Evolutionary game dynamics of controlled and automatic decision-making

NASA Astrophysics Data System (ADS)

Toupo, Danielle F. P.; Strogatz, Steven H.; Cohen, Jonathan D.; Rand, David G.

2015-07-01

We integrate dual-process theories of human cognition with evolutionary game theory to study the evolution of automatic and controlled decision-making processes. We introduce a model in which agents who make decisions using either automatic or controlled processing compete with each other for survival. Agents using automatic processing act quickly and so are more likely to acquire resources, but agents using controlled processing are better planners and so make more effective use of the resources they have. Using the replicator equation, we characterize the conditions under which automatic or controlled agents dominate, when coexistence is possible and when bistability occurs. We then extend the replicator equation to consider feedback between the state of the population and the environment. Under conditions in which having a greater proportion of controlled agents either enriches the environment or enhances the competitive advantage of automatic agents, we find that limit cycles can occur, leading to persistent oscillations in the population dynamics. Critically, however, these limit cycles only emerge when feedback occurs on a sufficiently long time scale. Our results shed light on the connection between evolution and human cognition and suggest necessary conditions for the rise and fall of rationality.

Evolutionary game dynamics of controlled and automatic decision-making.

PubMed

Toupo, Danielle F P; Strogatz, Steven H; Cohen, Jonathan D; Rand, David G

2015-07-01

We integrate dual-process theories of human cognition with evolutionary game theory to study the evolution of automatic and controlled decision-making processes. We introduce a model in which agents who make decisions using either automatic or controlled processing compete with each other for survival. Agents using automatic processing act quickly and so are more likely to acquire resources, but agents using controlled processing are better planners and so make more effective use of the resources they have. Using the replicator equation, we characterize the conditions under which automatic or controlled agents dominate, when coexistence is possible and when bistability occurs. We then extend the replicator equation to consider feedback between the state of the population and the environment. Under conditions in which having a greater proportion of controlled agents either enriches the environment or enhances the competitive advantage of automatic agents, we find that limit cycles can occur, leading to persistent oscillations in the population dynamics. Critically, however, these limit cycles only emerge when feedback occurs on a sufficiently long time scale. Our results shed light on the connection between evolution and human cognition and suggest necessary conditions for the rise and fall of rationality.

Integration and validation testing for PhEDEx, DBS and DAS with the PhEDEx LifeCycle agent

NASA Astrophysics Data System (ADS)

Boeser, C.; Chwalek, T.; Giffels, M.; Kuznetsov, V.; Wildish, T.

2014-06-01

The ever-increasing amount of data handled by the CMS dataflow and workflow management tools poses new challenges for cross-validation among different systems within CMS experiment at LHC. To approach this problem we developed an integration test suite based on the LifeCycle agent, a tool originally conceived for stress-testing new releases of PhEDEx, the CMS data-placement tool. The LifeCycle agent provides a framework for customising the test workflow in arbitrary ways, and can scale to levels of activity well beyond those seen in normal running. This means we can run realistic performance tests at scales not likely to be seen by the experiment for some years, or with custom topologies to examine particular situations that may cause concern some time in the future. The LifeCycle agent has recently been enhanced to become a general purpose integration and validation testing tool for major CMS services. It allows cross-system integration tests of all three components to be performed in controlled environments, without interfering with production services. In this paper we discuss the design and implementation of the LifeCycle agent. We describe how it is used for small-scale debugging and validation tests, and how we extend that to large-scale tests of whole groups of sub-systems. We show how the LifeCycle agent can emulate the action of operators, physicists, or software agents external to the system under test, and how it can be scaled to large and complex systems.

Suboptimal distributed control and estimation: application to a four coupled tanks system

NASA Astrophysics Data System (ADS)

Orihuela, Luis; Millán, Pablo; Vivas, Carlos; Rubio, Francisco R.

2016-06-01

The paper proposes an innovative estimation and control scheme that enables the distributed monitoring and control of large-scale processes. The proposed approach considers a discrete linear time-invariant process controlled by a network of agents that may both collect information about the evolution of the plant and apply control actions to drive its behaviour. The problem makes full sense when local observability/controllability is not assumed and the communication between agents can be exploited to reach system-wide goals. Additionally, to reduce agents bandwidth requirements and power consumption, an event-based communication policy is studied. The design procedure guarantees system stability, allowing the designer to trade-off performance, control effort and communication requirements. The obtained controllers and observers are implemented in a fully distributed fashion. To illustrate the performance of the proposed technique, experimental results on a quadruple-tank process are provided.

Workflow management in large distributed systems

NASA Astrophysics Data System (ADS)

Legrand, I.; Newman, H.; Voicu, R.; Dobre, C.; Grigoras, C.

2011-12-01

The MonALISA (Monitoring Agents using a Large Integrated Services Architecture) framework provides a distributed service system capable of controlling and optimizing large-scale, data-intensive applications. An essential part of managing large-scale, distributed data-processing facilities is a monitoring system for computing facilities, storage, networks, and the very large number of applications running on these systems in near realtime. All this monitoring information gathered for all the subsystems is essential for developing the required higher-level services—the components that provide decision support and some degree of automated decisions—and for maintaining and optimizing workflow in large-scale distributed systems. These management and global optimization functions are performed by higher-level agent-based services. We present several applications of MonALISA's higher-level services including optimized dynamic routing, control, data-transfer scheduling, distributed job scheduling, dynamic allocation of storage resource to running jobs and automated management of remote services among a large set of grid facilities.

What magnitude are observed non-target impacts from weed biocontrol?

PubMed

Suckling, David Maxwell; Sforza, René François Henri

2014-01-01

A systematic review focused by plant on non-target impacts from agents deliberately introduced for the biological control of weeds found significant non-target impacts to be rare. The magnitude of direct impact of 43 biocontrol agents on 140 non-target plants was retrospectively categorized using a risk management framework for ecological impacts of invasive species (minimal, minor, moderate, major, massive). The vast majority of agents introduced for classical biological control of weeds (>99% of 512 agents released) have had no known significant adverse effects on non-target plants thus far; major effects suppressing non-target plant populations could be expected to be detectable. Most direct non-target impacts on plants (91.6%) were categorized as minimal or minor in magnitude with no known adverse long-term impact on non-target plant populations, but a few cacti and thistles are affected at moderate (n = 3), major (n = 7) to massive (n = 1) scale. The largest direct impacts are from two agents (Cactoblastis cactorum on native cacti and Rhinocyllus conicus on native thistles), but these introductions would not be permitted today as more balanced attitudes exist to plant biodiversity, driven by both society and the scientific community. Our analysis shows (as far as is known), weed biological control agents have a biosafety track record of >99% of cases avoiding significant non-target impacts on plant populations. Some impacts could have been overlooked, but this seems unlikely to change the basic distribution of very limited adverse effects. Fewer non-target impacts can be expected in future because of improved science and incorporation of wider values. Failure to use biological control represents a significant opportunity cost from the certainty of ongoing adverse impacts from invasive weeds. It is recommended that a simple five-step scale be used to better communicate the risk of consequences from both action (classical biological control) and no action (ongoing impacts from invasive weeds).

What Magnitude Are Observed Non-Target Impacts from Weed Biocontrol?

PubMed Central

Suckling, David Maxwell; Sforza, René François Henri

2014-01-01

A systematic review focused by plant on non-target impacts from agents deliberately introduced for the biological control of weeds found significant non-target impacts to be rare. The magnitude of direct impact of 43 biocontrol agents on 140 non-target plants was retrospectively categorized using a risk management framework for ecological impacts of invasive species (minimal, minor, moderate, major, massive). The vast majority of agents introduced for classical biological control of weeds (>99% of 512 agents released) have had no known significant adverse effects on non-target plants thus far; major effects suppressing non-target plant populations could be expected to be detectable. Most direct non-target impacts on plants (91.6%) were categorized as minimal or minor in magnitude with no known adverse long-term impact on non-target plant populations, but a few cacti and thistles are affected at moderate (n = 3), major (n = 7) to massive (n = 1) scale. The largest direct impacts are from two agents (Cactoblastis cactorum on native cacti and Rhinocyllus conicus on native thistles), but these introductions would not be permitted today as more balanced attitudes exist to plant biodiversity, driven by both society and the scientific community. Our analysis shows (as far as is known), weed biological control agents have a biosafety track record of >99% of cases avoiding significant non-target impacts on plant populations. Some impacts could have been overlooked, but this seems unlikely to change the basic distribution of very limited adverse effects. Fewer non-target impacts can be expected in future because of improved science and incorporation of wider values. Failure to use biological control represents a significant opportunity cost from the certainty of ongoing adverse impacts from invasive weeds. It is recommended that a simple five-step scale be used to better communicate the risk of consequences from both action (classical biological control) and no action (ongoing impacts from invasive weeds). PMID:24454755

The evolution and devolution of cognitive control: The costs of deliberation in a competitive world

PubMed Central

Tomlin, Damon; Rand, David G.; Ludvig, Elliot A.; Cohen, Jonathan D.

2015-01-01

Dual-system theories of human cognition, under which fast automatic processes can complement or compete with slower deliberative processes, have not typically been incorporated into larger scale population models used in evolutionary biology, macroeconomics, or sociology. However, doing so may reveal important phenomena at the population level. Here, we introduce a novel model of the evolution of dual-system agents using a resource-consumption paradigm. By simulating agents with the capacity for both automatic and controlled processing, we illustrate how controlled processing may not always be selected over rigid, but rapid, automatic processing. Furthermore, even when controlled processing is advantageous, frequency-dependent effects may exist whereby the spread of control within the population undermines this advantage. As a result, the level of controlled processing in the population can oscillate persistently, or even go extinct in the long run. Our model illustrates how dual-system psychology can be incorporated into population-level evolutionary models, and how such a framework can be used to examine the dynamics of interaction between automatic and controlled processing that transpire over an evolutionary time scale. PMID:26078086

The evolution and devolution of cognitive control: The costs of deliberation in a competitive world.

PubMed

Tomlin, Damon; Rand, David G; Ludvig, Elliot A; Cohen, Jonathan D

2015-06-16

Dual-system theories of human cognition, under which fast automatic processes can complement or compete with slower deliberative processes, have not typically been incorporated into larger scale population models used in evolutionary biology, macroeconomics, or sociology. However, doing so may reveal important phenomena at the population level. Here, we introduce a novel model of the evolution of dual-system agents using a resource-consumption paradigm. By simulating agents with the capacity for both automatic and controlled processing, we illustrate how controlled processing may not always be selected over rigid, but rapid, automatic processing. Furthermore, even when controlled processing is advantageous, frequency-dependent effects may exist whereby the spread of control within the population undermines this advantage. As a result, the level of controlled processing in the population can oscillate persistently, or even go extinct in the long run. Our model illustrates how dual-system psychology can be incorporated into population-level evolutionary models, and how such a framework can be used to examine the dynamics of interaction between automatic and controlled processing that transpire over an evolutionary time scale.

Design and Simulation of Material-Integrated Distributed Sensor Processing with a Code-Based Agent Platform and Mobile Multi-Agent Systems

PubMed Central

Bosse, Stefan

2015-01-01

Multi-agent systems (MAS) can be used for decentralized and self-organizing data processing in a distributed system, like a resource-constrained sensor network, enabling distributed information extraction, for example, based on pattern recognition and self-organization, by decomposing complex tasks in simpler cooperative agents. Reliable MAS-based data processing approaches can aid the material-integration of structural-monitoring applications, with agent processing platforms scaled to the microchip level. The agent behavior, based on a dynamic activity-transition graph (ATG) model, is implemented with program code storing the control and the data state of an agent, which is novel. The program code can be modified by the agent itself using code morphing techniques and is capable of migrating in the network between nodes. The program code is a self-contained unit (a container) and embeds the agent data, the initialization instructions and the ATG behavior implementation. The microchip agent processing platform used for the execution of the agent code is a standalone multi-core stack machine with a zero-operand instruction format, leading to a small-sized agent program code, low system complexity and high system performance. The agent processing is token-queue-based, similar to Petri-nets. The agent platform can be implemented in software, too, offering compatibility at the operational and code level, supporting agent processing in strong heterogeneous networks. In this work, the agent platform embedded in a large-scale distributed sensor network is simulated at the architectural level by using agent-based simulation techniques. PMID:25690550

Design and simulation of material-integrated distributed sensor processing with a code-based agent platform and mobile multi-agent systems.

PubMed

Bosse, Stefan

2015-02-16

Multi-agent systems (MAS) can be used for decentralized and self-organizing data processing in a distributed system, like a resource-constrained sensor network, enabling distributed information extraction, for example, based on pattern recognition and self-organization, by decomposing complex tasks in simpler cooperative agents. Reliable MAS-based data processing approaches can aid the material-integration of structural-monitoring applications, with agent processing platforms scaled to the microchip level. The agent behavior, based on a dynamic activity-transition graph (ATG) model, is implemented with program code storing the control and the data state of an agent, which is novel. The program code can be modified by the agent itself using code morphing techniques and is capable of migrating in the network between nodes. The program code is a self-contained unit (a container) and embeds the agent data, the initialization instructions and the ATG behavior implementation. The microchip agent processing platform used for the execution of the agent code is a standalone multi-core stack machine with a zero-operand instruction format, leading to a small-sized agent program code, low system complexity and high system performance. The agent processing is token-queue-based, similar to Petri-nets. The agent platform can be implemented in software, too, offering compatibility at the operational and code level, supporting agent processing in strong heterogeneous networks. In this work, the agent platform embedded in a large-scale distributed sensor network is simulated at the architectural level by using agent-based simulation techniques.

Efficacy of flea beetle control of leafy spurge in Montana and South Dakota

Treesearch

Jack L. Butler; Matthew S. Parker; John T. Murphy

2006-01-01

Black (Aphthona lacertosa and Aphthona czwalinae) and brown (Aphthona nigriscutis) flea beetles are among the more successful biological control agents used in the control and management of leafy spurge on a relatively large scale in the Northern Great Plains. The objectives of this study were to document leafy...

Agent-Based Simulation for Interconnection-Scale Renewable Integration and Demand Response Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chassin, David P.; Behboodi, Sahand; Crawford, Curran

This paper collects and synthesizes the technical requirements, implementation, and validation methods for quasi-steady agent-based simulations of interconnectionscale models with particular attention to the integration of renewable generation and controllable loads. Approaches for modeling aggregated controllable loads are presented and placed in the same control and economic modeling framework as generation resources for interconnection planning studies. Model performance is examined with system parameters that are typical for an interconnection approximately the size of the Western Electricity Coordinating Council (WECC) and a control area about 1/100 the size of the system. These results are used to demonstrate and validate the methodsmore » presented.« less

Agent-Based Simulation for Interconnection-Scale Renewable Integration and Demand Response Studies

DOE PAGES

Chassin, David P.; Behboodi, Sahand; Crawford, Curran; ...

2015-12-23

This paper collects and synthesizes the technical requirements, implementation, and validation methods for quasi-steady agent-based simulations of interconnectionscale models with particular attention to the integration of renewable generation and controllable loads. Approaches for modeling aggregated controllable loads are presented and placed in the same control and economic modeling framework as generation resources for interconnection planning studies. Model performance is examined with system parameters that are typical for an interconnection approximately the size of the Western Electricity Coordinating Council (WECC) and a control area about 1/100 the size of the system. These results are used to demonstrate and validate the methodsmore » presented.« less

Polymer-directed synthesis of metal oxide-containing nanomaterials for electrochemical energy storage

NASA Astrophysics Data System (ADS)

Mai, Yiyong; Zhang, Fan; Feng, Xinliang

2013-12-01

Metal oxide-containing nanomaterials (MOCNMs) of controllable structures at the nano-scale have attracted considerable interest because of their great potential applications in electrochemical energy storage devices, such as lithium-ion batteries (LIBs) and supercapacitors. Among many structure-directing agents, polymers and macromolecules, including block copolymers (BCPs) and graphene, exhibit distinct advantages in the template-assisted synthesis of MOCNMs. In this feature article, we introduce the controlled preparation of MOCNMs employing BCPs and graphene as structure-directing agents. Typical synthetic strategies are presented for the control of structures and sizes as well as the improvement of physical properties and electrochemical performance of MOCNMs in LIBs and supercapacitors.

Polymer-directed synthesis of metal oxide-containing nanomaterials for electrochemical energy storage.

PubMed

Mai, Yiyong; Zhang, Fan; Feng, Xinliang

2014-01-07

Metal oxide-containing nanomaterials (MOCNMs) of controllable structures at the nano-scale have attracted considerable interest because of their great potential applications in electrochemical energy storage devices, such as lithium-ion batteries (LIBs) and supercapacitors. Among many structure-directing agents, polymers and macromolecules, including block copolymers (BCPs) and graphene, exhibit distinct advantages in the template-assisted synthesis of MOCNMs. In this feature article, we introduce the controlled preparation of MOCNMs employing BCPs and graphene as structure-directing agents. Typical synthetic strategies are presented for the control of structures and sizes as well as the improvement of physical properties and electrochemical performance of MOCNMs in LIBs and supercapacitors.

Optimal control in microgrid using multi-agent reinforcement learning.

PubMed

Li, Fu-Dong; Wu, Min; He, Yong; Chen, Xin

2012-11-01

This paper presents an improved reinforcement learning method to minimize electricity costs on the premise of satisfying the power balance and generation limit of units in a microgrid with grid-connected mode. Firstly, the microgrid control requirements are analyzed and the objective function of optimal control for microgrid is proposed. Then, a state variable "Average Electricity Price Trend" which is used to express the most possible transitions of the system is developed so as to reduce the complexity and randomicity of the microgrid, and a multi-agent architecture including agents, state variables, action variables and reward function is formulated. Furthermore, dynamic hierarchical reinforcement learning, based on change rate of key state variable, is established to carry out optimal policy exploration. The analysis shows that the proposed method is beneficial to handle the problem of "curse of dimensionality" and speed up learning in the unknown large-scale world. Finally, the simulation results under JADE (Java Agent Development Framework) demonstrate the validity of the presented method in optimal control for a microgrid with grid-connected mode. Copyright © 2012 ISA. Published by Elsevier Ltd. All rights reserved.

Halloysite clay nanotubes for controlled release of protective agents.

PubMed

Lvov, Yuri M; Shchukin, Dmitry G; Möhwald, Helmuth; Price, Ronald R

2008-05-01

Halloysite aluminosilicate nanotubes with a 15 nm lumen, 50 nm external diameter, and length of 800 +/- 300 nm have been developed as an entrapment system for loading, storage, and controlled release of anticorrosion agents and biocides. Fundamental research to enable the control of release rates from hours to months is being undertaken. By variation of internal fluidic properties, the formation of nanoshells over the nanotubes and by creation of smart caps at the tube ends it is possible to develop further means of controlling the rate of release. Anticorrosive halloysite coatings are in development and a self-healing approach has been developed for repair mechanisms through response activation to external impacts. In this Perspective, applications of halloysite as nanometer-scale containers are discussed, including the use of halloysite tubes as drug releasing agents, as biomimetic reaction vessels, and as additives in biocide and protective coatings. Halloysite nanotubes are available in thousands of tons, and remain sophisticated and novel natural nanomaterials which can be used for the loading of agents for metal and plastic anticorrosion and biocide protection.

Evaluation of biogeographical factors in the native range to improve the success of biological control agents in the introduced range

USDA-ARS?s Scientific Manuscript database

Biogeographical factors associated with Arundo donax in its native range were evaluated in reference to its key herbivore, an armored scale, Rhizaspidiotus donacis. Climate modeling from location data in Spain and France accurately predicted the native range of the scale in the warmer, drier parts o...

Rhizaspidiotus Donacis (Hemiptera, Diaspididae) Licensed Agent for control. First Results of Biological Monitoring Plan of Giant Reed in the U.S.

USDA-ARS?s Scientific Manuscript database

Field research studies in Spain conducted to determine the biology of the arundo scale, Rhizaspidiotus donacis, were consistent with laboratory studies conducted in the U.S. Although field data from Spain indicate that the arundo scale can significantly impact giant reed, Arundo donax, additional ti...

Resource Control in Large-Scale Mobile-Agents Systems

DTIC Science & Technology

2005-07-01

wakeup node schedule , much energy can be conserved. We also designed several protocols for global clock synchronization. The most interesting one is...choice as to which remote hosts to visit and in which order. Scheduling mobile-agent migration in a way that minimizes bandwidth and other resource...use, therefore, is both feasible and attractive. Dartmouth considered several variations of the scheduling problem, and devel- oped an algorithm for

The impacts of a stem boring weevil, Mecinus janthinus, on dalmatian toadflax, Linaria dalmatica

Treesearch

Marjolein Schat

2008-01-01

Classical biological control of weeds is generally considered an effective, safe, and cost effective tool for controlling widespread weeds in natural areas. However, only 60% of releases have become established and, of those, only 50% have led to control. Therefore, understanding the impacts of agents on target weeds across spatial scales, at different insect densities...

Thermal Destruction Of CB Contaminants Bound On Building ...

EPA Pesticide Factsheets

Symposium Paper An experimental and theoretical program has been initiated by the U.S. EPA to investigate issues of chemical/biological agent destruction in incineration systems when the agent in question is bound on common porous building interior materials. This program includes 3-dimensional computational fluid dynamics modeling with matrix-bound agent destruction kinetics, bench-scale experiments to determine agent destruction kinetics while bound on various matrices, and pilot-scale experiments to scale-up the bench-scale experiments to a more practical scale. Finally, model predictions are made to predict agent destruction and combustion conditions in two full-scale incineration systems that are typical of modern combustor design.

Impact of the Arundo scale Rhizaspidiotus donacis (Hemiptera: Diaspididae) on the weight of Arundo donax (Poaceae: Arundinoideae) rhizomes in Languedoc southern France and Mediterranean Spain

USDA-ARS?s Scientific Manuscript database

Arundo donax L. (Poaceae) is native to Mediterranean Europe and invasive in the Rio Grande Basin of North America. Rhizomes from nine sites in France and Spain infested with a candidate control agent, the armoured scale Rhizaspidiotus donacis (Hemiptera: Diaspididae) weighed 50% less than those fro...

Plant level impacts of the arundo scale (Rhizaspidiotus donacis) on growth and eco-physiology of the invasive giant reed

USDA-ARS?s Scientific Manuscript database

The sap-feeding armored arundo scale (Rhizaspidiotus donacis) has been permitted for use as a biological control agent for giant reed (Arundo donax L.), a non-native, highly invasive woody grass that infests waterways and riparian areas of the southwestern US and Mexico. We use a nested factorial d...

Event-Triggered Distributed Average Consensus Over Directed Digital Networks With Limited Communication Bandwidth.

PubMed

Li, Huaqing; Chen, Guo; Huang, Tingwen; Dong, Zhaoyang; Zhu, Wei; Gao, Lan

2016-12-01

In this paper, we consider the event-triggered distributed average-consensus of discrete-time first-order multiagent systems with limited communication data rate and general directed network topology. In the framework of digital communication network, each agent has a real-valued state but can only exchange finite-bit binary symbolic data sequence with its neighborhood agents at each time step due to the digital communication channels with energy constraints. Novel event-triggered dynamic encoder and decoder for each agent are designed, based on which a distributed control algorithm is proposed. A scheme that selects the number of channel quantization level (number of bits) at each time step is developed, under which all the quantizers in the network are never saturated. The convergence rate of consensus is explicitly characterized, which is related to the scale of network, the maximum degree of nodes, the network structure, the scaling function, the quantization interval, the initial states of agents, the control gain and the event gain. It is also found that under the designed event-triggered protocol, by selecting suitable parameters, for any directed digital network containing a spanning tree, the distributed average consensus can be always achieved with an exponential convergence rate based on merely one bit information exchange between each pair of adjacent agents at each time step. Two simulation examples are provided to illustrate the feasibility of presented protocol and the correctness of the theoretical results.

Quantitative comparison of topical aluminum salt solution efficacy for management of sweating: a randomized, controlled trial.

PubMed

Swary, Jillian H; West, Dennis P; Kakar, Rohit; Ortiz, Sara; Schaeffer, Matthew R; Veledar, Emir; Alam, Murad

2015-12-01

There is a lack of studies objectively comparing the efficacy of topical antiperspirants in reducing sweat. To objectively and quantitatively compare the efficacy of two aluminum salt solutions for the reduction of induced sweating. A subject, rater, and statistician-blinded, randomized, controlled trial. Nineteen subjects were exposed to a standardized heat challenge for 3 h. Topical agent A (20% aluminum chloride hexahydrate) was randomized to either axilla, and topical agent B (1% aluminum acetate) assigned to the contralateral side. A sauna suit induced sweating during three 30-min heat intervals: (1) with no study agents (pre); (2) with both study agents, one on each side; and (3) after the agents were washed off (post). Sweat levels were measured by securing Whatman(®) filter paper to each axilla and measuring the paper weight after each heat interval. The difference in paper weight following each heat interval between Study Agent A and Study Agent B was measured by a gravimetric scale. Topical agent A had a significantly greater effect at reducing axillary sweating than B (P = 0.0002). In a sweating simulation, 20% aluminum chloride hexahydrate quantitatively and objectively appeared to reduce sweat more effectively than 1% aluminum acetate. © 2015 Wiley Periodicals, Inc.

Incentive Control Strategies for Decision Problems with Parametric Uncertainties

NASA Astrophysics Data System (ADS)

Cansever, Derya H.

The central theme of this thesis is the design of incentive control policies in large scale systems with hierarchical decision structures, under the stipulation that the objective functionals of the agents at the lower level of the hierarchy are uncertain to the top-level controller (the leader). These uncertainties are modeled as a finite -dimensional parameter vector whose exact value constitutes private information to the relevant agent at the lower level. The approach we have adopted is to design incentive policies for the leader such that the dependence of the decision of the agents on the uncertain parameter is minimized. We have identified several classes of problems for which this approach is feasible. In particular, we have constructed policies whose performance is arbitrarily close to the solution of a version of the same problem that does not involve uncertainties. We have also shown that for a certain class of problem wherein the leader observes a linear combination of the agents' decisions, the leader can achieve the performance he would obtain if he had observed each decision separately.

Landscape epidemiology and control of pathogens with cryptic and long-distance dispersal: Sudden oak death in northern Californian forests

Treesearch

Joao A. N. Filipe; Richard C. Cobb; Ross K. Meentemeyer; Christopher A. Lee; Yana S. Valachovic; Alex R. Cook; David M. Rizzo; Christopher A. Gilligan

2012-01-01

Exotic pathogens and pests threaten ecosystem service, biodiversity, and crop security globally. If an invasive agent can disperse asymptomatically over long distances, multiple spatial and temporal scales interplay, making identification of effective strategies to regulate, monitor, and control disease extremely difficult. The management of outbreaks is also...

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

NASA Astrophysics Data System (ADS)

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

2008-12-01

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

Effect of spent mushroom substrate as a bulking agent on gaseous emissions and compost quality during pig manure composting.

PubMed

Li, Shuyan; Li, Danyang; Li, Jijin; Li, Yangyang; Li, Guoxue; Zang, Bing; Li, Yun

2018-05-01

The aim of this study was to investigate the gaseous emissions (CH 4 , N 2 O, and NH 3 ) and compost quality during the pig manure composting by adding spent mushroom substrate (SMS) as a bulking agent. The control treatment was also studied using corn stalk (CS) as a bulking agent. The experiment was conducted in a pilot scale composting reactor under aerobic condition with the initial C/N ratio of 20. Results showed that bulking agents significantly affected gaseous emissions and compost quality. Using SMS as a bulking agent improved composting efficiency by shortening the time for maturity. SMS increased germination index and humic acid of the final compost (by 13.44 and 41.94%, respectively) compared with CS. Furthermore, composting with SMS as a bulking agent could reduce nitrogen loss, NH 3 , and N 2 O emissions (by 13.57, 35.56, and 46.48%, respectively) compared with the control. SMS slightly increased CH 4 emission about 1.1 times of the CS. However, a 33.95% decrease in the global warming potential of CH 4 and N 2 O was obtained by adding SMS treatment. These results indicate that SMS is a favorable bulking agent for reducing gaseous emissions and increasing compost quality.

Perspectives on why digital ecologies matter: combining population genetics and ecologically informed agent-based models with GIS for managing dipteran livestock pests.

PubMed

Peck, Steven L

2014-10-01

It is becoming clear that handling the inherent complexity found in ecological systems is an essential task for finding ways to control insect pests of tropical livestock such as tsetse flies, and old and new world screwworms. In particular, challenging multivalent management programs, such as Area Wide Integrated Pest Management (AW-IPM), face daunting problems of complexity at multiple spatial scales, ranging from landscape level processes to those of smaller scales such as the parasite loads of individual animals. Daunting temporal challenges also await resolution, such as matching management time frames to those found on ecological and even evolutionary temporal scales. How does one deal with representing processes with models that involve multiple spatial and temporal scales? Agent-based models (ABM), combined with geographic information systems (GIS), may allow for understanding, predicting and managing pest control efforts in livestock pests. This paper argues that by incorporating digital ecologies in our management efforts clearer and more informed decisions can be made. I also point out the power of these models in making better predictions in order to anticipate the range of outcomes possible or likely. Copyright © 2014 International Atomic Energy Agency 2014. Published by Elsevier B.V. All rights reserved.

Effective landscape scale management of Cirsium arvense (Canada thistle) utilizing biological control

Treesearch

G. P. Markin; D. Larson

2013-01-01

The stem mining weevil, Ceutorhynchus litura Fabricius, the gall forming fly, Urophora cardui L., and the seedhead weevil, Larinus planus Fabricius, were established as biological control agents on an 1800 hectare multiple-habitat wildlife refuge in northwestern Oregon in the mid-1990s. At the time, Canada thistle was the most wide spread, aggressive, and difficult...

Robust scalable stabilisability conditions for large-scale heterogeneous multi-agent systems with uncertain nonlinear interactions: towards a distributed computing architecture

NASA Astrophysics Data System (ADS)

Manfredi, Sabato

2016-06-01

Large-scale dynamic systems are becoming highly pervasive in their occurrence with applications ranging from system biology, environment monitoring, sensor networks, and power systems. They are characterised by high dimensionality, complexity, and uncertainty in the node dynamic/interactions that require more and more computational demanding methods for their analysis and control design, as well as the network size and node system/interaction complexity increase. Therefore, it is a challenging problem to find scalable computational method for distributed control design of large-scale networks. In this paper, we investigate the robust distributed stabilisation problem of large-scale nonlinear multi-agent systems (briefly MASs) composed of non-identical (heterogeneous) linear dynamical systems coupled by uncertain nonlinear time-varying interconnections. By employing Lyapunov stability theory and linear matrix inequality (LMI) technique, new conditions are given for the distributed control design of large-scale MASs that can be easily solved by the toolbox of MATLAB. The stabilisability of each node dynamic is a sufficient assumption to design a global stabilising distributed control. The proposed approach improves some of the existing LMI-based results on MAS by both overcoming their computational limits and extending the applicative scenario to large-scale nonlinear heterogeneous MASs. Additionally, the proposed LMI conditions are further reduced in terms of computational requirement in the case of weakly heterogeneous MASs, which is a common scenario in real application where the network nodes and links are affected by parameter uncertainties. One of the main advantages of the proposed approach is to allow to move from a centralised towards a distributed computing architecture so that the expensive computation workload spent to solve LMIs may be shared among processors located at the networked nodes, thus increasing the scalability of the approach than the network size. Finally, a numerical example shows the applicability of the proposed method and its advantage in terms of computational complexity when compared with the existing approaches.

Effect of local drug delivery in chronic periodontitis patients: A meta-analysis

PubMed Central

Kalsi, Rupali; Vandana, K. L.; Prakash, Shobha

2011-01-01

Periodontal diseases are multi-factorial in etiology, and bacteria are one among these etiologic agents. Thus, an essential component of therapy is to eliminate or control these pathogens. This has been traditionally accomplished through mechanical means (scaling and root planing (SRP)), which is time-consuming, difficult, and, sometimes, ineffective. From about the past 30 years, locally delivered, anti-infective pharmacological agents, most recently employing sustained-release vehicles, have been introduced to achieve this goal. This systematic review is an effort to determine the efficacy of the currently available anti-infective agents, with and without concurrent SRP, in controlling chronic periodontitis. Four studies were included, which were all randomized controlled trials, incorporating a total patient population of 80, with 97 control sites and 111 test sites. A meta-analysis completed on these four studies including SRP and local sustained-release agents compared with SRP alone indicated significant adjunctive probing depth (PD) reduction for 10% Doxycycline hycylate (ATRIDOX), minocycline hydrochloride (ARESTIN), tetracycline hydrochloride (PERIODONTAL PLUS AB), and chlorhexidine gluconate (PERIOCHIP). Essentially, all studies reported substantial reductions in gingival inflammation, plaque scores, and bleeding indices, which were similar in both the control and the experimental groups. Use of antimicrobial sustained-release systems as an adjunct to SRP does not result in significant patient-centered adverse events. Local drug delivery combined with SRP appears to provide additional benefits in PD reduction compared with SRP alone. PMID:22368351

Six decades of industrial water treatment (1915-1975)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maguire, J.J.

1976-01-01

An extensive account of water treatment beginning with the internal treatment of boiler water used for steam generation in the teens to the later treatment of cooling water and industrial process water. In the teens external softening of boiler makeup water was recommended by various processes. In the twenties water problems intensified and research on boiler water scaling began and continued through the thirties. The mechanism of scale formation was studied, and a new Navy boiler compound was adopted. Langelier's Saturation Index work in 1936 served as a basis for early control of scaling by cooling water. In the fortiesmore » other controls and removers were recommended, and antifoam patents issued. In 1950 Berk proved nitrate an effective inhibitor, and in 1951 influence of boiler design and operation on steam contamination was presented. Internal chemical treatment programs continued to be refined in the sixties with synthetic dispersing agents, and Chelant treatments continued to dominate the seventies, with inspection times extended 2-3 years by their use. Besides treatment of industrial waters, evaluation of results also demanded attention and water quality standards were of concern. Research continues to develop more effective synthetic and naturally-occurring organic agents.« less

Extinguishing agent for magnesium fire, phases 5 and 6

NASA Astrophysics Data System (ADS)

Beeson, H. D.; Tapscott, R. E.; Mason, B. E.

1987-07-01

This report documents the validation testing of the extinguishing system for metal fires developed as part of Phases 1 to 4. The results of this validation testing form the basis of information from which draft military specifications necessary to procure the agent and the agent delivery system may be developed. The developed system was tested against a variety of large-scale metal fire scenarios and the capabilities of the system were assessed. In addition the response of the system to storage and to changes in ambient conditions was tested. Results of this testing revealed that the developed system represented a reliable metal fire extinguishing system that could control and extinguish very large metal fires. The specifications developed for the agent and for the delivery system are discussed in detail.

An Energy-Based Thermodynamic Stabilization Framework for Hybrid Control Design of Large-Scale Aerospace Systems

DTIC Science & Technology

2009-02-27

exchanged by means of line-of-sight sensors that experience periodic communication dropouts due to agent motion. Variation in network topology in...respiratory, and cardiovascular function by man- ual control based on the clinician’s experience and intuition. Open-loop control by clinical personnel can be...to ap- pear. [29] W. M. Haddad and J. M. Bailey, "Closed-Loop Control for Intensive Care Unit Seda- tion," Best Prac. Res. Clinical Anaesthesiology

The behavior of multiple independent managers and ecological traits interact to determine prevalence of weeds.

PubMed

Coutts, Shaun R; Yokomizo, Hiroyuki; Buckley, Yvonne M

2013-04-01

Management of damaging invasive plants is often undertaken by multiple decision makers, each managing only a small part of the invader's population. As weeds can move between properties and re-infest eradicated sites from unmanaged sources, the dynamics of multiple decision makers plays a significant role in weed prevalence and invasion risk at the landscape scale. We used a spatially explicit agent-based simulation to determine how individual agent behavior, in concert with weed population ecology, determined weed prevalence. We compared two invasive grass species that differ in ecology, control methods, and costs: Nassella trichotoma (serrated tussock) and Eragrostis curvula (African love grass). The way decision makers reacted to the benefit of management had a large effect on the extent of a weed. If benefits of weed control outweighed the costs, and either net benefit was very large or all agents were very sensitive to net benefits, then agents tended to act synchronously, reducing the pool of infested agents available to spread the weed. As N. trichotoma was more damaging than E. curvula and had more effective control methods, agents chose to manage it more often, which resulted in lower prevalence of N. trichotoma. A relatively low number of agents who were intrinsically less motivated to control weeds led to increased prevalence of both species. This was particularly apparent when long-distance dispersal meant each infested agent increased the invasion risk for a large portion of the landscape. In this case, a small proportion of land mangers reluctant to control, regardless of costs and benefits, could lead to the whole landscape being infested, even when local control stopped new infestations. Social pressure was important, but only if it was independent of weed prevalence, suggesting that early access to information, and incentives to act on that information, may be crucial in stopping a weed from infesting large areas. The response of our model to both behavioral and ecological parameters was highly nonlinear. This implies that the outcomes of weed management programs that deal with multiple land mangers could be highly variable in both space and through time.

Clinical study to know the efficacy of Amlexanox 5% with other topical Antiseptic, Analgesic and Anesthetic agents in treating minor RAS.

PubMed

Darshan, D D; Kumar, C N Vijay; Kumar, A D Manoj; Manikantan, N S; Balakrishnan, Dhanya; Uthkal, M P

2014-02-01

To evaluate the efficacy of topical antiinflammatory agent (amlexanox 5%), along with topical antiseptic, analgesic, and anesthetic agent (benzalkonium chloride 0.01%, choline salicylate 8.7% and lidocaine hydrochloride 2%), in promoting ulcer healing, decreasing ulcer size, erythema, pain and recurrence in minor RAS. A randomized control trial was conducted on 100 patients of RAS who fulfilled the inclusion criteria. The number, size, erythema and pain with the ulcer were recorded. Visual analogue scale (VAS) and erythema scale were used to record pain and erythema. 50 patients comprising the study group received anti inflammatory paste (amlexanox 5%) applied four times daily and the control group of 50 patients received topical antiseptic, analgesic, and anesthetic agent (benzalkonium chloride 0.01%, choline salicylate 8.7% and lidocaine hydrochloride 2%) paste, patients were evaluated after 3rd, 6th, 9th and on 30th, 60th day for recurrence. The study group had reduction in ulcer number, size; erythema, pain and frequency of ulcers during follow up. The healing period and recurrence of ulceration reduced in both the groups but the study group had significant reduction in 30th and 60th day follow up for recurrence of ulcers. Amlexanox 5% can reduce the frequency, duration and symptoms associated with the aphthous ulcers with no sideeffects attributed to the drug. How to cite the article: Darshan DD, Kumar CN, Kumar AD, Manikantan NS, Balakrishnan D, Uthkal MP. Clinical study to know the efficacy of Amlexanox 5% with other topical Antiseptic, Analgesic and Anesthetic agents in treating minor RAS. J Int Oral Health 2014;6(1);5-11.

Clinical study to know the efficacy of Amlexanox 5% with other topical Antiseptic, Analgesic and Anesthetic agents in treating minor RAS

PubMed Central

Darshan, D D; Kumar, C N Vijay; Kumar, A D Manoj; Manikantan, N S; Balakrishnan, Dhanya; Uthkal, M P

2014-01-01

Background: To evaluate the efficacy of topical antiinflammatory agent (amlexanox 5%), along with topical antiseptic, analgesic, and anesthetic agent (benzalkonium chloride 0.01%, choline salicylate 8.7% and lidocaine hydrochloride 2%), in promoting ulcer healing, decreasing ulcer size, erythema, pain and recurrence in minor RAS. Materials & Methods: A randomized control trial was conducted on 100 patients of RAS who fulfilled the inclusion criteria. The number, size, erythema and pain with the ulcer were recorded. Visual analogue scale (VAS) and erythema scale were used to record pain and erythema. 50 patients comprising the study group received anti inflammatory paste (amlexanox 5%) applied four times daily and the control group of 50 patients received topical antiseptic, analgesic, and anesthetic agent (benzalkonium chloride 0.01%, choline salicylate 8.7% and lidocaine hydrochloride 2%) paste, patients were evaluated after 3rd, 6th, 9th and on 30th, 60th day for recurrence. Results: The study group had reduction in ulcer number, size; erythema, pain and frequency of ulcers during follow up. The healing period and recurrence of ulceration reduced in both the groups but the study group had significant reduction in 30th and 60th day follow up for recurrence of ulcers. Conclusion: Amlexanox 5% can reduce the frequency, duration and symptoms associated with the aphthous ulcers with no sideeffects attributed to the drug. How to cite the article: Darshan DD, Kumar CN, Kumar AD, Manikantan NS, Balakrishnan D, Uthkal MP. Clinical study to know the efficacy of Amlexanox 5% with other topical Antiseptic, Analgesic and Anesthetic agents in treating minor RAS. J Int Oral Health 2014;6(1);5-11. PMID:24653596

Adaptivity in Agent-Based Routing for Data Networks

NASA Technical Reports Server (NTRS)

Wolpert, David H.; Kirshner, Sergey; Merz, Chris J.; Turner, Kagan

2000-01-01

Adaptivity, both of the individual agents and of the interaction structure among the agents, seems indispensable for scaling up multi-agent systems (MAS s) in noisy environments. One important consideration in designing adaptive agents is choosing their action spaces to be as amenable as possible to machine learning techniques, especially to reinforcement learning (RL) techniques. One important way to have the interaction structure connecting agents itself be adaptive is to have the intentions and/or actions of the agents be in the input spaces of the other agents, much as in Stackelberg games. We consider both kinds of adaptivity in the design of a MAS to control network packet routing. We demonstrate on the OPNET event-driven network simulator the perhaps surprising fact that simply changing the action space of the agents to be better suited to RL can result in very large improvements in their potential performance: at their best settings, our learning-amenable router agents achieve throughputs up to three and one half times better than that of the standard Bellman-Ford routing algorithm, even when the Bellman-Ford protocol traffic is maintained. We then demonstrate that much of that potential improvement can be realized by having the agents learn their settings when the agent interaction structure is itself adaptive.

40 CFR 152.403 - Definitions of fee categories.

Code of Federal Regulations, 2014 CFR

2014-07-01

... small-scale field testing of microbial pest control agents (40 CFR 172.3). [53 FR 19114, May 26, 1988... categories. (a) New chemical registration review means review of an application for registration of a pesticide product containing a chemical active ingredient which is not contained as an active ingredient in...

40 CFR 152.403 - Definitions of fee categories.

Code of Federal Regulations, 2010 CFR

2010-07-01

... small-scale field testing of microbial pest control agents (40 CFR 172.3). [53 FR 19114, May 26, 1988... categories. (a) New chemical registration review means review of an application for registration of a pesticide product containing a chemical active ingredient which is not contained as an active ingredient in...

40 CFR 152.403 - Definitions of fee categories.

Code of Federal Regulations, 2013 CFR

2013-07-01

... small-scale field testing of microbial pest control agents (40 CFR 172.3). [53 FR 19114, May 26, 1988... categories. (a) New chemical registration review means review of an application for registration of a pesticide product containing a chemical active ingredient which is not contained as an active ingredient in...

40 CFR 152.403 - Definitions of fee categories.

Code of Federal Regulations, 2011 CFR

2011-07-01

... small-scale field testing of microbial pest control agents (40 CFR 172.3). [53 FR 19114, May 26, 1988... categories. (a) New chemical registration review means review of an application for registration of a pesticide product containing a chemical active ingredient which is not contained as an active ingredient in...

40 CFR 152.403 - Definitions of fee categories.

Code of Federal Regulations, 2012 CFR

2012-07-01

... small-scale field testing of microbial pest control agents (40 CFR 172.3). [53 FR 19114, May 26, 1988... categories. (a) New chemical registration review means review of an application for registration of a pesticide product containing a chemical active ingredient which is not contained as an active ingredient in...

Intraguild Predation Among Biological Control Agents Used in Greenhouse Floriculture Crops: A Preliminary Review

USDA-ARS?s Scientific Manuscript database

Literature on intraguild predation (IGP) in greenhouse floriculture (GHFC) was reviewed. Despite production practices that could increase the incidence IGP, no studies concretely showed that IGP disrupts GHFC biocontrol. Further studies need to include large-scale trials over entire crop cycles. H...

A Distributed Platform for Global-Scale Agent-Based Models of Disease Transmission

PubMed Central

Parker, Jon; Epstein, Joshua M.

2013-01-01

The Global-Scale Agent Model (GSAM) is presented. The GSAM is a high-performance distributed platform for agent-based epidemic modeling capable of simulating a disease outbreak in a population of several billion agents. It is unprecedented in its scale, its speed, and its use of Java. Solutions to multiple challenges inherent in distributing massive agent-based models are presented. Communication, synchronization, and memory usage are among the topics covered in detail. The memory usage discussion is Java specific. However, the communication and synchronization discussions apply broadly. We provide benchmarks illustrating the GSAM’s speed and scalability. PMID:24465120

Green chemistry focus on optimization of silver nanoparticles using response surface methodology (RSM) and mosquitocidal activity: Anopheles stephensi (Diptera: Culicidae).

PubMed

Ondari Nyakundi, Erick; Padmanabhan, M Nalini

2015-01-01

There is an exigent necessity for development of environmental friendly bio-control agent(s) for elimination of mosquito due to increased resistance resurgence against synthetic control agents. Mosquito control strategy will lay a strong foundation to malaria exclusion or it can be curbed to certain level especially in the developing nations. In this study, silver nanoparticles were synthesized by green chemistry approach using Tridax procumbens leaf extract as a reducing agent. The reaction medium involved in the synthesis process was optimized by statistical experimental design using response surface methodology to obtain better yield, uniform size, shape and stability. Further, these synthesized nanoparticles were confirmed through UV-Visible, FT-IR spectroscopy, PSA and SEM Subsequently, the bioefficacy of these particles were investigated on Anopheles stephensi for larvicidal and pupicidal activity. Interestingly, time period of 90 min, temperature of 76±2 °C, pH 7.2±2, 2 mM silver nitrate (AgNO3), 3mM PEG and 2mM PVP showed excellent parameters for bioprocess design for large scale production of stabilized nanoparticles. A concentration of 5 ppm of PVP stabilized nanoparticles exhibited 100% mortality. Thus, the obtained results clearly suggest that silver nanoparticles stabilized by PEG and PVP may have important function as stabilizers, dispersants as well as larvicides for mosquito control. Copyright © 2015 Elsevier B.V. All rights reserved.

Biobotic insect swarm based sensor networks for search and rescue

NASA Astrophysics Data System (ADS)

Bozkurt, Alper; Lobaton, Edgar; Sichitiu, Mihail; Hedrick, Tyson; Latif, Tahmid; Dirafzoon, Alireza; Whitmire, Eric; Verderber, Alexander; Marin, Juan; Xiong, Hong

2014-06-01

The potential benefits of distributed robotics systems in applications requiring situational awareness, such as search-and-rescue in emergency situations, are indisputable. The efficiency of such systems requires robotic agents capable of coping with uncertain and dynamic environmental conditions. For example, after an earthquake, a tremendous effort is spent for days to reach to surviving victims where robotic swarms or other distributed robotic systems might play a great role in achieving this faster. However, current technology falls short of offering centimeter scale mobile agents that can function effectively under such conditions. Insects, the inspiration of many robotic swarms, exhibit an unmatched ability to navigate through such environments while successfully maintaining control and stability. We have benefitted from recent developments in neural engineering and neuromuscular stimulation research to fuse the locomotory advantages of insects with the latest developments in wireless networking technologies to enable biobotic insect agents to function as search-and-rescue agents. Our research efforts towards this goal include development of biobot electronic backpack technologies, establishment of biobot tracking testbeds to evaluate locomotion control efficiency, investigation of biobotic control strategies with Gromphadorhina portentosa cockroaches and Manduca sexta moths, establishment of a localization and communication infrastructure, modeling and controlling collective motion by learning deterministic and stochastic motion models, topological motion modeling based on these models, and the development of a swarm robotic platform to be used as a testbed for our algorithms.

A framework for identifying water management typologies for agent based modeling of water resources and its application in the Boise River Basin, USA.

NASA Astrophysics Data System (ADS)

Kaiser, K. E.; Flores, A. N.; Hillis, V.; Moroney, J.; Schneider, J.

2017-12-01

Modeling the management of water resources necessitates incorporation of complex social and hydrologic dynamics. Simulation of these socio-ecological systems requires characterization of the decision-making process of relevant actors, the mechanisms through which they exert control on the biophysical system, their ability to react and adapt to regional environmental conditions, and the plausible behaviors in response to changes in those conditions. Agent based models (ABMs) are a useful tool in simulating these complex adaptive systems because they can dynamically couple hydrological models and the behavior of decision making actors. ABMs can provide a flexible, integrated framework that can represent multi-scale interactions, and the heterogeneity of information networks and sources. However, the variability in behavior of water management actors across systems makes characterizing agent behaviors and relationships challenging. Agent typologies, or agent functional types (AFTs), group together individuals and/or agencies with similar functional roles, management objectives, and decision-making strategies. AFTs have been used to represent archetypal land managers in the agricultural and forestry sectors in large-scale socio-economic system models. A similar typology of water actors could simplify the representation of water management across river basins, and increase transferability and scaling of resulting ABMs. Here, we present a framework for identifying and classifying major water actors and show how we will link an ABM of water management to a regional hydrologic model in a western river basin. The Boise River Basin in southwest Idaho is an interesting setting to apply our AFT framework because of the diverse stakeholders and associated management objectives which include managing urban growth pressures and water supply in the face of climate change. Precipitation in the upper basin supplies 90% of the surface water used in the basin, thus managers of the reservoir system (located in the upper basin) must balance flood control for the metropolitan area with water supply for downstream agricultural and hydropower use. Identifying dominant water management typologies that include state and federal agencies will increase the transferability of water management ABMs in the western US.

Distributed Coordinated Control of Large-Scale Nonlinear Networks

DOE PAGES

Kundu, Soumya; Anghel, Marian

2015-11-08

We provide a distributed coordinated approach to the stability analysis and control design of largescale nonlinear dynamical systems by using a vector Lyapunov functions approach. In this formulation the large-scale system is decomposed into a network of interacting subsystems and the stability of the system is analyzed through a comparison system. However finding such comparison system is not trivial. In this work, we propose a sum-of-squares based completely decentralized approach for computing the comparison systems for networks of nonlinear systems. Moreover, based on the comparison systems, we introduce a distributed optimal control strategy in which the individual subsystems (agents) coordinatemore » with their immediate neighbors to design local control policies that can exponentially stabilize the full system under initial disturbances.We illustrate the control algorithm on a network of interacting Van der Pol systems.« less

Robust Structural Analysis and Design of Distributed Control Systems to Prevent Zero Dynamics Attacks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weerakkody, Sean; Liu, Xiaofei; Sinopoli, Bruno

We consider the design and analysis of robust distributed control systems (DCSs) to ensure the detection of integrity attacks. DCSs are often managed by independent agents and are implemented using a diverse set of sensors and controllers. However, the heterogeneous nature of DCSs along with their scale leave such systems vulnerable to adversarial behavior. To mitigate this reality, we provide tools that allow operators to prevent zero dynamics attacks when as many as p agents and sensors are corrupted. Such a design ensures attack detectability in deterministic systems while removing the threat of a class of stealthy attacks in stochasticmore » systems. To achieve this goal, we use graph theory to obtain necessary and sufficient conditions for the presence of zero dynamics attacks in terms of the structural interactions between agents and sensors. We then formulate and solve optimization problems which minimize communication networks while also ensuring a resource limited adversary cannot perform a zero dynamics attacks. Polynomial time algorithms for design and analysis are provided.« less

The role of fanatics in consensus formation

NASA Astrophysics Data System (ADS)

Gündüç, Semra

2015-08-01

A model of opinion dynamics with two types of agents as social actors are presented, using the Ising thermodynamic model as the dynamics template. The agents are considered as opportunists which live at sites and interact with the neighbors, or fanatics/missionaries which move from site to site randomly in persuasion of converting agents of opposite opinion with the help of opportunists. Here, the moving agents act as an external influence on the opportunists to convert them to the opposite opinion. It is shown by numerical simulations that such dynamics of opinion formation may explain some details of consensus formation even when one of the opinions are held by a minority. Regardless the distribution of the opinion, different size societies exhibit different opinion formation behavior and time scales. In order to understand general behavior, the scaling relations obtained by comparing opinion formation processes observed in societies with varying population and number of randomly moving agents are studied. For the proposed model two types of scaling relations are observed. In fixed size societies, increasing the number of randomly moving agents give a scaling relation for the time scale of the opinion formation process. The second type of scaling relation is due to the size dependent information propagation in finite but large systems, namely finite-size scaling.

Behavior control in the sensorimotor loop with short-term synaptic dynamics induced by self-regulating neurons.

PubMed

Toutounji, Hazem; Pasemann, Frank

2014-01-01

The behavior and skills of living systems depend on the distributed control provided by specialized and highly recurrent neural networks. Learning and memory in these systems is mediated by a set of adaptation mechanisms, known collectively as neuronal plasticity. Translating principles of recurrent neural control and plasticity to artificial agents has seen major strides, but is usually hampered by the complex interactions between the agent's body and its environment. One of the important standing issues is for the agent to support multiple stable states of behavior, so that its behavioral repertoire matches the requirements imposed by these interactions. The agent also must have the capacity to switch between these states in time scales that are comparable to those by which sensory stimulation varies. Achieving this requires a mechanism of short-term memory that allows the neurocontroller to keep track of the recent history of its input, which finds its biological counterpart in short-term synaptic plasticity. This issue is approached here by deriving synaptic dynamics in recurrent neural networks. Neurons are introduced as self-regulating units with a rich repertoire of dynamics. They exhibit homeostatic properties for certain parameter domains, which result in a set of stable states and the required short-term memory. They can also operate as oscillators, which allow them to surpass the level of activity imposed by their homeostatic operation conditions. Neural systems endowed with the derived synaptic dynamics can be utilized for the neural behavior control of autonomous mobile agents. The resulting behavior depends also on the underlying network structure, which is either engineered or developed by evolutionary techniques. The effectiveness of these self-regulating units is demonstrated by controlling locomotion of a hexapod with 18 degrees of freedom, and obstacle-avoidance of a wheel-driven robot.

Behavior control in the sensorimotor loop with short-term synaptic dynamics induced by self-regulating neurons

PubMed Central

Toutounji, Hazem; Pasemann, Frank

2014-01-01

The behavior and skills of living systems depend on the distributed control provided by specialized and highly recurrent neural networks. Learning and memory in these systems is mediated by a set of adaptation mechanisms, known collectively as neuronal plasticity. Translating principles of recurrent neural control and plasticity to artificial agents has seen major strides, but is usually hampered by the complex interactions between the agent's body and its environment. One of the important standing issues is for the agent to support multiple stable states of behavior, so that its behavioral repertoire matches the requirements imposed by these interactions. The agent also must have the capacity to switch between these states in time scales that are comparable to those by which sensory stimulation varies. Achieving this requires a mechanism of short-term memory that allows the neurocontroller to keep track of the recent history of its input, which finds its biological counterpart in short-term synaptic plasticity. This issue is approached here by deriving synaptic dynamics in recurrent neural networks. Neurons are introduced as self-regulating units with a rich repertoire of dynamics. They exhibit homeostatic properties for certain parameter domains, which result in a set of stable states and the required short-term memory. They can also operate as oscillators, which allow them to surpass the level of activity imposed by their homeostatic operation conditions. Neural systems endowed with the derived synaptic dynamics can be utilized for the neural behavior control of autonomous mobile agents. The resulting behavior depends also on the underlying network structure, which is either engineered or developed by evolutionary techniques. The effectiveness of these self-regulating units is demonstrated by controlling locomotion of a hexapod with 18 degrees of freedom, and obstacle-avoidance of a wheel-driven robot. PMID:24904403

Noise Response Data Reveal Novel Controllability Gramian for Nonlinear Network Dynamics

PubMed Central

Kashima, Kenji

2016-01-01

Control of nonlinear large-scale dynamical networks, e.g., collective behavior of agents interacting via a scale-free connection topology, is a central problem in many scientific and engineering fields. For the linear version of this problem, the so-called controllability Gramian has played an important role to quantify how effectively the dynamical states are reachable by a suitable driving input. In this paper, we first extend the notion of the controllability Gramian to nonlinear dynamics in terms of the Gibbs distribution. Next, we show that, when the networks are open to environmental noise, the newly defined Gramian is equal to the covariance matrix associated with randomly excited, but uncontrolled, dynamical state trajectories. This fact theoretically justifies a simple Monte Carlo simulation that can extract effectively controllable subdynamics in nonlinear complex networks. In addition, the result provides a novel insight into the relationship between controllability and statistical mechanics. PMID:27264780

Treating pain on skin graft donor sites: Review and clinical recommendations.

PubMed

Sinha, Sarthak; Schreiner, Amanda J; Biernaskie, Jeff; Nickerson, Duncan; Gabriel, Vincent A

2017-11-01

Split-thickness skin grafting is the most common reconstructive procedure in managing burn injuries. Harvesting split-thickness skin creates a new partial thickness wound referred to as the donor site. Pain at the donor site is reported to be one of the most distressing symptoms during the early postoperative period. Here, we (a) identify strategies for managing donor site pain, (b) assess the quality of individual studies, and (c) formulate evidence-based recommendations based on the amount and consistency of evidence. Our analysis revealed five distinct approaches to minimize donor site pain. These include: continuous subcutaneous local anesthetic infusion (three studies), subcutaneous anesthetic injection (five studies), topical agents (six studies), nonpharmacological interventions (three studies), and wound dressings (18 studies). Available randomized control trials typically evaluated pain on standardized scales (i.e. Visual Analog Scale, Numerical Rating Scale), and compared the experimental group with standard care. Recommended treatments include: (a) subcutaneous anesthetic injection of adrenaline-lidocaine; (b) ice application; (c) topical agents, such as lidocaine and bupivacaine; and (d) hydrocolloid- and polyurethane-based wound dressings accompanied with fibrin sealant. Methodologically sound randomized control trials examining the efficacy of modified tumescent solution, ropivacaine, plasma therapy, noncontact ultrasound, and morphine gels are lacking and should be a priority for future research.

39 CFR 233.8 - Expedited forfeiture proceedings for property seized for administrative forfeiture involving...

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Evidence, such as drug scales, drug distribution paraphernalia, drug records, drug packaging material, method of drug packaging, drug “cutting” agents and other equipment, that indicates an intent to process... a controlled substance is presumed to be for personal use when there are no indicia of illicit drug...

39 CFR 233.8 - Expedited forfeiture proceedings for property seized for administrative forfeiture involving...

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Evidence, such as drug scales, drug distribution paraphernalia, drug records, drug packaging material, method of drug packaging, drug “cutting” agents and other equipment, that indicates an intent to process... a controlled substance is presumed to be for personal use when there are no indicia of illicit drug...

Facilitating the Specification Capture and Transformation Process in the Development of Multi-Agent Systems

NASA Technical Reports Server (NTRS)

Filho, Aluzio Haendehen; Caminada, Numo; Haeusler, Edward Hermann; vonStaa, Arndt

2004-01-01

To support the development of flexible and reusable MAS, we have built a framework designated MAS-CF. MAS-CF is a component framework that implements a layered architecture based on contextual composition. Interaction rules, controlled by architecture mechanisms, ensure very low coupling, making possible the sharing of distributed services in a transparent, dynamic and independent way. These properties propitiate large-scale reuse, since organizational abstractions can be reused and propagated to all instances created from a framework. The objective is to reduce complexity and development time of multi-agent systems through the reuse of generic organizational abstractions.

Further Structural Intelligence for Sensors Cluster Technology in Manufacturing

PubMed Central

Mekid, Samir

2006-01-01

With the ever increasing complex sensing and actuating tasks in manufacturing plants, intelligent sensors cluster in hybrid networks becomes a rapidly expanding area. They play a dominant role in many fields from macro and micro scale. Global object control and the ability to self organize into fault-tolerant and scalable systems are expected for high level applications. In this paper, new structural concepts of intelligent sensors and networks with new intelligent agents are presented. Embedding new functionalities to dynamically manage cooperative agents for autonomous machines are interesting key enabling technologies most required in manufacturing for zero defects production.

Review of Pasteuria penetrans: Biology, Ecology, and Biological Control Potential.

PubMed

Chen, Z X; Dickson, D W

1998-09-01

Pasteuria penetrans is a mycelial, endospore-forming, bacterial parasite that has shown great potential as a biological control agent of root-knot nematodes. Considerable progress has been made during the last 10 years in understanding its biology and importance as an agent capable of effectively suppressing root-knot nematodes in field soil. The objective of this review is to summarize the current knowledge of the biology, ecology, and biological control potential of P. penetrans and other Pasteuria members. Pasteuria spp. are distributed worldwide and have been reported from 323 nematode species belonging to 116 genera of free-living, predatory, plant-parasitic, and entomopathogenic nematodes. Artificial cultivation of P. penetrans has met with limited success; large-scale production of endospores depends on in vivo cultivation. Temperature affects endospore attachment, germination, pathogenesis, and completion of the life cycle in the nematode pseudocoelom. The biological control potential of Pasteuria spp. have been demonstrated on 20 crops; host nematodes include Belonolaimus longicaudatus, Heterodera spp., Meloidogyne spp., and Xiphinema diversicaudatum. Pasteuria penetrans plays an important role in some suppressive soils. The efficacy of the bacterium as a biological control agent has been examined. Approximately 100,000 endospores/g of soil provided immediate control of the peanut root-knot nematode, whereas 1,000 and 5,000 endospores/g of soil each amplified in the host nematode and became suppressive after 3 years.

A randomized placebo-controlled trial to evaluate a novel noninjectable anesthetic gel with thermosetting agent during scaling and root planing in chronic periodontitis patients.

