Distributed Cooperative Optimal Control for Multiagent Systems on Directed Graphs: An Inverse Optimal Approach.

PubMed

Zhang, Huaguang; Feng, Tao; Yang, Guang-Hong; Liang, Hongjing

2015-07-01

In this paper, the inverse optimal approach is employed to design distributed consensus protocols that guarantee consensus and global optimality with respect to some quadratic performance indexes for identical linear systems on a directed graph. The inverse optimal theory is developed by introducing the notion of partial stability. As a result, the necessary and sufficient conditions for inverse optimality are proposed. By means of the developed inverse optimal theory, the necessary and sufficient conditions are established for globally optimal cooperative control problems on directed graphs. Basic optimal cooperative design procedures are given based on asymptotic properties of the resulting optimal distributed consensus protocols, and the multiagent systems can reach desired consensus performance (convergence rate and damping rate) asymptotically. Finally, two examples are given to illustrate the effectiveness of the proposed methods.

Distributed consensus for metamorphic systems using a gossip algorithm for CAT(0) metric spaces

NASA Astrophysics Data System (ADS)

Bellachehab, Anass; Jakubowicz, Jérémie

2015-01-01

We present an application of distributed consensus algorithms to metamorphic systems. A metamorphic system is a set of identical units that can self-assemble to form a rigid structure. For instance, one can think of a robotic arm composed of multiple links connected by joints. The system can change its shape in order to adapt to different environments via reconfiguration of its constituting units. We assume in this work that several metamorphic systems form a network: two systems are connected whenever they are able to communicate with each other. The aim of this paper is to propose a distributed algorithm that synchronizes all the systems in the network. Synchronizing means that all the systems should end up having the same configuration. This aim is achieved in two steps: (i) we cast the problem as a consensus problem on a metric space and (ii) we use a recent distributed consensus algorithm that only make use of metrical notions.

A new formation control of multiple underactuated surface vessels

NASA Astrophysics Data System (ADS)

Xie, Wenjing; Ma, Baoli; Fernando, Tyrone; Iu, Herbert Ho-Ching

2018-05-01

This work investigates a new formation control problem of multiple underactuated surface vessels. The controller design is based on input-output linearisation technique, graph theory, consensus idea and some nonlinear tools. The proposed smooth time-varying distributed control law guarantees that the multiple underactuated surface vessels globally exponentially converge to some desired geometric shape, which is especially centred at the initial average position of vessels. Furthermore, the stability analysis of zero dynamics proves that the orientations of vessels tend to some constants that are dependent on the initial values of vessels, and the velocities and control inputs of the vessels decay to zero. All the results are obtained under the communication scenarios of static directed balanced graph with a spanning tree. Effectiveness of the proposed distributed control scheme is demonstrated using a simulation example.

Distributed Leader-Following Finite-Time Consensus Control for Linear Multiagent Systems under Switching Topology

PubMed Central

Xu, Xiaole; Chen, Shengyong

2014-01-01

This paper investigates the finite-time consensus problem of leader-following multiagent systems. The dynamical models for all following agents and the leader are assumed the same general form of linear system, and the interconnection topology among the agents is assumed to be switching and undirected. We mostly consider the continuous-time case. By assuming that the states of neighbouring agents are known to each agent, a sufficient condition is established for finite-time consensus via a neighbor-based state feedback protocol. While the states of neighbouring agents cannot be available and only the outputs of neighbouring agents can be accessed, the distributed observer-based consensus protocol is proposed for each following agent. A sufficient condition is provided in terms of linear matrix inequalities to design the observer-based consensus protocol, which makes the multiagent systems achieve finite-time consensus under switching topologies. Then, we discuss the counterparts for discrete-time case. Finally, we provide an illustrative example to show the effectiveness of the design approach. PMID:24883367

Voter model with non-Poissonian interevent intervals

NASA Astrophysics Data System (ADS)

Takaguchi, Taro; Masuda, Naoki

2011-09-01

Recent analysis of social communications among humans has revealed that the interval between interactions for a pair of individuals and for an individual often follows a long-tail distribution. We investigate the effect of such a non-Poissonian nature of human behavior on dynamics of opinion formation. We use a variant of the voter model and numerically compare the time to consensus of all the voters with different distributions of interevent intervals and different networks. Compared with the exponential distribution of interevent intervals (i.e., the standard voter model), the power-law distribution of interevent intervals slows down consensus on the ring. This is because of the memory effect; in the power-law case, the expected time until the next update event on a link is large if the link has not had an update event for a long time. On the complete graph, the consensus time in the power-law case is close to that in the exponential case. Regular graphs bridge these two results such that the slowing down of the consensus in the power-law case as compared to the exponential case is less pronounced as the degree increases.

ACVIM consensus update on Lyme borreliosis in dogs and cats

PubMed Central

Gerber, Bernhard; Goldstein, Richard E.; Labato, Mary Anna; Lappin, Michael R.; Moore, George E.

2018-01-01

An update of the 2006 American College of Veterinary Internal Medicine (ACVIM) Small Animal Consensus Statement on Lyme Disease in Dogs: Diagnosis, Treatment, and Prevention was presented at the 2016 ACVIM Forum in Denver, CO, followed by panel and audience discussion and a drafted consensus statement distributed online to diplomates for comment. The updated consensus statement is presented below. The consensus statement aims to provide guidance on the diagnosis, treatment, and prevention of Lyme borreliosis in dogs and cats. PMID:29566442

Distributed Position-Based Consensus of Second-Order Multiagent Systems With Continuous/Intermittent Communication.

PubMed

Song, Qiang; Liu, Fang; Wen, Guanghui; Cao, Jinde; Yang, Xinsong

2017-04-24

This paper considers the position-based consensus in a network of agents with double-integrator dynamics and directed topology. Two types of distributed observer algorithms are proposed to solve the consensus problem by utilizing continuous and intermittent position measurements, respectively, where each observer does not interact with any other observers. For the case of continuous communication between network agents, some convergence conditions are derived for reaching consensus in the network with a single constant delay or multiple time-varying delays on the basis of the eigenvalue analysis and the descriptor method. When the network agents can only obtain intermittent position data from local neighbors at discrete time instants, the consensus in the network without time delay or with nonuniform delays is investigated by using the Wirtinger's inequality and the delayed-input approach. Numerical examples are given to illustrate the theoretical analysis.

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.

Prescribed performance distributed consensus control for nonlinear multi-agent systems with unknown dead-zone input

NASA Astrophysics Data System (ADS)

Cui, Guozeng; Xu, Shengyuan; Ma, Qian; Li, Yongmin; Zhang, Zhengqiang

2018-05-01

In this paper, the problem of prescribed performance distributed output consensus for higher-order non-affine nonlinear multi-agent systems with unknown dead-zone input is investigated. Fuzzy logical systems are utilised to identify the unknown nonlinearities. By introducing prescribed performance, the transient and steady performance of synchronisation errors are guaranteed. Based on Lyapunov stability theory and the dynamic surface control technique, a new distributed consensus algorithm for non-affine nonlinear multi-agent systems is proposed, which ensures cooperatively uniformly ultimately boundedness of all signals in the closed-loop systems and enables the output of each follower to synchronise with the leader within predefined bounded error. Finally, simulation examples are provided to demonstrate the effectiveness of the proposed control scheme.

Minimal-Approximation-Based Distributed Consensus Tracking of a Class of Uncertain Nonlinear Multiagent Systems With Unknown Control Directions.

PubMed

Choi, Yun Ho; Yoo, Sung Jin

2017-03-28

A minimal-approximation-based distributed adaptive consensus tracking approach is presented for strict-feedback multiagent systems with unknown heterogeneous nonlinearities and control directions under a directed network. Existing approximation-based consensus results for uncertain nonlinear multiagent systems in lower-triangular form have used multiple function approximators in each local controller to approximate unmatched nonlinearities of each follower. Thus, as the follower's order increases, the number of the approximators used in its local controller increases. However, the proposed approach employs only one function approximator to construct the local controller of each follower regardless of the order of the follower. The recursive design methodology using a new error transformation is derived for the proposed minimal-approximation-based design. Furthermore, a bounding lemma on parameters of Nussbaum functions is presented to handle the unknown control direction problem in the minimal-approximation-based distributed consensus tracking framework and the stability of the overall closed-loop system is rigorously analyzed in the Lyapunov sense.

Distributed k-Means Algorithm and Fuzzy c-Means Algorithm for Sensor Networks Based on Multiagent Consensus Theory.

PubMed

Qin, Jiahu; Fu, Weiming; Gao, Huijun; Zheng, Wei Xing

2016-03-03

This paper is concerned with developing a distributed k-means algorithm and a distributed fuzzy c-means algorithm for wireless sensor networks (WSNs) where each node is equipped with sensors. The underlying topology of the WSN is supposed to be strongly connected. The consensus algorithm in multiagent consensus theory is utilized to exchange the measurement information of the sensors in WSN. To obtain a faster convergence speed as well as a higher possibility of having the global optimum, a distributed k-means++ algorithm is first proposed to find the initial centroids before executing the distributed k-means algorithm and the distributed fuzzy c-means algorithm. The proposed distributed k-means algorithm is capable of partitioning the data observed by the nodes into measure-dependent groups which have small in-group and large out-group distances, while the proposed distributed fuzzy c-means algorithm is capable of partitioning the data observed by the nodes into different measure-dependent groups with degrees of membership values ranging from 0 to 1. Simulation results show that the proposed distributed algorithms can achieve almost the same results as that given by the centralized clustering algorithms.

Sampled-Data Consensus of Linear Multi-agent Systems With Packet Losses.

PubMed

Zhang, Wenbing; Tang, Yang; Huang, Tingwen; Kurths, Jurgen

In this paper, the consensus problem is studied for a class of multi-agent systems with sampled data and packet losses, where random and deterministic packet losses are considered, respectively. For random packet losses, a Bernoulli-distributed white sequence is used to describe packet dropouts among agents in a stochastic way. For deterministic packet losses, a switched system with stable and unstable subsystems is employed to model packet dropouts in a deterministic way. The purpose of this paper is to derive consensus criteria, such that linear multi-agent systems with sampled-data and packet losses can reach consensus. By means of the Lyapunov function approach and the decomposition method, the design problem of a distributed controller is solved in terms of convex optimization. The interplay among the allowable bound of the sampling interval, the probability of random packet losses, and the rate of deterministic packet losses are explicitly derived to characterize consensus conditions. The obtained criteria are closely related to the maximum eigenvalue of the Laplacian matrix versus the second minimum eigenvalue of the Laplacian matrix, which reveals the intrinsic effect of communication topologies on consensus performance. Finally, simulations are given to show the effectiveness of the proposed results.In this paper, the consensus problem is studied for a class of multi-agent systems with sampled data and packet losses, where random and deterministic packet losses are considered, respectively. For random packet losses, a Bernoulli-distributed white sequence is used to describe packet dropouts among agents in a stochastic way. For deterministic packet losses, a switched system with stable and unstable subsystems is employed to model packet dropouts in a deterministic way. The purpose of this paper is to derive consensus criteria, such that linear multi-agent systems with sampled-data and packet losses can reach consensus. By means of the Lyapunov function approach and the decomposition method, the design problem of a distributed controller is solved in terms of convex optimization. The interplay among the allowable bound of the sampling interval, the probability of random packet losses, and the rate of deterministic packet losses are explicitly derived to characterize consensus conditions. The obtained criteria are closely related to the maximum eigenvalue of the Laplacian matrix versus the second minimum eigenvalue of the Laplacian matrix, which reveals the intrinsic effect of communication topologies on consensus performance. Finally, simulations are given to show the effectiveness of the proposed results.

A consensus linkage map of lentil based on DArT markers from three RIL mapping populations.

PubMed

Ates, Duygu; Aldemir, Secil; Alsaleh, Ahmad; Erdogmus, Semih; Nemli, Seda; Kahriman, Abdullah; Ozkan, Hakan; Vandenberg, Albert; Tanyolac, Bahattin

2018-01-01

Lentil (Lens culinaris ssp. culinaris Medikus) is a diploid (2n = 2x = 14), self-pollinating grain legume with a haploid genome size of about 4 Gbp and is grown throughout the world with current annual production of 4.9 million tonnes. A consensus map of lentil (Lens culinaris ssp. culinaris Medikus) was constructed using three different lentils recombinant inbred line (RIL) populations, including "CDC Redberry" x "ILL7502" (LR8), "ILL8006" x "CDC Milestone" (LR11) and "PI320937" x "Eston" (LR39). The lentil consensus map was composed of 9,793 DArT markers, covered a total of 977.47 cM with an average distance of 0.10 cM between adjacent markers and constructed 7 linkage groups representing 7 chromosomes of the lentil genome. The consensus map had no gap larger than 12.67 cM and only 5 gaps were found to be between 12.67 cM and 6.0 cM (on LG3 and LG4). The localization of the SNP markers on the lentil consensus map were in general consistent with their localization on the three individual genetic linkage maps and the lentil consensus map has longer map length, higher marker density and shorter average distance between the adjacent markers compared to the component linkage maps. This high-density consensus map could provide insight into the lentil genome. The consensus map could also help to construct a physical map using a Bacterial Artificial Chromosome library and map based cloning studies. Sequence information of DArT may help localization of orientation scaffolds from Next Generation Sequencing data.

A consensus linkage map of lentil based on DArT markers from three RIL mapping populations

PubMed Central

Ates, Duygu; Aldemir, Secil; Alsaleh, Ahmad; Erdogmus, Semih; Nemli, Seda; Kahriman, Abdullah; Ozkan, Hakan; Vandenberg, Albert

2018-01-01

Background Lentil (Lens culinaris ssp. culinaris Medikus) is a diploid (2n = 2x = 14), self-pollinating grain legume with a haploid genome size of about 4 Gbp and is grown throughout the world with current annual production of 4.9 million tonnes. Materials and methods A consensus map of lentil (Lens culinaris ssp. culinaris Medikus) was constructed using three different lentils recombinant inbred line (RIL) populations, including “CDC Redberry” x “ILL7502” (LR8), “ILL8006” x “CDC Milestone” (LR11) and “PI320937” x “Eston” (LR39). Results The lentil consensus map was composed of 9,793 DArT markers, covered a total of 977.47 cM with an average distance of 0.10 cM between adjacent markers and constructed 7 linkage groups representing 7 chromosomes of the lentil genome. The consensus map had no gap larger than 12.67 cM and only 5 gaps were found to be between 12.67 cM and 6.0 cM (on LG3 and LG4). The localization of the SNP markers on the lentil consensus map were in general consistent with their localization on the three individual genetic linkage maps and the lentil consensus map has longer map length, higher marker density and shorter average distance between the adjacent markers compared to the component linkage maps. Conclusion This high-density consensus map could provide insight into the lentil genome. The consensus map could also help to construct a physical map using a Bacterial Artificial Chromosome library and map based cloning studies. Sequence information of DArT may help localization of orientation scaffolds from Next Generation Sequencing data. PMID:29351563

Distributed consensus for discrete-time heterogeneous multi-agent systems

NASA Astrophysics Data System (ADS)

Zhao, Huanyu; Fei, Shumin

2018-06-01

This paper studies the consensus problem for a class of discrete-time heterogeneous multi-agent systems. Two kinds of consensus algorithms will be considered. The heterogeneous multi-agent systems considered are converted into equivalent error systems by a model transformation. Then we analyse the consensus problem of the original systems by analysing the stability problem of the error systems. Some sufficient conditions for consensus of heterogeneous multi-agent systems are obtained by applying algebraic graph theory and matrix theory. Simulation examples are presented to show the usefulness of the results.

Non-fragile consensus algorithms for a network of diffusion PDEs with boundary local interaction

NASA Astrophysics Data System (ADS)

Xiong, Jun; Li, Junmin

2017-07-01

In this study, non-fragile consensus algorithm is proposed to solve the average consensus problem of a network of diffusion PDEs, modelled by boundary controlled heat equations. The problem deals with the case where the Neumann-type boundary controllers are corrupted by additive persistent disturbances. To achieve consensus between agents, a linear local interaction rule addressing this requirement is given. The proposed local interaction rules are analysed by applying a Lyapunov-based approach. The multiplicative and additive non-fragile feedback control algorithms are designed and sufficient conditions for the consensus of the multi-agent systems are presented in terms of linear matrix inequalities, respectively. Simulation results are presented to support the effectiveness of the proposed algorithms.

Global finite-time attitude consensus tracking control for a group of rigid spacecraft

NASA Astrophysics Data System (ADS)

Li, Penghua

2017-10-01

The problem of finite-time attitude consensus for multiple rigid spacecraft with a leader-follower architecture is investigated in this paper. To achieve the finite-time attitude consensus, at the first step, a distributed finite-time convergent observer is proposed for each follower to estimate the leader's attitude in a finite time. Then based on the terminal sliding mode control method, a new finite-time attitude tracking controller is designed such that the leader's attitude can be tracked in a finite time. Finally, a finite-time observer-based distributed control strategy is proposed. It is shown that the attitude consensus can be achieved in a finite time under the proposed controller. Simulation results are given to show the effectiveness of the proposed method.

Exon–intron organization of genes in the slime mold Physarum polycephalum

PubMed Central

Trzcinska-Danielewicz, Joanna; Fronk, Jan

2000-01-01

The slime mold Physarum polycephalum is a morphologically simple organism with a large and complex genome. The exon–intron organization of its genes exhibits features typical for protists and fungi as well as those characteristic for the evolutionarily more advanced species. This indicates that both the taxonomic position as well as the size of the genome shape the exon–intron organization of an organism. The average gene has 3.7 introns which are on average 138 bp, with a rather narrow size distribution. Introns are enriched in AT base pairs by 13% relative to exons. The consensus sequences at exon–intron boundaries resemble those found for other species, with minor differences between short and long introns. A unique feature of P.polycephalum introns is the strong preference for pyrimidines in the coding strand throughout their length, without a particular enrichment at the 3′-ends. PMID:10982858

SURVEY AND SUMMARY: exon-intron organization of genes in the slime mold Physarum polycephalum.

PubMed

Trzcinska-Danielewicz, J; Fronk, J

2000-09-15

The slime mold Physarum polycephalum is a morphologically simple organism with a large and complex genome. The exon-intron organization of its genes exhibits features typical for protists and fungi as well as those characteristic for the evolutionarily more advanced species. This indicates that both the taxonomic position as well as the size of the genome shape the exon-intron organization of an organism. The average gene has 3.7 introns which are on average 138 bp, with a rather narrow size distribution. Introns are enriched in AT base pairs by 13% relative to exons. The consensus sequences at exon-intron boundaries resemble those found for other species, with minor differences between short and long introns. A unique feature of P.polycephalum introns is the strong preference for pyrimidines in the coding strand throughout their length, without a particular enrichment at the 3'-ends.

Dynamical and topological aspects of consensus formation in complex networks

NASA Astrophysics Data System (ADS)

Chacoma, A.; Mato, G.; Kuperman, M. N.

2018-04-01

The present work analyzes a particular scenario of consensus formation, where the individuals navigate across an underlying network defining the topology of the walks. The consensus, associated to a given opinion coded as a simple message, is generated by interactions during the agent's walk and manifest itself in the collapse of the various opinions into a single one. We analyze how the topology of the underlying networks and the rules of interaction between the agents promote or inhibit the emergence of this consensus. We find that non-linear interaction rules are required to form consensus and that consensus is more easily achieved in networks whose degree distribution is narrower.

Practical comparison of distributed ledger technologies for IoT

NASA Astrophysics Data System (ADS)

Red, Val A.

2017-05-01

Existing distributed ledger implementations - specifically, several blockchain implementations - embody a cacophony of divergent capabilities augmenting innovations of cryptographic hashes, consensus mechanisms, and asymmetric cryptography in a wide variety of applications. Whether specifically designed for cryptocurrency or otherwise, several distributed ledgers rely upon modular mechanisms such as consensus or smart contracts. These components, however, can vary substantially among implementations; differences involving proof-of-work, practical byzantine fault tolerance, and other consensus approaches exemplify distinct distributed ledger variations. Such divergence results in unique combinations of modules, performance, latency, and fault tolerance. As implementations continue to develop rapidly due to the emerging nature of blockchain technologies, this paper encapsulates a snapshot of sensor and internet of things (IoT) specific implementations of blockchain as of the end of 2016. Several technical risks and divergent approaches preclude standardization of a blockchain for sensors and IoT in the foreseeable future; such issues will be assessed alongside the practicality of IoT applications among Hyperledger, Iota, and Ethereum distributed ledger implementations suggested for IoT. This paper contributes a comparison of existing distributed ledger implementations intended for practical sensor and IoT utilization. A baseline for characterizing distributed ledger implementations in the context of IoT and sensors is proposed. Technical approaches and performance are compared considering IoT size, weight, and power limitations. Consensus and smart contracts, if applied, are also analyzed for the respective implementations' practicality and security. Overall, the maturity of distributed ledgers with respect to sensor and IoT applicability will be analyzed for enterprise interoperability.

Improving control and estimation for distributed parameter systems utilizing mobile actuator-sensor network.

PubMed

Mu, Wenying; Cui, Baotong; Li, Wen; Jiang, Zhengxian

2014-07-01

This paper proposes a scheme for non-collocated moving actuating and sensing devices which is unitized for improving performance in distributed parameter systems. By Lyapunov stability theorem, each moving actuator/sensor agent velocity is obtained. To enhance state estimation of a spatially distributes process, two kinds of filters with consensus terms which penalize the disagreement of the estimates are considered. Both filters can result in the well-posedness of the collective dynamics of state errors and can converge to the plant state. Numerical simulations demonstrate that the effectiveness of such a moving actuator-sensor network in enhancing system performance and the consensus filters converge faster to the plant state when consensus terms are included. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

The Efficacy of Consensus Tree Methods for Summarizing Phylogenetic Relationships from a Posterior Sample of Trees Estimated from Morphological Data.

PubMed

O'Reilly, Joseph E; Donoghue, Philip C J

2018-03-01

Consensus trees are required to summarize trees obtained through MCMC sampling of a posterior distribution, providing an overview of the distribution of estimated parameters such as topology, branch lengths, and divergence times. Numerous consensus tree construction methods are available, each presenting a different interpretation of the tree sample. The rise of morphological clock and sampled-ancestor methods of divergence time estimation, in which times and topology are coestimated, has increased the popularity of the maximum clade credibility (MCC) consensus tree method. The MCC method assumes that the sampled, fully resolved topology with the highest clade credibility is an adequate summary of the most probable clades, with parameter estimates from compatible sampled trees used to obtain the marginal distributions of parameters such as clade ages and branch lengths. Using both simulated and empirical data, we demonstrate that MCC trees, and trees constructed using the similar maximum a posteriori (MAP) method, often include poorly supported and incorrect clades when summarizing diffuse posterior samples of trees. We demonstrate that the paucity of information in morphological data sets contributes to the inability of MCC and MAP trees to accurately summarise of the posterior distribution. Conversely, majority-rule consensus (MRC) trees represent a lower proportion of incorrect nodes when summarizing the same posterior samples of trees. Thus, we advocate the use of MRC trees, in place of MCC or MAP trees, in attempts to summarize the results of Bayesian phylogenetic analyses of morphological data.

The Efficacy of Consensus Tree Methods for Summarizing Phylogenetic Relationships from a Posterior Sample of Trees Estimated from Morphological Data

PubMed Central

O’Reilly, Joseph E; Donoghue, Philip C J

2018-01-01

Abstract Consensus trees are required to summarize trees obtained through MCMC sampling of a posterior distribution, providing an overview of the distribution of estimated parameters such as topology, branch lengths, and divergence times. Numerous consensus tree construction methods are available, each presenting a different interpretation of the tree sample. The rise of morphological clock and sampled-ancestor methods of divergence time estimation, in which times and topology are coestimated, has increased the popularity of the maximum clade credibility (MCC) consensus tree method. The MCC method assumes that the sampled, fully resolved topology with the highest clade credibility is an adequate summary of the most probable clades, with parameter estimates from compatible sampled trees used to obtain the marginal distributions of parameters such as clade ages and branch lengths. Using both simulated and empirical data, we demonstrate that MCC trees, and trees constructed using the similar maximum a posteriori (MAP) method, often include poorly supported and incorrect clades when summarizing diffuse posterior samples of trees. We demonstrate that the paucity of information in morphological data sets contributes to the inability of MCC and MAP trees to accurately summarise of the posterior distribution. Conversely, majority-rule consensus (MRC) trees represent a lower proportion of incorrect nodes when summarizing the same posterior samples of trees. Thus, we advocate the use of MRC trees, in place of MCC or MAP trees, in attempts to summarize the results of Bayesian phylogenetic analyses of morphological data. PMID:29106675

Highly preserved consensus gene modules in human papilloma virus 16 positive cervical cancer and head and neck cancers.

PubMed

Zhang, Xianglan; Cha, In-Ho; Kim, Ki-Yeol

2017-12-26

In this study, we investigated the consensus gene modules in head and neck cancer (HNC) and cervical cancer (CC). We used a publicly available gene expression dataset, GSE6791, which included 42 HNC, 14 normal head and neck, 20 CC and 8 normal cervical tissue samples. To exclude bias because of different human papilloma virus (HPV) types, we analyzed HPV16-positive samples only. We identified 3824 genes common to HNC and CC samples. Among these, 977 genes showed high connectivity and were used to construct consensus modules. We demonstrated eight consensus gene modules for HNC and CC using the dissimilarity measure and average linkage hierarchical clustering methods. These consensus modules included genes with significant biological functions, including ATP binding and extracellular exosome. Eigengen network analysis revealed the consensus modules were highly preserved with high connectivity. These findings demonstrate that HPV16-positive head and neck and cervical cancers share highly preserved consensus gene modules with common potentially therapeutic targets.

Highly preserved consensus gene modules in human papilloma virus 16 positive cervical cancer and head and neck cancers

PubMed Central

Zhang, Xianglan; Cha, In-Ho; Kim, Ki-Yeol

2017-01-01

In this study, we investigated the consensus gene modules in head and neck cancer (HNC) and cervical cancer (CC). We used a publicly available gene expression dataset, GSE6791, which included 42 HNC, 14 normal head and neck, 20 CC and 8 normal cervical tissue samples. To exclude bias because of different human papilloma virus (HPV) types, we analyzed HPV16-positive samples only. We identified 3824 genes common to HNC and CC samples. Among these, 977 genes showed high connectivity and were used to construct consensus modules. We demonstrated eight consensus gene modules for HNC and CC using the dissimilarity measure and average linkage hierarchical clustering methods. These consensus modules included genes with significant biological functions, including ATP binding and extracellular exosome. Eigengen network analysis revealed the consensus modules were highly preserved with high connectivity. These findings demonstrate that HPV16-positive head and neck and cervical cancers share highly preserved consensus gene modules with common potentially therapeutic targets. PMID:29371966

Distributed event-triggered consensus strategy for multi-agent systems under limited resources

NASA Astrophysics Data System (ADS)

Noorbakhsh, S. Mohammad; Ghaisari, Jafar

2016-01-01

The paper proposes a distributed structure to address an event-triggered consensus problem for multi-agent systems which aims at concurrent reduction in inter-agent communication, control input actuation and energy consumption. Following the proposed approach, asymptotic convergence of all agents to consensus requires that each agent broadcasts its sampled-state to the neighbours and updates its control input only at its own triggering instants, unlike the existing related works. Obviously, it decreases the network bandwidth usage, sensor energy consumption, computation resources usage and actuator wears. As a result, it facilitates the implementation of the proposed consensus protocol in the real-world applications with limited resources. The stability of the closed-loop system under an event-based protocol is proved analytically. Some numerical results are presented which confirm the analytical discussion on the effectiveness of the proposed design.

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.

Improving consensus contact prediction via server correlation reduction.

PubMed

Gao, Xin; Bu, Dongbo; Xu, Jinbo; Li, Ming

2009-05-06

Protein inter-residue contacts play a crucial role in the determination and prediction of protein structures. Previous studies on contact prediction indicate that although template-based consensus methods outperform sequence-based methods on targets with typical templates, such consensus methods perform poorly on new fold targets. However, we find out that even for new fold targets, the models generated by threading programs can contain many true contacts. The challenge is how to identify them. In this paper, we develop an integer linear programming model for consensus contact prediction. In contrast to the simple majority voting method assuming that all the individual servers are equally important and independent, the newly developed method evaluates their correlation by using maximum likelihood estimation and extracts independent latent servers from them by using principal component analysis. An integer linear programming method is then applied to assign a weight to each latent server to maximize the difference between true contacts and false ones. The proposed method is tested on the CASP7 data set. If the top L/5 predicted contacts are evaluated where L is the protein size, the average accuracy is 73%, which is much higher than that of any previously reported study. Moreover, if only the 15 new fold CASP7 targets are considered, our method achieves an average accuracy of 37%, which is much better than that of the majority voting method, SVM-LOMETS, SVM-SEQ, and SAM-T06. These methods demonstrate an average accuracy of 13.0%, 10.8%, 25.8% and 21.2%, respectively. Reducing server correlation and optimally combining independent latent servers show a significant improvement over the traditional consensus methods. This approach can hopefully provide a powerful tool for protein structure refinement and prediction use.

Second-Order Consensus in Multiagent Systems via Distributed Sliding Mode Control.

PubMed

Yu, Wenwu; Wang, He; Cheng, Fei; Yu, Xinghuo; Wen, Guanghui

2016-11-22

In this paper, the new decoupled distributed sliding-mode control (DSMC) is first proposed for second-order consensus in multiagent systems, which finally solves the fundamental unknown problem for sliding-mode control (SMC) design of coupled networked systems. A distributed full-order sliding-mode surface is designed based on the homogeneity with dilation for reaching second-order consensus in multiagent systems, under which the sliding-mode states are decoupled. Then, the SMC is applied to the decoupled sliding-mode states to reach their origin in finite time, which is the sliding-mode surface. The states of agents can first reach the designed sliding-mode surface in finite time and then move to the second-order consensus state along the surface in finite time as well. The DSMC designed in this paper can eliminate the influence of singularity problems and weaken the influence of chattering, which is still very difficult in the SMC systems. In addition, DSMC proposes a general decoupling framework for designing SMC in networked multiagent systems. Simulations are presented to verify the theoretical results in this paper.

Distributed control for energy-efficient and fast consensus in wireless sensor networks

NASA Astrophysics Data System (ADS)

Manfredi, Sabato; Tucci, Edmondo Di

2017-05-01

The paper proposes a distributed control of nodes transmission radii in energy-harvesting wireless sensor networks for simultaneously coping with energy consumption and consensus responsiveness requirement. The stability of the closed-loop network under the proposed control law is proved. Simulation validations show the effectiveness of the proposed approach in nominal scenario as well as in the presence of uncertain node power requirements and harvesting system supply.

Finite-time consensus for multi-agent systems with globally bounded convergence time under directed communication graphs

NASA Astrophysics Data System (ADS)

Fu, Junjie; Wang, Jin-zhi

2017-09-01

In this paper, we study the finite-time consensus problems with globally bounded convergence time also known as fixed-time consensus problems for multi-agent systems subject to directed communication graphs. Two new distributed control strategies are proposed such that leaderless and leader-follower consensus are achieved with convergence time independent on the initial conditions of the agents. Fixed-time formation generation and formation tracking problems are also solved as the generalizations. Simulation examples are provided to demonstrate the performance of the new controllers.

Decentralized Observer with a Consensus Filter for Distributed Discrete-Time Linear Systems

NASA Technical Reports Server (NTRS)

Acikmese, Behcet; Mandic, Milan

2011-01-01

This paper presents a decentralized observer with a consensus filter for the state observation of a discrete-time linear distributed systems. In this setup, each agent in the distributed system has an observer with a model of the plant that utilizes the set of locally available measurements, which may not make the full plant state detectable. This lack of detectability is overcome by utilizing a consensus filter that blends the state estimate of each agent with its neighbors' estimates. We assume that the communication graph is connected for all times as well as the sensing graph. It is proven that the state estimates of the proposed observer asymptotically converge to the actual plant states under arbitrarily changing, but connected, communication and sensing topologies. As a byproduct of this research, we also obtained a result on the location of eigenvalues, the spectrum, of the Laplacian for a family of graphs with self-loops.

Distributed Consensus of Stochastic Delayed Multi-agent Systems Under Asynchronous Switching.

PubMed

Wu, Xiaotai; Tang, Yang; Cao, Jinde; Zhang, Wenbing

2016-08-01

In this paper, the distributed exponential consensus of stochastic delayed multi-agent systems with nonlinear dynamics is investigated under asynchronous switching. The asynchronous switching considered here is to account for the time of identifying the active modes of multi-agent systems. After receipt of confirmation of mode's switching, the matched controller can be applied, which means that the switching time of the matched controller in each node usually lags behind that of system switching. In order to handle the coexistence of switched signals and stochastic disturbances, a comparison principle of stochastic switched delayed systems is first proved. By means of this extended comparison principle, several easy to verified conditions for the existence of an asynchronously switched distributed controller are derived such that stochastic delayed multi-agent systems with asynchronous switching and nonlinear dynamics can achieve global exponential consensus. Two examples are given to illustrate the effectiveness of the proposed method.

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.

Do Sell-Side Stock Analysts Exhibit Escalation of Commitment?

PubMed Central

Milkman, Katherine L.

2010-01-01

This paper presents evidence that when an analyst makes an out-of-consensus forecast of a company’s quarterly earnings that turns out to be incorrect, she escalates her commitment to maintaining an out-of-consensus view on the company. Relative to an analyst who was close to the consensus, the out-of-consensus analyst adjusts her forecasts for the current fiscal year’s earnings less in the direction of the quarterly earnings surprise. On average, this type of updating behavior reduces forecasting accuracy, so it does not seem to reflect superior private information. Further empirical results suggest that analysts do not have financial incentives to stand by extreme stock calls in the face of contradictory evidence. Managerial and financial market implications are discussed. PMID:21516220

Distributed robust finite-time nonlinear consensus protocols for multi-agent systems

NASA Astrophysics Data System (ADS)

Zuo, Zongyu; Tie, Lin

2016-04-01

This paper investigates the robust finite-time consensus problem of multi-agent systems in networks with undirected topology. Global nonlinear consensus protocols augmented with a variable structure are constructed with the aid of Lyapunov functions for each single-integrator agent dynamics in the presence of external disturbances. In particular, it is shown that the finite settling time of the proposed general framework for robust consensus design is upper bounded for any initial condition. This makes it possible for network consensus problems to design and estimate the convergence time offline for a multi-agent team with a given undirected information flow. Finally, simulation results are presented to demonstrate the performance and effectiveness of our finite-time protocols.

Developing clinical practice guidelines for Chinese herbal treatment of polycystic ovary syndrome: A mixed-methods modified Delphi study.

PubMed

Lai, Lily; Flower, Andrew; Moore, Michael; Lewith, George

2015-06-01

Preliminary evidence suggests Chinese herbal medicine (CHM) could be a viable treatment option for polycystic ovary syndrome (PCOS). Prior to conducting a clinical trial it is important to consider the characteristics of good clinical practice. This study aims to use professional consensus to establish good clinical practice guidelines for the CHM treatment of PCOS. CHM practitioners participated in a mixed-methods modified Delphi study involving three rounds of structured group communication. Round 1 involved qualitative interviews with practitioners to generate statements regarding good clinical practice. In round 2, these statements were distributed online to the same practitioners to rate their agreement using a 7-point Likert scale, where group consensus was defined as a median rating of ≥5. Statements reaching consensus were accepted for consideration onto the guideline whilst those not reaching consensus were re-distributed for consideration in round 3. Statements presented in the guidelines were graded from A (strong consensus) to D (no consensus) determined by median score and interquartile range. 11 CHM practitioners in the UK were recruited. After three Delphi rounds, 91 statement items in total had been considered, of which 89 (97.8%) reached consensus and 2 (2.2%) did not. The concluding set of guidelines consists of 85 items representing key features of CHM prescribing for PCOS. These guidelines can be viewed as an initial framework that captures fundamental principles of good clinical practice for CHM. Copyright © 2015 Elsevier Ltd. All rights reserved.

Distributed Data-aggregation Consensus for Sensor Networks: Relaxation of Consensus Concept and Convergence Property

DTIC Science & Technology

2014-08-01

consensus algorithm called randomized gossip is more suitable [7, 8]. In asynchronous randomized gossip algorithms, pairs of neighboring nodes exchange...messages and perform updates in an asynchronous and unattended manner, and they also 1 The class of broadcast gossip algorithms [9, 10, 11, 12] are...dynamics [2] and asynchronous pairwise randomized gossip [7, 8], broadcast gossip algorithms do not require that nodes know the identities of their

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

Hao, He; Lian, Jianming; Kalsi, Karanjit

The HVAC (Heating, Ventilation, and Air- Conditioning) system of commercial buildings is a complex system with a large number of dynamically interacting components. In particular, the thermal dynamics of each zone are coupled with those of the neighboring zones. In this paper, we study a multi-agent based approach to model and control commercial building HVAC system for providing grid services. In the multi-agent system (MAS), individual zones are modeled as agents that can communicate, interact, and negotiate with one another to achieve a common objective. We first propose a distributed characterization method on the aggregated airflow (and thus fan power)more » flexibility that the HVAC system can provide to the ancillary service market. Then, we propose a Nash-bargaining based airflow allocation strategy to track a dispatch signal (that is within the offered flexibility limit) while respecting the preference and flexibility of individual zones. Moreover, we devise a distributed algorithm to obtain the Nash bargaining solution via dual decomposition and average consensus. Numerical simulations illustrate that the proposed distributed protocols are much more scalable than the centralized approaches especially when the system becomes larger and more complex.« less

Hazardous workplace review program in Taiwan.

PubMed

Chang, Yi-Kuo; Chuang, Kuen-Yuan; Tseng, Jo-Ming; Lin, Fang-Chen; Su, Teh-Sheng

2013-01-01

In Taiwan, relevant mid-term plans and projects of mitigating occupational hazards have been launched in recent years in the hopes of lowering the incidence of occupational hazards. In light of the lack of objective methodologies for researches on issues pertaining occupational safety and health, this research aims to explore the priorities of safety and health issues through focal groups, expert questionnaires and interviews on relevant issues such as hazard installations identified in R181 Prevention of Major Industrial Accidents Recommendation, 1993 proposed during the 18th World Congress on Safety and Health at work in Seoul 2008. Results revealed that distribute reports of major domestic/foreign occupational disasters to relevant sectors for the prevention of major accidents is needed, both from the importance and feasibility analysis. It is the only topic that scored over 4 points in average for expert and focal group consensus. Furthermore, the experts and focal groups came to consensus in the ranking of priority for 4 items, namely: 1) Installations containing/using large quantities of hazardous materials should be prioritized for inspection, 2) Incorporation of hazard installation review/inspection into OSH management system accreditation, 3) Impose operation shutdown as a means of penalty) and 4) Prioritize the promotion of preliminary PHA.

An Interactive Multi-Model for Consensus on Climate Change

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

Kocarev, Ljupco

This project purports to develop a new scheme for forming consensus among alternative climate models, that give widely divergent projections as to the details of climate change, that is more intelligent than simply averaging the model outputs, or averaging with ex post facto weighting factors. The method under development effectively allows models to assimilate data from one another in run time with weights that are chosen in an adaptive training phase using 20th century data, so that the models synchronize with one another as well as with reality. An alternate approach that is being explored in parallel is the automatedmore » combination of equations from different models in an expert-system-like framework.« less

Optimal consensus algorithm integrated with obstacle avoidance

NASA Astrophysics Data System (ADS)

Wang, Jianan; Xin, Ming

2013-01-01

This article proposes a new consensus algorithm for the networked single-integrator systems in an obstacle-laden environment. A novel optimal control approach is utilised to achieve not only multi-agent consensus but also obstacle avoidance capability with minimised control efforts. Three cost functional components are defined to fulfil the respective tasks. In particular, an innovative nonquadratic obstacle avoidance cost function is constructed from an inverse optimal control perspective. The other two components are designed to ensure consensus and constrain the control effort. The asymptotic stability and optimality are proven. In addition, the distributed and analytical optimal control law only requires local information based on the communication topology to guarantee the proposed behaviours, rather than all agents' information. The consensus and obstacle avoidance are validated through simulations.

Experimental effects of climate messages vary geographically

NASA Astrophysics Data System (ADS)

Zhang, Baobao; van der Linden, Sander; Mildenberger, Matto; Marlon, Jennifer R.; Howe, Peter D.; Leiserowitz, Anthony

2018-05-01

Social science scholars routinely evaluate the efficacy of diverse climate frames using local convenience or nationally representative samples1-5. For example, previous research has focused on communicating the scientific consensus on climate change, which has been identified as a `gateway' cognition to other key beliefs about the issue6-9. Importantly, although these efforts reveal average public responsiveness to particular climate frames, they do not describe variation in message effectiveness at the spatial and political scales relevant for climate policymaking. Here we use a small-area estimation method to map geographical variation in public responsiveness to information about the scientific consensus as part of a large-scale randomized national experiment (n = 6,301). Our survey experiment finds that, on average, public perception of the consensus increases by 16 percentage points after message exposure. However, substantial spatial variation exists across the United States at state and local scales. Crucially, responsiveness is highest in more conservative parts of the country, leading to national convergence in perceptions of the climate science consensus across diverse political geographies. These findings not only advance a geographical understanding of how the public engages with information about scientific agreement, but will also prove useful for policymakers, practitioners and scientists engaged in climate change mitigation and adaptation.

Detecting reliable cognitive change in individual patients with the MATRICS Consensus Cognitive Battery.

PubMed

Gray, Bradley E; McMahon, Robert P; Green, Michael F; Seidman, Larry J; Mesholam-Gately, Raquelle I; Kern, Robert S; Nuechterlein, Keith H; Keefe, Richard S; Gold, James M

2014-10-01

Clinicians often need to evaluate the treatment response of an individual person and to know that observed change is true improvement or worsening beyond usual week-to-week changes. This paper gives clinicians tools to evaluate individual changes on the MATRICS Consensus Cognitive Battery (MCCB). We compare three different approaches: a descriptive analysis of MCCB test-retest performance with no intervention, a reliable change index (RCI) approach controlling for average practice effects, and a regression approach. Data were gathered as part of the MATRICS PASS study (Nuechterlein et al., 2008). A total of 159 people with schizophrenia completed the MCCB at baseline and 4weeks later. Data were analyzed using an RCI and a regression formula establishing confidence intervals. The RCI and regression approaches agree within one point when baseline values are close to the sample mean. However, the regression approach offers more accurate limits for expected change at the tails of the distribution of baseline scores. Although both approaches have their merits, the regression approach provides the most accurate measure of significant change across the full range of scores. As the RCI does not account for regression to the mean and has confidence limits that remain constant across baseline scores, the RCI approach effectively gives narrower confidence limits around an inaccurately predicted average change value. Further, despite the high test-retest reliability of the MCCB, a change in an individual's score must be relatively large to be confident that it is beyond normal month-to-month variation. Copyright © 2014 Elsevier B.V. All rights reserved.

A Secure Scheme for Distributed Consensus Estimation against Data Falsification in Heterogeneous Wireless Sensor Networks.

PubMed

Mi, Shichao; Han, Hui; Chen, Cailian; Yan, Jian; Guan, Xinping

2016-02-19

Heterogeneous wireless sensor networks (HWSNs) can achieve more tasks and prolong the network lifetime. However, they are vulnerable to attacks from the environment or malicious nodes. This paper is concerned with the issues of a consensus secure scheme in HWSNs consisting of two types of sensor nodes. Sensor nodes (SNs) have more computation power, while relay nodes (RNs) with low power can only transmit information for sensor nodes. To address the security issues of distributed estimation in HWSNs, we apply the heterogeneity of responsibilities between the two types of sensors and then propose a parameter adjusted-based consensus scheme (PACS) to mitigate the effect of the malicious node. Finally, the convergence property is proven to be guaranteed, and the simulation results validate the effectiveness and efficiency of PACS.

Observer-based consensus of networked thrust-propelled vehicles with directed graphs.

PubMed

Cang, Weiye; Li, Zhongkui; Wang, Hanlei

2017-11-01

In this paper, we investigate the consensus problem for networked underactuated thrust-propelled vehicles (TPVs) interacting on directed graphs. We propose distributed observer-based consensus protocols, which avoid the reliance on the measurements of translational velocities and accelerations. Using the input-output analysis, we present necessary and sufficient conditions to ensure that the observer-based protocols can achieve consensus for both the cases without and with constant communication delays, provided that the communication graph contains a directed spanning tree. Simulation examples are finally provided to illustrate the effectiveness of the control schemes. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Mean square consensus of leader-following multi-agent systems with measurement noises and time delays.

PubMed

Ren, Hongwei; Deng, Feiqi

2017-11-01

This paper investigates the mean square consensus problem of dynamical networks of leader-following multi-agent systems with measurement noises and time-varying delays. We consider that the fixed undirected communication topologies are connected. A neighbor-based tracking algorithm together with distributed estimators are presented. Using tools of algebraic graph theory and the Gronwall-Bellman-Halanay type inequality, we establish sufficient conditions to reach consensus in mean square sense via the proposed consensus protocols. Finally, a numerical simulation is provided to demonstrate the effectiveness of the obtained theoretical result. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Stability switches of arbitrary high-order consensus in multiagent networks with time delays.

PubMed

Yang, Bo

2013-01-01

High-order consensus seeking, in which individual high-order dynamic agents share a consistent view of the objectives and the world in a distributed manner, finds its potential broad applications in the field of cooperative control. This paper presents stability switches analysis of arbitrary high-order consensus in multiagent networks with time delays. By employing a frequency domain method, we explicitly derive analytical equations that clarify a rigorous connection between the stability of general high-order consensus and the system parameters such as the network topology, communication time-delays, and feedback gains. Particularly, our results provide a general and a fairly precise notion of how increasing communication time-delay causes the stability switches of consensus. Furthermore, under communication constraints, the stability and robustness problems of consensus algorithms up to third order are discussed in details to illustrate our central results. Numerical examples and simulation results for fourth-order consensus are provided to demonstrate the effectiveness of our theoretical results.

Coordinated single-phase control scheme for voltage unbalance reduction in low voltage network.

PubMed

Pullaguram, Deepak; Mishra, Sukumar; Senroy, Nilanjan

2017-08-13

Low voltage (LV) distribution systems are typically unbalanced in nature due to unbalanced loading and unsymmetrical line configuration. This situation is further aggravated by single-phase power injections. A coordinated control scheme is proposed for single-phase sources, to reduce voltage unbalance. A consensus-based coordination is achieved using a multi-agent system, where each agent estimates the averaged global voltage and current magnitudes of individual phases in the LV network. These estimated values are used to modify the reference power of individual single-phase sources, to ensure system-wide balanced voltages and proper power sharing among sources connected to the same phase. Further, the high X / R ratio of the filter, used in the inverter of the single-phase source, enables control of reactive power, to minimize voltage unbalance locally. The proposed scheme is validated by simulating a LV distribution network with multiple single-phase sources subjected to various perturbations.This article is part of the themed issue 'Energy management: flexibility, risk and optimization'. © 2017 The Author(s).

Identification of consensus biomarkers for predicting non-genotoxic hepatocarcinogens

PubMed Central

Huang, Shan-Han; Tung, Chun-Wei

2017-01-01

The assessment of non-genotoxic hepatocarcinogens (NGHCs) is currently relying on two-year rodent bioassays. Toxicogenomics biomarkers provide a potential alternative method for the prioritization of NGHCs that could be useful for risk assessment. However, previous studies using inconsistently classified chemicals as the training set and a single microarray dataset concluded no consensus biomarkers. In this study, 4 consensus biomarkers of A2m, Ca3, Cxcl1, and Cyp8b1 were identified from four large-scale microarray datasets of the one-day single maximum tolerated dose and a large set of chemicals without inconsistent classifications. Machine learning techniques were subsequently applied to develop prediction models for NGHCs. The final bagging decision tree models were constructed with an average AUC performance of 0.803 for an independent test. A set of 16 chemicals with controversial classifications were reclassified according to the consensus biomarkers. The developed prediction models and identified consensus biomarkers are expected to be potential alternative methods for prioritization of NGHCs for further experimental validation. PMID:28117354

A Consensus Genetic Map for Pinus taeda and Pinus elliottii and Extent of Linkage Disequilibrium in Two Genotype-Phenotype Discovery Populations of Pinus taeda

PubMed Central

Westbrook, Jared W.; Chhatre, Vikram E.; Wu, Le-Shin; Chamala, Srikar; Neves, Leandro Gomide; Muñoz, Patricio; Martínez-García, Pedro J.; Neale, David B.; Kirst, Matias; Mockaitis, Keithanne; Nelson, C. Dana; Peter, Gary F.; Echt, Craig S.

2015-01-01

A consensus genetic map for Pinus taeda (loblolly pine) and Pinus elliottii (slash pine) was constructed by merging three previously published P. taeda maps with a map from a pseudo-backcross between P. elliottii and P. taeda. The consensus map positioned 3856 markers via genotyping of 1251 individuals from four pedigrees. It is the densest linkage map for a conifer to date. Average marker spacing was 0.6 cM and total map length was 2305 cM. Functional predictions of mapped genes were improved by aligning expressed sequence tags used for marker discovery to full-length P. taeda transcripts. Alignments to the P. taeda genome mapped 3305 scaffold sequences onto 12 linkage groups. The consensus genetic map was used to compare the genome-wide linkage disequilibrium in a population of distantly related P. taeda individuals (ADEPT2) used for association genetic studies and a multiple-family pedigree used for genomic selection (CCLONES). The prevalence and extent of LD was greater in CCLONES as compared to ADEPT2; however, extended LD with LGs or between LGs was rare in both populations. The average squared correlations, r2, between SNP alleles less than 1 cM apart were less than 0.05 in both populations and r2 did not decay substantially with genetic distance. The consensus map and analysis of linkage disequilibrium establish a foundation for comparative association mapping and genomic selection in P. taeda and P. elliottii. PMID:26068575

Decentralised consensus-based formation tracking of multiple differential drive robots

NASA Astrophysics Data System (ADS)

Chu, Xing; Peng, Zhaoxia; Wen, Guoguang; Rahmani, Ahmed

2017-11-01

This article investigates the control problem for formation tracking of multiple nonholonomic robots under distributed manner which means each robot only needs local information exchange. A class of general state and input transform is introduced to convert the formation-tracking issue of multi-robot systems into the consensus-like problem with time-varying reference. The distributed observer-based protocol with nonlinear dynamics is developed for each robot to achieve the consensus tracking of the new system, which namely means a group of nonholonomic mobile robots can form the desired formation configuration with its centroid moving along the predefined reference trajectory. The finite-time stability of observer and control law is analysed rigorously by using the Lyapunov direct method, algebraic graph theory and matrix analysis. Numerical examples are finally provided to illustrate the effectiveness of the theory results proposed in this paper.

Resilient Distributed Estimation Through Adversary Detection

NASA Astrophysics Data System (ADS)

Chen, Yuan; Kar, Soummya; Moura, Jose M. F.

2018-05-01

This paper studies resilient multi-agent distributed estimation of an unknown vector parameter when a subset of the agents is adversarial. We present and analyze a Flag Raising Distributed Estimator ($\\mathcal{FRDE}$) that allows the agents under attack to perform accurate parameter estimation and detect the adversarial agents. The $\\mathcal{FRDE}$ algorithm is a consensus+innovations estimator in which agents combine estimates of neighboring agents (consensus) with local sensing information (innovations). We establish that, under $\\mathcal{FRDE}$, either the uncompromised agents' estimates are almost surely consistent or the uncompromised agents detect compromised agents if and only if the network of uncompromised agents is connected and globally observable. Numerical examples illustrate the performance of $\\mathcal{FRDE}$.

Beyond the Arcuate Fasciculus: Consensus and Controversy in the Connectional Anatomy of Language

ERIC Educational Resources Information Center

Dick, Anthony Steven; Tremblay, Pascale

2012-01-01

The growing consensus that language is distributed into large-scale cortical and subcortical networks has brought with it an increasing focus on the connectional anatomy of language, or how particular fibre pathways connect regions within the language network. Understanding connectivity of the language network could provide critical insights into…

Hidden multidimensional social structure modeling applied to biased social perception

NASA Astrophysics Data System (ADS)

Maletić, Slobodan; Zhao, Yi

2018-02-01

Intricacies of the structure of social relations are realized by representing a collection of overlapping opinions as a simplicial complex, thus building latent multidimensional structures, through which agents are, virtually, moving as they exchange opinions. The influence of opinion space structure on the distribution of opinions is demonstrated by modeling consensus phenomena when the opinion exchange between individuals may be affected by the false consensus effect. The results indicate that in the cases with and without bias, the road toward consensus is influenced by the structure of multidimensional space of opinions, and in the biased case, complete consensus is achieved. The applications of proposed modeling framework can easily be generalized, as they transcend opinion formation modeling.

Distributed MPC based consensus for single-integrator multi-agent systems.

PubMed

Cheng, Zhaomeng; Fan, Ming-Can; Zhang, Hai-Tao

2015-09-01

This paper addresses model predictive control schemes for consensus in multi-agent systems (MASs) with discrete-time single-integrator dynamics under switching directed interaction graphs. The control horizon is extended to be greater than one which endows the closed-loop system with extra degree of freedom. We derive sufficient conditions on the sampling period and the interaction graph to achieve consensus by using the property of infinite products of stochastic matrices. Consensus can be achieved asymptotically if the sampling period is selected such that the interaction graph among agents has a directed spanning tree jointly. Significantly, if the interaction graph always has a spanning tree, one can select an arbitrary large sampling period to guarantee consensus. Finally, several simulations are conducted to illustrate the effectiveness of the theoretical results. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Analysis of timescale to consensus in voting dynamics with more than two options

NASA Astrophysics Data System (ADS)

Wu, Degang; Szeto, Kwok Yip

2018-04-01

We generalize a binary majority-vote model on adaptive networks to its plurality-vote counterpart and analyze the timescale to consensus when voters are given more than two options. When opinions are uniformly distributed in the population of voters in the initial state, we find that the timescale to consensus is shorter than the binary vote model from both numerical simulations and mathematical analysis using the master equation for the three-state plurality-vote model. When intervention such as opinion conversion is allowed, as in the case of sudden change of mind of voter for any reason, the effort needed to push the fragmented three-opinion population in the thermodynamic limit to the consensus state, measured in minimal intervention cost, is less than that needed to push a polarized two-opinion population to the consensus state, when the degree (p ) of homophily is less than 0.8. For a finite system, the fragmented three-opinion population will spontaneously reach the consensus state, with faster time to consensus, compared to polarized two-opinion population, for a broad range of p .

Genomic Variability of Haemophilus influenzae Isolated from Mexican Children Determined by Using Enterobacterial Repetitive Intergenic Consensus Sequences and PCR

PubMed Central

Gomez-De-Leon, Patricia; Santos, Jose I.; Caballero, Javier; Gomez, Demostenes; Espinosa, Luz E.; Moreno, Isabel; Piñero, Daniel; Cravioto, Alejandro

2000-01-01

Genomic fingerprints from 92 capsulated and noncapsulated strains of Haemophilus influenzae from Mexican children with different diseases and healthy carriers were generated by PCR using the enterobacterial repetitive intergenic consensus (ERIC) sequences. A cluster analysis by the unweighted pair-group method with arithmetic averages based on the overall similarity as estimated from the characteristics of the genomic fingerprints, was conducted to group the strains. A total of 69 fingerprint patterns were detected in the H. influenzae strains. Isolates from patients with different diseases were represented by a variety of patterns, which clustered into two major groups. Of the 37 strains isolated from cases of meningitis, 24 shared patterns and were clustered into five groups within a similarity level of 1.0. One fragment of 1.25 kb was common to all meningitis strains. H. influenzae strains from healthy carriers presented fingerprint patterns different from those found in strains from sick children. Isolates from healthy individuals were more variable and were distributed differently from those from patients. The results show that ERIC-PCR provides a powerful tool for the determination of the distinctive pathogenicity potentials of H. influenzae strains and encourage its use for molecular epidemiology investigations. PMID:10878033

Distributed formation control of nonholonomic autonomous vehicle via RBF neural network

NASA Astrophysics Data System (ADS)

Yang, Shichun; Cao, Yaoguang; Peng, Zhaoxia; Wen, Guoguang; Guo, Konghui

2017-03-01

In this paper, RBF neural network consensus-based distributed control scheme is proposed for nonholonomic autonomous vehicles in a pre-defined formation along the specified reference trajectory. A variable transformation is first designed to convert the formation control problem into a state consensus problem. Then, the complete dynamics of the vehicles including inertia, Coriolis, friction model and unmodeled bounded disturbances are considered, which lead to the formation unstable when the distributed kinematic controllers are proposed based on the kinematics. RBF neural network torque controllers are derived to compensate for them. Some sufficient conditions are derived to accomplish the asymptotically stability of the systems based on algebraic graph theory, matrix theory, and Lyapunov theory. Finally, simulation examples illustrate the effectiveness of the proposed controllers.

Distributed Secure Coordinated Control for Multiagent Systems Under Strategic Attacks.

PubMed

Feng, Zhi; Wen, Guanghui; Hu, Guoqiang

2017-05-01

This paper studies a distributed secure consensus tracking control problem for multiagent systems subject to strategic cyber attacks modeled by a random Markov process. A hybrid stochastic secure control framework is established for designing a distributed secure control law such that mean-square exponential consensus tracking is achieved. A connectivity restoration mechanism is considered and the properties on attack frequency and attack length rate are investigated, respectively. Based on the solutions of an algebraic Riccati equation and an algebraic Riccati inequality, a procedure to select the control gains is provided and stability analysis is studied by using Lyapunov's method.. The effect of strategic attacks on discrete-time systems is also investigated. Finally, numerical examples are provided to illustrate the effectiveness of theoretical analysis.

A High Density Consensus Map of Rye (Secale cereale L.) Based on DArT Markers

PubMed Central

Myśków, Beata; Stojałowski, Stefan; Heller-Uszyńska, Katarzyna; Góralska, Magdalena; Brągoszewski, Piotr; Uszyński, Grzegorz; Kilian, Andrzej; Rakoczy-Trojanowska, Monika

2011-01-01

Background Rye (Secale cereale L.) is an economically important crop, exhibiting unique features such as outstanding resistance to biotic and abiotic stresses and high nutrient use efficiency. This species presents a challenge to geneticists and breeders due to its large genome containing a high proportion of repetitive sequences, self incompatibility, severe inbreeding depression and tissue culture recalcitrance. The genomic resources currently available for rye are underdeveloped in comparison with other crops of similar economic importance. The aim of this study was to create a highly saturated, multilocus linkage map of rye via consensus mapping, based on Diversity Arrays Technology (DArT) markers. Methodology/Principal Findings Recombinant inbred lines (RILs) from 5 populations (564 in total) were genotyped using DArT markers and subjected to linkage analysis using Join Map 4.0 and Multipoint Consensus 2.2 software. A consensus map was constructed using a total of 9703 segregating markers. The average chromosome map length ranged from 199.9 cM (2R) to 251.4 cM (4R) and the average map density was 1.1 cM. The integrated map comprised 4048 loci with the number of markers per chromosome ranging from 454 for 7R to 805 for 4R. In comparison with previously published studies on rye, this represents an eight-fold increase in the number of loci placed on a consensus map and a more than two-fold increase in the number of genetically mapped DArT markers. Conclusions/Significance Through the careful choice of marker type, mapping populations and the use of software packages implementing powerful algorithms for map order optimization, we produced a valuable resource for rye and triticale genomics and breeding, which provides an excellent starting point for more in-depth studies on rye genome organization. PMID:22163026

Distributed Estimation using Bayesian Consensus Filtering

DTIC Science & Technology

2014-06-06

Convergence rate analysis of distributed gossip (linear parameter) estimation: Fundamental limits and tradeoffs,” IEEE J. Sel. Topics Signal Process...Dimakis, S. Kar, J. Moura, M. Rabbat, and A. Scaglione, “ Gossip algorithms for distributed signal processing,” Proc. of the IEEE, vol. 98, no. 11, pp

76 FR 45471 - Energy Efficiency Standards for Distribution Transformers; Notice of Intent To Negotiate Proposed...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-29

... EERE-2010-BT-STD-0048] RIN 1904-AC04 Energy Efficiency Standards for Distribution Transformers; Notice...-type distribution transformers. The purpose of the subcommittee will be to discuss and, if possible, reach consensus on a proposed rule for the energy efficiency of distribution transformers, as authorized...

The sampled-data consensus of multi-agent systems with probabilistic time-varying delays and packet losses

NASA Astrophysics Data System (ADS)

Sui, Xin; Yang, Yongqing; Xu, Xianyun; Zhang, Shuai; Zhang, Lingzhong

2018-02-01

This paper investigates the consensus of multi-agent systems with probabilistic time-varying delays and packet losses via sampled-data control. On the one hand, a Bernoulli-distributed white sequence is employed to model random packet losses among agents. On the other hand, a switched system is used to describe packet dropouts in a deterministic way. Based on the special property of the Laplacian matrix, the consensus problem can be converted into a stabilization problem of a switched system with lower dimensions. Some mean square consensus criteria are derived in terms of constructing an appropriate Lyapunov function and using linear matrix inequalities (LMIs). Finally, two numerical examples are given to show the effectiveness of the proposed method.

Stem cell research ethics: consensus statement on emerging issues.

PubMed

Caulfield, Timothy; Ogbogu, Ubaka; Nelson, Erin; Einsiedel, Edna; Knoppers, Bartha; McDonald, Michael; Brunger, Fern; Downey, Robin; Fernando, Kanchana; Galipeau, Jacques; Geransar, Rose; Griener, Glenn; Grenier, Glenn; Hyun, Insoo; Isasi, Rosario; Kardel, Melanie; Knowles, Lori; Kucic, Terrence; Lotjonen, Salla; Lyall, Drew; Magnus, David; Mathews, Debra J H; Nisbet, Matthew; Nisker, Jeffrey; Pare, Guillaume; Pattinson, Shaun; Pullman, Daryl; Rudnicki, Michael; Williams-Jones, Bryn; Zimmerman, Susan

2007-10-01

This article is a consensus statement by an international interdisciplinary group of academic experts and Canadian policy-makers on emerging ethical, legal and social issues in human embryonic stem cells (hESC) research in Canada. The process of researching consensus included consultations with key stakeholders in hESC research (regulations, stem cell researchers, and research ethics experts), preparation and distribution of background papers, and an international workshop held in Montreal in February 2007 to discuss the papers and debate recommendations. The recommendations provided in the consensus statement focus on issues of immediate relevance to Canadian policy-makers, including informed consent to hESC research, the use of fresh embryos in research, management of conflicts of interest, and the relevance of public opinion research to policy-making.

Distributed Optimal Consensus Control for Multiagent Systems With Input Delay.

PubMed

Zhang, Huaipin; Yue, Dong; Zhao, Wei; Hu, Songlin; Dou, Chunxia; Huaipin Zhang; Dong Yue; Wei Zhao; Songlin Hu; Chunxia Dou; Hu, Songlin; Zhang, Huaipin; Dou, Chunxia; Yue, Dong; Zhao, Wei

2018-06-01

This paper addresses the problem of distributed optimal consensus control for a continuous-time heterogeneous linear multiagent system subject to time varying input delays. First, by discretization and model transformation, the continuous-time input-delayed system is converted into a discrete-time delay-free system. Two delicate performance index functions are defined for these two systems. It is shown that the performance index functions are equivalent and the optimal consensus control problem of the input-delayed system can be cast into that of the delay-free system. Second, by virtue of the Hamilton-Jacobi-Bellman (HJB) equations, an optimal control policy for each agent is designed based on the delay-free system and a novel value iteration algorithm is proposed to learn the solutions to the HJB equations online. The proposed adaptive dynamic programming algorithm is implemented on the basis of a critic-action neural network (NN) structure. Third, it is proved that local consensus errors of the two systems and weight estimation errors of the critic-action NNs are uniformly ultimately bounded while the approximated control policies converge to their target values. Finally, two simulation examples are presented to illustrate the effectiveness of the developed method.

Opinion formation and distribution in a bounded-confidence model on various networks

NASA Astrophysics Data System (ADS)

Meng, X. Flora; Van Gorder, Robert A.; Porter, Mason A.

2018-02-01

In the social, behavioral, and economic sciences, it is important to predict which individual opinions eventually dominate in a large population, whether there will be a consensus, and how long it takes for a consensus to form. Such ideas have been studied heavily both in physics and in other disciplines, and the answers depend strongly both on how one models opinions and on the network structure on which opinions evolve. One model that was created to study consensus formation quantitatively is the Deffuant model, in which the opinion distribution of a population evolves via sequential random pairwise encounters. To consider heterogeneity of interactions in a population along with social influence, we study the Deffuant model on various network structures (deterministic synthetic networks, random synthetic networks, and social networks constructed from Facebook data). We numerically simulate the Deffuant model and conduct regression analyses to investigate the dependence of the time to reach steady states on various model parameters, including a confidence bound for opinion updates, the number of participating entities, and their willingness to compromise. We find that network structure and parameter values both have important effects on the convergence time and the number of steady-state opinion groups. For some network architectures, we observe that the relationship between the convergence time and model parameters undergoes a transition at a critical value of the confidence bound. For some networks, the steady-state opinion distribution also changes from consensus to multiple opinion groups at this critical value.

A consensus view of fold space: Combining SCOP, CATH, and the Dali Domain Dictionary

PubMed Central

Day, Ryan; Beck, David A.C.; Armen, Roger S.; Daggett, Valerie

2003-01-01

We have determined consensus protein-fold classifications on the basis of three classification methods, SCOP, CATH, and Dali. These classifications make use of different methods of defining and categorizing protein folds that lead to different views of protein-fold space. Pairwise comparisons of domains on the basis of their fold classifications show that much of the disagreement between the classification systems is due to differing domain definitions rather than assigning the same domain to different folds. However, there are significant differences in the fold assignments between the three systems. These remaining differences can be explained primarily in terms of the breadth of the fold classifications. Many structures may be defined as having one fold in one system, whereas far fewer are defined as having the analogous fold in another system. By comparing these folds for a nonredundant set of proteins, the consensus method breaks up broad fold classifications and combines restrictive fold classifications into metafolds, creating, in effect, an averaged view of fold space. This averaged view requires that the structural similarities between proteins having the same metafold be recognized by multiple classification systems. Thus, the consensus map is useful for researchers looking for fold similarities that are relatively independent of the method used to compare proteins. The 30 most populated metafolds, representing the folds of about half of a nonredundant subset of the PDB, are presented here. The full list of metafolds is presented on the Web. PMID:14500873

A consensus view of fold space: combining SCOP, CATH, and the Dali Domain Dictionary.

PubMed

Day, Ryan; Beck, David A C; Armen, Roger S; Daggett, Valerie

2003-10-01

We have determined consensus protein-fold classifications on the basis of three classification methods, SCOP, CATH, and Dali. These classifications make use of different methods of defining and categorizing protein folds that lead to different views of protein-fold space. Pairwise comparisons of domains on the basis of their fold classifications show that much of the disagreement between the classification systems is due to differing domain definitions rather than assigning the same domain to different folds. However, there are significant differences in the fold assignments between the three systems. These remaining differences can be explained primarily in terms of the breadth of the fold classifications. Many structures may be defined as having one fold in one system, whereas far fewer are defined as having the analogous fold in another system. By comparing these folds for a nonredundant set of proteins, the consensus method breaks up broad fold classifications and combines restrictive fold classifications into metafolds, creating, in effect, an averaged view of fold space. This averaged view requires that the structural similarities between proteins having the same metafold be recognized by multiple classification systems. Thus, the consensus map is useful for researchers looking for fold similarities that are relatively independent of the method used to compare proteins. The 30 most populated metafolds, representing the folds of about half of a nonredundant subset of the PDB, are presented here. The full list of metafolds is presented on the Web.

Information Weighted Consensus for Distributed Estimation in Vision Networks

ERIC Educational Resources Information Center

Kamal, Ahmed Tashrif

2013-01-01

Due to their high fault-tolerance, ease of installation and scalability to large networks, distributed algorithms have recently gained immense popularity in the sensor networks community, especially in computer vision. Multi-target tracking in a camera network is one of the fundamental problems in this domain. Distributed estimation algorithms…

A statistical approach to estimate the 3D size distribution of spheres from 2D size distributions

USGS Publications Warehouse

Kong, M.; Bhattacharya, R.N.; James, C.; Basu, A.

