalize the molecular factors underlying physiological and pathological processes. In magnetic resonance imaging (MRI), complexes of paramagnetic metal ions, mostly lanthanides, are commonly used to enhance the intrinsic image contrast. They rely either on the relaxation effect of these metal chelates (T(1) agents), or on the phenomenon of paramagnetic chemical exchange saturation transfer (PARACEST agents). In both cases, responsive molecular magnetic resonance imaging probes can be designed to report on various biomarkers of biological interest. In this context, we review recent work in the literature and from our group on responsive T(1) and PARACEST MRI agents for the detection of biogenic metal ions (such as calcium or zinc), enzymatic activities, or neurotransmitter release. These examples illustrate the general strategies that can be applied to create molecular imaging agents with an MRI detectable response to biologically relevant parameters.

Quality of service agents in the internet

OpenAIRE

Schelén, Olov

1998-01-01

The Internet is a multi-purpose communication network supporting users and applications with different service demands. To meet these demands, mechanisms for service differentiation in the network are proposed. This thesis presents an admission control architecture where clients can make resource reservations through agents. For each domain in the network there is an agent responsible for admission control. The architecture provides scalable resource reservations for virtual leased lines. Res...

A novel plastification agent for cemented carbides extrusion molding

International Nuclear Information System (INIS)

Ji-Cheng Zhou; Bai-Yun Huang

2001-01-01

A type of novel plastification agent for plasticizing powder extrusion molding of cemented carbides has been developed. By optimizing their formulation and fabrication method, the novel plastification agent, with excellent properties and uniform distribution characters, were manufactured. The thermal debinding mechanism has been studied, the extruding rheological characteristics and debinding behaviors have been investigated. Using the newly developed plastification agent, the cemented carbides extrusion rods, with diameter up to 25 mm, have been manufactured. (author)

Cognitive conflict without explicit conflict monitoring in a dynamical agent.

Science.gov (United States)

Ward, Robert; Ward, Ronnie

2006-11-01

We examine mechanisms for resolving cognitive conflict in an embodied, situated, and dynamic agent, developed through an evolutionary learning process. The agent was required to solve problems of response conflict in a dual-target "catching" task, focusing response on one of the targets while ignoring the other. Conflict in the agent was revealed at the behavioral level in terms of increased latencies to the second target. This behavioral interference was correlated to peak violations of the network's stable state equation. At the level of the agent's neural network, peak violations were also correlated to periods of disagreement in source inputs to the agent's motor effectors. Despite observing conflict at these numerous levels, we did not find any explicit conflict monitoring mechanisms within the agent. We instead found evidence of a distributed conflict management system, characterized by competitive sources within the network. In contrast to the conflict monitoring hypothesis [Botvinick, M. M., Braver, T. S., Barch, D. M., Carter, C. S., & Cohen, J. D. (2001). Conflict monitoring and cognitive control. Psychological Review, 108(3), 624-652], this agent demonstrates that resolution of cognitive conflict does not require explicit conflict monitoring. We consider the implications of our results for the conflict monitoring hypothesis.

Properties of realgar bioleaching using an extremely acidophilic bacterium and its antitumor mechanism as an anticancer agent

Directory of Open Access Journals (Sweden)

Peng Chen

Full Text Available Abstract Realgar is a naturally occurring arsenic sulfide (or Xionghuang, in Chinese. It contains over 90% tetra-arsenic tetrasulfide (As4S4. Currently, realgar has been confirmed the antitumor activities, both in vitro and in vivo, of realgar extracted using Acidithiobacillus ferrooxidans (A. ferrooxidans. Bioleaching, a new technology to greatly improve the use rate of arsenic extraction from realgar using bacteria, is a novel methodology that addressed a limitation of the traditional method for realgar preparation. The present systematic review reports on the research progress in realgar bioleaching and its antitumor mechanism as an anticancer agent. A total of 93 research articles that report on the biological activity of extracts from realgar using bacteria and its preparation were presented in this review. The realgar bioleaching solution (RBS works by inducing apoptosis when it is used to treat tumor cells in vitro and in vivo. When it is used to treat animal model organisms in vivo, such as mice and Caenorhabditis elegans, tumor tissues grew more slowly, with mass necrosis. Meanwhile, the agent also showed obvious inhibition of tumor cell growth. Bioleaching technology greatly improves the utilization of realgar and is a novel methodology to improve the traditional method.

MARS, a Multi-Agent System for Assessing Rowers’ Coordination via Motion-Based Stigmergy

Directory of Open Access Journals (Sweden)

Mario G. C. A. Cimino

2013-09-01

Full Text Available A crucial aspect in rowing is having a synchronized, highly-efficient stroke. This is very difficult to obtain, due to the many interacting factors that each rower of the crew must perceive. Having a system that monitors and represents the crew coordination would be of great help to the coach during training sessions. In the literature, some methods already employ wireless sensors for capturing motion patterns that affect rowing performance. A challenging problem is to support the coach’s decisions at his same level of knowledge, using a limited number of sensors and avoiding the complexity of the biomechanical analysis of human movements. In this paper, we present a multi-agent information-processing system for on-water measuring of both the overall crew asynchrony and the individual rower asynchrony towards the crew. More specifically, in the system, the first level of processing is managed by marking agents, which release marks in a sensing space, according to the rowers’ motion. The accumulation of marks enables a stigmergic cooperation mechanism, generating collective marks, i.e., short-term memory structures in the sensing space. At the second level of processing, information provided by marks is observed by similarity agents, which associate a similarity degree with respect to optimal marks. Finally, the third level is managed by granulation agents, which extract asynchrony indicators for different purposes. The effectiveness of the system has been experimented on real-world scenarios. The study includes the problem statement and its characterization in the literature, as well as the proposed solving approach and initial experimental setting.

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

Synthesis of Laboratory Ultrasound Contrast Agents

Directory of Open Access Journals (Sweden)

Jaemin Oh

2013-10-01

Full Text Available Ultrasound Contrast Agents (UCAs were developed to maximize reflection contrast so that organs can be seen clearly in ultrasound imaging. UCAs increase the signal to noise ratio (SNR by linear and non-linear mechanisms and thus help more accurately visualize the internal organs and blood vessels. However, the UCAs on the market are not only expensive, but are also not optimized for use in various therapeutic research applications such as ultrasound-aided drug delivery. The UCAs fabricated in this study utilize conventional lipid and albumin for shell formation and perfluorobutane as the internal gas. The shape and density of the UCA bubbles were verified by optical microscopy and Cryo SEM, and compared to those of the commercially available UCAs, Definity® and Sonovue®. The size distribution and characteristics of the reflected signal were also analyzed using a particle size analyzer and ultrasound imaging equipment. Our experiments indicate that UCAs composed of spherical microbubbles, the majority of which were smaller than 1 um, were successfully synthesized. Microbubbles 10 um or larger were also identified when different shell characteristics and filters were used. These laboratory UCAs can be used for research in both diagnoses and therapies.

Compensatory help-seeking in young and older adults: does seeking help, help?

Science.gov (United States)

Alea, Nicole; Cunningham, Walter R

2003-01-01

Asking other people for help is a compensatory behavior that may be useful across the life span to enhance functioning. Seventy-two older and younger men and women were either allowed to ask for help or were not allowed to ask for help while solving reasoning problems. Although the older adults answered fewer problems correctly, they did not seek additional help to compensate for their lower levels of performance. Younger adults sought more help. There were no age differences, however, in the types of help sought: indirect help (e.g., hints) was sought more often than direct help (e.g., asking for the answer). Exploratory analyses revealed that one's ability level was a better indicator than age of the utility of help-seeking. Findings are interpreted in the context of social and task-related influences on the use of help-seeking as a compensatory behavior across the life span.

A role based coordination model in agent systems

Institute of Scientific and Technical Information of China (English)

ZHANG Ya-ying; YOU Jin-yuan

2005-01-01

Coordination technology addresses the construction of open, flexible systems from active and independent software agents in concurrent and distributed systems. In most open distributed applications, multiple agents need interaction and communication to achieve their overall goal. Coordination technologies for the Internet typically are concerned with enabling interaction among agents and helping them cooperate with each other.At the same time, access control should also be considered to constrain interaction to make it harmless. Access control should be regarded as the security counterpart of coordination. At present, the combination of coordination and access control remains an open problem. Thus, we propose a role based coordination model with policy enforcement in agent application systems. In this model, coordination is combined with access control so as to fully characterize the interactions in agent systems. A set of agents interacting with each other for a common global system task constitutes a coordination group. Role based access control is applied in this model to prevent unauthorized accesses. Coordination policy is enforced in a distributed manner so that the model can be applied to the open distributed systems such as Intemet. An Internet online auction system is presented as a case study to illustrate the proposed coordination model and finally the performance analysis of the model is introduced.

Anticlotting agents and the surgical management of glaucoma.

Science.gov (United States)

Sozeri, Yasemin; Salim, Sarwat

2018-03-01

A large subset of patients with glaucoma uses anticlotting agents. No standardized guidelines currently exist for managing these agents in the specific perioperative setting of glaucoma surgery. The present review focuses on currently available anticlotting agents, their influence on hemorrhagic complications following glaucoma surgery, and management strategies for their use in the perioperative period RECENT FINDINGS: Anticlotting agents increase the risk of perioperative hemorrhagic complications following glaucoma surgery. Other factors that increase that risk have been identified as well, including the type of glaucoma surgery, preoperative intraocular pressure, postoperative hypotony, previous ocular surgeries, and race. Although general guidelines in the perioperative management of blood thinning agents exist, the best way to apply these guidelines specifically to glaucoma surgery remains unclear. Blood thinners are widely used and can increase the risk of hemorrhagic complications in patients undergoing glaucoma surgery. Managing these agents in the perioperative setting is challenging and should be done in collaboration with the patient's primary care provider, hematologist, or cardiologist. Management strategies should be tailored to each individual's risk of hemorrhage versus thromboembolism. Additionally, surgical plans can be modified to help minimize hemorrhagic outcomes, especially in patients who are deemed to be at high risk for perioperative bleeding.

Better with Byzantine: Manipulation-Optimal Mechanisms

Science.gov (United States)

Othman, Abraham; Sandholm, Tuomas

A mechanism is manipulable if it is in some agents’ best interest to misrepresent their private information. The revelation principle establishes that, roughly, anything that can be accomplished by a manipulable mechanism can also be accomplished with a truthful mechanism. Yet agents often fail to play their optimal manipulations due to computational limitations or various flavors of incompetence and cognitive biases. Thus, manipulable mechanisms in particular should anticipate byzantine play. We study manipulation-optimal mechanisms: mechanisms that are undominated by truthful mechanisms when agents act fully rationally, and do better than any truthful mechanism if any agent fails to act rationally in any way. This enables the mechanism designer to do better than the revelation principle would suggest, and obviates the need to predict byzantine agents’ irrational behavior. We prove a host of possibility and impossibility results for the concept which have the impression of broadly limiting possibility. These results are largely in line with the revelation principle, although the considerations are more subtle and the impossibility not universal.

Molecular mechanisms of adaptive response to alkylating agents in Escherichia coli and some remarks on O(6)-methylguanine DNA-methyltransferase in other organisms.

Science.gov (United States)

Kleibl, Karol

2002-09-01

Alkylating agents are environmental genotoxic agents with mutagenic and carcinogenic potential, however, their properties are also exploited in the treatment of malignant diseases. O(6)-Methylguanine is an important adduct formed by methylating agents that, if not repaired, can lead to mutations and death. Its repair is carried out by O(6)-methylguanine DNA-methyltransferase (MTase) in an unique reaction in which methyl groups are transferred to the cysteine acceptor site of the protein itself. Exposure of Escherichia coli cells to sublethal concentrations of methylating agents triggers the expression of a set of genes, which allows the cells to tolerate DNA lesions, and this kind of inducible repair is called the adaptive response. The MTase of E. coli, encoded by the ada gene was the first MTase to be discovered and one of best characterised. Its repair and regulatory mechanisms are understood in considerable detail and this bacterial protein played a key role in identification of its counterparts in other living organisms. This review summarises the nature of alkylation damage in DNA and our current knowledge about the adaptive response in E. coli. I also include a brief mention of MTases from other organisms with the emphasis on the human MTase, which could play a crucial role in both cancer prevention and cancer treatment.

Use of Internet for Innovation Management by Extension Agents in ...

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User

This study examined extension agents' perception of the use of the Internet for ... Internet platform can .... items. It ranged from always, occasionally and never, which were assigned 3, 2 and .... Market location 's to help farmers sell produce.

Agent-based simulation of a financial market

Science.gov (United States)

Raberto, Marco; Cincotti, Silvano; Focardi, Sergio M.; Marchesi, Michele

2001-10-01

This paper introduces an agent-based artificial financial market in which heterogeneous agents trade one single asset through a realistic trading mechanism for price formation. Agents are initially endowed with a finite amount of cash and a given finite portfolio of assets. There is no money-creation process; the total available cash is conserved in time. In each period, agents make random buy and sell decisions that are constrained by available resources, subject to clustering, and dependent on the volatility of previous periods. The model proposed herein is able to reproduce the leptokurtic shape of the probability density of log price returns and the clustering of volatility. Implemented using extreme programming and object-oriented technology, the simulator is a flexible computational experimental facility that can find applications in both academic and industrial research projects.

Carbon emissions trading scheme exploration in China: A multi-agent-based model

International Nuclear Information System (INIS)

Tang, Ling; Wu, Jiaqian; Yu, Lean; Bao, Qin

2015-01-01

To develop a low-carbon economy, China launched seven pilot programs for carbon emissions trading (CET) in 2011 and plans to establish a nationwide CET mechanism in 2015. This paper formulated a multi-agent-based model to investigate the impacts of different CET designs in order to find the most appropriate one for China. The proposed bottom-up model includes all main economic agents in a general equilibrium framework. The simulation results indicate that (1) CET would effectively reduce carbon emissions, with a certain negative impact on the economy, (2) as for allowance allocation, the grandfathering rule is relatively moderate, while the benchmarking rule is more aggressive, (3) as for the carbon price, when the price level in the secondary CET market is regulated to be around RMB 40 per metric ton, a satisfactory emission mitigation effect can be obtained, (4) the penalty rate is suggested to be carefully designed to balance the economy development and mitigation effect, and (5) subsidy policy for energy technology improvement can effectively reduce carbon emissions without an additional negative impact on the economy. The results also indicate that the proposed novel model is a promising tool for CET policy making and analyses. -- Highlights: •A multi-agent-based model is proposed for carbon emissions trading (CET) in China. •Three agents are included: government, firms in different sectors and households. •The impacts of CET on the economy and environment in China are analyzed. •Different CET designs are simulated to find an appropriate policy for China. •Results confirm the effectiveness of the model and give helpful insights into CET design

An approach to knowledge dynamic maintenance for emotional agents

OpenAIRE

Fulladoza Dalibón, Santiago E.; Martínez, Diego C.; Simari, Guillermo Ricardo

2014-01-01

In this work we present an approach to emotional reasoning for believable agents, by introducing a mechanism to progressively build a map of knowledge for reasoning. We present the notion of inference graph for progressive reasoning in an emotional context. In this model, knowledge is partially highlighted and noticed by the agent.

Modeling and simulating human teamwork behaviors using intelligent agents

Science.gov (United States)

Fan, Xiaocong; Yen, John

2004-12-01

Among researchers in multi-agent systems there has been growing interest in using intelligent agents to model and simulate human teamwork behaviors. Teamwork modeling is important for training humans in gaining collaborative skills, for supporting humans in making critical decisions by proactively gathering, fusing, and sharing information, and for building coherent teams with both humans and agents working effectively on intelligence-intensive problems. Teamwork modeling is also challenging because the research has spanned diverse disciplines from business management to cognitive science, human discourse, and distributed artificial intelligence. This article presents an extensive, but not exhaustive, list of work in the field, where the taxonomy is organized along two main dimensions: team social structure and social behaviors. Along the dimension of social structure, we consider agent-only teams and mixed human-agent teams. Along the dimension of social behaviors, we consider collaborative behaviors, communicative behaviors, helping behaviors, and the underpinning of effective teamwork-shared mental models. The contribution of this article is that it presents an organizational framework for analyzing a variety of teamwork simulation systems and for further studying simulated teamwork behaviors.

Agent-based simulation of electricity markets : a literature review

International Nuclear Information System (INIS)

Sensfuss, F.; Genoese, M.; Genoese, M.; Most, D.

2007-01-01

The electricity sector in Europe and North America is undergoing considerable changes as a result of deregulation, issues related to climate change, and the integration of renewable resources within the electricity grid. This article reviewed agent-based simulation methods of analyzing electricity markets. The paper provided an analysis of research currently being conducted on electricity market designs and examined methods of modelling agent decisions. Methods of coupling long term and short term decisions were also reviewed. Issues related to single and multiple market analysis methods were discussed, as well as different approaches to integrating agent-based models with models of other commodities. The integration of transmission constraints within agent-based models was also discussed, and methods of measuring market efficiency were evaluated. Other topics examined in the paper included approaches to integrating investment decisions, carbon dioxide (CO 2 ) trading, and renewable support schemes. It was concluded that agent-based models serve as a test bed for the electricity sector, and will help to provide insights for future policy decisions. 74 refs., 6 figs

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

Science.gov (United States)

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

2015-12-01

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

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

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H. Faroqi

2015-12-01

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

Application of Agent Methodology in Healthcare Information Systems

Directory of Open Access Journals (Sweden)

Reem Abdalla

2017-02-01

Full Text Available This paper presents a case study to describe the features and the phases of the two agent methodologies. The Gaia methodology for agent oriented analysis and design, Tropos is a detailed agent oriented software engineering methodology to explore each methodology's ability to present solutions for small problems. Also we provide an attempt to discover whether the methodology is in fact understandable and usable. In addition we were collecting and taking notes of the advantages and weaknesses of these methodologies during the study analysis for each methodology and the relationships among their models. The Guardian Angle: Patient-Centered Health Information System (GA: PCHIS is the personal system to help track, manage, and interpret the subject's health history, and give advice to both patient and provider is used as the case study throughout the paper.

Learning in engineered multi-agent systems

Science.gov (United States)

Menon, Anup

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

Agent and user inhabited virtual communities: A case study

NARCIS (Netherlands)

Nijholt, Antinus; Howlett, R.J.; Jain, L.C.

2000-01-01

We report about ongoing research in a virtual reality environment where visitors can interact with agents that help them to obtain information, to perform certain transactions and to collaborate with them in order to get some tasks done. This environment is a laboratory for research and experiments

The Analysis of Customer Purchase Intention of Houses Using Real Estate Agent in Manado Based on Psychological Factors

OpenAIRE

Ticoalu, Vinny O.

2015-01-01

Real estate agent business field is become a trend nowadays. Real estate agent helped customers to buy or sell a house. Psychological factors has an influence in real estate agent busniess, customers mostly asked the opinion from others about the real estate agent in case they do not want to choose a wrong real estate agent. This research aims to analyze the influence of psychological factors on customers purchase intention in using real estate agent in Manado. This research used a multiple l...

Multi-agent integrated password management (MIPM) application secured with encryption

Science.gov (United States)

Awang, Norkhushaini; Zukri, Nurul Hidayah Ahmad; Rashid, Nor Aimuni Md; Zulkifli, Zuhri Arafah; Nazri, Nor Afifah Mohd

2017-10-01

Users use weak passwords and reuse them on different websites and applications. Password managers are a solution to store login information for websites and help users log in automatically. This project developed a system that acts as an agent managing passwords. Multi-Agent Integrated Password Management (MIPM) is an application using encryption that provides users with secure storage of their login account information such as their username, emails and passwords. This project was developed on an Android platform with an encryption agent using Java Agent Development Environment (JADE). The purpose of the embedded agents is to act as a third-party software to ease the encryption process, and in the future, the developed encryption agents can form part of the security system. This application can be used by the computer and mobile users. Currently, users log into many applications causing them to use unique passwords to prevent password leaking. The crypto agent handles the encryption process using an Advanced Encryption Standard (AES) 128-bit encryption algorithm. As a whole, MIPM is developed on the Android application to provide a secure platform to store passwords and has high potential to be commercialised for public use.

Agent-oriented Modeling for Collaborative Learning Environments: A Peer-to-Peer Helpdesk Case Study

NARCIS (Netherlands)

Guizzardi-Silva Souza, R.; Wagner, G.; Aroyo, L.M.

2002-01-01

In this paper, we present the analysis and modelling of Help&Learn, an agent-based peer-to-peer helpdesk system to support extra-class interactions among students and teachers. Help&Learn expands the student’s possibility of solving problems, getting involved in a cooperative learning experience

Exploring the MACH Model’s Potential as a Metacognitive Tool to Help Undergraduate Students Monitor Their Explanations of Biological Mechanisms

Science.gov (United States)

Trujillo, Caleb M.; Anderson, Trevor R.; Pelaez, Nancy J.

2016-01-01

When undergraduate biology students learn to explain biological mechanisms, they face many challenges and may overestimate their understanding of living systems. Previously, we developed the MACH model of four components used by expert biologists to explain mechanisms: Methods, Analogies, Context, and How. This study explores the implementation of the model in an undergraduate biology classroom as an educational tool to address some of the known challenges. To find out how well students’ written explanations represent components of the MACH model before and after they were taught about it and why students think the MACH model was useful, we conducted an exploratory multiple case study with four interview participants. We characterize how two students explained biological mechanisms before and after a teaching intervention that used the MACH components. Inductive analysis of written explanations and interviews showed that MACH acted as an effective metacognitive tool for all four students by helping them to monitor their understanding, communicate explanations, and identify explanatory gaps. Further research, though, is needed to more fully substantiate the general usefulness of MACH for promoting students’ metacognition about their understanding of biological mechanisms. PMID:27252295

Emotions and Actions Associated with Altruistic Helping and Punishment

Directory of Open Access Journals (Sweden)

Omar Tonsi Eldakar

2006-01-01

Full Text Available Evolutionary altruism (defined in terms of fitness effects exists in the context of punishment in addition to helping. We examine the proximate psychological mechanisms that motivate altruistic helping and punishment, including the effects of genetic relatedness, potential for future interactions, and individual differences in propensity to help and punish. A cheater who is a genetic relative provokes a stronger emotional reaction than a cheater who is a stranger, but the behavioral response is modulated to avoid making the transgression public in the case of cheating relatives. Numerous behavioral differences are not accompanied by emotional differences, suggesting that other psychological mechanisms dictate the specific response to emotion-provoking events. Paradoxically, there is a positive correlation between temptation to cheat and propensity to punish others for cheating, leading to a concept of “selfish punishment” that has been substantiated by a computer simulation model. This study demonstrates that fictional scenarios can provide an important methodological tool for studying the psychological basis of helping and punishment.

Putative neuroprotective agents in neuropsychiatric disorders.

Science.gov (United States)

Dodd, Seetal; Maes, Michael; Anderson, George; Dean, Olivia M; Moylan, Steven; Berk, Michael

2013-04-05

In many individuals with major neuropsychiatric disorders including depression, bipolar disorder and schizophrenia, their disease characteristics are consistent with a neuroprogressive illness. This includes progressive structural brain changes, cognitive and functional decline, poorer treatment response and an increasing vulnerability to relapse with chronicity. The underlying molecular mechanisms of neuroprogression are thought to include neurotrophins and regulation of neurogenesis and apoptosis, neurotransmitters, inflammatory, oxidative and nitrosative stress, mitochondrial dysfunction, cortisol and the hypothalamic-pituitary-adrenal axis, and epigenetic influences. Knowledge of the involvement of each of these pathways implies that specific agents that act on some or multiple of these pathways may thus block this cascade and have neuroprotective properties. This paper reviews the potential of the most promising of these agents, including lithium and other known psychotropics, aspirin, minocycline, statins, N-acetylcysteine, leptin and melatonin. These agents are putative neuroprotective agents for schizophrenia and mood disorders. Copyright © 2012 Elsevier Inc. All rights reserved.

Family involvement and helping behaviour in teams

OpenAIRE

Brummelhuis, L.L. ten; Lippe, T. van der; Kluwer, E.S.

2010-01-01

Helping behavior at work has become increasingly important, with organizations making more and more use of cooperative work practices. The difficulty is that employees are facing growing demands beyond the workplace. This study investigates the mechanisms by which family involvement (family structure, family tasks, family support) affects helping behavior in teams. Based on a sample of 495 team members, the results show that having a supportive partner and performing care tasks increase helpi...

Design and Application of an Intelligent Agent for Web Information Discovery

Institute of Scientific and Technical Information of China (English)

闵君; 冯珊; 唐超; 许立达

2003-01-01

With the propagation of applications on the internet, the internet has become a great information source which supplies users with valuable information. But it is hard for users to quickly acquire the right information on the web. This paper an intelligent agent for internet applications to retrieve and extract web information under user's guidance. The intelligent agent is made up of a retrieval script to identify web sources, an extraction script based on the document object model to express extraction process, a data translator to export the extracted information into knowledge bases with frame structures, and a data reasoning to reply users' questions. A GUI tool named Script Writer helps to generate the extraction script visually, and knowledge rule databases help to extract wanted information and to generate the answer to questions.

A conceptual and computational model of moral decision making in human and artificial agents.

Science.gov (United States)

Wallach, Wendell; Franklin, Stan; Allen, Colin

2010-07-01

Recently, there has been a resurgence of interest in general, comprehensive models of human cognition. Such models aim to explain higher-order cognitive faculties, such as deliberation and planning. Given a computational representation, the validity of these models can be tested in computer simulations such as software agents or embodied robots. The push to implement computational models of this kind has created the field of artificial general intelligence (AGI). Moral decision making is arguably one of the most challenging tasks for computational approaches to higher-order cognition. The need for increasingly autonomous artificial agents to factor moral considerations into their choices and actions has given rise to another new field of inquiry variously known as Machine Morality, Machine Ethics, Roboethics, or Friendly AI. In this study, we discuss how LIDA, an AGI model of human cognition, can be adapted to model both affective and rational features of moral decision making. Using the LIDA model, we will demonstrate how moral decisions can be made in many domains using the same mechanisms that enable general decision making. Comprehensive models of human cognition typically aim for compatibility with recent research in the cognitive and neural sciences. Global workspace theory, proposed by the neuropsychologist Bernard Baars (1988), is a highly regarded model of human cognition that is currently being computationally instantiated in several software implementations. LIDA (Franklin, Baars, Ramamurthy, & Ventura, 2005) is one such computational implementation. LIDA is both a set of computational tools and an underlying model of human cognition, which provides mechanisms that are capable of explaining how an agent's selection of its next action arises from bottom-up collection of sensory data and top-down processes for making sense of its current situation. We will describe how the LIDA model helps integrate emotions into the human decision-making process, and we

A knowledge base architecture for distributed knowledge agents

Science.gov (United States)

Riedesel, Joel; Walls, Bryan

1990-01-01

A tuple space based object oriented model for knowledge base representation and interpretation is presented. An architecture for managing distributed knowledge agents is then implemented within the model. The general model is based upon a database implementation of a tuple space. Objects are then defined as an additional layer upon the database. The tuple space may or may not be distributed depending upon the database implementation. A language for representing knowledge and inference strategy is defined whose implementation takes advantage of the tuple space. The general model may then be instantiated in many different forms, each of which may be a distinct knowledge agent. Knowledge agents may communicate using tuple space mechanisms as in the LINDA model as well as using more well known message passing mechanisms. An implementation of the model is presented describing strategies used to keep inference tractable without giving up expressivity. An example applied to a power management and distribution network for Space Station Freedom is given.

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

International Nuclear Information System (INIS)

Bockman, R.; Adelman, R.; Donnelly, R.; Brody, L.; Warrell, R.; Jones, K.W.

1990-01-01

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

AN INTELLIGENT CONVERSATION AGENT FOR HEALTH CARE DOMAIN

Directory of Open Access Journals (Sweden)

K. Karpagam

2014-04-01

Full Text Available Human Computer Interaction is one of the pervasive application areas of computer science to develop with multimodal interaction for information sharings. The conversation agent acts as the major core area for developing interfaces between a system and user with applied AI for proper responses. In this paper, the interactive system plays a vital role in improving knowledge in the domain of health through the intelligent interface between machine and human with text and speech. The primary aim is to enrich the knowledge and help the user in the domain of health using conversation agent to offer immediate response with human companion feel.

Intelligent virtual agents as language trainers facilitate multilingualism.

Science.gov (United States)

Macedonia, Manuela; Groher, Iris; Roithmayr, Friedrich

2014-01-01

intelligent virtual agents (IVAs) with human appearance and the capability to teach foreign language vocabulary. We report results from studies that we have conducted with Billie, an IVA employed as a vocabulary trainer, as well as research findings on the acceptance of the agent as a trainer by adults and children. The results show that Billie can train humans as well as a human teacher can and that both adults and children accept the IVA as a trainer. The advantages of IVAs are multiple. First, their teaching methods can be based on neuropsychological research findings concerning memory and learning practice. Second, virtual teachers can provide individualized training. Third, they coach users during training, are always supportive, and motivate learners to train. Fourth, agents will reside in the user's mobile devices and thus be at the user's disposal everywhere and anytime. Agents in apps will make foreign language training accessible to anybody at low cost. This will enable people around the world, including physically, financially, and geographically disadvantaged persons, to learn a foreign language and help to facilitate multilingualism.