PubMed

Dayakar, M M; Akbar, S M

2016-01-01

To study the efficacy of a noninjectable anesthetic gel with a thermosetting agent in the reduction of pain during scaling and root planing (SRP) in untreated chronic periodontitis patients. This study is a randomized, double-masked, split-mouth, placebo-controlled trial. Thirty patients were enrolled who underwent SRP in a split-mouth (right side/left side) manner. Before commencement of SRP, both quadrants on each side were isolated and had a randomized gel (either placebo or test gel) placed in the periodontal pockets for 30 s. The pain was measured using numerical rating scale (NRS) and verbal rating scale (VRS). The median NRS pain score for the patients treated with the anesthetic test gel was 1 (range: 0-4) as opposed to 5 (range: 3-7) in the placebo treated patients. The mean rank of pain score using NRS in test gel was 16.18 as compared to 44.82 in placebo treated sites. Hence, significant reduction in pain was found in test gel as compared to placebo using NRS (P < 0.001). The VRS showed that the majority of patients reported no pain or mild pain with a median of 1 as compared to placebo treated sites with a median of 2 suggestive of moderate pain. The NRS and VRS pain scores showed that the side treated with anesthetic gel was statistically more effective than the placebo in reducing pain during SRP.

Delivering Cognitive Behavior Therapy to Young Adults With Symptoms of Depression and Anxiety Using a Fully Automated Conversational Agent (Woebot): A Randomized Controlled Trial

PubMed Central

Vierhile, Molly

2017-01-01

Background Web-based cognitive-behavioral therapeutic (CBT) apps have demonstrated efficacy but are characterized by poor adherence. Conversational agents may offer a convenient, engaging way of getting support at any time. Objective The objective of the study was to determine the feasibility, acceptability, and preliminary efficacy of a fully automated conversational agent to deliver a self-help program for college students who self-identify as having symptoms of anxiety and depression. Methods In an unblinded trial, 70 individuals age 18-28 years were recruited online from a university community social media site and were randomized to receive either 2 weeks (up to 20 sessions) of self-help content derived from CBT principles in a conversational format with a text-based conversational agent (Woebot) (n=34) or were directed to the National Institute of Mental Health ebook, “Depression in College Students,” as an information-only control group (n=36). All participants completed Web-based versions of the 9-item Patient Health Questionnaire (PHQ-9), the 7-item Generalized Anxiety Disorder scale (GAD-7), and the Positive and Negative Affect Scale at baseline and 2-3 weeks later (T2). Results Participants were on average 22.2 years old (SD 2.33), 67% female (47/70), mostly non-Hispanic (93%, 54/58), and Caucasian (79%, 46/58). Participants in the Woebot group engaged with the conversational agent an average of 12.14 (SD 2.23) times over the study period. No significant differences existed between the groups at baseline, and 83% (58/70) of participants provided data at T2 (17% attrition). Intent-to-treat univariate analysis of covariance revealed a significant group difference on depression such that those in the Woebot group significantly reduced their symptoms of depression over the study period as measured by the PHQ-9 (F=6.47; P=.01) while those in the information control group did not. In an analysis of completers, participants in both groups significantly reduced anxiety as measured by the GAD-7 (F1,54= 9.24; P=.004). Participants’ comments suggest that process factors were more influential on their acceptability of the program than content factors mirroring traditional therapy. Conclusions Conversational agents appear to be a feasible, engaging, and effective way to deliver CBT. PMID:28588005

Identifying chemicals of concern in hydraulic fracturing fluids used for oil production.

PubMed

Stringfellow, William T; Camarillo, Mary Kay; Domen, Jeremy K; Sandelin, Whitney L; Varadharajan, Charuleka; Jordan, Preston D; Reagan, Matthew T; Cooley, Heather; Heberger, Matthew G; Birkholzer, Jens T

2017-01-01

Chemical additives used for hydraulic fracturing and matrix acidizing of oil reservoirs were reviewed and priority chemicals of concern needing further environmental risk assessment, treatment demonstration, or evaluation of occupational hazards were identified. We evaluated chemical additives used for well stimulation in California, the third largest oil producing state in the USA, by the mass and frequency of use, as well as toxicity. The most frequently used chemical additives in oil development were gelling agents, cross-linkers, breakers, clay control agents, iron and scale control agents, corrosion inhibitors, biocides, and various impurities and product stabilizers used as part of commercial mixtures. Hydrochloric and hydrofluoric acids, used for matrix acidizing and other purposes, were reported infrequently. A large number and mass of solvents and surface active agents were used, including quaternary ammonia compounds (QACs) and nonionic surfactants. Acute toxicity was evaluated and many chemicals with low hazard to mammals were identified as potentially hazardous to aquatic environments. Based on an analysis of quantities used, toxicity, and lack of adequate hazard evaluation, QACs, biocides, and corrosion inhibitors were identified as priority chemicals of concern that deserve further investigation. Copyright © 2016 Elsevier Ltd. All rights reserved.

How Students Create Motivationally Supportive Learning Environments for Themselves: The Concept of Agentic Engagement

ERIC Educational Resources Information Center

Reeve, Johnmarshall

2013-01-01

The present study introduced "agentic engagement" as a newly proposed student-initiated pathway to greater achievement and greater motivational support. Study 1 developed the brief, construct-congruent, and psychometrically strong Agentic Engagement Scale. Study 2 provided evidence for the scale's construct and predictive validity, as…

Job stress and agentic-communal personality traits related to serum cortisol levels of male workers in a Japanese medium-sized company: a cross-sectional study.

PubMed

Hirokawa, Kumi; Taniguchi, Toshiyo; Fujii, Yasuhito

2015-02-01

Although serum cortisol is a widely accepted index of stress levels, associations between job stress and cortisol levels have been inconsistent. Individual differences in personality traits were discussed as one compelling explanation for this discrepancy. Agentic-communal personality traits have been examined as possible predictive factors for psychological stress. This study investigated correlations among agentic-communal personality traits and serum cortisol levels. It was also investigated whether job stress levels modified correlations between agentic-communal personality and cortisol levels. Participants were 198 male workers (mean age = 52.2 years) employed by a shipbuilding company in Japan. Questionnaire data and blood samples were collected during an annual health checkup. Participants completed a self-report questionnaire that included the Job Content Questionnaire (JCQ) that assesses job control as job stress levels the Communion-Agency scale (CAS) and questions regarding health behaviors. Communion positively correlated with serum cortisol levels and unmitigated agency negatively correlated with serum cortisol levels. Stratified by job control, communion positively correlated with serum cortisol levels and agency negatively correlated with serum cortisol levels in participants with low levels of job control. Unmitigated agency negatively correlated with serum cortisol levels in participants with high levels of job control. Levels of job control may modify correlations of gender-related personality with serum cortisol levels. Especially with exposure to high job stress, male workers with high femininity (i.e., high communion and low agency) were more likely to have a high stress response as measured by serum cortisol levels.

Cellular Decomposition Based Hybrid-Hierarchical Control Systems with Applications to Flight Management Systems

NASA Technical Reports Server (NTRS)

Caines, P. E.

1999-01-01

The work in this research project has been focused on the construction of a hierarchical hybrid control theory which is applicable to flight management systems. The motivation and underlying philosophical position for this work has been that the scale, inherent complexity and the large number of agents (aircraft) involved in an air traffic system imply that a hierarchical modelling and control methodology is required for its management and real time control. In the current work the complex discrete or continuous state space of a system with a small number of agents is aggregated in such a way that discrete (finite state machine or supervisory automaton) controlled dynamics are abstracted from the system's behaviour. High level control may then be either directly applied at this abstracted level, or, if this is in itself of significant complexity, further layers of abstractions may be created to produce a system with an acceptable degree of complexity at each level. By the nature of this construction, high level commands are necessarily realizable at lower levels in the system.

Climate as an agent of change in forest landscapes

Treesearch

Louis R. Iverson; Anantha M. Prasad; Stephen N. Matthews; Matthew P. Peters

2014-01-01

Climate is the primary force that controls forest composition and the broad-scale distribution of forests. The climate has always been changing, but the changes now underway are different—they are faster and they are intermingled with other disturbances promoted by increasing human pressures. The projected climate change during the twenty-first century will...

JV Task 98 - Controlling Mercury Emissions for Utilities Firing Lignites from North America

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steven Benson

2007-06-15

This project compiled and summarized the findings and conclusions of research, development, and demonstration projects on controlling mercury from lignite coals. A significant amount of work has been conducted since 1994 on mercury in lignite, mercury measurement in flue gases, sorbent, sorbent enhancement additives, oxidation agent development, and full-scale demonstration of mercury control technologies. This report is focused on providing the lignite industry with an understanding of mercury issues associated with the combustion of lignite, as well as providing vital information on the methods to control mercury emissions in coal-fired power plants.

Liquefaction process

DOEpatents

Gorbaty, Martin L.; Stone, John B.; Poddar, Syamal K.

1982-01-01

Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by pretreatment with a combination of pretreating agents comprising SO.sub.2 and an oxidizing agent. The pretreatment is believed to convert at least a portion of the scale-forming components and particularly calcium, to the corresponding sulfate prior to liquefaction. The pretreatment may be accomplished with the combination of pretreating agents either simultaneously by using a mixture comprising SO.sub.2 and an oxidizing agent or sequentially by first treating with SO.sub.2 and then with an oxidizing agent.

Localized Enzymatic Degradation of Polymers: Physics and Scaling Laws

NASA Astrophysics Data System (ADS)

Lalitha Sridhar, Shankar; Vernerey, Franck

2018-03-01

Biodegradable polymers are naturally abundant in living matter and have led to great advances in controlling environmental pollution due to synthetic polymer products, harnessing renewable energy from biofuels, and in the field of biomedicine. One of the most prevalent mechanisms of biodegradation involves enzyme-catalyzed depolymerization by biological agents. Despite numerous studies dedicated to understanding polymer biodegradation in different environments, a simple model that predicts the macroscopic behavior (mass and structural loss) in terms of microphysical processes (enzyme transport and reaction) is lacking. An interesting phenomenon occurs when an enzyme source (released by a biological agent) attacks a tight polymer mesh that restricts free diffusion. A fuzzy interface separating the intact and fully degraded polymer propagates away from the source and into the polymer as the enzymes diffuse and react in time. Understanding the characteristics of this interface will provide crucial insight into the biodegradation process and potential ways to precisely control it. In this work, we present a centrosymmetric model of biodegradation by characterizing the moving fuzzy interface in terms of its speed and width. The model predicts that the characteristics of this interface are governed by two time scales, namely the polymer degradation and enzyme transport times, which in turn depend on four main polymer and enzyme properties. A key finding of this work is simple scaling laws that can be used to guide biodegradation of polymers in different applications.

Minoxidil-associated anorexia in an infant with refractory hypertension.

PubMed

Vesoulis, Zachary A; Attarian, Stephanie J; Zeller, Brandy; Cole, Francis Sessions

2014-12-01

Minoxidil is a potent antihypertensive used as an adjunctive agent in refractory hypertension. It exerts an antihypertensive effect through two mechanisms: selective arterial vasodilation by activation of potassium channels in the vascular smooth muscle and stimulation of carotid and aortic baroreceptors, leading to downstream release of renin and norepinephrine. Although frequently cited in reviews of antihypertensive agents, limited data about the use of minoxidil in neonates are available. We describe an infant girl, born at 35 weeks of gestation, who was diagnosed with idiopathic hypertension after extensive diagnostic evaluation. Adequate blood pressure control was not achieved with captopril, amlodipine, and clonidine. Oliguria secondary to captopril and rapid-onset congestive heart failure due to persistent hypertension led to the introduction of intravenous agents labetalol and nitroprusside. Although adequate blood pressure control was achieved, attempts to transition back to oral agents were unsuccessful, prompting the use of minoxidil as an alternative agent. Although good blood pressure control was achieved, the infant's oral intake plummeted from 210 to 63 ml/kg/day. The anorexia quickly resolved after stopping minoxidil, and she was discharged home at 5 months of age receiving propranolol, amlodipine, and doxazosin. Use of the Naranjo adverse drug reaction probability scale indicated a definite relationship (score of 10) between the patient's development of anorexia and minoxidil therapy. To our knowledge, there have been no previous reports of minoxidil-associated anorexia in preterm or term infants. Clinicians should be aware that anorexia is a possible adverse effect of minoxidil in this patient population when initiating the drug in similar patients. © 2014 Pharmacotherapy Publications, Inc.

A population-based study of the comparative effectiveness of second-generation antipsychotics vs older antimanic agents in bipolar disorder.

PubMed

Bauer, Mark S; Miller, Christopher J; Li, Mingfei; Bajor, Laura A; Lee, Austin

2016-09-01

Numerous antimanic treatments have been introduced over the past two decades, particularly second-generation antipsychotics (SGAs). However, it is not clear whether such newer agents provide any advantage over older treatments. A historical cohort design investigated the nationwide population of outpatients with bipolar disorder treated in the Department of Veterans Affairs who were newly initiated on an antimanic agent between 2003 and 2010 (N=27 727). The primary outcome was likelihood of all-cause hospitalization during the year after initiation, controlling for numerous demographic, clinical, and treatment characteristics. Potential correlates of effect were explored by investigating time to initiation of a second antimanic agent or antidepressant. After control for covariates, those initiated on lithium or valproate monotherapy, compared to those beginning SGA monotherapy, were significantly less likely to be hospitalized, had a longer time to hospitalization, and had fewer hospitalizations in the subsequent year. Those on combination treatment had a significantly higher likelihood of hospitalization, although they also had a longer time to addition of an additional antimanic agent or antidepressant. The present analysis of a large and unselected nationwide population provides important complementary data to that from controlled trials. Although various mechanisms may be responsible for the results, the data support the utilization of lithium or valproate, rather than SGAs, as the initial antimanic treatment in bipolar disorder. A large-scale, prospective, randomized, pragmatic clinical trial comparing the initiation of SGA monotherapy to that of lithium or valproate monotherapy is a logical next step. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Water diffusion-exchange effect on the paramagnetic relaxation enhancement in off-resonance rotating frame

NASA Astrophysics Data System (ADS)

Zhang, Huiming; Xie, Yang; Ji, Tongyu

2007-06-01

The off-resonance rotating frame technique based on the spin relaxation properties of off-resonance T1 ρ can significantly increase the sensitivity of detecting paramagnetic labeling at high magnetic fields by MRI. However, the in vivo detectable dimension for labeled cell clusters/tissues in T1 ρ-weighted images is limited by the water diffusion-exchange between mesoscopic scale compartments. An experimental investigation of the effect of water diffusion-exchange between compartments on the paramagnetic relaxation enhancement of paramagnetic agent compartment is presented for in vitro/ in vivo models. In these models, the size of paramagnetic agent compartment is comparable to the mean diffusion displacement of water molecules during the long RF pulses that are used to generate the off-resonance rotating frame. The three main objectives of this study were: (1) to qualitatively correlate the effect of water diffusion-exchange with the RF parameters of the long pulse and the rates of water diffusion, (2) to explore the effect of water diffusion-exchange on the paramagnetic relaxation enhancement in vitro, and (3) to demonstrate the paramagnetic relaxation enhancement in vivo. The in vitro models include the water permeable dialysis tubes or water permeable hollow fibers embedded in cross-linked proteins gels. The MWCO of the dialysis tubes was chosen from 0.1 to 15 kDa to control the water diffusion rate. Thin hollow fibers were chosen to provide sub-millimeter scale compartments for the paramagnetic agents. The in vivo model utilized the rat cerebral vasculatures as a paramagnetic agent compartment, and intravascular agents (Gd-DTPA) 30-BSA were administrated into the compartment via bolus injections. Both in vitro and in vivo results demonstrate that the paramagnetic relaxation enhancement is predominant in the T1 ρ-weighted image in the presence of water diffusion-exchange. The T1 ρ contrast has substantially higher sensitivity than the conventional T1 contrast in detecting paramagnetic agents, especially at low paramagnetic agent volumetric fractions, low paramagnetic agent concentrations, and low RF amplitudes. Short pulse duration, short pulse recycle delay and efficient paramagnetic relaxation can reduce the influence of water diffusion-exchange on the paramagnetic enhancement. This study paves the way for the design of off-resonance rotating experiments to detect labeled cell clusters/tissue compartments in vivo at a sub-millimeter scale.

Intelligent Design of Nano-Scale Molecular Imaging Agents

PubMed Central

Kim, Sung Bae; Hattori, Mitsuru; Ozawa, Takeaki

2012-01-01

Visual representation and quantification of biological processes at the cellular and subcellular levels within living subjects are gaining great interest in life science to address frontier issues in pathology and physiology. As intact living subjects do not emit any optical signature, visual representation usually exploits nano-scale imaging agents as the source of image contrast. Many imaging agents have been developed for this purpose, some of which exert nonspecific, passive, and physical interaction with a target. Current research interest in molecular imaging has mainly shifted to fabrication of smartly integrated, specific, and versatile agents that emit fluorescence or luminescence as an optical readout. These agents include luminescent quantum dots (QDs), biofunctional antibodies, and multifunctional nanoparticles. Furthermore, genetically encoded nano-imaging agents embedding fluorescent proteins or luciferases are now gaining popularity. These agents are generated by integrative design of the components, such as luciferase, flexible linker, and receptor to exert a specific on–off switching in the complex context of living subjects. In the present review, we provide an overview of the basic concepts, smart design, and practical contribution of recent nano-scale imaging agents, especially with respect to genetically encoded imaging agents. PMID:23235326

Intelligent design of nano-scale molecular imaging agents.

PubMed

Kim, Sung Bae; Hattori, Mitsuru; Ozawa, Takeaki

2012-12-12

Visual representation and quantification of biological processes at the cellular and subcellular levels within living subjects are gaining great interest in life science to address frontier issues in pathology and physiology. As intact living subjects do not emit any optical signature, visual representation usually exploits nano-scale imaging agents as the source of image contrast. Many imaging agents have been developed for this purpose, some of which exert nonspecific, passive, and physical interaction with a target. Current research interest in molecular imaging has mainly shifted to fabrication of smartly integrated, specific, and versatile agents that emit fluorescence or luminescence as an optical readout. These agents include luminescent quantum dots (QDs), biofunctional antibodies, and multifunctional nanoparticles. Furthermore, genetically encoded nano-imaging agents embedding fluorescent proteins or luciferases are now gaining popularity. These agents are generated by integrative design of the components, such as luciferase, flexible linker, and receptor to exert a specific on-off switching in the complex context of living subjects. In the present review, we provide an overview of the basic concepts, smart design, and practical contribution of recent nano-scale imaging agents, especially with respect to genetically encoded imaging agents.

Remote Imaging Applied to Schistosomiasis Control: The Anning River Project

NASA Technical Reports Server (NTRS)

Seto, Edmund Y. W.; Maszle, Don R.; Spear, Robert C.; Gong, Peng

1997-01-01

The use of satellite imaging to remotely detect areas of high risk for transmission of infectious disease is an appealing prospect for large-scale monitoring of these diseases. The detection of large-scale environmental determinants of disease risk, often called landscape epidemiology, has been motivated by several authors (Pavlovsky 1966; Meade et al. 1988). The basic notion is that large-scale factors such as population density, air temperature, hydrological conditions, soil type, and vegetation can determine in a coarse fashion the local conditions contributing to disease vector abundance and human contact with disease agents. These large-scale factors can often be remotely detected by sensors or cameras mounted on satellite or aircraft platforms and can thus be used in a predictive model to mark high risk areas of transmission and to target control or monitoring efforts. A review of satellite technologies for this purpose was recently presented by Washino and Wood (1994) and Hay (1997) and Hay et al. (1997).

Exploring the role of fire, succession, climate, and weather on landscape dynamics using comparative modeling

Treesearch

Robert E. Keane; Geoffrey J. Cary; Mike D. Flannigan; Russell A. Parsons; Ian D. Davies; Karen J. King; Chao Li; Ross A. Bradstock; Malcolm Gill

2013-01-01

An assessment of the relative importance of vegetation change and disturbance as agents of landscape change under current and future climates would (1) provide insight into the controls of landscape dynamics, (2) help inform the design and development of coarse scale spatially explicit ecosystem models such as Dynamic Global Vegetation Models (DGVMs), and (3) guide...

Designing Cyber Exercises

DTIC Science & Technology

2014-10-01

maneuver • Traditional “ Brick and Mortar ” training models – Difficult to train regularly due to logistics/budget restrictions – Doesn’t scale...complexity, scenario, location , and resources available • Scalable 4-cell planning construct – Exercise Control (White Cell) – Threat Emulation (Red...business impact) • Collaborative effort  Trusted Agents ( SMEs ) – Threats – Cyber defense capabilities – Policies and procedures – Project and/or

From nano- to macro-scale: nanotechnology approaches for spatially controlled delivery of bioactive factors for bone and cartilage engineering.

PubMed

Santo, Vítor E; Gomes, Manuela E; Mano, João F; Reis, Rui L

2012-07-01

The field of biomaterials has advanced towards the molecular and nanoscale design of bioactive systems for tissue engineering, regenerative medicine and drug delivery. Spatial cues are displayed in the 3D extracellular matrix and can include signaling gradients, such as those observed during chemotaxis. Architectures range from the nanometer to the centimeter length scales as exemplified by extracellular matrix fibers, cells and macroscopic shapes. The main focus of this review is the application of a biomimetic approach by the combination of architectural cues, obtained through the application of micro- and nanofabrication techniques, with the ability to sequester and release growth factors and other bioactive agents in a spatiotemporal controlled manner for bone and cartilage engineering.

A real-time architecture for time-aware agents.

PubMed

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.

Collectives for Multiple Resource Job Scheduling Across Heterogeneous Servers

NASA Technical Reports Server (NTRS)

Tumer, K.; Lawson, J.

2003-01-01

Efficient management of large-scale, distributed data storage and processing systems is a major challenge for many computational applications. Many of these systems are characterized by multi-resource tasks processed across a heterogeneous network. Conventional approaches, such as load balancing, work well for centralized, single resource problems, but breakdown in the more general case. In addition, most approaches are often based on heuristics which do not directly attempt to optimize the world utility. In this paper, we propose an agent based control system using the theory of collectives. We configure the servers of our network with agents who make local job scheduling decisions. These decisions are based on local goals which are constructed to be aligned with the objective of optimizing the overall efficiency of the system. We demonstrate that multi-agent systems in which all the agents attempt to optimize the same global utility function (team game) only marginally outperform conventional load balancing. On the other hand, agents configured using collectives outperform both team games and load balancing (by up to four times for the latter), despite their distributed nature and their limited access to information.

A randomized placebo-controlled trial to evaluate a novel noninjectable anesthetic gel with thermosetting agent during scaling and root planing in chronic periodontitis patients

PubMed Central

Dayakar, MM; Akbar, SM

2016-01-01

Aim: To study the efficacy of a noninjectable anesthetic gel with a thermosetting agent in the reduction of pain during scaling and root planing (SRP) in untreated chronic periodontitis patients. Materials and Methods: This study is a randomized, double-masked, split-mouth, placebo-controlled trial. Thirty patients were enrolled who underwent SRP in a split-mouth (right side/left side) manner. Before commencement of SRP, both quadrants on each side were isolated and had a randomized gel (either placebo or test gel) placed in the periodontal pockets for 30 s. The pain was measured using numerical rating scale (NRS) and verbal rating scale (VRS). Results: The median NRS pain score for the patients treated with the anesthetic test gel was 1 (range: 0-4) as opposed to 5 (range: 3-7) in the placebo treated patients. The mean rank of pain score using NRS in test gel was 16.18 as compared to 44.82 in placebo treated sites. Hence, significant reduction in pain was found in test gel as compared to placebo using NRS (P < 0.001). The VRS showed that the majority of patients reported no pain or mild pain with a median of 1 as compared to placebo treated sites with a median of 2 suggestive of moderate pain. Conclusions: The NRS and VRS pain scores showed that the side treated with anesthetic gel was statistically more effective than the placebo in reducing pain during SRP. PMID:27051372

Dynamics and Steady States in Excitable Mobile Agent Systems

NASA Astrophysics Data System (ADS)

Peruani, Fernando; Sibona, Gustavo J.

2008-04-01

We study the spreading of excitations in 2D systems of mobile agents where the excitation is transmitted when a quiescent agent keeps contact with an excited one during a nonvanishing time. We show that the steady states strongly depend on the spatial agent dynamics. Moreover, the coupling between exposition time (ω) and agent-agent contact rate (CR) becomes crucial to understand the excitation dynamics, which exhibits three regimes with CR: no excitation for low CR, an excited regime in which the number of quiescent agents (S) is inversely proportional to CR, and, for high CR, a novel third regime, model dependent, where S scales with an exponent ξ-1, with ξ being the scaling exponent of ω with CR.

From Metchnikoff to Monsanto and beyond: the path of microbial control.

PubMed

Lord, Jeffrey C

2005-05-01

In 125 years since Metchnikoff proposed the use of Metarhizium anisopliae to control the wheat cockchafer and brought about the first field trials, microbial control has progressed from the application of naturalists' observations to biotechnology and precision delivery. This review highlights major milestones in its evolution and presents a perspective on its current direction. Fungal pathogens, the most eye-catching agents, dominated the early period, but major mycological control efforts for chinch bugs and citrus pests in the US had questionable success, and interest waned. The discoveries of Bacillus popilliae and Bacillus thuringiensis began the era of practical and commercially viable microbial control. A program to control the Japanese beetle in the US led to the discovery of both B. popilliae and Steinernema glaseri, the first nematode used as a microbial control agent. Viral insect control became practical in the latter half of the 20th century, and the first registration was obtained with the Heliothis nuclear polyhedrosis virus in 1975. Now strategies are shifting for microbial control. While Bt transgenic crops are now planted on millions of hectares, the successes of more narrowly defined microbial control are mainly in small niches. Commercial enthusiasm for traditional microbial control agents has been unsteady in recent years. The prospects of microbial insecticide use on vast areas of major crops are now viewed more realistically. Regulatory constraints, activist resistance, benign and efficacious chemicals, and limited research funding all drive changes in focus. Emphasis is shifting to monitoring, conservation, integration with chemical pesticides, and selection of favorable venues such as organic agriculture and countries that have low costs, mild regulatory climates, modest chemical inputs, and small scale farming.

Consensus for linear multi-agent system with intermittent information transmissions using the time-scale theory

NASA Astrophysics Data System (ADS)

Taousser, Fatima; Defoort, Michael; Djemai, Mohamed

2016-01-01

This paper investigates the consensus problem for linear multi-agent system with fixed communication topology in the presence of intermittent communication using the time-scale theory. Since each agent can only obtain relative local information intermittently, the proposed consensus algorithm is based on a discontinuous local interaction rule. The interaction among agents happens at a disjoint set of continuous-time intervals. The closed-loop multi-agent system can be represented using mixed linear continuous-time and linear discrete-time models due to intermittent information transmissions. The time-scale theory provides a powerful tool to combine continuous-time and discrete-time cases and study the consensus protocol under a unified framework. Using this theory, some conditions are derived to achieve exponential consensus under intermittent information transmissions. Simulations are performed to validate the theoretical results.

Collective learning for the emergence of social norms in networked multiagent systems.

PubMed

Yu, Chao; Zhang, Minjie; Ren, Fenghui

2014-12-01

Social norms such as social rules and conventions play a pivotal role in sustaining system order by regulating and controlling individual behaviors toward a global consensus in large-scale distributed systems. Systematic studies of efficient mechanisms that can facilitate the emergence of social norms enable us to build and design robust distributed systems, such as electronic institutions and norm-governed sensor networks. This paper studies the emergence of social norms via learning from repeated local interactions in networked multiagent systems. A collective learning framework, which imitates the opinion aggregation process in human decision making, is proposed to study the impact of agent local collective behaviors on the emergence of social norms in a number of different situations. In the framework, each agent interacts repeatedly with all of its neighbors. At each step, an agent first takes a best-response action toward each of its neighbors and then combines all of these actions into a final action using ensemble learning methods. Extensive experiments are carried out to evaluate the framework with respect to different network topologies, learning strategies, numbers of actions, influences of nonlearning agents, and so on. Experimental results reveal some significant insights into the manipulation and control of norm emergence in networked multiagent systems achieved through local collective behaviors.

Intraarticular local anesthesia: can it reduce pain related to MR or CT arthrography of the shoulder?

PubMed

Choo, Hye Jung; Lee, Sun Joo; Kim, Dong Wook; Choi, Seok Jin; Lee, In Sook

2013-04-01

The objective of this study was to prospectively evaluate whether intraarticular anesthesia can reduce pain after MR or CT arthrography of the shoulder. This study included 120 patients who underwent CT or MR arthrography of the shoulder. The patients were randomized into two groups: the study group (n = 60), each administered an intraarticular injection of the contrast agent mixed with a local anesthetic (2% mepivacaine); and the control group (n = 60), each injected with the contrast agent only. Each patient's pain level was assessed at five phases-baseline and immediately, 2 hours, 1 day, and 2 days after injection-by using a visual analog scale or a verbal rating scale. The net pain score at each phase was also calculated. The pain course and net pain score were compared between study and control groups by repeated-measures analysis of variance. After the patients were divided into subgroups according to patient- or procedure-related factors, the efficacy of the intraarticular local anesthetic in each subgroup was evaluated. The pain course showed a quadratic trend and was not significantly different between study and control groups. The net pain score also was not significantly different between the two groups. No subgroup showed a significantly different efficacy of the intraarticular local anesthetic between the two groups. Intraarticular local anesthesia did not reduce arthrography-related pain.

Malaria vector control: from past to future.

PubMed

Raghavendra, Kamaraju; Barik, Tapan K; Reddy, B P Niranjan; Sharma, Poonam; Dash, Aditya P

2011-04-01

Malaria is one of the most common vector-borne diseases widespread in the tropical and subtropical regions. Despite considerable success of malaria control programs in the past, malaria still continues as a major public health problem in several countries. Vector control is an essential part for reducing malaria transmission and became less effective in recent years, due to many technical and administrative reasons, including poor or no adoption of alternative tools. Of the different strategies available for vector control, the most successful are indoor residual spraying and insecticide-treated nets (ITNs), including long-lasting ITNs and materials. Earlier DDT spray has shown spectacular success in decimating disease vectors but resulted in development of insecticide resistance, and to control the resistant mosquitoes, organophosphates, carbamates, and synthetic pyrethroids were introduced in indoor residual spraying with needed success but subsequently resulted in the development of widespread multiple insecticide resistance in vectors. Vector control in many countries still use insecticides in the absence of viable alternatives. Few developments for vector control, using ovitraps, space spray, biological control agents, etc., were encouraging when used in limited scale. Likewise, recent introduction of safer vector control agents, such as insect growth regulators, biocontrol agents, and natural plant products have yet to gain the needed scale of utility for vector control. Bacterial pesticides are promising and are effective in many countries. Environmental management has shown sufficient promise for vector control and disease management but still needs advocacy for inter-sectoral coordination and sometimes are very work-intensive. The more recent genetic manipulation and sterile insect techniques are under development and consideration for use in routine vector control and for these, standardized procedures and methods are available but need thorough understanding of biology, ethical considerations, and sufficiently trained manpower for implementation being technically intensive methods. All the methods mentioned in the review that are being implemented or proposed for implementation needs effective inter-sectoral coordination and community participation. The latest strategy is evolution-proof insecticides that include fungal biopesticides, Wolbachia, and Denso virus that essentially manipulate the life cycle of the mosquitoes were found effective but needs more research. However, for effective vector control, integrated vector management methods, involving use of combination of effective tools, is needed and is also suggested by Global Malaria Control Strategy. This review article raises issues associated with the present-day vector control strategies and state opportunities with a focus on ongoing research and recent advances to enable to sustain the gains achieved so far.

Delivering Cognitive Behavior Therapy to Young Adults With Symptoms of Depression and Anxiety Using a Fully Automated Conversational Agent (Woebot): A Randomized Controlled Trial.

PubMed

Fitzpatrick, Kathleen Kara; Darcy, Alison; Vierhile, Molly

2017-06-06

Web-based cognitive-behavioral therapeutic (CBT) apps have demonstrated efficacy but are characterized by poor adherence. Conversational agents may offer a convenient, engaging way of getting support at any time. The objective of the study was to determine the feasibility, acceptability, and preliminary efficacy of a fully automated conversational agent to deliver a self-help program for college students who self-identify as having symptoms of anxiety and depression. In an unblinded trial, 70 individuals age 18-28 years were recruited online from a university community social media site and were randomized to receive either 2 weeks (up to 20 sessions) of self-help content derived from CBT principles in a conversational format with a text-based conversational agent (Woebot) (n=34) or were directed to the National Institute of Mental Health ebook, "Depression in College Students," as an information-only control group (n=36). All participants completed Web-based versions of the 9-item Patient Health Questionnaire (PHQ-9), the 7-item Generalized Anxiety Disorder scale (GAD-7), and the Positive and Negative Affect Scale at baseline and 2-3 weeks later (T2). Participants were on average 22.2 years old (SD 2.33), 67% female (47/70), mostly non-Hispanic (93%, 54/58), and Caucasian (79%, 46/58). Participants in the Woebot group engaged with the conversational agent an average of 12.14 (SD 2.23) times over the study period. No significant differences existed between the groups at baseline, and 83% (58/70) of participants provided data at T2 (17% attrition). Intent-to-treat univariate analysis of covariance revealed a significant group difference on depression such that those in the Woebot group significantly reduced their symptoms of depression over the study period as measured by the PHQ-9 (F=6.47; P=.01) while those in the information control group did not. In an analysis of completers, participants in both groups significantly reduced anxiety as measured by the GAD-7 (F 1,54 = 9.24; P=.004). Participants' comments suggest that process factors were more influential on their acceptability of the program than content factors mirroring traditional therapy. Conversational agents appear to be a feasible, engaging, and effective way to deliver CBT. ©Kathleen Kara Fitzpatrick, Alison Darcy, Molly Vierhile. Originally published in JMIR Mental Health (http://mental.jmir.org), 06.06.2017.

Multi-scale analysis of a household level agent-based model of landcover change.

PubMed

Evans, Tom P; Kelley, Hugh

2004-08-01

Scale issues have significant implications for the analysis of social and biophysical processes in complex systems. These same scale implications are likewise considerations for the design and application of models of landcover change. Scale issues have wide-ranging effects from the representativeness of data used to validate models to aggregation errors introduced in the model structure. This paper presents an analysis of how scale issues affect an agent-based model (ABM) of landcover change developed for a research area in the Midwest, USA. The research presented here explores how scale factors affect the design and application of agent-based landcover change models. The ABM is composed of a series of heterogeneous agents who make landuse decisions on a portfolio of cells in a raster-based programming environment. The model is calibrated using measures of fit derived from both spatial composition and spatial pattern metrics from multi-temporal landcover data interpreted from historical aerial photography. A model calibration process is used to find a best-fit set of parameter weights assigned to agents' preferences for different landuses (agriculture, pasture, timber production, and non-harvested forest). Previous research using this model has shown how a heterogeneous set of agents with differing preferences for a portfolio of landuses produces the best fit to landcover changes observed in the study area. The scale dependence of the model is explored by varying the resolution of the input data used to calibrate the model (observed landcover), ancillary datasets that affect land suitability (topography), and the resolution of the model landscape on which agents make decisions. To explore the impact of these scale relationships the model is run with input datasets constructed at the following spatial resolutions: 60, 90, 120, 150, 240, 300 and 480 m. The results show that the distribution of landuse-preference weights differs as a function of scale. In addition, with the gradient descent model fitting method used in this analysis the model was not able to converge to an acceptable fit at the 300 and 480 m spatial resolutions. This is a product of the ratio of the input cell resolution to the average parcel size in the landscape. This paper uses these findings to identify scale considerations in the design, development, validation and application of ABMs of landcover change.

Attitude coordination of multi-HUG formation based on multibody system theory

NASA Astrophysics Data System (ADS)

Xue, Dong-yang; Wu, Zhi-liang; Qi, Er-mai; Wang, Yan-hui; Wang, Shu-xin

2017-04-01

Application of multiple hybrid underwater gliders (HUGs) is a promising method for large scale, long-term ocean survey. Attitude coordination has become a requisite for task execution of multi-HUG formation. In this paper, a multibody model is presented for attitude coordination among agents in the HUG formation. The HUG formation is regarded as a multi-rigid body system. The interaction between agents in the formation is described by artificial potential field (APF) approach. Attitude control torque is composed of a conservative torque generated by orientation potential field and a dissipative term related with angular velocity. Dynamic modeling of the multibody system is presented to analyze the dynamic process of the HUG formation. Numerical calculation is carried out to simulate attitude synchronization with two kinds of formation topologies. Results show that attitude synchronization can be fulfilled based on the multibody method described in this paper. It is also indicated that different topologies affect attitude control quality with respect to energy consumption and adjusting time. Low level topology should be adopted during formation control scheme design to achieve a better control effect.

Male fertility: psychiatric considerations.

PubMed

Hall, Elise; Burt, Vivien K

2012-02-01

To examine: 1) current knowledge on normal biologic variation of seminal parameters; 2) how stress and psychological factors affect sperm quality in fertile and infertile males; and 3) how mental illness and psychopharmacologic agents can affect male fertility. English-language Medline, Embase, and Psycinfo were searched for relevant publications (from 1970 to January 2011) for systematic review. None. None. None. Possible effects of stress, mood, and psychotropic medications on male factor fertility. Male-factor infertility is influenced by myriad factors (obesity, tobacco, etc.). Stress alone may reduce testosterone levels and spermatogenesis. Infertility assessment and treatment can lead to distress and negatively affect sperm samples. Available research has failed to control for potentially confounding variables. Although some trends have been identified, larger-scale studies that adequately control all confounding variables are needed before conclusions can be made about the relationship between stress, psychotropic agents, and male infertility. Copyright © 2012 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Comparison of anxiety between smokers and nonsmokers with acute myocardial infarction.

PubMed

Sheahan, Sharon L; Rayens, Mary K; An, Kyungeh; Riegel, Barbara; McKinley, Sharon; Doering, Lynn; Garvin, Bonnie J; Moser, Debra K

2006-11-01

Increased anxiety correlates with increased complications after acute myocardial infarction. Anxiety levels and use of anxiolytic agents have not been compared between smokers and nonsmokers hospitalized because of acute myocardial infarction. To compare anxiety level, sociodemographic factors, and clinical variables between smokers and nonsmokers hospitalized with acute myocardial infarction and to examine predictors of use of beta-blockers and anxiolytic agents among smokers and nonsmokers. Secondary data analysis of a prospective multisite study on anxiety in 181 smokers and 351 nonsmokers with acute myocardial infarction. Anxiety was measured by using the State Trait Anxiety Inventory and the anxiety subscale of the Basic Symptom Inventory within 72 hours of admission. Smokers reported higher anxiety levels than nonsmokers reported on both anxiety scales. Female smokers reported the highest anxiety and peak pain levels of all, yet women were the least likely to receive anxiolytic agents. Smoking status was not a predictor for anxiety level when sex, peak pain, use of beta-blockers in the hospital, and age were controlled for. However, smokers were twice as likely as nonsmokers to receive an anxiolytic agent and 60% more likely to receive a beta-blocker in the emergency department, and smokers were 80% more likely than nonsmokers to receive an anxiolytic agent during hospitalization when these variables were controlled. Older female smokers are at risk for complications because they are older than their male counterparts and less likely to receive beta-blockers and antianxiety medications in the emergency department.

Bio-inspired magnetic swimming microrobots for biomedical applications.

PubMed

Peyer, Kathrin E; Zhang, Li; Nelson, Bradley J

2013-02-21

Microrobots have been proposed for future biomedical applications in which they are able to navigate in viscous fluidic environments. Nature has inspired numerous microrobotic locomotion designs, which are suitable for propulsion generation at low Reynolds numbers. This article reviews the various swimming methods with particular focus on helical propulsion inspired by E. coli bacteria. There are various magnetic actuation methods for biomimetic and non-biomimetic microrobots, such as rotating fields, oscillating fields, or field gradients. They can be categorized into force-driven or torque-driven actuation methods. Both approaches are reviewed and a previous publication has shown that torque-driven actuation scales better to the micro- and nano-scale than force-driven actuation. Finally, the implementation of swarm or multi-agent control is discussed. The use of multiple microrobots may be beneficial for in vivo as well as in vitro applications. Thus, the frequency-dependent behavior of helical microrobots is discussed and preliminary experimental results are presented showing the decoupling of an individual agent within a group of three microrobots.

Manipulating biological agents and cells in micro-scale volumes for applications in medicine

PubMed Central

Tasoglu, Savas; Gurkan, Umut Atakan; Wang, ShuQi

2013-01-01

Recent technological advances provide new tools to manipulate cells and biological agents in micro/nano-liter volumes. With precise control over small volumes, the cell microenvironment and other biological agents can be bioengineered; interactions between cells and external stimuli can be monitored; and the fundamental mechanisms such as cancer metastasis and stem cell differentiation can be elucidated. Technological advances based on the principles of electrical, magnetic, chemical, optical, acoustic, and mechanical forces lead to novel applications in point-of-care diagnostics, regenerative medicine, in vitro drug testing, cryopreservation, and cell isolation/purification. In this review, we first focus on the underlying mechanisms of emerging examples for cell manipulation in small volumes targeting applications such as tissue engineering. Then, we illustrate how these mechanisms impact the aforementioned biomedical applications, discuss the associated challenges, and provide perspectives for further development. PMID:23575660

Riot Control Agents

MedlinePlus

... 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 ...

Agent Transparency for an Autonomous Squad Member

DTIC Science & Technology

2015-05-01

C. Attentional  Control  Survey  41  Appendix D. System Usability Scale  45  Appendix E. Modified Jian Pre‐Post Trust Survey  47  Appendix F.  Posttest ...failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE...information in a simulation-based unmanned ground vehicle monitoring task. Three groups were tested with visual displays representing 1 of 3 types of

Large-Scale Operations Management Test of Use of the White Amur for Control of Problem Aquatic Plants. Report 1. Baseline Studies. Volume VIII. Summary of Baseline Studies and Data.

DTIC Science & Technology

1982-05-01

in May 1976, and, by July 1976, all sampling techniques were employed. In addition to routine displays of data analysis such as frequency tables and...amphibian and reptile communities in large aquatic habitats in Florida, comparison with similar herpetofaunal assemblages or populations is not possible... field environment was initiated at Lake Conway near Orlando, Fla., to study the effectiveness of the fish as a biological macrophyte control agent. A

Scaled-up production of poacic acid, a plant-derived antifungal agent

DOE PAGES

Yue, Fengxia; Gao, Ruili; Piotrowski, Jeff S.; ...

2017-09-01

Poacic acid, a decarboxylated product from 8–5-diferulic acid that is commonly found in monocot lignocellulosic hydrolysates, has been identified as a natural antifungal agent against economically significant fungi and oomycete plant pathogens. Starting from commercially available or monocot-derivable ferulic acid, a three-step synthetic procedure has been developed for the production of poacic acid needed for field testing in a controlled agricultural setting. First, ferulic acid was esterified to produce ethyl ferulate in 92% yield. Second, peroxidase-catalyzed free radical dehydrodimerization of ethyl ferulate produced crude diferulates, mainly 8–5-diferulate, in 91% yield. Finally, crystalline poacic acid was obtained in 25% yield viamore » alkaline hydrolysis of the crude diferulates after purification by flash-column chromatography. Thus, this new procedure offers two key improvements relevant to large-scale production: 1) bubbling air through the reaction mixture in the second step to remove acetone greatly improves the recovery efficiency of the crude diferulates; and 2) telescoping minor impurities directly into the alkaline hydrolysis step eliminates the need for additional column purifications, thus reducing the overall cost of production and removing a major impediment to process scale-up.« less

Scaled-up production of poacic acid, a plant-derived antifungal agent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yue, Fengxia; Gao, Ruili; Piotrowski, Jeff S.

Poacic acid, a decarboxylated product from 8–5-diferulic acid that is commonly found in monocot lignocellulosic hydrolysates, has been identified as a natural antifungal agent against economically significant fungi and oomycete plant pathogens. Starting from commercially available or monocot-derivable ferulic acid, a three-step synthetic procedure has been developed for the production of poacic acid needed for field testing in a controlled agricultural setting. First, ferulic acid was esterified to produce ethyl ferulate in 92% yield. Second, peroxidase-catalyzed free radical dehydrodimerization of ethyl ferulate produced crude diferulates, mainly 8–5-diferulate, in 91% yield. Finally, crystalline poacic acid was obtained in 25% yield viamore » alkaline hydrolysis of the crude diferulates after purification by flash-column chromatography. Thus, this new procedure offers two key improvements relevant to large-scale production: 1) bubbling air through the reaction mixture in the second step to remove acetone greatly improves the recovery efficiency of the crude diferulates; and 2) telescoping minor impurities directly into the alkaline hydrolysis step eliminates the need for additional column purifications, thus reducing the overall cost of production and removing a major impediment to process scale-up.« less

Towards effective payoffs in the prisoner’s dilemma game on scale-free networks

NASA Astrophysics Data System (ADS)

Szolnoki, Attila; Perc, Matjaž; Danku, Zsuzsa

2008-03-01

We study the transition towards effective payoffs in the prisoner's dilemma game on scale-free networks by introducing a normalization parameter guiding the system from accumulated payoffs to payoffs normalized with the connectivity of each agent. We show that during this transition the heterogeneity-based ability of scale-free networks to facilitate cooperative behavior deteriorates continuously, eventually collapsing with the results obtained on regular graphs. The strategy donations and adaptation probabilities of agents with different connectivities are studied. Results reveal that strategies generally spread from agents with larger towards agents with smaller degree. However, this strategy adoption flow reverses sharply in the fully normalized payoff limit. Surprisingly, cooperators occupy the hubs even if the averaged cooperation level due to partly normalized payoffs is moderate.

Scaling and criticality in a stochastic multi-agent model of a financial market

NASA Astrophysics Data System (ADS)

Lux, Thomas; Marchesi, Michele

1999-02-01

Financial prices have been found to exhibit some universal characteristics that resemble the scaling laws characterizing physical systems in which large numbers of units interact. This raises the question of whether scaling in finance emerges in a similar way - from the interactions of a large ensemble of market participants. However, such an explanation is in contradiction to the prevalent `efficient market hypothesis' in economics, which assumes that the movements of financial prices are an immediate and unbiased reflection of incoming news about future earning prospects. Within this hypothesis, scaling in price changes would simply reflect similar scaling in the `input' signals that influence them. Here we describe a multi-agent model of financial markets which supports the idea that scaling arises from mutual interactions of participants. Although the `news arrival process' in our model lacks both power-law scaling and any temporal dependence in volatility, we find that it generates such behaviour as a result of interactions between agents.

Modelling financial markets with agents competing on different time scales and with different amount of information

NASA Astrophysics Data System (ADS)

Wohlmuth, Johannes; Andersen, Jørgen Vitting

2006-05-01

We use agent-based models to study the competition among investors who use trading strategies with different amount of information and with different time scales. We find that mixing agents that trade on the same time scale but with different amount of information has a stabilizing impact on the large and extreme fluctuations of the market. Traders with the most information are found to be more likely to arbitrage traders who use less information in the decision making. On the other hand, introducing investors who act on two different time scales has a destabilizing effect on the large and extreme price movements, increasing the volatility of the market. Closeness in time scale used in the decision making is found to facilitate the creation of local trends. The larger the overlap in commonly shared information the more the traders in a mixed system with different time scales are found to profit from the presence of traders acting at another time scale than themselves.

Propagation, cascades, and agreement dynamics in complex communication and social networks

NASA Astrophysics Data System (ADS)

Lu, Qiming

Many modern and important technological, social, information and infrastructure systems can be viewed as complex systems with a large number of interacting components. Models of complex networks and dynamical interactions, as well as their applications are of fundamental interests in many aspects. Here, several stylized models of multiplex propagation and opinion dynamics are investigated on complex and empirical social networks. We first investigate cascade dynamics in threshold-controlled (multiplex) propagation on random geometric networks. We find that such local dynamics can serve as an efficient, robust, and reliable prototypical activation protocol in sensor networks in responding to various alarm scenarios. We also consider the same dynamics on a modified network by adding a few long-range communication links, resulting in a small-world network. We find that such construction can further enhance and optimize the speed of the network's response, while keeping energy consumption at a manageable level. We also investigate a prototypical agent-based model, the Naming Game, on two-dimensional random geometric networks. The Naming Game [A. Baronchelli et al., J. Stat. Mech.: Theory Exp. (2006) P06014.] is a minimal model, employing local communications that captures the emergence of shared communication schemes (languages) in a population of autonomous semiotic agents. Implementing the Naming Games with local broadcasts on random geometric graphs, serves as a model for agreement dynamics in large-scale, autonomously operating wireless sensor networks. Further, it captures essential features of the scaling properties of the agreement process for spatially-embedded autonomous agents. Among the relevant observables capturing the temporal properties of the agreement process, we investigate the cluster-size distribution and the distribution of the agreement times, both exhibiting dynamic scaling. We also present results for the case when a small density of long-range communication links are added on top of the random geometric graph, resulting in a "small-world"-like network and yielding a significantly reduced time to reach global agreement. We construct a finite-size scaling analysis for the agreement times in this case. When applying the model of Naming Game on empirical social networks, this stylized agent-based model captures essential features of agreement dynamics in a network of autonomous agents, corresponding to the development of shared classification schemes in a network of artificial agents or opinion spreading and social dynamics in social networks. Our study focuses on the impact that communities in the underlying social graphs have on the outcome of the agreement process. We find that networks with strong community structure hinder the system from reaching global agreement; the evolution of the Naming Game in these networks maintains clusters of coexisting opinions indefinitely. Further, we investigate agent-based network strategies to facilitate convergence to global consensus.

Evolution of public opinions in closed societies influenced by broadcast media

NASA Astrophysics Data System (ADS)

Fan, Kangqi; Pedrycz, Witold

2017-04-01

Studies on opinion evolution in a closed society can help people design strategies to emancipate from the control of public opinions and prevent the diffusion of extremism. In this work, the social judgment based opinion (SJBO) dynamics model is extended to explore the collective debates in a closed system that consists of a social network and a broadcast network. The broadcast network is a group of channels through which the so-called broadcast media or mainstream media transmit the same opinion to social agents. Numerical experiments show that the broadcast media can assimilate most of the agents when contrarians are absent. Including agents' diverse attitudes toward the broadcast media, although downsizes the supporters of broadcast media, fails to make contrarians outnumber the supporters. The dominance of broadcast media in a closed system can be overturned by introducing a small number of inflexible contrarians. Influenced by the competition between contrarians and broadcast media, few centrists survive the collective debates. The scale of supporters is maximized when agents neither have their own initial opinions nor have access to the contrarians, whereas the development of contrarians can be boosted when agents start with non-zero opinions and the repulsion to broadcast media is taken into consideration.

Exercise, character strengths, well-being, and learning climate in the prediction of performance over a 6-month period at a call center.

PubMed

Moradi, Saleh; Nima, Ali A; Rapp Ricciardi, Max; Archer, Trevor; Garcia, Danilo

2014-01-01

Performance monitoring might have an adverse influence on call center agents' well-being. We investigate how performance, over a 6-month period, is related to agents' perceptions of their learning climate, character strengths, well-being (subjective and psychological), and physical activity. Agents (N = 135) self-reported perception of the learning climate (Learning Climate Questionnaire), character strengths (Values In Action Inventory Short Version), well-being (Positive Affect, Negative Affect Schedule, Satisfaction With Life Scale, Psychological Well-Being Scales Short Version), and how often/intensively they engaged in physical activity. Performance, "time on the phone," was monitored for 6 consecutive months by the same system handling the calls. Performance was positively related to having opportunities to develop, the character strengths clusters of Wisdom and Knowledge (e.g., curiosity for learning, perspective) and Temperance (e.g., having self-control, being prudent, humble, and modest), and exercise frequency. Performance was negatively related to the sense of autonomy and responsibility, contentedness, the character strengths clusters of Humanity and Love (e.g., helping others, cooperation) and Justice (e.g., affiliation, fairness, leadership), positive affect, life satisfaction and exercise Intensity. Call centers may need to create opportunities to develop to increase agents' performance and focus on individual differences in the recruitment and selection of agents to prevent future shortcomings or worker dissatisfaction. Nevertheless, performance measurement in call centers may need to include other aspects that are more attuned with different character strengths. After all, allowing individuals to put their strengths at work should empower the individual and at the end the organization itself. Finally, physical activity enhancement programs might offer considerable positive work outcomes.

Exercise, character strengths, well-being, and learning climate in the prediction of performance over a 6-month period at a call center

PubMed Central

Moradi, Saleh; Nima, Ali A.; Rapp Ricciardi, Max; Archer, Trevor; Garcia, Danilo

2014-01-01

Background: Performance monitoring might have an adverse influence on call center agents' well-being. We investigate how performance, over a 6-month period, is related to agents' perceptions of their learning climate, character strengths, well-being (subjective and psychological), and physical activity. Method: Agents (N = 135) self-reported perception of the learning climate (Learning Climate Questionnaire), character strengths (Values In Action Inventory Short Version), well-being (Positive Affect, Negative Affect Schedule, Satisfaction With Life Scale, Psychological Well-Being Scales Short Version), and how often/intensively they engaged in physical activity. Performance, “time on the phone,” was monitored for 6 consecutive months by the same system handling the calls. Results: Performance was positively related to having opportunities to develop, the character strengths clusters of Wisdom and Knowledge (e.g., curiosity for learning, perspective) and Temperance (e.g., having self-control, being prudent, humble, and modest), and exercise frequency. Performance was negatively related to the sense of autonomy and responsibility, contentedness, the character strengths clusters of Humanity and Love (e.g., helping others, cooperation) and Justice (e.g., affiliation, fairness, leadership), positive affect, life satisfaction and exercise Intensity. Conclusion: Call centers may need to create opportunities to develop to increase agents' performance and focus on individual differences in the recruitment and selection of agents to prevent future shortcomings or worker dissatisfaction. Nevertheless, performance measurement in call centers may need to include other aspects that are more attuned with different character strengths. After all, allowing individuals to put their strengths at work should empower the individual and at the end the organization itself. Finally, physical activity enhancement programs might offer considerable positive work outcomes. PMID:25002853

40 CFR 300.910 - Authorization of use.

Code of Federal Regulations, 2012 CFR

2012-07-01

... dispersants, surface washing agents, surface collecting agents, bioremediation agents, or miscellaneous oil... agents, surface collecting agents, bioremediation agents, or miscellaneous oil spill control agents on..., bioremediation agent, or miscellaneous oil spill control agent, including products not listed on the NCP Product...

40 CFR 300.910 - Authorization of use.

Code of Federal Regulations, 2013 CFR

2013-07-01

... dispersants, surface washing agents, surface collecting agents, bioremediation agents, or miscellaneous oil... agents, surface collecting agents, bioremediation agents, or miscellaneous oil spill control agents on..., bioremediation agent, or miscellaneous oil spill control agent, including products not listed on the NCP Product...

40 CFR 300.910 - Authorization of use.

Code of Federal Regulations, 2014 CFR

2014-07-01

... dispersants, surface washing agents, surface collecting agents, bioremediation agents, or miscellaneous oil... agents, surface collecting agents, bioremediation agents, or miscellaneous oil spill control agents on..., bioremediation agent, or miscellaneous oil spill control agent, including products not listed on the NCP Product...

40 CFR 300.910 - Authorization of use.

Code of Federal Regulations, 2010 CFR

2010-07-01

... dispersants, surface washing agents, surface collecting agents, bioremediation agents, or miscellaneous oil... agents, surface collecting agents, bioremediation agents, or miscellaneous oil spill control agents on..., bioremediation agent, or miscellaneous oil spill control agent, including products not listed on the NCP Product...

Role of time in symbiotic systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Agrawala, A.K.

1996-12-31

All systems have a dynamics which reflects the changes in the system in time and, therefore, have to maintain a notion of time, either explicitly or implicitly. Traditionally, the notion of time in constructed systems has been implicitly specified at design time through rigid structures such as sampled data systems which operate with a fixed time tick, feedback systems which are designed reflecting a fixed time scale for the dynamics of the system as well as the controller responses, etc. In biological systems, the sense of time is a key element but it is not rigidly structured, even though allmore » such systems have a clear notion of time. We define the notion of time in systems in terms of temporal locality, time scale and time horizon. Temporal locality gives the notion of the accuracy with which the system knows about the current time. Time scale reflects the scale indicating the smallest and the largest granularity considered. It also reflects the reaction time. The time horizon indicates the time beyond which the system considers to be distant future and may not take it into account in its actions. Note that the temporal locality, time scale and the time horizon may be different for different types of actions of a system, thereby permitting the system to use multiple notions of time concurrently. In multi agent systems each subsystem may have its own notion of time but when intentions take place a coordination is necessary. Such coordination requires that the notions of time for different agents of the system be consistent. Clearly, the consistency requirement in this case does not mean exactly identical but implies that different agents can coordinate their actions which must take place in time. When the actions only require a determinate ordering the required coordination is much less severe than the case requiring actions to take place at the same time.« less

Single Agent Polysaccharopeptide Delays Metastases and Improves Survival in Naturally Occurring Hemangiosarcoma

PubMed Central

Brown, Dorothy Cimino; Reetz, Jennifer

2012-01-01

The 2008 World Health Organization World Cancer Report describes global cancer incidence soaring with many patients living in countries that lack resources for cancer control. Alternative treatment strategies that can reduce the global disease burden at manageable costs must be developed. Polysaccharopeptide (PSP) is the bioactive agent from the mushroom Coriolus versicolor. Studies indicate PSP has in vitro antitumor activities and inhibits the growth of induced tumors in animal models. Clear evidence of clinically relevant benefits of PSP in cancer patients, however, is lacking. The investment of resources required to complete large-scale, randomized controlled trials of PSP in cancer patients is more easily justified if antitumor and survival benefits are documented in a complex animal model of a naturally occurring cancer that parallels human disease. Because of its high metastatic rate and vascular origin, canine hemangiosarcoma is used for investigations in antimetastatic and antiangiogenic therapies. In this double-blind randomized multidose pilot study, high-dose PSP significantly delayed the progression of metastases and afforded the longest survival times reported in canine hemangiosarcoma. These data suggest that, for those cancer patients for whom advanced treatments are not accessible, PSP as a single agent might offer significant improvements in morbidity and mortality. PMID:22988473

Outcome of Molecular Targeted Agents Plus Chemotherapy for Second-Line Therapy of Metastatic Colorectal Cancer: A Meta-Analysis of Randomized Trials.

PubMed

Pei, Xueqing; Liu, Yu; Sun, Liwei; Zhang, Jun; Fang, Yuanyuan; Liao, Xin; Liu, Jian; Zhang, Cuntai; Yin, Tiejun

2016-12-01

The aim of this study was to evaluate the efficacy and toxicity of molecular targeted agents plus chemotherapy compared with chemotherapy alone as second-line therapy for patients with metastatic colorectal cancer (mCRC). We identified randomized controlled trials that compared molecular targeted agents plus chemotherapy with chemotherapy alone by searching the PubMed and Embase databases for articles published between January 2000 and September 2015. The outcome measures included progression-free survival, overall survival, objective response rate, and adverse events. Two investigators independently performed the information retrieval, screening, and data extraction. Stata 10.0 software was used to statistically analyze the extracted data. In accordance with our inclusion criteria, 11 trials, with a total of 7440 patients, were included in this meta-analysis through rounds of selection. We divided the biologic agents used into 3 subgroups based on the type of biologic agents-vascular endothelial growth factor (VEGF) inhibitor, epidermal growth factor receptor inhibitor, and other pathway inhibitors. Our results suggested that the regimen of a molecular targeted agent plus chemotherapy had a significant advantage in progression-free survival, overall survival, and objective response rate over chemotherapy alone (hazard ratio, 0.74; 95% confidence interval [CI], 0.70-0.78; hazard ratio, 0.88; 95% CI, 0.83-0.93; risk ratio, 2.24; 95% CI: 1.58-3.17, respectively). However, the rate of grade ≥ 3 adverse events was also higher in the combination therapy arm (risk ratio, 1.25; 95% CI, 1.17-1.33). Subgroup analysis showed that the combination of VEGF inhibitor with chemotherapy had a significant advantage in PFS, OS, and ORR over chemotherapy alone, but there was also a higher risk ratio in adverse events for this combination compared with the control group. In conclusion, a molecular targeted agent, especially VEGF inhibitor, plus chemotherapy is a worthwhile combination for patients with metastatic colorectal cancer as second-line therapy. However, more randomized controlled trials on a larger scale are needed for evaluating the value of epidermal growth factor receptor and other pathway inhibitors. Copyright © 2016 Elsevier Inc. All rights reserved.

Prevalence of minor psychiatric disorders in socio-educational agents in the state of Rio Grande do Sul.

PubMed

Greco, Patrícia Bitencourt Toscani; Magnago, Tânia Solange Bosi de Souza; Urbanetto, Janete de Souza; da Luz, Emanuelli Mancio Ferreira; Prochnow, Andrea

2015-01-01

To determine the prevalence and factors associated with minor psychiatric disorders (MPD) in socio-educational agents. It is a cross-sectional study with 381 socio-educational agents the Centers for Socio-Educational Services in the State of Rio Grande do Sul, Brazil. The Brazilian versions of the Scale of Demand-control-social support at work and the Self Reporting Questionnaire-20 have been applied. The results showed a prevalence of suspicion MPD of 50.1%. They showed to be related to suspicion of MPD : being female (55.7%), having age up to 44 years old (58.5%), no physical activity (57.4%), do not have time for leisure (75%), make use of medication (61.4%), require medical attention (56.9%) and psychological counseling (72.7%), not being satisfied with the workplace (61.7%) and need for time off from work (65.6%). The study provides important data about the mental health of agents, showing the need for the involvement of managers and of the health service of worker's health in planning actions to promote health of these workers.

Supporting stress management for women undergoing the early stages of fertility treatment: a cluster-randomized controlled trial.