2005-01-01

Size distribution of rigidly embedded spheres in a groundmass is usually determined from measurements of the radii of the two-dimensional (2D) circular cross sections of the spheres in random flat planes of a sample, such as in thin sections or polished slabs. Several methods have been devised to find a simple factor to convert the mean of such 2D size distributions to the actual 3D mean size of the spheres without a consensus. We derive an entirely theoretical solution based on well-established probability laws and not constrained by limitations of absolute size, which indicates that the ratio of the means of measured 2D and estimated 3D grain size distribution should be r/4 (=.785). Actual 2D size distribution of the radii of submicron sized, pure Fe0 globules in lunar agglutinitic glass, determined from backscattered electron images, is tested to fit the gamma size distribution model better than the log-normal model. Numerical analysis of 2D size distributions of Fe0 globules in 9 lunar soils shows that the average mean of 2D/3D ratio is 0.84, which is very close to the theoretical value. These results converge with the ratio 0.8 that Hughes (1978) determined for millimeter-sized chondrules from empirical measurements. We recommend that a factor of 1.273 (reciprocal of 0.785) be used to convert the determined 2D mean size (radius or diameter) of a population of spheres to estimate their actual 3D size. ?? 2005 Geological Society of America.

Epidemic failure detection and consensus for extreme parallelism

DOE PAGES

Katti, Amogh; Di Fatta, Giuseppe; Naughton, Thomas; ...

2017-02-01

Future extreme-scale high-performance computing systems will be required to work under frequent component failures. The MPI Forum s User Level Failure Mitigation proposal has introduced an operation, MPI Comm shrink, to synchronize the alive processes on the list of failed processes, so that applications can continue to execute even in the presence of failures by adopting algorithm-based fault tolerance techniques. This MPI Comm shrink operation requires a failure detection and consensus algorithm. This paper presents three novel failure detection and consensus algorithms using Gossiping. The proposed algorithms were implemented and tested using the Extreme-scale Simulator. The results show that inmore » all algorithms the number of Gossip cycles to achieve global consensus scales logarithmically with system size. The second algorithm also shows better scalability in terms of memory and network bandwidth usage and a perfect synchronization in achieving global consensus. The third approach is a three-phase distributed failure detection and consensus algorithm and provides consistency guarantees even in very large and extreme-scale systems while at the same time being memory and bandwidth efficient.« less

AMS 4.0: consensus prediction of post-translational modifications in protein sequences.

PubMed

Plewczynski, Dariusz; Basu, Subhadip; Saha, Indrajit

2012-08-01

We present here the 2011 update of the AutoMotif Service (AMS 4.0) that predicts the wide selection of 88 different types of the single amino acid post-translational modifications (PTM) in protein sequences. The selection of experimentally confirmed modifications is acquired from the latest UniProt and Phospho.ELM databases for training. The sequence vicinity of each modified residue is represented using amino acids physico-chemical features encoded using high quality indices (HQI) obtaining by automatic clustering of known indices extracted from AAindex database. For each type of the numerical representation, the method builds the ensemble of Multi-Layer Perceptron (MLP) pattern classifiers, each optimising different objectives during the training (for example the recall, precision or area under the ROC curve (AUC)). The consensus is built using brainstorming technology, which combines multi-objective instances of machine learning algorithm, and the data fusion of different training objects representations, in order to boost the overall prediction accuracy of conserved short sequence motifs. The performance of AMS 4.0 is compared with the accuracy of previous versions, which were constructed using single machine learning methods (artificial neural networks, support vector machine). Our software improves the average AUC score of the earlier version by close to 7 % as calculated on the test datasets of all 88 PTM types. Moreover, for the selected most-difficult sequence motifs types it is able to improve the prediction performance by almost 32 %, when compared with previously used single machine learning methods. Summarising, the brainstorming consensus meta-learning methodology on the average boosts the AUC score up to around 89 %, averaged over all 88 PTM types. Detailed results for single machine learning methods and the consensus methodology are also provided, together with the comparison to previously published methods and state-of-the-art software tools. The source code and precompiled binaries of brainstorming tool are available at http://code.google.com/p/automotifserver/ under Apache 2.0 licensing.

Minimum-Time Consensus-Based Approach for Power System Applications

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

Yang, Tao; Wu, Di; Sun, Yannan

2016-02-01

This paper presents minimum-time consensus based distributed algorithms for power system applications, such as load shedding and economic dispatch. The proposed algorithms are capable of solving these problems in a minimum number of time steps instead of asymptotically as in most of existing studies. Moreover, these algorithms are applicable to both undirected and directed communication networks. Simulation results are used to validate the proposed algorithms.

76 FR 50148 - Notice of Intent to Negotiate Proposed Rule on Energy Efficiency Standards for Distribution...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-12

... Intent to Negotiate Proposed Rule on Energy Efficiency Standards for Distribution Transformers AGENCY... transformers. The purpose of the subcommittee will be to discuss and, if possible, reach consensus on a proposed rule for the energy efficiency of distribution transformers, as authorized by the Energy Policy...

A distributed algorithm for machine learning

NASA Astrophysics Data System (ADS)

Chen, Shihong

2018-04-01

This paper considers a distributed learning problem in which a group of machines in a connected network, each learning its own local dataset, aim to reach a consensus at an optimal model, by exchanging information only with their neighbors but without transmitting data. A distributed algorithm is proposed to solve this problem under appropriate assumptions.

Study of consensus-based time synchronization in wireless sensor networks.

PubMed

He, Jianping; Li, Hao; Chen, Jiming; Cheng, Peng

2014-03-01

Recently, various consensus-based protocols have been developed for time synchronization in wireless sensor networks. However, due to the uncertainties lying in both the hardware fabrication and network communication processes, it is not clear how most of the protocols will perform in real implementations. In order to reduce such gap, this paper investigates whether and how the typical consensus-based time synchronization protocols can tolerate the uncertainties in practical sensor networks through extensive testbed experiments. For two typical protocols, i.e., Average Time Synchronization (ATS) and Maximum Time Synchronization (MTS), we first analyze how the time synchronization accuracy will be affected by various uncertainties in the system. Then, we implement both protocols on our sensor network testbed consisted of Micaz nodes, and investigate the time synchronization performance and robustness under various network settings. Noticing that the synchronized clocks under MTS may be slightly faster than the desirable clock, by adopting both maximum consensus and minimum consensus, we propose a modified protocol, MMTS, which is able to drive the synchronized clocks closer to the desirable clock while maintaining the convergence rate and synchronization accuracy of MTS. © 2013 ISA. Published by ISA. All rights reserved.

PROSPECT improves cis-acting regulatory element prediction by integrating expression profile data with consensus pattern searches

PubMed Central

Fujibuchi, Wataru; Anderson, John S. J.; Landsman, David

2001-01-01

Consensus pattern and matrix-based searches designed to predict cis-acting transcriptional regulatory sequences have historically been subject to large numbers of false positives. We sought to decrease false positives by incorporating expression profile data into a consensus pattern-based search method. We have systematically analyzed the expression phenotypes of over 6000 yeast genes, across 121 expression profile experiments, and correlated them with the distribution of 14 known regulatory elements over sequences upstream of the genes. Our method is based on a metric we term probabilistic element assessment (PEA), which is a ranking of potential sites based on sequence similarity in the upstream regions of genes with similar expression phenotypes. For eight of the 14 known elements that we examined, our method had a much higher selectivity than a naïve consensus pattern search. Based on our analysis, we have developed a web-based tool called PROSPECT, which allows consensus pattern-based searching of gene clusters obtained from microarray data. PMID:11574681

Analyses of integrated aircraft cabin contaminant monitoring network based on Kalman consensus filter.

PubMed

Wang, Rui; Li, Yanxiao; Sun, Hui; Chen, Zengqiang

2017-11-01

The modern civil aircrafts use air ventilation pressurized cabins subject to the limited space. In order to monitor multiple contaminants and overcome the hypersensitivity of the single sensor, the paper constructs an output correction integrated sensor configuration using sensors with different measurement theories after comparing to other two different configurations. This proposed configuration works as a node in the contaminant distributed wireless sensor monitoring network. The corresponding measurement error models of integrated sensors are also proposed by using the Kalman consensus filter to estimate states and conduct data fusion in order to regulate the single sensor measurement results. The paper develops the sufficient proof of the Kalman consensus filter stability when considering the system and the observation noises and compares the mean estimation and the mean consensus errors between Kalman consensus filter and local Kalman filter. The numerical example analyses show the effectiveness of the algorithm. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

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

Katti, Amogh; Di Fatta, Giuseppe; Naughton, Thomas

Future extreme-scale high-performance computing systems will be required to work under frequent component failures. The MPI Forum s User Level Failure Mitigation proposal has introduced an operation, MPI Comm shrink, to synchronize the alive processes on the list of failed processes, so that applications can continue to execute even in the presence of failures by adopting algorithm-based fault tolerance techniques. This MPI Comm shrink operation requires a failure detection and consensus algorithm. This paper presents three novel failure detection and consensus algorithms using Gossiping. The proposed algorithms were implemented and tested using the Extreme-scale Simulator. The results show that inmore » all algorithms the number of Gossip cycles to achieve global consensus scales logarithmically with system size. The second algorithm also shows better scalability in terms of memory and network bandwidth usage and a perfect synchronization in achieving global consensus. The third approach is a three-phase distributed failure detection and consensus algorithm and provides consistency guarantees even in very large and extreme-scale systems while at the same time being memory and bandwidth efficient.« less

Sznajd Opinion Dynamics with Global and Local Neighborhood

NASA Astrophysics Data System (ADS)

Schulze, Christian

In this modification of the Sznajd consensus model on the square lattice, two people of arbitrary distance who agree in their opinions convince their nearest neighbors of this opinion. Similarly to the mean field theory of Slanina and Lavicka, the times needed to reach consensus are distributed exponentially and are quite small. The width of the phase transition vanishes reciprocally to the linear lattice dimension. Advertising has effects independent of the system size. For more than two opinions, three opinions reach a consensus in roughly half of the samples, and four only rarely and only for small lattices. Up to 109 agents were simulated.

Event-triggered consensus tracking of multi-agent systems with Lur'e nonlinear dynamics

NASA Astrophysics Data System (ADS)

Huang, Na; Duan, Zhisheng; Wen, Guanghui; Zhao, Yu

2016-05-01

In this paper, distributed consensus tracking problem for networked Lur'e systems is investigated based on event-triggered information interactions. An event-triggered control algorithm is designed with the advantages of reducing controller update frequency and sensor energy consumption. By using tools of ?-procedure and Lyapunov functional method, some sufficient conditions are derived to guarantee that consensus tracking is achieved under a directed communication topology. Meanwhile, it is shown that Zeno behaviour of triggering time sequences is excluded for the proposed event-triggered rule. Finally, some numerical simulations on coupled Chua's circuits are performed to illustrate the effectiveness of the theoretical algorithms.

Saturation of an Intra-Gene Pool Linkage Map: Towards a Unified Consensus Linkage Map for Fine Mapping and Synteny Analysis in Common Bean

PubMed Central

Galeano, Carlos H.; Fernandez, Andrea C.; Franco-Herrera, Natalia; Cichy, Karen A.; McClean, Phillip E.; Vanderleyden, Jos; Blair, Matthew W.

2011-01-01

Map-based cloning and fine mapping to find genes of interest and marker assisted selection (MAS) requires good genetic maps with reproducible markers. In this study, we saturated the linkage map of the intra-gene pool population of common bean DOR364×BAT477 (DB) by evaluating 2,706 molecular markers including SSR, SNP, and gene-based markers. On average the polymorphism rate was 7.7% due to the narrow genetic base between the parents. The DB linkage map consisted of 291 markers with a total map length of 1,788 cM. A consensus map was built using the core mapping populations derived from inter-gene pool crosses: DOR364×G19833 (DG) and BAT93×JALO EEP558 (BJ). The consensus map consisted of a total of 1,010 markers mapped, with a total map length of 2,041 cM across 11 linkage groups. On average, each linkage group on the consensus map contained 91 markers of which 83% were single copy markers. Finally, a synteny analysis was carried out using our highly saturated consensus maps compared with the soybean pseudo-chromosome assembly. A total of 772 marker sequences were compared with the soybean genome. A total of 44 syntenic blocks were identified. The linkage group Pv6 presented the most diverse pattern of synteny with seven syntenic blocks, and Pv9 showed the most consistent relations with soybean with just two syntenic blocks. Additionally, a co-linear analysis using common bean transcript map information against soybean coding sequences (CDS) revealed the relationship with 787 soybean genes. The common bean consensus map has allowed us to map a larger number of markers, to obtain a more complete coverage of the common bean genome. Our results, combined with synteny relationships provide tools to increase marker density in selected genomic regions to identify closely linked polymorphic markers for indirect selection, fine mapping or for positional cloning. PMID:22174773

Identifying patients and clinical scenarios for use of long-acting injectable antipsychotics - expert consensus survey part 1.

PubMed

Sajatovic, Martha; Ross, Ruth; Legacy, Susan N; Correll, Christoph U; Kane, John M; DiBiasi, Faith; Fitzgerald, Heather; Byerly, Matthew

2018-01-01

To assess expert consensus on barriers and facilitators for long-acting injectable antipsychotic (LAI) use and provide clinical recommendations on issues where clinical evidence is lacking, including identifying appropriate clinical situations for LAI use. A 50-question survey comprising 916 response options was distributed to 42 research experts and high prescribers with extensive LAI experience. Respondents rated options on relative appropriateness/importance using a 9-point scale. Consensus was determined using chi-square test of score distributions. Mean (standard deviation) ratings were calculated. Responses to 29 questions (577 options) relating to appropriate patients and clinical scenarios for LAI use are reported. Recommendations aligned with research on risk factors for nonadherence and poor outcomes for patients with schizophrenia/schizoaffective or bipolar disorder. Findings suggested, contrary to general practice patterns, that LAI use may be appropriate earlier in the disease course and in younger patients. Results for bipolar disorder were similar to those for schizophrenia but with less consensus. Numerous facilitators of LAI prescribing were considered important, particularly that LAIs may reduce relapses and improve outcomes. Findings support wider use of LAIs in patients with schizophrenia/schizoaffective and bipolar disorders beyond the setting of poor adherence and earlier use in the disease course.

Improving consensus structure by eliminating averaging artifacts

PubMed Central

KC, Dukka B

2009-01-01

Background Common structural biology methods (i.e., NMR and molecular dynamics) often produce ensembles of molecular structures. Consequently, averaging of 3D coordinates of molecular structures (proteins and RNA) is a frequent approach to obtain a consensus structure that is representative of the ensemble. However, when the structures are averaged, artifacts can result in unrealistic local geometries, including unphysical bond lengths and angles. Results Herein, we describe a method to derive representative structures while limiting the number of artifacts. Our approach is based on a Monte Carlo simulation technique that drives a starting structure (an extended or a 'close-by' structure) towards the 'averaged structure' using a harmonic pseudo energy function. To assess the performance of the algorithm, we applied our approach to Cα models of 1364 proteins generated by the TASSER structure prediction algorithm. The average RMSD of the refined model from the native structure for the set becomes worse by a mere 0.08 Å compared to the average RMSD of the averaged structures from the native structure (3.28 Å for refined structures and 3.36 A for the averaged structures). However, the percentage of atoms involved in clashes is greatly reduced (from 63% to 1%); in fact, the majority of the refined proteins had zero clashes. Moreover, a small number (38) of refined structures resulted in lower RMSD to the native protein versus the averaged structure. Finally, compared to PULCHRA [1], our approach produces representative structure of similar RMSD quality, but with much fewer clashes. Conclusion The benchmarking results demonstrate that our approach for removing averaging artifacts can be very beneficial for the structural biology community. Furthermore, the same approach can be applied to almost any problem where averaging of 3D coordinates is performed. Namely, structure averaging is also commonly performed in RNA secondary prediction [2], which could also benefit from our approach. PMID:19267905

Observer-based distributed adaptive iterative learning control for linear multi-agent systems

NASA Astrophysics Data System (ADS)

Li, Jinsha; Liu, Sanyang; Li, Junmin

2017-10-01

This paper investigates the consensus problem for linear multi-agent systems from the viewpoint of two-dimensional systems when the state information of each agent is not available. Observer-based fully distributed adaptive iterative learning protocol is designed in this paper. A local observer is designed for each agent and it is shown that without using any global information about the communication graph, all agents achieve consensus perfectly for all undirected connected communication graph when the number of iterations tends to infinity. The Lyapunov-like energy function is employed to facilitate the learning protocol design and property analysis. Finally, simulation example is given to illustrate the theoretical analysis.

Geochemical fractionation and pollution assessment of Zn, Cu, and Fe in surface sediments from Shadegan Wildlife Refuge, southwest of Iran.

PubMed

Chaharlang, Behnam Heidari; Bakhtiari, Alireza Riyahi; Mohammadi, Jahangard; Farshchi, Parvin

2017-09-01

This research focuses on the fractionation and distribution patterns of heavy metals (Zn, Cu, and Fe) in surficial sediments collected from Shadegan Wildlife Refuge, the biggest wetland in southern part of Iran, to provide an overall classification for the sources of metals in the study area using a sequential extraction method. For this purpose, a four-step sequential extraction technique was applied to define the partitioning of the metals into different geochemical phases of the sediment. The results illustrated that the average total level of Zn, Cu, and Fe in surface sediments were 55.20 ± 16.04, 22.86 ± 5.68, and 25,979.01 ± 6917.91 μg/g dw, respectively. On the average, the chemical partitioning of all metals in most stations was in the order of residual >oxidizable-organic > acid-reducible > exchangeable. In the same way, the results of calculated geochemical indices revealed that Cu, Zn, and Fe concentrations are mainly influenced by lithogenic origins. Compared with consensus-based SQGs, Cu was likely to result in occasionally harmful biological effects on the biota.

Development of a consensus core dataset in juvenile dermatomyositis for clinical use to inform research

PubMed Central

McCann, Liza J; Pilkington, Clarissa A; Huber, Adam M; Ravelli, Angelo; Appelbe, Duncan; Kirkham, Jamie J; Williamson, Paula R; Aggarwal, Amita; Christopher-Stine, Lisa; Constantin, Tamas; Feldman, Brian M; Lundberg, Ingrid; Maillard, Sue; Mathiesen, Pernille; Murphy, Ruth; Pachman, Lauren M; Reed, Ann M; Rider, Lisa G; van Royen-Kerkof, Annet; Russo, Ricardo; Spinty, Stefan; Wedderburn, Lucy R

2018-01-01

Objectives This study aimed to develop consensus on an internationally agreed dataset for juvenile dermatomyositis (JDM), designed for clinical use, to enhance collaborative research and allow integration of data between centres. Methods A prototype dataset was developed through a formal process that included analysing items within existing databases of patients with idiopathic inflammatory myopathies. This template was used to aid a structured multistage consensus process. Exploiting Delphi methodology, two web-based questionnaires were distributed to healthcare professionals caring for patients with JDM identified through email distribution lists of international paediatric rheumatology and myositis research groups. A separate questionnaire was sent to parents of children with JDM and patients with JDM, identified through established research networks and patient support groups. The results of these parallel processes informed a face-to-face nominal group consensus meeting of international myositis experts, tasked with defining the content of the dataset. This developed dataset was tested in routine clinical practice before review and finalisation. Results A dataset containing 123 items was formulated with an accompanying glossary. Demographic and diagnostic data are contained within form A collected at baseline visit only, disease activity measures are included within form B collected at every visit and disease damage items within form C collected at baseline and annual visits thereafter. Conclusions Through a robust international process, a consensus dataset for JDM has been formulated that can capture disease activity and damage over time. This dataset can be incorporated into national and international collaborative efforts, including existing clinical research databases. PMID:29084729

Resources, indicators, data management, dissemination and use in health information systems in sub-Saharan Africa: results of a questionnaire-based survey.

PubMed

Mbondji, Peter Ebongue; Kebede, Derege; Soumbey-Alley, Edoh William; Zielinski, Chris; Kouvividila, Wenceslas; Lusamba-Dikassa, Paul-Samson

2014-05-01

To describe the status of health information systems in 14 sub-Saharan African countries of the World Health Organization African Region. A questionnaire-based survey. Fourteen sub-Saharan African countries of the African Region. Key informants in the ministries of health, national statistics offices, health programmes, donors and technical agencies. State of resources, indicators, data sources, data management, information products, dissemination and use of health information. The highest average score was in the identification and harmonisation of indicators (73%), reflecting successful efforts to identify priority indicators and reach international consensus on indicators for several diseases. This was followed by information products (63%), which indicated the availability of accurate and reliable data. The lowest score (41%) was in data management, the ability to collect, store, analyse and distribute data, followed by resources - policy and planning, human and financial resources, and infrastructure (53%). Data sources (e.g. censuses, surveys) were on average inadequate with a score of 56%. The average score for dissemination and use of health information was 57%, which indicated limited or inadequate use of data for advocacy, planning and decision-making. National health information systems are weak in the surveyed countries and much more needs to be done to improve the quality and relevance of data, and their management, sharing and use for policy-making and decision-making. © The Royal Society of Medicine.

Event-triggered Kalman-consensus filter for two-target tracking sensor networks.

PubMed

Su, Housheng; Li, Zhenghao; Ye, Yanyan

2017-11-01

This paper is concerned with the problem of event-triggered Kalman-consensus filter for two-target tracking sensor networks. According to the event-triggered protocol and the mean-square analysis, a suboptimal Kalman gain matrix is derived and a suboptimal event-triggered distributed filter is obtained. Based on the Kalman-consensus filter protocol, all sensors which only depend on its neighbors' information can track their corresponding targets. Furthermore, utilizing Lyapunov method and matrix theory, some sufficient conditions are presented for ensuring the stability of the system. Finally, a simulation example is presented to verify the effectiveness of the proposed event-triggered protocol. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Applied Swarm-based medicine: collecting decision trees for patterns of algorithms analysis.

PubMed

Panje, Cédric M; Glatzer, Markus; von Rappard, Joscha; Rothermundt, Christian; Hundsberger, Thomas; Zumstein, Valentin; Plasswilm, Ludwig; Putora, Paul Martin

2017-08-16

The objective consensus methodology has recently been applied in consensus finding in several studies on medical decision-making among clinical experts or guidelines. The main advantages of this method are an automated analysis and comparison of treatment algorithms of the participating centers which can be performed anonymously. Based on the experience from completed consensus analyses, the main steps for the successful implementation of the objective consensus methodology were identified and discussed among the main investigators. The following steps for the successful collection and conversion of decision trees were identified and defined in detail: problem definition, population selection, draft input collection, tree conversion, criteria adaptation, problem re-evaluation, results distribution and refinement, tree finalisation, and analysis. This manuscript provides information on the main steps for successful collection of decision trees and summarizes important aspects at each point of the analysis.

Convergence Rate Analysis of Distributed Gossip (Linear Parameter) Estimation: Fundamental Limits and Tradeoffs

NASA Astrophysics Data System (ADS)

Kar, Soummya; Moura, José M. F.

2011-08-01

The paper considers gossip distributed estimation of a (static) distributed random field (a.k.a., large scale unknown parameter vector) observed by sparsely interconnected sensors, each of which only observes a small fraction of the field. We consider linear distributed estimators whose structure combines the information \\emph{flow} among sensors (the \\emph{consensus} term resulting from the local gossiping exchange among sensors when they are able to communicate) and the information \\emph{gathering} measured by the sensors (the \\emph{sensing} or \\emph{innovations} term.) This leads to mixed time scale algorithms--one time scale associated with the consensus and the other with the innovations. The paper establishes a distributed observability condition (global observability plus mean connectedness) under which the distributed estimates are consistent and asymptotically normal. We introduce the distributed notion equivalent to the (centralized) Fisher information rate, which is a bound on the mean square error reduction rate of any distributed estimator; we show that under the appropriate modeling and structural network communication conditions (gossip protocol) the distributed gossip estimator attains this distributed Fisher information rate, asymptotically achieving the performance of the optimal centralized estimator. Finally, we study the behavior of the distributed gossip estimator when the measurements fade (noise variance grows) with time; in particular, we consider the maximum rate at which the noise variance can grow and still the distributed estimator being consistent, by showing that, as long as the centralized estimator is consistent, the distributed estimator remains consistent.

ISSLS Prize Winner: Consensus on the Clinical Diagnosis of Lumbar Spinal Stenosis: Results of an International Delphi Study.

PubMed

Tomkins-Lane, Christy; Melloh, Markus; Lurie, Jon; Smuck, Matt; Battié, Michele C; Freeman, Brian; Samartzis, Dino; Hu, Richard; Barz, Thomas; Stuber, Kent; Schneider, Michael; Haig, Andrew; Schizas, Constantin; Cheung, Jason Pui Yin; Mannion, Anne F; Staub, Lukas; Comer, Christine; Macedo, Luciana; Ahn, Sang-Ho; Takahashi, Kazuhisa; Sandella, Danielle

2016-08-01

Delphi. The aim of this study was to obtain an expert consensus on which history factors are most important in the clinical diagnosis of lumbar spinal stenosis (LSS). LSS is a poorly defined clinical syndrome. Criteria for defining LSS are needed and should be informed by the experience of expert clinicians. Phase 1 (Delphi Items): 20 members of the International Taskforce on the Diagnosis and Management of LSS confirmed a list of 14 history items. An online survey was developed that permits specialists to express the logical order in which they consider the items, and the level of certainty ascertained from the questions. Phase 2 (Delphi Study) Round 1: Survey distributed to members of the International Society for the Study of the Lumbar Spine. Round 2: Meeting of 9 members of Taskforce where consensus was reached on a final list of 10 items. Round 3: Final survey was distributed internationally. Phase 3: Final Taskforce consensus meeting. A total of 279 clinicians from 29 different countries, with a mean of 19 (±SD: 12) years in practice participated. The six top items were "leg or buttock pain while walking," "flex forward to relieve symptoms," "feel relief when using a shopping cart or bicycle," "motor or sensory disturbance while walking," "normal and symmetric foot pulses," "lower extremity weakness," and "low back pain." Significant change in certainty ceased after six questions at 80% (P < .05). This is the first study to reach an international consensus on the clinical diagnosis of LSS, and suggests that within six questions clinicians are 80% certain of diagnosis. We propose a consensus-based set of "seven history items" that can act as a pragmatic criterion for defining LSS in both clinical and research settings, which in the long term may lead to more cost-effective treatment, improved health care utilization, and enhanced patient outcomes. 2.

Development of Weighted Distributions of REPs for Dioxin-Like Compounds: Implications for Risk Assessment

EPA Science Inventory

In their recent reevaluation of the TEF methodology, the WHO expert panel indicated that consideration should be given to developing weighted distributions of REP values to establish TEFs for each dioxin-like compound (DLC). As such, we developed a consensus-based weighting frame...

High-risk CTV delineation for cervix brachytherapy: Application of GEC-ESTRO guidelines in Australia and New Zealand.

PubMed

Vinod, Shalini K; Lim, Karen; Bell, Lauren; Veera, Jacqueline; Ohanessian, Lucy; Juresic, Ewa; Borok, Nira; Chan, Phillip; Chee, Raphael; Do, Viet; Govindarajulu, Geetha; Sridharan, Swetha; Johnson, Carol; Moses, Daniel; Van Dyk, Sylvia; Holloway, Lois

2017-02-01

Image-based brachytherapy for cervical cancer using MRI has been implemented in Australia and New Zealand. The aims of this study were to measure variability in High-risk CTV (HR-CTV) delineation and evaluate dosimetric consequences of this. Nine radiation oncologists, one radiation therapist and two radiologists contoured HR-CTV on 3T MRI datasets from ten consecutive patients undergoing cervical brachytherapy at a single institution. Contour comparisons were performed using the Dice Similarity Coefficient (DSC) and Mean Absolute Surface Distance (MASD). Two reference contours were created for brachytherapy planning: a Simultaneous Truth and Performance Level Estimation (STAPLE) and a consensus contour (CONSENSUS). Optimized plans (8 Gy) for both these contours were applied to individual participant's contours to assess D90 and D100 coverage of HR CTV. To compare variability in dosimetry, relative standard deviation (rSD) was calculated. Good concordance (mean DSC≥0.7, MASD≤5 mm) was achieved in 8/10 cases when compared to the STAPLE reference and 6/10 cases when compared to the CONSENSUS reference. Greatest variation was visually seen in the cranio-caudal direction. The average mean rSD across all patients was 27% and 34% for the STAPLE HR-CTV D90 and D100, respectively, and 28% and 35% for the CONSENSUS HR-CTV D90 and D100. Delineation uncertainty resulted in an average dosimetric uncertainty of ±1.5-1.6 Gy per fraction based on an 8 Gy prescribed fraction. Delineation of HR-CTV for cervical cancer brachytherapy was consistent amongst observers, suggesting similar interpretation of GEC-ESTRO guidelines. Despite the good concordance, there was dosimetric variation noted, which could be clinically significant. © 2016 The Royal Australian and New Zealand College of Radiologists.

Breast screening: the use of consensus opinion for all recalls.

PubMed

Matcham, N J; Ridley, N T F; Taylor, S J; Cook, J-L; Scolding, J

2004-06-01

The quality of a breast-screening programme is measured not only by it's cancer detection rates (sensitivity), but also by it's recall rates and positive predictive values (specificity). False positive screens, which lead to assessments with benign outcomes, can cause psychological and physical morbidity in previously well women. In 1999 the Wiltshire breast-screening programme adopted a novel recall strategy whereby all films marked for recall are subject to consensus opinion--even women "recalled" by both original readers may be returned to routine screening. Since 1999 our recall rates have fallen from above to below the national averages (prevalent 7.2% and incident 3.0% in 2001/02). Specificity has increased over the same period such that approximately one in seven women assessed will be diagnosed with cancer. The consensus meetings provide a forum for teaching and are very popular with our film readers, who all report reduced levels of stress. Copyright 2003 Elsevier Ltd.

Evolutionary diversity and potential recombinogenic role of integration targets of non-LTR retrotransposons

PubMed Central

Gentles, Andrew J.; Kohany, Oleksiy; Jurka, Jerzy

2005-01-01

Short interspersed elements (SINEs) make up a significant fraction of total DNA in mammalian genomes, providing a rich substrate for chromosomal rearrangements by SINE-SINE recombinations. Proliferation of mammalian SINEs is mediated primarily by LINE1 (L1) non-LTR retrotransposons that preferentially integrate at DNA sequence targets with average length ~15 bp and containing conserved endonucleolytic nicking signals at both ends. We report that sequence variations in the first of the two nicking signals, represented by a 5′TT-AAAA consensus sequence, affect the position of the second signal thus leading to target site duplications (TSDs) of different lengths. The length distribution of TSDs appears to be affected also by L1-encoded enzyme variants, since targets with the same 5′ nicking site can be of different average length in different mammalian species. Taking this into account, we re-analyzed the second nicking site and found that it is larger and includes more conserved sites than previously appreciated, with a consensus of 5′ANTNTN-AA. We also studied potential involvement of the nicking sites in stimulating recombinations between SINE elements. We determined that SINE elements retaining TSDs with perfect 5′TT-AAAA nicking sites appear to be lost relatively rapidly from the human and rat genomes, and less rapidly from dog. We speculate that the introduction of single-strand DNA breaks induced by recurring endonucleolytic attacks at these sites, combined with the ubiquitousness of SINEs, may significantly promote recombination between repetitive elements, leading to the observed losses. At the same time new L1 subfamilies may be selected for “incompatibility” with pre-existing targets. This provides a possible driving force for the continual emergence of new L1 subfamilies which, in turn, may affect selection of L1-dependent SINE subfamilies. PMID:15944437

Consensus seeking in a network of discrete-time linear agents with communication noises

NASA Astrophysics Data System (ADS)

Wang, Yunpeng; Cheng, Long; Hou, Zeng-Guang; Tan, Min; Zhou, Chao; Wang, Ming

2015-07-01

This paper studies the mean square consensus of discrete-time linear time-invariant multi-agent systems with communication noises. A distributed consensus protocol, which is composed of the agent's own state feedback and the relative states between the agent and its neighbours, is proposed. A time-varying consensus gain a[k] is applied to attenuate the effect of noises which inherits in the inaccurate measurement of relative states with neighbours. A polynomial, namely 'parameter polynomial', is constructed. And its coefficients are the parameters in the feedback gain vector of the proposed protocol. It turns out that the parameter polynomial plays an important role in guaranteeing the consensus of linear multi-agent systems. By the proposed protocol, necessary and sufficient conditions for mean square consensus are presented under different topology conditions: (1) if the communication topology graph has a spanning tree and every node in the graph has at least one parent node, then the mean square consensus can be achieved if and only if ∑∞k = 0a[k] = ∞, ∑∞k = 0a2[k] < ∞ and all roots of the parameter polynomial are in the unit circle; (2) if the communication topology graph has a spanning tree and there exits one node without any parent node (the leader-follower case), then the mean square consensus can be achieved if and only if ∑∞k = 0a[k] = ∞, limk → ∞a[k] = 0 and all roots of the parameter polynomial are in the unit circle; (3) if the communication topology graph does not have a spanning tree, then the mean square consensus can never be achieved. Finally, one simulation example on the multiple aircrafts system is provided to validate the theoretical analysis.

Development of a consensus core dataset in juvenile dermatomyositis for clinical use to inform research.

PubMed

McCann, Liza J; Pilkington, Clarissa A; Huber, Adam M; Ravelli, Angelo; Appelbe, Duncan; Kirkham, Jamie J; Williamson, Paula R; Aggarwal, Amita; Christopher-Stine, Lisa; Constantin, Tamas; Feldman, Brian M; Lundberg, Ingrid; Maillard, Sue; Mathiesen, Pernille; Murphy, Ruth; Pachman, Lauren M; Reed, Ann M; Rider, Lisa G; van Royen-Kerkof, Annet; Russo, Ricardo; Spinty, Stefan; Wedderburn, Lucy R; Beresford, Michael W

2018-02-01

This study aimed to develop consensus on an internationally agreed dataset for juvenile dermatomyositis (JDM), designed for clinical use, to enhance collaborative research and allow integration of data between centres. A prototype dataset was developed through a formal process that included analysing items within existing databases of patients with idiopathic inflammatory myopathies. This template was used to aid a structured multistage consensus process. Exploiting Delphi methodology, two web-based questionnaires were distributed to healthcare professionals caring for patients with JDM identified through email distribution lists of international paediatric rheumatology and myositis research groups. A separate questionnaire was sent to parents of children with JDM and patients with JDM, identified through established research networks and patient support groups. The results of these parallel processes informed a face-to-face nominal group consensus meeting of international myositis experts, tasked with defining the content of the dataset. This developed dataset was tested in routine clinical practice before review and finalisation. A dataset containing 123 items was formulated with an accompanying glossary. Demographic and diagnostic data are contained within form A collected at baseline visit only, disease activity measures are included within form B collected at every visit and disease damage items within form C collected at baseline and annual visits thereafter. Through a robust international process, a consensus dataset for JDM has been formulated that can capture disease activity and damage over time. This dataset can be incorporated into national and international collaborative efforts, including existing clinical research databases. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Follow-up after gastrectomy for cancer: the Charter Scaligero Consensus Conference.

PubMed

Baiocchi, Gian Luca; D'Ugo, Domenico; Coit, Daniel; Hardwick, Richard; Kassab, Paulo; Nashimoto, Atsushi; Marrelli, Daniele; Allum, William; Berruti, Alfredo; Chandramohan, Servarayan Murugesan; Coburn, Natalie; Gonzàlez-Moreno, Santiago; Hoelscher, Arnulf; Jansen, Edwin; Leja, Marcis; Mariette, Christophe; Meyer, Hans-Joachim; Mönig, Stefan; Morgagni, Paolo; Ott, Katia; Preston, Shaun; Rha, Sun Young; Roviello, Franco; Sano, Takeshi; Sasako, Mitsuru; Shimada, Hideaki; Schuhmacher, Cristoph; So Bok-Yan, Jimmy; Strong, Vivian; Yoshikawa, Takaki; Terashima, Masanori; Ter-Ovanesov, Michail; Van der Velde, Cornelis; Memo, Maurizio; Castelli, Francesco; Pecorelli, Sergio; Detogni, Claudio; Kodera, Yasuhiro; de Manzoni, Giovanni

2016-01-01

Presently, there is no scientific evidence supporting a definite role for follow-up after gastrectomy for cancer, and clinical practices are quite different around the globe. The aim of this consensus conference was to present an ideal prototype of follow-up after gastrectomy for cancer, based on shared experiences and taking into account the need to rationalize the diagnostic course without losing the possibility of detecting local recurrence at a potentially curable stage. On June 19-22, 2013 in Verona (Italy), during the 10th International Gastric Cancer Congress (IGCC) of the International Gastric Cancer Association, a consensus meeting was held, concluding a 6-month, Web-based, consensus conference entitled "Rationale of oncological follow-up after gastrectomy for cancer." Forty-eight experts, with a geographical distribution reflecting different health cultures worldwide, participated in the consensus conference, and 39 attended the consensus meeting. Six statements were finally approved, displayed in a plenary session and signed by the vast majority of the 10th IGCC participants. These statements are attached as an annex to the Charter Scaligero on Gastric Cancer. After gastrectomy for cancer, oncological follow-up should be offered to patients; it should be tailored to the stage of the disease, mainly based on cross-sectional imaging, and should be discontinued after 5 years.

Comprehensive management of recurrent thyroid cancer: An American Head and Neck Society consensus statement: AHNS consensus statement.

PubMed

Scharpf, Joseph; Tuttle, Michael; Wong, Richard; Ridge, Drew; Smith, Russell; Hartl, Dana; Levine, Robert; Randolph, Gregory

2016-12-01

This American Head and Neck Society (AHNS) consensus statement focuses on the detection and management of recurrent thyroid cancer. This document describes the radiologic approach to defining structural recurrent disease and the operative and nonoperative rationale in addressing identified structural disease to create equipoise in the personalized treatment strategy for the patient. The recommendations of this AHNS multidisciplinary consensus panel of the American Head and Neck Society are intended to help guide all multidisciplinary clinicians who diagnose or manage adult patients with thyroid cancer. The consensus panel is comprised of members of the American Head and Neck Society and its Endocrine Surgical Committee, and there is representation from medical endocrinology and both national and international surgical representation drawn from general/endocrine surgery and otolaryngology/head and neck surgery. Authors provided expertise for their respective sections, and consensus recommendations were made regarding the evaluation and treatment of recurrent thyroid cancer. Evidence-based literature support is drawn from thyroid cancer studies, recurrent thyroid cancer studies, and American Thyroid Association (ATA) guidelines. The manuscript was then distributed to members of the American Head and Neck Society Endocrine Committee and governing counsel for further feedback. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1862-1869, 2016. © 2016 Wiley Periodicals, Inc.

How Many Conformations Need To Be Sampled To Obtain Converged QM/MM Energies? The Curse of Exponential Averaging.

PubMed

Ryde, Ulf

2017-11-14

Combined quantum mechanical and molecular mechanical (QM/MM) calculations is a popular approach to study enzymatic reactions. They are often based on a set of minimized structures obtained on snapshots from a molecular dynamics simulation to include some dynamics of the enzyme. It has been much discussed how the individual energies should be combined to obtain a final estimate of the energy, but the current consensus seems to be to use an exponential average. Then, the question is how many snapshots are needed to reach a reliable estimate of the energy. In this paper, I show that the question can be easily be answered if it is assumed that the energies follow a Gaussian distribution. Then, the outcome can be simulated based on a single parameter, σ, the standard deviation of the QM/MM energies from the various snapshots, and the number of required snapshots can be estimated once the desired accuracy and confidence of the result has been specified. Results for various parameters are presented, and it is shown that many more snapshots are required than is normally assumed. The number can be reduced by employing a cumulant approximation to second order. It is shown that most convergence criteria work poorly, owing to the very bad conditioning of the exponential average when σ is large (more than ∼7 kJ/mol), because the energies that contribute most to the exponential average have a very low probability. On the other hand, σ serves as an excellent convergence criterion.

Sampled-data consensus in switching networks of integrators based on edge events

NASA Astrophysics Data System (ADS)

Xiao, Feng; Meng, Xiangyu; Chen, Tongwen

2015-02-01

This paper investigates the event-driven sampled-data consensus in switching networks of multiple integrators and studies both the bidirectional interaction and leader-following passive reaction topologies in a unified framework. In these topologies, each information link is modelled by an edge of the information graph and assigned a sequence of edge events, which activate the mutual data sampling and controller updates of the two linked agents. Two kinds of edge-event-detecting rules are proposed for the general asynchronous data-sampling case and the synchronous periodic event-detecting case. They are implemented in a distributed fashion, and their effectiveness in reducing communication costs and solving consensus problems under a jointly connected topology condition is shown by both theoretical analysis and simulation examples.

The Consensus Project: Survey of the peer-reviewed scientific literature to determine the degree of consensus on anthropogenic climate change

NASA Astrophysics Data System (ADS)

Nuccitelli, D. A.; Cook, J.; Jokimäki, A.; Skuce, A. G.; Green, S. A.; Painting, R.; Morrison, G. W.; Reitano, R.; Richardson, M.; Honeycutt, R.; Winkler, B.; Tamblyn, G.

2012-12-01

Prior studies have identified a consensus amongst climate science experts regarding anthropogenic global warming (AGW) as outlined by the Intergovernmental Panel on Climate Change (Oreskes 2004). Despite this evidence, a poll of 1010 American adults (Leiserowitz et al. 2011) revealed that only 15% believed that a large majority (>81%) of climate scientists think that global warming is caused mostly by human activities. This lack of public awareness of the consensus has hindered the implementation of climate policy, in the United States in particular. Using an online abstract classification and rating system in combination with an email survey of the papers' authors, a team of 24 contributors to the weblog Skeptical Science undertook an analysis of 12,465 abstracts published between 1991 and 2011, listed in the Web of Science with the keywords "global warming" and/or "global climate change". Each abstract was reviewed independently at least twice, based on the abstract and the title, with no reference to the authorship. This study represents the single largest survey of peer-reviewed climate research, and the large sample size allows for identification of patterns in climate research over time. Abstracts were classified based on subject focus, using a set of written criteria, as one of "impacts", "methods", "mitigation", "paleoclimate", or "opinion"; and rated according to degree of endorsement or rejection of AGW: three categories each of explicit/implicit endorsement and rejection, and a neutral category. Abstracts that referred to a changing climate but did not assert or reject a linkage to human-produced greenhouse gases were rated "neutral", and this rating proved to be by far the most common, comprising approximately 67% of total abstracts. Endorsement categories made up approximately 33% of all abstracts examined, whereas those rejecting AGW comprised less than 1%. Overall, endorsements outnumbered rejections approximately 50-to-1, consistent with the 97-98% AGW consensus found in previous studies (Doran and Zimmerman 2009 and Anderegg et al. 2010). 2011 had the most total papers surveyed at 1,683. An average of 3.7 rejections per year were identified, with a maximum of 9 in 2011. Endorsements averaged 187 per year, with a maximum of 521 in 2011. These results represent the most comprehensive confirmation of the AGW consensus to date.

A consensus process on management of major burns accidents: lessons learned from the café fire in Volendam, The Netherlands.

PubMed

Welling, L; Boers, M; Mackie, D P; Patka, P; Bierens, J J L M; Luitse, J S K; Kreis, R W

2006-01-01

The optimum response to the different stages of a major burns incident is still not established. The fire in a café in Volendam on New Year's Eve 2000 was the worst incident in recent Dutch history and resulted in mass burn casualties. The fire has been the subject of several investigations concerned with organisational and medical aspects. Based on the findings in these investigations, a multidisciplinary research group started a consensus study. The aim of this study was to further identify areas of improvement in the care after mass burns incidents. The consensus process comprised three postal rounds (Delphi Method) and a consensus conference (modified nominal group technique). The multidisciplinary panel consisted of 26 Dutch-speaking experts, working in influential positions within the sphere of disaster management and healthcare. In response to the postal questionnaires, consensus was reached for 66 per cent of the statements. Six topics were subsequently discussed during the consensus conference; three topics were discussed within the plenary session and three during subgroup meetings. During the conference, consensus was reached for seven statements (one subject generated two statements). In total, the panel agreed on 21 statements. These covered the following topics: registration and evaluation of disaster care, capacity planning for disasters, pre hospital care of victims of burns disasters, treatment and transportation priorities, distribution of casualties (including interhospital transports), diagnosis and treatment and education and training. In disaster medicine, the paper shows how a consensus process is a suitable tool to identify areas of improvement of care after mass burns incidents.

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.

Distributed Sensing and Processing: A Graphical Model Approach

DTIC Science & Technology

2005-11-30

that Ramanujan graph toplogies maximize the convergence rate of distributed detection consensus algorithms, improving over three orders of...small world type network designs. 14. SUBJECT TERMS Ramanujan graphs, sensor network topology, sensor network...that Ramanujan graphs, for which there are explicit algebraic constructions, have large eigenratios, converging much faster than structured graphs

Gossip and Distributed Kalman Filtering: Weak Consensus Under Weak Detectability

NASA Astrophysics Data System (ADS)

Kar, Soummya; Moura, José M. F.

2011-04-01

The paper presents the gossip interactive Kalman filter (GIKF) for distributed Kalman filtering for networked systems and sensor networks, where inter-sensor communication and observations occur at the same time-scale. The communication among sensors is random; each sensor occasionally exchanges its filtering state information with a neighbor depending on the availability of the appropriate network link. We show that under a weak distributed detectability condition: 1. the GIKF error process remains stochastically bounded, irrespective of the instability properties of the random process dynamics; and 2. the network achieves \\emph{weak consensus}, i.e., the conditional estimation error covariance at a (uniformly) randomly selected sensor converges in distribution to a unique invariant measure on the space of positive semi-definite matrices (independent of the initial state.) To prove these results, we interpret the filtered states (estimates and error covariances) at each node in the GIKF as stochastic particles with local interactions. We analyze the asymptotic properties of the error process by studying as a random dynamical system the associated switched (random) Riccati equation, the switching being dictated by a non-stationary Markov chain on the network graph.

On the Distribution of Protein Refractive Index Increments

PubMed Central

Zhao, Huaying; Brown, Patrick H.; Schuck, Peter

2011-01-01

The protein refractive index increment, dn/dc, is an important parameter underlying the concentration determination and the biophysical characterization of proteins and protein complexes in many techniques. In this study, we examine the widely used assumption that most proteins have dn/dc values in a very narrow range, and reappraise the prediction of dn/dc of unmodified proteins based on their amino acid composition. Applying this approach in large scale to the entire set of known and predicted human proteins, we obtain, for the first time, to our knowledge, an estimate of the full distribution of protein dn/dc values. The distribution is close to Gaussian with a mean of 0.190 ml/g (for unmodified proteins at 589 nm) and a standard deviation of 0.003 ml/g. However, small proteins <10 kDa exhibit a larger spread, and almost 3000 proteins have values deviating by more than two standard deviations from the mean. Due to the widespread availability of protein sequences and the potential for outliers, the compositional prediction should be convenient and provide greater accuracy than an average consensus value for all proteins. We discuss how this approach should be particularly valuable for certain protein classes where a high dn/dc is coincidental to structural features, or may be functionally relevant such as in proteins of the eye. PMID:21539801

On the distribution of protein refractive index increments.

PubMed

Zhao, Huaying; Brown, Patrick H; Schuck, Peter

2011-05-04

The protein refractive index increment, dn/dc, is an important parameter underlying the concentration determination and the biophysical characterization of proteins and protein complexes in many techniques. In this study, we examine the widely used assumption that most proteins have dn/dc values in a very narrow range, and reappraise the prediction of dn/dc of unmodified proteins based on their amino acid composition. Applying this approach in large scale to the entire set of known and predicted human proteins, we obtain, for the first time, to our knowledge, an estimate of the full distribution of protein dn/dc values. The distribution is close to Gaussian with a mean of 0.190 ml/g (for unmodified proteins at 589 nm) and a standard deviation of 0.003 ml/g. However, small proteins <10 kDa exhibit a larger spread, and almost 3000 proteins have values deviating by more than two standard deviations from the mean. Due to the widespread availability of protein sequences and the potential for outliers, the compositional prediction should be convenient and provide greater accuracy than an average consensus value for all proteins. We discuss how this approach should be particularly valuable for certain protein classes where a high dn/dc is coincidental to structural features, or may be functionally relevant such as in proteins of the eye. Copyright © 2011 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Local communities obstruct global consensus: Naming game on multi-local-world networks

NASA Astrophysics Data System (ADS)

Lou, Yang; Chen, Guanrong; Fan, Zhengping; Xiang, Luna

2018-02-01

Community structure is essential for social communications, where individuals belonging to the same community are much more actively interacting and communicating with each other than those in different communities within the human society. Naming game, on the other hand, is a social communication model that simulates the process of learning a name of an object within a community of humans, where the individuals can generally reach global consensus asymptotically through iterative pair-wise conversations. The underlying network indicates the relationships among the individuals. In this paper, three typical topologies, namely random-graph, small-world and scale-free networks, are employed, which are embedded with the multi-local-world community structure, to study the naming game. Simulations show that (1) the convergence process to global consensus is getting slower as the community structure becomes more prominent, and eventually might fail; (2) if the inter-community connections are sufficiently dense, neither the number nor the size of the communities affects the convergence process; and (3) for different topologies with the same (or similar) average node-degree, local clustering of individuals obstruct or prohibit global consensus to take place. The results reveal the role of local communities in a global naming game in social network studies.

Systematic review and consensus guidelines for environmental sampling of Burkholderia pseudomallei.

PubMed

Limmathurotsakul, Direk; Dance, David A B; Wuthiekanun, Vanaporn; Kaestli, Mirjam; Mayo, Mark; Warner, Jeffrey; Wagner, David M; Tuanyok, Apichai; Wertheim, Heiman; Yoke Cheng, Tan; Mukhopadhyay, Chiranjay; Puthucheary, Savithiri; Day, Nicholas P J; Steinmetz, Ivo; Currie, Bart J; Peacock, Sharon J

2013-01-01

Burkholderia pseudomallei, a Tier 1 Select Agent and the cause of melioidosis, is a Gram-negative bacillus present in the environment in many tropical countries. Defining the global pattern of B. pseudomallei distribution underpins efforts to prevent infection, and is dependent upon robust environmental sampling methodology. Our objective was to review the literature on the detection of environmental B. pseudomallei, update the risk map for melioidosis, and propose international consensus guidelines for soil sampling. An international working party (Detection of Environmental Burkholderia pseudomallei Working Party (DEBWorP)) was formed during the VIth World Melioidosis Congress in 2010. PubMed (January 1912 to December 2011) was searched using the following MeSH terms: pseudomallei or melioidosis. Bibliographies were hand-searched for secondary references. The reported geographical distribution of B. pseudomallei in the environment was mapped and categorized as definite, probable, or possible. The methodology used for detecting environmental B. pseudomallei was extracted and collated. We found that global coverage was patchy, with a lack of studies in many areas where melioidosis is suspected to occur. The sampling strategies and bacterial identification methods used were highly variable, and not all were robust. We developed consensus guidelines with the goals of reducing the probability of false-negative results, and the provision of affordable and 'low-tech' methodology that is applicable in both developed and developing countries. The proposed consensus guidelines provide the basis for the development of an accurate and comprehensive global map of environmental B. pseudomallei.

A new world natural vegetation map for global change studies.

PubMed

Lapola, David M; Oyama, Marcos D; Nobre, Carlos A; Sampaio, Gilvan

2008-06-01

We developed a new world natural vegetation map at 1 degree horizontal resolution for use in global climate models. We used the Dorman and Sellers vegetation classification with inclusion of a new biome: tropical seasonal forest, which refers to both deciduous and semi-deciduous tropical forests. SSiB biogeophysical parameters values for this new biome type are presented. Under this new vegetation classification we obtained a consensus map between two global natural vegetation maps widely used in climate studies. We found that these two maps assign different biomes in ca. 1/3 of the continental grid points. To obtain a new global natural vegetation map, non-consensus areas were filled according to regional consensus based on more than 100 regional maps available on the internet. To minimize the risk of using poor quality information, the regional maps were obtained from reliable internet sources, and the filling procedure was based on the consensus among several regional maps obtained from independent sources. The new map was designed to reproduce accurately both the large-scale distribution of the main vegetation types (as it builds on two reliable global natural vegetation maps) and the regional details (as it is based on the consensus of regional maps).

Human variability in mercury toxicokinetics and steady state biomarker ratios.

PubMed

Bartell, S M; Ponce, R A; Sanga, R N; Faustman, E M

2000-10-01

Regulatory guidelines regarding methylmercury exposure depend on dose-response models relating observed mercury concentrations in maternal blood, cord blood, and maternal hair to developmental neurobehavioral endpoints. Generalized estimates of the maternal blood-to-hair, blood-to-intake, or hair-to-intake ratios are necessary for linking exposure to biomarker-based dose-response models. Most assessments have used point estimates for these ratios; however, significant interindividual and interstudy variability has been reported. For example, a maternal ratio of 250 ppm in hair per mg/L in blood is commonly used in models, but a 1990 WHO review reports mean ratios ranging from 140 to 370 ppm per mg/L. To account for interindividual and interstudy variation in applying these ratios to risk and safety assessment, some researchers have proposed representing the ratios with probability distributions and conducting probabilistic assessments. Such assessments would allow regulators to consider the range and like-lihood of mercury exposures in a population, rather than limiting the evaluation to an estimate of the average exposure or a single conservative exposure estimate. However, no consensus exists on the most appropriate distributions for representing these parameters. We discuss published reviews of blood-to-hair and blood-to-intake steady state ratios for mercury and suggest statistical approaches for combining existing datasets to form generalized probability distributions for mercury distribution ratios. Although generalized distributions may not be applicable to all populations, they allow a more informative assessment than point estimates where individual biokinetic information is unavailable. Whereas development and use of these distributions will improve existing exposure and risk models, additional efforts in data generation and model development are required.

Dynamic Involvement of Real World Objects in the IoT: A Consensus-Based Cooperation Approach

PubMed Central

Pilloni, Virginia; Atzori, Luigi; Mallus, Matteo

2017-01-01

A significant role in the Internet of Things (IoT) will be taken by mobile and low-cost unstable devices, which autonomously self-organize and introduce highly dynamic and heterogeneous scenarios for the deployment of distributed applications. This entails the devices to cooperate to dynamically find the suitable combination of their involvement so as to improve the system reliability while following the changes in their status. Focusing on the above scenario, we propose a distributed algorithm for resources allocation that is run by devices that can perform the same task required by the applications, allowing for a flexible and dynamic binding of the requested services with the physical IoT devices. It is based on a consensus approach, which maximizes the lifetime of groups of nodes involved and ensures the fulfillment of the requested Quality of Information (QoI) requirements. Experiments have been conducted with real devices, showing an improvement of device lifetime of more than 20%, with respect to a uniform distribution of tasks. PMID:28257030

Dynamic Involvement of Real World Objects in the IoT: A Consensus-Based Cooperation Approach.

PubMed

Pilloni, Virginia; Atzori, Luigi; Mallus, Matteo

2017-03-01

A significant role in the Internet of Things (IoT) will be taken by mobile and low-cost unstable devices, which autonomously self-organize and introduce highly dynamic and heterogeneous scenarios for the deployment of distributed applications. This entails the devices to cooperate to dynamically find the suitable combination of their involvement so as to improve the system reliability while following the changes in their status. Focusing on the above scenario, we propose a distributed algorithm for resources allocation that is run by devices that can perform the same task required by the applications, allowing for a flexible and dynamic binding of the requested services with the physical IoT devices. It is based on a consensus approach, which maximizes the lifetime of groups of nodes involved and ensures the fulfillment of the requested Quality of Information (QoI) requirements. Experiments have been conducted with real devices, showing an improvement of device lifetime of more than 20 % , with respect to a uniform distribution of tasks.

Fuzzy adaptive iterative learning coordination control of second-order multi-agent systems with imprecise communication topology structure

NASA Astrophysics Data System (ADS)

Chen, Jiaxi; Li, Junmin

2018-02-01

In this paper, we investigate the perfect consensus problem for second-order linearly parameterised multi-agent systems (MAS) with imprecise communication topology structure. Takagi-Sugeno (T-S) fuzzy models are presented to describe the imprecise communication topology structure of leader-following MAS, and a distributed adaptive iterative learning control protocol is proposed with the dynamic of leader unknown to any of the agent. The proposed protocol guarantees that the follower agents can track the leader perfectly on [0,T] for the consensus problem. Under alignment condition, a sufficient condition of the consensus for closed-loop MAS is given based on Lyapunov stability theory. Finally, a numerical example and a multiple pendulum system are given to illustrate the effectiveness of the proposed algorithm.

Terminal Sliding Mode-Based Consensus Tracking Control for Networked Uncertain Mechanical Systems on Digraphs.

PubMed

Chen, Gang; Song, Yongduan; Guan, Yanfeng

2018-03-01

This brief investigates the finite-time consensus tracking control problem for networked uncertain mechanical systems on digraphs. A new terminal sliding-mode-based cooperative control scheme is developed to guarantee that the tracking errors converge to an arbitrarily small bound around zero in finite time. All the networked systems can have different dynamics and all the dynamics are unknown. A neural network is used at each node to approximate the local unknown dynamics. The control schemes are implemented in a fully distributed manner. The proposed control method eliminates some limitations in the existing terminal sliding-mode-based consensus control methods and extends the existing analysis methods to the case of directed graphs. Simulation results on networked robot manipulators are provided to show the effectiveness of the proposed control algorithms.

[First SIBEN clinical consensus: diagnostic and therapeutic approach to patent ductus arteriosus in premature newborns].

PubMed

Golombek, S G; Sola, A; Baquero, H; Borbonet, D; Cabañas, F; Fajardo, C; Goldsmit, G; Lemus, L; Miura, E; Pellicer, A; Pérez, J M; Rogido, M; Zambosco, G; van Overmeire, B

2008-11-01

To report the process and results of the first neonatal clinical consensus of the Ibero-American region. Two recognized experts in the field (Clyman and Van Overmeire) and 45 neonatologists from 23 countries were invited for active participation and collaboration. We developed 46 questions of clinical-physiological relevance in all aspects of patent ductus arteriosus (PDA). Guidelines for consensus process, literature search and future preparation of educational material and authorship were developed, reviewed and agreed by all. Participants from different countries were distributed in groups, and assigned to interact and work together to answer 3-5 questions, reviewing all global literature and local factors. Answers and summaries were received, collated and reviewed by 2 coordinators and the 2 experts. Participants and experts met in Granada, Spain for 4.5 h (lectures by experts, presentations by groups, discussion, all literature available). 31 neonatologists from 16 countries agreed to participate. Presentations by each group and general discussion were used to develop a consensus regarding: general management, availability of drugs (indomethacin vs. ibuprofen), costs, indications for echo/surgery, etc. Many steps were learnt by all present in a collaborative forum. This first consensus group of Ibero-American neonatologists SIBEN led to active and collaborative participation of neonatologists of 16 countries, improved education of all participants and ended with consensus development on clinical approaches to PDA. Furthermore, it provides recommendations for clinical care reached by consensus. Additionally, it will serve as a useful foundation for future SIBEN Consensus on other topics and it could become valuable as a model to decrease disparity in care and improve outcomes in this and other regions.

Autoimmune Retinopathy: Current Concepts and Practices (An American Ophthalmological Society Thesis).

PubMed

Sen, H Nida; Grange, Landon; Akanda, Marib; Fox, Austin

2017-08-01

To elicit and evaluate opinions in the diagnosis and management of nonparaneoplastic autoimmune retinopathy (npAIR) among members of the American Uveitis Society (AUS) and to further the development of consensus and criteria in the diagnosis and management of npAIR. We hypothesize that despite lack of any clear guidelines, a general consensus in the clinical diagnosis and treatment of npAIR exists among uveitis experts. A literature review was performed and a panel of uveitis experts was consulted to formulate a survey regarding the diagnosis and management of npAIR. An online survey of 10 questions was developed, and a link was distributed through the AUS membership discussion list. We defined "general consensus" as meaning that a majority (>50%) of the respondents provided the same answer to a question. Fifty-four members of the AUS responded to the survey. Thirty-eight members (70.4%) see one to three AIR patients per year. Greater than 50% consensus was reached on most items, particularly items relating to diagnostic features and tests (up to 96% consensus). The diagnosis and management of npAIR is challenging, as standardized clinical and laboratory diagnostic criteria have yet to be established. The results of this study support the presence of consensus regarding certain aspects of npAIR, but also indicate the need for developing clear clinical diagnostic criteria and treatment guidelines.

Synthetic and natural consensus design for engineering charge within an affibody targeting epidermal growth factor receptor.

PubMed

Case, Brett A; Hackel, Benjamin J

2016-08-01

Protein ligand charge can impact physiological delivery with charge reduction often benefiting performance. Yet neutralizing mutations can be detrimental to protein function. Herein, three approaches are evaluated to introduce charged-to-neutral mutations of three cations and three anions within an affibody engineered to bind epidermal growth factor receptor. These approaches-combinatorial library sorting or consensus design, based on natural homologs or library-sorted mutants-are used to identify mutations with favorable affinity, stability, and recombinant yield. Consensus design, based on 942 affibody homologs, yielded a mutant of modest function (Kd  = 11 ±4 nM, Tm  = 62°C, and yield = 4.0 ± 0.8 mg/L as compared to 5.3 ± 1.7 nM, 71°C, and 3.5 ± 0.3 mg/L for the parental affibody). Extension of consensus design to 10 additional mutants exhibited varied performance including a substantially improved mutant (Kd  = 6.9 ± 1.4 nM, Tm  = 71°C, and 12.7 ± 0.9 mg/L yield). Sorting a homolog-based combinatorial library of 7 × 10(5) mutants generated a distribution of mutants with lower stability and yield, but did identify one strongly binding variant (Kd  = 1.2 ± 0.3 nM, Tm  = 69°C, and 6.0 ± 0.4 mg/L yield). Synthetic consensus design, based on the amino acid distribution in functional library mutants, yielded higher affinities (P = 0.05) with comparable stabilities and yields. The best of four analyzed clones had Kd  = 1.7 ± 0.5 nM, Tm  = 68°C, and 7.0 ± 0.5 mg/L yield. While all three approaches were effective in creating targeted affibodies with six charged-to-neutral mutations, synthetic consensus design proved to be the most robust. Synthetic consensus design provides a valuable tool for ligand engineering, particularly in the context of charge manipulation. Biotechnol. Bioeng. 2016;113: 1628-1638. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Laboratory for Computer Science Progress Report 21, July 1983-June 1984.

DTIC Science & Technology

1984-06-01

Systems 269 4. Distributed Consensus 270 5. Election of a Leader in a Distributed Ring of Processors 273 6. Distributed Network Algorithms 274 7. Diagnosis...multiprocessor systems. This facility, funded by the new!y formed Strategic Computing Program of the Defense Advanced Research Projects Agency, will enable...Academic Staff P. Szo)ovits, Group Leader R. Patil Collaborating Investigators M. Criscitiello, M.D., Tufts-New England Medical Center Hospital R

Ultracapacitors for automotive applications

NASA Astrophysics Data System (ADS)

Ashtiani, Cyrus; Wright, Randy; Hunt, Gary

In response to a growing consensus in the auto industry that ultracapacitors can potentially play a key role in the modern vehicle power distribution network, a task force was created at the United States Advanced Battery Consortium (USABC) to tackle issues facing the fledging industry. The task force embarked on first developing and establishing standards for performance and abuse tolerance of ultracapacitors in collaboration with the U.S. Department of Energy and National Labs. Subsequently, potential applications in the automotive industry were identified and a consensus requirement specification was drawn as a development guide for the industry.

Distributed Finite-Time Cooperative Control of Multiple High-Order Nonholonomic Mobile Robots.

PubMed

Du, Haibo; Wen, Guanghui; Cheng, Yingying; He, Yigang; Jia, Ruting

2017-12-01

The consensus problem of multiple nonholonomic mobile robots in the form of high-order chained structure is considered in this paper. Based on the model features and the finite-time control technique, a finite-time cooperative controller is explicitly constructed which guarantees that the states consensus is achieved in a finite time. As an application of the proposed results, finite-time formation control of multiple wheeled mobile robots is studied and a finite-time formation control algorithm is proposed. To show effectiveness of the proposed approach, a simulation example is given.

Leader–follower fixed-time consensus of multi-agent systems with high-order integrator dynamics

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

Tian, Bailing; Zuo, Zongyu; Wang, Hong

The leader-follower fixed-time consensus of high-order multi-agent systems with external disturbances is investigated in this paper. A novel sliding manifold is designed to ensure that the tracking errors converge to zero in a fixed-time during the sliding motion. Then, a distributed control law is designed based on Lyapunov technique to drive the system states to the sliding manifold in finite-time independent of initial conditions. Finally, the efficiency of the proposed method is illustrated by numerical simulations.

Expert Consensus for Discharge Referral Decisions Using Online Delphi

PubMed Central

Bowles, Kathy H.; Holmes, John H.; Naylor, Mary D.; Liberatore, Matthew; Nydick, Robert

2003-01-01

This paper describes the results of using a modified Delphi approach designed to achieve consensus from eight discharge planning experts regarding the decision to refer hospitalized older adults for post-discharge follow-up. Experts reviewed 150 cases using an online website designed to facilitate their interaction and efforts to reach agreement on the need for a referral for post-discharge care and the appropriate site for such care. In contrast to an average of eight weeks to complete just 50 cases using the traditional mail method, the first online Delphi round for 150 cases were completed in six weeks. Data provided by experts suggest that online Delphi is a time efficient and acceptable methodology for reaching group consensus. Other benefits include instant access to Delphi decision results, live knowledge of the time requirements and progress of each expert, and cost savings in postage, paper, copying, and storage of paper documents. This online Delphi methodology is highly recommended. PMID:14728143

Distributed containment control of heterogeneous fractional-order multi-agent systems with communication delays

NASA Astrophysics Data System (ADS)

Yang, Hongyong; Han, Fujun; Zhao, Mei; Zhang, Shuning; Yue, Jun

2017-08-01

Because many networked systems can only be characterized with fractional-order dynamics in complex environments, fractional-order calculus has been studied deeply recently. When diverse individual features are shown in different agents of networked systems, heterogeneous fractional-order dynamics will be used to describe the complex systems. Based on the distinguishing properties of agents, heterogeneous fractional-order multi-agent systems (FOMAS) are presented. With the supposition of multiple leader agents in FOMAS, distributed containment control of FOMAS is studied in directed weighted topologies. By applying Laplace transformation and frequency domain theory of the fractional-order operator, an upper bound of delays is obtained to ensure containment consensus of delayed heterogenous FOMAS. Consensus results of delayed FOMAS in this paper can be extended to systems with integer-order models. Finally, numerical examples are used to verify our results.

Hadza Color Terms Are Sparse, Diverse, and Distributed, and Presage the Universal Color Categories Found in Other World Languages

PubMed Central

Lindsey, Delwin T.; Brainard, David H.; Apicella, Coren L.

2016-01-01

In our empirical and theoretical study of color naming among the Hadza, a Tanzanian hunter-gatherer group, we show that Hadza color naming is sparse (the color appearance of many stimulus tiles was not named), diverse (there was little consensus in the terms for the color appearance of most tiles), and distributed (the universal color categories of world languages are revealed in nascent form within the Hadza language community, when we analyze the patterns of how individual Hadza deploy color terms). Using our Hadza data set, Witzel shows an association between two measures of color naming performance and the chroma of the stimuli. His prediction of which colored tiles will be named with what level of consensus, while interesting, does not alter the validity of our conclusions. PMID:28781734

Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: report of the AAPM and ESTRO.