Qualitative Description and Quantitative Optimization of Tactical Reconnaissance Agents System Organization

Directory of Open Access Journals (Sweden)

Xiong Li

2012-08-01

Full Text Available In this paper, the problem of qualitative description and quantitative optimization for tactical reconnaissance agents system organization is considered with objective of higher teamwork efficiency and more reasonable task balancing strategies. By analyzing tactical reconnaissance system and its environment, task-(role-entity agent mapping mechanism and agents in system organization, the system framework is qualitatively described. By transforming the system into an interaction task request-service mechanism queuing system, a Markov chain of system state transition is obtained, since its state transition process in interaction is Markov process and accords with real tactical reconnaissance behaviors. By solving the state transition equations, the inherent relationship of tactical reconnaissance agents is found and the optimized system configuration is obtained. The established simulation demonstration system proves that the proposed approach and model are feasible and effective.

Polypropylenes foam consisting of thermally expandable microcapsule as blowing agent

Science.gov (United States)

Jeoung, Sun Kyung; Hwang, Ye Jin; Lee, Hyun Wook; Kwak, Sung Bok; Han, In-Soo; Ha, Jin Uk

2016-03-01

The structure of thermally expandable microcapsule (TEMs) is consisted of a thermoplastic shell which is filled with liquid hydrocarbon at core. The shell of TEMs becomes soft when the temperature is higher than boiling temperature of liquid hydrocarbon. The shell of TEMs is expanded under the high temperature because the inner pressure of TEMs is increased by vaporization of hydrocarbon core. Therefore, the TEMs are applicable for blowing agents and light weight fillers. In this research, we fabricated the polypropylene (PP) foam by using the TEMs and chemical blowing agents and compared to their physical properties. The density of the specimen was decreased when the contents of chemical blowing agents and TEMs were increased. In addition, the mechanical properties (i.e. tensile strength and impact strength) of specimens were deteriorated with increasing amount of chemical blowing agents and TEMs. However, PP foam produced with TEMs showed higher impact strength than the one with the chemical blowing agent. In order to clarify the dependence of impact strength of PP foam as the blowing agent, the morphology difference of the PP foams was investigated. Expanding properties of PP foams produced with TEMs was changed with TEMs content of PP foams. Processing conditions also influenced the mechanical properties of PP foam containing TEMs.

Multi-agent simulation of competitive electricity markets: Autonomous systems cooperation for European market modeling

International Nuclear Information System (INIS)

Santos, Gabriel; Pinto, Tiago; Morais, Hugo; Sousa, Tiago M.; Pereira, Ivo F.; Fernandes, Ricardo; Praça, Isabel; Vale, Zita

2015-01-01

Highlights: • Definition of an ontology allowing the communication between multi-agents systems. • Social welfare evaluation in different electricity markets. • Demonstration of the use of the proposed ontology between two multi-agents systems. • Strategic biding in electricity markets. • European electricity markets comparison. - Abstract: The electricity market restructuring, and its worldwide evolution into regional and even continental scales, along with the increasing necessity for an adequate integration of renewable energy sources, is resulting in a rising complexity in power systems operation. Several power system simulators have been developed in recent years with the purpose of helping operators, regulators, and involved players to understand and deal with this complex and constantly changing environment. The main contribution of this paper is given by the integration of several electricity market and power system models, respecting to the reality of different countries. This integration is done through the development of an upper ontology which integrates the essential concepts necessary to interpret all the available information. The continuous development of Multi-Agent System for Competitive Electricity Markets platform provides the means for the exemplification of the usefulness of this ontology. A case study using the proposed multi-agent platform is presented, considering a scenario based on real data that simulates the European Electricity Market environment, and comparing its performance using different market mechanisms. The main goal is to demonstrate the advantages that the integration of various market models and simulation platforms have for the study of the electricity markets’ evolution

Children's Attributions of Intentions to an Invisible Agent

Science.gov (United States)

Bering, Jesse M.; Parker, Becky D.

2006-01-01

Children ages 3-9 years were informed that an invisible agent (Princess Alice) would help them play a forced-choice game by "telling them, somehow, when they chose the wrong box," whereas a matched control group of children were not given this supernatural prime. On 2 unexpected event trials, an experimenter triggered a simulated unexpected event…

Behavioral and Nondirective Guided Self-Help for Parents of Children with Externalizing Behavior: Mediating Mechanisms in a Head-To-Head Comparison.

Science.gov (United States)

Katzmann, Josepha; Hautmann, Christopher; Greimel, Lisa; Imort, Stephanie; Pinior, Julia; Scholz, Kristin; Döpfner, Manfred

2017-05-01

Parent training (PT) delivered as a guided self-help intervention may be a cost- and time-effective intervention in the treatment of children with externalizing disorders. In face-to-face PT, parenting strategies have repeatedly been identified as mediating mechanisms for the decrease of children's problem behavior. Few studies have examined possible mediating effects in guided self-help interventions for parents. The present study aimed to investigate possible mediating variables of a behaviorally oriented guided self-help program for parents of children with externalizing problems compared to a nondirective intervention in a clinical sample. A sample of 110 parents of children with externalizing disorders (80 % boys) were randomized to either a behaviorally oriented or a nondirective guided self-help program. Four putative mediating variables were examined simultaneously in a multiple mediation model using structural equation modelling. The outcomes were child symptoms of ADHD and ODD as well as child externalizing problems, assessed at posttreatment. Analyses showed a significant indirect effect for dysfunctional parental attributions in favor of the group receiving the behavioral program, and significant effects of the behavioral program on positive and negative parenting and parental self-efficacy, compared to the nondirective intervention. Our results indicate that a decrease of dysfunctional parental attributions leads to a decrease of child externalizing problems when parents take part in a behaviorally oriented guided self-help program. However, none of the putative mediating variables could explain the decrease in child externalizing behavior problems in the nondirective group. A change in dysfunctional parental attributions should be considered as a possible mediator in the context of PT.

An agent-based model for integrated emotion regulation and contagion in socially affected decision making

OpenAIRE

Manzoor, A.; Treur, J.

2015-01-01

This paper addresses an agent-based computational social agent model for the integration of emotion regulation, emotion contagion and decision making in a social context. The model integrates emotion-related valuing, in order to analyse the role of emotions in socially affected decision making. The agent-based model is illustrated for the interaction between two persons. Simulation experiments for different kinds of scenarios help to understand how decisions can be affected by regulating the ...

Therapeutic neuroprotective agents for amyotrophic lateral sclerosis

Science.gov (United States)

Pandya, Rachna S.; Zhu, Haining; Li, Wei; Bowser, Robert; Friedlander, Robert M.

2014-01-01

Amyotrophic lateral sclerosis (ALS) is a fatal chronic neurodegenerative disease whose hallmark is proteinaceous, ubiquitinated, cytoplasmic inclusions in motor neurons and surrounding cells. Multiple mechanisms proposed as responsible for ALS pathogenesis include dysfunction of protein degradation, glutamate excitotoxicity, mitochondrial dysfunction, apoptosis, oxidative stress, and inflammation. It is therefore essential to gain a better understanding of the underlying disease etiology and search for neuroprotective agents that might delay disease onset, slow progression, prolong survival, and ultimately reduce the burden of disease. Because riluzole, the only Food and Drug Administration (FDA)-approved treatment, prolongs the ALS patient’s life by only 3 months, new therapeutic agents are urgently needed. In this review, we focus on studies of various small pharmacological compounds targeting the proposed pathogenic mechanisms of ALS and discuss their impact on disease progression. PMID:23864030

From automata to animate beings: the scope and limits of attributing socialness to artificial agents.

Science.gov (United States)

Hortensius, Ruud; Cross, Emily S

2018-05-11

Understanding the mechanisms and consequences of attributing socialness to artificial agents has important implications for how we can use technology to lead more productive and fulfilling lives. Here, we integrate recent findings on the factors that shape behavioral and brain mechanisms that support social interactions between humans and artificial agents. We review how visual features of an agent, as well as knowledge factors within the human observer, shape attributions across dimensions of socialness. We explore how anthropomorphism and dehumanization further influence how we perceive and interact with artificial agents. Based on these findings, we argue that the cognitive reconstruction within the human observer is likely to be far more crucial in shaping our interactions with artificial agents than previously thought, while the artificial agent's visual features are possibly of lesser importance. We combine these findings to provide an integrative theoretical account based on the "like me" hypothesis, and discuss the key role played by the Theory-of-Mind network, especially the temporal parietal junction, in the shift from mechanistic to social attributions. We conclude by highlighting outstanding questions on the impact of long-term interactions with artificial agents on the behavioral and brain mechanisms of attributing socialness to these agents. © 2018 New York Academy of Sciences.

Development of (F-18)-Labeled Amyloid Imaging Agents for PET

International Nuclear Information System (INIS)

Mathis, C.A.

2007-01-01

The applicant proposes to design and synthesize a series of fluorine-18-labeled radiopharmaceuticals to be used as amyloid imaging agents for positron emission tomography (PET). The investigators will conduct comprehensive iterative in vitro and in vivo studies based upon well defined acceptance criteria in order to identify lead agents suitable for human studies. The long term goals are to apply the selected radiotracers as potential diagnostic agents of Alzheimer's disease (AD), as surrogate markers of amyloid in the brain to determine the efficacy of anti-amyloid therapeutic drugs, and as tools to help address basic scientific questions regarding the progression of the neuropathology of AD, such as testing the 'amyloid cascade hypothesis' which holds that amyloid accumulation is the primary cause of AD.

Pharmacoeconomics of inhaled anesthetic agents: considerations for the pharmacist.

Science.gov (United States)

Chernin, Eric L

2004-10-15

Types of economic analyses used for inhaled anesthetic agents, factors to consider in calculating the cost of inhaled anesthetics, limitations of pharmacoeconomic studies of these agents, and strategies for controlling inhaled anesthetic costs are discussed. Inhaled anesthetic agents comprise a substantial component of drug budgets. Calculation of the cost of administering an inhaled anesthetic should take into consideration the cost per mL, potency, waste, concentration and duration of gas delivery, fresh gas flow rate, molecular weight, and density. The use of newer inhaled anesthetic agents with low solubility in blood and tissue provides a more rapid recovery from anesthesia than older, more soluble agents, and also provides the same level of control of depth of anesthesia at a lower fresh gas flow rate and possibly a lower cost than older agents at a higher fresh gas flow rate. A more rapid recovery may facilitate fast-track recovery and yield cost savings if it allows the completion of additional surgical cases or allows a reduction in personnel overtime expenses. Interpretation of pharmacoeconomic studies of inhaled anesthetics requires an appreciation of the limitations in methodology and ability to extrapolate results from one setting to another. Pharmacists' efforts to reduce anesthetic waste and collaborate with anesthesiologists to improve the use of these agents can help contain costs, but improving scheduling and efficiency in the operating room has a greater potential to reduce operating room costs. Much can be done to control costs of anesthetic agents without compromising availability of these agents and patient care.

Mobile agents affect worm spreading in wireless ad hoc networks

International Nuclear Information System (INIS)

Huang, Zi-Gang; Sun, Jin-Tu; Wang, Ying-Hai; Wang, Sheng-Jun; Xu, Xin-Jian

2009-01-01

Considering the dynamic nature of portable computing devices with wireless communication capability, an extended model is introduced for worm spreading in the wireless ad hoc network, with a population of mobile agents in a planar distribution, starting from an initial infected seed. The effect of agents' mobility on worm spreading is investigated via extensive Monte Carlo simulations. The threshold behavior and the dynamics of worm epidemics in the wireless networks are greatly affected by both agents' mobility and spatial and temporal correlations. The medium access control mechanism for the wireless communication promotes the sensitivity of the spreading dynamics to agents' mobility

Hypertension management: rationale for triple therapy based on mechanisms of action.

Science.gov (United States)

Neutel, Joel M; Smith, David H G

2013-10-01

An estimated 25% of patients will require 3 antihypertensive agents to achieve blood pressure (BP) control; combination therapy is thus an important strategy in hypertension treatment. This review discusses the triple-therapy combination of an angiotensin receptor blocker (ARB) or direct renin antagonist (DRI) with a calcium channel blocker (CCB) and a diuretic, with a focus on mechanisms of action. Multiple physiologic pathways contribute to hypertension. Combining antihypertensive agents not only better targets the underlying pathways, but also helps blunt compensatory responses that may be triggered by single-agent therapy. DRIs and ARBs target the renin-angiotensin-aldosterone system (RAAS) at the initial and final steps, respectively, and both classes lower BP by reducing the effects of angiotensin-2; however, ARBs may trigger a compensatory increase in renin activity. Dihydropyridine CCBs target L-type calcium channels and lower BP through potent vasodilation, but can trigger compensatory activation of the sympathetic nervous system (SNS) and RAAS. Thiazide diuretics lower BP initially through sodium depletion and plasma volume reduction, followed by total peripheral resistance reduction, but can also trigger compensatory activation of the SNS and RAAS. The combination of an agent targeting the RAAS with a CCB and diuretic is rational, and triple combinations of valsartan/amlodipine/hydrochlorothiazide, olmesartan/amlodipine/hydrochlorothiazide, and aliskiren/amlodipine/hydrochlorothiazide have demonstrated greater effectiveness compared with their respective dual-component combinations. In addition, single-pill, fixed-dose combinations can address barriers to BP control including clinical inertia and poor adherence. Fixed-dose antihypertensive combination products capitalize on complementary mechanisms of action and have been shown to result in improved BP control. © 2012 John Wiley & Sons Ltd.

Mechanical properties of styrene-butadiene rubber cured by ionizing radiation in the presence of sulfur and polyfunctional agent

International Nuclear Information System (INIS)

Basfar, A.A.; Al-Harithy, F.A.; Abdel-Aziz, M.M.

1997-01-01

The mechanical Properties of Styrene-Butadiene Rubber (SBR) samples cured by a combination of sulfur and ionizing radiation in the presence of polyfunctional crosslinking agent were studied. SBR formulations containing various concentrations of trimethyl propane triacrylate (TMPTA) were irradiated at absorbed doses in the range of 35-200 kGy. The influence of TMPTA on the mechanical properties, solubility % and swelling % were investigated. The various formulations were compared at the same crosslink density as determined by 200% modulus (i.e. tensile strength at 200% elongation). The increase in TMPTA concentration has led to the decrease in the absorbed dose required to achieve full-cure conditions. Another set of SBR formulations containing partial levels of sulfur in the presence of the same TMPTA concentrations as the earlier formulations were irradiated at the same absorbed dose range. The presence of sulfur has further decreased the absorbed dose required to achieve full-cure conditions. Thermal stability of the two sets of SBR formulations as studied by Thermogravimetric Analyzer (TGA) and Differential Scanning Calorimeter (DSC) remained unchanged over the entire range of absorbed dose

Quantum-enhanced deliberation of learning agents using trapped ions

Science.gov (United States)

Dunjko, V.; Friis, N.; Briegel, H. J.

2015-02-01

A scheme that successfully employs quantum mechanics in the design of autonomous learning agents has recently been reported in the context of the projective simulation (PS) model for artificial intelligence. In that approach, the key feature of a PS agent, a specific type of memory which is explored via random walks, was shown to be amenable to quantization, allowing for a speed-up. In this work we propose an implementation of such classical and quantum agents in systems of trapped ions. We employ a generic construction by which the classical agents are ‘upgraded’ to their quantum counterparts by a nested process of adding coherent control, and we outline how this construction can be realized in ion traps. Our results provide a flexible modular architecture for the design of PS agents. Furthermore, we present numerical simulations of simple PS agents which analyze the robustness of our proposal under certain noise models.

Reverse engineering a social agent-based hidden markov model--visage.

Science.gov (United States)

Chen, Hung-Ching Justin; Goldberg, Mark; Magdon-Ismail, Malik; Wallace, William A

2008-12-01

We present a machine learning approach to discover the agent dynamics that drives the evolution of the social groups in a community. We set up the problem by introducing an agent-based hidden Markov model for the agent dynamics: an agent's actions are determined by micro-laws. Nonetheless, We learn the agent dynamics from the observed communications without knowing state transitions. Our approach is to identify the appropriate micro-laws corresponding to an identification of the appropriate parameters in the model. The model identification problem is then formulated as a mixed optimization problem. To solve the problem, we develop a multistage learning process for determining the group structure, the group evolution, and the micro-laws of a community based on the observed set of communications among actors, without knowing the semantic contents. Finally, to test the quality of our approximations and the feasibility of the approach, we present the results of extensive experiments on synthetic data as well as the results on real communities, such as Enron email and Movie newsgroups. Insight into agent dynamics helps us understand the driving forces behind social evolution.

MAINS: MULTI-AGENT INTELLIGENT SERVICE ARCHITECTURE FOR CLOUD COMPUTING

Directory of Open Access Journals (Sweden)

T. Joshva Devadas

2014-04-01

Full Text Available Computing has been transformed to a model having commoditized services. These services are modeled similar to the utility services water and electricity. The Internet has been stunningly successful over the course of past three decades in supporting multitude of distributed applications and a wide variety of network technologies. However, its popularity has become the biggest impediment to its further growth with the handheld devices mobile and laptops. Agents are intelligent software system that works on behalf of others. Agents are incorporated in many innovative applications in order to improve the performance of the system. Agent uses its possessed knowledge to react with the system and helps to improve the performance. Agents are introduced in the cloud computing is to minimize the response time when similar request is raised from an end user in the globe. In this paper, we have introduced a Multi Agent Intelligent system (MAINS prior to cloud service models and it was tested using sample dataset. Performance of the MAINS layer was analyzed in three aspects and the outcome of the analysis proves that MAINS Layer provides a flexible model to create cloud applications and deploying them in variety of applications.

A computational model of the allocentric and egocentric spatial memory by means of virtual agents, or how simple virtual agents can help to build complex computational models

Czech Academy of Sciences Publication Activity Database

Brom, C.; Vyhnánek, J.; Lukavský, Jiří; Waller, D.; Kadlec, R.

17-18, JUL-AUG 2012 (2012), s. 1-24 ISSN 1389-0417 Institutional research plan: CEZ:AV0Z70250504 Keywords : spatial cognition * disorientation effect * intelligent virtual agent Subject RIV: AN - Psychology Impact factor: 0.750, year: 2012

An embodiment effect in computer-based learning with animated pedagogical agents.

Science.gov (United States)

Mayer, Richard E; DaPra, C Scott

2012-09-01

How do social cues such as gesturing, facial expression, eye gaze, and human-like movement affect multimedia learning with onscreen agents? To help address this question, students were asked to twice view a 4-min narrated presentation on how solar cells work in which the screen showed an animated pedagogical agent standing to the left of 11 successive slides. Across three experiments, learners performed better on a transfer test when a human-voiced agent displayed human-like gestures, facial expression, eye gaze, and body movement than when the agent did not, yielding an embodiment effect. In Experiment 2 the embodiment effect was found when the agent spoke in a human voice but not in a machine voice. In Experiment 3, the embodiment effect was found both when students were told the onscreen agent was consistent with their choice of agent characteristics and when inconsistent. Students who viewed a highly embodied agent also rated the social attributes of the agent more positively than did students who viewed a nongesturing agent. The results are explained by social agency theory, in which social cues in a multimedia message prime a feeling of social partnership in the learner, which leads to deeper cognitive processing during learning, and results in a more meaningful learning outcome as reflected in transfer test performance.

Functionalized gold nanoparticle supported sensory mechanisms applied in detection of chemical and biological threat agents: A review

International Nuclear Information System (INIS)

Upadhyayula, Venkata K.K.

2012-01-01

Highlights: ► Smart sensors are needed for detection of chemical and biological threat agents. ► Smart sensors detect analytes with rapid speed, high sensitivity and selectivity. ► Functionalized gold nanoparticles (GNPs) can potentially smart sense threat agents. ► Functionalized GNPs support multiple analytical methods for sensing threat agents. ► Threat agents of all types can be detected using functionalized GNPs. - Abstract: There is a great necessity for development of novel sensory concepts supportive of smart sensing capabilities in defense and homeland security applications for detection of chemical and biological threat agents. A smart sensor is a detection device that can exhibit important features such as speed, sensitivity, selectivity, portability, and more importantly, simplicity in identifying a target analyte. Emerging nanomaterial based sensors, particularly those developed by utilizing functionalized gold nanoparticles (GNPs) as a sensing component potentially offer many desirable features needed for threat agent detection. The sensitiveness of physical properties expressed by GNPs, e.g. color, surface plasmon resonance, electrical conductivity and binding affinity are significantly enhanced when they are subjected to functionalization with an appropriate metal, organic or biomolecular functional groups. This sensitive nature of functionalized GNPs can be potentially exploited in the design of threat agent detection devices with smart sensing capabilities. In the presence of a target analyte (i.e., a chemical or biological threat agent) a change proportional to concentration of the analyte is observed, which can be measured either by colorimetric, fluorimetric, electrochemical or spectroscopic means. This article provides a review of how functionally modified gold colloids are applied in the detection of a broad range of threat agents, including radioactive substances, explosive compounds, chemical warfare agents, biotoxins, and

Functionalized gold nanoparticle supported sensory mechanisms applied in detection of chemical and biological threat agents: A review

Energy Technology Data Exchange (ETDEWEB)

Upadhyayula, Venkata K.K., E-mail: Upadhyayula.Venkata@epa.gov [Oak Ridge Institute of Science and Education (ORISE), MC-100-44, PO Box 117, Oak Ridge, TN 37831 (United States)

2012-02-17

Highlights: Black-Right-Pointing-Pointer Smart sensors are needed for detection of chemical and biological threat agents. Black-Right-Pointing-Pointer Smart sensors detect analytes with rapid speed, high sensitivity and selectivity. Black-Right-Pointing-Pointer Functionalized gold nanoparticles (GNPs) can potentially smart sense threat agents. Black-Right-Pointing-Pointer Functionalized GNPs support multiple analytical methods for sensing threat agents. Black-Right-Pointing-Pointer Threat agents of all types can be detected using functionalized GNPs. - Abstract: There is a great necessity for development of novel sensory concepts supportive of smart sensing capabilities in defense and homeland security applications for detection of chemical and biological threat agents. A smart sensor is a detection device that can exhibit important features such as speed, sensitivity, selectivity, portability, and more importantly, simplicity in identifying a target analyte. Emerging nanomaterial based sensors, particularly those developed by utilizing functionalized gold nanoparticles (GNPs) as a sensing component potentially offer many desirable features needed for threat agent detection. The sensitiveness of physical properties expressed by GNPs, e.g. color, surface plasmon resonance, electrical conductivity and binding affinity are significantly enhanced when they are subjected to functionalization with an appropriate metal, organic or biomolecular functional groups. This sensitive nature of functionalized GNPs can be potentially exploited in the design of threat agent detection devices with smart sensing capabilities. In the presence of a target analyte (i.e., a chemical or biological threat agent) a change proportional to concentration of the analyte is observed, which can be measured either by colorimetric, fluorimetric, electrochemical or spectroscopic means. This article provides a review of how functionally modified gold colloids are applied in the detection of a broad

Study on collaborative optimization control of ventilation and radon reduction system based on multi-agent technology

International Nuclear Information System (INIS)

Dai Jianyong; Meng Lingcong; Zou Shuliang

2015-01-01

According to the radioactive safety features such as radon and its progeny, combined with the theory of ventilation system, structure of multi-agent system for ventilation and radon reduction system is constructed with the application of multi agent technology. The function attribute of the key agent and the connection between the nodes in the multi-agent system are analyzed to establish the distributed autonomous logic structure and negotiation mechanism of multi agent system of ventilation and radon reduction system, and thus to implement the coordination optimization control of the multi-agent system. The example analysis shows that the system structure of the multi-agent system of ventilation and reducing radon system and its collaborative mechanism can improve and optimize the radioactive pollutants control, which provides a theoretical basis and important application prospect. (authors)

Inclusion Complexes of Sunscreen Agents with β-Cyclodextrin: Spectroscopic and Molecular Modeling Studies

Directory of Open Access Journals (Sweden)

Nathir A. F. Al-Rawashdeh

2013-01-01

Full Text Available The inclusion complexes of selected sunscreen agents, namely, oxybenzone (Oxy, octocrylene (Oct, and ethylhexyl-methoxycinnamate (Cin with β-cyclodextrin (β-CD were studied by UV-Vis spectroscopy, differential scanning calorimetry (DSC, 13C NMR techniques, and molecular mechanics (MM calculations and modeling. Molecular modeling (MM study of the entire process of the formation of 1 : 1 stoichiometry sunscreen agent/β-cyclodextrin structures has been used to contribute to the understanding and rationalization of the experimental results. Molecular mechanics calculations, together with 13C NMR measurements, for the complex with β-CD have been used to describe details of the structural, energetic, and dynamic features of host-guest complex. Accurate structures of CD inclusion complexes have been derived from molecular mechanics (MM calculations and modeling. The photodegradation reaction of the sunscreen agents' molecules in lotion was explored using UV-Vis spectroscopy. It has been demonstrated that the photostability of these selected sunscreen agents has been enhanced upon forming inclusion complexes with β-CD in lotion. The results of this study demonstrate that β-CD can be utilized as photostabilizer additive for enhancing the photostability of the selected sunscreen agents' molecules.

Hydrothermal Synthesis and Mechanism of Unusual Zigzag Ag2Te and Ag2Te/C Core-Shell Nanostructures

Directory of Open Access Journals (Sweden)

Saima Manzoor

2014-01-01

Full Text Available A single step surfactant-assisted hydrothermal route has been developed for the synthesis of zigzag silver telluride nanowires with diameter of 50–60 nm and length of several tens of micrometers. Silver nitrate (AgNO3 and sodium tellurite (Na2TeO3, are the precursors and polyvinylpyrrolidone (PVP is used as surfactant in the presence of the reducing agent, that is, hydrazine hydrate (N2H4·H2O. In addition to the zigzag nanowires a facile hydrothermal reduction-carbonization route is proposed for the preparation of uniform core-shell Ag2Te/C nanowires. In case of Ag2Te/C synthesis process the same precursors are employed for Ag and Te along with the ethylene glycol used as reducing agent and glucose as the carbonizing agent. Morphological and compositional properties of the prepared products are analyzed with the help of scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy, respectively. The detailed formation mechanism of the zigzag morphology and reduction-carbonization growth mechanism for core-shell nanowires are illustrated on the bases of experimental results.

Market-Based Coordination and Auditing Mechanisms for Self-Interested Multi-Robot Systems

Science.gov (United States)

Ham, MyungJoo

2009-01-01

We propose market-based coordinated task allocation mechanisms, which allocate complex tasks that require synchronized and collaborated services of multiple robot agents to robot agents, and an auditing mechanism, which ensures proper behaviors of robot agents by verifying inter-agent activities, for self-interested, fully-distributed, and…

Handling machine breakdown for dynamic scheduling by a colony of cognitive agents in a holonic manufacturing framework

Directory of Open Access Journals (Sweden)

T. K. Jana

2015-09-01

Full Text Available There is an ever increasing need of providing quick, yet improved solution to dynamic scheduling by better responsiveness following simple coordination mechanism to better adapt to the changing environments. In this endeavor, a cognitive agent based approach is proposed to deal with machine failure. A Multi Agent based Holonic Adaptive Scheduling (MAHoAS architecture is developed to frame the schedule by explicit communication between the product holons and the resource holons in association with the integrated process planning and scheduling (IPPS holon under normal situation. In the event of breakdown of a resource, the cooperation is sought by implicit communication. Inspired by the cognitive behavior of human being, a cognitive decision making scheme is proposed that reallocates the incomplete task to another resource in the most optimized manner and tries to expedite the processing in view of machine failure. A metamorphic algorithm is developed and implemented in Oracle 9i to identify the best candidate resource for task re-allocation. Integrated approach to process planning and scheduling realized under Multi Agent System (MAS framework facilitates dynamic scheduling with improved performance under such situations. The responsiveness of the resources having cognitive capabilities helps to overcome the adverse consequences of resource failure in a better way.

Evaluation of Market Design Agents: The Mertacor Perspective

Science.gov (United States)

Stavrogiannis, Lampros C.; Mitkas, Pericles A.

The annual Trading Agent Competition for Market Design, CAT, provides a testbed to study the mechanisms that modern stock exchanges use in their effort to attract potential traders while maximizing their profit. This paper presents an evaluation of the agents that participated in the 2008 competition. The evaluation is based on the analysis of the CAT finals as well as on the results obtained from post-tournament experiments. We present Mertacor, our entrant for 2008, and compare it with the other available agents. In addition, we introduce a simple yet effective way of computing the global competitive equilibrium that Mertacor utilizes and discuss its importance for the game.