PubMed

Mori, Akiko

2009-06-01

The purpose of this study was to determine the effects of a support program for the stress management of women undergoing fertility treatment to reduce stress related to infertility and treatment. We randomly assigned seven institutions into an experimental group (four institutions, n = 96) and a control group (three institutions, n = 44) using cluster randomization. The women in the experimental group were asked to continue stress management homework for 3 months. A nurse provided feedback on the homework every month. Those in the control group were given only the booklet. The primary outcomes were the risk ratios of "depression" and "anxiety" according to the Hospital Anxiety and Depression Scale. The secondary outcomes were "health status" from the Medical Outcomes Study Short-Form 36-item Health Survey (SF-36) v2 and "satisfaction" from the Visual Analogue Scale. We excluded 15 women who became pregnant and performed an intention-to-treat analysis of 125 women. There were no differences in the incidence of depression and anxiety between the experimental and control groups. There were significant interaction effects between the program and time in the scores of the two subscales of SF-36 and the summary. There was no difference in satisfaction. The use of ovulation-enhancing agents showed that the scores of "role functioning physical" and "physical component summary" in the non-use subgroup were higher at 2 and 3 months in the experimental group, compared to the control group. Positive effects of the support program were observed on two subscales of the SF-36 in the subgroup that did not use ovulation-enhancing agents.

Large-Scale Cooperative Task Distribution on Peer-to-Peer Networks

DTIC Science & Technology

2012-01-01

SUBTITLE Large-scale cooperative task distribution on peer-to-peer networks 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...of agents, and each agent attempts to form a coalition with its most profitable partner. The second algorithm builds upon the Shapley for- mula [37...ters at the second layer. These Category Layer clusters each represent a single resource, and agents join one or more clusters based on their

Agent based reasoning for the non-linear stochastic models of long-range memory

NASA Astrophysics Data System (ADS)

Kononovicius, A.; Gontis, V.

2012-02-01

We extend Kirman's model by introducing variable event time scale. The proposed flexible time scale is equivalent to the variable trading activity observed in financial markets. Stochastic version of the extended Kirman's agent based model is compared to the non-linear stochastic models of long-range memory in financial markets. The agent based model providing matching macroscopic description serves as a microscopic reasoning of the earlier proposed stochastic model exhibiting power law statistics.

Pedestrian simulation and distribution in urban space based on visibility analysis and agent simulation

NASA Astrophysics Data System (ADS)

Ying, Shen; Li, Lin; Gao, Yurong

2009-10-01

Spatial visibility analysis is the important direction of pedestrian behaviors because our visual conception in space is the straight method to get environment information and navigate your actions. Based on the agent modeling and up-tobottom method, the paper develop the framework about the analysis of the pedestrian flow depended on visibility. We use viewshed in visibility analysis and impose the parameters on agent simulation to direct their motion in urban space. We analyze the pedestrian behaviors in micro-scale and macro-scale of urban open space. The individual agent use visual affordance to determine his direction of motion in micro-scale urban street on district. And we compare the distribution of pedestrian flow with configuration in macro-scale urban environment, and mine the relationship between the pedestrian flow and distribution of urban facilities and urban function. The paper first computes the visibility situations at the vantage point in urban open space, such as street network, quantify the visibility parameters. The multiple agents use visibility parameters to decide their direction of motion, and finally pedestrian flow reach to a stable state in urban environment through the simulation of multiple agent system. The paper compare the morphology of visibility parameters and pedestrian distribution with urban function and facilities layout to confirm the consistence between them, which can be used to make decision support in urban design.

Operational-scale application of entomopathogenic fungi for control of Sahelian grasshoppers

PubMed Central

Kooyman, C.; Bateman, R. P.; Langewald, J.; Lomer, C. J.; Ouambama, Z.; Thomas, M. B.

1997-01-01

Locusts and grasshoppers regularly threaten agricultural production across large parts of the developed and developing worlds. Recent concerns over the health and environmental impacts of standard chemical control measures have led to a demand for alternative, more environmentally benign control technologies. Here we present the results of a field study to investigate the potential of inundative biological control for control of grasshoppers in the Sahelian region of Africa. The biocontrol agent was an oil-based biopesticide formulation of a naturally occurring entomopathogenic fungus, Metarhizium flavoviride. This was applied at a rate of 2l ha-1 to a total area of 150 ha using standard equipment normally used for the application of chemical pesticides. Twenty-one days after application, an 80 per cent reduction in grasshopper populations was recorded in treated plots, relative to control populations in equivalent unsprayed areas. We think that this is the first operational-scale application of a biopesticide to demonstrate significant population reductions of key Sahelian grasshopper pests. This represents a substantial development in locust and grasshopper control, and should open the way for a new era of integrated control strategies where reliance on conventional chemicals is reduced.

Effect of pre-cooling injection site on pain perception in pediatric dentistry: “A randomized clinical trial”

PubMed Central

Ghaderi, Faezeh; Banakar, Shahin; Rostami, Shima

2013-01-01

Background: Injection of local anesthesia is one of the most important reasons for development of avoidance behavior in children. Efforts have been performed to decrease pain perception of injection. The present research evaluated the effect of cooling the injection site on pain perception before infiltration of local anesthetics. Materials and Methods: A prospective single-blind crossover clinical trial was used to investigate pain perception in 50 healthy pediatric patients who needed bilateral buccal infiltration of local anesthetics for dental treatment. They received a topical anesthetic agent (Benzocaine) on one side (control) for 1 min and topical anesthetic agent plus one minute of ice pack on the other side (trial) prior to the injection. A dentist blind to the study assessed the patients’ reaction during injection. Wilcoxon and Mann-Whitney U tests were used for statistical analysis. Statistical significance was defined at P < 0.05. Results: The means of sound, eye, and motor scales (SEM) were 4.06 ± 1.32 and 5.44 ± 1.79 for the study and control groups, respectively. The means of visual analogue scales (VAS) for the study and control groups were 42.20 ± 12.70 and 58.40 ± 16.83, respectively; with statistically significant differences between the two groups (P < 0.05). Conclusion: Cooling the injection site before infiltration of local anesthetics in the buccal mucosa for 1 min, reduced pain perceived by pediatric patients. PMID:24379869

Decentralized Opportunistic Spectrum Resources Access Model and Algorithm toward Cooperative Ad-Hoc Networks.

PubMed

Liu, Ming; Xu, Yang; Mohammed, Abdul-Wahid

2016-01-01

Limited communication resources have gradually become a critical factor toward efficiency of decentralized large scale multi-agent coordination when both system scales up and tasks become more complex. In current researches, due to the agent's limited communication and observational capability, an agent in a decentralized setting can only choose a part of channels to access, but cannot perceive or share global information. Each agent's cooperative decision is based on the partial observation of the system state, and as such, uncertainty in the communication network is unavoidable. In this situation, it is a major challenge working out cooperative decision-making under uncertainty with only a partial observation of the environment. In this paper, we propose a decentralized approach that allows agents cooperatively search and independently choose channels. The key to our design is to build an up-to-date observation for each agent's view so that a local decision model is achievable in a large scale team coordination. We simplify the Dec-POMDP model problem, and each agent can jointly work out its communication policy in order to improve its local decision utilities for the choice of communication resources. Finally, we discuss an implicate resource competition game, and show that, there exists an approximate resources access tradeoff balance between agents. Based on this discovery, the tradeoff between real-time decision-making and the efficiency of cooperation using these channels can be well improved.

Efficacy of Chaetomium Species as Biological Control Agents against Phytophthora nicotianae Root Rot in Citrus

PubMed Central

Wattanachai, Pongnak; Kasem, Soytong; Poeaim, Supattra

2015-01-01

Thailand is one of the largest citrus producers in Southeast Asia. Pathogenic infection by Phytophthora, however, has become one of major impediments to production. This study identified a pathogenic oomycete isolated from rotted roots of pomelo (Citrus maxima) in Thailand as Phytophthora nicotianae by the internal transcribed spacer ribosomal DNA sequence analysis. Then, we examined the in vitro and in vivo effects of Chaetomium globosum, Chaetomium lucknowense, Chaetomium cupreum and their crude extracts as biological control agents in controlling this P. nicotianae strain. Represent as antagonists in biculture test, the tested Chaetomium species inhibited mycelial growth by 50~56% and parasitized the hyphae, resulting in degradation of P. nicotianae mycelia after 30 days. The crude extracts of these Chaetomium species exhibited antifungal activities against mycelial growth of P. nicotianae, with effective doses of 2.6~101.4 µg/mL. Under greenhouse conditions, application of spores and methanol extracts of these Chaetomium species to pomelo seedlings inoculated with P. nicotianae reduced root rot by 66~71% and increased plant weight by 72~85% compared to that in the control. The method of application of antagonistic spores to control the disease was simple and economical, and it may thus be applicable for large-scale, highly effective biological control of this pathogen. PMID:26539045

SPARK: A Framework for Multi-Scale Agent-Based Biomedical Modeling.

PubMed

Solovyev, Alexey; Mikheev, Maxim; Zhou, Leming; Dutta-Moscato, Joyeeta; Ziraldo, Cordelia; An, Gary; Vodovotz, Yoram; Mi, Qi

2010-01-01

Multi-scale modeling of complex biological systems remains a central challenge in the systems biology community. A method of dynamic knowledge representation known as agent-based modeling enables the study of higher level behavior emerging from discrete events performed by individual components. With the advancement of computer technology, agent-based modeling has emerged as an innovative technique to model the complexities of systems biology. In this work, the authors describe SPARK (Simple Platform for Agent-based Representation of Knowledge), a framework for agent-based modeling specifically designed for systems-level biomedical model development. SPARK is a stand-alone application written in Java. It provides a user-friendly interface, and a simple programming language for developing Agent-Based Models (ABMs). SPARK has the following features specialized for modeling biomedical systems: 1) continuous space that can simulate real physical space; 2) flexible agent size and shape that can represent the relative proportions of various cell types; 3) multiple spaces that can concurrently simulate and visualize multiple scales in biomedical models; 4) a convenient graphical user interface. Existing ABMs of diabetic foot ulcers and acute inflammation were implemented in SPARK. Models of identical complexity were run in both NetLogo and SPARK; the SPARK-based models ran two to three times faster.

Autonomous Decentralized Voltage Profile Control of Super Distributed Energy System using Multi-agent Technology

NASA Astrophysics Data System (ADS)

Tsuji, Takao; Hara, Ryoichi; Oyama, Tsutomu; Yasuda, Keiichiro

A super distributed energy system is a future energy system in which the large part of its demand is fed by a huge number of distributed generators. At one time some nodes in the super distributed energy system behave as load, however, at other times they behave as generator - the characteristic of each node depends on the customers' decision. In such situation, it is very difficult to regulate voltage profile over the system due to the complexity of power flows. This paper proposes a novel control method of distributed generators that can achieve the autonomous decentralized voltage profile regulation by using multi-agent technology. The proposed multi-agent system employs two types of agent; a control agent and a mobile agent. Control agents generate or consume reactive power to regulate the voltage profile of neighboring nodes and mobile agents transmit the information necessary for VQ-control among the control agents. The proposed control method is tested through numerical simulations.

40 CFR 300.920 - Addition of products to Schedule.

Code of Federal Regulations, 2011 CFR

2011-07-01

... manufacturer of his decision in writing. (b) Surface washing agents, surface collecting agents, bioremediation... collecting agent, bioremediation agent, or miscellaneous oil spill control agent to the NCP Product Schedule... collecting agent, bioremediation agent, or miscellaneous oil spill control agent. On the basis of this data...

40 CFR 300.920 - Addition of products to Schedule.

Code of Federal Regulations, 2014 CFR

2014-07-01

... manufacturer of his decision in writing. (b) Surface washing agents, surface collecting agents, bioremediation... collecting agent, bioremediation agent, or miscellaneous oil spill control agent to the NCP Product Schedule... collecting agent, bioremediation agent, or miscellaneous oil spill control agent. On the basis of this data...

40 CFR 300.920 - Addition of products to Schedule.

Code of Federal Regulations, 2012 CFR

2012-07-01

... manufacturer of his decision in writing. (b) Surface washing agents, surface collecting agents, bioremediation... collecting agent, bioremediation agent, or miscellaneous oil spill control agent to the NCP Product Schedule... collecting agent, bioremediation agent, or miscellaneous oil spill control agent. On the basis of this data...

40 CFR 300.920 - Addition of products to Schedule.

Code of Federal Regulations, 2013 CFR

2013-07-01

... manufacturer of his decision in writing. (b) Surface washing agents, surface collecting agents, bioremediation... collecting agent, bioremediation agent, or miscellaneous oil spill control agent to the NCP Product Schedule... collecting agent, bioremediation agent, or miscellaneous oil spill control agent. On the basis of this data...

40 CFR 300.920 - Addition of products to Schedule.

Code of Federal Regulations, 2010 CFR

2010-07-01

... manufacturer of his decision in writing. (b) Surface washing agents, surface collecting agents, bioremediation... collecting agent, bioremediation agent, or miscellaneous oil spill control agent to the NCP Product Schedule... collecting agent, bioremediation agent, or miscellaneous oil spill control agent. On the basis of this data...

75 FR 7548 - Amendments to the Select Agents Controls in Export Control Classification Number (ECCN) 1C360 on...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-22

...-91434-01] RIN 0694-AE67 Amendments to the Select Agents Controls in Export Control Classification Number... controls on certain select agents identified in Export Control Classification Number (ECCN) 1C360 on the...) list of select agents and toxins. The changes made by APHIS were part of a biennial review and...

A Parallel Sliding Region Algorithm to Make Agent-Based Modeling Possible for a Large-Scale Simulation: Modeling Hepatitis C Epidemics in Canada.

PubMed

Wong, William W L; Feng, Zeny Z; Thein, Hla-Hla

2016-11-01

Agent-based models (ABMs) are computer simulation models that define interactions among agents and simulate emergent behaviors that arise from the ensemble of local decisions. ABMs have been increasingly used to examine trends in infectious disease epidemiology. However, the main limitation of ABMs is the high computational cost for a large-scale simulation. To improve the computational efficiency for large-scale ABM simulations, we built a parallelizable sliding region algorithm (SRA) for ABM and compared it to a nonparallelizable ABM. We developed a complex agent network and performed two simulations to model hepatitis C epidemics based on the real demographic data from Saskatchewan, Canada. The first simulation used the SRA that processed on each postal code subregion subsequently. The second simulation processed the entire population simultaneously. It was concluded that the parallelizable SRA showed computational time saving with comparable results in a province-wide simulation. Using the same method, SRA can be generalized for performing a country-wide simulation. Thus, this parallel algorithm enables the possibility of using ABM for large-scale simulation with limited computational resources.

Population dynamics and impacts of the red-headed leafy spurge stem borer on leafy spurge (Euphorbia esula)

Treesearch

Robert A. Progar; George Markin; Joseph Milan; Tom Barbouletos; Matthew J. Rinella

2011-01-01

We evaluated the efficacy of the biological control agent, red-headed leafy spurge stem borer, against the nonnative invasive plant leafy spurge. Our three treatments were release of the biological control agent into uncaged plots, release of the biological control agent into plots caged to prevent agent escape, and control plots caged to prevent agent entry. These...

Liquefaction process

DOEpatents

Poddar, Syamal K.

1981-01-01

Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by pretreatment with a combination of pretreating agents comprising SO.sub.2 and an oxidizing agent. It is essential to effective operation that the moisture content of the solid carbonaceous material be within the range from about 10 to about 25 wt %, based on dry solid carbonaceous material, during the pretreatment. The pretreatment is believed to convert at least a portion of the scale-forming components and particularly calcium, to the corresponding sulfate prior to liquefaction. The pretreatment may be accomplished with the combination of pretreating agents either simultaneously by using a mixture comprising SO.sub.2 and a gaseous oxidizing agent or sequentially by first treating with SO.sub.2 and then with an oxidizing agent.

Evolution of wealth in a non-conservative economy driven by local Nash equilibria.

PubMed

Degond, Pierre; Liu, Jian-Guo; Ringhofer, Christian

2014-11-13

We develop a model for the evolution of wealth in a non-conservative economic environment, extending a theory developed in Degond et al. (2014 J. Stat. Phys. 154, 751-780 (doi:10.1007/s10955-013-0888-4)). The model considers a system of rational agents interacting in a game-theoretical framework. This evolution drives the dynamics of the agents in both wealth and economic configuration variables. The cost function is chosen to represent a risk-averse strategy of each agent. That is, the agent is more likely to interact with the market, the more predictable the market, and therefore the smaller its individual risk. This yields a kinetic equation for an effective single particle agent density with a Nash equilibrium serving as the local thermodynamic equilibrium. We consider a regime of scale separation where the large-scale dynamics is given by a hydrodynamic closure with this local equilibrium. A class of generalized collision invariants is developed to overcome the difficulty of the non-conservative property in the hydrodynamic closure derivation of the large-scale dynamics for the evolution of wealth distribution. The result is a system of gas dynamics-type equations for the density and average wealth of the agents on large scales. We recover the inverse Gamma distribution, which has been previously considered in the literature, as a local equilibrium for particular choices of the cost function. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Effect of crystals and fibrous network polymer additives on cellular morphology of microcellular foams

NASA Astrophysics Data System (ADS)

Miyamoto, Ryoma; Utano, Tatsumi; Yasuhara, Shunya; Ishihara, Shota; Ohshima, Masahiro

2015-05-01

In this study, the core-back foam injection molding was used for preparing microcelluar polypropylene (PP) foam with either a 1,3:2,4 bis-O-(4-methylbenzylidene)-D-sorbitol gelling agent (Gel-all MD) or a fibros network polymer additive (Metablen 3000). Both agent and addiive could effectively control the celluar morphology in foams but somehow different ways. In course of cooling the polymer with Gel-all MD in the mold caity, the agent enhanced the crystal nucleation and resulted in the large number of small crystals. The crystals acted as effective bubble nucleation agent in foaming process. Thus, the agent reduced the cell size and increased the cell density, drastically. Furthermore, the small crystals provided an inhomogenuity to the expanding cell wall and produced the high open cell content with nano-scale fibril structure. Gell-all as well as Metablene 3000 formed a gel-like fibrous network in melt. The network increased the elongational viscosity and tended to prevent the cell wall from breaking up. The foaming temperature window was widened by the presence of the network. Especially, the temperature window where the macro-fibrous structure was formed was expanded to the higher temperature. The effects of crystal nucleating agent and PTFE on crystals' size and number, viscoelsticity, rheological propreties of PP and cellular morphology were compared and thorougly investigated.

Effect of propofol versus sodium thiopental on electroconvulsive therapy in major depressive disorder: a randomized double-blind controlled clinical trial.

PubMed

Purtuloğlu, Tark; Özdemir, Barbaros; Erdem, Murat; Deniz, Süleyman; Balkç, Adem; Ünlü, Gazi; Öznur, Taner

2013-03-01

To compare propofol and sodium thiopental as anesthetic agents for electroconvulsive therapy (ECT) in major depression with respect to clinical effect. Participants were composed of 96 patients with depression who were administered either propofol or sodium thiopental as an anesthetic agent for bilateral ECT. The Hamilton Depression Rating Scale was administered at baseline and after 6 treatments. Algorithm-based charge dosing was used. There was a statistically significant difference between the groups regarding postintervention Hamilton Depression Rating Scale score. The preintervention mean (SD) scores in the propofol group and the sodium thiopental group were 37.3 (2.2) and 36.7 (1.2), respectively. The postintervention mean (SD) scores in the propofol group and the sodium thiopental group were 10.7 (1.8) and 13.4 (3.3), respectively. No correlation was found between clinical response and age, weight, and body mass index. There was no association between the groups' seizure time and duration of recovery. In conclusion, propofol may improve major depressive disorder more than sodium thiopental in patients who are receiving ECT.

Development of superior asphalt recycling agents. Phase 1, Technical feasibility. Final technical progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bullin, J.A.; Davison, R.R.; Glover, C.J.

1997-07-01

After an introduction and a literature survey in Chap. 1, Chap. 2 describes the tasks, together with objectives and important results obtained for each task throughout the entire project. Chaps. 3 thru 7 detail work in developing a qualitative and quantitative knowledge of asphalt oxidation, composition dependence of asphalt properties, and guidelines for producing superior asphalt binders through composition control. They also detail the development of a kinetic model for asphalt oxidative aging and present an understanding of the composition dependence of asphalt oxidation as well as other performance-related properties. Chaps. 8 and 9 compare the aging performance of recycledmore » blends produced using commercial recycling agents and industrial supercritical fractions as rejuvenating agents. Oxidative aging of the recycled blends were evaluated along with the performance of the recycled blends in terms of the strategic highway research program performance grading procedure. Chap. 10 summarizes the work completed in the areas of processing schemes development, projection updates, and scale-up and commercialization plans.« less

Use of additive and pretreatment to control odors in municipal kitchen waste during aerobic composting.

PubMed

Yuan, Jing; Yang, Qingyuan; Zhang, Zhiye; Li, Guoxue; Luo, Wenhai; Zhang, Difang

2015-11-01

The effects of adding a bulking agent and chemically pretreating municipal kitchen waste before aerobic composting were studied using a laboratory-scale system. The system used 20-L reactors and each test lasted 28days. The objective was to decrease NH3 and H2S emissions during composting. The bulking agent, dry cornstalks, was mixed with the kitchen waste to give a mixture containing 15% (wet weight) bulking agent. A combined treatment was also conducted, in which kitchen waste mixed with the bulking agent was pretreated with ferric chloride (FeCl3). Less leachate was produced by the composted kitchen waste mixed with bulking agent than by the kitchen waste alone, when the materials had reached the required maturity. The presence of cornstalks also caused less H2S to be emitted, but had little impact on the amount of NH3 emitted. The FeCl3 was found to act as an effective chemical flocculant, and its presence significantly decreased the amounts of NH3 and H2S emitted. Kitchen waste mixed with cornstalks and treated with FeCl3 emitted 42% less NH3 and 76% less H2S during composting than did pure kitchen waste. Copyright © 2015. Published by Elsevier B.V.

Clinical evaluation of the efficacy of fluoride adhesive tape (F-PVA) in reducing dentin hypersensitivity.

PubMed

Lee, Sang-Ho; Lee, Nan-Young; Lee, In-Hwa

2013-06-01

To evaluate the in vivo effectiveness of an experimental 2.26% fluoride polyvinyl alcohol (F-PVA) tape in reducing dentin hypersensitivity. 30 healthy men and women (total of 79 teeth) in their third decade of life with dentin hypersensitivity were enrolled in this study. The subjects were divided into four groups: three experimental groups were treated with fluoride agents (F-PVA tape, Vanish varnish, and ClinPro XT varnish), and a control group was treated with gelatin as a placebo. Each fluoride agent was applied according to the manufacturer's instructions. Stimulation was applied to the subjects' teeth using compressed air and ice sticks before applying the agent, as well as at 3 days and 4, 8, and 12 weeks after applying the agent. The degree of pain was measured using a visual analogue scale (VAS). The VAS scores were significantly (P < 0.05) decreased at 3 days and at 4, 8, and 12 weeks from baseline in both the air stream and ice stick tests. The reduction in the VAS scores for the three fluoride agents was decreased 8 weeks after their application. The F-PVA tape was found to be more effective for dentin hypersensitivity than the Vanish varnish and ClinPro XT varnish at 4 and 8 weeks of the examination period.

Twitter web-service for soft agent reporting in persistent surveillance systems

NASA Astrophysics Data System (ADS)

Rababaah, Haroun; Shirkhodaie, Amir

2010-04-01

Persistent surveillance is an intricate process requiring monitoring, gathering, processing, tracking, and characterization of many spatiotemporal events occurring concurrently. Data associated with events can be readily attained by networking of hard (physical) sensors. Sensors may have homogeneous or heterogeneous (hybrid) sensing modalities with different communication bandwidth requirements. Complimentary to hard sensors are human observers or "soft sensors" that can report occurrences of evolving events via different communication devices (e.g., texting, cell phones, emails, instant messaging, etc.) to the command control center. However, networking of human observers in ad-hoc way is rather a difficult task. In this paper, we present a Twitter web-service for soft agent reporting in persistent surveillance systems (called Web-STARS). The objective of this web-service is to aggregate multi-source human observations in hybrid sensor networks rapidly. With availability of Twitter social network, such a human networking concept can not only be realized for large scale persistent surveillance systems (PSS), but also, it can be employed with proper interfaces to expedite rapid events reporting by human observers. The proposed technique is particularly suitable for large-scale persistent surveillance systems with distributed soft and hard sensor networks. The efficiency and effectiveness of the proposed technique is measured experimentally by conducting several simulated persistent surveillance scenarios. It is demonstrated that by fusion of information from hard and soft agents improves understanding of common operating picture and enhances situational awareness.

Biomimetic synthesis of silver nanoparticles using the fish scales of Labeo rohita and their application as catalysts for the reduction of aromatic nitro compounds

NASA Astrophysics Data System (ADS)

Sinha, Tanur; Ahmaruzzaman, M.; Sil, A. K.; Bhattacharjee, Archita

2014-10-01

In this article, a cleaner, greener, cheaper and environment friendly method for the generation of self assembled silver nanoparticles (Ag NPs) applying a simple irradiation technique using the aqueous extract of the fish scales (which is considered as a waste material) of Labeo rohita is described. Gelatin is considered as the major ingredient responsible for the reduction as well as stabilisation of the self assembled Ag NPs. The size and morphology of the individual Ag NPs can be tuned by controlling the various reaction parameters, such as temperature, concentration, and pH. Studies showed that on increasing concentration and pH Ag NPs size decreases, while on increasing temperature, Ag NPs size increases. The present process does not need any external reducing agent, like sodium borohydride or hydrazine or others and gelatin itself can play a dual role: a ‘reducing agent' and ‘stabilisation agent' for the formation of gelatin-Ag NPs colloidal dispersion. The synthesized Ag NPs were characterised by Ultraviolet-Visible spectroscopy (UV-Vis), Transmission electron microscopy (TEM) and Selected area electron diffraction (SAED) analyses. The synthesized Ag NPs was used to study the catalytic reduction of various aromatic nitro compounds in aqueous and three different micellar media. The hydrophobic and electrostatic interaction between the micelle and the substrate is responsible for the catalytic activity of the nanoparticles in micelle.

From symptoms to social functioning: differential effects of antidepressant therapy.

PubMed

Kasper, S

1999-05-01

Significant impairments in social functioning frequently occur simultaneously with depressive symptoms. The implications of such impairments extend beyond the depressed individual to their family, friends and society at large. Classical rating scales such as the Hamilton rating scale for depression primarily assess the core symptoms of depression. A range of rating scales are available, both self-reporting and administered by clinician; however, many have been criticised for their unspecified conceptual background and for being complex and time-consuming. While antidepressants in general appear to improve social functioning, no clear advantage for any single class of agent has been reported. Recently, a new self-report rating scale, the Social Adaptation Self-evaluation Scale, has been developed and used to compare the novel selective noradrenaline reuptake inhibitor, reboxetine, with the selective serotonin re-uptake inhibitor, fluoxetine. The noradrenergic agent, reboxetine, was shown to be significantly more effective in improving social functioning than the serotonergic agent, fluoxetine. These findings are consistent with previous observations that noradrenaline may preferentially improve vigilance, motivation and self-perception.

Non-target effects of an introduced biological control agent on deer mouse ecology

Treesearch

Dean E. Pearson; Kevin S. McKelvey; Leonard F. Ruggiero

2000-01-01

Release of exotic insects as biological control agents is a common approach to controlling exotic plants. Though controversy has ensued regarding the deleterious direct effects of biological control agents to non-target species, few have examined the indirect effects of a "well-behaved" biological control agent on native fauna. We studied a grassland in west-...

40 CFR 152.20 - Exemptions for pesticides adequately regulated by another Federal agency.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Federal agency. (a) Certain biological control agents. (1) Except as provided by paragraphs (a)(3) and (a)(4) of this section, all biological control agents are exempt from FIFRA requirements. (2) If the Agency determines that an individual biological control agent or class of biological control agents is no...

40 CFR 152.20 - Exemptions for pesticides adequately regulated by another Federal agency.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Federal agency. (a) Certain biological control agents. (1) Except as provided by paragraphs (a)(3) and (a)(4) of this section, all biological control agents are exempt from FIFRA requirements. (2) If the Agency determines that an individual biological control agent or class of biological control agents is no...

Validation of a hot water rinse and lactic acid spray in combination with scaling for treating hide-on carcasses to control biotype I strains of Escherichia coli used as surrogates for Shiga toxin-producing E. coli

USDA-ARS?s Scientific Manuscript database

Scalding of hide-on bob veal carcasses with or without standard scalding chemical agents typically used for hogs, followed by an 82.2degreeC hot water wash and lactic acid spray (applied at ambient temperature) prior to chilling, was evaluated to determine its effectiveness in reducing the levels of...

Fire as a control agent of demographic structure and plant performance of a rare Mediterranean endemic geophyte.

PubMed

Diadema, Katia; Médail, Frédéric; Bretagnolle, François

2007-09-01

We examine the effects of fire and/or surrounding vegetation cover on demographic stage densities and plant performance for a rare endemic geophyte, Acis nicaeensis (Alliaceae), in Mediterranean xerophytic grasslands of the 'Alpes-Maritimes' French 'département', through sampling plots in unburned and burned treatments. Fire increases density of flowering individuals and seedling emergence, as well as clump densities and number of individuals per clump, per limiting vegetation height and cover, and increasing bare soil cover. In contrast, fire has no effect on reproductive success. Nevertheless, two growing seasons after fire, all parameters of demographic stages and plant performance do not significantly differ between the two treatments. Small-scale fire is beneficial for the regeneration of this threatened geophyte at a short-time scale. In this context, a conservation planning with small and controlled fires could maintain the regeneration window for populations of rare Mediterranean geophytes.

Laser therapy may be better than topical desensitizing agents for treating dentin hypersensitivity.

PubMed

Blatz, Markus B

2012-09-01

Two independent reviewers screened the databases MEDLINE, EMBASE, the Cochrane Central Register of ControlledTrials, the National Research Register, and the Cochrane Oral HealthGroup'sTrials Register for articles written in English between 1977 and January1, 2010. The inclusion criteria comprised randomized controlled trials (RCTs) involving the application of laser desensitizing procedures and topical desensitizing agents in patients with at least 2 or more hypersensitive teeth confirmed by evaporative stimulus or tactile hypersensitivity assessment. Trial groups needed to receive laser therapy, whereas the control groups received topical desensitizing agents, such as fluoride varnish, dentin bonding agents, or others. Outcomes had to be measured by clinical performance (decrease of hypersensitivity) and/or patients' self-assessment. Studies with loss in follow-up greater than 20% or with confusing data/probable errors were excluded. A total of 176 potential relevant titles, abstracts, and articles were found, 28 of which were screened for further evaluation. Out of these, 8 trials met all inclusion criteria, involving a total of 234 patients. The quality of these trials was assessed according to the Cochrane Handbook for Systematic Reviews of Interventions. Accordingly, only 1 study was classified as A level, 5 as B level, and 2 as C level. A meta-analysis was not performed because of the heterogeneity of the studies. Studies that assess the application of laser desensitizing procedures in reducing dentinal hypersensitivity. The primary outcome was reduction of tooth sensitivity following treatment with either a laser or a topical desensitizing agent. Evaluations were made at varying intervals up to 6 months after treatment. Eight trials reporting on a total of 234 patients were included based on the specified criteria and 20 articles were excluded. Sample size in each of the included studies varied from 20 to 70 patients with differing follow-up intervals of up to 6 months. Most studies used Visual Analog Scale scores or other subjective tools to assess sensitivity. All 8 studies compared one kind of laser versus one kind of topical desensitizingagent. However, types of lasers as well as types of desensitizing agents differed among the reviewed studies. Half of the studies compared gallium-aluminum-arsenide (GaAlAs) lasers with various topical desensitizing agents; however, findings were conflicting. Two moderate-quality trials indicated that GaAlAs laser and the control desensitizing agents preformed similarly. Another moderate-quality trial demonstrated that the application of a bonding agent was significantly better than a GaAlAs laser in the reduction of hypersensitivity. The only reviewed study that was classified as an A-level study revealed a significantly greater immediate and long-term desensitizing effect than the control. The remaining studies involved Nd:YAG, Er:YAG, and CO(2) lasers, all of them reporting a slightly greater decrease in sensitivity as compared with topical desensitizing agents. Five of 8s tudies reported on the safety of laser application and did not find any detrimental pulpal effects, allergic reactions, or clinically detectable complications during follow-up. The authors concluded that the results obtained from the 8 studies included in this systematic review were conflicting but indicated a slight clinical advantage of laser therapy over topical medicaments in the treatment of dentin hypersensitivity. It was further concluded that application of lasers under controlled parameters for this indication may not lead to adverse effects. Copyright © 2012. Published by Mosby, Inc. All rights reserved.

On the Ni-Ion release rate from surfaces of binary NiTi shape memory alloys

NASA Astrophysics Data System (ADS)

Ševčíková, Jana; Bártková, Denisa; Goldbergová, Monika; Kuběnová, Monika; Čermák, Jiří; Frenzel, Jan; Weiser, Adam; Dlouhý, Antonín

2018-01-01

The study is focused on Ni-ion release rates from NiTi surfaces exposed in the cell culture media and human vascular endothelial cell (HUVEC) culture environments. The NiTi surface layers situated in the depth of 70 μm below a NiTi oxide scale are affected by interactions between the NiTi alloys and the bio-environments. The finding was proved with use of inductively coupled plasma mass spectrometry and electron microscopy experiments. As the exclusive factor controlling the Ni-ion release rates was not only thicknesses of the oxide scale, but also the passivation depth, which was two-fold larger. Our experimental data strongly suggested that some other factors, in addition to the Ni concentration in the oxide scale, admittedly hydrogen soaking deep below the oxide scale, must be taken into account in order to rationalize the concentrations of Ni-ions released into the bio-environments. The suggested role of hydrogen as the surface passivation agent is also in line with the fact that the Ni-ion release rates considerably decrease in NiTi samples that were annealed in controlled hydrogen atmospheres prior to bio-environmental exposures.

Biodiversity and disease: a synthesis of ecological perspectives on Lyme disease transmission.

USGS Publications Warehouse

Wood, Chelsea L.; Lafferty, Kevin D.

2013-01-01

Recent reviews have argued that disease control is among the ecosystem services yielded by biodiversity. Lyme disease (LD) is commonly cited as the best example of the ‘diluting’ effect of biodiversity on disease transmission, but many studies document the opposite relationship, showing that human LD risk can increase with forestation. Here, we unify these divergent perspectives and find strong evidence for a positive link between biodiversity and LD at broad spatial scales (urban to suburban to rural) and equivocal evidence for a negative link between biodiversity and LD at varying levels of biodiversity within forests. This finding suggests that, across zoonotic disease agents, the biodiversity–disease relationship is scale dependent and complex.

Agent Based Modeling Applications for Geosciences

NASA Astrophysics Data System (ADS)

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 a thermodynamic framework as a set of reactions that roll-up the integrated effect that diverse biological communities exert on a geological system. This approach may work well to predict the effect of certain biological communities in specific environments in which experimental data is available. However, it does not further our knowledge of how the geobiological system actually functions on a micro scale. Agent-based techniques may provide a framework to explore the fundamental interactions required to explain the system-wide behavior. This presentation will present a survey of several promising applications of agent-based modeling approaches to problems in the geosciences and describe specific contributions to some of the inherent challenges facing this approach.

Prophylactic isopropyl alcohol inhalation and intravenous ondansetron versus ondansetron alone in the prevention of postoperative nausea and vomiting in high-risk patients.

PubMed

Radford, Kennett D; Fuller, Thomas N; Bushey, Brent; Daniel, Carole; Pellegrini, Joseph E

2011-08-01

Patients identified as high risk for postoperative nausea and vomiting (PONV) are often treated prophylactically with intravenous (IV) ondansetron and an additional agent. Limited options exist for a second agent with no adverse effects. The purpose of this investigation was to determine if combining the prophylactic inhalation of isopropyl alcohol (IPA) vapors, an agent with no adverse effects, with IV ondansetron would be more effective than IV ondansetron alone in the prevention of PONV in high-risk patients. A total of 76 patients at high risk for PONV were randomized into control (n = 38) and experimental (n = 38) groups. All patients received IV ondansetron before emergence from general anesthesia. In addition, the experimental group inhaled IPA vapors before induction. Severity of PONV was measured using a 0 to 10 verbal numeric rating scale. Other measured variables included time to onset and incidence of PONV, 24-hour composite nausea score, and satisfaction with nausea control. No significant differences in demographics, surgical or anesthesia time, number of risk factors, severity or incidence of PONV, or satisfaction scores were noted. Prophylactic inhalation of IPA vapors in combination with IV ondansetron was no more efficacious than IV ondansetron alone in the prevention of PONV in a high-risk population.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahault, Benoit Alexandre; Saxena, Avadh Behari; Nisoli, Cristiano

We introduce a minimal agent-based model to qualitatively conceptualize the allocation of limited wealth among more abundant opportunities. We study the interplay of power, satisfaction and frustration in the problem of wealth distribution, concentration, and inequality. This framework allows us to compare subjective measures of frustration and satisfaction to collective measures of fairness in wealth distribution, such as the Lorenz curve and the Gini index. We find that a completely libertarian, law-of-the-jungle setting, where every agent can acquire wealth from, or lose wealth to, anybody else invariably leads to a complete polarization of the distribution of wealth vs. opportunity, onlymore » minimally ameliorated by disorder in a non-optimized society. The picture is however dramatically modified when hard constraints are imposed over agents, and they are forced to share wealth with neighbors on a network. We discuss the case of random networks and scale free networks. We then propose an out of equilibrium dynamics of the networks, based on a competition of power and frustration in the decision-making of agents that leads to network evolution. We show that the ratio of power and frustration controls different dynamical regimes separated by kinetic transition and characterized by drastically different values of the indices of equality.« less

Heat-resistant agent used for control sand of steam huff and puff heavy oil well

NASA Astrophysics Data System (ADS)

Zhang, F. S.; Liu, G. L.; Lu, Y. J.; Xiong, X. C.; Ma, J. H.; Su, H. M.

2018-01-01

Heat-resistant agent containing hydroxymethyl group was synthesized from coal tar, which has similar structure with phenolic resin and could improve the heat resistance of phenolic resin sand control agent. The results showed that the heat resistance of the sand control agent was improved by adding 10% to 30% heat-resistant agent, after 280°C high temperature treatment for 7d, the compressive strength of consolidated core was increased to more than 5MPa. The compressive strength of consolidation core was not decreased after immersion in formation water, crude oil, acid or alkaline medium, which showed good resistance to medium immersion. The sand control agent had small core damage and the core permeability damage ratio of sand control agent consolidation was only 18.7%.

Scale-free memory model for multiagent reinforcement learning. Mean field approximation and rock-paper-scissors dynamics

NASA Astrophysics Data System (ADS)

Lubashevsky, I.; Kanemoto, S.

2010-07-01

A continuous time model for multiagent systems governed by reinforcement learning with scale-free memory is developed. The agents are assumed to act independently of one another in optimizing their choice of possible actions via trial-and-error search. To gain awareness about the action value the agents accumulate in their memory the rewards obtained from taking a specific action at each moment of time. The contribution of the rewards in the past to the agent current perception of action value is described by an integral operator with a power-law kernel. Finally a fractional differential equation governing the system dynamics is obtained. The agents are considered to interact with one another implicitly via the reward of one agent depending on the choice of the other agents. The pairwise interaction model is adopted to describe this effect. As a specific example of systems with non-transitive interactions, a two agent and three agent systems of the rock-paper-scissors type are analyzed in detail, including the stability analysis and numerical simulation. Scale-free memory is demonstrated to cause complex dynamics of the systems at hand. In particular, it is shown that there can be simultaneously two modes of the system instability undergoing subcritical and supercritical bifurcation, with the latter one exhibiting anomalous oscillations with the amplitude and period growing with time. Besides, the instability onset via this supercritical mode may be regarded as “altruism self-organization”. For the three agent system the instability dynamics is found to be rather irregular and can be composed of alternate fragments of oscillations different in their properties.

Development of agent-based on-line adaptive signal control (ASC) framework using connected vehicle (CV) technology.

DOT National Transportation Integrated Search

2016-04-01

In this study, we developed an adaptive signal control (ASC) framework for connected vehicles (CVs) using agent-based modeling technique. : The proposed framework consists of two types of agents: 1) vehicle agents (VAs); and 2) signal controller agen...

Memory Transmission in Small Groups and Large Networks: An Agent-Based Model.

PubMed

Luhmann, Christian C; Rajaram, Suparna

2015-12-01

The spread of social influence in large social networks has long been an interest of social scientists. In the domain of memory, collaborative memory experiments have illuminated cognitive mechanisms that allow information to be transmitted between interacting individuals, but these experiments have focused on small-scale social contexts. In the current study, we took a computational approach, circumventing the practical constraints of laboratory paradigms and providing novel results at scales unreachable by laboratory methodologies. Our model embodied theoretical knowledge derived from small-group experiments and replicated foundational results regarding collaborative inhibition and memory convergence in small groups. Ultimately, we investigated large-scale, realistic social networks and found that agents are influenced by the agents with which they interact, but we also found that agents are influenced by nonneighbors (i.e., the neighbors of their neighbors). The similarity between these results and the reports of behavioral transmission in large networks offers a major theoretical insight by linking behavioral transmission to the spread of information. © The Author(s) 2015.

Integrating adaptive behaviour in large-scale flood risk assessments: an Agent-Based Modelling approach

NASA Astrophysics Data System (ADS)

Haer, Toon; Aerts, Jeroen

2015-04-01

Between 1998 and 2009, Europe suffered over 213 major damaging floods, causing 1126 deaths, displacing around half a million people. In this period, floods caused at least 52 billion euro in insured economic losses making floods the most costly natural hazard faced in Europe. In many low-lying areas, the main strategy to cope with floods is to reduce the risk of the hazard through flood defence structures, like dikes and levees. However, it is suggested that part of the responsibility for flood protection needs to shift to households and businesses in areas at risk, and that governments and insurers can effectively stimulate the implementation of individual protective measures. However, adaptive behaviour towards flood risk reduction and the interaction between the government, insurers, and individuals has hardly been studied in large-scale flood risk assessments. In this study, an European Agent-Based Model is developed including agent representatives for the administrative stakeholders of European Member states, insurers and reinsurers markets, and individuals following complex behaviour models. The Agent-Based Modelling approach allows for an in-depth analysis of the interaction between heterogeneous autonomous agents and the resulting (non-)adaptive behaviour. Existing flood damage models are part of the European Agent-Based Model to allow for a dynamic response of both the agents and the environment to changing flood risk and protective efforts. By following an Agent-Based Modelling approach this study is a first contribution to overcome the limitations of traditional large-scale flood risk models in which the influence of individual adaptive behaviour towards flood risk reduction is often lacking.

Adaptive consensus of scale-free multi-agent system by randomly selecting links

NASA Astrophysics Data System (ADS)

Mou, Jinping; Ge, Huafeng

2016-06-01

This paper investigates an adaptive consensus problem for distributed scale-free multi-agent systems (SFMASs) by randomly selecting links, where the degree of each node follows a power-law distribution. The randomly selecting links are based on the assumption that every agent decides to select links among its neighbours according to the received data with a certain probability. Accordingly, a novel consensus protocol with the range of the received data is developed, and each node updates its state according to the protocol. By the iterative method and Cauchy inequality, the theoretical analysis shows that all errors among agents converge to zero, and in the meanwhile, several criteria of consensus are obtained. One numerical example shows the reliability of the proposed methods.

The Extended Mind: Coupling Environment and Brain

NASA Astrophysics Data System (ADS)

Vrobel, Susie

2010-11-01

This paper describes embodiment and cognitive extension as examples of strong anticipation as defined by Dubois. Clark and Chalmers formulated a thesis which states that parts of the environment, if coupled successfully, can become part of the extended mind. This coupling, be it deliberate or unintentional, shifts the observer-world boundary outwards when the observer encompasses parts of his environment. The resulting extended observer forms a new systemic whole, which consists of both the assimilated context and the recalibrated version of the original observer. Recalibration occurs when conditioning and adaptation lead to corresponding changes on the neural level, for instance, when an agent compensates for delays in a control loop. Plasticity is a prerequisite for any successful incorporation of external structures. However, uncoupled parts of the observer must remain inviolate in order to preserve the boundary. Neither the extended mind nor the core observer are absolute concepts. Depending on whether we focus on local-scale interactions or on large-scale behaviour, boundaries are formed at different interfacial cuts, which lead to either an endo- or an exo-perspective or endo- or exo-anticipation, respectively. For biological extended agents which undergo a transition from exo- to endo-states, a tell-tale sign of a successful exo-endo transition is invisibility. This invisibility occurs when the agent is no longer aware of the delay originally introduced into the control loop by the assimilated part of the environment. Explaining the world in terms of effective causality is not sufficient to account for extended minds. The latter require explanations in terms of final causation. For extended minds, this ordering principle comes in the shape of nested hierarchical layers. The interfaces of these layers may have merged for an endo-observer, whereas an exo-observer can make out the detailed structure, including artificially introduced delays. A sufficient condition for an endo-observer to turn into an extended mind is the formation of a new systemic whole as a result of shifting the interfacial cut between exo-and endo-world outwards. However, this is only a necessary condition for an extended agent with strong anticipatory properties. It is invisibility which is a sufficient condition for strong or endo-anticipation.

Antidepressant Efficacy of the Antimuscarinic Drug Scopolamine

PubMed Central

Furey, Maura L.; Drevets, Wayne C.

2010-01-01

Context The need for improved therapeutic agents that more quickly and effectively treat depression is critical. In a pilot study we evaluated the role of the cholinergic system in cognitive symptoms of depression and unexpectedly observed rapid reductions in depression severity following the administration of the antimuscarinic drug scopolamine hydrobromide (4 μg/kg intravenously) compared with placebo (P=.002). Subsequently a clinical trial was designed to assess more specifically the antidepressant efficacy of scopolamine. Objective To evaluate scopolamine as a potential antidepressant agent. Design Two studies were conducted: a double-blind, placebo-controlled, dose-finding study followed by a double-blind, placebo-controlled, crossover clinical trial. Setting The National Institute of Mental Health. Patients Currently depressed outpatients aged 18 to 50 years meeting DSM-IV criteria for recurrent major depressive disorder or bipolar disorder. Of 39 eligible patients, 19 were randomized and 18 completed the trial. Interventions Multiple sessions including intravenous infusions of placebo or scopolamine hydrobromide (4 μg/kg). Individuals were randomized to a placebo/ scopolamine or scopolamine/placebo sequence (series of 3 placebo sessions and series of 3 scopolamine sessions). Sessions occurred 3 to 5 days apart. Main Outcome Measures Psychiatric evaluations using the Montgomery-Asberg Depression Rating Scale and the Hamilton Anxiety Rating Scale were performed to assess antidepressant and antianxiety responses to scopolamine. Results The placebo/scopolamine group showed no significant change during placebo infusion vs baseline; reductions in depression and anxiety rating scale scores (P<.001 for both) were observed after the administration of scopolamine compared with placebo. The scopolamine/placebo group also showed reductions in depression and anxiety rating scale scores (P<.001 for both) after the administration of scopolamine, relative to baseline, and these effects persisted as they received placebo. In both groups, improvement was significant at the first evaluation after scopolamine administration (P≤.002). Conclusion Rapid, robust antidepressant responses to the antimuscarinic scopolamine occurred in currently depressed patients who predominantly had poor prognoses. PMID:17015814

The Effects of Level of Autonomy on Human-Agent Teaming for Multi-Robot Control and Local Security Maintenance

DTIC Science & Technology

2013-11-01

different types of tasks, the associated costs of task switching also increase (Squire et al., 2006). Task switching costs may be increased with higher...switching costs as well, particularly when managing robot teams of increasing size (Squire et al., 2006). 1.3 Individual Differences The effects of...Research: Ready to Deliver the Promises. Mind 2003, 2 (3), 4. Jian, J.; Bisantz, A. M.; Drury , C. G. Foundations for an Empirically Determined Scale

Concurrent Learning of Control in Multi agent Sequential Decision Tasks

DTIC Science & Technology

2018-04-17

Concurrent Learning of Control in Multi-agent Sequential Decision Tasks The overall objective of this project was to develop multi-agent reinforcement...learning (MARL) approaches for intelligent agents to autonomously learn distributed control policies in decentral- ized partially observable...shall be subject to any oenalty for failing to comply with a collection of information if it does not display a currently valid OMB control number

Imidacloprid as a Potential Agent for the Systemic Control of Sand Flies

DTIC Science & Technology

2011-03-01

Imidacloprid as a potential agent for the systemic control of sand flies Gideon Wasserberg1,4*, Richard... imidacloprid as a systemic control agent. First, to evaluate the blood-feeding effect, we fed adult female Phlebotomus papatasi with imidacloprid ...mortality was obtained with a dose of only 250 ppm. Overall, results support the feasibility of imidacloprid as a systemic control agent that

Controlled teleportation with the control of two groups of agents via entanglement

NASA Astrophysics Data System (ADS)

He, Xiao-Ling; Liu, Man; Yang, Chui-Ping

2015-03-01

We present a way for implementing controlled teleportation of an arbitrary unknown pure state of a qutrit with the control of two groups of agents via entanglement. In our proposal, the sender can successfully teleport the qutrit state to a distant receiver with the help of all agents. However, if one agent in each group does not cooperate, the receiver cannot gain any information (including amplitude information or phase information or both) about the qutrit state to be teleported. Since a qubit is a special case of a qutrit when the state lies in a fixed two-dimensional subspace of the qutrit, the present proposal can be also applied in the implementation of controlled teleportation of an arbitrary unknown pure state of a qubit with many control agents in two groups. We note that our proposal is the first one to use two groups of agents to achieve controlled teleportation.

Computation of the target state and feedback controls for time optimal consensus in multi-agent systems

NASA Astrophysics Data System (ADS)

Mulla, Ameer K.; Patil, Deepak U.; Chakraborty, Debraj

2018-02-01

N identical agents with bounded inputs aim to reach a common target state (consensus) in the minimum possible time. Algorithms for computing this time-optimal consensus point, the control law to be used by each agent and the time taken for the consensus to occur, are proposed. Two types of multi-agent systems are considered, namely (1) coupled single-integrator agents on a plane and, (2) double-integrator agents on a line. At the initial time instant, each agent is assumed to have access to the state information of all the other agents. An algorithm, using convexity of attainable sets and Helly's theorem, is proposed, to compute the final consensus target state and the minimum time to achieve this consensus. Further, parts of the computation are parallelised amongst the agents such that each agent has to perform computations of O(N2) run time complexity. Finally, local feedback time-optimal control laws are synthesised to drive each agent to the target point in minimum time. During this part of the operation, the controller for each agent uses measurements of only its own states and does not need to communicate with any neighbouring agents.

An Intelligent Control for the Distributed Flexible Network Photovoltaic System using Autonomous Control and Agent

NASA Astrophysics Data System (ADS)

Park, Sangsoo; Miura, Yushi; Ise, Toshifumi

This paper proposes an intelligent control for the distributed flexible network photovoltaic system using autonomous control and agent. The distributed flexible network photovoltaic system is composed of a secondary battery bank and a number of subsystems which have a solar array, a dc/dc converter and a load. The control mode of dc/dc converter can be selected based on local information by autonomous control. However, if only autonomous control using local information is applied, there are some problems associated with several cases such as voltage drop on long power lines. To overcome these problems, the authors propose introducing agents to improve control characteristics. The autonomous control with agents is called as intelligent control in this paper. The intelligent control scheme that employs the communication between agents is applied for the model system and proved with simulation using PSCAD/EMTDC.

Integrating macro and micro scale approaches in the agent-based modeling of residential dynamics

NASA Astrophysics Data System (ADS)

Saeedi, Sara

2018-06-01

With the advancement of computational modeling and simulation (M&S) methods as well as data collection technologies, urban dynamics modeling substantially improved over the last several decades. The complex urban dynamics processes are most effectively modeled not at the macro-scale, but following a bottom-up approach, by simulating the decisions of individual entities, or residents. Agent-based modeling (ABM) provides the key to a dynamic M&S framework that is able to integrate socioeconomic with environmental models, and to operate at both micro and macro geographical scales. In this study, a multi-agent system is proposed to simulate residential dynamics by considering spatiotemporal land use changes. In the proposed ABM, macro-scale land use change prediction is modeled by Artificial Neural Network (ANN) and deployed as the agent environment and micro-scale residential dynamics behaviors autonomously implemented by household agents. These two levels of simulation interacted and jointly promoted urbanization process in an urban area of Tehran city in Iran. The model simulates the behavior of individual households in finding ideal locations to dwell. The household agents are divided into three main groups based on their income rank and they are further classified into different categories based on a number of attributes. These attributes determine the households' preferences for finding new dwellings and change with time. The ABM environment is represented by a land-use map in which the properties of the land parcels change dynamically over the simulation time. The outputs of this model are a set of maps showing the pattern of different groups of households in the city. These patterns can be used by city planners to find optimum locations for building new residential units or adding new services to the city. The simulation results show that combining macro- and micro-level simulation can give full play to the potential of the ABM to understand the driving mechanism of urbanization and provide decision-making support for urban management.

Scale converters. [Dissolution of scale deposits

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rybacki, R.L.

1979-04-03

A water-soluble maleate salt, preferably disodium maleate, is described as a scale solubilizer. Such salts convert scale into a water-soluble compound without the conventional step of employing either an acid wash or a sequestering agent. 10 claims.

Naturalizing Sense of Agency with a Hierarchical Event-Control Approach

PubMed Central

Kumar, Devpriya; Srinivasan, Narayanan

2014-01-01

Unraveling the mechanisms underlying self and agency has been a difficult scientific problem. We argue for an event-control approach for naturalizing the sense of agency by focusing on the role of perception-action regularities present at different hierarchical levels and contributing to the sense of self as an agent. The amount of control at different levels of the control hierarchy determines the sense of agency. The current study investigates this approach in a set of two experiments using a scenario containing multiple agents sharing a common goal where one of the agents is partially controlled by the participant. The participant competed with other agents for achieving the goal and subsequently answered questions on identification (which agent was controlled by the participant), the degree to which they are confident about their identification (sense of identification) and the degree to which the participant believed he/she had control over his/her actions (sense of authorship). Results indicate a hierarchical relationship between goal-level control (higher level) and perceptual-motor control (lower level) for sense of agency. Sense of identification ratings increased with perceptual-motor control when the goal was not completed but did not vary with perceptual-motor control when the goal was completed. Sense of authorship showed a similar interaction effect only in experiment 2 that had only one competing agent unlike the larger number of competing agents in experiment 1. The effect of hierarchical control can also be seen in the misidentification pattern and misidentification was greater with the agent affording greater control. Results from the two studies support the event-control approach in understanding sense of agency as grounded in control. The study also offers a novel paradigm for empirically studying sense of agency and self. PMID:24642834

Biodiversity and disease: a synthesis of ecological perspectives on Lyme disease transmission.

PubMed

Wood, Chelsea L; Lafferty, Kevin D

2013-04-01

Recent reviews have argued that disease control is among the ecosystem services yielded by biodiversity. Lyme disease (LD) is commonly cited as the best example of the 'diluting' effect of biodiversity on disease transmission, but many studies document the opposite relationship, showing that human LD risk can increase with forestation. Here, we unify these divergent perspectives and find strong evidence for a positive link between biodiversity and LD at broad spatial scales (urban to suburban to rural) and equivocal evidence for a negative link between biodiversity and LD at varying levels of biodiversity within forests. This finding suggests that, across zoonotic disease agents, the biodiversity-disease relationship is scale dependent and complex. Copyright © 2012 Elsevier Ltd. All rights reserved.

INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY: Consensus of Multi-Agent Systems with Prestissimo Scale-Free Networks

NASA Astrophysics Data System (ADS)

Yang, Hong-Yong; Lu, Lan; Cao, Ke-Cai; Zhang, Si-Ying

2010-04-01

In this paper, the relations of the network topology and the moving consensus of multi-agent systems are studied. A consensus-prestissimo scale-free network model with the static preferential-consensus attachment is presented on the rewired link of the regular network. The effects of the static preferential-consensus BA network on the algebraic connectivity of the topology graph are compared with the regular network. The robustness gain to delay is analyzed for variable network topology with the same scale. The time to reach the consensus is studied for the dynamic network with and without communication delays. By applying the computer simulations, it is validated that the speed of the convergence of multi-agent systems can be greatly improved in the preferential-consensus BA network model with different configuration.

CATS-based Air Traffic Controller Agents

NASA Technical Reports Server (NTRS)

Callantine, Todd J.

2002-01-01

This report describes intelligent agents that function as air traffic controllers. Each agent controls traffic in a single sector in real time; agents controlling traffic in adjoining sectors can coordinate to manage an arrival flow across a given meter fix. The purpose of this research is threefold. First, it seeks to study the design of agents for controlling complex systems. In particular, it investigates agent planning and reactive control functionality in a dynamic environment in which a variety perceptual and decision making skills play a central role. It examines how heuristic rules can be applied to model planning and decision making skills, rather than attempting to apply optimization methods. Thus, the research attempts to develop intelligent agents that provide an approximation of human air traffic controller behavior that, while not based on an explicit cognitive model, does produce task performance consistent with the way human air traffic controllers operate. Second, this research sought to extend previous research on using the Crew Activity Tracking System (CATS) as the basis for intelligent agents. The agents use a high-level model of air traffic controller activities to structure the control task. To execute an activity in the CATS model, according to the current task context, the agents reference a 'skill library' and 'control rules' that in turn execute the pattern recognition, planning, and decision-making required to perform the activity. Applying the skills enables the agents to modify their representation of the current control situation (i.e., the 'flick' or 'picture'). The updated representation supports the next activity in a cycle of action that, taken as a whole, simulates air traffic controller behavior. A third, practical motivation for this research is to use intelligent agents to support evaluation of new air traffic control (ATC) methods to support new Air Traffic Management (ATM) concepts. Current approaches that use large, human-in-the-loop simulations are unquestionably valuable for this purpose, but pose considerable logistical, fiscal, and experimental control problems. First, data analysis is extremely complicated, owing simply to the large number of participants and data sources in such simulations. In addition, experienced human air traffic controllers working adjacent sectors tend to flexibly adapt to the evolving control problem - potentially shifting to other strategies than those under investigation. In addition, their performance is tightly coupled to the control interface, which in the development phase may support some concepts and supporting strategies better than others. A simple shift in strategy by one controller can change the character of a particular traffic scenario dramatically, which makes experimental comparison of ATC performance under different traffic scenarios difficult. Training a given team of controllers on operations under a new ATM concept for a sufficient period of time could avert such difficulties, but instituting an adequate training program is expensive and logistically difficult.

Resilient distributed control in the presence of misbehaving agents in networked control systems.

PubMed

Zeng, Wente; Chow, Mo-Yuen

2014-11-01

In this paper, we study the problem of reaching a consensus among all the agents in the networked control systems (NCS) in the presence of misbehaving agents. A reputation-based resilient distributed control algorithm is first proposed for the leader-follower consensus network. The proposed algorithm embeds a resilience mechanism that includes four phases (detection, mitigation, identification, and update), into the control process in a distributed manner. At each phase, every agent only uses local and one-hop neighbors' information to identify and isolate the misbehaving agents, and even compensate their effect on the system. We then extend the proposed algorithm to the leaderless consensus network by introducing and adding two recovery schemes (rollback and excitation recovery) into the current framework to guarantee the accurate convergence of the well-behaving agents in NCS. The effectiveness of the proposed method is demonstrated through case studies in multirobot formation control and wireless sensor networks.

Power Calculations and Placebo Effect for Future Clinical Trials in Progressive Supranuclear Palsy

PubMed Central

Stamelou, Maria; Schöpe, Jakob; Wagenpfeil, Stefan; Ser, Teodoro Del; Bang, Jee; Lobach, Iryna Y.; Luong, Phi; Respondek, Gesine; Oertel, Wolfgang H.; Boxer, Adam L.; Höglinger, Günter U.

2016-01-01

Background Two recent randomized, placebo-controlled trials of putative disease-modifying agents (davunetide, tideglusib) in progressive supranuclear palsy (PSP) failed to show efficacy, but generated data relevant for future trials. Methods We provide sample size calculations based on data collected in 187 PSP patients assigned to placebo in these trials. A placebo effect was calculated. Results The total PSP-Rating Scale required the least number of patients per group (N = 51) to detect a 50% change in the 1-year progression and 39 when including patients with ≤ 5 years disease duration. The Schwab and England Activities of Daily Living required 70 patients per group and was highly correlated with the PSP-Rating Scale. A placebo effect was not detected in these scales. Conclusions We propose the 1-year PSP-Rating Scale score change as the single primary readout in clinical neuroprotective or disease-modifying trials. The Schwab and England Activities of Daily Living could be used as a secondary outcome. PMID:26948290

17 CFR 240.17Ad-10 - Prompt posting of certificate detail to master securityholder files, maintenance of accurate...

Code of Federal Regulations, 2014 CFR

2014-04-01

... between co-transfer agents and recordkeeping transfer agents, maintenance of current control book...-transfer agents and recordkeeping transfer agents, maintenance of current control book, retention of certificate detail and “buy-in” of physical over-issuance. (a)(1) Every recordkeeping transfer agent shall...

Distributed Evaluation Functions for Fault Tolerant Multi-Rover Systems

NASA Technical Reports Server (NTRS)

Agogino, Adrian; Turner, Kagan

2005-01-01

The ability to evolve fault tolerant control strategies for large collections of agents is critical to the successful application of evolutionary strategies to domains where failures are common. Furthermore, while evolutionary algorithms have been highly successful in discovering single-agent control strategies, extending such algorithms to multiagent domains has proven to be difficult. In this paper we present a method for shaping evaluation functions for agents that provide control strategies that both are tolerant to different types of failures and lead to coordinated behavior in a multi-agent setting. This method neither relies of a centralized strategy (susceptible to single point of failures) nor a distributed strategy where each agent uses a system wide evaluation function (severe credit assignment problem). In a multi-rover problem, we show that agents using our agent-specific evaluation perform up to 500% better than agents using the system evaluation. In addition we show that agents are still able to maintain a high level of performance when up to 60% of the agents fail due to actuator, communication or controller faults.

Pythium species and isolate diversity influence inhibition by the biological control agent Streptomyces lydicus

USDA-ARS?s Scientific Manuscript database

Disease control of soilborne pathogens by biological control agents has often been inconsistent under field conditions. One factor that may contribute to this inconsistency is the variability in response among pathogen populations and/or communities to the selected biological control agent. One hund...