PubMed

Perez-Calatayud, Jose; Ballester, Facundo; Das, Rupak K; Dewerd, Larry A; Ibbott, Geoffrey S; Meigooni, Ali S; Ouhib, Zoubir; Rivard, Mark J; Sloboda, Ron S; Williamson, Jeffrey F

2012-05-01

Recommendations of the American Association of Physicists in Medicine (AAPM) and the European Society for Radiotherapy and Oncology (ESTRO) on dose calculations for high-energy (average energy higher than 50 keV) photon-emitting brachytherapy sources are presented, including the physical characteristics of specific (192)Ir, (137)Cs, and (60)Co source models. This report has been prepared by the High Energy Brachytherapy Source Dosimetry (HEBD) Working Group. This report includes considerations in the application of the TG-43U1 formalism to high-energy photon-emitting sources with particular attention to phantom size effects, interpolation accuracy dependence on dose calculation grid size, and dosimetry parameter dependence on source active length. Consensus datasets for commercially available high-energy photon sources are provided, along with recommended methods for evaluating these datasets. Recommendations on dosimetry characterization methods, mainly using experimental procedures and Monte Carlo, are established and discussed. Also included are methodological recommendations on detector choice, detector energy response characterization and phantom materials, and measurement specification methodology. Uncertainty analyses are discussed and recommendations for high-energy sources without consensus datasets are given. Recommended consensus datasets for high-energy sources have been derived for sources that were commercially available as of January 2010. Data are presented according to the AAPM TG-43U1 formalism, with modified interpolation and extrapolation techniques of the AAPM TG-43U1S1 report for the 2D anisotropy function and radial dose function.

Explosion probability of unexploded ordnance: expert beliefs.

PubMed

MacDonald, Jacqueline Anne; Small, Mitchell J; Morgan, M G

2008-08-01

This article reports on a study to quantify expert beliefs about the explosion probability of unexploded ordnance (UXO). Some 1,976 sites at closed military bases in the United States are contaminated with UXO and are slated for cleanup, at an estimated cost of $15-140 billion. Because no available technology can guarantee 100% removal of UXO, information about explosion probability is needed to assess the residual risks of civilian reuse of closed military bases and to make decisions about how much to invest in cleanup. This study elicited probability distributions for the chance of UXO explosion from 25 experts in explosive ordnance disposal, all of whom have had field experience in UXO identification and deactivation. The study considered six different scenarios: three different types of UXO handled in two different ways (one involving children and the other involving construction workers). We also asked the experts to rank by sensitivity to explosion 20 different kinds of UXO found at a case study site at Fort Ord, California. We found that the experts do not agree about the probability of UXO explosion, with significant differences among experts in their mean estimates of explosion probabilities and in the amount of uncertainty that they express in their estimates. In three of the six scenarios, the divergence was so great that the average of all the expert probability distributions was statistically indistinguishable from a uniform (0, 1) distribution-suggesting that the sum of expert opinion provides no information at all about the explosion risk. The experts' opinions on the relative sensitivity to explosion of the 20 UXO items also diverged. The average correlation between rankings of any pair of experts was 0.41, which, statistically, is barely significant (p= 0.049) at the 95% confidence level. Thus, one expert's rankings provide little predictive information about another's rankings. The lack of consensus among experts suggests that empirical studies are needed to better understand the explosion risks of UXO.

An updated Asia Pacific Consensus Recommendations on colorectal cancer screening.

PubMed

Sung, J J Y; Ng, S C; Chan, F K L; Chiu, H M; Kim, H S; Matsuda, T; Ng, S S M; Lau, J Y W; Zheng, S; Adler, S; Reddy, N; Yeoh, K G; Tsoi, K K F; Ching, J Y L; Kuipers, E J; Rabeneck, L; Young, G P; Steele, R J; Lieberman, D; Goh, K L

2015-01-01

Since the publication of the first Asia Pacific Consensus on Colorectal Cancer (CRC) in 2008, there are substantial advancements in the science and experience of implementing CRC screening. The Asia Pacific Working Group aimed to provide an updated set of consensus recommendations. Members from 14 Asian regions gathered to seek consensus using other national and international guidelines, and recent relevant literature published from 2008 to 2013. A modified Delphi process was adopted to develop the statements. Age range for CRC screening is defined as 50-75 years. Advancing age, male, family history of CRC, smoking and obesity are confirmed risk factors for CRC and advanced neoplasia. A risk-stratified scoring system is recommended for selecting high-risk patients for colonoscopy. Quantitative faecal immunochemical test (FIT) instead of guaiac-based faecal occult blood test (gFOBT) is preferred for average-risk subjects. Ancillary methods in colonoscopy, with the exception of chromoendoscopy, have not proven to be superior to high-definition white light endoscopy in identifying adenoma. Quality of colonoscopy should be upheld and quality assurance programme should be in place to audit every aspects of CRC screening. Serrated adenoma is recognised as a risk for interval cancer. There is no consensus on the recruitment of trained endoscopy nurses for CRC screening. Based on recent data on CRC screening, an updated list of recommendations on CRC screening is prepared. These consensus statements will further enhance the implementation of CRC screening in the Asia Pacific region. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Use of cultural consensus analysis to evaluate expert feedback of median safety.

PubMed

Kim, Tae-Gyu; Donnell, Eric T; Lee, Dongmin

2008-07-01

Cultural consensus analysis is a statistical method that can be used to assess participant responses to survey questions. The technique concurrently estimates the knowledge of each survey participant and estimates the culturally correct answer to each question asked, based on the existence of consensus among survey participants. The main objectives of this paper are to present the cultural consensus methodology and apply it to a set of median design and safety survey data that were collected using the Delphi method. A total of 21 Delphi survey participants were asked to answer research questions related to cross-median crashes. It was found that the Delphi panel had agreeable opinions with respect to the association of average daily traffic (ADT) and heavy vehicle percentage combination on the risk of cross-median crashes; relative importance of additional factors, other than ADT, median width, and crash history that may contribute to cross-median crashes; and, the relative importance of geometric factors that may be associated with the likelihood of cross-median crashes. Therefore, the findings from the cultural consensus analysis indicate that the expert panel selected to participate in the Delphi survey shared a common knowledge pool relative to the association between median design and safety. There were, however, diverse opinions regarding median barrier type and its preferred placement location. The panel showed a higher level of knowledge on the relative importance regarding the association of geometric factors on cross-median crashes likelihood than on other issues considered. The results of the cultural consensus analysis of the present median design and safety survey data could be used to design a focused field study of median safety.

Systematic Review and Consensus Guidelines for Environmental Sampling of Burkholderia pseudomallei

PubMed Central

Limmathurotsakul, Direk; Dance, David A. B.; Wuthiekanun, Vanaporn; Kaestli, Mirjam; Mayo, Mark; Warner, Jeffrey; Wagner, David M.; Tuanyok, Apichai; Wertheim, Heiman; Yoke Cheng, Tan; Mukhopadhyay, Chiranjay; Puthucheary, Savithiri; Day, Nicholas P. J.; Steinmetz, Ivo; Currie, Bart J.; Peacock, Sharon J.

2013-01-01

Background Burkholderia pseudomallei, a Tier 1 Select Agent and the cause of melioidosis, is a Gram-negative bacillus present in the environment in many tropical countries. Defining the global pattern of B. pseudomallei distribution underpins efforts to prevent infection, and is dependent upon robust environmental sampling methodology. Our objective was to review the literature on the detection of environmental B. pseudomallei, update the risk map for melioidosis, and propose international consensus guidelines for soil sampling. Methods/Principal Findings An international working party (Detection of Environmental Burkholderia pseudomallei Working Party (DEBWorP)) was formed during the VIth World Melioidosis Congress in 2010. PubMed (January 1912 to December 2011) was searched using the following MeSH terms: pseudomallei or melioidosis. Bibliographies were hand-searched for secondary references. The reported geographical distribution of B. pseudomallei in the environment was mapped and categorized as definite, probable, or possible. The methodology used for detecting environmental B. pseudomallei was extracted and collated. We found that global coverage was patchy, with a lack of studies in many areas where melioidosis is suspected to occur. The sampling strategies and bacterial identification methods used were highly variable, and not all were robust. We developed consensus guidelines with the goals of reducing the probability of false-negative results, and the provision of affordable and ‘low-tech’ methodology that is applicable in both developed and developing countries. Conclusions/Significance The proposed consensus guidelines provide the basis for the development of an accurate and comprehensive global map of environmental B. pseudomallei. PMID:23556010

Distributed Optimization Design of Continuous-Time Multiagent Systems With Unknown-Frequency Disturbances.

PubMed

Wang, Xinghu; Hong, Yiguang; Yi, Peng; Ji, Haibo; Kang, Yu

2017-05-24

In this paper, a distributed optimization problem is studied for continuous-time multiagent systems with unknown-frequency disturbances. A distributed gradient-based control is proposed for the agents to achieve the optimal consensus with estimating unknown frequencies and rejecting the bounded disturbance in the semi-global sense. Based on convex optimization analysis and adaptive internal model approach, the exact optimization solution can be obtained for the multiagent system disturbed by exogenous disturbances with uncertain parameters.

Political opinion formation: Initial opinion distribution and individual heterogeneity of tolerance

NASA Astrophysics Data System (ADS)

Jin, Cheng; Li, Yifu; Jin, Xiaogang

2017-02-01

Opinion dynamics on networks have received serious attention for its profound prospects in social behaviours and self-organized systems. However, political opinion formation, as one typical and significant case, remains lacking in discussion. Previous agent-based simulations propose various models that are based on different mechanisms like the coevolution between network topology and status transition. Nonetheless, even under the same network topology and with the same simple mechanism, forming opinions can still be uncertain. In this work, we propose two features, the initial distribution of opinions and the individual heterogeneity of tolerances on opinion changing, in political opinion formation. These two features are imbedded in the network construction phase of a classical model. By comparing multi simple-party systems, along with a detailed analysis on the two-party system, we capture the critical phenomenon of fragmentation, polarization and consensus both in the persistent stable stage and in-process. We further introduce the average ratio of nearest neighbours to characterize the stage of opinion formation. The results show that the initial distribution of opinions leads to different evolution results on similar random networks. In addition, the existence of stubborn nodes plays a special role: only nodes that are extremely stubborn can cause the change of final opinion distribution while in other cases they only delay the time to reach stability. If stubborn nodes are small in number, their effects are confined within a small range. This theoretical work goes deeper on an existing model, it is an early exploration on qualitative and quantitative simulation of party competition.

Informed herbivore movement and interplant communication determine the effects of induced resistance in an individual-based model.

PubMed

Rubin, Ilan N; Ellner, Stephen P; Kessler, André; Morrell, Kimberly A

2015-09-01

1. Plant induced resistance to herbivory affects the spatial distribution of herbivores, as well as their performance. In recent years, theories regarding the benefit to plants of induced resistance have shifted from ideas of optimal resource allocation towards a more eclectic set of theories that consider spatial and temporal plant variability and the spatial distribution of herbivores among plants. However, consensus is lacking on whether induced resistance causes increased herbivore aggregation or increased evenness, as both trends have been experimentally documented. 2. We created a spatial individual-based model that can describe many plant-herbivore systems with induced resistance, in order to analyse how different aspects of induced resistance might affect herbivore distribution, and the total damage to a plant population, during a growing season. 3. We analyse the specific effects on herbivore aggregation of informed herbivore movement (preferential movement to less-damaged plants) and of information transfer between plants about herbivore attacks, in order to identify mechanisms driving both aggregation and evenness. We also investigate how the resulting herbivore distributions affect the total damage to plants and aggregation of damage. 4. Even, random and aggregated herbivore distributions can all occur in our model with induced resistance. Highest levels of aggregation occurred in the models with informed herbivore movement, and the most even distributions occurred when the average number of herbivores per plant was low. With constitutive resistance, only random distributions occur. Damage to plants was spatially correlated, unless plants recover very quickly from damage; herbivore spatial autocorrelation was always weak. 5. Our model and results provide a simple explanation for the apparent conflict between experimental results, indicating that both increased aggregation and increased evenness of herbivores can result from induced resistance. We demonstrate that information transfer from plants to herbivores, and from plants to neighbouring plants, can both be major factors in determining non-random herbivore distributions. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Cluster-Based Maximum Consensus Time Synchronization for Industrial Wireless Sensor Networks.

PubMed

Wang, Zhaowei; Zeng, Peng; Zhou, Mingtuo; Li, Dong; Wang, Jintao

2017-01-13

Time synchronization is one of the key technologies in Industrial Wireless Sensor Networks (IWSNs), and clustering is widely used in WSNs for data fusion and information collection to reduce redundant data and communication overhead. Considering IWSNs' demand for low energy consumption, fast convergence, and robustness, this paper presents a novel Cluster-based Maximum consensus Time Synchronization (CMTS) method. It consists of two parts: intra-cluster time synchronization and inter-cluster time synchronization. Based on the theory of distributed consensus, the proposed method utilizes the maximum consensus approach to realize the intra-cluster time synchronization, and adjacent clusters exchange the time messages via overlapping nodes to synchronize with each other. A Revised-CMTS is further proposed to counteract the impact of bounded communication delays between two connected nodes, because the traditional stochastic models of the communication delays would distort in a dynamic environment. The simulation results show that our method reduces the communication overhead and improves the convergence rate in comparison to existing works, as well as adapting to the uncertain bounded communication delays.

Cluster-Based Maximum Consensus Time Synchronization for Industrial Wireless Sensor Networks †

PubMed Central

Wang, Zhaowei; Zeng, Peng; Zhou, Mingtuo; Li, Dong; Wang, Jintao

2017-01-01

Time synchronization is one of the key technologies in Industrial Wireless Sensor Networks (IWSNs), and clustering is widely used in WSNs for data fusion and information collection to reduce redundant data and communication overhead. Considering IWSNs’ demand for low energy consumption, fast convergence, and robustness, this paper presents a novel Cluster-based Maximum consensus Time Synchronization (CMTS) method. It consists of two parts: intra-cluster time synchronization and inter-cluster time synchronization. Based on the theory of distributed consensus, the proposed method utilizes the maximum consensus approach to realize the intra-cluster time synchronization, and adjacent clusters exchange the time messages via overlapping nodes to synchronize with each other. A Revised-CMTS is further proposed to counteract the impact of bounded communication delays between two connected nodes, because the traditional stochastic models of the communication delays would distort in a dynamic environment. The simulation results show that our method reduces the communication overhead and improves the convergence rate in comparison to existing works, as well as adapting to the uncertain bounded communication delays. PMID:28098750

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

Stassi, D.; Ma, H.; Schmidt, T. G., E-mail: taly.gilat-schmidt@marquette.edu

Purpose: Reconstructing a low-motion cardiac phase is expected to improve coronary artery visualization in coronary computed tomography angiography (CCTA) exams. This study developed an automated algorithm for selecting the optimal cardiac phase for CCTA reconstruction. The algorithm uses prospectively gated, single-beat, multiphase data made possible by wide cone-beam imaging. The proposed algorithm differs from previous approaches because the optimal phase is identified based on vessel image quality (IQ) directly, compared to previous approaches that included motion estimation and interphase processing. Because there is no processing of interphase information, the algorithm can be applied to any sampling of image phases, makingmore » it suited for prospectively gated studies where only a subset of phases are available. Methods: An automated algorithm was developed to select the optimal phase based on quantitative IQ metrics. For each reconstructed slice at each reconstructed phase, an image quality metric was calculated based on measures of circularity and edge strength of through-plane vessels. The image quality metric was aggregated across slices, while a metric of vessel-location consistency was used to ignore slices that did not contain through-plane vessels. The algorithm performance was evaluated using two observer studies. Fourteen single-beat cardiac CT exams (Revolution CT, GE Healthcare, Chalfont St. Giles, UK) reconstructed at 2% intervals were evaluated for best systolic (1), diastolic (6), or systolic and diastolic phases (7) by three readers and the algorithm. Pairwise inter-reader and reader-algorithm agreement was evaluated using the mean absolute difference (MAD) and concordance correlation coefficient (CCC) between the reader and algorithm-selected phases. A reader-consensus best phase was determined and compared to the algorithm selected phase. In cases where the algorithm and consensus best phases differed by more than 2%, IQ was scored by three readers using a five point Likert scale. Results: There was no statistically significant difference between inter-reader and reader-algorithm agreement for either MAD or CCC metrics (p > 0.1). The algorithm phase was within 2% of the consensus phase in 15/21 of cases. The average absolute difference between consensus and algorithm best phases was 2.29% ± 2.47%, with a maximum difference of 8%. Average image quality scores for the algorithm chosen best phase were 4.01 ± 0.65 overall, 3.33 ± 1.27 for right coronary artery (RCA), 4.50 ± 0.35 for left anterior descending (LAD) artery, and 4.50 ± 0.35 for left circumflex artery (LCX). Average image quality scores for the consensus best phase were 4.11 ± 0.54 overall, 3.44 ± 1.03 for RCA, 4.39 ± 0.39 for LAD, and 4.50 ± 0.18 for LCX. There was no statistically significant difference (p > 0.1) between the image quality scores of the algorithm phase and the consensus phase. Conclusions: The proposed algorithm was statistically equivalent to a reader in selecting an optimal cardiac phase for CCTA exams. When reader and algorithm phases differed by >2%, image quality as rated by blinded readers was statistically equivalent. By detecting the optimal phase for CCTA reconstruction, the proposed algorithm is expected to improve coronary artery visualization in CCTA exams.« less

Information spread in networks: Games, optimal control, and stabilization

NASA Astrophysics Data System (ADS)

Khanafer, Ali

This thesis focuses on designing efficient mechanisms for controlling information spread in networks. We consider two models for information spread. The first one is the well-known distributed averaging dynamics. The second model is a nonlinear one that describes virus spread in computer and biological networks. We seek to design optimal, robust, and stabilizing controllers under practical constraints. For distributed averaging networks, we study the interaction between a network designer and an adversary. We consider two types of attacks on the network. In Attack-I, the adversary strategically disconnects a set of links to prevent the nodes from reaching consensus. Meanwhile, the network designer assists the nodes in reaching consensus by changing the weights of a limited number of links in the network. We formulate two problems to describe this competition where the order in which the players act is reversed in the two problems. Although the canonical equations provided by the Pontryagin's Maximum Principle (MP) seem to be intractable, we provide an alternative characterization for the optimal strategies that makes connection to potential theory. Further, we provide a sufficient condition for the existence of a saddle-point equilibrium (SPE) for the underlying zero-sum game. In Attack-II, the designer and the adversary are both capable of altering the measurements of all nodes in the network by injecting global signals. We impose two constraints on both players: a power constraint and an energy constraint. We assume that the available energy to each player is not sufficient to operate at maximum power throughout the horizon of the game. We show the existence of an SPE and derive the optimal strategies in closed form for this attack scenario. As an alternative to the "network designer vs. adversary" framework, we investigate the possibility of stabilizing unknown network diffusion processes using a distributed mechanism, where the uncertainty is due to an attack on the network. To this end, we propose a distributed version of the classical logic-based supervisory control scheme. Given a network of agents whose dynamics contain unknown parameters, the distributed supervisory control scheme is used to assist the agents to converge to a certain set-point without requiring them to have explicit knowledge of that set-point. Unlike the classical supervisory control scheme where a centralized supervisor makes switching decisions among the candidate controllers, in our scheme, each agent is equipped with a local supervisor that switches among the available controllers. The switching decisions made at a certain agent depend only on the information from its neighboring agents. We provide sufficient conditions for stabilization and apply our framework to the distributed averaging problem in the presence of large modeling uncertainty. For infected networks, we study the stability properties of a susceptible-infected-susceptible (SIS) diffusion model, so-called the n-intertwined Markov model, over arbitrary network topologies. Similar to the majority of infection spread dynamics, this model exhibits a threshold phenomenon. When the curing rates in the network are high, the all-healthy state is the unique equilibrium over the network. Otherwise, an endemic equilibrium state emerges, where some infection remains within the network. Using notions from positive systems theory, we provide conditions for the global asymptotic stability of the equilibrium points in both cases over strongly and weakly connected directed networks based on the value of the basic reproduction number, a fundamental quantity in the study of epidemics. Furthermore, we demonstrate that the n-intertwined Markov model can be viewed as a best-response dynamical system of a concave game among the nodes. This characterization allows us to cast new infection spread dynamics; additionally, we provide a sufficient condition, for the global convergence to the all-healthy state, that can be checked in a distributed fashion. Moreover, we investigate the problem of stabilizing the network when the curing rates of a limited number of nodes can be controlled. In particular, we characterize the number of controllers required for a class of undirected graphs. We also design optimal controllers capable of minimizing the total infection in the network at minimum cost. Finally, we outline a set of open problems in the area of information spread control.

Using the modified Delphi method to establish clinical consensus for the diagnosis and treatment of patients with rotator cuff pathology.

PubMed

Eubank, Breda H; Mohtadi, Nicholas G; Lafave, Mark R; Wiley, J Preston; Bois, Aaron J; Boorman, Richard S; Sheps, David M

2016-05-20

Patients presenting to the healthcare system with rotator cuff pathology do not always receive high quality care. High quality care occurs when a patient receives care that is accessible, appropriate, acceptable, effective, efficient, and safe. The aim of this study was twofold: 1) to develop a clinical pathway algorithm that sets forth a stepwise process for making decisions about the diagnosis and treatment of rotator cuff pathology presenting to primary, secondary, and tertiary healthcare settings; and 2) to establish clinical practice guidelines for the diagnosis and treatment of rotator cuff pathology to inform decision-making processes within the algorithm. A three-step modified Delphi method was used to establish consensus. Fourteen experts representing athletic therapy, physiotherapy, sport medicine, and orthopaedic surgery were invited to participate as the expert panel. In round 1, 123 best practice statements were distributed to the panel. Panel members were asked to mark "agree" or "disagree" beside each statement, and provide comments. The same voting method was again used for round 2. Round 3 consisted of a final face-to-face meeting. In round 1, statements were grouped and reduced to 44 statements that met consensus. In round 2, five statements reached consensus. In round 3, ten statements reached consensus. Consensus was reached for 59 statements representing five domains: screening, diagnosis, physical examination, investigations, and treatment. The final face-to-face meeting was also used to develop clinical pathway algorithms (i.e., clinical care pathways) for three types of rotator cuff pathology: acute, chronic, and acute-on-chronic. This consensus guideline will help to standardize care, provide guidance on the diagnosis and treatment of rotator cuff pathology, and assist in clinical decision-making for all healthcare professionals.

Use of systemic corticosteroids for atopic dermatitis: International Eczema Council consensus statement.

PubMed

Drucker, A M; Eyerich, K; de Bruin-Weller, M S; Thyssen, J P; Spuls, P I; Irvine, A D; Girolomoni, G; Dhar, S; Flohr, C; Murrell, D F; Paller, A S; Guttman-Yassky, E

2018-03-01

Guidelines discourage the use of systemic corticosteroids for atopic dermatitis (AD), but their use remains widespread. To reach consensus among an international group of AD experts on the use of systemic corticosteroids for AD. A survey consisting of statements accompanied by visual analogue scales ranging from 'strongly disagree' to 'neutral' to 'strongly agree' was distributed to the International Eczema Council (IEC). Consensus was reached in agreement on a statement if < 30% of respondents marked to the left of 'neutral' towards 'strongly disagree'. Sixty of 77 (78%) IEC members participated. Consensus was reached on 12 statements, including that systemic corticosteroids should generally be avoided but can be used rarely for severe AD under certain circumstances, including a lack of other treatment options, as a bridge to other systemic therapies or phototherapy, during acute flares in need of immediate relief, in anticipation of a major life event or in the most severe cases. If used, treatment should be limited to the short term. Most respondents agreed that systemic corticosteroids should never be used in children, but consensus was not reached on that statement. The conclusions of our expert group are limited by a dearth of high-quality published evidence. If more stringent consensus criteria were applied (e.g. requiring < 20% of respondents marking towards 'strongly disagree'), consensus would have been reached on fewer statements. Based on expert opinion from the IEC, routine use of systemic corticosteroids for AD is generally discouraged and should be reserved for special circumstances. © 2017 The Authors. British Journal of Dermatology published by John Wiley & Sons Ltd on behalf of British Association of Dermatologists.

Contribution of climate, soil, and MODIS predictors when modeling forest inventory invasive species distribution using forest inventory data

Treesearch

Dumitru Salajanu; Dennis Jacobs

2010-01-01

Forest inventory and analysis data are used to monitor the presence and extent of certain non-native invasive species. Effective control of its spread requires quality spatial distribution information. There is no clear consensus why some ecosystems are more favorable to non-native species. The objective of this study is to evaluate the reelative contribution of geo-...

Distributed Hybrid Information and Plan Consensus HIPC for Semi-autonomous UAV Teams

DTIC Science & Technology

2015-09-18

finalized. To do all of the onboard computations we are using Raspberry Pi B+’s (this hardware as shown in Fig. 16.) These computers are used to do all...public release. Figure 16: Raspberry Pi hardware Figure 17: Raspberry Pi hardware with case and DigiMesh Xbee Figure 18: Team of 11 Raspberry Pi powered...agents with Digimesh Xbee communication hardware. DISTRIBUTION A: Distribution approved for public release. Figure 19: Raspberry Pi network in real

Hierarchical Bayesian analysis of outcome- and process-based social preferences and beliefs in Dictator Games and sequential Prisoner's Dilemmas.

PubMed

Aksoy, Ozan; Weesie, Jeroen

2014-05-01

In this paper, using a within-subjects design, we estimate the utility weights that subjects attach to the outcome of their interaction partners in four decision situations: (1) binary Dictator Games (DG), second player's role in the sequential Prisoner's Dilemma (PD) after the first player (2) cooperated and (3) defected, and (4) first player's role in the sequential Prisoner's Dilemma game. We find that the average weights in these four decision situations have the following order: (1)>(2)>(4)>(3). Moreover, the average weight is positive in (1) but negative in (2), (3), and (4). Our findings indicate the existence of strong negative and small positive reciprocity for the average subject, but there is also high interpersonal variation in the weights in these four nodes. We conclude that the PD frame makes subjects more competitive than the DG frame. Using hierarchical Bayesian modeling, we simultaneously analyze beliefs of subjects about others' utility weights in the same four decision situations. We compare several alternative theoretical models on beliefs, e.g., rational beliefs (Bayesian-Nash equilibrium) and a consensus model. Our results on beliefs strongly support the consensus effect and refute rational beliefs: there is a strong relationship between own preferences and beliefs and this relationship is relatively stable across the four decision situations. Copyright © 2014 Elsevier Inc. All rights reserved.

Comparative Assessment of Models and Methods To Calculate Grid Electricity Emissions.

PubMed

Ryan, Nicole A; Johnson, Jeremiah X; Keoleian, Gregory A

2016-09-06

Due to the complexity of power systems, tracking emissions attributable to a specific electrical load is a daunting challenge but essential for many environmental impact studies. Currently, no consensus exists on appropriate methods for quantifying emissions from particular electricity loads. This paper reviews a wide range of the existing methods, detailing their functionality, tractability, and appropriate use. We identified and reviewed 32 methods and models and classified them into two distinct categories: empirical data and relationship models and power system optimization models. To illustrate the impact of method selection, we calculate the CO2 combustion emissions factors associated with electric-vehicle charging using 10 methods at nine charging station locations around the United States. Across the methods, we found an up to 68% difference from the mean CO2 emissions factor for a given charging site among both marginal and average emissions factors and up to a 63% difference from the average across average emissions factors. Our results underscore the importance of method selection and the need for a consensus on approaches appropriate for particular loads and research questions being addressed in order to achieve results that are more consistent across studies and allow for soundly supported policy decisions. The paper addresses this issue by offering a set of recommendations for determining an appropriate model type on the basis of the load characteristics and study objectives.

A photon spectrometric dose-rate constant determination for the Advantage Pd-103 brachytherapy source

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

Chen, Zhe Jay; Bongiorni, Paul; Nath, Ravinder

Purpose: Although several dosimetric characterizations using Monte Carlo simulation and thermoluminescent dosimetry (TLD) have been reported for the new Advantage Pd-103 source (IsoAid, LLC, Port Richey, FL), no AAPM consensus value has been established for the dosimetric parameters of the source. The aim of this work was to perform an additional dose-rate constant ({Lambda}) determination using a recently established photon spectrometry technique (PST) that is independent of the published TLD and Monte Carlo techniques. Methods: Three Model IAPD-103A Advantage Pd-103 sources were used in this study. The relative photon energy spectrum emitted by each source along the transverse axis wasmore » measured using a high-resolution germanium spectrometer designed for low-energy photons. For each source, the dose-rate constant was determined from its emitted energy spectrum. The PST-determined dose-rate constant ({sub PST}{Lambda}) was then compared to those determined by TLD ({sub TLD}{Lambda}) and Monte Carlo ({sub MC}{Lambda}) techniques. A likely consensus {Lambda} value was estimated as the arithmetic mean of the average {Lambda} values determined by each of three different techniques. Results: The average {sub PST}{Lambda} value for the three Advantage sources was found to be (0.676{+-}0.026) cGyh{sup -1} U{sup -1}. Intersource variation in {sub PST}{Lambda} was less than 0.01%. The {sub PST}{Lambda} was within 2% of the reported {sub MC}{Lambda} values determined by PTRAN, EGSnrc, and MCNP5 codes. It was 3.4% lower than the reported {sub TLD}{Lambda}. A likely consensus {Lambda} value was estimated to be (0.688{+-}0.026) cGyh{sup -1} U{sup -1}, similar to the AAPM consensus values recommended currently for the Theragenics (Buford, GA) Model 200 (0.686{+-}0.033) cGyh{sup -1} U{sup -1}, the NASI (Chatsworth, CA) Model MED3633 (0.688{+-}0.033) cGyh{sup -1} U{sup -1}, and the Best Medical (Springfield, VA) Model 2335 (0.685{+-}0.033) cGyh{sup -1} U{sup -1} {sup 103}Pd sources. Conclusions: An independent {Lambda} determination has been performed for the Advantage Pd-103 source. The {sub PST}{Lambda} obtained in this work provides additional information needed for establishing a more accurate consensus {Lambda} value for the Advantage Pd-103 source.« less

Shared Activity Coordination

NASA Technical Reports Server (NTRS)

Clement, Bradley J.; Barrett, Anthony C.

2003-01-01

Interacting agents that interleave planning and execution must reach consensus on their commitments to each other. In domains where agents have varying degrees of interaction and different constraints on communication and computation, agents will require different coordination protocols in order to efficiently reach consensus in real time. We briefly describe a largely unexplored class of real-time, distributed planning problems (inspired by interacting spacecraft missions), new challenges they pose, and a general approach to solving the problems. These problems involve self-interested agents that have infrequent communication but collaborate on joint activities. We describe a Shared Activity Coordination (SHAC) framework that provides a decentralized algorithm for negotiating the scheduling of shared activities in a dynamic environment, a soft, real-time approach to reaching consensus during execution with limited communication, and a foundation for customizing protocols for negotiating planner interactions. We apply SHAC to a realistic simulation of interacting Mars missions and illustrate the simplicity of protocol development.

Continual coordination through shared activities

NASA Technical Reports Server (NTRS)

Clement, Bradley J.; Barrett, Anthony C.

2003-01-01

Interacting agents that interleave planning and execution must reach consensus on their commitments to each other. In domains where agents have varying degrees of interaction and different constraints on communication and computation, agents will require different coordination protocols in order to efficiently reach consensus in real time. We briefly describe a largely unexplored class of realtime, distributed planning problems (inspired by interacting spacecraft missions), new challenges they pose, and a general approach to solving the problems. These problems involve self-interested agents that have infrequent communication but collaborate on joint activities. We describe a Shared Activity Coordination (SHAC) framework that provides a decentralized algorithm for negotiating the scheduling of shared activities over the lifetimes of separate missions, a soft, real-time approach to reaching consensus during execution with limited communication, and a foundation for customizing protocols for negotiating planner interactions. We apply SHAC to a realistic simulation of interacting Mars missions and illustrate the simplicity of protocol development.

Distributed attitude synchronization of formation flying via consensus-based virtual structure

NASA Astrophysics Data System (ADS)

Cong, Bing-Long; Liu, Xiang-Dong; Chen, Zhen

2011-06-01

This paper presents a general framework for synchronized multiple spacecraft rotations via consensus-based virtual structure. In this framework, attitude control systems for formation spacecrafts and virtual structure are designed separately. Both parametric uncertainty and external disturbance are taken into account. A time-varying sliding mode control (TVSMC) algorithm is designed to improve the robustness of the actual attitude control system. As for the virtual attitude control system, a behavioral consensus algorithm is presented to accomplish the attitude maneuver of the entire formation and guarantee a consistent attitude among the local virtual structure counterparts during the attitude maneuver. A multiple virtual sub-structures (MVSSs) system is introduced to enhance current virtual structure scheme when large amounts of spacecrafts are involved in the formation. The attitude of spacecraft is represented by modified Rodrigues parameter (MRP) for its non-redundancy. Finally, a numerical simulation with three synchronization situations is employed to illustrate the effectiveness of the proposed strategy.

A Pragmatic Approach to Patch Testing Atopic Dermatitis Patients: Clinical Recommendations Based on Expert Consensus Opinion.

PubMed

Chen, Jennifer K; Jacob, Sharon E; Nedorost, Susan T; Hanifin, Jon M; Simpson, Eric L; Boguniewicz, Mark; Watsky, Kalman L; Lugo-Somolinos, Aida; Hamann, Carsten R; Eberting, Cheryl Lee; Silverberg, Jonathan I; Thyssen, Jacob P

2016-01-01

Allergic contact dermatitis (ACD) may complicate the clinical course of atopic dermatitis (AD), and patch testing remains the criterion standard for diagnosing ACD. To date, there have been no guidelines or consensus recommendations on when and how to patch test individuals with AD. Failure to patch test when appropriate may result in overlooking an important and potentially curable complicating comorbidity. In this article, we present consensus recommendations regarding when to perform patch testing in the AD patient, best practices, and common pitfalls. Patch testing should be considered in AD patients with dermatitis that fails to improve with topical therapy; with atypical/changing distribution of dermatitis, or pattern suggestive of ACD; with therapy-resistant hand eczema in the working population; with adult- or adolescent-onset AD; and/or before initiating systemic immunosuppressants for the treatment of dermatitis. A suggested patch testing algorithm for AD patients is provided.

Selecting for Honors Programs: A Matter of Motivational Awareness

ERIC Educational Resources Information Center

Weerheijm, Ron; Weerheijm, Jeske

2012-01-01

The honors programs at the Universities of Applied Sciences in the Netherlands were almost all initiated around 2008 and thus so far have yielded few data about outcomes, but we have a broad consensus that the honors programs should provide a better-than-average professional for the workplace and should give students a chance to perform to the…

Charter-School Management Organizations: Diverse Strategies and Diverse Student Impacts. Updated Edition

ERIC Educational Resources Information Center

Furgeson, Joshua; Gill, Brian; Haimson, Joshua; Killewald, Alexandra; McCullough, Moira; Nichols-Barrer, Ira; Verbitsky-Savitz, Natalya; Teh, Bing-ru; Bowen, Melissa; Demeritt, Allison; Hill, Paul; Lake, Robin

2012-01-01

Charter schools--public schools of choice that are operated autonomously, outside the direct control of local school districts--have become more prevalent over the past two decades. There is no consensus about whether, on average, charter schools are doing better or worse than conventional public schools at promoting the achievement of their…

Determinants of Colour Constancy and the Blue Bias

PubMed Central

Gegenfurtner, Karl

2017-01-01

We investigated several sensory and cognitive determinants of colour constancy across 40 illumination hues. In the first experiment, we measured colour naming for the illumination and for the colour induced by the illumination on the colorimetric grey. Results confirmed that the induced colours are approximately complementary to the colour of the illumination. In the second experiment, we measured colour constancy using achromatic adjustments. Average colour constancy was perfect under the blue daylight illumination and decreased in colour directions away from the blue daylight illumination due to undershooting and a strong blue bias. Apart from this blue bias, colour constancy was not related to illumination discrimination and to chromatic detection measured previously with the same setup and stimuli. We also observed a strong negative relationship between the degree of colour constancy and the consensus of naming the illumination colour. Constancy coincided with a low naming consensus, in particular because bluish illumination colours were sometimes seen as achromatic. Blue bias and category consensus alone explained >68%, and all determinants together explained >94% of the variance of achromatic adjustments. These findings suggest that colour constancy is optimised for blue daylight. PMID:29348910

β-Carotene Is an Important Vitamin A Source for Humans123

PubMed Central

Grune, Tilman; Lietz, Georg; Palou, Andreu; Ross, A. Catharine; Stahl, Wilhelm; Tang, Guangweng; Thurnham, David; Yin, Shi-an; Biesalski, Hans K.

2010-01-01

Experts in the field of carotenoids met at the Hohenheim consensus conference in July 2009 to elucidate the current status of β-carotene research and to summarize the current knowledge with respect to the chemical properties, physiological function, and intake of β-carotene. The experts discussed 17 questions and reached an agreement formulated in a consensus answer in each case. These consensus answers are based on published valid data, which were carefully reviewed by the individual experts and are justified here by background statements. Ascertaining the impact of β-carotene on the total dietary intake of vitamin A is complicated, because the efficiency of conversion of β-carotene to retinol is not a single ratio and different conversion factors have been used in various surveys and following governmental recommendations within different countries. However, a role of β-carotene in fulfilling the recommended intake for vitamin A is apparent from a variety of studies. Thus, besides elucidating the various functions, distribution, and uptake of β-carotene, the consensus conference placed special emphasis on the provitamin A function of β-carotene and the role of β-carotene in the realization of the required/recommended total vitamin A intake in both developed and developing countries. There was consensus that β-carotene is a safe source of vitamin A and that the provitamin A function of β-carotene contributes to vitamin A intake. PMID:20980645

Discrepancy between earthquake rates implied by historic earthquakes and a consensus geologic source model for California

USGS Publications Warehouse

Petersen, M.D.; Cramer, C.H.; Reichle, M.S.; Frankel, A.D.; Hanks, T.C.

2000-01-01

We examine the difference between expected earthquake rates inferred from the historical earthquake catalog and the geologic data that was used to develop the consensus seismic source characterization for the state of California [California Department of Conservation, Division of Mines and Geology (CDMG) and U.S. Geological Survey (USGS) Petersen et al., 1996; Frankel et al., 1996]. On average the historic earthquake catalog and the seismic source model both indicate about one M 6 or greater earthquake per year in the state of California. However, the overall earthquake rates of earthquakes with magnitudes (M) between 6 and 7 in this seismic source model are higher, by at least a factor of 2, than the mean historic earthquake rates for both southern and northern California. The earthquake rate discrepancy results from a seismic source model that includes earthquakes with characteristic (maximum) magnitudes that are primarily between M 6.4 and 7.1. Many of these faults are interpreted to accommodate high strain rates from geologic and geodetic data but have not ruptured in large earthquakes during historic time. Our sensitivity study indicates that the rate differences between magnitudes 6 and 7 can be reduced by adjusting the magnitude-frequency distribution of the source model to reflect more characteristic behavior, by decreasing the moment rate available for seismogenic slip along faults, by increasing the maximum magnitude of the earthquake on a fault, or by decreasing the maximum magnitude of the background seismicity. However, no single parameter can be adjusted, consistent with scientific consensus, to eliminate the earthquake rate discrepancy. Applying a combination of these parametric adjustments yields an alternative earthquake source model that is more compatible with the historic data. The 475-year return period hazard for peak ground and 1-sec spectral acceleration resulting from this alternative source model differs from the hazard resulting from the standard CDMG-USGS model by less than 10% across most of California but is higher (generally about 10% to 30%) within 20 km from some faults.

Current management of acute diverticulitis: a survey of Australasian surgeons.

PubMed

Jaung, Rebekah; Robertson, Jason; Rowbotham, David; Bissett, Ian

2016-03-11

To evaluate the current practice and degree of consensus amongst Australasian surgeons regarding non-surgical management of acute diverticulitis (AD) and to determine whether newer approaches to management are being translated into practice. An online survey was distributed to all Australasian colorectal surgeons and all general surgeons in the Auckland region. Responses were collected over two months and analysed to identify points of consensus and areas of significant difference in opinion between these groups. Responses were received from a total of 99 of 200 (49.5%) colorectal surgeons, and 19 of 36 (52.7%) general surgeons. The Hinchey Classification was the most commonly used measure of disease severity, used by 67 (95.7%) colorectal surgeons and 12 (92.3%) general surgeons. There was lack of consensus around important aspects of AD management, including antibiotic therapy, and use and modality of follow-up imaging. Selective antibiotic therapy and use of anti-inflammatory medication as adjuncts to treatment were practised by a minority of those surveyed. Newer approaches to management were being utilised by some respondents. The lack of consensus regarding management of AD may be a consequence of a paucity of high-level evidence to support specific management approaches, particularly in patients with uncomplicated AD.

Protein model quality assessment prediction by combining fragment comparisons and a consensus Cα contact potential

PubMed Central

Zhou, Hongyi; Skolnick, Jeffrey

2009-01-01

In this work, we develop a fully automated method for the quality assessment prediction of protein structural models generated by structure prediction approaches such as fold recognition servers, or ab initio methods. The approach is based on fragment comparisons and a consensus Cα contact potential derived from the set of models to be assessed and was tested on CASP7 server models. The average Pearson linear correlation coefficient between predicted quality and model GDT-score per target is 0.83 for the 98 targets which is better than those of other quality assessment methods that participated in CASP7. Our method also outperforms the other methods by about 3% as assessed by the total GDT-score of the selected top models. PMID:18004783

Gauging Item Alignment through Online Systems While Controlling for Rater Effects

ERIC Educational Resources Information Center

Anderson, Daniel; Irvin, Shawn; Alonzo, Julie; Tindal, Gerald A.

2015-01-01

The alignment of test items to content standards is critical to the validity of decisions made from standards-based tests. Generally, alignment is determined based on judgments made by a panel of content experts with either ratings averaged or via a consensus reached through discussion. When the pool of items to be reviewed is large, or the…

The National Study of Charter Management Organization (CMO) Effectiveness. Charter-School Management Organizations: Diverse Strategies and Diverse Student Impacts

ERIC Educational Resources Information Center

Furgeson, Joshua; Gill, Brian; Haimson, Joshua; Killewald, Alexandra; McCullough, Moira; Nichols-Barrer, Ira; Teh, Bing-ru; Verbitsky-Savitz, Natalya; Bowen, Melissa; Demeritt, Allison; Hill, Paul; Lake, Robin

2011-01-01

Charter schools--public schools of choice that are operated autonomously, outside the direct control of local school districts--have become more prevalent over the past two decades. There is no consensus about whether, on average, charter schools are doing better or worse than conventional public schools at promoting the achievement of their…

Automated selection of the optimal cardiac phase for single-beat coronary CT angiography reconstruction.

PubMed

Stassi, D; Dutta, S; Ma, H; Soderman, A; Pazzani, D; Gros, E; Okerlund, D; Schmidt, T G

2016-01-01

Reconstructing a low-motion cardiac phase is expected to improve coronary artery visualization in coronary computed tomography angiography (CCTA) exams. This study developed an automated algorithm for selecting the optimal cardiac phase for CCTA reconstruction. The algorithm uses prospectively gated, single-beat, multiphase data made possible by wide cone-beam imaging. The proposed algorithm differs from previous approaches because the optimal phase is identified based on vessel image quality (IQ) directly, compared to previous approaches that included motion estimation and interphase processing. Because there is no processing of interphase information, the algorithm can be applied to any sampling of image phases, making it suited for prospectively gated studies where only a subset of phases are available. An automated algorithm was developed to select the optimal phase based on quantitative IQ metrics. For each reconstructed slice at each reconstructed phase, an image quality metric was calculated based on measures of circularity and edge strength of through-plane vessels. The image quality metric was aggregated across slices, while a metric of vessel-location consistency was used to ignore slices that did not contain through-plane vessels. The algorithm performance was evaluated using two observer studies. Fourteen single-beat cardiac CT exams (Revolution CT, GE Healthcare, Chalfont St. Giles, UK) reconstructed at 2% intervals were evaluated for best systolic (1), diastolic (6), or systolic and diastolic phases (7) by three readers and the algorithm. Pairwise inter-reader and reader-algorithm agreement was evaluated using the mean absolute difference (MAD) and concordance correlation coefficient (CCC) between the reader and algorithm-selected phases. A reader-consensus best phase was determined and compared to the algorithm selected phase. In cases where the algorithm and consensus best phases differed by more than 2%, IQ was scored by three readers using a five point Likert scale. There was no statistically significant difference between inter-reader and reader-algorithm agreement for either MAD or CCC metrics (p > 0.1). The algorithm phase was within 2% of the consensus phase in 15/21 of cases. The average absolute difference between consensus and algorithm best phases was 2.29% ± 2.47%, with a maximum difference of 8%. Average image quality scores for the algorithm chosen best phase were 4.01 ± 0.65 overall, 3.33 ± 1.27 for right coronary artery (RCA), 4.50 ± 0.35 for left anterior descending (LAD) artery, and 4.50 ± 0.35 for left circumflex artery (LCX). Average image quality scores for the consensus best phase were 4.11 ± 0.54 overall, 3.44 ± 1.03 for RCA, 4.39 ± 0.39 for LAD, and 4.50 ± 0.18 for LCX. There was no statistically significant difference (p > 0.1) between the image quality scores of the algorithm phase and the consensus phase. The proposed algorithm was statistically equivalent to a reader in selecting an optimal cardiac phase for CCTA exams. When reader and algorithm phases differed by >2%, image quality as rated by blinded readers was statistically equivalent. By detecting the optimal phase for CCTA reconstruction, the proposed algorithm is expected to improve coronary artery visualization in CCTA exams.

Survival of extreme opinions

NASA Astrophysics Data System (ADS)

Hsu, Jiann-wien; Huang, Ding-wei

2009-12-01

We study the survival of extreme opinions in various processes of consensus formation. All the opinions are treated equally and subjected to the same rules of changing. We investigate three typical models to reach a consensus in each case: (A) personal influence, (B) influence from surroundings, and (C) influence to surroundings. Starting with uniformly distributed random opinions, our calculated results show that the extreme opinions can survive in both models (A) and (B), but not in model (C). We obtain a conclusion that both personal influence and passive adaptation to the environment are not sufficient enough to eradicate all the extreme opinions. Only the active persuasion to change the surroundings eliminates the extreme opinions completely.

Simulation study of entropy production in the one-dimensional Vlasov system

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

Dai, Zongliang, E-mail: liangliang1223@gmail.com; Wang, Shaojie

2016-07-15

The coarse-grain averaged distribution function of the one-dimensional Vlasov system is obtained by numerical simulation. The entropy productions in cases of the random field, the linear Landau damping, and the bump-on-tail instability are computed with the coarse-grain averaged distribution function. The computed entropy production is converged with increasing length of coarse-grain average. When the distribution function differs slightly from a Maxwellian distribution, the converged value agrees with the result computed by using the definition of thermodynamic entropy. The length of the coarse-grain average to compute the coarse-grain averaged distribution function is discussed.

Using beta binomials to estimate classification uncertainty for ensemble models.

PubMed

Clark, Robert D; Liang, Wenkel; Lee, Adam C; Lawless, Michael S; Fraczkiewicz, Robert; Waldman, Marvin

2014-01-01

Quantitative structure-activity (QSAR) models have enormous potential for reducing drug discovery and development costs as well as the need for animal testing. Great strides have been made in estimating their overall reliability, but to fully realize that potential, researchers and regulators need to know how confident they can be in individual predictions. Submodels in an ensemble model which have been trained on different subsets of a shared training pool represent multiple samples of the model space, and the degree of agreement among them contains information on the reliability of ensemble predictions. For artificial neural network ensembles (ANNEs) using two different methods for determining ensemble classification - one using vote tallies and the other averaging individual network outputs - we have found that the distribution of predictions across positive vote tallies can be reasonably well-modeled as a beta binomial distribution, as can the distribution of errors. Together, these two distributions can be used to estimate the probability that a given predictive classification will be in error. Large data sets comprised of logP, Ames mutagenicity, and CYP2D6 inhibition data are used to illustrate and validate the method. The distributions of predictions and errors for the training pool accurately predicted the distribution of predictions and errors for large external validation sets, even when the number of positive and negative examples in the training pool were not balanced. Moreover, the likelihood of a given compound being prospectively misclassified as a function of the degree of consensus between networks in the ensemble could in most cases be estimated accurately from the fitted beta binomial distributions for the training pool. Confidence in an individual predictive classification by an ensemble model can be accurately assessed by examining the distributions of predictions and errors as a function of the degree of agreement among the constituent submodels. Further, ensemble uncertainty estimation can often be improved by adjusting the voting or classification threshold based on the parameters of the error distribution. Finally, the profiles for models whose predictive uncertainty estimates are not reliable provide clues to that effect without the need for comparison to an external test set.

Effects of communication burstiness on consensus formation and tipping points in social dynamics

NASA Astrophysics Data System (ADS)

Doyle, C.; Szymanski, B. K.; Korniss, G.

2017-06-01

Current models for opinion dynamics typically utilize a Poisson process for speaker selection, making the waiting time between events exponentially distributed. Human interaction tends to be bursty though, having higher probabilities of either extremely short waiting times or long periods of silence. To quantify the burstiness effects on the dynamics of social models, we place in competition two groups exhibiting different speakers' waiting-time distributions. These competitions are implemented in the binary naming game and show that the relevant aspect of the waiting-time distribution is the density of the head rather than that of the tail. We show that even with identical mean waiting times, a group with a higher density of short waiting times is favored in competition over the other group. This effect remains in the presence of nodes holding a single opinion that never changes, as the fraction of such committed individuals necessary for achieving consensus decreases dramatically when they have a higher head density than the holders of the competing opinion. Finally, to quantify differences in burstiness, we introduce the expected number of small-time activations and use it to characterize the early-time regime of the system.

Renewable Energy Power Generation Estimation Using Consensus Algorithm

NASA Astrophysics Data System (ADS)

Ahmad, Jehanzeb; Najm-ul-Islam, M.; Ahmed, Salman

2017-08-01

At the small consumer level, Photo Voltaic (PV) panel based grid tied systems are the most common form of Distributed Energy Resources (DER). Unlike wind which is suitable for only selected locations, PV panels can generate electricity almost anywhere. Pakistan is currently one of the most energy deficient countries in the world. In order to mitigate this shortage the Government has recently announced a policy of net-metering for residential consumers. After wide spread adoption of DERs, one of the issues that will be faced by load management centers would be accurate estimate of the amount of electricity being injected in the grid at any given time through these DERs. This becomes a critical issue once the penetration of DER increases beyond a certain limit. Grid stability and management of harmonics becomes an important consideration where electricity is being injected at the distribution level and through solid state controllers instead of rotating machinery. This paper presents a solution using graph theoretic methods for the estimation of total electricity being injected in the grid in a wide spread geographical area. An agent based consensus approach for distributed computation is being used to provide an estimate under varying generation conditions.

Quantifying Federal Funding and Scholarly Output Related to the Academic Emergency Medicine Consensus Conferences

PubMed Central

Nishijima, Daniel K.; Dinh, Tu; May, Larissa; Yadav, Kabir; Gaddis, Gary M.; Cone, David C.

2014-01-01

Purpose Since 2000, Academic Emergency Medicine (AEM), the journal of the Society for Academic Emergency Medicine, has presented a one-day consensus conference to generate a research agenda for advancement of a scientific topic. One of the 12 annual issues of AEM is reserved for the proceedings of these conferences. The purpose of this study was to measure academic productivity of these conferences by evaluating subsequent federal research funding received by authors of conference manuscripts and calculating citation counts of conference papers. Method This was a cross-sectional study conducted during August and September 2012. NIH RePORTER was searched to identify subsequent federal funding obtained by authors of the consensus conference issues from 2000 to 2010. Funded projects were coded as related or unrelated to conference topic. Citation counts for all conference manuscripts were quantified using Scopus and Google Scholar. Simple descriptive statistics were reported. Results 852 individual authors contributed to 280 papers published in the 11 consensus conference issues. 137 authors (16%) obtained funding for 318 projects. A median of 22 topic-related projects per conference (range 10–97 projects) accounted for a median of $20,488,331 per conference (range $7,779,512–122,918,205). The average (±SD) number of citations per paper was 15.7 ±20.5 in Scopus and 23.7 ±32.6 in Google Scholar. Conclusions The authors of consensus conference manuscripts obtained significant federal grant support for follow-up research related to conference themes. In addition, the manuscripts generated by these conferences were frequently cited. Conferences devoted to research agenda development appear to be an academically worthwhile endeavor. PMID:24280853

Identification of QTLs associated with oil content in a high-oil Brassica napus cultivar and construction of a high-density consensus map for QTLs comparison in B. napus.

PubMed

Wang, Xiaodong; Wang, Hao; Long, Yan; Li, Dianrong; Yin, Yongtai; Tian, Jianhua; Chen, Li; Liu, Liezhao; Zhao, Weiguo; Zhao, Yajun; Yu, Longjiang; Li, Maoteng

2013-01-01

Increasing seed oil content is one of the most important goals in breeding of rapeseed (B. napus L.). To dissect the genetic basis of oil content in B. napus, a large and new double haploid (DH) population containing 348 lines was obtained from a cross between 'KenC-8' and 'N53-2', two varieties with >10% difference in seed oil content, and this population was named the KN DH population. A genetic linkage map consisting of 403 markers was constructed, which covered a total length of 1783.9 cM with an average marker interval of 4.4 cM. The KN DH population was phenotyped in eight natural environments and subjected to quantitative trait loci (QTL) analysis for oil content. A total of 63 identified QTLs explaining 2.64-17.88% of the phenotypic variation were identified, and these QTLs were further integrated into 24 consensus QTLs located on 11 chromosomes using meta-analysis. A high-density consensus map with 1335 marker loci was constructed by combining the KN DH map with seven other published maps based on the common markers. Of the 24 consensus QTLs in the KN DH population, 14 were new QTLs including five new QTLs in A genome and nine in C genome. The analysis revealed that a larger population with significant differences in oil content gave a higher power detecting new QTLs for oil content, and the construction of the consensus map provided a new clue for comparing the QTLs detected in different populations. These findings enriched our knowledge of QTLs for oil content and should be a potential in marker-assisted breeding of B. napus.

Identification of QTLs Associated with Oil Content in a High-Oil Brassica napus Cultivar and Construction of a High-Density Consensus Map for QTLs Comparison in B. napus

PubMed Central

Long, Yan; Li, Dianrong; Yin, Yongtai; Tian, Jianhua; Chen, Li; Liu, Liezhao; Zhao, Weiguo; Zhao, Yajun; Yu, Longjiang; Li, Maoteng

2013-01-01

Increasing seed oil content is one of the most important goals in breeding of rapeseed (B. napus L.). To dissect the genetic basis of oil content in B. napus, a large and new double haploid (DH) population containing 348 lines was obtained from a cross between ‘KenC-8’ and ‘N53-2’, two varieties with >10% difference in seed oil content, and this population was named the KN DH population. A genetic linkage map consisting of 403 markers was constructed, which covered a total length of 1783.9 cM with an average marker interval of 4.4 cM. The KN DH population was phenotyped in eight natural environments and subjected to quantitative trait loci (QTL) analysis for oil content. A total of 63 identified QTLs explaining 2.64–17.88% of the phenotypic variation were identified, and these QTLs were further integrated into 24 consensus QTLs located on 11 chromosomes using meta-analysis. A high-density consensus map with 1335 marker loci was constructed by combining the KN DH map with seven other published maps based on the common markers. Of the 24 consensus QTLs in the KN DH population, 14 were new QTLs including five new QTLs in A genome and nine in C genome. The analysis revealed that a larger population with significant differences in oil content gave a higher power detecting new QTLs for oil content, and the construction of the consensus map provided a new clue for comparing the QTLs detected in different populations. These findings enriched our knowledge of QTLs for oil content and should be a potential in marker-assisted breeding of B. napus. PMID:24312482

Patellar Instability Management: A Survey of the International Patellofemoral Study Group.

PubMed

Liu, Joseph N; Steinhaus, Michael E; Kalbian, Irene L; Post, William R; Green, Daniel W; Strickland, Sabrina M; Shubin Stein, Beth E

2017-10-01

Although patellofemoral instability is among the most prevalent knee disorders, the management of patients with this condition is complex and remains variable, given the lack of long-term, high-level clinical outcome studies to compare various operative and nonoperative modalities. To discover a consensus within treatment controversies in patellofemoral instability among experienced knee surgeons with a specific interest in the patellofemoral joint. Expert opinion; Level of evidence, 5. A 3-step modified Delphi technique was used to establish a consensus. A 34-question, case-based online survey regarding patellofemoral instability was distributed to all active members of the International Patellofemoral Study Group. Consensus statements were generated if at least 66% of the respondents agreed and then redistributed to the same panel. Modifications to the consensus statements were made based on the iterative feedback process until no discordance was encountered in the third stage. Eight consensus statements were achieved. Nonoperative management is the current standard of care for a first-time dislocation in the absence of an osteochondral fragment or loose body requiring excision (100% agreement). In patients with a first-time dislocation with an operative osteochondral fracture requiring excision or repair, patellar instability should be addressed concurrently (89% agreement). Recurrent instability should be treated surgically, with most surgeons favoring medial reconstruction (77%-86% agreement). While there is general agreement that bony procedures should be performed to correct underlying bony deformities, there is no consensus regarding the most appropriate type of procedure performed. Lateral release should not be performed in isolation for the treatment of patellar instability (89% agreement). Despite the consensus generated in this study, our current understanding remains limited by a lack of high-level evidence as well as the numerous complex variables influencing treatment decision making. High-quality, multicenter randomized controlled trials, particularly those directly comparing specific surgical treatment methods while controlling for underlying risk factors, are needed to address these areas of uncertainty.

Treatment of Osteoporosis in Australian Residential Aged Care Facilities: Update on Consensus Recommendations for Fracture Prevention

PubMed Central

Duque, Gustavo; Lord, Stephen R.; Mak, Jenson; Ganda, Kirtan; Close, Jacqueline J.T.; Ebeling, Peter; Papaioannou, Alexandra; Inderjeeth, Charles A.

2016-01-01

Background Older people living in residential aged care facilities (RACFs) are at a higher risk of suffering fractures than the community-dwelling older population. The first Consensus Conference on Treatment of Osteoporosis in RACFs in Australia, held in Sydney in July 2009, aimed to address some of the issues relating to the treatment of older residents with osteoporosis in RACFs. Considering that the field of osteoporosis diagnosis and management has significantly advanced in the last 5 years and that new evidence has been generated from studies performed within RACFs, a Second Consensus Conference was held in Sydney in November 2014. Methods An expert panel met in November 2014 in Penrith, NSW, Australia in an attempt to reach a consensus on diverse issues related to the treatment of osteoporosis at RACFs. Participants were selected by the scientific committee on the basis of their practice in an RACF and/or major published articles. The co-chairs distributed topics randomly to all participants, who then had to propose a statement on each topic for approval by the conference after a short, evidence-based presentation, when possible. Results This article provides an update on the most relevant evidence on osteoporosis in older people living in RACFs graded according to its level, quality, and relevance. Conclusion As with the first consensus, it is hoped that this statement will constitute an important guide to aid physicians in their decision making while practicing at RACFs. PMID:27349626

Healthy food procurement and nutrition standards in public facilities: evidence synthesis and consensus policy recommendations

PubMed Central

Kim D., Raine; Kayla, Atkey; Dana Lee, Dana Lee; Alexa R., Ferdinands; Dominique, Beaulieu; Susan, Buhler; Norm, Campbell; Brian, Cook; Mary, L’Abbé; Ashley, Lederer; David, Mowat; Joshna, Maharaj; Candace, Nykiforuk; Jacob, Shelley; Jacqueline, Street

2018-01-01

Abstract Introduction: Unhealthy foods are widely available in public settings across Canada, contributing to diet-related chronic diseases, such as obesity. This is a concern given that public facilities often provide a significant amount of food for consumption by vulnerable groups, including children and seniors. Healthy food procurement policies, which support procuring, distributing, selling, and/or serving healthier foods, have recently emerged as a promising strategy to counter this public health issue by increasing access to healthier foods. Although numerous Canadian health and scientific organizations have recommended such policies, they have not yet been broadly implemented in Canada. Methods: To inform further policy action on healthy food procurement in a Canadian context, we: (1) conducted an evidence synthesis to assess the impact of healthy food procurement policies on health outcomes and sales, intake, and availability of healthier food, and (2) hosted a consensus conference in September 2014. The consensus conference invited experts with public health/nutrition policy research expertise, as well as health services and food services practitioner experience, to review evidence, share experiences, and develop a consensus statement/recommendations on healthy food procurement in Canada. Results: Findings from the evidence synthesis and consensus recommendations for healthy food procurement in Canada are described. Specifically, we outline recommendations for governments, publicly funded institutions, decision-makers and professionals, citizens, and researchers. Conclusion: Implementation of healthy food procurement policies can increase Canadians’ access to healthier foods as part of a broader vision for food policy in Canada. PMID:29323862

The consensus in the two-feature two-state one-dimensional Axelrod model revisited

NASA Astrophysics Data System (ADS)

Biral, Elias J. P.; Tilles, Paulo F. C.; Fontanari, José F.

2015-04-01

The Axelrod model for the dissemination of culture exhibits a rich spatial distribution of cultural domains, which depends on the values of the two model parameters: F, the number of cultural features and q, the common number of states each feature can assume. In the one-dimensional model with F = q = 2, which is closely related to the constrained voter model, Monte Carlo simulations indicate the existence of multicultural absorbing configurations in which at least one macroscopic domain coexist with a multitude of microscopic ones in the thermodynamic limit. However, rigorous analytical results for the infinite system starting from the configuration where all cultures are equally likely show convergence to only monocultural or consensus configurations. Here we show that this disagreement is due simply to the order that the time-asymptotic limit and the thermodynamic limit are taken in the simulations. In addition, we show how the consensus-only result can be derived using Monte Carlo simulations of finite chains.

[Colorectal cancer screening: follow-up of patients with adenomatous and colorectal cancer].

PubMed

Antonino, Anca-Teodora; Anca, Antonino; Frei, Alain; Ali-el-Wafa, Abdou; Kessler-Brondolo, Véra; Dorta, Gian

2008-01-23

The different methods of colorectal cancer screening are discussed. Our recommendations had not changed: we recommend as colorectal cancer screening a colonoscopy at the age of 50 years in all healthy persons with average risk for colorectal cancer. A 2007 interdisciplinary consensus conference revised the Swiss recommendations for the follow-up of patients with operated colorectal cancer or after polypectomy.

A Rawlsian approach to distribute responsibilities in networks.

PubMed

Doorn, Neelke

2010-06-01

Due to their non-hierarchical structure, socio-technical networks are prone to the occurrence of the problem of many hands. In the present paper an approach is introduced in which people's opinions on responsibility are empirically traced. The approach is based on the Rawlsian concept of Wide Reflective Equilibrium (WRE) in which people's considered judgments on a case are reflectively weighed against moral principles and background theories, ideally leading to a state of equilibrium. Application of the method to a hypothetical case with an artificially constructed network showed that it is possible to uncover the relevant data to assess a consensus amongst people in terms of their individual WRE. It appeared that the moral background theories people endorse are not predictive for their actual distribution of responsibilities but that they indicate ways of reasoning and justifying outcomes. Two ways of ascribing responsibilities were discerned, corresponding to two requirements of a desirable responsibility distribution: fairness and completeness. Applying the method triggered learning effects, both with regard to conceptual clarification and moral considerations, and in the sense that it led to some convergence of opinions. It is recommended to apply the method to a real engineering case in order to see whether this approach leads to an overlapping consensus on a responsibility distribution which is justifiable to all and in which no responsibilities are left unfulfilled, therewith trying to contribute to the solution of the problem of many hands.

Content modification attacks on consensus seeking multi-agent system with double-integrator dynamics.

PubMed

Dong, Yimeng; Gupta, Nirupam; Chopra, Nikhil

2016-11-01

In this paper, vulnerability of a distributed consensus seeking multi-agent system (MAS) with double-integrator dynamics against edge-bound content modification cyber attacks is studied. In particular, we define a specific edge-bound content modification cyber attack called malignant content modification attack (MCoMA), which results in unbounded growth of an appropriately defined group disagreement vector. Properties of MCoMA are utilized to design detection and mitigation algorithms so as to impart resilience in the considered MAS against MCoMA. Additionally, the proposed detection mechanism is extended to detect the general edge-bound content modification attacks (not just MCoMA). Finally, the efficacies of the proposed results are illustrated through numerical simulations.

Content modification attacks on consensus seeking multi-agent system with double-integrator dynamics

NASA Astrophysics Data System (ADS)

Dong, Yimeng; Gupta, Nirupam; Chopra, Nikhil

2016-11-01

In this paper, vulnerability of a distributed consensus seeking multi-agent system (MAS) with double-integrator dynamics against edge-bound content modification cyber attacks is studied. In particular, we define a specific edge-bound content modification cyber attack called malignant content modification attack (MCoMA), which results in unbounded growth of an appropriately defined group disagreement vector. Properties of MCoMA are utilized to design detection and mitigation algorithms so as to impart resilience in the considered MAS against MCoMA. Additionally, the proposed detection mechanism is extended to detect the general edge-bound content modification attacks (not just MCoMA). Finally, the efficacies of the proposed results are illustrated through numerical simulations.

Distinctive Sediment and Adjacent Groundwater Microbial Communities in Bangladesh Aquifers Suggested Through Microbial Lipid Distribution and δ13C Analysis

NASA Astrophysics Data System (ADS)

Martin, K. J. W.; van Geen, A.; Bostick, B. C.; Mailloux, B. J.; Ahmed, K. M.; Choudhury, I.; Slater, G.

2016-12-01

Arsenic groundwater contamination throughout shallow aquifer sediments in Southern Asia has resulted in a large-scale human health crisis. There is a strong consensus that microbial iron reduction coupled to organic carbon oxidation is the predominant mechanism driving this arsenic release. However, limited research has examined the composition and functioning of the indigenous microbial communities. Further, such research has varied between studies targeting microbial communities associated with groundwater versus those associated with sediments. The overall aim of this research study was to use microbial lipid biomarkers of bacterial and micro-eukaryal (phospholipid fatty acids (PLFA)) and archaea (di- and tetra- bound ether lipids) distributions and δ13C analysis to compare the indigenous sedimentary-associated microbial communities with the groundwater-associated microbial communities in Bangladesh aquifers. Field sampling was carried out at four locations (Site B, F, SAM and CAT) in the Araihazar Upazila, Bangladesh in 2013 and 2015. A significant difference (p<0.00001) was found between the cell abundances in the groundwater-associated (2.8 x 101 to 3.0 x 102 cells/mL) (n=9) and the sediment-associated communities (averaging 1.1 x 107 cells/gram (n=19). Long-chain fatty acid methyl esters (FAME's) (C22-C29) derived from micro-eukaryotes were present in the sediments of both Site B and F comprising up to 17 % and 7% (mole %) of the total FAME distribution respectively but not detected in any of the groundwater filters. Shallow Site B sedimentary PLFA showed a progressive depletion in δ13C with depth from -24 to -31 ‰, whereas Site F sedimentary PLFA from similar depths did not show the same trend. Groundwater PLFA from Site B (14 m) contained FAME 18:1 with an average δ13C of -41‰, possibly indicating methanogenic activity (methanogen lipid analysis is ongoing). The results of this study highly suggests that Bangaldesh aquifer sediment and groundwater microbial communties are distinctive and cannot be used interchangably within future research studies investigating microbal arsenic release in these systems.

Genetic map of artichoke × wild cardoon: toward a consensus map for Cynara cardunculus.

PubMed

Sonnante, Gabriella; Gatto, Angela; Morgese, Anita; Montemurro, Francesco; Sarli, Giulio; Blanco, Emanuela; Pignone, Domenico

2011-11-01

An integrated consensus linkage map is proposed for globe artichoke. Maternal and paternal genetic maps were constructed on the basis of an F(1) progeny derived from crossing an artichoke genotype (Mola) with its progenitor, the wild cardoon (Tolfa), using EST-derived SSRs, genomic SSRs, AFLPs, ten genes, and two morphological traits. For most genes, mainly belonging to the chlorogenic acid pathway, new markers were developed. Five of these were SNP markers analyzed through high-resolution melt technology. From the maternal (Mola) and paternal (Tolfa) maps, an integrated map was obtained, containing 337 molecular and one morphological markers ordered in 17 linkage groups (LGs), linked between Mola and Tolfa. The integrated map covers 1,488.8 cM, with an average distance of 4.4 cM between markers. The map was aligned with already existing maps for artichoke, and 12 LGs were linked via 31 bridge markers. LG numbering has been proposed. A total of 124 EST-SSRs and two genes were mapped here for the first time, providing a framework for the construction of a functional map in artichoke. The establishment of a consensus map represents a necessary condition to plan a complete sequencing of the globe artichoke genome.