Defining Game Mechanics

DEFF Research Database (Denmark)

Sicart (Vila), Miguel Angel

2008-01-01

This article defins game mechanics in relation to rules and challenges. Game mechanics are methods invoked by agents for interacting with the game world. I apply this definition to a comparative analysis of the games Rez, Every Extend Extra and Shadow of the Colossus that will show the relevance...... of a formal definition of game mechanics. Udgivelsesdato: Dec 2008...

A Magnetic Set-Up to Help Teach Newton's Laws

Science.gov (United States)

Panijpan, Bhinyo; Sujarittham, Thanida; Arayathanitkul, Kwan; Tanamatayarat, Jintawat; Nopparatjamjomras, Suchai

2009-01-01

A set-up comprising a magnetic disc, a solenoid and a mechanical balance was used to teach first-year physics students Newton's third law with the help of a free body diagram. The image of a floating magnet immobilized by the solenoid's repulsive force should help dispel a common misconception of students as regards the first law: that stationary…

Biological Select Agents and Toxins: Risk-Based Assessment Management and Oversight.

Energy Technology Data Exchange (ETDEWEB)

Burnett, LouAnn Crawford; Brodsky, Benjamin H.

2016-12-01

Sandia National Laboratories' International Biological and Chemical Threat Reduction (SNL/IBCTR) conducted, on behalf of the Federal Select Agent Program (FSAP), a review of risk assessment in modern select agent laboratories. This review and analysis consisted of literature review, interviews of FSAP staff, entities regulated by FSAP, and deliberations of an expert panel. Additionally, SNL/IBCTR reviewed oversight mechanisms used by industries, US agencies, and other countries for high-consequence risks (e.g, nuclear, chemical, or biological materials, aviation, off-shore drilling, etc.) to determine if alternate oversight mechanisms existed that might be applicable to FSAP oversight of biological select agents and toxins. This report contains five findings, based on these reviews and analyses, with recommendations and suggested actions for FSAP to consider.

Mechanical properties of self-curing concrete (SCUC

Directory of Open Access Journals (Sweden)

Magda I. Mousa

2015-12-01

Full Text Available The mechanical properties of concrete containing self-curing agents are investigated in this paper. In this study, two materials were selected as self-curing agents with different amounts, and the addition of silica fume was studied. The self-curing agents were, pre-soaked lightweight aggregate (Leca; 0.0%, 10%, 15%, and 20% of volume of sand; or polyethylene-glycol (Ch.; 1%, 2%, and 3% by weight of cement. To carry out this study the cement content of 300, 400, 500 kg/m3, water/cement ratio of 0.5, 0.4, 0.3 and 0.0%, 15% silica fume of weight of cement as an additive were used in concrete mixes. The mechanical properties were evaluated while the concrete specimens were subjected to air curing regime (in the laboratory environment with 25 °C, 65% R.H. during the experiment. The results show that, the use of self-curing agents in concrete effectively improved the mechanical properties. The concrete used polyethylene-glycol as self-curing agent, attained higher values of mechanical properties than concrete with saturated Leca. In all cases, either 2% Ch. or 15% Leca was the optimum ratio compared with the other ratios. Higher cement content and/or lower water/cement ratio lead(s to more efficient performance of self-curing agents in concrete. Incorporation of silica fume into self-curing concrete mixture enhanced all mechanical properties, not only due to its pozzolanic reaction, but also due to its ability to retain water inside concrete.

How Helpdesk Agents Help Clients

NARCIS (Netherlands)

Steehouder, M.F.

2007-01-01

Helpdesks are an important channel for supporting users of technical products and software. This study analyses some phenomena in telephone helpdesk calls, using conversational analysis as a methodological and theoretical framework. Helpdesk calls are characterized by the common goal of the helpdesk

A novel self-organizing E-Learner community model with award and exchange mechanisms.

Science.gov (United States)

Yang, Fan; Shen, Rui-min; Han, Peng

2004-11-01

How to share experience and resources among learners is becoming one of the hottest topics in the field of E-Learning collaborative techniques. An intuitive way to achieve this objective is to group learners which can help each other into the same community and help them learn collaboratively. In this paper, we proposed a novel community self-organization model based on multi-agent mechanism, which can automatically group learners with similar preferences and capabilities. In particular, we proposed award and exchange schemas with evaluation and preference track records to raise the performance of this algorithm. The description of learner capability, the matchmaking process, the definition of evaluation and preference track records, the rules of award and exchange schemas and the self-organization algorithm are all discussed in this paper. Meanwhile, a prototype has been built to verify the validity and efficiency of the algorithm. Experiments based on real learner data showed that this mechanism can organize learner communities properly and efficiently; and that it has sustainable improved efficiency and scalability.

Innovative agents in cancer prevention.

Science.gov (United States)

Manson, Margaret M; Farmer, Peter B; Gescher, Andreas; Steward, William P

2005-01-01

There are many facets to cancer prevention: a good diet, weight control and physical activity, a healthy environment, avoidance of carcinogens such as those in tobacco smoke, and screening of populations at risk to allow early detection. But there is also the possibility of using drugs or naturally occurring compounds to prevent initiation of, or to suppress, tumour growth. Only a few such agents have been used to date in the clinic with any success, and these include non-steroidal anti-inflammatory drugs for colon, finasteride for prostate and tamoxifen or raloxifene for breast tumours. An ideal chemopreventive agent would restore normal growth control to a preneoplastic or cancerous cell population by modifying aberrant signalling pathways or inducing apoptosis (or both) in cells beyond repair. Characteristics for such an agent include selectivity for damaged or transformed cells, good bioavailability and more than one mechanism of action to foil redundancy or crosstalk in signalling pathways. As more research effort is being targeted towards this area, the distinction between chemotherapeutic and chemopreventive agents is blurring. Chemotherapeutic drugs are now being designed to target over- or under-active signalling molecules within cancer cells, a philosophy which is just as relevant in chemoprevention. Development of dietary agents is particularly attractive because of our long-standing exposure to them, their relative lack of toxicity, and encouraging indications from epidemiology. The carcinogenic process relies on the cell's ability to proliferate abnormally, evade apoptosis, induce angiogenesis and metastasise to distant sites. In vitro studies with a number of different diet-derived compounds suggest that there are molecules capable of modulating each of these aspects of tumour growth. However, on the negative side many of them have rather poor bioavailability. The challenge is to uncover their multiple mechanisms of action in order to predict their

Technetium SPECT agents for imaging heart and brain

International Nuclear Information System (INIS)

Linder, K.E.

1990-01-01

One major goal of radiopharmaceutical research has been the development of technetium-based perfusion tracers for SPECT imaging of the heart and brain. The recent clinical introduction of the technetium complexes HM-PAO, ECD and DMG-2MP for brain imaging, and of CDO-MEB and MIBI for heart imaging promises to revolutionize the field of nuclear medicine. All of these agents appear to localize in the target tissue in proportion to blood flow, but their mechanisms of localization and/or retention may differ quite widely. In this talk, a survey of the new technetium SPECT agents will be presented. The inorganic and biological chemistry of these complexes, mechanisms of uptake and retention, QSAR studies, and potential clinical applications are discussed

Profiling the Buzz Agent: Product Referral and the Study of Social Community and Brand Attachment

Directory of Open Access Journals (Sweden)

Danny Pimentel Claro

2015-04-01

Full Text Available The buzz agent is any consumer perceived by others as a source of product referral. Previous literature in word of mouth (WOM has looked into characteristics of individuals who successfully persuade others to choose a brand. While there have been studies in this field, the literature is still scattered and little has been done to profile the consumer playing the buzz-agent role. We aim to deepen our understanding about the consumer who must be recruited as a buzz agent by a firm in a WOM marketing (WOMM initiative. The proposed profile is comprised of three key characteristics: the consumer’s position in the social community, nature of ties in the community and brand attachment. We tested our hypotheses with a survey of 542 consumers from a controlled population. Rather than relying on self-reported questions about referral behavior, we asked respondents in the population to name the individuals to whom the respondents go to obtain information to help pick a brand. This accurately pinpoints which individuals fit the profile of a buzz agent. Results show that buzz agents are popular in their social community (friends and tech experts, carry dissimilar brands as target consumers and are product experts. Our study identifies a profile of consumers that helps firms select buzz agents for WOMM initiatives.

Effect of Bagasse Chemical Pulping and Coupling Agent on the Physical - Mechanical Properties of Composites Based on Bagasse pulp/Low density polyethylene

Directory of Open Access Journals (Sweden)

maryam allahdadi

2016-12-01

Full Text Available In this research, effect of reinforcing bagasse pulp and raw bagasse fibers and applying coupling agent MAPE (Maleic Anhydride Polyethylene on physical-mechanical properties of low density polyethylene (LDPE composites were studided. Fresh bagasse were collected from an experimental field in Khuzestan and after investigating anatomy and chemical properties of Different pulp fibers including monoethanolamine (MEA bagasse pulp, alkaline sulfite-anthraquinone (AS bagasse pulp, bleached soda (BS bagasse pulp, unbleached soda (UNS bagasse pulp and raw bagasse fibers (B were prepared. Then, composites with 30wt.% fiber content were manufactured by twin-screw extrusion followed by compression molding processing. The mechanical and physical properties of these composites were analyzed and compared. Results revealed that the chemical pulping dissolved a fraction of lignin and hemicelluloses so that the linkage potential and aspect ratio of bagasse fibers was improved and consequently, as compared with the raw bagasse fibers, bagasse pulp fibers have better reinforcing capability. The best overall properties were achieved with MEA and AS/AQ fibers. Addition of 5% (wt/wt of coupling agent MAPE resulted in a significant enhancement in the tensile strength, tensile modulus and impact strength in line with the improvement of the fiber-matrix interfacial adhesion making more effective the transfer of stress from the matrix to the rigid reinforcement.

Managing Data in Help4Mood

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Maria K. Wolters

2013-03-01

Full Text Available Help4Mood is a system that supports the treatment of people with depression in the community. It collects rich cognitive, psychomotor, and motor data through a Personal Monitoring System and a Virtual Agent, which is then analysed by a Decision Support System; analysis results are fed back to patients and their treating clinicians. In this paper, we describe how the complex data is managed and discuss ethical issues. Data is stored in functional units that correspond to treatment relevant entities. Custom XML DTDs are defined for each unit, which are used to exchange information between system components. As far as possible, observations and findings are coded using SNOMED CT to ensure interoperability with other applications such as Electronic Health Records.

Family involvement and helping behavior in teams

NARCIS (Netherlands)

Brummelhuis, L.L. ten; Lippe, A.G. van der; Kluwer, E.S.

2010-01-01

Helping behavior at work has become increasingly important, with organizations making more and more use of cooperative work practices. The difficulty is that employees are facing growing demands beyond the workplace. This study investigates the mechanisms by which family involvement ( family

Family involvement and helping behaviour in teams

NARCIS (Netherlands)

Brummelhuis, L.L. ten; Lippe, T. van der; Kluwer, E.S.

2010-01-01

Helping behavior at work has become increasingly important, with organizations making more and more use of cooperative work practices. The difficulty is that employees are facing growing demands beyond the workplace. This study investigates the mechanisms by which family involvement (family

Design of New-Generation Usable Forms of Topical Haemostatic Agents Containing Chitosan

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Dorota Zielińska

2017-12-01

Full Text Available Designing usable forms of topical haemostatic agents is the most important activity during the design process, resulting in strengthened functional properties of the final medical devices. This study aimed to propose indications for a research programme based on risk management supporting the development of two usable forms of a topical haemostatic agent: chitosan/alginate lyophilized foam and chitosan/alginate impregnated gauze. Both of the usable forms of the topical haemostatic agent, being the main part of the modified combat gauze, were fabricated using the chitosan/alginate complex. Risk analysis is helpful in developing an appropriate research programme, significantly reducing the risk to an acceptable level.

Controling the scattering of Intralipid by using optical clearing agents

International Nuclear Information System (INIS)

Wen Xiang; Luo Qingming; Zhu Dan; Tuchin, Valery V

2009-01-01

Optical clearing agents (OCAs) with high refractive indices and hyperosmolarity can enhance the penetration of light in tissues by reducing scattering in tissues. However, the mechanism of tissue optical clearing is not much clear for the complex interaction between tissues and OCAs. In this work, Intralipid was mixed with different concentrations of OCAs, i.e. dimethyl sulfoxide (DMSO), glycerol, 1,4-butanediol, 1,2-propanediol, poly-ethylene glycol 200 (PEG200) and poly-ethylene glycol 400 (PEG400). Except for PEG200 and PEG400 that make aggregation of particles, the others kept the mixture uniform. The reduced scattering coefficients of uniform mixtures were predicted with Mie theory and measured by a commercially available spectrophotometer with an integrating sphere. The results show that all of the OCAs used enhance the optical clearing effect of Intralipid. If OCAs do not change the structure of Intralipid, Mie theory prediction matches well with the measurements. And the higher the refractive index of OCA, the smaller the reduced scattering coefficient. A simple formula deduced can quantitatively predict the optical clearing effect caused by OCAs. This work is helpful for clarifying the mechanism of tissue optical clearing, which will make the effect of optical clearing of tissue predictable and controllable.

Intelligent Virtual Agents as Language Trainers Facilitate Multilingualism

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Manuela eMacedonia

2014-04-01

Full Text Available In this paper we introduce a new generation of language trainers: intelligent virtual agents (IVAs with human appearance and the capability to teach foreign language vocabulary. We report results from studies that we have conducted with Billie, an IVA employed as a vocabulary trainer, as well as research findings on the acceptance of the agent as a trainer by adults and children. The results show that Billie can train humans as well as a human teacher can and that both adults and children accept the IVA as a trainer. The advantages of IVAs are multiple. First, their teaching methods can be based on neuropsychological research findings concerning memory and learning practice. Second, virtual teachers can provide individualized training. Third, they coach users during training, are always supportive, and motivate learners to train. Fourth, agents will reside in the user’s mobile devices and thus be at the user’s disposal everywhere and anytime. Agents in apps will make foreign language training accessible to anybody at low cost. This will enable people around the world, including physically, financially and geographically disadvantaged persons, to learn a foreign language and help to facilitate multilingualism.

Self-curing concrete with different self-curing agents

Science.gov (United States)

Gopala krishna sastry, K. V. S.; manoj kumar, Putturu

2018-03-01

Concrete is recognised as a versatile construction material globally. Properties of concrete depend upon, to a greater extent, the hydration of cement and microstructure of hydrated cement. Congenial atmosphere would aid the hydration of cement and hence curing of concrete becomes essential, till a major portion of the hydration process is completed. But in areas of water inadequacy and concreting works at considerable heights, curing is problematic. Self-Curing or Internal Curing technique overcomes these problems. It supplies redundant moisture, for more than sufficient hydration of cement and diminish self-desiccation. Self-Curing agents substantially help in the conservation of water in concrete, by bringing down the evaporation during the hydration of Concrete. The present study focuses on the impact of self-curing agents such as Poly Ethylene Glycol (PEG), Poly Vinyl Alcohol (PVA) and Super Absorbent Polymer (SAP) on the concrete mix of M25 grade (reference mix). The effect of these agents on strength properties of Concrete such as compressive strength, split tensile strength and flexural strength was observed on a comparative basis which revealed that PEG 4000 was the most effective among all the agents.

Quantum-enhanced deliberation of learning agents using trapped ions

International Nuclear Information System (INIS)

Dunjko, V; Friis, N; Briegel, H J

2015-01-01

A scheme that successfully employs quantum mechanics in the design of autonomous learning agents has recently been reported in the context of the projective simulation (PS) model for artificial intelligence. In that approach, the key feature of a PS agent, a specific type of memory which is explored via random walks, was shown to be amenable to quantization, allowing for a speed-up. In this work we propose an implementation of such classical and quantum agents in systems of trapped ions. We employ a generic construction by which the classical agents are ‘upgraded’ to their quantum counterparts by a nested process of adding coherent control, and we outline how this construction can be realized in ion traps. Our results provide a flexible modular architecture for the design of PS agents. Furthermore, we present numerical simulations of simple PS agents which analyze the robustness of our proposal under certain noise models. (paper)

A hybrid agent-based approach for modeling microbiological systems.

Science.gov (United States)

Guo, Zaiyi; Sloot, Peter M A; Tay, Joc Cing

2008-11-21

Models for systems biology commonly adopt Differential Equations or Agent-Based modeling approaches for simulating the processes as a whole. Models based on differential equations presuppose phenomenological intracellular behavioral mechanisms, while models based on Multi-Agent approach often use directly translated, and quantitatively less precise if-then logical rule constructs. We propose an extendible systems model based on a hybrid agent-based approach where biological cells are modeled as individuals (agents) while molecules are represented by quantities. This hybridization in entity representation entails a combined modeling strategy with agent-based behavioral rules and differential equations, thereby balancing the requirements of extendible model granularity with computational tractability. We demonstrate the efficacy of this approach with models of chemotaxis involving an assay of 10(3) cells and 1.2x10(6) molecules. The model produces cell migration patterns that are comparable to laboratory observations.

A real-time architecture for time-aware agents.

Science.gov (United States)

Prouskas, Konstantinos-Vassileios; Pitt, Jeremy V

2004-06-01

This paper describes the specification and implementation of a new three-layer time-aware agent architecture. This architecture is designed for applications and environments where societies of humans and agents play equally active roles, but interact and operate in completely different time frames. The architecture consists of three layers: the April real-time run-time (ART) layer, the time aware layer (TAL), and the application agents layer (AAL). The ART layer forms the underlying real-time agent platform. An original online, real-time, dynamic priority-based scheduling algorithm is described for scheduling the computation time of agent processes, and it is shown that the algorithm's O(n) complexity and scalable performance are sufficient for application in real-time domains. The TAL layer forms an abstraction layer through which human and agent interactions are temporally unified, that is, handled in a common way irrespective of their temporal representation and scale. A novel O(n2) interaction scheduling algorithm is described for predicting and guaranteeing interactions' initiation and completion times. The time-aware predicting component of a workflow management system is also presented as an instance of the AAL layer. The described time-aware architecture addresses two key challenges in enabling agents to be effectively configured and applied in environments where humans and agents play equally active roles. It provides flexibility and adaptability in its real-time mechanisms while placing them under direct agent control, and it temporally unifies human and agent interactions.

From moral agents to moral factors: the structural ethics approach

NARCIS (Netherlands)

Brey, Philip A.E.; Kroes, P.; Verbeek, P.P.C.C.

2014-01-01

It has become a popular position in the philosophy of technology to claim that some or all technological artifacts can qualify as moral agents. This position has been developed to account for the moral role of technological artifacts in society and to help clarify the moral responsibility of

On (Group) Strategy-Proof Mechanisms without Payment for Facility Location Games

DEFF Research Database (Denmark)

Thang, Nguyen Kim

2010-01-01

in an allowable location that minimizes the utilitarian social cost — the sum of agents costs. A mechanism is strategyproof (SP) if no agent may misreport its locations and be better off; it is group-strategyproof (GSP) if no coalition of agents benefits by jointly misreporting their locations The requirement...... for (G)SP in this setting makes optimum placement of the facility impossible and, therefore, we consider approximation (G)SP mechanisms. For SP mechanisms, we give a simple 3-approximation randomized mechanism and also provide asymptotic lower bounds for different variants. For GSP mechanisms, a (2N + 1......We characterize the performance of strategyproof and group-strategyproof social choice rules, for placing a facility on the nodes of a metric network inhabited by N autonomous self-interested agents. Every agent owns a set of locations and caters to minimization of its cost which is the total...

Unibot, a Universal Agent Architecture for Robots

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Saša Mladenović

2017-01-01

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

Interactions of radiation with novel chemotherapeutic agents: Taxanes and nucleoside analogs

International Nuclear Information System (INIS)

Milas, Luka

1997-01-01

The combination of chemotherapeutic agents and radiotherapy is an appealing approach to improving the results of cancer treatment. By their independent action or interactive action chemotherapeutic drugs reduce cell burden in tumors undergoing radiotherapy, thereby increasing the chances of tumor control. In addition, the drugs may spatially cooperate with radiotherapy through their systemic action on metastatic disease. Recently, a number of new chemotherapeutic agents have been introduced for cancer treatment, which in addition have high potential to increase therapeutic ratio of radiotherapy. These agents include taxanes (paclitaxel and docetaxel) and the nucleoside analogs fludarabine and gemcitabine. Paclitaxel is a natural product isolated from the bark of Taxus brevifolia and taxotere is a semisynthetic analogue of paclitaxel prepared from needle extracts of Taxus baccata. By binding to cellular tubulin structures, taxanes interfere with tubulin polymerization and promote microtubule assembly, resulting in accumulation of cells in the radiosensitive G2 and M phases of the cell cycle. In vivo studies have demonstrated two major mechanisms of tumor radioenhancement by taxanes: mitotic arrest and tumor reoxygenation. Fludarabine and gemcitabine inhibit DNA synthesis and the repair of radiation-induced chromosome breaks. The mechanism of their radioenhancing activity include inhibition of repair of radiation induced damage, apoptosis induction and cell cycle synchronization. Because both classes of these agents affect radioresponse of normal dose-limiting tissues much less than that of tumors, they can greatly increase therapeutic ratio of radiotherapy. The objective of this course is to overview the rationale for using these drugs as radioenhancing agents, the experimental findings in preclinical studies, the mechanisms of their interaction, and the clinical application of these agents

Modelling complex systems of heterogeneous agents to better design sustainability transitions policy

NARCIS (Netherlands)

Mercure, J.F.A.; Pollitt, H.; Bassi, A.M.; Viñuales, J.E.; Edwards, N.R.

2016-01-01

This article proposes a fundamental methodological shift in the modelling of policy interventions for sustainability transitions in order to account for complexity (e.g. self-reinforcing mechanisms, such as technology lock-ins, arising from multi-agent interactions) and agent heterogeneity (e.g.

The role of independent agents in the success of health insurance market reforms.

Science.gov (United States)

Hall, M A

2000-01-01

The impact of reforms on the health insurance markets cannot be understood without more information about the role played by insurance agents and a closer analysis of their contribution. An in-depth, qualitative study of insurance-market reforms in seven illustrative states forms the basis for this report on how agents help to shape the efficiency and fairness of insurance markets. Different types of agents relate to insurers in their own ways and are compensated differently. This study shows agents to be almost uniformly enthusiastic about guaranteed-issue requirements and other components of market reforms. Although insurers devise strategies for manipulating agents in order to avoid undesirable business, these opportunities are limited and do not appear to be seriously undermining the effectiveness of market reforms. Despite the layer of cost that agents add to the system, they play an important role in making market reforms work, and they fill essential information and service functions for which many purchasers have no ready substitute.

Transcriptional responses of the nerve agent-sensitive brain regions amygdala, hippocampus, piriform cortex, septum, and thalamus following exposure to the organophosphonate anticholinesterase sarin

Directory of Open Access Journals (Sweden)

Meyerhoff James L

2011-07-01

Full Text Available Abstract Background Although the acute toxicity of organophosphorus nerve agents is known to result from acetylcholinesterase inhibition, the molecular mechanisms involved in the development of neuropathology following nerve agent-induced seizure are not well understood. To help determine these pathways, we previously used microarray analysis to identify gene expression changes in the rat piriform cortex, a region of the rat brain sensitive to nerve agent exposure, over a 24-h time period following sarin-induced seizure. We found significant differences in gene expression profiles and identified secondary responses that potentially lead to brain injury and cell death. To advance our understanding of the molecular mechanisms involved in sarin-induced toxicity, we analyzed gene expression changes in four other areas of the rat brain known to be affected by nerve agent-induced seizure (amygdala, hippocampus, septum, and thalamus. Methods We compared the transcriptional response of these four brain regions to sarin-induced seizure with the response previously characterized in the piriform cortex. In this study, rats were challenged with 1.0 × LD50 sarin and subsequently treated with atropine sulfate, 2-pyridine aldoxime methylchloride, and diazepam. The four brain regions were collected at 0.25, 1, 3, 6, and 24 h after seizure onset, and total RNA was processed for microarray analysis. Results Principal component analysis identified brain region and time following seizure onset as major sources of variability within the dataset. Analysis of variance identified genes significantly changed following sarin-induced seizure, and gene ontology analysis identified biological pathways, functions, and networks of genes significantly affected by sarin-induced seizure over the 24-h time course. Many of the molecular functions and pathways identified as being most significant across all of the brain regions were indicative of an inflammatory response. There

Mechanistic origin of dragon-kings in a population of competing agents

Science.gov (United States)

Johnson, N.; Tivnan, B.

2012-05-01

We analyze the mechanistic origins of the extreme behaviors that arise in an idealized model of a population of competing agents, such as traders in a market. These extreme behaviors exhibit the defining characteristics of `dragon-kings'. Our model comprises heterogeneous agents who repeatedly compete for some limited resource, making binary choices based on the strategies that they have in their possession. It generalizes the well-known Minority Game by allowing agents whose strategies have not made accurate recent predictions, to step out of the competition until their strategies improve. This generates a complex dynamical interplay between the number V of active agents (mimicking market volume) and the imbalance D between the decisions made (mimicking excess demand). The wide spectrum of extreme behaviors which emerge, helps to explain why no unique relationship has been identified between the price and volume during real market crashes and rallies.

Dissemination of Cultural Norms and Values: Agent-Based Modeling

Directory of Open Access Journals (Sweden)

Denis Andreevich Degterev

2016-12-01

Full Text Available This article shows how agent-based modeling allows us to explore the mechanisms of the dissemination of cultural norms and values both within one country and in the whole world. In recent years, this type of simulation is particularly prevalent in the analysis of international relations, becoming more popular than the system dynamics and discrete event simulation. The use of agent-based modeling in the analysis of international relations is connected with the agent-structure problem in international relations. Structure and agents act as interdependent and dynamically changing in the process of interaction between entities. Agent-structure interaction could be modeled by means of the theory of complex adaptive systems with the use of agent-based modeling techniques. One of the first examples of the use of agent-based modeling in political science is a model of racial segregation T. Shellinga. On the basis of this model, the author shows how the change in behavioral patterns at micro-level impacts on the macro-level. Patterns are changing due to the dynamics of cultural norms and values, formed by mass-media and other social institutes. The author shows the main areas of modern application of agent-based modeling in international studies including the analysis of ethnic conflicts, the formation of international coalitions. Particular attention is paid to Robert Axelrod approach based on the use of genetic algorithms to the spread of cultural norms and values. Agent-based modeling shows how to how to create such conditions that the norms that originally are not shared by a significant part of the population, eventually spread everywhere. Practical application of these algorithms is shown by the author of the article on the example of the situation in Ukraine in 2015-2016. The article also reveals the mechanisms of international spread of cultural norms and values. The main think-tanks using agent-based modeling in international studies are

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.

Efeito de herbicidas sobre agentes fitopatogênicos = Effect of herbicides on phytopathogenic agents

Directory of Open Access Journals (Sweden)

Daniel Dias Rosa

2010-07-01

Full Text Available Na agricultura moderna, diversas tecnologias auxiliam no aumento daprodutividade, sendo o herbicida uma delas, mas existem consequências atreladas ao seu uso, como os diversos efeitos sobre organismos não alvos. Neste trabalho, objetivou-se verificar esses efeitos sobre agentes fitopatogênicos, assim como avaliar o efeito do herbicida glyphosate sobre diversas doenças, em plantas de soja transgênicas.Verificou-se forte ação fungicida com o uso do herbicida glyphosate, assim como os outros avaliados “in vitro”, sobre os fungos testados, e os mesmos resultados foram observados nas plantas em condição de campo.In modern agriculture, several technologies have helped increase productivity, and herbicide is one of them. However, there are consequences linked to its use, such as the various effects on non-target organisms. The purpose of this work was to verify these effects on phytopathogenic agents, as well as assess the effect of glyphosate on diseases in transgenic soybean. There was a strong fungicide action using glyphosate herbicide as well as with the others evaluated in vitro regarding fungi tested. The same results were observed in plants in field conditions.

Ab Initio Modeling Of Friction Reducing Agents Shows Quantum Mechanical Interactions Can Have Macroscopic Manifestation.