Indirect nontarget effects of host-specific biological control agents: Implications for biological control

Treesearch

Dean E. Pearson; Ragan M. Callaway

2005-01-01

Classical biological control of weeds currently operates under the assumption that biological control agents are safe (i.e., low risk) if they do not directly attack nontarget species. However, recent studies indicate that even highly host-specific biological control agents can impact nontarget species through indirect effects. This finding has profound...

Potential of Biological Agents in Decontamination of Agricultural Soil

PubMed Central

Javaid, Muhammad Kashif; Ashiq, Mehrban; Tahir, Muhammad

2016-01-01

Pesticides are widely used for the control of weeds, diseases, and pests of cultivated plants all over the world, mainly since the period after the Second World War. The use of pesticides is very extensive to control harm of pests all over the globe. Persistent nature of most of the synthetic pesticides causes serious environmental concerns. Decontamination of these hazardous chemicals is very essential. This review paper elaborates the potential of various biological agents in decontamination of agricultural soils. The agricultural crop fields are contaminated by the periodic applications of pesticides. Biodegradation is an ecofriendly, cost-effective, highly efficient approach compared to the physical and chemical methods which are expensive as well as unfriendly towards environment. Biodegradation is sensitive to the concentration levels of hydrogen peroxide and nitrogen along with microbial community, temperature, and pH changes. Experimental work for optimum conditions at lab scale can provide very fruitful results about specific bacterial, fungal strains. This study revealed an upper hand of bioremediation over physicochemical approaches. Further studies should be carried out to understand mechanisms of biotransformation. PMID:27293964

Potential of Biological Agents in Decontamination of Agricultural Soil.

PubMed

Javaid, Muhammad Kashif; Ashiq, Mehrban; Tahir, Muhammad

2016-01-01

Pesticides are widely used for the control of weeds, diseases, and pests of cultivated plants all over the world, mainly since the period after the Second World War. The use of pesticides is very extensive to control harm of pests all over the globe. Persistent nature of most of the synthetic pesticides causes serious environmental concerns. Decontamination of these hazardous chemicals is very essential. This review paper elaborates the potential of various biological agents in decontamination of agricultural soils. The agricultural crop fields are contaminated by the periodic applications of pesticides. Biodegradation is an ecofriendly, cost-effective, highly efficient approach compared to the physical and chemical methods which are expensive as well as unfriendly towards environment. Biodegradation is sensitive to the concentration levels of hydrogen peroxide and nitrogen along with microbial community, temperature, and pH changes. Experimental work for optimum conditions at lab scale can provide very fruitful results about specific bacterial, fungal strains. This study revealed an upper hand of bioremediation over physicochemical approaches. Further studies should be carried out to understand mechanisms of biotransformation.

ZnO and TiO2 nanoparticles as novel antimicrobial agents for oral hygiene: a review

NASA Astrophysics Data System (ADS)

Khan, Shams Tabrez; Al-Khedhairy, Abdulaziz A.; Musarrat, Javed

2015-06-01

Oral cavity is inhabited by more than 25,000 different bacterial phylotypes; some of them cause systemic infections in addition to dental and periodontal diseases. Emergence of multiple antibiotic resistance among these bacteria necessitates the development of alternative antimicrobial agents that are safe, stable, and relatively economic. This review focuses on the significance of metal oxide nanoparticles, especially zinc oxide and titanium dioxide nanoparticles as supplementary antimicrobials for controlling oral infections and biofilm formation. Indeed, the ZnO NPs and TiO2 NPs have exhibited significant antimicrobial activity against oral bacteria at concentrations which is not toxic in in vivo toxicity assays. These nanoparticles are being produced at an industrial scale for use in a variety of commercial products including food products. Thus, the application of ZnO and TiO2 NPs as nanoantibiotics for the development of mouthwashes, dental pastes, and other oral hygiene materials is envisaged. It is also suggested that these NPs could serve as healthier, innocuous, and effective alternative for controlling both the dental biofilms and oral planktonic bacteria with lesser side effects and antibiotic resistance.

Population dynamics and impacts of the red-headed leafy spurge stem borer on leafy spurge

Treesearch

R. A. Progar; G. P. Markin; J. Milan; T. Barbouletos; M. J. Rinella

2013-01-01

We evaluated the efficacy of the biological control agent, red-headed leafy spurge stem borer (Oberea erythrocephala Schrank.) against the nonnative invasive plant leafy spurge (Euphorbia esula L.). Our three treatments were release of the biological control agent into uncaged plots, release of the biological control agent into plots caged to prevent agent escape and...

Using Agent Base Models to Optimize Large Scale Network for Large System Inventories

NASA Technical Reports Server (NTRS)

Shameldin, Ramez Ahmed; Bowling, Shannon R.

2010-01-01

The aim of this paper is to use Agent Base Models (ABM) to optimize large scale network handling capabilities for large system inventories and to implement strategies for the purpose of reducing capital expenses. The models used in this paper either use computational algorithms or procedure implementations developed by Matlab to simulate agent based models in a principal programming language and mathematical theory using clusters, these clusters work as a high performance computational performance to run the program in parallel computational. In both cases, a model is defined as compilation of a set of structures and processes assumed to underlie the behavior of a network system.

Scaling laws of strategic behavior and size heterogeneity in agent dynamics

NASA Astrophysics Data System (ADS)

Vaglica, Gabriella; Lillo, Fabrizio; Moro, Esteban; Mantegna, Rosario N.

2008-03-01

We consider the financial market as a model system and study empirically how agents strategically adjust the properties of large orders in order to meet their preference and minimize their impact. We quantify this strategic behavior by detecting scaling relations between the variables characterizing the trading activity of different institutions. We also observe power-law distributions in the investment time horizon, in the number of transactions needed to execute a large order, and in the traded value exchanged by large institutions, and we show that heterogeneity of agents is a key ingredient for the emergence of some aggregate properties characterizing this complex system.

Consensus positive position feedback control for vibration attenuation of smart structures

NASA Astrophysics Data System (ADS)

Omidi, Ehsan; Nima Mahmoodi, S.

2015-04-01

This paper presents a new network-based approach for active vibration control in smart structures. In this approach, a network with known topology connects collocated actuator/sensor elements of the smart structure to one another. Each of these actuators/sensors, i.e., agent or node, is enhanced by a separate multi-mode positive position feedback (PPF) controller. The decentralized PPF controlled agents collaborate with each other in the designed network, under a certain consensus dynamics. The consensus constraint forces neighboring agents to cooperate with each other such that the disagreement between the time-domain actuation of the agents is driven to zero. The controller output of each agent is calculated using state-space variables; hence, optimal state estimators are designed first for the proposed observer-based consensus PPF control. The consensus controller is numerically investigated for a flexible smart structure, i.e., a thin aluminum beam that is clamped at its both ends. Results demonstrate that the consensus law successfully imposes synchronization between the independently controlled agents, as the disagreements between the decentralized PPF controller variables converge to zero in a short time. The new consensus PPF controller brings extra robustness to vibration suppression in smart structures, where malfunctions of an agent can be compensated for by referencing the neighboring agents’ performance. This is demonstrated in the results by comparing the new controller with former centralized PPF approach.

The effect of topical mitomycin C on full-thickness burns.

PubMed

Tennyson, Heath; Helling, Eric R; Wiseman, Joseph; Dick, Edward; Lyons, Robert C

2007-09-15

Burns result in substantial morbidity because of fibroblast proliferation and contracture. Mitomycin C is a chemotherapeutic agent known to suppress fibroblast proliferation. It is used in ophthalmologic disorders and reduces scarring in upper aerodigestive surgery. No study of the effect of mitomycin C on cutaneous burns has been performed. This study examined burn healing in the presence of topical mitomycin C by evaluation of wound appearance, contraction, and histology in a pig model. Standardized full-thickness burns were produced on the flanks of three pigs. One animal received no further therapy and was an external control. Two animals underwent placement of topical mitomycin C, 0.4 mg/ml, on selected burn sites for 5 minutes. This was repeated 2 and 4 weeks after injury. Evaluation was performed at 2 and 6 months using a clinical assessment scale and a visual analogue scale. Scar length and histologic analysis were also evaluated. Clinical assessment scale and visual analogue scale scores showed improved appearance in the untreated external control wounds versus the untreated internal control and treated wounds (p < 0.001). Wound contraction was not significantly different between groups. Histologic characteristics between groups were similar except for epidermal hyperplasia, which was decreased in the untreated external control (p < 0.05) at 2 months after treatment. Topical mitomycin C treatment of full-thickness burn wounds at 0.4 mg/cc for three courses does not improve, and may worsen, clinical appearance and scarring during early healing. There is no difference in histology during the long-term healing process. Scar contraction was unchanged.

Nanoparticles for cancer imaging: The good, the bad, and the promise

PubMed Central

Chapman, Sandra; Dobrovolskaia, Marina; Farahani, Keyvan; Goodwin, Andrew; Joshi, Amit; Lee, Hakho; Meade, Thomas; Pomper, Martin; Ptak, Krzysztof; Rao, Jianghong; Singh, Ravi; Sridhar, Srinivas; Stern, Stephan; Wang, Andrew; Weaver, John B.; Woloschak, Gayle; Yang, Lily

2014-01-01

Summary Recent advances in molecular imaging and nanotechnology are providing new opportunities for biomedical imaging with great promise for the development of novel imaging agents. The unique optical, magnetic, and chemical properties of materials at the scale of nanometers allow the creation of imaging probes with better contrast enhancement, increased sensitivity, controlled biodistribution, better spatial and temporal information, multi-functionality and multi-modal imaging across MRI, PET, SPECT, and ultrasound. These features could ultimately translate to clinical advantages such as earlier detection, real time assessment of disease progression and personalized medicine. However, several years of investigation into the application of these materials to cancer research has revealed challenges that have delayed the successful application of these agents to the field of biomedical imaging. Understanding these challenges is critical to take full advantage of the benefits offered by nano-sized imaging agents. Therefore, this article presents the lessons learned and challenges encountered by a group of leading researchers in this field, and suggests ways forward to develop nanoparticle probes for cancer imaging. Published by Elsevier Ltd. PMID:25419228

Multiscale Spectroscopy of Diffusing Molecules in Crowded Environments

NASA Astrophysics Data System (ADS)

Heikal, Ahmed A.

2015-06-01

Living cells are known to be crowded with organelles, biomembranes, and macromolecules such as proteins, DNA, RNA, and actin filaments. It is believed that such macromolecular crowding affect biomolecular diffusion, protein-protein and protein-substrate interaction, and protein folding. In this contribution, I will discuss our recent results on rotational and translational diffusion of small and large molecules in crowded environments using time-resolved anisotropy and fluorescence correlation spectroscopy methods. In these studies, rhodamine green and enhanced green fluorescent protein are used as fluorescent probes diffusing in buffers enriched with biomimetic crowding agents such as Ficoll-70, bovine serum albumin (BSA), and ovalbumin. Controlled experiments on pure and glycerol-rich buffers were carried out as environments with variable, homogeneous viscosity. Our results indicate that the microviscosity differs from the corresponding bulk viscosity, depending on the nature of crowding agents (i.e., proteins versus polymers), the concentration of crowding agents and spatio-temporal scaling of our experimental approach. Our findings provide a foundation for fluorescence-based studies of diffusion and binding of biomolecules in the crowded milieu of living cells.

Synthetic virus seeds for improved vaccine safety: Genetic reconstruction of poliovirus seeds for a PER.C6 cell based inactivated poliovirus vaccine.

PubMed

Sanders, Barbara P; Edo-Matas, Diana; Papic, Natasa; Schuitemaker, Hanneke; Custers, Jerome H H V

2015-10-13

Safety of vaccines can be compromised by contamination with adventitious agents. One potential source of adventitious agents is a vaccine seed, typically derived from historic clinical isolates with poorly defined origins. Here we generated synthetic poliovirus seeds derived from chemically synthesized DNA plasmids encoding the sequence of wild-type poliovirus strains used in marketed inactivated poliovirus vaccines. The synthetic strains were phenotypically identical to wild-type polioviruses as shown by equivalent infectious titers in culture supernatant and antigenic content, even when infection cultures are scaled up to 10-25L bioreactors. Moreover, the synthetic seeds were genetically stable upon extended passaging on the PER.C6 cell culture platform. Use of synthetic seeds produced on the serum-free PER.C6 cell platform ensures a perfectly documented seed history and maximum control over starting materials. It provides an opportunity to maximize vaccine safety which increases the prospect of a vaccine end product that is free from adventitious agents. Copyright © 2015 Elsevier Ltd. All rights reserved.

Controllability of multi-agent systems with time-delay in state and switching topology

NASA Astrophysics Data System (ADS)

Ji, Zhijian; Wang, Zidong; Lin, Hai; Wang, Zhen

2010-02-01

In this article, the controllability issue is addressed for an interconnected system of multiple agents. The network associated with the system is of the leader-follower structure with some agents taking leader role and others being followers interconnected via the neighbour-based rule. Sufficient conditions are derived for the controllability of multi-agent systems with time-delay in state, as well as a graph-based uncontrollability topology structure is revealed. Both single and double integrator dynamics are considered. For switching topology, two algebraic necessary and sufficient conditions are derived for the controllability of multi-agent systems. Several examples are also presented to illustrate how to control the system to shape into the desired configurations.

Experimental Evaluation of Suitability of Selected Multi-Criteria Decision-Making Methods for Large-Scale Agent-Based Simulations.

PubMed

Tučník, Petr; Bureš, Vladimír

2016-01-01

Multi-criteria decision-making (MCDM) can be formally implemented by various methods. This study compares suitability of four selected MCDM methods, namely WPM, TOPSIS, VIKOR, and PROMETHEE, for future applications in agent-based computational economic (ACE) models of larger scale (i.e., over 10 000 agents in one geographical region). These four MCDM methods were selected according to their appropriateness for computational processing in ACE applications. Tests of the selected methods were conducted on four hardware configurations. For each method, 100 tests were performed, which represented one testing iteration. With four testing iterations conducted on each hardware setting and separated testing of all configurations with the-server parameter de/activated, altogether, 12800 data points were collected and consequently analyzed. An illustrational decision-making scenario was used which allows the mutual comparison of all of the selected decision making methods. Our test results suggest that although all methods are convenient and can be used in practice, the VIKOR method accomplished the tests with the best results and thus can be recommended as the most suitable for simulations of large-scale agent-based models.

Age, education, and the gender gap in the sense of control.

PubMed

Slagsvold, Britt; Sørensen, Annemette

2008-01-01

High sense of control is related to benefits in many aspects of life, and education is known to be strongly related to sense of control. In this article we explore why women tend to feel a lower sense of control than men, and why the sense of control tends to be lower among the elderly than among younger people. In particular we explore the role played by education in explaining age- and gender differences in sense of control. The analysis is based on data from the first wave of the Norwegian NorLAG study, with a representative sample of adults aged 40-79 in 30 municipalities. We find that education accounts for some of the age and gender differences in sense of control, but the mediating effects of education are rather modest. We find an increasing gender gap in sense of control with age, and this increasing gap is completely explained by differences in education. Gender differences in sense of control is explained completely by four factors, which are related to resources and power; physical health, education, living with a partner, and leadership experience. Age differences in sense of control are only partially explained. Education, physical health and employment status cuts the age effect on sense of control to half. The effect of education on sense of control is partly mediated through what we suggest are tangible benefits of education, namely health, employment, and leadership experience. Education also influences individuals through socialization mechanisms. We view agentive orientation as a psychological benefit of education, and measure this characteristic with Bem's (1981) sex-role scale on masculinity. Agentive orientation completely explains the remaining effect of education on sense of control.

Driving performance of stable outpatients with depression undergoing real-world treatment.

PubMed

Miyata, Akemi; Iwamoto, Kunihiro; Kawano, Naoko; Aleksic, Branko; Ando, Masahiko; Ebe, Kazutoshi; Fujita, Kiyoshi; Yokoyama, Motonori; Akiyama, Tsuyoshi; Igarashi, Yoshio; Ozaki, Norio

2018-06-01

Although the effects of psychotropics on driving ability have received much attention, little research is available on driving performance of stable outpatients with depression undergoing real-world treatment. This observational study investigated driving performance, cognitive functions, and depressive symptomatology of partly remitted outpatients with depression under daily-practice psychopharmacologic treatment. Seventy stable outpatients with depression and 67 healthy volunteers were enrolled. Patients' prescriptions were not controlled in order to capture the real-world treatment environment. Participants underwent three driving tasks - road-tracking, car-following, and harsh-braking - using a driving simulator, and three cognitive tasks - Continuous Performance Test, Wisconsin Card Sorting Test, and Trail-Making Test. The Symptom Assessment Scale - Structured Interview Guide for the Hamilton Depression Rating Scale, Beck Depression Inventory-II, Social Adaptation Self-Evaluation Scale, and Stanford Sleepiness Scale were also completed. Although many patients received various pharmacologic treatments, there were no significant differences in the three driving tasks between outpatients with depression and healthy controls. Difficulty of maintaining set in the Wisconsin Card Sorting Test was significantly increased in patients with depression. Results on the Social Adaptation Self-Evaluation Scale were significantly associated with road-tracking and car-following performance, in contrast to results on the Hamilton Depression Rating Scale and the Beck Depression Inventory-II. We conclude that partly remitted depressive patients under steady-state pharmacologic treatment do not differ from healthy controls with respect to driving performance, which seems to be more affected by psychosocial functioning than by pharmacologic agents. This, however, should be investigated systematically in an off/on study. © 2018 The Authors. Psychiatry and Clinical Neurosciences © 2018 Japanese Society of Psychiatry and Neurology.

[Six-month follow-up study of drug treatment for cannabis addiction: comparison study of four drugs].

PubMed

Shoenfeld, Netta; Bodnik, Dana; Rosenberg, Oded; Kotler, Moshe; Dannon, Pinhas

2011-12-01

Marijuana addiction is one of the most common forms of addiction worldwide. A variety of reasons for use exist, however, there are only a few tested treatments with frequent relapses. In this study, we examined the efficacy of four pharmacotherapy agents for the treatment of marijuana addiction: naltrexone, bupropion, escitalopram and bromazepam. A total of 59 patients were randomly assigned into four groups. Each group received one of the pharmacological agents for 120 days. Four types of questionnaires were employed: The Hamilton Rating Scale for Depression--21 items, the Hamilton Rating Scale for Anxiety, the Global Assessment of Functioning and a Visual Analogue Scale for perceived need of the drug. In addition, random urine tests were performed to detect tetrahydrocannabinol [THC). Naltrexone proved to be the most efficacious of the four agents, with only four dropouts. Other agents proved less efficacious with six, seven and eights dropouts for bupropion, bromazepam and escitalopram, respectively. In addition, naltrexone was most efficacious in reducing anxiety and depression rates, and increasing functioning and perceived need for drug use. Out of four pharmacological agents, naltrexone proved to be most efficacious in treating marijuana addiction and related disorders. Further studies are needed to confirm our results.

Cooperation in N-person evolutionary snowdrift game in scale-free Barabási Albert networks

NASA Astrophysics Data System (ADS)

Lee, K. H.; Chan, Chun-Him; Hui, P. M.; Zheng, Da-Fang

2008-09-01

Cooperation in the N-person evolutionary snowdrift game (NESG) is studied in scale-free Barabási-Albert (BA) networks. Due to the inhomogeneity of the network, two versions of NESG are proposed and studied. In a model where the size of the competing group varies from agent to agent, the fraction of cooperators drops as a function of the payoff parameter. The networking effect is studied via the fraction of cooperative agents for nodes with a particular degree. For small payoff parameters, it is found that the small- k agents are dominantly cooperators, while large- k agents are of non-cooperators. Studying the spatial correlation reveals that cooperative agents will avoid to be nearest neighbors and the correlation disappears beyond the next-nearest neighbors. The behavior can be explained in terms of the networking effect and payoffs. In another model with a fixed size of competing groups, the fraction of cooperators could show a non-monotonic behavior in the regime of small payoff parameters. This non-trivial behavior is found to be a combined effect of the many agents with the smallest degree in the BA network and the increasing fraction of cooperators among these agents with the payoff for small payoffs.

Human computer interactions in next-generation of aircraft smart navigation management systems: task analysis and architecture under an agent-oriented methodological approach.

PubMed

Canino-Rodríguez, José M; García-Herrero, Jesús; Besada-Portas, Juan; Ravelo-García, Antonio G; Travieso-González, Carlos; Alonso-Hernández, Jesús B

2015-03-04

The limited efficiency of current air traffic systems will require a next-generation of Smart Air Traffic System (SATS) that relies on current technological advances. This challenge means a transition toward a new navigation and air-traffic procedures paradigm, where pilots and air traffic controllers perform and coordinate their activities according to new roles and technological supports. The design of new Human-Computer Interactions (HCI) for performing these activities is a key element of SATS. However efforts for developing such tools need to be inspired on a parallel characterization of hypothetical air traffic scenarios compatible with current ones. This paper is focused on airborne HCI into SATS where cockpit inputs came from aircraft navigation systems, surrounding traffic situation, controllers' indications, etc. So the HCI is intended to enhance situation awareness and decision-making through pilot cockpit. This work approach considers SATS as a system distributed on a large-scale with uncertainty in a dynamic environment. Therefore, a multi-agent systems based approach is well suited for modeling such an environment. We demonstrate that current methodologies for designing multi-agent systems are a useful tool to characterize HCI. We specifically illustrate how the selected methodological approach provides enough guidelines to obtain a cockpit HCI design that complies with future SATS specifications.

The rationale and design of the Beta-blocker to LOwer CArdiovascular Dialysis Events (BLOCADE) Feasibility Study.

PubMed

Roberts, Matthew A; Pilmore, Helen L; Ierino, Francesco L; Badve, Sunil V; Cass, Alan; Garg, Amit X; Hawley, Carmel M; Isbel, Nicole M; Krum, Henry; Pascoe, Elaine M; Tonkin, Andrew M; Vergara, Liza A; Perkovic, Vlado

2015-03-01

The Beta-blocker to LOwer CArdiovascular Dialysis Events (BLOCADE) Feasibility Study aims to determine the feasibility of a large-scale randomized controlled trial with clinical endpoints comparing the beta-blocking agent carvedilol with placebo in patients receiving dialysis. The BLOCADE Feasibility Study is a randomized, double-blind, placebo-controlled, parallel group feasibility study comparing the beta-blocking agent carvedilol with placebo. Patients receiving dialysis for ≥3 months and who are aged ≥50 years, or who are ≥18 years and have diabetes or cardiovascular disease, were eligible. The primary outcome was the proportion of participants who complete a 6-week run-in phase in which all participants received carvedilol titrated from 3.125 mg twice daily to 6.25 mg twice daily. Other measures included how many patients are screened, the proportion recruited, the overall recruitment rate, the proportion of participants who remain on study drug for 12 months and the incidence of intra-dialytic hypotension while on randomized treatment. The BLOCADE Feasibility Study commenced recruiting in May 2011 and involves 11 sites in Australia and New Zealand. The BLOCADE Feasibility Study will inform the design of a larger clinical endpoint study to determine whether beta-blocking agents provide benefit to patients receiving dialysis, and define whether such a study is feasible. © 2014 Asian Pacific Society of Nephrology.

Reliability and Factor Structure of the Attitude toward Tutoring Agent Scale (ATTAS)

ERIC Educational Resources Information Center

Adcock, Amy B.; Van Eck, Richard N.

2005-01-01

Pedagogical agents are gaining acceptance as effective learning tools (Baylor & Ryu, 2003; Moreno, Mayer, Spires & Lester 2001; Moreno, 2004). The increase in the use of agents highlights the need for standardized measurements for evaluating user performance in these environments. While learning gains are a primary variable of interest in such…

Collaborating Fuzzy Reinforcement Learning Agents

NASA Technical Reports Server (NTRS)

Berenji, Hamid R.

1997-01-01

Earlier, we introduced GARIC-Q, a new method for doing incremental Dynamic Programming using a society of intelligent agents which are controlled at the top level by Fuzzy Relearning and at the local level, each agent learns and operates based on ANTARCTIC, a technique for fuzzy reinforcement learning. In this paper, we show that it is possible for these agents to compete in order to affect the selected control policy but at the same time, they can collaborate while investigating the state space. In this model, the evaluator or the critic learns by observing all the agents behaviors but the control policy changes only based on the behavior of the winning agent also known as the super agent.

Application of 1-hydroxyethylidene-1, 1-diphosphonic acid in boiler water for industrial boilers.

PubMed

Zeng, Bin; Li, Mao-Dong; Zhu, Zhi-Ping; Zhao, Jun-Ming; Zhang, Hui

2013-01-01

The primary method used for boiler water treatment is the addition of chemicals to industrial boilers to prevent corrosion and scaling. The static scale inhibition method was used to evaluate the scale inhibition performance of 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP). Autoclave static experiments were used to study the corrosion inhibition properties of the main material for industrial boilers (20# carbon steel) with an HEDP additive in the industrial boiler water medium. The electrochemical behavior of HEDP on carbon steel corrosion control was investigated using electrochemical impedance spectroscopy and Tafel polarization techniques. Experimental results indicate that HEDP can have a good scale inhibition effect when added at a quantity of 5 to 7 mg/L at a test temperature of not more than 100 °C. To achieve a high scale inhibition rate, the HEDP dosage must be increased when the test temperature exceeds 100 °C. Electrochemical and autoclave static experimental results suggest that HEDP has a good corrosion inhibition effect on 20# carbon steel at a concentration of 25 mg/L. HEDP is an excellent water treatment agent.

Postprocedural pain in shoulder arthrography: differences between using preservative-free normal saline and normal saline with benzyl alcohol as an intraarticular contrast diluent.

PubMed

Storey, Troy F; Gilbride, George; Clifford, Kelly

2014-11-01

The purpose of this study was to prospectively evaluate the effect of benzyl alcohol, a common preservative in normal saline, on postprocedural pain after intraarticular injection for direct shoulder MR arthrography. From April 2011 through January 2013, 138 patients underwent direct shoulder MR arthrography. Using the Wong-Baker Faces Pain Scale, patients were asked to report their shoulder pain level immediately before and immediately after the procedure and then were contacted by telephone 6, 24, and 48 hours after the procedure. Fourteen patients did not receive the prescribed amount of contrast agent for diagnostic reasons or did not complete follow-up. Sixty-two patients received an intraarticular solution including preservative-free normal saline (control group) and 62 patients received an intraarticular solution including normal saline with 0.9% benzyl alcohol as a contrast diluent (test group). Patients were randomized as to which intraarticular diluent they received. Fluoroscopic and MR images were reviewed for extracapsular contrast agent administration or extravasation, full-thickness rotator cuff tears, and adhesive capsulitis. The effect of preservative versus control on pain level was estimated with multiple regression, which included time after procedure as the covariate and accounted for repeated measures over patients. Pain scale scores were significantly (p = 0.0382) higher (0.79 units; 95% CI, 0.034-1.154) with benzyl alcohol preservative compared with control (saline). In both study arms, the pain scale scores decreased slightly after the procedure, increased by roughly 1 unit over baseline for the test group and 0.3 unit over baseline for the control group by 6 hours after the procedure, were 0.50 unit over baseline for the test group and 0.12 unit over baseline for the control group at 24 hours, then fell to be slightly greater than baseline at 48 hours with benzyl alcohol and slightly less than baseline without benzyl alcohol. These trends over time were highly significant (p < 0.0001). Shoulder arthrography is often associated with postprocedural discomfort that begins immediately after the procedure and resolves by 48 hours. There is significantly increased patient discomfort at 6 and 48 hours when using normal saline preserved with benzyl alcohol as a diluent compared with using normal saline without preservative as a diluent.

Biological control agents elevate hantavirus by subsidizing deer mouse populations

Treesearch

Dean E. Pearson; Ragan M. Callaway

2006-01-01

Biological control of exotic invasive plants using exotic insects is practiced under the assumption that biological control agents are safe if they do not directly attack non-target species. We tested this assumption by evaluating the potential for two host-specific biological control agents (Urophora spp.), widely established in North America for spotted...

Impact of Heparan Sulfate Chains and Sulfur-Mediated Bonds on the Mechanical Properties of Bovine Lens Capsule

PubMed Central

Dyksterhuis, L.D.; White, J.F.; Hickey, M.; Kirby, N.; Mudie, S.; Hawley, A.; Vashi, A.; Nigro, J.; Werkmeister, J.A.; Ramshaw, J.A.M.

2011-01-01

We assessed the importance of glycosaminoglycans and sulfur-mediated bonds for the mechanical properties of lens capsules by comparing the stress-strain responses from control and treated pairs of bovine source. No significant change in mechanical properties was observed upon reduction of disulfide bonds. However, removal of glycosaminoglycan chains resulted in a significantly stiffer lens capsule, whereas high concentrations of reducing agent, which is expected to reduce the recently reported sulfilimine bond of collagen IV, resulted in a significantly less stiff lens capsule. A comparison of the diffraction patterns of the control and strongly reduced lens capsules indicated structural rearrangements on a nanometer scale. PMID:21539774

Fire extinguishing agents for oxygen-enriched atmospheres

NASA Astrophysics Data System (ADS)

Plugge, M. A.; Wilson, C. W.; Zallen, D. M.; Walker, J. L.

1985-12-01

Fire-suppression agent requirements for extinguishing fires in oxygen-enriched atmospheres were determined employing small-, medium-, large-, and full-scale test apparatuses. The small- and medium-scale tests showed that a doubling of the oxygen concentration required five times more HALON for extinguishment. For fires of similar size and intensity, the effect of oxygen enrichment of the diluent volume in the HC-131A was not as grate as in the smaller compartments of the B-52 which presented a higher damage scenario. The full-scale tests showed that damage to the airframe was as important a factor in extinguishment as oxygen enrichment.

Osmolarity: a decisive parameter of bowel agents in intestinal magnetic resonance imaging.

PubMed

Borthne, Arne S; Abdelnoor, Michael; Storaas, Trygve; Pierre-Jerome, Claude; Kløw, Nils-E

2006-06-01

The aim was to evaluate the importance of the osmolarity of different oral agents for bowel distension and the level of related adverse events. The longitudinal design included the exposition of different oral MR agents on two separate occasions. Four groups of volunteers were randomly given 350 ml gastrografin of three different concentrations and water. On the second occasion they received mannitol, iohexol or iodixanol with equivalent osmolarities, but the control group (water) received mannitol. We recorded the outcomes as the degree of bowel distension determined as the mean bowel section area and the total level of discomfort recorded from a visual analogue scale (VAS). The statistical analysis included scatter plots with the best-fitted line with linear regression to study the association between osmolarity and section area and the association between osmolarity and adverse events. A dose-response association was found between increasing osmolarity levels and bowel area in square centimeters (P = 0.00001). A similar dose-response association existed between increasing levels of osmolarity and adverse events (P = 0.001). Osmolarity appears to be more important for bowel distension than the physico-chemical characteristics of the nonabsorbable oral agents. The optimum osmolarity level is determined by the patient's tolerance of the adverse events.

[Control of blood pressure in hypertensive patients on combination therapy].

PubMed

de la Sierra, Alejandro; Oliveras, Anna; Armario, Pedro; Lucas, Silvia

2015-02-20

The impact of antihypertensive treatment on blood pressure (BP) control is fairly unknown. The aim of the study was to evaluate the degree of BP control and its relationship with treatment-related factors in hypertensive patients treated with 2 or 3 agents and attended in referral units. We studied 1,337 hypertensive subjects (41% women) with a mean age (SD) of 63 (12) years, who were receiving 2 or 3 antihypertensive drugs. The degree of BP control was estimated in a single visit by the proportion of patients with BP below 140/90mmHg. BP was controlled in 767 patients (57%). Lack of BP control was related to older age (12% risk for each 10-year increase) and the presence of microalbuminuria (64% risk increase). In those treated with 2 agents, BP control was 61%, without differences between those treated with fixed-drug or free combinations. BP control in those treated with 3 agents was 55%, higher in those receiving 3 agents in a fixed-drug combination (68%) compared with those on 3 agents administered separately (52%; P=.025). Drug classes used in combinations did not influence the degree of BP control. The degree of BP control in patients treated with 2 or 3 agents is 57%. Microalbuminuria is related to a lack of BP control. In those receiving 3 agents, the use of fixed-drug combinations is associated with better BP control. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

Emergency management of chemical weapons injuries.

PubMed

Anderson, Peter D

2012-02-01

The potential for chemical weapons to be used in terrorism is a real possibility. Classes of chemical weapons include nerve agents, vesicants (blister agents), choking agents, incapacitating agents, riot control agents, blood agents, and toxic industrial chemicals. The nerve agents work by blocking the actions of acetylcholinesterase leading to a cholinergic syndrome. Nerve agents include sarin, tabun, VX, cyclosarin, and soman. The vesicants include sulfur mustard and lewisite. The vesicants produce blisters and also damage the upper airways. Choking agents include phosgene and chlorine gas. Choking agents cause pulmonary edema. Incapacitating agents include fentanyl and its derivatives and adamsite. Riot control agents include Mace and pepper spray. Blood agents include cyanide. The mechanism of toxicity for cyanide is blocking oxidative phosphorylation. Toxic industrial chemicals include agents such as formaldehyde, hydrofluoric acid, and ammonia.

42 CFR 73.13 - Restricted experiments.

Code of Federal Regulations, 2013 CFR

2013-10-01

... acquisition could compromise the control of disease agents in humans, veterinary medicine, or agriculture, or... control of disease agents in humans, veterinary medicine, or agriculture, or recombinant and/or synthetic... trait naturally, if such acquisition could compromise the control of disease agents in humans...

Volttron version 5.0

DOE Office of Scientific and Technical Information (OSTI.GOV)

VOLTTRON is an agent execution platform providing services to its agents that allow them to easily communicate with physical devices and other resources. VOLTTRON delivers an innovative distributed control and sensing software platform that supports modern control strategies, including agent-based and transaction-based controls. It enables mobile and stationary software agents to perform information gathering, processing, and control actions. VOLTTRON can independently manage a wide range of applications, such as HVAC systems, electric vehicles, distributed energy or entire building loads, leading to improved operational efficiency.

[Job stress in agents at the socio-educational service centers in the state of Rio Grande do Sul].

PubMed

Greco, Patrícia Bitencourt Toscani; Magnago, Tânia Solange Bosi de Souza; Beck, Carmem Lúcia Colomé; Urbanetto, Janete de Souza; Prochnow, Andrea

2013-03-01

The study was both to understand the association of work stress, socio-demographic and labor characteristics, habits and working conditions of the Socio-educational agents in the state of Rio Grande do Sul Brazil. It was a cross-sectional study with 881 agents of the Socio-educational Service Centers in the state of Rio Grande do Sul. The Brazilian version of the Job Stress Scale for assessment of work stress has been applied. Were classified in a situation of high strain 19.2% of the agents. The following factors were related to job stress, the need for counseling lack of leisure time, day shift work, dissatisfaction with the workplace, the need for absence from work due to health problems and insufficient scale work. There is a need to further research working conditions and execution of Occupational Health Service acting in order to minimize the effects of psychological demands at work of a socio-educational agent

On the decentralized observer/controller strategy for disturbance rejection

NASA Astrophysics Data System (ADS)

Faria, Cassio T.; Dong, ZhongZhe; Zhang, Xueji

2017-04-01

Centralized controllers and state estimation strategies are the most common topology implemented for disturbance rejection in smart systems. Although this architecture has been proven to be feasible the advances in computation power and size of logic devices can also enable the implementation of decentralized strategies which, on a large scale, can lead to an overall reliability increase of the system. The goal of this paper is to present this concept within the field of disturbance rejection for smart systems and to explore its capabilities and bottlenecks. A simple example is carried out for a composite plate with two controller/estimator centers. Simulation is used to validate the efficacy of the topology and a design procedure is proposed to guarantee the consensus of the agents within the network.

Climatic controls on hurricane patterns: a 1200-y near-annual record from Lighthouse Reef, Belize

NASA Astrophysics Data System (ADS)

Denommee, K. C.; Bentley, S. J.; Droxler, A. W.

2014-01-01

Tropical cyclones (TCs) are powerful agents of destruction, and understanding climatic controls on TC patterns is of great importance. Over timescales of seasons to several decades, relationships among TC track, frequency, intensity and basin-scale climate changes are well documented by instrumental records. Over centuries to millennia, climate-shift influence on TC regimes remains poorly constrained. To better understand these relationships, records from multiple locations of TC strikes spanning millennia with high temporal resolution are required, but such records are rare. Here we report on a highly detailed sedimentary proxy record of paleo-TC strikes from the Blue Hole of Lighthouse Reef, Belize. Our findings provide an important addition to other high-resolution records, which collectively demonstrate that shifts between active and inactive TC regimes have occurred contemporaneously with shifts hemispheric-scale oceanic and atmospheric circulation patterns such as MDR SSTs and NAO mode, rather than with changes in local climate phenomena as has previously been suggested.

Time-variable stress transfer across a megathrust from seismic to Wilson cycle scale

NASA Astrophysics Data System (ADS)

Rosenau, Matthias; Angiboust, Samuel; Moreno, Marcos; Schurr, Bernd; Oncken, Onno

2013-04-01

During the lifetime of a convergent plate margin stress transfer across the plate interface (a megathrust) can be expected to vary at multiple timescales. At short time scales (years to decades), a subduction megathrust interface appears coupled (accumulating shear stress) at shallow depth (seismogenic zone <350°C) in a laterally heterogeneous fashion. Highly coupled areas are prerequisite to areas of large slip (asperities) during future earthquakes but the correlation is rarely unequivocal suggesting that the coupling pattern is transient during the interseismic period. As temperature, structure and material properties are unlike to change at short time scales as well as at short distance along strike, fluid pressure change is invoked as the prime agent of lateral and time-variable stress transfer at short time (seismic cycle) scale and beyond. On longer time scales (up to Wilson cycles), additional agents of time-variable stress change are discussed. Shear tests using velocity weakening rock analogue material suggest that in a conditionally stable regime the effective normal load controls both the geodetic and the seismic coupling (fraction of convergence velocity accommodated by interseismic backslip/seismic slip). Accordingly seismic coupling decreases from 80% to 20% as the pore fluid pressure increases from hydrostatic to near-lithostatic. Moreover, the experiments demonstrate that at sub-seismic cycle scale the geodetic coupling (locking) is not only proportional to effective normal load but also to relative shear stress. For areas of near complete stress drop locking might systematically decrease over the interseismic period from >80-95 % shortly after an earthquake to backslip at significant fractions of plate convergence rate (<5-45 % locking) later in the seismic cycle. If we allow pore fluid pressures to change at sub-seismic cycle scale a single location along a megathrust may thus appear fully locked after an earthquake while fully unlocked before an earthquake. The mechanisms and timescales of fluid pressure changes along a megathrust are yet to be explored but a valid hypothesis seems to be that non-volcanic tremor and slow slip below the seismogenic zone represent short term episodes of metamorphic fluid infiltration into the shallow megathrust. A megathrust fault valve mechanism clocked by the greatest earthquakes then accounts for cyclic fluid pressure build up and drainage at sub-seismic cycle scale. As pore pressure dynamics are controlled primarily by permeability which in turn is controlled by structure and material properties, then more long term coupling transients associated with structural evolution of the plate margin can be implied. Fluid controlled transients might interfere with transients and secular trends resulting from changes in material strength and plate tectonic forces over the Wilson cycle resulting in a multispectral stress-transfer pattern associated with convergent margin evolution. Because of the viscous damping effect of the underlying asthenosphere, however, only longterm transients (periods >1-10 ka) are transmitted into the engaged plates. We therefore speculate that the multispectral nature of stress transfer across a megathrust filtered through the asthenosphere explains transient fault activity in some intraplate settings.

76 FR 3076 - Availability of an Environmental Assessment for a Biological Control Agent for Air Potato

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-19

...] Availability of an Environmental Assessment for a Biological Control Agent for Air Potato AGENCY: Animal and... environmental assessment (EA) relative to the control of air potato (Dioscorea bulbifera). The EA considers the... States for use as a biological control agent to reduce the severity of air potato infestations. We are...

Balancing Human and Inter-Agent Influences for Shared Control of Bio-Inspired Collectives

DTIC Science & Technology

2014-10-01

the higher-level intelligence and ingenuity of a human operator as well as the collective intelligence and robustness of a bio-inspired collective...for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway...agents, or that receive information from, but are not directly controlled by, a human operator . Unlike, agents in the human-controlled partition, agents

Biologic interventions for fatigue in rheumatoid arthritis.

PubMed

Almeida, Celia; Choy, Ernest H S; Hewlett, Sarah; Kirwan, John R; Cramp, Fiona; Chalder, Trudie; Pollock, Jon; Christensen, Robin

2016-06-06

Fatigue is a common and potentially distressing symptom for patients with rheumatoid arthritis (RA), with no accepted evidence-based management guidelines. Evidence suggests that biologic interventions improve symptoms and signs in RA as well as reducing joint damage. To evaluate the effect of biologic interventions on fatigue in rheumatoid arthritis. We searched the following electronic databases up to 1 April 2014: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Current Controlled Trials Register, the National Research Register Archive, The UKCRN Portfolio Database, AMED, CINAHL, PsycINFO, Social Science Citation Index, Web of Science, and Dissertation Abstracts International. In addition, we checked the reference lists of articles identified for inclusion for additional studies and contacted key authors. We included randomised controlled trials if they evaluated a biologic intervention in people with rheumatoid arthritis and had self reported fatigue as an outcome measure. Two reviewers selected relevant trials, assessed methodological quality and extracted data. Where appropriate, we pooled data in meta-analyses using a random-effects model. We identified 32 studies for inclusion in this current review. Twenty studies evaluated five anti-tumour necrosis factor (anti-TNF) biologic agents (adalimumab, certolizumab, etanercept, golimumab and infliximab), and 12 studies focused on five non-anti-TNF biologic agents (abatacept, canakinumab, rituximab, tocilizumab and an anti-interferon gamma monoclonal antibody). All but two of the studies were double-blind randomised placebo-controlled trials. In some trials, patients could receive concomitant disease-modifying anti-rheumatic drugs (DMARDs). These studies added either biologics or placebo to DMARDs. Investigators did not change the dose of the latter from baseline. In total, these studies included 9946 participants in the intervention groups and 4682 participants in the control groups. Overall, quality of randomised controlled trials was moderate with a low to unclear risk of bias in the reporting of the outcome of fatigue. We downgraded the quality of the studies from high to moderate because of potential reporting bias (studies included post hoc analyses favouring reporting of positive result and did not always include all randomised individuals). Some studies recruited only participants with early disease. The studies used five different instruments to assess fatigue in these studies: the Functional Assessment of Chronic Illness Therapy Fatigue Domain (FACIT-F), Short Form-36 Vitality Domain (SF-36 VT), Visual Analogue Scale (VAS) (0 to 100 or 0 to 10) and the Numerical Rating Scale (NRS). We calculated standard mean differences for pooled data in meta-analyses. Overall treatment by biologic agents led to statistically significant reduction in fatigue with a standardised mean difference of -0.43 (95% confidence interval (CI) -0.38 to -0.49). This equates to a difference of 6.45 units (95% CI 5.7 to 7.35) of FACIT-F score (range 0 to 52). Both types of biologic agents achieved a similar level of improvement: for anti-TNF agents, this stood at -0.42 (95% CI -0.35 to -0.49), equivalent to 6.3 units (95% CI 5.3 to 7.4) on the FACIT-F score; and for non-anti-TNF agents, it was -0.46 (95% CI -0.39 to -0.53), equivalent to 6.9 units (95% CI 5.85 to 7.95) on the FACIT-F score. In most studies, the double-blind period was 24 weeks or less. No study assessed long-term changes in fatigue. Treatment with biologic interventions in patients with active RA can lead to a small to moderate improvement in fatigue. The magnitude of improvement is similar for anti-TNF and non-anti-TNF biologics. However, it is unclear whether the improvement results from a direct action of the biologics on fatigue or indirectly through reduction in inflammation, disease activity or some other mechanism.

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

NASA Technical Reports Server (NTRS)

Tumer, Kagan

2005-01-01

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

Biotechnological synthesis of functional nanomaterials.

PubMed

Lloyd, Jonathan R; Byrne, James M; Coker, Victoria S

2011-08-01

Biological systems, especially those using microorganisms, have the potential to offer cheap, scalable and highly tunable green synthetic routes for the production of the latest generation of nanomaterials. Recent advances in the biotechnological synthesis of functional nano-scale materials are described. These nanomaterials range from catalysts to novel inorganic antimicrobials, nanomagnets, remediation agents and quantum dots for electronic and optical devices. Where possible, the roles of key biological macromolecules in controlling production of the nanomaterials are highlighted, and also technological limitations that must be addressed for widespread implementation are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Multi-Scale Behavioral Modeling and Analysis Promoting a Fundamental Understanding of Agent-Based System Design and Operation

DTIC Science & Technology

2007-03-01

Chains," Mathematics of Control, Signals, and Systems, vol. 3(1), pp. 1-29, 1990. [4] A . Arnold, J . A . Carrillo, and I. Gamba, "Low and High Field...Aronson, C. L. A ., and J . L. Vázquez, "Interfaces with a corner point in one- dimensional porous medium flow," Comm. Pure Appl. Math, vol. 38(4), pp. 375...K. Levin, "Damage analysis of fiber composites," Computer Methods in Applied Mechanics and Engineering. [10] K. S. Barber, A . Goel, T. J . Graser, T

A development framework for distributed artificial intelligence

NASA Technical Reports Server (NTRS)

Adler, Richard M.; Cottman, Bruce H.

1989-01-01

The authors describe distributed artificial intelligence (DAI) applications in which multiple organizations of agents solve multiple domain problems. They then describe work in progress on a DAI system development environment, called SOCIAL, which consists of three primary language-based components. The Knowledge Object Language defines models of knowledge representation and reasoning. The metaCourier language supplies the underlying functionality for interprocess communication and control access across heterogeneous computing environments. The metaAgents language defines models for agent organization coordination, control, and resource management. Application agents and agent organizations will be constructed by combining metaAgents and metaCourier building blocks with task-specific functionality such as diagnostic or planning reasoning. This architecture hides implementation details of communications, control, and integration in distributed processing environments, enabling application developers to concentrate on the design and functionality of the intelligent agents and agent networks themselves.

CATS-based Agents That Err

NASA Technical Reports Server (NTRS)

Callantine, Todd J.

2002-01-01

This report describes preliminary research on intelligent agents that make errors. Such agents are crucial to the development of novel agent-based techniques for assessing system safety. The agents extend an agent architecture derived from the Crew Activity Tracking System that has been used as the basis for air traffic controller agents. The report first reviews several error taxonomies. Next, it presents an overview of the air traffic controller agents, then details several mechanisms for causing the agents to err in realistic ways. The report presents a performance assessment of the error-generating agents, and identifies directions for further research. The research was supported by the System-Wide Accident Prevention element of the FAA/NASA Aviation Safety Program.

The organization and control of an evolving interdependent population

PubMed Central

Vural, Dervis C.; Isakov, Alexander; Mahadevan, L.

2015-01-01

Starting with Darwin, biologists have asked how populations evolve from a low fitness state that is evolutionarily stable to a high fitness state that is not. Specifically of interest is the emergence of cooperation and multicellularity where the fitness of individuals often appears in conflict with that of the population. Theories of social evolution and evolutionary game theory have produced a number of fruitful results employing two-state two-body frameworks. In this study, we depart from this tradition and instead consider a multi-player, multi-state evolutionary game, in which the fitness of an agent is determined by its relationship to an arbitrary number of other agents. We show that populations organize themselves in one of four distinct phases of interdependence depending on one parameter, selection strength. Some of these phases involve the formation of specialized large-scale structures. We then describe how the evolution of independence can be manipulated through various external perturbations. PMID:26040593

Entropic determination of the phase transition in a coevolving opinion-formation model.

PubMed

Burgos, E; Hernández, Laura; Ceva, H; Perazzo, R P J

2015-03-01

We study an opinion formation model by the means of a coevolving complex network where the vertices represent the individuals, characterized by their evolving opinions, and the edges represent the interactions among them. The network adapts to the spreading of opinions in two ways: not only connected agents interact and eventually change their thinking but an agent may also rewire one of its links to a neighborhood holding the same opinion as his. The dynamics, based on a global majority rule, depends on an external parameter that controls the plasticity of the network. We show how the information entropy associated to the distribution of group sizes allows us to locate the phase transition between a phase of full consensus and another, where different opinions coexist. We also determine the minimum size of the most informative sampling. At the transition the distribution of the sizes of groups holding the same opinion is scale free.

Optimal Routing and Control of Multiple Agents Moving in a Transportation Network and Subject to an Arrival Schedule and Separation Constraints

NASA Technical Reports Server (NTRS)

Sadovsky, A. V.; Davis, D.; Isaacson, D. R.

2012-01-01

We address the problem of navigating a set of moving agents, e.g. automated guided vehicles, through a transportation network so as to bring each agent to its destination at a specified time. Each pair of agents is required to be separated by a minimal distance, generally agent-dependent, at all times. The speed range, initial position, required destination, and required time of arrival at destination for each agent are assumed provided. The movement of each agent is governed by a controlled differential equation (state equation). The problem consists in choosing for each agent a path and a control strategy so as to meet the constraints and reach the destination at the required time. This problem arises in various fields of transportation, including Air Traffic Management and train coordination, and in robotics. The main contribution of the paper is a model that allows to recast this problem as a decoupled collection of problems in classical optimal control and is easily generalized to the case when inertia cannot be neglected. Some qualitative insight into solution behavior is obtained using the Pontryagin Maximum Principle. Sample numerical solutions are computed using a numerical optimal control solver.

Competition-Driven Network Dynamics: Emergence of a Scale-Free Leadership Structure and Collective Efficiency

NASA Astrophysics Data System (ADS)

Anghel, M.; Toroczkai, Zoltán; Bassler, Kevin E.; Korniss, G.

2004-02-01

Using the minority game as a model for competition dynamics, we investigate the effects of interagent communications across a network on the global evolution of the game. Agent communication across this network leads to the formation of an influence network, which is dynamically coupled to the evolution of the game, and it is responsible for the information flow driving the agents' actions. We show that the influence network spontaneously develops hubs with a broad distribution of in-degrees, defining a scale-free robust leadership structure. Furthermore, in realistic parameter ranges, facilitated by information exchange on the network, agents can generate a high degree of cooperation making the collective almost maximally efficient.

Key Facts about Tularemia

MedlinePlus

... Methyl isocyanate Case Definition: Methyl Isocyanate Poisoning Mustard gas (H) (sulfur mustard) Facts About Sulfur Mustard Case ... choking/lung agents Ricin Riot control agents/tear gas Facts About Riot Control Agents Case Definition: Riot ...

Strategies for efficient numerical implementation of hybrid multi-scale agent-based models to describe biological systems

PubMed Central

Cilfone, Nicholas A.; Kirschner, Denise E.; Linderman, Jennifer J.

2015-01-01

Biologically related processes operate across multiple spatiotemporal scales. For computational modeling methodologies to mimic this biological complexity, individual scale models must be linked in ways that allow for dynamic exchange of information across scales. A powerful methodology is to combine a discrete modeling approach, agent-based models (ABMs), with continuum models to form hybrid models. Hybrid multi-scale ABMs have been used to simulate emergent responses of biological systems. Here, we review two aspects of hybrid multi-scale ABMs: linking individual scale models and efficiently solving the resulting model. We discuss the computational choices associated with aspects of linking individual scale models while simultaneously maintaining model tractability. We demonstrate implementations of existing numerical methods in the context of hybrid multi-scale ABMs. Using an example model describing Mycobacterium tuberculosis infection, we show relative computational speeds of various combinations of numerical methods. Efficient linking and solution of hybrid multi-scale ABMs is key to model portability, modularity, and their use in understanding biological phenomena at a systems level. PMID:26366228

Naming games in two-dimensional and small-world-connected random geometric networks.

PubMed

Lu, Qiming; Korniss, G; Szymanski, B K

2008-01-01

We investigate a prototypical agent-based model, the naming game, on two-dimensional random geometric networks. The naming game [Baronchelli, J. Stat. Mech.: Theory Exp. (2006) P06014] is a minimal model, employing local communications that captures the emergence of shared communication schemes (languages) in a population of autonomous semiotic agents. Implementing the naming games with local broadcasts on random geometric graphs, serves as a model for agreement dynamics in large-scale, autonomously operating wireless sensor networks. Further, it captures essential features of the scaling properties of the agreement process for spatially embedded autonomous agents. Among the relevant observables capturing the temporal properties of the agreement process, we investigate the cluster-size distribution and the distribution of the agreement times, both exhibiting dynamic scaling. We also present results for the case when a small density of long-range communication links are added on top of the random geometric graph, resulting in a "small-world"-like network and yielding a significantly reduced time to reach global agreement. We construct a finite-size scaling analysis for the agreement times in this case.

Grey-scale ultrasonography for monitoring industrial exposure to hepatotoxic agents.

PubMed

Taylor, K J; Williams, D M; Smith, P M; Duck, B W

1975-05-31

Industrial exposure to several potentially hepatotoxic agents, such as vinyl-chloride monomer may occur, and there is a need for non-vasive, diagnostic techniques to detect and monitor progressive pathological processes in liver or spleen. Grey-scale ultrasonography permits display of detailed anatomy and pathology in the liver, portal veins, and spleen. The combination of fine resolution, non-invasiveness, absence of ionising radiation hazard, and portable equipment makes the technique ideal for screening populations at risk.

Measuring indigenous photosynthetic organisms to detect chemical warefare agents in water

DOEpatents

Greenbaum, Elias; Sanders, Charlene A.

2005-11-15

A method of testing water to detect the presence of a chemical or biological warfare agent is disclosed. The method is carried out by establishing control data by providing control water containing indigenous organisms but substantially free of a chemical and a biological warfare agent. Then measuring photosynthetic activity of the control water with a fluorometer to obtain control data to compare with test data to detect the presence of the chemical or agent. The test data is gathered by providing test water comprising the same indigenous organisms as contained in the control water. Further, the test water is suspected of containing the chemical or agent to be tested for. Photosynthetic activity is also measured by fluorescence induction in the test water using a fluorometer.

Combining agent-based modeling and life cycle assessment for the evaluation of mobility policies.

PubMed

Florent, Querini; Enrico, Benetto

2015-02-03

This article presents agent-based modeling (ABM) as a novel approach for consequential life cycle assessment (C-LCA) of large scale policies, more specifically mobility-related policies. The approach is validated at the Luxembourgish level (as a first case study). The agent-based model simulates the car market (sales, use, and dismantling) of the population of users in the period 2013-2020, following the implementation of different mobility policies and available electric vehicles. The resulting changes in the car fleet composition as well as the hourly uses of the vehicles are then used to derive consistent LCA results, representing the consequences of the policies. Policies will have significant environmental consequences: when using ReCiPe2008, we observe a decrease of global warming, fossil depletion, acidification, ozone depletion, and photochemical ozone formation and an increase of metal depletion, ionizing radiations, marine eutrophication, and particulate matter formation. The study clearly shows that the extrapolation of LCA results for the circulating fleet at national scale following the introduction of the policies from the LCAs of single vehicles by simple up-scaling (using hypothetical deployment scenarios) would be flawed. The inventory has to be directly conducted at full scale and to this aim, ABM is indeed a promising approach, as it allows identifying and quantifying emerging effects while modeling the Life Cycle Inventory of vehicles at microscale through the concept of agents.

Enhancement of biological control agents for use against forest insect pests and diseases through biotechnology

NASA Technical Reports Server (NTRS)

Slavicek, James M.

1991-01-01

Research and development efforts in our research group are focused on the generation of more efficacious biological control agents through the techniques of biotechnology for use against forest insect pests and diseases. Effective biological controls for the gypsy moth and for tree fungal wilt pathogens are under development. The successful use of Gypchek, a formulation of the Lymantria dispar nuclear polyhedrosis virus (LdNPV), in gypsy moth control programs has generated considerable interest in that agent. As a consequence of its specificity, LdPNV has negligible adverse ecological impacts compared to most gypsy moth control agents. However, LdNPV is not competitive with other control agents in terms of cost and efficacy. We are investigating several parameters of LdNPV replication and polyhedra production in order to enhance viral potency and efficacy thus mitigating the current disadvantages of LdNPV for gypsy moth control, and have identified LdNPV variants that will facilitate these efforts. Tree endophytic bacteria that synthesize antifungal compounds were identified and an antibiotic compound from one of these bacteria was characterized. The feasibility of developing tree endophytes as biological control agents for tree vascular fungal pathogens is being investigated.

Pharmacotherapy for obesity: novel agents and paradigms

PubMed Central

Manning, Sean; Pucci, Andrea

2014-01-01

Public health initiatives focused on obesity prevention and lifestyle intervention programmes for patients with obesity have struggled to contain the obesity epidemic to date. In recent years, antiobesity drug therapies have had a limited role in clinical treatment algorithms for patients with obesity. Indeed, a number of high-profile antiobesity drug suspensions have markedly impacted upon the landscape of obesity pharmacotherapy. In this review, we discuss the advent of an increasing array of pharmacotherapeutic agents, which are effective both in inducing weight loss and in maintaining weight loss achieved by lifestyle measures. The development of these drugs as antiobesity agents has followed varying paths, ranging from lorcaserin, a selective serotonin agent, exploiting the beneficial central actions of fenfluramine but without the associated systemic side effects, to liraglutide, a gut hormone already used as a glucose-lowering drug but with appetite-suppressant properties, or the novel drug combination of phentermine/topiramate, two ‘old’ drugs used in lower doses than with previous therapeutic uses, resulting in an additive effect on weight loss and fewer side effects. We summarize the key findings from recent randomized controlled trials of these three drugs. Although these agents lead to clinically important weight loss when used as monotherapy, the use of antiobesity drugs as adjunctive therapy post intensive lifestyle intervention could prove to be the most successful strategy. Moreover, a progressive approach to obesity pharmacotherapy perhaps offers the best opportunity to finally address the obesity crisis on a mass scale. PMID:24790728

Youth Depression Alleviation-Augmentation with an anti-inflammatory agent (YoDA-A): protocol and rationale for a placebo-controlled randomized trial of rosuvastatin and aspirin.

PubMed

Quinn, Amelia L; Dean, Olivia M; Davey, Christopher G; Kerr, Melissa; Harrigan, Susy M; Cotton, Sue M; Chanen, Andrew M; Dodd, Seetal; Ratheesh, Aswin; Amminger, G Paul; Phelan, Mark; Williams, Amber; Mackinnon, Andrew; Giorlando, Francesco; Baird, Shelley; Rice, Simon; O'Shea, Melissa; Schäfer, Miriam R; Mullen, Edward; Hetrick, Sarah; McGorry, Patrick; Berk, Michael

2018-02-01

There is growing support for the role of inflammation and oxidative stress in the pathophysiology of major depressive disorder (MDD). This has led to the development of novel strategies targeting inflammation in the treatment of depression. Rosuvastatin and aspirin have well-documented, anti-inflammatory and antioxidant properties. The aim of the Youth Depression Alleviation: Augmentation with an anti-inflammatory agent (YoDA-A) study is to determine whether individuals receiving adjunctive anti-inflammatory agents, aspirin and rosuvastatin experience a reduction in the severity of MDD compared with individuals receiving placebo. YoDA-A is a 12-week triple-blind, randomized controlled trial funded by the National Health and Medical Research Council, Australia. Participants aged 15-25, with moderate-to-severe MDD, are allocated to receive either 10 mg/day rosuvastatin, 100 mg/day aspirin, or placebo, in addition to treatment as usual. Participants are assessed at baseline and at weeks 4, 8, 12 and 26. The primary outcome is change in the Montgomery-Åsberg Depression Rating Scale (MADRS) from baseline to week 12. The study is planned to be completed in 2017. At date of publication, 85 participants have been recruited. Timely and targeted intervention for youth MDD is crucial. Given the paucity of new agents to treat youth MDD, adjunctive trials are not only pragmatic and 'real-world', but additionally aim to target shortfalls in conventional medications. This study has the potential to first provide two new adjunctive treatment options for youth MDD; aspirin and rosuvastatin. Second, this study will serve as proof of principle of the role of inflammation in MDD. © 2015 Wiley Publishing Asia Pty Ltd.

Ultrasound-mediated cavitation does not decrease the activity of small molecule, antibody or viral-based medicines.

PubMed

Myers, Rachel; Grundy, Megan; Rowe, Cliff; Coviello, Christian M; Bau, Luca; Erbs, Philippe; Foloppe, Johann; Balloul, Jean-Marc; Story, Colin; Coussios, Constantin C; Carlisle, Robert

2018-01-01

The treatment of cancer using nanomedicines is limited by the poor penetration of these potentially powerful agents into and throughout solid tumors. Externally controlled mechanical stimuli, such as the generation of cavitation-induced microstreaming using ultrasound (US), can provide a means of improving nanomedicine delivery. Notably, it has been demonstrated that by focusing, monitoring and controlling the US exposure, delivery can be achieved without damage to surrounding tissue or vasculature. However, there is a risk that such stimuli may disrupt the structure and thereby diminish the activity of the delivered drugs, especially complex antibody and viral-based nanomedicines. In this study, we characterize the impact of cavitation on four different agents, doxorubicin (Dox), cetuximab, adenovirus (Ad) and vaccinia virus (VV), representing a scale of sophistication from a simple small-molecule drug to complex biological agents. To achieve tight regulation of the level and duration of cavitation exposure, a "cavitation test rig" was designed and built. The activity of each agent was assessed with and without exposure to a defined cavitation regime which has previously been shown to provide effective and safe delivery of agents to tumors in preclinical studies. The fluorescence profile of Dox remained unchanged after exposure to cavitation, and the efficacy of this drug in killing a cancer cell line remained the same. Similarly, the ability of cetuximab to bind its epidermal growth factor receptor target was not diminished following exposure to cavitation. The encoding of the reporter gene luciferase within the Ad and VV constructs tested here allowed the infectivity of these viruses to be easily quantified. Exposure to cavitation did not impact on the activity of either virus. These data provide compelling evidence that the US parameters used to safely and successfully delivery nanomedicines to tumors in preclinical models do not detrimentally impact on the structure or activity of these nanomedicines.