The Norwegian General Practice--Nursing Home criteria (NORGEP-NH) for potentially inappropriate medication use: A web-based Delphi study.

PubMed

Nyborg, Gunhild; Straand, Jørund; Klovning, Atle; Brekke, Mette

2015-06-01

To develop a set of explicit criteria for pharmacologically inappropriate medication use in nursing homes. In an expert panel, a three-round Delphi consensus process was conducted via survey software. Norway. Altogether 80 participants - specialists in geriatrics or clinical pharmacology, physicians in nursing homes and experienced pharmacists - agreed to participate in the survey. Of these, 62 completed the first round, and 49 panellists completed all three rounds (75.4% of those ultimately entering the survey). The authors developed a list of 27 criteria based on the Norwegian General Practice (NORGEP) criteria, literature, and clinical experience. The main outcome measure was the panellists' evaluation of the clinical relevance of each suggested criterion on a digital Likert scale from 1 (no clinical relevance) to 10. In the first round panellists could also suggest new criteria to be included in the process. For each criterion, degree of consensus was based on the average Likert score and corresponding standard deviation (SD). A list of 34 explicit criteria for potentially inappropriate medication use in nursing homes was developed through a three-round web-based Delphi consensus process. Degree of consensus increased with each round. No criterion was voted out. Suggestions from the panel led to the inclusion of seven additional criteria in round two. The NORGEP-NH list may serve as a tool in the prescribing process and in medication list reviews and may also be used in quality assessment and for research purposes.

Failure mode and effects analysis: an empirical comparison of failure mode scoring procedures.

PubMed

Ashley, Laura; Armitage, Gerry

2010-12-01

To empirically compare 2 different commonly used failure mode and effects analysis (FMEA) scoring procedures with respect to their resultant failure mode scores and prioritization: a mathematical procedure, where scores are assigned independently by FMEA team members and averaged, and a consensus procedure, where scores are agreed on by the FMEA team via discussion. A multidisciplinary team undertook a Healthcare FMEA of chemotherapy administration. This included mapping the chemotherapy process, identifying and scoring failure modes (potential errors) for each process step, and generating remedial strategies to counteract them. Failure modes were scored using both an independent mathematical procedure and a team consensus procedure. Almost three-fifths of the 30 failure modes generated were scored differently by the 2 procedures, and for just more than one-third of cases, the score discrepancy was substantial. Using the Healthcare FMEA prioritization cutoff score, almost twice as many failure modes were prioritized by the consensus procedure than by the mathematical procedure. This is the first study to empirically demonstrate that different FMEA scoring procedures can score and prioritize failure modes differently. It found considerable variability in individual team members' opinions on scores, which highlights the subjective and qualitative nature of failure mode scoring. A consensus scoring procedure may be most appropriate for FMEA as it allows variability in individuals' scores and rationales to become apparent and to be discussed and resolved by the team. It may also yield team learning and communication benefits unlikely to result from a mathematical procedure.

Defining the Medical Library Association research agenda: methodology and final results from a consensus process

PubMed Central

Eldredge, Jonathan D.; Harris, Martha R.; Ascher, Marie T.

2009-01-01

Objective: Using a group consensus methodology, the research sought to generate a list of the twelve to fifteen most important and answerable research questions in health sciences librarianship as part of a broader effort to implement the new Medical Library Association (MLA) research policy. Methods: The delphi method was used. The committee distributed a brief survey to all estimated 827 MLA leaders and 237 MLA Research Section members, requesting they submit what they considered to be the most important and answerable research questions facing the profession. The submitted questions were then subjected to 2 rounds of voting to produce a short list of top-ranked questions. Results: The survey produced 62 questions from 54 MLA leaders and MLA Research Section members, who responded from an estimated potential population of 1,064 targeted colleagues. These questions were considered by the process participants to be the most important and answerable research questions facing the profession. Through 2 rounds of voting, these 62 questions were reduced to the final 12 highest priority questions. Conclusion: The modified delphi method accomplished its desired survey and consensus goals. Future survey and consensus processes will be revised to generate more initial questions and to distill a larger number of ranked prioritized research questions. PMID:19626143

Waif goodbye! Average-size female models promote positive body image and appeal to consumers.

PubMed

Diedrichs, Phillippa C; Lee, Christina

2011-10-01

Despite consensus that exposure to media images of thin fashion models is associated with poor body image and disordered eating behaviours, few attempts have been made to enact change in the media. This study sought to investigate an effective alternative to current media imagery, by exploring the advertising effectiveness of average-size female fashion models, and their impact on the body image of both women and men. A sample of 171 women and 120 men were assigned to one of three advertisement conditions: no models, thin models and average-size models. Women and men rated average-size models as equally effective in advertisements as thin and no models. For women with average and high levels of internalisation of cultural beauty ideals, exposure to average-size female models was associated with a significantly more positive body image state in comparison to exposure to thin models and no models. For men reporting high levels of internalisation, exposure to average-size models was also associated with a more positive body image state in comparison to viewing thin models. These findings suggest that average-size female models can promote positive body image and appeal to consumers.

Distributed Load Shedding over Directed Communication Networks with Time Delays

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

Yang, Tao; Wu, Di

When generation is insufficient to support all loads under emergencies, effective and efficient load shedding needs to be deployed in order to maintain the supply-demand balance. This paper presents a distributed load shedding algorithm, which makes efficient decision based on the discovered global information. In the global information discovery process, each load only communicates with its neighboring load via directed communication links possibly with arbitrarily large but bounded time varying communication delays. We propose a novel distributed information discovery algorithm based on ratio consensus. Simulation results are used to validate the proposed method.

European consensus statement on leptospirosis in dogs and cats

USDA-ARS?s Scientific Manuscript database

Leptospirosis is a zoonotic disease of worldwide distribution affecting most mammalian species. Clinical leptospirosis is common in dogs but seems to be rare in cats. Both dogs and cats however, can shed leptospires in the urine. This is problematic as it can lead to exposure of humans. The control ...

The Poleward Shift of Storm Tracks Under Climate Change: Tracking Cyclones in CMIP5

NASA Astrophysics Data System (ADS)

Kaspi, Y.; Tamarin, T.

2017-12-01

Extratropical cyclones dominate the distribution of precipitation and wind in the midlatitudes, and therefore their frequency, intensity, and paths have a significant effect on weather and climate. Comprehensive climate models forced by enhanced greenhouse gas emissions suggest that under a climate change scenario, the latitudinal band of storm tracks would shift poleward. While the poleward shift is a robust response across most models, there is currently no consensus on what is the dominant dynamical mechanism. Here we use a Lagrangian approach to study the poleward shift, by employing a storm-tracking algorithm on an ensemble of CMIP5 models forced by increased CO2 emissions. We demonstrate that in addition to a poleward shift in the latitude of storm genesis, associated with the expansion of the Hadley cell, the averaged cyclonic storm also propagates more poleward until it reaches its maximum intensity. A mechanism for enhanced poleward motion of cyclones in a warmer climate is proposed, supported by idealized global warming experiments, and relates the shift to changes in upper level jet and atmospheric water vapour content. Our results imply that under the RCP8.5 climate change scenario, the averaged latitude of peak cyclone intensity shifts poleward by about 1.2○ (1.0○) in the Atlantic (Pacific) storm track in the Northern Hemisphere (NH), and by about 1.6○ in the Southern Hemisphere (SH) storm track. These changes in cyclone tracks can have a significant impact on midlatitude climate.

Refining the Global Spatial Limits of Dengue Virus Transmission by Evidence-Based Consensus

PubMed Central

Brady, Oliver J.; Gething, Peter W.; Bhatt, Samir; Messina, Jane P.; Brownstein, John S.; Hoen, Anne G.; Moyes, Catherine L.; Farlow, Andrew W.; Scott, Thomas W.; Hay, Simon I.

2012-01-01

Background Dengue is a growing problem both in its geographical spread and in its intensity, and yet current global distribution remains highly uncertain. Challenges in diagnosis and diagnostic methods as well as highly variable national health systems mean no single data source can reliably estimate the distribution of this disease. As such, there is a lack of agreement on national dengue status among international health organisations. Here we bring together all available information on dengue occurrence using a novel approach to produce an evidence consensus map of the disease range that highlights nations with an uncertain dengue status. Methods/Principal Findings A baseline methodology was used to assess a range of evidence for each country. In regions where dengue status was uncertain, additional evidence types were included to either clarify dengue status or confirm that it is unknown at this time. An algorithm was developed that assesses evidence quality and consistency, giving each country an evidence consensus score. Using this approach, we were able to generate a contemporary global map of national-level dengue status that assigns a relative measure of certainty and identifies gaps in the available evidence. Conclusion The map produced here provides a list of 128 countries for which there is good evidence of dengue occurrence, including 36 countries that have previously been classified as dengue-free by the World Health Organization and/or the US Centers for Disease Control. It also identifies disease surveillance needs, which we list in full. The disease extents and limits determined here using evidence consensus, marks the beginning of a five-year study to advance the mapping of dengue virus transmission and disease risk. Completion of this first step has allowed us to produce a preliminary estimate of population at risk with an upper bound of 3.97 billion people. This figure will be refined in future work. PMID:22880140

Refining the global spatial limits of dengue virus transmission by evidence-based consensus.

PubMed

Brady, Oliver J; Gething, Peter W; Bhatt, Samir; Messina, Jane P; Brownstein, John S; Hoen, Anne G; Moyes, Catherine L; Farlow, Andrew W; Scott, Thomas W; Hay, Simon I

2012-01-01

Dengue is a growing problem both in its geographical spread and in its intensity, and yet current global distribution remains highly uncertain. Challenges in diagnosis and diagnostic methods as well as highly variable national health systems mean no single data source can reliably estimate the distribution of this disease. As such, there is a lack of agreement on national dengue status among international health organisations. Here we bring together all available information on dengue occurrence using a novel approach to produce an evidence consensus map of the disease range that highlights nations with an uncertain dengue status. A baseline methodology was used to assess a range of evidence for each country. In regions where dengue status was uncertain, additional evidence types were included to either clarify dengue status or confirm that it is unknown at this time. An algorithm was developed that assesses evidence quality and consistency, giving each country an evidence consensus score. Using this approach, we were able to generate a contemporary global map of national-level dengue status that assigns a relative measure of certainty and identifies gaps in the available evidence. The map produced here provides a list of 128 countries for which there is good evidence of dengue occurrence, including 36 countries that have previously been classified as dengue-free by the World Health Organization and/or the US Centers for Disease Control. It also identifies disease surveillance needs, which we list in full. The disease extents and limits determined here using evidence consensus, marks the beginning of a five-year study to advance the mapping of dengue virus transmission and disease risk. Completion of this first step has allowed us to produce a preliminary estimate of population at risk with an upper bound of 3.97 billion people. This figure will be refined in future work.

QMEANclust: estimation of protein model quality by combining a composite scoring function with structural density information.

PubMed

Benkert, Pascal; Schwede, Torsten; Tosatto, Silvio Ce

2009-05-20

The selection of the most accurate protein model from a set of alternatives is a crucial step in protein structure prediction both in template-based and ab initio approaches. Scoring functions have been developed which can either return a quality estimate for a single model or derive a score from the information contained in the ensemble of models for a given sequence. Local structural features occurring more frequently in the ensemble have a greater probability of being correct. Within the context of the CASP experiment, these so called consensus methods have been shown to perform considerably better in selecting good candidate models, but tend to fail if the best models are far from the dominant structural cluster. In this paper we show that model selection can be improved if both approaches are combined by pre-filtering the models used during the calculation of the structural consensus. Our recently published QMEAN composite scoring function has been improved by including an all-atom interaction potential term. The preliminary model ranking based on the new QMEAN score is used to select a subset of reliable models against which the structural consensus score is calculated. This scoring function called QMEANclust achieves a correlation coefficient of predicted quality score and GDT_TS of 0.9 averaged over the 98 CASP7 targets and perform significantly better in selecting good models from the ensemble of server models than any other groups participating in the quality estimation category of CASP7. Both scoring functions are also benchmarked on the MOULDER test set consisting of 20 target proteins each with 300 alternatives models generated by MODELLER. QMEAN outperforms all other tested scoring functions operating on individual models, while the consensus method QMEANclust only works properly on decoy sets containing a certain fraction of near-native conformations. We also present a local version of QMEAN for the per-residue estimation of model quality (QMEANlocal) and compare it to a new local consensus-based approach. Improved model selection is obtained by using a composite scoring function operating on single models in order to enrich higher quality models which are subsequently used to calculate the structural consensus. The performance of consensus-based methods such as QMEANclust highly depends on the composition and quality of the model ensemble to be analysed. Therefore, performance estimates for consensus methods based on large meta-datasets (e.g. CASP) might overrate their applicability in more realistic modelling situations with smaller sets of models based on individual methods.

Imitation Combined with a Characteristic Stimulus Duration Results in Robust Collective Decision-Making.

PubMed

Toulet, Sylvain; Gautrais, Jacques; Bon, Richard; Peruani, Fernando

2015-01-01

For group-living animals, reaching consensus to stay cohesive is crucial for their fitness, particularly when collective motion starts and stops. Understanding the decision-making at individual and collective levels upon sudden disturbances is central in the study of collective animal behavior, and concerns the broader question of how information is distributed and evaluated in groups. Despite the relevance of the problem, well-controlled experimental studies that quantify the collective response of groups facing disruptive events are lacking. Here we study the behavior of small-sized groups of uninformed individuals subject to the departure and stop of a trained conspecific. We find that the groups reach an effective consensus: either all uninformed individuals follow the trained one (and collective motion occurs) or none does. Combining experiments and a simple mathematical model we show that the observed phenomena results from the interplay between simple mimetic rules and the characteristic duration of the stimulus, here, the time during which the trained individual is moving away. The proposed mechanism strongly depends on group size, as observed in the experiments, and even if group splitting can occur, the most likely outcome is always a coherent collective group response (consensus). The prevalence of a consensus is expected even if the groups of naives face conflicting information, e.g. if groups contain two subgroups of trained individuals, one trained to stay and one trained to leave. Our results indicate that collective decision-making and consensus in (small) animal groups are likely to be self-organized phenomena that do not involve concertation or even communication among the group members.

GREIT: a unified approach to 2D linear EIT reconstruction of lung images.

PubMed

Adler, Andy; Arnold, John H; Bayford, Richard; Borsic, Andrea; Brown, Brian; Dixon, Paul; Faes, Theo J C; Frerichs, Inéz; Gagnon, Hervé; Gärber, Yvo; Grychtol, Bartłomiej; Hahn, Günter; Lionheart, William R B; Malik, Anjum; Patterson, Robert P; Stocks, Janet; Tizzard, Andrew; Weiler, Norbert; Wolf, Gerhard K

2009-06-01

Electrical impedance tomography (EIT) is an attractive method for clinically monitoring patients during mechanical ventilation, because it can provide a non-invasive continuous image of pulmonary impedance which indicates the distribution of ventilation. However, most clinical and physiological research in lung EIT is done using older and proprietary algorithms; this is an obstacle to interpretation of EIT images because the reconstructed images are not well characterized. To address this issue, we develop a consensus linear reconstruction algorithm for lung EIT, called GREIT (Graz consensus Reconstruction algorithm for EIT). This paper describes the unified approach to linear image reconstruction developed for GREIT. The framework for the linear reconstruction algorithm consists of (1) detailed finite element models of a representative adult and neonatal thorax, (2) consensus on the performance figures of merit for EIT image reconstruction and (3) a systematic approach to optimize a linear reconstruction matrix to desired performance measures. Consensus figures of merit, in order of importance, are (a) uniform amplitude response, (b) small and uniform position error, (c) small ringing artefacts, (d) uniform resolution, (e) limited shape deformation and (f) high resolution. Such figures of merit must be attained while maintaining small noise amplification and small sensitivity to electrode and boundary movement. This approach represents the consensus of a large and representative group of experts in EIT algorithm design and clinical applications for pulmonary monitoring. All software and data to implement and test the algorithm have been made available under an open source license which allows free research and commercial use.

Treatment of Osteoporosis in Australian Residential Aged Care Facilities: Update on Consensus Recommendations for Fracture Prevention.

PubMed

Duque, Gustavo; Lord, Stephen R; Mak, Jenson; Ganda, Kirtan; Close, Jacqueline J T; Ebeling, Peter; Papaioannou, Alexandra; Inderjeeth, Charles A

2016-09-01

Older people living in residential aged care facilities (RACFs) are at a higher risk of suffering fractures than the community-dwelling older population. The first Consensus Conference on Treatment of Osteoporosis in RACFs in Australia, held in Sydney in July 2009, aimed to address some of the issues relating to the treatment of older residents with osteoporosis in RACFs. Considering that the field of osteoporosis diagnosis and management has significantly advanced in the last 5 years and that new evidence has been generated from studies performed within RACFs, a Second Consensus Conference was held in Sydney in November 2014. An expert panel met in November 2014 in Penrith, NSW, Australia in an attempt to reach a consensus on diverse issues related to the treatment of osteoporosis at RACFs. Participants were selected by the scientific committee on the basis of their practice in an RACF and/or major published articles. The co-chairs distributed topics randomly to all participants, who then had to propose a statement on each topic for approval by the conference after a short, evidence-based presentation, when possible. This article provides an update on the most relevant evidence on osteoporosis in older people living in RACFs graded according to its level, quality, and relevance. As with the first consensus, it is hoped that this statement will constitute an important guide to aid physicians in their decision making while practicing at RACFs. Copyright © 2016 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.

Group for Research and Assessment of Psoriasis and Psoriatic Arthritis/Outcome Measures in Rheumatology Consensus-Based Recommendations and Research Agenda for Use of Composite Measures and Treatment Targets in Psoriatic Arthritis.

PubMed

Coates, Laura C; FitzGerald, Oliver; Merola, Joseph F; Smolen, Josef; van Mens, Leonieke J J; Bertheussen, Heidi; Boehncke, Wolf-Henning; Callis Duffin, Kristina; Campbell, Willemina; de Wit, Maarten; Gladman, Dafna; Gottlieb, Alice; James, Jana; Kavanaugh, Arthur; Kristensen, Lars Erik; Kvien, Tore K; Luger, Thomas; McHugh, Neil; Mease, Philip; Nash, Peter; Ogdie, Alexis; Rosen, Cheryl F; Strand, Vibeke; Tillett, William; Veale, Douglas J; Helliwell, Philip S

2018-03-01

A meeting was convened by the Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) and Outcome Measures in Rheumatology (OMERACT) to further the development of consensus among physicians and patients regarding composite disease activity measures and targets in psoriatic arthritis (PsA). Prior to the meeting, physicians and patients completed surveys on outcome measures. A consensus meeting of 26 rheumatologists, dermatologists, and patient research partners reviewed evidence on composite measures and potential treatment targets plus results of the surveys. The meeting consisted of plenary presentations, breakout sessions, and group discussions. International experts including members of GRAPPA and OMERACT were invited to the meeting, including the developers of all of the measures discussed. After discussions, participants voted on proposals for use, and consensus was established in a second survey. Survey results from 128 health care professionals and 139 patients were analyzed alongside a systematic literature review summarizing evidence. A weighted vote was cast for composite measures. For randomized controlled trials, the most popular measures were the PsA disease activity score (40 votes) and the GRAPPA composite index (28 votes). For clinical practice, the most popular measures were an average of scores on 3 visual analog scales (45 votes) and the disease activity in PsA score (26 votes). After discussion, there was no consensus on a composite measure. The group agreed that several composite measures could be used and that future studies should allow further validation and comparison. The group unanimously agreed that remission should be the ideal target, with minimal disease activity (MDA)/low disease activity as a feasible alternative. The target should include assessment of musculoskeletal disease, skin disease, and health-related quality of life. The group recommended a treatment target of very low disease activity (VLDA) or MDA. Consensus was not reached on a continuous measure of disease activity. In the interim, the group recommended several composites. Consensus was reached on a treatment target of VLDA/MDA. An extensive research agenda was composed and recommends that data on all PsA clinical domains be collected in ongoing studies. © 2017, American College of Rheumatology.

Atlas Based Segmentation and Mapping of Organs at Risk from Planning CT for the Development of Voxel-Wise Predictive Models of Toxicity in Prostate Radiotherapy

NASA Astrophysics Data System (ADS)

Acosta, Oscar; Dowling, Jason; Cazoulat, Guillaume; Simon, Antoine; Salvado, Olivier; de Crevoisier, Renaud; Haigron, Pascal

The prediction of toxicity is crucial to managing prostate cancer radiotherapy (RT). This prediction is classically organ wise and based on the dose volume histograms (DVH) computed during the planning step, and using for example the mathematical Lyman Normal Tissue Complication Probability (NTCP) model. However, these models lack spatial accuracy, do not take into account deformations and may be inappropiate to explain toxicity events related with the distribution of the delivered dose. Producing voxel wise statistical models of toxicity might help to explain the risks linked to the dose spatial distribution but is challenging due to the difficulties lying on the mapping of organs and dose in a common template. In this paper we investigate the use of atlas based methods to perform the non-rigid mapping and segmentation of the individuals' organs at risk (OAR) from CT scans. To build a labeled atlas, 19 CT scans were selected from a population of patients treated for prostate cancer by radiotherapy. The prostate and the OAR (Rectum, Bladder, Bones) were then manually delineated by an expert and constituted the training data. After a number of affine and non rigid registration iterations, an average image (template) representing the whole population was obtained. The amount of consensus between labels was used to generate probabilistic maps for each organ. We validated the accuracy of the approach by segmenting the organs using the training data in a leave one out scheme. The agreement between the volumes after deformable registration and the manually segmented organs was on average above 60% for the organs at risk. The proposed methodology provides a way to map the organs from a whole population on a single template and sets the stage to perform further voxel wise analysis. With this method new and accurate predictive models of toxicity will be built.

Creating "Intelligent" Climate Model Ensemble Averages Using a Process-Based Framework

NASA Astrophysics Data System (ADS)

Baker, N. C.; Taylor, P. C.

2014-12-01

The CMIP5 archive contains future climate projections from over 50 models provided by dozens of modeling centers from around the world. Individual model projections, however, are subject to biases created by structural model uncertainties. As a result, ensemble averaging of multiple models is often used to add value to model projections: consensus projections have been shown to consistently outperform individual models. Previous reports for the IPCC establish climate change projections based on an equal-weighted average of all model projections. However, certain models reproduce climate processes better than other models. Should models be weighted based on performance? Unequal ensemble averages have previously been constructed using a variety of mean state metrics. What metrics are most relevant for constraining future climate projections? This project develops a framework for systematically testing metrics in models to identify optimal metrics for unequal weighting multi-model ensembles. A unique aspect of this project is the construction and testing of climate process-based model evaluation metrics. A climate process-based metric is defined as a metric based on the relationship between two physically related climate variables—e.g., outgoing longwave radiation and surface temperature. Metrics are constructed using high-quality Earth radiation budget data from NASA's Clouds and Earth's Radiant Energy System (CERES) instrument and surface temperature data sets. It is found that regional values of tested quantities can vary significantly when comparing weighted and unweighted model ensembles. For example, one tested metric weights the ensemble by how well models reproduce the time-series probability distribution of the cloud forcing component of reflected shortwave radiation. The weighted ensemble for this metric indicates lower simulated precipitation (up to .7 mm/day) in tropical regions than the unweighted ensemble: since CMIP5 models have been shown to overproduce precipitation, this result could indicate that the metric is effective in identifying models which simulate more realistic precipitation. Ultimately, the goal of the framework is to identify performance metrics for advising better methods for ensemble averaging models and create better climate predictions.

Risk stratification of childhood medulloblastoma in the molecular era: the current consensus.

PubMed

Ramaswamy, Vijay; Remke, Marc; Bouffet, Eric; Bailey, Simon; Clifford, Steven C; Doz, Francois; Kool, Marcel; Dufour, Christelle; Vassal, Gilles; Milde, Till; Witt, Olaf; von Hoff, Katja; Pietsch, Torsten; Northcott, Paul A; Gajjar, Amar; Robinson, Giles W; Padovani, Laetitia; André, Nicolas; Massimino, Maura; Pizer, Barry; Packer, Roger; Rutkowski, Stefan; Pfister, Stefan M; Taylor, Michael D; Pomeroy, Scott L

2016-06-01

Historical risk stratification criteria for medulloblastoma rely primarily on clinicopathological variables pertaining to age, presence of metastases, extent of resection, histological subtypes and in some instances individual genetic aberrations such as MYC and MYCN amplification. In 2010, an international panel of experts established consensus defining four main subgroups of medulloblastoma (WNT, SHH, Group 3 and Group 4) delineated by transcriptional profiling. This has led to the current generation of biomarker-driven clinical trials assigning WNT tumors to a favorable prognosis group in addition to clinicopathological criteria including MYC and MYCN gene amplifications. However, outcome prediction of non-WNT subgroups is a challenge due to inconsistent survival reports. In 2015, a consensus conference was convened in Heidelberg with the objective to further refine the risk stratification in the context of subgroups and agree on a definition of risk groups of non-infant, childhood medulloblastoma (ages 3-17). Published and unpublished data over the past 5 years were reviewed, and a consensus was reached regarding the level of evidence for currently available biomarkers. The following risk groups were defined based on current survival rates: low risk (>90 % survival), average (standard) risk (75-90 % survival), high risk (50-75 % survival) and very high risk (<50 % survival) disease. The WNT subgroup and non-metastatic Group 4 tumors with whole chromosome 11 loss or whole chromosome 17 gain were recognized as low-risk tumors that may qualify for reduced therapy. High-risk strata were defined as patients with metastatic SHH or Group 4 tumors, or MYCN-amplified SHH medulloblastomas. Very high-risk patients are Group 3 with metastases or SHH with TP53 mutation. In addition, a number of consensus points were reached that should be standardized across future clinical trials. Although we anticipate new data will emerge from currently ongoing and recently completed clinical trials, this consensus can serve as an outline for prioritization of certain molecular subsets of tumors to define and validate risk groups as a basis for future clinical trials.

Risk stratification of childhood medulloblastoma in the molecular era: The Current Consensus

PubMed Central

Ramaswamy, Vijay; Remke, Marc; Bouffet, Eric; Bailey, Simon; Clifford, Steven C.; Doz, Francois; Kool, Marcel; Dufour, Christelle; Vassal, Gilles; Milde, Till; Witt, Olaf; von Hoff, Katja; Pietsch, Torsten; Northcott, Paul A.; Gajjar, Amar; Robinson, Giles W.; Padovani, Laetitia; André, Nicolas; Massimino, Maura; Pizer, Barry; Packer, Roger; Rutkowski, Stefan; Pfister, Stefan M.; Taylor, Michael D.; Pomeroy, Scott L.

2016-01-01

Historical risk stratification criteria for medulloblastoma rely primarily on clinicopathological variables pertaining to age, presence of metastases, extent of resection, histological subtypes and in some instances individual genetic aberrations such as MYC and MYCN amplification. In 2010, an international panel of experts established consensus defining four main subgroups of medulloblastoma (WNT, SHH, Group 3 and Group 4) delineated by transcriptional profiling. This has led to the current generation of biomarker-driven clinical trials assigning WNT tumors to a favorable prognosis group in addition to clinicopathological criteria including MYC and MYCN gene amplifications. However, outcome prediction of non-WNT subgroups is a challenge due to inconsistent survival reports. In 2015, a consensus conference was convened in Heidelberg with the objective to further refine the risk stratification in the context of subgroups and agree on a definition of risk groups of non-infant, childhood medulloblastoma (ages 3–17). Published and unpublished data over the past five years were reviewed, and a consensus was reached regarding the level of evidence for currently available biomarkers. The following risk groups were defined based on current survival rates: low risk (>90% survival), average (standard) risk (75–90% survival), high risk (50–75% survival) and very high risk (<50% survival) disease. The WNT subgroup and non-metastatic Group 4 tumors with whole chromosome 11 loss or whole chromosome 17 gain were recognized as low risk tumors that may qualify for reduced therapy. High-risk strata were defined as patients with metastatic SHH or Group 4 tumors, or MYCN amplified SHH medulloblastomas. Very high-risk patients are Group 3 with metastases or SHH with TP53 mutation. In addition, a number of consensus points were reached that should be standardized across future clinical trials. Although we anticipate new data will emerge from currently ongoing and recently completed clinical trials, this consensus can serve as an outline for prioritization of certain molecular subsets of tumors to define and validate risk groups as a basis for future clinical trials. PMID:27040285

A reference consensus genetic map for molecular markers and economically important traits in faba bean (Vicia faba L.)

PubMed Central

2013-01-01

Background Faba bean (Vicia faba L.) is among the earliest domesticated crops from the Near East. Today this legume is a key protein feed and food worldwide and continues to serve an important role in culinary traditions throughout Middle East, Mediterranean region, China and Ethiopia. Adapted to a wide range of soil types, the main faba bean breeding objectives are to improve yield, resistance to biotic and abiotic stresses, seed quality and other agronomic traits. Genomic approaches aimed at enhancing faba bean breeding programs require high-quality genetic linkage maps to facilitate quantitative trait locus analysis and gene tagging for use in a marker-assisted selection. The objective of this study was to construct a reference consensus map in faba bean by joining the information from the most relevant maps reported so far in this crop. Results A combination of two approaches, increasing the number of anchor loci in diverse mapping populations and joining the corresponding genetic maps, was used to develop a reference consensus map in faba bean. The map was constructed from three main recombinant inbreed populations derived from four parental lines, incorporates 729 markers and is based on 69 common loci. It spans 4,602 cM with a range from 323 to 1041 loci in six main linkage groups or chromosomes, and an average marker density of one locus every 6 cM. Locus order is generally well maintained between the consensus map and the individual maps. Conclusion We have constructed a reliable and fairly dense consensus genetic linkage map that will serve as a basis for genomic approaches in faba bean research and breeding. The core map contains a larger number of markers than any previous individual map, covers existing gaps and achieves a wider coverage of the large faba bean genome as a whole. This tool can be used as a reference resource for studies in different genetic backgrounds, and provides a framework for transferring genetic information when using different marker technologies. Combined with syntenic approaches, the consensus map will increase marker density in selected genomic regions and will be useful for future faba bean molecular breeding applications. PMID:24377374

A 1,681-locus consensus genetic map of cultivated cucumber including 67 NB-LRR resistance gene homolog and ten gene loci

PubMed Central

2013-01-01

Background Cucumber is an important vegetable crop that is susceptible to many pathogens, but no disease resistance (R) genes have been cloned. The availability of whole genome sequences provides an excellent opportunity for systematic identification and characterization of the nucleotide binding and leucine-rich repeat (NB-LRR) type R gene homolog (RGH) sequences in the genome. Cucumber has a very narrow genetic base making it difficult to construct high-density genetic maps. Development of a consensus map by synthesizing information from multiple segregating populations is a method of choice to increase marker density. As such, the objectives of the present study were to identify and characterize NB-LRR type RGHs, and to develop a high-density, integrated cucumber genetic-physical map anchored with RGH loci. Results From the Gy14 draft genome, 70 NB-containing RGHs were identified and characterized. Most RGHs were in clusters with uneven distribution across seven chromosomes. In silico analysis indicated that all 70 RGHs had EST support for gene expression. Phylogenetic analysis classified 58 RGHs into two clades: CNL and TNL. Comparative analysis revealed high-degree sequence homology and synteny in chromosomal locations of these RGH members between the cucumber and melon genomes. Fifty-four molecular markers were developed to delimit 67 of the 70 RGHs, which were integrated into a genetic map through linkage analysis. A 1,681-locus cucumber consensus map including 10 gene loci and spanning 730.0 cM in seven linkage groups was developed by integrating three component maps with a bin-mapping strategy. Physically, 308 scaffolds with 193.2 Mbp total DNA sequences were anchored onto this consensus map that covered 52.6% of the 367 Mbp cucumber genome. Conclusions Cucumber contains relatively few NB-LRR RGHs that are clustered and unevenly distributed in the genome. All RGHs seem to be transcribed and shared significant sequence homology and synteny with the melon genome suggesting conservation of these RGHs in the Cucumis lineage. The 1,681-locus consensus genetic-physical map developed and the RGHs identified and characterized herein are valuable genomics resources that may have many applications such as quantitative trait loci identification, map-based gene cloning, association mapping, marker-assisted selection, as well as assembly of a more complete cucumber genome. PMID:23531125

Serving by local consensus in the public service location game.

PubMed

Sun, Yi-Fan; Zhou, Hai-Jun

2016-09-02

We discuss the issue of distributed and cooperative decision-making in a network game of public service location. Each node of the network can decide to host a certain public service incurring in a construction cost and serving all the neighboring nodes and itself. A pure consumer node has to pay a tax, and the collected tax is evenly distributed to all the hosting nodes to remedy their construction costs. If all nodes make individual best-response decisions, the system gets trapped in an inefficient situation of high tax level. Here we introduce a decentralized local-consensus selection mechanism which requires nodes to recommend their neighbors of highest local impact as candidate servers, and a node may become a server only if all its non-server neighbors give their assent. We demonstrate that although this mechanism involves only information exchange among neighboring nodes, it leads to socially efficient solutions with tax level approaching the lowest possible value. Our results may help in understanding and improving collective problem-solving in various networked social and robotic systems.

Biology-Inspired Distributed Consensus in Massively-Deployed Sensor Networks

NASA Technical Reports Server (NTRS)

Jones, Kennie H.; Lodding, Kenneth N.; Olariu, Stephan; Wilson, Larry; Xin, Chunsheng

2005-01-01

Promises of ubiquitous control of the physical environment by large-scale wireless sensor networks open avenues for new applications that are expected to redefine the way we live and work. Most of recent research has concentrated on developing techniques for performing relatively simple tasks in small-scale sensor networks assuming some form of centralized control. The main contribution of this work is to propose a new way of looking at large-scale sensor networks, motivated by lessons learned from the way biological ecosystems are organized. Indeed, we believe that techniques used in small-scale sensor networks are not likely to scale to large networks; that such large-scale networks must be viewed as an ecosystem in which the sensors/effectors are organisms whose autonomous actions, based on local information, combine in a communal way to produce global results. As an example of a useful function, we demonstrate that fully distributed consensus can be attained in a scalable fashion in massively deployed sensor networks where individual motes operate based on local information, making local decisions that are aggregated across the network to achieve globally-meaningful effects.

Serving by local consensus in the public service location game

PubMed Central

Sun, Yi-Fan; Zhou, Hai-Jun

2016-01-01

We discuss the issue of distributed and cooperative decision-making in a network game of public service location. Each node of the network can decide to host a certain public service incurring in a construction cost and serving all the neighboring nodes and itself. A pure consumer node has to pay a tax, and the collected tax is evenly distributed to all the hosting nodes to remedy their construction costs. If all nodes make individual best-response decisions, the system gets trapped in an inefficient situation of high tax level. Here we introduce a decentralized local-consensus selection mechanism which requires nodes to recommend their neighbors of highest local impact as candidate servers, and a node may become a server only if all its non-server neighbors give their assent. We demonstrate that although this mechanism involves only information exchange among neighboring nodes, it leads to socially efficient solutions with tax level approaching the lowest possible value. Our results may help in understanding and improving collective problem-solving in various networked social and robotic systems. PMID:27586793

Serving by local consensus in the public service location game

NASA Astrophysics Data System (ADS)

Sun, Yi-Fan; Zhou, Hai-Jun

2016-09-01

We discuss the issue of distributed and cooperative decision-making in a network game of public service location. Each node of the network can decide to host a certain public service incurring in a construction cost and serving all the neighboring nodes and itself. A pure consumer node has to pay a tax, and the collected tax is evenly distributed to all the hosting nodes to remedy their construction costs. If all nodes make individual best-response decisions, the system gets trapped in an inefficient situation of high tax level. Here we introduce a decentralized local-consensus selection mechanism which requires nodes to recommend their neighbors of highest local impact as candidate servers, and a node may become a server only if all its non-server neighbors give their assent. We demonstrate that although this mechanism involves only information exchange among neighboring nodes, it leads to socially efficient solutions with tax level approaching the lowest possible value. Our results may help in understanding and improving collective problem-solving in various networked social and robotic systems.

A Rawlsian Approach to Distribute Responsibilities in Networks

PubMed Central

2009-01-01

Due to their non-hierarchical structure, socio-technical networks are prone to the occurrence of the problem of many hands. In the present paper an approach is introduced in which people’s opinions on responsibility are empirically traced. The approach is based on the Rawlsian concept of Wide Reflective Equilibrium (WRE) in which people’s considered judgments on a case are reflectively weighed against moral principles and background theories, ideally leading to a state of equilibrium. Application of the method to a hypothetical case with an artificially constructed network showed that it is possible to uncover the relevant data to assess a consensus amongst people in terms of their individual WRE. It appeared that the moral background theories people endorse are not predictive for their actual distribution of responsibilities but that they indicate ways of reasoning and justifying outcomes. Two ways of ascribing responsibilities were discerned, corresponding to two requirements of a desirable responsibility distribution: fairness and completeness. Applying the method triggered learning effects, both with regard to conceptual clarification and moral considerations, and in the sense that it led to some convergence of opinions. It is recommended to apply the method to a real engineering case in order to see whether this approach leads to an overlapping consensus on a responsibility distribution which is justifiable to all and in which no responsibilities are left unfulfilled, therewith trying to contribute to the solution of the problem of many hands. PMID:19626463

Coordination of networked systems on digraphs with multiple leaders via pinning control

NASA Astrophysics Data System (ADS)

Chen, Gang; Lewis, Frank L.

2012-02-01

It is well known that achieving consensus among a group of multi-vehicle systems by local distributed control is feasible if and only if all nodes in the communication digraph are reachable from a single (root) node. In this article, we take into account a more general case that the communication digraph of the networked multi-vehicle systems is weakly connected and has two or more zero-in-degree and strongly connected subgraphs, i.e. there are two or more leader groups. Based on the pinning control strategy, the feasibility problem of achieving second-order controlled consensus is studied. At first, a necessary and sufficient condition is given when the topology is fixed. Then the method to design the controller and the rule to choose the pinned vehicles are discussed. The proposed approach allows us to extend several existing results for undirected graphs to directed balanced graphs. A sufficient condition is proposed in the case where the coupling topology is variable. As an illustrative example, a second-order controlled consensus scheme is applied to coordinate the movement of networked multiple mobile robots.

The first shall be last: Selection-driven minority becomes majority

NASA Astrophysics Data System (ADS)

Crokidakis, Nuno; de Oliveira, Paulo Murilo Castro

2014-09-01

Street demonstrations occur across the world. In Rio de Janeiro, in June/July 2013, they reach beyond one million people. A wrathful reader of O Globo, a leading newspaper in the same city, published a letter (Ferreira (2011) [10]) where many social questions are stated and answered Yes or No. These million people of street demonstrations share opinion consensus about a similar set of social issues. But they did not reach this consensus within such a huge numbered meeting. Earlier, they have met in diverse small groups where some of them could be convinced to change their mind by other few fellows. Suddenly, a macroscopic consensus emerges. Many other big manifestations are widespread all over the world in recent times, and are supposed to remain in the future. The interesting questions are: (1) How a binary-option opinion distributed among some population evolves in time, through local changes that occurred within small-group meetings? and (2) Is there some natural selection rule acting upon? Here, we address these questions through an agent-based model.

The Need for Screening, Assessment, and Treatment for Cognitive Dysfunction in Multiple Sclerosis

PubMed Central

Benedict, Ralph H.B.; Gromisch, Elizabeth S.; DeLuca, John

2012-01-01

Cognitive dysfunction is observed in about half of people with multiple sclerosis (MS), and MS health-care professionals face the challenge of screening, assessing, and treating patients for cognitive problems. Considering the inconsistent or limited empirical evidence to assist in this task, a multidisciplinary consensus conference of MS experts, sponsored by the Consortium of Multiple Sclerosis Centers (CMSC), was held on September 24, 2010, to address these issues. Key articles from the literature on these topics were distributed prior to the meeting, and CMSC member professionals were surveyed on clinical practices related to screening, assessment, and treatment for cognitive problems. The purpose of the meeting was threefold: 1) to achieve a multidisciplinary perspective on practices for screening, monitoring, evaluating, and treating MS patients for cognitive problems; 2) to propose consensus candidate measures for screening and/or monitoring for cognitive problems in MS that neurologists or nurses might administer on a regular basis; and 3) to propose consensus treatment approaches from a multidisciplinary perspective. This article summarizes the conclusions of the conference participants and provides preliminary suggestions for screening and brief assessment. PMID:24453735

Phenomenology and classification of dystonia: a consensus update

PubMed Central

Albanese, Alberto; Bhatia, Kailash; Bressman, Susan B.; DeLong, Mahlon R.; Fahn, Stanley; Fung, Victor S.C.; Hallett, Mark; Jankovic, Joseph; Jinnah, H.A.; Klein, Christine; Lang, Anthony E.; Mink, Jonathan W.; Teller, Jan K.

2013-01-01

This report describes the consensus outcome of an international panel consisting of investigators with years of experience in this field that reviewed the definition and classification of dystonia. Agreement was obtained based on a consensus development methodology during three in-person meetings and manuscript review by mail. Dystonia is defined as a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements, postures, or both. Dystonic movements are typically patterned and twisting, and may be tremulous. Dystonia is often initiated or worsened by voluntary action and associated with overflow muscle activation. Dystonia is classified along two axes: clinical characteristics, including age at onset, body distribution, temporal pattern and associated features (additional movement disorders or neurological features), and etiology, which includes nervous system pathology and inheritance. The clinical characteristics fall into several specific dystonia syndromes that help to guide diagnosis and treatment. We provide here a new general definition of dystonia and propose a new classification. We encourage clinicians and researchers to use these innovative definition and classification and test them in the clinical setting on a variety of patients with dystonia. PMID:23649720

Identifying Best Practices in the Dissemination of Intelligence to First Responders in the Fire and EMS Services

DTIC Science & Technology

2010-09-01

claim that a daily brief may tend to desensitize the average first responder and they may not read it regularly. The consensus was that a weekly...they risked becoming ineffective and could lead to desensitization to the information provided. 41 Figure 6. Responses to Question 5...information sharing between fire service organizations. State fire chiefs associations, in collaboration with the FSIE, should advertise the benefits of

A consensus genetic map of cowpea [Vigna unguiculata (L) Walp.] and synteny based on EST-derived SNPs.

PubMed

Muchero, Wellington; Diop, Ndeye N; Bhat, Prasanna R; Fenton, Raymond D; Wanamaker, Steve; Pottorff, Marti; Hearne, Sarah; Cisse, Ndiaga; Fatokun, Christian; Ehlers, Jeffrey D; Roberts, Philip A; Close, Timothy J

2009-10-27

Consensus genetic linkage maps provide a genomic framework for quantitative trait loci identification, map-based cloning, assessment of genetic diversity, association mapping, and applied breeding in marker-assisted selection schemes. Among "orphan crops" with limited genomic resources such as cowpea [Vigna unguiculata (L.) Walp.] (2n = 2x = 22), the use of transcript-derived SNPs in genetic maps provides opportunities for automated genotyping and estimation of genome structure based on synteny analysis. Here, we report the development and validation of a high-throughput EST-derived SNP assay for cowpea, its application in consensus map building, and determination of synteny to reference genomes. SNP mining from 183,118 ESTs sequenced from 17 cDNA libraries yielded approximately 10,000 high-confidence SNPs from which an Illumina 1,536-SNP GoldenGate genotyping array was developed and applied to 741 recombinant inbred lines from six mapping populations. Approximately 90% of the SNPs were technically successful, providing 1,375 dependable markers. Of these, 928 were incorporated into a consensus genetic map spanning 680 cM with 11 linkage groups and an average marker distance of 0.73 cM. Comparison of this cowpea genetic map to reference legumes, soybean (Glycine max) and Medicago truncatula, revealed extensive macrosynteny encompassing 85 and 82%, respectively, of the cowpea map. Regions of soybean genome duplication were evident relative to the simpler diploid cowpea. Comparison with Arabidopsis revealed extensive genomic rearrangement with some conserved microsynteny. These results support evolutionary closeness between cowpea and soybean and identify regions for synteny-based functional genomics studies in legumes.

[Materiality Analysis of Health Plans Based on Stakeholder Engagement and the Issues Included at ISO 26000:2010].

PubMed

Moyano Santiago, Miguel Angel; Rivera Lirio, Juana María

2017-01-18

Health plans of the Spanish autonomous communities can incorporate sustainable development criteria in its development. There have been no analysis or proposals about development and indicators. The goal is to add a contribution to help build better health plans aimed at sustainable development and help to manage economic, social and environmental impacts of health systems criteria. We used a variation of the RAND/UCLA or modified Delphi technique method. The process consisted of a bibliographical and context matters and issues related to health and social responsibility analysis based on ISO 26000: 2010. A survey by deliberately to a selection of 70 expert members of the identified stakeholders was carried out and a discussion group was held to determine the consensus on the issues addressed in the survey sample. The research was conducted in 2015. From the literature review 33 health issues included in ISO 26000:2010 were obtained. 7 survey proved relevant high consensus, 8 relevance and average consensus and 18 with less relevance and high level of dissent. The expert group excluded 4 of the 18 subjects with less consensus. 29 issues included 33 at work, divided into 7 subjects contained in the guide ISO 26000 of social responsibility, were relevant stakeholders regarding possible inclusion in health plans. Considering the direct relationship published by ISO (International Organization for Standardization) among the issues ISO 26000 and the economic, social and environmental indicators in GRI (Global Reporting Initiative) in its G4 version, a panel with monitoring indicators related to relevant issues were elaborated.

A Kolmogorov-Smirnov test for the molecular clock based on Bayesian ensembles of phylogenies

PubMed Central

Antoneli, Fernando; Passos, Fernando M.; Lopes, Luciano R.

2018-01-01

Divergence date estimates are central to understand evolutionary processes and depend, in the case of molecular phylogenies, on tests of molecular clocks. Here we propose two non-parametric tests of strict and relaxed molecular clocks built upon a framework that uses the empirical cumulative distribution (ECD) of branch lengths obtained from an ensemble of Bayesian trees and well known non-parametric (one-sample and two-sample) Kolmogorov-Smirnov (KS) goodness-of-fit test. In the strict clock case, the method consists in using the one-sample Kolmogorov-Smirnov (KS) test to directly test if the phylogeny is clock-like, in other words, if it follows a Poisson law. The ECD is computed from the discretized branch lengths and the parameter λ of the expected Poisson distribution is calculated as the average branch length over the ensemble of trees. To compensate for the auto-correlation in the ensemble of trees and pseudo-replication we take advantage of thinning and effective sample size, two features provided by Bayesian inference MCMC samplers. Finally, it is observed that tree topologies with very long or very short branches lead to Poisson mixtures and in this case we propose the use of the two-sample KS test with samples from two continuous branch length distributions, one obtained from an ensemble of clock-constrained trees and the other from an ensemble of unconstrained trees. Moreover, in this second form the test can also be applied to test for relaxed clock models. The use of a statistically equivalent ensemble of phylogenies to obtain the branch lengths ECD, instead of one consensus tree, yields considerable reduction of the effects of small sample size and provides a gain of power. PMID:29300759

Distributed Optimization for a Class of Nonlinear Multiagent Systems With Disturbance Rejection.

PubMed

Wang, Xinghu; Hong, Yiguang; Ji, Haibo

2016-07-01

The paper studies the distributed optimization problem for a class of nonlinear multiagent systems in the presence of external disturbances. To solve the problem, we need to achieve the optimal multiagent consensus based on local cost function information and neighboring information and meanwhile to reject local disturbance signals modeled by an exogenous system. With convex analysis and the internal model approach, we propose a distributed optimization controller for heterogeneous and nonlinear agents in the form of continuous-time minimum-phase systems with unity relative degree. We prove that the proposed design can solve the exact optimization problem with rejecting disturbances.

Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks

PubMed Central

Artuñedo, Antonio; del Toro, Raúl M.; Haber, Rodolfo E.

2017-01-01

Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller (TLC) network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks. PMID:28445398

Finite-Horizon H∞ Consensus Control of Time-Varying Multiagent Systems With Stochastic Communication Protocol.

PubMed

Zou, Lei; Wang, Zidong; Gao, Huijun; Alsaadi, Fuad E

2017-03-31

This paper is concerned with the distributed H∞ consensus control problem for a discrete time-varying multiagent system with the stochastic communication protocol (SCP). A directed graph is used to characterize the communication topology of the multiagent network. The data transmission between each agent and the neighboring ones is implemented via a constrained communication channel where only one neighboring agent is allowed to transmit data at each time instant. The SCP is applied to schedule the signal transmission of the multiagent system. A sequence of random variables is utilized to capture the scheduling behavior of the SCP. By using the mapping technology combined with the Hadamard product, the closed-loop multiagent system is modeled as a time-varying system with a stochastic parameter matrix. The purpose of the addressed problem is to design a cooperative controller for each agent such that, for all probabilistic scheduling behaviors, the H∞ consensus performance is achieved over a given finite horizon for the closed-loop multiagent system. A necessary and sufficient condition is derived to ensure the H∞ consensus performance based on the completing squares approach and the stochastic analysis technique. Then, the controller parameters are obtained by solving two coupled backward recursive Riccati difference equations. Finally, a numerical example is given to illustrate the effectiveness of the proposed controller design scheme.

Consensus-based training and assessment model for general surgery.

PubMed

Szasz, P; Louridas, M; de Montbrun, S; Harris, K A; Grantcharov, T P

2016-05-01

Surgical education is becoming competency-based with the implementation of in-training milestones. Training guidelines should reflect these changes and determine the specific procedures for such milestone assessments. This study aimed to develop a consensus view regarding operative procedures and tasks considered appropriate for junior and senior trainees, and the procedures that can be used as technical milestone assessments for trainee progression in general surgery. A Delphi process was followed where questionnaires were distributed to all 17 Canadian general surgery programme directors. Items were ranked on a 5-point Likert scale, with consensus defined as Cronbach's α of at least 0·70. Items rated 4 or above on the 5-point Likert scale by 80 per cent of the programme directors were included in the models. Two Delphi rounds were completed, with 14 programme directors taking part in round one and 11 in round two. The overall consensus was high (Cronbach's α = 0·98). The training model included 101 unique procedures and tasks, 24 specific to junior trainees, 68 specific to senior trainees, and nine appropriate to all. The assessment model included four procedures. A system of operative procedures and tasks for junior- and senior-level trainees has been developed along with an assessment model for trainee progression. These can be used as milestones in competency-based assessments. © 2016 BJS Society Ltd Published by John Wiley & Sons Ltd.

Consensus-Based Cooperative Control Based on Pollution Sensing and Traffic Information for Urban Traffic Networks.

PubMed

Artuñedo, Antonio; Del Toro, Raúl M; Haber, Rodolfo E

2017-04-26

Nowadays many studies are being conducted to develop solutions for improving the performance of urban traffic networks. One of the main challenges is the necessary cooperation among different entities such as vehicles or infrastructure systems and how to exploit the information available through networks of sensors deployed as infrastructures for smart cities. In this work an algorithm for cooperative control of urban subsystems is proposed to provide a solution for mobility problems in cities. The interconnected traffic lights controller ( TLC ) network adapts traffic lights cycles, based on traffic and air pollution sensory information, in order to improve the performance of urban traffic networks. The presence of air pollution in cities is not only caused by road traffic but there are other pollution sources that contribute to increase or decrease the pollution level. Due to the distributed and heterogeneous nature of the different components involved, a system of systems engineering approach is applied to design a consensus-based control algorithm. The designed control strategy contains a consensus-based component that uses the information shared in the network for reaching a consensus in the state of TLC network components. Discrete event systems specification is applied for modelling and simulation. The proposed solution is assessed by simulation studies with very promising results to deal with simultaneous responses to both pollution levels and traffic flows in urban traffic networks.

Pesticide applicators questionnaire content validation: A fuzzy delphi method.

PubMed

Manakandan, S K; Rosnah, I; Mohd Ridhuan, J; Priya, R

2017-08-01

The most crucial step in forming a set of survey questionnaire is deciding the appropriate items in a construct. Retaining irrelevant items and removing important items will certainly mislead the direction of a particular study. This article demonstrates Fuzzy Delphi method as one of the scientific analysis technique to consolidate consensus agreement within a panel of experts pertaining to each item's appropriateness. This method reduces the ambiguity, diversity, and discrepancy of the opinions among the experts hence enhances the quality of the selected items. The main purpose of this study was to obtain experts' consensus on the suitability of the preselected items on the questionnaire. The panel consists of sixteen experts from the Occupational and Environmental Health Unit of Ministry of Health, Vector-borne Disease Control Unit of Ministry of Health and Occupational and Safety Health Unit of both public and private universities. A set of questionnaires related to noise and chemical exposure were compiled based on the literature search. There was a total of six constructs with 60 items in which three constructs for knowledge, attitude, and practice of noise exposure and three constructs for knowledge, attitude, and practice of chemical exposure. The validation process replicated recent Fuzzy Delphi method that using a concept of Triangular Fuzzy Numbers and Defuzzification process. A 100% response rate was obtained from all the sixteen experts with an average Likert scoring of four to five. Post FDM analysis, the first prerequisite was fulfilled with a threshold value (d) ≤ 0.2, hence all the six constructs were accepted. For the second prerequisite, three items (21%) from noise-attitude construct and four items (40%) from chemical-practice construct had expert consensus lesser than 75%, which giving rise to about 12% from the total items in the questionnaire. The third prerequisite was used to rank the items within the constructs by calculating the average fuzzy numbers. The seven items which did not fulfill the second prerequisite similarly had lower ranks during the analysis, therefore those items were discarded from the final draft. Post FDM analysis, the experts' consensus on the suitability of the pre-selected items on the questionnaire set were obtained, hence it is now ready for further construct validation process.

A consensus embedding approach for segmentation of high resolution in vivo prostate magnetic resonance imagery

NASA Astrophysics Data System (ADS)

Viswanath, Satish; Rosen, Mark; Madabhushi, Anant

2008-03-01

Current techniques for localization of prostatic adenocarcinoma (CaP) via blinded trans-rectal ultrasound biopsy are associated with a high false negative detection rate. While high resolution endorectal in vivo Magnetic Resonance (MR) prostate imaging has been shown to have improved contrast and resolution for CaP detection over ultrasound, similarity in intensity characteristics between benign and cancerous regions on MR images contribute to a high false positive detection rate. In this paper, we present a novel unsupervised segmentation method that employs manifold learning via consensus schemes for detection of cancerous regions from high resolution 1.5 Tesla (T) endorectal in vivo prostate MRI. A significant contribution of this paper is a method to combine multiple weak, lower-dimensional representations of high dimensional feature data in a way analogous to classifier ensemble schemes, and hence create a stable and accurate reduced dimensional representation. After correcting for MR image intensity artifacts, such as bias field inhomogeneity and intensity non-standardness, our algorithm extracts over 350 3D texture features at every spatial location in the MR scene at multiple scales and orientations. Non-linear dimensionality reduction schemes such as Locally Linear Embedding (LLE) and Graph Embedding (GE) are employed to create multiple low dimensional data representations of this high dimensional texture feature space. Our novel consensus embedding method is used to average object adjacencies from within the multiple low dimensional projections so that class relationships are preserved. Unsupervised consensus clustering is then used to partition the objects in this consensus embedding space into distinct classes. Quantitative evaluation on 18 1.5 T prostate MR data against corresponding histology obtained from the multi-site ACRIN trials show a sensitivity of 92.65% and a specificity of 82.06%, which suggests that our method is successfully able to detect suspicious regions in the prostate.

Development of the first consensus genetic map of intermediate wheatgrass (Thinopyrum intermedium) using genotyping-by-sequencing.

PubMed

Kantarski, Traci; Larson, Steve; Zhang, Xiaofei; DeHaan, Lee; Borevitz, Justin; Anderson, James; Poland, Jesse

2017-01-01

Development of the first consensus genetic map of intermediate wheatgrass gives insight into the genome and tools for molecular breeding. Intermediate wheatgrass (Thinopyrum intermedium) has been identified as a candidate for domestication and improvement as a perennial grain, forage, and biofuel crop and is actively being improved by several breeding programs. To accelerate this process using genomics-assisted breeding, efficient genotyping methods and genetic marker reference maps are needed. We present here the first consensus genetic map for intermediate wheatgrass (IWG), which confirms the species' allohexaploid nature (2n = 6x = 42) and homology to Triticeae genomes. Genotyping-by-sequencing was used to identify markers that fit expected segregation ratios and construct genetic maps for 13 heterogeneous parents of seven full-sib families. These maps were then integrated using a linear programming method to produce a consensus map with 21 linkage groups containing 10,029 markers, 3601 of which were present in at least two populations. Each of the 21 linkage groups contained between 237 and 683 markers, cumulatively covering 5061 cM (2891 cM--Kosambi) with an average distance of 0.5 cM between each pair of markers. Through mapping the sequence tags to the diploid (2n = 2x = 14) barley reference genome, we observed high colinearity and synteny between these genomes, with three homoeologous IWG chromosomes corresponding to each of the seven barley chromosomes, and mapped translocations that are known in the Triticeae. The consensus map is a valuable tool for wheat breeders to map important disease-resistance genes within intermediate wheatgrass. These genomic tools can help lead to rapid improvement of IWG and development of high-yielding cultivars of this perennial grain that would facilitate the sustainable intensification of agricultural systems.

Fine-tuning structural RNA alignments in the twilight zone.

PubMed

Bremges, Andreas; Schirmer, Stefanie; Giegerich, Robert

2010-04-30

A widely used method to find conserved secondary structure in RNA is to first construct a multiple sequence alignment, and then fold the alignment, optimizing a score based on thermodynamics and covariance. This method works best around 75% sequence similarity. However, in a "twilight zone" below 55% similarity, the sequence alignment tends to obscure the covariance signal used in the second phase. Therefore, while the overall shape of the consensus structure may still be found, the degree of conservation cannot be estimated reliably. Based on a combination of available methods, we present a method named planACstar for improving structure conservation in structural alignments in the twilight zone. After constructing a consensus structure by alignment folding, planACstar abandons the original sequence alignment, refolds the sequences individually, but consistent with the consensus, aligns the structures, irrespective of sequence, by a pure structure alignment method, and derives an improved sequence alignment from the alignment of structures, to be re-submitted to alignment folding, etc.. This circle may be iterated as long as structural conservation improves, but normally, one step suffices. Employing the tools ClustalW, RNAalifold, and RNAforester, we find that for sequences with 30-55% sequence identity, structural conservation can be improved by 10% on average, with a large variation, measured in terms of RNAalifold's own criterion, the structure conservation index.

Quantifying catchment water balances and their uncertainties by expert elicitation

NASA Astrophysics Data System (ADS)

Sebok, Eva; Refsgaard, Jens Christian; Warmink, Jord J.; Stisen, Simon; Høgh Jensen, Karsten

2017-04-01

The increasing demand on water resources necessitates a more responsible and sustainable water management requiring a thorough understanding of hydrological processes both on small scale and on catchment scale. On catchment scale, the characterization of hydrological processes is often carried out by calculating a water balance based on the principle of mass conservation in hydrological fluxes. Assuming a perfect water balance closure and estimating one of these fluxes as a residual of the water balance is a common practice although this estimate will contain uncertainties related to uncertainties in the other components. Water balance closure on the catchment scale is also an issue in Denmark, thus, it was one of the research objectives of the HOBE hydrological observatory, that has been collecting data in the Skjern river catchment since 2008. Water balance components in the 1050 km2 Ahlergaarde catchment and the nested 120 km2 Holtum catchment, located in the glacial outwash plan of the Skjern catchment, were estimated using a multitude of methods. As the collected data enables the complex assessment of uncertainty of both the individual water balance components and catchment-scale water balances, the expert elicitation approach was chosen to integrate the results of the hydrological observatory. This approach relies on the subjective opinion of experts whose available knowledge and experience about the subject allows to integrate complex information from multiple sources. In this study 35 experts were involved in a multi-step elicitation process with the aim of (1) eliciting average annual values of water balance components for two nested catchments and quantifying the contribution of different sources of uncertainties to the total uncertainty in these average annual estimates; (2) calculating water balances for two catchments by reaching consensus among experts interacting in form of group discussions. To address the complex problem of water balance closure, the water balance was separated into five components: precipitation, evapotranspiration, surface runoff, recharge and subsurface outflow. During the study, experts first participated in individual interviews where they gave their opinion on the probability distribution of their water balance component of interest. The average annual values and uncertainty of water balance components and catchment-scale water balances were obtained at a later stage by reaching consensus during group discussions. The obtained water balance errors for the Ahlergaarde catchment and the Holtum catchment were -5 and -62 mm/yr, respectively, with an uncertainty of 66 and 86 mm/yr, respectively. As an advantage of the expert elicitation, drawing on the intuitive experience and capabilities of experts to assess complex, site-specific problems, not only the uncertainty of the water balance error was quantified, but the uncertainty of individual water balance components as well.

Role of noise and agents’ convictions on opinion spreading in a three-state voter-like model

NASA Astrophysics Data System (ADS)

Crokidakis, Nuno

2013-07-01

In this work we study opinion formation in a voter-like model defined on a square lattice of linear size L. The agents may be in three different states, representing any public debate with three choices (yes, no, undecided). We consider heterogeneous agents that have different convictions about their opinions. These convictions limit the capacity of persuasion of the individuals during the interactions. Moreover, there is a noise p that represents the probability of an individual spontaneously changing his opinion to the undecided state. Our simulations suggest that the system reaches stationary states for all values of p, with consensus states occurring only for the noiseless case p = 0. In this case, the relaxation times are distributed according to a log-normal function, with the average value τ growing with the lattice size as τ ∼ Lα, where α ≈ 0.9. We found a threshold value p* ≈ 0.9 above which the stationary fraction of undecided agents is greater than the fraction of decided ones. We also study the consequences of the presence of external effects in the system, which models the influence of mass media on opinion formation.

Does Hunger Contribute to Socioeconomic Gradients in Behavior?

PubMed Central

Nettle, Daniel

2017-01-01

Recent research has uncovered many examples of socioeconomic gradients in behavior and psychological states. As yet there is no theoretical consensus on the nature of the causal processes that produce these gradients. Here, I present the hunger hypothesis, namely the claim that part of the reason that people of lower socioeconomic position behave and feel as they do is that they are relatively often hungry. The hunger hypothesis applies in particular to impulsivity-hyperactivity, irritability-aggression, anxiety, and persistent narcotic use, all of which have been found to show socioeconomic gradients. I review multiple lines of evidence showing that hunger produces strong increases in these outcomes. I also review the literatures on food insufficiency and food insecurity to show that, within affluent societies, the poor experience a substantial burden of hunger, despite obtaining sufficient or excess calories on average. This leads to the distinctive prediction that hunger is an important mediator of the relationships between socioeconomic variables and the behavioral/psychological outcomes. This approach has a number of far-reaching implications, not least that some behavioral and psychological differences between social groups, though persistent under current economic arrangements, are potentially highly reversible with changes to the distribution of financial resources and food. PMID:28344567

A Framework for Multi-Stakeholder Decision-Making and ...

EPA Pesticide Factsheets

This contribution describes the implementation of the conditional-value-at-risk (CVaR) metric to create a general multi-stakeholder decision-making framework. It is observed that stakeholder dissatisfactions (distance to their individual ideal solutions) can be interpreted as random variables. We thus shape the dissatisfaction distribution and find an optimal compromise solution by solving a CVaR minimization problem parameterized in the probability level. This enables us to generalize multi-stakeholder settings previously proposed in the literature that minimizes average and worst-case dissatisfactions. We use the concept of the CVaR norm to give a geometric interpretation to this problem and use the properties of this norm to prove that the CVaR minimization problem yields Pareto optimal solutions for any choice of the probability level. We discuss a broad range of potential applications of the framework. We demonstrate the framework in a bio-waste processing facility location case study, where we seek compromise solutions (facility locations) that balance stakeholder priorities on transportation, safety, water quality, and capital costs. This conference presentation abstract explains a new decision-making framework that computes compromise solution alternatives (reach consensus) by mitigating dissatisfactions among stakeholders as needed for SHC Decision Science and Support Tools project.

Single Marker and Haplotype-Based Association Analysis of Semolina and Pasta Colour in Elite Durum Wheat Breeding Lines Using a High-Density Consensus Map.

PubMed

N'Diaye, Amidou; Haile, Jemanesh K; Cory, Aron T; Clarke, Fran R; Clarke, John M; Knox, Ron E; Pozniak, Curtis J

2017-01-01

Association mapping is usually performed by testing the correlation between a single marker and phenotypes. However, because patterns of variation within genomes are inherited as blocks, clustering markers into haplotypes for genome-wide scans could be a worthwhile approach to improve statistical power to detect associations. The availability of high-density molecular data allows the possibility to assess the potential of both approaches to identify marker-trait associations in durum wheat. In the present study, we used single marker- and haplotype-based approaches to identify loci associated with semolina and pasta colour in durum wheat, the main objective being to evaluate the potential benefits of haplotype-based analysis for identifying quantitative trait loci. One hundred sixty-nine durum lines were genotyped using the Illumina 90K Infinium iSelect assay, and 12,234 polymorphic single nucleotide polymorphism (SNP) markers were generated and used to assess the population structure and the linkage disequilibrium (LD) patterns. A total of 8,581 SNPs previously localized to a high-density consensus map were clustered into 406 haplotype blocks based on the average LD distance of 5.3 cM. Combining multiple SNPs into haplotype blocks increased the average polymorphism information content (PIC) from 0.27 per SNP to 0.50 per haplotype. The haplotype-based analysis identified 12 loci associated with grain pigment colour traits, including the five loci identified by the single marker-based analysis. Furthermore, the haplotype-based analysis resulted in an increase of the phenotypic variance explained (50.4% on average) and the allelic effect (33.7% on average) when compared to single marker analysis. The presence of multiple allelic combinations within each haplotype locus offers potential for screening the most favorable haplotype series and may facilitate marker-assisted selection of grain pigment colour in durum wheat. These results suggest a benefit of haplotype-based analysis over single marker analysis to detect loci associated with colour traits in durum wheat.

Multi-agent systems and their applications

DOE PAGES

Xie, Jing; Liu, Chen-Ching

2017-07-14

The number of distributed energy components and devices continues to increase globally. As a result, distributed control schemes are desirable for managing and utilizing these devices, together with the large amount of data. In recent years, agent-based technology becomes a powerful tool for engineering applications. As a computational paradigm, multi agent systems (MASs) provide a good solution for distributed control. Here in this paper, MASs and applications are discussed. A state-of-the-art literature survey is conducted on the system architecture, consensus algorithm, and multi-agent platform, framework, and simulator. In addition, a distributed under-frequency load shedding (UFLS) scheme is proposed using themore » MAS. Simulation results for a case study are presented. The future of MASs is discussed in the conclusion.« less

Multi-agent systems and their applications

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

Xie, Jing; Liu, Chen-Ching

The number of distributed energy components and devices continues to increase globally. As a result, distributed control schemes are desirable for managing and utilizing these devices, together with the large amount of data. In recent years, agent-based technology becomes a powerful tool for engineering applications. As a computational paradigm, multi agent systems (MASs) provide a good solution for distributed control. Here in this paper, MASs and applications are discussed. A state-of-the-art literature survey is conducted on the system architecture, consensus algorithm, and multi-agent platform, framework, and simulator. In addition, a distributed under-frequency load shedding (UFLS) scheme is proposed using themore » MAS. Simulation results for a case study are presented. The future of MASs is discussed in the conclusion.« less

Ring-averaged ion velocity distribution function probe for laboratory magnetized plasma experiment

NASA Astrophysics Data System (ADS)

Kawamori, Eiichirou; Chen, Jinting; Lin, Chiahsuan; Lee, Zongmau

2017-10-01

Ring-averaged velocity distribution function of ions at a fixed guiding center position is a fundamental quantity in the gyrokinetic plasma physics. We have developed a diagnostic tool for the ring averaged velocity distribution function of ions for laboratory plasma experiments, which is named as the ring-averaged ion distribution function probe (RIDFP). The RIDFP is a set of ion collectors for different velocities. It is designed to be immersed in magnetized plasmas and achieves momentum selection of incoming ions by the selection of the ion Larmor radii. To nullify the influence of the sheath potential surrounding the RIDFP on the orbits of the incoming ions, the electrostatic potential of the RIDFP body is automatically adjusted to coincide with the space potential of the target plasma with the use of an emissive probe and a voltage follower. The developed RIDFP successfully measured the equilibrium ring-averaged velocity distribution function of a laboratory magnetized plasma, which was in accordance with the Maxwellian distribution having an ion temperature of 0.2 eV.