Science.gov (United States)

Hernández Velázquez, J D; Barroso-Flores, J; Gama Goicochea, A

2016-11-23

Two of the most commonly encountered friction-reducing agents used in plastic sheet production are the amides known as erucamide and behenamide, which despite being almost identical chemically, lead to markedly different values of the friction coefficient. To understand the origin of this contrasting behavior, in this work we model brushes made of these two types of linear-chain molecules using quantum mechanical numerical simulations under the density functional theory at the B97D/6-31G(d,p) level of theory. Four chains of erucamide and behenamide were linked to a 2 × 10 zigzag graphene sheet and optimized both in vacuum and in continuous solvent using the SMD implicit solvation model. We find that erucamide chains tend to remain closer together through π-π stacking interactions arising from the double bonds located at C13-C14, a feature behenamide lacks, and thus a more spread configuration is obtained with the latter. It is argued that this arrangement of the erucamide chains is responsible for the lower friction coefficient of erucamide brushes, compared with behenamide brushes, which is a macroscopic consequence of cooperative quantum mechanical interactions. While only quantum level interactions are modeled here, we show that behenamide chains are more spread out in the brush than erucamide chains as a consequence of those interactions. The spread-out configuration allows more solvent particles to penetrate the brush, leading in turn to more friction, in agreement with macroscopic measurements and mesoscale simulations of the friction coefficient reported in the literature.

Comment 2 on workshop in political institutions - principal-agent relationships

International Nuclear Information System (INIS)

Feeny, D.

1992-01-01

In recent decades, economic analysis has been extended to situations in which there are important asymmetries of information between actors. One important class of these situations are principal-agent relationships, in which one party, the agent, acts on behalf of the other, the principal. In such situations of incomplete and asymmetric information (in which the agent may be better informed than the principal), is it possible to devise mechanisms to ensure that the agent acts in the best interests of the principal? How can we construct relationships so that physicians act in the best interests of patients, lawyer in the best interests of their clients, or public officials in the best interests of their constituents?

Agent-based Modelling, a new kind of research

DEFF Research Database (Denmark)

Held, Fabian P.; Wilkinson, Ian F.; Marks, Robert E.

2014-01-01

guidelines to help plan and structure the development of a theory about the causes of such a phenomenon in conjunction with a matching ABM. We argue that research about complex social phenomena is still largely fundamental research and therefore an iterative and cyclical development process of both theory......We discuss the use of Agent-based Modelling for the development and testing of theories about emergent social phenomena in marketing and the social sciences in general. We address both theoretical aspects about the types of phenomena that are suitably addressed with this approach and practical...... development. The main goal of this paper was to make research on complex social systems more accessible and help anticipate and structure the research process....

Efficient priority queueing routing strategy on networks of mobile agents

Science.gov (United States)

Wu, Gan-Hua; Yang, Hui-Jie; Pan, Jia-Hui

2018-03-01

As a consequence of their practical implications for communications networks, traffic dynamics on complex networks have recently captivated researchers. Previous routing strategies for improving transport efficiency have paid little attention to the orders in which the packets should be forwarded, just simply used first-in-first-out queue discipline. Here, we apply a priority queuing discipline and propose a shortest-distance-first routing strategy on networks of mobile agents. Numerical experiments reveal that the proposed scheme remarkably improves both the network throughput and the packet arrival rate and reduces both the average traveling time and the rate of waiting time to traveling time. Moreover, we find that the network capacity increases with an increase in both the communication radius and the number of agents. Our work may be helpful for the design of routing strategies on networks of mobile agents.

From old alkylating agents to new minor groove binders.

Science.gov (United States)

Puyo, Stéphane; Montaudon, Danièle; Pourquier, Philippe

2014-01-01

Alkylating agents represent the oldest class of anticancer agents with the approval of mechloretamine by the FDA in 1949. Even though their clinical use is far beyond the use of new targeted therapies, they still occupy a major place in the treatment of specific malignancies, sometimes representing the unique option for the treatment of refractory tumors. Here, we are reviewing the major classes of alkylating agents, with a particular focus on the latest generations of compounds that specifically target the minor groove of the DNA. These naturally occurring derivatives have a unique mechanism of action that explains the recent regain of interest in developing new classes of alkylating agents that could be used in combination with other anticancer drugs to enhance tumor response in the clinic. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Potential of radiosensitizing agents in cancer chemo-radiotherapy

Directory of Open Access Journals (Sweden)

Girdhani S

2005-01-01

Full Text Available Potential of herbs and other plant-based formulations have been increasingly recognized in prevention and treatment of human diseases including cancer. There exist enormous prospect for screening and evaluation of herbal/plant products for developing effective radiosensitization and radioprotection relevant to nuclear research program. Investigations in our laboratory have focused on the mechanism of activity of variety of anticancer and antioxidant agents, namely, Eugenol, (EU, Ellagic acid (EA, Triphala (TPL, Tocopherol Succinate (TOS and Arachidonic acid on normal and cancer cells with view to design effective protocols in practical radioprotection and cancer radiotherapy. This paper is mainly focused on studies on cytotoxic effects on cancer cell lines. Results have shown that these agents produced radiosensitizing action involving oxidative damage, membrane alteration and damage to nucleic acid in various human cell lines. Studies were performed employing fluorescence probes and electron spin resonance methods and gel electrophoresis protocols. It has been found that cytotoxic effect was induced by initiating membrane oxidative damage and by triggering intracellular generation of reactive oxygen species (ROS by gamma radiation in combination with phytochemicals like TPL, EA and TOS in tumor cell line Ehrlich Ascites (EAC, Human cervical (HeLa and breast (MCF-7 cells. Membrane damage and ROS generation was measured by DPH and DCF-FDA fluorescent probes respectively after exposure to low to moderate doses of gamma radiation. This talk will present the cytotoxic effects of phytochemicals in combination with ionizing radiation. It is emphasized that modulation of membrane peroxidative damage and intra cellular ROS may help achieve efficient killing of cancer cells which may provide a new approach to developing effective treatment of cancer.

The structure of intelligent agent projecting and the possibilities of its execution

Directory of Open Access Journals (Sweden)

Yefremov M.F.

2017-04-01

Full Text Available Most of today’s information systems are not designed for independent decision making, behavior of such systems should be incorporated at the design stage. Entering the conditions that are not included by system developers, lead to a crash. The exponential growth of computing power of modern processors leads to an increase in range of tasks that can be automated, and an increase in their complexity. Partially testing helps to solve the problem, but it has a drawback, precisely the behavior of the system is usually tested in conditions which are already taken into account at the design stage. One approach to address this problem is the agent-oriented programming and the use of multi-agent systems. The aim of the work is to highlight contemporary approaches: a definition of agent concepts, applications of multi-agent systems, mathematical model agent, modern methods of design and implementation of intelligent agents, also covered approaches to the definition of the concept of an intelligent agent, the application of intelligent agents and multi-agent systems, and methods theoretically agent and describe its implementation. The basis of these methods of abstract description of the intelligent agent is the works of M.Wooldridge and N.Jennings. We propose several methods to describe such behaviors of intelligent agent as self-learning, goal setting and forecasting, and planning. Therefore we cover the concept of «intent» and widespread mental (beliefs-desires-intentions BDI architecture of intelligent agent, as well as the proposed methods of their description in the framework of the developed formalism.

Secure Route Structures for Parallel Mobile Agents Based Systems Using Fast Binary Dispatch

Directory of Open Access Journals (Sweden)

Yan Wang

2005-01-01

Full Text Available In a distributed environment, where a large number of computers are connected together to enable the large-scale sharing of data and computing resources, agents, especially mobile agents, are the tools for autonomously completing tasks on behalf of their owners. For applications of large-scale mobile agents, security and efficiency are of great concern. In this paper, we present a fast binary dispatch model and corresponding secure route structures for mobile agents dispatched in parallel to protect the dispatch routes of agents while ensuring the dispatch efficiency. The fast binary dispatch model is simple but efficient with a dispatch complexity of O(log2n. The secure route structures adopt the combination of public-key encryption and digital signature schemes and expose minimal route information to hosts. The nested structure can help detect attacks as early as possible. We evaluated the various models both analytically and empirically.

Agent-based services for B2B electronic commerce

Science.gov (United States)

Fong, Elizabeth; Ivezic, Nenad; Rhodes, Tom; Peng, Yun

2000-12-01

The potential of agent-based systems has not been realized yet, in part, because of the lack of understanding of how the agent technology supports industrial needs and emerging standards. The area of business-to-business electronic commerce (b2b e-commerce) is one of the most rapidly developing sectors of industry with huge impact on manufacturing practices. In this paper, we investigate the current state of agent technology and the feasibility of applying agent-based computing to b2b e-commerce in the circuit board manufacturing sector. We identify critical tasks and opportunities in the b2b e-commerce area where agent-based services can best be deployed. We describe an implemented agent-based prototype system to facilitate the bidding process for printed circuit board manufacturing and assembly. These activities are taking place within the Internet Commerce for Manufacturing (ICM) project, the NIST- sponsored project working with industry to create an environment where small manufacturers of mechanical and electronic components may participate competitively in virtual enterprises that manufacture printed circuit assemblies.

Agent Programming Languages and Logics in Agent-Based Simulation

DEFF Research Database (Denmark)

Larsen, John

2018-01-01

and social behavior, and work on verification. Agent-based simulation is an approach for simulation that also uses the notion of agents. Although agent programming languages and logics are much less used in agent-based simulation, there are successful examples with agents designed according to the BDI...

Improving Agent Bidding in Power Stock Markets through a Data Mining Enhanced Agent Platform

Science.gov (United States)

Chrysopoulos, Anthony C.; Symeonidis, Andreas L.; Mitkas, Pericles A.

Like in any other auctioning environment, entities participating in Power Stock Markets have to compete against other in order to maximize own revenue. Towards the satisfaction of their goal, these entities (agents - human or software ones) may adopt different types of strategies - from na?ve to extremely complex ones - in order to identify the most profitable goods compilation, the appropriate price to buy or sell etc, always under time pressure and auction environment constraints. Decisions become even more difficult to make in case one takes the vast volumes of historical data available into account: goods’ prices, market fluctuations, bidding habits and buying opportunities. Within the context of this paper we present Cassandra, a multi-agent platform that exploits data mining, in order to extract efficient models for predicting Power Settlement prices and Power Load values in typical Day-ahead Power markets. The functionality of Cassandra is discussed, while focus is given on the bidding mechanism of Cassandra’s agents, and the way data mining analysis is performed in order to generate the optimal forecasting models. Cassandra has been tested in a real-world scenario, with data derived from the Greek Energy Stock market.

PEG conjugates in clinical development or use as anticancer agents: an overview.

Science.gov (United States)

Pasut, Gianfranco; Veronese, Francesco M

2009-11-12

During the almost forty years of PEGylation, several antitumour agents, either proteins, peptides or low molecular weight drugs, have been considered for polymer conjugation but only few entered clinical phase studies. The results from the first clinical trials have shared and improved the knowledge on biodistribution, clearance, mechanism of action and stability of a polymer conjugate in vivo. This has helped to design conjugates with improved features. So far, most of the PEG conjugates comprise of a protein, which in the native form has serious shortcomings that limit the full exploitation of its therapeutic action. The main issues can be short in vivo half-life, instability towards degrading enzymes or immunogenicity. PEGylation proved to be effective in shielding sensitive sites at the protein surface, such as antigenic epitopes and enzymatic degradable sequences, as well as in prolonging the drug half-life by decreasing the kidney clearance. In this review PEG conjugates of proteins or low molecular weight drugs, in clinical development or use as anticancer agents, will be taken into consideration. In the case of PEG-protein derivatives the most represented are depleting enzymes, which act by degrading amino acids essential for cancer cells. Interestingly, PEGylated conjugates have been also considered as adjuvant therapy in many standard anticancer protocols, in this regard the case of PEG-G-CSF and PEG-interferons will be presented.

Mechanisms of oxide dissolution by acid chelating agents

International Nuclear Information System (INIS)

Blesa, M.A.; Maroto, A.J.G.

1982-01-01

In this paper, the different possible rate controlling processes in the dissolution of metallic oxides are examined. In particular, the following situations are assessed: mass-transfer control; coupling of mass-transfer and reactions at the interface; interface equilibration with the solution; various interface disruption and reconstruction phenomena. For each of the above mentioned cases, the influence of variables such as reagent concentration, temperature, pH, fluid hydrodynamics and general and specific catalysts is discussed. Depending upon the particular situation it is found that a more rational basis for the development of reagent is given by these considerations. The influence of chelating agents on both the thermodynamics and kinetics of the process is discussed, and the results of experimental studies in batch on magnetite and various ferrites are presented and discussed. For this purpose, several reagents were studied, including some very effective ones like thioglycolic acid, and others commonly used in actual decontamination, like ethylenediaminetetraacetic acid and oxalic acid. The relation to other (reductive) chemical decontamination procedures is discussed. The relevance of these studies to decontamination of metallic surfaces is discussed

Protection by thiols against poisoning by radiomimetic agents. Chapter 8

International Nuclear Information System (INIS)

Bacq, Z.M.

1975-01-01

A review is presented of reports of studies aimed at detecting a protective effect of thiols against radiomimetic alkylating agents such as those used in cancer therapy (nitrogen mustards (HN2), sarcolysine, busulfan, etc.). Protection by thiols against alkylating agents has been observed in mammals, plant cells, bacteria, isolated mammalian cells and in model systems. The lack of correlation between the protective power of various thiols against radiomimetic agents and ionizing radiations indicates that different mechanisms are involved. Studies have been made of the toxicity of the protector and the competition factor, increased excretion of detoxication products of alkylating agents, decreased alkylation of DNA and RNA both in vivo and in vitro, the protection of hematopoietic tissues, tumours and the adrenal cortex, and the modification of the effects of nitrosoalkylamines, carbon tetrachloride and fungistatics by thiols. The restriction of DNA alkylation by the competitive removal of radiomimetic agents is thought to account for the protective effect of thiols against radiomimetic agents. (U.K.)

Effects of pore forming agents of potassium bicarbonate and drug loading method against dissolution mechanisms of amoxicillin drugs encapsulated in hydrogel full-Ipn chitosan-poly(N-vinylcaprolactam) as a floating drug delivery system

Science.gov (United States)

Aini, Nurul; Rahayu, Dyah Utami Cahyaning; Budianto, Emil

2018-04-01

The limitation of amoxicillin trihydrate in the treatment of H. pylori bacteria is relatively short retention time in the stomach. The FDDS (Floating Drug Delivery System) amoxicillin trihydrate into a chitosan-poly(N-vinylcaprolactam) full-Ipn hydrogel matrix using a pore-forming agent KHCO3 is expected to overcome these limitations. The pore-forming agent to be used is 15% KHCO3 compound. Chemical kinetics approach is performed to determine the dissolution mechanism of amoxicillin trihydrate from K-PNVCL hydrogel in vitro on gastric pH and characterization using SEM performed to confirm the dissolution mechanism. Hydrogels with the addition of pore-forming agents will be loading in situ loading and post loading. Fourier Transform Infra Red (FTIR) spectroscopy was used to characterize K-PNVCL and UV-Vis hydrogels used to calculate the efficiency of encapsulation and drug dissolution rate in K-PNVCL hydrogel. Hydrogel K-PNVCL / KHCO3 that encapsulated by in situ loading method resulted in an encapsulation efficiency of 93.5% and dissolution of 93.4%. While the Hydrogel K-PNVCL / KHCO3 which is drug encapsulation resulted in an encapsulation efficiency of 87.2% with dissolution of 81.5%. Chemical kinetics approach to in situ encapsulation of loading and post loading shows the dissolution mechanism occurring in the K-PNVCL / KHCO3 hydrogel matrix occurs by diffusion. Observation using optical microscope and SEM showed the mechanism of drug dissolution in Hydrogel K-PNVCL occurred by diffusion.

Genetic Algorithms for Agent-Based Infrastructure Interdependency Modeling and Analysis

Energy Technology Data Exchange (ETDEWEB)

May Permann

2007-03-01

Today’s society relies greatly upon an array of complex national and international infrastructure networks such as transportation, electric power, telecommunication, and financial networks. This paper describes initial research combining agent-based infrastructure modeling software and genetic algorithms (GAs) to help optimize infrastructure protection and restoration decisions. This research proposes to apply GAs to the problem of infrastructure modeling and analysis in order to determine the optimum assets to restore or protect from attack or other disaster. This research is just commencing and therefore the focus of this paper is the integration of a GA optimization method with a simulation through the simulation’s agents.

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

An Agent-based Modeling of Water-Food Nexus towards Sustainable Management of Urban Water Resources

Science.gov (United States)

Esmaeili, N.; Kanta, L.

2017-12-01

Growing population, urbanization, and climate change have put tremendous stress on water systems in many regions. A shortage in water system not only affects water users of a municipality but also that of food system. About 70% of global water is withdrawn for agriculture; livestock and dairy productions are also dependent on water availability. Although researchers and policy makers have identified and emphasized the water-food (WF) nexus in recent decade, most existing WF models offer strategies to reduce trade-offs and to generate benefits without considering feedback loops and adaptations between those systems. Feedback loops between water and food system can help understand long-term behavioral trends between water users of the integrated WF system which, in turn, can help manage water resources sustainably. An Agent-based modeling approach is applied here to develop a conceptual framework of WF systems. All water users in this system are modeled as agents, who are capable of making decisions and can adapt new behavior based on inputs from other agents in a shared environment through a set of logical and mathematical rules. Residential and commercial/industrial consumers are represented as municipal agents; crop, livestock, and dairy farmers are represented as food agents; and water management officials are represented as policy agent. During the period of water shortage, policy agent will propose/impose various water conservation measures, such as adapting water-efficient technologies, banning outdoor irrigation, implementing supplemental irrigation, using recycled water for livestock/dairy production, among others. Municipal and food agents may adapt conservation strategies and will update their demand accordingly. Emergent properties of the WF nexus will arise through dynamic interactions between various actors of water and food system. This model will be implemented to a case study for resource allocation and future policy development.

[Effect of prokinetic agents on the electrical activity of stomach and duodenum in rats].

Science.gov (United States)

Li, Fujun; Zou, Yiyou; Huang, Tianhui

2009-07-01

To determine the effect of prokinetic agents such as domperidone, mosapride, clarithromycin, and itopride on the electrical activity of the stomach and duodenum in SD rats,and also to explore the mechanism. The organism functional experiment system BL-420E was used to record the myoelectrical activity in the stomach and duodenum of SD rats in all groups using domperidone, mosapride, itopride, clarithromycin, and physiological saline on the interdigestive phase. The effect of the prokinetic agents on the amplitude and frequency of gastric and duodenal electromyogram in the SD rats was compared. The antagonists such as atropine, phentolamine, and propranolol were added to investigate the mechanism of action with all prokinetic agents. All prokinetic agents increased the amplitude and frequency of gastric and duodenal fast waves in the SD rats(Pitopride was the most obvious among the 3 groups (Pitopride, and physiological saline were inhibited by atropine(PItopride, mosapride, domperidone, and clarithromycin can increase the amplitude and frequency of gastric and duodenal fast waves in the SD rats. The mechanism may be related to cholinergic receptors, but not adrenergic receptors.

Negotiating on location, timing, duration, and participant in agent-mediated joint activity-travel scheduling

Science.gov (United States)

Ma, Huiye; Ronald, Nicole; Arentze, Theo A.; Timmermans, Harry J. P.

2013-10-01

Agent-based simulation has become an important modeling approach in activity-travel analysis. Social activities account for a large amount of travel and have an important effect on activity-travel scheduling. Participants in joint activities usually have various options regarding location, participants, and timing and take different approaches to make their decisions. In this context, joint activity participation requires negotiation among agents involved, so that conflicts among the agents can be addressed. Existing mechanisms do not fully provide a solution when utility functions of agents are nonlinear and non-monotonic. Considering activity-travel scheduling in time and space as an application, we propose a novel negotiation approach, which takes into account these properties, such as continuous and discrete issues, and nonlinear and non-monotonic utility functions, by defining a concession strategy and a search mechanism. The results of experiments show that agents having these properties can negotiate efficiently. Furthermore, the negotiation procedure affects individuals’ choices of location, timing, duration, and participants.

The relation between young children's physiological arousal and their motivation to help others.

Science.gov (United States)

Hepach, Robert; Vaish, Amrisha; Müller, Katharina; Tomasello, Michael

2017-10-10

Children are motivated to help others from an early age. However, little is known about the internal biological mechanisms underlying their motivation to help. Here, we compiled data from five separate studies in which children, ranging in age from 18 months to 5.5 years, witnessed an adult needing help. In all studies, we assessed both (1) children's internal physiological arousal via changes in their pupil dilation, and (2) the latency and likelihood of them providing help. The results showed that the greater the baseline-corrected change in children's internal arousal in response to witnessing the need situation, the faster and more likely children were to help the adult. This was not the case for the baseline measure of children's tonic arousal state. Together, these results suggest that children's propensity to help is systematically related to their physiological arousal after they witness others needing help. This sheds new light on the biological mechanisms underlying not only young children's social perception but also their prosocial motivation more generally. Copyright © 2017 Elsevier Ltd. All rights reserved.

Perspectives in the development of hybrid bifunctional antitumour agents.

Science.gov (United States)

Musso, Loana; Dallavalle, Sabrina; Zunino, Franco

2015-08-15

In spite of the development of a large number of novel target-specific antitumour agents, the single-agent therapy is in general not able to provide an effective durable control of the malignant process. The limited efficacy of the available agents (both conventional cytotoxic and novel target-specific) reflects not only the expression of defence mechanisms, but also the complexity of tumour cell alterations and the redundancy of survival pathways, thus resulting in tumour cell ability to survive under stress conditions. A well-established strategy to improve the efficacy of antitumour therapy is the rational design of drug combinations aimed at achieving synergistic effects and overcoming drug resistance. An alternative strategy could be the use of agents designed to inhibit simultaneously multiple cellular targets relevant to tumour growth/survival. Among these novel agents are hybrid bifunctional drugs, i.e. compounds resulting by conjugation of different drugs or containing the pharmocophores of different drugs. This strategy has been pursued using various conventional or target-specific agents (with DNA damaging agents and histone deacetylase inhibitors as the most exploited compounds). A critical overview of the most representative compounds is provided with emphasis on the HDAC inhibitor-based hybrid agents. In spite of some promising results, the actual pharmacological advantages of the hybrid agents remain to be defined. This commentary summarizes the recent advances in this field and highlights the pharmacological basis for a rational design of hybrid bifunctional agents. Copyright © 2015. Published by Elsevier Inc.

Smart Aerospace eCommerce: Using Intelligent Agents in a NASA Mission Services Ordering Application

Science.gov (United States)

Moleski, Walt; Luczak, Ed; Morris, Kim; Clayton, Bill; Scherf, Patricia; Obenschain, Arthur F. (Technical Monitor)

2002-01-01

This paper describes how intelligent agent technology was successfully prototyped and then deployed in a smart eCommerce application for NASA. An intelligent software agent called the Intelligent Service Validation Agent (ISVA) was added to an existing web-based ordering application to validate complex orders for spacecraft mission services. This integration of intelligent agent technology with conventional web technology satisfies an immediate NASA need to reduce manual order processing costs. The ISVA agent checks orders for completeness, consistency, and correctness, and notifies users of detected problems. ISVA uses NASA business rules and a knowledge base of NASA services, and is implemented using the Java Expert System Shell (Jess), a fast rule-based inference engine. The paper discusses the design of the agent and knowledge base, and the prototyping and deployment approach. It also discusses future directions and other applications, and discusses lessons-learned that may help other projects make their aerospace eCommerce applications smarter.

DNA Damage Induced by Alkylating Agents and Repair Pathways

OpenAIRE

Natsuko Kondo; Akihisa Takahashi; Koji Ono; Takeo Ohnishi

2010-01-01

The cytotoxic effects of alkylating agents are strongly attenuated by cellular DNA repair processes, necessitating a clear understanding of the repair mechanisms. Simple methylating agents form adducts at N- and O-atoms. N-methylations are removed by base excision repair, AlkB homologues, or nucleotide excision repair (NER). O 6-methylguanine (MeG), which can eventually become cytotoxic and mutagenic, is repaired by O 6-methylguanine-DNA methyltransferase, and O 6MeG:T mispairs are recognized...

Wealth distribution across communities of adaptive financial agents

Science.gov (United States)

DeLellis, Pietro; Garofalo, Franco; Lo Iudice, Francesco; Napoletano, Elena

2015-08-01

This paper studies the trading volumes and wealth distribution of a novel agent-based model of an artificial financial market. In this model, heterogeneous agents, behaving according to the Von Neumann and Morgenstern utility theory, may mutually interact. A Tobin-like tax (TT) on successful investments and a flat tax are compared to assess the effects on the agents’ wealth distribution. We carry out extensive numerical simulations in two alternative scenarios: (i) a reference scenario, where the agents keep their utility function fixed, and (ii) a focal scenario, where the agents are adaptive and self-organize in communities, emulating their neighbours by updating their own utility function. Specifically, the interactions among the agents are modelled through a directed scale-free network to account for the presence of community leaders, and the herding-like effect is tested against the reference scenario. We observe that our model is capable of replicating the benefits and drawbacks of the two taxation systems and that the interactions among the agents strongly affect the wealth distribution across the communities. Remarkably, the communities benefit from the presence of leaders with successful trading strategies, and are more likely to increase their average wealth. Moreover, this emulation mechanism mitigates the decrease in trading volumes, which is a typical drawback of TTs.

Structure, Mechanics and Flow Properties of Fractured Shale: Core-Scale Experimentation and In-situ Imaging

Science.gov (United States)

Abdelmalek, B. F.; Karpyn, Z.; Liu, S.

2014-12-01

Over the last several years, hydrocarbon exploitation and development in North America has been heavily centered on shale gas plays. However, the physical attributes of shales and their manifestation on transport properties and storage capacity remain poorly understood. Therefore, more experimentally based data are needed to fill the gaps in understanding both transport and storage of fluids in shale. The proposed work includes installation and testing of an experimental system which is capable of monitoring the dynamic evolution of shale core permeability under variable loading conditions and in coordination with X-ray microCT imaging. The goal of this study is to better understand and quantify fluid flow patterns and associated transport dynamics of fractured shale samples. The independent variables considered in this study are: mechanical loading and pore pressure. The mechanical response of shale core is captured for different loading paths. To best replicate the in-situ production scenario, the pore pressure is progressively depleted to mimic pressure decline. During the course of experimentation, permeability is estimated using the pulse-decay method under tri-axial stress boundary conditions. Simultaneously, X-ray microCT imaging is used with a tracer gas that is allowed to flow through the sample as an illuminating agent. In the presence of an illuminating agent, either Xenon or Krypton, the X-ray CT scanner can image fractures, global pathways and diffusional fronts in the matrix, as well as sorption sites that reflect heterogeneities in the sample and localized deformation. Anticipated results from these experiments will help quantify permeability evolution as a function of different loading conditions and pore pressure depletion. Also, the X-ray images will help visualize the change of flow patterns and the intensity of sorption as a function of mechanical loading and pore pressure.

African Logistics Agents and Middlemen as Cultural Brokers in Guangzhou

Directory of Open Access Journals (Sweden)

Gordon Mathews

2015-01-01

Full Text Available This article begins by asking how African traders learn to adjust to the foreign world of Guangzhou, China, and suggests that African logistics agents and middlemen serve as cultural brokers for these traders. After defining “cultural broker” and discussing why these brokers are not usually Chinese, it explores this role as played by ten logistics agents/middlemen from Kenya, Nigeria, Ghana and the Democratic Republic of the Congo. As logistics agents, these people help their customers in practically adjusting to Chinese life, and as middlemen they serve to grease the wheels of commerce between African customers and Chinese suppliers. This is despite their own ambivalent views of China as a place to live. They play an essential role in enabling harmonious relations between Africans and Chinese in Guangzhou, even though they see themselves not as cultural brokers but simply as businessmen.

Quantum mechanical/molecular mechanical and docking study of the novel analogues based on hybridization of common pharmacophores as potential anti-breast cancer agents.

Science.gov (United States)

Asadi, Parvin; Khodarahmi, Ghadamali; Farrokhpour, Hossein; Hassanzadeh, Farshid; Saghaei, Lotfollah

2017-06-01

In an attempt to identify some new potential leads as anti-breast cancer agents, novel hybrid compounds were designed by molecular hybridization approach. These derivatives were structurally derived from hybrid benzofuran-imidazole and quinazolinone derivatives, which had shown good cytotoxicity against the breast cancer cell line (MCF-7). Since aromatase enzyme (CYP19) is highly expressed in the MCF-7 cell line, the binding of these novel hybrid compounds to aromatase was investigated using the docking method. In this study, due to the positive charge on the imidazole ring of the designed ligands and also, the presence of heme iron in the active site of the enzyme, it was decided to optimize the ligand inside the protein to obtain more realistic atomic charges for it. Quantum mechanical/molecular mechanical (QM/MM) method was used to obtain more accurate atomic charges of ligand for docking calculations by considering the polarization effects of CYP19 on ligands. It was observed that the refitted charge improved the binding energy of the docked compounds. Also, the results showed that these novel hybrid compounds were adopted properly within the aromatase binding site, thereby suggesting that they could be potential inhibitors of aromatase. The main binding modes in these complexes were through hydrophobic and H bond interactions showing agreement with the basic physicochemical features of known anti aromatase compounds. Finally, the complex structures obtained from the docking study were used for single point QM/MM calculations to obtain more accurate electronic interaction energy, considering the electronic polarization of the ligand by its protein environment.