Ultrasound-mediated cavitation does not decrease the activity of small molecule, antibody or viral-based medicines

PubMed Central

Myers, Rachel; Grundy, Megan; Rowe, Cliff; Coviello, Christian M; Bau, Luca; Erbs, Philippe; Foloppe, Johann; Balloul, Jean-Marc; Story, Colin; Coussios, Constantin C; Carlisle, Robert

2018-01-01

The treatment of cancer using nanomedicines is limited by the poor penetration of these potentially powerful agents into and throughout solid tumors. Externally controlled mechanical stimuli, such as the generation of cavitation-induced microstreaming using ultrasound (US), can provide a means of improving nanomedicine delivery. Notably, it has been demonstrated that by focusing, monitoring and controlling the US exposure, delivery can be achieved without damage to surrounding tissue or vasculature. However, there is a risk that such stimuli may disrupt the structure and thereby diminish the activity of the delivered drugs, especially complex antibody and viral-based nanomedicines. In this study, we characterize the impact of cavitation on four different agents, doxorubicin (Dox), cetuximab, adenovirus (Ad) and vaccinia virus (VV), representing a scale of sophistication from a simple small-molecule drug to complex biological agents. To achieve tight regulation of the level and duration of cavitation exposure, a “cavitation test rig” was designed and built. The activity of each agent was assessed with and without exposure to a defined cavitation regime which has previously been shown to provide effective and safe delivery of agents to tumors in preclinical studies. The fluorescence profile of Dox remained unchanged after exposure to cavitation, and the efficacy of this drug in killing a cancer cell line remained the same. Similarly, the ability of cetuximab to bind its epidermal growth factor receptor target was not diminished following exposure to cavitation. The encoding of the reporter gene luciferase within the Ad and VV constructs tested here allowed the infectivity of these viruses to be easily quantified. Exposure to cavitation did not impact on the activity of either virus. These data provide compelling evidence that the US parameters used to safely and successfully delivery nanomedicines to tumors in preclinical models do not detrimentally impact on the structure or activity of these nanomedicines. PMID:29391793

Ensuring congruency in multiscale modeling: towards linking agent based and continuum biomechanical models of arterial adaptation.

PubMed

Hayenga, Heather N; Thorne, Bryan C; Peirce, Shayn M; Humphrey, Jay D

2011-11-01

There is a need to develop multiscale models of vascular adaptations to understand tissue-level manifestations of cellular level mechanisms. Continuum-based biomechanical models are well suited for relating blood pressures and flows to stress-mediated changes in geometry and properties, but less so for describing underlying mechanobiological processes. Discrete stochastic agent-based models are well suited for representing biological processes at a cellular level, but not for describing tissue-level mechanical changes. We present here a conceptually new approach to facilitate the coupling of continuum and agent-based models. Because of ubiquitous limitations in both the tissue- and cell-level data from which one derives constitutive relations for continuum models and rule-sets for agent-based models, we suggest that model verification should enforce congruency across scales. That is, multiscale model parameters initially determined from data sets representing different scales should be refined, when possible, to ensure that common outputs are consistent. Potential advantages of this approach are illustrated by comparing simulated aortic responses to a sustained increase in blood pressure predicted by continuum and agent-based models both before and after instituting a genetic algorithm to refine 16 objectively bounded model parameters. We show that congruency-based parameter refinement not only yielded increased consistency across scales, it also yielded predictions that are closer to in vivo observations.

Enzyme-inducing anticonvulsants increase plasma clearance of dexmedetomidine: a pharmacokinetic and pharmacodynamic study.

PubMed

Flexman, Alana M; Wong, Harvey; Riggs, K Wayne; Shih, Tina; Garcia, Paul A; Vacas, Susana; Talke, Pekka O

2014-05-01

Dexmedetomidine is useful during mapping of epileptic foci as it facilitates electrocorticography unlike most other anesthetic agents. Patients with seizure disorders taking enzyme-inducing anticonvulsants appear to be resistant to its sedative effects. The objective of the study was to compare the pharmacokinetic and pharmacodynamic profile of dexmedetomidine in healthy volunteers with volunteers with seizure disorders receiving enzyme-inducing anticonvulsant medications. Dexmedetomidine was administered using a step-wise, computer-controlled infusion to healthy volunteers (n = 8) and volunteers with seizure disorders (n = 8) taking phenytoin or carbamazapine. Sedation and dexmedetomidine plasma levels were assessed at baseline, during the infusion steps, and after discontinuation of the infusion. Sedation was assessed by using the Observer's Assessment of Alertness/Sedation Scale, Ramsay Sedation Scale, and Visual Analog Scale and processed electroencephalography (entropy) monitoring. Pharmacokinetic analysis was performed on both groups, and differences between groups were determined using the standard two-stage approach. A two-compartment model was fit to dexmedetomidine concentration-time data. Dexmedetomidine plasma clearance was 43% higher in the seizure group compared with the control group (42.7 vs. 29.9 l/h; P = 0.007). In contrast, distributional clearance and the volume of distribution of the central and peripheral compartments were similar between the groups. No difference in sedation was detected between the two groups during a controlled range of target plasma concentrations. This study demonstrates that subjects with seizure disorders taking enzyme-inducing anticonvulsant medications have an increased plasma clearance of dexmedetomidine as compared with healthy control subjects.

Experimental Evaluation of Suitability of Selected Multi-Criteria Decision-Making Methods for Large-Scale Agent-Based Simulations

PubMed Central

2016-01-01

Multi-criteria decision-making (MCDM) can be formally implemented by various methods. This study compares suitability of four selected MCDM methods, namely WPM, TOPSIS, VIKOR, and PROMETHEE, for future applications in agent-based computational economic (ACE) models of larger scale (i.e., over 10 000 agents in one geographical region). These four MCDM methods were selected according to their appropriateness for computational processing in ACE applications. Tests of the selected methods were conducted on four hardware configurations. For each method, 100 tests were performed, which represented one testing iteration. With four testing iterations conducted on each hardware setting and separated testing of all configurations with the–server parameter de/activated, altogether, 12800 data points were collected and consequently analyzed. An illustrational decision-making scenario was used which allows the mutual comparison of all of the selected decision making methods. Our test results suggest that although all methods are convenient and can be used in practice, the VIKOR method accomplished the tests with the best results and thus can be recommended as the most suitable for simulations of large-scale agent-based models. PMID:27806061

Using Animated Agents in Learner-Controlled Training: The Effects of Design Control

ERIC Educational Resources Information Center

Behrend, Tara S.; Thompson, Lori Foster

2012-01-01

Animated agents have the potential to increase engagement and learning during online training by acting as personalized tutors. However, little is known about the conditions that make these agents most effective. In this study, 183 e-learners completed a Microsoft Excel training course. Approximately half were assigned an agent with predetermined…

Indirect effects of host-specific biological control agents

Treesearch

Dean E. Pearson; Ragan M. Callaway

2003-01-01

Biological control is a crucial tool in the battle against biological invasions, but biocontrol agents can have a deleterious impact on native species. Recognition of risks associated with host shifting has increased the emphasis on host specificity of biocontrol agents for invasive weeds. However, recent studies indicate host-specific biocontrol agents can...

Proceedings 3rd NASA/IEEE Workshop on Formal Approaches to Agent-Based Systems (FAABS-III)

NASA Technical Reports Server (NTRS)

Hinchey, Michael (Editor); Rash, James (Editor); Truszkowski, Walt (Editor); Rouff, Christopher (Editor)

2004-01-01

These preceedings contain 18 papers and 4 poster presentation, covering topics such as: multi-agent systems, agent-based control, formalism, norms, as well as physical and biological models of agent-based systems. Some applications presented in the proceedings include systems analysis, software engineering, computer networks and robot control.

System and method for secure group transactions

DOEpatents

Goldsmith, Steven Y [Rochester, MN

2006-04-25

A method and a secure system, processing on one or more computers, provides a way to control a group transaction. The invention uses group consensus access control and multiple distributed secure agents in a network environment. Each secure agent can organize with the other secure agents to form a secure distributed agent collective.

17 CFR 240.17Ad-10 - Prompt posting of certificate detail to master securityholder files, maintenance of accurate...

Code of Federal Regulations, 2012 CFR

2012-04-01

... between co-transfer agents and recordkeeping transfer agents, maintenance of current control book... securityholder files, maintenance of accurate securityholder files, communications between co-transfer agents and recordkeeping transfer agents, maintenance of current control book, retention of certificate detail and “buy-in...

17 CFR 240.17Ad-10 - Prompt posting of certificate detail to master securityholder files, maintenance of accurate...

Code of Federal Regulations, 2013 CFR

2013-04-01

... between co-transfer agents and recordkeeping transfer agents, maintenance of current control book... securityholder files, maintenance of accurate securityholder files, communications between co-transfer agents and recordkeeping transfer agents, maintenance of current control book, retention of certificate detail and “buy-in...

17 CFR 240.17Ad-10 - Prompt posting of certificate detail to master securityholder files, maintenance of accurate...

Code of Federal Regulations, 2011 CFR

2011-04-01

... between co-transfer agents and recordkeeping transfer agents, maintenance of current control book... securityholder files, maintenance of accurate securityholder files, communications between co-transfer agents and recordkeeping transfer agents, maintenance of current control book, retention of certificate detail and “buy-in...

Complex dynamics and empirical evidence (Invited Paper)

NASA Astrophysics Data System (ADS)

Delli Gatti, Domenico; Gaffeo, Edoardo; Giulioni, Gianfranco; Gallegati, Mauro; Kirman, Alan; Palestrini, Antonio; Russo, Alberto

2005-05-01

Standard macroeconomics, based on a reductionist approach centered on the representative agent, is badly equipped to explain the empirical evidence where heterogeneity and industrial dynamics are the rule. In this paper we show that a simple agent-based model of heterogeneous financially fragile agents is able to replicate a large number of scaling type stylized facts with a remarkable degree of statistical precision.

Integrated control of lateral and vertical vehicle dynamics based on multi-agent system

NASA Astrophysics Data System (ADS)

Huang, Chen; Chen, Long; Yun, Chaochun; Jiang, Haobin; Chen, Yuexia

2014-03-01

The existing research of the integrated chassis control mainly focuses on the different evaluation indexes and control strategy. Among the different evaluation indexes, the comprehensive properties are usually not considered based on the non-linear superposition principle. But, the control strategy has some shortages on tyre model with side-slip angle, road adhesion coefficient, vertical load and velocity. In this paper, based on belief, desire and intention(BDI)-agent model framework, the TYRE agent, electric power steering(EPS) agent and active suspension system(ASS) agent are proposed. In the system(SYS) agent, the coordination mechanism is employed to manage interdependences and conflicts among other agents, so as to improve the flexibility, adaptability, and robustness of the global control system. Due to the existence of the simulation demand of dynamic performance, the vehicle multi-body dynamics model is established by SIMPACK. And then the co-simulation analysis is conducted to evaluate the proposed multi-agent system(MAS) controller. The simulation results demonstrate that the MAS has good effect on the performance of EPS and ASS. Meantime, the better road feeling for the driver is provided considering the multiple and complex driving traffic. Finally, the MAS rapid control prototyping is built to conduct the real vehicle test. The test results are consistent to the simulation results, which verifies the correctness of simulation. The proposed research ensures the driving safety, enhances the handling stability, and improves the ride comfort.

[Progress in researches on pathogens, epidemiology and integrated control of diseases on Salvia miltiorrhiza in China].

PubMed

Wang, Tie-Lin; Guan, Wei; Sun, Kai; Wang, Sheng; Chi, Xiu-Lian; Guo, Lan-Ping

2018-06-01

Danshen (Salvia miltiorrhiza) is a perennial herbal plant as a bulk commodity of traditional Chinese medicinal material. With the growing market demand, the planting scale of Danshen has been fast enlarged. The occurance of diseases on Danshen has become as a major threaten of its production. Root diseases are most devastated on Danshen. Rootrot is the most important disease, and Fusarium wilt comes second. Leaf spot occurs most on aerial part of Danshen. In the Danshen industry, the chemical control is most commonly used, with biological agents as supplements. This review summarized the symptom, pathogen, epidemiology, and control method of 7 diseases on Danshen (rootrot, Fusarium wilt, southern blight, root knot nematode, leaf spot, leaf red and virus diseases), providing guidelines for disease diagnostics, pathogen isolation and identification, proper pesticide application and integrated control. Copyright© by the Chinese Pharmaceutical Association.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scheinker, Alexander

Here, we study control of the angular-velocity actuated nonholonomic unicycle, via a simple, bounded extremum seeking controller which is robust to external disturbances and measurement noise. The vehicle performs source seeking despite not having any position information about itself or the source, able only to sense a noise corrupted scalar value whose extremum coincides with the unknown source location. In order to control the angular velocity, rather than the angular heading directly, a controller is developed such that the closed loop system exhibits multiple time scales and requires an analysis approach expanding the previous work of Kurzweil, Jarnik, Sussmann, andmore » Liu, utilizing weak limits. We provide analytic proof of stability and demonstrate how this simple scheme can be extended to include position-independent source seeking, tracking, and collision avoidance of groups on autonomous vehicles in GPS-denied environments, based only on a measure of distance to an obstacle, which is an especially important feature for an autonomous agent.« less

Massive Multi-Agent Systems Control

NASA Technical Reports Server (NTRS)

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

2004-01-01

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

N-acetylcysteine, a glutamate modulator, in the treatment of trichotillomania: a double-blind, placebo-controlled study.

PubMed

Grant, Jon E; Odlaug, Brian L; Kim, Suck Won

2009-07-01

Trichotillomania is characterized by repetitive hair pulling that causes noticeable hair loss. Data on the pharmacologic treatment of trichotillomania are limited to conflicting studies of serotonergic medications. N-acetylcysteine, an amino acid, seems to restore the extracellular glutamate concentration in the nucleus accumbens and, therefore, offers promise in the reduction of compulsive behavior. To determine the efficacy and tolerability of N-acetylcysteine in adults with trichotillomania. Twelve-week, double-blind, placebo-controlled trial. Ambulatory care center. Fifty individuals with trichotillomania (45 women and 5 men; mean [SD] age, 34.3 [12.1] years). N-acetylcysteine (dosing range, 1200-2400 mg/d) or placebo was administered for 12 weeks. Patients were assessed using the Massachusetts General Hospital Hair Pulling Scale, the Clinical Global Impression scale, the Psychiatric Institute Trichotillomania Scale, and measures of depression, anxiety, and psychosocial functioning. Outcomes were examined using analysis of variance modeling analyses and linear regression in an intention-to-treat population. Patients assigned to receive N-acetylcysteine had significantly greater reductions in hair-pulling symptoms as measured using the Massachusetts General Hospital Hair Pulling Scale (P < .001) and the Psychiatric Institute Trichotillomania Scale (P = .001). Fifty-six percent of patients "much or very much improved" with N-acetylcysteine use compared with 16% taking placebo (P = .003). Significant improvement was initially noted after 9 weeks of treatment. This study, the first to our knowledge that examines the efficacy of a glutamatergic agent in the treatment of trichotillomania, found that N-acetylcysteine demonstrated statistically significant reductions in trichotillomania symptoms. No adverse events occurred in the N-acetylcysteine group, and N-acetylcysteine was well tolerated. Pharmacologic modulation of the glutamate system may prove to be useful in the control of a range of compulsive behaviors. clinicaltrials.gov Identifier: NCT00354770.

Agent-based modeling of malaria vectors: the importance of spatial simulation.

PubMed

Bomblies, Arne

2014-07-03

The modeling of malaria vector mosquito populations yields great insight into drivers of malaria transmission at the village scale. Simulation of individual mosquitoes as "agents" in a distributed, dynamic model domain may be greatly beneficial for simulation of spatial relationships of vectors and hosts. In this study, an agent-based model is used to simulate the life cycle and movement of individual malaria vector mosquitoes in a Niger Sahel village, with individual simulated mosquitoes interacting with their physical environment as well as humans. Various processes that are known to be epidemiologically important, such as the dependence of parity on flight distance between developmental habitat and blood meal hosts and therefore spatial relationships of pools and houses, are readily simulated using this modeling paradigm. Impacts of perturbations can be evaluated on the basis of vectorial capacity, because the interactions between individuals that make up the population- scale metric vectorial capacity can be easily tracked for simulated mosquitoes and human blood meal hosts, without the need to estimate vectorial capacity parameters. As expected, model results show pronounced impacts of pool source reduction from larvicide application and draining, but with varying degrees of impact depending on the spatial relationship between pools and human habitation. Results highlight the importance of spatially-explicit simulation that can model individuals such as in an agent-based model. The impacts of perturbations on village scale malaria transmission depend on spatial locations of individual mosquitoes, as well as the tracking of relevant life cycle events and characteristics of individual mosquitoes. This study demonstrates advantages of using an agent-based approach for village-scale mosquito simulation to address questions in which spatial relationships are known to be important.

A hierarchical distributed control model for coordinating intelligent systems

NASA Technical Reports Server (NTRS)

Adler, Richard M.

1991-01-01

A hierarchical distributed control (HDC) model for coordinating cooperative problem-solving among intelligent systems is described. The model was implemented using SOCIAL, an innovative object-oriented tool for integrating heterogeneous, distributed software systems. SOCIAL embeds applications in 'wrapper' objects called Agents, which supply predefined capabilities for distributed communication, control, data specification, and translation. The HDC model is realized in SOCIAL as a 'Manager'Agent that coordinates interactions among application Agents. The HDC Manager: indexes the capabilities of application Agents; routes request messages to suitable server Agents; and stores results in a commonly accessible 'Bulletin-Board'. This centralized control model is illustrated in a fault diagnosis application for launch operations support of the Space Shuttle fleet at NASA, Kennedy Space Center.

Multi-Agent Architecture with Support to Quality of Service and Quality of Control

NASA Astrophysics Data System (ADS)

Poza-Luján, Jose-Luis; Posadas-Yagüe, Juan-Luis; Simó-Ten, Jose-Enrique

Multi Agent Systems (MAS) are one of the most suitable frameworks for the implementation of intelligent distributed control system. Agents provide suitable flexibility to give support to implied heterogeneity in cyber-physical systems. Quality of Service (QoS) and Quality of Control (QoC) parameters are commonly utilized to evaluate the efficiency of the communications and the control loop. Agents can use the quality measures to take a wide range of decisions, like suitable placement on the control node or to change the workload to save energy. This article describes the architecture of a multi agent system that provides support to QoS and QoC parameters to optimize de system. The architecture uses a Publish-Subscriber model, based on Data Distribution Service (DDS) to send the control messages. Due to the nature of the Publish-Subscribe model, the architecture is suitable to implement event-based control (EBC) systems. The architecture has been called FSACtrl.

Simulating the wealth distribution with a Richest-Following strategy on scale-free network

NASA Astrophysics Data System (ADS)

Hu, Mao-Bin; Jiang, Rui; Wu, Qing-Song; Wu, Yong-Hong

2007-07-01

In this paper, we investigate the wealth distribution with agents playing evolutionary games on a scale-free social network adopting the Richest-Following strategy. Pareto's power-law distribution (1897) of wealth is demonstrated with power factor in agreement with that of US or Japan. Moreover, the agent's personal wealth is proportional to its number of contacts (connectivity), and this leads to the phenomenon that the rich gets richer and the poor gets relatively poorer, which agrees with the Matthew Effect.

Development of the Technologies for Stabilization Treatment of the Water of the Recycling Cooling Systems at Thermal Power Plants

NASA Astrophysics Data System (ADS)

Vlasov, S. M.; Chichirova, N. D.; Chichirov, A. A.; Vlasova, A. Yu.; Filimonova, A. A.; Prosvirnina, D. V.

2018-02-01

A turbine-condensate cooling system is one of the less stable and most hard-to-control systems of maintaining optimal water chemistry. A laboratory recycling cooling water test facility, UVO-0.3, was developed for physical simulation of innovative zero-discharge water chemistry conditions and improvement of technological flowcharts of stabilization treatment of the initial and circulating water of the recycling cooling systems at thermal power plants. Experiments were conducted in the UVO-0.3 facility to investigate the processes that occur in the recycling water supply system and master new technologies of stabilization of the initial and circulating water. It is shown that, when using untreated initial water, scaling cannot be prevented even under low concentration levels. The main reason for the activation of scale depositing is the desorption of carbon dioxide that results in alkalization of the circulating water and, as a consequence, a displacement of the chemical reaction equilibrium towards the formation of slightly soluble hardness ions. Some techniques, viz., liming and alkalization of the initial water and the by-pass treatment of the circulating water, are considered. New engineering solutions have been developed for reducing the amount of scale-forming substances in the initial and circulating water. The best results were obtained by pretreating the initial water with alkalizing agents and simultaneously bypassing and treating part of the circulating water. The obtained experimental data underlie the process flowcharts of stabilization treatment of the initial and circulating TPP water that ensure scale-free and noncorrosive operation and meet the corresponding environmental requirements. Under the bypassing, the specific rates of the agents and the residual hardness are reduced compared with the conventional pretreatment.

Distributed optimization system and method

DOEpatents

Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

2003-06-10

A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

Distributed Optimization System

DOEpatents

Hurtado, John E.; Dohrmann, Clark R.; Robinett, III, Rush D.

2004-11-30

A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

Opinion formation of free speech on the directed social network

NASA Astrophysics Data System (ADS)

Su, Jiongming; Ma, Hongxu; Liu, Baohong; Li, Qi

2014-12-01

A dynamical model with continuous opinion is proposed to study how the speech order and the topology of directed social network affect the opinion formation of free speech. In the model, agents express their opinions one by one with random order (RO) or probability order (PO), other agents paying attentions to the speaking agent, receive provider's opinion, update their opinions and then express their new opinions in their turns. It is proved that with the same agent j repeats its opinion more, other agents who pay their attentions to j and include j's opinion in their confidence level at initial time, will continue approaching j's opinion. Simulation results reveal that on directed scale-free network: (1) the model for PO forms fewer opinion clusters, larger maximum cluster (MC), smaller standard deviation (SD), and needs less waiting time to reach a middle level of consensus than RO; (2) as the parameter of scale-free degree distribution decreases or the confidence level increases, the results often get better for both speech orders; (3) the differences between PO and RO get smaller as the size of network decreases.

Antiscalant properties of Spergularia rubra and Parietaria officinalis aqueous solutions

NASA Astrophysics Data System (ADS)

Cheap-Charpentier, Hélène; Gelus, Dominique; Pécoul, Nathalie; Perrot, Hubert; Lédion, Jean; Horner, Olivier; Sadoun, Jonathan; Cachet, Xavier; Litaudon, Marc; Roussi, Fanny

2016-06-01

The formation of calcium carbonate in water has important implications in industry. Chemical antiscalant is usually used to control scale depositions. Plant extracts have been recently used as new green antiscalant agents, as they can be easily prepared and are environmentally friendly. In this study, stock aqueous solutions of Spergularia rubra and Parietaria officinalis, two plants used in traditional medicine to treat or prevent urolithiasis, were obtained by infusion. The antiscaling properties of these extracts towards CaCO3 formation were tested by using chronoamperometry and Fast Controlled Precipitation methods. The aqueous solution of S. rubra was further fractionated to isolate compounds of lower polarity. Their efficiency towards CaCO3 precipitation was characterized by Fast Controlled Precipitation method. The inhibiting efficiency of this fractionated solution was greater than that of the stock aqueous solution.

Optical control of antibacterial activity

NASA Astrophysics Data System (ADS)

Velema, Willem A.; van der Berg, Jan Pieter; Hansen, Mickel J.; Szymanski, Wiktor; Driessen, Arnold J. M.; Feringa, Ben L.

2013-11-01

Bacterial resistance is a major problem in the modern world, stemming in part from the build-up of antibiotics in the environment. Novel molecular approaches that enable an externally triggered increase in antibiotic activity with high spatiotemporal resolution and auto-inactivation are highly desirable. Here we report a responsive, broad-spectrum, antibacterial agent that can be temporally activated with light, whereupon it auto-inactivates on the scale of hours. The use of such a ‘smart’ antibiotic might prevent the build-up of active antimicrobial material in the environment. Reversible optical control over active drug concentration enables us to obtain pharmacodynamic information. Precisely localized control of activity is achieved, allowing the growth of bacteria to be confined to defined patterns, which has potential for the development of treatments that avoid interference with the endogenous microbial population in other parts of the organism.

A social-level macro-governance mode for collaborative manufacturing processes

NASA Astrophysics Data System (ADS)

Gao, Ji; Lv, Hexin; Jin, Zhiyong; Xu, Ping

2017-08-01

This paper proposes the social-level macro-governance mode for innovating the popular centralized control for CoM (Collaborative Manufacturing) processes, and makes this mode depend on the support from three aspects of technologies standalone and complementary: social-level CoM process norms, CoM process supervision system, and rational agents as the brokers of enterprises. It is the close coupling of those technologies that redounds to removing effectively the uncontrollability obstacle confronted with by cross-management-domain CoM processes. As a result, this mode enables CoM applications to be implemented by uniting the centralized control of CoM partners for respective CoM activities, and therefore provides a new distributed CoM process control mode to push forward the convenient development and large-scale deployment of SME-oriented CoM applications.

Using software agents to preserve individual health data confidentiality in micro-scale geographical analyses.

PubMed

Kamel Boulos, Maged N; Cai, Qiang; Padget, Julian A; Rushton, Gerard

2006-04-01

Confidentiality constraints often preclude the release of disaggregate data about individuals, which limits the types and accuracy of the results of geographical health analyses that could be done. Access to individually geocoded (disaggregate) data often involves lengthy and cumbersome procedures through review boards and committees for approval (and sometimes is not possible). Moreover, current data confidentiality-preserving solutions compatible with fine-level spatial analyses either lack flexibility or yield less than optimal results (because of confidentiality-preserving changes they introduce to disaggregate data), or both. In this paper, we present a simulation case study to illustrate how some analyses cannot be (or will suffer if) done on aggregate data. We then quickly review some existing data confidentiality-preserving techniques, and move on to explore a solution based on software agents with the potential of providing flexible, controlled (software-only) access to unmodified confidential disaggregate data and returning only results that do not expose any person-identifiable details. The solution is thus appropriate for micro-scale geographical analyses where no person-identifiable details are required in the final results (i.e., only aggregate results are needed). Our proposed software agent technique also enables post-coordinated analyses to be designed and carried out on the confidential database(s), as needed, compared to a more conventional solution based on the Web Services model that would only support a rigid, pre-coordinated (pre-determined) and rather limited set of analyses. The paper also provides an exploratory discussion of mobility, security, and trust issues associated with software agents, as well as possible directions/solutions to address these issues, including the use of virtual organizations. Successful partnerships between stakeholder organizations, proper collaboration agreements, clear policies, and unambiguous interpretations of laws and regulations are also much needed to support and ensure the success of any technological solution.

Examining the Resilience of Crop Production, Livestock Carrying Capacity, and Woodland Density in a Rural Zimbabwean Socio-Ecological System Using Agent-Based Models Representing Human Management Decisions

NASA Astrophysics Data System (ADS)

Eitzel Solera, M. V.; Neves, K.; Veski, A.; Solera, J.; Omoju, O. E.; Mawere Ndlovu, A.; Wilson, K.

2016-12-01

As climate change increases the pressures on arid ecosystems by changing timing and amount of rainfall, understanding the ways in which human management choices affect the resilience of these systems becomes key to their sustainability. On marginal farmland in Mazvihwa, Midlands Province, the historical carrying capacity of livestock has been consistently surprisingly high. We explore this phenomenon by building an agent-based model in NetLogo from a wealth of long-term data generated by the community-based participatory research team of The Muonde Trust, a Zimbabwean non-governmental organization. We combine the accumulated results of 35 years of indigenous and local knowledge with national datasets such as rainfall records. What factors keep the carrying capacity high? What management choices can maintain crops, livestock, and woodland at levels necessary for the community's survival? How do these choices affect long-term sustainability, and does increasing resilience at one scale reduce resilience at another scale? We use our agent-based model to explore the feedbacks between crops, livestock, and woodland and the impacts of various human choices as well as temporal and spatial ecological variation. By testing different scenarios, we disentangle the complex interactions between these components. We find that some factors out of the community's control can strongly affect the sustainability of the system through times of drought, and that supplementary feed may maintain livestock potentially at the expense of other resources. The challenges to resilience encountered by the farmers in Mazvihwa are not unique - many indigenous and rural people face drought and the legacies of colonialism, which contribute to lowered resilience to external challenges such as climate change, epidemics, and political instability. Using the agent-based model as a tool for synthesis and exploration initiates discussion about resilience-enhancing management choices for Mazvihwa's farmer-researchers.

Predicting spillover risk to non-target plants pre-release: Bikasha collaris a potential biological control agent of Chinese tallowtree (Triadica sebifera)

USDA-ARS?s Scientific Manuscript database

Quarantine host range tests accurately predict direct risk of biological control agents to non-target species. However, a well-known indirect effect of biological control of weeds releases is spillover damage to non-target species. Spillover damage may occur when the population of agents achieves ou...

Lessons learned from the implementation of remote control for the interoperability standard ISO/IEEE11073-20601 in a standard weighing scale.

PubMed

Barrón-González, Héctor Gilberto; Martínez-Espronceda, Miguel; Trigo, Jesús Daniel; Led, Santiago; Serrano, Luis

2016-01-01

The Point of Care (PoC) version of the interoperability standard ISO/IEEE11073 (X73) provided a mechanism to control remotely agents through documents X73-10201 and X73-20301. The newer version of X73 oriented to Personal Health Devices (PHD) has no mechanisms to do such a thing. The authors are working toward a common proposal with the PHD Working Group (PHD-WG) in order to adapt the remote control capabilities from X73PoC to X73PHD. However, this theoretical adaptation has to be implemented and tested to evaluate whether or not its inclusion entails an acceptable overhead and extra cost. Such proof-of-concept assessment is the main objective of this paper. For the sake of simplicity, a weighing scale with a configurable operation was chosen as use case. First, in a previous stage of the research - the model was defined. Second, the implementation methodology - both in terms of hardware and software - was defined and executed. Third, an evaluation methodology to test the remote control features was defined. Then, a thorough comparison between a weighing scale with and without remote control was performed. The results obtained indicate that, when implementing remote control in a weighing scale, the relative weight of such feature represents an overhead of as much as 53%, whereas the number of Implementation Conformance Statements (ICSs) to be satisfied by the manufacturer represent as much as 34% regarding the implementation without remote control. The new feature facilitates remote control of PHDs but, at the same time, increases overhead and costs, and, therefore, manufacturers need to weigh this trade-off. As a conclusion, this proof-of-concept helps in fostering the evolution of the remote control proposal to extend X73PHD and promotes its inclusion as part of the standard, as well as it illustrates the methodological steps for its extrapolation to other specializations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Synthesis, Characterization, and Multimillion-Atom Simulation of Halogen-Based Energetic Materials for Agent Defeat

DTIC Science & Technology

2013-04-01

DTRA-TR-13-23 Synthesis, Characterization, and Multimillion -Atom Simulation of Halogen-Based Energetic Materials for Agent Defeat Approved for...reagents for the destruction of biologically active materials and a simulation of their reactions on a multimillion atom scale with quantum...explosives for destruction of chemical & biological agents. Multimillion -atom molecular dynamics simulations with quantum mechanical accuracy were

Postteneral Protein Feeding may Improve Biological Control Efficiency of Aphytis lingnanensis and Aphytis melinus

PubMed Central

Vanaclocha, Pilar; Papacek, Dan; Verdú, Maria Jesús; Urbaneja, Alberto

2014-01-01

Abstract The augmentative releases of mass-reared Aphytis spp. (Hymenoptera: Aphelinidae) parasitoids are widely used against armored scales. The nutritional status and the initial egg load of Aphytis spp. females are key to their success as biological control agents. For these reasons, this work focuses on the study of providing a protein feed to Aphytis lingnanensis (Compere) and A. melinus DeBach to improve the egg load before their release. The addition of protein to a honey diet during the first 2 d after the adult parasitoid emergence increased the initial egg load in both species of parasitoids by more than five eggs. Furthermore, the addition of protein increased the total number of eggs laid by A. lingnanensis on oleander scale, Aspidiotus nerii Bouché (Hemiptera: Diaspididae). In contrast, this effect was not observed on A. melinus probably because A. nerii is considered a suboptimal host for this parasitoid. The host-feeding activities of the two Aphytis species were differentially affected by the addition of protein to their diets. These results may have direct implications for augmentative biological control programs, especially during transportation from insectaries to the field, a period of time when parasitoids are deprived of hosts. PMID:25502042

Bacillus thuringiensis: fermentation process and risk assessment. A short review.

PubMed

Capalbo, D M

1995-01-01

Several factors make the local production of Bacillus thuringiensis (Bt) highly appropriate for pest control in developing nations. Bt can be cheaply produced on a wide variety of low cost, organic substrates. Local production results in considerable savings in hard currency which otherwise would be spent on importation of chemical and biological insecticides. The use of Bt in Brazil has been limited in comparison with chemical insecticides. Although Bt is imported, some Brazilian researchers have been working on its development and production. Fermentation processes (submerged and semi-solid) were applied, using by-products from agro-industries. As the semi-solid fermentation process demonstrated to be interesting for Bt endotoxins production, it could be adopted for small scale local production. Although promising results had been achieved, national products have not been registered due to the absence of a specific legislation for biological products. Effective actions are being developed in order to solve this gap. Regardless of the biocontrol agents being considered atoxic and harmless to the environment, information related to direct and indirect effects of microbials are still insufficient in many cases. The risk analysis of the use of microbial control agents is of upmost importance nowadays, and is also discussed.

Complexities, Catastrophes and Cities: Emergency Dynamics in Varying Scenarios and Urban Topologies

NASA Astrophysics Data System (ADS)

Narzisi, Giuseppe; Mysore, Venkatesh; Byeon, Jeewoong; Mishra, Bud

Complex Systems are often characterized by agents capable of interacting with each other dynamically, often in non-linear and non-intuitive ways. Trying to characterize their dynamics often results in partial differential equations that are difficult, if not impossible, to solve. A large city or a city-state is an example of such an evolving and self-organizing complex environment that efficiently adapts to different and numerous incremental changes to its social, cultural and technological infrastructure [1]. One powerful technique for analyzing such complex systems is Agent-Based Modeling (ABM) [9], which has seen an increasing number of applications in social science, economics and also biology. The agent-based paradigm facilitates easier transfer of domain specific knowledge into a model. ABM provides a natural way to describe systems in which the overall dynamics can be described as the result of the behavior of populations of autonomous components: agents, with a fixed set of rules based on local information and possible central control. As part of the NYU Center for Catastrophe Preparedness and Response (CCPR1), we have been exploring how ABM can serve as a powerful simulation technique for analyzing large-scale urban disasters. The central problem in Disaster Management is that it is not immediately apparent whether the current emergency plans are robust against such sudden, rare and punctuated catastrophic events.

Modeling and simulation of evacuation behavior using fuzzy logic in a goal finding application

NASA Astrophysics Data System (ADS)

Sharma, Sharad; Ogunlana, Kola; Sree, Swetha

2016-05-01

Modeling and simulation has been widely used as a training and educational tool for depicting different evacuation strategies and damage control decisions during evacuation. However, there are few simulation environments that can include human behavior with low to high levels of fidelity. It is well known that crowd stampede induced by panic leads to fatalities as people are crushed or trampled. Our proposed goal finding application can be used to model situations that are difficult to test in real-life due to safety considerations. It is able to include agent characteristics and behaviors. Findings of this model are very encouraging as agents are able to assume various roles to utilize fuzzy logic on the way to reaching their goals. Fuzzy logic is used to model stress, panic and the uncertainty of emotions. The fuzzy rules link these parts together while feeding into behavioral rules. The contributions of this paper lies in our approach of utilizing fuzzy logic to show learning and adaptive behavior of agents in a goal finding application. The proposed application will aid in running multiple evacuation drills for what-if scenarios by incorporating human behavioral characteristics that can scale from a room to building. Our results show that the inclusion of fuzzy attributes made the evacuation time of the agents closer to the real time drills.

Leaderless consensus for the fractional-order nonlinear multi-agent systems under directed interaction topology

NASA Astrophysics Data System (ADS)

Bai, Jing; Wen, Guoguang; Rahmani, Ahmed

2018-04-01

Leaderless consensus for the fractional-order nonlinear multi-agent systems is investigated in this paper. At the first part, a control protocol is proposed to achieve leaderless consensus for the nonlinear single-integrator multi-agent systems. At the second part, based on sliding mode estimator, a control protocol is given to solve leaderless consensus for the the nonlinear single-integrator multi-agent systems. It shows that the control protocol can improve the systems' convergence speed. At the third part, a control protocol is designed to accomplish leaderless consensus for the nonlinear double-integrator multi-agent systems. To judge the systems' stability in this paper, two classic continuous Lyapunov candidate functions are chosen. Finally, several worked out examples under directed interaction topology are given to prove above results.

Pharmacological interventions for prevention or treatment of postoperative pain in people undergoing laparoscopic cholecystectomy.

PubMed

Gurusamy, Kurinchi Selvan; Vaughan, Jessica; Toon, Clare D; Davidson, Brian R

2014-03-28

While laparoscopic cholecystectomy is generally considered less painful than open surgery, pain is one of the important reasons for delayed discharge after day-surgery and overnight stay following laparoscopic cholecystectomy. The safety and effectiveness of different pharmacological interventions such as non-steroidal anti-inflammatory drugs, opioids, and anticonvulsant analgesics in people undergoing laparoscopic cholecystectomy is unknown. To assess the benefits and harms of different analgesics in people undergoing laparoscopic cholecystectomy. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Science Citation Index Expanded, and the World Health Organization International Clinical Trials Registry Platform portal (WHO ICTRP) to March 2013 to identify randomised clinical trials of relevance to this review. We considered only randomised clinical trials (irrespective of language, blinding, or publication status) comparing different pharmacological interventions with no intervention or inactive controls for outcomes related to benefit in this review. We considered comparative non-randomised studies with regards to treatment-related harms. We also considered trials that compared one class of drug with another class of drug for this review. Two review authors collected the data independently. We analysed the data with both fixed-effect and random-effects models using Review Manager 5 analysis. For each outcome, we calculated the risk ratio (RR) or mean difference (MD) with 95% confidence intervals (CI). We included 25 trials with 2505 participants randomised to the different pharmacological agents and inactive controls. All the trials were at unclear risk of bias. Most trials included only low anaesthetic risk people undergoing elective laparoscopic cholecystectomy. Participants were allowed to take additional analgesics as required in 24 of the trials. The pharmacological interventions in all the included trials were aimed at preventing pain after laparoscopic cholecystectomy. There were considerable differences in the pharmacological agents used and the methods of administration. The estimated effects of the intervention on the proportion of participants who were discharged as day-surgery, the length of hospital stay, or the time taken to return to work were imprecise in all the comparisons in which these outcomes were reported (very low quality evidence). There was no mortality in any of the groups in the two trials that reported mortality (183 participants, very low quality evidence). Differences in serious morbidity outcomes between the groups were imprecise across all the comparisons (very low quality evidence). None of the trials reported patient quality of life or time taken to return to normal activity. The pain at 4 to 8 hours was generally reduced by about 1 to 2 cm on the visual analogue scale of 1 to 10 cm in the comparisons involving the different pharmacological agents and inactive controls (low or very low quality evidence). The pain at 9 to 24 hours was generally reduced by about 0.5 cm (a modest reduction) on the visual analogue scale of 1 to 10 cm in the comparisons involving the different pharmacological agents and inactive controls (low or very low quality evidence). There is evidence of very low quality that different pharmacological agents including non-steroidal anti-inflammatory drugs, opioid analgesics, and anticonvulsant analgesics reduce pain scores in people at low anaesthetic risk undergoing elective laparoscopic cholecystectomy. However, the decision to use these drugs has to weigh the clinically small reduction in pain against uncertain evidence of serious adverse events associated with many of these agents. Further randomised clinical trials of low risk of systematic and random errors are necessary. Such trials should include important clinical outcomes such as quality of life and time to return to work in their assessment.

Xgrid admin guide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strauss, Charlie E M

2010-01-01

Xgrid, with a capital-X is the name for Apple's grid computing system. With a lower case x, xgrid is the name of the command line utility that clients can use, among other ways, to submit jobs to a controller. An Xgrid divides into three logical components: Agent, Controller and Client. Client computers submit jobs (a set of tasks) they want run to a Controller computer. The Controller queues the Client jobs and distributes tasks to Agent computers. Agent computers run the tasks and report their output and status back to the controller where it is stored until deleted by themore » Client. The Clients can asynchronously query the controller about the status of a job and the results. Any OSX computer can be any of these. A single mac can be more than one: it's possible to be Agent, Controller and Client at the same time. There is one Controller per Grid. Clients can submit jobs to Controllers of different grids. Agents can work for more than one grid. Xgrid's setup has a pleasantly small palette of choices. The first two decisions to make are the kind of authentication & authorization to use and if a shared file system is needed. A shared file system that all the agents can access can be very beneficial for many computing problems, but it is not appropriate for every network.« less

Agent Based Modeling: Fine-Scale Spatio-Temporal Analysis of Pertussis

NASA Astrophysics Data System (ADS)

Mills, D. A.

2017-10-01

In epidemiology, spatial and temporal variables are used to compute vaccination efficacy and effectiveness. The chosen resolution and scale of a spatial or spatio-temporal analysis will affect the results. When calculating vaccination efficacy, for example, a simple environment that offers various ideal outcomes is often modeled using coarse scale data aggregated on an annual basis. In contrast to the inadequacy of this aggregated method, this research uses agent based modeling of fine-scale neighborhood data centered around the interactions of infants in daycare and their families to demonstrate an accurate reflection of vaccination capabilities. Despite being able to prevent major symptoms, recent studies suggest that acellular Pertussis does not prevent the colonization and transmission of Bordetella Pertussis bacteria. After vaccination, a treated individual becomes a potential asymptomatic carrier of the Pertussis bacteria, rather than an immune individual. Agent based modeling enables the measurable depiction of asymptomatic carriers that are otherwise unaccounted for when calculating vaccination efficacy and effectiveness. Using empirical data from a Florida Pertussis outbreak case study, the results of this model demonstrate that asymptomatic carriers bias the calculated vaccination efficacy and reveal a need for reconsidering current methods that are widely used for calculating vaccination efficacy and effectiveness.

High performance cellular level agent-based simulation with FLAME for the GPU.

PubMed

Richmond, Paul; Walker, Dawn; Coakley, Simon; Romano, Daniela

2010-05-01

Driven by the availability of experimental data and ability to simulate a biological scale which is of immediate interest, the cellular scale is fast emerging as an ideal candidate for middle-out modelling. As with 'bottom-up' simulation approaches, cellular level simulations demand a high degree of computational power, which in large-scale simulations can only be achieved through parallel computing. The flexible large-scale agent modelling environment (FLAME) is a template driven framework for agent-based modelling (ABM) on parallel architectures ideally suited to the simulation of cellular systems. It is available for both high performance computing clusters (www.flame.ac.uk) and GPU hardware (www.flamegpu.com) and uses a formal specification technique that acts as a universal modelling format. This not only creates an abstraction from the underlying hardware architectures, but avoids the steep learning curve associated with programming them. In benchmarking tests and simulations of advanced cellular systems, FLAME GPU has reported massive improvement in performance over more traditional ABM frameworks. This allows the time spent in the development and testing stages of modelling to be drastically reduced and creates the possibility of real-time visualisation for simple visual face-validation.

Modeling Multi-Agent Self-Organization through the Lens of Higher Order Attractor Dynamics.

PubMed

Butner, Jonathan E; Wiltshire, Travis J; Munion, A K

2017-01-01

Social interaction occurs across many time scales and varying numbers of agents; from one-on-one to large-scale coordination in organizations, crowds, cities, and colonies. These contexts, are characterized by emergent self-organization that implies higher order coordinated patterns occurring over time that are not due to the actions of any particular agents, but rather due to the collective ordering that occurs from the interactions of the agents. Extant research to understand these social coordination dynamics (SCD) has primarily examined dyadic contexts performing rhythmic tasks. To advance this area of study, we elaborate on attractor dynamics, our ability to depict them visually, and quantitatively model them. Primarily, we combine difference/differential equation modeling with mixture modeling as a way to infer the underlying topological features of the data, which can be described in terms of attractor dynamic patterns. The advantage of this approach is that we are able to quantify the self-organized dynamics that agents exhibit, link these dynamics back to activity from individual agents, and relate it to other variables central to understanding the coordinative functionality of a system's behavior. We present four examples that differ in the number of variables used to depict the attractor dynamics (1, 2, and 6) and range from simulated to non-simulated data sources. We demonstrate that this is a flexible method that advances scientific study of SCD in a variety of multi-agent systems.

RESEARCH NEEDS FOR SCALING UP INDOOR SINK EFFECT MODELS

EPA Science Inventory

The events of 11 September 2001 underscored the need to study the vulnerability of buildings to weapons of mass destruction, including chemical, biological, physical, and radiological agents. Should these agents be released inside a building, they would interact with interior sur...

Predicting the host range of Nystalea ebalea: secondary plant chemistry and host selection by a surrogate biological control agent of Schinus terebinthifolia

USDA-ARS?s Scientific Manuscript database

The safety of weed biological control depends upon the selection and utilization of the target weed by the agent while causing minimal harm to non-target species. Selection of weed species by biological control agents is determined by the presence of behavioral cues, generally host secondary plant c...

Adaptive architectures for resilient control of networked multiagent systems in the presence of misbehaving agents

NASA Astrophysics Data System (ADS)

Torre, Gerardo De La; Yucelen, Tansel

2018-03-01

Control algorithms of networked multiagent systems are generally computed distributively without having a centralised entity monitoring the activity of agents; and therefore, unforeseen adverse conditions such as uncertainties or attacks to the communication network and/or failure of agent-wise components can easily result in system instability and prohibit the accomplishment of system-level objectives. In this paper, we study resilient coordination of networked multiagent systems in the presence of misbehaving agents, i.e. agents that are subject to exogenous disturbances that represent a class of adverse conditions. In particular, a distributed adaptive control architecture is presented for directed and time-varying graph topologies to retrieve a desired networked multiagent system behaviour. Apart from the existing relevant literature that make specific assumptions on the graph topology and/or the fraction of misbehaving agents, we show that the considered class of adverse conditions can be mitigated by the proposed adaptive control approach that utilises a local state emulator - even if all agents are misbehaving. Illustrative numerical examples are provided to demonstrate the theoretical findings.

Modelling of Robotized Manufacturing Systems Using MultiAgent Formalism

NASA Astrophysics Data System (ADS)

Foit, K.; Gwiazda, A.; Banaś, W.

2016-08-01

The evolution of manufacturing systems has greatly accelerated due to development of sophisticated control systems. On top of determined, one way production flow the need of decision making has arisen as a result of growing product range that are manufactured simultaneously, using the same resources. On the other hand, the intelligent flow control could address the “bottleneck” problem caused by the machine failure. This sort of manufacturing systems uses advanced control algorithms that are introduced by the use of logic controllers. The complex algorithms used in the control systems requires to employ appropriate methods during the modelling process, like the agent-based one, which is the subject of this paper. The concept of an agent is derived from the object-based methodology of modelling, so it meets the requirements of representing the physical properties of the machines as well as the logical form of control systems. Each agent has a high level of autonomy and could be considered separately. The multi-agent system consists of minimum two agents that can interact and modify the environment, where they act. This may lead to the creation of self-organizing structure, what could be interesting feature during design and test of manufacturing system.

Palatability of oral antibiotics among children in an urban primary care center.

PubMed

Angelilli, M L; Toscani, M; Matsui, D M; Rieder, M J

2000-03-01

To evaluate the palatability of antimicrobial agents effective against beta-lactamase-producing bacteria in American children. In a taste test of 4 antimicrobial agents, azithromycin (cherry flavored), cefprozil (bubble gum flavored), cefixime (strawberry flavored), and amoxicillin-clavulanic acid (banana flavored) were compared. An urban inner-city primary care clinic. A volunteer sample of 30 healthy children (aged 5-8 years). Palatability was determined using a single-blind taste test of 4 flavored antimicrobial agents. The 4 antimicrobial agents used were azithromycin, cefprozil, cefixime, and amoxicillin-clavulanic acid. After each antimicrobial test dose, subjects rated the taste on a 10-cm visual analog scale incorporating a facial hedonic scale. Preference assessments for the best-tasting and worst-tasting agent were also conducted. Of the 20 children who expressed a preference, significantly more children (9 [45%], P<.05) selected the cefixime preparation as the best-tasting formulation compared with the other preparations. The cefixime preparation was also significantly the least likely to be selected as the worst-tasting preparation (2 [10%], P<.05). There were no significant differences between the other 3 preparations with respect to being selected as either the best or worst tasting. The mean (+/- SD) visual analog scale score for cefixime was highest (8.53 [2.49]) compared with the scores for azithromycin (6.78 [3.45]), cefprozil (6.26 [4.04]), and amoxicillin-clavulanic acid (6.24 [4.01]). The cefixime preparation was most commonly rated as best tasting by children.

The Analgesic Efficacy of Nonsteroidal Anti-inflammatory Agents (NSAIDs) in Patients Undergoing Cesarean Deliveries: A Meta-Analysis.

PubMed

Zeng, Angela M; Nami, Nina F; Wu, Christopher L; Murphy, Jamie D

Postoperative pain after cesarean delivery, which accounts for approximately 1 in 3 live births in the United States, can be severe in many patients. Nonsteroidal anti-inflammatory agents (NSAIDs) are potent analgesics that are effective in the treatment of postoperative pain. In this meta-analysis, we assessed the analgesic efficacy of NSAIDs in postoperative cesarean delivery patients. An electronic literature search of the Library of Medicine's PubMed, Cochrane CENTRAL, Scopus, and EMBASE databases was conducted in May 2013 and updated in January 2015 (Appendix, Supplemental Digital Content 1, http://links.lww.com/AAP/A174). Searches were limited to randomized controlled trials. The primary outcome variable was visual analog scale or numerical rating scale pain scores. Secondary outcomes included cumulative postoperative opioid consumption and opioid-related adverse effects (drowsiness/sedation, nausea, and vomiting). Data extraction was performed independently by 2 reviewers. Extracted data were input into Review Manager. Twenty-two randomized controlled trials compared a NSAID (n = 639) to a control (n = 674). Patients in the NSAID group versus control reported lower pain scores at 12 hours (P = 0.003) and at 24 hours (P < 0.001). Subgroup analysis showed a significant difference in pain scores at 24 hours, with patients receiving NSAIDs via intravenous/intramuscular (P < 0.001) route, but not the oral (P = 0.39) or rectal routes (P = 0.99). Significantly lower average pain scores were reported for pain with movement at 24 hours in the NSAID group (P = 0.001). Patients in the NSAID group versus controls consumed significantly less opioids (P < 0.001) and had significantly less drowsiness/sedation (P = 0.03), but there was no significant difference between the groups with regard to nausea or vomiting (P = 0.48 and P = 0.17, respectively). The perioperative use of NSAIDs in cesarean delivery patients will result in a significantly lower pain scores, less opioid consumption, and less drowsiness/sedation but no difference in nausea or vomiting compared to those who did not receive NSAIDs. Further research should address the optimal NSAID regimen and examine the effect of improved analgesia on patient-centered outcomes such as patient satisfaction and quality of breastfeeding.

High-throughput assay for optimising microbial biological control agent production and delivery

USDA-ARS?s Scientific Manuscript database

Lack of technologies to produce and deliver effective biological control agents (BCAs) is a major barrier to their commercialization. A myriad of variables associated with BCA cultivation, formulation, drying, storage, and reconstitution processes complicates agent quality maximization. An efficie...

Hierarchical Controlled Remote State Preparation by Using a Four-Qubit Cluster State

NASA Astrophysics Data System (ADS)

Ma, Peng-Cheng; Chen, Gui-Bin; Li, Xiao-Wei; Zhan, You-Bang

2018-06-01

We propose a scheme for hierarchical controlled remote preparation of an arbitrary single-qubit state via a four-qubit cluster state as the quantum channel. In this scheme, a sender wishes to help three agents to remotely prepare a quantum state, respectively. The three agents are divided into two grades, that is, an agent is in the upper grade and other two agents are in the lower grade. In this process of remote state preparation, the agent of the upper grade only needs the assistance of any one of the other two agents for recovering the sender's original state, while an agent of the lower grade needs the collaboration of all the other two agents. In other words, the agents of two grades have different authorities to reconstruct sender's original state.

Addressing Production System Failures Using Multi-agent Control

NASA Astrophysics Data System (ADS)

Gautam, Rajesh; Miyashita, Kazuo

Output in high-volume production facilities is limited by bottleneck machines. We propose a control mechanism by modeling workstations as agents that pull jobs from other agents based on their current WIP level and requirements. During failures, when flows of some jobs are disrupted, the agents pull alternative jobs to maintain utilization of their capacity at a high level. In this paper, we empirically demonstrate that the proposed mechanism can react to failures more appropriately than other control mechanisms using a benchmark problem of a semiconductor manufacturing process.

Intelligent microchip networks: an agent-on-chip synthesis framework for the design of smart and robust sensor networks

NASA Astrophysics Data System (ADS)

Bosse, Stefan

2013-05-01

Sensorial materials consisting of high-density, miniaturized, and embedded sensor networks require new robust and reliable data processing and communication approaches. Structural health monitoring is one major field of application for sensorial materials. Each sensor node provides some kind of sensor, electronics, data processing, and communication with a strong focus on microchip-level implementation to meet the goals of miniaturization and low-power energy environments, a prerequisite for autonomous behaviour and operation. Reliability requires robustness of the entire system in the presence of node, link, data processing, and communication failures. Interaction between nodes is required to manage and distribute information. One common interaction model is the mobile agent. An agent approach provides stronger autonomy than a traditional object or remote-procedure-call based approach. Agents can decide for themselves, which actions are performed, and they are capable of flexible behaviour, reacting on the environment and other agents, providing some degree of robustness. Traditionally multi-agent systems are abstract programming models which are implemented in software and executed on program controlled computer architectures. This approach does not well scale to micro-chip level and requires full equipped computers and communication structures, and the hardware architecture does not consider and reflect the requirements for agent processing and interaction. We propose and demonstrate a novel design paradigm for reliable distributed data processing systems and a synthesis methodology and framework for multi-agent systems implementable entirely on microchip-level with resource and power constrained digital logic supporting Agent-On-Chip architectures (AoC). The agent behaviour and mobility is fully integrated on the micro-chip using pipelined communicating processes implemented with finite-state machines and register-transfer logic. The agent behaviour, interaction (communication), and mobility features are modelled and specified on a machine-independent abstract programming level using a state-based agent behaviour language (APL). With this APL a high-level agent compiler is able to synthesize a hardware model (RTL, VHDL), a software model (C, ML), or a simulation model (XML) suitable to simulate a multi-agent system using the SeSAm simulator framework. Agent communication is provided by a simple tuple-space database implemented on node level providing fault tolerant access of global data. A novel synthesis development kit (SynDK) based on a graph-structured database approach is introduced to support the rapid development of compilers and synthesis tools, used for example for the design and implementation of the APL compiler.

Chemical Warfare Agent Decontamination Efficacy Testing Large-Scale Chamber mVHP (registered trademerk) Decontamination System Evaluation

DTIC Science & Technology

2010-02-01

APPENDIXES A. COUPON STOCK MATERIAL AND PREPARATION 141 B. CONTROL CHARTS 143 C. ANALYTICAL INSTRUMENTATION PARAMETERS 171 D. COUPON CHAIN-OF...were cut from stock material. Vitron® is a registered trademark of Vitron Manufacturing, Phoenix, AZ Kapton® is a register trademark of E.I. DuPont... Eft Wipe Wipe Ext. Eff. 15M 15M 15M 15M 0 300 600 0 4/4 5/5 5/5 4/4 3,740,999 ± 2,377,014 135876 ±51295 50896 ± 38227 120004 ±8130

Spatial Control of Cell Transfection Using Soluble or Solid-Phase Redox Agents and a Redox-Active Ferrocenyl Lipid

PubMed Central

Aytar, Burcu S.; Muller, John P. E.; Kondo, Yukishige; Abbott, Nicholas L.; Lynn, David M.

2013-01-01

We report principles for active, user-defined control over the locations and timing with which DNA is expressed in cells. Our approach exploits unique properties of a ferrocenyl cationic lipid that is inactive when oxidized, but active when chemically reduced. We show that methods that exert spatial control over the administration of reducing agents can lead to local activation of lipoplexes and spatial control over gene expression. The versatility of this approach is demonstrated using both soluble and solid-phase reducing agents. These methods provide control over cell transfection, including methods for remote activation and the patterning of expression using solid-phase redox agents, that are difficult to achieve using conventional lipoplexes. PMID:23965341

Spatial control of cell transfection using soluble or solid-phase redox agents and a redox-active ferrocenyl lipid.

PubMed

Aytar, Burcu S; Muller, John P E; Kondo, Yukishige; Abbott, Nicholas L; Lynn, David M

2013-09-11

We report principles for active, user-defined control over the locations and timing with which DNA is expressed in cells. Our approach exploits unique properties of a ferrocenyl cationic lipid that is inactive when oxidized, but active when chemically reduced. We show that methods that exert spatial control over the administration of reducing agents can lead to local activation of lipoplexes and spatial control over gene expression. The versatility of this approach is demonstrated using both soluble and solid-phase reducing agents. These methods provide control over cell transfection, including methods for remote activation and the patterning of expression using solid-phase redox agents, that are difficult to achieve using conventional lipoplexes.

Comparative Evaluation of Firefighting Foam Agents

DTIC Science & Technology

1979-08-01

incorporating these basic concepts under a military specification, are being produced on a world-wide MIL - F - 24385 , Navy (reference 6). basis. The original...Program Office for 24385 (Navy), Fire Extinguishing Aircraft Ground Fire Suppression and Agent, Aqueous- F Ilm-Forming-Foam Rescue, SMF, AGFSkS 71-1...fluoroprotein foams (FPF), and three protein foam (?’ F ) agents. Large-scale fire tests were performed under fixed fire conditions employing air

Escape and evade control policies for ensuring the physical security of nonholonomic, ground-based, unattended mobile sensor nodes

NASA Astrophysics Data System (ADS)

Mascarenas, David; Stull, Christopher; Farrar, Charles

2011-06-01

In order to realize the wide-scale deployment of high-endurance, unattended mobile sensing technologies, it is vital to ensure the self-preservation of the sensing assets. Deployed mobile sensor nodes face a variety of physical security threats including theft, vandalism and physical damage. Unattended mobile sensor nodes must be able to respond to these threats with control policies that facilitate escape and evasion to a low-risk state. In this work the Precision Immobilization Technique (PIT) problem has been considered. The PIT maneuver is a technique that a pursuing, car-like vehicle can use to force a fleeing vehicle to abruptly turn ninety degrees to the direction of travel. The abrupt change in direction generally causes the fleeing driver to lose control and stop. The PIT maneuver was originally developed by law enforcement to end vehicular pursuits in a manner that minimizes damage to the persons and property involved. It is easy to imagine that unattended autonomous convoys could be targets of this type of action by adversarial agents. This effort focused on developing control policies unattended mobile sensor nodes could employ to escape, evade and recover from PIT-maneuver-like attacks. The development of these control policies involved both simulation as well as small-scale experimental testing. The goal of this work is to be a step toward ensuring the physical security of unattended sensor node assets.

Modeling the Internet of Things, Self-Organizing and Other Complex Adaptive Communication Networks: A Cognitive Agent-Based Computing Approach.

PubMed

Laghari, Samreen; Niazi, Muaz A

2016-01-01

Computer Networks have a tendency to grow at an unprecedented scale. Modern networks involve not only computers but also a wide variety of other interconnected devices ranging from mobile phones to other household items fitted with sensors. This vision of the "Internet of Things" (IoT) implies an inherent difficulty in modeling problems. It is practically impossible to implement and test all scenarios for large-scale and complex adaptive communication networks as part of Complex Adaptive Communication Networks and Environments (CACOONS). The goal of this study is to explore the use of Agent-based Modeling as part of the Cognitive Agent-based Computing (CABC) framework to model a Complex communication network problem. We use Exploratory Agent-based Modeling (EABM), as part of the CABC framework, to develop an autonomous multi-agent architecture for managing carbon footprint in a corporate network. To evaluate the application of complexity in practical scenarios, we have also introduced a company-defined computer usage policy. The conducted experiments demonstrated two important results: Primarily CABC-based modeling approach such as using Agent-based Modeling can be an effective approach to modeling complex problems in the domain of IoT. Secondly, the specific problem of managing the Carbon footprint can be solved using a multiagent system approach.

A Novel Network Attack Audit System based on Multi-Agent Technology

NASA Astrophysics Data System (ADS)

Jianping, Wang; Min, Chen; Xianwen, Wu

A network attack audit system which includes network attack audit Agent, host audit Agent and management control center audit Agent is proposed. And the improved multi-agent technology is carried out in the network attack audit Agent which has achieved satisfactory audit results. The audit system in terms of network attack is just in-depth, and with the function improvement of network attack audit Agent, different attack will be better analyzed and audit. In addition, the management control center Agent should manage and analyze audit results from AA (or HA) and audit data on time. And the history files of network packets and host log data should also be audit to find deeper violations that cannot be found in real time.