Ring-averaged ion velocity distribution function probe for laboratory magnetized plasma experiment.

PubMed

Kawamori, Eiichirou; Chen, Jinting; Lin, Chiahsuan; Lee, Zongmau

2017-10-01

Ring-averaged velocity distribution function of ions at a fixed guiding center position is a fundamental quantity in the gyrokinetic plasma physics. We have developed a diagnostic tool for the ring averaged velocity distribution function of ions for laboratory plasma experiments, which is named as the ring-averaged ion distribution function probe (RIDFP). The RIDFP is a set of ion collectors for different velocities. It is designed to be immersed in magnetized plasmas and achieves momentum selection of incoming ions by the selection of the ion Larmor radii. To nullify the influence of the sheath potential surrounding the RIDFP on the orbits of the incoming ions, the electrostatic potential of the RIDFP body is automatically adjusted to coincide with the space potential of the target plasma with the use of an emissive probe and a voltage follower. The developed RIDFP successfully measured the equilibrium ring-averaged velocity distribution function of a laboratory magnetized plasma, which was in accordance with the Maxwellian distribution having an ion temperature of 0.2 eV.

Quantification of Emphysema: A Bullae Distribution Based Approach

NASA Astrophysics Data System (ADS)

Tan, Kok Liang; Tanaka, Toshiyuki; Nakamura, Hidetoshi; Shirahata, Toru; Sugiura, Hiroaki

Computed tomography (CT)-based quantifications of emphysema encompass, and are not limited to, the ratio of the low-attenuation area, the bullae size, and the distribution of bullae in the lung. The standard CT-based emphysema describing indices include the mean lung density, the percentage of area of low attenuation [the pixel index (PI)] and the bullae index (BI). These standard emphysema describing indices are not expressive for describing the distribution of bullae in the lung. Consequently, the goal of this paper is to present a new emphysema describing index, the bullae congregation index (BCI), that describes whether bullae gather in a specific area of the lung and form a nearly single mass, and if so, how dense the mass of bullae is in the lung. BCI ranges from zero to ten corresponding to sparsely distributed bullae to densely distributed bullae. BCI is calculated based on the relative distance between every pair of bullae in the lung. The bullae pair distances are sorted into 200 distance classes. A smaller distance class corresponds to a closer proximity between the bullae. BCI is derived by calculating the percentage of the area of bullae in the lung that are separated by a certain distance class. Four bullae congregation classes are defined based on BCI. We evaluate BCI using 114 CT images that are hand-annotated by a radiologist into four bullae congregation classes. The average four-class classification accuracy of BCI is 88.21%. BCI correlates better than PI, BI and other standard statistical dispersion based methods with the radiological consensus-classified bullae congregation class.While BCI is not a specific index for indicating emphysema severity, it complements the existing set of emphysema describing indices to facilitate a more thorough knowledge about the emphysematous conditions in the lung. BCI is especially useful when it comes to comparing the distribution of bullae for cases with approximately the same PI, BI or PI and BI. BCI is easy to interpret and potentitally helpful for the purpose of comparative study and progressive monitoring of emphysema.

A High Density Consensus Genetic Map of Tetraploid Cotton That Integrates Multiple Component Maps through Molecular Marker Redundancy Check

PubMed Central

Blenda, Anna; Fang, David D.; Rami, Jean-François; Garsmeur, Olivier; Luo, Feng; Lacape, Jean-Marc

2012-01-01

A consensus genetic map of tetraploid cotton was constructed using six high-density maps and after the integration of a sequence-based marker redundancy check. Public cotton SSR libraries (17,343 markers) were curated for sequence redundancy using 90% as a similarity cutoff. As a result, 20% of the markers (3,410) could be considered as redundant with some other markers. The marker redundancy information had been a crucial part of the map integration process, in which the six most informative interspecific Gossypium hirsutum×G. barbadense genetic maps were used for assembling a high density consensus (HDC) map for tetraploid cotton. With redundant markers being removed, the HDC map could be constructed thanks to the sufficient number of collinear non-redundant markers in common between the component maps. The HDC map consists of 8,254 loci, originating from 6,669 markers, and spans 4,070 cM, with an average of 2 loci per cM. The HDC map presents a high rate of locus duplications, as 1,292 markers among the 6,669 were mapped in more than one locus. Two thirds of the duplications are bridging homoeologous AT and DT chromosomes constitutive of allopolyploid cotton genome, with an average of 64 duplications per AT/DT chromosome pair. Sequences of 4,744 mapped markers were used for a mutual blast alignment (BBMH) with the 13 major scaffolds of the recently released Gossypium raimondii genome indicating high level of homology between the diploid D genome and the tetraploid cotton genetic map, with only a few minor possible structural rearrangements. Overall, the HDC map will serve as a valuable resource for trait QTL comparative mapping, map-based cloning of important genes, and better understanding of the genome structure and evolution of tetraploid cotton. PMID:23029214

Coordination and standardization of federal sedimentation activities

USGS Publications Warehouse

Glysson, G. Douglas; Gray, John R.

1997-01-01

- precipitation information critical to water resources management. Memorandum M-92-01 covers primarily freshwater bodies and includes activities, such as "development and distribution of consensus standards, field-data collection and laboratory analytical methods, data processing and interpretation, data-base management, quality control and quality assurance, and water- resources appraisals, assessments, and investigations." Research activities are not included.

A Participatory Modeling Application of a Distributed Hydrologic Model in Nuevo Leon, Mexico for the 2010 Hurricane Alex Flood Event

NASA Astrophysics Data System (ADS)

Baish, A. S.; Vivoni, E. R.; Payan, J. G.; Robles-Morua, A.; Basile, G. M.

2011-12-01

A distributed hydrologic model can help bring consensus among diverse stakeholders in regional flood planning by producing quantifiable sets of alternative futures. This value is acute in areas with high uncertainties in hydrologic conditions and sparse observations. In this study, we conduct an application of the Triangulated Irregular Network (TIN)-based Real-time Integrated Basin Simulator (tRIBS) in the Santa Catarina basin of Nuevo Leon, Mexico, where Hurricane Alex in July 2010 led to catastrophic flooding of the capital city of Monterrey. Distributed model simulations utilize best-available information on the regional topography, land cover, and soils obtained from Mexican government agencies or analysis of remotely-sensed imagery from MODIS and ASTER. Furthermore, we developed meteorological forcing for the flood event based on multiple data sources, including three local gauge networks, satellite-based estimates from TRMM and PERSIANN, and the North American Land Data Assimilation System (NLDAS). Remotely-sensed data allowed us to quantify rainfall distributions in the upland, rural portions of the Santa Catarina that are sparsely populated and ungauged. Rural areas had significant contributions to the flood event and as a result were considered by stakeholders for flood control measures, including new reservoirs and upland vegetation management. Participatory modeling workshops with the stakeholders revealed a disconnect between urban and rural populations in regard to understanding the hydrologic conditions of the flood event and the effectiveness of existing and potential flood control measures. Despite these challenges, the use of the distributed flood forecasts developed within this participatory framework facilitated building consensus among diverse stakeholders and exploring alternative futures in the basin.

Evaluation of a shortened QIAsymphony DNA extraction protocol for stool samples using a multiplex real-time PCR for the detection of enteric pathogens.

PubMed

van Zanten, E; Wisselink, G J; Stoll, S; Alvarez, R; Kooistra-Smid, A M D

2011-02-01

A shortened DNA extraction protocol for the QIAsymphony SP was evaluated by quantitative and qualitative comparison of real-time PCR results of 150 co-extracted stool samples. The average ∆Cycle threshold value for positive pathogenic targets was 0.28 Ct. A consensus of 96.91%, with a correlation coefficient of 0.9880 was recorded. Copyright © 2010 Elsevier B.V. All rights reserved.

Learning consensus in adversarial environments

NASA Astrophysics Data System (ADS)

Vamvoudakis, Kyriakos G.; García Carrillo, Luis R.; Hespanha, João. P.

2013-05-01

This work presents a game theory-based consensus problem for leaderless multi-agent systems in the presence of adversarial inputs that are introducing disturbance to the dynamics. Given the presence of enemy components and the possibility of malicious cyber attacks compromising the security of networked teams, a position agreement must be reached by the networked mobile team based on environmental changes. The problem is addressed under a distributed decision making framework that is robust to possible cyber attacks, which has an advantage over centralized decision making in the sense that a decision maker is not required to access information from all the other decision makers. The proposed framework derives three tuning laws for every agent; one associated with the cost, one associated with the controller, and one with the adversarial input.

Survivable algorithms and redundancy management in NASA's distributed computing systems

NASA Technical Reports Server (NTRS)

Malek, Miroslaw

1992-01-01

The design of survivable algorithms requires a solid foundation for executing them. While hardware techniques for fault-tolerant computing are relatively well understood, fault-tolerant operating systems, as well as fault-tolerant applications (survivable algorithms), are, by contrast, little understood, and much more work in this field is required. We outline some of our work that contributes to the foundation of ultrareliable operating systems and fault-tolerant algorithm design. We introduce our consensus-based framework for fault-tolerant system design. This is followed by a description of a hierarchical partitioning method for efficient consensus. A scheduler for redundancy management is introduced, and application-specific fault tolerance is described. We give an overview of our hybrid algorithm technique, which is an alternative to the formal approach given.

Workshop on Treatment of and Postexposure Prophylaxis for Burkholderia pseudomallei and B. mallei Infection, 2010

PubMed Central

Garges, Susan; Aurigemma, Rosemarie; Baccam, Prasith; Blaney, David D.; Cheng, Allen C.; Currie, Bart J.; Dance, David; Gee, Jay E.; Larsen, Joseph; Limmathurotsakul, Direk; Morrow, Meredith G.; Norton, Robert; O’Mara, Elizabeth; Peacock, Sharon J.; Pesik, Nicki; Rogers, L. Paige; Schweizer, Herbert P.; Steinmetz, Ivo; Tan, Gladys; Tan, Patrick; Wiersinga, W. Joost; Wuthiekanun, Vanaporn; Smith, Theresa L.

2012-01-01

The US Public Health Emergency Medical Countermeasures Enterprise convened subject matter experts at the 2010 HHS Burkholderia Workshop to develop consensus recommendations for postexposure prophylaxis against and treatment for Burkholderia pseudomallei and B. mallei infections, which cause melioidosis and glanders, respectively. Drugs recommended by consensus of the participants are ceftazidime or meropenem for initial intensive therapy, and trimethoprim/sulfamethoxazole or amoxicillin/clavulanic acid for eradication therapy. For postexposure prophylaxis, recommended drugs are trimethoprim/sulfamethoxazole or co-amoxiclav. To improve the timely diagnosis of melioidosis and glanders, further development and wide distribution of rapid diagnostic assays were also recommended. Standardized animal models and B. pseudomallei strains are needed for further development of therapeutic options. Training for laboratory technicians and physicians would facilitate better diagnosis and treatment options. PMID:23171644

Workshop on treatment of and postexposure prophylaxis for Burkholderia pseudomallei and B. mallei Infection, 2010.

PubMed

Lipsitz, Rebecca; Garges, Susan; Aurigemma, Rosemarie; Baccam, Prasith; Blaney, David D; Cheng, Allen C; Currie, Bart J; Dance, David; Gee, Jay E; Larsen, Joseph; Limmathurotsakul, Direk; Morrow, Meredith G; Norton, Robert; O'Mara, Elizabeth; Peacock, Sharon J; Pesik, Nicki; Rogers, L Paige; Schweizer, Herbert P; Steinmetz, Ivo; Tan, Gladys; Tan, Patrick; Wiersinga, W Joost; Wuthiekanun, Vanaporn; Smith, Theresa L

2012-12-01

The US Public Health Emergency Medical Countermeasures Enterprise convened subject matter experts at the 2010 HHS Burkholderia Workshop to develop consensus recommendations for postexposure prophylaxis against and treatment for Burkholderia pseudomallei and B. mallei infections, which cause melioidosis and glanders, respectively. Drugs recommended by consensus of the participants are ceftazidime or meropenem for initial intensive therapy, and trimethoprim/sulfamethoxazole or amoxicillin/clavulanic acid for eradication therapy. For postexposure prophylaxis, recommended drugs are trimethoprim/sulfamethoxazole or co-amoxiclav. To improve the timely diagnosis of melioidosis and glanders, further development and wide distribution of rapid diagnostic assays were also recommended. Standardized animal models and B. pseudomallei strains are needed for further development of therapeutic options. Training for laboratory technicians and physicians would facilitate better diagnosis and treatment options.

Source localization of rhythmic ictal EEG activity: a study of diagnostic accuracy following STARD criteria.

PubMed

Beniczky, Sándor; Lantz, Göran; Rosenzweig, Ivana; Åkeson, Per; Pedersen, Birthe; Pinborg, Lars H; Ziebell, Morten; Jespersen, Bo; Fuglsang-Frederiksen, Anders

2013-10-01

Although precise identification of the seizure-onset zone is an essential element of presurgical evaluation, source localization of ictal electroencephalography (EEG) signals has received little attention. The aim of our study was to estimate the accuracy of source localization of rhythmic ictal EEG activity using a distributed source model. Source localization of rhythmic ictal scalp EEG activity was performed in 42 consecutive cases fulfilling inclusion criteria. The study was designed according to recommendations for studies on diagnostic accuracy (STARD). The initial ictal EEG signals were selected using a standardized method, based on frequency analysis and voltage distribution of the ictal activity. A distributed source model-local autoregressive average (LAURA)-was used for the source localization. Sensitivity, specificity, and measurement of agreement (kappa) were determined based on the reference standard-the consensus conclusion of the multidisciplinary epilepsy surgery team. Predictive values were calculated from the surgical outcome of the operated patients. To estimate the clinical value of the ictal source analysis, we compared the likelihood ratios of concordant and discordant results. Source localization was performed blinded to the clinical data, and before the surgical decision. Reference standard was available for 33 patients. The ictal source localization had a sensitivity of 70% and a specificity of 76%. The mean measurement of agreement (kappa) was 0.61, corresponding to substantial agreement (95% confidence interval (CI) 0.38-0.84). Twenty patients underwent resective surgery. The positive predictive value (PPV) for seizure freedom was 92% and the negative predictive value (NPV) was 43%. The likelihood ratio was nine times higher for the concordant results, as compared with the discordant ones. Source localization of rhythmic ictal activity using a distributed source model (LAURA) for the ictal EEG signals selected with a standardized method is feasible in clinical practice and has a good diagnostic accuracy. Our findings encourage clinical neurophysiologists assessing ictal EEGs to include this method in their armamentarium. Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.

Proficiency testing program for the determination of total arsenic, cadmium, and lead in seawater shrimp.

PubMed

Kong, Mei-Fung; Chan, Serena; Wong, Yiu-Chung

2008-01-01

The proficiency testing (PT) program for 97 worldwide laboratories for determining total arsenic, cadmium, and lead in seawater shrimp under the auspices of the Asia-Pacific Laboratory Accreditation Cooperation (APLAC) is discussed. The program is one of the APLAC PT series whose primary purposes are to establish mutual agreement on the equivalence of the operation of APLAC member laboratories and to take corrective actions if testing deficiencies are identified. Pooled data for Cd and Pb were normally distributed with interlaboratory variations of 21.9 and 34.8%, respectively. The corresponding consensus mean values estimated by robust statistics were in good agreement with those obtained in the homogeneity tests. However, a bimodal distribution was observed from the determination of total As, in which 14 out of 74 participants reported much smaller values (0.482-6.4 mg/kg) as compared with the mean values of 60.9 mg/kg in the homogeneity test. The use of consensus mean is known to have significant deviation from the true value in bi- or multimodal distribution. Therefore, the mode value, a better estimate of central tendency, was chosen to assess participants' performance for total As. Estimates of the overall uncertainty from participants varied in this program, and some were recommended to acquire more comprehensive exposure toward important criteria as stipulated in ISO/IEC 17025.

Log-normal distribution from a process that is not multiplicative but is additive.

PubMed

Mouri, Hideaki

2013-10-01

The central limit theorem ensures that a sum of random variables tends to a Gaussian distribution as their total number tends to infinity. However, for a class of positive random variables, we find that the sum tends faster to a log-normal distribution. Although the sum tends eventually to a Gaussian distribution, the distribution of the sum is always close to a log-normal distribution rather than to any Gaussian distribution if the summands are numerous enough. This is in contrast to the current consensus that any log-normal distribution is due to a product of random variables, i.e., a multiplicative process, or equivalently to nonlinearity of the system. In fact, the log-normal distribution is also observable for a sum, i.e., an additive process that is typical of linear systems. We show conditions for such a sum, an analytical example, and an application to random scalar fields such as those of turbulence.

vSDC: a method to improve early recognition in virtual screening when limited experimental resources are available.

PubMed

Chaput, Ludovic; Martinez-Sanz, Juan; Quiniou, Eric; Rigolet, Pascal; Saettel, Nicolas; Mouawad, Liliane

2016-01-01

In drug design, one may be confronted to the problem of finding hits for targets for which no small inhibiting molecules are known and only low-throughput experiments are available (like ITC or NMR studies), two common difficulties encountered in a typical academic setting. Using a virtual screening strategy like docking can alleviate some of the problems and save a considerable amount of time by selecting only top-ranking molecules, but only if the method is very efficient, i.e. when a good proportion of actives are found in the 1-10 % best ranked molecules. The use of several programs (in our study, Gold, Surflex, FlexX and Glide were considered) shows a divergence of the results, which presents a difficulty in guiding the experiments. To overcome this divergence and increase the yield of the virtual screening, we created the standard deviation consensus (SDC) and variable SDC (vSDC) methods, consisting of the intersection of molecule sets from several virtual screening programs, based on the standard deviations of their ranking distributions. SDC allowed us to find hits for two new protein targets by testing only 9 and 11 small molecules from a chemical library of circa 15,000 compounds. Furthermore, vSDC, when applied to the 102 proteins of the DUD-E benchmarking database, succeeded in finding more hits than any of the four isolated programs for 13-60 % of the targets. In addition, when only 10 molecules of each of the 102 chemical libraries were considered, vSDC performed better in the number of hits found, with an improvement of 6-24 % over the 10 best-ranked molecules given by the individual docking programs.Graphical abstractIn drug design, for a given target and a given chemical library, the results obtained with different virtual screening programs are divergent. So how to rationally guide the experimental tests, especially when only a few number of experiments can be made? The variable Standard Deviation Consensus (vSDC) method was developed to answer this issue. Left panel the vSDC principle consists of intersecting molecule sets, chosen on the basis of the standard deviations of their ranking distributions, obtained from various virtual screening programs. In this study Glide, Gold, FlexX and Surflex were used and tested on the 102 targets of the DUD-E database. Right panel Comparison of the average percentage of hits found with vSDC and each of the four programs, when only 10 molecules from each of the 102 chemical libraries of the DUD-E database were considered. On average, vSDC was capable of finding 38 % of the findable hits, against 34 % for Glide, 32 % for Gold, 16 % for FlexX and 14 % for Surflex, showing that with vSDC, it was possible to overcome the unpredictability of the virtual screening results and to improve them.

Comparing Distributions of Environmental Outcomes for Regulatory Environmental Justice Analysis

PubMed Central

Maguire, Kelly; Sheriff, Glenn

2011-01-01

Economists have long been interested in measuring distributional impacts of policy interventions. As environmental justice (EJ) emerged as an ethical issue in the 1970s, the academic literature has provided statistical analyses of the incidence and causes of various environmental outcomes as they relate to race, income, and other demographic variables. In the context of regulatory impacts, however, there is a lack of consensus regarding what information is relevant for EJ analysis, and how best to present it. This paper helps frame the discussion by suggesting a set of questions fundamental to regulatory EJ analysis, reviewing past approaches to quantifying distributional equity, and discussing the potential for adapting existing tools to the regulatory context. PMID:21655146

"WWW.MDTF.ORG": a World Wide Web forum for developing open-architecture, freely distributed, digital teaching file software by participant consensus.

PubMed

Katzman, G L; Morris, D; Lauman, J; Cochella, C; Goede, P; Harnsberger, H R

2001-06-01

To foster a community supported evaluation processes for open-source digital teaching file (DTF) development and maintenance. The mechanisms used to support this process will include standard web browsers, web servers, forum software, and custom additions to the forum software to potentially enable a mediated voting protocol. The web server will also serve as a focal point for beta and release software distribution, which is the desired end-goal of this process. We foresee that www.mdtf.org will provide for widespread distribution of open source DTF software that will include function and interface design decisions from community participation on the website forums.

An international Delphi study examining health promotion and health education in nursing practice, education and policy.

PubMed

Whitehead, Dean

2008-04-01

To arrive at an expert consensus in relation to health promotion and health education constructs as they apply to nursing practice, education and policy. Nursing has often been maligned and criticized, both inside and outside of the profession, for its ability to understand and conduct effective health promotion and health education-related activities. In the absence of an expert-based consensus, nurses may find it difficult to progress beyond the current situation. In the absence of any previously published nursing-related consensus research, this study seeks to fill that knowledge-gap. A two-round Delphi technique via email correspondence. A first-round qualitative questionnaire used open-ended questions for defining health promotion and health education. This was both in general terms and as participants believed these concepts related to the clinical, theoretical (academic/educational) and the policy (political) setting in nursing. Line-by-line qualitative content and thematic analysis of the first-round data generated 13 specific categories. These categories contained 134 statement items. The second-round questionnaire comprised the identified 134 statements. Using a five-point Likert scale (ranging from 1 = strongly disagree to 5 = strongly agree) participants scored and rated their level of agreement/disagreement against the listed items. Data from the second-round was descriptively analysed according to distribution and central tendency measures. An expert consensus was reached on 65 of the original 134 statements. While some minor contradiction was demonstrated, strong consensus emerged around the issues of defining health promotion and health education and the emergence of a wider health promotion and health education role for nursing. No consensus was reached on only one of the 13 identified topic categories - that of 'nurses working with other disciplines and agencies in a health education and health promotion role.' This study provides a hitherto previously absent expert consensus on the current position of health promotion and health education, in nursing and predictions for their future course. Its findings represent an important step for nurses as they seek to become increasingly active and influential within wider health promotion and health education arenas. Relevance to clinical practice. Delphi studies do not necessarily offer indisputable fact. This study, however, with its strong consensus on the majority of original statements is a good indicator as to how nursing experts currently view health promotion and health education constructs. Expert consensus offers a useful form of measure against current and future clinical practice and helps to build a firm foundation for change. Nurses, then, are advised here to refer to the findings presented, that they remain contextually and conceptually clear, as they embark on current and future health promotion-related activities.

Evaluating the construct of triage acuity against a set of reference vignettes developed via modified Delphi method.

PubMed

Twomey, Michèle; Wallis, Lee A; Myers, Jonathan E

2014-07-01

To evaluate the construct of triage acuity as measured by the South African Triage Scale (SATS) against a set of reference vignettes. A modified Delphi method was used to develop a set of reference vignettes. Delphi participants completed a 2-round consensus-building process, and independently assigned triage acuity ratings to 100 written vignettes unaware of the ratings given by others. Triage acuity ratings were summarised for all vignettes, and only those that reached 80% consensus during round 2 were included in the reference set. Triage ratings for the reference vignettes given by two independent experts using the SATS were compared with the ratings given by the international Delphi panel. Measures of sensitivity, specificity, associated percentages for over-triage/under-triage were used to evaluate the construct of triage acuity (as measured by the SATS) by examining the association between the ratings by the two experts and the international panel. On completion of the Delphi process, 42 of the 100 vignettes reached 80% consensus on their acuity rating and made up the reference set. On average, over all acuity levels, sensitivity was 74% (CI 64% to 82%), specificity 92% (CI 87% to 94%), under-triage occurred 14% (CI 8% to 23%) and over-triage 12% (CI 8% to 23%) of the time. The results of this study provide an alternative to evaluating triage scales against the construct of acuity as measured with the SATS. This method of using 80% consensus vignettes may, however, systematically bias the validity estimate towards better performance. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Time for change: a roadmap to guide the implementation of the World Anti-Doping Code 2015

PubMed Central

Dvorak, Jiri; Baume, Norbert; Botré, Francesco; Broséus, Julian; Budgett, Richard; Frey, Walter O; Geyer, Hans; Harcourt, Peter Rex; Ho, Dave; Howman, David; Isola, Victor; Lundby, Carsten; Marclay, François; Peytavin, Annie; Pipe, Andrew; Pitsiladis, Yannis P; Reichel, Christian; Robinson, Neil; Rodchenkov, Grigory; Saugy, Martial; Sayegh, Souheil; Segura, Jordi; Thevis, Mario; Vernec, Alan; Viret, Marjolaine; Vouillamoz, Marc; Zorzoli, Mario

2014-01-01

A medical and scientific multidisciplinary consensus meeting was held from 29 to 30 November 2013 on Anti-Doping in Sport at the Home of FIFA in Zurich, Switzerland, to create a roadmap for the implementation of the 2015 World Anti-Doping Code. The consensus statement and accompanying papers set out the priorities for the antidoping community in research, science and medicine. The participants achieved consensus on a strategy for the implementation of the 2015 World Anti-Doping Code. Key components of this strategy include: (1) sport-specific risk assessment, (2) prevalence measurement, (3) sport-specific test distribution plans, (4) storage and reanalysis, (5) analytical challenges, (6) forensic intelligence, (7) psychological approach to optimise the most deterrent effect, (8) the Athlete Biological Passport (ABP) and confounding factors, (9) data management system (Anti-Doping Administration & Management System (ADAMS), (10) education, (11) research needs and necessary advances, (12) inadvertent doping and (13) management and ethics: biological data. True implementation of the 2015 World Anti-Doping Code will depend largely on the ability to align thinking around these core concepts and strategies. FIFA, jointly with all other engaged International Federations of sports (Ifs), the International Olympic Committee (IOC) and World Anti-Doping Agency (WADA), are ideally placed to lead transformational change with the unwavering support of the wider antidoping community. The outcome of the consensus meeting was the creation of the ad hoc Working Group charged with the responsibility of moving this agenda forward. PMID:24764550

Opinion formation driven by PageRank node influence on directed networks

NASA Astrophysics Data System (ADS)

Eom, Young-Ho; Shepelyansky, Dima L.

2015-10-01

We study a two states opinion formation model driven by PageRank node influence and report an extensive numerical study on how PageRank affects collective opinion formations in large-scale empirical directed networks. In our model the opinion of a node can be updated by the sum of its neighbor nodes' opinions weighted by the node influence of the neighbor nodes at each step. We consider PageRank probability and its sublinear power as node influence measures and investigate evolution of opinion under various conditions. First, we observe that all networks reach steady state opinion after a certain relaxation time. This time scale is decreasing with the heterogeneity of node influence in the networks. Second, we find that our model shows consensus and non-consensus behavior in steady state depending on types of networks: Web graph, citation network of physics articles, and LiveJournal social network show non-consensus behavior while Wikipedia article network shows consensus behavior. Third, we find that a more heterogeneous influence distribution leads to a more uniform opinion state in the cases of Web graph, Wikipedia, and Livejournal. However, the opposite behavior is observed in the citation network. Finally we identify that a small number of influential nodes can impose their own opinion on significant fraction of other nodes in all considered networks. Our study shows that the effects of heterogeneity of node influence on opinion formation can be significant and suggests further investigations on the interplay between node influence and collective opinion in networks.

Time for change: a roadmap to guide the implementation of the World Anti-Doping Code 2015.

PubMed

Dvorak, Jiri; Baume, Norbert; Botré, Francesco; Broséus, Julian; Budgett, Richard; Frey, Walter O; Geyer, Hans; Harcourt, Peter Rex; Ho, Dave; Howman, David; Isola, Victor; Lundby, Carsten; Marclay, François; Peytavin, Annie; Pipe, Andrew; Pitsiladis, Yannis P; Reichel, Christian; Robinson, Neil; Rodchenkov, Grigory; Saugy, Martial; Sayegh, Souheil; Segura, Jordi; Thevis, Mario; Vernec, Alan; Viret, Marjolaine; Vouillamoz, Marc; Zorzoli, Mario

2014-05-01

A medical and scientific multidisciplinary consensus meeting was held from 29 to 30 November 2013 on Anti-Doping in Sport at the Home of FIFA in Zurich, Switzerland, to create a roadmap for the implementation of the 2015 World Anti-Doping Code. The consensus statement and accompanying papers set out the priorities for the antidoping community in research, science and medicine. The participants achieved consensus on a strategy for the implementation of the 2015 World Anti-Doping Code. Key components of this strategy include: (1) sport-specific risk assessment, (2) prevalence measurement, (3) sport-specific test distribution plans, (4) storage and reanalysis, (5) analytical challenges, (6) forensic intelligence, (7) psychological approach to optimise the most deterrent effect, (8) the Athlete Biological Passport (ABP) and confounding factors, (9) data management system (Anti-Doping Administration & Management System (ADAMS), (10) education, (11) research needs and necessary advances, (12) inadvertent doping and (13) management and ethics: biological data. True implementation of the 2015 World Anti-Doping Code will depend largely on the ability to align thinking around these core concepts and strategies. FIFA, jointly with all other engaged International Federations of sports (Ifs), the International Olympic Committee (IOC) and World Anti-Doping Agency (WADA), are ideally placed to lead transformational change with the unwavering support of the wider antidoping community. The outcome of the consensus meeting was the creation of the ad hoc Working Group charged with the responsibility of moving this agenda forward.

Expert Consensus Survey on Medication Adherence in Psychiatric Patients and Use of a Digital Medicine System.

PubMed

Hatch, Ainslie; Docherty, John P; Carpenter, Daniel; Ross, Ruth; Weiden, Peter J

2017-07-01

There is an unmet need to objectively assess adherence problems that are a common cause of unexplained or unexpected suboptimal outcome. A digital medicine system (DMS) has been developed to address this need in patients with serious mental illness. To conduct a quantitative expert consensus survey to (1) assess relative importance of causes of suboptimal outcomes, (2) examine modalities used to assess adherence, (3) provide guidance on when and how to use the DMS in clinical practice once available, and (4) suggest interventions for specific reasons for nonadherence. A panel of 58 experts in psychiatry completed a 23-question survey (October 13 through December 23, 2013) and rated their responses on a 9-point Likert scale. A χ² test of score distributions was used to determine consensus (P < .05). The panel rated adherence as the most important factor in suboptimal outcomes and yet the least likely to be assessed accurately. All predefined uses of the DMS received high mean first-line ratings (≥ 7.4). The experts recognized the utility of the DMS in managing adherence problems, identified clinical situations appropriate for DMS, and assessed potential benefits and challenges of this technology. Consensus was reached on first-line interventions for 10 of 11 reasons for nonadherence. The results provide a guide to clinicians on the evaluation of suboptimal outcomes, when and how to use the DMS, and the most appropriate interventions to address detected adherence problems. © Copyright 2017 Physicians Postgraduate Press, Inc.

Potential breeding distributions of U.S. birds predicted with both short-term variability and long-term average climate data

Treesearch

Brooke L. Bateman; Anna M. Pidgeon; Volker C. Radeloff; Curtis H. Flather; Jeremy VanDerWal; H. Resit Akcakaya; Wayne E. Thogmartin; Thomas P. Albright; Stephen J. Vavrus; Patricia J. Heglund

2016-01-01

Climate conditions, such as temperature or precipitation, averaged over several decades strongly affect species distributions, as evidenced by experimental results and a plethora of models demonstrating statistical relations between species occurrences and long-term climate averages. However, long-term averages can conceal climate changes that have occurred in...

Averaging in SU(2) open quantum random walk

NASA Astrophysics Data System (ADS)

Clement, Ampadu

2014-03-01

We study the average position and the symmetry of the distribution in the SU(2) open quantum random walk (OQRW). We show that the average position in the central limit theorem (CLT) is non-uniform compared with the average position in the non-CLT. The symmetry of distribution is shown to be even in the CLT.

Exploring the Sensitivity of Horn's Parallel Analysis to the Distributional Form of Random Data

ERIC Educational Resources Information Center

Dinno, Alexis

2009-01-01

Horn's parallel analysis (PA) is the method of consensus in the literature on empirical methods for deciding how many components/factors to retain. Different authors have proposed various implementations of PA. Horn's seminal 1965 article, a 1996 article by Thompson and Daniel, and a 2004 article by Hayton, Allen, and Scarpello all make assertions…

Assessing net ecosystem carbon exchange of U.S. terrestrial ecosystems by integrating eddy covariance flux measurements and satellite observations

Treesearch

Jingfeng Xiaoa; Qianlai Zhuang; Beverly E. Law; Dennis D. Baldocchi; Jiquan Chen; al. et.

2011-01-01

More accurate projections of future carbon dioxide concentrations in the atmosphere and associated climate change depend on improved scientific understanding of the terrestrial carbon cycle. Despite the consensus that U.S. terrestrial ecosystems provide a carbon sink, the size, distribution, and interannual variability of this sink remain uncertain. Here we report a...

Timing Interactions in Social Simulations: The Voter Model

NASA Astrophysics Data System (ADS)

Fernández-Gracia, Juan; Eguíluz, Víctor M.; Miguel, Maxi San

The recent availability of huge high resolution datasets on human activities has revealed the heavy-tailed nature of the interevent time distributions. In social simulations of interacting agents the standard approach has been to use Poisson processes to update the state of the agents, which gives rise to very homogeneous activity patterns with a well defined characteristic interevent time. As a paradigmatic opinion model we investigate the voter model and review the standard update rules and propose two new update rules which are able to account for heterogeneous activity patterns. For the new update rules each node gets updated with a probability that depends on the time since the last event of the node, where an event can be an update attempt (exogenous update) or a change of state (endogenous update). We find that both update rules can give rise to power law interevent time distributions, although the endogenous one more robustly. Apart from that for the exogenous update rule and the standard update rules the voter model does not reach consensus in the infinite size limit, while for the endogenous update there exist a coarsening process that drives the system toward consensus configurations.

The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: combining correlated Gaussian posterior distributions

DOE PAGES

Sánchez, Ariel G.; Grieb, Jan Niklas; Salazar-Albornoz, Salvador; ...

2016-09-30

The cosmological information contained in anisotropic galaxy clustering measurements can often be compressed into a small number of parameters whose posterior distribution is well described by a Gaussian. Here, we present a general methodology to combine these estimates into a single set of consensus constraints that encode the total information of the individual measurements, taking into account the full covariance between the different methods. We also illustrate this technique by applying it to combine the results obtained from different clustering analyses, including measurements of the signature of baryon acoustic oscillations and redshift-space distortions, based on a set of mock cataloguesmore » of the final SDSS-III Baryon Oscillation Spectroscopic Survey (BOSS). Our results show that the region of the parameter space allowed by the consensus constraints is smaller than that of the individual methods, highlighting the importance of performing multiple analyses on galaxy surveys even when the measurements are highly correlated. Our paper is part of a set that analyses the final galaxy clustering data set from BOSS. The methodology presented here is used in Alam et al. to produce the final cosmological constraints from BOSS.« less

Professionalism in residency training: is there a generation gap?

PubMed

Borrero, Sonya; McGinnis, Kathleen A; McNeil, Melissa; Frank, Janine; Conigliaro, Rosemarie L

2008-01-01

Teaching and evaluating professionalism is part of the Accreditation Council for Graduate Medical Education's training requirements for postgraduate education. Defining what constitutes professional behavior is the first step in this endeavor. Difficulty in teaching and evaluating professionalism may stem from generational differences between teachers and trainees in their definition of professional behavior. We sought to explore the magnitude of generational differences by asking faculty and residents to evaluate behaviors along a continuum of professionalism. A questionnaire composed of 16 vignettes describing unprofessional behaviors was distributed to a sample of internal medicine trainees and faculty. For each specific behavior described, participants were asked to rate the severity of the infraction on a 4-point scale. Within each group, responses were distributed across severity categories for most vignettes. There were no significant differences in the responses of trainees versus faculty for any of the vignettes except two. There is little consensus for determining the severity of unprofessional behaviors among faculty and trainees at one urban university training program. However, this lack of consensus does not appear to have a generational basis. Attributing difficulties in teaching and assessing professionalism cannot be blamed on differences between the generations.

Sporadic Schwannomatosis: A Systematic Review Following the 2005 Consensus Statement.

PubMed

Chick, Gregoire; Victor, Jan; Poujade, Thibault; Hollevoet, Nadine

2018-06-14

 To identify the frequency of reports of sporadic schwannomatosis, the types of patients affected, and the nerves affected.  We identified all case reports and case series that reported on patients with sporadic schwannomatosis according to established criteria.  The initial search yielded 1,597 studies, of which 15 were included. A total of 38 of 55 individuals met the inclusion criteria. The mean age of the patients was 48 years; 41% were male. Thirty-three patients had peripheral nerve tumors, and 17 had spinal tumors. Twelve had tumors in both locations. Tumor distribution was unilateral in 25 of 30 cases (83.3%) and segmental (limited to one limb or five or fewer contiguous segments of the spine) in 28 of 38 cases (73.7%).  This systematic review quantified the number of individuals who meet the criteria for sporadic schwannomatosis and better described this population to facilitate the classification of neurofibromatosis in regard to the 2005 consensus statement. Unilateral or segmental distribution of nerve tumors are key aspects when dealing with multiple noncutaneous schwannomas without involvement of the vestibular nerve. Georg Thieme Verlag KG Stuttgart · New York.

Estimating sales and sales market share from sales rank data for consumer appliances

NASA Astrophysics Data System (ADS)

Touzani, Samir; Van Buskirk, Robert

2016-06-01

Our motivation in this work is to find an adequate probability distribution to fit sales volumes of different appliances. This distribution allows for the translation of sales rank into sales volume. This paper shows that the log-normal distribution and specifically the truncated version are well suited for this purpose. We demonstrate that using sales proxies derived from a calibrated truncated log-normal distribution function can be used to produce realistic estimates of market average product prices, and product attributes. We show that the market averages calculated with the sales proxies derived from the calibrated, truncated log-normal distribution provide better market average estimates than sales proxies estimated with simpler distribution functions.

Phenomenology and classification of dystonia: a consensus update.

PubMed

Albanese, Alberto; Bhatia, Kailash; Bressman, Susan B; Delong, Mahlon R; Fahn, Stanley; Fung, Victor S C; Hallett, Mark; Jankovic, Joseph; Jinnah, Hyder A; Klein, Christine; Lang, Anthony E; Mink, Jonathan W; Teller, Jan K

2013-06-15

This report describes the consensus outcome of an international panel consisting of investigators with years of experience in this field that reviewed the definition and classification of dystonia. Agreement was obtained based on a consensus development methodology during 3 in-person meetings and manuscript review by mail. Dystonia is defined as a movement disorder characterized by sustained or intermittent muscle contractions causing abnormal, often repetitive, movements, postures, or both. Dystonic movements are typically patterned and twisting, and may be tremulous. Dystonia is often initiated or worsened by voluntary action and associated with overflow muscle activation. Dystonia is classified along 2 axes: clinical characteristics, including age at onset, body distribution, temporal pattern and associated features (additional movement disorders or neurological features); and etiology, which includes nervous system pathology and inheritance. The clinical characteristics fall into several specific dystonia syndromes that help to guide diagnosis and treatment. We provide here a new general definition of dystonia and propose a new classification. We encourage clinicians and researchers to use these innovative definition and classification and test them in the clinical setting on a variety of patients with dystonia. © 2013 Movement Disorder Society. © 2013 Movement Disorder Society.

Standards of scientific conduct: are there any?

PubMed

Kalichman, Michael; Sweet, Monica; Plemmons, Dena

2014-12-01

The practice of research is full of ethical challenges, many of which might be addressed through the teaching of responsible conduct of research (RCR). Although such training is increasingly required, there is no clear consensus about either the goals or content of an RCR curriculum. The present study was designed to assess community standards in three domains of research practice: authorship, collaboration, and data management. A survey, developed through advice from content matter experts, focus groups, and interviews, was distributed in November 2010 to U.S. faculty from 50 graduate programs for each of four different disciplines: microbiology, neuroscience, nursing, and psychology. The survey addressed practices and perceived standards, as well as perceptions about teaching and learning. Over 1,300 responses (response rate of 21 %) yielded statistically significant differences in responses to nearly all questions. However the magnitude of these differences was typically small, leaving little reason to argue for community consensus on standards. For nearly all questions asked, the clear finding was that there was nothing approaching consensus. These results may be useful not so much to teach what the standards are, but to increase student awareness of the diversity of those standards in reported practice.

Standards of Scientific Conduct: Are there any?

PubMed Central

Kalichman, Michael; Sweet, Monica; Plemmons, Dena

2014-01-01

The practice of research is full of ethical challenges, many of which might be addressed through the teaching of responsible conduct of research (RCR). Although such training is increasingly required, there is no clear consensus about either the goals or content of an RCR curriculum. The present study was designed to assess community standards in three domains of research practice: authorship, collaboration, and data management. A survey, developed through advice from content matter experts, focus groups, and interviews, was distributed in November 2010 to U.S. faculty from 50 graduate programs for each of four different disciplines: microbiology, neuroscience, nursing, and psychology. The survey addressed practices and perceived standards, as well as perceptions about teaching and learning. Over 1,300 responses (response rate of 21%) yielded statistically significant differences in responses to nearly all questions. However the magnitude of these differences was typically small, leaving little reason to argue for community consensus on standards. For nearly all questions asked, the clear finding was that there was nothing approaching consensus. These results may be useful not so much to teach what the standards are, but to increase student awareness of the diversity of those standards in reported practice. PMID:24337932

Management of Helicobacter pylori infection in Latin America: A Delphi technique-based consensus

PubMed Central

Rollan, Antonio; Arab, Juan Pablo; Camargo, M Constanza; Candia, Roberto; Harris, Paul; Ferreccio, Catterina; Rabkin, Charles S; Gana, Juan Cristóbal; Cortés, Pablo; Herrero, Rolando; Durán, Luisa; García, Apolinaria; Toledo, Claudio; Espino, Alberto; Lustig, Nicole; Sarfatis, Alberto; Figueroa, Catalina; Torres, Javier; Riquelme, Arnoldo

2014-01-01

AIM: To optimize diagnosis and treatment guidelines for this geographic region, a panel of gastroenterologists, epidemiologists, and basic scientists carried out a structured evaluation of available literature. METHODS: Relevant questions were distributed among the experts, who generated draft statements for consideration by the entire panel. A modified three-round Delphi technique method was used to reach consensus. Critical input was also obtained from representatives of the concerned medical community. The quality of the evidence and level of recommendation supporting each statement was graded according to United States Preventive Services Task Force criteria. RESULTS: A group of ten experts was established. The survey included 15 open-ended questions that were distributed among the experts, who assessed the articles associated with each question. The levels of agreement achieved by the panel were 50% in the first round, 73.3% in the second round and 100% in the third round. Main consensus recommendations included: (1) when available, urea breath and stool antigen test (HpSA) should be used for non-invasive diagnosis; (2) detect and eradicate Helicobacter pylori (H. pylori) in all gastroscopy patients to decrease risk of peptic ulcer disease, prevent o retard progression in patients with preneoplastic lesions, and to prevent recurrence in patients treated for gastric cancer; (3) further investigate implementation issues and health outcomes of H. pylori eradication for primary prevention of gastric cancer in high-risk populations; (4) prescribe standard 14-d triple therapy or sequential therapy for first-line treatment; (5) routinely assess eradication success post-treatment in clinical settings; and (6) select second- and third-line therapies according to antibiotic susceptibility testing. CONCLUSION: These achievable steps toward better region-specific management can be expected to improve clinical health outcomes. PMID:25152601

Norms as Group-Level Constructs: Investigating School-Level Teen Pregnancy Norms and Behaviors.

PubMed

Mollborn, Stefanie; Domingue, Benjamin W; Boardman, Jason D

2014-09-01

Social norms are a group-level phenomenon, but past quantitative research has rarely measured them in the aggregate or considered their group-level properties. We used the school-based design of the National Longitudinal Study of Adolescent Health to measure normative climates regarding teen pregnancy across 75 U.S. high schools. We distinguished between the strength of a school's norm against teen pregnancy and the consensus around that norm. School-level norm strength and dissensus were strongly (r = -0.65) and moderately (r = 0.34) associated with pregnancy prevalence within schools, respectively. Normative climate partially accounted for observed racial differences in school pregnancy prevalence, but norms were a stronger predictor than racial composition. As hypothesized, schools with both a stronger average norm against teen pregnancy and greater consensus around the norm had the lowest pregnancy prevalence. Results highlight the importance of group-level normative processes and of considering the local school environment when designing policies to reduce teen pregnancy.

Building Responsive Health Systems to Help Communities Affected by Migration: An International Delphi Consensus

PubMed Central

Pottie, Kevin; Hui, Charles; Rahman, Prinon; Ingleby, David; Akl, Elie A.; Russell, Grant; Ling, Li; Wickramage, Kolitha; Mosca, Davide; Brindis, Claire D.

2017-01-01

Persons affected by migration require health systems that are responsive and adaptable to the needs of both disadvantaged migrants and non-migrant populations. The objective of this study is to support health systems for populations affected by migration. Materials and Methods: An international Delphi consensus process was used to identify policy approaches to improve health systems for populations affected by migration. Participants were leading migrant health experts from Americas, Europe, Middle East, Asia, and Australasia. We calculated average ranking scores and qualitatively analyzed open-ended questions. Results: Participants identified the following key areas as priorities for policy development: health inequities, system discrimination, migrant related health data, disadvantaged migrant sub-groups, and considerations for disadvantaged non-migrant populations. Highly ranked items to improve health systems were: Health Equity Impact Assessment, evidence based guidelines, and the International Organization for Migration annual reports. Discussion: Policy makers need tools, data and resources to address health systems challenges. Policies need to avoid preventable deaths of migrants and barriers to basic health services. PMID:28165380

Norms as Group-Level Constructs: Investigating School-Level Teen Pregnancy Norms and Behaviors

PubMed Central

Mollborn, Stefanie; Domingue, Benjamin W.; Boardman, Jason D.

2015-01-01

Social norms are a group-level phenomenon, but past quantitative research has rarely measured them in the aggregate or considered their group-level properties. We used the school-based design of the National Longitudinal Study of Adolescent Health to measure normative climates regarding teen pregnancy across 75 U.S. high schools. We distinguished between the strength of a school's norm against teen pregnancy and the consensus around that norm. School-level norm strength and dissensus were strongly (r = -0.65) and moderately (r = 0.34) associated with pregnancy prevalence within schools, respectively. Normative climate partially accounted for observed racial differences in school pregnancy prevalence, but norms were a stronger predictor than racial composition. As hypothesized, schools with both a stronger average norm against teen pregnancy and greater consensus around the norm had the lowest pregnancy prevalence. Results highlight the importance of group-level normative processes and of considering the local school environment when designing policies to reduce teen pregnancy. PMID:26074628

A Consensus Model of Human Apolipoprotein A-I in its Monomeric and Lipid-free State

PubMed Central

Melchior, John T.; Walker, Ryan G.; Cooke, Allison L.; Morris, Jamie; Castleberry, Mark; Thompson, Thomas B.; Jones, Martin K.; Song, Hyun D.; Rye, Kerry-Anne; Oda, Mike N.; Sorci-Thomas, Mary G.; Thomas, Michael J.; Heinecke, Jay W.; Mei, Xiaohu; Atkinson, David; Segrest, Jere P.; Lund-Katz, Sissel; Phillips, Michael C.; Davidson, W. Sean

2017-01-01

Apolipoprotein (apo)A-I is an organizing scaffold protein that is critical to high density lipoprotein (HDL) structure and metabolism, likely mediating many of its cardioprotective properties. However, HDL biogenesis is poorly understood as lipid-free apoA-I has been notoriously resistant to high resolution structural study. Published models from low resolution techniques share certain features but vary considerably in shape and secondary structure. To tackle this central issue in lipoprotein biology, we assembled an unprecedented team of lipoprotein structural biologists and set out to build a consensus model of monomeric lipid-free human apoA-I. Combining novel and published cross-link constraints, small angle X-ray scattering (SAXS), hydrogen-deuterium exchange (H-DX) and crystallography data, we propose a time averaged model consistent with much of the experimental data published over the last 40 years. The model provides a long sought platform for understanding and testing details of HDL biogenesis, structure and function. PMID:29131142

Fine-tuning structural RNA alignments in the twilight zone

PubMed Central

2010-01-01

Background A widely used method to find conserved secondary structure in RNA is to first construct a multiple sequence alignment, and then fold the alignment, optimizing a score based on thermodynamics and covariance. This method works best around 75% sequence similarity. However, in a "twilight zone" below 55% similarity, the sequence alignment tends to obscure the covariance signal used in the second phase. Therefore, while the overall shape of the consensus structure may still be found, the degree of conservation cannot be estimated reliably. Results Based on a combination of available methods, we present a method named planACstar for improving structure conservation in structural alignments in the twilight zone. After constructing a consensus structure by alignment folding, planACstar abandons the original sequence alignment, refolds the sequences individually, but consistent with the consensus, aligns the structures, irrespective of sequence, by a pure structure alignment method, and derives an improved sequence alignment from the alignment of structures, to be re-submitted to alignment folding, etc.. This circle may be iterated as long as structural conservation improves, but normally, one step suffices. Conclusions Employing the tools ClustalW, RNAalifold, and RNAforester, we find that for sequences with 30-55% sequence identity, structural conservation can be improved by 10% on average, with a large variation, measured in terms of RNAalifold's own criterion, the structure conservation index. PMID:20433706

Three-dimensional impact angle constrained distributed guidance law design for cooperative attacks.

PubMed

Wang, Xianghua; Lu, Xiao

2018-02-01

In this paper, a novel cooperative guidance law is proposed to make multiple missiles in the three-dimensional (3-D) space hit simultaneously the same target at pre-specified impact angles. Firstly, the normal accelerations which change the velocity direction (flight-path and heading angle) are designed such that all missiles will fly along the desired line of sight (LOS) after a given time which ensures the hit-to-kill interception at the desired impact angles; then the consensus variable is constructed using available information and can reach consensus under the proposed tangential acceleration which determines the velocity magnitude. Hence simultaneous hit-to-kill attack is achieved. Finally, some simulation studies are performed to verify the effectiveness of the proposed scheme. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Core competency model for the family planning public health nurse.

PubMed

Hewitt, Caroline M; Roye, Carol; Gebbie, Kristine M

2014-01-01

A core competency model for family planning public health nurses has been developed, using a three stage Delphi Method with an expert panel of 40 family planning senior administrators, community/public health nursing faculty and seasoned family planning public health nurses. The initial survey was developed from the 2011 Title X Family Planning program priorities. The 32-item survey was distributed electronically via SurveyMonkey(®). Panelist attrition was low, and participation robust resulting in the final 28-item model, suggesting that the Delphi Method was a successful technique through which to achieve consensus. Competencies with at least 75% consensus were included in the model and those competencies were primarily related to education/counseling and administration of medications and contraceptives. The competencies identified have implications for education/training, certification and workplace performance. © 2014 Wiley Periodicals, Inc.

Expectations of recovery and functional outcomes following thoracolumbar trauma: an evidence-based medicine process to determine what surgeons should be telling their patients.

PubMed

Schouten, Rowan; Lewkonia, Peter; Noonan, Vanessa K; Dvorak, Marcel F; Fisher, Charles G

2015-01-01

The aim of this study was to define the expected functional and health-related quality of life outcomes following common thoracolumbar injuries on the basis of consensus expert opinion and the best available literature. Patient expectations are primarily determined by the information provided by health care professionals, and these expectations have been shown to influence outcome in various medical and surgical conditions. This paper presents Part 2 of a multiphase study designed to investigate the impact of patient expectations on outcomes following spinal injury. Part 1 demonstrated substantial variability in the information surgeons are communicating to patients. Defining the expected outcomes following thoracolumbar injury would allow further analysis of this relationship and enable surgeons to more accurately and consistently inform patients. Expert opinion was assembled by distributing questionnaires comprising 4 cases representative of common thoracolumbar injuries to members of the Spine Trauma Study Group (STSG). The 4 cases included a thoracolumbar junction burst fracture treated nonoperatively or with posterior transpedicular instrumentation, a low lumbar (L-4) burst fracture treated nonoperatively, and a thoracolumbar junction flexion-distraction injury managed with posterior fusion. For each case, 5 questions about expected outcomes were posed. The questions related to the proportion of patients who are pain free, the proportion who have regained full range of motion, and the patients' recreational activity restrictions and personal care and social life limitations, all at 1 year following injury, as well as the timing of return to work and length of hospital stay. Responses were analyzed and combined with the results of a systematic literature review on the same injuries to define the expected outcomes. The literature review identified 38 appropriate studies that met the preset inclusion criteria. Published data were available for all injuries, but not all outcomes were available for each type of injury. The survey was completed by 31 (57%) of 53 surgeons representing 24 trauma centers across North America (15), Europe (5), India (1), Mexico (1), Japan (1) and Israel (1). Consensus expert opinion supplemented the available literature and was used exclusively when published data were lacking. For example, 1 year following cast or brace treatment of a thoracolumbar burst fracture, the expected outcomes include a 40% chance of being pain free, a 70% chance of regaining pre-injury range of motion, and an expected ability to participate in high-impact exercise and contact sport with no or minimal limitation. Consensus expert opinion predicts reemployment within 4-6 months. The length of inpatient stay averages 4-5 days. This synthesis of the best available literature and consensus opinion of surgeons with extensive clinical experience in spine trauma reflects the optimal methodology for determining functional prognosis after thoracolumbar trauma. By providing consistent, accurate information surgeons will help patients develop realistic expectations and potentially optimize outcomes.

Distributed Nash Equilibrium Seeking for Generalized Convex Games with Shared Constraints

NASA Astrophysics Data System (ADS)

Sun, Chao; Hu, Guoqiang

2018-05-01

In this paper, we deal with the problem of finding a Nash equilibrium for a generalized convex game. Each player is associated with a convex cost function and multiple shared constraints. Supposing that each player can exchange information with its neighbors via a connected undirected graph, the objective of this paper is to design a Nash equilibrium seeking law such that each agent minimizes its objective function in a distributed way. Consensus and singular perturbation theories are used to prove the stability of the system. A numerical example is given to show the effectiveness of the proposed algorithms.

Esophageal cancer screening in achalasia: is there a consensus?

PubMed

Ravi, K; Geno, D M; Katzka, D A

2015-04-01

Achalasia is an important but relatively uncommon disorder. While highly effective therapeutic options exist, esophageal cancer remains a long-term potential complication. The risk of esophageal cancer in achalasia remains unclear, with current guidelines recommending against routine endoscopic screening. However, given limited data and conflicting opinion, it is unknown whether consensus regarding screening practices in achalasia among experts exists. A 10-question survey to assess screening practices in achalasia was created and distributed to 28 experts in the area of achalasia. Experts were identified based on publications and meeting presentations in the field. Survey responses were received from 17 of 28 (61%) experts. Wide geographic distribution was seen among respondents, with eight (47%) from Europe or Australia, seven (41%) from the United States, and two (12%) from Asia. Screening for esophageal cancer was inconsistent, with nine (53%) experts endorsing the practice and eight (47%) not. Screening practices did not differ among geographic regions. No consensus regarding the risk for esophageal cancer in achalasia was seen, with three experts reporting no increased risk compared with the general population, eight experts a lifetime risk of 0.1-0.5%, three experts a 0.5-1% risk, two experts a 1-2% risk, and one expert a 3-5% risk. However, these differences in perception of risk did not influence screening practices. Upper endoscopy was utilized among all experts who endorsed screening. However, practices still varied with screening commencing at or within 1 year of diagnosis in two practices compared with 5 and 10 years in three respective practices each. Surveillance intervals also varied, performed every 2 years in four practices, every 3 years in four practices, and every 5 years in one practice. Practice variation in the management of achalasia itself was also seen, with initial treatment with Heller myotomy endorsed by eight experts, pneumatic dilation by five experts, and two each endorsing peroral endoscopic myotomy or no specific preference. In addition, while 82% (14/17) of experts endorsed long-term follow up of patients, no consensus regarding long-term follow up existed, with annual follow up in eight practices, every 3-6 months in three practices, and every 2 years in three practices. Large practice variation in the long-term management of achalasia exists among experts in the field. Only a slight majority of experts endorse screening for esophageal cancer in achalasia, and no consensus exists regarding how surveillance should be structured even among this group. Interestingly, the lack of consensus on cancer screening parallels a lack of agreement on initial treatment of achalasia. These findings suggest a need for greater homogeneity in the management of longstanding achalasia and cancer screening. Further, this study highlights the need for more data on this topic to foster greater agreement. © 2014 International Society for Diseases of the Esophagus.

Patterns and Features of Global Uranium Resources and Production

NASA Astrophysics Data System (ADS)

Wang, Feifei; Song, Zisheng; Cheng, Xianghu; Huanhuan, MA

2017-11-01

With the entry into force of the Paris Agreement, the development of clean and low-carbon energy has become the consensus of the world. Nuclear power is one energy that can be vigorously developed today and in the future. Its sustainable development depends on a sufficient supply of uranium resources. It is of great practical significance to understand the distribution pattern of uranium resources and production. Based on the latest international authoritative reports and data, this paper analysed the distribution of uranium resources, the distribution of resources and production in the world, and the developing tendency in future years. The results show that the distribution of uranium resources is uneven in the world, and the discrepancies between different type deposits is very large. Among them, sandstone-type uranium deposits will become the main type owing to their advantages of wide distribution, minor environmental damage, mature mining technology and high economic benefit.

Distributed Optimal Consensus Over Resource Allocation Network and Its Application to Dynamical Economic Dispatch.

PubMed

Li, Chaojie; Yu, Xinghuo; Huang, Tingwen; He, Xing; Chaojie Li; Xinghuo Yu; Tingwen Huang; Xing He; Li, Chaojie; Huang, Tingwen; He, Xing; Yu, Xinghuo

2018-06-01

The resource allocation problem is studied and reformulated by a distributed interior point method via a -logarithmic barrier. By the facilitation of the graph Laplacian, a fully distributed continuous-time multiagent system is developed for solving the problem. Specifically, to avoid high singularity of the -logarithmic barrier at boundary, an adaptive parameter switching strategy is introduced into this dynamical multiagent system. The convergence rate of the distributed algorithm is obtained. Moreover, a novel distributed primal-dual dynamical multiagent system is designed in a smart grid scenario to seek the saddle point of dynamical economic dispatch, which coincides with the optimal solution. The dual decomposition technique is applied to transform the optimization problem into easily solvable resource allocation subproblems with local inequality constraints. The good performance of the new dynamical systems is, respectively, verified by a numerical example and the IEEE six-bus test system-based simulations.

Skew-t fits to mortality data--can a Gaussian-related distribution replace the Gompertz-Makeham as the basis for mortality studies?

PubMed

Clark, Jeremy S C; Kaczmarczyk, Mariusz; Mongiało, Zbigniew; Ignaczak, Paweł; Czajkowski, Andrzej A; Klęsk, Przemysław; Ciechanowicz, Andrzej

2013-08-01

Gompertz-related distributions have dominated mortality studies for 187 years. However, nonrelated distributions also fit well to mortality data. These compete with the Gompertz and Gompertz-Makeham data when applied to data with varying extents of truncation, with no consensus as to preference. In contrast, Gaussian-related distributions are rarely applied, despite the fact that Lexis in 1879 suggested that the normal distribution itself fits well to the right of the mode. Study aims were therefore to compare skew-t fits to Human Mortality Database data, with Gompertz-nested distributions, by implementing maximum likelihood estimation functions (mle2, R package bbmle; coding given). Results showed skew-t fits obtained lower Bayesian information criterion values than Gompertz-nested distributions, applied to low-mortality country data, including 1711 and 1810 cohorts. As Gaussian-related distributions have now been found to have almost universal application to error theory, one conclusion could be that a Gaussian-related distribution might replace Gompertz-related distributions as the basis for mortality studies.

A Test of the Interstellar Boundary EXplorer Ribbon Formation in the Outer Heliosheath

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

Gamayunov, Konstantin V.; Rassoul, Hamid; Heerikhuisen, Jacob, E-mail: kgamayunov@fit.edu

NASA’s Interstellar Boundary EXplorer ( IBEX ) mission is imaging energetic neutral atoms (ENAs) propagating to Earth from the outer heliosphere and local interstellar medium (LISM). A dominant feature in all ENA maps is a ribbon of enhanced fluxes that was not predicted before IBEX . While more than a dozen models of the ribbon formation have been proposed, consensus has gathered around the so-called secondary ENA model. Two classes of secondary ENA models have been proposed; the first class assumes weak scattering of the energetic pickup protons in the LISM, and the second class assumes strong but spatially localizedmore » scattering. Here we present a numerical test of the “weak scattering” version of the secondary ENA model using our gyro-averaged kinetic model for the evolution of the phase-space distribution of protons in the outer heliosheath. As input for our test, we use distributions of the primary ENAs from our MHD-plasma/kinetic-neutral model of the heliosphere-LISM interaction. The magnetic field spectrum for the large-scale interstellar turbulence and an upper limit for the amplitude of small-scale local turbulence (SSLT) generated by protons are taken from observations by Voyager 1 in the LISM. The hybrid simulations of energetic protons are also used to set the bounding wavenumbers for the spectrum of SSLT. Our test supports the “weak scattering” version. This makes an additional solid step on the way to understanding the origin and formation of the IBEX ribbon and thus to improving our understanding of the interaction between the heliosphere and the LISM.« less

A diameter distribution approach to estimating average stand dominant height in Appalachian hardwoods

Treesearch

John R. Brooks

2007-01-01

A technique for estimating stand average dominant height based solely on field inventory data is investigated. Using only 45.0919 percent of the largest trees per acre in the diameter distribution resulted in estimates of average dominant height that were within 4.3 feet of the actual value, when averaged over stands of very different structure and history. Cubic foot...

Flexible Multi agent Algorithm for Distributed Decision Making

DTIC Science & Technology

2015-01-01

How, J. P. Consensus - Based Auction Approaches for Decentralized task Assignment. Proceedings of the AIAA Guidance, Navigation, and Control...G. ; Kim, Y. Market- based Decentralized Task Assignment for Cooperative UA V Mission Including Rendezvous. Proceedings of the AIAA Guidance...scalable and adaptable to a variety of specific mission tasks . Additionally, the algorithm could easily be adapted for use on land or sea- based systems

Enhancing FBI Terrorism and Homeland Security Information Sharing With State, Local and Tribal Agencies

DTIC Science & Technology

2010-09-01

the proposed NSI implementation (PM-ISE, 2008). The ISE reported, in October 2009, that the Los Angeles Police Department ( LAPD ) ISE...position of the Department of Defense or the U.S. Government. IRB Protocol number ________________. 12a. DISTRIBUTION / AVAILABILITY STATEMENT...critical, priority issue for all levels of government. The consensus of all three categories of literature was that government information sharing

Cooperative Adaptive Output Regulation for Second-Order Nonlinear Multiagent Systems With Jointly Connected Switching Networks.

PubMed

Liu, Wei; Huang, Jie

2018-03-01

This paper studies the cooperative global robust output regulation problem for a class of heterogeneous second-order nonlinear uncertain multiagent systems with jointly connected switching networks. The main contributions consist of the following three aspects. First, we generalize the result of the adaptive distributed observer from undirected jointly connected switching networks to directed jointly connected switching networks. Second, by performing a new coordinate and input transformation, we convert our problem into the cooperative global robust stabilization problem of a more complex augmented system via the distributed internal model principle. Third, we solve the stabilization problem by a distributed state feedback control law. Our result is illustrated by the leader-following consensus problem for a group of Van der Pol oscillators.

Framework of behavioral indicators evaluating TB health promotion outcomes: a modified Delphi study of TB policymakers and health workers.

PubMed

Li, Ying; Ehiri, John; Hu, Daiyu; Oren, Eyal; Cao, Jia

2015-12-15

Although TB health promotion directed at policy makers and healthcare workers (HCWs) is considered important to tuberculosis (TB) control, no indicators currently assess the impact of such promotional activities. This article is the second in a series of papers that seek to establish a framework of behavioral indicators for outcome evaluation of TB health promotion, using the Delphi method. In the first article, we sought to establish a framework of behavioral indicators for outcome evaluation of TB health promotion among TB suspects and patients. The objective of this second article is to present an indicator framework that can be used to assess behavioral outcomes of TB health promotion directed at policy makers and HCWs. A two-round, modified Delphi method was used to establish the indicators. Sixteen experts who were knowledgeable and experienced in the field of TB control were consulted in Delphi surveys. A questionnaire was developed following 4 steps, and involved ranking indicators on a five-point Likert scale. The consensus level was 70 %. Median, mode, and Coefficient of variation (CV) were used to describe expert responses. An authority coefficient (Cr) was used to assess the degree of each expert's authority. Consensus was achieved following the two survey rounds and several iterations among the experts. For TB health-promotion activities directed at policymakers, the experts reached consensus on 2 domains ("Resource inputs" and "Policymaking and monitoring behaviors"), 4 subdomains ("Human resources" among others), and 13 indicators ("Human resources per 100,000 person" among others). For TB health-promotion activities directed at HCWs, the experts reached consensus on 5 domains ("Self-protective behaviors" among others), 6 sub-domains ("Preventing infection" among others), and 15 indicators ("Average hours of daily workplace disinfection by ultraviolet radiation" among others). This study identified a conceptual framework of core behavioral indicators to evaluate TB health-promotion activities directed at policymakers and HCWs involved in TB control. Validation in other parts of the world could lead to global consensus on behavioral indicators to evaluate TB health promotion targeted at policymakers and HCWs.

Proposal for a definition of lifelong premature ejaculation based on epidemiological stopwatch data.

PubMed

Waldinger, Marcel D; Zwinderman, Aeilko H; Olivier, Berend; Schweitzer, Dave H

2005-07-01

Consensus on a definition of premature ejaculation has not yet been reached because of debates based on subjective authority opinions and nonstandardized assessment methods to measure ejaculation time and ejaculation control. To provide a definition for lifelong premature ejaculation that is based on epidemiological evidence including the neurobiological and psychological approach. We used the 0.5 and 2.5 percentiles as accepted standards of disease definition in a skewed distribution. We applied these percentiles in a stopwatch-determined intravaginal ejaculation latency time (IELT) distribution of 491 nonselected men from five different countries. The practical consequences of 0.5% and 2.5% cutoff points for disease definition were taken into consideration by reviewing current knowledge of feelings of control and satisfaction in relation to ejaculatory performance of the general male population. Literature arguments to be used in a proposed consensus on a definition of premature ejaculation. The stopwatch-determined IELT distribution is positively skewed. The 0.5 percentile equates to an IELT of 0.9 minute and the 2.5 percentile an IELT of 1.3 minutes. However, there are no available data in the literature on feelings of control or satisfaction in relation to ejaculatory latency time in the general male population. Random male cohort studies are needed to end all speculation on this subject. Exact stopwatch time assessment of IELT in a multinational study led us to propose that all men with an IELT of less than 1 minute (belonging to the 0.5 percentile) have "definite" premature ejaculation, while men with IELTs between 1 and 1.5 minutes (between 0.5 and 2.5 percentile) have "probable" premature ejaculation. Severity of premature ejaculation (nonsymptomatic, mild, moderate, severe) should be defined in terms of associated psychological problems. We define lifelong premature ejaculation as a neurobiological dysfunction with an unacceptable increase of risk to develop sexual and psychological problems anywhere in a lifetime. By defining premature ejaculation from an authority-defined disorder into a dysfunction based on epidemiological evidence it is possible to establish consensus based on epidemiological evidence. Additional epidemiological stopwatch studies are needed for a final decision of IELT values at both percentile cutoff points.

Implementation of formal learning objectives during a physical medicine and rehabilitation sports medicine rotation.