Laser photoacoustic spectroscopy helps fight terrorism: High sensitivity detection of chemical Warfare Agent and explosives

Science.gov (United States)

Patel, C. K. N.

2008-01-01

Tunable laser photoacoustic spectroscopy is maturing rapidly in its applications to real world problems. One of the burning problems of the current turbulent times is the threat of terrorist acts against civilian population. This threat appears in two distinct forms. The first is the potential release of chemical warfare agents (CWA), such as the nerve agents, in a crowded environment. An example of this is the release of Sarin by Aum Shinrikyo sect in a crowded Tokyo subway in 1995. An example of the second terrorist threat is the ever-present possible suicide bomber in crowded environment such as airports, markets and large buildings. Minimizing the impact of both of these threats requires early detection of the presence of the CWAs and explosives. Photoacoustic spectroscopy is an exquisitely sensitive technique for the detection of trace gaseous species, a property that Pranalytica has extensively exploited in its CO2 laser based commercial instrumentation for the sub-ppb level detection of a number of industrially important gases including ammonia, ethylene, acrolein, sulfur hexafluoride, phosphine, arsine, boron trichloride and boron trifluoride. In this presentation, I will focus, however, on our recent use of broadly tunable single frequency high power room temperature quantum cascade lasers (QCL) for the detection of the CWAs and explosives. Using external grating cavity geometry, we have developed room temperature QCLs that produce continuously tunable single frequency CW power output in excess of 300 mW at wavelengths covering 5 μm to 12 μm. I will present data that show a CWA detection capability at ppb levels with false alarm rates below 1:108. I will also show the capability of detecting a variety of explosives at a ppb level, again with very low false alarm rates. Among the explosives, we have demonstrated the capability of detecting homemade explosives such as triacetone triperoxide and its liquid precursor, acetone which is a common household

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

Agent-based Modeling Automated: Data-driven Generation of Innovation Diffusion Models

NARCIS (Netherlands)

Jensen, T.; Chappin, E.J.L.

2016-01-01

Simulation modeling is useful to gain insights into driving mechanisms of diffusion of innovations. This study aims to introduce automation to make identification of such mechanisms with agent-based simulation modeling less costly in time and labor. We present a novel automation procedure in which

Mechanical Ventilation

Science.gov (United States)

... ventilation is a life support treatment. A mechanical ventilator is a machine that helps people breathe when ... to breathe enough on their own. The mechanical ventilator is also called a ventilator , respirator, or breathing ...

Influence of Chloride-Ion Adsorption Agent on Chloride Ions in Concrete and Mortar

Directory of Open Access Journals (Sweden)

Gai-Fei Peng

2014-04-01

Full Text Available The influence of a chloride-ion adsorption agent (Cl agent in short, composed of zeolite, calcium aluminate hydrate and calcium nitrite, on the ingress of chloride ions into concrete and mortar has been experimentally studied. The permeability of concrete was measured, and the chloride ion content in mortar was tested. The experimental results reveal that the Cl agent could adsorb chloride ions effectively, which had penetrated into concrete and mortar. When the Cl agent was used at a dosage of 6% by mass of cementitious materials in mortar, the resistance to the penetration of chloride ions could be improved greatly, which was more pronounced when a combination of the Cl agent and fly ash or slag was employed. Such an effect is not the result of the low permeability of the mortar, but might be a result of the interaction between the Cl agent and the chloride ions penetrated into the mortar. There are two possible mechanisms for the interaction between the Cl agent and chloride ion ingress. One is the reaction between calcium aluminate hydrate in the Cl agent and chloride ions to form Friedel’s salt, and the other one is that calcium aluminate hydrate reacts with calcium nitrite to form AFm during the early-age hydration of mortar and later the NO2− in AFm is replaced by chloride ions, which then penetrate into the mortar, also forming Friedel’s salt. More research is needed to confirm the mechanisms.

Memory effects induce structure in social networks with activity-driven agents

International Nuclear Information System (INIS)

Medus, A D; Dorso, C O

2014-01-01

Activity-driven modelling has recently been proposed as an alternative growth mechanism for time varying networks,displaying power-law degree distribution in time-aggregated representation. This approach assumes memoryless agents developing random connections with total disregard of their previous contacts. Thus, such an assumption leads to time-aggregated random networks that do not reproduce the positive degree-degree correlation and high clustering coefficient widely observed in real social networks. In this paper, we aim to study the incidence of the agents' long-term memory on the emergence of new social ties. To this end, we propose a dynamical network model assuming heterogeneous activity for agents, together with a triadic-closure step as main connectivity mechanism. We show that this simple mechanism provides some of the fundamental topological features expected for real social networks in their time-aggregated picture. We derive analytical results and perform extensive numerical simulations in regimes with and without population growth. Finally, we present an illustrative comparison with two case studies, one comprising face-to-face encounters in a closed gathering, while the other one corresponding to social friendship ties from an online social network. (paper)

The Role of Conversation Policy in Carrying Out Agent Conversations

International Nuclear Information System (INIS)

Link, Hamilton E.; Phillips, Laurence R.

1999-01-01

Structured conversation diagrams, or conversation specifications, allow agents to have predictable interactions and achieve predefined information-based goals, but they lack the flexibility needed to function robustly in an unpredictable environment. We propose a mechanism that combines a typical conversation structure with a separately established policy to generate an actual conversation. The word ''policy'' connotes a high-level direction external to a specific planned interaction with the environment. Policies, which describe acceptable procedures and influence decisions, can be applied to broad sets of activity. Based on their observation of issues related to a policy, agents may dynamically adjust their communication patterns. The policy object describes limitations, constraints, and requirements that may affect the conversation in certain circumstances. Using this new mechanism of interaction simplifies the description of individual conversations and allows domain-specific issues to be brought to bear more easily during agent communication. By following the behavior of the conversation specification when possible and deferring to the policy to derive behavior in exceptional circumstances, an agent is able to function predictably under normal situations and still act rationally in abnormal situations. Different conversation policies applied to a given conversation specification can change the nature of the interaction without changing the specification

Balancing repair and tolerance of DNA damage caused by alkylating agents.

Science.gov (United States)

Fu, Dragony; Calvo, Jennifer A; Samson, Leona D

2012-01-12

Alkylating agents constitute a major class of frontline chemotherapeutic drugs that inflict cytotoxic DNA damage as their main mode of action, in addition to collateral mutagenic damage. Numerous cellular pathways, including direct DNA damage reversal, base excision repair (BER) and mismatch repair (MMR), respond to alkylation damage to defend against alkylation-induced cell death or mutation. However, maintaining a proper balance of activity both within and between these pathways is crucial for a favourable response of an organism to alkylating agents. Furthermore, the response of an individual to alkylating agents can vary considerably from tissue to tissue and from person to person, pointing to genetic and epigenetic mechanisms that modulate alkylating agent toxicity.

Co-creating value through agents interaction within service network

International Nuclear Information System (INIS)

Okdinawati, L.; Simatupang, T.M.; Sunitiyoso, Y.

2017-01-01

The purpose of this paper is to gives further understanding on value co-creation mechanisms in B-to-B service network by reinforcing the processes, the relationships, and influences of other agents where Collaborative Transportation Management (CTM) forms might be best employed. Design/methodology/approach: In order to model the interactions among agents in the collaboration processes and the value co-creation processes, this research used three collaboration cases in Indonesia. Then, the agent-based simulation was used to capture both the collaboration process and the value co-creation process of the three collaboration cases. Findings: The interactions among the agents both inside and outside their collaboration environment determined agent’s role as a value co-creator. The willingness of an agent to accept the opinion of another agent determined the degree of their willingness to co-operate and to change their strategies, and perceptions. Therefore, influenced the size of the value obtained by them in each collaboration process. Research limitations/implications: The findings of the simulations subject to assumptions based on the collaboration cases. Further research is related to how to encourage agents to co-operate and adjust their perceptions. Practical implications: It is crucial for the practitioners to interact with another agent both inside and outside their collaboration environment. The opinions of another agent inside the collaboration environment also need to be considered. Originality/value: This research is derived from its emphasis on how a value is co-created by reinforcing both the collaborative processes and the interactions among agents as well as on how CTM might be best employed.

Co-creating value through agents interaction within service network

Energy Technology Data Exchange (ETDEWEB)

Okdinawati, L.; Simatupang, T.M.; Sunitiyoso, Y.

2017-07-01

The purpose of this paper is to gives further understanding on value co-creation mechanisms in B-to-B service network by reinforcing the processes, the relationships, and influences of other agents where Collaborative Transportation Management (CTM) forms might be best employed. Design/methodology/approach: In order to model the interactions among agents in the collaboration processes and the value co-creation processes, this research used three collaboration cases in Indonesia. Then, the agent-based simulation was used to capture both the collaboration process and the value co-creation process of the three collaboration cases. Findings: The interactions among the agents both inside and outside their collaboration environment determined agent’s role as a value co-creator. The willingness of an agent to accept the opinion of another agent determined the degree of their willingness to co-operate and to change their strategies, and perceptions. Therefore, influenced the size of the value obtained by them in each collaboration process. Research limitations/implications: The findings of the simulations subject to assumptions based on the collaboration cases. Further research is related to how to encourage agents to co-operate and adjust their perceptions. Practical implications: It is crucial for the practitioners to interact with another agent both inside and outside their collaboration environment. The opinions of another agent inside the collaboration environment also need to be considered. Originality/value: This research is derived from its emphasis on how a value is co-created by reinforcing both the collaborative processes and the interactions among agents as well as on how CTM might be best employed.

The impact of calcium carbonate as pore forming agent and drug entrapment method towards drug dissolution mechanism of amoxicillin trihydrate encapsulated by chitosan-methyl cellulose semi-IPN hydrogel for floating drug delivery system

Science.gov (United States)

Dewantara, Fauzi; Budianto, Emil

2018-04-01

Chitosan-methyl cellulose semi-IPN hydrogel is used as floating drug delivery system, and calcium carbonate also added as pore forming agent. The hydrogel network arranged by not only using biopolymer chitosan and methyl cellulose, but also the crosslink agent that is glutaraldehyde. Amoxicillin trihydrate entrapped into the polymer network with two different method, in situ loading and post loading. Furthermore both method has been tested for drug entrapment efficiency along with drug dissolution test, and the result for drug entrapment efficiency is in situ loading method has highest value of 100%, compared to post loading method which has value only 71%. Moreover, at the final time of drug dissolution test shows in situ loading method has value of 96% for total accumulative of drug dissolution, meanwhile post loading method has 72%. The value of drug dissolution test from both method is used for analyzing drug dissolution mechanism of amoxicillin trihydrate from hydrogel network with four mathematical drug mechanism models as parameter. The polymer network encounter destructive degradation causes by acid solution which used as dissolution medium, and the level of degradation is observed with optical microscope. However the result shows that degradation of the polymer network doesn't affect drug dissolution mechanism directly. Although the pore forming agent causes the pore inside the hydrogel network create interconnection and it was quite influential to drug dissolution mechanism. Interconnected pore is observed with Scanning Electron Microscope (SEM) and shows that the amount and area of interconnected pore inside the hydrogel network is increasing as drug dissolution goes on.

An alarm filtering system for an automated process: a multiple-agent approach

International Nuclear Information System (INIS)

Khoualdi, Kamel

1994-01-01

Nowadays, the supervision process of industrial installations is more and more complex involving the automation of their control. A malfunction generates an avalanche of alarms. The operator, in charge of the supervision, must face the incident and execute right actions to recover a normal situation. Generally, he is drowned under the great number of alarms. Our aim, in the frame of our researches, is to perform an alarm filtering system for an automated metro line, to help the operator finding the main alarm responsible for the malfunction. Our works are divided into two parts, both dealing with study and development of an alarm filtering system but using two different approaches. The first part is developed in the frame of the SARA project (an operator assistance system for an automated metro line) which is an expert system prototype helping the operators of a command center. In this part, a centralized approach has been used representing the events with a single event graph and using a global procedure to perform diagnosis. This approach has itself shown its limits. In the second part of our works, we have considered the distributed artificial intelligence (DAI) techniques, and more especially the multi-agent approach. The multi-agent approach has been motivated by the natural distribution of the metro line equipment and by the fact that each equipment has its own local control and knowledge. Thus, each equipment has been considered as an autonomous agent. Through agents cooperation, the system is able to determine the main alarm and the faulty equipment responsible for the incident. A prototype, written in SPIRAL (a tool for knowledge-based system) is running on a workstation. This prototype has allowed the concretization and the validation of our multi-agent approach. (author) [fr

A critical survey of agent-based wholesale electricity market models

International Nuclear Information System (INIS)

Weidlich, Anke; Veit, Daniel

2008-01-01

The complexity of electricity markets calls for rich and flexible modeling techniques that help to understand market dynamics and to derive advice for the design of appropriate regulatory frameworks. Agent-Based Computational Economics (ACE) is a fairly young research paradigm that offers methods for realistic electricity market modeling. A growing number of researchers have developed agent-based models for simulating electricity markets. The diversity of approaches makes it difficult to overview the field of ACE electricity research; this literature survey should guide the way through and describe the state-of-the-art of this research area. In a conclusive summary, shortcomings of existing approaches and open issues that should be addressed by ACE electricity researchers are critically discussed. (author)

Performance Evaluation of Bidding-Based Multi-Agent Scheduling Algorithms for Manufacturing Systems

Directory of Open Access Journals (Sweden)

Antonio Gordillo

2014-10-01

Full Text Available Artificial Intelligence techniques have being applied to many problems in manufacturing systems in recent years. In the specific field of manufacturing scheduling many studies have been published trying to cope with the complexity of the manufacturing environment. One of the most utilized approaches is (multi agent-based scheduling. Nevertheless, despite the large list of studies reported in this field, there is no resource or scientific study on the performance measure of this type of approach under very common and critical execution situations. This paper focuses on multi-agent systems (MAS based algorithms for task allocation, particularly in manufacturing applications. The goal is to provide a mechanism to measure the performance of agent-based scheduling approaches for manufacturing systems under key critical situations such as: dynamic environment, rescheduling, and priority change. With this mechanism it will be possible to simulate critical situations and to stress the system in order to measure the performance of a given agent-based scheduling method. The proposed mechanism is a pioneering approach for performance evaluation of bidding-based MAS approaches for manufacturing scheduling. The proposed method and evaluation methodology can be used to run tests in different manufacturing floors since it is independent of the workshop configuration. Moreover, the evaluation results presented in this paper show the key factors and scenarios that most affect the market-like MAS approaches for manufacturing scheduling.

A Mechanism for Fair Distribution of Resources without Payments

Science.gov (United States)

Christoforou, Evgenia; Anta, Antonio Fernández; Santos, Agustín

2016-01-01

We design a mechanism for Fair and Efficient Distribution of Resources (FEDoR) in the presence of strategic agents. We consider a multiple-instances, Bayesian setting, where in each round the preference of an agent over the set of resources is a private information. We assume that in each of r rounds n agents are competing for k non-identical indivisible goods, (n > k). In each round the strategic agents declare how much they value receiving any of the goods in the specific round. The agent declaring the highest valuation receives the good with the highest value, the agent with the second highest valuation receives the second highest valued good, etc. Hence we assume a decision function that assigns goods to agents based on their valuations. The novelty of the mechanism is that no payment scheme is required to achieve truthfulness in a setting with rational/strategic agents. The FEDoR mechanism takes advantage of the repeated nature of the framework, and through a statistical test is able to punish the misreporting agents and be fair, truthful, and socially efficient. FEDoR is fair in the sense that, in expectation over the course of the rounds, all agents will receive the same good the same amount of times. FEDoR is an eligible candidate for applications that require fair distribution of resources over time. For example, equal share of bandwidth for nodes through the same point of access. But further on, FEDoR can be applied in less trivial settings like sponsored search, where payment is necessary and can be given in the form of a flat participation fee. FEDoR can be a good candidate in a setting like that to solve the problem of starvation of publicity slots for some advertisers that have a difficult time determining their true valuations. To this extent we perform a comparison with traditional mechanisms applied to sponsored search, presenting the advantage of FEDoR. PMID:27227992

A Mechanism for Fair Distribution of Resources without Payments.

Science.gov (United States)

Christoforou, Evgenia; Anta, Antonio Fernández; Santos, Agustín

2016-01-01

We design a mechanism for Fair and Efficient Distribution of Resources (FEDoR) in the presence of strategic agents. We consider a multiple-instances, Bayesian setting, where in each round the preference of an agent over the set of resources is a private information. We assume that in each of r rounds n agents are competing for k non-identical indivisible goods, (n > k). In each round the strategic agents declare how much they value receiving any of the goods in the specific round. The agent declaring the highest valuation receives the good with the highest value, the agent with the second highest valuation receives the second highest valued good, etc. Hence we assume a decision function that assigns goods to agents based on their valuations. The novelty of the mechanism is that no payment scheme is required to achieve truthfulness in a setting with rational/strategic agents. The FEDoR mechanism takes advantage of the repeated nature of the framework, and through a statistical test is able to punish the misreporting agents and be fair, truthful, and socially efficient. FEDoR is fair in the sense that, in expectation over the course of the rounds, all agents will receive the same good the same amount of times. FEDoR is an eligible candidate for applications that require fair distribution of resources over time. For example, equal share of bandwidth for nodes through the same point of access. But further on, FEDoR can be applied in less trivial settings like sponsored search, where payment is necessary and can be given in the form of a flat participation fee. FEDoR can be a good candidate in a setting like that to solve the problem of starvation of publicity slots for some advertisers that have a difficult time determining their true valuations. To this extent we perform a comparison with traditional mechanisms applied to sponsored search, presenting the advantage of FEDoR.

A Mechanism for Fair Distribution of Resources without Payments.

Directory of Open Access Journals (Sweden)

Evgenia Christoforou

Full Text Available We design a mechanism for Fair and Efficient Distribution of Resources (FEDoR in the presence of strategic agents. We consider a multiple-instances, Bayesian setting, where in each round the preference of an agent over the set of resources is a private information. We assume that in each of r rounds n agents are competing for k non-identical indivisible goods, (n > k. In each round the strategic agents declare how much they value receiving any of the goods in the specific round. The agent declaring the highest valuation receives the good with the highest value, the agent with the second highest valuation receives the second highest valued good, etc. Hence we assume a decision function that assigns goods to agents based on their valuations. The novelty of the mechanism is that no payment scheme is required to achieve truthfulness in a setting with rational/strategic agents. The FEDoR mechanism takes advantage of the repeated nature of the framework, and through a statistical test is able to punish the misreporting agents and be fair, truthful, and socially efficient. FEDoR is fair in the sense that, in expectation over the course of the rounds, all agents will receive the same good the same amount of times. FEDoR is an eligible candidate for applications that require fair distribution of resources over time. For example, equal share of bandwidth for nodes through the same point of access. But further on, FEDoR can be applied in less trivial settings like sponsored search, where payment is necessary and can be given in the form of a flat participation fee. FEDoR can be a good candidate in a setting like that to solve the problem of starvation of publicity slots for some advertisers that have a difficult time determining their true valuations. To this extent we perform a comparison with traditional mechanisms applied to sponsored search, presenting the advantage of FEDoR.

Effects of treatment with antimicrobial agents on the human colonic microflora

OpenAIRE

Rafii, Fatemeh

2008-01-01

Fatemeh Rafii, John B Sutherland, Carl E CernigliaDivision of Microbiology, National Center for Toxicological Research, FDA, Jefferson, AR, USAAbstract: Antimicrobial agents are the most valuable means available for treating bacterial infections. However, the administration of therapeutic doses of antimicrobial agents to patients is a leading cause of disturbance of the normal gastrointestinal microflora. This disturbance results in diminishing the natural defense mechanisms provided by the c...

The influence of starch oxidization and aluminate coupling agent on interfacial interaction, rheological behavior, mechanical and thermal properties of poly(propylene carbonate)/starch blends

Science.gov (United States)

Jiang, Guo; Zhang, Shui-Dong; Huang, Han-Xiong; The Key Laboratory of Polymer Processing Engineering of the Ministry of Education Team

Poly(propylene carbonate) (PPC) is a kind of new biodegradable polymer that is synthesized by copolymerization of propylene oxide and carbon dioxide. In this work, PPC end-capped with maleic anhydride (PPCMA)/thermoplastic starch (TPS), PPCMA/thermoplastic oxidized starch (TPOS) and PPCMA/AL-TPOS (TPOS modified by aluminate coupling agent) blends were prepared by melt blending to improve its thermal and mechanical properties. FTIR results showed that there existed hydrogen-bonding interaction between PPCMA and starch. SEM observation revealed that the compatibility between PPCMA and TPOS was improved by the oxidation of starch. The enhanced interfacial interactions between PPCMA and TPOS led to a better performance of PPC blends such as storage modulus (G'), loss modulus (G''), complex viscosity (η*), tensile strength and thermal properties. Furthermore, the modification of TPOS by aluminate coupling agent (AL) facilitated the dispersion of oxidized starch in PPC matrix, and resulted in increasing the tensile strength and thermal stability. National Natural Science Foundation of China, National Science Fund of Guangdong Province.

Breaking the Barrier to Slow Water Exchange Rates for Optimal Magnetic Resonance Detection of paraCEST Agents.

Science.gov (United States)

Fernando, W Shirangi; Martins, André F; Zhao, Piyu; Wu, Yunkou; Kiefer, Garry E; Platas-Iglesias, Carlos; Sherry, A Dean

2016-03-21

EuDOTA-tetraamide complexes as paraCEST agents offer an attractive platform for designing biological sensors and responsive agents. The early versions of these agents showed low sensitivity at temperature and power levels suitable for in vivo applications partly due to non-optimal water exchange rates. Here we report two new EuDOTA derivatives having glutamyl-phosphonate side arms that display the slowest water exchange rates of any other paraCEST agent reported so far. The advantages of such systems are demonstrated experimentally both in vitro and in vivo and DFT calculations were performed to help understand the physical-chemical reasons for this interesting behavior.

Synergistic Effects of Nucleating Agents and Plasticizers on the Crystallization Behavior of Poly(lactic acid

Directory of Open Access Journals (Sweden)

Xuetao Shi

2015-01-01

Full Text Available The synergistic effect of nucleating agents and plasticizers on the thermal and mechanical performance of PLA nanocomposites was investigated with the objective of increasing the crystallinity and balancing the stiffness and toughness of PLA mechanical properties. Calcium carbonate, halloysite nanotubes, talc and LAK (sulfates were compared with each other as heterogeneous nucleating agents. Both the DSC isothermal and non-isothermal studies indicated that talc and LAK were the more effective nucleating agents among the selected fillers. Poly(D-lactic acid (PDLA acted also as a nucleating agent due to the formation of the PLA stereocomplex. The half crystallization time was reduced by the addition of talc to about 2 min from 37.5 min of pure PLA by the isothermal crystallization study. The dynamic mechanical thermal study (DMTA indicated that nanofillers acted as both reinforcement fillers and nucleating agents in relation to the higher storage modulus. The plasticized PLA studied by DMTA indicated a decreasing glass transition temperature with the increasing of the PEG content. The addition of nanofiller increased the Young’s modulus. PEG had the plasticization effect of increasing the break deformation, while sharply decreasing the stiffness and strength of PLA. The synergistic effect of nanofillers and plasticizer achieved the balance between stiffness and toughness with well-controlled crystallization.

Merging Agents and Cloud Services in Industrial Applications

Directory of Open Access Journals (Sweden)

Francisco P. Maturana

2014-01-01

Full Text Available A novel idea to combine agent technology and cloud computing for monitoring a plant floor system is presented. Cloud infrastructure has been leveraged as the main mechanism for hosting the data and processing needs of a modern industrial information system. The cloud offers unlimited storage and data processing in a near real-time fashion. This paper presents a software-as-a-service (SaaS architecture for augmenting industrial plant-floor reporting capabilities. This reporting capability has been architected using networked agents, worker roles, and scripts for building a scalable data pipeline and analytics system.

Chemical warfare agents.

Science.gov (United States)

Kuca, Kamil; Pohanka, Miroslav

2010-01-01

Chemical warfare agents are compounds of different chemical structures. Simple molecules such as chlorine as well as complex structures such as ricin belong to this group. Nerve agents, vesicants, incapacitating agents, blood agents, lung-damaging agents, riot-control agents and several toxins are among chemical warfare agents. Although the use of these compounds is strictly prohibited, the possible misuse by terrorist groups is a reality nowadays. Owing to this fact, knowledge of the basic properties of these substances is of a high importance. This chapter briefly introduces the separate groups of chemical warfare agents together with their members and the potential therapy that should be applied in case someone is intoxicated by these agents.

Helping You Help Me: The Role of Diagnostic (In)congruence in the Helping Process within Organizations

OpenAIRE

Fisher, Colin M.; Pillemer, Julianna; Amabile, Teresa M.

2014-01-01

Through an inductive, multi-method field study at a major design firm, we investigated the helping process in project work and how that process affects the success of a helping episode, as perceived by help-givers and/or -receivers. We used daily diary entries and weekly interviews from four project teams, and a separate sample of critical incident interviews, to induce process models of successful and unsuccessful helping episodes. We found that, in unsuccessful episodes, help-givers and -re...

Logics for Intelligent Agents and Multi-Agent Systems

NARCIS (Netherlands)

Meyer, John-Jules Charles

2014-01-01

This chapter presents the history of the application of logic in a quite popular paradigm in contemporary computer science and artificial intelligence, viz. the area of intelligent agents and multi-agent systems. In particular we discuss the logics that have been used to specify single agents, the

Helping HELP with limited resources: the Luquillo experience

Science.gov (United States)

F.N. Scatena; JR Ortiz-Zayas; J.F. Blanco-Libreros

2008-01-01

By definition the HELP approach involves the active participation of individuals from a wide range of disciplines and backgrounds, including representatives of industry, academics, natural resource managers, and local officials and community leaders. While there is considerable enthusiasm and support for the integrated HELP approach, a central problem for all HELP...

Action observation and robotic agents: learning and anthropomorphism.

Science.gov (United States)

Press, Clare

2011-05-01

The 'action observation network' (AON), which is thought to translate observed actions into motor codes required for their execution, is biologically tuned: it responds more to observation of human, than non-human, movement. This biological specificity has been taken to support the hypothesis that the AON underlies various social functions, such as theory of mind and action understanding, and that, when it is active during observation of non-human agents like humanoid robots, it is a sign of ascription of human mental states to these agents. This review will outline evidence for biological tuning in the AON, examining the features which generate it, and concluding that there is evidence for tuning to both the form and kinematic profile of observed movements, and little evidence for tuning to belief about stimulus identity. It will propose that a likely reason for biological tuning is that human actions, relative to non-biological movements, have been observed more frequently while executing corresponding actions. If the associative hypothesis of the AON is correct, and the network indeed supports social functioning, sensorimotor experience with non-human agents may help us to predict, and therefore interpret, their movements. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Psychological Self as Actor, Agent, and Author.

Science.gov (United States)

McAdams, Dan P

2013-05-01

The psychological self may be construed as a reflexive arrangement of the subjective "I" and the constructed "Me," evolving and expanding over the human life course. The psychological self begins life as a social actor, construed in terms of performance traits and social roles. By the end of childhood, the self has become a motivated agent, too, as personal goals, motives, values, and envisioned projects for the future become central features of how the I conceives of the Me. A third layer of selfhood begins to form in the adolescent and emerging adulthood years, when the self as autobiographical author aims to construct a story of the Me, to provide adult life with broad purpose and a dynamic sense of temporal continuity. An integrative theory that envisions the psychological self as a developing I-Me configuration of actor, agent, and author helps to synthesize a wide range of conceptions and findings on the self from social, personality, cognitive, cultural, and developmental psychology and from sociology and other social sciences. The actor-agent-author framework also sheds new light on studies of self-regulation, self-esteem, self-continuity, and the relationship between self and culture. © The Author(s) 2013.

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.

Employ a Mobile Agent for Making a Payment

Directory of Open Access Journals (Sweden)

Yan Wang

2008-01-01

Full Text Available The mobile agent paradigm offers flexibility and autonomy to e-commerce applications. But it is challenging to employ a mobile agent to make a payment due to the security consideration. In this paper, we propose a new agent-assisted secure payment protocol, which is based on SET payment protocol and aims at enabling the dispatched consumer-agent to autonomously sign contracts and make the payment on behalf of the cardholder after having found the best merchant, without the possibility of disclosing any secret to any participant. This is realized by adopting the Signature-Share scheme, and employing a Trusted Third Party (TTP. In the proposed protocol, the principle that each participant knows what is strictly necessary for his/her role is followed as in SET. In addition, mechanisms have been devised for preventing and detecting double payment, overspending and overpayment attacks. Finally the security properties of the proposed protocol are studied analytically. In comparison with other existing models, the proposed protocol is more efficient and can detect more attacks.