Trapping and dynamic manipulation of polystyrene beads mimicking circulating tumor cells using targeted magnetic/photoacoustic contrast agents

NASA Astrophysics Data System (ADS)

Wei, Chen-Wei; Xia, Jinjun; Pelivanov, Ivan; Hu, Xiaoge; Gao, Xiaohu; O'Donnell, Matthew

2012-10-01

Results on magnetically trapping and manipulating micro-scale beads circulating in a flow field mimicking metastatic cancer cells in human peripheral vessels are presented. Composite contrast agents combining magneto-sensitive nanospheres and highly optical absorptive gold nanorods were conjugated to micro-scale polystyrene beads. To efficiently trap the targeted objects in a fast stream, a dual magnet system consisting of two flat magnets to magnetize (polarize) the contrast agent and an array of cone magnets producing a sharp gradient field to trap the magnetized contrast agent was designed and constructed. A water-ink solution with an optical absorption coefficient of 10 cm-1 was used to mimic the optical absorption of blood. Magnetomotive photoacoustic imaging helped visualize bead trapping, dynamic manipulation of trapped beads in a flow field, and the subtraction of stationary background signals insensitive to the magnetic field. The results show that trafficking micro-scale objects can be effectively trapped in a stream with a flow rate up to 12 ml/min and the background can be significantly (greater than 15 dB) suppressed. It makes the proposed method very promising for sensitive detection of rare circulating tumor cells within high flow vessels with a highly absorptive optical background.

Bounded extremum seeking for angular velocity actuated control of nonholonomic unicycle

DOE PAGES

Scheinker, Alexander

2016-08-17

Here, we study control of the angular-velocity actuated nonholonomic unicycle, via a simple, bounded extremum seeking controller which is robust to external disturbances and measurement noise. The vehicle performs source seeking despite not having any position information about itself or the source, able only to sense a noise corrupted scalar value whose extremum coincides with the unknown source location. In order to control the angular velocity, rather than the angular heading directly, a controller is developed such that the closed loop system exhibits multiple time scales and requires an analysis approach expanding the previous work of Kurzweil, Jarnik, Sussmann, andmore » Liu, utilizing weak limits. We provide analytic proof of stability and demonstrate how this simple scheme can be extended to include position-independent source seeking, tracking, and collision avoidance of groups on autonomous vehicles in GPS-denied environments, based only on a measure of distance to an obstacle, which is an especially important feature for an autonomous agent.« less

Comparison among four commonly used demineralizing agents for root conditioning. A scanning electron microscopy

PubMed Central

do AMARAL, Nathalia Godoy; de REZENDE, Maria Lúcia Rubo; HIRATA, Fabiana; RODRIGUES, Marcus Gustavo Silva; SANT'ANA, Adriana Campos Passanezi; GREGHI, Sebastião Luiz Aguiar; PASSANEZI, Euloir

2011-01-01

Dental roots that have been exposed to the oral cavity and periodontal pocket environment present superficial changes, which can prevent connective tissue reattachment. Demineralizing agents have been used as an adjunct to the periodontal treatment aiming at restoring the biocompatibility of roots. Objective This study compared four commonly used demineralizing agents for their capacity of removing smear layer and opening dentin tubules. Methods Fifty fragments of human dental roots previously exposed to periodontal disease were scaled and randomly divided into the following groups of treatment: 1) CA: demineralization with citric acid for 3 min; 2) TC-HCl: demineralization with tetracycline-HCl for 3 min; 3) EDTA: demineralization with EDTA for 3 min; 4) PA: demineralization with 37% phosphoric acid for 3 min; 5)Control: rubbing of saline solution for 3 min. Scanning electron microscopy was used to check for the presence of residual smear layer and for measuring the number and area of exposed dentin tubules. Results Smear layer was present in 100% of the specimens from the groups PA and control; in 80% from EDTA group; in 33.3% from TC-HCl group and 0% from CA group. The mean numbers of exposed dentin tubules in a standardized area were: TC-HCl=43.8±25.2; CA=39.3±37; PA=12.1±16.3; EDTA=4.4±7.5 and Control=2.3±5.7. The comparison showed significant differences between the following pairs of groups: TC-HCl and Control; TC-HCl and EDTA; CA and Control; and CA and EDTA. The mean percentages of area occupied by exposed dentin tubules were: CA=0.12±0.17%; TC-HCl=0.08±0.06%; PA=0.03±0.05%; EDTA=0.01±0.01% and Control=0±0%. The CA group differed significantly from the others except for the TC-HCl group. Conclusion There was a decreasing ability for smear layer removal and dentin tubule widening as follows: AC>TC-HCl>PA>EDTA. This information can be of value as an extra parameter for choosing one of them for root conditioning. PMID:21986651

Formalizing Knowledge in Multi-Scale Agent-Based Simulations

PubMed Central

Somogyi, Endre; Sluka, James P.; Glazier, James A.

2017-01-01

Multi-scale, agent-based simulations of cellular and tissue biology are increasingly common. These simulations combine and integrate a range of components from different domains. Simulations continuously create, destroy and reorganize constituent elements causing their interactions to dynamically change. For example, the multi-cellular tissue development process coordinates molecular, cellular and tissue scale objects with biochemical, biomechanical, spatial and behavioral processes to form a dynamic network. Different domain specific languages can describe these components in isolation, but cannot describe their interactions. No current programming language is designed to represent in human readable and reusable form the domain specific knowledge contained in these components and interactions. We present a new hybrid programming language paradigm that naturally expresses the complex multi-scale objects and dynamic interactions in a unified way and allows domain knowledge to be captured, searched, formalized, extracted and reused. PMID:29338063

Formalizing Knowledge in Multi-Scale Agent-Based Simulations.

PubMed

Somogyi, Endre; Sluka, James P; Glazier, James A

2016-10-01

Multi-scale, agent-based simulations of cellular and tissue biology are increasingly common. These simulations combine and integrate a range of components from different domains. Simulations continuously create, destroy and reorganize constituent elements causing their interactions to dynamically change. For example, the multi-cellular tissue development process coordinates molecular, cellular and tissue scale objects with biochemical, biomechanical, spatial and behavioral processes to form a dynamic network. Different domain specific languages can describe these components in isolation, but cannot describe their interactions. No current programming language is designed to represent in human readable and reusable form the domain specific knowledge contained in these components and interactions. We present a new hybrid programming language paradigm that naturally expresses the complex multi-scale objects and dynamic interactions in a unified way and allows domain knowledge to be captured, searched, formalized, extracted and reused.

A one-pot parallel reductive amination of aldehydes with heteroaromatic amines.

PubMed

Bogolubsky, Andrey V; Moroz, Yurii S; Mykhailiuk, Pavel K; Panov, Dmitriy M; Pipko, Sergey E; Konovets, Anzhelika I; Tolmachev, Andrey

2014-08-11

A parallel reductive amination of heteroaromatic amines has been performed using a combination of ZnCl2-TMSOAc (activating agents) and NaBH(OAc)3 (reducing agent). A library of diverse secondary amines was easily prepared on a 50-300 mg scale.

Engineering large-scale agent-based systems with consensus

NASA Technical Reports Server (NTRS)

Bokma, A.; Slade, A.; Kerridge, S.; Johnson, K.

1994-01-01

The paper presents the consensus method for the development of large-scale agent-based systems. Systems can be developed as networks of knowledge based agents (KBA) which engage in a collaborative problem solving effort. The method provides a comprehensive and integrated approach to the development of this type of system. This includes a systematic analysis of user requirements as well as a structured approach to generating a system design which exhibits the desired functionality. There is a direct correspondence between system requirements and design components. The benefits of this approach are that requirements are traceable into design components and code thus facilitating verification. The use of the consensus method with two major test applications showed it to be successful and also provided valuable insight into problems typically associated with the development of large systems.

Comparison of the Effect of Dentin Bonding, Dentin Sealing Agents on the Microleakage of Provisional Crowns Fabricated with Direct and Indirect Technique-An Invitro Study

PubMed Central

Muthukumar, B; Kumar, M Vasantha

2015-01-01

Background Postoperative sensitivity after temporization is a common complaint in Fixed Partial Denture patients. It is caused by weak and ill fitting temporary restorations which results in microleakage. This can be controlled by providing good temporary restorations and by coating the exposed dentinal tubules of the prepared tooth with dentin bonding agent or dental varnish. Aim The purpose of the study was to determine the effect of dentin-bonding, dentin sealing agents on the microleakage of temporary crowns made by tooth colored auto polymerizing resin fabricated with direct and indirect technique. Materials and Methods Thirty premolar and molar human teeth were collected which were extracted recently was used for the study. The teeth were marked and divided into 3 groups each containing 10 nos. They were individually mounted with self-cure acrylic resin. It was then mounted on a milling machine and crown preparations done. Temporary crowns were fabricated by direct and indirect method with two types of materials. In group A (Control group), the temporary crowns fabricated with both direct and indirect method were cemented directly with temporary luting cement. In group B dentine-bonding agent (solobond M) was applied once to the prepared surface of each tooth specimen before the cementation of temporary crowns where as in case of group C a single layer of dental varnish is applied prior to crown cementation. The entire specimens were immersed in 1% methylene blue and allowed to undergo thermal treatment. It was then sectioned in a hard tissue microtome. Each section was evaluated for dye penetration into the dentin tubules by comparing it with a visual scale. Statistical Analysis SPSS Version 13 software was used for non-parametric data analysis by a qualified statistician. P-values less than 0.05 (p-value<0.05) were considered to be statistically significant. Results Group B (Dentin Bonding Agent) specimens cemented with crowns fabricated in direct technique showed the least amount of microleakage when compared with group A and group C. Group C (Dental Varnish) specimen showed comparatively more amount of microleakage than that of group B. Group A (control group) specimens showed the maximum amount of microleakage. Conclusion The application of a single layer of Dental varnish appears to be of no significant benefit when compared to crowns cemented with the application of Dentin bonding agent on the tooth surface. The application of a single layer of Dentin bonding agent (Solobond M) and temporary crowns fabricated with direct technique may be of some benefit for crown preparations as an interim measure prior to the luting of final crown. PMID:26266219

Autonomous Shepherding Behaviors of Multiple Target Steering Robots.

PubMed

Lee, Wonki; Kim, DaeEun

2017-11-25

This paper presents a distributed coordination methodology for multi-robot systems, based on nearest-neighbor interactions. Among many interesting tasks that may be performed using swarm robots, we propose a biologically-inspired control law for a shepherding task, whereby a group of external agents drives another group of agents to a desired location. First, we generated sheep-like robots that act like a flock. We assume that each agent is capable of measuring the relative location and velocity to each of its neighbors within a limited sensing area. Then, we designed a control strategy for shepherd-like robots that have information regarding where to go and a steering ability to control the flock, according to the robots' position relative to the flock. We define several independent behavior rules; each agent calculates to what extent it will move by summarizing each rule. The flocking sheep agents detect the steering agents and try to avoid them; this tendency leads to movement of the flock. Each steering agent only needs to focus on guiding the nearest flocking agent to the desired location. Without centralized coordination, multiple steering agents produce an arc formation to control the flock effectively. In addition, we propose a new rule for collecting behavior, whereby a scattered flock or multiple flocks are consolidated. From simulation results with multiple robots, we show that each robot performs actions for the shepherding behavior, and only a few steering agents are needed to control the whole flock. The results are displayed in maps that trace the paths of the flock and steering robots. Performance is evaluated via time cost and path accuracy to demonstrate the effectiveness of this approach.

Autonomous Shepherding Behaviors of Multiple Target Steering Robots

PubMed Central

Lee, Wonki; Kim, DaeEun

2017-01-01

This paper presents a distributed coordination methodology for multi-robot systems, based on nearest-neighbor interactions. Among many interesting tasks that may be performed using swarm robots, we propose a biologically-inspired control law for a shepherding task, whereby a group of external agents drives another group of agents to a desired location. First, we generated sheep-like robots that act like a flock. We assume that each agent is capable of measuring the relative location and velocity to each of its neighbors within a limited sensing area. Then, we designed a control strategy for shepherd-like robots that have information regarding where to go and a steering ability to control the flock, according to the robots’ position relative to the flock. We define several independent behavior rules; each agent calculates to what extent it will move by summarizing each rule. The flocking sheep agents detect the steering agents and try to avoid them; this tendency leads to movement of the flock. Each steering agent only needs to focus on guiding the nearest flocking agent to the desired location. Without centralized coordination, multiple steering agents produce an arc formation to control the flock effectively. In addition, we propose a new rule for collecting behavior, whereby a scattered flock or multiple flocks are consolidated. From simulation results with multiple robots, we show that each robot performs actions for the shepherding behavior, and only a few steering agents are needed to control the whole flock. The results are displayed in maps that trace the paths of the flock and steering robots. Performance is evaluated via time cost and path accuracy to demonstrate the effectiveness of this approach. PMID:29186836

Self Organized Multi Agent Swarms (SOMAS) for Network Security Control

DTIC Science & Technology

2009-03-01

Normal hierarchy vs entangled hierarchy 2.5.7 Quantifying Entangledness . While self organization means that the swarm develops a consistent structure of...flexibility due to centralization of control and com- munication. Thus, self organized, entangled hierarchy multi-agent swarms are evolved in this study to...technique. The resulting design exhibits a self organized multi-agent swarm (SOMAS) with entangled hierarchical control and communication through the

Evasion in the plane

NASA Technical Reports Server (NTRS)

Leitmann, G.; Liu, H. S.

1977-01-01

Dynamic systems were considered subject to control by two agents, one of whom desires that no trajectory of the system emanating from outside a given set, intersects that set no matter what the admissible actions of the other agent. Constructive conditions sufficient to yield a feedback control for the agent seeking avoidance were employed to deduce an evader control for the planar pursuit-evasion problem with bounded normal accelerations.

Chelant Enhanced Solution Processing for Wafer Scale Synthesis of Transition Metal Dichalcogenide Thin Films.

PubMed

Ionescu, Robert; Campbell, Brennan; Wu, Ryan; Aytan, Ece; Patalano, Andrew; Ruiz, Isaac; Howell, Stephen W; McDonald, Anthony E; Beechem, Thomas E; Mkhoyan, K Andre; Ozkan, Mihrimah; Ozkan, Cengiz S

2017-07-25

It is of paramount importance to improve the control over large area growth of high quality molybdenum disulfide (MoS 2 ) and other types of 2D dichalcogenides. Such atomically thin materials have great potential for use in electronics, and are thought to make possible the first real applications of spintronics. Here in, a facile and reproducible method of producing wafer scale atomically thin MoS 2 layers has been developed using the incorporation of a chelating agent in a common organic solvent, dimethyl sulfoxide (DMSO). Previously, solution processing of a MoS 2 precursor, ammonium tetrathiomolybdate ((NH 4 ) 2 MoS 4 ), and subsequent thermolysis was used to produce large area MoS 2 layers. Our work here shows that the use of ethylenediaminetetraacetic acid (EDTA) in DMSO exerts superior control over wafer coverage and film thickness, and the results demonstrate that the chelating action and dispersing effect of EDTA is critical in growing uniform films. Raman spectroscopy, photoluminescence (PL), x-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM) and high-resolution scanning transmission electron microscopy (HR-STEM) indicate the formation of homogenous few layer MoS 2 films at the wafer scale, resulting from the novel chelant-in-solution method.

FGD Additives to Segregate and Sequester Mercury in Solid Byproducts - Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Searcy, K; Bltyhe, G M; Steen, W A

2012-02-28

Many mercury control strategies for U.S. coal-fired power generating plants involve co-benefit capture of oxidized mercury from flue gases treated by wet flue gas desulfurization (FGD) systems. For these processes to be effective at overall mercury control, the captured mercury must not be re-emitted to the atmosphere or into surface or ground water. The project sought to identify scrubber additives and FGD operating conditions under which mercury re-emissions would decrease and mercury would remain in the liquor and be blown down from the system in the chloride purge stream. After exiting the FGD system, mercury would react with precipitating agentsmore » to form stable solid byproducts and would be removed in a dewatering step. The FGD gypsum solids, free of most of the mercury, could then be disposed or processed for reuse as wallboard or in other beneficial reuse. The project comprised extensive bench-scale FGD scrubber tests in Phases I and II. During Phase II, the approaches developed at the bench scale were tested at the pilot scale. Laboratory wastewater treatment tests measured the performance of precipitating agents in removing mercury from the chloride purge stream. Finally, the economic viability of the approaches tested was evaluated.« less

Biological control agents elevate hantavirus by subsidizing deer mouse populations.

PubMed

Pearson, Dean E; Callaway, Ragan M

2006-04-01

Biological control of exotic invasive plants using exotic insects is practiced under the assumption that biological control agents are safe if they do not directly attack non-target species. We tested this assumption by evaluating the potential for two host-specific biological control agents (Urophora spp.), widely established in North America for spotted knapweed (Centaurea maculosa) control, to indirectly elevate Sin Nombre hantavirus by providing food subsidies to populations of deer mice (Peromyscus maniculatus), the primary reservoir for the virus. We show that seropositive deer mice (mice testing positive for hantavirus) were over three times more abundant in the presence of the biocontrol food subsidy. Elevating densities of seropositive mice may increase risk of hantavirus infection in humans and significantly alter hantavirus ecology. Host specificity alone does not ensure safe biological control. To minimize indirect risks to non-target species, biological control agents must suppress pest populations enough to reduce their own numbers.

Surveys for Biological Control Agents of Hydrilla verticillata in the People’s Republic of China in 2013

DTIC Science & Technology

2017-03-01

Hydrilla was rare at this site and only male plants were collected at 0.5-1 m from shore and a depth of 0.5-1m. The lake/wetlands were explored by boat...ER D C/ EL T R- 17 -3 Aquatic Plant Control Research Program Surveys for Biological Control Agents of Hydrilla verticillata in the...acwc.sdp.sirsi.net/client/default. Aquatic Plant Control Research Program ERDC/EL TR-17-3 March 2017 Surveys for Biological Control Agents of

An equation-free approach to agent-based computation: Bifurcation analysis and control of stationary states

NASA Astrophysics Data System (ADS)

Siettos, C. I.; Gear, C. W.; Kevrekidis, I. G.

2012-08-01

We show how the equation-free approach can be exploited to enable agent-based simulators to perform system-level computations such as bifurcation, stability analysis and controller design. We illustrate these tasks through an event-driven agent-based model describing the dynamic behaviour of many interacting investors in the presence of mimesis. Using short bursts of appropriately initialized runs of the detailed, agent-based simulator, we construct the coarse-grained bifurcation diagram of the (expected) density of agents and investigate the stability of its multiple solution branches. When the mimetic coupling between agents becomes strong enough, the stable stationary state loses its stability at a coarse turning point bifurcation. We also demonstrate how the framework can be used to design a wash-out dynamic controller that stabilizes open-loop unstable stationary states even under model uncertainty.

Stationary average consensus protocol for a class of heterogeneous high-order multi-agent systems with application for aircraft

NASA Astrophysics Data System (ADS)

Rezaei, Mohammad Hadi; Menhaj, Mohammad Bagher

2018-01-01

This paper investigates the stationary average consensus problem for a class of heterogeneous-order multi-agent systems. The goal is to bring the positions of agents to the average of their initial positions while letting the other states converge to zero. To this end, three different consensus protocols are proposed. First, based on the auxiliary variables information among the agents under switching directed networks and state-feedback control, a protocol is proposed whereby all the agents achieve stationary average consensus. In the second and third protocols, by resorting to only measurements of relative positions of neighbouring agents under fixed balanced directed networks, two control frameworks are presented with two strategies based on state-feedback and output-feedback control. Finally, simulation results are given to illustrate the effectiveness of the proposed protocols.

Effect of Antithrombotic Agents on the Patency of PTFE-Covered Stents in the Inferior Vena Cava: An Experimental Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makutani, Shiro; Kichikawa, Kimihiko; Uchida, Hideo

Purpose: To evaluate the efficacy of antithrombotic agents in the prevention of stenosis of polytetrafluoroethylene (PTFE)-covered stents in the venous system. Methods: Spiral Z stents covered with PTFE (PTFE-covered stents) were placed in the inferior vena cava (IVC) of 34 dogs. Nineteen dogs, used as a control group, were sacrificed at 2, 4, and 12 weeks. Fifteen dogs, previously given antithrombotic agents [cilostazol (n= 5), warfarin potassium (n= 5), cilostazol plus warfarin potassium (n= 5)] were sacrificed at 4 weeks, and then examined angiographically and histopathologically. The effect of the antithrombotic agents was compared between groups. Results: The patency ratemore » of the antithrombotic agent group was 93% (14/15), which was higher than the control group rate of 63% (12/19). The mean stenosis rate of the patent stent at both ends and at the midportion was lower at 4 weeks in the antithrombotic agent group than in the control group. In particular, the mean stenosis rate in the cilostazol plus warfarin potassium group was significantly lower than the control group (Tukey's test, p < 0.05). The mean neointimal thickness of the patent stent at both ends and at the midportion was thinner at 4 weeks in the antithrombotic agent group than in the control group. In particular, the thickness of the neointima in the cilostazol plus warfarin potassium group was significantly decreased when compared with the control group (Tukey's test p < 0.05). At 4 weeks, endothelialization in the antithrombotic agent group tended to be almost identical to that in the control group. Conclusion: The present study suggests that administration of an antithrombotic agent is an effective way of preventing the stenosis induced by a neointimal thickening of PTFE-covered stents in the venous system.« less

Randomized, Double-Blind, Split-Face Study Evaluating Fractional Ablative Erbium:YAG Laser-Mediated Trans-Epidermal Delivery of Cosmetic Actives and a Novel Acoustic Pressure Wave Ultrasound Technology for the Treatment of Skin Aging, Melasma, and Acne Scars.

PubMed

Alexiades, Macrene

2015-11-01

Fractional laser resurfacing enhances trans-epidermal delivery (TED), however laser penetration depths >250- μm fail to substantively increase drug delivery. Evaluate the safety and efficacy of a novel acoustic pressure wave ultrasound device following fractional ablative Er:YAG 2940-nm laser (FELR) and topical agents for rhytids, melasma, and acne scars. Randomized, blinded, parallel group split-face side-by-side, controlled study evaluating FELR and topical anti-aging and anti-pigment agents to entire face succeeded by ultrasound to randomized side. Fifteen subjects were enrolled to three treatment arms:rhytids, melasma, and acne scars. Two monthly treatments were administered with 1, 3, and 6 month follow-up. Efficacy was assessed by Comprehensive Grading Scale of Rhytids, Laxity, and Photoaging by Investigator and two blinded physician evaluators. Subject assessments, digital photographs, and reflectance spectroscopic analyses were obtained. Rhytid severity was reduced from a mean of 3.25 to 2.60 on the 4-point grading scale. Spectrophotometric analysis demonstrated increases in lightness (L*) and reductions in redness (a*) and pigment (b*), with greater improvements on the ultrasound side as compared to FELR and topicals alone. Moderate erythema post-treatment resolved in 7 days and no serious adverse events were observed. In this randomized, paired split-face clinical study, FELR-facilitated TED of topical anti-aging actives with ultrasound treatment is safe and effective with improvement in rhytids, melasma, and acne scars. Statistically significant greater improvement in pigment levels was observed on the ultrasound side as compared to FELR-TED and topical agents alone.

Low-cost periodontal therapy.

PubMed

Slots, Jørgen

2012-10-01

Periodontitis is a complex infectious disease that affects low-income individuals disproportionately. Periodontitis is associated with specific bacterial species and herpesviruses, and successful prevention and treatment of the disease is contingent upon effective control of these pathogens. This article presents an efficacious, highly safe, minimally invasive, practical and low-cost periodontal therapy that involves professional and patient-administered mechanical therapy and antimicrobial agents. The major components are scaling for calculus removal, periodontal pocket irrigation with potent antiseptics, and treatment with systemic antibiotics for advanced disease. Povidone-iodine and sodium hypochlorite have all the characteristics for becoming the first-choice antiseptics in the management of periodontal diseases. Both agents show excellent antibacterial and antiviral properties, are readily available throughout the world, have been safely used in periodontal therapy for decades, offer significant benefits for individuals with very limited financial resources, and are well accepted by most dental professionals and patients. Four per cent chlorhexidine applied with a toothbrush to the most posterior part to the tongue dorsum can markedly reduce or eliminate halitosis in most individuals. Systemic antibiotics are used to treat periodontopathic bacteria that are not readily reached by topical therapy, such as pathogens within gingival tissue, within furcation defects, at the base of periodontal pockets, and on the tongue, tonsils and buccal mucosae. Valuable antibiotic therapies are amoxicillin-metronidazole (250 mg of amoxicillin and 250 mg of metronidazole, three times daily for 8 days) for young and middle-aged patients, and ciprofloxacin-metronidazole (500 mg of each, twice daily for 8 days) for elderly patients and for patients in developing countries who frequently harbor enteric rods subgingivally. Scaling to remove dental calculus and the prudent use of inexpensive antimicrobial agents can significantly retard or arrest progressive periodontitis in the great majority of patients. © 2012 John Wiley & Sons A/S.

Hierarchically controlled remote preparation of an arbitrary single-qubit state by using a four-qubit |χ > entangled state

NASA Astrophysics Data System (ADS)

Ma, Peng-Cheng; Chen, Gui-Bin; Li, Xiao-Wei; Zhan, You-Bang

2018-05-01

In this paper, we present a scheme for Hierarchically controlled remote preparation of an arbitrary single-qubit state via a four-qubit |χ > state as the quantum channel. In this scheme, a sender wishes to help three agents to remotely prepare a quantum state, respectively. The three agents are divided into two grades, that is, an agent is in the upper grade and other two agents are in the lower grade. It is shown that the agent of the upper grade only needs the assistance of any one of the other two agents for recovering the sender's original state, while an agent of the lower grade needs the collaboration of all the other two agents. In other words, the agents of two grades have different authorities to recover sender's original state.

Development of an animal model of fibrous cholangitis in pigs.

PubMed

Lainakis, Nektarios G; Papalois, Apostolos; Agrogiannis, Georgios; Antonopoulos, Constantine N; Michail, Panagiotis; Bastounis, Elias; Patsouris, Efstathios; Felekouras, Evangelos

2014-04-01

The aim of this study was to develop a model of fibrous cholangitis in the offspring of gravid domestic pigs through the administration of 1,4-phenylene diisothiocyanate (DITC). Six young domestic pigs and two gravid pigs with their offspring (21 pigs) were used as experimental models and six wild-type animals were used as controls. All pigs were divided into five main groups and five subgroups, according to their developmental stage and time of exposure to DITC. The following histopathological characteristics were quantitatively evaluated on a scale of 0-5: ductal proliferation, periportal fibrosis, inflammatory infiltration, periductal fibrosis and edema, intraluminal fibrosis, duct wall thickening, epithelial apoptosis, and arterial hyperplasia/hypertrophy. Statistically significant differences were observed for most of the histopathological markers between the group of pigs' offspring that received DITC at early gestation and their control group. Moreover, the group of animals that were exposed to the agent at early gestation exhibited significant differences for all histopathological characteristics compared to the animals that were exposed at late gestation. On the other hand, no statistically significant differences were observed between the group of animals that received the agent at late gestation and their healthy controls. Administration of DITC to domestic pigs in early pregnancy may induce histopathological patterns of fibrous cholangitis to their offspring imitating biliary atresia. This model may provide insight to the pathogenesis of the obstructive cholangitis in pigs.

Scaling up as Catachresis

ERIC Educational Resources Information Center

Tobin, Joseph

2005-01-01

The metaphor of scaling up is the wrong one to use for describing and prescribing educational change. Many of the strategies being employed to achieve scaling up are counter-productive: they conceive of practitioners as delivery agents or consumers, rather than as co-constructors of change. An approach to educational innovation based on the…

Remote Agent Demonstration

NASA Technical Reports Server (NTRS)

Dorais, Gregory A.; Kurien, James; Rajan, Kanna

1999-01-01

We describe the computer demonstration of the Remote Agent Experiment (RAX). The Remote Agent is a high-level, model-based, autonomous control agent being validated on the NASA Deep Space 1 spacecraft.

Intensified agriculture favors evolved resistance to biological control.

PubMed

Tomasetto, Federico; Tylianakis, Jason M; Reale, Marco; Wratten, Steve; Goldson, Stephen L

2017-04-11

Increased regulation of chemical pesticides and rapid evolution of pesticide resistance have increased calls for sustainable pest management. Biological control offers sustainable pest suppression, partly because evolution of resistance to predators and parasitoids is prevented by several factors (e.g., spatial or temporal refuges from attacks, reciprocal evolution by control agents, and contrasting selection pressures from other enemy species). However, evolution of resistance may become more probable as agricultural intensification reduces the availability of refuges and diversity of enemy species, or if control agents have genetic barriers to evolution. Here we use 21 y of field data from 196 sites across New Zealand to show that parasitism of a key pasture pest ( Listronotus bonariensis ; Argentine stem weevil) by an introduced parasitoid ( Microctonus hyperodae ) was initially nationally successful but then declined by 44% (leading to pasture damage of c. 160 million New Zealand dollars per annum). This decline was not attributable to parasitoid numbers released, elevation, or local climatic variables at sample locations. Rather, in all locations the decline began 7 y (14 host generations) following parasitoid introduction, despite releases being staggered across locations in different years. Finally, we demonstrate experimentally that declining parasitism rates occurred in ryegrass Lolium perenne , which is grown nationwide in high-intensity was significantly less than in adjacent plots of a less-common pasture grass ( Lolium multiflorum ), indicating that resistance to parasitism is host plant-dependent. We conclude that low plant and enemy biodiversity in intensive large-scale agriculture may facilitate the evolution of host resistance by pests and threaten the long-term viability of biological control.

Comparing large-scale computational approaches to epidemic modeling: agent-based versus structured metapopulation models.

PubMed

Ajelli, Marco; Gonçalves, Bruno; Balcan, Duygu; Colizza, Vittoria; Hu, Hao; Ramasco, José J; Merler, Stefano; Vespignani, Alessandro

2010-06-29

In recent years large-scale computational models for the realistic simulation of epidemic outbreaks have been used with increased frequency. Methodologies adapt to the scale of interest and range from very detailed agent-based models to spatially-structured metapopulation models. One major issue thus concerns to what extent the geotemporal spreading pattern found by different modeling approaches may differ and depend on the different approximations and assumptions used. We provide for the first time a side-by-side comparison of the results obtained with a stochastic agent-based model and a structured metapopulation stochastic model for the progression of a baseline pandemic event in Italy, a large and geographically heterogeneous European country. The agent-based model is based on the explicit representation of the Italian population through highly detailed data on the socio-demographic structure. The metapopulation simulations use the GLobal Epidemic and Mobility (GLEaM) model, based on high-resolution census data worldwide, and integrating airline travel flow data with short-range human mobility patterns at the global scale. The model also considers age structure data for Italy. GLEaM and the agent-based models are synchronized in their initial conditions by using the same disease parameterization, and by defining the same importation of infected cases from international travels. The results obtained show that both models provide epidemic patterns that are in very good agreement at the granularity levels accessible by both approaches, with differences in peak timing on the order of a few days. The relative difference of the epidemic size depends on the basic reproductive ratio, R0, and on the fact that the metapopulation model consistently yields a larger incidence than the agent-based model, as expected due to the differences in the structure in the intra-population contact pattern of the approaches. The age breakdown analysis shows that similar attack rates are obtained for the younger age classes. The good agreement between the two modeling approaches is very important for defining the tradeoff between data availability and the information provided by the models. The results we present define the possibility of hybrid models combining the agent-based and the metapopulation approaches according to the available data and computational resources.

75 FR 28232 - Availability of an Environmental Assessment for a Biological Control Agent for Hemlock Woolly...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-20

... conditions. Existing HWA management options include chemical control and silvicultural control, which, in...] Availability of an Environmental Assessment for a Biological Control Agent for Hemlock Woolly Adelgid AGENCY... environmental assessment relative to the control of hemlock woolly adelgid (Adelges tsugae). The environmental...

Fitness voter model: Damped oscillations and anomalous consensus.

PubMed

Woolcock, Anthony; Connaughton, Colm; Merali, Yasmin; Vazquez, Federico

2017-09-01

We study the dynamics of opinion formation in a heterogeneous voter model on a complete graph, in which each agent is endowed with an integer fitness parameter k≥0, in addition to its + or - opinion state. The evolution of the distribution of k-values and the opinion dynamics are coupled together, so as to allow the system to dynamically develop heterogeneity and memory in a simple way. When two agents with different opinions interact, their k-values are compared, and with probability p the agent with the lower value adopts the opinion of the one with the higher value, while with probability 1-p the opposite happens. The agent that keeps its opinion (winning agent) increments its k-value by one. We study the dynamics of the system in the entire 0≤p≤1 range and compare with the case p=1/2, in which opinions are decoupled from the k-values and the dynamics is equivalent to that of the standard voter model. When 0≤p<1/2, agents with higher k-values are less persuasive, and the system approaches exponentially fast to the consensus state of the initial majority opinion. The mean consensus time τ appears to grow logarithmically with the number of agents N, and it is greatly decreased relative to the linear behavior τ∼N found in the standard voter model. When 1/2

Research on ultrasonic excitation for the removal of drilling fluid plug, paraffin deposition plug, polymer plug and inorganic scale plug for near-well ultrasonic processing technology.

PubMed

Wang, Zhenjun; Zeng, Jing; Song, Hao; Li, Feng

2017-05-01

Near-well ultrasonic processing technology attracts more attention due to its simple operation, high adaptability, low cost and no pollution to the formation. Although this technology has been investigated in detail through laboratory experiments and field tests, systematic and intensive researches are absent for certain major aspects, such as whether ultrasonic excitation is better than chemical agent for any plugs removal; whether ultrasound-chemical combination plug removal technology has the best plugs removal effect. In this paper, the comparison of removing drilling fluid plug, paraffin deposition plug, polymer plug and inorganic scale plug using ultrasonic excitation, chemical agent and ultrasound-chemical combination plug removal technology is investigated. Results show that the initial core permeability and ultrasonic frequency play a significant role in plug removal. Ultrasonic excitation and chemical agent have different impact on different plugs. The comparison results show that the effect of removing any plugs using ultrasound-chemicals composite plug removal technology is obviously better than that using ultrasonic excitation or chemical agent alone. Such conclusion proves that ultrasonic excitation and chemical agent can cause synergetic effects. Copyright © 2016 Elsevier B.V. All rights reserved.

Transmission, Human Population, and Pathogenicity: the Ebola Case in Point.

PubMed

Delgado, Rafael; Simón, Fernando

2018-03-01

The 2013-2016 Ebola outbreak in West Africa has been the largest ever of a known disease in a new context that produced an unprecedented impact and is changing the international approach to responding to public health emergencies. The unprecedented scale of the outbreak, the use of advanced technology for detecting and characterizing the infectious agent, along with the opportunity to treat patients in modern facilities have greatly increased our knowledge of the disease and its transmission. Also, for the first time, an important international effort has been deployed to control the spread of the epidemic by providing care to patients and by adopting basic measures of public health control. Apart from supportive treatment and intensive therapy with fluids and electrolytes, no new compounds have been proved to be clinically effective to treat Ebola virus disease; however, a specific vaccine has shown significant protection in clinical trials in Guinea, opening an expectation for controlling future outbreaks.

The agent-based spatial information semantic grid

NASA Astrophysics Data System (ADS)

Cui, Wei; Zhu, YaQiong; Zhou, Yong; Li, Deren

2006-10-01

Analyzing the characteristic of multi-Agent and geographic Ontology, The concept of the Agent-based Spatial Information Semantic Grid (ASISG) is defined and the architecture of the ASISG is advanced. ASISG is composed with Multi-Agents and geographic Ontology. The Multi-Agent Systems are composed with User Agents, General Ontology Agent, Geo-Agents, Broker Agents, Resource Agents, Spatial Data Analysis Agents, Spatial Data Access Agents, Task Execution Agent and Monitor Agent. The architecture of ASISG have three layers, they are the fabric layer, the grid management layer and the application layer. The fabric layer what is composed with Data Access Agent, Resource Agent and Geo-Agent encapsulates the data of spatial information system so that exhibits a conceptual interface for the Grid management layer. The Grid management layer, which is composed with General Ontology Agent, Task Execution Agent and Monitor Agent and Data Analysis Agent, used a hybrid method to manage all resources that were registered in a General Ontology Agent that is described by a General Ontology System. The hybrid method is assembled by resource dissemination and resource discovery. The resource dissemination push resource from Local Ontology Agent to General Ontology Agent and the resource discovery pull resource from the General Ontology Agent to Local Ontology Agents. The Local Ontology Agent is derived from special domain and describes the semantic information of local GIS. The nature of the Local Ontology Agents can be filtrated to construct a virtual organization what could provides a global scheme. The virtual organization lightens the burdens of guests because they need not search information site by site manually. The application layer what is composed with User Agent, Geo-Agent and Task Execution Agent can apply a corresponding interface to a domain user. The functions that ASISG should provide are: 1) It integrates different spatial information systems on the semantic The Grid management layer establishes a virtual environment that integrates seamlessly all GIS notes. 2) When the resource management system searches data on different spatial information systems, it transfers the meaning of different Local Ontology Agents rather than access data directly. So the ability of search and query can be said to be on the semantic level. 3) The data access procedure is transparent to guests, that is, they could access the information from remote site as current disk because the General Ontology Agent could automatically link data by the Data Agents that link the Ontology concept to GIS data. 4) The capability of processing massive spatial data. Storing, accessing and managing massive spatial data from TB to PB; efficiently analyzing and processing spatial data to produce model, information and knowledge; and providing 3D and multimedia visualization services. 5) The capability of high performance computing and processing on spatial information. Solving spatial problems with high precision, high quality, and on a large scale; and process spatial information in real time or on time, with high-speed and high efficiency. 6) The capability of sharing spatial resources. The distributed heterogeneous spatial information resources are Shared and realizing integrated and inter-operated on semantic level, so as to make best use of spatial information resources,such as computing resources, storage devices, spatial data (integrating from GIS, RS and GPS), spatial applications and services, GIS platforms, 7) The capability of integrating legacy GIS system. A ASISG can not only be used to construct new advanced spatial application systems, but also integrate legacy GIS system, so as to keep extensibility and inheritance and guarantee investment of users. 8) The capability of collaboration. Large-scale spatial information applications and services always involve different departments in different geographic places, so remote and uniform services are needed. 9) The capability of supporting integration of heterogeneous systems. Large-scale spatial information systems are always synthetically applications, so ASISG should provide interoperation and consistency through adopting open and applied technology standards. 10) The capability of adapting dynamic changes. Business requirements, application patterns, management strategies, and IT products always change endlessly for any departments, so ASISG should be self-adaptive. Two examples are provided in this paper, those examples provide a detailed way on how you design your semantic grid based on Multi-Agent systems and Ontology. In conclusion, the semantic grid of spatial information system could improve the ability of the integration and interoperability of spatial information grid.

46 CFR 185.612 - Fire protection equipment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... releasing the extinguishing agent should the local manual release or stop valve controls fail to operate... at or near each pull box and stop valve control and in the space where the extinguishing agent...-VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED”. Where a different extinguishing agent is installed, that...

Engineering of Paraoxonases for Pre- and Post-treatment of Intoxication by a Broad Spectrum of Nerve Agents and Pesticides

DTIC Science & Technology

2014-08-01

chemical warfare nerve agents (CWNA). Enzymes identified in these screens should be capable of catalytically neutralizing the target agent under...soluble form. 4. Large-scale production of selected enzyme candidates, and their kinetic, structural and pharmacological evaluation 6...employed, with an enzyme protein concentration of 0.5-2 mM in the assay cuvette, the activity measured was indistinguishable from the rate of

Probable hypoglycemic adverse drug reaction associated with prickly pear cactus, glipizide, and metformin in a patient with type 2 diabetes mellitus.

PubMed

Sobieraj, Diana M; Freyer, Craig W

2010-01-01

To report a case of an adverse drug reaction (ADR) in a patient with type 2 diabetes mellitus taking prickly pear cactus (PPC), glipizide, and metformin. A 58-year-old Mexican male with type 2 diabetes mellitus being treated with metformin 1000 mg twice daily and extended-release glipizide 10 mg daily was referred to the pharmacist for medication education. He denied taking herbal supplements or experiencing hypoglycemia. Two hemoglobin A(1c) values (6.8% and 6.7%) obtained over the past year demonstrated glycemic control, which was supported by his reported fasting blood glucose readings of 113-132 mg/dL. One month later, the patient reported 4 hypoglycemic events with blood glucose readings of 49-68 mg/dL, which resulted in discontinuation of glipizide. One month later, the patient denied any further hypoglycemia. During medication reconciliation he reported consuming crude PPC pads daily for 2 months for glucose control. Literature suggests that PPC has an effect on lowering blood glucose levels in patients with type 2 diabetes mellitus, although few identified data describe ADRs from combining PPC with other agents used in treating type 2 diabetes mellitus. A literature search of MEDLINE (through December 2009) using the search terms diabetes mellitus, prickly pear cactus, nopal, opuntia, metformin, glipizide, glyburide, glimepiride, and sulfonylurea revealed no case reports of the described ADR. One case report describing the blood glucose-lowering effect of PPC in a patient concurrently taking oral antihyperglycemics documented an episode of hypoglycemia, although the Naranjo probability scale was not applied. One patient survey discovered the most common drug-herbal interaction in the given population to be between PPC and antihyperglycemic agents, resulting in hypoglycemia. In our case, use of the Naranjo probability scale suggests the ADR to be probable. The mechanism may be due to the additive glucose lowering of the 3 agents consumed concurrently by the patient. Patients with type 2 diabetes mellitus should be routinely counseled about the use of herbal products to minimize the risk of ADRs.

Nanostructuring of Aluminum Alloy Powders by Cryogenic Attrition with Hydrogen-Free Process Control Agent

DTIC Science & Technology

2015-02-01

Nanostructuring of Aluminum Alloy Powders by Cryogenic Attrition with Hydrogen-Free Process Control Agent by Frank Kellogg , Clara Hofmeister...Process Control Agent Frank Kellogg Bowhead Science and Technology Clara Hofmeister Advanced Materials Processing and Analysis Center...NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Frank Kellogg , Clara Hofmeister, Anit Giri, and Kyu Cho 5d. PROJECT NUMBER 5e

A Quantum Approach to Multi-Agent Systems (MAS), Organizations, and Control

DTIC Science & Technology

2003-06-01

interdependent interactions between individuals represented approximately as vocal harmonic I resonators. Then the growth rate of an organization fits ...A quantum approach to multi-agent systems (MAS), organizations , and control W.F. Lawless Paine College 1235 15th Street Augusta, GA 30901...AND SUBTITLE A quantum approach to multi-agent systems (MAS), organizations , and control 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT

Many-Agent Controlled Teleportation of Multi-qubit Quantum Information via Quantum Entanglement Swapping

NASA Astrophysics Data System (ADS)

Zhang, Zhan-Jun; Liu, Yi-Min; Man, Zhong-Xiao

2005-11-01

We present a method to teleport multi-qubit quantum information in an easy way from a sender to a receiver via the control of many agents in a network. Only when all the agents collaborate with the quantum information receiver can the unknown states in the sender's qubits be fully reconstructed in the receiver's qubits. In our method, agents's control parameters are obtained via quantum entanglement swapping. As the realization of the many-agent controlled teleportation is concerned, compared to the recent method [C.P. Yang, et al., Phys. Rev. A 70 (2004) 022329], our present method considerably reduces the preparation difficulty of initial states and the identification difficulty of entangled states, moreover, it does not need local Hadamard operations and it is more feasible in technology. The project supported by National Natural Science Foundation of China under Grant No. 10304022

A Real-Time Rover Executive based On Model-Based Reactive Planning

NASA Technical Reports Server (NTRS)

Bias, M. Bernardine; Lemai, Solange; Muscettola, Nicola; Korsmeyer, David (Technical Monitor)

2003-01-01

This paper reports on the experimental verification of the ability of IDEA (Intelligent Distributed Execution Architecture) effectively operate at multiple levels of abstraction in an autonomous control system. The basic hypothesis of IDEA is that a large control system can be structured as a collection of interacting control agents, each organized around the same fundamental structure. Two IDEA agents, a system-level agent and a mission-level agent, are designed and implemented to autonomously control the K9 rover in real-time. The system is evaluated in the scenario where the rover must acquire images from a specified set of locations. The IDEA agents are responsible for enabling the rover to achieve its goals while monitoring the execution and safety of the rover and recovering from dangerous states when necessary. Experiments carried out both in simulation and on the physical rover, produced highly promising results.

Flower-like NiO structures: Controlled hydrothermal synthesis and electrochemical characteristic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chai, Hui; Chen, Xuan; Key Laboratory of Advanced Functional Materials, Institute of Applied Chemistry, Xinjiang University, Urumqi 830046, Xinjiang

Graphical abstract: Flower-like porous NiO was obtained via thermal decomposition of the precursor prepared by a hydrothermal process using hexamethylenetetramine and polyethylene glycol as hydrolysis-controlling agent and surfactant, respectively. The morphology and microstructure of as-synthesized NiO were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results of electrochemical measurements demonstrated that the flower-like porous NiO has high capacity (340 F g{sup −1}) with excellent cycling performance as electrode materials of electrochemical capacitors (ECs), which may be attributed to the unique microstrcture of NiO. Data analyses indicated that NiO with novel porousmore » structure attractive for practical and large-scale applications in electrochemical capacitors. Display Omitted Highlights: ► Synthesis and characterization of NiO with novel porous structure is presented in this work. ► The electrochemical performance of product was examined. ► NiO with excellent performance as electrode materials may be due to the unique microstrcture. ► NiO with novel porous structure attractive for practical with high capacity (340 F g{sup −1}). -- Abstract: Flower-like porous NiO was obtained by thermal decomposition of the precursor prepared by a hydrothermal process with hexamethylenetetramine and polyethylene glycol as hydrolysis-controlling agent and surfactant, respectively. The morphology and microstructure of as-synthesized NiO were characterized by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The resulting structures of NiO exhibited porous like petal building blocks. The electrochemical measurements’ results demonstrated that flower-like porous NiO has high capacity (340 F g{sup −1}) with excellent cycling performance as electrode materials for electrochemical capacitors, which may be attributed to the unique structure of NiO. The results indicated that NiO with novel porous structure has been attractive for practical and large-scale applications in electrochemical capacitors.« less

Biocontrol of fouling pests: Effect of diversity, identity and density of control agents.

PubMed

Atalah, Javier; Newcombe, Emma M; Zaiko, Anastasija

2016-04-01

Augmentative biocontrol, using native natural enemies, has been suggested as a promising tool to control marine biofouling pests on artificial structures. However, there are still important knowledge gaps to be addressed before biocontrol can be considered as a management tool. In a field experiment on floating marine structures we examined intra- and interspecific consumer interactions among biocontrol agents on different surface orientations. We tested the effect of identity, density and diversity of three invertebrates (the 11-arm seastar Coscinasterias muricata, the sea urchin Evechinus chloroticus and the gastropod Cook's turban Cookia sulcata) to reduce established biofouling and to prevent fouling growth on defouled surfaces. High densities of biocontrol agents were not more effective at fouling control (cover and biomass) than low densities. Nor did multi-species treatments function more effectively than mono-specific ones. However, biocontrol agent identity was important, with the 11-arm seastar and Cook's turban being the most effective at fouling reduction and prevention, respectively. Surface orientation had a strong effect on the effectiveness of control agents, with the best results obtained on vertical compared to diagonal and underside surfaces. This study confirmed the potential of biocontrol as a management tool for marine pest, indicating that identity is more important than richness and density of control agents. It also highlighted the limitations of this approach on diagonal and underside surfaces, where control agents have limited retention ability. Copyright © 2016 Elsevier Ltd. All rights reserved.

State-wide hospital clinical laboratory plan for measuring cholinesterase activity for individuals suspected of exposure to nerve agent chemical weapons.

PubMed

Wu, Alan H B; Smith, Andrew; McComb, Robert; Bowers, George N; Makowski, Gregory S; McKay, Charles A; Vena, Jason; McDonagh, John; Hopfer, Sidney; Sena, Salvatore F; Malkus, Herbert; Forte, Elaine; Kelly, Katherine

2008-02-01

Hospital laboratories currently lack the capacity to provide emergency determination of cholinesterase activity. We have developed a hospital-based 3-tiered system to test plasma for butyrylcholinesterase (BChE) activity and whole blood for red cell acetylcholinesterase (AChE) activity using available technology and personnel. Interagency communications, toxidrome definition, and patient triage will be coordinated by the Connecticut Department of Public Health and the Poison Control Center. Initial BChE data documents good precision between institutions (coefficient of variation < 8%). Laboratory testing of plasma or blood for cholinesterase activity is important in the management of nerve agent exposure and in ruling out disease in those with non-specific symptoms in the setting of a terrorist attack or accidental exposure. Rapid availability of strong hospital-based analytic support in a smoothly functioning network of clinical, public health, and laboratory services will facilitate overall regional response to chemical terrorism or large scale HazMat events.

Fall Risk Assessment in Geriatric-Psychiatric Inpatients to Lower Events (FRAGILE).

PubMed

Nanda, Sudip; Dey, Tanujit; Gulstrand, Rudolph E; Cudnik, Daniel; Haller, Harold S

2011-02-01

The objectives of this retrospective case-control study were to identify risk factors of falls in geriatric-psychiatric inpatients and develop a screening tool to accurately predict falls. The study sample consisted of 225 geriatric-psychiatric inpatients at a Midwestern referral facility. The sample included 136 inpatients who fell and a random stratified sample of 89 inpatients who did not fall. Data collected included age, gender, activities of daily living, and nursing parameters such as bathing assistance, bed height, use of bed rails, one-on-one observation, fall warning system, Conley Scale fall risk assessment, medical diagnosis, and medications. History of falls, impaired judgment, impaired gait, dizziness, delusions, delirium, chronic use of sedative or antipsychotic agents, and anticholinergic urinary bladder medications significantly increased fall risk. Alzheimer's disease, acute use of sedative or anti-psychotic agents, and depression reduced fall risk. A falls risk tool, Fall Risk Assessment in Geriatric-psychiatric Inpatients to Lower Events (FRAGILE), was developed for assessment and risk stratification with new diagnoses or medications. Copyright 2011, SLACK Incorporated.

Reprint of: Clinical management of tardive dyskinesia: Five steps to success.

PubMed

Citrome, Leslie

2018-06-15

Tardive dyskinesia (TD) has long been thought to be a generally irreversible consequence of the use of dopamine receptor blocking agents. There is now an opportunity to successfully manage this condition with agents approved by the US Food and Drug Administration. This is important because TD has not been eliminated with the use of second-generation antipsychotics, and the expansion of antipsychotics to treat conditions other than schizophrenia has resulted in millions of additional individuals at risk for developing TD. Recognition of TD requires careful observation; a structured approach using the Abnormal Involuntary Movement Scale is encouraged. Harm reduction can be achieved by using antipsychotics judiciously when possible and by paying attention to other modifiable risk factors such as drug-induced parkinsonian symptoms and the use of anticholinergic medication. Once TD has emerged and is associated with dysfunction or distress, treatment with a VMAT2 inhibitor such as deutetrabenazine or valbenazine is well supported by several controlled clinical trials. Copyright © 2017 Elsevier B.V. All rights reserved.

Clinical management of tardive dyskinesia: Five steps to success.

PubMed

Citrome, Leslie

2017-12-15

Tardive dyskinesia (TD) has long been thought to be a generally irreversible consequence of the use of dopamine receptor blocking agents. There is now an opportunity to successfully manage this condition with agents approved by the US Food and Drug Administration. This is important because TD has not been eliminated with the use of second-generation antipsychotics, and the expansion of antipsychotics to treat conditions other than schizophrenia has resulted in millions of additional individuals at risk for developing TD. Recognition of TD requires careful observation; a structured approach using the Abnormal Involuntary Movement Scale is encouraged. Harm reduction can be achieved by using antipsychotics judiciously when possible and by paying attention to other modifiable risk factors such as drug-induced parkinsonian symptoms and the use of anticholinergic medication. Once TD has emerged and is associated with dysfunction or distress, treatment with a VMAT2 inhibitor such as deutetrabenazine or valbenazine is well supported by several controlled clinical trials. Copyright © 2017 Elsevier B.V. All rights reserved.

Virtual agents in a simulated virtual training environment

NASA Technical Reports Server (NTRS)

Achorn, Brett; Badler, Norman L.

1993-01-01

A drawback to live-action training simulations is the need to gather a large group of participants in order to train a few individuals. One solution to this difficulty is the use of computer-controlled agents in a virtual training environment. This allows a human participant to be replaced by a virtual, or simulated, agent when only limited responses are needed. Each agent possesses a specified set of behaviors and is capable of limited autonomous action in response to its environment or the direction of a human trainee. The paper describes these agents in the context of a simulated hostage rescue training session, involving two human rescuers assisted by three virtual (computer-controlled) agents and opposed by three other virtual agents.

Firefighting and Emergency Response Study of Advanced Composites Aircraft. Objective 2: Firefighting Effectiveness of Technologies and Agents on Composite Aircraft Fires

DTIC Science & Technology

2011-12-31

current methods used for aluminum-skinned aircraft. To this end, a series of medium-scale fire experiments were performed on aerospace composite materials...History.....................................................................................................................4 3. METHODS , ASSUMPTIONS AND...4.3. Agent Cost Analysis ..........................................................................................................21 5. CONCLUSIONS

SYNTHESIS OF HIGHLY FLUORINATED CHLOROFORMATES AND THEIR USE AS DERIVATIZING AGENTS FOR HYDROPHILIC COMPOUNDS AND DRINKING WATER DISINFECTION BY-PRODUCTS

EPA Science Inventory

A rapid, safe and efficient procedure was developed to synthesize perfluorinated chloroformates in the small scale generally required to perform analytical derivatizations. This new family of derivatizing agents allows straightforward derivatization of highly polar compounds, co...

Density Control of Multi-Agent Systems with Safety Constraints: A Markov Chain Approach

NASA Astrophysics Data System (ADS)

Demirer, Nazli

The control of systems with autonomous mobile agents has been a point of interest recently, with many applications like surveillance, coverage, searching over an area with probabilistic target locations or exploring an area. In all of these applications, the main goal of the swarm is to distribute itself over an operational space to achieve mission objectives specified by the density of swarm. This research focuses on the problem of controlling the distribution of multi-agent systems considering a hierarchical control structure where the whole swarm coordination is achieved at the high-level and individual vehicle/agent control is managed at the low-level. High-level coordination algorithms uses macroscopic models that describes the collective behavior of the whole swarm and specify the agent motion commands, whose execution will lead to the desired swarm behavior. The low-level control laws execute the motion to follow these commands at the agent level. The main objective of this research is to develop high-level decision control policies and algorithms to achieve physically realizable commanding of the agents by imposing mission constraints on the distribution. We also make some connections with decentralized low-level motion control. This dissertation proposes a Markov chain based method to control the density distribution of the whole system where the implementation can be achieved in a decentralized manner with no communication between agents since establishing communication with large number of agents is highly challenging. The ultimate goal is to guide the overall density distribution of the system to a prescribed steady-state desired distribution while satisfying desired transition and safety constraints. Here, the desired distribution is determined based on the mission requirements, for example in the application of area search, the desired distribution should match closely with the probabilistic target locations. The proposed method is applicable for both systems with a single agent and systems with large number of agents due to the probabilistic nature, where the probability distribution of each agent's state evolves according to a finite-state and discrete-time Markov chain (MC). Hence, designing proper decision control policies requires numerically tractable solution methods for the synthesis of Markov chains. The synthesis problem has the form of a Linear Matrix Inequality Problem (LMI), with LMI formulation of the constraints. To this end, we propose convex necessary and sufficient conditions for safety constraints in Markov chains, which is a novel result in the Markov chain literature. In addition to LMI-based, offline, Markov matrix synthesis method, we also propose a QP-based, online, method to compute a time-varying Markov matrix based on the real-time density feedback. Both problems are convex optimization problems that can be solved in a reliable and tractable way, utilizing existing tools in the literature. A Low Earth Orbit (LEO) swarm simulations are presented to validate the effectiveness of the proposed algorithms. Another problem tackled as a part of this research is the generalization of the density control problem to autonomous mobile agents with two control modes: ON and OFF. Here, each mode consists of a (possibly overlapping) finite set of actions, that is, there exist a set of actions for the ON mode and another set for the OFF mode. We give formulation for a new Markov chain synthesis problem, with additional measurements for the state transitions, where a policy is designed to ensure desired safety and convergence properties for the underlying Markov chain.

Connection adaption for control of networked mobile chaotic agents.

PubMed

Zhou, Jie; Zou, Yong; Guan, Shuguang; Liu, Zonghua; Xiao, Gaoxi; Boccaletti, S

2017-11-22

In this paper, we propose a strategy for the control of mobile chaotic oscillators by adaptively rewiring connections between nearby agents with local information. In contrast to the dominant adaptive control schemes where coupling strength is adjusted continuously according to the states of the oscillators, our method does not request adaption of coupling strength. As the resulting interaction structure generated by this proposed strategy is strongly related to unidirectional chains, by investigating synchronization property of unidirectional chains, we reveal that there exists a certain coupling range in which the agents could be controlled regardless of the length of the chain. This feature enables the adaptive strategy to control the mobile oscillators regardless of their moving speed. Compared with existing adaptive control strategies for networked mobile agents, our proposed strategy is simpler for implementation where the resulting interaction networks are kept unweighted at all time.

Distributed neural network control for adaptive synchronization of uncertain dynamical multiagent systems.

PubMed

Peng, Zhouhua; Wang, Dan; Zhang, Hongwei; Sun, Gang

2014-08-01

This paper addresses the leader-follower synchronization problem of uncertain dynamical multiagent systems with nonlinear dynamics. Distributed adaptive synchronization controllers are proposed based on the state information of neighboring agents. The control design is developed for both undirected and directed communication topologies without requiring the accurate model of each agent. This result is further extended to the output feedback case where a neighborhood observer is proposed based on relative output information of neighboring agents. Then, distributed observer-based synchronization controllers are derived and a parameter-dependent Riccati inequality is employed to prove the stability. This design has a favorable decouple property between the observer and the controller designs for nonlinear multiagent systems. For both cases, the developed controllers guarantee that the state of each agent synchronizes to that of the leader with bounded residual errors. Two illustrative examples validate the efficacy of the proposed methods.

MIDAS: a practical Bayesian design for platform trials with molecularly targeted agents.

PubMed

Yuan, Ying; Guo, Beibei; Munsell, Mark; Lu, Karen; Jazaeri, Amir

2016-09-30

Recent success of immunotherapy and other targeted therapies in cancer treatment has led to an unprecedented surge in the number of novel therapeutic agents that need to be evaluated in clinical trials. Traditional phase II clinical trial designs were developed for evaluating one candidate treatment at a time and thus not efficient for this task. We propose a Bayesian phase II platform design, the multi-candidate iterative design with adaptive selection (MIDAS), which allows investigators to continuously screen a large number of candidate agents in an efficient and seamless fashion. MIDAS consists of one control arm, which contains a standard therapy as the control, and several experimental arms, which contain the experimental agents. Patients are adaptively randomized to the control and experimental agents based on their estimated efficacy. During the trial, we adaptively drop inefficacious or overly toxic agents and 'graduate' the promising agents from the trial to the next stage of development. Whenever an experimental agent graduates or is dropped, the corresponding arm opens immediately for testing the next available new agent. Simulation studies show that MIDAS substantially outperforms the conventional approach. The proposed design yields a significantly higher probability for identifying the promising agents and dropping the futile agents. In addition, MIDAS requires only one master protocol, which streamlines trial conduct and substantially decreases the overhead burden. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

MIDAS: A Practical Bayesian Design for Platform Trials with Molecularly Targeted Agents

PubMed Central

Yuan, Ying; Guo, Beibei; Munsell, Mark; Lu, Karen; Jazaeri, Amir

2016-01-01

Recent success of immunotherapy and other targeted therapies in cancer treatment has led to an unprecedented surge in the number of novel therapeutic agents that need to be evaluated in clinical trials. Traditional phase II clinical trial designs were developed for evaluating one candidate treatment at a time, and thus not efficient for this task. We propose a Bayesian phase II platform design, the Multi-candidate Iterative Design with Adaptive Selection (MIDAS), which allows investigators to continuously screen a large number of candidate agents in an efficient and seamless fashion. MIDAS consists of one control arm, which contains a standard therapy as the control, and several experimental arms, which contain the experimental agents. Patients are adaptively randomized to the control and experimental agents based on their estimated efficacy. During the trial, we adaptively drop inefficacious or overly toxic agents and “graduate” the promising agents from the trial to the next stage of development. Whenever an experimental agent graduates or is dropped, the corresponding arm opens immediately for testing the next available new agent. Simulation studies show that MIDAS substantially outperforms the conventional approach. The proposed design yields a significantly higher probability for identifying the promising agents and dropping the futile agents. In addition, MIDAS requires only one master protocol, which streamlines trial conduct and substantially decreases the overhead burden. PMID:27112322

[Analyses of pesticides in drinking water from small-scale water supplies in Schleswig-Holstein, Germany].

PubMed

Hippelein, M; Matthiessen, A; Kolychalow, O; Ostendorp, G

2012-12-01

In rural areas of Schleswig-Holstein, Germany, drinking water for about 37 000 people is provided by approximately 10 000 small-scale water supplies. For those wells data on pesticides in the drinking water are rare. In this study 100 small-scale water supplies, mainly situated in areas with intensive agriculture, fruit-growing or tree-nursery, were selected and the drinking water was analysed for pesticides. In 68 samples at least one agent or metabolite was detectable, 38 samples showed multiple contaminations. The metabolites dimethylsulfamide and chloridazone-desphenyl were found in nearly 40% of the wells in concentrations up to 42 µg/L. Bentazone was the most frequently detected biocidal agent. These data show that pesticides in drinking water from small-scale supplies are a notable issue in preventive public health. © Georg Thieme Verlag KG Stuttgart · New York.

The Use of Software Agents for Autonomous Control of a DC Space Power System

NASA Technical Reports Server (NTRS)

May, Ryan D.; Loparo, Kenneth A.

2014-01-01

In order to enable manned deep-space missions, the spacecraft must be controlled autonomously using on-board algorithms. A control architecture is proposed to enable this autonomous operation for an spacecraft electric power system and then implemented using a highly distributed network of software agents. These agents collaborate and compete with each other in order to implement each of the control functions. A subset of this control architecture is tested against a steadystate power system simulation and found to be able to solve a constrained optimization problem with competing objectives using only local information.

Impact of Release Rates on the Effectiveness of Augmentative Biological Control Agents

PubMed Central

Crowder, David W.