PubMed

Smith, Jay; Laskowski, Edward R; Newcomer-Aney, Karen L; Thompson, Jeffrey M; Schaefer, Michael P; Morfe, Erasmus G

2005-04-01

To develop and implement formal learning objectives during a physical medicine and rehabilitation sports medicine rotation and characterize resident experiences with the objectives over a 16-mo period. Prospective, including learning objective development, implementation, and postrotation survey. A total of 69 learning objectives were developed by physical medicine and rehabilitation staff physician consensus, including 39 core objectives. Eighteen residents completed 4-wk sports medicine rotations from January 2003 through April 2004. Residents completed an average of 31 total objectives (45%; range, 3-52), of which 24 (62%; range, 3-35) were core. Residents completed the highest percentage of knee (60%), shoulder (57%), and ankle-foot (57%) objectives and reported that objectives related to these areas were most effective to facilitate learning. In general, residents reported that objective content was good and that the objectives delineated important concepts to learn during the rotation. Seventeen of 18 residents indicated that the objectives should be permanently implemented into the sports rotation and that similar objectives should be developed for other rotations. Based on our experience and the recommendations of residents, the average resident should be able to complete approximately 30 objectives during a typical 4-wk rotation. Successful implementation of specific, consensus-derived learning objectives is possible within the context of a busy clinical practice. Our initial physician staff and resident experience with the objectives suggests that this model may be useful as a supplementary educational tool in physical medicine and rehabilitation residency programs.

Relaxation of Distributed Data Aggregation for Underwater Acoustic Sensor Networks

DTIC Science & Technology

2014-03-31

2 3.1 Gossip algorithms for distributed averaging . . . . . . . . . . . . . . . . . 3 3.2 Distributed particle filtering...algorithm that had direct access to all of the measurements. We use gossip algorithms (discussed in Section 3.1) to diffuse information across the...2 3.1 Gossip algorithms for distributed averaging We begin by discussing gossip algorithms, which we use to synchronize and spread infor- mation

Pelvic Normal Tissue Contouring Guidelines for Radiation Therapy: A Radiation Therapy Oncology Group Consensus Panel Atlas

PubMed Central

Gay, Hiram A.; Barthold, H. Joseph; O’Meara, Elizabeth; Bosch, Walter R.; El Naqa, Issam; Al-Lozi, Rawan; Rosenthal, Seth A.; Lawton, Colleen; Lee, W. Robert; Sandler, Howard; Zietman, Anthony; Myerson, Robert; Dawson, Laura A.; Willett, Christopher; Kachnic, Lisa A.; Jhingran, Anuja; Portelance, Lorraine; Ryu, Janice; Small, William; Gaffney, David; Viswanathan, Akila N.; Michalski, Jeff M.

2012-01-01

Purpose To define a male and female pelvic normal tissue contouring atlas for Radiation Therapy Oncology Group (RTOG) trials. Methods and Materials One male pelvis computed tomography (CT) data set and one female pelvis CT data set were shared via the Image-Guided Therapy QA Center. A total of 16 radiation oncologists participated. The following organs at risk were contoured in both CT sets: anus, anorectum, rectum (gastrointestinal and genitourinary definitions), bowel NOS (not otherwise specified), small bowel, large bowel, and proximal femurs. The following were contoured in the male set only: bladder, prostate, seminal vesicles, and penile bulb. The following were contoured in the female set only: uterus, cervix, and ovaries. A computer program used the binomial distribution to generate 95% group consensus contours. These contours and definitions were then reviewed by the group and modified. Results The panel achieved consensus definitions for pelvic normal tissue contouring in RTOG trials with these standardized names: Rectum, AnoRectum, SmallBowel, Colon, BowelBag, Bladder, UteroCervix, Adnexa_R, Adnexa_L, Prostate, SeminalVesc, PenileBulb, Femur_R, and Femur_L. Two additional normal structures whose purpose is to serve as targets in anal and rectal cancer were defined: AnoRectumSig and Mesorectum. Detailed target volume contouring guidelines and images are discussed. Conclusions Consensus guidelines for pelvic normal tissue contouring were reached and are available as a CT image atlas on the RTOG Web site. This will allow uniformity in defining normal tissues for clinical trials delivering pelvic radiation and will facilitate future normal tissue complication research. PMID:22483697

Superior ab initio identification, annotation and characterisation of TEs and segmental duplications from genome assemblies.

PubMed

Zeng, Lu; Kortschak, R Daniel; Raison, Joy M; Bertozzi, Terry; Adelson, David L

2018-01-01

Transposable Elements (TEs) are mobile DNA sequences that make up significant fractions of amniote genomes. However, they are difficult to detect and annotate ab initio because of their variable features, lengths and clade-specific variants. We have addressed this problem by refining and developing a Comprehensive ab initio Repeat Pipeline (CARP) to identify and cluster TEs and other repetitive sequences in genome assemblies. The pipeline begins with a pairwise alignment using krishna, a custom aligner. Single linkage clustering is then carried out to produce families of repetitive elements. Consensus sequences are then filtered for protein coding genes and then annotated using Repbase and a custom library of retrovirus and reverse transcriptase sequences. This process yields three types of family: fully annotated, partially annotated and unannotated. Fully annotated families reflect recently diverged/young known TEs present in Repbase. The remaining two types of families contain a mixture of novel TEs and segmental duplications. These can be resolved by aligning these consensus sequences back to the genome to assess copy number vs. length distribution. Our pipeline has three significant advantages compared to other methods for ab initio repeat identification: 1) we generate not only consensus sequences, but keep the genomic intervals for the original aligned sequences, allowing straightforward analysis of evolutionary dynamics, 2) consensus sequences represent low-divergence, recently/currently active TE families, 3) segmental duplications are annotated as a useful by-product. We have compared our ab initio repeat annotations for 7 genome assemblies to other methods and demonstrate that CARP compares favourably with RepeatModeler, the most widely used repeat annotation package.

Superior ab initio identification, annotation and characterisation of TEs and segmental duplications from genome assemblies

PubMed Central

Zeng, Lu; Kortschak, R. Daniel; Raison, Joy M.

2018-01-01

Transposable Elements (TEs) are mobile DNA sequences that make up significant fractions of amniote genomes. However, they are difficult to detect and annotate ab initio because of their variable features, lengths and clade-specific variants. We have addressed this problem by refining and developing a Comprehensive ab initio Repeat Pipeline (CARP) to identify and cluster TEs and other repetitive sequences in genome assemblies. The pipeline begins with a pairwise alignment using krishna, a custom aligner. Single linkage clustering is then carried out to produce families of repetitive elements. Consensus sequences are then filtered for protein coding genes and then annotated using Repbase and a custom library of retrovirus and reverse transcriptase sequences. This process yields three types of family: fully annotated, partially annotated and unannotated. Fully annotated families reflect recently diverged/young known TEs present in Repbase. The remaining two types of families contain a mixture of novel TEs and segmental duplications. These can be resolved by aligning these consensus sequences back to the genome to assess copy number vs. length distribution. Our pipeline has three significant advantages compared to other methods for ab initio repeat identification: 1) we generate not only consensus sequences, but keep the genomic intervals for the original aligned sequences, allowing straightforward analysis of evolutionary dynamics, 2) consensus sequences represent low-divergence, recently/currently active TE families, 3) segmental duplications are annotated as a useful by-product. We have compared our ab initio repeat annotations for 7 genome assemblies to other methods and demonstrate that CARP compares favourably with RepeatModeler, the most widely used repeat annotation package. PMID:29538441

Delphi-RAND consensus of the Spanish Society of Internal Medicine on the controversies in anticoagulant therapy and prophylaxis in medical diseases. INTROMBIN Project (Uncertainty in thromboprophylaxis in internal medicine).

PubMed

Ruiz-Ruiz, F; Medrano, F J; Navarro-Puerto, M A; Rodríguez-Torres, P; Romero-Alonso, A; Santos-Lozano, J M; Alonso-Ortiz Del Rio, C; Varela-Aguilar, J M; Calderón, E J; Marín-León, I

2018-05-21

The aim of this study was to determine the opinion of internists on the management of anticoagulation and thromboembolism prophylaxis in complex clinical scenarios in which the risk-benefit ratio of surgery is narrow and to develop a consensus document on the use of drugs anticoagulant therapy in this patient group. To this end, we identified by consensus the clinical areas of greatest uncertainty, a survey was created with 20 scenarios laid out in 40 clinical questions, and we reviewed the specific literature. The survey was distributed among the internists of the Spanish Society of Internal Medicine (SEMI) and was completed by 290 of its members. The consensus process was implemented by changing the Delphi-RAND appropriateness method in an anonymous, double-round process that enabled an expert panel to identify the areas of agreement and uncertainty. In our case, we also added the survey results to the panel, a methodological innovation that helps provide additional information on the standard clinical practice. The result of the process is a set of 19 recommendations formulated by SEMI experts, which helps establish guidelines for action on anticoagulant therapy in complex scenarios (high risk or active haemorrhage, short life expectancy, coexistence of antiplatelet therapy or comorbidities such as kidney disease and liver disease), which are not uncommon in standard clinical practice. Copyright © 2018 Elsevier España, S.L.U. and Sociedad Española de Medicina Interna (SEMI). All rights reserved.

Moving forward through consensus: protocol for a modified Delphi approach to determine the top research priorities in the field of orthopaedic oncology.

PubMed

Schneider, Patricia; Evaniew, Nathan; Rendon, Juan Sebastian; McKay, Paula; Randall, R Lor; Turcotte, Robert; Vélez, Roberto; Bhandari, Mohit; Ghert, Michelle

2016-05-24

Orthopaedic oncology researchers face several obstacles in the design and execution of randomised controlled trials, including finite fiscal resources to support the rising costs of clinical research and insufficient patient volume at individual sites. As a result, high-quality research to guide clinical practice has lagged behind other surgical subspecialties. A focused approach is imperative to design a research programme that is economical, streamlined and addresses clinically relevant endpoints. The primary objective of this study will be to use a consensus-based approach to identify research priorities for international clinical trials in orthopaedic oncology. We will conduct a 3-phase modified Delphi method consisting of 2 sequential rounds of anonymous web-based questionnaires (phases I and II), and an in-person consensus meeting (phase III). Participants will suggest research questions that they believe are of particular importance to the field (phase I), and individually rate each proposed question on 5 criteria (phase II). Research questions that meet predetermined consensus thresholds will be brought forward to the consensus meeting (phase III) for discussion by an expert panel. Following these discussions, the expert panel will be asked to assign scores for each research question, and research questions meeting predetermined criteria will be brought forward for final ranking. The expert panel will then be asked to rank the top 3 research questions, and these 3 research questions will be distributed to the initial group of participants for validation. An ethics application is currently under review with the Hamilton Integrated Research Ethics Board in Hamilton, Ontario, Canada. The results of this initiative will be disseminated through peer-reviewed publications and conference presentations. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

The influence of local majority opinions on the dynamics of the Sznajd model

NASA Astrophysics Data System (ADS)

Crokidakis, Nuno

2014-03-01

In this work we study a Sznajd-like opinion dynamics on a square lattice of linear size L. For this purpose, we consider that each agent has a convincing power C, that is a time-dependent quantity. Each high convincing power group of four agents sharing the same opinion may convince its neighbors to follow the group opinion, which induces an increase of the group's convincing power. In addition, we have considered that a group with a local majority opinion (3 up/1 down spins or 1 up/3 down spins) can persuade the agents neighboring the group with probability p, since the group's convincing power is high enough. The two mechanisms (convincing powers and probability p) lead to an increase of the competition among the opinions, which avoids dictatorship (full consensus, all spins parallel) for a wide range of model's parameters, and favors the occurrence of democratic states (partial order, the majority of spins pointing in one direction). We have found that the relaxation times of the model follow log-normal distributions, and that the average relaxation time τ grows with system size as τ ~ L5/2, independent of p. We also discuss the occurrence of the usual phase transition of the Sznajd model.

Greedy Gossip With Eavesdropping

NASA Astrophysics Data System (ADS)

Ustebay, Deniz; Oreshkin, Boris N.; Coates, Mark J.; Rabbat, Michael G.

2010-07-01

This paper presents greedy gossip with eavesdropping (GGE), a novel randomized gossip algorithm for distributed computation of the average consensus problem. In gossip algorithms, nodes in the network randomly communicate with their neighbors and exchange information iteratively. The algorithms are simple and decentralized, making them attractive for wireless network applications. In general, gossip algorithms are robust to unreliable wireless conditions and time varying network topologies. In this paper we introduce GGE and demonstrate that greedy updates lead to rapid convergence. We do not require nodes to have any location information. Instead, greedy updates are made possible by exploiting the broadcast nature of wireless communications. During the operation of GGE, when a node decides to gossip, instead of choosing one of its neighbors at random, it makes a greedy selection, choosing the node which has the value most different from its own. In order to make this selection, nodes need to know their neighbors' values. Therefore, we assume that all transmissions are wireless broadcasts and nodes keep track of their neighbors' values by eavesdropping on their communications. We show that the convergence of GGE is guaranteed for connected network topologies. We also study the rates of convergence and illustrate, through theoretical bounds and numerical simulations, that GGE consistently outperforms randomized gossip and performs comparably to geographic gossip on moderate-sized random geometric graph topologies.

The supernova - supernova remnant connection through multi-dimensional magnetohydrodynamic modeling

NASA Astrophysics Data System (ADS)

Orlando, S.; Miceli, M.; Petruk, O.; Ono, M.

2017-10-01

Supernova remnants (SNRs) are diffuse extended sources often characterized by a rather complex morphology and a highly non-uniform distribution of ejecta. General consensus is that such a morphology reflects, on one hand, pristine structures and features of the progenitor supernova (SN) explosion and, on the other hand, the early interaction of the SN blast wave with the inhomogeneous circumstellar medium (CSM) formed in the latest stages of the progenitor star's evolution. Deciphering X-ray observations of SNRs, therefore, might open the possibility to reconstruct the ejecta structure as it was soon after the SN explosion and the structure and geometry of the medium immediately surrounding the progenitor star. This requires accurate and detailed models which describe the evolution from the on-set of the SN to the full remnant development and which connect the X-ray emission properties of the remnants to the progenitor SNe. Here we show how multi-dimensional SN-SNR magnetohydrodynamic models have been very effective in deciphering X-ray observations of SNR Cassiopeia A and SN 1987A. This has allowed us to unveil the average structure of ejecta in the immediate aftermath of the SN explosion and to constrain the 3D pre-supernova structure and geometry of the environment surrounding the progenitor SN.

The macroeconomic determinants of health.

PubMed

Subramanian, S V; Belli, Paolo; Kawachi, Ichiro

2002-01-01

Why are some societies healthier than others? The consensus in development economics is that the health achievement of nations has to do with their levels of economic development. Higher per capita incomes, through steady and stable economic growth, increase a nation's capacity to purchase the necessary economic goods and services that promote health. In this paper, we review the conceptual and empirical linkages between poverty and poor health in both developing and developed countries. The empirical evidence is overwhelming that poverty, measured at the level of societies as well as individuals, is causally related to poor health of societies and individuals, respectively. Recent macroeconomic research has also drawn attention to the role of health as a form of human capital that is vital for achieving economic stability. In particular, attention has been drawn toward the ways in which unhealthy societies impede the process of economic development. However, the reciprocal connection between economic prosperity and improved health is neither automatic nor universal. Other features of society, such as the equality in the distribution of the national wealth, seem to matter as well for improving average population health and especially for reducing inequalities in health. We conclude by arguing for a need to reexamine the way in which health is conceptualized within the macroeconomic development framework.

Bona-fide method for the determination of short range order and transport properties in a ferro-aluminosilicate slag

PubMed Central

Karalis, Konstantinos T.; Dellis, Dimitrios; Antipas, Georgios S. E.; Xenidis, Anthimos

2016-01-01

The thermodynamics, structural and transport properties (density, melting point, heat capacity, thermal expansion coefficient, viscosity and electrical conductivity) of a ferro-aluminosilicate slag have been studied in the solid and liquid state (1273–2273 K) using molecular dynamics. The simulations were based on a Buckingham-type potential, which was extended here, to account for the presence of Cr and Cu. The potential was optimized by fitting pair distribution function partials to values determined by Reverse Monte Carlo modelling of X-ray and neutron diffraction experiments. The resulting short range order features and ring statistics were in tight agreement with experimental data and created consensus for the accurate prediction of transport properties. Accordingly, calculations yielded rational values both for the average heat capacity, equal to 1668.58 J/(kg·K), and for the viscosity, in the range of 4.09–87.64 cP. The potential was consistent in predicting accurate values for mass density (i.e. 2961.50 kg/m3 vs. an experimental value of 2940 kg/m3) and for electrical conductivity (5.3–233 S/m within a temperature range of 1273.15–2273.15 K). PMID:27455915

Single Marker and Haplotype-Based Association Analysis of Semolina and Pasta Colour in Elite Durum Wheat Breeding Lines Using a High-Density Consensus Map

PubMed Central

Haile, Jemanesh K.; Cory, Aron T.; Clarke, Fran R.; Clarke, John M.; Knox, Ron E.; Pozniak, Curtis J.

2017-01-01

Association mapping is usually performed by testing the correlation between a single marker and phenotypes. However, because patterns of variation within genomes are inherited as blocks, clustering markers into haplotypes for genome-wide scans could be a worthwhile approach to improve statistical power to detect associations. The availability of high-density molecular data allows the possibility to assess the potential of both approaches to identify marker-trait associations in durum wheat. In the present study, we used single marker- and haplotype-based approaches to identify loci associated with semolina and pasta colour in durum wheat, the main objective being to evaluate the potential benefits of haplotype-based analysis for identifying quantitative trait loci. One hundred sixty-nine durum lines were genotyped using the Illumina 90K Infinium iSelect assay, and 12,234 polymorphic single nucleotide polymorphism (SNP) markers were generated and used to assess the population structure and the linkage disequilibrium (LD) patterns. A total of 8,581 SNPs previously localized to a high-density consensus map were clustered into 406 haplotype blocks based on the average LD distance of 5.3 cM. Combining multiple SNPs into haplotype blocks increased the average polymorphism information content (PIC) from 0.27 per SNP to 0.50 per haplotype. The haplotype-based analysis identified 12 loci associated with grain pigment colour traits, including the five loci identified by the single marker-based analysis. Furthermore, the haplotype-based analysis resulted in an increase of the phenotypic variance explained (50.4% on average) and the allelic effect (33.7% on average) when compared to single marker analysis. The presence of multiple allelic combinations within each haplotype locus offers potential for screening the most favorable haplotype series and may facilitate marker-assisted selection of grain pigment colour in durum wheat. These results suggest a benefit of haplotype-based analysis over single marker analysis to detect loci associated with colour traits in durum wheat. PMID:28135299

Automated Quantification of the Landing Error Scoring System With a Markerless Motion-Capture System.

PubMed

Mauntel, Timothy C; Padua, Darin A; Stanley, Laura E; Frank, Barnett S; DiStefano, Lindsay J; Peck, Karen Y; Cameron, Kenneth L; Marshall, Stephen W

2017-11-01

  The Landing Error Scoring System (LESS) can be used to identify individuals with an elevated risk of lower extremity injury. The limitation of the LESS is that raters identify movement errors from video replay, which is time-consuming and, therefore, may limit its use by clinicians. A markerless motion-capture system may be capable of automating LESS scoring, thereby removing this obstacle.   To determine the reliability of an automated markerless motion-capture system for scoring the LESS.   Cross-sectional study.   United States Military Academy.   A total of 57 healthy, physically active individuals (47 men, 10 women; age = 18.6 ± 0.6 years, height = 174.5 ± 6.7 cm, mass = 75.9 ± 9.2 kg).   Participants completed 3 jump-landing trials that were recorded by standard video cameras and a depth camera. Their movement quality was evaluated by expert LESS raters (standard video recording) using the LESS rubric and by software that automates LESS scoring (depth-camera data). We recorded an error for a LESS item if it was present on at least 2 of 3 jump-landing trials. We calculated κ statistics, prevalence- and bias-adjusted κ (PABAK) statistics, and percentage agreement for each LESS item. Interrater reliability was evaluated between the 2 expert rater scores and between a consensus expert score and the markerless motion-capture system score.   We observed reliability between the 2 expert LESS raters (average κ = 0.45 ± 0.35, average PABAK = 0.67 ± 0.34; percentage agreement = 0.83 ± 0.17). The markerless motion-capture system had similar reliability with consensus expert scores (average κ = 0.48 ± 0.40, average PABAK = 0.71 ± 0.27; percentage agreement = 0.85 ± 0.14). However, reliability was poor for 5 LESS items in both LESS score comparisons.   A markerless motion-capture system had the same level of reliability as expert LESS raters, suggesting that an automated system can accurately assess movement. Therefore, clinicians can use the markerless motion-capture system to reliably score the LESS without being limited by the time requirements of manual LESS scoring.

Genome-wide SNP identification for the construction of a high-resolution genetic map of Japanese flounder (Paralichthys olivaceus): applications to QTL mapping of Vibrio anguillarum disease resistance and comparative genomic analysis

PubMed Central

Shao, Changwei; Niu, Yongchao; Rastas, Pasi; Liu, Yang; Xie, Zhiyuan; Li, Hengde; Wang, Lei; Jiang, Yong; Tai, Shuaishuai; Tian, Yongsheng; Sakamoto, Takashi; Chen, Songlin

2015-01-01

High-resolution genetic maps are essential for fine mapping of complex traits, genome assembly, and comparative genomic analysis. Single-nucleotide polymorphisms (SNPs) are the primary molecular markers used for genetic map construction. In this study, we identified 13,362 SNPs evenly distributed across the Japanese flounder (Paralichthys olivaceus) genome. Of these SNPs, 12,712 high-confidence SNPs were subjected to high-throughput genotyping and assigned to 24 consensus linkage groups (LGs). The total length of the genetic linkage map was 3,497.29 cM with an average distance of 0.47 cM between loci, thereby representing the densest genetic map currently reported for Japanese flounder. Nine positive quantitative trait loci (QTLs) forming two main clusters for Vibrio anguillarum disease resistance were detected. All QTLs could explain 5.1–8.38% of the total phenotypic variation. Synteny analysis of the QTL regions on the genome assembly revealed 12 immune-related genes, among them 4 genes strongly associated with V. anguillarum disease resistance. In addition, 246 genome assembly scaffolds with an average size of 21.79 Mb were anchored onto the LGs; these scaffolds, comprising 522.99 Mb, represented 95.78% of assembled genomic sequences. The mapped assembly scaffolds in Japanese flounder were used for genome synteny analyses against zebrafish (Danio rerio) and medaka (Oryzias latipes). Flounder and medaka were found to possess almost one-to-one synteny, whereas flounder and zebrafish exhibited a multi-syntenic correspondence. The newly developed high-resolution genetic map, which will facilitate QTL mapping, scaffold assembly, and genome synteny analysis of Japanese flounder, marks a milestone in the ongoing genome project for this species. PMID:25762582

Using Network Dynamical Influence to Drive Consensus

NASA Astrophysics Data System (ADS)

Punzo, Giuliano; Young, George F.; MacDonald, Malcolm; Leonard, Naomi E.

2016-05-01

Consensus and decision-making are often analysed in the context of networks, with many studies focusing attention on ranking the nodes of a network depending on their relative importance to information routing. Dynamical influence ranks the nodes with respect to their ability to influence the evolution of the associated network dynamical system. In this study it is shown that dynamical influence not only ranks the nodes, but also provides a naturally optimised distribution of effort to steer a network from one state to another. An example is provided where the “steering” refers to the physical change in velocity of self-propelled agents interacting through a network. Distinct from other works on this subject, this study looks at directed and hence more general graphs. The findings are presented with a theoretical angle, without targeting particular applications or networked systems; however, the framework and results offer parallels with biological flocks and swarms and opportunities for design of technological networks.

Argumentation for coordinating shared activities

NASA Technical Reports Server (NTRS)

Clement, Bradley J.; Barrett, Anthony C.; Schaffer, Steven R.

2004-01-01

an increasing need for space missions to be able to collaboratively (and competitively) develop plans both within and across missions. In addition, interacting spacecraft that interleave onboard planning and execution must reach consensus on their commitments to each other prior to execution. In domains where missions have varying degrees of interaction and different constraints on communication and computation, the missions will require different coordination protocols in order to efficiently reach consensus with in their imposed deadlines. We describe a Shared Activity Coordination (SHAC) framework that provides a decentralized algorithm for negotiating the scheduling of shared activities over the lifetimes of multiple agents and a foundation for customizing protocols for negotiating planner interactions. We investigate variations of a few simple protocols based on argumentation and distributed constraints satisfaction techniques and evaluate their abilities to reach consistent solutions according to computation, time, and communication costs in an abstract domain where spacecraft propose joint measurements.

[Association between distribution of bacillary dysentery and meteorological factors in Beijing, 2004-2015].

PubMed

Du, Z; Zhang, J; Lu, J X; Lu, L P

2018-05-10

Objective: To analyze the distribution characteristics of bacillary dysentery in Beijing during 2004-2015 and evaluate the influence of meteorological factors on the temporal and spatial distribution of bacillary dysentery. Methods: The incidence data of bacterial dysentery and meteorological data in Beijing from 2004 to 2015 were collected. Descriptive epidemiological analysis was conducted to study the distribution characteristics of bacterial dysentery. Linear correlation analysis and multiple linear regression analysis were carried out to investigate the relationship between the incidence of bacillary dysentery and average precipitation, average air temperature, sunshine hours, average wind speed, average air pressure, gale and rain days. Results: A total of 280 704 cases of bacterial dysentery, including 36 deaths, were reported from 2004 to 2015 in Beijing, the average annual incidence was 130.15/100 000. The annual incidence peak was mainly between May and October, the cases occurred during this period accounted for 80.75 % of the total, and the incidence was highest in age group 0 year. The population distribution showed that most cases were children outside child care settings and students, and the sex ratio of the cases was 1.22∶1. The reported incidence of bacillary dysentery was positively associated with average precipitation, average air temperature and rain days with the correlation coefficients of 0.931, 0.878 and 0.888, but it was negatively associated with the average pressure, the correlation coefficient was -0.820. Multiple linear regression equation for fitting analysis of bacillary dysentery and meteorological factors was Y =3.792+0.162 X (1). Conclusion: The reported incidence of bacillary dysentery in Beijing was much higher than national level. The annual incidence peak was during July to August, and the average precipitation was an important meteorological factor influencing the incidence of bacillary dysentery.

Average BER of subcarrier intensity modulated free space optical systems over the exponentiated Weibull fading channels.

PubMed

Wang, Ping; Zhang, Lu; Guo, Lixin; Huang, Feng; Shang, Tao; Wang, Ranran; Yang, Yintang

2014-08-25

The average bit error rate (BER) for binary phase-shift keying (BPSK) modulation in free-space optical (FSO) links over turbulence atmosphere modeled by the exponentiated Weibull (EW) distribution is investigated in detail. The effects of aperture averaging on the average BERs for BPSK modulation under weak-to-strong turbulence conditions are studied. The average BERs of EW distribution are compared with Lognormal (LN) and Gamma-Gamma (GG) distributions in weak and strong turbulence atmosphere, respectively. The outage probability is also obtained for different turbulence strengths and receiver aperture sizes. The analytical results deduced by the generalized Gauss-Laguerre quadrature rule are verified by the Monte Carlo simulation. This work is helpful for the design of receivers for FSO communication systems.

Genotypic and Functional Impact of HIV-1 Adaptation to Its Host Population during the North American Epidemic

PubMed Central

Carlson, Jonathan M.; Chan, Benjamin; Chopera, Denis R.; Brumme, Chanson J.; Markle, Tristan J.; Martin, Eric; Shahid, Aniqa; Anmole, Gursev; Mwimanzi, Philip; Nassab, Pauline; Penney, Kali A.; Rahman, Manal A.; Milloy, M.-J.; Schechter, Martin T.; Markowitz, Martin; Carrington, Mary; Walker, Bruce D.; Wagner, Theresa; Buchbinder, Susan; Fuchs, Jonathan; Koblin, Beryl; Mayer, Kenneth H.; Harrigan, P. Richard; Brockman, Mark A.; Poon, Art F. Y.; Brumme, Zabrina L.

2014-01-01

HLA-restricted immune escape mutations that persist following HIV transmission could gradually spread through the viral population, thereby compromising host antiviral immunity as the epidemic progresses. To assess the extent and phenotypic impact of this phenomenon in an immunogenetically diverse population, we genotypically and functionally compared linked HLA and HIV (Gag/Nef) sequences from 358 historic (1979–1989) and 382 modern (2000–2011) specimens from four key cities in the North American epidemic (New York, Boston, San Francisco, Vancouver). Inferred HIV phylogenies were star-like, with approximately two-fold greater mean pairwise distances in modern versus historic sequences. The reconstructed epidemic ancestral (founder) HIV sequence was essentially identical to the North American subtype B consensus. Consistent with gradual diversification of a “consensus-like” founder virus, the median “background” frequencies of individual HLA-associated polymorphisms in HIV (in individuals lacking the restricting HLA[s]) were ∼2-fold higher in modern versus historic HIV sequences, though these remained notably low overall (e.g. in Gag, medians were 3.7% in the 2000s versus 2.0% in the 1980s). HIV polymorphisms exhibiting the greatest relative spread were those restricted by protective HLAs. Despite these increases, when HIV sequences were analyzed as a whole, their total average burden of polymorphisms that were “pre-adapted” to the average host HLA profile was only ∼2% greater in modern versus historic eras. Furthermore, HLA-associated polymorphisms identified in historic HIV sequences were consistent with those detectable today, with none identified that could explain the few HIV codons where the inferred epidemic ancestor differed from the modern consensus. Results are therefore consistent with slow HIV adaptation to HLA, but at a rate unlikely to yield imminent negative implications for cellular immunity, at least in North America. Intriguingly, temporal changes in protein activity of patient-derived Nef (though not Gag) sequences were observed, suggesting functional implications of population-level HIV evolution on certain viral proteins. PMID:24762668

Contouring variability of human- and deformable-generated contours in radiotherapy for prostate cancer

NASA Astrophysics Data System (ADS)

Gardner, Stephen J.; Wen, Ning; Kim, Jinkoo; Liu, Chang; Pradhan, Deepak; Aref, Ibrahim; Cattaneo, Richard, II; Vance, Sean; Movsas, Benjamin; Chetty, Indrin J.; Elshaikh, Mohamed A.

2015-06-01

This study was designed to evaluate contouring variability of human-and deformable-generated contours on planning CT (PCT) and CBCT for ten patients with low-or intermediate-risk prostate cancer. For each patient in this study, five radiation oncologists contoured the prostate, bladder, and rectum, on one PCT dataset and five CBCT datasets. Consensus contours were generated using the STAPLE method in the CERR software package. Observer contours were compared to consensus contour, and contour metrics (Dice coefficient, Hausdorff distance, Contour Distance, Center-of-Mass [COM] Deviation) were calculated. In addition, the first day CBCT was registered to subsequent CBCT fractions (CBCTn: CBCT2-CBCT5) via B-spline Deformable Image Registration (DIR). Contours were transferred from CBCT1 to CBCTn via the deformation field, and contour metrics were calculated through comparison with consensus contours generated from human contour set. The average contour metrics for prostate contours on PCT and CBCT were as follows: Dice coefficient—0.892 (PCT), 0.872 (CBCT-Human), 0.824 (CBCT-Deformed); Hausdorff distance—4.75 mm (PCT), 5.22 mm (CBCT-Human), 5.94 mm (CBCT-Deformed); Contour Distance (overall contour)—1.41 mm (PCT), 1.66 mm (CBCT-Human), 2.30 mm (CBCT-Deformed); COM Deviation—2.01 mm (PCT), 2.78 mm (CBCT-Human), 3.45 mm (CBCT-Deformed). For human contours on PCT and CBCT, the difference in average Dice coefficient between PCT and CBCT (approx. 2%) and Hausdorff distance (approx. 0.5 mm) was small compared to the variation between observers for each patient (standard deviation in Dice coefficient of 5% and Hausdorff distance of 2.0 mm). However, additional contouring variation was found for the deformable-generated contours (approximately 5.0% decrease in Dice coefficient and 0.7 mm increase in Hausdorff distance relative to human-generated contours on CBCT). Though deformable contours provide a reasonable starting point for contouring on CBCT, we conclude that contours generated with B-Spline DIR require physician review and editing if they are to be used in the clinic.

Mobile Phone Apps for Inflammatory Bowel Disease Self-Management: A Systematic Assessment of Content and Tools.

PubMed

Con, Danny; De Cruz, Peter

2016-02-01

The rising incidence of inflammatory bowel disease (IBD) over the past decade has resulted in increased health care utilization and longer IBD outpatient waiting lists. Self-management is recognized as an important aspect of chronic disease management but its application to IBD has been limited. The age of IBD onset in a majority of patients is in their 20s to 30s. Mobile phone apps are a technology familiar to young adults and represent an opportunity to explore self-management as a new model of health care delivery for IBD. The aim of this study was to explore the content and tools of existing IBD apps to identify functionalities that may facilitate patient self-management. We systematically assessed apps targeted at IBD patients via searches of Google (Android devices) and Apple (iOS devices) app stores with pre-defined inclusion and exclusion criteria. Apps were assessed for specific functionalities; presence of professional medical involvement; consistency with international IBD guidelines based on "complete," "partial," or "absent" coverage of consensus statements derived from the European Crohn's and Colitis Organisation, American College of Gastroenterology, and the Gastroenterology Society of Australia; comprehensiveness of data that could be entered; and average pricing. Of the 238 apps screened, 26 apps were assessed, including 10 available on Android platforms, 8 on iOS platforms, and 8 on both. Over half (14/26, 54%) of the apps had diary functionalities; over a third (10/26, 39%) provided health information about IBD. None of the apps offered decision support to facilitate the self-initiation of medical therapy. Five of 26 (19%) had professional medical involvement in their design. Apps demonstrated "complete" coverage of only 38% of the international consensus statements explored. The average price of the apps was AUD$1.37. Apps may provide a useful adjunct to the management of IBD patients. However, a majority of current apps suffer from a lack of professional medical involvement and limited coverage of international consensus guidelines. Future studies and app design for IBD should include professional medical involvement, evidence-based guidelines, and functionalities with decision support that are specifically tailored to patient self-management.

Non-relativistic Free–Free Emission due to the n -distribution of Electrons—Radiative Cooling and Thermally Averaged and Total Gaunt Factors

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

De Avillez, Miguel A.; Breitschwerdt, Dieter, E-mail: mavillez@galaxy.lca.uevora.pt

Tracking the thermal evolution of plasmas, characterized by an n -distribution, using numerical simulations, requires the determination of the emission spectra and of the radiative losses due to free–free emission from the corresponding temperature-averaged and total Gaunt factors. Detailed calculations of the latter are presented and associated with n -distributed electrons with the parameter n ranging from 1 (corresponding to the Maxwell–Boltzmann distribution) to 100. The temperature-averaged and total Gaunt factors with decreasing n tend toward those obtained with the Maxwell–Boltzmann distribution. Radiative losses due to free–free emission in a plasma evolving under collisional ionization equilibrium conditions and composed bymore » H, He, C, N, O, Ne, Mg, Si, S, and Fe ions, are presented. These losses decrease with a decrease in the parameter n , reaching a minimum when n  = 1, and thus converge with the loss of thermal plasma. Tables of the thermal-averaged and total Gaunt factors calculated for n -distributions, and a wide range of electron and photon energies, are presented.« less

Initiating/maintaining long-acting injectable antipsychotics in schizophrenia/schizoaffective or bipolar disorder - expert consensus survey part 2.

PubMed

Sajatovic, Martha; Ross, Ruth; Legacy, Susan N; Byerly, Matthew; Kane, John M; DiBiasi, Faith; Fitzgerald, Heather; Correll, Christoph U

2018-01-01

The aim of this study was to provide recommendations on initiating and maintaining long-acting injectable antipsychotics (LAIs) in individuals with schizophrenia/schizoaffective or bipolar disorder. A 50-question survey comprising 916 response options was completed by 34 expert researchers and high prescribers with extensive LAI experience, rating relative appropriateness/importance on a 9-point scale. Consensus was determined using chi-square test of score distributions. Results of 21 questions comprising 339 response options regarding LAI initiation, maintenance treatment, adequate trial definition, identifying treatment nonresponse, and switching are reported. Experts agreed that the most important LAI selection factor was patient response/tolerability to previous antipsychotics. An adequate therapeutic LAI trial was defined as the time to steady state ± 1-2 injection cycles. Experts suggested that oral efficacy and tolerability should be established before switching to an LAI, without consensus on the required time, and that the time for oral supplementation and next injection interval should be determined by the time to attainment of therapeutic LAI levels. Most experts agreed that ≥1 adequate LAI trial is needed to identify the lack of efficacy. There was little agreement about strategies for switching between LAIs. Expert guidance may aid clinicians in their decisions regarding initiating/maintaining LAIs in individuals with schizophrenia/schizoaffective or bipolar disorder.

Do familiar teammates request and accept more backup? Transactive memory in air traffic control.

PubMed

Smith-Jentsch, Kimberly A; Kraiger, Kurt; Cannon-Bowers, Janis A; Salas, Eduardo

2009-04-01

The present study investigated factors that explain when and why different groups of teammates are more likely to request and accept backup from one another when needed in an environment characterized by extreme time pressure and severe consequences of error: commercial air traffic control (ATC). Transactive memory theory states that teammates develop consensus regarding the distribution of their relative expertise as well as confidence in that expertise over time and that this facilitates coordination processes. The present study investigated whether this theory could help to explain between-team differences in requesting and accepting backup when needed. The present study used cross-sectional data collected from 51 commercial ATC teams. Hypotheses were tested using multiple regression analysis. Teammates with greater experience working together requested and accepted backup from one another more than those with lesser experience working together. Teammate knowledge consensus and perceived team efficacy appear to have mediated this relationship. Transactive memory theory extends to high-stress environments in which members' expertise is highly overlapping. Teammates' shared mental models about one another increase the likelihood that they will request and accept backup. Teammate familiarity should be considered when choosing among potential replacement team members. Training strategies that accelerate the development of teammate knowledge consensus and team efficacy are warranted.

A Survey Examining Photopatch Test and Phototest Methodologies of Contact Dermatologists in the United States: Platform for Developing A Consensus.

PubMed

Asemota, Eseosa; Crawford, Glen; Kovarik, Carrie; Brod, Bruce A

There is currently no standardized protocol for photopatch testing and phototesting in the United States. Certain testing paramaters (such as chemicals tested, time between test application and irradiation, and time of final interpretation) vary from provider to provider. These variations may impact comparability and consistency of test results. The goal of our survey-based study was to outline the photopatch test and phototest protocols used by US contact dermatologists. The information obtained will aid in the development of a national consensus on testing methodologies. Based on a literature search conducted on differences in testing methodologies, we constructed a questionnaire. The survey was distributed at the American Contact Dermatitis Society annual meeting and via the American Contact Dermatitis Society Web site. Standard descriptive analysis was performed on data obtained. Of the 800 dermatologists contacted, 117 agreed to participate in the survey. Among these respondents, 64 (54.8%) conduct photopatch testing. Results of the survey are presented, and they confirm that a variety of techniques and testing materials are used. It would be beneficial to enlist a panel of expert contact dermatologists to create by formal consensus, using these research findings, a standard photopatch test protocol for use in this country.

Using a color-coded ambigraphic nucleic acid notation to visualize conserved palindromic motifs within and across genomes

PubMed Central

2014-01-01

Background Ambiscript is a graphically-designed nucleic acid notation that uses symbol symmetries to support sequence complementation, highlight biologically-relevant palindromes, and facilitate the analysis of consensus sequences. Although the original Ambiscript notation was designed to easily represent consensus sequences for multiple sequence alignments, the notation’s black-on-white ambiguity characters are unable to reflect the statistical distribution of nucleotides found at each position. We now propose a color-augmented ambigraphic notation to encode the frequency of positional polymorphisms in these consensus sequences. Results We have implemented this color-coding approach by creating an Adobe Flash® application ( http://www.ambiscript.org) that shades and colors modified Ambiscript characters according to the prevalence of the encoded nucleotide at each position in the alignment. The resulting graphic helps viewers perceive biologically-relevant patterns in multiple sequence alignments by uniquely combining color, shading, and character symmetries to highlight palindromes and inverted repeats in conserved DNA motifs. Conclusion Juxtaposing an intuitive color scheme over the deliberate character symmetries of an ambigraphic nucleic acid notation yields a highly-functional nucleic acid notation that maximizes information content and successfully embodies key principles of graphic excellence put forth by the statistician and graphic design theorist, Edward Tufte. PMID:24447494

Tailoring of EIA-649-1: Definition of Major (Class I) Engineering Change Proposal

DTIC Science & Technology

2015-05-15

MISSILE SYSTEMS CENTER TAILORING TAILORING OF EIA -649-1: DEFINITION OF MAJOR (CLASS I) ENGINEERING CHANGE PROPOSAL APPROVED FOR...PUBLIC RELEASE; DISTRIBUTION IS UNLIMITED 1 Tailoring of EIA -649-1: Definition of Major (Class I) ECP. 1. Intent of this Tailoring Document...This tailoring document remedies a requirements gap in the industry consensus standard, EIA -649-1: 2015. Specifically, this tailoring provides a

Middle-Class Consensus, Social Capital and the Mechanics of Economic Development

DTIC Science & Technology

2005-01-01

Michael, Social Capital and Regional Mobility, Nr. 4/2002. "* Schdfer, Wolf, EU-Erweiterung: Anmerkungen zum Balassa - Samuelson -Effekt, Nr. 3/2002...variations, while the argument of both the present paper and most of the previous literature on inequality and growth refers to long-run growth effects of...Diskussionsbeitriige zur Finanzwissenschaft " Josten, Stefan, Crime, Inequality, and Economic Growth. A Classical Argument for Distributional Equality

Distributed Matrix Completion: Applications to Cooperative Positioning in Noisy Environments

DTIC Science & Technology

2013-12-11

positioning, and a gossip version of low-rank approximation were developed. A convex relaxation for positioning in the presence of noise was shown...computing the leading eigenvectors of a large data matrix through gossip algorithms. A new algorithm is proposed that amounts to iteratively multiplying...generalization of gossip algorithms for consensus. The algorithms outperform state-of-the-art methods in a communication-limited scenario. Positioning via

Generalized Distributed Consensus-based Algorithms for Uncertain Systems and Networks

DTIC Science & Technology

2010-01-01

time linear systems with markovian jumping parameters and additive disturbances. SIAM Journal on Control and Optimization, 44(4):1165– 1191, 2005... time marko- vian jump linear systems , in the presence of delayed mode observations. Proceed- ings of the 2008 IEEE American Control Conference, pages...Markovian Jump Linear System state estimation . . . . 147 6 Conclusions 152 A Discrete- Time Coupled Matrix Equations 156 A.1 Properties of a special

Recommendations on reintroduction of agalsidase Beta for patients with fabry disease in europe, following a period of shortage.

PubMed

Linthorst, Gabor E; Burlina, Alessandro P; Cecchi, Franco; Cox, Timothy M; Fletcher, Janice M; Feldt-Rasmussen, Ulla; Giugliani, Roberto; Hollak, Carla E M; Houge, Gunnar; Hughes, Derralynn; Kantola, Iikka; Lachmann, Robin; Lopez, Monica; Ortiz, Alberto; Parini, Rossella; Rivera, Alberto; Rolfs, Arndt; Ramaswami, Uma; Svarstad, Einar; Tondel, Camilla; Tylki-Szymanska, Anna; Vujkovac, Bojan; Waldek, Steven; West, Michael; Weidemann, F; Mehta, Atul

2013-01-01

The interruption of the manufacturing process of agalsidase beta has led to a worldwide shortage of this drug. In the EU, nearly all patients initially reduced their agalsidase beta dose, and many of these switched to agalsidase alfa (Replagal Shire HGT). The clinical consequences of this period of drug shortage need to be further evaluated. A gradual increase of agalsidase beta supply is now expected. This implies that patients could resume or even commence agalsidase beta treatment. Guidance for prioritization of patients is needed to support equitable distribution of agalsidase beta to EU member states. To achieve this, in absence of level I clinical evidence, a draft consensus proposal was initiated and distributed. No full consensus was achieved, as there is disagreement regarding the indications for switching patients from agalsidase alfa to agalsidase beta. Some physicians support the concept that the 1.0 mg/kg EOW dose of agalsidase beta is more effective than agalsidase alfa at 0.2 mg/kg EOW, while others believe that at recommended dose, the preparations are equivalent. In light of these difficulties and the uncertainties with respect to supply of agalsidase beta, recommendations were agreed upon by a subgroup of physicians. These current recommendations focus on prioritization of criteria indicative of disease progression.

TAGCNA: A Method to Identify Significant Consensus Events of Copy Number Alterations in Cancer

PubMed Central

Yuan, Xiguo; Zhang, Junying; Yang, Liying; Zhang, Shengli; Chen, Baodi; Geng, Yaojun; Wang, Yue

2012-01-01

Somatic copy number alteration (CNA) is a common phenomenon in cancer genome. Distinguishing significant consensus events (SCEs) from random background CNAs in a set of subjects has been proven to be a valuable tool to study cancer. In order to identify SCEs with an acceptable type I error rate, better computational approaches should be developed based on reasonable statistics and null distributions. In this article, we propose a new approach named TAGCNA for identifying SCEs in somatic CNAs that may encompass cancer driver genes. TAGCNA employs a peel-off permutation scheme to generate a reasonable null distribution based on a prior step of selecting tag CNA markers from the genome being considered. We demonstrate the statistical power of TAGCNA on simulated ground truth data, and validate its applicability using two publicly available cancer datasets: lung and prostate adenocarcinoma. TAGCNA identifies SCEs that are known to be involved with proto-oncogenes (e.g. EGFR, CDK4) and tumor suppressor genes (e.g. CDKN2A, CDKN2B), and provides many additional SCEs with potential biological relevance in these data. TAGCNA can be used to analyze the significance of CNAs in various cancers. It is implemented in R and is freely available at http://tagcna.sourceforge.net/. PMID:22815924

Large-scale dark diversity estimates: new perspectives with combined methods.

PubMed

Ronk, Argo; de Bello, Francesco; Fibich, Pavel; Pärtel, Meelis

2016-09-01

Large-scale biodiversity studies can be more informative if observed diversity in a study site is accompanied by dark diversity, the set of absent although ecologically suitable species. Dark diversity methodology is still being developed and a comparison of different approaches is needed. We used plant data at two different scales (European and seven large regions) and compared dark diversity estimates from two mathematical methods: species co-occurrence (SCO) and species distribution modeling (SDM). We used plant distribution data from the Atlas Florae Europaeae (50 × 50 km grid cells) and seven different European regions (10 × 10 km grid cells). Dark diversity was estimated by SCO and SDM for both datasets. We examined the relationship between the dark diversity sizes (type II regression) and the overlap in species composition (overlap coefficient). We tested the overlap probability according to the hypergeometric distribution. We combined the estimates of the two methods to determine consensus dark diversity and composite dark diversity. We tested whether dark diversity and completeness of site diversity (log ratio of observed and dark diversity) are related to various natural and anthropogenic factors differently than simple observed diversity. Both methods provided similar dark diversity sizes and distribution patterns; dark diversity is greater in southern Europe. The regression line, however, deviated from a 1:1 relationship. The species composition overlap of two methods was about 75%, which is much greater than expected by chance. Both consensus and composite dark diversity estimates showed similar distribution patterns. Both dark diversity and completeness measures exhibit relationships to natural and anthropogenic factors different than those exhibited by observed richness. In summary, dark diversity revealed new biodiversity patterns which were not evident when only observed diversity was examined. A new perspective in dark diversity studies can incorporate a combination of methods.

Aedes (Finlaya) Japonicus (Diptera: Culicidae), a Newly Recognized Mosquito in the United States: Analyses of Genetic Variation in the United States and Putative Source Populations

DTIC Science & Technology

2001-01-01

with arithmetic average, UPGMA Swofford et al. 1996) using the NEIGHBOR and CONSENSUS programs from PHYLIP version 3.57~ (Felsenstein 1995). To...and Maryland samples). The presence/absence matrix is available (http:/ / wrbu.si.edu/wrbu.html). The trees that resulted from the UPGMA analysis...Ae- j. yaeyamensis (2) I . 0.2 I . 0.1 Genetic distance I 0.0 Fig 5. UPGMA dendrogram based on BAPD loci using Nei’s standard genetic

Population Structure of the Primary Malaria Vector in South America, Anopheles darlingi, Using Isozyme, Random Amplified Polymorphic DNA, Internal Transcribed Spacer 2, and Morphologic Markers

DTIC Science & Technology

1999-01-01

distances and identities and Roger?’ genetic distances were clustered by the unweighted pair group method using arithmetic average ( UPGMA ) to produce...Seattle, WA) using the NEIGHBOR program with the UPGMA option and a phenogram was produced with DRAWGRAM, also in PHYLIP 3.X RAPDBOOT5’ was used to...generate 100 pseudoreplicate distance matrices, which were collapsed to form 100 trees with UPGMA . The bootstrap consensus tree was derived from the 100

ALTERNATIVE APPROACH TO ESTIMATING CANCER ...

EPA Pesticide Factsheets

The alternative approach for estimating cancer potency from inhalation exposure to asbestos seeks to improve the methods developed by USEPA (1986). This efforts seeks to modify the the current approach for estimating cancer potency for lung cancer and mesothelioma to account for the current scientific consensus that cancer risk from asbestos depends both on mineral type and on particle size distribution. In brief, epidemiological exposure-response data for lung cancer and mesothelioma in asbestos workers are combined with estimates of the mineral type(s) and partical size distribution at each exposure location in order to estimate potency factors that are specific to a selected set of mineral type and size

Distributed-observer-based cooperative control for synchronization of linear discrete-time multi-agent systems.

PubMed

Liang, Hongjing; Zhang, Huaguang; Wang, Zhanshan

2015-11-01

This paper considers output synchronization of discrete-time multi-agent systems with directed communication topologies. The directed communication graph contains a spanning tree and the exosystem as its root. Distributed observer-based consensus protocols are proposed, based on the relative outputs of neighboring agents. A multi-step algorithm is presented to construct the observer-based protocols. In light of the discrete-time algebraic Riccati equation and internal model principle, synchronization problem is completed. At last, numerical simulation is provided to verify the effectiveness of the theoretical results. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

Micropore-induced capillarity enhances bone distribution in vivo in biphasic calcium phosphate scaffolds.

PubMed

Rustom, Laurence E; Boudou, Thomas; Lou, Siyu; Pignot-Paintrand, Isabelle; Nemke, Brett W; Lu, Yan; Markel, Mark D; Picart, Catherine; Wagoner Johnson, Amy J

2016-10-15

The increasing demand for bone repair solutions calls for the development of efficacious bone scaffolds. Biphasic calcium phosphate (BCP) scaffolds with both macropores and micropores (MP) have improved healing compared to those with macropores and no micropores (NMP), but the role of micropores is unclear. Here, we evaluate capillarity induced by micropores as a mechanism that can affect bone growth in vivo. Three groups of cylindrical scaffolds were implanted in pig mandibles for three weeks: MP were implanted either dry (MP-Dry), or after submersion in phosphate buffered saline, which fills pores with fluid and therefore suppresses micropore-induced capillarity (MP-Wet); NMP were implanted dry. The amount and distribution of bone in the scaffolds were quantified using micro-computed tomography. MP-Dry had a more homogeneous bone distribution than MP-Wet, although the average bone volume fraction, BVF‾, was not significantly different for these two groups (0.45±0.03 and 0.37±0.03, respectively). There was no significant difference in the radial bone distribution of NMP and MP-Wet, but the BVF‾, of NMP was significantly lower among the three groups (0.25±0.02). These results suggest that micropore-induced capillarity enhances bone regeneration by improving the homogeneity of bone distribution in BCP scaffolds. The explicit design and use of capillarity in bone scaffolds may lead to more effective treatments of large and complex bone defects. The increasing demand for bone repair calls for more efficacious bone scaffolds and calcium phosphate-based materials are considered suitable for this application. Macropores (>100μm) are necessary for bone ingrowth and vascularization. However, studies have shown that microporosity (<20μm) also enhances growth, but there is no consensus on the controlling mechanisms. In previous in vitro work, we suggested that micropore-induced capillarity had the potential to enhance bone growth in vivo. This work illustrates the positive effects of capillarity on bone regeneration in vivo; it demonstrates that micropore-induced capillarity significantly enhances the bone distribution in the scaffold. The results will impact the design of scaffolds to better exploit capillarity and improve treatments for large and load-bearing bone defects. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Stochastic Growth Theory of Spatially-Averaged Distributions of Langmuir Fields in Earth's Foreshock

NASA Technical Reports Server (NTRS)

Boshuizen, Christopher R.; Cairns, Iver H.; Robinson, P. A.

2001-01-01

Langmuir-like waves in the foreshock of Earth are characteristically bursty and irregular, and are the subject of a number of recent studies. Averaged over the foreshock, it is observed that the probability distribution is power-law P(bar)(log E) in the wave field E with the bar denoting this averaging over position, In this paper it is shown that stochastic growth theory (SGT) can explain a power-law spatially-averaged distributions P(bar)(log E), when the observed power-law variations of the mean and standard deviation of log E with position are combined with the log normal statistics predicted by SGT at each location.

Distributed estimation for adaptive sensor selection in wireless sensor networks

NASA Astrophysics Data System (ADS)

Mahmoud, Magdi S.; Hassan Hamid, Matasm M.

2014-05-01

Wireless sensor networks (WSNs) are usually deployed for monitoring systems with the distributed detection and estimation of sensors. Sensor selection in WSNs is considered for target tracking. A distributed estimation scenario is considered based on the extended information filter. A cost function using the geometrical dilution of precision measure is derived for active sensor selection. A consensus-based estimation method is proposed in this paper for heterogeneous WSNs with two types of sensors. The convergence properties of the proposed estimators are analyzed under time-varying inputs. Accordingly, a new adaptive sensor selection (ASS) algorithm is presented in which the number of active sensors is adaptively determined based on the absolute local innovations vector. Simulation results show that the tracking accuracy of the ASS is comparable to that of the other algorithms.

Incidence and prevalence of elite male cricket injuries using updated consensus definitions.

PubMed

Orchard, John W; Kountouris, Alex; Sims, Kevin

2016-01-01

T20 (Twenty20 or 20 over) cricket has emerged in the last decade as the most popular form of cricket (in terms of spectator attendances). International consensus cricket definitions, first published in 2005, were updated in 2016 to better reflect the rise to prominence of T20 cricket. Injury incidence and prevalence rates were calculated using the new international methods and units for elite senior male Australian cricketers over the past decade (season 2006-2007 to season 2015-2016 inclusive). Over the past 10 seasons, average match injury incidence, for match time-loss injuries, was 155 injuries/1,000 days of play, with the highest daily rates in 50-over cricket, followed by 20-over cricket and First-Class matches. Annual injury incidence was 64 injuries/100 players per season, and average annual injury prevalence was 12.5% (although fast bowlers averaged 20.6%, much higher than other positions). The most common injury was the hamstring strain (seasonal incidence 8.7 injuries/100 players per season). The most prevalent injury was lumbar stress fractures (1.9% of players unavailable at all times owing to these injuries, which represents 15% of all missed playing time). The hamstring strain has emerged from being one of the many common injuries in elite cricket a decade ago to being clearly the most common injury in the sport at the elite level. This is presumably in association with increased T20 cricket. Lumbar stress fractures in fast bowlers are still the most prevalent injury in the sport of cricket at the elite level, although these injuries are more associated with high workloads arising from the longer forms of the game. Domestic and international matches have very similar match injury incidence rates across the formats, but injury prevalence is higher in international players as they play for most of the year without a substantial off-season.

Incidence and prevalence of elite male cricket injuries using updated consensus definitions

PubMed Central

Orchard, John W; Kountouris, Alex; Sims, Kevin

2016-01-01

Background T20 (Twenty20 or 20 over) cricket has emerged in the last decade as the most popular form of cricket (in terms of spectator attendances). International consensus cricket definitions, first published in 2005, were updated in 2016 to better reflect the rise to prominence of T20 cricket. Methods Injury incidence and prevalence rates were calculated using the new international methods and units for elite senior male Australian cricketers over the past decade (season 2006–2007 to season 2015–2016 inclusive). Results Over the past 10 seasons, average match injury incidence, for match time-loss injuries, was 155 injuries/1,000 days of play, with the highest daily rates in 50-over cricket, followed by 20-over cricket and First-Class matches. Annual injury incidence was 64 injuries/100 players per season, and average annual injury prevalence was 12.5% (although fast bowlers averaged 20.6%, much higher than other positions). The most common injury was the hamstring strain (seasonal incidence 8.7 injuries/100 players per season). The most prevalent injury was lumbar stress fractures (1.9% of players unavailable at all times owing to these injuries, which represents 15% of all missed playing time). Discussion The hamstring strain has emerged from being one of the many common injuries in elite cricket a decade ago to being clearly the most common injury in the sport at the elite level. This is presumably in association with increased T20 cricket. Lumbar stress fractures in fast bowlers are still the most prevalent injury in the sport of cricket at the elite level, although these injuries are more associated with high workloads arising from the longer forms of the game. Domestic and international matches have very similar match injury incidence rates across the formats, but injury prevalence is higher in international players as they play for most of the year without a substantial off-season. PMID:28008292

Distributional behavior of diffusion coefficients obtained by single trajectories in annealed transit time model

NASA Astrophysics Data System (ADS)

Akimoto, Takuma; Yamamoto, Eiji

2016-12-01

Local diffusion coefficients in disordered systems such as spin glass systems and living cells are highly heterogeneous and may change over time. Such a time-dependent and spatially heterogeneous environment results in irreproducibility of single-particle-tracking measurements. Irreproducibility of time-averaged observables has been theoretically studied in the context of weak ergodicity breaking in stochastic processes. Here, we provide rigorous descriptions of equilibrium and non-equilibrium diffusion processes for the annealed transit time model, which is a heterogeneous diffusion model in living cells. We give analytical solutions for the mean square displacement (MSD) and the relative standard deviation of the time-averaged MSD for equilibrium and non-equilibrium situations. We find that the time-averaged MSD grows linearly with time and that the time-averaged diffusion coefficients are intrinsically random (irreproducible) even in the long-time measurements in non-equilibrium situations. Furthermore, the distribution of the time-averaged diffusion coefficients converges to a universal distribution in the sense that it does not depend on initial conditions. Our findings pave the way for a theoretical understanding of distributional behavior of the time-averaged diffusion coefficients in disordered systems.

Efficient packet transportation on complex networks with nonuniform node capacity distribution

NASA Astrophysics Data System (ADS)

He, Xuan; Niu, Kai; He, Zhiqiang; Lin, Jiaru; Jiang, Zhong-Yuan

2015-03-01

Provided that node delivery capacity may be not uniformly distributed in many realistic networks, we present a node delivery capacity distribution in which each node capacity is composed of uniform fraction and degree related proportion. Based on the node delivery capacity distribution, we construct a novel routing mechanism called efficient weighted routing (EWR) strategy to enhance network traffic capacity and transportation efficiency. Compared with the shortest path routing and the efficient routing strategies, the EWR achieves the highest traffic capacity. After investigating average path length, network diameter, maximum efficient betweenness, average efficient betweenness, average travel time and average traffic load under extensive simulations, it indicates that the EWR appears to be a very effective routing method. The idea of this routing mechanism gives us a good insight into network science research. The practical use of this work is prospective in some real complex systems such as the Internet.

Expert validation of a teamwork assessment rubric: A modified Delphi study.

PubMed

Parratt, Jenny A; Fahy, Kathleen M; Hutchinson, Marie; Lohmann, Gui; Hastie, Carolyn R; Chaseling, Marilyn; O'Brien, Kylie

2016-01-01

Teamwork is a 'soft skill' employability competence desired by employers. Poor teamwork skills in healthcare have an impact on adverse outcomes. Teamwork skills are rarely the focus of teaching and assessment in undergraduate courses. The TeamUP Rubric is a tool used to teach and evaluate undergraduate students' teamwork skills. Students also use the rubric to give anonymised peer feedback during team-based academic assignments. The rubric's five domains focus on planning, environment, facilitation, conflict management and individual contribution; each domain is grounded in relevant theory. Students earn marks for their teamwork skills; validity of the assessment rubric is critical. To what extent do experts agree that the TeamUP Rubric is a valid assessment of 'teamwork skills'? Modified Delphi technique incorporating Feminist Collaborative Conversations. A heterogeneous panel of 35 professionals with recognised expertise in communications and/or teamwork. Three Delphi rounds using a survey that included the rubric were conducted either face-to-face, by telephone or online. Quantitative analysis yielded item content validity indices (I-CVI); minimum consensus was pre-set at 70%. An average of the I-CVI also yielded sub-scale (domain) (D-CVI/Ave) and scale content validity indices (S-CVI/Ave). After each Delphi round, qualitative data were analysed and interpreted; Feminist Collaborative Conversations by the research team aimed to clarify and confirm consensus about the wording of items on the rubric. Consensus (at 70%) was obtained for all but one behavioural descriptor of the rubric. We modified that descriptor to address expert concerns. The TeamUP Rubric (Version 4) can be considered to be well validated at that level of consensus. The final rubric reflects underpinning theory, with no areas of conceptual overlap between rubric domains. The final TeamUP Rubric arising from this study validly measures individual student teamwork skills and can be used with confidence in the university setting. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pelvic Normal Tissue Contouring Guidelines for Radiation Therapy: A Radiation Therapy Oncology Group Consensus Panel Atlas

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

Gay, Hiram A., E-mail: hgay@radonc.wustl.edu; Barthold, H. Joseph; Beth Israel Deaconess Medical Center, Boston, MA

2012-07-01

Purpose: To define a male and female pelvic normal tissue contouring atlas for Radiation Therapy Oncology Group (RTOG) trials. Methods and Materials: One male pelvis computed tomography (CT) data set and one female pelvis CT data set were shared via the Image-Guided Therapy QA Center. A total of 16 radiation oncologists participated. The following organs at risk were contoured in both CT sets: anus, anorectum, rectum (gastrointestinal and genitourinary definitions), bowel NOS (not otherwise specified), small bowel, large bowel, and proximal femurs. The following were contoured in the male set only: bladder, prostate, seminal vesicles, and penile bulb. The followingmore » were contoured in the female set only: uterus, cervix, and ovaries. A computer program used the binomial distribution to generate 95% group consensus contours. These contours and definitions were then reviewed by the group and modified. Results: The panel achieved consensus definitions for pelvic normal tissue contouring in RTOG trials with these standardized names: Rectum, AnoRectum, SmallBowel, Colon, BowelBag, Bladder, UteroCervix, Adnexa{sub R}, Adnexa{sub L}, Prostate, SeminalVesc, PenileBulb, Femur{sub R}, and Femur{sub L}. Two additional normal structures whose purpose is to serve as targets in anal and rectal cancer were defined: AnoRectumSig and Mesorectum. Detailed target volume contouring guidelines and images are discussed. Conclusions: Consensus guidelines for pelvic normal tissue contouring were reached and are available as a CT image atlas on the RTOG Web site. This will allow uniformity in defining normal tissues for clinical trials delivering pelvic radiation and will facilitate future normal tissue complication research.« less

Neuropathic pain phenotyping by international consensus (NeuroPPIC) for genetic studies: a NeuPSIG systematic review, Delphi survey, and expert panel recommendations

PubMed Central

van Hecke, Oliver; Kamerman, Peter R.; Attal, Nadine; Baron, Ralf; Bjornsdottir, Gyda; Bennett, David L.H.; Bennett, Michael I.; Bouhassira, Didier; Diatchenko, Luda; Freeman, Roy; Freynhagen, Rainer; Haanpää, Maija; Jensen, Troels S.; Raja, Srinivasa N.; Rice, Andrew S.C.; Seltzer, Ze'ev; Thorgeirsson, Thorgeir E.; Yarnitsky, David; Smith, Blair H.

2015-01-01

Abstract For genetic research to contribute more fully to furthering our knowledge of neuropathic pain, we require an agreed, valid, and feasible approach to phenotyping, to allow collaboration and replication in samples of sufficient size. Results from genetic studies on neuropathic pain have been inconsistent and have met with replication difficulties, in part because of differences in phenotypes used for case ascertainment. Because there is no consensus on the nature of these phenotypes, nor on the methods of collecting them, this study aimed to provide guidelines on collecting and reporting phenotypes in cases and controls for genetic studies. Consensus was achieved through a staged approach: (1) systematic literature review to identify all neuropathic pain phenotypes used in previous genetic studies; (2) Delphi survey to identify the most useful neuropathic pain phenotypes and their validity and feasibility; and (3) meeting of experts to reach consensus on the optimal phenotype(s) to be collected from patients with neuropathic pain for genetic studies. A basic “entry level” set of phenotypes was identified for any genetic study of neuropathic pain. This set identifies cases of “possible” neuropathic pain, and controls, and includes: (1) a validated symptom-based questionnaire to determine whether any pain is likely to be neuropathic; (2) body chart or checklist to identify whether the area of pain distribution is neuroanatomically logical; and (3) details of pain history (intensity, duration, any formal diagnosis). This NeuroPPIC “entry level” set of phenotypes can be expanded by more extensive and specific measures, as determined by scientific requirements and resource availability. PMID:26469320

Physical Restraints: Consensus of a Research Definition Using a Modified Delphi Technique.

PubMed

Bleijlevens, Michel H C; Wagner, Laura M; Capezuti, Elizabeth; Hamers, Jan P H

2016-11-01

To develop an internationally accepted research definition of physical restraint. Comprehensive literature search followed by a web-based, three-round, modified Delphi technique comprising reviews and feedback. Clinical care settings. An international group of 48 experts consisting of researchers and clinicians from 14 countries who have made sustained contribution to research and clinical application in the field of physical restraint in clinical care. Data were collected using an online survey program and one in-person meeting. Results of the online survey and the in-person meeting were used for distribution in subsequent rounds until consensus on a definition was reached. Consensus was defined as 90% of the participating experts agreeing with the proposed definition of physical restraint. Thirty-four different definitions were identified during the literature search and served as a starting point for the modified Delphi technique. After three rounds, 45 (95.7%) of 47 remaining experts agreed with the newly proposed definition: "Physical restraint is defined as any action or procedure that prevents a person's free body movement to a position of choice and/or normal access to his/her body by the use of any method, attached or adjacent to a person's body that he/she cannot control or remove easily." A multidisciplinary, internationally representative panel of experts reached consensus on a research definition for physical restraints in older persons. This is a necessary step toward improved comparisons of the prevalence of physical restraint use across studies and countries. This definition can further guide research interventions aimed at reducing use of physical restraints. © 2016, Copyright the Authors Journal compilation © 2016, The American Geriatrics Society.

Defining consensus norms for palliative care of people with intellectual disabilities in Europe, using Delphi methods: A White Paper from the European Association of Palliative Care

PubMed Central

Tuffrey-Wijne, Irene; McLaughlin, Dorry; Curfs, Leopold; Dusart, Anne; Hoenger, Catherine; McEnhill, Linda; Read, Sue; Ryan, Karen; Satgé, Daniel; Straßer, Benjamin; Westergård, Britt-Evy; Oliver, David

2015-01-01

Background: People with intellectual disabilities often present with unique challenges that make it more difficult to meet their palliative care needs. Aim: To define consensus norms for palliative care of people with intellectual disabilities in Europe. Design: Delphi study in four rounds: (1) a taskforce of 12 experts from seven European countries drafted the norms, based on available empirical knowledge and regional/national guidelines; (2) using an online survey, 34 experts from 18 European countries evaluated the draft norms, provided feedback and distributed the survey within their professional networks. Criteria for consensus were clearly defined; (3) modifications and recommendations were made by the taskforce; and (4) the European Association for Palliative Care reviewed and approved the final version. Setting and participants: Taskforce members: identified through international networking strategies. Expert panel: a purposive sample identified through taskforce members’ networks. Results: A total of 80 experts from 15 European countries evaluated 52 items within the following 13 norms: equity of access, communication, recognising the need for palliative care, assessment of total needs, symptom management, end-of-life decision making, involving those who matter, collaboration, support for family/carers, preparing for death, bereavement support, education/training and developing/managing services. None of the items scored less than 86% agreement, making a further round unnecessary. In light of respondents’ comments, several items were modified and one item was deleted. Conclusion: This White Paper presents the first guidance for clinical practice, policy and research related to palliative care for people with intellectual disabilities based on evidence and European consensus, setting a benchmark for changes in policy and practice. PMID:26346181

Development and validation of a mass casualty conceptual model.

