WorldWideScience

Sample records for mechanism helps agents

  1. Toddlers Selectively Help Fair Agents

    Directory of Open Access Journals (Sweden)

    Luca Surian

    2017-06-01

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

  2. Agent Persuasion Mechanism of Acquaintance

    Science.gov (United States)

    Jinghua, Wu; Wenguang, Lu; Hailiang, Meng

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

  3. Computer Agent's Role in Modeling an Online Math Help User

    OpenAIRE

    Dragana Martinovic

    2007-01-01

    This paper investigates perspectives of deployments of open learner model on mathematics online help sites. It proposes enhancing a regular human-to-human interaction with an involvement of a computer agent suitable for tracking users, checking their input and making useful suggestions. Such a design would provide the most support for the interlocutors while keeping the nature of existing environment intact. Special considerations are given to peer-to-peer and expert-to-student mathematics on...

  4. Computer Agent's Role in Modeling an Online Math Help User

    Directory of Open Access Journals (Sweden)

    Dragana Martinovic

    2007-06-01

    Full Text Available This paper investigates perspectives of deployments of open learner model on mathematics online help sites. It proposes enhancing a regular human-to-human interaction with an involvement of a computer agent suitable for tracking users, checking their input and making useful suggestions. Such a design would provide the most support for the interlocutors while keeping the nature of existing environment intact. Special considerations are given to peer-to-peer and expert-to-student mathematics online help that is free of charge and asynchronous. Examples from other collaborative, Web-based environments are also discussed. Suggestions for improving the existing architectures are given, based on the results of a number of studies on on-line learning systems.

  5. Mechanisms of bacterial resistance to antimicrobial agents.

    NARCIS (Netherlands)

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

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

  6. Multi-Agent Design and Implementation for an Online Peer Help System

    Science.gov (United States)

    Meng, Anbo

    2014-01-01

    With the rapid advance of e-learning, the online peer help is playing increasingly important role. This paper explores the application of MAS to an online peer help system (MAPS). In the design phase, the architecture of MAPS is proposed, which consists of a set of agents including the personal agent, the course agent, the diagnosis agent, the DF…

  7. Mechanisms of resistance to alkylating agents

    OpenAIRE

    Damia, G.; D‘Incalci, M.

    1998-01-01

    Alkylating agents are the most widely used anticancer drugs whose main target is the DNA, although how exactly the DNA lesions cause cell death is still not clear. The emergence of resistance to this class of drugs as well as to other antitumor agents is one of the major causes of failure of cancer treatment. This paper reviews some of the best characterized mechanisms of resistance to alkylating agents. Pre- and post-target mechanisms are recognized, the former able to limit the formation of...

  8. An improved 2-agent kidney exchange mechanism

    DEFF Research Database (Denmark)

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

    2015-01-01

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

  9. 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

  10. Detection of Alkylating Agents using Electrical and Mechanical Means

    Science.gov (United States)

    Gerchikov, Yulia; Borzin, Elena; Gannot, Yair; Shemesh, Ariel; Meltzman, Shai; Hertzog-Ronen, Carmit; Tal, Shay; Stolyarova, Sara; Nemirovsky, Yael; Tessler, Nir; Eichen, Yoav

    2011-08-01

    Alkylating agents are reactive molecules having at least one polar bond between a carbon atom and a good leaving group. These often simple molecules are frequently used in organic synthesis, as sterilizing agents in agriculture and even as anticancer agents in medicine. Unfortunately, for over a century, some of the highly reactive alkylating agents are also being used as blister chemical warfare agents. Being relatively simple to make, the risk is that these will be applied by terrorists as poor people warfare agents. The detection and identification of such alkylating agents is not a simple task because of their high reactivity and simple structure of the reactive site. Here we report on new approaches to the detection and identification of such alkylating agents using electrical (organic field effect transistors) and mechanical (microcantilevers) means.

  11. Detection of Alkylating Agents using Electrical and Mechanical Means

    International Nuclear Information System (INIS)

    Gerchikov, Yulia; Borzin, Elena; Gannot, Yair; Shemesh, Ariel; Meltzman, Shai; Hertzog-Ronen, Carmit; Eichen, Yoav; Tal, Shay; Stolyarova, Sara; Nemirovsky, Yael; Tessler, Nir

    2011-01-01

    Alkylating agents are reactive molecules having at least one polar bond between a carbon atom and a good leaving group. These often simple molecules are frequently used in organic synthesis, as sterilizing agents in agriculture and even as anticancer agents in medicine. Unfortunately, for over a century, some of the highly reactive alkylating agents are also being used as blister chemical warfare agents. Being relatively simple to make, the risk is that these will be applied by terrorists as poor people warfare agents. The detection and identification of such alkylating agents is not a simple task because of their high reactivity and simple structure of the reactive site. Here we report on new approaches to the detection and identification of such alkylating agents using electrical (organic field effect transistors) and mechanical (microcantilevers) means.

  12. Detection of Alkylating Agents using Electrical and Mechanical Means

    Energy Technology Data Exchange (ETDEWEB)

    Gerchikov, Yulia; Borzin, Elena; Gannot, Yair; Shemesh, Ariel; Meltzman, Shai; Hertzog-Ronen, Carmit; Eichen, Yoav [Schulich Department of Chemistry, Technion-Israel Institute of Technology, Technion City, 32000, Haifa (Israel) (Israel); Tal, Shay [Present address: Systems Biology Department, Harvard Medical School, Boston, MA 02115 (United States); Stolyarova, Sara; Nemirovsky, Yael; Tessler, Nir, E-mail: chryoav@tx.technion.ac.il [Department of Electrical Engineering, Technion-Israel Institute of Technology, Technion City, 32000, Haifa (Israel)

    2011-08-17

    Alkylating agents are reactive molecules having at least one polar bond between a carbon atom and a good leaving group. These often simple molecules are frequently used in organic synthesis, as sterilizing agents in agriculture and even as anticancer agents in medicine. Unfortunately, for over a century, some of the highly reactive alkylating agents are also being used as blister chemical warfare agents. Being relatively simple to make, the risk is that these will be applied by terrorists as poor people warfare agents. The detection and identification of such alkylating agents is not a simple task because of their high reactivity and simple structure of the reactive site. Here we report on new approaches to the detection and identification of such alkylating agents using electrical (organic field effect transistors) and mechanical (microcantilevers) means.

  13. Study of Crossling Agent and Couplink Agent Synergism on Mechanical Properties of HDPE-Cu Composites

    International Nuclear Information System (INIS)

    Mashuri; Sujud, A.A.; Karo Karo, Aloma

    2001-01-01

    The effects of crosslink agents, coupling agents and synergism on mechanical properties of HDPE-Cu composites materials has been investigated. The crosslink was made with dicumyl peroxide as crosslink agents of 2% concentration, so the interface adhesion of matrix-filler was made with 3-amino propyl triethoxysilane as coupling agents of 0.5% concentration. The results of research's showed, that the crosslink and interface adhesion of matrix-filler can increase tensile strength and elongation at break of HDPE-Cu composites. The synergism of two agents can increase tensile strength to 20% and elongation at break to 23% of HDPE-Cu composites materials

  14. Mechanisms of chemoresistance to alkylating agents in malignant glioma.

    Science.gov (United States)

    Sarkaria, Jann N; Kitange, Gaspar J; James, C David; Plummer, Ruth; Calvert, Hilary; Weller, Michael; Wick, Wolfgang

    2008-05-15

    Intrinsic or acquired chemoresistance to alkylating agents is a major cause of treatment failure in patients with malignant brain tumors. Alkylating agents, the mainstay of treatment for brain tumors, damage the DNA and induce apoptosis, but the cytotoxic activity of these agents is dependent on DNA repair pathways. For example, O6-methylguanine DNA adducts can cause double-strand breaks, but this is dependent on a functional mismatch repair pathway. Thus, tumor cell lines deficient in mismatch repair are resistant to alkylating agents. Perhaps the most important mechanism of resistance to alkylating agents is the DNA repair enzyme O6-methylguanine methyltransferase, which can eliminate the cytotoxic O6-methylguanine DNA adduct before it causes harm. Another mechanism of resistance to alkylating agents is the base excision repair (BER) pathway. Consequently, efforts are ongoing to develop effective inhibitors of BER. Poly(ADP-ribose)polymerase plays a pivotal role in BER and is an important therapeutic target. Developing effective strategies to overcome chemoresistance requires the identification of reliable preclinical models that recapitulate human disease and which can be used to facilitate drug development. This article describes the diverse mechanisms of chemoresistance operating in malignant glioma and efforts to develop reliable preclinical models and novel pharmacologic approaches to overcome resistance to alkylating agents.

  15. 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.

  16. 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.

  17. Help seeking in aggressive and nonaggressive boys as a function of social or mechanical mediation of assistance.

    Science.gov (United States)

    Shea, B J; Routh, D K; Cottrell, N B; Brecht, J M

    1973-04-01

    The behavior of preadolescent and adolescent boys, rated as aggressive and nonaggressive, was examined to test predictions from Bandura and Walters' social-learning theory and from Weiss and Miller's punishment model of audience-observation effects. The subjects were given a bogus motor task, actually insoluble, with help available on each trial. For half the subjects, help was given through the mediation of a social agent; for the rest, help was on a nonsocial, mechanically mediated basis. The groups for whom help was socially mediated made fewer help-seeking responses and decreased the number of such responses over successive trial blocks. The predictions from Bandura and Walters' theory were not supported, since neither age nor degree of aggressiveness had an effect on help-seeking responses. The results were, however, consistent with the punishment model of audience effects.

  18. 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.

  19. 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.

  20. Information Sharing Mechanism among Mobile Agents In Ad-hoc Network Environment and Its Applications

    Directory of Open Access Journals (Sweden)

    Kunio Umetsuji

    2004-12-01

    Full Text Available Mobile agents are programs that can move from one site to another in a network with their data and states. Mobile agents are expected to be an essential tool in pervasive computing. In multi platform environment, it is important to communicate with mobile agents only using their universal or logical name not using their physical locations. More, in an ad-hoc network environment, an agent can migrate autonomously and communicate with other agents on demand. It is difficult that mobile agent grasps the position information on other agents correctly each other, because mobile agent processes a task while moving a network successively. In order to realize on-demand mutual communication among mobile agents without any centralized servers, we propose a new information sharing mechanism within mobile agents. In this paper, we present a new information sharing mechanism within mobile agents. The method is a complete peer based and requires no agent servers to manage mobile agent locations. Therefore, a mobile agent can get another mobile agent, communicate with it and shares information stored in the agent without any knowledge of the location of the target mobile agent. The basic idea of the mechanism is an introduction of Agent Ring, Agent Chain and Shadow Agent. With this mechanism, each agent can communicate with other agents in a server-less environment, which is suitable for ad-hoc agent network and an agent system can manage agents search and communications efficiently.

  1. 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.

  2. 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)

  3. 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)

  4. 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.

  5. 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)

  6. 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…

  7. 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.

  8. 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

  9. 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.

  10. 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

  11. Mechanisms of action of quinone-containing alkylating agents: DNA alkylation by aziridinylquinones.

    Science.gov (United States)

    Hargreaves, R H; Hartley, J A; Butler, J

    2000-11-01

    Aziridinyl quinones can be activated by cellular reductases eg. DT-diaphorase and cytochrome P450 reductase to form highly reactive DNA alkylating agents. The mechanisms by which this activation and alkylation take place are many and varied. Using clinically relevant and experimental agents this review will describe many of these mechanisms. The agents discussed are Mitomycin C, EO9 and analogues, diaziridinylbenzoquinones and the pyrrolo[1, 2-alpha]benzimidazolequinones.

  12. [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.

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. 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

  18. Mechanical properties of moso bamboo treated with chemical agents

    Science.gov (United States)

    Benhua Fei; Zhijia Liu; Zehui Jiang; Zhiyong Cai

    2013-01-01

    Bamboo is a type of biomass material and has great potential as a bioenergy resource for the future in China. Surface chemical and thermal–mechanical behavior play an important role in the manufacturing process of bamboo composites and pellets. In this study, moso bamboo was treated by sodium hydrate solution and acetic acid solution. Surface chemical and dynamic...

  19. 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

  20. Electrophysiological mechanisms of sophocarpine as a potential antiarrhythmic agent.

    Science.gov (United States)

    Yang, Zhi-fang; Li, Ci-zhen; Wang, Wei; Chen, Ying-min; Zhang, Ying; Liu, Yuan-mou; Wang, Hong-wei

    2011-03-01

    To examine the electrophysiological effects of sophocarpine on action potentials (AP) and ionic currents of cardiac myocytes and to compare some of these effects with those of amiodarone. Langendorff perfusion set-up was used in isolated guinea pig heart, and responses to sophocarpine were monitored using electrocardiograph. Conventional microelectrode, voltage clamp technique and perforated patch were employed to record fast response AP (fAP), slow response AP (sAP) and ionic currents in guinea pig papillary muscle or rabbit sinus node cells. Tachyarrhythmia produced by isoprenaline (15 μmol/L) could be reversed by sophocarpine (300 μmol/L). Sophocarpine (10 μmol/L) decreased the amplitude by 4.0%, maximal depolarization velocity (V(max)) of the fAP by 24.4%, and Na(+) current (I(Na)) by 18.0%, while it prolonged the effective refractory period (ERP) by 21.1%. The same concentration of sophocarpine could also decrease the amplitude and V(max) of the sAP, by 26.8% and 25.7%, respectively, and attenuated the Ca(2+) current (I(CaL)) and the K(+) tail current substantially. Comparison of sophocarpine with amiodarone demonstrated that both prolonged the duration and the ERP of fAP and sAP, both decreased the amplitude and V(max) of the fAP and sAP, and both slowed the automatic heart rate. Sophocarpine could reverse isoprenaline-induced arrhythmia and inhibit I(Na), I(CaL), and I(Kr) currents. The electrophysiological effects of sophocarpine are similar to those of amiodarone, which might be regarded as a prospective antiarrhythmic agent.

  1. Biosynthetic mechanism for sunscreens of the biocontrol agent Lysobacter enzymogenes.

    Directory of Open Access Journals (Sweden)

    Yan Wang

    Full Text Available Lysobacter are ubiquitous environmental bacteria emerging as novel biocontrol agents and new sources of anti-infectives. So far, very little effort has been invested in the study of the biology of these Gram-negative gliding bacteria. Many Lysobacter species are characterized by their yellow-orange appearance. Using transposon mutagenesis, we identified a stand-alone polyketide synthase (PKS gene cluster required for the pigment production in L. enzymogenes OH11. The yellow pigments were abolished in the "white" mutants generated by target-specific deletions of ketosynthase (KS, acyl carrier protein, or ketoreductase. Spectroscopic data suggested that the pigments belong to xanthomonadin-like aryl polyenes. Polyene-type polyketides are known to be biosynthesized by modular PKS (Type I, not by stand-alone PKS (Type II which always contain the heterodimer KS-CLF (chain-length factor as the key catalytic component. Remarkably, this aryl polyene PKS complex only contains the KS (ORF17, but not the CLF. Instead, a hypothetical protein (ORF16 is located immediately next to ORF17. ORF16-17 homologs are widespread in numerous uncharacterized microbial genomes, in which an ORF17 homolog is always accompanied by an ORF16 homolog. The deletion of ORF16 eliminated pigment production, and homology modeling suggested that ORF16 shares a structural similarity to the N-terminal half of CLF. A point-mutation of glutamine (Q166A that is the conserved active site of known CLF abolished pigment production. The "white" mutants are significantly more sensitive to UV/visible light radiation or H2O2 treatment than the wild type. These results unveil the first example of Type II PKS-synthesized polyene pigments and show that the metabolites serve as Lysobacter "sunscreens" that are important for the survival of these ubiquitous environmental organisms.

  2. Mechanical and dynamic characteristics of encapsulated microbubbles coupled by magnetic nanoparticles as multifunctional imaging and drug delivery agents

    Science.gov (United States)

    Guo, Gepu; Lu, Lu; Yin, Leilei; Tu, Juan; Guo, Xiasheng; Wu, Junru; Xu, Di; Zhang, Dong

    2014-11-01

    Development of magnetic encapsulated microbubble agents that can integrate multiple diagnostic and therapeutic functions is a key focus in both biomedical engineering and nanotechnology and one which will have far-reaching impact on medical diagnosis and therapies. However, properly designing multifunctional agents that can satisfy particular diagnostic/therapeutic requirements has been recognized as rather challenging, because there is a lack of comprehensive understanding of how the integration of magnetic nanoparticles to microbubble encapsulating shells affects their mechanical properties and dynamic performance in ultrasound imaging and drug delivery. Here, a multifunctional imaging contrast and in-situ gene/drug delivery agent was synthesized by coupling super paramagnetic iron oxide nanoparticles (SPIOs) into albumin-shelled microbubbles. Systematical studies were performed to investigate the SPIO-concentration-dependence of microbubble mechanical properties, acoustic scattering response, inertial cavitation activity and ultrasound-facilitated gene transfection effect. These demonstrated that, with the increasing SPIO concentration, the microbubble mean diameter and shell stiffness increased and ultrasound scattering response and inertial cavitation activity could be significantly enhanced. However, an optimized ultrasound-facilitated vascular endothelial growth factor transfection outcome would be achieved by adopting magnetic albumin-shelled microbubbles with an appropriate SPIO concentration of 114.7 µg ml-1. The current results would provide helpful guidance for future development of multifunctional agents and further optimization of their diagnostic/therapeutic performance in clinic.

  3. Mechanical and dynamic characteristics of encapsulated microbubbles coupled by magnetic nanoparticles as multifunctional imaging and drug delivery agents

    International Nuclear Information System (INIS)

    Guo, Gepu; Lu, Lu; Tu, Juan; Guo, Xiasheng; Zhang, Dong; Yin, Leilei; Wu, Junru; Xu, Di

    2014-01-01

    Development of magnetic encapsulated microbubble agents that can integrate multiple diagnostic and therapeutic functions is a key focus in both biomedical engineering and nanotechnology and one which will have far-reaching impact on medical diagnosis and therapies. However, properly designing multifunctional agents that can satisfy particular diagnostic/therapeutic requirements has been recognized as rather challenging, because there is a lack of comprehensive understanding of how the integration of magnetic nanoparticles to microbubble encapsulating shells affects their mechanical properties and dynamic performance in ultrasound imaging and drug delivery. Here, a multifunctional imaging contrast and in-situ gene/drug delivery agent was synthesized by coupling super paramagnetic iron oxide nanoparticles (SPIOs) into albumin-shelled microbubbles. Systematical studies were performed to investigate the SPIO-concentration-dependence of microbubble mechanical properties, acoustic scattering response, inertial cavitation activity and ultrasound-facilitated gene transfection effect. These demonstrated that, with the increasing SPIO concentration, the microbubble mean diameter and shell stiffness increased and ultrasound scattering response and inertial cavitation activity could be significantly enhanced. However, an optimized ultrasound-facilitated vascular endothelial growth factor transfection outcome would be achieved by adopting magnetic albumin-shelled microbubbles with an appropriate SPIO concentration of 114.7 µg ml −1 . The current results would provide helpful guidance for future development of multifunctional agents and further optimization of their diagnostic/therapeutic performance in clinic. (paper)

  4. Clemastine as Antimicrobial Agent: Effectiveness and Mechanism of Action

    Directory of Open Access Journals (Sweden)

    S.Fazli Bazaz

    1991-07-01

    Full Text Available In this investigation, the antimicrobial activity of Clemastine was studied.The Minimum Inhibitory Concentrations (MICs of this drug against some bacteria were determined using tube dilution method.To find out the bactericidal activity of Clemastine, the number of living bacteria in the presence of drug was counted by a culture method (pour plate method. Thereafter, the preservative effectiveness of Clemastine was studied in detail using standard method (USP 1985.The results show a good antibacterial but not antifungal activity."nIn considering the mechanism of action of Clemastine, it can be seen that the drug has some effect on cell membrane permeability and causes leakage of intracellular material including the K+ .Comparing the bactericidal results with the leakage of K+, shows that the leakage may be due to the bactericidal activity of the drug.

  5. 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.

  6. 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

  7. 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.

  8. 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

  9. 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 ...

  10. 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)

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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?

  16. 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.

  17. 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.

  18. 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

  19. 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 %

  20. 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.

  1. 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.

  2. 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.

  3. An agent-based QoS provisioning mechanism for WDM optical networks

    Science.gov (United States)

    Ouyang, Yong; Zeng, Qingji; Yue, Ling

    2004-04-01

    This paper addresses QoS provisioning mechanisms in the WDM optical networks. With the appearance of metropolitan optical network, a hierarchical metro and wide area optical network will be envisioned in the near future. This hierarchical optical transport network is often divided into optical domains by geography, administration and technology, which usually employ different QoS routing algorithms and policies. To provide end-to-end optical QoS is becoming a new challenge for the optical network design. In this paper, we first give an overview of issues on the QoS provisioning in data, control and management planes of the WDM optical network. And then three provisioning approaches are analyzed and compared. Finally, we propose an agent-based hybrid centralized/distributed QoS provisioning mechanism based on the concept of domain agent. This agent-based hybrid mechanism employs centralized approach in the domain and distributed approach between domains. It offers scalability and intra-domain optimal QoS routing. It also keeps independence and interoperability between domains.

  4. 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.

  5. 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.

  6. How diagnostic tests help to disentangle the mechanisms underlying neuropathic pain symptoms in painful neuropathies.

    Science.gov (United States)

    Truini, Andrea; Cruccu, Giorgio

    2016-02-01

    Neuropathic pain, ie, pain arising directly from a lesion or disease affecting the somatosensory afferent pathway, manifests with various symptoms, the commonest being ongoing burning pain, electrical shock-like sensations, and dynamic mechanical allodynia. Reliable insights into the mechanisms underlying neuropathic pain symptoms come from diagnostic tests documenting and quantifying somatosensory afferent pathway damage in patients with painful neuropathies. Neurophysiological investigation and skin biopsy studies suggest that ongoing burning pain primarily reflects spontaneous activity in nociceptive-fiber pathways. Electrical shock-like sensations presumably arise from high-frequency ectopic bursts generated in demyelinated, nonnociceptive, Aβ fibers. Although the mechanisms underlying dynamic mechanical allodynia remain debatable, normally innocuous stimuli might cause pain by activating spared and sensitized nociceptive afferents. Extending the mechanistic approach to neuropathic pain symptoms might advance targeted therapy for the individual patient and improve testing for new drugs.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Diabetic retinopathy: Proteomic approaches to help the differential diagnosis and to understand the underlying molecular mechanisms.

    Science.gov (United States)

    Csősz, Éva; Deák, Eszter; Kalló, Gergő; Csutak, Adrienne; Tőzsér, József

    2017-01-06

    Diabetic retinopathy is the most common diabetic eye disease and a leading cause of blindness among patients with diabetes. The appearance and the severity of the symptoms correlate with the duration of diabetes and poor blood glucose level management. Diabetic retinopathy is also categorized as a chronic low-level inflammatory disease; the high blood glucose level promotes the accumulation of the advanced glycation end products and leads to the stimulation of monocytes and macrophages. Examination of protein level alterations in tears using state-of the art proteomics techniques have identified several proteins as possible biomarkers for the different stages of the diabetic retinopathy. Some of the differentially expressed tear proteins have a role in the barrier function of tears linking the diabetic retinopathy with another eye complication of diabetes, namely the diabetic keratopathy resulting in impaired wound healing. Understanding the molecular events leading to the eye complications caused by hyperglycemia may help the identification of novel biomarkers as well as therapeutic targets in order to improve quality of life of diabetic patients. Diabetic retinopathy (DR), the leading cause of blindness among diabetic patients can develop without any serious symptoms therefore the early detection is crucial. Because of the increasing prevalence there is a high need for improved screening methods able to diagnose DR as soon as possible. The non-invasive collection and the relatively high protein concentration make the tear fluid a good source for biomarker discovery helping the early diagnosis. In this work we have reviewed the administration of advanced proteomics techniques used in tear biomarker studies and the identified biomarkers with potential to improve the already existing screening methods for DR detection. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. How can EPR spectroscopy help to unravel molecular mechanisms of flavin-dependent photoreceptors?

    Directory of Open Access Journals (Sweden)

    Daniel eNohr

    2015-09-01

    Full Text Available Electron paramagnetic resonance (EPR spectroscopy is a well-established spectroscopic method for the examination of paramagnetic molecules. Proteins can contain paramagnetic moieties in form of stable cofactors, transiently formed intermediates, or spin labels artificially introduced to cysteine sites. The focus of this review is to evaluate potential scopes of application of EPR to the emerging field of optogenetics. The main objective for EPR spectroscopy in this context is to unravel the complex mechanisms of light-active proteins, from their primary photoreaction to downstream signal transduction. An overview of recent results from the family of flavin-containing, blue-light dependent photoreceptors is given. In detail, mechanistic similarities and differences are condensed from the three classes of flavoproteins, the cryptochromes, LOV (Light-oxygen-voltage, and BLUF (blue-light using FAD domains. Additionally, a concept that includes spin-labeled proteins and examination using modern pulsed EPR is introduced, which allows for a precise mapping of light-induced conformational changes.

  20. How can EPR spectroscopy help to unravel molecular mechanisms of flavin-dependent photoreceptors?

    Science.gov (United States)

    Nohr, Daniel; Rodriguez, Ryan; Weber, Stefan; Schleicher, Erik

    2015-01-01

    Electron paramagnetic resonance (EPR) spectroscopy is a well-established spectroscopic method for the examination of paramagnetic molecules. Proteins can contain paramagnetic moieties in form of stable cofactors, transiently formed intermediates, or spin labels artificially introduced to cysteine sites. The focus of this review is to evaluate potential scopes of application of EPR to the emerging field of optogenetics. The main objective for EPR spectroscopy in this context is to unravel the complex mechanisms of light-active proteins, from their primary photoreaction to downstream signal transduction. An overview of recent results from the family of flavin-containing, blue-light dependent photoreceptors is given. In detail, mechanistic similarities and differences are condensed from the three classes of flavoproteins, the cryptochromes, LOV (Light-oxygen-voltage), and BLUF (blue-light using FAD) domains. Additionally, a concept that includes spin-labeled proteins and examination using modern pulsed EPR is introduced, which allows for a precise mapping of light-induced conformational changes.

  1. Mitochondrial genome sequencing helps show the evolutionary mechanism of mitochondrial genome formation in Brassica

    Science.gov (United States)

    2011-01-01

    Background Angiosperm mitochondrial genomes are more complex than those of other organisms. Analyses of the mitochondrial genome sequences of at least 11 angiosperm species have showed several common properties; these cannot easily explain, however, how the diverse mitotypes evolved within each genus or species. We analyzed the evolutionary relationships of Brassica mitotypes by sequencing. Results We sequenced the mitotypes of cam (Brassica rapa), ole (B. oleracea), jun (B. juncea), and car (B. carinata) and analyzed them together with two previously sequenced mitotypes of B. napus (pol and nap). The sizes of whole single circular genomes of cam, jun, ole, and car are 219,747 bp, 219,766 bp, 360,271 bp, and 232,241 bp, respectively. The mitochondrial genome of ole is largest as a resulting of the duplication of a 141.8 kb segment. The jun mitotype is the result of an inherited cam mitotype, and pol is also derived from the cam mitotype with evolutionary modifications. Genes with known functions are conserved in all mitotypes, but clear variation in open reading frames (ORFs) with unknown functions among the six mitotypes was observed. Sequence relationship analysis showed that there has been genome compaction and inheritance in the course of Brassica mitotype evolution. Conclusions We have sequenced four Brassica mitotypes, compared six Brassica mitotypes and suggested a mechanism for mitochondrial genome formation in Brassica, including evolutionary events such as inheritance, duplication, rearrangement, genome compaction, and mutation. PMID:21988783

  2. 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.