2007-01-01

To access the effect of augmentative biological control agents, 31 articles were reviewed that investigated the impact of release rates of 35 augmentative biological control agents on the control of 42 arthropod pests. In 64% of the cases, the release rate of the biological control agent did not significantly affect the density or mortality of the pest insect. Results where similar when parasitoidsor predators were utilized as the natural enemy. Within any order of natural enemy, there were more cases where release rates did not affect augmentative biological control than cases where release rates were significant. There were more cases in which release rates did not affect augmentative biological control when pests were from the orders Hemiptera, Acari, or Diptera, but not with pests from the order Lepidoptera. In most cases, there was an optimal release rate that produced effective control of a pest species. This was especially true when predators were used as a biological control agent. Increasing the release rate above the optimal rate did not improve control of the pest and thus would be economically detrimental. Lower release rates were of ten optimal when biological control was used in conjunction with insecticides. In many cases, the timing and method of biological control applications were more significant factors impacting the effectiveness of biological control than the release rate. Additional factors that may limit the relative impact of release rates include natural enemy fecundity, establishment rates, prey availability, dispersal, and cannibalism. PMID:20307240

Systemic risk on different interbank network topologies

NASA Astrophysics Data System (ADS)

Lenzu, Simone; Tedeschi, Gabriele

2012-09-01

In this paper we develop an interbank market with heterogeneous financial institutions that enter into lending agreements on different network structures. Credit relationships (links) evolve endogenously via a fitness mechanism based on agents' performance. By changing the agent's trust on its neighbor's performance, interbank linkages self-organize themselves into very different network architectures, ranging from random to scale-free topologies. We study which network architecture can make the financial system more resilient to random attacks and how systemic risk spreads over the network. To perturb the system, we generate a random attack via a liquidity shock. The hit bank is not automatically eliminated, but its failure is endogenously driven by its incapacity to raise liquidity in the interbank network. Our analysis shows that a random financial network can be more resilient than a scale free one in case of agents' heterogeneity.

Adaptive method with intercessory feedback control for an intelligent agent

DOEpatents

Goldsmith, Steven Y.

2004-06-22

An adaptive architecture method with feedback control for an intelligent agent provides for adaptively integrating reflexive and deliberative responses to a stimulus according to a goal. An adaptive architecture method with feedback control for multiple intelligent agents provides for coordinating and adaptively integrating reflexive and deliberative responses to a stimulus according to a goal. Re-programming of the adaptive architecture is through a nexus which coordinates reflexive and deliberator components.

Distributed environmental control

NASA Technical Reports Server (NTRS)

Cleveland, Gary A.

1992-01-01

We present an architecture of distributed, independent control agents designed to work with the Computer Aided System Engineering and Analysis (CASE/A) simulation tool. CASE/A simulates behavior of Environmental Control and Life Support Systems (ECLSS). We describe a lattice of agents capable of distributed sensing and overcoming certain sensor and effector failures. We address how the architecture can achieve the coordinating functions of a hierarchical command structure while maintaining the robustness and flexibility of independent agents. These agents work between the time steps of the CASE/A simulation tool to arrive at command decisions based on the state variables maintained by CASE/A. Control is evaluated according to both effectiveness (e.g., how well temperature was maintained) and resource utilization (the amount of power and materials used).

Pre-release biological control agent recommendations for swallow-wort (Vincetoxicum spp.) informed by demographic matrix models

USDA-ARS?s Scientific Manuscript database

Weed biological control workers have advocated for the advance assessment of agent efficacy in order to minimize the release of host-specific but ineffective agents. One method involves demographic matrix modeling of target weed populations in order to identify plant life stage transitions that cont...

Losers in the 'Rock-Paper-Scissors' game: The role of non-hierarchical competition and chaos as biodiversity sustaining agents in aquatic systems

EPA Science Inventory

Processes occurring within small areas (patch-scale) that influence species richness and spatial heterogeneity of larger areas (landscape-scale) have long been an interest of ecologists. This research focused on the role of patch-scale deterministic chaos arising in phytoplankton...

A Systematic Review of Pedagogical Agents' Persona, Motivation, and Cognitive Load Implications for Learners

ERIC Educational Resources Information Center

Schroeder, Noah L.; Adesope, Olusola O.

2014-01-01

After more than a decade of pedagogical agent research, this review synthesizes the affective implications of learning with pedagogical agents. The review investigates different affective measures within 99 pedagogical agent outcome measures. The results suggest that learners may prefer pedagogical agents compared to non-agent control conditions,…

Situation Awareness of Onboard System Autonomy

NASA Technical Reports Server (NTRS)

Schreckenghost, Debra; Thronesbery, Carroll; Hudson, Mary Beth

2005-01-01

We have developed intelligent agent software for onboard system autonomy. Our approach is to provide control agents that automate crew and vehicle systems, and operations assistants that aid humans in working with these autonomous systems. We use the 3 Tier control architecture to develop the control agent software that automates system reconfiguration and routine fault management. We use the Distributed Collaboration and Interaction (DCI) System to develop the operations assistants that provide human services, including situation summarization, event notification, activity management, and support for manual commanding of autonomous system. In this paper we describe how the operations assistants aid situation awareness of the autonomous control agents. We also describe our evaluation of the DCI System to support control engineers during a ground test at Johnson Space Center (JSC) of the Post Processing System (PPS) for regenerative water recovery.

Understanding Group/Party Affiliation Using Social Networks and Agent-Based Modeling

NASA Technical Reports Server (NTRS)

Campbell, Kenyth

2012-01-01

The dynamics of group affiliation and group dispersion is a concept that is most often studied in order for political candidates to better understand the most efficient way to conduct their campaigns. While political campaigning in the United States is a very hot topic that most politicians analyze and study, the concept of group/party affiliation presents its own area of study that producers very interesting results. One tool for examining party affiliation on a large scale is agent-based modeling (ABM), a paradigm in the modeling and simulation (M&S) field perfectly suited for aggregating individual behaviors to observe large swaths of a population. For this study agent based modeling was used in order to look at a community of agents and determine what factors can affect the group/party affiliation patterns that are present. In the agent-based model that was used for this experiment many factors were present but two main factors were used to determine the results. The results of this study show that it is possible to use agent-based modeling to explore group/party affiliation and construct a model that can mimic real world events. More importantly, the model in the study allows for the results found in a smaller community to be translated into larger experiments to determine if the results will remain present on a much larger scale.

Modeling the Internet of Things, Self-Organizing and Other Complex Adaptive Communication Networks: A Cognitive Agent-Based Computing Approach

PubMed Central

2016-01-01

Background Computer Networks have a tendency to grow at an unprecedented scale. Modern networks involve not only computers but also a wide variety of other interconnected devices ranging from mobile phones to other household items fitted with sensors. This vision of the "Internet of Things" (IoT) implies an inherent difficulty in modeling problems. Purpose It is practically impossible to implement and test all scenarios for large-scale and complex adaptive communication networks as part of Complex Adaptive Communication Networks and Environments (CACOONS). The goal of this study is to explore the use of Agent-based Modeling as part of the Cognitive Agent-based Computing (CABC) framework to model a Complex communication network problem. Method We use Exploratory Agent-based Modeling (EABM), as part of the CABC framework, to develop an autonomous multi-agent architecture for managing carbon footprint in a corporate network. To evaluate the application of complexity in practical scenarios, we have also introduced a company-defined computer usage policy. Results The conducted experiments demonstrated two important results: Primarily CABC-based modeling approach such as using Agent-based Modeling can be an effective approach to modeling complex problems in the domain of IoT. Secondly, the specific problem of managing the Carbon footprint can be solved using a multiagent system approach. PMID:26812235

Mother Nature versus human nature: public compliance with evacuation and quarantine.

PubMed

Manuell, Mary-Elise; Cukor, Jeffrey

2011-04-01

Effectively controlling the spread of contagious illnesses has become a critical focus of disaster planning. It is likely that quarantine will be a key part of the overall public health strategy utilised during a pandemic, an act of bioterrorism or other emergencies involving contagious agents. While the United States lacks recent experience of large-scale quarantines, it has considerable accumulated experience of large-scale evacuations. Risk perception, life circumstance, work-related issues, and the opinions of influential family, friends and credible public spokespersons all play a role in determining compliance with an evacuation order. Although the comparison is not reported elsewhere to our knowledge, this review of the principal factors affecting compliance with evacuations demonstrates many similarities with those likely to occur during a quarantine. Accurate identification and understanding of barriers to compliance allows for improved planning to protect the public more effectively. © 2011 The Author(s). Disasters © Overseas Development Institute, 2011.

Who is more efficient: Teacher or pedagogical agents?

NASA Astrophysics Data System (ADS)

Lee, Tien Tien; Mustapha, Nur Hanani

2017-05-01

The purpose of the study is to investigate the impact of pedagogical agent's and teacher's role on students' understanding and motivation in the learning of Electrochemistry. Interactive Multimedia Module with Pedagogical Agents, EC Lab (IMMPA EC Lab) was used in this study. IMMPA EC Lab consists of five subunits in Electrochemistry topic. The research was a non-equivalent control group quasi experimental design involving two treatment groups and one control group. The first treatment group studied Electrochemistry with expert agent (Professor T) while the second treatment group studied Electrochemistry with learning companion agent (Lisa). On the other hand, the control group learned Electrochemistry with their Chemistry teacher using the material in the IMMPA EC Lab. The study was conducted at a secondary science school in the Pasir Puteh district involving 74 form four students. The instruments used in this research were the Electrochemistry achievement tests in the form of pre-test and post-test, IMMPA EC Lab and motivation questionnaire. ANCOVA results found that there was no significant difference among the three groups in post-test. On the other hand, One-way ANOVA test proved that there were significant differences for the post-motivation scores between the control group and the treatment groups. Post motivation mean scores for expert agent treatment group and learning companion treatment group surpassed the control group. The study focus on the impact of pedagogical agents with different roles on students' learning and motivation should be promoted. Various versions of pedagogical agents that fulfil the good characteristics should be designed to enhance students' learning and motivation.

Biocontrol of foliar pathogens: mechanisms and application.

PubMed

Elad, Y

2003-01-01

Biocontrol offers attractive alternatives or supplements to the use of conventional methods for plant disease management. Vast experience has been gained in the biocontrol of plant diseases. Prevention of infection by biocontrol agents or suppression of disease is based on various modes of action. Pathogens are typically affected by certain modes of actions and not by others according to their nature (i.e. biotrophs vs. necrotrophs). Resistance in the host plant may be induced locally or systemically by either live or dead cells of the biocontrol agent and may affect pathogens of various groups. As some pathogens are negatively affected by lake of nutrients in the infection court, competition for nutrients and space was long recognized as antagonism trait. Antibiosis and hyperparasitism affect pathogens of various groups. Other valid mechanisms are reduction of the saprophytic ability and reducing spore dissemination. Recently it was revealed that restraining of pathogenicity factors of the pathogens, i.e. host hydrolyzing proteins or reactive oxygen species takes place when biocontrol is used. It is likely that several modes of action concomitantly participate in pathogens suppression but the relative importance of each one of them is not clear. Examples of effective prevention of infection in the phyllosphere that rely on multiple modes of action will be demonstrated with Trichodermo harzianum T39 (TRICHODEX), Bacillus mycoides and Pichia guilermondii, a filamentous fungus, bacterium and yeast biocontrol agents, respectively. Several commercial products based on microorganisms have been developed and are starting to penetrate the market. However, large-scale use is still limited because of variability and inconsistency of biocontrol activity. In some cases this may be caused by sensitivity of the biocontrol agents to environmental influences. Ways to overcome biocontrol limitations and to improve its efficacy are i. integration of biocontrol with chemical fungicides on a calendar basis or according to ecological requirements of the biocontrol agents relying on the advise of a decision support system; ii. introduction of two or more biocontrol agents in a mixture, assuming that each one of them has different ecological requirements and/or different modes of action. Implementation of one (or more) of these approaches, using biocontrol preparations mentioned above lowered the variability and increased the consistency of disease suppression. The expected long-term result of the implementation of these suggested strategies is reduced risk of uncontrolled epidemics and increase of confidence of growers in using this non-chemical control measure on a large scale.

Coordination of fractional-order nonlinear multi-agent systems via distributed impulsive control

NASA Astrophysics Data System (ADS)

Ma, Tiedong; Li, Teng; Cui, Bing

2018-01-01

The coordination of fractional-order nonlinear multi-agent systems via distributed impulsive control method is studied in this paper. Based on the theory of impulsive differential equations, algebraic graph theory, Lyapunov stability theory and Mittag-Leffler function, two novel sufficient conditions for achieving the cooperative control of a class of fractional-order nonlinear multi-agent systems are derived. Finally, two numerical simulations are verified to illustrate the effectiveness and feasibility of the proposed method.

The effect of sodium hypochlorite application on the success of calcium hydroxide and mineral trioxide aggregate pulpotomies in primary teeth.

PubMed

Akcay, Merve; Sari, Saziye

2014-01-01

This study's purpose was to evaluate the success of calcium hydroxide (CH) and mineral trioxide aggregate (MTA) pulpotomies following the use of five percent sodium hypochlorite (NaOCl) as an antibacterial agent to clean the chamber prior to application of the pulpotomy agent. A total of 128 teeth were randomly divided into two pulpotomy groups (CH or MTA). The teeth in each pulpotomy group, CH and MTA, were further randomly divided into subgroups to receive either the NaOCl (experimental) or saline (control) cleaning agent prior to applying the pulpotomy agent. The treatments were followed clinically and radiographically for 12 months. The radiographic success rates were 84 percent for CH NaOCl, 74 percent for CH saline control, 97 percent for MTA NaOCl, and 100 percent for MTA saline control. There were no significant differences between the radiographic success rates in the CH and MTA subgroups (CH NaOCl-CH control and MTA NaOCl-MTA control); no significant differences were observed when comparing the CH NaOCl-MTA NaOCl groups and the CH NaOCl-MTA control groups. Use of sodium hypochlorite as an antibacterial agent prior to application of the pulpotomy agent improved the success of calcium hydroxide pulpotomies to equal the success of mineral trioxide aggregate pulpotomies for observation up to 12 months.

Bacterial magnetic particles improve testes-mediated transgene efficiency in mice.

PubMed

Wang, Chao; Sun, Guanghong; Wang, Ye; Kong, Nana; Chi, Yafei; Yang, Leilei; Xin, Qiliang; Teng, Zhen; Wang, Xu; Wen, Yujun; Li, Ying; Xia, Guoliang

2017-11-01

Nano-scaled materials have been proved to be ideal DNA carriers for transgene. Bacterial magnetic particles (BMPs) help to reduce the toxicity of polyethylenimine (PEI), an efficient gene-transferring agent, and assist tissue transgene ex vivo. Here, the effectiveness of the BMP-PEI complex-conjugated foreign DNAs (BPDs) in promoting testes-mediated gene transfer (TMGT) in mouse was compared with that of liposome-conjugated foreign DNAs. The results proved that through testes injection, the clusters of BPDs successfully reached the cytoplasm and the nuclear of spermatogenesis cell, and expressed in testes of transgene founder mice. Additionally, the ratio of founder mice obtained from BPDs (88%) is about 3 times higher than the control (25%) (p < 0.05). Interestingly, the motility of sperms recovered from epididymis of the founder mice from BPD group were significantly improved, as compared with the control (p < 0.01). Based on classic breeding, the ratio of transgene mice within the first filial was significantly higher in BPDs compared with the control (73.8% versus 11.6%, p < 0.05). TMGT in this study did not produce visible histological changes in the testis. In conclusion, nano-scaled BPDs could be an alternative strategy for efficiently producing transgene mice in vivo.

Surfactants as blackbird stressing agents

USGS Publications Warehouse

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

1970-01-01

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

Host Plant Associations of an Entomopathogenic Variety of the Fungus, Colletotrichum acutatum, Recovered from the Elongate Hemlock Scale, Fiorinia externa

PubMed Central

Marcelino, José A. P.; Gouli, Svetlana; Parker, Bruce L.; Skinner, Margaret; Schwarzberg, Lora; Giordano, Rosanna

2009-01-01

A fungal epizootic has been detected in populations of the scale Fiorinia externa Ferris (Hemiptera: Diaspididae) in the eastern hemlock, Tsuga canadensis (L.) Carrière (Pinales: Pinaceae), of several northeastern states. Colletotrichum acutatum Simmonds var. fioriniae Marcelino and Gouli var. nov. inedit (Phyllachorales: Phyllachoraceae), a well-known plant pathogen, was the most commonly recovered fungus from these infected scales. This is the second report of a Colletotrichum sp. infecting scale insects. In Brazil C. gloeosporioides f. sp. ortheziidae recovered from Orthezia praelonga is under development as a biopesticide for citrus production. C. acutatum was detected growing endophytically in 28 species of plants within the epizootic areas. DNA sequences of the High Mobility Box at the MAT 1–2, mating type gene indicate that Colletotrichum sp. isolates recovered from scale insects and plants within epizootic areas were identical. Results from plant bioassays showed that this entomopathogenic Colletotrichum variety grew endophytically in all of the plants tested without causing external symptoms or signs of infection, with the exception of strawberry plants where mild symptoms of infection were observed. The implications of these findings with respect to the use of this fungus as a biological control agent are discussed. PMID:19613851

Measured and perceived effects of computerized scientist mentors on student learning and motivation in science

NASA Astrophysics Data System (ADS)

Bowman, Catherine Dodds Dunham

Unease about declining U.S. science literacy and inquiry skills drives much innovation in science education, including the quest for authentic science experiences for students. One response is student-scientist partnerships (SSP), involving small numbers of students in scientific investigations with scientist mentors. Alternatively, science inquiry programs provide large numbers of students with opportunities to pursue their own investigations but without extensive access to experts, potentially limiting the possible cognitive and affective gains. This mixed methods study investigates whether it is possible to replicate some of SSPs' benefits on a larger scale through use of a computerized agent designed as a "virtual" scientist mentor. Middle school students (N=532) were randomly assigned to two versions of an agent (or to a control group) providing either content-only or content and interpersonal mentoring while they participated in a three-week curriculum. Results indicate that, on average, students gained in content knowledge but there was no statistically significant difference between the three conditions. In terms of motivation, students exhibited no change, on average, with no statistically significant difference between the three conditions. These data indicate that the treatment conditions neither facilitate nor inhibit student learning and motivation. Interviews with a subsample (n=70), however, suggest that students believe the agents facilitated their learning, eased the workload, provided a trusted source of information, and were enjoyable to use. Teachers reported that the agents provided alternative views of scientists and science, generated class discussion, and met the needs of high and low-achieving students. This difference between measured and perceived benefits may result from measures that were not sufficiently sensitive to capture differences. Alternatively, a more sophisticated agent might better replicate mentoring functions known to produce cognitive and affective gains. Even without established learning or motivational gains, practitioners may want to employ agents for their ability to provide reliable information, expanded perspectives on science and scientists, and a non-intimidating setting for students to ask questions. For computerized agent researchers, this study provides a first step in exploring the affordances and challenges of sustained use of agents in real school settings with the goal of improving science education.

Differences in seasonal variation between two biotypes of Megamelus scutellaris (Hemiptera: Delphacidae), a biological control agent for Eichhornia crassipes in Florida.

USDA-ARS?s Scientific Manuscript database

Climate matching between the native and adventive ranges of insects used for biological control is a generally accepted strategy for both increasing the likelihood of establishing an agent, as well as improving its overall performance, thereby maximizing the potential utility of an agent across the...

17 CFR 240.17Ad-10 - Prompt posting of certificate detail to master securityholder files, maintenance of accurate...

Code of Federal Regulations, 2010 CFR

2010-04-01

... between co-transfer agents and recordkeeping transfer agents, maintenance of current control book... Supervised Investment Bank Holding Company Rules § 240.17Ad-10 Prompt posting of certificate detail to master... recordkeeping transfer agents, maintenance of current control book, retention of certificate detail and “buy-in...

Distributed Planning in a Mixed-Initiative Environment

DTIC Science & Technology

2008-06-01

Knowledge Sources Control Remote Blackboard Remote Knowledge Sources Remot e Data Remot e Data Java Distributed Blackboard Figure 3 - Distributed...an interface agent or planning agent and the second type is a critic agent. Agents in the DEEP architecture extend and use the Java Agent...chosen because it is fully implemented in Java , and supports these requirements. 2.3.3 Interface Agents Interface agents are the interfaces through

DOE Office of Scientific and Technical Information (OSTI.GOV)

Durham, M.D.

The purpose of this research program is to identify and evaluate a variety of additives capable of increasing particle cohesion which could be used for improving collection efficiency in an ESP. A three-phase screening process will be used to provide the, evaluation of many additives in a logical and cost-effective manner. The three step approach involves the following experimental setups: 1. Provide a preliminary screening in the laboratory by measuring the effects of various conditioning agents on reentrainment of flyash particles in an electric field operating at simulated flue gas conditions. 2. Evaluate the successful additives using a 100 acfmmore » bench-scale ESP operating on actual flue gas. 3. Obtain the data required for scaling up the technology by testing the two or three most promising conditioning agents at the pilot scale.« less

Visual analytics of geo-social interaction patterns for epidemic control.

PubMed

Luo, Wei

2016-08-10

Human interaction and population mobility determine the spatio-temporal course of the spread of an airborne disease. This research views such spreads as geo-social interaction problems, because population mobility connects different groups of people over geographical locations via which the viruses transmit. Previous research argued that geo-social interaction patterns identified from population movement data can provide great potential in designing effective pandemic mitigation. However, little work has been done to examine the effectiveness of designing control strategies taking into account geo-social interaction patterns. To address this gap, this research proposes a new framework for effective disease control; specifically this framework proposes that disease control strategies should start from identifying geo-social interaction patterns, designing effective control measures accordingly, and evaluating the efficacy of different control measures. This framework is used to structure design of a new visual analytic tool that consists of three components: a reorderable matrix for geo-social mixing patterns, agent-based epidemic models, and combined visualization methods. With real world human interaction data in a French primary school as a proof of concept, this research compares the efficacy of vaccination strategies between the spatial-social interaction patterns and the whole areas. The simulation results show that locally targeted vaccination has the potential to keep infection to a small number and prevent spread to other regions. At some small probability, the local control strategies will fail; in these cases other control strategies will be needed. This research further explores the impact of varying spatial-social scales on the success of local vaccination strategies. The results show that a proper spatial-social scale can help achieve the best control efficacy with a limited number of vaccines. The case study shows how GS-EpiViz does support the design and testing of advanced control scenarios in airborne disease (e.g., influenza). The geo-social patterns identified through exploring human interaction data can help target critical individuals, locations, and clusters of locations for disease control purposes. The varying spatial-social scales can help geographically and socially prioritize limited resources (e.g., vaccines).

Non-target effects of an introduced biological control agent on deer mouse ecology.

PubMed

Pearson, D E; McKelvey, K S; Ruggiero, L F

2000-01-01

Release of exotic insects as biological control agents is a common approach to controlling exotic plants. Though controversy has ensued regarding the deleterious direct effects of biological control agents to non-target species, few have examined the indirect effects of a "well-behaved" biological control agent on native fauna. We studied a grassland in west-central Montana infested with spotted knapweed (Centaurea maculosa) to examine the effects of knapweed invasion and two gall flybiological control agents (Urophora affinis and U. quadrifasciata) on the native deer mouse (Peromyscus maniculatus). Stomach-content analysis revealed that Urophora were the primary food item in Peromyscus diets for most of the year and made up 84-86% of the winter diet. Stomach contents indicated that wild-caught mice consumed on average up to 247 Urophora larvae mouse -1 day -1 , while feeding trials revealed that deer mice could depredate nearly 5 times as many larvae under laboratory conditions. In feeding trials, deer mice selected knapweed seedheads with greater numbers of galls while avoiding uninfested seedheads. When Urophora larvae were present in knapweed seedheads, deer mice selected microhabitats with moderately high (31-45% cover) and high knapweed infestation (≥46% cover). After Urophora emerged and larvae were unavailable to Peromyscus, mice reversed habitat selection to favor sites dominated by native-prairie with low knapweed infestation (0-15%). Establishment of the biological control agent, Urophora spp., has altered deer mouse diets and habitat selection by effecting changes in foraging strategies. Deer mice and other predators may reduce Urophora populations below a threshold necessary to effectively control spotted knapweed.

Self-Contained AFFF Sprinkler System,

DTIC Science & Technology

1982-05-01

aqueous film forming foam ( AFFF ). Such systems are...supply. Extinguishing Agents All fire tests were run with a pre-mixed solution of 6% aqueous film forming foam ( AFFF ) agent in accordance with MIL-F...Applying Aqueous Film Forming Foam on Large-Scale Fires", Civil and Environmental Engineering Development Office (Air Force Systems Command) Report

Development and application of a real-time testbed for multiagent system interoperability: A case study on hierarchical microgrid control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cintuglu, Mehmet Hazar; Youssef, Tarek; Mohammed, Osama A.

This article presents the development and application of a real-time testbed for multiagent system interoperability. As utility independent private microgrids are installed constantly, standardized interoperability frameworks are required to define behavioral models of the individual agents for expandability and plug-and-play operation. In this paper, we propose a comprehensive hybrid agent framework combining the foundation for intelligent physical agents (FIPA), IEC 61850, and data distribution service (DDS) standards. The IEC 61850 logical node concept is extended using FIPA based agent communication language (ACL) with application specific attributes and deliberative behavior modeling capability. The DDS middleware is adopted to enable a real-timemore » publisher-subscriber interoperability mechanism between platforms. The proposed multi-agent framework was validated in a laboratory based testbed involving developed intelligent electronic device (IED) prototypes and actual microgrid setups. Experimental results were demonstrated for both decentralized and distributed control approaches. Secondary and tertiary control levels of a microgrid were demonstrated for decentralized hierarchical control case study. A consensus-based economic dispatch case study was demonstrated as a distributed control example. Finally, it was shown that the developed agent platform is industrially applicable for actual smart grid field deployment.« less

Development and application of a real-time testbed for multiagent system interoperability: A case study on hierarchical microgrid control

DOE PAGES

Cintuglu, Mehmet Hazar; Youssef, Tarek; Mohammed, Osama A.

2016-08-10

This article presents the development and application of a real-time testbed for multiagent system interoperability. As utility independent private microgrids are installed constantly, standardized interoperability frameworks are required to define behavioral models of the individual agents for expandability and plug-and-play operation. In this paper, we propose a comprehensive hybrid agent framework combining the foundation for intelligent physical agents (FIPA), IEC 61850, and data distribution service (DDS) standards. The IEC 61850 logical node concept is extended using FIPA based agent communication language (ACL) with application specific attributes and deliberative behavior modeling capability. The DDS middleware is adopted to enable a real-timemore » publisher-subscriber interoperability mechanism between platforms. The proposed multi-agent framework was validated in a laboratory based testbed involving developed intelligent electronic device (IED) prototypes and actual microgrid setups. Experimental results were demonstrated for both decentralized and distributed control approaches. Secondary and tertiary control levels of a microgrid were demonstrated for decentralized hierarchical control case study. A consensus-based economic dispatch case study was demonstrated as a distributed control example. Finally, it was shown that the developed agent platform is industrially applicable for actual smart grid field deployment.« less

Product Categories under the National Contingency Plan Subpart J

EPA Pesticide Factsheets

There are five types authorized for use in oil spill cleanups, defined in 40 CFR 300.5. They are bioremediation agents, dispersants, sorbents, surface collecting agents, surface washing agents, and miscellaneous oil spill control agents.

Preparation of Water Suspensions of Nanocalcite for Cultural Heritage Applications.

PubMed

Coltelli, Maria-Beatrice; Paolucci, Dario; Castelvetro, Valter; Bianchi, Sabrina; Mascha, Elisabeth; Panariello, Luca; Pesce, Cecilia; Weber, Johannes; Lazzeri, Andrea

2018-04-19

The consolidation of degraded carbonate stone used in ancient monuments is an important topic for European cultural heritage conservation. The products most frequently used as consolidants are based on tetraalkoxy- or alkylalkoxy-silanes (in particular tetraethyl-orthosilicate, TEOS), resulting in the formation of relatively stable amorphous silica or alkylated (hydrophobic) silica inside the stone pores. However, silica is not chemically compatible with carbonate stones; in this respect, nanocalcite may be a suitable alternative. The present work concerns the preparation of water suspensions of calcite nanoparticles (CCNPs) by controlled carbonation of slaked lime using a pilot-scale reactor. A simplified design of experiment was adopted for product optimization. Calcite nanoparticles of narrow size distribution averaging about 30 nm were successfully obtained, the concentration of the interfacial agent and the size of CaO being the most critical parameters. Primary nanoparticle aggregation causing flocculation could be substantially prevented by the addition of polymeric dispersants. Copolymer-based dispersants were produced in situ by controlled heterophase polymerisation mediated by an amphiphilic macro-RAFT (reversible addition-fragmentation transfer) agent. The stabilized CCNP aqueous dispersions were then applied on carbonate and silicate substrates; Scanning Electron Microscopy (SEM)analysis of cross-sections allowed the evaluation of pore penetration, interfacial binding, and bridging (gap-filling) properties of these novel consolidants.

Preparation of Water Suspensions of Nanocalcite for Cultural Heritage Applications

PubMed Central

Coltelli, Maria-Beatrice; Paolucci, Dario; Bianchi, Sabrina; Mascha, Elisabeth; Panariello, Luca; Pesce, Cecilia; Weber, Johannes

2018-01-01

The consolidation of degraded carbonate stone used in ancient monuments is an important topic for European cultural heritage conservation. The products most frequently used as consolidants are based on tetraalkoxy- or alkylalkoxy-silanes (in particular tetraethyl-orthosilicate, TEOS), resulting in the formation of relatively stable amorphous silica or alkylated (hydrophobic) silica inside the stone pores. However, silica is not chemically compatible with carbonate stones; in this respect, nanocalcite may be a suitable alternative. The present work concerns the preparation of water suspensions of calcite nanoparticles (CCNPs) by controlled carbonation of slaked lime using a pilot-scale reactor. A simplified design of experiment was adopted for product optimization. Calcite nanoparticles of narrow size distribution averaging about 30 nm were successfully obtained, the concentration of the interfacial agent and the size of CaO being the most critical parameters. Primary nanoparticle aggregation causing flocculation could be substantially prevented by the addition of polymeric dispersants. Copolymer-based dispersants were produced in situ by controlled heterophase polymerisation mediated by an amphiphilic macro-RAFT (reversible addition-fragmentation transfer) agent. The stabilized CCNP aqueous dispersions were then applied on carbonate and silicate substrates; Scanning Electron Microscopy (SEM)analysis of cross-sections allowed the evaluation of pore penetration, interfacial binding, and bridging (gap-filling) properties of these novel consolidants. PMID:29671800

Attributable causes of cancer in Japan in 2005--systematic assessment to estimate current burden of cancer attributable to known preventable risk factors in Japan.

PubMed

Inoue, M; Sawada, N; Matsuda, T; Iwasaki, M; Sasazuki, S; Shimazu, T; Shibuya, K; Tsugane, S

2012-05-01

To contribute to evidence-based policy decision making for national cancer control, we conducted a systematic assessment to estimate the current burden of cancer attributable to known preventable risk factors in Japan in 2005. We first estimated the population attributable fractions (PAFs) of each cancer attributable to known risk factors from relative risks derived primarily from Japanese pooled analyses and large-scale cohort studies and the prevalence of exposure in the period around 1990. Using nationwide vital statistics records and incidence estimates, we then estimated the attributable cancer incidence and mortality in 2005. In 2005, ≈ 55% of cancer among men was attributable to preventable risk factors in Japan. The corresponding figure was lower among women, but preventable risk factors still accounted for nearly 30% of cancer. In men, tobacco smoking had the highest PAF (30% for incidence and 35% for mortality, respectively) followed by infectious agents (23% and 23%). In women, in contrast, infectious agents had the highest PAF (18% and 19% for incidence and mortality, respectively) followed by tobacco smoking (6% and 8%). In Japan, tobacco smoking and infections are major causes of cancer. Further control of these factors will contribute to substantial reductions in cancer incidence and mortality in Japan.

Rapid Detection of Pathogens

DOE Office of Scientific and Technical Information (OSTI.GOV)

David Perlin

2005-08-14

Pathogen identification is a crucial first defense against bioterrorism. A major emphasis of our national biodefense strategy is to establish fast, accurate and sensitive assays for diagnosis of infectious diseases agents. Such assays will ensure early and appropriate treatment of infected patients. Rapid diagnostics can also support infection control measures, which monitor and limit the spread of infectious diseases agents. Many select agents are highly transmissible in the early stages of disease, and it is critical to identify infected patients and limit the risk to the remainder of the population and to stem potential panic in the general population. Nucleicmore » acid-based molecular approaches for identification overcome many of the deficiencies associated with conventional culture methods by exploiting both large- and small-scale genomic differences between organisms. PCR-based amplification of highly conserved ribosomal RNA (rRNA) genes, intergenic sequences, and specific toxin genes is currently the most reliable approach for bacterial, fungal and many viral pathogenic agents. When combined with fluorescence-based oligonucleotide detection systems, this approach provides real-time, quantitative, high fidelity analysis capable of single nucleotide allelic discrimination (4). These probe systems offer rapid turn around time (<2 h) and are suitable for high throughput, automated multiplex operations that are critical for clinical diagnostic laboratories. In this pilot program, we have used molecular beacon technology invented at the Public health Research Institute to develop a new generation of molecular probes to rapidly detect important agents of infectious diseases. We have also developed protocols to rapidly extract nucleic acids from a variety of clinical specimen including and blood and tissue to for detection in the molecular assays. This work represented a cooperative research development program between the Kramer-Tyagi/Perlin labs on probe development and the Perlin lab in sample preparation and testing in animal models.« less

Network flow of mobile agents enhances the evolution of cooperation

NASA Astrophysics Data System (ADS)

Ichinose, G.; Satotani, Y.; Nagatani, T.

2018-01-01

We study the effect of contingent movement on the persistence of cooperation on complex networks with empty nodes. Each agent plays the Prisoner's Dilemma game with its neighbors and then it either updates the strategy depending on the payoff difference with neighbors or it moves to another empty node if not satisfied with its own payoff. If no neighboring node is empty, each agent stays at the same site. By extensive evolutionary simulations, we show that the medium density of agents enhances cooperation where the network flow of mobile agents is also medium. Moreover, if the movements of agents are more frequent than the strategy updating, cooperation is further promoted. In scale-free networks, the optimal density for cooperation is lower than other networks because agents get stuck at hubs. Our study suggests that keeping a smooth network flow is significant for the persistence of cooperation in ever-changing societies.

Ionic Transport through Chemically Functionalized Hydrogen Peroxide-Sensitive Asymmetric Nanopores.

PubMed

Ali, Mubarak; Ahmed, Ishtiaq; Nasir, Saima; Ramirez, Patricio; Niemeyer, Christof M; Mafe, Salvador; Ensinger, Wolfgang

2015-09-09

We describe the fabrication of a chemical-sensitive nanofluidic device based on asymmetric nanopores whose transport characteristics can be modulated upon exposure to hydrogen peroxide (H2O2). We show experimentally and theoretically that the current-voltage curves provide a suitable method to monitor the H2O2-mediated change in pore surface characteristics from the electronic readouts. We demonstrate also that the single pore characteristics can be scaled to the case of a multipore membrane whose electric outputs can be readily controlled. Because H2O2 is an agent significant for medical diagnostics, the results should be useful for sensing nanofluidic devices.

Highly ordered nanocomposites via a monomer self-assembly in situ condensation approach

DOEpatents

Gin, D.L.; Fischer, W.M.; Gray, D.H.; Smith, R.C.

1998-12-15

A method for synthesizing composites with architectural control on the nanometer scale is described. A polymerizable lyotropic liquid-crystalline monomer is used to form an inverse hexagonal phase in the presence of a second polymer precursor solution. The monomer system acts as an organic template, providing the underlying matrix and order of the composite system. Polymerization of the template in the presence of an optional cross-linking agent with retention of the liquid-crystalline order is carried out followed by a second polymerization of the second polymer precursor within the channels of the polymer template to provide an ordered nanocomposite material. 13 figs.

PERFILS: a program for the quantitative treatment of footprinting data.

PubMed

Salas, X; Portugal, J

1993-10-01

PERFILS, a computer program written in Borland TurboPascal, performs quantitative analysis of footprinting experiments using any IBM PC or compatible microcomputer. The program uses the height of the bands obtained from densitometric scanning of footprinting autoradiographs to calculate a differential cleavage plot. Such a plot displays, on a logarithmic scale, the difference of susceptibility of a DNA fragment to DNase I, or any other cleaving agent, in the presence of any ligand versus the sequence. PERFILS calculates the fractional cleavage values for control and ligand, giving a table of values for each internucleotidic bond and rendering the differential cleavage plot in only a few seconds.

Highly ordered nanocomposites via a monomer self-assembly in situ condensation approach

DOEpatents

Gin, Douglas L.; Fischer, Walter M.; Gray, David H.; Smith, Ryan C.

1998-01-01

A method for synthesizing composites with architectural control on the nanometer scale is described. A polymerizable lyotropic liquid-crystalline monomer is used to form an inverse hexagonal phase in the presence of a second polymer precursor solution. The monomer system acts as an organic template, providing the underlying matrix and order of the composite system. Polymerization of the template in the presence of an optional cross-linking agent with retention of the liquid-crystalline order is carried out followed by a second polymerization of the second polymer precursor within the channels of the polymer template to provide an ordered nanocomposite material.

Market-oriented Programming Using Small-world Networks for Controlling Building Environments

NASA Astrophysics Data System (ADS)

Shigei, Noritaka; Miyajima, Hiromi; Osako, Tsukasa

The market model, which is one of the economic activity models, is modeled as an agent system, and applying the model to the resource allocation problem has been studied. For air conditioning control of building, which is one of the resource allocation problems, an effective method based on the agent system using auction has been proposed for traditional PID controller. On the other hand, it has been considered that this method is performed by decentralized control. However, its decentralization is not perfect, and its performace is not enough. In this paper, firstly, we propose a perfectly decentralized agent model and show its performance. Secondly, in order to improve the model, we propose the agent model based on small-world model. The effectiveness of the proposed model is shown by simulation.

Is the efficacy of biological control against plant diseases likely to be more durable than that of chemical pesticides?

PubMed Central

Bardin, Marc; Ajouz, Sakhr; Comby, Morgane; Lopez-Ferber, Miguel; Graillot, Benoît; Siegwart, Myriam; Nicot, Philippe C.

2015-01-01

The durability of a control method for plant protection is defined as the persistence of its efficacy in space and time. It depends on (i) the selection pressure exerted by it on populations of plant pathogens and (ii) on the capacity of these pathogens to adapt to the control method. Erosion of effectiveness of conventional plant protection methods has been widely studied in the past. For example, apparition of resistance to chemical pesticides in plant pathogens or pests has been extensively documented. The durability of biological control has often been assumed to be higher than that of chemical control. Results concerning pest management in agricultural systems have shown that this assumption may not always be justified. Resistance of various pests to one or several toxins of Bacillus thuringiensis and apparition of resistance of the codling moth Cydia pomonella to the C. pomonella granulovirus have, for example, been described. In contrast with the situation for pests, the durability of biological control of plant diseases has hardly been studied and no scientific reports proving the loss of efficiency of biological control agents against plant pathogens in practice has been published so far. Knowledge concerning the possible erosion of effectiveness of biological control is essential to ensure a durable efficacy of biological control agents on target plant pathogens. This knowledge will result in identifying risk factors that can foster the selection of strains of plant pathogens resistant to biological control agents. It will also result in identifying types of biological control agents with lower risk of efficacy loss, i.e., modes of action of biological control agents that does not favor the selection of resistant isolates in natural populations of plant pathogens. An analysis of the scientific literature was then conducted to assess the potential for plant pathogens to become resistant to biological control agents. PMID:26284088

Output Consensus of Heterogeneous Linear Multi-Agent Systems by Distributed Event-Triggered/Self-Triggered Strategy.

PubMed

Hu, Wenfeng; Liu, Lu; Feng, Gang

2016-09-02

This paper addresses the output consensus problem of heterogeneous linear multi-agent systems. We first propose a novel distributed event-triggered control scheme. It is shown that, with the proposed control scheme, the output consensus problem can be solved if two matrix equations are satisfied. Then, we further propose a novel self-triggered control scheme, with which continuous monitoring is avoided. By introducing a fixed timer into both event- and self-triggered control schemes, Zeno behavior can be ruled out for each agent. The effectiveness of the event- and self-triggered control schemes is illustrated by an example.

77 FR 71702 - Possession, Use, and Transfer of Select Agents and Toxins; Biennial Review

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-04

... of Select Agents and Toxins; Biennial Review AGENCY: Centers for Disease Control and Prevention (CDC... designated certain select agents and toxins as Tier 1 agents. DATES: Effective Date: Effective December 4, 2012. FOR FURTHER INFORMATION CONTACT: Robbin Weyant, Director, Division of Select Agents and Toxins...

Adjustably Autonomous Multi-agent Plan Execution with an Internal Spacecraft Free-Flying Robot Prototype

NASA Technical Reports Server (NTRS)

Dorais, Gregory A.; Nicewarner, Keith

2006-01-01

We present an multi-agent model-based autonomy architecture with monitoring, planning, diagnosis, and execution elements. We discuss an internal spacecraft free-flying robot prototype controlled by an implementation of this architecture and a ground test facility used for development. In addition, we discuss a simplified environment control life support system for the spacecraft domain also controlled by an implementation of this architecture. We discuss adjustable autonomy and how it applies to this architecture. We describe an interface that provides the user situation awareness of both autonomous systems and enables the user to dynamically edit the plans prior to and during execution as well as control these agents at various levels of autonomy. This interface also permits the agents to query the user or request the user to perform tasks to help achieve the commanded goals. We conclude by describing a scenario where these two agents and a human interact to cooperatively detect, diagnose and recover from a simulated spacecraft fault.

Multi-Agent Diagnosis and Control of an Air Revitalization System for Life Support in Space

NASA Technical Reports Server (NTRS)

Malin, Jane T.; Kowing, Jeffrey; Nieten, Joseph; Graham, Jeffrey s.; Schreckenghost, Debra; Bonasso, Pete; Fleming, Land D.; MacMahon, Matt; Thronesbery, Carroll

2000-01-01

An architecture of interoperating agents has been developed to provide control and fault management for advanced life support systems in space. In this adjustable autonomy architecture, software agents coordinate with human agents and provide support in novel fault management situations. This architecture combines the Livingstone model-based mode identification and reconfiguration (MIR) system with the 3T architecture for autonomous flexible command and control. The MIR software agent performs model-based state identification and diagnosis. MIR identifies novel recovery configurations and the set of commands required for the recovery. The AZT procedural executive and the human operator use the diagnoses and recovery recommendations, and provide command sequencing. User interface extensions have been developed to support human monitoring of both AZT and MIR data and activities. This architecture has been demonstrated performing control and fault management for an oxygen production system for air revitalization in space. The software operates in a dynamic simulation testbed.

The Multidimensional Aggression Scale for the Structured Doll Play Interview

ERIC Educational Resources Information Center

Abramson, Paul R.; And Others

1974-01-01

A multidimensional aggression scoring system for preschool children's responses to the structured doll play interview is described. The system, which incorporates previous investigator's findings, scales doll play responses along three dimensions of aggression: intensity, agent, and directionality. (Author)

Cross-scale drivers of natural disturbances prone to anthropogenic amplification: Dynamics of biome-wide bark beetle eruptions

Treesearch

Kenneth F. Raffa; Brian H. Aukema; Barbara J. Bentz; Allan L. Carroll; Jeffrey A. Hicke; Monica G. Turner; William H. Romme

2008-01-01

Biome-scale disturbances by eruptive herbivores provide valuable insights into species interactions, ecosystem-function, and impacts of global change. We present a conceptual framework using one system as a model, emphasizing interactions across levels of biological hierarchy and spatiotemporal scales. Bark beetles are major natural disturbance agents in western North...

Male bladder cancer risk and occupational exposure according to a job-exposure matrix-a case-control study in British Columbia, Canada.

PubMed

Richardson, Kathryn; Band, Pierre R; Astrakianakis, George; Le, Nhu D

2007-12-01

The authors investigated the risk of bladder cancer in association with exposure to over 12 000 occupational chemical agents, complex mixtures, and other substances (hereafter referred to as chemical agents). Adult males diagnosed with cancer between 1983 and 1990 in British Columbia, Canada, were surveyed. Detailed occupational histories and confounding information was provided by a self-administered questionnaire. Cancer controls were matched to bladder cancer cases, resulting in 1062 cases and 8057 controls for the analysis. An extensive United-States-based job-exposure matrix was applied to estimate cumulative exposure to occupational chemical agents. Odds ratios for bladder cancer due to exposure to chemical agents were estimated via conditional logistic regression analyses, adjusted for important confounders. A significantly (P<0.05) increased risk was detected for ever exposure to 635 chemical agents, and 341 chemical agents exhibited a significantly increasing dose-response relationship. Adjustment for multiple comparisons resulted in a subset of 29 chemical agents that continued to show significant results. A principal components analysis classified these 29 chemical agents into five independent groups, distinguished mainly by job. Exposures to these chemical agents were largely due to employment in the logging and construction industries and occupations involving motor vehicles. Consistent results were observed for bladder carcinogens reported in the literature. This study suggests that several specific chemical agents were significantly associated with the risk of bladder cancer. The chemical agents were mainly derivatives or combustion products of fossil fuels. The results corroborate important findings from the literature and document a risk for specific chemical agents not previously reported.

Access Control for Cooperation Systems Based on Group Situation

NASA Astrophysics Data System (ADS)

Kim, Minsoo; Joshi, James B. D.; Kim, Minkoo

Cooperation systems characterize many emerging environments such as ubiquitous and pervasive systems. Agent based cooperation systems have been proposed in the literature to address challenges of such emerging application environments. A key aspect of such agent based cooperation system is the group situation that changes dynamically and governs the requirements of the cooperation. While individual agent context is important, the overall cooperation behavior is more driven by the group context because of relationships and interactions between agents. Dynamic access control based on group situation is a crucial challenge in such cooperation systems. In this paper we propose a dynamic role based access control model for cooperation systems based on group situation. The model emphasizes capability based agent to role mapping and group situation based permission assignment to allow capturing dynamic access policies that evolve continuously.

Observer-based output consensus of a class of heterogeneous multi-agent systems with unmatched disturbances

NASA Astrophysics Data System (ADS)

Zhang, Jiancheng; Zhu, Fanglai

2018-03-01

In this paper, the output consensus of a class of linear heterogeneous multi-agent systems with unmatched disturbances is considered. Firstly, based on the relative output information among neighboring agents, we propose an asymptotic sliding-mode based consensus control scheme, under which, the output consensus error can converge to zero by removing the disturbances from output channels. Secondly, in order to reach the consensus goal, we design a novel high-order unknown input observer for each agent. It can estimate not only each agent's states and disturbances, but also the disturbances' high-order derivatives, which are required in the control scheme aforementioned above. The observer-based consensus control laws and the convergence analysis of the consensus error dynamics are given. Finally, a simulation example is provided to verify the validity of our methods.

Efficacy of venlafaxine extended-release capsules in nondepressed outpatients with generalized anxiety disorder: A 6-month randomized controlled trial.

PubMed

Gelenberg, A J; Lydiard, R B; Rudolph, R L; Aguiar, L; Haskins, J T; Salinas, E

2000-06-21

Generalized anxiety disorder (GAD) is a chronic disorder that is associated with debilitating psychic and somatic symptoms. Venlafaxine extended-release (XR) capsules have been shown to be effective in short-term treatment of patients with GAD without major depressive disorder (MDD), but long-term data are needed to establish whether this agent confers persistent benefits. To compare the 6-month efficacy and safety of a flexible dosage of venlafaxine XR in outpatients with GAD without associated MDD. Six-month, randomized, double-blind, placebo-controlled, parallel-group trial conducted May 1996 to October 1997. Fourteen outpatient clinics and private psychiatric practices in the United States. A total of 251 outpatients aged 18 years or older who met Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) criteria for GAD, had sufficient symptoms to require treatment, and did not have coexisting MDD. Participants were randomly assigned to receive either placebo (n=127) or venlafaxine XR (75, 150, or 225 mg/d, as required to control symptoms; n=124) for 28 weeks. Changes from baseline in the Hamilton Rating Scale for Anxiety (HAM-A) total score, the HAM-A psychic anxiety factor score, and the Clinical Global Impressions (CGI) scale Severity of Illness and Global Improvement scores, compared by intervention group. During weeks 6 through 28, response rates in the venlafaxine XR group were 69% or higher compared with rates of 42% to 46% in the placebo group (P<.001). By an evaluable-patient analysis, venlafaxine XR compared with placebo significantly improved anxiety scores from week 1 or 2 through week 28 on all primary efficacy measures, including the HAM-A total (P<.001), the HAM-A psychic anxiety factor (P<.001), and the CGI scale scores (P<.001). Adjusted mean changes from baseline to week 28 using last-observation-carried-forward methods were for HAM-A, venlafaxine XR -13.4, placebo -8.7 (P<.001); for HAM-A psychic anxiety score, venlafaxine XR -7.4, placebo -4.2 (P<.001); and for CGI-Improvement, venlafaxine XR 2.2, placebo 3.0 (P<.001). The most common treatment-emergent adverse event was nausea, followed by somnolence and dry mouth. This study is the first placebo-controlled demonstration of the long-term efficacy of any drug class in treating outpatients with DSM-IV-diagnosed GAD. Venlafaxine XR is an effective, rapidly acting, safe, once-daily agent for both the short- and long-term treatment of anxiety and may provide an important alternative to currently available anxiolytics. JAMA. 2000.

Correlation between information diffusion and opinion evolution on social media

NASA Astrophysics Data System (ADS)

Xiong, Fei; Liu, Yun; Zhang, Zhenjiang

2014-12-01

Information diffusion and opinion evolution are often treated as two independent processes. Opinion models assume the topic reaches each agent and agents initially have their own ideas. In fact, the processes of information diffusion and opinion evolution often intertwine with each other. Whether the influence between these two processes plays a role in the system state is unclear. In this paper, we collected more than one million real data from a well-known social platform, and analysed large-scale user diffusion behaviour and opinion formation. We found that user inter-event time follows a two-scaling power-law distribution with two different power exponents. Public opinion stabilizes quickly and evolves toward the direction of convergence, but the consensus state is prevented by a few opponents. We propose a three-state opinion model accompanied by information diffusion. Agents form and exchange their opinions during information diffusion. Conversely, agents' opinions also influence their diffusion actions. Simulations show that the model with a correlation of the two processes produces similar statistical characteristics as empirical results. A fast epidemic process drives individual opinions to converge more obviously. Unlike previous epidemic models, the number of infected agents does not always increase with the update rate, but has a peak with an intermediate value of the rate.

Combination of glycolic acid peel and topical 20% azelaic acid cream in melasma patients: efficacy and improvement in quality of life.

PubMed

Dayal, Surabhi; Sahu, Priyadarshini; Dua, Ruchika

2017-03-01

Glycolic acid (GA) peel is one of the most versatile agents in the treatment of melasma. GA peeling alone or in combination with topical hypopigmenting agents has shown encouraging results. However, there is paucity of controlled trial demonstrating the efficacy of glycolic peel in conjunction with topical azelaic acid (AA). We therefore sought to highlight the efficacy and safety of this combination in melasma. To assess the clinical efficacy, safety and reduction in melasma quality of life (MELASQOL) scores on combining serial GA peels with topical 20% AA cream in epidermal melasma. Sixty patients of epidermal melasma were enrolled for 24 weeks. Patients were divided into two groups: (1) Study group received serial GA peel every 3 weeks with twice daily 20% AA cream, and (2) control group received only 20% AA cream. Clinical improvement was assessed objectively using Melasma Area Severity Index (MASI). Melasma-related quality of life was measured by MELASQOL scale in both groups. Side effects were observed at each visit. The improvement in MASI and percentage decrease in MASI scoring were statistically significant 12 weeks onwards in study group as compared to control group. There was also a significant reduction in MELASQOL scores in study group as compared to control group after treatment. Minor reversible side effects were observed in both groups, which did not require cessation of therapy. GA peel enhances therapeutic efficacy of topical AA cream for treatment of melasma, with improvement in quality of life without serious side effects. © 2016 Wiley Periodicals, Inc.

Use of atypical antipsychotics for treatment-resistant major depressive disorder.

PubMed

Papakostas, George I; Shelton, Richard C

2008-12-01

Despite the progressive increase in the number of pharmacologic agents with potential antidepressant activity, many patients suffering from major depressive disorder (MDD) continue to be symptomatic. Clearly, an urgent need exists to develop safer, better tolerated, and more effective treatments for MDD. Use of atypical antipsychotic agents as adjunctive treatment for treatment-resistant MDD (TRD) represents one such effort toward novel pharmacotherapy development. Atypical antipsychotic agents have been hypothesized to be beneficial in treating mood disorders, including TRD, as a result of their complex mechanisms of action. After an initial series of positive case reports, series, and small clinical trials, subsequent larger-scale projects have yielded conflicting results. However, more recently, larger-scale clinical trials have supported the effectiveness of at least some of these medications. This review summarizes the existing data regarding the effectiveness of these medications in treating TRD, including biochemical rationale and clinical data.

Adaptive tracking control of leader-following linear multi-agent systems with external disturbances

NASA Astrophysics Data System (ADS)

Lin, Hanquan; Wei, Qinglai; Liu, Derong; Ma, Hongwen

2016-10-01

In this paper, the consensus problem for leader-following linear multi-agent systems with external disturbances is investigated. Brownian motions are used to describe exogenous disturbances. A distributed tracking controller based on Riccati inequalities with an adaptive law for adjusting coupling weights between neighbouring agents is designed for leader-following multi-agent systems under fixed and switching topologies. In traditional distributed static controllers, the coupling weights depend on the communication graph. However, coupling weights associated with the feedback gain matrix in our method are updated by state errors between neighbouring agents. We further present the stability analysis of leader-following multi-agent systems with stochastic disturbances under switching topology. Most traditional literature requires the graph to be connected all the time, while the communication graph is only assumed to be jointly connected in this paper. The design technique is based on Riccati inequalities and algebraic graph theory. Finally, simulations are given to show the validity of our method.

Large-scale quarantine following biological terrorism in the United States: scientific examination, logistic and legal limits, and possible consequences.

PubMed

Barbera, J; Macintyre, A; Gostin, L; Inglesby, T; O'Toole, T; DeAtley, C; Tonat, K; Layton, M

2001-12-05

Concern for potential bioterrorist attacks causing mass casualties has increased recently. Particular attention has been paid to scenarios in which a biological agent capable of person-to-person transmission, such as smallpox, is intentionally released among civilians. Multiple public health interventions are possible to effect disease containment in this context. One disease control measure that has been regularly proposed in various settings is the imposition of large-scale or geographic quarantine on the potentially exposed population. Although large-scale quarantine has not been implemented in recent US history, it has been used on a small scale in biological hoaxes, and it has been invoked in federally sponsored bioterrorism exercises. This article reviews the scientific principles that are relevant to the likely effectiveness of quarantine, the logistic barriers to its implementation, legal issues that a large-scale quarantine raises, and possible adverse consequences that might result from quarantine action. Imposition of large-scale quarantine-compulsory sequestration of groups of possibly exposed persons or human confinement within certain geographic areas to prevent spread of contagious disease-should not be considered a primary public health strategy in most imaginable circumstances. In the majority of contexts, other less extreme public health actions are likely to be more effective and create fewer unintended adverse consequences than quarantine. Actions and areas for future research, policy development, and response planning efforts are provided.

Design of Genetic Algorithms for Topology Control of Unmanned Vehicles

DTIC Science & Technology

2010-01-01

decentralised topology control mechanism distributed among active running software agents to achieve a uniform spread of terrestrial unmanned vehicles...14. ABSTRACT We present genetic algorithms (GAs) as a decentralised topology control mechanism distributed among active running software agents to...inspired topology control algorithm. The topology control of UVs using a decentralised solution over an unknown geographical terrain is a challenging

On-lattice agent-based simulation of populations of cells within the open-source Chaste framework.

PubMed

Figueredo, Grazziela P; Joshi, Tanvi V; Osborne, James M; Byrne, Helen M; Owen, Markus R

2013-04-06

Over the years, agent-based models have been developed that combine cell division and reinforced random walks of cells on a regular lattice, reaction-diffusion equations for nutrients and growth factors; and ordinary differential equations for the subcellular networks regulating the cell cycle. When linked to a vascular layer, this multiple scale model framework has been applied to tumour growth and therapy. Here, we report on the creation of an agent-based multi-scale environment amalgamating the characteristics of these models within a Virtual Physiological Human (VPH) Exemplar Project. This project enables reuse, integration, expansion and sharing of the model and relevant data. The agent-based and reaction-diffusion parts of the multi-scale model have been implemented and are available for download as part of the latest public release of Chaste (Cancer, Heart and Soft Tissue Environment; http://www.cs.ox.ac.uk/chaste/), part of the VPH Toolkit (http://toolkit.vph-noe.eu/). The environment functionalities are verified against the original models, in addition to extra validation of all aspects of the code. In this work, we present the details of the implementation of the agent-based environment, including the system description, the conceptual model, the development of the simulation model and the processes of verification and validation of the simulation results. We explore the potential use of the environment by presenting exemplar applications of the 'what if' scenarios that can easily be studied in the environment. These examples relate to tumour growth, cellular competition for resources and tumour responses to hypoxia (low oxygen levels). We conclude our work by summarizing the future steps for the expansion of the current system.

Ecological host-range of Lilioceris cheni (Coleoptera: Chrysomelidae), a biological control agent of Dioscorea bulbifera L.

USDA-ARS?s Scientific Manuscript database

Open-field host-specificity testing assesses the host-range of a biological control agent in a setting that permits the agent to use its full complement of host-seeking behaviors. This form of testing, particularly when it includes a no-choice phase in which the target weed is killed, may provide th...

Evaluation of establishment of Cyphocleonus achates and its potential impact on spotted knapweed

Treesearch

Nancy Sturdevant; Sandy Kegley; Yvette Ortega; Dean Pearson

2006-01-01

Environmental characteristics of a site may greatly influence the establishment and impact of biological control agents on the target weed. A biological control agent that is highly successful in one region may be virtually ineffective in another (Gurr and Wratten 2000). To maximize the use of limited availability of agents and financial resources, we should...

Wealth distribution, Pareto law, and stretched exponential decay of money: Computer simulations analysis of agent-based models

NASA Astrophysics Data System (ADS)

Aydiner, Ekrem; Cherstvy, Andrey G.; Metzler, Ralf

2018-01-01

We study by Monte Carlo simulations a kinetic exchange trading model for both fixed and distributed saving propensities of the agents and rationalize the person and wealth distributions. We show that the newly introduced wealth distribution - that may be more amenable in certain situations - features a different power-law exponent, particularly for distributed saving propensities of the agents. For open agent-based systems, we analyze the person and wealth distributions and find that the presence of trap agents alters their amplitude, leaving however the scaling exponents nearly unaffected. For an open system, we show that the total wealth - for different trap agent densities and saving propensities of the agents - decreases in time according to the classical Kohlrausch-Williams-Watts stretched exponential law. Interestingly, this decay does not depend on the trap agent density, but rather on saving propensities. The system relaxation for fixed and distributed saving schemes are found to be different.

A CSP-Based Agent Modeling Framework for the Cougaar Agent-Based Architecture

NASA Technical Reports Server (NTRS)

Gracanin, Denis; Singh, H. Lally; Eltoweissy, Mohamed; Hinchey, Michael G.; Bohner, Shawn A.

2005-01-01

Cognitive Agent Architecture (Cougaar) is a Java-based architecture for large-scale distributed agent-based applications. A Cougaar agent is an autonomous software entity with behaviors that represent a real-world entity (e.g., a business process). A Cougaar-based Model Driven Architecture approach, currently under development, uses a description of system's functionality (requirements) to automatically implement the system in Cougaar. The Communicating Sequential Processes (CSP) formalism is used for the formal validation of the generated system. Two main agent components, a blackboard and a plugin, are modeled as CSP processes. A set of channels represents communications between the blackboard and individual plugins. The blackboard is represented as a CSP process that communicates with every agent in the collection. The developed CSP-based Cougaar modeling framework provides a starting point for a more complete formal verification of the automatically generated Cougaar code. Currently it is used to verify the behavior of an individual agent in terms of CSP properties and to analyze the corresponding Cougaar society.

Wealth condensation in a Barabasi-Albert network

NASA Astrophysics Data System (ADS)

Vázquez-Montejo, J.; Huerta-Quintanilla, R.; Rodríguez-Achach, M.

2010-04-01

We study the flow of money among agents in a Barabasi-Albert (BA) scale free network, where each network node represents an agent and money exchange interactions are established through links. The system allows money trade between two agents at a time, betting a fraction f of the poorer’s agent wealth. We also allow for the bet to be biased, giving the poorer agent a winning probability p. In the no network case there is a phase transition involving a relationship between p and f. In the networked case, we also found a condensation interface, however, this is not a complete condensation due to the presence of clusters in the network and its topology. As can be expected, the winner is always a well-connected agent, but we also found that the mean wealth decreases with the agents’ connectivity.

Multiscale diffusion of a molecular probe in a crowded environment: a concept

NASA Astrophysics Data System (ADS)

Currie, Megan; Thao, Chang; Timerman, Randi; Welty, Robb; Berry, Brenden; Sheets, Erin D.; Heikal, Ahmed A.