PubMed

Culley, Joan M; Effken, Judith A

2010-03-01

To develop and validate a conceptual model that provides a framework for the development and evaluation of information systems for mass casualty events. The model was designed based on extant literature and existing theoretical models. A purposeful sample of 18 experts validated the model. Open-ended questions, as well as a 7-point Likert scale, were used to measure expert consensus on the importance of each construct and its relationship in the model and the usefulness of the model to future research. Computer-mediated applications were used to facilitate a modified Delphi technique through which a panel of experts provided validation for the conceptual model. Rounds of questions continued until consensus was reached, as measured by an interquartile range (no more than 1 scale point for each item); stability (change in the distribution of responses less than 15% between rounds); and percent agreement (70% or greater) for indicator questions. Two rounds of the Delphi process were needed to satisfy the criteria for consensus or stability related to the constructs, relationships, and indicators in the model. The panel reached consensus or sufficient stability to retain all 10 constructs, 9 relationships, and 39 of 44 indicators. Experts viewed the model as useful (mean of 5.3 on a 7-point scale). Validation of the model provides the first step in understanding the context in which mass casualty events take place and identifying variables that impact outcomes of care. This study provides a foundation for understanding the complexity of mass casualty care, the roles that nurses play in mass casualty events, and factors that must be considered in designing and evaluating information-communication systems to support effective triage under these conditions.

Particle Size Distributions Obtained Through Unfolding 2D Sections: Towards Accurate Distributions of Nebular Solids in the Allende Meteorite

NASA Technical Reports Server (NTRS)

Christoffersen, P. A.; Simon, Justin I.; Ross, D. K.; Friedrich, J. M.; Cuzzi, J. N.

2012-01-01

Size distributions of nebular solids in chondrites suggest an efficient sorting of these early forming objects within the protoplanetary disk. The effect of this sorting has been documented by investigations of modal abundances of CAIs (e.g., [1-4]) and chondrules (e.g., [5-8]). Evidence for aerodynamic sorting in the disk is largely qualitative, and needs to be carefully assessed. It may be a way of concentrating these materials into planetesimal-mass clumps, perhaps 100 fs of ka after they formed. A key parameter is size/density distributions of particles (i.e., chondrules, CAIs, and metal grains), and in particular, whether the radius-density product (rxp) is a better metric for defining the distribution than r alone [9]. There is no consensus between r versus rxp based models. Here we report our initial tests and preliminary results, which when expanded will be used to test the accuracy of current dynamical disk models.

What is normal nasal airflow? A computational study of 22 healthy adults

PubMed Central

Zhao, Kai; Jiang, Jianbo

2014-01-01

Objective Nasal airflow is essential for functioning of the human nose. Given individual variation in nasal anatomy, there is yet no consensus what constitutes normal nasal airflow patterns. We attempt to obtain such information that is essential to differentiate disease-related variations. Methods Computational fluid dynamics (CFD) simulated nasal airflow in 22 healthy subjects during resting breathing. Streamline patterns, airflow distributions, velocity profiles, pressure, wall stress, turbulence, and vortical flow characteristics under quasi-steady state were analyzed. Patency ratings, acoustically measured minimum cross-sectional area (MCA), and rhinomanometric nasal resistance (NR) were examined for potential correlations with morphological and airflow-related variables. Results Common features across subjects included: >50% total pressure-drop reached near the inferior turbinate head; wall shear stress, NR, turbulence energy, and vorticity were lower in the turbinate than in the nasal valve region. However, location of the major flow path and coronal velocity distributions varied greatly across individuals. Surprisingly, on average, more flow passed through the middle than the inferior meatus and correlated with better patency ratings (r=-0.65, p<0.01). This middle flow percentage combined with peak post-vestibule nasal heat loss and MCA accounted for >70% of the variance in subjective patency ratings and predicted patency categories with 86% success. Nasal index correlated with forming of the anterior dorsal vortex. Expected for resting breathing, the functional impact for local and total turbulence, vorticity, and helicity was limited. As validation, rhinomanometric NR significantly correlated with CFD simulations (r=0.53, p<0.01). Conclusion Significant variations of nasal airflow found among healthy subjects; Key features may have clinically relevant applications. PMID:24664528

Mass balance, meteorology, area altitude distribution, glacier-surface altitude, ice motion, terminus position, and runoff at Gulkana Glacier, Alaska, 1996 balance year

USGS Publications Warehouse

March, Rod S.

2003-01-01

The 1996 measured winter snow, maximum winter snow, net, and annual balances in the Gulkana Glacier Basin were evaluated on the basis of meteorological, hydrological, and glaciological data. Averaged over the glacier, the measured winter snow balance was 0.87 meter on April 18, 1996, 1.1 standard deviation below the long-term average; the maximum winter snow balance, 1.06 meters, was reached on May 28, 1996; and the net balance (from August 30, 1995, to August 24, 1996) was -0.53 meter, 0.53 standard deviation below the long-term average. The annual balance (October 1, 1995, to September 30, 1996) was -0.37 meter. Area-averaged balances were reported using both the 1967 and 1993 area altitude distributions (the numbers previously given in this abstract use the 1993 area altitude distribution). Net balance was about 25 percent less negative using the 1993 area altitude distribution than the 1967 distribution. Annual average air temperature was 0.9 degree Celsius warmer than that recorded with the analog sensor used since 1966. Total precipitation catch for the year was 0.78 meter, 0.8 standard deviations below normal. The annual average wind speed was 3.5 meters per second in the first year of measuring wind speed. Annual runoff averaged 1.50 meters over the basin, 1.0 standard deviation below the long-term average. Glacier-surface altitude and ice-motion changes measured at three index sites document seasonal ice-speed and glacier-thickness changes. Both showed a continuation of a slowing and thinning trend present in the 1990s. The glacier terminus and lower ablation area were defined for 1996 with a handheld Global Positioning System survey of 126 locations spread out over about 4 kilometers on the lower glacier margin. From 1949 to 1996, the terminus retreated about 1,650 meters for an average retreat rate of 35 meters per year.

Effect of improved TLD dosimetry on the determination of dose rate constants for {sup 125}I and {sup 103}Pd brachytherapy seeds

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

Rodriguez, M., E-mail: manuel.rodriguez@rmp.uhn.ca; Rogers, D. W. O.

Purpose: To more accurately account for the relative intrinsic energy dependence and relative absorbed-dose energy dependence of TLDs when used to measure dose rate constants (DRCs) for {sup 125}I and {sup 103}Pd brachytherapy seeds, to thereby establish revised “measured values” for all seeds and compare the revised values with Monte Carlo and consensus values. Methods: The relative absorbed-dose energy dependence, f{sup rel}, for TLDs and the phantom correction, P{sub phant}, are calculated for {sup 125}I and {sup 103}Pd seeds using the EGSnrc BrachyDose and DOSXYZnrc codes. The original energy dependence and phantom corrections applied to DRC measurements are replaced bymore » calculated (f{sup rel}){sup −1} and P{sub phant} values for 24 different seed models. By comparing the modified measured DRCs to the MC values, an appropriate relative intrinsic energy dependence, k{sub bq}{sup rel}, is determined. The new P{sub phant} values and relative absorbed-dose sensitivities, S{sub AD}{sup rel}, calculated as the product of (f{sup rel}){sup −1} and (k{sub bq}{sup rel}){sup −1}, are used to individually revise the measured DRCs for comparison with Monte Carlo calculated values and TG-43U1 or TG-43U1S1 consensus values. Results: In general, f{sup rel} is sensitive to the energy spectra and models of the brachytherapy seeds. Values may vary up to 8.4% among {sup 125}I and {sup 103}Pd seed models and common TLD shapes. P{sub phant} values depend primarily on the isotope used. Deduced (k{sub bq}{sup rel}){sup −1} values are 1.074 ± 0.015 and 1.084 ± 0.026 for {sup 125}I and {sup 103}Pd seeds, respectively. For (1 mm){sup 3} chips, this implies an overall absorbed-dose sensitivity relative to {sup 60}Co or 6 MV calibrations of 1.51 ± 1% and 1.47 ± 2% for {sup 125}I and {sup 103}Pd seeds, respectively, as opposed to the widely used value of 1.41. Values of P{sub phant} calculated here have much lower statistical uncertainties than literature values, but systematic uncertainties from density and composition uncertainties are significant. Using these revised values with the literature’s DRC measurements, the average discrepancies between revised measured values and Monte Carlo values are 1.2% and 0.2% for {sup 125}I and {sup 103}Pd seeds, respectively, compared to average discrepancies for the original measured values of 4.8%. On average, the revised measured values are 4.3% and 5.9% lower than the original measured values for {sup 103}Pd and {sup 125}I seeds, respectively. The average of revised DRCs and Monte Carlo values is 3.8% and 2.8% lower for {sup 125}I and {sup 103}Pd seeds, respectively, than the consensus values in TG-43U1 or TG-43U1S1. Conclusions: This work shows that f{sup rel} is TLD shape and seed model dependent suggesting a need to update the generalized energy response dependence, i.e., relative absorbed-dose sensitivity, measured 25 years ago and applied often to DRC measurements of {sup 125}I and {sup 103}Pd brachytherapy seeds. The intrinsic energy dependence for LiF TLDs deduced here is consistent with previous dosimetry studies and emphasizes the need to revise the DRC consensus values reported by TG-43U1 or TG-43U1S1.« less

A core phylogeny of Dictyostelia inferred from genomes representative of the eight major and minor taxonomic divisions of the group.

PubMed

Singh, Reema; Schilde, Christina; Schaap, Pauline

2016-11-17

Dictyostelia are a well-studied group of organisms with colonial multicellularity, which are members of the mostly unicellular Amoebozoa. A phylogeny based on SSU rDNA data subdivided all Dictyostelia into four major groups, but left the position of the root and of six group-intermediate taxa unresolved. Recent phylogenies inferred from 30 or 213 proteins from sequenced genomes, positioned the root between two branches, each containing two major groups, but lacked data to position the group-intermediate taxa. Since the positions of these early diverging taxa are crucial for understanding the evolution of phenotypic complexity in Dictyostelia, we sequenced six representative genomes of early diverging taxa. We retrieved orthologs of 47 housekeeping proteins with an average size of 890 amino acids from six newly sequenced and eight published genomes of Dictyostelia and unicellular Amoebozoa and inferred phylogenies from single and concatenated protein sequence alignments. Concatenated alignments of all 47 proteins, and four out of five subsets of nine concatenated proteins all produced the same consensus phylogeny with 100% statistical support. Trees inferred from just two out of the 47 proteins, individually reproduced the consensus phylogeny, highlighting that single gene phylogenies will rarely reflect correct species relationships. However, sets of two or three concatenated proteins again reproduced the consensus phylogeny, indicating that a small selection of genes suffices for low cost classification of as yet unincorporated or newly discovered dictyostelid and amoebozoan taxa by gene amplification. The multi-locus consensus phylogeny shows that groups 1 and 2 are sister clades in branch I, with the group-intermediate taxon D. polycarpum positioned as outgroup to group 2. Branch II consists of groups 3 and 4, with the group-intermediate taxon Polysphondylium violaceum positioned as sister to group 4, and the group-intermediate taxon Dictyostelium polycephalum branching at the base of that whole clade. Given the data, the approximately unbiased test rejects all alternative topologies favoured by SSU rDNA and individual proteins with high statistical support. The test also rejects monophyletic origins for the genera Acytostelium, Polysphondylium and Dictyostelium. The current position of Acytostelium ellipticum in the consensus phylogeny indicates that somatic cells were lost twice in Dictyostelia.

Hyperspectral remote sensing of plant biochemistry using Bayesian model averaging with variable and band selection

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

Zhao, Kaiguang; Valle, Denis; Popescu, Sorin

2013-05-15

Model specification remains challenging in spectroscopy of plant biochemistry, as exemplified by the availability of various spectral indices or band combinations for estimating the same biochemical. This lack of consensus in model choice across applications argues for a paradigm shift in hyperspectral methods to address model uncertainty and misspecification. We demonstrated one such method using Bayesian model averaging (BMA), which performs variable/band selection and quantifies the relative merits of many candidate models to synthesize a weighted average model with improved predictive performances. The utility of BMA was examined using a portfolio of 27 foliage spectral–chemical datasets representing over 80 speciesmore » across the globe to estimate multiple biochemical properties, including nitrogen, hydrogen, carbon, cellulose, lignin, chlorophyll (a or b), carotenoid, polar and nonpolar extractives, leaf mass per area, and equivalent water thickness. We also compared BMA with partial least squares (PLS) and stepwise multiple regression (SMR). Results showed that all the biochemicals except carotenoid were accurately estimated from hyerspectral data with R2 values > 0.80.« less

Groin Pain Syndrome Italian Consensus Conference on terminology, clinical evaluation and imaging assessment in groin pain in athlete

PubMed Central

Bisciotti, G N; Volpi, P; Zini, R; Auci, A; Aprato, A; Belli, A; Bellistri, G; Benelli, P; Bona, S; Bonaiuti, D; Carimati, G; Canata, G L; Cassaghi, G; Cerulli, S; Delle Rose, G; Di Benedetto, P; Di Marzo, F; Di Pietto, F; Felicioni, L; Ferrario, L; Foglia, A; Galli, M; Gervasi, E; Gia, L; Giammattei, C; Guglielmi, A; Marioni, A; Moretti, B; Niccolai, R; Orgiani, N; Pantalone, A; Parra, F; Quaglia, A; Respizzi, F; Ricciotti, L; Pereira Ruiz, M T; Russo, A; Sebastiani, E; Tancredi, G; Tosi, F; Vuckovic, Z

2016-01-01

The nomenclature and the lack of consensus of clinical evaluation and imaging assessment in groin pain generate significant confusion in this field. The Groin Pain Syndrome Italian Consensus Conference has been organised in order to prepare a consensus document regarding taxonomy, clinical evaluation and imaging assessment for groin pain. A 1-day Consensus Conference was organised on 5 February 2016, in Milan (Italy). 41 Italian experts with different backgrounds participated in the discussion. A consensus document previously drafted was discussed, eventually modified, and finally approved by all members of the Consensus Conference. Unanimous consensus was reached concerning: (1) taxonomy (2) clinical evaluation and (3) imaging assessment. The synthesis of these 3 points is included in this paper. The Groin Pain Syndrome Italian Consensus Conference reached a consensus on three main points concerning the groin pain syndrome assessment, in an attempt to clarify this challenging medical problem. PMID:28890800

Distributed cooperative regulation for multiagent systems and its applications to power systems: a survey.

PubMed

Hu, Jianqiang; Li, Yaping; Yong, Taiyou; Cao, Jinde; Yu, Jie; Mao, Wenbo

2014-01-01

Cooperative regulation of multiagent systems has become an active research area in the past decade. This paper reviews some recent progress in distributed coordination control for leader-following multiagent systems and its applications in power system and mainly focuses on the cooperative tracking control in terms of consensus tracking control and containment tracking control. Next, methods on how to rank the network nodes are summarized for undirected/directed network, based on which one can determine which follower should be connected to leaders such that partial followers can perceive leaders' information. Furthermore, we present a survey of the most relevant scientific studies investigating the regulation and optimization problems in power systems based on distributed strategies. Finally, some potential applications in the frequency tracking regulation of smart grids are discussed at the end of the paper.

Distributed Cooperative Regulation for Multiagent Systems and Its Applications to Power Systems: A Survey

PubMed Central

Li, Yaping; Yong, Taiyou; Yu, Jie; Mao, Wenbo

2014-01-01

Cooperative regulation of multiagent systems has become an active research area in the past decade. This paper reviews some recent progress in distributed coordination control for leader-following multiagent systems and its applications in power system and mainly focuses on the cooperative tracking control in terms of consensus tracking control and containment tracking control. Next, methods on how to rank the network nodes are summarized for undirected/directed network, based on which one can determine which follower should be connected to leaders such that partial followers can perceive leaders' information. Furthermore, we present a survey of the most relevant scientific studies investigating the regulation and optimization problems in power systems based on distributed strategies. Finally, some potential applications in the frequency tracking regulation of smart grids are discussed at the end of the paper. PMID:25243199

REC-1 and HIM-5 distribute meiotic crossovers and function redundantly in meiotic double-strand break formation in Caenorhabditis elegans

PubMed Central

Chung, George; Rose, Ann M.; Petalcorin, Mark I.R.; Martin, Julie S.; Kessler, Zebulin; Sanchez-Pulido, Luis; Ponting, Chris P.; Yanowitz, Judith L.; Boulton, Simon J.

2015-01-01

The Caenorhabditis elegans gene rec-1 was the first genetic locus identified in metazoa to affect the distribution of meiotic crossovers along the chromosome. We report that rec-1 encodes a distant paralog of HIM-5, which was discovered by whole-genome sequencing and confirmed by multiple genome-edited alleles. REC-1 is phosphorylated by cyclin-dependent kinase (CDK) in vitro, and mutation of the CDK consensus sites in REC-1 compromises meiotic crossover distribution in vivo. Unexpectedly, rec-1; him-5 double mutants are synthetic-lethal due to a defect in meiotic double-strand break formation. Thus, we uncovered an unexpected robustness to meiotic DSB formation and crossover positioning that is executed by HIM-5 and REC-1 and regulated by phosphorylation. PMID:26385965

Molecular Isotopic Distribution Analysis (MIDAs) with Adjustable Mass Accuracy

NASA Astrophysics Data System (ADS)

Alves, Gelio; Ogurtsov, Aleksey Y.; Yu, Yi-Kuo

2014-01-01

In this paper, we present Molecular Isotopic Distribution Analysis (MIDAs), a new software tool designed to compute molecular isotopic distributions with adjustable accuracies. MIDAs offers two algorithms, one polynomial-based and one Fourier-transform-based, both of which compute molecular isotopic distributions accurately and efficiently. The polynomial-based algorithm contains few novel aspects, whereas the Fourier-transform-based algorithm consists mainly of improvements to other existing Fourier-transform-based algorithms. We have benchmarked the performance of the two algorithms implemented in MIDAs with that of eight software packages (BRAIN, Emass, Mercury, Mercury5, NeutronCluster, Qmass, JFC, IC) using a consensus set of benchmark molecules. Under the proposed evaluation criteria, MIDAs's algorithms, JFC, and Emass compute with comparable accuracy the coarse-grained (low-resolution) isotopic distributions and are more accurate than the other software packages. For fine-grained isotopic distributions, we compared IC, MIDAs's polynomial algorithm, and MIDAs's Fourier transform algorithm. Among the three, IC and MIDAs's polynomial algorithm compute isotopic distributions that better resemble their corresponding exact fine-grained (high-resolution) isotopic distributions. MIDAs can be accessed freely through a user-friendly web-interface at http://www.ncbi.nlm.nih.gov/CBBresearch/Yu/midas/index.html.

Molecular Isotopic Distribution Analysis (MIDAs) with adjustable mass accuracy.

PubMed

Alves, Gelio; Ogurtsov, Aleksey Y; Yu, Yi-Kuo

2014-01-01

In this paper, we present Molecular Isotopic Distribution Analysis (MIDAs), a new software tool designed to compute molecular isotopic distributions with adjustable accuracies. MIDAs offers two algorithms, one polynomial-based and one Fourier-transform-based, both of which compute molecular isotopic distributions accurately and efficiently. The polynomial-based algorithm contains few novel aspects, whereas the Fourier-transform-based algorithm consists mainly of improvements to other existing Fourier-transform-based algorithms. We have benchmarked the performance of the two algorithms implemented in MIDAs with that of eight software packages (BRAIN, Emass, Mercury, Mercury5, NeutronCluster, Qmass, JFC, IC) using a consensus set of benchmark molecules. Under the proposed evaluation criteria, MIDAs's algorithms, JFC, and Emass compute with comparable accuracy the coarse-grained (low-resolution) isotopic distributions and are more accurate than the other software packages. For fine-grained isotopic distributions, we compared IC, MIDAs's polynomial algorithm, and MIDAs's Fourier transform algorithm. Among the three, IC and MIDAs's polynomial algorithm compute isotopic distributions that better resemble their corresponding exact fine-grained (high-resolution) isotopic distributions. MIDAs can be accessed freely through a user-friendly web-interface at http://www.ncbi.nlm.nih.gov/CBBresearch/Yu/midas/index.html.

Plan averaging for multicriteria navigation of sliding window IMRT and VMAT

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

Craft, David, E-mail: dcraft@partners.org; Papp, Dávid; Unkelbach, Jan

2014-02-15

Purpose: To describe a method for combining sliding window plans [intensity modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT)] for use in treatment plan averaging, which is needed for Pareto surface navigation based multicriteria treatment planning. Methods: The authors show that by taking an appropriately defined average of leaf trajectories of sliding window plans, the authors obtain a sliding window plan whose fluence map is the exact average of the fluence maps corresponding to the initial plans. In the case of static-beam IMRT, this also implies that the dose distribution of the averaged plan is the exact dosimetricmore » average of the initial plans. In VMAT delivery, the dose distribution of the averaged plan is a close approximation of the dosimetric average of the initial plans. Results: The authors demonstrate the method on three Pareto optimal VMAT plans created for a demanding paraspinal case, where the tumor surrounds the spinal cord. The results show that the leaf averaged plans yield dose distributions that approximate the dosimetric averages of the precomputed Pareto optimal plans well. Conclusions: The proposed method enables the navigation of deliverable Pareto optimal plans directly, i.e., interactive multicriteria exploration of deliverable sliding window IMRT and VMAT plans, eliminating the need for a sequencing step after navigation and hence the dose degradation that is caused by such a sequencing step.« less

Comparing the performance of FA, DFA and DMA using different synthetic long-range correlated time series

PubMed Central

Shao, Ying-Hui; Gu, Gao-Feng; Jiang, Zhi-Qiang; Zhou, Wei-Xing; Sornette, Didier

2012-01-01

Notwithstanding the significant efforts to develop estimators of long-range correlations (LRC) and to compare their performance, no clear consensus exists on what is the best method and under which conditions. In addition, synthetic tests suggest that the performance of LRC estimators varies when using different generators of LRC time series. Here, we compare the performances of four estimators [Fluctuation Analysis (FA), Detrended Fluctuation Analysis (DFA), Backward Detrending Moving Average (BDMA), and Centred Detrending Moving Average (CDMA)]. We use three different generators [Fractional Gaussian Noises, and two ways of generating Fractional Brownian Motions]. We find that CDMA has the best performance and DFA is only slightly worse in some situations, while FA performs the worst. In addition, CDMA and DFA are less sensitive to the scaling range than FA. Hence, CDMA and DFA remain “The Methods of Choice” in determining the Hurst index of time series. PMID:23150785

A Simple Sequence Repeat- and Single-Nucleotide Polymorphism-Based Genetic Linkage Map of the Brown Planthopper, Nilaparvata lugens

PubMed Central

Jairin, Jirapong; Kobayashi, Tetsuya; Yamagata, Yoshiyuki; Sanada-Morimura, Sachiyo; Mori, Kazuki; Tashiro, Kosuke; Kuhara, Satoru; Kuwazaki, Seigo; Urio, Masahiro; Suetsugu, Yoshitaka; Yamamoto, Kimiko; Matsumura, Masaya; Yasui, Hideshi

2013-01-01

In this study, we developed the first genetic linkage map for the major rice insect pest, the brown planthopper (BPH, Nilaparvata lugens). The linkage map was constructed by integrating linkage data from two backcross populations derived from three inbred BPH strains. The consensus map consists of 474 simple sequence repeats, 43 single-nucleotide polymorphisms, and 1 sequence-tagged site, for a total of 518 markers at 472 unique positions in 17 linkage groups. The linkage groups cover 1093.9 cM, with an average distance of 2.3 cM between loci. The average number of marker loci per linkage group was 27.8. The sex-linkage group was identified by exploiting X-linked and Y-specific markers. Our linkage map and the newly developed markers used to create it constitute an essential resource and a useful framework for future genetic analyses in BPH. PMID:23204257

Asia Pacific consensus recommendations for colorectal cancer screening.

PubMed

Sung, J J Y; Lau, J Y W; Young, G P; Sano, Y; Chiu, H M; Byeon, J S; Yeoh, K G; Goh, K L; Sollano, J; Rerknimitr, R; Matsuda, T; Wu, K C; Ng, S; Leung, S Y; Makharia, G; Chong, V H; Ho, K Y; Brooks, D; Lieberman, D A; Chan, F K L

2008-08-01

Colorectal cancer (CRC) is rapidly increasing in Asia, but screening guidelines are lacking. Through reviewing the literature and regional data, and using the modified Delphi process, the Asia Pacific Working Group on Colorectal Cancer and international experts launch consensus recommendations aiming to improve the awareness of healthcare providers of the changing epidemiology and screening tests available. The incidence, anatomical distribution and mortality of CRC among Asian populations are not different compared with Western countries. There is a trend of proximal migration of colonic polyps. Flat or depressed lesions are not uncommon. Screening for CRC should be started at the age of 50 years. Male gender, smoking, obesity and family history are risk factors for colorectal neoplasia. Faecal occult blood test (FOBT, guaiac-based and immunochemical tests), flexible sigmoidoscopy and colonoscopy are recommended for CRC screening. Double-contrast barium enema and CT colonography are not preferred. In resource-limited countries, FOBT is the first choice for CRC screening. Polyps 5-9 mm in diameter should be removed endoscopically and, following a negative colonoscopy, a repeat examination should be performed in 10 years. Screening for CRC should be a national health priority in most Asian countries. Studies on barriers to CRC screening, education for the public and engagement of primary care physicians should be undertaken. There is no consensus on whether nurses should be trained to perform endoscopic procedures for screening of colorectal neoplasia.

Kinetic energy distribution of multiply charged ions in Coulomb explosion of Xe clusters.

PubMed

Heidenreich, Andreas; Jortner, Joshua

2011-02-21

We report on the calculations of kinetic energy distribution (KED) functions of multiply charged, high-energy ions in Coulomb explosion (CE) of an assembly of elemental Xe(n) clusters (average size (n) = 200-2171) driven by ultra-intense, near-infrared, Gaussian laser fields (peak intensities 10(15) - 4 × 10(16) W cm(-2), pulse lengths 65-230 fs). In this cluster size and pulse parameter domain, outer ionization is incomplete∕vertical, incomplete∕nonvertical, or complete∕nonvertical, with CE occurring in the presence of nanoplasma electrons. The KEDs were obtained from double averaging of single-trajectory molecular dynamics simulation ion kinetic energies. The KEDs were doubly averaged over a log-normal cluster size distribution and over the laser intensity distribution of a spatial Gaussian beam, which constitutes either a two-dimensional (2D) or a three-dimensional (3D) profile, with the 3D profile (when the cluster beam radius is larger than the Rayleigh length) usually being experimentally realized. The general features of the doubly averaged KEDs manifest the smearing out of the structure corresponding to the distribution of ion charges, a marked increase of the KEDs at very low energies due to the contribution from the persistent nanoplasma, a distortion of the KEDs and of the average energies toward lower energy values, and the appearance of long low-intensity high-energy tails caused by the admixture of contributions from large clusters by size averaging. The doubly averaged simulation results account reasonably well (within 30%) for the experimental data for the cluster-size dependence of the CE energetics and for its dependence on the laser pulse parameters, as well as for the anisotropy in the angular distribution of the energies of the Xe(q+) ions. Possible applications of this computational study include a control of the ion kinetic energies by the choice of the laser intensity profile (2D∕3D) in the laser-cluster interaction volume.

Guidelines on "Standards of management of idiopathic scoliosis with corrective braces in everyday clinics and in clinical research": SOSORT Consensus 2008

PubMed Central

Negrini, Stefano; Grivas, Theodoros B; Kotwicki, Tomasz; Rigo, Manuel; Zaina, Fabio

2009-01-01

Background Reported failure rates,(defined based on percentage of cases progressing to surgery) of corrective bracing for idiopathic scoliosis are highly variable. This may be due to the quality of the brace itself, but also of the patient care during treatment. The latter is sometimes neglected, even though it is considered a main determinant of good results among conservative experts of SOSORT. The aim of this paper was to develop and verify the Consensus on management of scoliosis patients treated with braces Methods We followed a Delphi process in four steps, distributing and gradually changing according to the results a set of recommendations: we involved the SOSORT Board twice, then all SOSORT members twice, with a Pre-Meeting Questionnaire (PMQ), and during a Consensus Session at the SOSORT Athens Meeting with a Meeting Questionnaire (MQ). We set a 90% agreement as the minimum to be reached. Results We had a 71% response rate to PMQ, and 66.7% to MQ. Since the PMQ we had a good agreement (no answers below 72% – 70.2% over 90%). With the MQ the agreement consistently increased for all the answers previously below 90% (no answers below 83%, 75% over 90%). With increasing experience in bracing all numerical criteria tended to become more strict. We finally produced a set of 14 recommendations, grouped in 6 Domains (Experience/competence, Behaviours, Prescription, Construction, Brace Check, Follow-up). Conclusion The Consensus permits establishment of recommendations concerning the standards of management of idiopathic scoliosis with bracing, with the aim to increase efficacy and compliance to treatment. The SOSORT recommends to professionals engaged in patient care to follow the guidelines of this Consensus in their clinical practice. The SOSORT criteria should also be followed in clinical research studies to achieve a minimum quality of care. If the aim is to verify the efficacy of bracing these criteria should be companions of the methodological research criteria for bracing proposed by other societies. PMID:19149877

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

Results of APL rain gauge network measurements in mid-Atlantic coast region and comparisons of distributions with CCIR models

NASA Technical Reports Server (NTRS)

Goldhirsh, Julius; Gebo, Norman; Rowland, John

1988-01-01

In this effort are described cumulative rain rate distributions for a network of nine tipping bucket rain gauge systems located in the mid-Atlantic coast region in the vicinity of the NASA Wallops Flight Facility, Wallops Island, Virginia. The rain gauges are situated within a gridded region of dimensions of 47 km east-west by 70 km north-south. Distributions are presented for the individual site measurements and the network average for the year period June 1, 1986 through May 31, 1987. A previous six year average distribution derived from measurements at one of the site locations is also presented. Comparisons are given of the network average, the CCIR (International Radio Consultative Committee) climatic zone, and the CCIR functional model distributions, the latter of which approximates a log normal at the lower rain rate and a gamma function at the higher rates.

It Ain't (Just) the Heat, It's the Humanity: Increasing Public Understanding of Scientific Consensus and Its Role in Climate Literacy

NASA Astrophysics Data System (ADS)

Jacobs, P.; Cook, J.; Nuccitelli, D.

2014-12-01

An overwhelming scientific consensus exists on the issue of anthropogenic climate change. Unfortunately, public perception of expert agreement remains low- only around 1 in 10 Americans correctly estimates the actual level of consensus on the topic. Moreover, several recent studies have demonstrated the pivotal role that perceived consensus plays in the public's acceptance of key scientific facts about environmental problems, as well as their willingness to support policy to address them. This "consensus gap", between the high level of scientific agreement vs. the public's perception of it, has led to calls for increased consensus messaging. However this call has been challenged by a number of different groups: climate "skeptics" in denial about the existence and validity of the consensus; some social science researchers and journalists who believe that such messages will be ineffective or counterproductive; and even some scientists and science advocates who downplay the value of consensus in science generally. All of these concerns can be addressed by effectively communicating the role of consensus within science to the public, as well as the conditions under which consensus is likely to be correct. Here, we demonstrate that the scientific consensus on anthropogenic climate change satisfies these conditions, and discuss past examples of purported consensus that failed or succeeded to satisfy them as well. We conclude by discussing the way in which scientific consensus is interpreted by the public, and how consensus messaging can improve climate literacy.

Application of an iterative least-squares waveform inversion of strong-motion and teleseismic records to the 1978 Tabas, Iran, earthquake

USGS Publications Warehouse

Hartzell, S.; Mendoza, C.

1991-01-01

An iterative least-squares technique is used to simultaneously invert the strong-motion records and teleseismic P waveforms for the 1978 Tabas, Iran, earthquake to deduce the rupture history. The effects of using different data sets and different parametrizations of the problem (linear versus nonlinear) are considered. A consensus of all the inversion runs indicates a complex, multiple source for the Tabas earthquake, with four main source regions over a fault length of 90 km and an average rupture velocity of 2.5 km/sec. -from Authors

[The reentrant binomial model of nuclear anomalies growth in rhabdomyosarcoma RA-23 cell populations under increasing doze of rare ionizing radiation].

PubMed

Alekseeva, N P; Alekseev, A O; Vakhtin, Iu B; Kravtsov, V Iu; Kuzovatov, S N; Skorikova, T I

2008-01-01

Distributions of nuclear morphology anomalies in transplantable rabdomiosarcoma RA-23 cell populations were investigated under effect of ionizing radiation from 0 to 45 Gy. Internuclear bridges, nuclear protrusions and dumbbell-shaped nuclei were accepted for morphological anomalies. Empirical distributions of the number of anomalies per 100 nuclei were used. The adequate model of reentrant binomial distribution has been found. The sum of binomial random variables with binomial number of summands has such distribution. Averages of these random variables were named, accordingly, internal and external average reentrant components. Their maximum likelihood estimations were received. Statistical properties of these estimations were investigated by means of statistical modeling. It has been received that at equally significant correlation between the radiation dose and the average of nuclear anomalies in cell populations after two-three cellular cycles from the moment of irradiation in vivo the irradiation doze significantly correlates with internal average reentrant component, and in remote descendants of cell transplants irradiated in vitro - with external one.

A laid-back trip through the Hennigian Forests

PubMed Central

2017-01-01

Background This paper is a comment on the idea of matrix-free Cladistics. Demonstration of this idea’s efficiency is a major goal of the study. Within the proposed framework, the ordinary (phenetic) matrix is necessary only as “source” of Hennigian trees, not as a primary subject of the analysis. Switching from the matrix-based thinking to the matrix-free Cladistic approach clearly reveals that optimizations of the character-state changes are related not to the real processes, but to the form of the data representation. Methods We focused our study on the binary data. We wrote the simple ruby-based script FORESTER version 1.0 that helps represent a binary matrix as an array of the rooted trees (as a “Hennigian forest”). The binary representations of the genomic (DNA) data have been made by script 1001. The Average Consensus method as well as the standard Maximum Parsimony (MP) approach has been used to analyze the data. Principle findings The binary matrix may be easily re-written as a set of rooted trees (maximal relationships). The latter might be analyzed by the Average Consensus method. Paradoxically, this method, if applied to the Hennigian forests, in principle can help to identify clades despite the absence of the direct evidence from the primary data. Our approach may handle the clock- or non clock-like matrices, as well as the hypothetical, molecular or morphological data. Discussion Our proposal clearly differs from the numerous phenetic alignment-free techniques of the construction of the phylogenetic trees. Dealing with the relations, not with the actual “data” also distinguishes our approach from all optimization-based methods, if the optimization is defined as a way to reconstruct the sequences of the character-state changes on a tree, either the standard alignment-based techniques or the “direct” alignment-free procedure. We are not viewing our recent framework as an alternative to the three-taxon statement analysis (3TA), but there are two major differences between our recent proposal and the 3TA, as originally designed and implemented: (1) the 3TA deals with the three-taxon statements or minimal relationships. According to the logic of 3TA, the set of the minimal trees must be established as a binary matrix and used as an input for the parsimony program. In this paper, we operate directly with maximal relationships written just as trees, not as binary matrices, while also using the Average Consensus method instead of the MP analysis. The solely ‘reversal’-based groups can always be found by our method without the separate scoring of the putative reversals before analyses. PMID:28740753

The distribution of first-passage times and durations in FOREX and future markets

NASA Astrophysics Data System (ADS)

Sazuka, Naoya; Inoue, Jun-ichi; Scalas, Enrico

2009-07-01

Possible distributions are discussed for intertrade durations and first-passage processes in financial markets. The view-point of renewal theory is assumed. In order to represent market data with relatively long durations, two types of distributions are used, namely a distribution derived from the Mittag-Leffler survival function and the Weibull distribution. For the Mittag-Leffler type distribution, the average waiting time (residual life time) is strongly dependent on the choice of a cut-off parameter tmax, whereas the results based on the Weibull distribution do not depend on such a cut-off. Therefore, a Weibull distribution is more convenient than a Mittag-Leffler type if one wishes to evaluate relevant statistics such as average waiting time in financial markets with long durations. On the other hand, we find that the Gini index is rather independent of the cut-off parameter. Based on the above considerations, we propose a good candidate for describing the distribution of first-passage time in a market: The Weibull distribution with a power-law tail. This distribution compensates the gap between theoretical and empirical results more efficiently than a simple Weibull distribution. It should be stressed that a Weibull distribution with a power-law tail is more flexible than the Mittag-Leffler distribution, which itself can be approximated by a Weibull distribution and a power-law. Indeed, the key point is that in the former case there is freedom of choice for the exponent of the power-law attached to the Weibull distribution, which can exceed 1 in order to reproduce decays faster than possible with a Mittag-Leffler distribution. We also give a useful formula to determine an optimal crossover point minimizing the difference between the empirical average waiting time and the one predicted from renewal theory. Moreover, we discuss the limitation of our distributions by applying our distribution to the analysis of the BTP future and calculating the average waiting time. We find that our distribution is applicable as long as durations follow a Weibull law for short times and do not have too heavy a tail.

Can a limited double reading/second opinion of initially recalled breast ultrasound screening examinations improve radiologists' performances?

NASA Astrophysics Data System (ADS)

Gur, David; Harnist, Kimberly; Gizienski, Terri-Ann; Zuley, Margarita; Hakim, Christiane; Lu, Amy; Sumkin, Jules; Abrams, Gordon; Ganott, Marie A.; Kelly, Amy E.; Tyma, Cathy S.; Chang, Thomas; BÓ§hm-Vélez, Marcella; Sobolewski, Robin

2018-03-01

Interpretations of breast ultrasound screening examinations result in high recall rates and large inter-radiologist variability, frequently leading to "conservative" recommendations. Double reading of all breast ultrasound screening examinations is cost prohibitive, but double reading of only "initially recalled" cases may prove efficacious. We assessed changes in recommendations, if any, by providing a consensus second opinion in a limited subset of examinations initially recommended for recall. We performed a retrospective reader study with 197 ultrasound examinations (97 not recalled and 100 recalled clinically). First, we generated a consensus "second opinion" consisting of the majority vote of three independent readings of each case by experienced ultrasound interpreters. During the reader study that followed, if the reader recommended a "recall" and the "consensus second opinion" did not, a message to that effect was displayed and the reader was asked to re-review the exam and re-assess if, knowing the second opinion, a re-rating of the case was warranted. We compared performance levels pre- and post- the second opinion. The second opinion resulted in "no recall" recommendations of 141 cases in the entire set, including four cancer cases missed by all three readers. On average, radiologists received "warning" messages in 30 cases (range 15-50), or in 15% of cases. Rating changes (downgrades to no recall) occurred in 36 of these cases. These changes resulted in a possible recall rate reduction of 28% in prompted cases or 14% overall recall reduction, while increasing the false negative rate by only one case missed by 2 readers ( 1%).

Achieving 90% Adoption of Clinical Practice Guidelines Using the Delphi Consensus Method in a Large Orthopedic Group.

PubMed

Bini, Stefano A; Mahajan, John

2016-11-01

Little is known about the implementation rate of clinical practice guidelines (CPGs). Our purpose was to report on the adoption rate of CPGs created and implemented by a large orthopedic group using the Delphi consensus method. The draft CPGs were created before the group's annual meeting by 5 teams each assigned a subset of topics. The draft guidelines included a statement and a summary of the available evidence. Each guideline was debated in both small-group and plenary sessions. Voting was anonymous and a 75% supermajority was required for passage. A Likert scale was used to survey the patient's experience with the process at 1 week, and the Kirkpatrick evaluation model was used to gauge the efficacy of the process over a 6-month time frame. Eighty-five orthopedic surgeons attended the meeting. Fifteen guidelines grouped into 5 topics were created. All passed. Eighty-six percent of attendees found the process effective and 84% felt that participating in the process made it more likely that they would adopt the guidelines. At 1 week, an average of 62% of attendees stated they were practicing the guideline as written (range: 35%-72%), and at 6 months, 96% stated they were practicing them (range: 82%-100%). We have demonstrated that a modified Delphi method for reaching consensus can be very effective in both creating CPGs and leading to their adoption. Further we have shown that the process is well received by participants and that an inclusionary approach can be highly successful. Copyright © 2016 Elsevier Inc. All rights reserved.

Defining future directions for endometriosis research: workshop report from the 2011 World Congress of Endometriosis In Montpellier, France.

PubMed

Rogers, Peter A W; D'Hooghe, Thomas M; Fazleabas, Asgerally; Giudice, Linda C; Montgomery, Grant W; Petraglia, Felice; Taylor, Robert N

2013-05-01

Endometriosis, defined as estrogen-dependent lesions containing endometrial glands and stroma outside the uterus, is a chronic and often painful gynecological condition that affects 6% to 10% of reproductive age women. Endometriosis has estimated annual costs of US $12 419 per woman (approximately €9579), comprising one-third of the direct health care costs with two-thirds attributed to loss of productivity. Decreased quality of life is the most important predictor of direct health care and total costs. It has been estimated that there is a mean delay of 6.7 years between onset of symptoms and a surgical diagnosis of endometriosis, and each affected woman loses on average 10.8 hours of work weekly, mainly owing to reduced effectiveness while working. To encourage and facilitate research into this debilitating disease, a consensus workshop to define future directions for endometriosis research was held as part of the 11th World Congress on Endometriosis in September 2011 in Montpellier, France. The objective of this workshop was to review and update the endometriosis research priorities consensus statement developed following the 10th World Congress on Endometriosis in 2008.(1) A total of 56 recommendations for research have been developed, grouped under 6 subheadings: (1) diagnosis, (2) classification and prognosis, (3) clinical trials, treatment, and outcomes, (4) epidemiology, (5) pathophysiology, and (6) research policy. By producing this consensus international research priorities statement, it is the hope of the workshop participants that researchers will be encouraged to develop new interdisciplinary research proposals that will attract increased funding support for work on endometriosis.

Defining Future Directions for Endometriosis Research

PubMed Central

D’Hooghe, Thomas M.; Fazleabas, Asgerally; Giudice, Linda C.; Montgomery, Grant W.; Petraglia, Felice; Taylor, Robert N.

2013-01-01

Endometriosis, defined as estrogen-dependent lesions containing endometrial glands and stroma outside the uterus, is a chronic and often painful gynecological condition that affects 6% to 10% of reproductive age women. Endometriosis has estimated annual costs of US $12 419 per woman (approximately €9579), comprising one-third of the direct health care costs with two-thirds attributed to loss of productivity. Decreased quality of life is the most important predictor of direct health care and total costs. It has been estimated that there is a mean delay of 6.7 years between onset of symptoms and a surgical diagnosis of endometriosis, and each affected woman loses on average 10.8 hours of work weekly, mainly owing to reduced effectiveness while working. To encourage and facilitate research into this debilitating disease, a consensus workshop to define future directions for endometriosis research was held as part of the 11th World Congress on Endometriosis in September 2011 in Montpellier, France. The objective of this workshop was to review and update the endometriosis research priorities consensus statement developed following the 10th World Congress on Endometriosis in 2008.1 A total of 56 recommendations for research have been developed, grouped under 6 subheadings: (1) diagnosis, (2) classification and prognosis, (3) clinical trials, treatment, and outcomes, (4) epidemiology, (5) pathophysiology, and (6) research policy. By producing this consensus international research priorities statement, it is the hope of the workshop participants that researchers will be encouraged to develop new interdisciplinary research proposals that will attract increased funding support for work on endometriosis. PMID:23427182

Competing opinions and stubborness: Connecting models to data.

PubMed

Burghardt, Keith; Rand, William; Girvan, Michelle

2016-03-01

We introduce a general contagionlike model for competing opinions that includes dynamic resistance to alternative opinions. We show that this model can describe candidate vote distributions, spatial vote correlations, and a slow approach to opinion consensus with sensible parameter values. These empirical properties of large group dynamics, previously understood using distinct models, may be different aspects of human behavior that can be captured by a more unified model, such as the one introduced in this paper.

The Consensus Problem in Unreliable Distributed Systems (A Brief Survey).

DTIC Science & Technology

1983-06-01

they might also reach conflicting conclusions about the outcome of the election and hence fail to reach agreement. Davies and Wakerly [21 realized this...15], and part (b) was shown by Dolev and Reischuk [10]. For practical applications , these bounds are not very encouraging, especially the t+I bound on...solutions is f2(n + t2)). Theorem 7, part (b) shows this bound "best possible" for authenticated algorithms. 6. Applications of Agreement Protocols The

Coordinated Path-Following in the Presence of Communication Losses and Time Delays

DTIC Science & Technology

2009-01-01

of Type I or Type II. The results are quite general in that they apply to a large class of PF control systems satisfying a certain input-to-state...Maggiore, State agreement for continuous- time coupled nonlinear systems , SIAM J. Control Optim., 46 (2007), pp. 288–307. [39] M. Mesbahi and F...40] L. Moreau, Stability of continuous- time distributed consensus algorithm, in Proceedings of the 43rd IEEE Conference on Decision and Control

Dual Coding Theory Explains Biphasic Collective Computation in Neural Decision-Making.

PubMed

Daniels, Bryan C; Flack, Jessica C; Krakauer, David C

2017-01-01

A central question in cognitive neuroscience is how unitary, coherent decisions at the whole organism level can arise from the distributed behavior of a large population of neurons with only partially overlapping information. We address this issue by studying neural spiking behavior recorded from a multielectrode array with 169 channels during a visual motion direction discrimination task. It is well known that in this task there are two distinct phases in neural spiking behavior. Here we show Phase I is a distributed or incompressible phase in which uncertainty about the decision is substantially reduced by pooling information from many cells. Phase II is a redundant or compressible phase in which numerous single cells contain all the information present at the population level in Phase I, such that the firing behavior of a single cell is enough to predict the subject's decision. Using an empirically grounded dynamical modeling framework, we show that in Phase I large cell populations with low redundancy produce a slow timescale of information aggregation through critical slowing down near a symmetry-breaking transition. Our model indicates that increasing collective amplification in Phase II leads naturally to a faster timescale of information pooling and consensus formation. Based on our results and others in the literature, we propose that a general feature of collective computation is a "coding duality" in which there are accumulation and consensus formation processes distinguished by different timescales.

Dual Coding Theory Explains Biphasic Collective Computation in Neural Decision-Making

PubMed Central

Daniels, Bryan C.; Flack, Jessica C.; Krakauer, David C.

2017-01-01

A central question in cognitive neuroscience is how unitary, coherent decisions at the whole organism level can arise from the distributed behavior of a large population of neurons with only partially overlapping information. We address this issue by studying neural spiking behavior recorded from a multielectrode array with 169 channels during a visual motion direction discrimination task. It is well known that in this task there are two distinct phases in neural spiking behavior. Here we show Phase I is a distributed or incompressible phase in which uncertainty about the decision is substantially reduced by pooling information from many cells. Phase II is a redundant or compressible phase in which numerous single cells contain all the information present at the population level in Phase I, such that the firing behavior of a single cell is enough to predict the subject's decision. Using an empirically grounded dynamical modeling framework, we show that in Phase I large cell populations with low redundancy produce a slow timescale of information aggregation through critical slowing down near a symmetry-breaking transition. Our model indicates that increasing collective amplification in Phase II leads naturally to a faster timescale of information pooling and consensus formation. Based on our results and others in the literature, we propose that a general feature of collective computation is a “coding duality” in which there are accumulation and consensus formation processes distinguished by different timescales. PMID:28634436

Potential breeding distributions of U.S. birds predicted with both short-term variability and long-term average climate data.

PubMed

Bateman, Brooke L; Pidgeon, Anna M; Radeloff, Volker C; Flather, Curtis H; VanDerWal, Jeremy; Akçakaya, H Resit; Thogmartin, Wayne E; Albright, Thomas P; Vavrus, Stephen J; Heglund, Patricia J

2016-12-01

Climate conditions, such as temperature or precipitation, averaged over several decades strongly affect species distributions, as evidenced by experimental results and a plethora of models demonstrating statistical relations between species occurrences and long-term climate averages. However, long-term averages can conceal climate changes that have occurred in recent decades and may not capture actual species occurrence well because the distributions of species, especially at the edges of their range, are typically dynamic and may respond strongly to short-term climate variability. Our goal here was to test whether bird occurrence models can be predicted by either covariates based on short-term climate variability or on long-term climate averages. We parameterized species distribution models (SDMs) based on either short-term variability or long-term average climate covariates for 320 bird species in the conterminous USA and tested whether any life-history trait-based guilds were particularly sensitive to short-term conditions. Models including short-term climate variability performed well based on their cross-validated area-under-the-curve AUC score (0.85), as did models based on long-term climate averages (0.84). Similarly, both models performed well compared to independent presence/absence data from the North American Breeding Bird Survey (independent AUC of 0.89 and 0.90, respectively). However, models based on short-term variability covariates more accurately classified true absences for most species (73% of true absences classified within the lowest quarter of environmental suitability vs. 68%). In addition, they have the advantage that they can reveal the dynamic relationship between species and their environment because they capture the spatial fluctuations of species potential breeding distributions. With this information, we can identify which species and guilds are sensitive to climate variability, identify sites of high conservation value where climate variability is low, and assess how species' potential distributions may have already shifted due recent climate change. However, long-term climate averages require less data and processing time and may be more readily available for some areas of interest. Where data on short-term climate variability are not available, long-term climate information is a sufficient predictor of species distributions in many cases. However, short-term climate variability data may provide information not captured with long-term climate data for use in SDMs. © 2016 by the Ecological Society of America.

Seeking worldwide professional consensus on the principles of end-of-life care for the critically ill. The Consensus for Worldwide End-of-Life Practice for Patients in Intensive Care Units (WELPICUS) study.

PubMed

Sprung, Charles L; Truog, Robert D; Curtis, J Randall; Joynt, Gavin M; Baras, Mario; Michalsen, Andrej; Briegel, Josef; Kesecioglu, Jozef; Efferen, Linda; De Robertis, Edoardo; Bulpa, Pierre; Metnitz, Philipp; Patil, Namrata; Hawryluck, Laura; Manthous, Constantine; Moreno, Rui; Leonard, Sara; Hill, Nicholas S; Wennberg, Elisabet; McDermid, Robert C; Mikstacki, Adam; Mularski, Richard A; Hartog, Christiane S; Avidan, Alexander

2014-10-15

Great differences in end-of-life practices in treating the critically ill around the world warrant agreement regarding the major ethical principles. This analysis determines the extent of worldwide consensus for end-of-life practices, delineates where there is and is not consensus, and analyzes reasons for lack of consensus. Critical care societies worldwide were invited to participate. Country coordinators were identified and draft statements were developed for major end-of-life issues and translated into six languages. Multidisciplinary responses using a web-based survey assessed agreement or disagreement with definitions and statements linked to anonymous demographic information. Consensus was prospectively defined as >80% agreement. Definitions and statements not obtaining consensus were revised based on comments of respondents, and then translated and redistributed. Of the initial 1,283 responses from 32 countries, consensus was found for 66 (81%) of the 81 definitions and statements; 26 (32%) had >90% agreement. With 83 additional responses to the original questionnaire (1,366 total) and 604 responses to the revised statements, consensus could be obtained for another 11 of the 15 statements. Consensus was obtained for informed consent, withholding and withdrawing life-sustaining treatment, legal requirements, intensive care unit therapies, cardiopulmonary resuscitation, shared decision making, medical and nursing consensus, brain death, and palliative care. Consensus was obtained for 77 of 81 (95%) statements. Worldwide consensus could be developed for the majority of definitions and statements about end-of-life practices. Statements achieving consensus provide standards of practice for end-of-life care; statements without consensus identify important areas for future research.

A framework for secure and decentralized sharing of medical imaging data via blockchain consensus.

PubMed

Patel, Vishal

2018-04-01

The electronic sharing of medical imaging data is an important element of modern healthcare systems, but current infrastructure for cross-site image transfer depends on trust in third-party intermediaries. In this work, we examine the blockchain concept, which enables parties to establish consensus without relying on a central authority. We develop a framework for cross-domain image sharing that uses a blockchain as a distributed data store to establish a ledger of radiological studies and patient-defined access permissions. The blockchain framework is shown to eliminate third-party access to protected health information, satisfy many criteria of an interoperable health system, and readily generalize to domains beyond medical imaging. Relative drawbacks of the framework include the complexity of the privacy and security models and an unclear regulatory environment. Ultimately, the large-scale feasibility of such an approach remains to be demonstrated and will depend on a number of factors which we discuss in detail.

MedBlock: Efficient and Secure Medical Data Sharing Via Blockchain.

PubMed

Fan, Kai; Wang, Shangyang; Ren, Yanhui; Li, Hui; Yang, Yintang

2018-06-21

With the development of electronic information technology, electronic medical records (EMRs) have been a common way to store the patients' data in hospitals. They are stored in different hospitals' databases, even for the same patient. Therefore, it is difficult to construct a summarized EMR for one patient from multiple hospital databases due to the security and privacy concerns. Meanwhile, current EMRs systems lack a standard data management and sharing policy, making it difficult for pharmaceutical scientists to develop precise medicines based on data obtained under different policies. To solve the above problems, we proposed a blockchain-based information management system, MedBlock, to handle patients' information. In this scheme, the distributed ledger of MedBlock allows the efficient EMRs access and EMRs retrieval. The improved consensus mechanism achieves consensus of EMRs without large energy consumption and network congestion. In addition, MedBlock also exhibits high information security combining the customized access control protocols and symmetric cryptography. MedBlock can play an important role in the sensitive medical information sharing.

Opinion diversity and community formation in adaptive networks

NASA Astrophysics Data System (ADS)

Yu, Y.; Xiao, G.; Li, G.; Tay, W. P.; Teoh, H. F.

2017-10-01

It is interesting and of significant importance to investigate how network structures co-evolve with opinions. In this article, we show that, a simple model integrating consensus formation, link rewiring, and opinion change allows complex system dynamics to emerge, driving the system into a dynamic equilibrium with the co-existence of diversified opinions. Specifically, similar opinion holders may form into communities yet with no strict community consensus; and rather than being separated into disconnected communities, different communities are connected by a non-trivial proportion of inter-community links. More importantly, we show that the complex dynamics may lead to different numbers of communities at the steady state with a given tolerance between different opinion holders. We construct a framework for theoretically analyzing the co-evolution process. Theoretical analysis and extensive simulation results reveal some useful insights into the complex co-evolution process, including the formation of dynamic equilibrium, the transition between different steady states with different numbers of communities, and the dynamics between opinion distribution and network modularity.

Is There a Consensus on Consensus Methodology? Descriptions and Recommendations for Future Consensus Research.

PubMed

Waggoner, Jane; Carline, Jan D; Durning, Steven J

2016-05-01

The authors of this article reviewed the methodology of three common consensus methods: nominal group process, consensus development panels, and the Delphi technique. The authors set out to determine how a majority of researchers are conducting these studies, how they are analyzing results, and subsequently the manner in which they are reporting their findings. The authors conclude with a set of guidelines and suggestions designed to aid researchers who choose to use the consensus methodology in their work.Overall, researchers need to describe their inclusion criteria. In addition to this, on the basis of the current literature the authors found that a panel size of 5 to 11 members was most beneficial across all consensus methods described. Lastly, the authors agreed that the statistical analyses done in consensus method studies should be as rigorous as possible and that the predetermined definition of consensus must be included in the ultimate manuscript. More specific recommendations are given for each of the three consensus methods described in the article.

Defining consensus: a systematic review recommends methodologic criteria for reporting of Delphi studies.

PubMed

Diamond, Ivan R; Grant, Robert C; Feldman, Brian M; Pencharz, Paul B; Ling, Simon C; Moore, Aideen M; Wales, Paul W

2014-04-01

To investigate how consensus is operationalized in Delphi studies and to explore the role of consensus in determining the results of these studies. Systematic review of a random sample of 100 English language Delphi studies, from two large multidisciplinary databases [ISI Web of Science (Thompson Reuters, New York, NY) and Scopus (Elsevier, Amsterdam, NL)], published between 2000 and 2009. About 98 of the Delphi studies purported to assess consensus, although a definition for consensus was only provided in 72 of the studies (64 a priori). The most common definition for consensus was percent agreement (25 studies), with 75% being the median threshold to define consensus. Although the authors concluded in 86 of the studies that consensus was achieved, consensus was only specified a priori (with a threshold value) in 42 of these studies. Achievement of consensus was related to the decision to stop the Delphi study in only 23 studies, with 70 studies terminating after a specified number of rounds. Although consensus generally is felt to be of primary importance to the Delphi process, definitions of consensus vary widely and are poorly reported. Improved criteria for reporting of methods of Delphi studies are required. Copyright © 2014 Elsevier Inc. All rights reserved.

Insights Into Upland Cotton (Gossypium hirsutum L.) Genetic Recombination Based on 3 High-Density Single-Nucleotide Polymorphism and a Consensus Map Developed Independently With Common Parents.

PubMed

Ulloa, Mauricio; Hulse-Kemp, Amanda M; De Santiago, Luis M; Stelly, David M; Burke, John J

2017-01-01

High-density linkage maps are vital to supporting the correct placement of scaffolds and gene sequences on chromosomes and fundamental to contemporary organismal research and scientific approaches to genetic improvement, especially in paleopolyploids with exceptionally complex genomes, eg, upland cotton ( Gossypium hirsutum L., "2n = 52"). Three independently developed intraspecific upland mapping populations were analyzed to generate 3 high-density genetic linkage single-nucleotide polymorphism (SNP) maps and a consensus map using the CottonSNP63K array. The populations consisted of a previously reported F 2 , a recombinant inbred line (RIL), and reciprocal RIL population, from "Phytogen 72" and "Stoneville 474" cultivars. The cluster file provided 7417 genotyped SNP markers, resulting in 26 linkage groups corresponding to the 26 chromosomes (c) of the allotetraploid upland cotton (AD) 1 arisen from the merging of 2 genomes ("A" Old World and "D" New World). Patterns of chromosome-specific recombination were largely consistent across mapping populations. The high-density genetic consensus map included 7244 SNP markers that spanned 3538 cM and comprised 3824 SNP bins, of which 1783 and 2041 were in the A t and D t subgenomes with 1825 and 1713 cM map lengths, respectively. Subgenome average distances were nearly identical, indicating that subgenomic differences in bin number arose due to the high numbers of SNPs on the D t subgenome. Examination of expected recombination frequency or crossovers (COs) on the chromosomes within each population of the 2 subgenomes revealed that COs were also not affected by the SNPs or SNP bin number in these subgenomes. Comparative alignment analyses identified historical ancestral A t -subgenomic translocations of c02 and c03, as well as of c04 and c05. The consensus map SNP sequences aligned with high congruency to the NBI assembly of Gossypium hirsutum . However, the genomic comparisons revealed evidence of additional unconfirmed possible duplications, inversions and translocations, and unbalance SNP sequence homology or SNP sequence/loci genomic dominance, or homeolog loci bias of the upland tetraploid A t and D t subgenomes. The alignments indicated that 364 SNP-associated previously unintegrated scaffolds can be placed in pseudochromosomes of the NBI G hirsutum assembly. This is the first intraspecific SNP genetic linkage consensus map assembled in G hirsutum with a core of reproducible mendelian SNP markers assayed on different populations and it provides further knowledge of chromosome arrangement of genic and nongenic SNPs. Together, the consensus map and RIL populations provide a synergistically useful platform for localizing and identifying agronomically important loci for improvement of the cotton crop.

ILAE survey of neuropsychology practice in pediatric epilepsy surgery evaluation.

PubMed

Berl, Madison M; Smith, Mary Lou; Bulteau, Christine

2017-06-01

To determine the extent to which specific neuropsychological measures are in common use around the world for the assessment of children who are candidates for epilepsy surgery. As part of the work of the International League Against Epilepsy Pediatric Surgical Task Force, a survey was developed and distributed online. The survey consisted of questions related to demographics, training experience, general practice, and specific measures used and at what frequency. Seventy-eight clinicians with an average of 13.5 years of experience from 19 countries responded to the survey; 69% were English-speaking. Pre- and post-neuropsychological evaluations were conducted with a majority of children undergoing surgical resection for epilepsy. There was high consistency (>90%) among the domains evaluated, while consistency rate among specific measures was more variable (range: 0-100%). Consistency rates were also lower among respondents in non-English-speaking countries. For English-speaking respondents, at least one measure within each domain was used by a majority (>75%) of clinicians; 19 specific measures met this criterion. There is consensus of measures used in neuropsychological studies of pediatric epilepsy patients which provides a basis for determining which measures to include in establishing a collaborative data repository to study surgical outcomes of pediatric epilepsy. Challenges include selecting measures that promote collaboration with centers in non-English-speaking countries and providing data from children under age 5.

SU-E-T-558: Assessing the Effect of Inter-Fractional Motion in Esophageal Sparing Plans.

PubMed

Williamson, R; Bluett, J; Niedzielski, J; Liao, Z; Gomez, D; Court, L

2012-06-01

To compare esophageal dose distributions in esophageal sparing IMRT plans with predicted dose distributions which include the effect of inter-fraction motion. Seven lung cancer patients were used, each with a standard and an esophageal sparing plan (74Gy, 2Gy fractions). The average max dose to esophagus was 8351cGy and 7758cGy for the standard and sparing plans, respectively. The average length of esophagus for which the total circumference was treated above 60Gy (LETT60) was 9.4cm in the standard plans and 5.8cm in the sparing plans. In order to simulate inter-fractional motion, a three-dimensional rigid shift was applied to the calculated dose field. A simulated course of treatment consisted of a single systematic shift applied throughout the treatment as well a random shift for each of the 37 fractions. Both systematic and random shifts were generated from Gaussian distributions of 3mm and 5mm standard deviation. Each treatment course was simulated 1000 times to obtain an expected distribution of the delivered dose. Simulated treatment dose received by the esophagus was less than dose seen in the treatment plan. The average reduction in maximum esophageal dose for the standard plans was 234cGy and 386cGY for the 3mm and 5mm Gaussian distributions, respectively. The average reduction in LETT60 was 0.6cm and 1.7cm, for the 3mm and 5mm distributions respectively. For the esophageal sparing plans, the average reduction in maximum esophageal dose was 94cGy and 202cGy for 3mm and 5mm Gaussian distributions, respectively. The average change in LETT60 for the esophageal sparing plans was smaller, at 0.1cm (increase) and 0.6cm (reduction), for the 3mm and 5mm distributions, respectively. Interfraction motion consistently reduced the maximum doses to the esophagus for both standard and esophageal sparing plans. © 2012 American Association of Physicists in Medicine.

The pivotal role of perceived scientific consensus in acceptance of science

NASA Astrophysics Data System (ADS)

Lewandowsky, Stephan; Gignac, Gilles E.; Vaughan, Samuel

2013-04-01

Although most experts agree that CO2 emissions are causing anthropogenic global warming (AGW), public concern has been declining. One reason for this decline is the `manufacture of doubt' by political and vested interests, which often challenge the existence of the scientific consensus. The role of perceived consensus in shaping public opinion is therefore of considerable interest: in particular, it is unknown whether consensus determines people's beliefs causally. It is also unclear whether perception of consensus can override people's `worldviews', which are known to foster rejection of AGW. Study 1 shows that acceptance of several scientific propositions--from HIV/AIDS to AGW--is captured by a common factor that is correlated with another factor that captures perceived scientific consensus. Study 2 reveals a causal role of perceived consensus by showing that acceptance of AGW increases when consensus is highlighted. Consensus information also neutralizes the effect of worldview.

Exit, cohesion, and consensus: social psychological moderators of consensus among adolescent peer groups

PubMed Central

Fisher, Jacob C.

2017-01-01

Virtually all social diffusion work relies on a common formal basis, which predicts that consensus will develop among a connected population as the result of diffusion. In spite of the popularity of social diffusion models that predict consensus, few empirical studies examine consensus, or a clustering of attitudes, directly. Those that do either focus on the coordinating role of strict hierarchies, or on the results of online experiments, and do not consider how consensus occurs among groups in situ. This study uses longitudinal data on adolescent social networks to show how meso-level social structures, such as informal peer groups, moderate the process of consensus formation. Using a novel method for controlling for selection into a group, I find that centralized peer groups, meaning groups with clear leaders, have very low levels of consensus, while cohesive peer groups, meaning groups where more ties hold the members of the group together, have very high levels of consensus. This finding is robust to two different measures of cohesion and consensus. This suggests that consensus occurs either through central leaders’ enforcement or through diffusion of attitudes, but that central leaders have limited ability to enforce when people can leave the group easily. PMID:29335675

Spatial analysis of extension fracture systems: A process modeling approach

USGS Publications Warehouse

Ferguson, C.C.

1985-01-01

Little consensus exists on how best to analyze natural fracture spacings and their sequences. Field measurements and analyses published in geotechnical literature imply fracture processes radically different from those assumed by theoretical structural geologists. The approach adopted in this paper recognizes that disruption of rock layers by layer-parallel extension results in two spacing distributions, one representing layer-fragment lengths and another separation distances between fragments. These two distributions and their sequences reflect mechanics and history of fracture and separation. Such distributions and sequences, represented by a 2 ?? n matrix of lengthsL, can be analyzed using a method that is history sensitive and which yields also a scalar estimate of bulk extension, e (L). The method is illustrated by a series of Monte Carlo experiments representing a variety of fracture-and-separation processes, each with distinct implications for extension history. Resulting distributions of e (L)are process-specific, suggesting that the inverse problem of deducing fracture-and-separation history from final structure may be tractable. ?? 1985 Plenum Publishing Corporation.

Mobile Phone Apps for Inflammatory Bowel Disease Self-Management: A Systematic Assessment of Content and Tools

PubMed Central

Con, Danny

2016-01-01

Background The rising incidence of inflammatory bowel disease (IBD) over the past decade has resulted in increased health care utilization and longer IBD outpatient waiting lists. Self-management is recognized as an important aspect of chronic disease management but its application to IBD has been limited. The age of IBD onset in a majority of patients is in their 20s to 30s. Mobile phone apps are a technology familiar to young adults and represent an opportunity to explore self-management as a new model of health care delivery for IBD. Objective The aim of this study was to explore the content and tools of existing IBD apps to identify functionalities that may facilitate patient self-management. Methods We systematically assessed apps targeted at IBD patients via searches of Google (Android devices) and Apple (iOS devices) app stores with pre-defined inclusion and exclusion criteria. Apps were assessed for specific functionalities; presence of professional medical involvement; consistency with international IBD guidelines based on “complete,” “partial,” or “absent” coverage of consensus statements derived from the European Crohn’s and Colitis Organisation, American College of Gastroenterology, and the Gastroenterology Society of Australia; comprehensiveness of data that could be entered; and average pricing. Results Of the 238 apps screened, 26 apps were assessed, including 10 available on Android platforms, 8 on iOS platforms, and 8 on both. Over half (14/26, 54%) of the apps had diary functionalities; over a third (10/26, 39%) provided health information about IBD. None of the apps offered decision support to facilitate the self-initiation of medical therapy. Five of 26 (19%) had professional medical involvement in their design. Apps demonstrated “complete” coverage of only 38% of the international consensus statements explored. The average price of the apps was AUD$1.37. Conclusions Apps may provide a useful adjunct to the management of IBD patients. However, a majority of current apps suffer from a lack of professional medical involvement and limited coverage of international consensus guidelines. Future studies and app design for IBD should include professional medical involvement, evidence-based guidelines, and functionalities with decision support that are specifically tailored to patient self-management. PMID:26831935

Robust prediction of consensus secondary structures using averaged base pairing probability matrices.