  3. 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

  4. 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.

  5. 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)

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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.

  11. 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...

  12. 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

  13. 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...

  14. 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

  15. 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

  16. Why direct effects of predation complicate the social brain hypothesis: And how incorporation of explicit proximate behavioral mechanisms might help.

    Science.gov (United States)

    van der Bijl, Wouter; Kolm, Niclas

    2016-06-01

    A growing number of studies have found that large brains may help animals survive by avoiding predation. These studies provide an alternative explanation for existing correlative evidence for one of the dominant hypotheses regarding the evolution of brain size in animals, the social brain hypothesis (SBH). The SBH proposes that social complexity is a major evolutionary driver of large brains. However, if predation both directly selects for large brains and higher levels of sociality, correlations between sociality and brain size may be spurious. We argue that tests of the SBH should take direct effects of predation into account, either by explicitly including them in comparative analyses or by pin-pointing the brain-behavior-fitness pathway through which the SBH operates. Existing data and theory on social behavior can then be used to identify precise candidate mechanisms and formulate new testable predictions. © 2016 WILEY Periodicals, Inc.

  17. 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.

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. The influence of modified zeolites as nucleating agents on crystallization behavior and mechanical properties of polypropylene

    International Nuclear Information System (INIS)

    Lv, Zhiping; Wang, Kunjun; Qiao, Zhihua; Wang, Wenjie

    2010-01-01

    Polypropylene (PP) composites with unmodified and modified zeolites were prepared by melt blending in single-screw extruder. The modified zeolites, diethoxy (distearoyl) silane (DDS)-zeolite 13X (DDS-13X) and diethoxy (distearoyl) silane-zeolite 5A (DDS-5A), were obtained by grafting diethoxy (distearoyl) silane onto zeolite 13X and 5A, respectively. The influence of the unmodified and modified zeolites as nucleating agents on properties of polypropylene was investigated with X-ray diffraction (XRD), differential scanning calorimetry (DSC), polarized light microscopy (PLM), Vicat softening temperature (VST) and mechanical properties test. The XRD results revealed that zeolite 13X and DDS-13X had a great influence on nucleation of PP compared to zeolite 5A and DDS-5A. The DSC results showed that the addition of small amount of modified zeolites lead to increase in crystallization temperature (T c ), initial crystallization temperature (T onset ) and crystallinity (X c ) of PP composites compared to unmodified zeolites, especially, DDS-13X was more effective than DDS-5A, and the highest crystallinity X c (50.48%) was observed in PP/0.3 wt.% DDS-13X, which was responsible to the higher tensile strength and flexural strength of PP/DDS-13X. The PP/DDS-5A, however, exhibited evident increase in flexural strength and a little change in tensile strength compared to pure PP. Moreover, as the addition amount of DDS-5A or DDS-13X up to 1 wt.%, the impact strength of both PP/DDS-5A and PP/DDS-13X reached 43 kJ/m 2 , which was about 2.8 times greater than that of the pure PP (11.3 kJ/m 2 ). These results were in good agreement with the spherulite morphology observed from PLM micrographs.

  4. 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

  5. Modeling oscillatory dynamics in brain microcircuits as a way to help uncover neurological disease mechanisms: A proposal

    Energy Technology Data Exchange (ETDEWEB)

    Skinner, F. K. [Toronto Western Research Institute, University Health Network, Krembil Discovery Tower, Toronto Western Hospital, 60 Leonard Street, 7th floor, 7KD411, Toronto, Ontario M5T 2S8 (Canada); Department of Medicine (Neurology), University of Toronto, 200 Elizabeth Street, Toronto, Ontario M5G 2C4 (Canada); Department of Physiology, University of Toronto Medical Sciences Building, 3rd Floor, 1 King' s College Circle, Toronto, Ontario M5S 1A8 (Canada); Ferguson, K. A. [Toronto Western Research Institute, University Health Network, Krembil Discovery Tower, Toronto Western Hospital, 60 Leonard Street, 7th floor, 7KD411, Toronto, Ontario M5T 2S8 (Canada); Department of Physiology, University of Toronto Medical Sciences Building, 3rd Floor, 1 King' s College Circle, Toronto, Ontario M5S 1A8 (Canada)

    2013-12-15

    There is an undisputed need and requirement for theoretical and computational studies in Neuroscience today. Furthermore, it is clear that oscillatory dynamical output from brain networks is representative of various behavioural states, and it is becoming clear that one could consider these outputs as measures of normal and pathological brain states. Although mathematical modeling of oscillatory dynamics in the context of neurological disease exists, it is a highly challenging endeavour because of the many levels of organization in the nervous system. This challenge is coupled with the increasing knowledge of cellular specificity and network dysfunction that is associated with disease. Recently, whole hippocampus in vitro preparations from control animals have been shown to spontaneously express oscillatory activities. In addition, when using preparations derived from animal models of disease, these activities show particular alterations. These preparations present an opportunity to address challenges involved with using models to gain insight because of easier access to simultaneous cellular and network measurements, and pharmacological modulations. We propose that by developing and using models with direct links to experiment at multiple levels, which at least include cellular and microcircuit, a cycling can be set up and used to help us determine critical mechanisms underlying neurological disease. We illustrate our proposal using our previously developed inhibitory network models in the context of these whole hippocampus preparations and show the importance of having direct links at multiple levels.

  6. Conception and realization of an expert system to help the interpretation of the mechanical shocks in a nuclear power plant

    International Nuclear Information System (INIS)

    Brunet, E.

    1988-01-01

    The computer system MIGRE, developed with the aim of helping the understanding of mechanical shocks in the nuclear power plant primary circuit. The MIGRE system allows the description of a study domain, the acquisition and exploitation of operational knowledges. The structural organization of the system is submitted to two constraints: in the first place, the system's operation depends on the accomplishment and development of an application, and on a diagnostic's research; the second constraint is the fact that the work space of PROLOG, on Macintoch, is restricted. A specific configuration is associated to each one of the work environments. The organization principle (in ''hierarchical Worlds'') of a program by PROLOG, allows to reach easily this kind of architecture. This principle makes a modular organization easy and allows to distinguish statical from dynamical steps of the system. The selection of the system different functions takes place by menus. The transition from one configuration to another is automatically effectuated and unseen by the user. Problems applying the Knowledge acquisition and the wandering bodies function, are also considered [fr

  7. 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...

  8. 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...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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…

  18. 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)

  19. 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)

  20. 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 ...

  1. Multifunctional foaming agent to prepare aluminum foam with enhanced mechanical properties

    Science.gov (United States)

    Li, Xun; Liu, Ying; Ye, Jinwen; An, Xuguang; Ran, Huaying

    2018-03-01

    In this paper, CuSO4 was used as foaming agent to prepare close cell Aluminum foam(Al foam) at the temperature range of 680 °C ∼ 758 °C for the first time. The results show that CuSO4 has multifunctional such as, foaming, viscosity increasing, reinforcement in Al matrix, it has a wide decomposition temperature range of 641 °C ∼ 816 °C, its sustain-release time is 5.5 min at 758 °C. The compression stress and energy absorption of CuSO4-Al foam is 6.89 Mpa and 4.82 × 106 J m‑3(compression strain 50%), which are 77.12% and 99.17% higher than that of TiH2-Al foam at the same porosity(76% in porosity) due to the reinforcement in Al matrix and uniform pore dispersion.

  2. 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.

  3. 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.

  4. 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.

  5. Mechanisms which help explain implementation of evidence-based practice in residential aged care facilities: a grounded theory study.

    Science.gov (United States)

    Masso, Malcolm; McCarthy, Grace; Kitson, Alison

    2014-07-01

    The context for the study was a nation-wide programme in Australia to implement evidence-based practice in residential aged care, in nine areas of practice, using a wide range of implementation strategies and involving 108 facilities. The study drew on the experiences of those involved in the programme to answer the question: what mechanisms influence the implementation of evidence-based practice in residential aged care and how do those mechanisms interact? The methodology used grounded theory from a critical realist perspective, informed by a conceptual framework that differentiates between the context, process and content of change. People were purposively sampled and invited to participate in semi-structured interviews, resulting in 44 interviews involving 51 people during 2009 and 2010. Participants had direct experience of implementation in 87 facilities, across nine areas of practice, in diverse locations. Sampling continued until data saturation was reached. The quality of the research was assessed using four criteria for judging trustworthiness: credibility, transferability, dependability and confirmability. Data analysis resulted in the identification of four mechanisms that accounted for what took place and participants' experiences. The core category that provided the greatest understanding of the data was the mechanism On Common Ground, comprising several constructs that formed a 'common ground' for change to occur. The mechanism Learning by Connecting recognised the ability to connect new knowledge with existing practice and knowledge, and make connections between actions and outcomes. Reconciling Competing Priorities was an ongoing mechanism whereby new practices had to compete with an existing set of constantly shifting priorities. Strategies for reconciling priorities ranged from structured approaches such as care planning to more informal arrangements such as conversations during daily work. The mechanism Exercising Agency bridged the gap between

  6. [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.

  7. Help Helps, but Only so Much: Research on Help Seeking with Intelligent Tutoring Systems

    Science.gov (United States)

    Aleven, Vincent; Roll, Ido; McLaren, Bruce M.; Koedinger, Kenneth R.

    2016-01-01

    Help seeking is an important process in self-regulated learning (SRL). It may influence learning with intelligent tutoring systems (ITSs), because many ITSs provide help, often at the student's request. The Help Tutor was a tutor agent that gave in-context, real-time feedback on students' help-seeking behavior, as they were learning with an ITS.…

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. Induction of Osmoadaptive Mechanisms and Modulation of Cellular Physiology Help Bacillus licheniformis Strain SSA 61 Adapt to Salt Stress

    Energy Technology Data Exchange (ETDEWEB)

    Paul, Sangeeta; Aggarwal, Chetana; Thakur, Jyoti Kumar; Bandeppa, G. S.; Khan, Md. Aslam; Pearson, Lauren M.; Babnigg, Gyorgy; Giometti, Carol S.; Joachimiak, Andrzej

    2015-01-06

    Bacillus licheniformis strain SSA 61, originally isolated from Sambhar salt lake, was observed to grow even in the presence of 25 % salt stress. Osmoadaptive mechanisms of this halotolerant B. licheniformis strain SSA 61, for long-term survival and growth under salt stress, were determined. Proline was the preferentially accumulated compatible osmolyte. There was also increased accumulation of antioxidants ascorbic acid and glutathione. Among the different antioxidative enzymes assayed, superoxide dismutase played the most crucial role in defense against salt-induced stress in the organism. Adaptation to stress by the organism involved modulation of cellular physiology at various levels. There was enhanced expression of known proteins playing essential roles in stress adaptation, such as chaperones DnaK and GroEL, and general stress protein YfkM and polynucleotide phosphorylase/polyadenylase. Proteins involved in amino acid biosynthetic pathway, ribosome structure, and peptide elongation were also overexpressed. Salt stress-induced modulation of expression of enzymes involved in carbon metabolism was observed. There was up-regulation of a number of enzymes involved in generation of NADH and NADPH, indicating increased cellular demand for both energy and reducing power.

  15. 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.

  16. A novel statistical algorithm for gene expression analysis helps differentiate pregnane X receptor-dependent and independent mechanisms of toxicity.

    Directory of Open Access Journals (Sweden)

    M Ann Mongan

    Full Text Available Genome-wide gene expression profiling has become standard for assessing potential liabilities as well as for elucidating mechanisms of toxicity of drug candidates under development. Analysis of microarray data is often challenging due to the lack of a statistical model that is amenable to biological variation in a small number of samples. Here we present a novel non-parametric algorithm that requires minimal assumptions about the data distribution. Our method for determining differential expression consists of two steps: 1 We apply a nominal threshold on fold change and platform p-value to designate whether a gene is differentially expressed in each treated and control sample relative to the averaged control pool, and 2 We compared the number of samples satisfying criteria in step 1 between the treated and control groups to estimate the statistical significance based on a null distribution established by sample permutations. The method captures group effect without being too sensitive to anomalies as it allows tolerance for potential non-responders in the treatment group and outliers in the control group. Performance and results of this method were compared with the Significant Analysis of Microarrays (SAM method. These two methods were applied to investigate hepatic transcriptional responses of wild-type (PXR(+/+ and pregnane X receptor-knockout (PXR(-/- mice after 96 h exposure to CMP013, an inhibitor of β-secretase (β-site of amyloid precursor protein cleaving enzyme 1 or BACE1. Our results showed that CMP013 led to transcriptional changes in hallmark PXR-regulated genes and induced a cascade of gene expression changes that explained the hepatomegaly observed only in PXR(+/+ animals. Comparison of concordant expression changes between PXR(+/+ and PXR(-/- mice also suggested a PXR-independent association between CMP013 and perturbations to cellular stress, lipid metabolism, and biliary transport.

  17. 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

  18. 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.

  19. 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

  20. 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

  1. 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.

  2. Capacity mechanisms: EU or National Issue? Are capacity remuneration mechanisms helping to build the market or just a symptom of what does not work?

    International Nuclear Information System (INIS)

    Parmigiani, Laura

    2012-10-01

    In a competitive energy system, generation investment choices are let to investors. It is then the responsibility of the market actors to invest and ensure peak, medium and base load generation, based on market perspectives and trends. If through actors' investments the stability of the system cannot be ensured (because, for example, peak generation is not sufficient to satisfy demand), some measures have to be taken. These can have economic and system integrity impacts on neighboring systems, especially if they are connected. This is precisely what is happening in the European electricity market. While the internal electricity market should be completed by 2014, the adoption by Member States of capacity remuneration mechanisms in an uncoordinated way may lead to new market distortions. Whereas national capacity remuneration mechanisms (CRMs) already exist in several European countries (e.g. Italy, Spain, Sweden), others have taken steps in the past months to implement CRMs (France, UK) or contemplated to introduce them (Germany). After the puzzle of more than 27 different regimes for incentivizing renewables, the same heterogeneity will appear in the capacity markets if no coherent and Europe-wide framework is proposed. While increased interconnections and market coupling will lead to more efficient and liquid markets at regional and EU levels, the opposite will happen if Member States adopt national solutions without looking beyond their borders. In order to understand why we have come this point, it is essential to start from the roots of the problem and to throw light on some false beliefs. It would be much easier to blame market liberalization and un-bundling or RES integration into the market. The truth is that both measures were important. Timing showed that the RES production is developing very fast and creates local over capacity in some national systems, while when there is no wind or sun, the conventional plants are still needed to supply the customers

  3. Search Help

    Science.gov (United States)

    Guidance and search help resource listing examples of common queries that can be used in the Google Search Appliance search request, including examples of special characters, or query term seperators that Google Search Appliance recognizes.

  4. 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

  5. The effect of process control agent on the structure and magnetic properties of nanocrystalline mechanically alloyed Fe–45% Ni powders

    Energy Technology Data Exchange (ETDEWEB)

    Gheisari, Kh., E-mail: khgheisari@scu.ac.ir [Department of Materials Science and Engineering, Faculty of Engineering, Shahid Chamran University, Ahvaz (Iran, Islamic Republic of); Javadpour, S. [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Shiraz (Iran, Islamic Republic of)

    2013-10-15

    In this study, nanocrystalline Fe-45 wt% Ni alloy powders were prepared by mechanical alloying via high-energy ball milling. The effect of adding stearic acid as a process control agent (PCA) on the particle size, structure and magnetic properties of Fe-45 wt% Ni alloy powders have been studied by X-ray diffraction, scanning electron microscope and vibrating sample magnetometer measurements. The results show that the addition of 1 wt% PCA causes fine uniform spherical powder particles of the fcc γ-(Fe, Ni) phase to be formed after 48 h milling time. It is also found that crystallite size, lattice strain and content of γ-(Fe, Ni) phase are three of the most important variables that are significantly affected by PCA content and can influence the magnetic properties. - Highlights: • Different amount of stearic acid as a PCA was used during milling. • Particle size and crystallite size decrease with increasing PCA content. • The addition of 1 wt% PCA leads to a good combination of structure and magnetic properties.

  6. Flame-Retardant and Thermal Degradation Mechanism of Caged Phosphate Charring Agent with Melamine Pyrophosphate for Polypropylene

    Directory of Open Access Journals (Sweden)

    Xuejun Lai

    2015-01-01

    Full Text Available An efficient caged phosphate charring agent named PEPA was synthesized and combined with melamine pyrophosphate (MPP to flame-retard polypropylene (PP. The effects of MPP/PEPA on the flame retardancy and thermal degradation of PP were investigated by limiting oxygen index (LOI, vertical burning test (UL-94, cone calorimetric test (CCT, and thermogravimetric analysis (TGA. It was found that PEPA showed an outstanding synergistic effect with MPP in flame retardant PP. When the content of PEPA was 13.3 wt% and MPP was 6.7 wt%, the LOI value of the flame retardant PP was 33.0% and the UL-94 test was classed as a V-0 rating. Meanwhile, the peak heat release rate (PHRR, average heat release rate (AV-HRR, and average mass loss rate (AV-MLR of the mixture were significantly reduced. The flame-retardant and thermal degradation mechanism of MPP/PEPA was investigated by TGA, Fourier transform infrared spectroscopy (FTIR, TG-FTIR, and scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDXS. It revealed that MPP/PEPA could generate the triazine oligomer and phosphorus-containing compound radicals which changed the thermal degradation behavior of PP. Meanwhile, a compact and thermostable intumescent char was formed and covered on the matrix surface to prevent PP from degrading and burning.

  7. 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.

  8. An overview of advanced reduction processes for bromate removal from drinking water: Reducing agents, activation methods, applications and mechanisms.

    Science.gov (United States)

    Xiao, Qian; Yu, Shuili; Li, Lei; Wang, Ting; Liao, Xinlei; Ye, Yubing

    2017-02-15

    Bromate (BrO 3 - ) is a possible human carcinogen regulated at a strict standard of 10μg/L in drinking water. Various techniques to eliminate BrO 3 - usually fall into three main categories: reducing bromide (Br - ) prior to formation of BrO 3 - , minimizing BrO 3 - formation during the ozonation process, and removing BrO 3 - from post-ozonation waters. However, the first two approaches exhibit low degradation efficiency and high treatment cost. The third workaround has obvious advantages, such as high reduction efficiency, more stable performance and easier combination with UV disinfection, and has therefore been widely implemented in water treatment. Recently, advanced reduction processes (ARPs), the photocatalysis of BrO 3 - , have attracted much attention due to improved performance. To increase the feasibility of photocatalytic systems, the focus of this work concerns new technological developments, followed by a summary of reducing agents, activation methods, operational parameters, and applications. The reaction mechanisms of two typical processes involving UV/sulfite homogeneous photocatalysis and UV/titanium dioxide heterogeneous photocatalysis are further summarized. The future research needs for ARPs to reach full-scale potential in drinking water treatment are suggested accordingly. Copyright © 2016. Published by Elsevier B.V.

  9. The effect of process control agent on the structure and magnetic properties of nanocrystalline mechanically alloyed Fe–45% Ni powders

    International Nuclear Information System (INIS)

    Gheisari, Kh.; Javadpour, S.

    2013-01-01

    In this study, nanocrystalline Fe-45 wt% Ni alloy powders were prepared by mechanical alloying via high-energy ball milling. The effect of adding stearic acid as a process control agent (PCA) on the particle size, structure and magnetic properties of Fe-45 wt% Ni alloy powders have been studied by X-ray diffraction, scanning electron microscope and vibrating sample magnetometer measurements. The results show that the addition of 1 wt% PCA causes fine uniform spherical powder particles of the fcc γ-(Fe, Ni) phase to be formed after 48 h milling time. It is also found that crystallite size, lattice strain and content of γ-(Fe, Ni) phase are three of the most important variables that are significantly affected by PCA content and can influence the magnetic properties. - Highlights: • Different amount of stearic acid as a PCA was used during milling. • Particle size and crystallite size decrease with increasing PCA content. • The addition of 1 wt% PCA leads to a good combination of structure and magnetic properties

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

  12. Research Help

    Science.gov (United States)

    1988-01-01

    The Electrosynthesis Co. Inc.'s Electrocinerator System integrates a highly effective air scrubber with an electrochemical cell to provide an apparatus capable of destroying virtually all toxic chemicals and airborne bacteria. Project (funded by DOD) is prospective means of decontaminating airborne chemicals and biological warfare agents. Also has broad civil use applicable to hospitals for destruction of airborne viruses and bacteria, and industrial use for elimination of toxic solvent vapors and malodorous emissions.

  13. 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

  14. 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

  15. Explanatory model of help-seeking and coping mechanisms among depressed women in three ethnic groups of Fars, Kurdish, and Turkish in Iran.

    Science.gov (United States)

    Dejman, Masoumeh; Ekblad, Solvig; Forouzan, Ameneh-Setareh; Baradaran-Eftekhari, Monir; Malekafzali, Hossein

    2008-07-01

    As one of the most prevalent diseases globally and as an important cause of disability, depressive disorders are responsible for as many as one in every five visits to primary care doctors. Cultural variations in clinical presentation, sometimes make it difficult to recognize the disorder resulting in patients not being diagnosed and not receiving appropriate treatment. To address this issue, we conducted a qualitative pilot study on three ethnic groups including Fars, Kurdish, and Turkish in Iran to test the use of qualitative methods in exploring the explanatory models of help-seeking and coping with depression (without psychotic feature) among Iranian women. A qualitative study design was used based on an explanatory model of illness framework. Individual interviews were conducted with key informant (n=6), and depressed female patients (n=6). A hypothetical case vignette was also used in focus group discussions and individual interviews with lay people (three focus groups including 25 participants and six individual interviews; n=31). There were a few differences regarding help-seeking and coping mechanisms among the three ethnic groups studied. The most striking differences were in the area of treatment. Non-psychotic depressive disorder in all ethnicities was related to an external stressor, and symptoms of illness were viewed as a response to an event in the social world. Coping mechanisms involved two strategies: (1) solving problems by seeking social support from family and neighbors, religious practice, and engaging in pleasurable activities, and (2) seeking medical support from psychologists and family counselors. The Fars group was far more likely to recommend professional treatment and visiting psychiatrists whereas the other two ethnic groups (i.e., Turks and Kurds) preferred to consult family counselors, psychologists or other alternative care providers, and traditional healers. The study has educational and clinical implications. Cultural reframing

  16. Synthesis, uptake mechanism characterization and biological evaluation of {sup 18}F labeled fluoroalkyl phenylalanine analogs as potential PET imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Wang Limin [Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104 (United States); Qu Wenchao; Lieberman, Brian P.; Ploessl, Karl [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Kung, Hank F., E-mail: kunghf@gmail.co [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19104 (United States); Department of Pharmacology, University of Pennsylvania, Philadelphia, PA 19104 (United States)

    2011-01-15

    Introduction: Amino acids based tracers represent a promising class of tumor metabolic imaging agents with successful clinical applications. Two new phenylalanine derivatives, p-(2-[{sup 18}F]fluoroethyl)-L-phenylalanine (FEP, [{sup 18}F]2) and p-(3-[{sup 18}F]fluoropropyl)-L-phenylalanine (FPP, [{sup 18}F]3) were synthesized and evaluated in comparison to clinically utilized O-(2-[{sup 18}F]fluoroethyl)-L-tyrosine (FET, [{sup 18}F]1). Methods: FEP ([{sup 18}F]2) and FPP ([{sup 18}F]3) were successfully synthesized by a rapid and efficient two-step nucleophilic fluorination of tosylate precursors and deprotection reaction. In vitro cell uptake studies were carried out in 9L glioma cells. In vivo studies, 9L tumor xenografts were implanted in Fisher 344 rats. Results: FEP ([{sup 18}F]2) and FPP ([{sup 18}F]3) could be efficiently labeled within 90 min with good enantiomeric purity (>95%), good yield (11-37%) and high specific activity (21-69 GBq/{mu}mol). Cell uptake studies showed FEP had higher uptake than FPP as well as reference ligand FET ([{sup 18}F]1). Uptake mechanism studies suggested that FEP is a selective substrate for system L and prefers its subtype LAT1. In vivo biodistribution studies demonstrated FEP had specific accumulation in tumor cells and tumor to background ratio reached 1.45 at 60 min. Small animal positron emission tomography (PET) imaging studies showed FEP was comparable to FET for imaging rats bearing 9L tumor model. FEP had high uptake in 9L tumor compared to surrounding tissue and was quickly excreted through urinary tract. Conclusion: Biological evaluations indicate that FEP ([{sup 18}F]2) is a potential useful tracer for tumor imaging with PET.

  17. Kinetics and Mechanism of Bioactivation via S-Oxygenation of Anti-Tubercular Agent Ethionamide by Peracetic Acid.

    Science.gov (United States)

    Chipiso, Kudzanai; Logan, Isabelle E; Eskew, Matthew W; Omondi, Benard; Simoyi, Reuben H

    2016-10-11

    The kinetics and mechanism of the oxidation of the important antitubercular agent, ethionamide, ETA (2-ethylthioisonicotinamide), by peracetic acid (PAA) have been studied. It is effectively a biphasic reaction with an initial rapid first phase of the reaction which is over in about 5 s and a second slower phase of the reaction which can run up to an hour. The first phase involves the addition of a single oxygen atom to ethionamide to form the S-oxide. The second phase involves further oxidation of the S-oxide to desulfurization of ETA to give 2-ethylisonicotinamide. In contrast to the stability of most organosulfur compounds, the S-oxide of ETA is relatively stable and can be isolated. In conditions of excess ETA, the stoichiometry of the reaction was strictly 1:1: CH 3 CO 3 H + Et(C 5 H 4 )C(═S)NH 2 → CH 3 CO 2 H + Et(C 5 H 4 )C(═NH)SOH. In this oxidation, it was apparent that only the sulfur center was the reactive site. Though ETA was ultimately desulfurized, only the S-oxide was stable. Electrospray ionization (ESI) spectral analysis did not detect any substantial formation of the sulfinic and sulfonic acids. This suggests that cleavage of the carbon-sulfur bond occurs at the sulfenic acid stage, resulting in the formation of an unstable sulfur species that can react further to form more stable sulfur species. In this oxidation, no sulfate formation was observed. ESI spectral analysis data showed a final sulfur species in the form of a dimeric sulfur monoxide species, H 3 S 2 O 2 . We derived a bimolecular rate constant for the formation of the S-oxide of (3.08 ± 0.72) × 10 2 M -1 s -1 . Oxidation of the S-oxide further to give 2-ethylisonicotinamide gave zero order kinetics.