Gd-HOPO Based High Relaxivity MRI Contrast Agents

Energy Technology Data Exchange (ETDEWEB)

Datta, Ankona; Raymond, Kenneth

2008-11-06

Tris-bidentate HOPO-based ligands developed in our laboratory were designed to complement the coordination preferences of Gd{sup 3+}, especially its oxophilicity. The HOPO ligands provide a hexadentate coordination environment for Gd{sup 3+} in which all he donor atoms are oxygen. Because Gd{sup 3+} favors eight or nine coordination, this design provides two to three open sites for inner-sphere water molecules. These water molecules rapidly exchange with bulk solution, hence affecting the relaxation rates of bulk water olecules. The parameters affecting the efficiency of these contrast agents have been tuned to improve contrast while still maintaining a high thermodynamic stability for Gd{sup 3+} binding. The Gd- HOPO-based contrast agents surpass current commercially available agents ecause of a higher number of inner-sphere water molecules, rapid exchange of inner-sphere water molecules via an associative mechanism, and a long electronic relaxation time. The contrast enhancement provided by these agents is at least twice that of commercial contrast gents, which are based on polyaminocarboxylate ligands.

Biological Agents

Science.gov (United States)

... E-Tools Safety and Health Topics / Biological Agents Biological Agents This page requires that javascript be enabled ... 202) 693-2300 if additional assistance is required. Biological Agents Menu Overview In Focus: Ebola Frederick A. ...

Getting Help

Science.gov (United States)

... Parents & Students Home > Special Features > Getting Help Getting Help Resources from NIAAA Treatment for Alcohol Problems: Finding ... and find ways to make a change. Professional help Your doctor. Primary care and mental health practitioners ...

Strategies for combating bacterial biofilms: A focus on anti-biofilm agents and their mechanisms of action

Science.gov (United States)

Roy, Ranita; Tiwari, Monalisa; Donelli, Gianfranco; Tiwari, Vishvanath

2018-01-01

ABSTRACT Biofilm refers to the complex, sessile communities of microbes found either attached to a surface or buried firmly in an extracellular matrix as aggregates. The biofilm matrix surrounding bacteria makes them tolerant to harsh conditions and resistant to antibacterial treatments. Moreover, the biofilms are responsible for causing a broad range of chronic diseases and due to the emergence of antibiotic resistance in bacteria it has really become difficult to treat them with efficacy. Furthermore, the antibiotics available till date are ineffective for treating these biofilm related infections due to their higher values of minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC), which may result in in-vivo toxicity. Hence, it is critically important to design or screen anti-biofilm molecules that can effectively minimize and eradicate biofilm related infections. In the present article, we have highlighted the mechanism of biofilm formation with reference to different models and various methods used for biofilm detection. A major focus has been put on various anti-biofilm molecules discovered or tested till date which may include herbal active compounds, chelating agents, peptide antibiotics, lantibiotics and synthetic chemical compounds along with their structures, mechanism of action and their respective MICs, MBCs, minimum biofilm inhibitory concentrations (MBICs) as well as the half maximal inhibitory concentration (IC50) values available in the literature so far. Different mode of action of anti biofilm molecules addressed here are inhibition via interference in the quorum sensing pathways, adhesion mechanism, disruption of extracellular DNA, protein, lipopolysaccharides, exopolysaccharides and secondary messengers involved in various signaling pathways. From this study, we conclude that the molecules considered here might be used to treat biofilm-associated infections after significant structural modifications, thereby

Significance and nature of bystander responses induced by various agents.

Science.gov (United States)

Verma, Neha; Tiku, Ashu Bhan

2017-07-01

Bystander effects in a biological system are the responses shown by non-targeted neighbouring cells/tissues/organisms. These responses are triggered by factors released from targeted cells when exposed to a stress inducing agent. The biological response to stress inducing agents is complex, owing to the diversity of mechanisms and pathways activated in directly targeted and bystander cells. These responses are highly variable and can be either beneficial or hazardous depending on the cell lines tested, dose of agent used, experimental end points and time course selected. Recently non-targeted cells have even been reported to rescue the directly exposed cells by releasing protective signals that might be induced by non-targeted bystander responses. The nature of bystander signal/s is not yet clear. However, there are evidences suggesting involvement of ROS, RNS, protein factors and even DNA molecules leading to the activation of a number of signaling pathways. These can act independently or in a cascade, to induce events leading to changes in gene expression patterns that could elicit detrimental or beneficial effects. Many review articles on radiation induced bystander responses have been published. However, to the best of our knowledge, a comprehensive review on bystander responses induced by other genotoxic chemicals and stress inducing agents has not been published so far. Therefore, the aim of the present review is to give an overview of the literature on different aspects of bystander responses: agents that induce these responses, factors that can modulate bystander responses and the mechanisms involved. Copyright © 2017 Elsevier B.V. All rights reserved.

In silico assessment of genetic variation in KCNA5 reveals multiple mechanisms of human atrial arrhythmogenesis

DEFF Research Database (Denmark)

Colman, Michael A; Ni, Haibo; Liang, Bo

2017-01-01

and quantify the functional impact of these KCNA5 mutations on atrial electrical activity. A multi-scale model of the human atria was updated to incorporate detailed experimental data on IKur from both wild-type and mutants. The effects of the mutations on human atrial action potential and rate dependence were...... provides new insights into understanding the mechanisms by which mutant IKur contributes to atrial arrhythmias. In addition, as IKur is an atrial-specific channel and a number of IKur-selective blockers have been developed as anti-AF agents, this study also helps to understand some contradictory results...

Photoacoustic tomography of joints aided by an Etanercept-conjugated gold nanoparticle contrast agent-an ex vivo preliminary rat study

International Nuclear Information System (INIS)

Chamberland, David L; Agarwal, Ashish; Kotov, Nicholas; Fowlkes, J Brian; Carson, Paul L; Wang Xueding

2008-01-01

Monitoring of anti-rheumatic drug delivery in experimental models and in human diseases would undoubtedly be very helpful for both basic research and clinical management of inflammatory diseases. In this study, we have investigated the potential of an emerging hybrid imaging technology-photoacoustic tomography-in noninvasive monitoring of anti-TNF drug delivery. After the contrast agent composed of gold nanorods conjugated with Etanercept molecules was produced, ELISA experiments were performed to prove the conjugation and to show that the conjugated anti-TNF-α drug was biologically active. PAT of ex vivo rat tail joints with the joint connective tissue enhanced by intra-articularly injected contrast agent was conducted to examine the performance of PAT in visualizing the distribution of the gold-nanorod-conjugated drug in articular tissues. By using the described system, gold nanorods with a concentration down to 1 pM in phantoms or 10 pM in biological tissues can be imaged with good signal-to-noise ratio and high spatial resolution. This study demonstrates the feasibility of conjugating TNF antagonist pharmaceutical preparations with gold nanorods, preservation of the mechanism of action of TNF antagonist along with preliminary evaluation of novel PAT technology in imaging optical contrast agents conjugated with anti-rheumatic drugs. Further in vivo studies on animals are warranted to test the specific binding between such conjugates and targeted antigen in joint tissues affected by inflammation

Thermodynamic and Mechanical Properties of Epon 862 With Curing Agent Detda by Molecular Simulation

National Research Council Canada - National Science Library

Tack, Jeremy L

2006-01-01

Fully atomistic molecular dynamics (MD) simulations were used to predict the properties of EPON 862 cross-linked with curing agent DETDA, a potentially useful epoxy resin for future applications of nanocomposites...

Describing the processes of propagation and eliminating wildfires with the use of agent models

Directory of Open Access Journals (Sweden)

G. A. Dorrer

2017-10-01

Full Text Available A new method of describing the processes of propagation and elimination of wildfires on the basis of agent-based modeling is proposed. The main structural units of the creation of such models are the classes of active objects (agents. Agent approach, combined with Geographic Information Systems (GIS can effectively describe the interaction of a large number of participants in the process to combat wildfires: fire spreading, fire crews, mechanization, aerial means and other. In this paper we propose a multi-agent model to predict the spread of wildfire edge and simulate the direct method of extinguishing a ground fire with non-mechanized crews. The model consist with two classes of agents, designated A and B. The burning fire edge is represented as a chain of A-agents, each of which simulates the burning of an elementary portion of vegetation fuel. Fire front movement (moving the A-agent described by the Hamilton-Jacobi equation with using the indicatrises of normal front rate of spread (figurotris. The configuration of the front calculated on basis the algorithm of mobile grids. Agents other type, B-agents, described extinguishing process; they move to the agents of A type and act on them, reducing the combustion intensity to zero. Modeling system presented as two-level coloured nested Petri Net, which describes the agents’ interaction semantics. This model is implemented as a GIS-oriented software system that can be useful both in the fire fighting management as well as in staff training tactics to fighting wildfires. Some examples of modeling decision making on а ground fire extinguishing are presented.

Ultrasound-induced Gas Release from Contrast Agent Microbubbles

NARCIS (Netherlands)

Postema, M.A.B.; Postema, Michiel; Bouakaz, Ayache; Versluis, Michel; de Jong, N.

2005-01-01

We investigated gas release from two hard-shelled ultrasound contrast agents by subjecting them to high-mechanical index (MI) ultrasound and simultaneously capturing high-speed photographs. At an insonifying frequency of 1.7 MHz, a larger percentage of contrast bubbles is seen to crack than at 0.5

Chimpanzees help each other upon request.

Directory of Open Access Journals (Sweden)

Shinya Yamamoto

2009-10-01

Full Text Available The evolution of altruism has been explained mainly from ultimate perspectives. However, it remains to be investigated from a proximate point of view how and in which situations such social propensity is achieved. We investigated chimpanzees' targeted helping in a tool transfer paradigm, and discuss the similarities and differences in altruism between humans and chimpanzees. Previously it has been suggested that chimpanzees help human experimenters by retrieving an object which the experimenter is trying to reach. In the present study, we investigated the importance of communicative interactions between chimpanzees themselves and the influence of conspecific partner's request on chimpanzees' targeted helping.We presented two tool-use situations (a stick-use situation and a straw-use situation in two adjacent booths, and supplied non-corresponding tools to paired chimpanzees in the two booths. For example, a chimpanzee in the stick-use situation was supplied with a straw, and the partner in the straw-use situation possessed a stick. Spontaneous tool transfer was observed between paired chimpanzees. The tool transfer events occurred predominantly following recipients' request. Even without any hope of reciprocation from the partner, the chimpanzees continued to help the partner as long as the partner required help.These results provide further evidence for altruistic helping in chimpanzees in the absence of direct personal gain or even immediate reciprocation. Our findings additionally highlight the importance of request as a proximate mechanism motivating prosocial behavior in chimpanzees whether between kin or non-kin individuals and the possible confounding effect of dominance on the symmetry of such interactions. Finally, in contrast to humans, our study suggests that chimpanzees rarely perform acts of voluntary altruism. Voluntary altruism in chimpanzees is not necessarily prompted by simple observation of another's struggle to attain a goal

Intrapleural agents for pleural infection: fibrinolytics and beyond.

Science.gov (United States)

Rahman, Najib M

2012-07-01

Pleural infection is a common, increasing clinical problem with a high morbidity and mortality. Medical management of pleural infection often fails, requiring invasive thoracic surgery to drain infected pleural collections, and for many years intrapleural agents have been assessed to reduce the need for surgical drainage and improve clinical outcomes. Randomized trials assessing intrapleural fibrinolytic agents have given conflicting results, and recent evidence provides important information on the role of intrapleural agents in the treatment of pleural infection, and the possible biology associated with infection progression in these patients. Pleural infection is increasing in both the adult and paediatric populations. The combined previous evidence assessing intrapleural fibrinolytics alone in pleural infection suggests lack of efficacy for clinically important outcomes. The Multi-Centre Intrapleural Sepsis Trial 2 (MIST2) study provides the first evidence of a novel treatment combination [intrapleural tissue plasminogen activator (tPA) combined with intrapleural deoxyribonuclease (DNase)], which significantly improves the chest radiograph compared with either agent alone or placebo, and has potentially important benefits to important clinical outcomes (need for surgery and hospital stay). The precise mechanism of action of combination fibrinolytic and DNase in pleural infection is speculative. Fibrinolytic therapy alone has not been proven to be of use in the treatment of pleural infection. The MIST2 study provides clear-cut evidence demonstrating improved chest radiographs, and highly suggestive secondary outcomes suggesting improved clinically important outcomes, using a combination of intrapleural tPA and DNase. This novel treatment combination may represent an important step in our understanding and treatment of pleural infection; however, larger clinical studies specifically addressing important clinical outcomes and further laboratory research describing

NMR chemical shift and J coupling parameterization and quantum mechanical reference spectrum simulation for selected nerve agent degradation products in aqueous conditions.

Science.gov (United States)

Koskela, Harri; Anđelković, Boban

2017-10-01

The spectral parameters of selected nerve agent degradation products relevant to the Chemical Weapons Convention, namely, ethyl methylphosphonate, isopropyl methylphosphonate, pinacolyl methylphosphonate and methylphosphonic acid, were studied in wide range of pH conditions and selected temperatures. The pH and temperature dependence of chemical shifts and J couplings was parameterized using Henderson-Hasselbalch-based functions. The obtained parameters allowed calculation of precise chemical shifts and J coupling constants in arbitrary pH conditions and typical measurement temperatures, thus facilitating quantum mechanical simulation of reference spectra in the chosen magnetic field strength for chemical verification. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Identification of Chemical Agents (Mimics) Residues after Destructive Adsorption Using TPD and UV-vis-IR and Raman

National Research Council Canada - National Science Library

Klabunde, Kenneth J

2001-01-01

Instrumentation was purchased that helps characterize the chemical structures and chemical reactions that occur when nanocrystalline metal oxides carry out destructive adsorption of chemical agents mimics. The residues (adducts...

Drug-induced liver injury due to antimicrobials, central nervous system agents, and nonsteroidal anti-inflammatory drugs.

Science.gov (United States)

Devarbhavi, Harshad; Andrade, Raúl J

2014-05-01

Antimicrobial agents including antituberculosis (anti-TB) agents are the most common cause of idiosyncratic drug-induced liver injury (DILI) and drug-induced liver failure across the world. Better molecular and genetic biomarkers are acutely needed to help identify those at risk of liver injury particularly for those needing antituberculosis therapy. Some antibiotics such as amoxicillin-clavulanate and isoniazid consistently top the lists of agents in retrospective and prospective DILI databases. Central nervous system agents, particularly antiepileptics, account for the second most common class of agents implicated in DILI registries. Hepatotoxicity from older antiepileptics such as carbamazepine, phenytoin, and phenobarbital are often associated with hypersensitivity features, whereas newer antiepileptic drugs have a more favorable safety profile. Antidepressants and nonsteroidal anti-inflammatory drugs carry very low risk of significant liver injury, but their prolific use make them important causes of DILI. Early diagnosis and withdrawal of the offending agent remain the mainstays of minimizing hepatotoxicity. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Pathological mechanism for delayed hyperenhancement of chronic scarred myocardium in contrast agent enhanced magnetic resonance imaging.

Directory of Open Access Journals (Sweden)

Jian Wang

Full Text Available OBJECTIVES: To evaluate possible mechanism for delayed hyperenhancement of scarred myocardium by investigating the relationship of contrast agent (CA first pass and delayed enhancement patterns with histopathological changes. MATERIALS AND METHODS: Eighteen pigs underwent 4 weeks ligation of 1 or 2 diagonal coronary arteries to induce chronic infarction. The hearts were then removed and perfused in a Langendorff apparatus. The hearts firstly experienced phosphorus 31 MR spectroscopy. The hearts in group I (n = 9 and II (n = 9 then received the bolus injection of Gadolinium diethylenetriamine pentaacetic acid (0.05 mmol/kg and gadolinium-based macromolecular agent (P792, 15 µmol/kg, respectively. First pass T2* MRI was acquired using a gradient echo sequence. Delayed enhanced T1 MRI was acquired with an inversion recovery sequence. Masson's trichrome and anti- von Willebrand Factor (vWF staining were performed for infarct characterization. RESULTS: Wash-in of both kinds of CA caused the sharp and dramatic T2* signal decrease of scarred myocardium similar to that of normal myocardium. Myocardial blood flow and microvessel density were significantly recovered in 4-week-old scar tissue. Steady state distribution volume (ΔR1 relaxation rate of Gd-DTPA was markedly higher in scarred myocardium than in normal myocardium, whereas ΔR1 relaxation rate of P792 did not differ significantly between scarred and normal myocardium. The ratio of extracellular volume to the total water volume was significantly greater in scarred myocardium than in normal myocardium. Scarred myocardium contained massive residual capillaries and dilated vessels. Histological stains indicated the extensively discrete matrix deposition and lack of cellular structure in scarred myocardium. CONCLUSIONS: Collateral circulation formation and residual vessel effectively delivered CA into scarred myocardium. However, residual vessel without abnormal hyperpermeability allowed Gd

An overview of the current methodologies used for evaluation of anti-fertility agents

Directory of Open Access Journals (Sweden)

Manisha Shah

2016-05-01

Full Text Available Discoveries in the past two decades have continued to improve our understanding of the mechanism of fertilization and animal models have played a significant role to define the basic mechanism of anti-fertility agents. In vivo models have been developed in the past years to study the anti-fertility agents. Methods that are used in anti-fertility study can be categorized into method including estimation of sex hormones, assessment of sperm motility and count, assessment of sperm viability and morphology, mating trial test body, sex organ weights, abortifacient activity, post-coital anti-fertility activity, effect on estrous cycle, anti-estrogenic activity, anti-gonadotrophic effect and quantification of fructose in seminal vesicle, histopathology, and biochemical methods. This review aims to highlight some of the new and currently, used experimental models that are used for the evaluation of anti-fertility agents.

Carbon allowance auction design of China's emissions trading scheme: A multi-agent-based approach

International Nuclear Information System (INIS)

Tang, Ling; Wu, Jiaqian; Yu, Lean; Bao, Qin

2017-01-01

In this paper, a multi-agent-based ETS simulation model is proposed for carbon allowance auction design in China. In the proposed model, two main agents, i.e., the government (the ETS implementer) and the firms in different sectors (the ETS targets), are considered. Under the ETS policy, all agents make various decisions individually according to their own goals, and interact with each other through three main markets: the commodity market, the primary carbon auction market and the secondary carbon trading market. Different popular auction designs are introduced into the ETS formulation to offer helpful insights into China's ETS design. (1) Generally, the ETS would lead to positive effects on China's carbon mitigation and energy structure improvement, but a negative impact on economy. (2) As for auction forms, the uniform-price design is relatively moderate, while the discriminative-price design is quite aggressive in both economic damage and emissions reduction. (3) As for carbon price, the uniform-price auction might generate a slightly higher market clearing price than the discriminative-price auction, and the prices under two auction rules fluctuate about RMB 40 per metric ton. (4) As for carbon cap, the total allowances in the carbon auction market should be carefully set to well balance economic growth and mitigation effect. - Highlights: • A multi-agent-based model is proposed for China's emissions trading scheme (ETS). • Two main economic agents are included: government and firms in different sectors. • Auction-based allocation for initial carbon allowances is especially investigated. • Economic and environmental impacts of different auction designs are analyzed. • Results confirm the validity of the model and give helpful insights into ETS design.

Symmetry-based reciprocity: evolutionary constraints on a proximate mechanism.

Science.gov (United States)

Campennì, Marco; Schino, Gabriele

2016-01-01

Background. While the evolution of reciprocal cooperation has attracted an enormous attention, the proximate mechanisms underlying the ability of animals to cooperate reciprocally are comparatively neglected. Symmetry-based reciprocity is a hypothetical proximate mechanism that has been suggested to be widespread among cognitively unsophisticated animals. Methods. We developed two agent-based models of symmetry-based reciprocity (one relying on an arbitrary tag and the other on interindividual proximity) and tested their ability both to reproduce significant emergent features of cooperation in group living animals and to promote the evolution of cooperation. Results. Populations formed by agents adopting symmetry-based reciprocity showed differentiated "social relationships" and a positive correlation between cooperation given and received: two common aspects of animal cooperation. However, when reproduction and selection across multiple generations were added to the models, agents adopting symmetry-based reciprocity were outcompeted by selfish agents that never cooperated. Discussion. In order to evolve, hypothetical proximate mechanisms must be able to stand competition from alternative strategies. While the results of our simulations require confirmation using analytical methods, we provisionally suggest symmetry-based reciprocity is to be abandoned as a possible proximate mechanism underlying the ability of animals to reciprocate cooperative interactions.

A Study on the Rheological and Mechanical Properties of Photo-Curable Ceramic/Polymer Composites with Different Silane Coupling Agents for SLA 3D Printing Technology.

Science.gov (United States)

Song, Se Yeon; Park, Min Soo; Lee, Jung Woo; Yun, Ji Sun

2018-02-07

Silane coupling agents (SCAs) with different organofunctional groups were coated on the surfaces of Al₂O₃ ceramic particles through hydrolysis and condensation reactions, and the SCA-coated Al₂O₃ ceramic particles were dispersed in a commercial photopolymer based on interpenetrating networks (IPNs). The organofunctional groups that have high radical reactivity and are more effective in UV curing systems are usually functional groups based on acryl, such as acryloxy groups, methacrloxy groups, and acrylamide groups, and these silane coupling agents seem to improve interfacial adhesion and dispersion stability. The coating morphology and the coating thickness distribution of SCA-coated Al₂O₃ ceramic particles according to the different organofunctional groups were observed by FE-TEM. The initial dispersibility and dispersion stability of the SCA-coated Al₂O₃/High-temp composite solutions were investigated by relaxation NMR and Turbiscan. The rheological properties of the composite solutions were investigated by viscoelastic analysis and the mechanical properties of 3D-printed objects were observed with a nanoindenter.

Direct binding of ledipasvir to HCV NS5A: mechanism of resistance to an HCV antiviral agent.

Directory of Open Access Journals (Sweden)

Hyock Joo Kwon

Full Text Available Ledipasvir, a direct acting antiviral agent (DAA targeting the Hepatitis C Virus NS5A protein, exhibits picomolar activity in replicon cells. While its mechanism of action is unclear, mutations that confer resistance to ledipasvir in HCV replicon cells are located in NS5A, suggesting that NS5A is the direct target of ledipasvir. To date co-precipitation and cross-linking experiments in replicon or NS5A transfected cells have not conclusively shown a direct, specific interaction between NS5A and ledipasvir. Using recombinant, full length NS5A, we show that ledipasvir binds directly, with high affinity and specificity, to NS5A. Ledipasvir binding to recombinant NS5A is saturable with a dissociation constant in the low nanomolar range. A mutant form of NS5A (Y93H that confers resistance to ledipasvir shows diminished binding to ledipasvir. The current study shows that ledipasvir inhibits NS5A through direct binding and that resistance to ledipasvir is the result of a reduction in binding affinity to NS5A mutants.

Going Online: Helping Technical Communicators Help Translators.

Science.gov (United States)

Flint, Patricia; Lord van Slyke, Melanie; Starke-Meyerring, Doreen; Thompson, Aimee

1999-01-01

Explains why technical communicators should help translators. Offers tips for creating "translation-friendly" documentation. Describes the research and design process used by the authors to create an online tutorial that provides technical communicators at a medical technology company the information they need to help them write and…

Contrast agents for cardiac angiography: effects of a nonionic agent vs. a standard ionic agent

International Nuclear Information System (INIS)

Bettmann, M.A.; Bourdillon, P.D.; Barry, W.H.; Brush, K.A.; Levin, D.C.

1984-01-01

The effects on cardiac hemodynamics and of a standard contrast agent, sodium methylglucamine diatrizoate [Renografin 76] were compared with the effects of a new nonionic agent (iohexol) in a double-blind study in 51 patietns undergoing coronary angiography and left ventriculography. No significant alteration in measured blood parameters occurred with either contrast agent. Hemodynamic changes occurred with both, but were significantly greater with the standard renografin than with the low-osmolality, nonionic iohexol. After left ventriculography, heart rate increased and peripheral arterial pressure fell with both agents, but less with iohexol. It is concluded that iohexol causes less alteration in cardiac function than does the agent currently most widely used. Nonionic contrast material is likely to improve the safety of coronary angiography, particularly in those patients at greatest risk

Targeted Anticancer Immunotoxins and Cytotoxic Agents with Direct Killing Moieties

Directory of Open Access Journals (Sweden)

Koji Kawakami

2006-01-01

Full Text Available Despite the progress of the bioinformatics approach to characterize cell-surface antigens and receptors on tumor cells, it remains difficult to generate novel cancer vaccines or neutralizing monoclonal antibody therapeutics. Among targeted cancer therapeutics, biologicals with targetable antibodies or ligands conjugated or fused to toxins or chemicals for direct cell-killing ability have been developed over the last 2 decades. These conjugated or fused chimeric proteins are termed immunotoxins or cytotoxic agents. Two agents, DAB389IL-2 (ONTAKTM targeting the interleukin-2 receptor and CD33-calicheamicin (Mylotarg®, have been approved by the FDA for cutaneous T-cell lymphoma (CTCL and relapsed acute myeloid leukemia (AML, respectively. Such targetable agents, including RFB4(dsFv-PE38 (BL22, IL13-PE38QQR, and Tf-CRM107, are being tested in clinical trials. Several agents using unique technology such as a cleavable adapter or immunoliposomes with antibodies are also in the preclinical stage. This review summarizes the generation, mechanism, and development of these agents. In addition, possible future directions of this therapeutic approach are discussed.

Emerging medical informatics with case-based reasoning for aiding clinical decision in multi-agent system.

Science.gov (United States)

Shen, Ying; Colloc, Joël; Jacquet-Andrieu, Armelle; Lei, Kai

2015-08-01

This research aims to depict the methodological steps and tools about the combined operation of case-based reasoning (CBR) and multi-agent system (MAS) to expose the ontological application in the field of clinical decision support. The multi-agent architecture works for the consideration of the whole cycle of clinical decision-making adaptable to many medical aspects such as the diagnosis, prognosis, treatment, therapeutic monitoring of gastric cancer. In the multi-agent architecture, the ontological agent type employs the domain knowledge to ease the extraction of similar clinical cases and provide treatment suggestions to patients and physicians. Ontological agent is used for the extension of domain hierarchy and the interpretation of input requests. Case-based reasoning memorizes and restores experience data for solving similar problems, with the help of matching approach and defined interfaces of ontologies. A typical case is developed to illustrate the implementation of the knowledge acquisition and restitution of medical experts. Copyright © 2015 Elsevier Inc. All rights reserved.

Behavior believability in virtual worlds: agents acting when they need to.

Science.gov (United States)

Avradinis, Nikos; Panayiotopoulos, Themis; Anastassakis, George

2013-12-01

Believability has been a perennial goal for the intelligent virtual agent community. One important aspect of believability largely consists in demonstrating autonomous behavior, consistent with the agent's personality and motivational state, as well as the world conditions. Autonomy, on behalf of the agent, implies the existence of an internal structure and mechanism that allows the agent to have its own needs and interests, based on which the agent will dynamically select and generate goals that will in turn lead to self-determined behavior. Intrinsic motivation allows the agent to function and demonstrate behavior, even when no external stimulus is present, due to the constant change of its internal emotional and physiological state. The concept of motivation has already been investigated by research works on intelligent agents, trying to achieve autonomy. The current work presents an architecture and model to represent and manage internal driving factors in intelligent virtual agents, using the concept of motivations. Based on Maslow and Alderfer's bio-psychological needs theories, we present a motivational approach to represent human needs and produce emergent behavior through motivation synthesis. Particular attention is given to basic, physiological level needs, which are the basis of behavior and can produce tendency to action even when there is no other interaction with the environment.

Helping Oxytocin Deliver: Considerations in the Development of Oxytocin-Based Therapeutics for Brain Disorders.

Directory of Open Access Journals (Sweden)

Kai eMacdonald

2013-03-01

Full Text Available Concerns regarding a drought in psychopharmacology have risen from many quarters. From one perspective, the wellspring of bedrock medications for anxiety disorders, depression, and schizophrenia was serendipitously discovered over thirty year ago, the swell of pharmaceutical investment in drug discovery has receded, and the pipeline’s flow of medications with unique mechanisms of action (i.e. glutamatergic agents, CRF antagonists has slowed to a trickle. Might oxytocin (OT-based therapeutics be an oasis? Though a large basic science literature and a slowly increasing number of studies in human diseases support this hope, the bulk of extant OT studies in humans are single-dose studies on normals, and do not directly relate to improvements in human brain-based diseases. Instead, these studies have left us with a field pregnant with therapeutic possibilities, but barren of definitive treatments. In this clinically-oriented review, we discuss the extant OT literature with an eye toward helping OT deliver on its promise as a therapeutic agent. To this end, we identify ten key questions that we believe future OT research should address. From this overview, several conclusions are clear: 1 the OT system represents an extremely promising target for novel CNS drug development; 2 there is a pressing need for rigorous, randomized controlled clinical trials targeting actual patients; and 3 in order to inform the design and execution of these vital trials, we need further translational studies addressing the questions posed in this review. Looking forward, we extend a cautious hope that the next decade of OT research will birth oxytocin-targetted therapeutics that can truly deliver on this system’s therapeutic potential.