2015-08-01

Living cells are crowded with macromolecules and organelles. Yet, it is not fully understood how macromolecular crowding affects the myriad of biochemical reactions, transport and the structural stability of biomolecules that are essential to cellular function and survival. These molecular processes, with or without electrostatic interactions, in living cells are therefore expected to be distinct from those carried out in test tube in dilute solutions where excluded volumes are absent. Thus there is an urgent need to understand the macromolecular crowding effects on cellular and molecular biophysics towards quantitative cell biology. In this report, we investigated how biomimetic crowding affects both the rotational and translation diffusion of a small probe (rhodamine green, RhG). For biomimetic crowding agents, we used Ficoll-70 (synthetic polymer), bovine serum albumin and ovalbumin (proteins) at various concentrations in a buffer at room temperature. As a control, we carried out similar measurements on glycerolenriched buffer as an environment with homogeneous viscosity as a function of glycerol concentration. The corresponding bulk viscosity was measured independently to test the validity of the Stokes-Einstein model of a diffusing species undergoing a random walk. For rotational diffusion (ps-ns time scale), we used time-resolved anisotropy measurements to examine potential binding of RhG as a function of the crowding agents (surface structure and size). For translational diffusion (μs-s time scale), we used fluorescence correlation spectroscopy for single-molecule fluctuation analysis. Our results allow us to examine the diffusion model of a molecular probe in crowded environments as a function of concentration, length scale, homogeneous versus heterogeneous viscosity, size and surface structures. These biomimetic crowding studies, using non-invasive fluorescence spectroscopy methods, represent an important step towards understanding cellular biophysics and quantitative cell biology.

Control of oxidation-reduction potential during Cheddar cheese ripening and its effect on the production of volatile flavour compounds.

PubMed

Caldeo, Veronica; Hannon, John A; Hickey, Dara-Kate; Waldron, Dave; Wilkinson, Martin G; Beresford, Thomas P; McSweeney, Paul L H

2016-11-01

In cheese, a negative oxidation-reduction (redox) potential is required for the stability of aroma, especially that associated with volatile sulphur compounds. To control the redox potential during ripening, redox agents were added to the salted curd of Cheddar cheese before pressing. The control cheese contained only salt, while different oxidising or reducing agents were added with the NaCl to the experimental cheeses. KIO3 (at 0·05, 0·1 and 1%, w/w) was used as the oxidising agent while cysteine (at 2%, w/w) and Na2S2O4 (at 0·05 and 0·1%, w/w) were used as reducing agents. During ripening the redox potential of the cheeses made with the reducing agents did not differ significantly from the control cheese (E h ≈ -120 mV) while the cheeses made with 0·1 and 0·05% KIO3 had a significantly higher and positive redox potential in the first month of ripening. Cheese made with 1% KIO3 had positive values of redox potential throughout ripening but no starter lactic acid bacteria survived in this cheese; however, numbers of starter organisms in all other cheeses were similar. Principal component analysis (PCA) of the volatile compounds clearly separated the cheeses made with the reducing agents from cheeses made with the oxidising agents at 2 month of ripening. Cheeses with reducing agents were characterized by the presence of sulphur compounds whereas cheeses made with KIO3 were characterized mainly by aldehydes. At 6 month of ripening, separation by PCA was less evident. These findings support the hypothesis that redox potential could be controlled during ripening and that this parameter has an influence on the development of cheese flavour.

Biofouling of reverse osmosis membranes: effects of cleaning on biofilm microbial communities, membrane performance, and adherence of extracellular polymeric substances.

PubMed

Al Ashhab, Ashraf; Sweity, Amer; Bayramoglu, Bihter; Herzberg, Moshe; Gillor, Osnat

2017-05-01

Laboratory-scale reverse osmosis (RO) flat-sheet systems were used with two parallel flow cells, one treated with cleaning agents and a control (ie undisturbed). The cleaning efforts increased the affinity of extracellular polymeric substances (EPS) to the RO membrane and altered the biofilm surface structure. Analysis of the membrane biofilm community composition revealed the dominance of Proteobacteria. However, within the phylum Proteobacteria, γ-Proteobacteria dominated the cleaned membrane biofilm, while β-Proteobacteria dominated the control biofilm. The composition of the fungal phyla was also altered by cleaning, with enhancement of Ascomycota and suppression of Basidiomycota. The results suggest that repeated cleaning cycles select for microbial groups that strongly attach to the RO membrane surface by producing rigid and adhesive EPS that hampers membrane performance.

Research on e-commerce transaction networks using multi-agent modelling and open application programming interface

NASA Astrophysics Data System (ADS)

Piao, Chunhui; Han, Xufang; Wu, Harris

2010-08-01

We provide a formal definition of an e-commerce transaction network. Agent-based modelling is used to simulate e-commerce transaction networks. For real-world analysis, we studied the open application programming interfaces (APIs) from eBay and Taobao e-commerce websites and captured real transaction data. Pajek is used to visualise the agent relationships in the transaction network. We derived one-mode networks from the transaction network and analysed them using degree and betweenness centrality. Integrating multi-agent modelling, open APIs and social network analysis, we propose a new way to study large-scale e-commerce systems.

Emergent Societal Effects of Crimino-Social Forces in an Animat Agent Model

NASA Astrophysics Data System (ADS)

Scogings, Chris J.; Hawick, Ken A.

Societal behaviour can be studied at a causal level by perturbing a stable multi-agent model with new microscopic behaviours and observing the statistical response over an ensemble of simulated model systems. We report on the effects of introducing criminal and law-enforcing behaviours into a large scale animat agent model and describe the complex spatial agent patterns and population changes that result. Our well-established predator-prey substrate model provides a background framework against which these new microscopic behaviours can be trialled and investigated. We describe some quantitative results and some surprising conclusions concerning the overall societal health when individually anti-social behaviour is introduced.

Controllability of multi-agent systems with periodically switching topologies and switching leaders

NASA Astrophysics Data System (ADS)

Tian, Lingling; Zhao, Bin; Wang, Long

2018-05-01

This paper considers controllability of multi-agent systems with periodically switching topologies and switching leaders. The concept of m-periodic controllability is proposed, and a criterion for m-periodic controllability is established. The effect of the duration of subsystems on controllability is analysed by utilising a property of analytic functions. In addition, the influence of switching periods on controllability is investigated, and an algorithm is proposed to search for the fewest periods to ensure controllability. A necessary condition for m-periodic controllability is obtained from the perspective of eigenvectors of the subsystems' Laplacian matrices. For a system with switching leaders, it is proved that switching-leader controllability is equivalent to multiple-leader controllability. Furthermore, both the switching order and the tenure of agents being leaders have no effect on the controllability. Some examples are provided to illustrate the theoretical results.

Microbial control in Asia: a bellwether for the future?

PubMed

Gelernter, Wendy D

2007-07-01

Advances and barriers faced by microbial control efforts in Asia offer instructive insights for microbial control in general. The papers in this series, which are based on plenary lectures given at the Society for Invertebrate Pathology 2006 meeting in Wuhan, China, explore the history and current status of microbial control in China, Japan, and Southeast Asia, and in doing so, bring to light the following key assumptions that deserve further examination; (1) the adoption rate of microbial control is well documented; (2) microbial control agents can compete directly with conventional insecticides; (3) microbial control agents are relatively easy and inexpensive to produce and develop; (4) patents will promote innovation and investor interest in microbial control. Alternative viewpoints are presented that can hopefully aid in future efforts to develop more safe and effective microbial control agents.

Large-Scale Environmental Influences on Aquatic Animal Health

EPA Science Inventory

In the latter portion of the 20th century, North America experienced numerous large-scale mortality events affecting a broad diversity of aquatic animals. Short-term forensic investigations of these events have sometimes characterized a causative agent or condition, but have rare...

The Effect of Pacing on Learners' Perceptions of Pedagogical Agents

ERIC Educational Resources Information Center

Schroeder, Noah L.; Craig, Scotty D.

2017-01-01

This study examined the influence of three levels of learner control on learners' perceptions when learning with a pedagogical agent. Pedagogical agents have shown promise for improving learning and connections with learning materials within video-based instruction, and research has shown that agent design choices can influence how agents are…

Industrial antifoam agents impair ethanol fermentation and induce stress responses in yeast cells.

PubMed

Nielsen, Jens Christian; Senne de Oliveira Lino, Felipe; Rasmussen, Thomas Gundelund; Thykær, Jette; Workman, Christopher T; Basso, Thiago Olitta

2017-11-01

The Brazilian sugarcane industry constitutes one of the biggest and most efficient ethanol production processes in the world. Brazilian ethanol production utilizes a unique process, which includes cell recycling, acid wash, and non-aseptic conditions. Process characteristics, such as extensive CO 2 generation, poor quality of raw materials, and frequent contaminations, all lead to excessive foam formation during fermentations, which is treated with antifoam agents (AFA). In this study, we have investigated the impact of industrial AFA treatments on the physiology and transcriptome of the industrial ethanol strain Saccharomyces cerevisiae CAT-1. The investigated AFA included industrially used AFA acquired from Brazilian ethanol plants and commercially available AFA commonly used in the fermentation literature. In batch fermentations, it was shown that industrial AFA compromised growth rates and glucose uptake rates, while commercial AFA had no effect in concentrations relevant for defoaming purposes. Industrial AFA were further tested in laboratory scale simulations of the Brazilian ethanol production process and proved to decrease cell viability compared to the control, and the effects were intensified with increasing AFA concentrations and exposure time. Transcriptome analysis showed that AFA treatments induced additional stress responses in yeast cells compared to the control, shown by an up-regulation of stress-specific genes and a down-regulation of lipid biosynthesis, especially ergosterol. By documenting the detrimental effects associated with chemical AFA, we highlight the importance of developing innocuous systems for foam control in industrial fermentation processes.

Current levels of suppression of waterhyacinth in Florida by classical biological control agents

USDA-ARS?s Scientific Manuscript database

Waterhyacinth, Eichhornia crassipes, has been a global target for classical biological control efforts for decades. In Florida, herbicides are the primary tactic employed, usually without regard for the activities of the three biological control agents introduced intentionally during the 1970's, na...

Screening of botanical extracts for repellence against western corn rootworm larvae

USDA-ARS?s Scientific Manuscript database

The ability of Western corn rootworm (WCR) to develop resistance to various management practices enforces the development of new control options. Repellent substances can act as efficacy enhancing agents in WCR control with biological control agents. The present study investigated the potential repe...

Fixed and flexible formularies as cost-control mechanisms.

PubMed

Dewa, Carolyn S; Hoch, Jeffrey S

2003-06-01

The purpose of this review is to consider the prevalent types of fixed and flexible formularies, the general economic principles on which they are based and the evidence for their effectiveness in controlling rising drug expenditures. The principal-agent relationship and economic model underlying the various types of formularies are described. The principal-agent model describes a relationship where there is an asymmetry of information between two parties involved in a particular task. As a result of this asymmetry of information, the party with less information (the principal) allows the party with more information (the agent) to make decisions about that task or activity for them. In the case of formularies and cost-control, the principal is the payer. Depending on the incentives offered by the formulary, the agent can alternately be the prescriber, dispenser or patient. The success of a formulary type to control costs is dependent on two main factors. First, the payer (the principal) must identify the agent for whom it is reasonable to create incentives that incorporate the financial risks associated with use of the drugs. Second, the payer must develop a structure that best aligns the principal and agent objectives. The principal-agent framework serves as the vehicle through which the authors examine five major types of formularies (i.e., closed, best available price, reference-based pricing, tiered and open formularies) and their inherent incentives and limitations. The evidence for their effectiveness as cost-control mechanisms is reviewed and the system factors that can affect formulary success will be discussed. Finally, the authors' observations are summarized and interpreted, and suggested implications for future use of formularies in controlling the costs of pharmaceutical use are offered.

Treatment of primary Sjögren syndrome: a systematic review.

PubMed

Ramos-Casals, Manuel; Tzioufas, Athanasios G; Stone, John H; Sisó, Antoni; Bosch, Xavier

2010-07-28

A variety of topical and systemic drugs are available to treat primary Sjögren syndrome, although no evidence-based therapeutic guidelines are currently available. To summarize evidence on primary Sjögren syndrome drug therapy from randomized controlled trials. We searched MEDLINE and EMBASE for articles on drug therapy for primary Sjögren syndrome published between January 1, 1986, and April 30, 2010. Controlled trials of topical and systemic drugs including adult patients with primary Sjögren syndrome were selected as the primary information source. The search strategy yielded 37 trials. A placebo-controlled trial found significant improvement in the Schirmer and corneal staining scores, blurred vision, and artificial tear use in patients treated with topical ocular 0.05% cyclosporine. Three placebo-controlled trials found that pilocarpine was associated with improvements in dry mouth (61%-70% vs 24%-31% in the placebo group) and dry eye (42%-53% vs 26%). Two placebo-controlled trials found that cevimeline was associated with improvement in dry mouth (66%-76% vs 35%-37% in the placebo group) and dry eye (39%-72% vs 24%-30%). Small trials (<20 patients) found no significant improvement in sicca outcomes for oral prednisone or hydroxychloroquine and limited benefits for immunosuppressive agents (azathioprine and cyclosporine). A large trial found limited benefits for oral interferon alfa-2a. Two placebo-controlled trials of infliximab and etanercept did not achieve the primary outcome (a composite visual analog scale measuring joint pain, fatigue, and dryness); neither did 2 small trials (<30 patients) testing rituximab, although significant results were observed in some secondary outcomes and improvement compared with baseline. In primary Sjögren syndrome, evidence from controlled trials suggests benefits for pilocarpine and cevimeline for sicca features and topical cyclosporine for moderate or severe dry eye. Anti-tumor necrosis factor agents have not shown clinical efficacy, and larger controlled trials are needed to establish the efficacy of rituximab.

A comparative study on the impact of intra-articular injections of hyaluronic acid, tenoxicam and betametazon on the relief of temporomandibular joint disorder complaints.

PubMed

Gencer, Zeliha Kapusuz; Özkiriş, Mahmut; Okur, Aylin; Korkmaz, Murat; Saydam, Levent

2014-10-01

The aim of this study was to compare the efficacy of intra-articular injections of three different agents with well known anti-inflammatory properties. Between April 2010 and January 2013 a total of 100 patients who were diagnosed as temporomandibular joint disorder in the Department of Otolaryngology at Bozok University School of Medicine were prospectively studied. Patients with symptoms of jaw pain, limited or painful jaw movement, clicking or grating within the joint, were evaluated with temporomandibular CT to investigate the presence of cartilage or capsule degeneration. In the study group there were 55 female and 45 male patients who were non-responders to conventional anti-inflammatory treatment for TMJ complaints. The patients were randomly divided into four groups consisting of a control group and three different groups who underwent intra-articular injection of one given anti-inflammatory agent for each group. We injected saline solution to intra-articular space in the control group. Of three anti-inflammatory agents including hyaluronic acid (HA, Hyalgan intra-articular injection, Sodium hyaluronate 10 mg/ml, 2 ml injection syringe, Bilim Pharmaceutical Company, Istanbul, Turkey); betamethasone (CS, Diprospan flacon, 7.0 mg betamethasone/1 ml, Schering-Plough Pharmaceutical Company, Istanbul, Turkey) and; tenoxicam (TX, Tilcotil flacon, 20 mg tenoxicam/ml, Roche Pharmaceutical Company, Istanbul, Turkey) were administered intra-articularly under, ultrasonographic guidance. Following the completion of injections the, changes in subjective symptoms were compared with visual analogue scales, (VAS) scores at 1st and 6th weeks' follow-up visits between four groups. The HA group did significantly better pain relief scores compared to the, other groups at 1st and 6th weeks (p < 0.05). TX and CS groups' pain scores were better than control group values (p < 0.05, for both agents). The pain relief effect of TX was noted to decrease significantly between the 1st and 6th week (p < 0.05) (Fig. 1). We did not observe the same pattern in HA, CS and control (saline) groups between 1st and 6th week (p > 0.05). We found that HA produced better pain relief scores when compared to the other anti-inflammatory agents studied. The main disadvantage of HA is its relatively higher cost. Additionally it does not have a reimbursement status by state or private health insurance systems in Turkey. Despite the lower VAS scores, intra-articular TX and CS may be assessed as more economic alternatives to intra-articular HA injections. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Simulations of population dynamics of hemlock woolly adelgid and potential impact of biological control agents

Treesearch

Joseph S. Elkinton; Robert T. Trotter; Ann F. Paradis

2011-01-01

The hemlock woolly adelgid (Adelges tsugae) is a small invasive Hemipteran herbivore that threatens the continued presence and abundance of hemlock in eastern North America. Efforts to control the adelgid have focused on the introduction of classical biological control agents. These biological controls include six different species of predatory...

An Architecture for Controlling Multiple Robots

NASA Technical Reports Server (NTRS)

Aghazarian, Hrand; Pirjanian, Paolo; Schenker, Paul; Huntsberger, Terrance

2004-01-01

The Control Architecture for Multirobot Outpost (CAMPOUT) is a distributed-control architecture for coordinating the activities of multiple robots. In the CAMPOUT, multiple-agent activities and sensor-based controls are derived as group compositions and involve coordination of more basic controllers denoted, for present purposes, as behaviors. The CAMPOUT provides basic mechanistic concepts for representation and execution of distributed group activities. One considers a network of nodes that comprise behaviors (self-contained controllers) augmented with hyper-links, which are used to exchange information between the nodes to achieve coordinated activities. Group behavior is guided by a scripted plan, which encodes a conditional sequence of single-agent activities. Thus, higher-level functionality is composed by coordination of more basic behaviors under the downward task decomposition of a multi-agent planner

A problem of optimal control and observation for distributed homogeneous multi-agent system

NASA Astrophysics Data System (ADS)

Kruglikov, Sergey V.

2017-12-01

The paper considers the implementation of a algorithm for controlling a distributed complex of several mobile multi-robots. The concept of a unified information space of the controlling system is applied. The presented information and mathematical models of participants and obstacles, as real agents, and goals and scenarios, as virtual agents, create the base forming the algorithmic and software background for computer decision support system. The controlling scheme assumes the indirect management of the robotic team on the basis of optimal control and observation problem predicting intellectual behavior in a dynamic, hostile environment. A basic content problem is a compound cargo transportation by a group of participants in the case of a distributed control scheme in the terrain with multiple obstacles.

Social Facilitation Effects by Pedagogical Conversational Agent: Lexical Network Analysis in an Online Explanation Task

ERIC Educational Resources Information Center

Hayashi, Yugo

2015-01-01

The present study investigates web-based learning activities of undergraduate students who generate explanations about a key concept taught in a large-scale classroom. The present study used an online system with Pedagogical Conversational Agent (PCA), asked to explain about the key concept from different points and provided suggestions and…

Active Brownian agents with concentration-dependent chemotactic sensitivity.

PubMed

Meyer, Marcel; Schimansky-Geier, Lutz; Romanczuk, Pawel

2014-02-01

We study a biologically motivated model of overdamped, autochemotactic Brownian agents with concentration-dependent chemotactic sensitivity. The agents in our model move stochastically and produce a chemical ligand at their current position. The ligand concentration obeys a reaction-diffusion equation and acts as a chemoattractant for the agents, which bias their motion towards higher concentrations of the dynamically altered chemical field. We explore the impact of concentration-dependent response to chemoattractant gradients on large-scale pattern formation, by deriving a coarse-grained macroscopic description of the individual-based model, and compare the conditions for emergence of inhomogeneous solutions for different variants of the chemotactic sensitivity. We focus primarily on the so-called receptor-law sensitivity, which models a nonlinear decrease of chemotactic sensitivity with increasing ligand concentration. Our results reveal qualitative differences between the receptor law, the constant chemotactic response, and the so-called log law, with respect to stability of the homogeneous solution, as well as the emergence of different patterns (labyrinthine structures, clusters, and bubbles) via spinodal decomposition or nucleation. We discuss two limiting cases, where the model can be reduced to the dynamics of single species: (I) the agent density governed by a density-dependent effective diffusion coefficient and (II) the ligand field with an effective bistable, time-dependent reaction rate. In the end, we turn to single clusters of agents, studying domain growth and determining mean characteristics of the stationary inhomogeneous state. Analytical results are confirmed and extended by large-scale GPU simulations of the individual based model.

Opinion dynamics in two dimensions: domain coarsening leads to stable bi-polarization and anomalous scaling exponents

NASA Astrophysics Data System (ADS)

Velásquez-Rojas, F.; Vazquez, F.

2018-04-01

We study an opinion dynamics model that explores the competition between persuasion and compromise in a population of agents with nearest-neighbor interactions on a two-dimensional square lattice. Each agent can hold either a positive or a negative opinion orientation, and can have two levels of intensity—moderate and extremist. When two interacting agents have the same orientation they become extremists with persuasion probability p, while if they have opposite orientations they become moderate with compromise probability q. These updating rules lead to the formation of same-opinion domains with a coarsening dynamics that depends on the ratio r  =  p/q. The population initially evolves to a centralized state for small r, where domains are composed of moderate agents and coarsening is without surface tension, and to a bi-polarized state for large r, where domains are formed by extremist agents and coarsening is driven by curvature. Consensus in an extreme opinion is finally reached in a time that scales with the population size N and r as for small r and as for large r. Bi-polarization could be quite stable when the system falls into a striped state where agents organize into single-opinion horizontal, vertical or diagonal bands. An analysis of the stripe dynamics towards consensus allows us to obtain an approximate expression for τ, which shows that the exponent 1.64 is a result of the diffusion of the stripe interfaces combined with their roughness properties.

Pharmacoeconomics of inhaled anesthetic agents: considerations for the pharmacist.

PubMed

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.

Recombinant entomopathogenic agents: a review of biotechnological approaches to pest insect control.

PubMed

Karabörklü, Salih; Azizoglu, Ugur; Azizoglu, Zehra Busra

2017-12-18

Although the use of chemical pesticides has decreased in recent years, it is still a common method of pest control. However, chemical use leads to challenging problems. The harm caused by these chemicals and the length of time that they will remain in the environment is of great concern to the future and safety of humans. Therefore, developing new pest control agents that are safer and environmentally compatible, as well as assuring their widespread use is important. Entomopathogenic agents are microorganisms that play an important role in the biological control of pest insects and are eco-friendly alternatives to chemical control. They consist of viruses (non-cellular organisms), bacteria (prokaryotic organisms), fungi and protists (eukaryotic organisms), and nematodes (multicellular organisms). Genetic modification (recombinant technology) provides potential new methods for developing entomopathogens to manage pests. In this review, we focus on the important roles of recombinant entomopathogens in terms of pest insect control, placing them into perspective with other views to discuss, examine and evaluate the use of entomopathogenic agents in biological control.

Propagation of the state change induced by external forces in local interactions

NASA Astrophysics Data System (ADS)

Lu, Jianjun; Tokinaga, Shozo

2016-10-01

This paper analyses the propagation of the state changes of agents that are induced by external forces applied to a plane. In addition, we propose two models for the behavior of the agents placed on a lattice plane, both of which are affected by local interactions. We first assume that agents are allowed to move to another site to maximise their satisfaction. Second, we utilise a model in which the agents choose activities on each site. The results show that the migration (activity) patterns of agents in both models achieve stability without any external forces. However, when we apply an impulsive external force to the state of the agents, we then observe the propagation of the changes in the agents' states. Using simulation studies, we show the conditions for the propagation of the state changes of the agents. We also show the propagation of the state changes of the agents allocated in scale-free networks and discuss the estimation of the agents' decisions in real state changes. Finally, we discuss the estimation of the agents' decisions in real state temporal changes using economic and social data from Japan and the United States.

Chemical agents for the control of plaque and plaque microflora: an overview.

PubMed

Gaffar, A; Afflitto, J; Nabi, N

1997-10-01

This presentation provides an overview of the technologies available for the chemical control of plaque. It is generally accepted that the formation of dental plaque at the interfaces of tooth/gingiva is one of the major causes of gingival inflammation and dental caries. Several therapeutic approaches have been used to control dental plaque and supragingival infections. These include fluoride preparations such as stannous fluoride, oxygenating agents, anti-attachment agents, and cationic and non-cationic antibacterial agents. Among the fluoride preparations, stable stannous fluoride pastes and gels have been shown to reduce supragingival plaque, gingivitis, hypersensitivity and caries. The effect of the oxygenating agents on the supragingival plaque has been equivocal, but recent data indicate that a stable agent which provides sustained active oxygen release is effective in controlling plaque. A polymer, PVPA, which reduced attachment of bacteria to teeth was shown to significantly reduce plaque formation in humans. A new generation of antibacterials includes non-ionics such as triclosan, which in combination with a special polymer delivery system, has been shown to reduce plaque, gingivitis, supragingival calculus and dental caries in long-term studies conducted around the world. Unlike the first generation of agents, the triclosan/copolymer/sodium fluoride system is effective in long-term clinicals and does not cause staining of teeth, increase in calculus, or disturbance in the oral microbial ecology.

Identifying and individuating cognitive systems: a task-based distributed cognition alternative to agent-based extended cognition.

PubMed

Davies, Jim; Michaelian, Kourken

2016-08-01

This article argues for a task-based approach to identifying and individuating cognitive systems. The agent-based extended cognition approach faces a problem of cognitive bloat and has difficulty accommodating both sub-individual cognitive systems ("scaling down") and some supra-individual cognitive systems ("scaling up"). The standard distributed cognition approach can accommodate a wider variety of supra-individual systems but likewise has difficulties with sub-individual systems and faces the problem of cognitive bloat. We develop a task-based variant of distributed cognition designed to scale up and down smoothly while providing a principled means of avoiding cognitive bloat. The advantages of the task-based approach are illustrated by means of two parallel case studies: re-representation in the human visual system and in a biomedical engineering laboratory.

Flue gas conditioning for improved particle collection in electrostatic precipitators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Durham, M.D.

1992-04-27

The purpose of this research program is to identify and evaluate a variety of additives capable of increasing particle cohesion which could be used for improving collection efficiency in an ESP. A three-phase screening process will be used to provide the, evaluation of many additives in a logical and cost-effective manner. The three step approach involves the following experimental setups: 1. Provide a preliminary screening in the laboratory by measuring the effects of various conditioning agents on reentrainment of flyash particles in an electric field operating at simulated flue gas conditions. 2. Evaluate the successful additives using a 100 acfmmore » bench-scale ESP operating on actual flue gas. 3. Obtain the data required for scaling up the technology by testing the two or three most promising conditioning agents at the pilot scale.« less

Inhibition of Sulfide Mineral Oxidation by Surface Coating Agents: Batch

NASA Astrophysics Data System (ADS)

Choi, J.; Ji, M. K.; Yun, H. S.; Park, Y. T.; Gee, E. D.; Lee, W. R.; Jeon, B.-H.

2012-04-01

Mining activities and mineral industries have impacted on rapid oxidation of sulfide minerals such as pyrite (FeS2) which leads to Acid Mine Drainage (AMD) formation. Some of the abandoned mines discharge polluted water without proper environmental remediation treatments, largely because of financial constraints in treating AMD. Magnitude of the problem is considerable, especially in countries with a long history of mining. As metal sulfides become oxidized during mining activities, the aqueous environment becomes acid and rich in many metals, including iron, lead, mercury, arsenic and many others. The toxic heavy metals are responsible for the environmental deterioration of stream, groundwater and soils. Several strategies to remediate AMD contaminated sites have been proposed. Among the source inhibition and prevention technologies, microencapsulation (coating) has been considered as a promising technology. The encapsulation is based on inhibition of O2 diffusion by surface coating agent and is expected to control the oxidation of pyrite for a long time. Potential of several surface coating agents for preventing oxidation of metal sulfide minerals from both Young-Dong coal mine and Il-Gwang gold mine were examined by conducting batch experiments and field tests. Powdered pyrite as a standard sulfide mineral and rock samples from two mine outcrops were mixed with six coating agents (KH2PO4, MgO and KMnO4 as chemical agents, and apatite, cement and manganite as mineral agents) and incubated with oxidizing agents (H2O2 or NaClO). Batch experiments with Young-Dong coal mine samples showed least SO42- production in presence of KMnO4 (16% sulfate production compared to no surface coating agents) or cement (4%) within 8 days. In the case of Il-Gwang mine samples, least SO42- production was observed in presence of KH2PO4 (8%) or cement (2%) within 8 days. Field-scale pilot tests at Il-Gwang site also showed that addition of KH2PO4 decreased sulfate production from 200 to 13 mg L-1 and reduced Cu and Mn from 8 and 3 mg L-1 to below the detection limits, respectively. The experimental results suggested that the amendment of surface coating agents can be a promising alternative for inhibition of sulfide oxidation at AMD sites.

Special Agents Can Promote Cooperation in the Population

PubMed Central

Wang, Xin; Han, Jing; Han, Huawei

2011-01-01

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

House fly management with viral and botanical agents

USDA-ARS?s Scientific Manuscript database

House flies are major pests of human and animal health throughout the world and are among the most difficult to control because of resistance to every insecticide that has been developed for their control. A promising microbial agent for fly control is salivary gland hypertrophy virus (MdSGHV), a m...

Agent based models for testing city evacuation strategies under a flood event as strategy to reduce flood risk

NASA Astrophysics Data System (ADS)

Medina, Neiler; Sanchez, Arlex; Nokolic, Igor; Vojinovic, Zoran

2016-04-01

This research explores the uses of Agent Based Models (ABM) and its potential to test large scale evacuation strategies in coastal cities at risk from flood events due to extreme hydro-meteorological events with the final purpose of disaster risk reduction by decreasing human's exposure to the hazard. The first part of the paper corresponds to the theory used to build the models such as: Complex adaptive systems (CAS) and the principles and uses of ABM in this field. The first section outlines the pros and cons of using AMB to test city evacuation strategies at medium and large scale. The second part of the paper focuses on the central theory used to build the ABM, specifically the psychological and behavioral model as well as the framework used in this research, specifically the PECS reference model is cover in this section. The last part of this section covers the main attributes or characteristics of human beings used to described the agents. The third part of the paper shows the methodology used to build and implement the ABM model using Repast-Symphony as an open source agent-based modelling and simulation platform. The preliminary results for the first implementation in a region of the island of Sint-Maarten a Dutch Caribbean island are presented and discussed in the fourth section of paper. The results obtained so far, are promising for a further development of the model and its implementation and testing in a full scale city

Polarized XANES Monitors Femtosecond Structural Evolution of Photoexcited Vitamin B 12

DOE PAGES

Miller, Nicholas A.; Deb, Aniruddha; Alonso-Mori, Roberto; ...

2017-01-30

Ultrafast, polarization-selective time-resolved X-ray absorption near-edge structure (XANES) was used to characterize the photochemistry of vitamin B 12, cyanocobalamin (CNCbl), in solution. Cobalamins are important biological cofactors involved in methyl transfer, radical rearrangement, and light-activated gene regulation, while also holding promise as light-activated agents for spatiotemporal controlled delivery of therapeutics. We introduce polarized femtosecond XANES, combined with UV–visible spectroscopy, to reveal sequential structural evolution of CNCbl in the excited electronic state. Femtosecond polarized XANES provides the crucial structural dynamics link between computed potential energy surfaces and optical transient absorption spectroscopy. Polarization selectivity can be used to uniquely identify electronic contributionsmore » and structural changes, even in isotropic samples when well-defined electronic transitions are excited. Our XANES measurements reveal that the structural changes upon photoexcitation occur mainly in the axial direction, where elongation of the axial Co–CN bond and Co–N Im bond on a 110 fs time scale is followed by corrin ring relaxation on a 260 fs time scale. In conclusion, these observations expose features of the potential energy surfaces controlling cobalamin reactivity and deactivation.« less

Polarized XANES Monitors Femtosecond Structural Evolution of Photoexcited Vitamin B 12

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Nicholas A.; Deb, Aniruddha; Alonso-Mori, Roberto

Ultrafast, polarization-selective time-resolved X-ray absorption near-edge structure (XANES) was used to characterize the photochemistry of vitamin B 12, cyanocobalamin (CNCbl), in solution. Cobalamins are important biological cofactors involved in methyl transfer, radical rearrangement, and light-activated gene regulation, while also holding promise as light-activated agents for spatiotemporal controlled delivery of therapeutics. We introduce polarized femtosecond XANES, combined with UV–visible spectroscopy, to reveal sequential structural evolution of CNCbl in the excited electronic state. Femtosecond polarized XANES provides the crucial structural dynamics link between computed potential energy surfaces and optical transient absorption spectroscopy. Polarization selectivity can be used to uniquely identify electronic contributionsmore » and structural changes, even in isotropic samples when well-defined electronic transitions are excited. Our XANES measurements reveal that the structural changes upon photoexcitation occur mainly in the axial direction, where elongation of the axial Co–CN bond and Co–N Im bond on a 110 fs time scale is followed by corrin ring relaxation on a 260 fs time scale. In conclusion, these observations expose features of the potential energy surfaces controlling cobalamin reactivity and deactivation.« less

Cosine Kuramoto Based Distribution of a Convoy with Limit-Cycle Obstacle Avoidance Through the Use of Simulated Agents

NASA Astrophysics Data System (ADS)

Howerton, William

This thesis presents a method for the integration of complex network control algorithms with localized agent specific algorithms for maneuvering and obstacle avoidance. This method allows for successful implementation of group and agent specific behaviors. It has proven to be robust and will work for a variety of vehicle platforms. Initially, a review and implementation of two specific algorithms will be detailed. The first, a modified Kuramoto model was developed by Xu [1] which utilizes tools from graph theory to efficiently perform the task of distributing agents. The second algorithm developed by Kim [2] is an effective method for wheeled robots to avoid local obstacles using a limit-cycle navigation method. The results of implementing these methods on a test-bed of wheeled robots will be presented. Control issues related to outside disturbances not anticipated in the original theory are then discussed. A novel method of using simulated agents to separate the task of distributing agents from agent specific velocity and heading commands has been developed and implemented to address these issues. This new method can be used to combine various behaviors and is not limited to a specific control algorithm.

Approach for Autonomous Control of Unmanned Aerial Vehicle Using Intelligent Agents for Knowledge Creation

NASA Technical Reports Server (NTRS)

Dufrene, Warren R., Jr.

2004-01-01

This paper describes the development of a planned approach for Autonomous operation of an Unmanned Aerial Vehicle (UAV). A Hybrid approach will seek to provide Knowledge Generation through the application of Artificial Intelligence (AI) and Intelligent Agents (IA) for UAV control. The applications of several different types of AI techniques for flight are explored during this research effort. The research concentration is directed to the application of different AI methods within the UAV arena. By evaluating AI and biological system approaches. which include Expert Systems, Neural Networks. Intelligent Agents, Fuzzy Logic, and Complex Adaptive Systems, a new insight may be gained into the benefits of AI and CAS techniques applied to achieving true autonomous operation of these systems. Although flight systems were explored, the benefits should apply to many Unmanned Vehicles such as: Rovers. Ocean Explorers, Robots, and autonomous operation systems. A portion of the flight system is broken down into control agents that represent the intelligent agent approach used in AI. After the completion of a successful approach, a framework for applying an intelligent agent is presented. The initial results from simulation of a security agent for communication are presented.

Protection of Mobile Agents Execution Using a Modified Self-Validating Branch-Based Software Watermarking with External Sentinel

NASA Astrophysics Data System (ADS)

Tomàs-Buliart, Joan; Fernández, Marcel; Soriano, Miguel

Critical infrastructures are usually controlled by software entities. To monitor the well-function of these entities, a solution based in the use of mobile agents is proposed. Some proposals to detect modifications of mobile agents, as digital signature of code, exist but they are oriented to protect software against modification or to verify that an agent have been executed correctly. The aim of our proposal is to guarantee that the software is being executed correctly by a non trusted host. The way proposed to achieve this objective is by the improvement of the Self-Validating Branch-Based Software Watermarking by Myles et al.. The proposed modification is the incorporation of an external element called sentinel which controls branch targets. This technique applied in mobile agents can guarantee the correct operation of an agent or, at least, can detect suspicious behaviours of a malicious host during the execution of the agent instead of detecting when the execution of the agent have finished.

Controlling carbon-nanotube-phospholipid solubility by curvature-dependent self-assembly.

PubMed

Määttä, Jukka; Vierros, Sampsa; Sammalkorpi, Maria

2015-03-12

Control of aqueous dispersion is central in the processing and usage of nanoscale hydrophobic objects. However, selecting dispersive agents based on the size and form of the hydrophobic object and the role of coating morphology in dispersion efficiency remain important open questions. Here, the effect of the substrate and the dispersing molecule curvature, as well as, the influence of dispersant concentration on the adsorption morphology are examined by molecular simulations of graphene and carbon nanotube (CNT) substrates with phospholipids of varying curvature as the dispersing agents. Lipid spontaneous curvature is increased from close to zero (effectively cylindrical lipid) to highly positive (effectively conical lipid) by studying double tailed dipalmitoylphosphadidylcholine (DPPC) and single tailed lysophosphadidylcholine (LPC) which differ in the number of acyl chains but have identical headgroup. We find that lipids are good dispersion agents for both planar and curved nanoparticles and induce a dispersive barrier nonsize selectively. Differences in dispersion efficiency arise from lipid headgroup density and their extension from the hydrophobic substrate in the adsorption morphology. We map the packing morphology contributing factors and report that the aggregate morphologies depend on the competition of interactions rising from (1) hydrophobicity driven maximization of lipid-substrate contacts and lipid self-adhesion, (2) tail bending energy cost, (3) preferential alignment along the graphitic substrate principal axes, and (4) lipid headgroup preferential packing. Curved substrates adjust the morphology by changing the balance between the interaction strengths. Jointly, the findings show substrate curvature and dimensions are a way to tune lipid adsorption to desired, self-assembling patterns. Besides engineering dispersion efficiency, the findings could bear significance in designing materials with defined molecular scale, molecular coatings for orientation specific CNT assembly or lipid-based molecular masks and patterning on graphene.

12 CFR 612.2260 - Standards of conduct for agents.

Code of Federal Regulations, 2012 CFR

2012-01-01

... agents. (a) Agents of System institutions shall maintain high standards of honesty, integrity, and... business practices, to avoid or control situations that have inherent potential for sensitivity, either...

12 CFR 612.2260 - Standards of conduct for agents.

Code of Federal Regulations, 2014 CFR

2014-01-01

... agents. (a) Agents of System institutions shall maintain high standards of honesty, integrity, and... business practices, to avoid or control situations that have inherent potential for sensitivity, either...

12 CFR 612.2260 - Standards of conduct for agents.

Code of Federal Regulations, 2013 CFR

2013-01-01

... agents. (a) Agents of System institutions shall maintain high standards of honesty, integrity, and... business practices, to avoid or control situations that have inherent potential for sensitivity, either...

Toward Shared Working Space of Human and Robotic Agents Through Dipole Flow Field for Dependable Path Planning.

PubMed

Trinh, Lan Anh; Ekström, Mikael; Cürüklü, Baran

2018-01-01

Recent industrial developments in autonomous systems, or agents, which assume that humans and the agents share the same space or even work in close proximity, open for new challenges in robotics, especially in motion planning and control. In these settings, the control system should be able to provide these agents a reliable path following control when they are working in a group or in collaboration with one or several humans in complex and dynamic environments. In such scenarios, these agents are not only moving to reach their goals, i.e., locations, they are also aware of the movements of other entities to find a collision-free path. Thus, this paper proposes a dependable, i.e., safe, reliable and effective, path planning algorithm for a group of agents that share their working space with humans. Firstly, the method employs the Theta * algorithm to initialize the paths from a starting point to a goal for a set of agents. As Theta * algorithm is computationally heavy, it only reruns when there is a significant change of the environment. To deal with the movements of the agents, a static flow field along the configured path is defined. This field is used by the agents to navigate and reach their goals even if the planned trajectories are changed. Secondly, a dipole field is calculated to avoid the collision of agents with other agents and human subjects. In this approach, each agent is assumed to be a source of a magnetic dipole field in which the magnetic moment is aligned with the moving direction of the agent. The magnetic dipole-dipole interactions between these agents generate repulsive forces to help them to avoid collision. The effectiveness of the proposed approach has been evaluated with extensive simulations. The results show that the static flow field is able to drive agents to the goals with a small number of requirements to update the path of agents. Meanwhile, the dipole flow field plays an important role to prevent collisions. The combination of these two fields results in a safe path planning algorithm, with a deterministic outcome, to navigate agents to their desired goals.

Infectious Agents Trigger Trophic Cascades.

PubMed

Buck, Julia C; Ripple, William J

2017-09-01

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

Neurosciences and research on chemical weapons of mass destruction in Nazi Germany.

PubMed

Schmaltz, Florian

2006-09-01

As a side-product of industrial research, new chemical nerve agents (Tabun, Sarin, Soman) superior to those available to the Allied Forces were discovered in Nazi Germany. These agents were never used by Germany, even though they were produced at a large scale. This article explores the toxicological and physiological research into the mechanisms of action of these novel nerve agents, and the emergence of military research objectives in neurophysiological and neurotoxicological research. Recently declassified Allied military intelligence files document secret nerve agent research, leading to intensified research on anticholinesterase agents in the peripheral and the central nervous system. The article discusses the involvement of IG Farben scientists, educational, medical and military institutions, and of Nobel Prize laureate Richard Kuhn, director of the Kaiser Wilhelm Institute for Medical Research.

Intraperitoneal lignocaine (lidocaine) versus bupivacaine after laparoscopic cholecystectomy: results of a randomized controlled trial.

PubMed

Khan, Muhammad Rizwan; Raza, Rushna; Zafar, Syed Nabeel; Shamim, Faisal; Raza, Syed Ahsan; Pal, Khawaja Muhammad Inam; Zafar, Hasnain; Alvi, Rehman; Chawla, Tabish; Azmi, Rizwan

2012-12-01

Intraperitoneal local anesthetics have been shown to improve postoperative pain after laparoscopic cholecystectomy (LC). However, the choice of local anesthetic agent is debatable. We compared the analgesic efficacy of intraperitoneal lignocaine (lidocaine) versus bupivacaine after elective LC. We conducted a double-blind, randomized, controlled trial. We randomized consecutive patients undergoing LC into two groups. Group L received 10 mL 2% lignocaine (lidocaine), whereas Group B received 10 mL 0.5% bupivacaine, each diluted in 10 mL normal saline. All patients underwent standard perioperative anesthesia and analgesia protocol. We assessed patients at 0, 4, 8, 12, and 24 h postoperatively for pain using the visual analogue scale and verbal rating scale, and the need for additional analgesic medications. We analyzed a total of 206 patients: 106 in Group L and 100 in Group B. Demographic details were similar between groups (P > 0.05). Abdominal pain decreased significantly with time in both groups, with a similar mean response profile (P < 0.001). There was no statistically significant difference between groups with regard to abdominal or shoulder pain by both visual analogue scale and verbal rating scale at all five time intervals (P > 0.05). There was also no significant difference in the side effect profile of both drugs (P > 0.05). A lower proportion of patients in Group B required additional narcotic analgesia (87%) compared with Group L (94%). This difference was marginally significant (P = 0.057). Bupivacaine and lignocaine (lidocaine) are both safe and equally effective at decreasing postoperative pain after LC. Copyright © 2012 Elsevier Inc. All rights reserved.

Intranasal topical local anesthetic and decongestant for flexible nasendoscopy in children: a randomized, double-blind, placebo-controlled trial.

PubMed

Chadha, Neil K; Lam, Gilbert O A; Ludemann, Jeffrey P; Kozak, Frederick K

2013-12-01

To our knowledge, the present study is the first double-blind, randomized, placebo-controlled trial in children to compare nasal preparation sprays administered before flexible nasendoscopy with placebo. To compare the degree of pain experienced by children undergoing flexible nasendoscopy after 1 of 3 intranasal sprays: placebo, decongestant with topical local anesthetic (TLA), or decongestant without TLA. A randomized placebo-controlled trial with blinding of participants, caregivers, observers, and otolaryngologists was conducted in a tertiary pediatric otolaryngology ambulatory clinic. Participants included a consecutive sample of children aged 3 to 12 years requiring flexible nasendoscopy. Exclusion criteria included concomitant respiratory tract infection, known allergy to a trial agent, or previous flexible nasendoscopy. One hundred fifty-one children were assessed for eligibility; 24 eligible children refused participation and 69 were included and block-randomized. All completed the study, and there were no adverse events. Nasal spray administration of placebo (normal saline); xylometazoline hydrochloride, 0.05% (decongestant); or lidocaine hydrochloride, 1%, with xylometazoline hydrochloride, 0.05% (TLA with decongestant) was performed 10 minutes before flexible nasendoscopy. Primary outcome measure was the child-reported Wong-Baker Faces Pain (WBFP) scale. Secondary outcomes included the caregiver-proxy WBFP scale; the Face, Legs, Activity, Cry, and Consolability (FLACC) scale; and the physician-reported Difficulty of Procedure Visual Analog Scale (DPVAS). Twenty-three children were recruited in each of the intervention arms. Baseline characteristics were comparable between groups. The mean child-rated WBFP scale scores were 2.4, 1.8, and 2.2 for the placebo, decongestant, and TLA with decongestant groups, respectively (P = .45). Although the finding was statistically nonsignificant, decongestant had the lowest mean caregiver-proxy WBFP scale score, lowest observer-rated FLACC scale score, and highest physician-rated DPVAS score. Subgroup analysis did not demonstrate any correlation between the outcomes and age or sex. This study revealed no statistically significant difference in the discomfort experienced by children undergoing flexible nasendoscopy after placebo, decongestant, or TLA with decongestant. Decongestant was associated with the least discomfort (on child, caregiver, and observer-rated pain scale scores) and the lowest rating for difficulty of procedure. With these findings, the study suggests that there is no significant benefit of topical decongestant with or without TLA compared with placebo in reducing pain associated with pediatric flexible nasendoscopy. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT01351298.

Efficient Evaluation Functions for Multi-Rover Systems

NASA Technical Reports Server (NTRS)

Agogino, Adrian; Tumer, Kagan

2004-01-01

Evolutionary computation can be a powerful tool in cresting a control policy for a single agent receiving local continuous input. This paper extends single-agent evolutionary computation to multi-agent systems, where a collection of agents strives to maximize a global fitness evaluation function that rates the performance of the entire system. This problem is solved in a distributed manner, where each agent evolves its own population of neural networks that are used as the control policies for the agent. Each agent evolves its population using its own agent-specific fitness evaluation function. We propose to create these agent-specific evaluation functions using the theory of collectives to avoid the coordination problem where each agent evolves a population that maximizes its own fitness function, yet the system has a whole achieves low values of the global fitness function. Instead we will ensure that each fitness evaluation function is both "aligned" with the global evaluation function and is "learnable," i.e., the agents can readily see how their behavior affects their evaluation function. We then show how these agent-specific evaluation functions outperform global evaluation methods by up to 600% in a domain where a set of rovers attempt to maximize the amount of information observed while navigating through a simulated environment.

A Biologically Inspired Cooperative Multi-Robot Control Architecture

NASA Technical Reports Server (NTRS)

Howsman, Tom; Craft, Mike; ONeil, Daniel; Howell, Joe T. (Technical Monitor)

2002-01-01

A prototype cooperative multi-robot control architecture suitable for the eventual construction of large space structures has been developed. In nature, there are numerous examples of complex architectures constructed by relatively simple insects, such as termites and wasps, which cooperatively assemble their nests. The prototype control architecture emulates this biological model. Actions of each of the autonomous robotic construction agents are only indirectly coordinated, thus mimicking the distributed construction processes of various social insects. The robotic construction agents perform their primary duties stigmergically i.e., without direct inter-agent communication and without a preprogrammed global blueprint of the final design. Communication and coordination between individual agents occurs indirectly through the sensed modifications that each agent makes to the structure. The global stigmergic building algorithm prototyped during the initial research assumes that the robotic builders only perceive the current state of the structure under construction. Simulation studies have established that an idealized form of the proposed architecture was indeed capable of producing representative large space structures with autonomous robots. This paper will explore the construction simulations in order to illustrate the multi-robot control architecture.

Limits on relief through constrained exchange on random graphs

NASA Astrophysics Data System (ADS)

LaViolette, Randall A.; Ellebracht, Lory A.; Gieseler, Charles J.

2007-09-01

Agents are represented by nodes on a random graph (e.g., “small world”). Each agent is endowed with a zero-mean random value that may be either positive or negative. All agents attempt to find relief, i.e., to reduce the magnitude of that initial value, to zero if possible, through exchanges. The exchange occurs only between the agents that are linked, a constraint that turns out to dominate the results. The exchange process continues until Pareto equilibrium is achieved. Only 40-90% of the agents achieved relief on small-world graphs with mean degree between 2 and 40. Even fewer agents achieved relief on scale-free-like graphs with a truncated power-law degree distribution. The rate at which relief grew with increasing degree was slow, only at most logarithmic for all of the graphs considered; viewed in reverse, the fraction of nodes that achieve relief is resilient to the removal of links.

Computerized bioterrorism education and training for nurses on bioterrorism attack agents.

PubMed

Nyamathi, Adeline M; Casillas, Adrian; King, Major L; Gresham, Louise; Pierce, Elaine; Farb, Daniel; Wiechmann, Carrie; Weichmann, Carrie

2010-08-01

Biological agents have the ability to cause large-scale mass casualties. For this reason, their likely use in future terrorist attacks is a concern for national security. Recent studies show that nurses are ill prepared to deal with agents used in biological warfare. Achieving a goal for bioterrorism preparedness is directly linked to comprehensive education and training that enables first-line responders such as nurses to diagnose infectious agents rapidly. The study evaluated participants' responses to biological agents using a computerized bioterrorism education and training program versus a standard bioterrorism education and training program. Both programs improved participants' ability to complete and solve case studies involving the identification of specific biological agents. Participants in the computerized bioterrorism education and training program were more likely to solve the cases critically without reliance on expert consultants. However, participants in the standard bioterrorism education and training program reduced the use of unnecessary diagnostic tests.

Natural products for pest control: an analysis of their role, value and future.

PubMed

Gerwick, B Clifford; Sparks, Thomas C

2014-08-01

Natural products (NPs) have long been used as pesticides and have broadly served as a source of inspiration for a great many commercial synthetic organic fungicides, herbicides and insecticides that are in the market today. In light of the continuing need for new tools to address an ever-changing array of fungal, weed and insect pests, NPs continue to be a source of models and templates for the development of new pest control agents. Interestingly, an examination of the literature suggests that NP models exist for many of the pest control agents that were discovered by other means, suggesting that, had circumstances been different, these NPs could have served as inspiration for the discovery of a great many more of today's pest control agents. Here, an attempt is made to answer questions regarding the existence of an NP model for existing classes of pesticides and what is needed for the discovery of new NPs and NP models for pest control agents. © 2014 Society of Chemical Industry.

Blood-Brain Barrier: Real-time Feedback-controlled Focused Ultrasound Disruption by Using an Acoustic Emissions–based Controller

PubMed Central

Hynynen, Kullervo

2012-01-01

Purpose: To determine if focused ultrasound disruption of the blood-brain barrier (BBB) can be safely controlled by using real-time modulation of treatment pressures on the basis of acoustic emissions from the exposed microbubbles. Materials and Methods: All experiments were performed with the approval of the institutional animal care committee. Transcranial focused ultrasound (551.5 kHz, 10-msec bursts, 2-Hz pulse repetition frequency, 2 minute sonication) in conjunction with circulating microbubbles was applied in 86 locations in 27 rats to disrupt the BBB. Acoustic emissions captured during each burst by using a wideband polyvinylidene fluoride hydrophone were analyzed for spectral content and used to adjust treatment pressures. Pressures were increased incrementally after each burst until ultraharmonic emissions were detected, at which point the pressure was reduced to a percentage of the pressure required to induce the ultraharmonics and was maintained for the remainder of the sonication. Disruption was evaluated at contrast material–enhanced T1-weighted magnetic resonance (MR) imaging. Mean enhancement was calculated by averaging the signal intensity at the focus over a 3 × 3-pixel region of interest and comparing it with that in nonsonicated tissue. Histologic analysis was performed to determine the extent of damage to the tissue. Statistical analysis was performed by using Student t tests. Results: For sonications resulting in BBB disruption, the mean peak pressure was 0.28 MPa ± 0.05 (standard deviation) (range, 0.18–0.40 MPa). By using the control algorithm, a linear relationship was found between the scaling level and the mean enhancement on T1-weighted MR images after contrast agent injection. At a 50% scaling level, mean enhancement of 19.6% ± 1.7 (standard error of the mean) was achieved without inducing damage. At higher scaling levels, histologic analysis revealed gross tissue damage, while at a 50% scaling level, no damage was observed at high-field-strength MR imaging or histologic examination 8 days after treatment. Conclusion: This study demonstrates that acoustic emissions can be used to actively control focused ultrasound exposures for the safe induction of BBB disruption. © RSNA, 2012 PMID:22332065

Toward a new task assignment and path evolution (TAPE) for missile defense system (MDS) using intelligent adaptive SOM with recurrent neural networks (RNNs).

PubMed

Wang, Chi-Hsu; Chen, Chun-Yao; Hung, Kun-Neng

2015-06-01

In this paper, a new adaptive self-organizing map (SOM) with recurrent neural network (RNN) controller is proposed for task assignment and path evolution of missile defense system (MDS). We address the problem of N agents (defending missiles) and D targets (incoming missiles) in MDS. A new RNN controller is designed to force an agent (or defending missile) toward a target (or incoming missile), and a monitoring controller is also designed to reduce the error between RNN controller and ideal controller. A new SOM with RNN controller is then designed to dispatch agents to their corresponding targets by minimizing total damaging cost. This is actually an important application of the multiagent system. The SOM with RNN controller is the main controller. After task assignment, the weighting factors of our new SOM with RNN controller are activated to dispatch the agents toward their corresponding targets. Using the Lyapunov constraints, the weighting factors for the proposed SOM with RNN controller are updated to guarantee the stability of the path evolution (or planning) system. Excellent simulations are obtained using this new approach for MDS, which show that our RNN has the lowest average miss distance among the several techniques.

[An experimental study of the computer-controlled equipment for delivering volatile anesthetic agent].

PubMed

Sun, B; Li, W Z; Yue, Y; Jiang, C W; Xiao, L Y

2001-11-01

Our newly-designed computer-controlled equipment for delivering volatile anesthetic agent uses the subminiature singlechip processor as the central controlling unit. The variables, such as anesthesia method, anesthetic agent, the volume of respiratory loop, age of patient, sex, height, weight, environment temperature and the grade of ASA are all input from the keyboard. The anesthetic dosage, calculated by the singlechip processor, is converted into the signals controlling the pump to accurately deliver anesthetic agent into respiratory loop. We have designed an electrocircuit for the equipment to detect the status of the pump's operation, so we can assure of the safety and the stability of the equipment. The output precision of the equipment, with a good anti-jamming capability, is 1-2% for high flow anesthesia and 1-5% for closed-circuit anesthesia and its self-detecting working is reliable.

[Viral biosafety, biosecurity, and bioterrorism].

PubMed

Garin, D

2010-02-01

Intentional release of infectious agents has always been considered as a possible weapon. Today this risk has expanded from use for wartime mass destruction to small-scale terrorist acts. Viruses, some of tropical origin, constitute a special biological hazard for several reasons: great infectious potential, adaptability to the host, difficulty for diagnosis in the hospital, and absence of specific treatment for the main agents involved. Handling of the dangerous biological agents requires special biocontainment laboratories equipped and classified according to increasing risk up to level 4. This article discusses the modalities of classification.

[Biological and toxin terrorism weapons].

PubMed

Bokan, Slavko

2003-03-01

The use of biological agents and toxins in warfare and terrorism has a long history. Human, animal and plant pathogens and toxins can cause disease and can be used as a threat to humans, animals and staple crops. The same is true for biological agents. Although the use of biological agents and toxins in military conflicts has been a concern of military communities for many years, several recent events have increased the awareness of terrorist use of these weapons against civilian population. A Mass Casualty Biological (Toxin) Weapon (MCBTW) is any biological and toxin weapon capable of causing death or disease on a large scale, such that the military or civilian infrastructure of the state or organization being attacked is overwhelmed. A militarily significant (or terrorist) weapon is any weapon capable of affecting, directly or indirectly, that is physically or psychologically, the outcome of a military operation. Although many biological agents such as toxins and bioregulators can be used to cause diseases, there are only a few that can truly threaten civilian populations on a large scale. Bioregulators or modulators are biochemical compounds, such as peptides, that occur naturally in organisms. They are new class of weapons that can damage nervous system, alter moods, trigger psychological changes and kill. The potential military or terrorist use of bioregulators is similar to that of toxins. Some of these compounds are several hundred times more potent than traditional chemical warfare agents. Important features and military advantages of new bioregulators are novel sites of toxic action; rapid and specific effects; penetration of protective filters and equipment, and militarily effective physical incapacitation. This overview of biological agents and toxins is largely intended to help healthcare providers on all levels to make decisions in protecting general population from these agents.

Emergent Behavior of Coupled Barrier Island - Resort Systems

NASA Astrophysics Data System (ADS)

McNamara, D. E.; Werner, B. T.

2004-12-01

Barrier islands are attractive sites for resorts. Natural barrier islands experience beach erosion and island overwash during storms, beach accretion and dune building during inter-storm periods, and migration up the continental shelf as sea level rises. Beach replenishment, artificial dune building, seawalls, jetties and groins have been somewhat effective in protecting resorts against erosion and overwash during storms, but it is unknown how the coupled system will respond to long-term sea level rise. We investigate coupled barrier island - resort systems using an agent-based model with three components: natural barrier islands divided into a series of alongshore cells; resorts controlled by markets for tourism and hotel purchases; and coupling via storm damage to resorts and resort protection by government agents. Modeled barrier islands change by beach erosion, island overwash and inlet cutting during storms, and beach accretion, tidal delta growth and dune and vegetation growth between storms. In the resort hotel market, developer agents build hotels and hotel owning agents purchase them using predictions of future revenue and property appreciation, with the goal of maximizing discounted utility. In the tourism market, hotel owning agents set room rental prices to maximize profit and tourist agents choose vacation destinations maximizing a utility based on beach width, price and word-of-mouth. Government agents build seawalls, groins and jetties, and widen the beach and build up dunes by adding sand to protect resorts from storms, enhance beach quality, and maximize resort revenue. Results indicate that barrier islands and resorts evolve in a coupled manner to resort size saturation, with resorts protected against small-to-intermediate-scale storms under fairly stable sea level. Under extended, rapidly rising sea level, protection measures enhance the effect of large storms, leading to emergent behavior in the form of limit cycles or barrier submergence, depending on the relative rates of resort recovery from storms and sea level rise. The model is applied to Ocean City, Maryland and neighboring undeveloped Assateague Island National Seashore. Supported by the National Science Foundation, Geology and Paleontology Program, and the Andrew W. Mellon Foundation

KODAMA and VPC based Framework for Ubiquitous Systems and its Experiment

NASA Astrophysics Data System (ADS)

Takahashi, Kenichi; Amamiya, Satoshi; Iwao, Tadashige; Zhong, Guoqiang; Kainuma, Tatsuya; Amamiya, Makoto

Recently, agent technologies have attracted a lot of interest as an emerging programming paradigm. With such agent technologies, services are provided through collaboration among agents. At the same time, the spread of mobile technologies and communication infrastructures has made it possible to access the network anytime and from anywhere. Using agents and mobile technologies to realize ubiquitous computing systems, we propose a new framework based on KODAMA and VPC. KODAMA provides distributed management mechanisms by using the concept of community and communication infrastructure to deliver messages among agents without agents being aware of the physical network. VPC provides a method of defining peer-to-peer services based on agent communication with policy packages. By merging the characteristics of both KODAMA and VPC functions, we propose a new framework for ubiquitous computing environments. It provides distributed management functions according to the concept of agent communities, agent communications which are abstracted from the physical environment, and agent collaboration with policy packages. Using our new framework, we conducted a large-scale experiment in shopping malls in Nagoya, which sent advertisement e-mails to users' cellular phones according to user location and attributes. The empirical results showed that our new framework worked effectively for sales in shopping malls.

A Scalable and Robust Multi-Agent Approach to Distributed Optimization

NASA Technical Reports Server (NTRS)

Tumer, Kagan

2005-01-01

Modularizing a large optimization problem so that the solutions to the subproblems provide a good overall solution is a challenging problem. In this paper we present a multi-agent approach to this problem based on aligning the agent objectives with the system objectives, obviating the need to impose external mechanisms to achieve collaboration among the agents. This approach naturally addresses scaling and robustness issues by ensuring that the agents do not rely on the reliable operation of other agents We test this approach in the difficult distributed optimization problem of imperfect device subset selection [Challet and Johnson, 2002]. In this problem, there are n devices, each of which has a "distortion", and the task is to find the subset of those n devices that minimizes the average distortion. Our results show that in large systems (1000 agents) the proposed approach provides improvements of over an order of magnitude over both traditional optimization methods and traditional multi-agent methods. Furthermore, the results show that even in extreme cases of agent failures (i.e., half the agents fail midway through the simulation) the system remains coordinated and still outperforms a failure-free and centralized optimization algorithm.

7 CFR 4290.50 - Definition of terms.

Code of Federal Regulations, 2011 CFR

2011-01-01

... ownership, management, contract, or otherwise, are under the Control of one group or Person. Two or more..., director, employee or agent of a Corporate RBIC; (ii) A Control Person, employee or agent of a Partnership... any Person who contracts with a Control Person of a RBIC to be the Investment Adviser/Manager of such...

Opportunities for microbial control of pulse crop pests

USDA-ARS?s Scientific Manuscript database

The insect pest complex in U.S. pulse crops is almost an “orphan” in terms of developed microbial control agents that the grower can use. There are almost no registered microbial pest control agents (MPCA) for the different pulse pests. In some cases a microbial is registered for use against specifi...

78 FR 33692 - Implementation of the Understandings Reached at the 2012 Australia Group (AG) Plenary Meeting and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-05

... Australia Group (AG) ``List of Biological Agents for Export Control,'' as follows: b.1. Reconstructed.... Bacteria identified on the Australia Group (AG) ``List of Biological Agents for Export Control,'' as... Group (AG) ``List of Plant Pathogens for Export Control'']. b. Fungi, as follows: b.1. Colletotrichum...

Weight Control: Attitudes of Dieters and Change Agents.

ERIC Educational Resources Information Center

Parham, Ellen S.; And Others

1991-01-01

Survey explores attitudes toward weight loss/weight control among 2 groups of change agents--40 dietitians and 42 fitness instructors--and among 96 people trying to lose weight. Significant differences were found in terms of importance in weight control of diet, drugs, exercise, religion, and will power; in importance of being of normal weight;…