  18. Mechanism of MenE inhibition by acyl-adenylate analogues and discovery of novel antibacterial agents.

    Science.gov (United States)

    Matarlo, Joe S; Evans, Christopher E; Sharma, Indrajeet; Lavaud, Lubens J; Ngo, Stephen C; Shek, Roger; Rajashankar, Kanagalaghatta R; French, Jarrod B; Tan, Derek S; Tonge, Peter J

    2015-10-27

    MenE is an o-succinylbenzoyl-CoA (OSB-CoA) synthetase in the bacterial menaquinone biosynthesis pathway and is a promising target for the development of novel antibacterial agents. The enzyme catalyzes CoA ligation via an acyl-adenylate intermediate, and we have previously reported tight-binding inhibitors of MenE based on stable acyl-sulfonyladenosine analogues of this intermediate, including OSB-AMS (1), which has an IC50 value of ≤25 nM for Escherichia coli MenE. Herein, we show that OSB-AMS reduces menaquinone levels in Staphylococcus aureus, consistent with its proposed mechanism of action, despite the observation that the antibacterial activity of OSB-AMS is ∼1000-fold lower than the IC50 for enzyme inhibition. To inform the synthesis of MenE inhibitors with improved antibacterial activity, we have undertaken a structure-activity relationship (SAR) study stimulated by the knowledge that OSB-AMS can adopt two isomeric forms in which the OSB side chain exists either as an open-chain keto acid or a cyclic lactol. These studies revealed that negatively charged analogues of the keto acid form bind, while neutral analogues do not, consistent with the hypothesis that the negatively charged keto acid form of OSB-AMS is the active isomer. X-ray crystallography and site-directed mutagenesis confirm the importance of a conserved arginine for binding the OSB carboxylate. Although most lactol isomers tested were inactive, a novel difluoroindanediol inhibitor (11) with improved antibacterial activity was discovered, providing a pathway toward the development of optimized MenE inhibitors in the future.

  19. Prevention of depression and anxiety in adolescents: A randomized controlled trial testing the efficacy and mechanisms of Internet-based self-help problem-solving therapy

    Directory of Open Access Journals (Sweden)

    Schuurmans Josien

    2009-10-01

    Full Text Available Abstract Background Even though depression and anxiety are highly prevalent in adolescence, youngsters are not inclined to seek help in regular healthcare. Therapy through the Internet, however, has been found to appeal strongly to young people. The main aim of the present study is to examine the efficacy of preventive Internet-based guided self-help problem-solving therapy with adolescents reporting depressive and anxiety symptoms. A secondary objective is to test potential mediating and moderating variables in order to gain insight into how the intervention works and for whom it works best. Methods/design This study is a randomized controlled trial with an intervention condition group and a wait-list control group. The intervention condition group receives Internet-based self-help problem-solving therapy. Support is provided by a professional and delivered through email. Participants in the wait-list control group receive the intervention four months later. The study population consists of adolescents (12-18-year-olds from the general population who report mild to moderate depressive and/or anxiety symptoms and are willing to complete a self-help course. Primary outcomes are symptoms of depression and anxiety. Secondary outcomes are quality of life, social anxiety, and cost-effectiveness. The following variables are examined for their moderating role: demographics, motivation, treatment credibility and expectancy, externalizing behaviour, perceived social support from parents and friends, substance use, the experience of important life events, physical activity, the quality of the therapeutic alliance, and satisfaction. Mediator variables include problem-solving skills, worrying, mastery, and self-esteem. Data are collected at baseline and at 3 weeks, 5 weeks, 4 months, 8 months, and 12 months after baseline. Both intention-to-treat and completer analyses will be conducted. Discussion This study evaluates the efficacy and mechanisms of

  20. 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...

  1. Increasing Physical Activity Amongst Overweight and Obese Cancer Survivors Using an Alexa-Based Intelligent Agent for Patient Coaching: Protocol for the Physical Activity by Technology Help (PATH) Trial.

    Science.gov (United States)

    Hassoon, Ahmed; Schrack, Jennifer; Naiman, Daniel; Lansey, Dina; Baig, Yasmin; Stearns, Vered; Celentano, David; Martin, Seth; Appel, Lawrence

    2018-02-12

    Physical activity has established health benefits, but motivation and adherence remain challenging. We designed and launched a three-arm randomized trial to test artificial intelligence technology solutions to increase daily physical activity in cancer survivors. A single-center, three-arm randomized clinical trial with an allocation ration of 1:1:1: (A) control, in which participants are provided written materials about the benefits of physical activity; (B) text intervention, where participants receive daily motivation from a fully automated, data-driven algorithmic text message via mobile phone (Coachtext); and (C) Voice Assist intervention, where participants are provided with an in-home on demand autonomous Intelligent Agent using data driven Interactive Digital Voice Assist on the Amazon Alexa/Echo (MyCoach). The study runs for 5 weeks: a one-week run-in to establish baseline, followed by 4 weeks of intervention. Data for study outcomes is collected automatically through a wearable sensor, and data are transferred in real-time to the study server. The recruitment goal is 42 participants, 14 in each arm. Electronic health records are used to prescreen candidates, with 39 participants recruited to date. This study aims to investigate the effects of different types of intelligent technology solutions on promoting physical activity in cancer survivors. This innovative approach can easily be expanded and customized to other interventions. Early lessons from our initial participants are helping us develop additional advanced solutions to improve health outcomes. Retrospectively registered on July 10, 2017 at ClinicalTrials.gov: NCT03212079; https://clinicaltrials.gov/ct2/show/NCT03212079 (Archived by WebCite at http://www.webcitation.org/6wgvqjTji). ©Ahmed Hassoon, Jennifer Schrack, Daniel Naiman, Dina Lansey, Yasmin Baig, Vered Stearns, David Celentano, Seth Martin, Lawrence Appel. Originally published in JMIR Research Protocols (http

  2. 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

  3. Effect of process control agent (PCA) on the characteristics of mechanically alloyed Ti-Mg powders [Journal article

    CSIR Research Space (South Africa)

    Machio, Christopher N

    2011-03-01

    Full Text Available This paper reports the results of a study to determine the effect of process control agent (PCA) on the characteristics of Ti-Mg powders during milling. It has been shown that a 2% increase in PCA content leads to up to a 40% increase in yield...

  4. Organoruthenium Complexes with CN Ligands are Highly Potent Cytotoxic Agents that Act by a New Mechanism of Action

    Czech Academy of Sciences Publication Activity Database

    Novohradský, Vojtěch; Yellol, J.; Stuchlíková, O.; Santana, M.D.; Kostrhunová, Hana; Yellol, G.; Kašpárková, Jana; Bautista, D.; Ruiz, J.; Brabec, Viktor

    2017-01-01

    Roč. 23, č. 61 (2017), s. 15294-15299 ISSN 0947-6539 R&D Projects: GA ČR(CZ) GA17-05302S Institutional support: RVO:68081707 Keywords : chemotherapeutic-agents * ruthenium(ii) complexes * iridium(iii) complexes Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 5.317, year: 2016

  5. 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.

  6. 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.

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

    OpenAIRE

    Atmanand M. Bagoji; Shreekant M. Patil; Sharanappa T. Nandibewoor

    2016-01-01

    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...

  8. 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.

  9. Design of a Mobile Agents Based Solution to Distributional Management of Computer Networks, Taking into Account the Security Mechanisms

    Directory of Open Access Journals (Sweden)

    S. Bahrami

    2017-10-01

    Full Text Available Mobile agents (MAs is one of the technologies considered in the recent years to perform management processes. This technology provides the ability to move code in distributed environments and to connect with other resources and agents locally which makes it an appropriate technology in the development of software applications of distributed network, especially management systems. For using mobile agent technology, an infrastructure for the management of MAs is needed. In this project, an infrastructure called MCT management is introduced for network management. In this infrastructure, some protocols like SNMP are used to get management data for the network administrator. With respect to management ability, MAs can dynamically access the database SNMP (i.e. MIB and extract the data required by the managers. Most well-known methods are characterized by being static relative to code and location in which components cannot modify their location or code in a lifetime. However, the MAs method can dynamically increase communications, reduce costs and overcome certain limitations by changing location and components.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. DNA-Destabilizing Agents as an Alternative Approach for Targeting DNA: Mechanisms of Action and Cellular Consequences

    Directory of Open Access Journals (Sweden)

    Gaëlle Lenglet

    2010-01-01

    Full Text Available DNA targeting drugs represent a large proportion of the actual anticancer drug pharmacopeia, both in terms of drug brands and prescription volumes. Small DNA-interacting molecules share the ability of certain proteins to change the DNA helix's overall organization and geometrical orientation via tilt, roll, twist, slip, and flip effects. In this ocean of DNA-interacting compounds, most stabilize both DNA strands and very few display helix-destabilizing properties. These types of DNA-destabilizing effect are observed with certain mono- or bis-intercalators and DNA alkylating agents (some of which have been or are being developed as cancer drugs. The formation of locally destabilized DNA portions could interfere with protein/DNA recognition and potentially affect several crucial cellular processes, such as DNA repair, replication, and transcription. The present paper describes the molecular basis of DNA destabilization, the cellular impact on protein recognition, and DNA repair processes and the latter's relationships with antitumour efficacy.

  16. 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.

  17. 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.

  18. 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. ...

  19. Prevention of depression and anxiety in adolescents: A randomized controlled trial testing the efficacy and mechanisms of Internet-based self-help problem-solving therapy

    NARCIS (Netherlands)

    Hoek, N.W.; Schuurmans, J.; Koot, H.M.; Cuijpers, P.

    2009-01-01

    Background: Even though depression and anxiety are highly prevalent in adolescence, youngsters are not inclined to seek help in regular healthcare. Therapy through the Internet, however, has been found to appeal strongly to young people. The main aim of the present study is to examine the efficacy

  20. Having Students Create Short Video Clips to Help Transition from Naïve Conceptions about Mechanics to True Newtonian Physics

    Science.gov (United States)

    Corten-Gualtieri, Pascale; Ritter, Christian; Plumat, Jim; Keunings, Roland; Lebrun, Marcel; Raucent, Benoit

    2016-01-01

    Most students enter their first university physics course with a system of beliefs and intuitions which are often inconsistent with the Newtonian frame of reference. This article presents an experiment of collaborative learning aiming at helping first-year students in an engineering programme to transition from their naïve intuition about dynamics…

  1. Specificity and inhibitory mechanism of andrographolide and its analogues as antiasthma agents on NF-κB p50.

    Science.gov (United States)

    Nguyen, Van Sang; Loh, Xin Yi; Wijaya, Hadhi; Wang, Jigang; Lin, Qingsong; Lam, Yulin; Wong, Wai-Shiu Fred; Mok, Yu Keung

    2015-02-27

    Andrographolide (1) is a diterpenoid lactone with an α,β-unsaturated lactone group that inhibits NF-κB DNA binding. Andrographolide reacts with the nucleophilic Cys62 of NF-κB p50 through a Michael addition at the Δ(12(13)) exocylic double bond to form a covalent adduct. Using computer docking, site-directed mutagenesis, and mass spectrometry, the noncovalent interactions between andrographolide and additional binding site residues other than Cys62 were found to be essential for the covalent incorporation of andrographolide. Furthermore, the addition reaction of andrographolide on Cys62 was highly dependent on the redox conditions and on the vicinity of nearby, positively charged Arg residues in the conserved RxxRxR motif. The reaction mechanisms of several of the analogues were determined, showing that 14-deoxy-11,12-didehydroandrographolide (8) reacts with NF-κB p50 via a novel mechanism distinct from andrographolide. The noncovalent interaction and redox environment of the binding site should be considered, in addition to the electrophilicity, when designing a covalent drug. Analogues similar in structure appear to use distinct reaction mechanisms and may have very different cytotoxicities, e.g., compound 6.

  2. The analgesic agent tapentadol inhibits calcitonin gene-related peptide release from isolated rat brainstem via a serotonergic mechanism.

    Science.gov (United States)

    Greco, Maria Cristina; Navarra, Pierluigi; Tringali, Giuseppe

    2016-01-15

    In this study we tested the hypothesis that tapentadol inhibits GGRP release from the rat brainstem through a mechanism mediated by the inhibition of NA reuptake; as a second alternative hypothesis, we investigated whether tapentadol inhibits GGRP release via the inhibition of 5-HT reuptake. Rat brainstems were explanted and incubated in short-term experiments. CGRP released in the incubation medium was taken as a marker of CGRP release from the central terminals of trigeminal neurons within the brainstem. CGRP levels were measured by radioimmunoassay under basal conditions or in the presence of tapentadol; NA, 5-HT, clonidine, yohimbine and ondansetron were used as pharmacological tools to investigate the action mechanism of tapentadol. The α2-antagonist yohimbine failed to counteract the effects of tapentadol. Moreover, neither NA nor the α2-agonist clonidine per se inhibited K(+)-stimulated CGRP release, thereby indicating that the effects of tapentadol are nor mediated through the block of NA reuptake. Further experiments showed that 5-HT and tramadol, which inhibits both NA and 5-HT reuptake, significantly reduced K(+)-stimulated CGRP release. Moreover, the 5-HT3 antagonist ondansetron was able to counteract the effects of tapentadol in this system. This study provided pharmacological evidence that tapentadol inhibits stimulated CGRP release from the rat brainstem in vitro through a mechanism involving an increase in 5-HT levels in the system and the subsequent activation of 5-HT3 receptors. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Mechanical properties, morphology and thermal degradation of a biocomposite of polypropylene and curaua fibers: coupling agent effect

    Directory of Open Access Journals (Sweden)

    Barbara Mano

    2013-01-01

    Full Text Available Biocomposites of polymers with vegetal fibers have a broad spectrum of applications due to their high specific properties in comparison to their counterparts made with fiberglass. Polypropylene, PP, composites with curaua fiber compatibilized with different concentrations of maleic anhydride grafted polypropylene, PP-g-MA, were characterized according to their mechanical properties, morphologies and thermal stabilities in oxidative and inert atmospheres. The composites were prepared by single screw extrusion and injection molded specimens were used for testing. The composite with 20 wt % of curaua fiber with and without compatibilizer presented improved mechanical properties compared to pure PP. The use of PP-g-MA as a compatibilizer significantly increased fiber/matrix adhesion, however, the mechanical properties were only slightly improved in comparison with composites without compatibilizer. We observed an improvement in thermal stability of the composites, compared to that expected from the weighted average of the individual components, both under inert and oxidative atmospheres. Furthermore, the thermal stability improved under inert atmosphere as a function of the concentration of compatibilizer. In this situation, indeed, there was a different shift of the weight loss processes owing to the presence of the compatibilizer.

  4. Insight into the mechanism of action of temporin-SHa, a new broad-spectrum antiparasitic and antibacterial agent.

    Directory of Open Access Journals (Sweden)

    Zahid Raja

    Full Text Available Antimicrobial peptides (AMPs are promising drugs to kill resistant pathogens. In contrast to bacteria, protozoan parasites, such as Leishmania, were little studied. Therefore, the antiparasitic mechanism of AMPs is still unclear. In this study, we sought to get further insight into this mechanism by focusing our attention on temporin-SHa (SHa, a small broad-spectrum AMP previously shown to be active against Leishmania infantum. To improve activity, we designed analogs of SHa and compared the antibacterial and antiparasitic mechanisms. [K3]SHa emerged as a highly potent compound active against a wide range of bacteria, yeasts/fungi, and trypanosomatids (Leishmania and Trypanosoma, with leishmanicidal intramacrophagic activity and efficiency toward antibiotic-resistant strains of S. aureus and antimony-resistant L. infantum. Multipassage resistance selection demonstrated that temporins-SH, particularly [K3]SHa, are not prone to induce resistance in Escherichia coli. Analysis of the mode of action revealed that bacterial and parasite killing occur through a similar membranolytic mechanism involving rapid membrane permeabilization and depolarization. This was confirmed by high-resolution imaging (atomic force microscopy and field emission gun-scanning electron microscopy. Multiple combined techniques (nuclear magnetic resonance, surface plasmon resonance, differential scanning calorimetry allowed us to detail peptide-membrane interactions. [K3]SHa was shown to interact selectively with anionic model membranes with a 4-fold higher affinity (KD = 3 x 10-8 M than SHa. The amphipathic α-helical peptide inserts in-plane in the hydrophobic lipid bilayer and disrupts the acyl chain packing via a detergent-like effect. Interestingly, cellular events, such as mitochondrial membrane depolarization or DNA fragmentation, were observed in L. infantum promastigotes after exposure to SHa and [K3]SHa at concentrations above IC50. Our results indicate that these

  5. Impact of ambient gases on the mechanism of [Cs8Nb6O19]-promoted nerve-agent decomposition.

    Science.gov (United States)

    Kaledin, Alexey L; Driscoll, Darren M; Troya, Diego; Collins-Wildman, Daniel L; Hill, Craig L; Morris, John R; Musaev, Djamaladdin G

    2018-02-28

    The impact of ambient gas molecules (X), NO 2 , CO 2 and SO 2 on the structure, stability and decontamination activity of Cs 8 Nb 6 O 19 polyoxometalate was studied computationally and experimentally. It was found that Cs 8 Nb 6 O 19 absorbs these molecules more strongly than it adsorbs water and Sarin (GB) and that these interactions hinder nerve agent decontamination. The impacts of diamagnetic CO 2 and SO 2 molecules on polyoxoniobate Cs 8 Nb 6 O 19 were fundamentally different from that of NO 2 radical. At ambient temperatures, weak coordination of the first NO 2 radical to Cs 8 Nb 6 O 19 conferred partial radical character on the polyoxoniobate and promoted stronger coordination of the second NO 2 adsorbent to form a stable diamagnetic Cs 8 Nb 6 O 19 /(NO 2 ) 2 species. Moreover, at low temperatures, NO 2 radicals formed stable dinitrogen tetraoxide (N 2 O 4 ) that weakly interacted with Cs 8 Nb 6 O 19 . It was found that both in the absence and presence of ambient gas molecules, GB decontamination by the Cs 8 Nb 6 O 19 species proceeds via general base hydrolysis involving: (a) the adsorption of water and the nerve agent on Cs 8 Nb 6 O 19 /(X), (b) concerted hydrolysis of a water molecule on a basic oxygen atom of the polyoxoniobate and nucleophilic addition of the nascent OH group to the phosphorus center of Sarin, and (c) rapid reorganization of the formed pentacoordinated-phosphorus intermediate, followed by dissociation of either HF or isopropanol and formation of POM-bound isopropyl methyl phosphonic acid (i-MPA) or methyl phosphonofluoridic acid (MPFA), respectively. The presence of the ambient gas molecules increases the energy of the intermediate stationary points relative to the asymptote of the reactants and slightly increases the hydrolysis barrier. These changes closely correlate with the Cs 8 Nb 6 O 19 -X complexation energy. The most energetically stable intermediates of the GB hydrolysis and decontamination reaction were found to be Cs 8 Nb 6 O

  6. Hypothyroidism in Cancer Patients on Immune Checkpoint Inhibitors with anti-PD1 Agents: Insights on Underlying Mechanisms.

    Science.gov (United States)

    Alhusseini, M; Samantray, J

    2017-04-01

    Background: Immune therapy using monoclonal antibodies against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed cell death 1 receptor (PD-1) for various cancers have been reported to cause thyroid dysfunction. Little is known, however, about the underlying pathogenic mechanisms and the course of hypothyroidism that subsequently develops. In this report, we use the change in thyroglobulin and thyroid antibody levels in patients on immune therapy who develop hypothyroidism to better understand its pathogenesis as well as examine the status of hypothyroidism in the long term. Methods: We report a case series of 10 patients who developed hypothyroidism after initiation of immune therapy (either anti-PD-1 alone or in combination with anti-CTLA-4). Available thyroid antibodies including anti-thyroglobulin (anti-Tg), anti-thyroid peroxidase (anti-TPO), and thyroid stimulating immunoglobulin (TSI) were noted during the initial thyroiditis phase as well as the hypothyroid phase. Persistence or remission of hypothyroidism was noted at 6 months. Summary: During the thyroiditis phase, 50% of the patients had elevated Tg titers, 40% had elevated anti-Tg, and 40% had elevated TSI. All of these titers decreased during the hypothyroid phase. Permanent hypothyroidism was noted in 80% of the cases. Conclusion: Hypothyroidism following initiation of immune therapy has immunologic and non-immunologic mediated mechanisms and is likely to be persistent. © Georg Thieme Verlag KG Stuttgart · New York.

  7. Clinical efficacy and IL-17 targeting mechanism of Indigo naturalis as a topical agent in moderate psoriasis.

    Science.gov (United States)

    Cheng, Hui-Man; Wu, Yang-Chang; Wang, Qingmin; Song, Michael; Wu, Jackson; Chen, Dion; Li, Katherine; Wadman, Eric; Kao, Shung-Te; Li, Tsai-Chung; Leon, Francisco; Hayden, Karen; Brodmerkel, Carrie; Chris Huang, C

    2017-09-02

    Indigo naturalis is a Traditional Chinese Medicine (TCM) ingredient long-recognized as a therapy for several inflammatory conditions, including psoriasis. However, its mechanism is unknown due to lack of knowledge about the responsible chemical entity. We took a different approach to this challenge by investigating the molecular profile of Indigo naturalis treatment and impacted pathways. A randomized, double-blind, placebo-controlled clinical study was conducted using Indigo naturalis as topical monotherapy to treat moderate plaque psoriasis in a Chinese cohort (n = 24). Patients were treated with Indigo naturalis ointment (n = 16) or matched placebo (n = 8) twice daily for 8 weeks, with 1 week of follow-up. At week 8, significant improvements in Psoriasis Area and Severity Index (PASI) scores from baseline were observed in Indigo naturalis-treated patients (56.3% had 75% improvement [PASI 75] response) compared with placebo (0.0%). A gene expression signature of moderate psoriasis was established from baseline skin biopsies, which included the up-regulation of the interleukin (IL)-17 pathway as a key component; Indigo naturalis treatment resulted in most of these signature genes returning toward normal, including down-regulation of the IL-17 pathway. Using an in vitro keratinocyte assay, an IL-17-inhibitory effect was observed for tryptanthrin, a component of Indigo naturalis. This study demonstrated the clinical efficacy of Indigo naturalis in moderate psoriasis, and exemplified a novel experimental medicine approach to understand TCM targeting mechanisms. NCT01901705 .

  8. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. 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.

  11. Concepts, problems and the role of modifying agents in the relationship between recovery of cells' survival ability and mechanisms of repair of radiation lesions

    International Nuclear Information System (INIS)

    Orr, J.S.

    1984-01-01

    The two strands of the problem are the shapes and changes with time of cell survival curves on the one hand and the responses of cell constituents to radiation on the other. Evidence of correlations between results of studies of these two types of phenomena under the influence of a wide range of modifying agents is required to establish mechanisms. Recovery may be defined as referring to the whole cell, while repair should be regarded as a process carried out by one substance on another. The degrees of usefulness and possible deficiencies of a multi-hit/target model and a repair model for explaining cell survival curves and cell recovery are compared in a range of circumstances. A fully satisfactory model is not yet available. (author)

  12. The experimental study on protective effects and mechanisms of chelating agents of catechols amino carboxylic acid for radiation injury induced by actimides(Th-234)

    International Nuclear Information System (INIS)

    Chen, H. H.; Luo, M. C.; Sun, M. Z.; Hu, Y. X.; Wang, Y. H.; Jin, M. Y.; Cheng, W. Y.

    2002-01-01

    The decorporative efficacy and antioxidative action of prompt and delayed consecutive administration of catecholicpolyaminopolycarboxylate ligands, 7601 and 9501 for radiothorium in mice were investigated. DTPA and Vitamin E were used as positive controls. The competitive abilities of 7601 and 9501 to mobilize the thorium with BSA were studied. Their inhibition effects on superoxide anionas radicals were measured with electron spin resonance. The results showed that 7601 and 9501 are able to effectively prevent the internal radiation injury induced radiothorium, attributing to their double functions of pronounced removal effectiveness and antioxidative action. Their protective effects were better than DTPA and Vitamin E. The mechanisms of protective effects of 7601 and 9501 for internal radiation injury was close related to competitive ability of chelating agent to chelate the thorium with BSA and oxygen free radical scavenging activities

  13. The Botulinum Toxin as a Therapeutic Agent: Molecular Structure and Mechanism of Action in Motor and Sensory Systems.

    Science.gov (United States)

    Kumar, Raj; Dhaliwal, Harkiran Preet; Kukreja, Roshan Vijay; Singh, Bal Ram

    2016-02-01

    Botulinum neurotoxin (BoNT) produced by Clostridium botulinum is the most potent molecule known to mankind. Higher potency of BoNT is attributed to several factors, including structural and functional uniqueness, target specificity, and longevity. Although BoNT is an extremely toxic molecule, it is now increasingly used for the treatment of disorders related to muscle hyperactivity and glandular hyperactivity. Weakening of muscles due to peripheral action of BoNT produces a therapeutic effect. Depending on the target tissue, BoNT can block the cholinergic neuromuscular or cholinergic autonomic innervation of exocrine glands and smooth muscles. In recent observations of the analgesic properties of BoNT, the toxin modifies the sensory feedback loop to the central nervous system. Differential effects of BoNT in excitatory and inhibitory neurons provide a unique therapeutic tool. In this review the authors briefly summarize the structure and mechanism of actions of BoNT on motor and sensory neurons to explain its therapeutic effects and future potential. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  14. The effectiveness of processed grapefruit-seed extract as an antibacterial agent: II. Mechanism of action and in vitro toxicity.

    Science.gov (United States)

    Heggers, John P; Cottingham, John; Gusman, Jean; Reagor, Lee; McCoy, Lana; Carino, Edith; Cox, Robert; Zhao, Jian-Gang; Reagor, Lana

    2002-06-01

    Recent testimonials report grapefruit-seed extract, or GSE (Citricidal) to be effective against more than 800 bacterial and viral strains, 100 strains of fungus, and a large number of single and multicelled parasites. This study investigated GSE for antibacterial activity at varying time intervals and concentration levels and tissue toxicity at varying concentrations in an effort to determine if a concentration existed that was both microbicidal and nontoxic and in what period of time. Gram-negative and gram-positive isolates were introduced into graduated dilutions of GSE (twofold concentrations ranging from 1:1, through 1:512) for determination of bacterial activity. In vitro assays with human skin fibroblast cells were also performed at the same dilutions to determine toxicity. These tests indicated that from the 1:1 through the 1:128 concentrations, GSE remained toxic as well as bactericidal. However, test results indicated that at the 1:512 dilution, GSE remained bactericidal, but completely nontoxic. The initial data shows GSE to have antimicrobial properties against a wide range of gram-negative and gram-positive organisms at dilutions found to be safe. With the aid of scanning transmission electron microscopy (STEM), the mechanism of GSE's antibacterial activity was revealed. It was evident that GSE disrupts the bacterial membrane and liberates the cytoplasmic contents within 15 minutes after contact even at more dilute concentrations.

  15. Microfibrillated cellulose and borax as mechanical, O₂-barrier, and surface-modulating agents of pullulan biocomposite coatings on BOPP.