Exploring help-seeking for ADHD symptoms: a mixed-methods approach.

Science.gov (United States)

Bussing, Regina; Koro-Ljungberg, Mirka E; Gary, Faye; Mason, Dana M; Garvan, Cynthia W

2005-01-01

Gender and race differences in treatment rates for attention-deficit/hyperactivity disorder (ADHD) are well documented but poorly understood. Using a mixed-methods approach, this study examines parental help-seeking steps for elementary school students at high risk for ADHD. Parents of 259 students (male/female, African American/Caucasian) identified as being at high risk for ADHD completed diagnostic interviews and provided detailed accounts of help-seeking activities since they first became concerned about their child. Help-seeking steps (n=1,590) were analyzed using two methods: inductive analysis based on grounded theory, and deductive quantitative analysis of coded data derived from application of the network-episode model, merged subsequently with demographic and other characteristics. The inductive analysis revealed unique parental perceptions of their children's sick role and of the agents of identification and intervention for each of the four groups. Deductive analysis showed significant variations by race and gender in consultation experiences, in the person or entity being consulted and in the transactions occurring in the consultation, and in illness careers. ADHD symptoms are interpreted as having different implications for the sick role and the intervention, dependent on a child's gender and race. Educational interventions need to address cultural stereotypes contributing to inequitable access to treatment.

Synthesis of ultrasound contrast agents: characteristics and size distribution analysis (secondary publication)

Energy Technology Data Exchange (ETDEWEB)

Lee, Hak Jong [Program in Nano Science and Technology, Dept. of Transdisciplinary Studies, Seoul National University Graduate School of Convergence Science and Technology, Seoul (Korea, Republic of); Yoon, Tae Jong [Dept. of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam (Korea, Republic of); Yoon, Young Il [Dept. of Applied Bioscience, CHA University, Pocheon (Korea, Republic of)

2017-10-15

The purpose of this study was to establish a method for ultrasound (US) contrast agent synthesis and to evaluate the characteristics of the synthesized US contrast agent. A US contrast agent, composed of liposome and sulfur hexafluoride (SF6), was synthesized by dissolving 21 μmol 1,2-dihexadecanoyl-sn-glycero-3-phosphocholine (DPPC, C40H80NO8P), 9 μmol cholesterol, and 1.9 μmol of dihexadecylphosphate (DCP, [CH3(CH2)15O]2P(O)OH) in chloroform. After evaporation in a warm water bath and drying for 12-24 hours, the contrast agent was synthesized using the sonication process by the addition of a buffer and SF6 gas. The size distribution of the bubbles was analyzed using dynamic light scattering measurement methods. The degradation curve was evaluated by assessing the change in the number of contrast agent bubbles using light microscopy immediately, 12, 24, 36, 48, 60, 72, and 84 hours after synthesis. The echogenicity of the synthesized microbubbles was compared with commercially available microbubbles (SonoVue, Bracco). contrast agent was synthesized successfully using an evaporation-drying-sonication method. Most bubbles had a mean diameter of 154.2 nm and showed marked degradation 24 hours after synthesis. Although no statistically significant differences were observed between SonoVue and the synthesized contrast agent, a difference in echogenicity was observed between the synthesized contrast agent and saline (P<0.01). We successfully synthesized a US contrast agent using an evaporation-dryingsonication method. These results may help future research in the fields of anticancer drug delivery, gene delivery, targeted molecular imaging, and targeted therapy.

Synthesis of ultrasound contrast agents: characteristics and size distribution analysis (secondary publication)

International Nuclear Information System (INIS)

Lee, Hak Jong; Yoon, Tae Jong; Yoon, Young Il

2017-01-01

The purpose of this study was to establish a method for ultrasound (US) contrast agent synthesis and to evaluate the characteristics of the synthesized US contrast agent. A US contrast agent, composed of liposome and sulfur hexafluoride (SF6), was synthesized by dissolving 21 μmol 1,2-dihexadecanoyl-sn-glycero-3-phosphocholine (DPPC, C40H80NO8P), 9 μmol cholesterol, and 1.9 μmol of dihexadecylphosphate (DCP, [CH3(CH2)15O]2P(O)OH) in chloroform. After evaporation in a warm water bath and drying for 12-24 hours, the contrast agent was synthesized using the sonication process by the addition of a buffer and SF6 gas. The size distribution of the bubbles was analyzed using dynamic light scattering measurement methods. The degradation curve was evaluated by assessing the change in the number of contrast agent bubbles using light microscopy immediately, 12, 24, 36, 48, 60, 72, and 84 hours after synthesis. The echogenicity of the synthesized microbubbles was compared with commercially available microbubbles (SonoVue, Bracco). contrast agent was synthesized successfully using an evaporation-drying-sonication method. Most bubbles had a mean diameter of 154.2 nm and showed marked degradation 24 hours after synthesis. Although no statistically significant differences were observed between SonoVue and the synthesized contrast agent, a difference in echogenicity was observed between the synthesized contrast agent and saline (P<0.01). We successfully synthesized a US contrast agent using an evaporation-dryingsonication method. These results may help future research in the fields of anticancer drug delivery, gene delivery, targeted molecular imaging, and targeted therapy

Reinforcement Learning Multi-Agent Modeling of Decision-Making Agents for the Study of Transboundary Surface Water Conflicts with Application to the Syr Darya River Basin

Science.gov (United States)

Riegels, N.; Siegfried, T.; Pereira Cardenal, S. J.; Jensen, R. A.; Bauer-Gottwein, P.

2008-12-01

In most economics--driven approaches to optimizing water use at the river basin scale, the system is modelled deterministically with the goal of maximizing overall benefits. However, actual operation and allocation decisions must be made under hydrologic and economic uncertainty. In addition, river basins often cross political boundaries, and different states may not be motivated to cooperate so as to maximize basin- scale benefits. Even within states, competing agents such as irrigation districts, municipal water agencies, and large industrial users may not have incentives to cooperate to realize efficiency gains identified in basin- level studies. More traditional simulation--optimization approaches assume pre-commitment by individual agents and stakeholders and unconditional compliance on each side. While this can help determine attainable gains and tradeoffs from efficient management, such hardwired policies do not account for dynamic feedback between agents themselves or between agents and their environments (e.g. due to climate change etc.). In reality however, we are dealing with an out-of-equilibrium multi-agent system, where there is neither global knowledge nor global control, but rather continuous strategic interaction between decision making agents. Based on the theory of stochastic games, we present a computational framework that allows for studying the dynamic feedback between decision--making agents themselves and an inherently uncertain environment in a spatially and temporally distributed manner. Agents with decision-making control over water allocation such as countries, irrigation districts, and municipalities are represented by reinforcement learning agents and coupled to a detailed hydrologic--economic model. This approach emphasizes learning by agents from their continuous interaction with other agents and the environment. It provides a convenient framework for the solution of the problem of dynamic decision-making in a mixed cooperative / non

Multi-agent: a technique to implement geo-visualization of networked virtual reality

Science.gov (United States)

Lin, Zhiyong; Li, Wenjing; Meng, Lingkui

2007-06-01

Networked Virtual Reality (NVR) is a system based on net connected and spatial information shared, whose demands cannot be fully meet by the existing architectures and application patterns of VR to some extent. In this paper, we propose a new architecture of NVR based on Multi-Agent framework. which includes the detailed definition of various agents and their functions and full description of the collaboration mechanism, Through the prototype system test with DEM Data and 3D Models Data, the advantages of Multi-Agent based Networked Virtual Reality System in terms of the data loading time, user response time and scene construction time etc. are verified. First, we introduce the characters of Networked Virtual Realty and the characters of Multi-Agent technique in Section 1. Then we give the architecture design of Networked Virtual Realty based on Multi-Agent in Section 2.The Section 2 content includes the rule of task division, the multi-agent architecture design to implement Networked Virtual Realty and the function of agents. Section 3 shows the prototype implementation according to the design. Finally, Section 4 discusses the benefits of using Multi-Agent to implement geovisualization of Networked Virtual Realty.

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

Science.gov (United States)

de Diesbach, Pablo Brice

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

Pharmacology of dimethanesulfonate alkylating agents: busulfan and treosulfan.

Science.gov (United States)

Galaup, Ariane; Paci, Angelo

2013-03-01

Among the dimethanesulfonates, busulfan, in combination with other alkylating agents or nucleoside analogues, is the cornerstone of high-dose chemotherapy. It is used, and followed hematopoietic stem cell transplantation, for the treatment of various hematologic malignancies and immunodeficiencies. Treosulfan, which is a hydrophilic analogue of busulfan, was the first dimethanesufonate registered for the treatment of ovarian cancer. Recently, treosulfan has been investigated for the treatment of hematologic malignancies in combination with the same second agents before hematopoietic stem cell transplantation. This work reviews the pharmacological data of these two dimethanesulfonates alkylating agents. Specifically, the article looks at their chemistry, metabolism, anticancer activity, and their pharmacokinetics and pharmacodynamics. Busulfan has been investigated widely for more than three decades leading to a large and precise handling of this agent with numerous studies on activity and pharmacokinetics and pharmacodynamics. In contrast, the behavior of treosulfan is still under investigation and not fully described. The complexity of treosulfan's metabolism and mechanism of action gives rise to the need of a deeper understanding of its pharmacological activity in a context of high-dose chemotherapy. Specifically, there is a great need to better understand its pharmacokinetics/pharmacodynamics relationship.

A Composite Agent Architecture for Multi-Agent Simulations

OpenAIRE

VanPutte, Michael; Osborn, Brian; Hiles, John

2002-01-01

CGF Computer Generated Forces and Behavioral Representation The MOVES Institute’s Computer-Generated Autonomy Group has focused on a research goal of modeling complex and adaptive behavior while at the same time making the behavior easier to create and control. This research has led to several techniques for agent construction, that includes a social and organization relationship management engine, a composite agent architecture, an agent goal apparatus, a structure for capturi...

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.

Insomnia patients' help-seeking experiences.

Science.gov (United States)

Cheung, Janet M Y; Bartlett, Delwyn J; Armour, Carol L; Glozier, Nicholas; Saini, Bandana

2014-03-04

Timely access to appropriate treatment is important for optimizing insomnia management. To date, little is known about insomnia patients' treatment experiences or how they access and engage with the available health care resources. This study sought to capture the help-seeking experiences and behavioral patterns of patients with insomnia who are seeking or receiving specialist care. A purposive sample of 26 insomnia patients from specialist sleep and mental health clinics located in metropolitan New South Wales, Australia was recruited. Participants completed a brief questionnaire, followed by an in-depth, semi-structured interview. Interviews were digitally recorded, transcribed verbatim, and analyzed using framework analysis. Three key themes emerged from the data: patients' sleep beliefs, treatment beliefs, and accessing specialized care. The findings show that daytime symptoms arising from insomnia serve as important illness cues for patients to seek medical help. In addition, participants' treatment pathways highlight factors that prevent the widespread use of cognitive behavioral therapy for insomnia (CBT-I), including limited awareness about CBT-I, tentative referral mechanisms, limited service providers, and the high cost of CBT-I.

Novel cancer immunotherapy agents with survival benefit: recent successes and next steps

Science.gov (United States)

Sharma, Padmanee; Wagner, Klaus; Wolchok, Jedd D.; Allison, James P.

2012-01-01

The US Food and Drug Administration (FDA) recently approved two novel immunotherapy agents, sipuleucel-T and ipilimumab, which showed a survival benefit for patients with metastatic prostate cancer and melanoma, respectively. The mechanisms by which these agents provide clinical benefit are not completely understood. However, knowledge of these mechanisms will be crucial for probing human immune responses and tumour biology in order to understand what distinguishes responders from non-responders. The following next steps are necessary: first, the development of immune-monitoring strategies for the identification of relevant biomarkers; second, the establishment of guidelines for the assessment of clinical end points; and third, the evaluation of combination therapy strategies to improve clinical benefit. PMID:22020206

Mustard Group Chemical War Agents from Preventive Medicine Perspective

Directory of Open Access Journals (Sweden)

Muharrem Ucar

2007-06-01

Full Text Available Although many preventive efforts and treaties, chemical warfare agents have still been a severe assault form against both military and civilian individuals. The most important chemical warfare agents sulphur mustard and others are easy to handle and cheap those the important reasons to accept sulphur mustard as a chemical warfare agent. Many individuals attacked by sulphur mustard have severe health problems such as respiratory system diseases. After ten years of sulphur mustard exposure, several health problems such as respiratory tract problems (%42.5, eye problems (%40 and other systemic diseases have been observed to insist on induviduals when examined. Exposure of even single sulphur mustard exposure has been seen to result high level of disability and early deaths. In spite of the fact that there is no available antidote and/or remedy against sulphur mustard exposure, our country has an incremental chemical assault threat for both military personels and civilians because of its jeopolitics position. Experimental studies regarding sulphur mustard toxicity will be helpful for novel preventive strategies and antidot devolepment. [TAF Prev Med Bull 2007; 6(3.000: 209-214

Agents, Bayes, and Climatic Risks - a modular modelling approach

Directory of Open Access Journals (Sweden)

A. Haas

2005-01-01

Full Text Available When insurance firms, energy companies, governments, NGOs, and other agents strive to manage climatic risks, it is by no way clear what the aggregate outcome should and will be. As a framework for investigating this subject, we present the LAGOM model family. It is based on modules depicting learning social agents. For managing climate risks, our agents use second order probabilities and update them by means of a Bayesian mechanism while differing in priors and risk aversion. The interactions between these modules and the aggregate outcomes of their actions are implemented using further modules. The software system is implemented as a series of parallel processes using the CIAMn approach. It is possible to couple modules irrespective of the language they are written in, the operating system under which they are run, and the physical location of the machine.

Agents, Bayes, and Climatic Risks - a modular modelling approach

Science.gov (United States)

Haas, A.; Jaeger, C.

2005-08-01

When insurance firms, energy companies, governments, NGOs, and other agents strive to manage climatic risks, it is by no way clear what the aggregate outcome should and will be. As a framework for investigating this subject, we present the LAGOM model family. It is based on modules depicting learning social agents. For managing climate risks, our agents use second order probabilities and update them by means of a Bayesian mechanism while differing in priors and risk aversion. The interactions between these modules and the aggregate outcomes of their actions are implemented using further modules. The software system is implemented as a series of parallel processes using the CIAMn approach. It is possible to couple modules irrespective of the language they are written in, the operating system under which they are run, and the physical location of the machine.

Honey, an unexplored topical wound dressing agent in Nigerian ...

African Journals Online (AJOL)

This paper presents an overview of honey as a wound dressing agent, its mechanism of action, selected cases of wounds managed with honey and a survey of veterinarians' perception and usage of honey for wound management in Nigeria. Structured questionnaires were administered to veterinary practitioners ...

DNA Damage Induced by Alkylating Agents and Repair Pathways

Science.gov (United States)

Kondo, Natsuko; Takahashi, Akihisa; Ono, Koji; Ohnishi, Takeo

2010-01-01

The cytotoxic effects of alkylating agents are strongly attenuated by cellular DNA repair processes, necessitating a clear understanding of the repair mechanisms. Simple methylating agents form adducts at N- and O-atoms. N-methylations are removed by base excision repair, AlkB homologues, or nucleotide excision repair (NER). O6-methylguanine (MeG), which can eventually become cytotoxic and mutagenic, is repaired by O6-methylguanine-DNA methyltransferase, and O6MeG:T mispairs are recognized by the mismatch repair system (MMR). MMR cannot repair the O6MeG/T mispairs, which eventually lead to double-strand breaks. Bifunctional alkylating agents form interstrand cross-links (ICLs) which are more complex and highly cytotoxic. ICLs are repaired by complex of NER factors (e.g., endnuclease xeroderma pigmentosum complementation group F-excision repair cross-complementing rodent repair deficiency complementation group 1), Fanconi anemia repair, and homologous recombination. A detailed understanding of how cells cope with DNA damage caused by alkylating agents is therefore potentially useful in clinical medicine. PMID:21113301

Preclinical evaluation of molecular-targeted anticancer agents for radiotherapy

International Nuclear Information System (INIS)

Krause, Mechthild; Zips, Daniel; Thames, Howard D.; Kummermehr, Johann; Baumann, Michael

2006-01-01

The combination of molecular-targeted agents with irradiation is a highly promising avenue for cancer research and patient care. Molecular-targeted agents are in themselves not curative in solid tumours, whereas radiotherapy is highly efficient in eradicating tumour stem cells. Recurrences after high-dose radiotherapy are caused by only one or few surviving tumour stem cells. Thus, even if a novel agent has the potential to kill only few tumour stem cells, or if it interferes in mechanisms of radioresistance of tumours, combination with radiotherapy may lead to an important improvement in local tumour control and survival. To evaluate the effects of novel agents combined with radiotherapy, it is therefore necessary to use experimental endpoints which reflect the killing of tumour stem cells, in particular tumour control assays. Such endpoints often do not correlate with volume-based parameters of tumour response such as tumour regression and growth delay. This calls for radiotherapy specific research strategies in the preclinical testing of novel anti-cancer drugs, which in many aspects are different from research approaches for medical oncology

Infectious Agents as Stimuli of Trained Innate Immunity

Directory of Open Access Journals (Sweden)

Paulina Rusek

2018-02-01

Full Text Available The discoveries made over the past few years have modified the current immunological paradigm. It turns out that innate immunity cells can mount some kind of immunological memory, similar to that observed in the acquired immunity and corresponding to the defense mechanisms of lower organisms, which increases their resistance to reinfection. This phenomenon is termed trained innate immunity. It is based on epigenetic changes in innate immune cells (monocytes/macrophages, NK cells after their stimulation with various infectious or non-infectious agents. Many infectious stimuli, including bacterial or fungal cells and their components (LPS, β-glucan, chitin as well as viruses or even parasites are considered potent inducers of innate immune memory. Epigenetic cell reprogramming occurring at the heart of the phenomenon may provide a useful basis for designing novel prophylactic and therapeutic strategies to prevent and protect against multiple diseases. In this article, we present the current state of art on trained innate immunity occurring as a result of infectious agent induction. Additionally, we discuss the mechanisms of cell reprogramming and the implications for immune response stimulation/manipulation.

Help-Seeking and Help-Giving for Teen Dating Violence

Science.gov (United States)

Weisz, Arlene N.; Black, Beverly M.

2009-01-01

This article is based on numerous research projects conducted by the authors on adolescent dating violence. It reviews the results of those projects as they relate to how teens seek help for dating violence and how teens provide help to their friends in violent dating relationships. It concludes with helpful strategies for adults who work with…

Use of non-hyperaccumulator plant species for the phytoextraction of heavy metals using chelating agents

Directory of Open Access Journals (Sweden)

Lucas Anjos Souza

2013-08-01

Full Text Available Soil contamination by heavy metals is a challenge faced by many countries, and engineering technologies to solve this problem are expensive and can cause negative impacts on the environment. One way to minimise the levels of heavy metals in the soil is to use plants that can absorb and accumulate heavy metals into harvestable parts, a process called phytoextraction. Typical plant species used in research involving phytoextraction are heavy metal hyperaccumulators, but plants from this group are not good biomass producers and grow more slowly than most species; thus, they have an important role in helping scientists understand the mechanisms involved in accumulating high amounts of heavy metals without developing symptoms or dying. However, because of their slow growth, it is not practical to use these species for phytoextraction. An alternative approach is to use non-hyperaccumulator plants assisted by chelating agents, which may improve the ability of plants to accumulate more heavy metals than they would naturally. Chelating agents can be synthetic or organic acids, and the advantages and disadvantages of their use in improving the phytoextraction potential of non-hyperaccumulator plants are discussed in this article. We hope to draw attention to ways to improve the phytoextraction potential of non-hyperaccumulator plants that produce a large amount of biomass and to stimulate more research on phytoextraction-inducing substances.

Multirate delivery of multiple therapeutic agents from metal-organic frameworks

Directory of Open Access Journals (Sweden)

Alistair C. McKinlay

2014-12-01

Full Text Available The highly porous nature of metal-organic frameworks (MOFs offers great potential for the delivery of therapeutic agents. Here, we show that highly porous metal-organic frameworks can be used to deliver multiple therapeutic agents—a biologically active gas, an antibiotic drug molecule, and an active metal ion—simultaneously but at different rates. The possibilities offered by delivery of multiple agents with different mechanisms of action and, in particular, variable timescales may allow new therapy approaches. Here, we show that the loaded MOFs are highly active against various strains of bacteria.

Pursuit of communal values in an agentic manner: a way to happiness?

Science.gov (United States)

Abele, Andrea E.

2014-01-01

The present research studies the association between traits, values, and life satisfaction. While values should influence the direction of an individual’s goals and behavior, his/her traits impact effort-expenditure, efficiency, and persistence in goal-pursuit. We apply the framework of the “Big Two” of agency and communion (Bakan, 1966) for distinguishing the content of values and traits. While agentic content refers to qualities relevant for goal-attainment, such as assertiveness, competence or persistence, communal content refers to qualities relevant for the establishment and maintenance of social relationships, such as being friendly, helpful, or fair. We predict that high scores on communal values and high scores on agentic traits are associated with life satisfaction. We test these predictions in two studies conducted in different countries (Germany and Russia) with different cultural background. The findings support our reasoning: across both countries we find positive associations of communal values and agentic traits with life satisfaction; and individuals high in communal values and high in agentic traits are most satisfied with their lives. In Russia, the association of communal values with life satisfaction is moderated by agentic traits; in Germany, however, there is a main effect of communal values. PMID:25477843

Pursuit of communal values in an agentic manner: A way to happiness?

Directory of Open Access Journals (Sweden)

Andrea Elisabeth Abele

2014-11-01

Full Text Available The present research studies the association between traits, values and life satisfaction. While values should influence the direction of an individual’s goals and behaviour, his/her traits impact effort expenditure, efficiency and persistence in goal-pursuit. We apply the framework of the Big Two of agency and communion (Bakan, 1966 for distinguishing the content of values and traits. While agentic content refers to qualities relevant for goal-attainment, such as assertiveness, competence or persistence, communal content refers to qualities relevant for the establishment and maintenance of social relationships, such as being friendly, helpful, or fair. We predict that high scores on communal values and high scores on agentic traits are associated with life satisfaction. We test these predictions in two studies conducted in different countries (Germany and Russia with different cultural background. The findings support our reasoning: Across both countries we find positive associations of communal values and agentic traits with life satisfaction; and individuals high in communal values and high in agentic traits are most satisfied with their lives. In Russia, the association of communal values with life satisfaction is moderated by agentic traits; in Germany, however, there is a main effect of communal values.

Anaerobic reductive dechlorination of tetrachloroethene: how can dual Carbon-Chlorine isotopic measurements help elucidating the underlying reaction mechanism?

Science.gov (United States)

Badin, Alice; Buttet, Géraldine; Maillard, Julien; Holliger, Christof; Hunkeler, Daniel

2014-05-01

Chlorinated ethenes (CEs) such as tetrachloroethene (PCE) are common persistent groundwater contaminants. Among clean-up strategies applied to sites affected by such pollution, bioremediation has been considered with a growing interest as it represents a cost-effective, environmental friendly approach. This technique however sometimes leads to an incomplete and slow biodegradation of CEs resulting in an accumulation of toxic metabolites. Understanding the reaction mechanisms underlying anaerobic reductive dechlorination would thus help assessing PCE biodegradation in polluted sites. Stable isotope analysis can provide insight into reaction mechanisms. For chlorinated hydrocarbons, carbon (C) and chlorine (Cl) isotope data (δ13C and δ37Cl) tend to show a linear correlation with a slope (m ≡ ɛC/ɛCl) characteristic of the reaction mechanism [1]. This study hence aims at exploring the potential of a dual C-Cl isotope approach in the determination of the reaction mechanisms involved in PCE reductive dechlorination. C and Cl isotope fractionation were investigated during anaerobic PCE dechlorination by two bacterial consortia containing members of the Sulfurospirillum genus. The specificity in these consortia resides in the fact that they each conduct PCE reductive dechlorination catalysed by one different reductive dehalogenase, i.e. PceADCE which yields trichloroethene (TCE) and cis-dichloroethene (cDCE), and PceATCE which yields TCE only. The bulk C isotope enrichment factors were -3.6±0.3 o for PceATCE and -0.7±0.1o for PceADCE. The bulk Cl isotope enrichment factors were -1.3±0.2 o for PceATCE and -0.9±0.1 o for PceADCE. When applying the dual isotope approach, two m values of 2.7±0.1 and 0.7±0.2 were obtained for the reductive dehalogenases PceATCE and PceADCE, respectively. These results suggest that PCE can be degraded according to two different mechanisms. Furthermore, despite their highly similar protein sequences, each reductive dehalogenase seems

Emerging protein targets for metal-based pharmaceutical agents : An update

NARCIS (Netherlands)

de Almeida, Andreia; Oliveira, Bruno L.; Correia, Joao D. G.; Soveral, Graca; Casini, Angela

2013-01-01

The peculiar chemical properties of metal-based drugs impart innovative pharmacological profiles to this class of therapeutic and diagnostic agents, most likely in relation to novel molecular mechanisms still poorly understood. However, inorganic drugs have been scarcely considered for medicinal

Web of Data Evolution by Exploiting Agent Based-Argumentation

OpenAIRE

Chamekh , Fatma; Boulanger , Danielle; Talens , Guilaine

2015-01-01

International audience; Sharing knowledge and data coming from different sources is one of the biggest advantage of linked data. Keeping this knowledge graph up to date may take in account both ontology vocabularies and data since they should be consistent. Our general problem is to deal with web of data evolution in particular: We aim at assisting user in a such complex process. In this research work, we propose an agent based-argumentation framework to help user linked data changes. We assi...

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

DEFF Research Database (Denmark)

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

2017-01-01

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

Agent-based modeling traction force mediated compaction of cell-populated collagen gels using physically realistic fibril mechanics.

Science.gov (United States)

Reinhardt, James W; Gooch, Keith J

2014-02-01

Agent-based modeling was used to model collagen fibrils, composed of a string of nodes serially connected by links that act as Hookean springs. Bending mechanics are implemented as torsional springs that act upon each set of three serially connected nodes as a linear function of angular deflection about the central node. These fibrils were evaluated under conditions that simulated axial extension, simple three-point bending and an end-loaded cantilever. The deformation of fibrils under axial loading varied <0.001% from the analytical solution for linearly elastic fibrils. For fibrils between 100 μm and 200 μm in length experiencing small deflections, differences between simulated deflections and their analytical solutions were <1% for fibrils experiencing three-point bending and <7% for fibrils experiencing cantilever bending. When these new rules for fibril mechanics were introduced into a model that allowed for cross-linking of fibrils to form a network and the application of cell traction force, the fibrous network underwent macroscopic compaction and aligned between cells. Further, fibril density increased between cells to a greater extent than that observed macroscopically and appeared similar to matrical tracks that have been observed experimentally in cell-populated collagen gels. This behavior is consistent with observations in previous versions of the model that did not allow for the physically realistic simulation of fibril mechanics. The significance of the torsional spring constant value was then explored to determine its impact on remodeling of the simulated fibrous network. Although a stronger torsional spring constant reduced the degree of quantitative remodeling that occurred, the inclusion of torsional springs in the model was not necessary for the model to reproduce key qualitative aspects of remodeling, indicating that the presence of Hookean springs is essential for this behavior. These results suggest that traction force mediated matrix

Why humans might help strangers

Directory of Open Access Journals (Sweden)

Nichola Jayne Raihani

2015-02-01

Full Text Available Humans regularly help strangers, even when interactions are apparently unobserved and unlikely to be repeated. Such situations have been simulated in the laboratory using anonymous one-shot games (e.g. prisoner's dilemma where the payoff matrices used make helping biologically altruistic. As in real-life, participants often cooperate in the lab in these one-shot games with non-relatives, despite that fact that helping is under negative selection under these circumstances. Two broad explanations for such behavior prevail. The 'big mistake' or 'mismatch' theorists argue that behavior is constrained by psychological mechanisms that evolved predominantly in the context of repeated interactions with known individuals. In contrast, the cultural group selection theorists posit that humans have been selected to cooperate in anonymous one-shot interactions due to strong between-group competition, which creates interdependence among in-group members. We present these two hypotheses before discussing alternative routes by which humans could increase their direct fitness by cooperating with strangers under natural conditions. In doing so, we explain why the standard lab games do not capture real-life in various important aspects. First, asymmetries in the cost of perceptual errors regarding the context of the interaction (one-shot versus repeated; anonymous versus public might have selected for strategies that minimize the chance of making costly behavioral errors. Second, helping strangers might be a successful strategy for identifying other cooperative individuals in the population, where partner choice can turn strangers into interaction partners. Third, in many real-world situations individuals are able to parcel investments such that a one-shot interaction is turned into a repeated game of many decisions. Finally, in contrast to the assumptions of the prisoner's dilemma model, it is possible that benefits of cooperation follow a non-linear function of

Fast Conflict Resolution Based on Reinforcement Learning in Multi-agent System

Institute of Scientific and Technical Information of China (English)

PIAOSonghao; HONGBingrong; CHUHaitao

2004-01-01

In multi-agent system where each agen thas a different goal (even the team of agents has the same goal), agents must be able to resolve conflicts arising in the process of achieving their goal. Many researchers presented methods for conflict resolution, e.g., Reinforcement learning (RL), but the conventional RL requires a large computation cost because every agent must learn, at the same time the overlap of actions selected by each agent results in local conflict. Therefore in this paper, we propose a novel method to solve these problems. In order to deal with the conflict within the multi-agent system, the concept of potential field function based Action selection priority level (ASPL) is brought forward. In this method, all kinds of environment factor that may have influence on the priority are effectively computed with the potential field function. So the priority to access the local resource can be decided rapidly. By avoiding the complex coordination mechanism used in general multi-agent system, the conflict in multi-agent system is settled more efficiently. Our system consists of RL with ASPL module and generalized rules module. Using ASPL, RL module chooses a proper cooperative behavior, and generalized rule module can accelerate the learning process. By applying the proposed method to Robot Soccer, the learning process can be accelerated. The results of simulation and real experiments indicate the effectiveness of the method.