    Science.gov (United States)

    Cozzolino, Carlo A; Campanella, Gaetano; Türe, Hasan; Olsson, Richard T; Farris, Stefano

    2016-06-05

    Multifunctional composite coatings on bi-oriented polypropylene (BOPP) films were obtained using borax and microfibrillated cellulose (MFC) added to the main pullulan coating polymer. Spectroscopy analyses suggested that a first type of interaction occurred via hydrogen bonding between the C6OH group of pullulan and the hydroxyl groups of boric acid, while monodiol and didiol complexation represented a second mechanism. The deposition of the coatings yielded an increase in the elastic modulus of the entire plastic substrate (from ∼2GPa of the neat BOPP to ∼3.1GPa of the P/B+/MFC-coated BOPP). The addition of MFC yielded a decrease of both static and kinetic coefficients of friction of approximately 22% and 25%, respectively, as compared to the neat BOPP. All composite coatings dramatically increased the oxygen barrier performance of BOPP, especially under dry conditions. The deposition of the high hydrophilic coatings allowed to obtain highly wettable surfaces (water contact angle of ∼18°). Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Therapeutic Potential and Molecular Mechanisms of Emblica officinalis Gaertn in countering nephrotoxicity in rats induced by the chemotherapeutic agent cisplatin

    Directory of Open Access Journals (Sweden)

    Salma Malik

    2016-10-01

    Full Text Available Emblica officinalis Gaertn. belonging to family Euphorbiaceae is commonly known as Indian gooseberry or Amla in India. It is used as a ‘rejuvenating herb’ in traditional system of Indian medicine. It has been shown to possess antioxidant, anti-inflammatory and anti-apoptotic effects. Thus, on the basis of its biological effects, the present study was undertaken to evaluate the protective effect of the dried fruit extract of the E. Officinalis (EO in cisplatin-induced nephrotoxicity in rats and also to evaluate the mechanism of its nephroprotection. The study was done on male albino Wistar rats. They were divided into 6 groups (n=6 viz. control, cisplatin-control, cisplatin and EO (150, 300 and 600 mg/kg; p.o. respectively in different groups and EO only (600 mg/kg; p.o. only. EO was administered orally to the rats for a period of 10 days and on the 7th day, a single injection of cisplatin (8 mg/kg; i.p. was administered to the cisplatin-control and EO treatment groups. The rats were sacrificed on the 10th day. Cisplatin-control rats had deranged renal function parameters and the kidney histology confirmed the presence of acute tubular necrosis. Furthermore, there were increased oxidative stress, apoptosis and inflammation along with higher expression of MAPK pathway proteins in the rat kidney from the cisplatin-control group. Contrary to this, EO (600 mg/kg significantly normalized renal function, bolstered antioxidant status and ameliorated histological alterations. The inflammation and apoptosis were markedly lower in comparison to cisplatin-control rats. Furthermore, EO (600 mg/kg inhibited MAPK phosphorylation which was instrumental in preserving renal function and morphology. In conclusion, the results of our study demonstrated that EO attenuated cisplatin-induced nephrotoxicity in rats through suppression of MAPK induced inflammation and apoptosis.

  17. Border Injuries: An Analysis of Prehospital Demographics, Mechanisms, and Patterns of Injuries Encountered by USBP EMS Agents in the El Paso (Texas USA) Sector.

    Science.gov (United States)

    Baker, Russell A

    2017-08-01

    Study Objective The aim of this study was to evaluate Emergency Medical Services (EMS), use, injury mechanisms, prehospital assessments, and injuries among those receiving aid from the United States Border Patrol (USBP) in the El Paso (Texas USA) Sector. This is a time-series, retrospective analysis of all prehospital data for injuries among patients receiving care from USBP EMS on the US Mexico border in the El Paso sector from February 6, 2014 to February 6, 2016. A total of 473 documented EMS encounters occurred in this two-year period and demonstrated a male gender predominance (male 63%; female 37%) with the most prominent ages between 22-40 years old. The most prevalent EMS call types were medical (55%) and trauma (42%). The most common chief complaints were an injured or painful extremity (35%) and rash (13%). The most common USBP EMS provider primary impression was traumatic injury (34%), followed by fever/infection (17%) and extremity injury (7%); however, the most common secondary impression was also extremity injury (20%). The most common mechanism of injury was fall (26%) and motor vehicle accident (MVA; 22%). The USBP EMS was the first provider on scene in 96% of the MVAs. The author reports on injury patterns, mechanisms, chief complaints, EMS impressions, as well as demographics of patients reporting to USBP EMS. A knowledge of these injury patterns will be useful to EMS administrators and physicians along the US Mexico border. Baker RA . Border injuries: an analysis of prehospital demographics, mechanisms, and patterns of injuries encountered by USBP EMS agents in the El Paso (Texas USA) Sector. Prehosp Disaster Med. 2017;32(4):431-436.

  18. The biological significance of brain barrier mechanisms: help or hindrance in drug delivery to the central nervous system? [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Norman R. Saunders

    2016-03-01

    Full Text Available Barrier mechanisms in the brain are important for its normal functioning and development. Stability of the brain’s internal environment, particularly with respect to its ionic composition, is a prerequisite for the fundamental basis of its function, namely transmission of nerve impulses. In addition, the appropriate and controlled supply of a wide range of nutrients such as glucose, amino acids, monocarboxylates, and vitamins is also essential for normal development and function. These are all cellular functions across the interfaces that separate the brain from the rest of the internal environment of the body. An essential morphological component of all but one of the barriers is the presence of specialized intercellular tight junctions between the cells comprising the interface: endothelial cells in the blood-brain barrier itself, cells of the arachnoid membrane, choroid plexus epithelial cells, and tanycytes (specialized glial cells in the circumventricular organs. In the ependyma lining the cerebral ventricles in the adult brain, the cells are joined by gap junctions, which are not restrictive for intercellular movement of molecules. But in the developing brain, the forerunners of these cells form the neuroepithelium, which restricts exchange of all but the smallest molecules between cerebrospinal fluid and brain interstitial fluid because of the presence of strap junctions between the cells. The intercellular junctions in all these interfaces are the physical basis for their barrier properties. In the blood-brain barrier proper, this is combined with a paucity of vesicular transport that is a characteristic of other vascular beds. Without such a diffusional restrain, the cellular transport mechanisms in the barrier interfaces would be ineffective. Superimposed on these physical structures are physiological mechanisms as the cells of the interfaces contain various metabolic transporters and efflux pumps, often ATP-binding cassette (ABC

  19. Mechanical properties of hexaferite based magnet composite of SrFe12019 and BaFe12O19 with natural rubber bonding agent

    International Nuclear Information System (INIS)

    Waluyo, T.; Herman, Y.A.; Sudirman; Ridwan

    2000-01-01

    Research on mechanical properties at magnet composite of SrFe 12 0 19 (SrM) and BaFe 12 O 19 (BaM)magnet powder with natural rubber bonding agent have been done. The natural rubber used was rubber made of latex without vulcanization, The SrM powder having average particle size of 1.6 μm and flat shaped. and the BaM powder having particle size of 1.2 μm and nodular shaped. The production of composite carried out in Labo Plastomill at 100 o C and mixer speed of 30 rpm for 7 minutes. The result obtained from Labo Plastomill then made into sheets. Mechanical properties of the composite tested were strain, elongation break and hardness, The results showed that the highest strain of the SrM composite obtained at composition of 70% vol of powder that is 2,22 MPa, and 3,84 MPa for BaM composite at 50% vol. of powder The elongation break of SrM composite decreased by increasing of powder volume fraction, that is 90% at the composition or 70% vol. of powder, and 370% for BaM composite at 50% vol. fraction of powder. The highest hardness for SrM composite obtained at composition of of 70% vol. of powder, that is 95 SHA. and for the BaM composite at 50% vol. of powder. that is 52 SHA

  20. Mechanical properties of chemically modified Sansevieria trifasciata/natural rubber/high density polyethylene (STF/NR/HDPE) composites: Effect of silane coupling agent

    Science.gov (United States)

    Zakaria, Nurzam Ezdiani; Baharum, Azizah; Ahmad, Ishak

    2018-04-01

    The main objective of this research is to study the effects of chemical modification on the mechanical properties of treated Sansevieria trifasciata fiber/natural rubber/high density polyethylene (TSTF/NR/HDPE) composites. Processing of STF/NR/HDPE composites was done by using an internal mixer. The processing parameters used were 135°C for temperature and a mixing rotor speed of 55 rpm for 15 minutes. Filler loading was varied from 10% to 40% of STF and the fiber size used was 125 µm. The composite blends obtained then were pressed with a hot press machine to get test samples of 1 mm and 3 mm of thickness. Samples were evaluated via tensile tests, Izod impact test and scanning electron microscopy (SEM). Results showed that tensile strength and strain value decreased while tensile modulus increased when filler loading increased. Impact strength increased when filler loading increased and began to decrease after 10% of filler amount for treated composites. For untreated composites, impact strength began to decrease after 20% of filler loading. Chemical modification by using silane coupling agent has improved certain mechanical properties of the composites such as tensile strength, strain value and tensile modulus. Adding more amount of filler will also increase the viscosity and the stiffness of the materials.

  1. High-resolution high-speed dynamic mechanical spectroscopy of cells and other soft materials with the help of atomic force microscopy.

    Science.gov (United States)

    Dokukin, M; Sokolov, I

    2015-07-28

    Dynamic mechanical spectroscopy (DMS), which allows measuring frequency-dependent viscoelastic properties, is important to study soft materials, tissues, biomaterials, polymers. However, the existing DMS techniques (nanoindentation) have limited resolution when used on soft materials, preventing them from being used to study mechanics at the nanoscale. The nanoindenters are not capable of measuring cells, nanointerfaces of composite materials. Here we present a highly accurate DMS modality, which is a combination of three different methods: quantitative nanoindentation (nanoDMA), gentle force and fast response of atomic force microscopy (AFM), and Fourier transform (FT) spectroscopy. This new spectroscopy (which we suggest to call FT-nanoDMA) is fast and sensitive enough to allow DMS imaging of nanointerfaces, single cells, while attaining about 100x improvements on polymers in both spatial (to 10-70 nm) and temporal resolution (to 0.7 s/pixel) compared to the current art. Multiple frequencies are measured simultaneously. The use of 10 frequencies are demonstrated here (up to 300 Hz which is a rather relevant range for biological materials and polymers, in both ambient conditions and liquid). The method is quantitatively verified on known polymers and demonstrated on cells and polymers blends. Analysis shows that FT-nanoDMA is highly quantitative. The FT-nanoDMA spectroscopy can easily be implemented in the existing AFMs.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Reclassifying Anaphylaxis to Neuromuscular Blocking Agents Based on the Presumed Patho-Mechanism: IgE-Mediated, Pharmacological Adverse Reaction or “Innate Hypersensitivity”?

    Directory of Open Access Journals (Sweden)

    David Spoerl

    2017-06-01

    Full Text Available Approximately 60% of perioperative anaphylactic reactions are thought to be immunoglobulin IgE mediated, whereas 40% are thought to be non-IgE mediated hypersensitivity reactions (both considered non-dose-related type B adverse drug reactions. In both cases, symptoms are elicited by mast cell degranulation. Also, pharmacological reactions to drugs (type A, dose-related may sometimes mimic symptoms triggered by mast cell degranulation. In case of hypotension, bronchospasm, or urticarial rash due to mast cell degranulation, identification of the responsible mechanism is complicated. However, determination of the type of the underlying adverse drug reaction is of paramount interest for the decision of whether the culprit drug may be re-administered. Neuromuscular blocking agents (NMBA are among the most frequent cause of perioperative anaphylaxis. Recently, it has been shown that NMBA may activate mast cells independently from IgE antibodies via the human Mas-related G-protein-coupled receptor member X2 (MRGPRX2. In light of this new insight into the patho-mechanism of pseudo-allergic adverse drug reactions, in which as drug-receptor interaction results in anaphylaxis like symptoms, we critically reviewed the literature on NMBA-induced perioperative anaphylaxis. We challenge the dogma that NMBA mainly cause IgE-mediated anaphylaxis via an IgE-mediated mechanism, which is based on studies that consider positive skin test to be specific for IgE-mediated hypersensitivity. Finally, we discuss the question whether MRGPRX2 mediated pseudo-allergic reactions should be re-classified as type A adverse reactions.

  4. Will the Conscious-Subconscious Pacing Quagmire Help Elucidate the Mechanisms of Self-Paced Exercise? New Opportunities in Dual Process Theory and Process Tracing Methods.

    Science.gov (United States)

    Micklewright, Dominic; Kegerreis, Sue; Raglin, John; Hettinga, Florentina

    2017-07-01

    The extent to which athletic pacing decisions are made consciously or subconsciously is a prevailing issue. In this article we discuss why the one-dimensional conscious-subconscious debate that has reigned in the pacing literature has suppressed our understanding of the multidimensional processes that occur in pacing decisions. How do we make our decisions in real-life competitive situations? What information do we use and how do we respond to opponents? These are questions that need to be explored and better understood, using smartly designed experiments. The paper provides clarity about key conscious, preconscious, subconscious and unconscious concepts, terms that have previously been used in conflicting and confusing ways. The potential of dual process theory in articulating multidimensional aspects of intuitive and deliberative decision-making processes is discussed in the context of athletic pacing along with associated process-tracing research methods. In attempting to refine pacing models and improve training strategies and psychological skills for athletes, the dual-process framework could be used to gain a clearer understanding of (1) the situational conditions for which either intuitive or deliberative decisions are optimal; (2) how intuitive and deliberative decisions are biased by things such as perception, emotion and experience; and (3) the underlying cognitive mechanisms such as memory, attention allocation, problem solving and hypothetical thought.

  5. Characteristics and environmental fate of the anionic surfactant sodium lauryl ether sulphate (SLES) used as the main component in foaming agents for mechanized tunnelling

    International Nuclear Information System (INIS)

    Barra Caracciolo, Anna; Cardoni, Martina; Pescatore, Tanita; Patrolecco, Luisa

    2017-01-01

    The anionic surfactant sodium lauryl ether sulphate (SLES) is the main component of most commercial products used for soil conditioning in the excavation industry, in particular as lubricants for mechanized tunnelling. Its use during the excavation processes can result in either the subsequent possible re-use of the huge amount of soil debris as by-products (e.g. land covering) or its discharge as waste. Currently, there are neither SLES soil threshold limits in European legislation, nor comprehensive studies on the environmental risk for soil ecosystems in these exposure scenarios. In this context, the present paper reviews the available data on the intrinsic characteristics of persistence and the ecotoxicological effects of the anionic surfactant SLES. Although SLES is generally reported to be biodegradable in standard tests, with degradation rates between 7 h and 30 days, depending on the initial conditions, data on its biodegradation in environmental studies are quite scarce. Consequently, assessing SLES biodegradation rates in field conditions is crucial for evaluating if in residual concentrations (typically in the range 40–500 mg/kg in excavated soils) it can or not be a potential hazard for terrestrial and water organisms. Laboratory ecotoxicological tests pointed out detrimental effects of SLES for aquatic organisms, while data on the terrestrial species are rather poor so far and further studies at the expected environmental concentrations are necessary. Finally, the review reports the main analytical methods available for detecting anionic surfactants in solid matrices and the future research needed to improve knowledge on the possible environmental risks posed by the use of SLES in foaming agents for mechanized tunnelling. - Highlights: • Tons of excavated soil containing SLES are reused posing an environmental risk. • SLES can have detrimental effects on aquatic organisms exposed in lab test. • There is a need to improve knowledge on SLES

  6. Antibiotic Agents

    Science.gov (United States)

    ... effectiveness for specific conditions: antibacterial toothpaste helps control periodontal (gum) disease; antibacterial deodorants suppress odor-causing bacteria, and antidandruff shampoos help control dandruff. However, to ...

  7. Improving the spectrophotometric determination of the alkylating activity of anticancer agents: a new insight into the mechanism of the NBP method.

    Science.gov (United States)

    Dierickx, Karen M E; Journé, Fabrice; Gerbaux, Pascal; Morandini, Renato; Kauffmann, Jean-Michel; Ghanem, Ghanem E

    2009-02-15

    In this paper, the mechanism of the nitrobenzylpyridine (NBP) method to measure the alkylating activity of drugs originally described by Epstein et al. [J. Epstein, R.W. Rosenthal, R.J. Ess, Anal. Chem. 27 (1955) 1435-1439] and modified later by others was revisited using melphalan, m-sarcolysin, chlorambucil, cyclophosphamide and ifosfamide. Its direct application to determine the activity of these drugs in human serum and aqueous media is described and discussed. This method, based on the formation of a chromophore due to the reaction between the alkylating agent and NBP, was significantly improved by extracting as quickly as possible the reaction product(s) into chloroform before adding alkali to develop the color. This significantly limited the degradation by hydrolysis of the products and enhanced the yield of the end chromophore in the organic phase. The reaction time was optimized by monitoring each compound color development. The best reaction time for each compound was selected and a higher stability of the extracted color over at least 1h was obtained (compared to a couple of minutes in previous studies). Most interestingly, water evaporation due to heating had little or no effect on the linearity of standard curves evaluated in the micromolar concentration range. Both the sensitivity and reproducibility of the method were therefore significantly improved. There appears to be a direct correlation between compound hydrolysis and alkylation activity; the relative reactivity is different among the compounds owing to the rate of (i) production, (ii) the relative proportions and (iii) the hydrolysis of the intermediates. A general mechanism for the nucleophilic competitive substitution is proposed.

  8. Effect of process control agent on the porous structure and mechanical properties of a biomedical Ti-Sn-Nb alloy produced by powder metallurgy.

    Science.gov (United States)

    Nouri, A; Hodgson, P D; Wen, C E

    2010-04-01

    The influence of different amounts and types of process control agent (PCA), i.e., stearic acid and ethylene bis-stearamide, on the porous structure and mechanical properties of a biomedical Ti-16Sn-4Nb (wt.%) alloy was investigated. Alloy synthesis was performed on elemental metal powders using high-energy ball milling for 5h. Results indicated that varying the PCA content during ball milling led to a drastic change in morphology and particle-size distribution of the ball-milled powders. Porous titanium alloy samples sintered from the powders ball milled with the addition of various amounts of PCA also revealed different pore morphology and porosity. The Vickers hardness of the sintered titanium alloy samples exhibited a considerable increase with increasing PCA content. Moreover, the addition of larger amounts of PCA in the powder mixture resulted in a significant increase in the elastic modulus and peak stress for the sintered porous titanium alloy samples under compression. It should also be mentioned that the addition of PCA introduced contamination (mainly carbon and oxygen) into the sintered porous product. Crown Copyright 2009. Published by Elsevier Ltd. All rights reserved.

  9. 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…

  10. 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, ...

  11. 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

  12. Chemical Agents

    Science.gov (United States)

    ... CR) see Riot Control Agents Digitalis Distilled mustard (HD) see Sulfur mustard E Ethylene glycol F Fentanyls and other opioids H Hydrazine Hydrofluoric acid (hydrogen fluoride) Hydrogen chloride Hydrogen cyanide (AC) Hydrogen ...

  13. Help Teens Manage Diabetes

    Science.gov (United States)

    Skip Navigation Bar Home Current Issue Past Issues Help Teens Manage Diabetes Past Issues / Spring 2008 Table ... healthy behaviors, and conflict resolution. The CST training helps diabetic teens to make good decisions when it ...

  14. Help prevent hospital errors

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000618.htm Help prevent hospital errors To use the sharing features ... in the hospital. If You Are Having Surgery, Help Keep Yourself Safe Go to a hospital you ...

  15. Mechanics

    CERN Document Server

    Hartog, J P Den

    1961-01-01

    First published over 40 years ago, this work has achieved the status of a classic among introductory texts on mechanics. Den Hartog is known for his lively, discursive and often witty presentations of all the fundamental material of both statics and dynamics (and considerable more advanced material) in new, original ways that provide students with insights into mechanical relationships that other books do not always succeed in conveying. On the other hand, the work is so replete with engineering applications and actual design problems that it is as valuable as a reference to the practicing e

  16. Help with Hives

    Science.gov (United States)

    ... Staying Safe Videos for Educators Search English Español Help With Hives KidsHealth / For Kids / Help With Hives What's in this article? What Are ... about what happened. The doctor can try to help figure out what might be causing your hives, ...

  17. A helping hand

    NARCIS (Netherlands)

    Mirjam de Klerk; Alice de Boer; Sjoerd Kooiker; Inger Plaisier; Peggy Schyns

    2014-01-01

    Original title: Hulp geboden   The help provided to people with a care need is about to undergo major changes in the Netherlands. People who need help will be expected to rely more on help from members of their network. What are the opportunities for informal carers and volunteers, and where

  18. Helping for Change

    Science.gov (United States)

    Neuringer, Allen; Oleson, Kathryn C.

    2010-01-01

    In "Helping for Change," Allen Neuringer and Kathryn Oleson describe another strategy that individuals can use to achieve their green goals. You might ask, "How can helping someone else help me change when I'm in the habit of not fulfilling my own promises?" The authors answer that question by explaining how the social reinforcement in a helping…

  19. Toddlers Help a Peer.

    Science.gov (United States)

    Hepach, Robert; Kante, Nadine; Tomasello, Michael

    2017-09-01

    Toddlers are remarkably prosocial toward adults, yet little is known about their helping behavior toward peers. In the present study with 18- and 30-month-old toddlers (n = 192, 48 dyads per age group), one child needed help reaching an object to continue a task that was engaging for both children. The object was within reach of the second child who helped significantly more often compared to a no-need control condition. The helper also fulfilled the peer's need when the task was engaging only for the child needing help. These findings suggest that toddlers' skills and motivations of helping do not depend on having a competent and helpful recipient, such as an adult, but rather they are much more flexible and general. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

  20. Integral procedure to assess crack filling and mechanical contribution of polymer-based healing agent in encapsulation-based self-healing concrete

    NARCIS (Netherlands)

    Gilabert Villegas, Francisco Antonio; Van Tittelboom, Kim; Van Stappen, J.; Cnudde, Veerle; De Belie, Nele; Van Paepegem, Wim

    2017-01-01

    This work presents an experimental and numerical study to analyze the crack filling process in encapsulation-based self-healing concrete. A specimen consisting of two small concrete blocks has been designed containing capsules filled with a polyurethane-based healing agent. This design enables to

  1. Classical group theory adapted to the mechanism of Pt3Ni nanoparticle growth: the role of W(CO)6 as the "shape-controlling" agent.

    Science.gov (United States)

    Radtke, M; Ignaszak, A

    2016-01-07

    Classical group theory was applied to prove the Pt3Ni crystallographic transformation from Platonic cubic to Archimedean cuboctahedral structures and the formation of Pt3Ni polypods. The role of W(CO)6 as a shape-controlling agent is discussed with respect to the crystallographic features of the clusters and superstructures generated as control samples.

  2. Feedback mechanisms between water availability and water use in a semi-arid river basin: a geographically explicit multi-agent simulation approach

    NARCIS (Netherlands)

    van Oel, P.R.; Krol, Martinus S.; Hoekstra, Arjen Ysbert; Taddei, Renzo R.

    2010-01-01

    Understanding the processes responsible for the distribution of water availability over space and time is of great importance to spatial planning in a semi-arid river basin. In this study the usefulness of a multi-agent simulation (MAS) approach for representing these processes is discussed. A MAS

  3. 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.

  4. 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.

  5. Handi Helps, 1985

    Science.gov (United States)

    Handi Helps, 1985

    1985-01-01

    The six issues of Handi Helps presented here focus on specific issues of concern to the disabled, parents, and those working with the disabled. The two-page handi help fact sheets focus on the following topics: child sexual abuse prevention, asthma, scoliosis, the role of the occupational therapist, kidnapping, and muscular dystrophy. Each handi…

  6. 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).

  7. Mechanics

    CERN Document Server

    Chester, W

    1979-01-01

    When I began to write this book, I originally had in mind the needs of university students in their first year. May aim was to keep the mathematics simple. No advanced techniques are used and there are no complicated applications. The emphasis is on an understanding of the basic ideas and problems which require expertise but do not contribute to this understanding are not discussed. How­ ever, the presentation is more sophisticated than might be considered appropri­ ate for someone with no previous knowledge of the subject so that, although it is developed from the beginning, some previous acquaintance with the elements of the subject would be an advantage. In addition, some familiarity with element­ ary calculus is assumed but not with the elementary theory of differential equations, although knowledge of the latter would again be an advantage. It is my opinion that mechanics is best introduced through the motion of a particle, with rigid body problems left until the subject is more fully developed. Howev...

  8. 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)

  9. 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...

  10. [Biological agents].

    Science.gov (United States)

    Amano, Koichi

    2009-03-01

    There are two types of biological agents for the treatment of rheumatoid arthritis (RA); monoclonal antibodies and recombinant proteins. Among the latter, etanercept, a recombinant fusion protein of soluble TNF receptor and IgG was approved in 2005 in Japan. The post-marketing surveillance of 13,894 RA patients revealed the efficacy and safety profiles of etanercept in the Japanese population, as well as overseas studies. Abatacept, a recombinant fusion protein of CTLA4 and IgG, is another biological agent for RA. Two clinical trials disclosed the efficacy of abatacept for difficult-to-treat patients: the AIM for MTX-resistant cases and the ATTAIN for patients who are resistant to anti-TNF. The ATTEST trial suggested abatacept might have more acceptable safety profile than infliximab. These biologics are also promising for the treatment of RA for not only relieving clinical symptoms and signs but retarding structural damage.

  11. [The bonding mechanisms of base metals for metal-ceramic crown microstructure analysis of bonding agent and gold bond between porcelain and base metals].

    Science.gov (United States)

    Wang, C C; Hsu, C S

    1996-06-01

    The use of base metal alloys for porcelain fused to a metal crown and bridges has increased recently because of lower price, high hardness, high tensile strength and high elastic modulus. The addition of beryllium to base metal alloys increased fluidity and improved casting fitness. Beryllium also controlled surface oxidation and bonding strength. The bonding agent and gold bonding agent also affected the bonding strength between porcelain and metal alloys. Four commercially available ceramic base alloys were studied (two alloys contained beryllium element, another two did not). The purpose of this investigation was to study the microstructure between porcelain matrix, bonding agent and alloy matrix interfaces. A scanning electron micro-probe analyzer and energy dispersive X-ray spectroscopy (EDXS) were used to study the distribution of elements (Ni, Cr, Mo, Cu, O, Si, Sn, Al) in four base alloys. The following results were obtained: 1. The thickness of the oxidized layer of Rexillium III alloy and Unitbond alloy (contained beryllium) was thinner than Unibond alloy and Wiron 88 alloy (no beryllium). 2. The thickness of the oxidized layer of alloys in air (10 minutes and 30 minutes) was thinner in Unitbond (2.45 microns and 3.80 microns) and thicker in Wiron 88 (4.39 microns and 5.96 microns). 3. The thickness of the oxidized layer occurring for a duration of ten minutes (in vaccum) showed that the Rexillium III alloy was the thinnest (1.93 microns), and Wiron 88 alloy was the thickest (2.30 microns). But in thirty minutes (vacuum), Unitbond alloy was the thinnest (3.37 microns), and Wiron 88 alloy was the thickest (5.51 microns). 4. The intensity of Cr elements was increased obviously near the interface between Unitbond alloy, Wiron 88 alloy (no beryllium) and oxidized layer, but the intensity of Ni and Mo elements was slightly increased. The intensity of Cr element was not increased markedly between Rexillium III alloy, Unitbond alloy (beryllium) and oxidized

  12. 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.

  13. 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.

  14. Hooked on Helping

    Science.gov (United States)

    Longhurst, James; McCord, Joan

    2014-01-01

    In this article, teens presenting at a symposium on peer-helping programs describe how caring for others fosters personal growth and builds positive group cultures. Their individual thoughts and opinions are expressed.

  15. Divorce: Helping Children Cope.

    Science.gov (United States)

    Cook, Alicia S.; McBride, Jean

    1982-01-01

    Examines children's reactions to the divorce process and explores ways in which adults can promote growth and adjustment in children of divorce. Suggests ways in which parents, teachers, and counselors can help children. (RC)

  16. 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.

  17. Comparative Studies on Thermal, Mechanical, and Flame Retardant Properties of PBT Nanocomposites via Different Oxidation State Phosphorus-Containing Agents Modified Amino-CNTs.

    Science.gov (United States)

    Zhu, San-E; Wang, Li-Li; Chen, Hao; Yang, Wei; Yuen, Anthony Chun-Yin; Chen, Timothy Bo-Yuan; Luo, Cheng; Bi, Wen-Mei; Hu, En-Zhu; Zhang, Jian; Si, Jing-Yu; Lu, Hong-Dian; Hu, Kun-Hong; Chan, Qing Nian; Yeoh, Guan Heng

    2018-01-26

    High-performance poly(1,4-butylene terephthalate) (PBT) nanocomposites have been developed via the consideration of phosphorus-containing agents and amino-carbon nanotube (A-CNT). One-pot functionalization method has been adopted to prepare functionalized CNTs via the reaction between A-CNT and different oxidation state phosphorus-containing agents, including chlorodiphenylphosphine (DPP-Cl), diphenylphosphinic chloride (DPP(O)-Cl), and diphenyl phosphoryl chloride (DPP(O₃)-Cl). These functionalized CNTs, DPP(O x )-A-CNTs ( x = 0, 1, 3), were, respectively, mixed with PBT to obtain the CNT-based polymer nanocomposites through a melt blending method. Scanning electron microscope observations demonstrated that DPP(O x )-A-CNT nanoadditives were homogeneously distributed within PBT matrix compared to A-CNT. The incorporation of DPP(O x )-A-CNT improved the thermal stability of PBT. Moreover, PBT/DPP(O₃)-A-CNT showed the highest crystallization temperature and tensile strength, due to the superior dispersion and interfacial interactions between DPP(O₃)-A-CNT and PBT. PBT/DPP(O)-A-CNT exhibited the best flame retardancy resulting from the excellent carbonization effect. The radicals generated from decomposed polymer were effectively trapped by DPP(O)-A-CNT, leading to the reduction of heat release rate, smoke production rate, carbon dioxide and carbon monoxide release during cone calorimeter tests.

  18. 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

  19. 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.

  20. 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).

  1. 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.

  2. Being 'green' helps profitability?

    International Nuclear Information System (INIS)

    Austin, D.

    1999-01-01

    Pollution reduction beyond regulatory compliance is gaining momentum among firms, but managers ask if being 'green' helps profitability. Evidence suggests it doesn't hurt, but when we see environmentally attractive firms with sound financial performance, it cannot yet say which is cause and which is effect [it

  3. Helping Students Avoid Plagiarism.

    Science.gov (United States)

    Wilhoit, Stephen

    1994-01-01

    Discusses how and why college students commit plagiarism, suggesting techniques that instructors can use to help student avoid plagiarism. Instructors should define and discuss plagiarism thoroughly; discuss hypothetical cases; review the conventions of quoting and documenting material; require multiple drafts of essays; and offer responses…

  4. Help with Hearing

    Science.gov (United States)

    ... be placed early to help speech and language development. If your child needs “tubes” (see below), they can be put ... example, instead of saying the sound /t/, your child may always substitute the sound /k/. The words “toy” and "truck” then come out as “kay” and “ ...

  5. Helping Kids Handle Worry

    Science.gov (United States)

    ... world around them, preteens also may worry about world events or issues they hear about on the news or at ... the news. Parents can help by discussing these issues, offering accurate ... and stress about a world event that's beyond your control, kids are likely ...

  6. Helping Them Grow.

    Science.gov (United States)

    Kreidler, William J.; And Others

    1995-01-01

    Three articles present suggestions to help elementary teachers promote student development. The first describes games that encourage a sense of community. The second deals with making parent teacher conferences a positive experience. The third discusses how to give confused children who are involved in custody battles an alternative to acting out.…

  7. Helping Struggling Teachers.

    Science.gov (United States)

    Tucker, Pamela

    2001-01-01

    About 5 to 15 percent of teachers in 2.7 million public-education classrooms are marginal or incompetent. Assistance plans offer structure, purpose, and remedial help. Plans have six components: definition of the problem, statement of objectives, intervention strategies, a timeline, data-collection procedures, and final judgment. (MLH)

  8. Help from the strings

    CERN Multimedia

    2007-01-01

    "How can the nature of basic particles be defined beyond the mechanisms presiding over their creation? Besides the standard model of particle physics - resulting from the postulations of quantum mechanics - contemporary science has pinned its hopes on the totally new unifying notion provided by the highly mathematical string theory."(2 pages)

  9. Radioprotective Agents

    Directory of Open Access Journals (Sweden)

    Ilker Kelle

    2008-01-01

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

  10. Inhibition of phosphatidylinositol 3-kinase promotes tumor cell resistance to chemotherapeutic agents via a mechanism involving delay in cell cycle progression

    International Nuclear Information System (INIS)

    McDonald, Gail T.; Sullivan, Richard; Pare, Genevieve C.; Graham, Charles H.

    2010-01-01

    Approaches to overcome chemoresistance in cancer cells have involved targeting specific signaling pathways such as the phosphatidylinositol 3-kinase (PI3K) pathway, a stress response pathway known to be involved in the regulation of cell survival, apoptosis and growth. The present study determined the effect of PI3K inhibition on the clonogenic survival of human cancer cells following exposure to various chemotherapeutic agents. Treatment with the PI3K inhibitors LY294002 or Compound 15e resulted in increased survival of MDA-MB-231 breast carcinoma cells after exposure to doxorubicin, etoposide, 5-fluorouracil, and vincristine. Increased survival following PI3K inhibition was also observed in DU-145 prostate, HCT-116 colon and A-549 lung carcinoma cell lines exposed to doxorubicin. Increased cell survival mediated by LY294002 was correlated with a decrease in cell proliferation, which was linked to an increase in the proportion of cells in the G 1 phase of the cell cycle. Inhibition of PI3K signaling also resulted in higher levels of the cyclin-dependent kinase inhibitors p21 Waf1/Cip1 and p27 Kip1 ; and knockdown of p27 kip1 with siRNA attenuated resistance to doxorubicin in cells treated with LY294002. Incubation in the presence of LY294002 after exposure to doxorubicin resulted in decreased cell survival. These findings provide evidence that PI3K inhibition leads to chemoresistance in human cancer cells by causing a delay in cell cycle; however, the timing of PI3K inhibition (either before or after exposure to anti-cancer agents) may be a critical determinant of chemosensitivity.

  11. 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.

  12. 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 ...

  13. In vitro Antagonistic Mechanisms of Trichoderma spp. and Talaromyces flavus to Control Gaeumannomyces graminis var. tritici the Causal Agent of Wheat Take-all Disease

    Directory of Open Access Journals (Sweden)

    Seddighe Mohammadi

    2015-07-01

    Full Text Available Wheat take-all disease caused by Gaeumannomyces graminis var. tritici has recently been detected in different regions of Iran. With respect to biocontrol effect of Trichoderma spp. on many pathogenic fungi, seven isolates of Trichoderma and four isolates of Talaromyces were in vitro evaluated in terms of their biological control against the disease causal agent. In dual culture test the five isolates showed efficient competition for colonization against pathogenic fungus and the highest percentages of inhibition belonging to Talaromyces flavus 60 and Talaromyces flavus 136 were 59.52 and 57.61%, respectively. Microscopic investigations showed that in regions where antagonistic isolates and Gaeumannomyces graminis var. tritici coincide, hyphal contact, penetration and fragmentation of Gaeumannomyces graminis var. tritici were observed. Investigating the effect of volatile and non-volatile compounds at 10 ml concentration showed that the highest inhibition percentage on mycelium growth of the pathogen caused by T. harzianum (44.76% and T. longibrachiatum (52.38% respectively.

  14. Hematopoietic stem cell mobilizing agents G-CSF, cyclophosphamide or AMD3100 have distinct mechanisms of action on bone marrow HSC niches and bone formation.

    Science.gov (United States)

    Winkler, I G; Pettit, A R; Raggatt, L J; Jacobsen, R N; Forristal, C E; Barbier, V; Nowlan, B; Cisterne, A; Bendall, L J; Sims, N A; Lévesque, J-P

    2012-07-01

    The CXCR4 antagonist AMD3100 is progressively replacing cyclophosphamide (CYP) as adjuvant to granulocyte colony-stimulating factor (G-CSF) to mobilize hematopoietic stem cells (HSC) for autologous transplants in patients who failed prior mobilization with G-CSF alone. It has recently emerged that G-CSF mediates HSC mobilization and inhibits bone formation via specific bone marrow (BM) macrophages. We compared the effect of these three mobilizing agents on BM macrophages, bone formation, osteoblasts, HSC niches and HSC reconstitution potential. Both G-CSF and CYP suppressed niche-supportive macrophages and osteoblasts, and inhibited expression of endosteal cytokines resulting in major impairment of HSC reconstitution potential remaining in the mobilized BM. In sharp contrast, although AMD3100 was effective at mobilizing HSC, it did not suppress osteoblasts, endosteal cytokine expression or reconstitution potential of HSC remaining in the mobilized BM. In conclusion, although G-CSF, CYP and AMD3100 efficiently mobilize HSC into the blood, their effects on HSC niches and bone formation are distinct with both G-CSF and CYP targeting HSC niche function and bone formation, whereas AMD3100 directly targets HSC without altering niche function or bone formation.

  15. 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

  16. Exploration of a Chemo-Mechanical Technique for the Isolation of Nanofibrillated Cellulosic Fiber from Oil Palm Empty Fruit Bunch as a Reinforcing Agent in Composites Materials

    OpenAIRE

    Ireana Yusra A. Fatah; H. P. S. Abdul Khalil; Md. Sohrab Hossain; Astimar A. Aziz; Yalda Davoudpour; Rudi Dungani; Amir Bhat

    2014-01-01

    The aim of the present study was to determine the influence of sulphuric acid hydrolysis and high-pressure homogenization as an effective chemo-mechanical process for the isolation of quality nanofibrillated cellulose (NFC). The cellulosic fiber was isolated from oil palm empty fruit bunch (OPEFB) using acid hydrolysis methods and, subsequently, homogenized using a high-pressure homogenizer to produce NFC. The structural analysis and the crystallinity of the raw fiber and extracted cellulose ...

  17. 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

  18. Corona helps curb losses

    Energy Technology Data Exchange (ETDEWEB)

    Laasonen, M.; Lahtinen, M.; Lustre, L.

    1996-11-01

    The greatest power losses in electricity transmission arise through a phenomenon called load losses. Corona losses caused by the surface discharge of electricity also constitute a considerable cost item. IVS, the nationwide network company, is investigating corona- induced losses, and has also commissioned similar research from IVO International, the Technical Research Centre of Finland (VTT) and from Tampere University of Technology. The research work strives to gain more in-depth knowledge on the phenomenon of frosting and its impact on corona losses. The correct prediction of frost helps reduce corona losses, while also cutting costs considerably. (orig.)

  19. Foundation helps refurbish buildings

    International Nuclear Information System (INIS)

    Camenzind, B.

    2006-01-01

    This article looks at the activities of the Swiss 'Climate-Cent' foundation, which is helping support the energetic refurbishment of building envelopes. The conditions which have to be fulfilled to receive grants are explained. Work supported includes the replacement of windows and the insulation of roofs and attics as well as outside walls. Details on the financial support provided and examples of projects supported are given. The source of the finance needed to provide such support - a voluntary levy on petrol - and further support provided in certain Swiss cantons is commented on

  20. Technology for helping people

    CERN Multimedia

    Rosaria Marraffino

    2014-01-01

    The first THE Port hackathon problem-solving workshop was held at CERN from 31 October to 2 November in the framework of the 60th anniversary celebrations. The aim of the event was to develop technological projects that can help to solve the day-to-day needs of people living in areas of the planet that experience conflicts or natural disasters.   Collage of shots from THE Port hackathon. Credit: THE Port association The event was dedicated to humanitarian and social topics inspired by members of non-governmental organisations‬. “There is plenty of room for technology to help in humanitarian fields. That’s why we came up with the idea of bringing people together to work on these topics,” explains Ines Knäpper, Project Manager of THE Port hackathon. “We started six months ago setting up THE Port association.* The success of the event was only possible because of the joint effort of a team of roughly twenty people. They were inspired by the aim...

  1. The Helpful House

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    Many everyday tasks are difficult—even impossible for people confined to wheelchairs.Now a unique house near Baltimore,Md., demonstrates how technology can make a building truly accessible. Developed by Volunteers for Medical Engineering in conjunction with several nonprofit organizations, Future Home takes advantage of off-the-shelf electronic controls that operate nearly all electrical and mechanical systems.

  2. Eugenia uniflora L. Essential Oil as a Potential Anti-Leishmania Agent: Effects on Leishmania amazonensis and Possible Mechanisms of Action

    OpenAIRE

    Rodrigues, Klinger Antonio da Franca; Amorim, Layane Val?ria; de Oliveira, Jamylla Mirck Guerra; Dias, Clarice Noleto; Moraes, Denise Fernandes Coutinho; Andrade, Eloisa Helena de Aguiar; Maia, Jose Guilherme Soares; Carneiro, Sabrina Maria Portela; Carvalho, Fernando A?cio de Amorim

    2013-01-01

    Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO) by using gas chromatography-mass spectrometry (GC-MS) and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components...

  3. Exploration of a Chemo-Mechanical Technique for the Isolation of Nanofibrillated Cellulosic Fiber from Oil Palm Empty Fruit Bunch as a Reinforcing Agent in Composites Materials

    Directory of Open Access Journals (Sweden)

    Ireana Yusra A. Fatah

    2014-10-01

    Full Text Available The aim of the present study was to determine the influence of sulphuric acid hydrolysis and high-pressure homogenization as an effective chemo-mechanical process for the isolation of quality nanofibrillated cellulose (NFC. The cellulosic fiber was isolated from oil palm empty fruit bunch (OPEFB using acid hydrolysis methods and, subsequently, homogenized using a high-pressure homogenizer to produce NFC. The structural analysis and the crystallinity of the raw fiber and extracted cellulose were carried out by Fourier transform infrared spectroscopy (FT-IR and X-ray diffraction (XRD. The morphology and thermal stability were investigated by scanning electron microscopy (SEM, transmission electron microscopy (TEM and thermogravimetric (TGA analyses, respectively. The FTIR results showed that lignin and hemicellulose were removed effectively from the extracted cellulose nanofibrils. XRD analysis revealed that the percentage of crystallinity was increased from raw EFB to microfibrillated cellulose (MFC, but the decrease for NFC might due to a break down the hydrogen bond. The size of the NFC was determined within the 5 to 10 nm. The TGA analysis showed that the isolated NFC had high thermal stability. The finding of present study reveals that combination of sulphuric acid hydrolysis and high-pressure homogenization could be an effective chemo-mechanical process to isolate cellulose nanofibers from cellulosic plant fiber for reinforced composite materials.

  4. Eugenia uniflora L. Essential Oil as a Potential Anti-Leishmania Agent: Effects on Leishmania amazonensis and Possible Mechanisms of Action

    Science.gov (United States)

    Amorim, Layane Valéria; de Oliveira, Jamylla Mirck Guerra; Dias, Clarice Noleto; Moraes, Denise Fernandes Coutinho; Andrade, Eloisa Helena de Aguiar; Maia, Jose Guilherme Soares; Carneiro, Sabrina Maria Portela; Carvalho, Fernando Aécio de Amorim

    2013-01-01

    Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO) by using gas chromatography-mass spectrometry (GC-MS) and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components were sesquiterpenes (91.92%), with curzerene (47.3%), γ-elemene (14.25%), and trans-β-elemenone (10.4%) being the major constituents. The bioactivity shown by EuEO against promastigotes (IC50, 3.04 μg·mL−1) and amastigotes (IC50, 1.92 μg·mL−1) suggested significant anti-Leishmania activity. In the cytotoxicity determination, EuEO was 20 times more toxic to amastigotes than to macrophages. Hemolytic activity was 63.22% at the highest concentration tested (400 μg·mL−1); however, there appeared to be no toxicity at 50 μg·mL−1. While the data show that EuEO activity is not mediated by nitric oxide production, they do suggest that macrophage activation may be involved in EuEO anti-Leishmania activity, as evidenced by increases in both the phagocytic capacity and the lysosomal activity. More studies are needed to determine in vivo activity as well as additional mechanisms of the anti-Leishmania activity. PMID:23533469

  5. Eugenia uniflora L. Essential Oil as a Potential Anti-Leishmania Agent: Effects on Leishmania amazonensis and Possible Mechanisms of Action

    Directory of Open Access Journals (Sweden)

    Klinger Antonio da Franca Rodrigues

    2013-01-01

    Full Text Available Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO by using gas chromatography-mass spectrometry (GC-MS and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components were sesquiterpenes (91.92%, with curzerene (47.3%, γ-elemene (14.25%, and trans-β-elemenone (10.4% being the major constituents. The bioactivity shown by EuEO against promastigotes (IC50, 3.04 μg·mL−1 and amastigotes (IC50, 1.92 μg·mL−1 suggested significant anti-Leishmania activity. In the cytotoxicity determination, EuEO was 20 times more toxic to amastigotes than to macrophages. Hemolytic activity was 63.22% at the highest concentration tested (400 μg·mL−1; however, there appeared to be no toxicity at 50 μg·mL−1. While the data show that EuEO activity is not mediated by nitric oxide production, they do suggest that macrophage activation may be involved in EuEO anti-Leishmania activity, as evidenced by increases in both the phagocytic capacity and the lysosomal activity. More studies are needed to determine in vivo activity as well as additional mechanisms of the anti-Leishmania activity.

  6. Underlying mechanism of regulatory actions of diclofenac, a nonsteroidal anti-inflammatory agent, on neuronal potassium channels and firing: an experimental and theoretical study.

    Science.gov (United States)

    Huang, C W; Hung, T Y; Liao, Y K; Hsu, M C; Wu, S N

    2013-06-01

    Diclofenac (DIC), a nonsteroidal anti-inflammatory drug, is known to exert anti-nociceptive and anti-convulsant actions; however, its effects on ion currents, in neurons remain debatable. We aimed to investigate (1) potential effects of diclofenac on membrane potential and potassium currents in differentiated NSC-34 neuronal cells and dorsal root ganglion (DRG) neurons with whole-cell patch-clamp technology, and (2) firing of action potentials (APs), using a simulation model from hippocampal CA1 pyramidal neurons based on diclofenac's effects on potassium currents. In the NSC-34 cells, diclofenac exerted an inhibitory effect on delayed-rectifier K⁺ current (I(KDR)) with an IC₅₀ value of 73 μM. Diclofenac not merely inhibited the I(KDR) amplitude in response to membrane depolarization, but also accelerated the process of current inactivation. The inhibition by diclofenac of IK(DR) was not reversed by subsequent application of either naloxone. Importantly, diclofenac (300 μM) increased the amplitude of M-type K⁺ current (I)(KM)), while flupirtine (10 μM) or meclofenamic acid (10 μM) enhanced it effectively. Consistently, diclofenac (100 μM) increased the amplitude of I(KM) and diminished the I(KDR) amplitude, with a shortening of inactivation time constant in DRG neurons. Furthermore, by using the simulation modeling, we demonstrated the potential electrophysiological mechanisms underlying changes in AP firing caused by diclofenac. During the exposure to diclofenac, the actions on both I(KM) and I(KDR) could be potential mechanism through which it influences the excitability of fast-spiking neurons. Caution needs to be made in attributing the effects of diclofenac primarily to those produced by the activation of I(KM).

  7. Eugenia uniflora L. Essential Oil as a Potential Anti-Leishmania Agent: Effects on Leishmania amazonensis and Possible Mechanisms of Action.

    Science.gov (United States)

    Rodrigues, Klinger Antonio da Franca; Amorim, Layane Valéria; de Oliveira, Jamylla Mirck Guerra; Dias, Clarice Noleto; Moraes, Denise Fernandes Coutinho; Andrade, Eloisa Helena de Aguiar; Maia, Jose Guilherme Soares; Carneiro, Sabrina Maria Portela; Carvalho, Fernando Aécio de Amorim

    2013-01-01

    Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO) by using gas chromatography-mass spectrometry (GC-MS) and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components were sesquiterpenes (91.92%), with curzerene (47.3%), γ -elemene (14.25%), and trans- β -elemenone (10.4%) being the major constituents. The bioactivity shown by EuEO against promastigotes (IC50, 3.04  μ g·mL(-1)) and amastigotes (IC50, 1.92  μ g·mL(-1)) suggested significant anti-Leishmania activity. In the cytotoxicity determination, EuEO was 20 times more toxic to amastigotes than to macrophages. Hemolytic activity was 63.22% at the highest concentration tested (400  μ g·mL(-1)); however, there appeared to be no toxicity at 50  μ g·mL(-1). While the data show that EuEO activity is not mediated by nitric oxide production, they do suggest that macrophage activation may be involved in EuEO anti-Leishmania activity, as evidenced by increases in both the phagocytic capacity and the lysosomal activity. More studies are needed to determine in vivo activity as well as additional mechanisms of the anti-Leishmania activity.

  8. Effect of drug loading method against drug dissolution mechanism of encapsulated amoxicillin trihydrate in matrix of semi-IPN chitosan-poly(N-vinylpyrrolidone) hydrogel with KHCO3 as pore forming agent in floating drug delivery system

    Science.gov (United States)

    Fimantari, Khansa; Budianto, Emil

    2018-04-01

    Helicobacterpylori infection can be treated using trihydrate amoxicillin. However, this treatment is not effective enough, as the conventional dosage treatment has a relatively short retention time in the human stomach. In the present study, the amoxicillin trihydrate drug will be encapsulated into a semi-IPN K-PNVP hydrogel matrix with 7,5% KHCO3 as a pore-forming agent. The encapsulated drug is tested with in vitro method to see the efficiency of its encapsulation and dissolution. The hydrogel in situ loading produces an encapsulation efficiency value. The values of the encapsulation efficiency are 95% and 98%, while post loading hydrogel yields an encapsulation efficiency value is 77% and the dissolution is 84%. The study of drug dissolution mechanism was done by using mathematical equation model to know its kinetics and its mechanism of dissolution. The post loading hydrogel was done by using thefirst-order model, while hydrogel in situ loading used Higuchi model. The Korsmeyer-Peppas model shows that post loading hydrogel dissolution mechanism is a mixture of diffusion and erosion, and in situ loading hydrogel in the form of diffusion. It is supported by the results of hydrogel characterization, before and after dissolution test with an optical microscope. The results of the optical microscope show that the hydrogel surface before and after the dissolution tested for both methods shows the change becomes rougher.

  9. 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...

  10. Rhenium(V) oxo complexes relevant to technetium renal imaging agents derived from mercaptoacetylglycylglycylaminobenzoic acid isomers. Structural and molecular mechanics studies

    International Nuclear Information System (INIS)

    Hansen, L.; Taylor, A. Jr; Marzilli, L.G.; Cini, R.

    1992-01-01

    The synthesis and characterization of three rhenium(V) oxo complexes derived from isomers of mercaptoacetylglycylglycylaminobenzoic acid (MAG 2 -ABAH 5 ) are reported. The isomers were synthesized from o-, m- and p-aminobenzoic acid and differed in the position of the terminal carboxyl group. The anions of 8-10, [ReO(MAG 2 -*ABAH)] - (* = para (8), meta (9), ortho (10)), contained the tetraanionic form of the ligands with the carboxyl group protonated. Compounds 8,9, and 10 were synthesized by exchange reactions of ReOCl 3 (Me 2 SO)(Ph 3 P) under moderate conditions and were isolated as [Ph 4 P] + , [Bu 4 N] + , and [Ph 4 P] + salts, respectively. The structures of 8 and 10 were determined by X-ray diffraction methods; except for the location of the carboxyl group, the structures are similar. The coordination geometry is pseudo square pyramidal, with nitrogen and sulfur donor atoms forming a square base and the oxo ligand at the apex. The orientation of the carboxyl group in 10 is anti to the Re double-bond O group. Since the carboxyl groups are protonated in 8 and 10 and in other relevant structures from this class of radiopharmaceuticals including [Ph 4 As][TcO(MAG 3 H)] (MAG 3 H = tetraanionic form of mercaptoacetyltriglycine), the authors developed molecular mechanics parameters that allowed them to calculate the structures of 8, 10, and [TcO(MAG 3 H)] - . They then extended the calculations to all three isomeric complexes in their deprotonated forms and to [TcO(MAG 3 )] 2- in order to approximate their solution phase structures. They conclude that the [TcO(MAG 3 )] 2- species is conformationally flexible, and they have made an initial assessment of structures vs renal clearance

  11. Alert for an epidemic of oral cancer due to use of the betel quid substitutes gutkha and pan masala: a review of agents and causative mechanisms.

    Science.gov (United States)

    Nair, Urmila; Bartsch, Helmut; Nair, Jagadeesan

    2004-07-01

    In south-east Asia, Taiwan and Papua New Guinea, smoking, alcohol consumption and chewing of betel quid with or without tobacco or areca nut with or without tobacco are the predominant causes of oral cancer. In most areas, betel quid consists of a mixture of areca nut, slaked lime, catechu and several condiments according to taste, wrapped in a betel leaf. Almost all habitual chewers use tobacco with or without the betel quid. In the last few decades, small, attractive and inexpensive sachets of betel quid substitutes have become widely available. Aggressively advertised and marketed, often claimed to be safer products, they are consumed by the very young and old alike, particularly in India, but also among migrant populations from these areas world wide. The product is basically a flavoured and sweetened dry mixture of areca nut, catechu and slaked lime with tobacco (gutkha) or without tobacco (pan masala). These products have been strongly implicated in the recent increase in the incidence of oral submucous fibrosis, especially in the very young, even after a short period of use. This precancerous lesion, which has a high rate of malignant transformation, is extremely debilitating and has no known cure. The use of tobacco with lime, betel quid with tobacco, betel quid without tobacco and areca nut have been classified as carcinogenic to humans. As gutkha and pan masala are mixtures of several of these ingredients, their carcinogenic affect can be surmised. We review evidence that strongly supports causative mechanisms for genotoxicity and carcinogenicity of these substitute products. Although some recent curbs have been put on the manufacture and sale of these products, urgent action is needed to permanently ban gutkha and pan masala, together with the other established oral cancer-causing tobacco products. Further, education to reduce or eliminate home-made preparations needs to be accelerated.

  12. Synthesis, enzyme inhibitory kinetics mechanism and computational study of N-(4-methoxyphenethyl-N-(substituted-4-methylbenzenesulfonamides as novel therapeutic agents for Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Muhammad Athar Abbasi

    2018-06-01

    Full Text Available The present study comprises the synthesis of a new series of sulfonamides derived from 4-methoxyphenethylamine (1. The synthesis was initiated by the reaction of 1 with 4-methylbenzenesulfonyl chloride (2 in aqueous sodium carbonate solution at pH 9 to yield N-(4-methoxyphenethyl-4-methylbenzensulfonamide (3.This parent molecule 3 was subsequently treated with various alkyl/aralkyl halides, (4a–j, using N,N-dimethylformamide (DMF as solvent and LiH as activator to produce a series of new N-(4-methoxyphenethyl-N-(substituted-4-methylbenzenesulfonamides (5a–j. The structural characterization of these derivatives was carried out by spectroscopic techniques like IR, 1H-NMR, and 13C-NMR. The elemental analysis data was also coherent with spectral data of these molecules. The inhibitory effects on acetylcholinesterase and DPPH were evaluated and it was observed that N-(4-Methoxyphenethyl-4-methyl-N-(2-propylbenzensulfonamide (5c showed acetylcholinesterase inhibitory activity 0.075 ± 0.001 (IC50 0.075 ± 0.001 µM comparable to Neostigmine methylsulfate (IC50 2.038 ± 0.039 µM.The docking studies of synthesized ligands 5a–j were also carried out against acetylcholinesterase (PDBID 4PQE to compare the binding affinities with IC50 values. The kinetic mechanism analyzed by Lineweaver-Burk plots demonstrated that compound (5c inhibits the acetylcholinesterase competitively to form an enzyme inhibitor complex. The inhibition constants Ki calculated from Dixon plots for compound (5c is 2.5 µM. It was also found from kinetic analysis that derivative 5c irreversible enzyme inhibitor complex. It is proposed on the basis of our investigation that title compound 5c may serve as lead structure for the design of more potent acetylcholinesterase inhibitors.