Nutraceuticals as therapeutic agents for atherosclerosis.

Science.gov (United States)

Moss, Joe W E; Williams, Jessica O; Ramji, Dipak P

2018-05-01

Atherosclerosis, a chronic inflammatory disorder of medium and large arteries and an underlying cause of cardiovascular disease (CVD), is responsible for a third of all global deaths. Current treatments for CVD, such as optimized statin therapy, are associated with considerable residual risk and several side effects in some patients. The outcome of research on the identification of alternative pharmaceutical agents for the treatment of CVD has been relatively disappointing with many promising leads failing at the clinical level. Nutraceuticals, products from food sources with health benefits beyond their nutritional value, represent promising agents in the prevention of CVD or as an add-on therapy with current treatments. This review will highlight the potential of several nutraceuticals, including polyunsaturated fatty acids, flavonoids and other polyphenols, as anti-CVD therapies based on clinical and pre-clinical mechanism-based studies. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

The complete genome sequence of Bacillus velezensis 9912D reveals its biocontrol mechanism as a novel commercial biological fungicide agent.

Science.gov (United States)

Pan, Hua-Qi; Li, Qing-Lian; Hu, Jiang-Chun

2017-04-10

A Bacillus sp. 9912 mutant, 9912D, was approved as a new biological fungicide agent by the Ministry of Agriculture of the People's Republic of China in 2016 owing to its excellent inhibitory effect on various plant pathogens and being environment-friendly. Here, we present the genome of 9912D with a circular chromosome having 4436 coding DNA sequences (CDSs), and a circular plasmid encoding 59 CDSs. This strain was finally designated as Bacillus velezensis based on phylogenomic analyses. Genome analysis revealed a total of 19 candidate gene clusters involved in secondary metabolite biosynthesis, including potential new type II lantibiotics. The absence of fengycin biosynthetic gene cluster is noteworthy. Our data offer insights into the genetic, biological and physiological characteristics of this strain and aid in deeper understanding of its biocontrol mechanism. Copyright © 2017 Elsevier B.V. All rights reserved.

Dynamic Matching Markets and the Deferred Acceptance Mechanism

DEFF Research Database (Denmark)

Kennes, John; Monte, Daniel; Tumennasan, Norovsambuu

In many dynamic matching markets, priorities depend on previous allocations. In such environments, agents on the proposing side can manipulate the period-by-period deferred acceptance (DA) mechanism. We show that the fraction of agents with incentives to manipulate the DA mechanism approaches zero...... as the market size increases. In addition, we provide a novel al- gorithm to calculate the percentage of markets that can be manipulated. Based on randomly generated data, we find that the DA becomes approximately non-manipulable when the schools capacity reaches 20. Our theoretical and simulation results...... together justify the implementation of the period-by-period DA mechanism in dynamic markets....

Contrast agent enhanced pQCT of articular cartilage

Energy Technology Data Exchange (ETDEWEB)

Kallioniemi, A S [Department of Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland); Jurvelin, J S [Department of Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland); Nieminen, M T [Department of Diagnostic Radiology, POB 50, 90029 OYS, Oulu University Hospital, Oulu (Finland); Lammi, M J [Department of Anatomy, Institute of Biomedicine, University of Kuopio, POB 1627, 70211 Kuopio (Finland); Toeyraes, J [Department of Physics, University of Kuopio, POB 1627, 70211 Kuopio (Finland)

2007-02-21

degraded articular cartilage in vitro. As high resolution imaging of e.g. the knee joint is possible with pQCT, the present technique may be further developed for in vivo quantification of PG depletion in osteoarthritic cartilage. However, careful in vitro and in vivo characterization of diffusion mechanics and optimal contrast agent concentrations are needed before diagnostic applications are feasible.

Contrast agent enhanced pQCT of articular cartilage

Science.gov (United States)

Kallioniemi, A. S.; Jurvelin, J. S.; Nieminen, M. T.; Lammi, M. J.; Töyräs, J.

2007-02-01

degraded articular cartilage in vitro. As high resolution imaging of e.g. the knee joint is possible with pQCT, the present technique may be further developed for in vivo quantification of PG depletion in osteoarthritic cartilage. However, careful in vitro and in vivo characterization of diffusion mechanics and optimal contrast agent concentrations are needed before diagnostic applications are feasible.

Contrast agent enhanced pQCT of articular cartilage

International Nuclear Information System (INIS)

Kallioniemi, A S; Jurvelin, J S; Nieminen, M T; Lammi, M J; Toeyraes, J

2007-01-01

articular cartilage in vitro. As high resolution imaging of e.g. the knee joint is possible with pQCT, the present technique may be further developed for in vivo quantification of PG depletion in osteoarthritic cartilage. However, careful in vitro and in vivo characterization of diffusion mechanics and optimal contrast agent concentrations are needed before diagnostic applications are feasible

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...

Oxidative decontamination of chemical and biological warfare agents using L-Gel.

Science.gov (United States)

Raber, Ellen; McGuire, Raymond

2002-08-05

A decontamination method has been developed using a single reagent that is effective both against chemical warfare (CW) and biological warfare (BW) agents. The new reagent, "L-Gel", consists of an aqueous solution of a mild commercial oxidizer, Oxone, together with a commercial fumed silica gelling agent, Cab-O-Sil EH-5. L-Gel is non-toxic, environmentally friendly, relatively non-corrosive, maximizes contact time because of its thixotropic nature, clings to walls and ceilings, and does not harm carpets or painted surfaces. The new reagent also addresses the most demanding requirements for decontamination in the civilian sector, including availability, low maintenance, ease of application and deployment by a variety of dispersal mechanisms, minimal training and acceptable expense. Experiments to test the effectiveness of L-Gel were conducted at Lawrence Livermore National Laboratory and independently at four other locations. L-Gel was tested against all classes of chemical warfare agents and against various biological warfare agent surrogates, including spore-forming bacteria and non-virulent strains of real biological agents. Testing showed that L-Gel is as effective against chemical agents and biological materials, including spores, as the best military decontaminants.

Eye-closure helps memory by reducing cognitiveload and enhancing visualisation

NARCIS (Netherlands)

Vredeveldt, A.; Hitch, G.J.; Baddeley, A.D.

2011-01-01

Closing the eyes helps memory. We investigated the mechanisms underlying the eyeclosure effect by exposing 80 eyewitnesses to different types of distraction during the witness interview: blank screen (control), eyes closed, visual distraction, and auditory distraction. We examined the cognitive load

RNA-Seq reveals the molecular mechanism of trapping and killing of root-knot nematodes by nematode-trapping fungi.

Science.gov (United States)

Pandit, Ramesh; Patel, Reena; Patel, Namrata; Bhatt, Vaibhav; Joshi, Chaitanya; Singh, Pawan Kumar; Kunjadia, Anju

2017-04-01

Nematode-trapping fungi are well known for their inherent potential to trap and kill nematodes using specialized trapping devices. However, the molecular mechanisms underlying the trapping and subsequent processes are still unclear. Therefore, in this study, we examined differential genes expression in two nematode-trapping fungi after baiting with nematode extracts. In Arthrobotrys conoides, 809 transcripts associated with diverse functions such as signal transduction, morphogenesis, stress response and peroxisomal proteins, proteases, chitinases and genes involved in the host-pathogen interaction showed differential expression with fold change (>±1.5 fold) in the presence of nematode extract with FDR (p-value nematode-trapping fungi for its host. The findings illustrate the molecular mechanism of fungal parasitism in A. conoides which may be helpful in developing a potential biocontrol agent against parasitic nematodes.

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.

Riot Control Agents

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

Allelopathic potential of some biocontrol agents for the control of ...

African Journals Online (AJOL)

The adverse effect of synthetic pesticides on human health and the natural ecosystem necessitate the need to explore natural mechanisms of disease control in plants. This study evaluated the allelopathic potential of five biocontrol agents: Trichoderma longibrachiatum, Trichoderma asperellum, Bacillus subtilis, Bacillus ...

A review on common chemical hemostatic agents in restorative dentistry

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Pardis Tarighi

2014-01-01

Full Text Available Control of hemorrhage is one of the challenging situations dentists confront during deep cavity preparation and before impressions or cementation of restorations. For the best bond and least contamination it is necessary to be familiar with the hemostatic agents available on the market and to be able to choose the appropriate one for specific situations. This review tries to introduce the commercially available hemostatic agents, discusses their components and their specific features. The most common chemical agents that are widely used in restorative and prosthodontic dentistry according to their components and mechanism of action as well as their special uses are introduced. PubMed and Google Scholar were searched for studies involving gingival retraction and hemostatic agents from 1970 to 2013. Key search words including: "gingival retraction techniques, impression technique, hemostasis and astringent" were searched. Based on the information available in the literature, in order to achieve better results with impression taking and using resin bonding techniques, common hemostatic agents might be recommended before or during acid etching; they should be rinsed off properly and it is recommended that they be used with etch-and-rinse adhesive systems.

Overview on Analysis of Free Metabolites for Detection of Exposure to Chemical Warfare Agents

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Grigoriu Nicoleta

2015-06-01

Full Text Available Chemical warfare agents (CWA’s induce complex toxicological effects with major adverse consequences for those exposed. For many chemical agents there is a need for research and development of analytical toxicological methods for a rapid and certain confirmation of those exposures. The certain methods will help for establishing the laboratory diagnosis for applying the proper therapy; the treatment of only contaminated people, decreasing the stress level in the medical community in management of crisis situations, increasing the survival rate of the population exposed to the contamination, supervision of professional exposure, judicial analysis in case of suspicious terrorist activities.

Rewiring the network. What helps an innovation to diffuse?

International Nuclear Information System (INIS)

Sznajd-Weron, Katarzyna; Szwabiński, Janusz; Weron, Rafał; Weron, Tomasz

2014-01-01

A fundamental question related to innovation diffusion is how the structure of the social network influences the process. Empirical evidence regarding real-world networks of influence is very limited. On the other hand, agent-based modeling literature reports different, and at times seemingly contradictory, results. In this paper we study innovation diffusion processes for a range of Watts–Strogatz networks in an attempt to shed more light on this problem. Using the so-called Sznajd model as the backbone of opinion dynamics, we find that the published results are in fact consistent and allow us to predict the role of network topology in various situations. In particular, the diffusion of innovation is easier on more regular graphs, i.e. with a higher clustering coefficient. Moreover, in the case of uncertainty—which is particularly high for innovations connected to public health programs or ecological campaigns—a more clustered network will help the diffusion. On the other hand, when social influence is less important (i.e. in the case of perfect information), a shorter path will help the innovation to spread in the society and—as a result—the diffusion will be easiest on a random graph. (paper)

Herbal radiation countermeasure agents: promising role in the management of radiological/nuclear exigencies

International Nuclear Information System (INIS)

Arora, Rajesh; Sharma, A.; Kumar, R.; Tripathi, R.P.

2008-01-01

In the future, there is a need to substantially boost biomass production and employ elicitors/precursors for improving the production of radioprotective compounds from such alternative sources for ensuring a sustainable supply of the high-value, low volume radioprotective molecules. Chemical fingerprinting, identification and characterization of bioactive constituents using modem analytical techniques and evaluation of their multifaceted mode of action at genomic/proteomic level is also the need of the hour. Such data will help in the development of novel, safe and effective radiation countermeasure agents for human use. Herbal radiation countermeasure agents, including several dietary agents, are likely to find large-scale acceptance in most countries in view of their widespread acceptance, holistic mode of action, less toxicity and economical nature. Endeavours made at INMAS in this direction are likely to fructify in coming years and radiation countermeasure agents from several of these herbal sources would become available, possibly several would be obtainable over-the-counter, for use by civilians, military personnel, first emergency responders and other rescue and recovery personnel. (author)

Constructing Secure Mobile Agent Systems Using the Agent Operating System

NARCIS (Netherlands)

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

2009-01-01

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

Nondestructive Intervention to Multi-Agent Systems through an Intelligent Agent

Science.gov (United States)

Han, Jing; Wang, Lin

2013-01-01

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

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

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Jing Han

Full Text Available 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.

Current and Emerging Topical Antibacterials and Antiseptics: Agents, Action, and Resistance Patterns.

Science.gov (United States)

Williamson, Deborah A; Carter, Glen P; Howden, Benjamin P

2017-07-01

Bacterial skin infections represent some of the most common infectious diseases globally. Prevention and treatment of skin infections can involve application of a topical antimicrobial, which may be an antibiotic (such as mupirocin or fusidic acid) or an antiseptic (such as chlorhexidine or alcohol). However, there is limited evidence to support the widespread prophylactic or therapeutic use of topical agents. Challenges involved in the use of topical antimicrobials include increasing rates of bacterial resistance, local hypersensitivity reactions (particularly to older agents, such as bacitracin), and concerns about the indiscriminate use of antiseptics potentially coselecting for antibiotic resistance. We review the evidence for the major clinical uses of topical antibiotics and antiseptics. In addition, we review the mechanisms of action of common topical agents and define the clinical and molecular epidemiology of antimicrobial resistance in these agents. Moreover, we review the potential use of newer and emerging agents, such as retapamulin and ebselen, and discuss the role of antiseptic agents in preventing bacterial skin infections. A comprehensive understanding of the clinical efficacy and drivers of resistance to topical agents will inform the optimal use of these agents to preserve their activity in the future. Copyright © 2017 American Society for Microbiology.

Report on NCI symposium: comparison of mechanisms of carcinogenesis by radiation and chemical agents. II. Cellular and animal models

International Nuclear Information System (INIS)

Fry, R.J.M.

1984-01-01

The point at which the common final pathway for induction of cancer by chemical carcinogens and ionizing radiation has not been identified. Although common molecular targets are suggested by recent findings about the role of oncogenes, the mechanism by which the deposition of radiation energy and the formation of adducts or other DNA lesions induced by chemicals affects the changes in the relevant targets may be quite different. The damage to DNA that plays no part in the transformation events, but that influences the stability of the genome, and therefore, the probability of subsequent changes that influence tumorigenesis may be more readily induced by some agents than others. Similarly, the degree of cytotoxic effects that disrupt tissue integrity and increase the probability of expression of initiated cells may be dependent on the type of carcinogen. Also, evidence was presented that repair of the initial lesions could be demonstrated after exposure to low-LET radiation but not after exposure to chemical carcinogens

Report on NCI symposium: comparison of mechanisms of carcinogenesis by radiation and chemical agents. II. Cellular and animal models

Energy Technology Data Exchange (ETDEWEB)

Fry, R.J.M.

1984-01-01

The point at which the common final pathway for induction of cancer by chemical carcinogens and ionizing radiation has not been identified. Although common molecular targets are suggested by recent findings about the role of oncogenes, the mechanism by which the deposition of radiation energy and the formation of adducts or other DNA lesions induced by chemicals affects the changes in the relevant targets may be quite different. The damage to DNA that plays no part in the transformation events, but that influences the stability of the genome, and therefore, the probability of subsequent changes that influence tumorigenesis may be more readily induced by some agents than others. Similarly, the degree of cytotoxic effects that disrupt tissue integrity and increase the probability of expression of initiated cells may be dependent on the type of carcinogen. Also, evidence was presented that repair of the initial lesions could be demonstrated after exposure to low-LET radiation but not after exposure to chemical carcinogens.

Enzymes and other agents that enhance cell wall extensibility

Science.gov (United States)

Cosgrove, D. J.

1999-01-01

Polysaccharides and proteins are secreted to the inner surface of the growing cell wall, where they assemble into a network that is mechanically strong, yet remains extensible until the cells cease growth. This review focuses on the agents that directly or indirectly enhance the extensibility properties of growing walls. The properties of expansins, endoglucanases, and xyloglucan transglycosylases are reviewed and their postulated roles in modulating wall extensibility are evaluated. A summary model for wall extension is presented, in which expansin is a primary agent of wall extension, whereas endoglucanases, xyloglucan endotransglycosylase, and other enzymes that alter wall structure act secondarily to modulate expansin action.

Organizations as Socially Constructed Agents in the Agent Oriented Paradigm

NARCIS (Netherlands)

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

2005-01-01

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

A Study on the Rheological and Mechanical Properties of Photo-Curable Ceramic/Polymer Composites with Different Silane Coupling Agents for SLA 3D Printing Technology

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Se Yeon Song

2018-02-01

Full Text Available Silane coupling agents (SCAs with different organofunctional groups were coated on the surfaces of Al2O3 ceramic particles through hydrolysis and condensation reactions, and the SCA-coated Al2O3 ceramic particles were dispersed in a commercial photopolymer based on interpenetrating networks (IPNs. The organofunctional groups that have high radical reactivity and are more effective in UV curing systems are usually functional groups based on acryl, such as acryloxy groups, methacrloxy groups, and acrylamide groups, and these silane coupling agents seem to improve interfacial adhesion and dispersion stability. The coating morphology and the coating thickness distribution of SCA-coated Al2O3 ceramic particles according to the different organofunctional groups were observed by FE-TEM. The initial dispersibility and dispersion stability of the SCA-coated Al2O3/High-temp composite solutions were investigated by relaxation NMR and Turbiscan. The rheological properties of the composite solutions were investigated by viscoelastic analysis and the mechanical properties of 3D-printed objects were observed with a nanoindenter.

Fast Flux Watch: A mechanism for online detection of fast flux networks

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Basheer N. Al-Duwairi

2014-07-01

Full Text Available Fast flux networks represent a special type of botnets that are used to provide highly available web services to a backend server, which usually hosts malicious content. Detection of fast flux networks continues to be a challenging issue because of the similar behavior between these networks and other legitimate infrastructures, such as CDNs and server farms. This paper proposes Fast Flux Watch (FF-Watch, a mechanism for online detection of fast flux agents. FF-Watch is envisioned to exist as a software agent at leaf routers that connect stub networks to the Internet. The core mechanism of FF-Watch is based on the inherent feature of fast flux networks: flux agents within stub networks take the role of relaying client requests to point-of-sale websites of spam campaigns. The main idea of FF-Watch is to correlate incoming TCP connection requests to flux agents within a stub network with outgoing TCP connection requests from the same agents to the point-of-sale website. Theoretical and traffic trace driven analysis shows that the proposed mechanism can be utilized to efficiently detect fast flux agents within a stub network.

Electroanalysis of cardioselective beta-adrenoreceptor blocking agent acebutolol by disposable graphite pencil electrodes with detailed redox mechanism

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Atmanand M. Bagoji

2016-12-01

Full Text Available A simple economic graphite pencil electrode (GPE was used for analysis of cardioselective, hydrophilic-adrenoreceptor blocking agent, acebutolol (ACBT using the cyclic voltammetric, linear sweep voltammetric, differential pulse voltammetric (DPV, and square-wave voltammetric (SWV techniques. The dependence of the current on pH, concentration, and scan rate was investigated to optimize the experimental condition for determination of ACBT. The electrochemical behavior of the ACBT at GPE was a diffusion-controlled process. A probable electro-redox mechanism was proposed. Under the optimal conditions, the anodic peak current was linearly proportional to the concentration of ACBT in the range from 1.00 to 15.0 μM with a limit of detection 1.26 × 10−8 M for DPV and 1.28 × 10−8 M for the SWV. This method was applied for quantitative determination of the ACBT levels in urine as real samples. The obtained recovery ranges for ACBT in urine were from 95.4 to101% as found by the standard addition technique. Further interference study was also carried with some common interfering substances.

Evaluation of in vitro antibacterial effect of room curing polymethylmethacrylate material adding nano-silver base inorganic antibacterial agents

International Nuclear Information System (INIS)

Jia Chunli; Wang Xiaorong; Zhang Citong; Sun Shiqun; Yang Yun

2012-01-01

Objective: To investigate the antibacterial effect of room curing polymethylmethacrylate (PMMA) material adding nano-silver base inorganic antibacterial agent and to detect the changes of its mechanical property. Methods: Nano-silver base inorganic antibacterial agent was added to the room curing PMMA material in the range of 0.5% -3.0% at an interval of 0.5% by ball milling specimen. Antibacterial rates of the specimens were detected by film method. Bending strength, impact strength, and wear resistance of the specimens were respectively detected on electronic universal testing machine, impact test machine and friction and wear test machine. Results: The antibacterial rates of Streptococcus mutans and Candida albicans were more than 50% when antibiotics content was 1.0% . The antibacterial rates of Streptococcus mutans and Candida albicans were more than 90% when the antibiotics content was 2.5% . The three mechanical properties were increased compared with control group when the antibacterial agents were in the range of 1.0% -1.5% . Then the three mechanical properties were decreased with the increasing of antimicrobial concentration. When the antibiotics content was 2.0% , the wear resistance had significant difference compared with control group (P<0.05); when the antibiotics content was 2.5% , the bending strength and impact strength had significant difference compared with control group (P<0.05). Conclusion: The antibacterial effect of room curing PMMA adding nano-silver base inorganic antibacterial agent is ideal. The antibacterial rate is increased gradually with the increasing content of antibacterial agents. There is no significant effect on the mechanical properties of room curing PMMA material, but the antibacterial effects are satisfied when the content of antibacterial agents is 2.0% . (authors)

CONCEPTION OF BI-FOLD AUTHENTICATED AGENT – MONITORED TRANSACTION ARCHITECTURE

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Srivatsan Sridharan

2014-06-01

Full Text Available The aim of this paper is to provide an introduction towards the architectural design of a bi-fold authenticated agent-monitored transaction model. The focus is primarily on implementation in ATM systems which provide the following facilities of withdrawing currency at any remote terminal, verification of the end users identity using Personal Identification Number and an authentic One-Time-Session-Dependent Key generation and validation through the mobile. This system requires building up of an third party agent which would establish a secure session to the bank application with the terminal only after a series of authentication mechanism without compromising the privacy of any individual. The customers, without any insider privileges, can withdraw currency without being detected by any mechanisms of theft of card and eaves dropping of the Password from the card holders within the terminal software are also a major threat yet to be addressed. A basic solution is the terminals having bi-fold authentication mechanisms where mobile dependent one time session dependent key is being generated with authenticity being ensured and the confidentiality being maintained. In such a system, the correctness burden on the terminal’s code is significantly less as the customers have been given the chance to authorize themselves from their hand-held devices and are allowed to withdraw currency in terminal only after their identity is proved by a series of authentication procedures. In this paper along with the bi-fold authentication implementation, architectural design of the agent which is being introduced is also briefed.

Understanding the plant-microbe interaction molecular mechanisms for better exploitation of bio-control agents to enhance sustainable agricultural practices

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Indu Kumari

2017-10-01

Full Text Available Trichoderma spp. are well-known bio-control agents which promote the plant growth and suppress the pathogen infection. The beneficial effects are attributed to the production of phytohormones, antibiotics, siderophores and secondary metabolites (SM. Trichodermin and Harzianum A, SMs have documented anti-fungal activities as well. Tri5 gene encodes for trichodiene synthase (TS contains a terpene fold and involved at the initial step of the biosynthetic pathway of these molecules. Furthermore, domain analysis of proteins from diverse organisms showed that the terpene fold has functional diversity with diverse applications in agriculture, medicine and applied biotechnology. These proteins can be classified into single and multi-domains based on their structures. It was observed that multi-domain proteins carry additional helices which may regulate the catalytic efficiency. Further, activity enhancing mutations with potentially higher catalytic activities were screened. In an offshoot to the above work, we have analyzed binding of Trichodermin with the 25S rRNA that constitutes the petidyltransferase centre (PTC. The trichodermin resistance protein (60S ribosomal protein L3 was reported to overcome the inhibitory effects of trichothecene compounds. Normal mode analysis and MD of trichodermin resistance protein and 25S consisting of PTC showed that the W-finger region of the protein may move towards 25S rRNA and may block the binding pocket of the trichodermin. These results may lead to develop strategies for higher TS activity and the mechanism of action of these molecules involved in plant-microbe interactions. These may be further exploited for enhancing the efficiency of these biotechnological agents used in sustainable agriculture.

Anticipated Guilt for not Helping and Anticipated Warm Glow for Helping are Differently Impacted by Personal Responsibility to Help

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Arvid Erlandsson

2016-09-01

Full Text Available One important motivation for people behaving prosocially is that they want to avoid negative and obtain positive emotions. In the prosocial behavior literature however, the motivations to avoid negative emotions (e.g. guilt and to approach positive emotions (e.g. warm glow are rarely separated, and sometimes even aggregated into a single mood-management construct. The aim of this study was to investigate whether anticipated guilt if not helping and anticipated warm glow if helping are influenced similarly or differently when varying situational factors related to personal responsibility to help. Helping scenarios were created and pilot tests established that each helping scenario could be formulated both in a high-responsibility version and in a low-responsibility version. In Study 1 participants read high-responsibility and low-responsibility helping scenarios, and rated either their anticipated guilt if not helping or their anticipated warm glow if helping (i.e. separate evaluation. Study 2 was similar but here participants rated both their anticipated guilt if not helping and their anticipated warm glow if helping (i.e. joint evaluation. Anticipated guilt was clearly higher in the high-responsibility versions, but anticipated warm glow was unaffected (in Studies 1a and 1b, or even higher in the low-responsibility versions (Study 2. In Studies 3 (where anticipated guilt and warm glow were evaluated separately and 4 (where they were evaluated jointly, personal responsibility to help was manipulated within-subjects. Anticipated guilt was again constantly higher in the high-responsibility versions but for many types of responsibility-manipulations, anticipated warm glow was higher in the low-responsibility versions. The results suggest that we anticipate guilt if not fulfilling our responsibility but that we anticipate warm glow primarily when doing over and beyond our responsibility. We argue that future studies investigating motivations for

Anticipated Guilt for Not Helping and Anticipated Warm Glow for Helping Are Differently Impacted by Personal Responsibility to Help

Science.gov (United States)

Erlandsson, Arvid; Jungstrand, Amanda Å.; Västfjäll, Daniel

2016-01-01

One important motivation for people behaving prosocially is that they want to avoid negative and obtain positive emotions. In the prosocial behavior literature however, the motivations to avoid negative emotions (e.g., guilt) and to approach positive emotions (e.g., warm glow) are rarely separated, and sometimes even aggregated into a single mood-management construct. The aim of this study was to investigate whether anticipated guilt if not helping and anticipated warm glow if helping are influenced similarly or differently when varying situational factors related to personal responsibility to help. Helping scenarios were created and pilot tests established that each helping scenario could be formulated both in a high-responsibility version and in a low-responsibility version. In Study 1 participants read high-responsibility and low-responsibility helping scenarios, and rated either their anticipated guilt if not helping or their anticipated warm glow if helping (i.e., separate evaluation). Study 2 was similar but here participants rated both their anticipated guilt if not helping and their anticipated warm glow if helping (i.e., joint evaluation). Anticipated guilt was clearly higher in the high-responsibility versions, but anticipated warm glow was unaffected (in Studies 1a and 1b), or even higher in the low-responsibility versions (Study 2). In Studies 3 (where anticipated guilt and warm glow were evaluated separately) and 4 (where they were evaluated jointly), personal responsibility to help was manipulated within-subjects. Anticipated guilt was again constantly higher in the high-responsibility versions but for many types of responsibility-manipulations, anticipated warm glow was higher in the low-responsibility versions. The results suggest that we anticipate guilt if not fulfilling our responsibility but that we anticipate warm glow primarily when doing over and beyond our responsibility. We argue that future studies investigating motivations for helping