  13. Interacting agents in finance

    NARCIS (Netherlands)

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

    2008-01-01

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

  14. Riot Control Agents

    Science.gov (United States)

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

  15. 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.

  16. CHARACTERISTIC OF MECHANISMS OF ANTIULCEROGENIC ACTION OF AGENTS OF VANILLOID RECEPTORS (TRPV1 ON THE MODEL OF GASTROPATHY INDUCED BY ACETYLSALICYLIC ACID

    Directory of Open Access Journals (Sweden)

    F. V. Hladkykh

    2017-01-01

    Full Text Available One of the main problems of the use of acetylsalicylic acid (ASA is its withdrawal or initial “non-prescription” resulted from the prior developed or potential side effects in the gastrointestinal tract. In this case, the reasons for the abolition of ASA are not only serious complications in the form of gastrointestinal bleeding or perforations, butalso dyspeptic phenomena that are accompanied by the ongoing development of aspirin-induced gastroenteropathy. The aim of the study. To characterize the mechanisms of antiulcerogenic action of agonist TRPV1 (transient receptor potential vanilloid 1 vanillin (100 mg/kg on the model of subchronic ASA-induced gastropathy in rats. Materials and methods. The study was performed on 35 mature male rats. Gastropathy induced by ASA was simulated by a fiveday intragastric (i.g. introduction via the orogastric probe of an ASA suspension of 150 mg/kg/ day during 5 days. Omeprazole (50 mg/kg, i.g. and vanillin (100 mg/kg, i.g. were administered in the form of suspensions 60 minutes prior to the use of ASA. The concentration of malonic dialdehyde, and the activity of catalase were determined in the homogenates of gastric mucosa. The prooxidant/antioxidant ratio (ProAntidex was calculated dased on the ratio of catalase activity (mcat/kg and the concentration of malondialdehyde (MDA concentration (umol/kg. The content of NO metabolites in the stomach tissues was determined by the method of Miranda K.M. et al. Results and discussion. Preventive prophylactic use of vanillin (100 mg/kg leads to the decrease in the intensity of processes of lipid peroxidation in the gastric mucosa caused by the action of ASA (150 mg/kg. This was indicated by a statistically significant (p≤0.05 decrease of 26.4% in MDA content and an increase in catalase activity by 29.0% relatively to those animalswith ASA-induced gastropathy without correction. Also, the use of vanillin resulted in a statistically significant (p≤0.05 increase in

  17. 3,4-Dihydro-1,3-2H-benzoxazines: Novel reducing agents through one electron donation mechanism and their application as the formation of nano-metallic silver coating

    Energy Technology Data Exchange (ETDEWEB)

    Kaewvilai, Attaphon [Department of Materials Engineering, Faculty of Engineering, Kasetsart University, Chatuchak, Bangkok, 10900 (Thailand); Wattanathana, Worawat [Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900 (Thailand); Jongrungruangchok, Suchada [Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Rangsit University, Pathumthani, 12000 (Thailand); Veranitisagul, Chatchai [Department of Material and Metallurgical Engineering, Faculty of Engineering, Rajamangala University of Technology Thanyaburi, Klong 6, Thanyaburi, Pathumthani, 12110 (Thailand); Koonsaeng, Nattamon [Department of Chemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, 10900 (Thailand); Laobuthee, Apirat, E-mail: fengapl@ku.ac.th [Department of Materials Engineering, Faculty of Engineering, Kasetsart University, Chatuchak, Bangkok, 10900 (Thailand)

    2015-11-01

    3,4-dihydro-1,3-2H-benzoxazines as novel one-electron donators for silver(I) ion into nano-metallic silver was firstly found and reported. The silver formation from nano-spherical particles to coral-like and dendrite-like structures was presented. With respect to the characterization results, the feasible reaction mechanism of the silver formation was proposed as an electron donated from benzoxazine to silver(I) ion, resulting in a radical cationic species of benzoxazine and silver(0). Based on this reduction process, a new approach for nano-silver coating on various surfaces such as fumed silica (SiO{sub 2}), titanium dioxide (TiO{sub 2}), carbon black (CB), chitosan (CS) including plastic sheet (polycarbonate, PC) and pellet (polyvinyl alcohol, PVA), was also revealed. Besides the nano-silver coated products were applied as antimicrobials fillers for Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 9341, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 2785 and Candida albicans ATCC 10231. - Highlights: • Benzoxazines were discovered to be novel reducing agents for silver(I) ion. • The speculated mechanism of the one electron donation process was investigated. • Dendrite structure of silver was formed from spherical silver nanoparticles. • A new approach for nano metallic-silver coating on various surfaces was revealed. • The nano-silver coated products were applied as antimicrobials fillers.

  18. 3,4-Dihydro-1,3-2H-benzoxazines: Novel reducing agents through one electron donation mechanism and their application as the formation of nano-metallic silver coating

    International Nuclear Information System (INIS)

    Kaewvilai, Attaphon; Wattanathana, Worawat; Jongrungruangchok, Suchada; Veranitisagul, Chatchai; Koonsaeng, Nattamon; Laobuthee, Apirat

    2015-01-01

    3,4-dihydro-1,3-2H-benzoxazines as novel one-electron donators for silver(I) ion into nano-metallic silver was firstly found and reported. The silver formation from nano-spherical particles to coral-like and dendrite-like structures was presented. With respect to the characterization results, the feasible reaction mechanism of the silver formation was proposed as an electron donated from benzoxazine to silver(I) ion, resulting in a radical cationic species of benzoxazine and silver(0). Based on this reduction process, a new approach for nano-silver coating on various surfaces such as fumed silica (SiO_2), titanium dioxide (TiO_2), carbon black (CB), chitosan (CS) including plastic sheet (polycarbonate, PC) and pellet (polyvinyl alcohol, PVA), was also revealed. Besides the nano-silver coated products were applied as antimicrobials fillers for Staphylococcus aureus ATCC 25923, Bacillus subtilis ATCC 6633, Micrococcus luteus ATCC 9341, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 2785 and Candida albicans ATCC 10231. - Highlights: • Benzoxazines were discovered to be novel reducing agents for silver(I) ion. • The speculated mechanism of the one electron donation process was investigated. • Dendrite structure of silver was formed from spherical silver nanoparticles. • A new approach for nano metallic-silver coating on various surfaces was revealed. • The nano-silver coated products were applied as antimicrobials fillers.

  19. 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

  20. 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…

  1. Helping Your Child through Early Adolescence -- Helping Your Child Series

    Science.gov (United States)

    ... Bibliography Acknowledgements Tips to Help Your Child through Early Adolescence No Child Left Behind Printable ... Information About... Transforming Teaching Family and Community Engagement Early Learning Helping Your Child Our mission is to promote student achievement and ...

  2. Nanocompósitos de polietileno/argila bentonita nacional: influência da argila e do agente compatibilizante PE-g-MA nas propriedades mecânicas e de inflamabilidade Polyethylene/national bentonite clay nanocomposites: influence of clay and PE-g-MA coupling agent on the mechanical properties and flammability

    Directory of Open Access Journals (Sweden)

    Gustavo F. Brito

    2008-06-01

    Full Text Available Nanocompósitos de polietileno de alta densidade/argila bentonita nacional foram preparados por intercalação por fusão. A influência da adição da argila sem tratamento e da argila tratada com o sal quaternário de amônio Cetremide e do polietileno graftizado com anidrido maléico (PE-g-MA como agente compatibilizante foi avaliada. Os sistemas obtidos foram caracterizados por inflamabilidade, propriedades mecânicas e reológicas, difração de raios X e microscopia eletrônica de transmissão. Os resultados de difração de raios X e microscopia eletrônica de transmissão indicaram a obtenção de nanocompósitos com estruturas parcialmente esfoliadas e/ou intercaladas que conduziram ao aumento do módulo de elasticidade e do valor do torque. O teste de inflamabilidade mostrou que a adição da argila na matriz polimérica e a presença do PE-g-MA retardaram a velocidade de queima do sistema, ou seja, diminuíram a inflamabilidade do PE puro. Em geral, o sistema contendo o agente compatibilizante (PE-g-MA exibiu melhorias na estabilidade térmica e nanocompósitos parcialmente esfoliados foram formados, quando comparados à matriz de polietileno de alta densidade. O polietileno graftizado com anidrido maléico não apenas promoveu a esfoliação da argila, mas também facilitou a adesão carga-matriz, obtendo-se com isso melhorias nos resultados mecânicos do sistema.High density polyethylene/national bentonite clay nanocomposites were prepared with the melt intercalation technique. The effect of the clay without treatment and clay treated with quaternary ammonium salt Cetremide with polyethylene-graft-maleic anhydride as coupling agent was evaluated. The systems were characterized by flammability, mechanical and rheological properties, X ray diffraction and transmission electron microscopy. In general, the results of X ray diffraction and transmission electron microscopy showed partially exfoliated and/or intercalated structures with

  3. 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.

  4. 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...

  5. 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.

  6. 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

  7. 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

  8. Reasoning about emotional agents

    OpenAIRE

    Meyer, J.-J.

    2004-01-01

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

  9. 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.

  10. 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.

  11. New Vaccines Help Protect You

    Science.gov (United States)

    ... Bar Home Current Issue Past Issues New Vaccines Help Protect You Past Issues / Fall 2006 Table of ... with a few deaths. Therefore, this vaccine will help reduce one of our most common and potentially ...

  12. Help My House Program Profile

    Science.gov (United States)

    Learn about Help My House, a program that helps participants reduce their utility bills by nearly 35 percent through low-cost loans for EE improvements. Learn more about the key features, approaches, funding sources, and achievements of this program.

  13. 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

  14. 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...

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 'The money can be a motivator, to me a little, but mostly PBF just helps me to do better in my job.' An exploration of the motivational mechanisms of performance-based financing for health workers in Malawi.

    Science.gov (United States)

    Lohmann, Julia; Wilhelm, Danielle; Kambala, Christabel; Brenner, Stephan; Muula, Adamson S; De Allegri, Manuela

    2018-03-01

    Performance-based financing (PBF) is assumed to improve health care delivery by motivating health workers to enhance their work performance. However, the exact motivational mechanisms through which PBF is assumed to produce such changes are poorly understood to date. Although PBF is increasingly recognized as a complex health systems intervention, its motivational effect for individual health workers is still often reduced to financial 'carrots and sticks' in the literature and discourse. Aiming to contribute to the development of a more comprehensive understanding of the motivational mechanisms, we explored how PBF impacted health worker motivation in the context of the Malawian Results-based Financing for Maternal and Newborn Health (RBF4MNH) Initiative. We conducted in-depth interviews with 41 nurses, medical assistants and clinical officers from primary- and secondary-level health facilities 1 and 2 years after the introduction of RBF4MNH in 2013. Six categories of motivational mechanisms emerged: RBF4MNH motivated health workers to improve their performance (1) by acting as a periodic wake-up call to deficiencies in their day-to-day practice; (2) by providing direction and goals to work towards; (3) by strengthening perceived ability to perform successfully at work and triggering a sense of accomplishment; (4) by instilling feelings of recognition; (5) by altering social dynamics, improving team work towards a common goal, but also introducing social pressure; and (6) by offering a 'nice to have' opportunity to earn extra income. However, respondents also perceived weaknesses of the intervention design, implementation-related challenges and contextual constraints that kept RBF4MNH from developing its full motivating potential. Our results underline PBF's potential to affect health workers' motivation in ways which go far beyond the direct effects of financial rewards to individuals. We strongly recommend considering all motivational mechanisms more explicitly

  1. Effect of γ-aminopropyltriethoxy silane (γ-APS) coupling agent on mechanical and morphological properties of high density polyethylene (HDPE)/acrylonitrile butadiene rubber (NBR)/palm pressed fibre (PPF) composites

    Science.gov (United States)

    Norizan, Nabila Najwa; Santiagoo, Ragunathan; Ismail, Hanafi

    2017-07-01

    The fabrication of High Density Polyethylene (HDPE)/ Acrylonitrile-butadiene rubber (NBR)/ Palm Pressed Fibre (PPF) composite were investigated. The effect of γ-Aminopropyltriethoxy Silane (APS) as coupling agent on the properties of HDPE/ NBR/ PPF composite were studied. The composites were melt mixed using heated two roll mill at 180°C and speed of 15rpm with six different loading (100/0/10, 80/20/10, 70/30/10, 60/40/10, 50/50/10, and 40/60/10). The effects of γ-APS silane on mechanical, and morphological properties were examined using universal tensile machine (UTM) and scanning electron microscopy (SEM), respectively. Tensile strength and Young's modulus of HDPE/ NBR/ PPF composites decrease with increasing of NBR loading, whilst increasing the elongation at break. However, treated composites have resulted 3% to 29%, and 9% to 19%, higher in tensile strength and young's modulus compared to untreated composites. This was due to the better adhesion between HDPE/ NBR matrices and PPF filler with the presence of silanol moieties. From the morphological study, the micrograph of treated composites has proved the well bonded and good attachment of PPF filler with HDPE/ NBR matrices which resulted to better tensile strength to the HDPE/ NBR/ PPF composites.

  2. Effect drug loading process on dissolution mechanism of encapsulated amoxicillin trihydrate in hydrogel semi-IPN chitosan methyl cellulose with pore forming agent KHCO3 as a floating drug delivery system

    Science.gov (United States)

    Fithawati, Garnis; Budianto, Emil

    2018-04-01

    Common treatment for Helicobacter pylori by repeated oral consumption of amoxicillin trihydrate is not effective. Amoxicillin trihydrate has a very short residence time in stomach which leads into its ineffectiveness. Residence time of amoxicillin trihydrate can be improved by encapsulating amoxicillin trihydrate into a floating drug delivery system. In this study, amoxicillin trihydrate is encapsulated into hydrogel semi-IPN chitosan methyl cellulose matrix as a floating drug delivery system and then treated with 20% KHCO3 as pore forming agent. Drug loading process used are in-situ loading and post loading. In-situ loading process has higher efficiency percentage and dissolution percentage than post loading process. In-situ loading process resulted 100% efficiency with 92,70% dissolution percentage. Post loading process resulted 98,7% efficiency with 90,42% dissolution percentage. Mechanism of drug dissolution study by kinetics approach showed both in-situ loading process and post loading process are diffusion and degradation process (n=0,4913) and (n=0,4602) respectively. These results are supported by characterization data from optical microscope and scanning electron microscopy (SEM). Data from optical microscope showed both loading process resulted in coarser hydrogel surface. Characterization using SEM showed elongated pores in both loading process after dissolution test.

  3. Help!

    Science.gov (United States)

    Adams, Caralee

    2006-01-01

    This article presents ten time-saving ideas for teachers. One great time-saving tip is to come in an hour early once or twice a week for grading papers. It is also a great idea if teachers will not give tests on Friday in order to reduce their weekend work.

  4. 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.)

  5. 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. 

  6. Endure and call for help

    NARCIS (Netherlands)

    Lucas Gomes Marques Barbosa, Dani; Dicke, Marcel; Kranenburg, Twan; Aartsma, Yavanna; Beek, van Teris A.; Huigens, Martinus E.; Loon, van Joop J.A.

    2017-01-01

    Plants have evolved inducible resistance and tolerance mechanisms against insect herbivores. Resistance mechanisms that affect herbivorous insects directly can be effective against generalist herbivores, but will not deter specialist herbivores from attacking the plant. Tolerance mechanisms and

  7. Radiopharmaceutical scanning agents

    International Nuclear Information System (INIS)

    1976-01-01

    This invention is directed to dispersions useful in preparing radiopharmaceutical scanning agents, to technetium labelled dispersions, to methods for preparing such dispersions and to their use as scanning agents

  8. Taskable Reactive Agent Communities

    National Research Council Canada - National Science Library

    Myers, Karen

    2002-01-01

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

  9. Helping your teen with depression

    Science.gov (United States)

    Teen depression - helping; Teen depression - talk therapy; Teen depression - medicine ... teen the most. The most effective treatments for depression are: Talk therapy Antidepressant medicines If your teen ...

  10. 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.

  11. Users, Bystanders and Agents

    DEFF Research Database (Denmark)

    Krummheuer, Antonia Lina

    2015-01-01

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

  12. Asymptotically Optimal Agents

    OpenAIRE

    Lattimore, Tor; Hutter, Marcus

    2011-01-01

    Artificial general intelligence aims to create agents capable of learning to solve arbitrary interesting problems. We define two versions of asymptotic optimality and prove that no agent can satisfy the strong version while in some cases, depending on discounting, there does exist a non-computable weak asymptotically optimal agent.

  13. Reasoning about emotional agents

    NARCIS (Netherlands)

    Meyer, J.-J.

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

  14. 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.

  15. Using focal mechanism solutions to correlate earthquakes with faults in the Lake Tahoe-Truckee area, California and Nevada, and to help design LiDAR surveys for active-fault reconnaissance

    Science.gov (United States)

    Cronin, V. S.; Lindsay, R. D.

    2011-12-01

    Geomorphic analysis of hillshade images produced from aerial LiDAR data has been successful in identifying youthful fault traces. For example, the recently discovered Polaris fault just northwest of Lake Tahoe, California/Nevada, was recognized using LiDAR data that had been acquired by local government to assist land-use planning. Subsequent trenching by consultants under contract to the US Army Corps of Engineers has demonstrated Holocene displacement. The Polaris fault is inferred to be capable of generating a magnitude 6.4-6.9 earthquake, based on its apparent length and offset characteristics (Hunter and others, 2011, BSSA 101[3], 1162-1181). Dingler and others (2009, GSA Bull 121[7/8], 1089-1107) describe paleoseismic or geomorphic evidence for late Neogene displacement along other faults in the area, including the West Tahoe-Dollar Point, Stateline-North Tahoe, and Incline Village faults. We have used the seismo-lineament analysis method (SLAM; Cronin and others, 2008, Env Eng Geol 14[3], 199-219) to establish a tentative spatial correlation between each of the previously mentioned faults, as well as with segments of the Dog Valley fault system, and one or more earthquake(s). The ~18 earthquakes we have tentatively correlated with faults in the Tahoe-Truckee area occurred between 1966 and 2008, with magnitudes between 3 and ~6. Given the focal mechanism solution for a well-located shallow-focus earthquake, the nodal planes can be projected to Earth's surface as represented by a DEM, plus-or-minus the vertical and horizontal uncertainty in the focal location, to yield two seismo-lineament swaths. The trace of the fault that generated the earthquake is likely to be found within one of the two swaths [1] if the fault surface is emergent, and [2] if the fault surface is approximately planar in the vicinity of the focus. Seismo-lineaments from several of the earthquakes studied overlap in a manner that suggests they are associated with the same fault. The surface

  16. Helping Teens Resist Sexual Pressure

    Science.gov (United States)

    ... Listen Español Text Size Email Print Share Helping Teens Resist Sexual Pressure Page Content Article Body Teens are more ... younger the first time they had intercourse. Helping Teens Resist Sexual Pressure “The pressure on teenagers to have sex ...

  17. Radiographic scanning agent

    International Nuclear Information System (INIS)

    Bevan, J.A.

    1983-01-01

    This invention relates to radiodiagnostic agents and more particularly to a composition and method for preparing a highly effective technetium-99m-based bone scanning agent. One deficiency of x-ray examination is the inability of that technique to detect skeletal metastases in their incipient stages. It has been discovered that the methanehydroxydiphosphonate bone mineral-seeking agent is unique in that it provides the dual benefits of sharp radiographic imaging and excellent lesion detection when used with technetium-99m. This agent can also be used with technetium-99m for detecting soft tissue calcification in the manner of the inorganic phosphate radiodiagnostic agents

  18. Agente adaptable y aprendizaje

    Directory of Open Access Journals (Sweden)

    Arturo Angel Lara Rivero

    2013-05-01

    Full Text Available En este trabajo se contrasta el concepto de agente programado con el de agente complejo adaptable, se presenta una nueva visión ligada al aprendizaje y la estructura del agente. La imagen del agente se analiza considerando los modelos internos, la práctica, el concepto de rutina y la influencia en su comportamiento, y la importancia del aprendizaje ex ante y ex post. Por último se muestra que la resolución de problemas está sujeta a restricciones del agente y se describen las formas de explorar el espacio de soluciones mediante tres tipos de exploración: exhaustiva, aleatoria y selectiva.

  19. Multi agent gathering waste system

    Directory of Open Access Journals (Sweden)

    Álvaro LOZANO MURCIEGO

    2016-07-01

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

  20. Mechanical science

    CERN Document Server

    Bolton, W C

    2013-01-01

    This book gives comprehensive coverage of mechanical science for HNC/HND students taking mechanical engineering courses, including all topics likely to be covered in both years of such courses, as well as for first year undergraduate courses in mechanical engineering. It features 500 problems with answers and 200 worked examples. The third edition includes a new section on power transmission and an appendix on mathematics to help students with the basic notation of calculus and solution of differential equations.

  1. Managing Data in Help4Mood

    Directory of Open Access Journals (Sweden)

    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.

  2. 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…

  3. 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.

  4. 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.

  5. 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…

  6. Going Local to Find Help

    Science.gov (United States)

    ... Cover Story: Traumatic Brain Injury Going Local to Find Help Past Issues / Fall 2008 Table of Contents ... phone numbers, maps and directions, such as To Find Out More: Visit www.ninds.nih.gov/Disorders/ ...

  7. Menopause: Medicines to Help You

    Science.gov (United States)

    ... For Consumers Consumer Information by Audience For Women Menopause--Medicines to Help You Share Tweet Linkedin Pin ... Email Print Print and Share (PDF 375 KB) Menopause (sometimes called “the change of life”) is a ...

  8. 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.

  9. Agent Architectures for Compliance

    Science.gov (United States)

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

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

  10. 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

  11. Stabilized radiographic scanning agents

    International Nuclear Information System (INIS)

    Fawzi, M.B.

    1982-01-01

    Stable compositions useful as technetium 99m-based scintigraphic agents comprise gentisic acid or a pharmaceutically-acceptable salt or ester thereof in combination with a pertechnetate reducing agent or dissolved in pertechnetate-99m (sup(99m)TcOsub(4)sup(-)) solution. The compositions are especially useful in combination with a phosphate or phosphonate material that carries the radionuclide to bone, thus providing a skeletal imaging agent

  12. 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...

  13. 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.

  14. Contrast agents for MRI

    International Nuclear Information System (INIS)

    Bonnemain, B.

    1994-01-01

    Contrast agents MRI (Magnetic Resonance Imaging) have been developed to improve the diagnostic information obtained by this technic. They mainly interact on T1 and T2 parameters and increase consequently normal to abnormal tissues contrast. The paramagnetic agents which mainly act on longitudinal relaxation rate (T1) are gadolinium complexes for which stability is the main parameter to avoid any release of free gadolinium. The superparamagnetic agents that decrease signal intensity by an effect on transversal relaxation rate (T2) are developed for liver, digestive and lymph node imaging. Many area of research are now opened for optimal use of present and future contrast agents in MRI. (author). 28 refs., 4 tabs

  15. Decontamination Data - Blister Agents

    Data.gov (United States)

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

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

    African Journals Online (AJOL)

    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.

  17. 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...

  18. 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.

  19. Helping Teachers Help Themselves: Professional Development That Makes a Difference

    Science.gov (United States)

    Patton, Kevin; Parker, Melissa; Tannehill, Deborah

    2015-01-01

    For school administrators to facilitate impactful teacher professional development, a shift in thinking that goes beyond the acquisition of new skills and knowledge to helping teachers rethink their practice is required. Based on review of the professional development literature and our own continued observations of professional development, this…

  20. 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.

  1. 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....

  2. 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.

  3. 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…

  4. 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...

  5. 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

  6. 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

  7. 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.

  8. 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

  9. Change Agent Survival Guide

    Science.gov (United States)

    Dunbar, Folwell L.

    2011-01-01

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

  10. Teaching Tourism Change Agents

    DEFF Research Database (Denmark)

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

    2017-01-01

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

  11. Travel Agent Course Outline.

    Science.gov (United States)

    British Columbia Dept. of Education, Victoria.

    Written for college entry-level travel agent training courses, this course outline can also be used for inservice training programs offered by travel agencies. The outline provides information on the work of a travel agent and gives clear statements on what learners must be able to do by the end of their training. Material is divided into eight…

  12. Radiographic scintiscanning agent

    International Nuclear Information System (INIS)

    Bevan, J.A.

    1979-01-01

    A new technetium-based scintiscanning agent has been prepared comprising a water soluble sup(99m)Tc-methanehydroxydiphosphonate in combination with a reducing agent selected from stannous, ferrous, chromous and titanous salts. As an additional stabilizer salts and esters of gentisic or ascorbic acids have been used. (E.G.)

  13. Radiographic scanning agent

    International Nuclear Information System (INIS)

    Tofe, A.J.

    1976-01-01

    A stable radiographic scanning agent on a sup(99m)Tc basis has been developed. The substance contains a pertechnetate reduction agent, tin(II)-chloride, chromium(II)-chloride, or iron(II)-sulphate, as well as an organospecific carrier and ascorbic acid or a pharmacologically admissible salt or ester of ascorbic acid. (VJ) [de

  14. Stable radiographic scanning agents

    International Nuclear Information System (INIS)

    1976-01-01

    Stable compositions which are useful in the preparation of Technetium-99m-based scintigraphic agents are discussed. They are comprised of ascorbic acid or a pharmaceutically acceptable salt or ester thereof in combination with a pertechnetate reducing agent or dissolved in oxidized pertechnetate-99m (sup(99m)TcO 4 - ) solution

  15. Hyperthermia and chemotherapy agent

    International Nuclear Information System (INIS)

    Roizin-Towle, L.; Hall, E.J.

    1981-01-01

    The use of chemotherapeutic agents for the treatment of cancer dates back to the late 19th century, but the modern era of chemotherapy drugs was ushered in during the 1940's with the development of the polyfunctional alkylating agent. Since then, numerous classes of drugs have evolved and the combined use of antineoplastic agents with other treatment modalities such as radiation or heat, remains a large relatively unexplored area. This approach, combining local hyperthermia with chemotherapy agents affords a measure of targeting and selective toxicity not previously available for drugs. In this paper, the effects of adriamycin, bleomycin and cis-platinum are examined. The adjuvant use of heat may also reverse the resistance of hypoxic cells noted for some chemotherapy agents

  16. 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.

  17. Grief: Helping Young Children Cope

    Science.gov (United States)

    Wood, Frances B.

    2008-01-01

    In their role as caregivers supporting the children they teach, it is important for teachers to understand the grieving process and recognize symptoms of grief. The author explains Elisabeth Kubler-Ross's five stages of grief and offers 10 classroom strategies to help young children cope with their feelings.

  18. Unpaid help: who does what?

    NARCIS (Netherlands)

    Mirjam de Klerk; Alice de Boer; Sjoerd Kooiker; Peggy Schyns

    2015-01-01

    Original title: Informele hulp: wie doet er wat? There is currently a great deal of interest in the Netherlands in people’s reliance on their own networks in times of need. What can people do for each other when someone needs help because of health problems? And what are they already

  19. Helping fans to get fit.

    Science.gov (United States)

    Trueland, Jennifer

    A health and weight loss programme supported by nurses and delivered by professional football clubs in Scotland has been hailed a success in helping men to lose weight sustainably. It uses participants love of football to motivate them to make healthy lifestyle changes.

  20. HELP: Healthy Early Literacy Program

    Science.gov (United States)

    Rader, Laura A.

    2008-01-01

    A daily intensive supplemental reading and writing program was developed to assist students who were: 1. identified with a language disability and 2. identified as at-risk for reading failure in an urban elementary school. The purpose of the program was to help these students understand and develop the connection between oral and written language…

  1. Osteoporosis Treatment: Medications Can Help

    Science.gov (United States)

    ... help Osteoporosis treatment may involve medication along with lifestyle change. Get answers to some of the most common ... 2017. Khan M, et al. Drug-related adverse events of osteoporosis therapy. ... and management of osteoporosis. European Journal of Rheumatology. 2017;4: ...

  2. Motivational Maturity and Helping Behavior

    Science.gov (United States)

    Haymes, Michael; Green, Logan

    1977-01-01

    Maturity in conative development (type of motivation included in Maslow's needs hierarchy) was found to be predictive of helping behavior in middle class white male college students. The effects of safety and esteem needs were compared, and the acceptance of responsibility was also investigated. (GDC)

  3. Exercises to help prevent falls

    Science.gov (United States)

    ... help prevent falls because it can: Make your muscles stronger and more flexible Improve your balance Increase how ... To make your calves and ankle muscles stronger: Hold on to a solid ... of a chair. Stand with your back straight and slightly bend ...

  4. 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.

  5. 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.

  6. 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...

  7. Biological warfare agents

    Directory of Open Access Journals (Sweden)

    Duraipandian Thavaselvam

    2010-01-01

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

  8. Biological warfare agents

    Science.gov (United States)

    Thavaselvam, Duraipandian; Vijayaraghavan, Rajagopalan

    2010-01-01

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

  9. 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.

  10. 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...

  11. Fluid mechanics

    International Nuclear Information System (INIS)

    Granger, R.A.

    1985-01-01

    This text offers the most comprehensive approach available to fluid mechanics. The author takes great care to insure a physical understanding of concepts grounded in applied mathematics. The presentation of theory is followed by engineering applications, helping students develop problem-solving skills from the perspective of a professional engineer. Extensive use of detailed examples reinforces the understanding of theoretical concepts

  12. Culturally Aware Agent Communication

    DEFF Research Database (Denmark)

    Rehm, Matthias; Nakano, Yukiko; Koda, Tomoko

    2012-01-01

    Agent based interaction in the form of Embodied Conversational Agents (ECAs) has matured over the last decade and agents have become more and more sophisticated in terms of their verbal and nonverbal behavior like facial expressions or gestures. Having such “natural” communication channels...... available for expressing not only task-relevant but also socially and psychologically relevant information makes it necessary to take influences into account that are not readily implemented like emotions or cultural heuristics. These influences have a huge impact on the success of an interaction...

  13. Agent-Based Optimization

    CERN Document Server

    Jędrzejowicz, Piotr; Kacprzyk, Janusz

    2013-01-01

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

  14. 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.

  15. Motivational maturity and helping behavior.

    Science.gov (United States)

    Haymes, M; Green, L

    1977-12-01

    This study was undertaken to examine the independent influences of conative development (the Maslow needs hierarchy) upon behavioral aspects of prosocial orientations. It provides a behavioral demonstration of conative effects in a helping paradigm, among college-age men. A comparison of the conative data across the ages of 15-22 provided a cross-sectional view of conative development itself. Conative maturity was found to be predictive of greater helping among college-age men. Situational demands were demonstrated which tended to mask, but not override, these predispositional influences on helping. The cross-sectional data on conative development point to probable movement to early esteem concerns among high school men who have reached the conative level of love and belonging. On the other hand, the stability across the years of 15-22 of proportion of safety concerns suggests fixation of such concerns in those exhibiting them in high school. Results are discussed in terms of conative growth for development of prosocial orientations.

  16. 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...

  17. 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.

  18. Delta agent (Hepatitis D)

    Science.gov (United States)

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

  19. 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...

  20. Agents Within our Midst

    Science.gov (United States)

    2012-03-14

    agents; and the development of bio -monitoring protocols for civilian and service personnel during a chemical attack. These efforts have resulted in greater...produced by staphylococcal bacteria that is and is classified as a CDC select agent which has the potential to be used as a biological weapon .1...NMR chemical shift perturbation titrations with Fab (fragment, antigen binding regions) domains of 20B1, 14G8, and 6D3 using deuterated (2H) SEB

  1. Adrenal imaging agents

    International Nuclear Information System (INIS)

    Davis, M.A.; Hanson, R.N.; Holman, B.L.

    1980-01-01

    The goals of this proposal are the development of selenium-containing analogs of the aromatic amino acids as imaging agents for the pancreas and of the adrenal cortex enzyme inhibitors as imaging agents for adrenal pathology. The objects for this year include (a) the synthesis of methylseleno derivatives of phenylalanine and tryptophan, and (b) the preparation and evaluation of radiolabeled iodobenzoyl derivatives of the selenazole and thiazole analogs of metyrapone and SU-9055

  2. 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

  3. 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...

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. Ação de diferentes agentes curtentes utilizados no curtimento de peles de coelhos: testes físico-mecânicos dos couros - DOI: 10.4025/actascianimsci.v31i4.5592 Action of different tanning agents used on rabbit hide tanning: physical-mechanic tests - DOI: 10.4025/actascianimsci.v31i4.5592

    Directory of Open Access Journals (Sweden)

    Nilson do Prado Franco

    2009-10-01

    Full Text Available O objetivo do experimento foi avaliar a ação de diferentes agentes curtentes no processamento das peles de coelhos, sobre a resistência do couro. Cinquenta peles de coelhos foram submetidas a diferentes agentes curtentes na etapa de curtimento (T1 = 6% sais de cromo Chromossal B®, T2 = 22% tanino vegetal Clarotan-x8®; T3 = 22% tanino sintético Syntac CW®; T4 = 12% tanino vegetal Weibull® + 10% tanino sintético Syntac F®; T5 = 22% tanino vegetal Weibull®. Foram retirados os corpos de prova do couro, na região dorsal, no sentido longitudinal e transversal em relação ao eixo céfalo-caudal. Os agentes curtentes e retirada dos corpos de prova não influenciaram no teste de tração (9,28 a 11,63 N mm-2 e força aplicada (17,91 N a 24,85 N nos testes. Os curtimentos com sais de cromo (62,85% e Clarotan–x8® (70,28% proporcionaram maiores valores de alongamento em relação aos demais agentes curtentes utilizados. Os corpos de prova do couro no sentido transversal (59,12% apresentaram maior alongamento comparado ao longitudinal (49,72%. Os curtimentos com sais de cromo (22,70 N mm-1, Clarotan–x8® (25,94 N mm-1 e Weibull® (21,58 N mm-1 proporcionaram couros com maior resistência ao rasgamento. O sentido de retirada dos corpos de prova no couro não influenciou no rasgamento progressivo. As técnicas de curtimento com sais de cromo e Clarotan-x8® proporcionaram couros com melhores valores de resistência ao alongamento e rasgamento progressivo.The objective of the experiment was to evaluate the action of different tanning agents in the processing of rabbit hides over skin resistance. Fifty skins of rabbit hides were submitted to different tanning agents in the tanning stage (T1 = 6% Chromossal B® chrome salts; T2 = 22% Clarotan–x8® vegetable tannin; T3 = 22% Syntac CW® synthetic tannin; T4 = 12% Weibull® vegetable tannin + 10% Syntac F® synthetic tannin; T5 = 22% Weibull® vegetable tannin. The specimens were removed from

  9. Perceptions of Help Given to Healthy Older Mothers by Adult Daughters: Ways of Initiating Help and Types of Help Given

    Science.gov (United States)

    Martini, Tanya S.; Grusec, Joan E.; Bernardini, Silvia Cortese

    2003-01-01

    Older mother-adult daughter dyads (N = 43) addressed two issues pertaining to the ways in which help is initiated (offered, requested, and imposed help) and type of help given (instrumental help, advice, and emotional support) a) mothers' reasoning about these aspects of help, and b) daughters' understanding of mothers' feelings. Both groups noted…

  10. How to help teachers' voices.

    Science.gov (United States)

    Saatweber, Margarete

    2008-01-01

    It has been shown that teachers are at high risk of developing occupational dysphonia, and it has been widely accepted that the vocal characteristics of a speaker play an important role in determining the reactions of listeners. The functions of breathing, breathing movement, breathing tonus, voice vibrations and articulation tonus are transmitted to the listener. So we may conclude that listening to the teacher's voice at school influences children's behavior and the perception of spoken language. This paper presents the concept of Schlaffhorst-Andersen including exercises to help teachers improve their voice, breathing, movement and their posture. Copyright 2008 S. Karger AG, Basel.

  11. 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.

  12. 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

  13. 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...

  14. 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.

  15. Monitoring volatile anaesthetic agents

    International Nuclear Information System (INIS)

    Russell, W.J.

    2000-01-01

    Full text: The methods that have been used for monitoring volatile anaesthetic agents depend on some physical property such as Density, Refractometry, Mass, Solubility, Raman scattering, or Infra-red absorption. Today, refractometry and infra-red techniques are the most common. Refractometry is used for the calibration of vaporizers. All anaesthetic agents increase the refractive index of the carrier gas. Provided the mixture is known then the refractive change measures the concentration of the volatile anaesthetic agent. Raman Scattering is when energy hits a molecule a very small fraction of the energy is absorbed and re-emitted at one or more lower frequencies. The shift in frequency is a function of the chemical bonds and is a fingerprint of the substance irradiated. Electromagnetic (Infra-red) has been the commonest method of detection of volatile agents. Most systems use a subtractive system, i.e. the agent in the sampling cell absorbed some of the infrared energy and the photo-detector therefore received less energy. A different approach is where the absorbed energy is converted into a pressure change and detected as sound (Acoustic monitor). This gives a more stable zero reference. More recently, the detector systems have used multiple narrow-band wavelengths in the infrared bands and by shape matching or matrix computing specific agent identification is achieved and the concentration calculated. In the early Datex AS3 monitors, a spectral sweep across the 3 micron infrared band was used to create spectral fingerprints. The recently released AS3 monitors use a different system with five very narrow band filters in the 8-10 micron region. The transmission through each of these filters is a value in a matrix which is solved by a micro computer to identify the agent and its concentration. These monitors can assist in improving the safety and efficiency of our anaesthetics but do not ensure that the patient is completely anaesthetized. Copyright (2000

  16. Monitoring volatile anaesthetic agents

    Energy Technology Data Exchange (ETDEWEB)

    Russell, W J [Royal Adelaide Hospital, SA (Australia). Department of Anaesthesia and Intensive Care

    2000-12-01

    Full text: The methods that have been used for monitoring volatile anaesthetic agents depend on some physical property such as Density, Refractometry, Mass, Solubility, Raman scattering, or Infra-red absorption. Today, refractometry and infra-red techniques are the most common. Refractometry is used for the calibration of vaporizers. All anaesthetic agents increase the refractive index of the carrier gas. Provided the mixture is known then the refractive change measures the concentration of the volatile anaesthetic agent. Raman Scattering is when energy hits a molecule a very small fraction of the energy is absorbed and re-emitted at one or more lower frequencies. The shift in frequency is a function of the chemical bonds and is a fingerprint of the substance irradiated. Electromagnetic (Infra-red) has been the commonest method of detection of volatile agents. Most systems use a subtractive system, i.e. the agent in the sampling cell absorbed some of the infrared energy and the photo-detector therefore received less energy. A different approach is where the absorbed energy is converted into a pressure change and detected as sound (Acoustic monitor). This gives a more stable zero reference. More recently, the detector systems have used multiple narrow-band wavelengths in the infrared bands and by shape matching or matrix computing specific agent identification is achieved and the concentration calculated. In the early Datex AS3 monitors, a spectral sweep across the 3 micron infrared band was used to create spectral fingerprints. The recently released AS3 monitors use a different system with five very narrow band filters in the 8-10 micron region. The transmission through each of these filters is a value in a matrix which is solved by a micro computer to identify the agent and its concentration. These monitors can assist in improving the safety and efficiency of our anaesthetics but do not ensure that the patient is completely anaesthetized. Copyright (2000

  17. College mechanics

    CERN Document Server

    Şengül, Caner

    2016-01-01

    College Mechanics QueBank has been designed to be different, enthusiastic, interesting and helpful to you. Therefore, it is not just a test bank about mechanics but also it is like a compass in order to find your way in mechanics Each chapter in this book is put in an order to follow a hierarchy of the mechanics topics; from vectors to simple harmonic motion. Throughout the book there are many multiple choice and long answer questions for you to solve. They have been created for YGS, LYS, SAT, IB or other standardized exams in the world because mechanics has no boundaries and so Physics has no country. Learn the main principle of each chapter and explore the daily life applications. Then you can start to solve the questions by planning a problem solving method carefully. Finally, enjoy solving the questions and discover the meachanics of the universe once more.

  18. 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.

  19. Agent independent task planning

    Science.gov (United States)

    Davis, William S.

    1990-01-01

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

  20. Do Dogs Provide Information Helpfully?

    Directory of Open Access Journals (Sweden)

    Patrizia Piotti

    Full Text Available Dogs are particularly skilful during communicative interactions with humans. Dogs' abilities to use human communicative cues in cooperative contexts outcompete those of other species, and might be the result of selection pressures during domestication. Dogs also produce signals to direct the attention of humans towards outside entities, a behaviour often referred to as showing behaviour. This showing behaviour in dogs is thought to be something dogs use intentionally and referentially. However, there is currently no evidence that dogs communicate helpfully, i.e. to inform an ignorant human about a target that is of interest to the human but not to the dog. Communicating with a helpful motive is particularly interesting because it might suggest that dogs understand the human's goals and need for information. In study 1, we assessed whether dogs would abandon an object that they find interesting in favour of an object useful for their human partner, a random novel distractor, or an empty container. Results showed that it was mainly self-interest that was driving the dogs' behaviour. The dogs mainly directed their behaviour towards the object they had an interest in, but dogs were more persistent when showing the object relevant to the human, suggesting that to some extent they took the humans interest into account. Another possibility is that dogs' behaviour was driven by an egocentric motivation to interact with novel targets and that the dogs' neophila might have masked their helpful tendencies. Therefore, in study 2 the dogs had initial access to both objects, and were expected to indicate only one (relevant or distractor. The human partner interacted with the dog using vocal communication in half of the trials, and remaining silent in the other half. Dogs from both experimental groups, i.e. indicating the relevant object or indicating the distractor, established joint attention with the human. However, the human's vocal communication and the

  1. Do Dogs Provide Information Helpfully?

    Science.gov (United States)

    Piotti, Patrizia; Kaminski, Juliane

    2016-01-01

    Dogs are particularly skilful during communicative interactions with humans. Dogs' abilities to use human communicative cues in cooperative contexts outcompete those of other species, and might be the result of selection pressures during domestication. Dogs also produce signals to direct the attention of humans towards outside entities, a behaviour often referred to as showing behaviour. This showing behaviour in dogs is thought to be something dogs use intentionally and referentially. However, there is currently no evidence that dogs communicate helpfully, i.e. to inform an ignorant human about a target that is of interest to the human but not to the dog. Communicating with a helpful motive is particularly interesting because it might suggest that dogs understand the human's goals and need for information. In study 1, we assessed whether dogs would abandon an object that they find interesting in favour of an object useful for their human partner, a random novel distractor, or an empty container. Results showed that it was mainly self-interest that was driving the dogs' behaviour. The dogs mainly directed their behaviour towards the object they had an interest in, but dogs were more persistent when showing the object relevant to the human, suggesting that to some extent they took the humans interest into account. Another possibility is that dogs' behaviour was driven by an egocentric motivation to interact with novel targets and that the dogs' neophila might have masked their helpful tendencies. Therefore, in study 2 the dogs had initial access to both objects, and were expected to indicate only one (relevant or distractor). The human partner interacted with the dog using vocal communication in half of the trials, and remaining silent in the other half. Dogs from both experimental groups, i.e. indicating the relevant object or indicating the distractor, established joint attention with the human. However, the human's vocal communication and the presence of the

  2. Do Dogs Provide Information Helpfully?

    Science.gov (United States)

    Piotti, Patrizia; Kaminski, Juliane

    2016-01-01

    Dogs are particularly skilful during communicative interactions with humans. Dogs’ abilities to use human communicative cues in cooperative contexts outcompete those of other species, and might be the result of selection pressures during domestication. Dogs also produce signals to direct the attention of humans towards outside entities, a behaviour often referred to as showing behaviour. This showing behaviour in dogs is thought to be something dogs use intentionally and referentially. However, there is currently no evidence that dogs communicate helpfully, i.e. to inform an ignorant human about a target that is of interest to the human but not to the dog. Communicating with a helpful motive is particularly interesting because it might suggest that dogs understand the human’s goals and need for information. In study 1, we assessed whether dogs would abandon an object that they find interesting in favour of an object useful for their human partner, a random novel distractor, or an empty container. Results showed that it was mainly self-interest that was driving the dogs’ behaviour. The dogs mainly directed their behaviour towards the object they had an interest in, but dogs were more persistent when showing the object relevant to the human, suggesting that to some extent they took the humans interest into account. Another possibility is that dogs’ behaviour was driven by an egocentric motivation to interact with novel targets and that the dogs’ neophila might have masked their helpful tendencies. Therefore, in study 2 the dogs had initial access to both objects, and were expected to indicate only one (relevant or distractor). The human partner interacted with the dog using vocal communication in half of the trials, and remaining silent in the other half. Dogs from both experimental groups, i.e. indicating the relevant object or indicating the distractor, established joint attention with the human. However, the human’s vocal communication and the presence

  3. Neuropathic pain: is quantitative sensory testing helpful?

    Science.gov (United States)

    Krumova, Elena K; Geber, Christian; Westermann, Andrea; Maier, Christoph

    2012-08-01

    Neuropathic pain arises as a consequence of a lesion or disease affecting the somatosensory system and is characterised by a combination of positive and negative sensory symptoms. Quantitative sensory testing (QST) examines the sensory perception after application of different mechanical and thermal stimuli of controlled intensity and the function of both large (A-beta) and small (A-delta and C) nerve fibres, including the corresponding central pathways. QST can be used to determine detection, pain thresholds and stimulus-response curves and can thus detect both negative and positive sensory signs, the second ones not being assessed by other methods. Similarly to all other psychophysical tests QST requires standardised examination, instructions and data evaluation to receive valid and reliable results. Since normative data are available, QST can contribute also to the individual diagnosis of neuropathy, especially in the case of isolated small-fibre neuropathy, in contrast to the conventional electrophysiology which assesses only large myelinated fibres. For example, detection of early stages of subclinical neuropathy in symptomatic or asymptomatic patients with diabetes mellitus can be helpful to optimise treatment and identify diabetic foot at risk of ulceration. QST assessed the individual's sensory profile and thus can be valuable to evaluate the underlying pain mechanisms which occur in different frequencies even in the same neuropathic pain syndromes. Furthermore, assessing the exact sensory phenotype by QST might be useful in the future to identify responders to certain treatments in accordance to the underlying pain mechanisms.

  4. 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.

  5. REACHING THE COMPUTING HELP DESK

    CERN Multimedia

    Miguel MARQUINA; Roger WOOLNOUGH; IT/User Support

    1999-01-01

    The way to contact the Computing Help Desk (also known as 'UCO' and hosted by IT Division as an entry point for general computing issues) has been streamlined in order to facilitate access to it. A new telephone line and email address have been set: Phone number: 78888Email: Helpdesk@cern.chhopefully easier to remember. Both entries are operational since last December. The previous number and email address remain valid and have been turned into aliases of the above. However we encourage using the latter at your convenience from now on. For additional information please see the article published at the CERN Computing Newsletter 233:http://consult.cern.ch/cnl/233/art_uco.htmlDo not hesitate to contact us (by email to User.Relations@cern.ch) for additional information or feedback regarding this matter.Nicole Cremel, Miguel Marquina, Roger WoolnoughIT/UserSupport

  6. REACHING THE COMPUTING HELP DESK

    CERN Multimedia

    Miguel Marquina

    2000-01-01

    You may find it useful to glue the information below, e.g. near/at your computer, for those occasions when access to computer services is not possible. It presents the way to contact the Computing Help Desk (hosted by IT Division as an entry point for general computing issues). Do not hesitate to contact us (by email to User.Relations@cern.ch) for additional information or feedback regarding this matter.Your contact for general computing problems or queriesPhone number:(+41 22 76) 78888Opening Hours:From Monday to Friday 8:30-17:30Email:Helpdesk@cern.chWeb:http://consult.cern.ch/service/helpdeskMiguel MarquinaIT Division/UserSupport

  7. Plutonium helps probe protein, superconductor

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Scientists are finding that plutonium can be a useful research tool that may help them answer important questions in fields as diverse as biochemistry and solid-state physics. This paper reports that U.S. research involving plutonium is confined to the Department of Energy's national laboratories and centers around nuclear weapons technology, waste cleanup and disposal, and health effects. But at Los Alamos National Laboratory, scientists also are using plutonium to probe the biochemical behavior of calmodulin, a key calcium-binding protein that mediates calcium-regulated processes in biological systems. At Argonne National Laboratory, another team is trying to learn how a superconductor's properties are affected by the 5f electrons of an actinide like plutonium

  8. [Supramolecular Agents for Theranostics].

    Science.gov (United States)

    Deyev, S M; Lebedenko, E N

    2015-01-01

    This mini-review summarizes recent data obtained in the process of creation of a versatile module platform suitable for construction of supramolecular theranostic agents. As an example, we consider multifunctional hybrid agents for imaging and elimination of cancer cells. The use of an adapter protein system barnase:barstar for producing targeted multifunctional hybrid structures on the basis of highly specific peptides and mini-antibodies as addressing modules and recombinant proteins and/or nanoparticles of different nature (quantum dots, nanogold, magnetic nanoparticles, nanodiamonds, upconverting nanophosphores, polymer nanoparticles) as agents visualizing and damaging cancer cells is described. New perspectives for creation of selective and highly effective compounds for theranostics and personified medicine are contemplated.

  9. Teaching tourism change agents

    DEFF Research Database (Denmark)

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

    2017-01-01

    This article discuss es know ledge, competencies and skills Master’s students should obtain during their academic studies and particularly, the differences between teaching about a topic and teaching to do. This is ex emplified by experiential learning theory and the case of a change management...... course that is part of a Tourism Master’s program, where a major challenge is not only to teach students about change and change agents, but to teach them how change feels and ho w to become change agents. The c hange management course contains an experiment inspired by experiential teaching literature...... and methods. The experiment seeks to make students not only hear/learn about change agency and management, but to make them feel cha nge, hereby enabling them to develop the skills and competencies necessary for them to take on the role as change agent s and thus enable them to play key role s in implementing...

  10. 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

  11. 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

  12. Agents unleashed a public domain look at agent technology

    CERN Document Server

    Wayner, Peter

    1995-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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.

  15. Intervention: Help a Loved One Overcome Addiction

    Science.gov (United States)

    Intervention: Help a loved one overcome addiction An intervention can motivate someone to seek help for alcohol or drug misuse, compulsive eating, or ... successful. By Mayo Clinic Staff It's challenging to help a loved one struggling with any type of ...

  16. 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

  17. 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.

  18. 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)

  19. Unibot, a Universal Agent Architecture for Robots

    Directory of Open Access Journals (Sweden)

    Saša Mladenović

    2017-01-01

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

  20. 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.

  1. Leaching mechanisms

    International Nuclear Information System (INIS)

    Dougherty, D.R.; Colombo, P.

    1984-01-01

    Sufficient data are lacking to provide a basis for adequately assessing the long term leaching behavior of solidified low level radioactive waste forms in their disposal environment. Although the release of radioactivity from a waste form to an aqueous environment is recognized to be due to one or more mechanisms such as diffusion, dissolution, corrosion or ion exchange, the leaching mechanisms and the factors which control the leaching behavior of waste forms are not fully understood. This study will determine the prevailing mechanisms for a variety of selected LLW solidification agents which are being considered for use by defense and commercial generators and which will cover the broadest possible number of mechanisms. The investigation will proceed by the postulation of mathematical models representative of the prevailing mechanism(s) and the use of statistically designed experiments to test the actual leaching behavior of laborattory samples against the postulated representations. Maximum use of existing leach data in the literature will be made by incorporating literature results into a computerized data base along with the experimental results generated in this task

  2. 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.

  3. SECOND BUYING AGENT

    CERN Multimedia

    SPL - SERVICES ACHATS

    2000-01-01

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

  4. Socially Intelligent Tutor Agents

    NARCIS (Netherlands)

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

    2003-01-01

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

  5. Alternative inerting agents

    CSIR Research Space (South Africa)

    Du

    1997-08-01

    Full Text Available Final Project Report ALTERNATIVE INERTING AGENTS Author/s: J J L DU PLESSIS Research Agency: OSIR MINING TECHNOLOGY Project No: Date: 3 2 7 2 COL 443 APRIL 1999 N’ ) ( G~6~ I Title: 9 / The results show...

  6. Multimodal training between agents

    DEFF Research Database (Denmark)

    Rehm, Matthias

    2003-01-01

    In the system Locator1, agents are treated as individual and autonomous subjects that are able to adapt to heterogenous user groups. Applying multimodal information from their surroundings (visual and linguistic), they acquire the necessary concepts for a successful interaction. This approach has...

  7. Stabilized radiographic scanning agent

    International Nuclear Information System (INIS)

    Fawzi, M.B.

    1979-01-01

    A stable composition useful in preparation of technetium-99m-based radiographic scanning agents has been developed. The composition contains a stabilizing amount of gentisate stabilizer selected from gentisic acid and its soluble pharmaceutically-acceptable salts and esthers. (E.G.)

  8. A waterproofing agent

    Energy Technology Data Exchange (ETDEWEB)

    Shchipanov, A.I.; Bass, U.M.; Belousov, E.D.; Chernova, S.P.; Gioev, K.A.; Perlin, L.M.; Shapiro, B.O.; Silantev, U.R.

    1979-12-25

    A waterproofing agent is proposed with improved physiomechanical properties. The agent contains (by parts): bitumens: 100; emulsifier: .6-5; polyvinylpyrrolidone: .4-8; synthetic latex: 5.24; a corrosion inhibitor: .2-10; SPL methyl methacrylate with chloroprene: 2.24; hydrochlorinated amine of adduct diethylene triamine with diglycidyl diamine: 2-10, water: 118-220. The agent is prepared using either periodic or continuous action in emulsifying dispersion machines. The bitumen is dispersed in the machine in an aqueous emulsifying solution in which polyvinylpyrrolidone and the corrosion inihibitor are first introduced. Then a synthetic latex solution is introduced into the bitumen emulsion while being mixed in rotor-type turbulent mixers; a solution and a hydrochlorinated amine of adduct diethylene triamine with diglycidyl diamine solution until a homogeneous mixture is obtained. Example: a waterproofing agent is obtained in parts: bitumen 100, emulsifyer (oxidized petrolatum): .6; polyvinylpyrrolidone: .4; synthetic latex (nitrile): 5; corrosion inhibitor (guanidine chromate): .2, SPL:2; and water 118. The properties of the proposed composition are better than the properties of the composition currently used.

  9. Product and Agent

    DEFF Research Database (Denmark)

    Montecino, Alex; Valero, Paola

    2015-01-01

    In this paper we will explore how the “mathematics teacher” becomes a subject and, at the same time, is subjected as part of diverse dispositive of power. We argue that the mathematics teacher becomes both a product and a social agent, which has been set, within current societies, from the ideas...

  10. E-Learning Agents

    Science.gov (United States)

    Gregg, Dawn G.

    2007-01-01

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

  11. Engineering mechanics

    CERN Document Server

    Gross, Dietmar; Schröder, Jörg; Wall, Wolfgang A; Rajapakse, Nimal

    Statics is the first volume of a three-volume textbook on Engineering Mechanics. The authors, using a time-honoured straightforward and flexible approach, present the basic concepts and principles of mechanics in the clearest and simplest form possible to advanced undergraduate engineering students of various disciplines and different educational backgrounds. An important objective of this book is to develop problem solving skills in a systematic manner. Another aim of this volume is to provide engineering students as well as practising engineers with a solid foundation to help them bridge the gap between undergraduate studies on the one hand and advanced courses on mechanics and/or practical engineering problems on the other. The book contains numerous examples, along with their complete solutions. Emphasis is placed upon student participation in problem solving. The contents of the book correspond to the topics normally covered in courses on basic engineering mechanics at universities and colleges. Now in i...

  12. 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...

  13. 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.

  14. 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.

  15. 网络购物中的多重委托代理与诚信激励机制研究%Research on multiple principal -agent and integrity incentive mechanism in online shopping

    Institute of Scientific and Technical Information of China (English)

    杨皎平; 张恒俊; 张野

    2013-01-01

      采用博弈论的方法分析了网购市场中的委托代理关系,研究得出:当前的网购市场中,由于消费者和网购平台之间是一个控制较弱的委托代理关系,并且两种利益的不一致,导致了网购平台不能按照消费者的意愿去监管在线卖方,如果能通过建立一定的制度,将消费者的利益和网购平台的利益进行绑定整合,网购平台将会付出更多的努力去监管在线卖方使其提供高质量的产品,从事诚信交易。%The principal-agent relationship in online shopping market is analyzed using game theory , and the conclusions are that online shopping platform cannot regulate online seller in accordance with the willingness of consumers due to the weaker principal -agent relationship between consumers and online shopping platform and their inconsistent interests.We believe that online shopping platform may pay more efforts to supervise online seller to provide high quality products and transact honestly if binding consumers 'interests with online shopping's through certain system.

  16. 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.

  17. Black Girls' Achievement in Middle Grades Mathematics: How Can Socializing Agents Help?

    Science.gov (United States)

    Young, Jemimah L.; Young, Jamaal Rashad; Capraro, Mary Margaret

    2017-01-01

    The middle grades mathematics classroom is full of transitions that students must overcome to become successful long-term learners of mathematics. This transition can be exorbitantly more tumultuous for Black girls who must overcome gender and racial mathematics achievement stereotypes. Mathematics identities and achievement socialization trends…

  18. Instructional Coaching through Dialogic Interaction: Helping a Teacher to Become Agentive in Her Practice

    Science.gov (United States)

    Haneda, Mari; Teemant, Annela; Sherman, Brandon

    2017-01-01

    We investigate the instructional coaching interactions between a kindergarten teacher and an experienced coach using the analytic lens of dialogic teaching. The data were collected in the context of a US professional development project that supports urban elementary school teachers in enacting critical sociocultural teaching practices. We…

  19. Topical antifungal agents: an update.

    Science.gov (United States)

    Diehl, K B

    1996-10-01

    So many topical antifungal agents have been introduced that it has become very difficult to select the proper agent for a given infection. Nonspecific agents have been available for many years, and they are still effective in many situations. These agents include Whitfield's ointment, Castellani paint, gentian violet, potassium permanganate, undecylenic acid and selenium sulfide. Specific antifungal agents include, among others, the polyenes (nystatin, amphotericin B), the imidazoles (metronidazole, clotrimazole) and the allylamines (terbinafine, naftifine). Although the choice of an antifungal agent should be based on an accurate diagnosis, many clinicians believe that topical miconazole is a relatively effective agent for the treatment of most mycotic infections. Terbinafine and other newer drugs have primary fungicidal effects. Compared with older antifungal agents, these newer drugs can be used in lower concentrations and shorter therapeutic courses. Studies are needed to evaluate the clinical efficacies and cost advantages of both newer and traditional agents.

  20. 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...

  1. Anti-Infectious Agents against MRSA

    Directory of Open Access Journals (Sweden)

    Nobuhiro Koyama

    2012-12-01

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

  2. Halon firefighting agents

    International Nuclear Information System (INIS)

    Pope, P.R.; Dalzell, G.A.

    1991-01-01

    This paper examines the current state of the International agreements on the use of halons and the subsequent National and industry approaches to the subject. It examines the definition of Essential Use and gives particular examples to clarify its interpretation. Alternative methods of loss control are reviewed. It does not address alternative active firefighting agents but examines the need for protection in particular areas. It addresses reduction of the hazards and consequences so that the need for protection can be minimized. Practical measures to minimize the installed quantities of halon are described. This covers specifications for new, essential, systems and the short term reduction of inventories in existing systems. The causes of leakage and accidental releases are studied and preventive measures are proposed. The paper concludes with an overview of the current research into replacement agents and the future outlook

  3. Blasting agent package

    Energy Technology Data Exchange (ETDEWEB)

    Fox, R.

    1971-03-17

    A protected preassembled package for blasting agents susceptible to desensitization by water consists of, in combination: (1) an inner rigid and self-supporting tube, the upper end of which is suited to be connected, or attached, to the discharge end of a loading hose for a blasting agent and the lower end of which is open; and (2) a flexible tubular liner made of water-resistant film, having a diameter greater than that of the inner tube and a length at least equal to the desired depth of its insertion into the borehole, the liner being sleeved over the length of the inner tube, the upper end of the liner being attached to the inner tube and the lower end of the liner being closed so as to prevent substantial discharge of the explosive mixture therefrom when the latter is pumped into it. (24 claims)

  4. 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

  5. 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

  6. Paying it forward: How helping others can reduce the psychological threat of receiving help

    NARCIS (Netherlands)

    Alvarez, K.; van Leeuwen, E.

    2015-01-01

    This paper shows that receiving help could be psychologically harmful for recipients, and passing on help to others after receiving help ("helping forward") is a good strategy to improve and restore help recipients' self-competence. Participants (N=87) received autonomy- or dependency-oriented help

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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

  12. Effect of drug loading method against the dissolution mechanism of encapsulated amoxicillin trihidrate drug in matrix of semi-IPN chitosan-poly (N-vinyl pyrrolidone) hydrogel with pore forming agent CaCO3

    Science.gov (United States)

    Nurjannah, Yanah; Budianto, Emil

    2018-04-01

    Heliobacter pylori (H.pylori) is a type of bacteria that causes inflammation in the lining of the stomach. The treatment of the bacterial infection by using conventional medicine which is amoxicillin trihidrate has a very short retention time in the stomach which is about 1-1,5 hours. Floating drug delivery system is expected to have a long retention time in the stomach so the efficiency of drug can be achieved. In this study, has been synthesized matrix of semi-IPN chitosan-Poly(N-vinil pyrrolidone) hydrogel with a pore-forming agent of CaCO3 under optimum conditions. Amoxicillin is encapsulated in a matrix hydrogel to be applied as a floating drug delivery system by in situ loading and post loading methods. The encapsulation efficiency and dissolution of in situ loading and post loading hydrogels are performed in vitro on gastric pH. In situ loading hydrogel shows higer percentage of encapsulation efficiency and dissolution compared to post loading hydrogel. The encapsulation efficiency of in situ and post loading hydrogels were 92,1% and 89,4%, respectively. The aim of drug dissolution by mathematical equation model is to know kinetics and the mecanism of dissolution. The kinetics release of in situ hydrogel tends to follow first order kinetics, while the post loading hydrogel follow the Higuchi model. The dissolution mecanism of hydrogels is erosion.

  13. 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.

  14. 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.

  15. 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.

  16. 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)

  17. 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.

  18. Three-agent Peer Evaluation

    OpenAIRE

    Vicki Knoblauch

    2008-01-01

    I show that every rule for dividing a dollar among three agents impartially (so that each agent's share depends only on her evaluation by her associates) underpays some agent by at least one-third of a dollar for some consistent profile of evaluations. I then produce an impartial division rule that never underpays or overpays any agent by more than one-third of a dollar, and for most consistent evaluation profiles does much better.

  19. Agent control of cooperating satellites

    OpenAIRE

    Lincoln, N.K.; Veres, S.M.; Dennis, Louise; Fisher, Michael; Lisitsa, Alexei

    2011-01-01

    A novel, hybrid, agent architecture for (small)swarms of satellites has been developed. The software architecture for each satellite comprises ahigh-level rational agent linked to a low-level control system. The rational agent forms dynamicgoals, decides how to tackle them and passes theactual implementation of these plans to the control layer. The rational agent also has access to aMatLabmodel of the satellite dynamics, thus allowing it to carry out selective hypothetical reasoningabout pote...

  20. Believable Social and Emotional Agents.

    Science.gov (United States)

    1996-05-01

    While building tools to support the creation of believable emotional agents, I had to make a number of important design decisions . Before describing...processing systems, it is difficult to give an artist direct control over the emotion - al aspects of the character. By making these decisions explicit, I hope...Woody on “Cheers”). Believable Agents BELIEVABLE SOCIAL AND EMOTIONAL AGENTS 11 Lesson: We don’t want agent architectures that enforce rationality and

  1. 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.

  2. 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.

  3. 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

  4. F-18 labelling agents

    International Nuclear Information System (INIS)

    Mikecz, P.

    2001-01-01

    In this presentation the production of fluorine-18, separation of [ 18 F]fluoride, converting fluoride into fluorine as well as fluorine incorporation into organic molecules are reviewed. Reaction schemes and technology schemes are included. Towards organic reactions, with help of small molecules of the 18 F can be introduced into a wide variety of radiopharmaceuticals. (author)

  5. Tips to Help You Get Active

    Science.gov (United States)

    ... A Step in the Right Direction Tips to Help You Get Active View or Print All Sections ... and quality of life. Being more active may help you manage your weight. Starting Physical Activity Healthy ...

  6. Help Protect Babies from Whooping Cough

    Science.gov (United States)

    ... this? Submit What's this? Submit Button Past Emails Help Protect Babies from Whooping Cough Language: English (US) ... Emails Language: English (US) Español (Spanish) File Formats Help: How do I view different file formats (PDF, ...

  7. Help, Resources and Information: National Opioids Crisis

    Science.gov (United States)

    ... Search Search Help, Resources and Information National Opioids Crisis Search Search Need Help? Call the National Helpline ... HHS 5-POINT STRATEGY TO COMBAT THE OPIOIDS CRISIS BETTER ADDICTION PREVENTION, TREATMENT, AND RECOVERY SERVICES BETTER ...

  8. Self-Help Groups and Professional Helpers.

    Science.gov (United States)

    Balgopal, Pallassana R.; And Others

    1986-01-01

    Suggests innovative solutions for mutual benefits for self-help groups and the professionals. Through a derivative paradigm the role of the professional helper within self-help groups is presented. (Author/BL)

  9. Physical Activity Helps Seniors Stay Mobile

    Science.gov (United States)

    ... Subscribe July 2014 Print this issue Health Capsule Physical Activity Helps Seniors Stay Mobile En español Send us your comments A carefully structured, moderate physical activity program helped vulnerable older people maintain their mobility. ...

  10. Synthesis and Antitumor Molecular Mechanism of Agents Based on Amino 2-(3′,4′,5′-Trimethoxybenzoyl)-benzo[b]furan: Inhibition of Tubulin and Induction of Apoptosis

    Science.gov (United States)

    Baraldi, Pier Giovanni; Lopez-Cara, Carlota; Cruz-Lopez, Olga; Carrion, Maria Dora; Salvador, Maria Kimatrai; Bermejo, Jaime; Estévez, Sara; Estévez, Francisco; Balzarini, Jan; Brancale, Andrea; Ricci, Antonio; Chen, Longchuan; Kim, Jae Gwan; Hamel, Ernest

    2011-01-01

    Induction of apoptosis is a promising strategy that could lead to the discovery of new molecules active in cancer chemotherapy. This property is generally observed when cells are treated with agents that target microtubules, dynamic structures that play a crucial role in cell division. Small molecules such as benzo[b]furans are attractive as inhibitors of tubulin polymerization. A new class of inhibitors of tubulin polymerization based on the 2-(3′,4′,5′-trimethoxybenzoyl)benzo[b]furan molecular skeleton, with the amino group placed at different positions on the benzene ring, were synthesized and evaluated for antiproliferative activity, inhibition of tubulin polymerization, and cell-cycle effects. The methoxy substitution pattern on the benzene portion of the benzo[b]furan moiety played an important role in affecting antiproliferative activity. In the series of 5-amino derivatives, the greatest inhibition of cell growth oc curred if the methoxy substituent is placed at the C6 position, whereas C7 substitution decreases potency. The most promising compound in this series is 2-(3′,4′,5′-trimethoxybenzoyl)-3-methyl-5-amino-6-methoxybenzo[b]furan (3h), which inhibits cancer cell growth at nanomolar concentrations (IC50=16–24 nm), and interacts strongly with tubulin by binding to the colchicine site. Sub-G1 apoptotic cells in cultures of HL-60 and U937 cells were observed by flow cytometric analysis after treatment with 3h in a concentration-dependent manner. We also show that compound 3h induces apoptosis by activation of caspase-3, -8, and -9, and this is associated with cytochrome c release from mitochondria. The introduction of an α-bromoacryloyl group increased antiproliferative activity with respect to the parent amino derivatives. PMID:21805646

  11. Chemical warfare agents

    Directory of Open Access Journals (Sweden)

    Vijayaraghavan R

    2010-01-01

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

  12. Chemical warfare agents

    Science.gov (United States)

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

    2010-01-01

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

  13. 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

  14. Help Options in CALL: A Systematic Review

    Science.gov (United States)

    Cardenas-Claros, Monica S.; Gruba, Paul A.

    2009-01-01

    This paper is a systematic review of research investigating help options in the different language skills in computer-assisted language learning (CALL). In this review, emerging themes along with is-sues affecting help option research are identified and discussed. We argue that help options in CALL are application resources that do not only seem…

  15. 6 FAQs About Helping Someone Quit Smoking

    Science.gov (United States)

    Many people want to help their friends and loved ones quit smoking. But, they often don't know how. Here are 6 frequently asked questions about how to help someone quit smoking to help you get the information you need.

  16. Helping Youth Decide: A Workshop Guide.

    Science.gov (United States)

    Duquette, Donna Marie; Boo, Katherine

    This guide was written to complement the publication "Helping Youth Decide," a manual designed to help parents develop effective parent-child communication and help their children make responsible decisions during the adolescent years. The workshop guide is intended to assist people who work with families to provide additional information and…

  17. Meteorology/Oceanography Help - Naval Oceanography Portal

    Science.gov (United States)

    section Advanced Search... Sections Home Time Earth Orientation Astronomy Meteorology Oceanography Ice You are here: Home › Help › Meteorology/Oceanography Help USNO Logo USNO Info Meteorology/Oceanography Help Send an e-mail regarding meteorology or oceanography products. Privacy Advisory Your E-Mail

  18. Will online chat help alleviate mood loneliness?

    Science.gov (United States)

    Hu, Mu

    2009-04-01

    The present study examines the relationship between social Internet use and loneliness and reviews the studies about this topic from both social psychology and computer-mediated communication literature, as a response to the call for interdisciplinary research from scholars in these two areas. Two hundred thirty-four people participated in both the survey testing trait loneliness and a 5-condition (face-to-face chatting, instant message chatting, watching video, writing assignments, and "do nothing") experiment. Participants reported increase of mood loneliness after chatting online. The level of mood loneliness after online chat was higher than that in face-to-face communication. For people with high trait loneliness, the mood loneliness increase in the computer-mediated communication condition was significantly higher than in the face-to-face communication condition. The author of the current study hopes to help clarify the mixed research findings in previous social Internet use literature about this topic and reminds communication researchers of the need to explore the constructs included in "psychological well-being" in terms of their nature, mechanism, causes, consequences, and furthermore, how they are related to communication.

  19. Development of Bicarbonate-Activated Peroxide as a Chemical and Biological Warfare Agent Decontaminant

    National Research Council Canada - National Science Library

    Richardson, David E

    2006-01-01

    ...) and other chemistry for the decontamination of chemical and biological warfare agents. The mechanism of formation of the active oxidant, peroxymonocarbonate, has been investigated in detail. New surfoxidants...

  20. Holograms as Teaching Agents

    Science.gov (United States)

    Walker, Robin A.

    2013-02-01

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

  1. Amphoteric surface active agents

    Directory of Open Access Journals (Sweden)

    Eissa, A.M. F.

    1995-10-01

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

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

  2. [New agents for hypercholesterolemia].

    Science.gov (United States)

    Pintó, Xavier; García Gómez, María Carmen

    2016-02-19

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

  3. WE-H-201-01: The Opportunities and Benefits of Helping LMICs: How Helping Them Can Help You

    Energy Technology Data Exchange (ETDEWEB)

    Pollard, J. [MD Anderson Cancer Center (United States)

    2016-06-15

    The desperate need for radiotherapy in low and mid-income countries (LMICs) has been well documented. Roughly 60 % of the worldwide incidence of cancer occurs in these resource-limited settings and the international community alongside governmental and non-profit agencies have begun publishing reports and seeking help from qualified volunteers. However, the focus of several reports has been on how dire the situation is and the magnitude of the problem, leaving most to feel overwhelmed and unsure as to how to help and why to get involved. This session will help to explain the specific ways that Medical Physicists can uniquely assist in this grand effort to help bring radiotherapy to grossly-underserved areas. Not only can these experts fulfill an important purpose, they also can benefit professionally, academically, emotionally and socially from the endeavor. By assisting others worldwide with their skillset, Medical Physicists can end up helping themselves. Learning Objectives: Understand the need for radiotherapy in LMICs. Understand which agencies are seeking Medical Physicists for help in LMICs. Understand the potential research funding mechanisms are available to establish academic collaborations with LMIC researchers/physicians. Understand the potential social and emotional benefits for both the physicist and the LMIC partners when collaborations are made. Understand the potential for collaboration with other high-income scientists that can develop as the physicist partners with other large institutions to assist LMICs. Wil Ngwa - A recent United Nations Study reports that in developing countries more people have access to cell phones than toilets. In Africa, only 63% of the population has access to piped water, yet, 93% of Africans have cell phone service. Today, these cell phones, Skype, WhatsApp and other information and communication technologies (ICTs) connect us in unprecedented ways and are increasingly recognized as powerful, indispensable to global

  4. WE-H-201-01: The Opportunities and Benefits of Helping LMICs: How Helping Them Can Help You

    International Nuclear Information System (INIS)

    Pollard, J.

    2016-01-01

    The desperate need for radiotherapy in low and mid-income countries (LMICs) has been well documented. Roughly 60 % of the worldwide incidence of cancer occurs in these resource-limited settings and the international community alongside governmental and non-profit agencies have begun publishing reports and seeking help from qualified volunteers. However, the focus of several reports has been on how dire the situation is and the magnitude of the problem, leaving most to feel overwhelmed and unsure as to how to help and why to get involved. This session will help to explain the specific ways that Medical Physicists can uniquely assist in this grand effort to help bring radiotherapy to grossly-underserved areas. Not only can these experts fulfill an important purpose, they also can benefit professionally, academically, emotionally and socially from the endeavor. By assisting others worldwide with their skillset, Medical Physicists can end up helping themselves. Learning Objectives: Understand the need for radiotherapy in LMICs. Understand which agencies are seeking Medical Physicists for help in LMICs. Understand the potential research funding mechanisms are available to establish academic collaborations with LMIC researchers/physicians. Understand the potential social and emotional benefits for both the physicist and the LMIC partners when collaborations are made. Understand the potential for collaboration with other high-income scientists that can develop as the physicist partners with other large institutions to assist LMICs. Wil Ngwa - A recent United Nations Study reports that in developing countries more people have access to cell phones than toilets. In Africa, only 63% of the population has access to piped water, yet, 93% of Africans have cell phone service. Today, these cell phones, Skype, WhatsApp and other information and communication technologies (ICTs) connect us in unprecedented ways and are increasingly recognized as powerful, indispensable to global

  5. Helping Behavior in Executives' Global Networks

    DEFF Research Database (Denmark)

    Miller, Stewart; Mors, Marie Louise; McDonald, Michael

    2014-01-01

    Drawing on research on helping behavior in networks at the upper echelons, we develop and test theory about helping behavior in senior executive networks. We examine the location and relational dependence of the network contact. Our results reveal that executives are more likely to perceive...... insiders in their network to be helpful, but geographic location has no effect on expectations of receiving help. With regards to relational dependence: executives who are more dependent on their contacts are more likely to perceive them to be helpful. We also look at whether perceived helpfulness affects...... an executive’s willingness to engage in risky new business development -- an important performance indicator - and indeed find that those executives that perceive their networks to be helpful are more likely to be willing to take risky decisions. We test these arguments using primary data on 1845 relationships...

  6. Handbook of compliant mechanisms

    CERN Document Server

    Howell, Larry L; Olsen, Brian M

    2013-01-01

    A fully illustrated reference book giving an easy-to-understand introduction to compliant mechanisms A broad compilation of compliant mechanisms to give inspiration and guidance to those interested in using compliant mechanisms in their designs, the Handbook of Compliant Mechanisms includes graphics and descriptions of many compliant mechanisms. It comprises an extensive categorization of devices that can be used to help readers identify compliant mechanisms related to their application. It also provides chapters on the basic background in compliant mechanisms, the categories o

  7. 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.)

  8. 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.)

  9. Quantum mechanics

    International Nuclear Information System (INIS)

    Basdevant, J.L.; Dalibard, J.; Joffre, M.

    2008-01-01

    All physics is quantum from elementary particles to stars and to the big-bang via semi-conductors and chemistry. This theory is very subtle and we are not able to explain it without the help of mathematic tools. This book presents the principles of quantum mechanics and describes its mathematical formalism (wave function, Schroedinger equation, quantum operators, spin, Hamiltonians, collisions,..). We find numerous applications in the fields of new technologies (maser, quantum computer, cryptography,..) and in astrophysics. A series of about 90 exercises with their answers is included. This book is based on a physics course at a graduate level. (A.C.)

  10. Electricity Market Manipulation: How Behavioral Modeling Can Help Market Design

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, Giulia [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-12-18

    The question of how to best design electricity markets to integrate variable and uncertain renewable energy resources is becoming increasingly important as more renewable energy is added to electric power systems. Current markets were designed based on a set of assumptions that are not always valid in scenarios of high penetrations of renewables. In a future where renewables might have a larger impact on market mechanisms as well as financial outcomes, there is a need for modeling tools and power system modeling software that can provide policy makers and industry actors with more realistic representations of wholesale markets. One option includes using agent-based modeling frameworks. This paper discusses how key elements of current and future wholesale power markets can be modeled using an agent-based approach and how this approach may become a useful paradigm that researchers can employ when studying and planning for power systems of the future.

  11. 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.

  12. Microencapsulation of chemotherapeutic agents

    International Nuclear Information System (INIS)

    Byun, Hong Sik

    1993-01-01

    Mixing various amounts of chemotherapeutic agents such as cisplatinum, 5-fluorouracil, mitomycin-C, and adriamycin with polymers such as poly-d, 1-lactide, ethylhydroxyethylcellulose, and polycaprolactone, several kinds of microcapsules were made. Among them, microcapsule made from ethylhydroxyethylcellulose showed best yield. Under light microscopy, the capsules were observed as particles with refractive properties. For the basic toxicity test, intraarterial administration of cisplatinum was done in 6 adult mongrel dogs. Follow-up angiography was accomplished in 2 wk intervals for 6 wks. Despite no significant difference in the histopathological examination between the embolized and normal kidneys, follow-up angiogram showed atrophy of renal cortex and diminished numbers of arterial branches in the embolized kidneys. In order to identify the structural properties of microcapsules, and to determine the drug content and the rate of release, further experiment is thought to be necessary. (Author)

  13. New MR contrast agent

    International Nuclear Information System (INIS)

    Grossman, C.D.; Subramanian, G.; Schneider, R.; Szeverenyi, N.E.; Rosenbaum, A.M.; Gagne, G.; Tillapaugh-Fay, G.; Berlin, R.; Ritter-Hrncirik, C.; Yu, S.

    1990-01-01

    This paper evaluates an MR contrast agent-meglumine tris-(2,6-dicarboxypyridine) gadolinium (III) or gadolinium dipicolinate (Gd-DPC)-produced in-house. Rats were anesthetized with pentobarbital. For renal imaging, bowel motion artifact was minimized with glucagon (0.014 mg/kg, intravenous (IV)). Enhanced images were generated on a 2-T chemical shift imaging system with a 31-cm horizontal bore magnet after IV injection of Gd-DPC (100 μM/kg). Coronal sections of the kidneys and sagittal sections of the brain, 2 mm thick, were made. Six to eight excitations and 128 or 356 phase-encoding steps were used for each image. Control animals were injected with equivalent doses of gadopentetate dimeglumine

  14. Effects of Oxytocin Administration on Receiving Help.

    Science.gov (United States)

    Human, Lauren J; Woolley, Joshua D; Mendes, Wendy Berry

    2017-11-27

    Receiving help can be a "mixed blessing." Despite the many psychosocial benefits it can carry, it sometimes has negative psychological consequences, such as loss in self-esteem or enhanced guilt. It is, therefore, important to understand the factors that modify responses to receiving help from others. We explored the role of the hormone oxytocin (OT) on affective and social responses to receiving help, given the putative role of OT in social bonding and attunement. To this end, we manipulated whether help was received from a same-sex interaction partner (confederate) versus a control condition, crossed with a double-blind administration of intranasal OT (vs. placebo), and examined subjective and observer-rated participant responses to help. We observed significant interactions between OT and the help manipulation. In the placebo condition, receiving help from the interaction partner compared with the control condition had negative consequences, such that participants reported greater negative affect and came to view themselves and their interaction partners more negatively after interacting together on several tasks. What is important, however, is that OT administration buffered against these negative subjective responses to receiving help. Further, outside observers rated participants who received OT administration as expressing greater happiness and gratitude in response to help, relative to those who received placebo. In sum, in the context of receiving help from a stranger, oxytocin administration fostered more positive affective and social responses. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  15. 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...

  16. 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

  17. 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

  18. 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…

  19. Statistical mechanics

    CERN Document Server

    Schwabl, Franz

    2006-01-01

    The completely revised new edition of the classical book on Statistical Mechanics covers the basic concepts of equilibrium and non-equilibrium statistical physics. In addition to a deductive approach to equilibrium statistics and thermodynamics based on a single hypothesis - the form of the microcanonical density matrix - this book treats the most important elements of non-equilibrium phenomena. Intermediate calculations are presented in complete detail. Problems at the end of each chapter help students to consolidate their understanding of the material. Beyond the fundamentals, this text demonstrates the breadth of the field and its great variety of applications. Modern areas such as renormalization group theory, percolation, stochastic equations of motion and their applications to critical dynamics, kinetic theories, as well as fundamental considerations of irreversibility, are discussed. The text will be useful for advanced students of physics and other natural sciences; a basic knowledge of quantum mechan...

  20. 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