PubMed

Kiryu, Hisanori; Kin, Taishin; Asai, Kiyoshi

2007-02-15

Recent transcriptomic studies have revealed the existence of a considerable number of non-protein-coding RNA transcripts in higher eukaryotic cells. To investigate the functional roles of these transcripts, it is of great interest to find conserved secondary structures from multiple alignments on a genomic scale. Since multiple alignments are often created using alignment programs that neglect the special conservation patterns of RNA secondary structures for computational efficiency, alignment failures can cause potential risks of overlooking conserved stem structures. We investigated the dependence of the accuracy of secondary structure prediction on the quality of alignments. We compared three algorithms that maximize the expected accuracy of secondary structures as well as other frequently used algorithms. We found that one of our algorithms, called McCaskill-MEA, was more robust against alignment failures than others. The McCaskill-MEA method first computes the base pairing probability matrices for all the sequences in the alignment and then obtains the base pairing probability matrix of the alignment by averaging over these matrices. The consensus secondary structure is predicted from this matrix such that the expected accuracy of the prediction is maximized. We show that the McCaskill-MEA method performs better than other methods, particularly when the alignment quality is low and when the alignment consists of many sequences. Our model has a parameter that controls the sensitivity and specificity of predictions. We discussed the uses of that parameter for multi-step screening procedures to search for conserved secondary structures and for assigning confidence values to the predicted base pairs. The C++ source code that implements the McCaskill-MEA algorithm and the test dataset used in this paper are available at http://www.ncrna.org/papers/McCaskillMEA/. Supplementary data are available at Bioinformatics online.

Conditional sampling technique to test the applicability of the Taylor hypothesis for the large-scale coherent structures

NASA Technical Reports Server (NTRS)

Hussain, A. K. M. F.

1980-01-01

Comparisons of the distributions of large scale structures in turbulent flow with distributions based on time dependent signals from stationary probes and the Taylor hypothesis are presented. The study investigated an area in the near field of a 7.62 cm circular air jet at a Re of 32,000, specifically having coherent structures through small-amplitude controlled excitation and stable vortex pairing in the jet column mode. Hot-wire and X-wire anemometry were employed to establish phase averaged spatial distributions of longitudinal and lateral velocities, coherent Reynolds stress and vorticity, background turbulent intensities, streamlines and pseudo-stream functions. The Taylor hypothesis was used to calculate spatial distributions of the phase-averaged properties, with results indicating that the usage of the local time-average velocity or streamwise velocity produces large distortions.

Constructive conflict and staff consensus in substance abuse treatment.

PubMed

Melnick, Gerald; Wexler, Harry K; Chaple, Michael; Cleland, Charles M

2009-03-01

Previous studies demonstrated the relationship between consensus among both staff and clients with client engagement in treatment and between client consensus and 1-year treatment outcomes. The present article explores the correlates of staff consensus, defined as the level of agreement among staff as to the importance of treatment activities in their program, using a national sample of 80 residential substance abuse treatment programs. Constructive conflict resolution had the largest effect on consensus. Low client-to-staff ratios, staff education, and staff experience in substance abuse treatment were also significantly related to consensus. Frequency of training, an expected correlate of consensus, was negatively associated with consensus, whereas frequency of supervision was not a significant correlate. The implications of the findings for future research and program improvement are discussed.

Scientists Are from Mars, Laypeople Are from Venus: An Evidence-Based Approach to Consensus Messaging

NASA Astrophysics Data System (ADS)

Cook, J.; Jacobs, P.; Nuccitelli, D.

2014-12-01

Laypeople use expert opinion as a mental shortcut to form views on complex scientific issues. This heuristic is particularly relevant in the case of climate change, where perception of consensus is one of the main predictors of public support for climate action. A low public perception of consensus (around 60% compared to the actual 97% consensus) is a significant stumbling block to meaningful climate action, underscoring the importance of closing the "consensus gap". However, some scientists question the efficacy or appropriateness of emphasizing consensus in climate communication. I'll summarize the social science research examining the importance and effectiveness of consensus messaging. I'll also present several case studies of consensus messaging employed by the team of communicators at the Skeptical Science website.

Factors to improve the interobserver agreement for gastric atrophy and intestinal metaplasia: consensus of definition and criteria.

PubMed

Kim, Sung Sun; Kook, Myeong-Cherl; Shin, Ok-Ran; Kim, Hee Sung; Bae, Han-Ik; Seo, An Na; Park, Do Youn; Choi, Il Ju; Kim, Young-Il; Nam, Byung Ho; Kim, Sohee

2018-04-01

Intestinal metaplasia and atrophy of the gastric mucosa are associated with Helicobacter pylori infection and are considered premalignant lesions. The updated Sydney system is used for these parameters, but experienced pathologists and consensus processes are required for interobserver agreement. We sought to determine the influence of the consensus process on the assessment of intestinal metaplasia and atrophy. Two study sets were used: consensus and validation. The consensus set was circulated and five gastrointestinal pathologists evaluated them independently using the updated Sydney system. The consensus of the definitions was then determined at the first consensus meeting. The same set was recirculated to determine the effect of the consensus. The second consensus meeting was held to standardise the grading criteria and the validation set was circulated to determine the influence. Two additional circulations were performed to assess the maintainance of consensus and intraobserver variability. Interobserver agreement of intestinal metaplasia and atrophy was improved through the consensus process (intestinal metaplasia: baseline κ = 0.52 versus final κ = 0.68, P = 0.006; atrophy: baseline κ = 0.19 versus final κ = 0.43, P < 0.001). Higher interobserver agreement in atrophy was observed after consensus regarding the definition (pre-consensus: κ = 0.19 versus post-consensus: κ = 0.34, P = 0.001). There was improved interobserver agreement in intestinal metaplasia after standardisation of the grading criteria (pre-standardisation: κ = 0.56 versus post-standardisation: κ = 0.71, P = 0.010). This study suggests that interobserver variability regarding intestinal metaplasia and atrophy may result from lack of a precise definition and fine criteria, and can be reduced by consensus of definition and standardisation of grading criteria. © 2017 John Wiley & Sons Ltd.

Biological assay using T cell response for Cry-consensus peptide designed for the peptide-based immunotherapy of Japanese cedar pollinosis.

PubMed

Kozutsumi, Daisuke; Tsunematsu, Masako; Yamaji, Taketo; Kino, Kohsuke

2007-01-01

Cry-consensus peptide is a linearly linked peptide of T-cell epitopes for the management of Japanese cedar (JC) pollinosis and is expected to become a new drug for immunotherapy. However, the mechanism of T-cell epitopes in allergic diseases is not well understood, and thus, a simple in vitro procedure for evaluation of its biological activity is desired. Peripheral blood mononuclear cells (PBMC) were isolated from 27 JC pollinosis patients and 10 healthy subjects, and cultured in vitro for 4 days in the presence of Cry-consensus peptide and (3)H-thymidine. The relationship between growth stimulation (stimulation index; SI) and antigen-specific IgE levels in serum was also investigated in JC pollinosis patients. Moreover, to confirm the importance of the primary sequence in Cry-consensus peptide, heat-treated Cry-consensus peptide and a mixture of the amino acids of which Cry-consensus peptide is composed, and their (3)H-thymidine uptake was compared with Cry-consensus peptide. Finally, whether Cry-consensus peptide stimulates PBMCs from healthy subjects was investigated. The mean SI of JC patients showed a good correlation with Cry-consensus peptide concentration in the culture medium; however, the SI was independent of the anti-Cry j 1 IgE level. Heat-denatured Cry-consensus peptide retained a PBMC proliferation stimulatory effect comparable to the original Cry-consensus peptide, while the mixture of amino acids constituting Cry-consensus peptide did not stimulate PBMC proliferation. PBMCs from healthy subjects did not respond to Cry-consensus peptide at all. These data indicate that the PBMC response of patients suffering from JC pollinosis to Cry-consensus peptide is specific for the sequence of T cell epitopes thereof and may be useful for the evaluation of the efficacy of Cry-consensus peptide in vivo.

Direct measurement of the electric-field distribution in a light-emitting electrochemical cell

NASA Astrophysics Data System (ADS)

Slinker, Jason D.; Defranco, John A.; Jaquith, Michael J.; Silveira, William R.; Zhong, Yu-Wu; Moran-Mirabal, Jose M.; Craighead, Harold G.; Abruña, Héctor D.; Marohn, John A.; Malliaras, George G.

2007-11-01

The interplay between ionic and electronic charge carriers in mixed conductors offers rich physics and unique device potential. In light-emitting electrochemical cells (LEECs), for example, the redistribution of ions assists the injection of electronic carriers and leads to efficient light emission. The mechanism of operation of LEECs has been controversial, as there is no consensus regarding the distribution of electric field in these devices. Here, we probe the operation of LEECs using electric force microscopy on planar devices. We show that obtaining the appropriate boundary conditions is essential for capturing the underlying device physics. A patterning scheme that avoids overlap between the mixed-conductor layer and the metal electrodes enabled the accurate in situ measurement of the electric-field distribution. The results show that accumulation and depletion of mobile ions near the electrodes create high interfacial electric fields that enhance the injection of electronic carriers.

REC-1 and HIM-5 distribute meiotic crossovers and function redundantly in meiotic double-strand break formation in Caenorhabditis elegans.

PubMed

Chung, George; Rose, Ann M; Petalcorin, Mark I R; Martin, Julie S; Kessler, Zebulin; Sanchez-Pulido, Luis; Ponting, Chris P; Yanowitz, Judith L; Boulton, Simon J

2015-09-15

The Caenorhabditis elegans gene rec-1 was the first genetic locus identified in metazoa to affect the distribution of meiotic crossovers along the chromosome. We report that rec-1 encodes a distant paralog of HIM-5, which was discovered by whole-genome sequencing and confirmed by multiple genome-edited alleles. REC-1 is phosphorylated by cyclin-dependent kinase (CDK) in vitro, and mutation of the CDK consensus sites in REC-1 compromises meiotic crossover distribution in vivo. Unexpectedly, rec-1; him-5 double mutants are synthetic-lethal due to a defect in meiotic double-strand break formation. Thus, we uncovered an unexpected robustness to meiotic DSB formation and crossover positioning that is executed by HIM-5 and REC-1 and regulated by phosphorylation. © 2015 Chung et al.; Published by Cold Spring Harbor Laboratory Press.

The dynamics of neuronal redundancy in decision making

NASA Astrophysics Data System (ADS)

Daniels, Bryan; Flack, Jessica; Krakauer, David

We propose two temporal phases of collective computation in a visual motion direction discrimination task by analyzing recordings from 169 neural channels in the prefrontal cortex of macaque monkeys. Phase I is a distributed phase in which uncertainty is substantially reduced by pooling information from many cells. Phase II is a redundant phase in which numerous single cells contain all the information present at the population level in Phase I. A dynamic distributed model connects low redundancy to a slow timescale of information aggregation, and provides a common explanation for both behaviors that differs only in the degree of recurrent excitation. We attribute the slow timescale of information accumulation to critical slowing down near the transition to a memory-carrying collective state. We suggest that this dynamic of slow distributed accumulation followed by fast collective propagation is a generic feature of robust collective computing systems related to consensus formation.

Screening method based on walking plantar impulse for detecting musculoskeletal senescence and injury.

PubMed

Fan, Yifang; Fan, Yubo; Li, Zhiyu; Newman, Tony; Lv, Changsheng; Zhou, Yi

2013-01-01

No consensus has been reached on how musculoskeletal system injuries or aging can be explained by a walking plantar impulse. We standardize the plantar impulse by defining a principal axis of plantar impulse. Based upon this standardized plantar impulse, two indexes are presented: plantar pressure record time series and plantar-impulse distribution along the principal axis of plantar impulse. These indexes are applied to analyze the plantar impulse collected by plantar pressure plates from three sources: Achilles tendon ruptures; elderly people (ages 62-71); and young people (ages 19-23). Our findings reveal that plantar impulse distribution curves for Achilles tendon ruptures change irregularly with subjects' walking speed changes. When comparing distribution curves of the young, we see a significant difference in the elderly subjects' phalanges plantar pressure record time series. This verifies our hypothesis that a plantar impulse can function as a means to assess and evaluate musculoskeletal system injuries and aging.

Integration of Model-Based Estimation Theory With an Adaptive Finite Volume Method for the Detection of a Moving Gaseous Source via a Mobile Sensor

DTIC Science & Technology

2012-02-29

couples the estimation scheme with the computational scheme, using one to enhance the other. Numerically, this switching changes several of the matrices...2011. 11. M.A. Demetriou, Enforcing and enhancing consensus of spatially distributed filters utilizing mobile sensor networks, Proceedings of the 49th...expected May, 2012. References [1] J. H. Seinfeld and S. N. Pandis, Atmospheric Chemistry and Physics: From Air Pollution to Climate Change. New York

The Analysis of the Strength, Distribution and Direction for the EEG Phase Synchronization by Musical Stimulus

NASA Astrophysics Data System (ADS)

Ogawa, Yutaro; Ikeda, Akira; Kotani, Kiyoshi; Jimbo, Yasuhiko

In this study, we propose the EEG phase synchronization analysis including not only the average strength of the synchronization but also the distribution and directions under the conditions that evoked emotion by musical stimuli. The experiment is performed with the two different musical stimuli that evoke happiness or sadness for 150 seconds. It is found that the average strength of synchronization indicates no difference between the right side and the left side of the frontal lobe during the happy stimulus, the distribution and directions indicate significant differences. Therefore, proposed analysis is useful for detecting emotional condition because it provides information that cannot be obtained only by the average strength of synchronization.

Determination of the boiling-point distribution by simulated distillation from n-pentane through n-tetratetracontane in 70 to 80 seconds.

PubMed

Lubkowitz, Joaquin A; Meneghini, Roberto I

2002-01-01

This work presents the carrying out of boiling-point distributions by simulated distillation with direct-column heating rather than oven-column heating. Column-heating rates of 300 degrees C/min are obtained yielding retention times of 73 s for n-tetratetracontane. The calibration curves of the retention time versus the boiling point, in the range of n-pentane to n-tetratetracontane, are identical to those obtained by slower oven-heating rates. The boiling-point distribution of the reference gas oil is compared with that obtained with column oven heating at rates of 15 to 40 degrees C/min. The results show boiling-point distribution values nearly the same (1-2 degrees F) as those obtained with oven column heating from the initial boiling point to 80% distilled off. Slightly higher differences are obtained (3-4 degrees F) for the 80% distillation to final boiling-point interval. Nonetheless, allowed consensus differences are never exceeded. Precision of the boiling-point distributions (expressed as standard deviations) are 0.1-0.3% for the data obtained in the direct column-heating mode.

Reducing false-positive detections by combining two stage-1 computer-aided mass detection algorithms

NASA Astrophysics Data System (ADS)

Bedard, Noah D.; Sampat, Mehul P.; Stokes, Patrick A.; Markey, Mia K.

2006-03-01

In this paper we present a strategy for reducing the number of false-positives in computer-aided mass detection. Our approach is to only mark "consensus" detections from among the suspicious sites identified by different "stage-1" detection algorithms. By "stage-1" we mean that each of the Computer-aided Detection (CADe) algorithms is designed to operate with high sensitivity, allowing for a large number of false positives. In this study, two mass detection methods were used: (1) Heath and Bowyer's algorithm based on the average fraction under the minimum filter (AFUM) and (2) a low-threshold bi-lateral subtraction algorithm. The two methods were applied separately to a set of images from the Digital Database for Screening Mammography (DDSM) to obtain paired sets of mass candidates. The consensus mass candidates for each image were identified by a logical "and" operation of the two CADe algorithms so as to eliminate regions of suspicion that were not independently identified by both techniques. It was shown that by combining the evidence from the AFUM filter method with that obtained from bi-lateral subtraction, the same sensitivity could be reached with fewer false-positives per image relative to using the AFUM filter alone.

Validation of an improved abnormality insertion method for medical image perception investigations

NASA Astrophysics Data System (ADS)

Madsen, Mark T.; Durst, Gregory R.; Caldwell, Robert T.; Schartz, Kevin M.; Thompson, Brad H.; Berbaum, Kevin S.

2009-02-01

The ability to insert abnormalities in clinical tomographic images makes image perception studies with medical images practical. We describe a new insertion technique and its experimental validation that uses complementary image masks to select an abnormality from a library and place it at a desired location. The method was validated using a 4-alternative forced-choice experiment. For each case, four quadrants were simultaneously displayed consisting of 5 consecutive frames of a chest CT with a pulmonary nodule. One quadrant was unaltered, while the other 3 had the nodule from the unaltered quadrant artificially inserted. 26 different sets were generated and repeated with order scrambling for a total of 52 cases. The cases were viewed by radiology staff and residents who ranked each quadrant by realistic appearance. On average, the observers were able to correctly identify the unaltered quadrant in 42% of cases, and identify the unaltered quadrant both times it appeared in 25% of cases. Consensus, defined by a majority of readers, correctly identified the unaltered quadrant in only 29% of 52 cases. For repeats, the consensus observer successfully identified the unaltered quadrant only once. We conclude that the insertion method can be used to reliably place abnormalities in perception experiments.

The S-Layer Glycoprotein of the Crenarchaeote Sulfolobus acidocaldarius Is Glycosylated at Multiple Sites with Chitobiose-Linked N-Glycans

PubMed Central

Peyfoon, Elham; Meyer, Benjamin; Hitchen, Paul G.; Panico, Maria; Morris, Howard R.; Haslam, Stuart M.; Albers, Sonja-Verena; Dell, Anne

2010-01-01

Glycosylation of the S-layer of the crenarchaea Sulfolobus acidocaldarius has been investigated using glycoproteomic methodologies. The mature protein is predicted to contain 31 N-glycosylation consensus sites with approximately one third being found in the C-terminal domain spanning residues L1004-Q1395. Since this domain is rich in Lys and Arg and therefore relatively tractable to glycoproteomic analysis, this study has focused on mapping its N-glycosylation. Our analysis identified nine of the 11 consensus sequence sites, and all were found to be glycosylated. This constitutes a remarkably high glycosylation density in the C-terminal domain averaging one site for each stretch of 30–40 residues. Each of the glycosylation sites observed was shown to be modified with a heterogeneous family of glycans, with the largest having a composition Glc1Man2GlcNAc2 plus 6-sulfoquinovose (QuiS), consistent with the tribranched hexasaccharide previously reported in the cytochrome b558/566 of S. acidocaldarius. S. acidocaldarius is the only archaeal species whose N-glycans are known to be linked via the chitobiose core disaccharide that characterises the N-linked glycans of Eukarya. PMID:20936123

Singer Responses to Sound Fields with a Simulated Reflection

NASA Astrophysics Data System (ADS)

NOSON, D.; SATO, S.; SAKAI, H.; ANDO, Y.

2000-04-01

While numerous recent studies have reported results concerning improvements to stage acoustics for orchestral performers, the preferred acoustical conditions on performing stages for singers has received limited attention in the past 20 years. A series of acoustical modifications have been proposed for a Seattle church to improve the acoustics for both the listeners and the performing choir. An on-site preliminary study was made to determine what acoustical changes might be important to singers. During solo fast-tempo singing and duet singing, singer preference increased with simulated short-delay reflections. The results suggest a potential for new reflectors to produce noticeable improvement in the choir acoustics. Subsequently, a solo singer study was conducted to establish preferred range of time delays for a single-simulated reflection. When singing faster-tempo music, the consensus of preference is statistically significant and the preferred delay averages 20 ms, while with a slow-tempo piece, the singers were not consistent in their judgment of preference and a strong individual variability predominated in the pair-comparison tests. The results point the way for an examination of a wider range of time delays and music motifs to acquire a clearer picture of consensus and individual preference for time-delayed reflections.

How Well Does LCA Model Land Use Impacts on Biodiversity?--A Comparison with Approaches from Ecology and Conservation.

PubMed

Curran, Michael; de Souza, Danielle Maia; Antón, Assumpció; Teixeira, Ricardo F M; Michelsen, Ottar; Vidal-Legaz, Beatriz; Sala, Serenella; Milà i Canals, Llorenç

2016-03-15

The modeling of land use impacts on biodiversity is considered a priority in life cycle assessment (LCA). Many diverging approaches have been proposed in an expanding literature on the topic. The UNEP/SETAC Life Cycle Initiative is engaged in building consensus on a shared modeling framework to highlight best-practice and guide model application by practitioners. In this paper, we evaluated the performance of 31 models from both the LCA and the ecology/conservation literature (20 from LCA, 11 from non-LCA fields) according to a set of criteria reflecting (i) model completeness, (ii) biodiversity representation, (iii) impact pathway coverage, (iv) scientific quality, and (v) stakeholder acceptance. We show that LCA models tend to perform worse than those from ecology and conservation (although not significantly), implying room for improvement. We identify seven best-practice recommendations that can be implemented immediately to improve LCA models based on existing approaches in the literature. We further propose building a "consensus model" through weighted averaging of existing information, to complement future development. While our research focuses on conceptual model design, further quantitative comparison of promising models in shared case studies is an essential prerequisite for future informed model choice.

Mini-midi-mito: adapting the amplification and sequencing strategy of mtDNA to the degradation state of crime scene samples.

PubMed

Berger, Cordula; Parson, Walther

2009-06-01

The degradation state of some biological traces recovered from the crime scene requires the amplification of very short fragments to attain a useful mitochondrial (mt)DNA sequence. We have previously introduced two mini-multiplex assays that amplify 10 overlapping control region (CR) fragments in two separate multiplex PCRs, which brought successful CR consensus sequences from even highly degraded DNA extracts. This procedure requires a total of 20 sequencing reactions per sample, which is laborious and cost intensive. For only moderately degraded samples that we encounter more frequently with typical mtDNA casework material, we developed two new multiplex assays that use a subset of the mini-amplicon primers but embrace larger fragments (midis) and require only 10 sequencing reactions to build a double-stranded CR consensus sequence. We used a preceding mtDNA quantitation step by real-time PCR with two different target fragments (143 and 283 bp) that roughly correspond to the average fragment sizes of the different multiplex approaches to estimate size-dependent mtDNA quantities and to aid the choice of the appropriate PCR multiplexes with respect to quality of the results and required costs.

Tracking Electroencephalographic Changes Using Distributions of Linear Models: Application to Propofol-Based Depth of Anesthesia Monitoring.

PubMed

Kuhlmann, Levin; Manton, Jonathan H; Heyse, Bjorn; Vereecke, Hugo E M; Lipping, Tarmo; Struys, Michel M R F; Liley, David T J

2017-04-01

Tracking brain states with electrophysiological measurements often relies on short-term averages of extracted features and this may not adequately capture the variability of brain dynamics. The objective is to assess the hypotheses that this can be overcome by tracking distributions of linear models using anesthesia data, and that anesthetic brain state tracking performance of linear models is comparable to that of a high performing depth of anesthesia monitoring feature. Individuals' brain states are classified by comparing the distribution of linear (auto-regressive moving average-ARMA) model parameters estimated from electroencephalographic (EEG) data obtained with a sliding window to distributions of linear model parameters for each brain state. The method is applied to frontal EEG data from 15 subjects undergoing propofol anesthesia and classified by the observers assessment of alertness/sedation (OAA/S) scale. Classification of the OAA/S score was performed using distributions of either ARMA parameters or the benchmark feature, Higuchi fractal dimension. The highest average testing sensitivity of 59% (chance sensitivity: 17%) was found for ARMA (2,1) models and Higuchi fractal dimension achieved 52%, however, no statistical difference was observed. For the same ARMA case, there was no statistical difference if medians are used instead of distributions (sensitivity: 56%). The model-based distribution approach is not necessarily more effective than a median/short-term average approach, however, it performs well compared with a distribution approach based on a high performing anesthesia monitoring measure. These techniques hold potential for anesthesia monitoring and may be generally applicable for tracking brain states.

Consensus on consensus: a synthesis of consensus estimates on human-caused global warming

NASA Astrophysics Data System (ADS)

Cook, John; Oreskes, Naomi; Doran, Peter T.; Anderegg, William R. L.; Verheggen, Bart; Maibach, Ed W.; Carlton, J. Stuart; Lewandowsky, Stephan; Skuce, Andrew G.; Green, Sarah A.; Nuccitelli, Dana; Jacobs, Peter; Richardson, Mark; Winkler, Bärbel; Painting, Rob; Rice, Ken

2016-04-01

The consensus that humans are causing recent global warming is shared by 90%-100% of publishing climate scientists according to six independent studies by co-authors of this paper. Those results are consistent with the 97% consensus reported by Cook et al (Environ. Res. Lett. 8 024024) based on 11 944 abstracts of research papers, of which 4014 took a position on the cause of recent global warming. A survey of authors of those papers (N = 2412 papers) also supported a 97% consensus. Tol (2016 Environ. Res. Lett. 11 048001) comes to a different conclusion using results from surveys of non-experts such as economic geologists and a self-selected group of those who reject the consensus. We demonstrate that this outcome is not unexpected because the level of consensus correlates with expertise in climate science. At one point, Tol also reduces the apparent consensus by assuming that abstracts that do not explicitly state the cause of global warming (‘no position’) represent non-endorsement, an approach that if applied elsewhere would reject consensus on well-established theories such as plate tectonics. We examine the available studies and conclude that the finding of 97% consensus in published climate research is robust and consistent with other surveys of climate scientists and peer-reviewed studies.

Scaling analysis on Indian foreign exchange market

NASA Astrophysics Data System (ADS)

Sarkar, A.; Barat, P.

2006-05-01

In this paper, we investigate the scaling behavior of the average daily exchange rate returns of the Indian Rupee against four foreign currencies: namely, US Dollar, Euro, Great Britain Pound and Japanese Yen. The average daily exchange rate return of the Indian Rupee against US Dollar is found to exhibit a persistent scaling behavior and follow Levy stable distribution. On the contrary, the average daily exchange rate returns of the other three foreign currencies do not show persistency or antipersistency and follow Gaussian distribution.

[Ecological suitability regionalization for Gastrodia elata in Zhaotong based on Maxent and ArcGIS].

PubMed

Shi, Zi-Wei; Ma, Cong-Ji; Kang, Chuan-Zhi; Wang, Li; Zhang, Zhi-Hui; Chen, Jun-Fei; Zhang, Xiao-Bo; Liu, Da-Hui

2016-09-01

In this paper, the potential distribution information and ecological suitability regionalization for Gastrodia elata in Zhaotong were studied based on the climate, terrain, soil and vegetation factors analysis by Maxent and ArcGIS. The results showed that the highly potential distribution (suitability index>0.6) mainly located in Zhaotong, Yunnan province（Zhenxiong,Yiliang and Daguan county, with an area of 2 872 km²）, and Bijie, Guizhou province （Hezhang,Bijie,Weining county, 1 251 km²）. The AUC of ROC curve was above 0.99, indicating that the predictive results with the Maxent model were highly precise. The main ecological factors determining the potential distribution were the altitude, average rainfall in November, average rainfall in October, vegetation types, average rainfall in March, average rainfall in April,soil types,isothermal characteristic and average rainfall in June. The environmental variables in the highly potential areas were determined as altitude around 1 450-2 200 m,annual average temperature around 18.0-20.4 ℃,annual average precipitation around 900 mm,yellow soil or yellow brown soil,and acid sandy loam or slightly acidic sandy loam.The results will provide valuable references for plantation regionalization and the siting for imitation wild planting of G. elata in Zhaotong. Copyright© by the Chinese Pharmaceutical Association.

Climate Impacts of CALIPSO-Guided Corrections to Black Carbon Aerosol Vertical Distributions in a Global Climate Model

NASA Astrophysics Data System (ADS)

Kovilakam, Mahesh; Mahajan, Salil; Saravanan, R.; Chang, Ping

2017-10-01

We alleviate the bias in the tropospheric vertical distribution of black carbon aerosols (BC) in the Community Atmosphere Model (CAM4) using the Cloud-Aerosol and Infrared Pathfinder Satellite Observations (CALIPSO)-derived vertical profiles. A suite of sensitivity experiments are conducted with 1x, 5x, and 10x the present-day model estimated BC concentration climatology, with (corrected, CC) and without (uncorrected, UC) CALIPSO-corrected BC vertical distribution. The globally averaged top of the atmosphere radiative flux perturbation of CC experiments is ˜8-50% smaller compared to uncorrected (UC) BC experiments largely due to an increase in low-level clouds. The global average surface temperature increases, the global average precipitation decreases, and the ITCZ moves northward with the increase in BC radiative forcing, irrespective of the vertical distribution of BC. Further, tropical expansion metrics for the poleward extent of the Northern Hemisphere Hadley cell (HC) indicate that simulated HC expansion is not sensitive to existing model biases in BC vertical distribution.

The statistical average of optical properties for alumina particle cluster in aircraft plume

NASA Astrophysics Data System (ADS)

Li, Jingying; Bai, Lu; Wu, Zhensen; Guo, Lixin

2018-04-01

We establish a model for lognormal distribution of monomer radius and number of alumina particle clusters in plume. According to the Multi-Sphere T Matrix (MSTM) theory, we provide a method for finding the statistical average of optical properties for alumina particle clusters in plume, analyze the effect of different distributions and different detection wavelengths on the statistical average of optical properties for alumina particle cluster, and compare the statistical average optical properties under the alumina particle cluster model established in this study and those under three simplified alumina particle models. The calculation results show that the monomer number of alumina particle cluster and its size distribution have a considerable effect on its statistical average optical properties. The statistical average of optical properties for alumina particle cluster at common detection wavelengths exhibit obvious differences, whose differences have a great effect on modeling IR and UV radiation properties of plume. Compared with the three simplified models, the alumina particle cluster model herein features both higher extinction and scattering efficiencies. Therefore, we may find that an accurate description of the scattering properties of alumina particles in aircraft plume is of great significance in the study of plume radiation properties.

Sources and distribution of allochthonous organic matter in surface sediment from the Seomjin River to the southern inner shelf of Korea

NASA Astrophysics Data System (ADS)

Badejo, Adegoke Olugboyega; Hyun, Sangmin; Kim, Wonnyon; Ju, Se-Jong; Song, Bareum

2017-12-01

The spatial distributions of δ13C, δ15N, and n-alkanes were investigated to determine the source and transportation of allochthonous organic matter from the mouth of the Seomjin River to the southern inner shelf break of Korea. Total organic carbon (%) ranged from 0.3% to 1.6% (average = 0.80%, n = 81), and the C/N ratio varied from 2.4 to 12.4 (average = 6.76, n = 81). The δ13C values ranged from -25.86 to -20.26‰ (average = -21.47‰, n = 81), and δ15N values ranged from 4.37‰ to 8.57‰ (average = 6.72‰, n = 81). The contribution of the terrestrial fraction of organic matter to the total ranged from 4.4% to 97.7% (average = 24.4%, n = 81), suggesting higher amounts around the catchment area and lower amounts in the offshore area. The concentration of total n-alkanes ( nC25 - nC35) was higher at the boundary between the outer bay and inner shelf break (BOBIS). Average chain length and the carbon preference index both indicated that major leaf wax n-alkanes accounted for the observed distribution of terrestrial organic matter, and were dominant in the inner shelf break (around BOBIS) and outer shelf break. Based on the spatial distribution of the total n-alkanes and the sum of nC27, nC29, and nC31, the terrestrial organic matter distribution was considered to be controlled by local oceanographic conditions, especially at the center of the BOBIS. In addition to enabling the distribution and source of terrestrial organic matter to be identified, the n-alkanes indicated that minor anthropogenic allochthonous organic materials were superimposed on the total organic materials in the central part of Yeosu Bay and the catchment area. The n-alkane indices revealed weathered petroleum contamination, with contamination levels being relatively low at the present time.

Performance of an Advanced MOS System in the 1996-97 National Collegiate Weather Forecasting Contest.

NASA Astrophysics Data System (ADS)

Vislocky, Robert L.; Fritsch, J. Michael

1997-12-01

A prototype advanced model output statistics (MOS) forecast system that was entered in the 1996-97 National Collegiate Weather Forecast Contest is described and its performance compared to that of widely available objective guidance and to contest participants. The prototype system uses an optimal blend of aviation (AVN) and nested grid model (NGM) MOS forecasts, explicit output from the NGM and Eta guidance, and the latest surface weather observations from the forecast site. The forecasts are totally objective and can be generated quickly on a personal computer. Other "objective" forms of guidance tracked in the contest are 1) the consensus forecast (i.e., the average of the forecasts from all of the human participants), 2) the combination of NGM raw output (for precipitation forecasts) and NGM MOS guidance (for temperature forecasts), and 3) the combination of Eta Model raw output (for precipitation forecasts) and AVN MOS guidance (for temperature forecasts).Results show that the advanced MOS system finished in 20th place out of 737 original entrants, or better than approximately 97% of the human forecasters who entered the contest. Moreover, the advanced MOS system was slightly better than consensus (23d place). The fact that an objective forecast system finished ahead of consensus is a significant accomplishment since consensus is traditionally a very formidable "opponent" in forecast competitions. Equally significant is that the advanced MOS system was superior to the traditional guidance products available from the National Centers for Environmental Prediction (NCEP). Specifically, the combination of NGM raw output and NGM MOS guidance finished in 175th place, and the combination of Eta Model raw output and AVN MOS guidance finished in 266th place. The latter result is most intriguing since the proposed elimination of all NGM products would likely result in a serious degradation of objective products disseminated by NCEP, unless they are replaced with equal or better substitutes. On the other hand, the positive performance of the prototype advanced MOS system shows that it is possible to create a single objective product that is not only superior to currently available objective guidance products, but is also on par with some of the better human forecasters.

The management of Legg-Calvé-Perthes' disease: is there a consensus? : A study of clinical practice preferred by the members of the European Paediatric Orthopaedic Society.

PubMed

Hefti, Fritz; Clarke, N M P

2007-03-01

The aim of the study was to find out whether or not there is consensus among experienced pediatric orthopaedists about the management of certain clinical scenarios in Legg-Calvé-Perthes' disease. A questionnaire was sent to all 297 members of the European Paediatric Orthopaedic Society (EPOS) describing four cases of Legg-Calvé-Perthes' disease (LCPD) with two X-rays each and a short description of the clinical scenario. Two of the patients were younger and two were older than six years of age. From both age groups there was one with a good range of motion and an X-ray classified as Herring A or B, while the other patient had a poor range of motion and an X-ray classified as Herring C. EPO members were asked to choose from various treatment options or to describe any other therapy that they would advise in the clinical scenarios. One-hundred and fifty members answered the questionnaire. The participants had an average of 20 years of experience in pediatric orthopaedics. There was a consensus that no surgery should be performed in a young patient with a good range of motion and that there should be no weight relief when older with a good range of motion. Conservative containment treatment (abduction splint, Petrie cast) and arthrodiastasis was suggested in only very few centres. There was a tendency to perform an operation when the patient is older with a poor range of motion and to perform operative treatment only when there were subluxation or head at risk signs. pelvic osteotomies or a combination of pelvic and femoral osteotomies rather than femoral osteotomies alone. Age did not determine the indication for treatment and there was no agreement on the indications for physiotherapy. There was also no consensus on the type of pelvic osteotomy to be used. The study showed that indications for the treatment of LCPD is based more on the personal experience of the surgeon rather than on scientific data.

District-level hospital trauma care audit filters: Delphi technique for defining context-appropriate indicators for quality improvement initiative evaluation in developing countries

PubMed Central

Stewart, Barclay T; Gyedu, Adam; Quansah, Robert; Addo, Wilfred Larbi; Afoko, Akis; Agbenorku, Pius; Amponsah-Manu, Forster; Ankomah, James; Appiah-Denkyira, Ebenezer; Baffoe, Peter; Debrah, Sam; Donkor, Peter; Dorvlo, Theodor; Japiong, Kennedy; Kushner, Adam L; Morna, Martin; Ofosu, Anthony; Oppong-Nketia, Victor; Tabiri, Stephen; Mock, Charles

2015-01-01

Introduction Prospective clinical audit of trauma care improves outcomes for the injured in high-income countries (HICs). However, equivalent, context-appropriate audit filters for use in low- and middle-income country (LMIC) district-level hospitals have not been well established. We aimed to develop context-appropriate trauma care audit filters for district-level hospitals in Ghana, was well as other LMICs more broadly. Methods Consensus on trauma care audit filters was built between twenty panelists using a Delphi technique with four anonymous, iterative surveys designed to elicit: i) trauma care processes to be measured; ii) important features of audit filters for the district-level hospital setting; and iii) potentially useful filters. Filters were ranked on a scale from 0 – 10 (10 being very useful). Consensus was measured with average percent majority opinion (APMO) cut-off rate. Target consensus was defined a priori as: a median rank of ≥9 for each filter and an APMO cut-off rate of ≥0.8. Results Panelists agreed on trauma care processes to target (e.g. triage, phases of trauma assessment, early referral if needed) and specific features of filters for district-level hospital use (e.g. simplicity, unassuming of resource capacity). APMO cut-off rate increased successively: Round 1 - 0.58; Round 2 - 0.66; Round 3 - 0.76; and Round 4 - 0.82. After Round 4, target consensus on 22 trauma care and referral-specific filters was reached. Example filters include: triage - vital signs are recorded within 15 minutes of arrival (must include breathing assessment, heart rate, blood pressure, oxygen saturation if available); circulation - a large bore IV was placed within 15 minutes of patient arrival; referral - if referral is activated, the referring clinician and receiving facility communicate by phone or radio prior to transfer. Conclusion This study proposes trauma care audit filters appropriate for LMIC district-level hospitals. Given the successes of similar filters in HICs and obstetric care filters in LMICs, the collection and reporting of prospective trauma care audit filters may be an important step toward improving care for the injured at district-level hospitals in LMICs. PMID:26492882

Improved model quality assessment using ProQ2.

PubMed

Ray, Arjun; Lindahl, Erik; Wallner, Björn

2012-09-10

Employing methods to assess the quality of modeled protein structures is now standard practice in bioinformatics. In a broad sense, the techniques can be divided into methods relying on consensus prediction on the one hand, and single-model methods on the other. Consensus methods frequently perform very well when there is a clear consensus, but this is not always the case. In particular, they frequently fail in selecting the best possible model in the hard cases (lacking consensus) or in the easy cases where models are very similar. In contrast, single-model methods do not suffer from these drawbacks and could potentially be applied on any protein of interest to assess quality or as a scoring function for sampling-based refinement. Here, we present a new single-model method, ProQ2, based on ideas from its predecessor, ProQ. ProQ2 is a model quality assessment algorithm that uses support vector machines to predict local as well as global quality of protein models. Improved performance is obtained by combining previously used features with updated structural and predicted features. The most important contribution can be attributed to the use of profile weighting of the residue specific features and the use features averaged over the whole model even though the prediction is still local. ProQ2 is significantly better than its predecessors at detecting high quality models, improving the sum of Z-scores for the selected first-ranked models by 20% and 32% compared to the second-best single-model method in CASP8 and CASP9, respectively. The absolute quality assessment of the models at both local and global level is also improved. The Pearson's correlation between the correct and local predicted score is improved from 0.59 to 0.70 on CASP8 and from 0.62 to 0.68 on CASP9; for global score to the correct GDT_TS from 0.75 to 0.80 and from 0.77 to 0.80 again compared to the second-best single methods in CASP8 and CASP9, respectively. ProQ2 is available at http://proq2.wallnerlab.org.

International recommendation for a comprehensive neuropathologic workup of epilepsy surgery brain tissue: A consensus Task Force report from the ILAE Commission on Diagnostic Methods.

PubMed

Blümcke, Ingmar; Aronica, Eleonora; Miyata, Hajime; Sarnat, Harvey B; Thom, Maria; Roessler, Karl; Rydenhag, Bertil; Jehi, Lara; Krsek, Pavel; Wiebe, Samuel; Spreafico, Roberto

2016-03-01

Epilepsy surgery is an effective treatment in many patients with drug-resistant focal epilepsies. An early decision for surgical therapy is facilitated by a magnetic resonance imaging (MRI)-visible brain lesion congruent with the electrophysiologically abnormal brain region. Recent advances in the pathologic diagnosis and classification of epileptogenic brain lesions are helpful for clinical correlation, outcome stratification, and patient management. However, application of international consensus classification systems to common epileptic pathologies (e.g., focal cortical dysplasia [FCD] and hippocampal sclerosis [HS]) necessitates standardized protocols for neuropathologic workup of epilepsy surgery specimens. To this end, the Task Force of Neuropathology from the International League Against Epilepsy (ILAE) Commission on Diagnostic Methods developed a consensus standard operational procedure for tissue inspection, distribution, and processing. The aims are to provide a systematic framework for histopathologic workup, meeting minimal standards and maximizing current and future opportunities for morphofunctional correlations and molecular studies for both clinical care and research. Whenever feasible, anatomically intact surgical specimens are desirable to enable systematic analysis in selective hippocampectomies, temporal lobe resections, and lesional or nonlesional neocortical samples. Correct orientation of sample and the sample's relation to neurophysiologically aberrant sites requires good communication between pathology and neurosurgical teams. Systematic tissue sampling of 5-mm slabs along a defined anatomic axis and application of a limited immunohistochemical panel will ensure a reliable differential diagnosis of main pathologies encountered in epilepsy surgery. Wiley Periodicals, Inc. © 2016 International League Against Epilepsy.

Hunter-Gatherer Color Naming Provides New Insight into the Evolution of Color Terms.

PubMed

Lindsey, Delwin T; Brown, Angela M; Brainard, David H; Apicella, Coren L

2015-09-21

Most people name the myriad colors in the environment using between two and about a dozen color terms, with great variation within and between languages. Investigators generally agree that color lexicons evolve from fewer terms to more terms, as technology advances and color communication becomes increasingly important. However, little is understood about the color naming systems at the least technologically advanced end of the continuum. The Hadza people of Tanzania are nomadic hunter-gatherers who live a subsistence lifestyle that was common before the advent of agriculture (see Supplemental Experimental Procedures, section I;), suggesting that the Hadzane language should be at an early stage of color lexicon evolution. When Hadza, Somali, and US informants named 23 color samples, Hadza informants named only the black, white, and red samples with perfect consensus. Otherwise, they used low-consensus terms or responded "don't know." However, even low-consensus color terms grouped test colors into lexical categories that aligned with those found in other world languages. Furthermore, information-theoretic analysis showed that color communication efficiency within the Hadza, Somali, and US language communities falls on the same continuum as other world languages. Thus, the structure of color categories is in place in Hadzane, even though words for many of the categories are not in general use. These results suggest that even very simple color lexicons include precursors of many color categories but that these categories are initially represented in a diverse and distributed fashion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Revisiting control establishments for emerging energy hubs

NASA Astrophysics Data System (ADS)

Nasirian, Vahidreza

Emerging small-scale energy systems, i.e., microgrids and smartgrids, rely on centralized controllers for voltage regulation, load sharing, and economic dispatch. However, the central controller is a single-point-of-failure in such a design as either the controller or attached communication links failure can render the entire system inoperable. This work seeks for alternative distributed control structures to improve system reliability and help to the scalability of the system. A cooperative distributed controller is proposed that uses a noise-resilient voltage estimator and handles global voltage regulation and load sharing across a DC microgrid. Distributed adaptive droop control is also investigated as an alternative solution. A droop-free distributed control is offered to handle voltage/frequency regulation and load sharing in AC systems. This solution does not require frequency measurement and, thus, features a fast frequency regulation. Distributed economic dispatch is also studied, where a distributed protocol is designed that controls generation units to merge their incremental costs into a consensus and, thus, push the entire system to generate with the minimum cost. Experimental verifications and Hardware-in-the-Loop (HIL) simulations are used to study efficacy of the proposed control protocols.

The temporal organization of behavior on periodic food schedules.

PubMed Central

Reid, A K; Bacha, G; Morán, C

1993-01-01

Various theories of temporal control and schedule induction imply that periodic schedules temporally modulate an organism's motivational states within interreinforcement intervals. This speculation has been fueled by frequently observed multimodal activity distributions created by averaging across interreinforcement intervals. We tested this hypothesis by manipulating the cost associated with schedule-induced activities and the availability of other activities to determine the degree to which (a) the temporal distributions of activities within the interreinforcement interval are fixed or can be temporally displaced, (b) rats can reallocate activities across different interreinforcement intervals, and (c) noninduced activities can substitute for schedule-induced activities. Obtained multimodal activity distributions created by averaging across interreinforcement intervals were not representative of the transitions occurring within individual intervals, so the averaged multimodal distributions should not be assumed to represent changes in the subject's motivational states within the interval. Rather, the multimodal distributions often result from averaging across interreinforcement intervals in which only a single activity occurs. A direct influence of the periodic schedule on the motivational states implies that drinking and running should occur at different periods within the interval, but in three experiments the starting times of drinking and running within interreinforcement intervals were equal. Thus, the sequential pattern of drinking and running on periodic schedules does not result from temporal modulation of motivational states within interreinforcement intervals. PMID:8433061

Electron energy distribution function in the divertor region of the COMPASS tokamak during neutral beam injection heating

NASA Astrophysics Data System (ADS)

Hasan, E.; Dimitrova, M.; Havlicek, J.; Mitošinková, K.; Stöckel, J.; Varju, J.; Popov, Tsv K.; Komm, M.; Dejarnac, R.; Hacek, P.; Panek, R.; the COMPASS Team

2018-02-01

This paper presents the results from swept probe measurements in the divertor region of the COMPASS tokamak in D-shaped, L-mode discharges, with toroidal magnetic field BT = 1.15 T, plasma current Ip = 180 kA and line-average electron densities varying from 2 to 8×1019 m-3. Using neutral beam injection heating, the electron energy distribution function is studied before and during the application of the beam. The current-voltage characteristics data are processed using the first-derivative probe technique. This technique allows one to evaluate the plasma potential and the real electron energy distribution function (respectively, the electron temperatures and densities). At the low average electron density of 2×1019 m-3, the electron energy distribution function is bi-Maxwellian with a low-energy electron population with temperatures 4-6 eV and a high-energy electron group 12-25 eV. As the line-average electron density is increased, the electron temperatures decrease. At line-average electron densities above 7×1019 m-3, the electron energy distribution function is found to be Maxwellian with a temperature of 6-8.5 eV. The effect of the neutral beam injection heating power in the divertor region is also studied.

Ultra-fast consensus of discrete-time multi-agent systems with multi-step predictive output feedback

NASA Astrophysics Data System (ADS)

Zhang, Wenle; Liu, Jianchang

2016-04-01

This article addresses the ultra-fast consensus problem of high-order discrete-time multi-agent systems based on a unified consensus framework. A novel multi-step predictive output mechanism is proposed under a directed communication topology containing a spanning tree. By predicting the outputs of a network several steps ahead and adding this information into the consensus protocol, it is shown that the asymptotic convergence factor is improved by a power of q + 1 compared to the routine consensus. The difficult problem of selecting the optimal control gain is solved well by introducing a variable called convergence step. In addition, the ultra-fast formation achievement is studied on the basis of this new consensus protocol. Finally, the ultra-fast consensus with respect to a reference model and robust consensus is discussed. Some simulations are performed to illustrate the effectiveness of the theoretical results.

Intraarticular Facet Injections for Low Back Pain: Design Considerations, Consensus Methodology to Develop the Protocol for a Randomized Controlled Trial.

PubMed

Mars, Tom; Ellard, David R; Antrobus, James H L; Cairns, Melinda; Underwood, Martin; Haywood, Kirstie; Keohane, Susie; Sandhu, Harbinder; Griffiths, Frances

2015-01-01

Since the publication of guidelines by the UK National Institute for Health and Care Excellence (NICE) and the American Pain Society guidelines for low back pain in 2009 there have been deep divisions in the pain treatment community about the use of therapeutic intraarticular facet joint injections. While evidence for the effectiveness or not of intraarticular facet joint injections remains sparse, uncertainty will remain. The Warwick feasibility study, along with a concurrent study with a different design led by another group, aims to provide a stable platform from which the effectiveness and cost effectiveness of intraarticular facet joint injections added to normal care could be evaluated in randomized controlled trials (RCTs). To reach consensus on key design considerations for the Warwick facet feasibility study from which the study protocol and working manuals will be developed. A consensus conference involving expert professionals and lay members. Preliminary work identified 5 key design considerations for deliberation at our consensus conference. Three concerned patient assessment and treatment: diagnosis of possible facet joint pain, interaarticular facet joint injection technique, and best usual care. Two concerned trial analysis: a priori sub-groups and minimally important difference and are reported elsewhere. We did systematic evidence reviews of the design considerations and summarized the evidence. Our design questions and evidence summaries were distributed to all delegates. This formed the basis for discussions on the day. Clinical experts in all aspects of facet joint injection from across the UK along with lay people were invited via relevant organizations. Nominal group technique was used in 15 facilitated initial small group discussions. Further discussion and ranking was undertaken in plenary. All small group and plenary results were recorded and checked and verified post conference. Where necessary participants were contacted via email to resolve outstanding issues. Fifty-two delegates attended the conference with lay people and all relevant professions represented. Consensus was reached on the details of how to assess patients for facet joint pain, undertake the injections, and deliver usual care. Where post conference checking of results revealed errors in calculating ranking results on the day, consensus was reached by email consultation. All but 3 delegates agreed to be associated with the outcome. Allocating one day for discussing a wide range of topics imposed time pressure on discussion and calculation of the numerous rankings. Through the use of an evidence-based, systematic, inclusive, and transparent process we have established consensus from expert health professionals in the UK, with lay input, on the clinical assessment of suspected facet joint pain, interaarticular injection for facet joint pain, and best usual care for use in a feasibility study for a proposed pragmatic clinical trial of interaarticular facet joint injections. This provides a strong basis for a clinical trial that will be acceptable to the pain treatment community.

A common monitoring framework for ending preventable maternal mortality, 2015-2030: phase I of a multi-step process.

PubMed

Moran, Allisyn C; Jolivet, R Rima; Chou, Doris; Dalglish, Sarah L; Hill, Kathleen; Ramsey, Kate; Rawlins, Barbara; Say, Lale

2016-08-26

While global maternal mortality declined 44 % between 1990 and 2015, the majority of countries fell short of attaining Millennium Development Goal targets. The Sustainable Development Goals (SDGs), adopted in late 2015, include a target to reduce national maternal mortality ratios (MMR) to achieve a global average of 70 per 100,000 live births by 2030. A comprehensive paper outlining Strategies toward Ending Preventable Maternal Mortality (EPMM) was launched in February 2015 to support achievement of the SDG global targets. To date, there has not been consensus on a set of core metrics to track progress toward the overall global maternal mortality target, which has made it difficult to systematically monitor maternal health status and programs over time. The World Health Organization (WHO), Maternal Health Taskforce (MHTF), and the US Agency for International Development (USAID) along with its flagship Maternal and Child Survival Program (MCSP), facilitated a consultative process to seek consensus on maternal health indicators for global monitoring and reporting by all countries. Consensus was reached on 12 indicators and four priority areas for further indicator development and testing. These indicators are being harmonized with the Every Newborn Action Plan core metrics for a joint global maternal newborn monitoring framework. Next steps include a similar process to agree upon indicators to monitor social, political and economic determinants of maternal health and survival highlighted in the EPMM strategies. This process provides a foundation for the maternal health community to work collaboratively to track progress on core global indicators. It is important that actors continue to work together through transparent and participatory processes to track progress to end preventable maternal mortality and achieve the SDG maternal mortality targets.

QSAR Modeling of Rat Acute Toxicity by Oral Exposure

PubMed Central

Zhu, Hao; Martin, Todd M.; Ye, Lin; Sedykh, Alexander; Young, Douglas M.; Tropsha, Alexander

2009-01-01

Few Quantitative Structure-Activity Relationship (QSAR) studies have successfully modeled large, diverse rodent toxicity endpoints. In this study, a comprehensive dataset of 7,385 compounds with their most conservative lethal dose (LD50) values has been compiled. A combinatorial QSAR approach has been employed to develop robust and predictive models of acute toxicity in rats caused by oral exposure to chemicals. To enable fair comparison between the predictive power of models generated in this study versus a commercial toxicity predictor, TOPKAT (Toxicity Prediction by Komputer Assisted Technology), a modeling subset of the entire dataset was selected that included all 3,472 compounds used in the TOPKAT’s training set. The remaining 3,913 compounds, which were not present in the TOPKAT training set, were used as the external validation set. QSAR models of five different types were developed for the modeling set. The prediction accuracy for the external validation set was estimated by determination coefficient R2 of linear regression between actual and predicted LD50 values. The use of the applicability domain threshold implemented in most models generally improved the external prediction accuracy but expectedly led to the decrease in chemical space coverage; depending on the applicability domain threshold, R2 ranged from 0.24 to 0.70. Ultimately, several consensus models were developed by averaging the predicted LD50 for every compound using all 5 models. The consensus models afforded higher prediction accuracy for the external validation dataset with the higher coverage as compared to individual constituent models. The validated consensus LD50 models developed in this study can be used as reliable computational predictors of in vivo acute toxicity. PMID:19845371

[Endoprosthesis failure in the ankle joint : Histopathological diagnostics and classification].

PubMed

Müller, S; Walther, M; Röser, A; Krenn, V

2017-03-01

Endoprostheses of the ankle joint show higher revision rates of 3.29 revisions per 100 component years. The aims of this study were the application and modification of the consensus classification of the synovia-like interface membrane (SLIM) for periprosthetic failure of the ankle joint, the etiological clarification of periprosthetic pseudocysts and a detailed measurement of proliferative activity (Ki67) in the region of osteolysis. Tissue samples from 159 patients were examined according to the criteria of the standardized consensus classification. Of these, 117 cases were derived from periprosthetic membranes of the ankle. The control group included 42 tissue specimens from the hip and knee joints. Particle identification and characterization were carried out using the particle algorithm. An immunohistochemical examination with Ki67 proliferation was performed in all cases of ankle pseudocysts and 19 control cases. The consensus classification of SLIM is transferrable to endoprosthetic failure of the ankle joint. Periprosthetic pseudocysts with the histopathological characteristics of the appropriate SLIM subtype were detectable in 39 cases of ankle joint endoprostheses (33.3%). The mean value of the Ki67 index was 14% and showed an increased proliferation rate in periprosthetic pseudocysts of the ankle (p-value 0.02037). In periprosthetic pseudocysts an above average higher detection rate of type 1 SLIM induced by abrasion (51.3%) with an increased Ki67 proliferation fraction (p-value 0.02037) was found, which can be interpreted as local destructive intraosseus synovialitis. This can be the reason for formation of pseudocystic osteolysis caused by high mechanical stress in ankle endoprostheses. A simplified diagnostic classification scoring system of dysfunctional endoprostheses of the ankle is proposed for collation of periprosthetic pseudocysts, ossifications and the Ki67 proliferation fraction.

Quantitative structure-activity relationship modeling of rat acute toxicity by oral exposure.

PubMed

Zhu, Hao; Martin, Todd M; Ye, Lin; Sedykh, Alexander; Young, Douglas M; Tropsha, Alexander

2009-12-01

Few quantitative structure-activity relationship (QSAR) studies have successfully modeled large, diverse rodent toxicity end points. In this study, a comprehensive data set of 7385 compounds with their most conservative lethal dose (LD(50)) values has been compiled. A combinatorial QSAR approach has been employed to develop robust and predictive models of acute toxicity in rats caused by oral exposure to chemicals. To enable fair comparison between the predictive power of models generated in this study versus a commercial toxicity predictor, TOPKAT (Toxicity Prediction by Komputer Assisted Technology), a modeling subset of the entire data set was selected that included all 3472 compounds used in TOPKAT's training set. The remaining 3913 compounds, which were not present in the TOPKAT training set, were used as the external validation set. QSAR models of five different types were developed for the modeling set. The prediction accuracy for the external validation set was estimated by determination coefficient R(2) of linear regression between actual and predicted LD(50) values. The use of the applicability domain threshold implemented in most models generally improved the external prediction accuracy but expectedly led to the decrease in chemical space coverage; depending on the applicability domain threshold, R(2) ranged from 0.24 to 0.70. Ultimately, several consensus models were developed by averaging the predicted LD(50) for every compound using all five models. The consensus models afforded higher prediction accuracy for the external validation data set with the higher coverage as compared to individual constituent models. The validated consensus LD(50) models developed in this study can be used as reliable computational predictors of in vivo acute toxicity.

The study of PDF turbulence models in combustion

NASA Technical Reports Server (NTRS)

Hsu, Andrew T.

1991-01-01

The accurate prediction of turbulent combustion is still beyond reach for today's computation techniques. It is the consensus of the combustion profession that the predictions of chemically reacting flow were poor if conventional turbulence models were used. The main difficulty lies in the fact that the reaction rate is highly nonlinear, and the use of averaged temperature, pressure, and density produces excessively large errors. The probability density function (PDF) method is the only alternative at the present time that uses local instant values of the temperature, density, etc. in predicting chemical reaction rate, and thus it is the only viable approach for turbulent combustion calculations.

Cancer-Related Fatigue and Its Associations with Depression and Anxiety: A Systematic Review

PubMed Central

Brown, Linda F.; Kroenke, Kurt

2010-01-01

Background Fatigue is an important symptom in cancer and has been shown to be associated with psychological distress. Objectives This review assesses evidence regarding associations of CRF with depression and anxiety. Methods Database searches yielded 59 studies reporting correlation coefficients or odds ratios. Results Combined sample size was 12,103. Average correlation of fatigue with depression, weighted by sample size, was 0.56 and for anxiety, 0.46. Thirty-one instruments were used to assess fatigue, suggesting a lack of consensus on measurement. Conclusion This review confirms the association of fatigue with depression and anxiety. Directionality needs to be better delineated in longitudinal studies. PMID:19855028

Prevention and management of noncommunicable disease: the IOC Consensus Statement, Lausanne 2013.

PubMed

Matheson, Gordon O; Klügl, Martin; Engebretsen, Lars; Bendiksen, Fredrik; Blair, Steven N; Börjesson, Mats; Budgett, Richard; Derman, Wayne; Erdener, Uğur; Ioannidis, John P A; Khan, Karim M; Martinez, Rodrigo; van Mechelen, Willem; Mountjoy, Margo; Sallis, Robert E; Schwellnus, Martin; Shultz, Rebecca; Soligard, Torbjørn; Steffen, Kathrin; Sundberg, Carl Johan; Weiler, Richard; Ljungqvist, Arne

2013-11-01

Morbidity and mortality from preventable, noncommunicable chronic disease (NCD) threatens the health of our populations and our economies. The accumulation of vast amounts of scientific knowledge has done little to change this. New and innovative thinking is essential to foster new creative approaches that leverage and integrate evidence through the support of big data, technology, and design thinking. The purpose of this paper is to summarize the results of a consensus meeting on NCD prevention sponsored by the International Olympic Committee (IOC) in April 2013. Within the context of advocacy for multifaceted systems change, the IOC's focus is to create solutions that gain traction within health care systems. The group of participants attending the meeting achieved consensus on a strategy for the prevention and management of chronic disease that includes the following: 1. Focus on behavioral change as the core component of all clinical programs for the prevention and management of chronic disease. 2. Establish actual centers to design, implement, study, and improve preventive programs for chronic disease. 3. Use human-centered design (HCD) in the creation of prevention programs with an inclination to action, rapid prototyping and multiple iterations. 4. Extend the knowledge and skills of Sports and Exercise Medicine (SEM) professionals to build new programs for the prevention and treatment of chronic disease focused on physical activity, diet, and lifestyle. 5. Mobilize resources and leverage networks to scale and distribute programs of prevention. True innovation lies in the ability to align thinking around these core strategies to ensure successful implementation of NCD prevention and management programs within health care. The IOC and SEM community are in an ideal position to lead this disruptive change. The outcome of the consensus meeting was the creation of the IOC Non-Communicable Diseases ad hoc Working Group charged with the responsibility of moving this agenda forward.

Prevention and management of non-communicable disease: the IOC consensus statement, Lausanne 2013.

PubMed

Matheson, Gordon O; Klügl, Martin; Engebretsen, Lars; Bendiksen, Fredrik; Blair, Steven N; Börjesson, Mats; Budgett, Richard; Derman, Wayne; Erdener, Uğur; Ioannidis, John P A; Khan, Karim M; Martinez, Rodrigo; van Mechelen, Willem; Mountjoy, Margo; Sallis, Robert E; Schwellnus, Martin; Shultz, Rebecca; Soligard, Torbjørn; Steffen, Kathrin; Sundberg, Carl Johan; Weiler, Richard; Ljungqvist, Arne

2013-11-01

Morbidity and mortality from preventable, non-communicable chronic disease (NCD) threatens the health of our populations and our economies. The accumulation of vast amounts of scientific knowledge has done little to change this. New and innovative thinking is essential to foster new creative approaches that leverage and integrate evidence through the support of big data, technology, and design thinking. The purpose of this paper is to summarize the results of a consensus meeting on NCD prevention sponsored by the International Olympic Committee (IOC) in April, 2013. Within the context of advocacy for multifaceted systems change, the IOC's focus is to create solutions that gain traction within health care systems. The group of participants attending the meeting achieved consensus on a strategy for the prevention and management of chronic disease that includes the following: 1. Focus on behavioural change as the core component of all clinical programs for the prevention and management of chronic disease. 2. Establish actual centres to design, implement, study, and improve preventive programs for chronic disease. 3. Use human-centered design in the creation of prevention programs with an inclination to action, rapid prototyping and multiple iterations. 4. Extend the knowledge and skills of Sports and Exercise Medicine (SEM) professionals to build new programs for the prevention and treatment of chronic disease focused on physical activity, diet and lifestyle. 5. Mobilize resources and leverage networks to scale and distribute programs of prevention. True innovation lies in the ability to align thinking around these core strategies to ensure successful implementation of NCD prevention and management programs within health care. The IOC and SEM community are in an ideal position to lead this disruptive change. The outcome of the consensus meeting was the creation of the IOC Non-Communicable Diseases ad-hoc Working Group charged with the responsibility of moving this agenda forward.

Prevention and management of non-communicable disease: the IOC consensus statement, Lausanne 2013.

PubMed

Matheson, Gordon O; Klügl, Martin; Engebretsen, Lars; Bendiksen, Fredrik; Blair, Steven N; Börjesson, Mats; Budgett, Richard; Derman, Wayne; Erdener, Ugur; Ioannidis, John P A; Khan, Karim M; Martinez, Rodrigo; Van Mechelen, Willem; Mountjoy, Margo; Sallis, Robert E; Schwellnus, Martin; Shultz, Rebecca; Soligard, Torbjørn; Steffen, Kathrin; Sundberg, Carl Johan; Weiler, Richard; Ljungqvist, Arne

2013-11-01

Morbidity and mortality from preventable, non-communicable chronic disease (NCD) threatens the health of our populations and our economies. The accumulation of vast amounts of scientific knowledge has done little to change this. New and innovative thinking is essential to foster new creative approaches that leverage and integrate evidence through the support of big data, technology and design thinking. The purpose of this paper is to summarise the results of a consensus meeting on NCD prevention sponsored by the IOC in April 2013. Within the context of advocacy for multifaceted systems change, the IOC's focus is to create solutions that gain traction within healthcare systems. The group of participants attending the meeting achieved consensus on a strategy for the prevention and management of chronic disease that includes the following: (1) Focus on behavioural change as the core component of all clinical programmes for the prevention and management of chronic disease. (2) Establish actual centres to design, implement, study and improve preventive programmes for chronic disease. (3) Use human-centred design in the creation of prevention programmes with an inclination to action, rapid prototyping and multiple iterations. (4) Extend the knowledge and skills of Sports and Exercise Medicine (SEM) professionals to build new programmes for the prevention and treatment of chronic disease focused on physical activity, diet and lifestyle. (5) Mobilise resources and leverage networks to scale and distribute programmes of prevention. True innovation lies in the ability to align thinking around these core strategies to ensure successful implementation of NCD prevention and management programmes within healthcare. The IOC and SEM community are in an ideal position to lead this disruptive change. The outcome of the consensus meeting was the creation of the IOC Non-Communicable Diseases ad hoc Working Group charged with the responsibility of moving this agenda forward.

Methodological Quality of Consensus Guidelines in Implant Dentistry.

PubMed

Faggion, Clovis Mariano; Apaza, Karol; Ariza-Fritas, Tania; Málaga, Lilian; Giannakopoulos, Nikolaos Nikitas; Alarcón, Marco Antonio

2017-01-01

Consensus guidelines are useful to improve clinical decision making. Therefore, the methodological evaluation of these guidelines is of paramount importance. Low quality information may guide to inadequate or harmful clinical decisions. To evaluate the methodological quality of consensus guidelines published in implant dentistry using a validated methodological instrument. The six implant dentistry journals with impact factors were scrutinised for consensus guidelines related to implant dentistry. Two assessors independently selected consensus guidelines, and four assessors independently evaluated their methodological quality using the Appraisal of Guidelines for Research & Evaluation (AGREE) II instrument. Disagreements in the selection and evaluation of guidelines were resolved by consensus. First, the consensus guidelines were analysed alone. Then, systematic reviews conducted to support the guidelines were included in the analysis. Non-parametric statistics for dependent variables (Wilcoxon signed rank test) was used to compare both groups. Of 258 initially retrieved articles, 27 consensus guidelines were selected. Median scores in four domains (applicability, rigour of development, stakeholder involvement, and editorial independence), expressed as percentages of maximum possible domain scores, were below 50% (median, 26%, 30.70%, 41.70%, and 41.70%, respectively). The consensus guidelines and consensus guidelines + systematic reviews data sets could be compared for 19 guidelines, and the results showed significant improvements in all domain scores (p < 0.05). Methodological improvement of consensus guidelines published in major implant dentistry journals is needed. The findings of the present study may help researchers to better develop consensus guidelines in implant dentistry, which will improve the quality and trust of information needed to make proper clinical decisions.

Methodological Quality of Consensus Guidelines in Implant Dentistry

PubMed Central

Faggion, Clovis Mariano; Apaza, Karol; Ariza-Fritas, Tania; Málaga, Lilian; Giannakopoulos, Nikolaos Nikitas; Alarcón, Marco Antonio

2017-01-01

Background Consensus guidelines are useful to improve clinical decision making. Therefore, the methodological evaluation of these guidelines is of paramount importance. Low quality information may guide to inadequate or harmful clinical decisions. Objective To evaluate the methodological quality of consensus guidelines published in implant dentistry using a validated methodological instrument. Methods The six implant dentistry journals with impact factors were scrutinised for consensus guidelines related to implant dentistry. Two assessors independently selected consensus guidelines, and four assessors independently evaluated their methodological quality using the Appraisal of Guidelines for Research & Evaluation (AGREE) II instrument. Disagreements in the selection and evaluation of guidelines were resolved by consensus. First, the consensus guidelines were analysed alone. Then, systematic reviews conducted to support the guidelines were included in the analysis. Non-parametric statistics for dependent variables (Wilcoxon signed rank test) was used to compare both groups. Results Of 258 initially retrieved articles, 27 consensus guidelines were selected. Median scores in four domains (applicability, rigour of development, stakeholder involvement, and editorial independence), expressed as percentages of maximum possible domain scores, were below 50% (median, 26%, 30.70%, 41.70%, and 41.70%, respectively). The consensus guidelines and consensus guidelines + systematic reviews data sets could be compared for 19 guidelines, and the results showed significant improvements in all domain scores (p < 0.05). Conclusions Methodological improvement of consensus guidelines published in major implant dentistry journals is needed. The findings of the present study may help researchers to better develop consensus guidelines in implant dentistry, which will improve the quality and trust of information needed to make proper clinical decisions. PMID:28107405

International Society of Urological Pathology (ISUP) Consensus Conference on Handling and Staging of Radical Prostatectomy Specimens. Working group 4: seminal vesicles and lymph nodes.

PubMed

Berney, Daniel M; Wheeler, Thomas M; Grignon, David J; Epstein, Jonathan I; Griffiths, David F; Humphrey, Peter A; van der Kwast, Theo; Montironi, Rodolfo; Delahunt, Brett; Egevad, Lars; Srigley, John R

2011-01-01

The 2009 International Society of Urological Pathology Consensus Conference in Boston made recommendations regarding the standardization of pathology reporting of radical prostatectomy specimens. Issues relating to the infiltration of tumor into the seminal vesicles and regional lymph nodes were coordinated by working group 4. There was a consensus that complete blocking of the seminal vesicles was not necessary, although sampling of the junction of the seminal vesicles and prostate was mandatory. There was consensus that sampling of the vas deferens margins was not obligatory. There was also consensus that muscular wall invasion of the extraprostatic seminal vesicle only should be regarded as seminal vesicle invasion. Categorization into types of seminal vesicle spread was agreed by consensus to be not necessary. For examination of lymph nodes, there was consensus that special techniques such as frozen sectioning were of use only in high-risk cases. There was no consensus on the optimal sampling method for pelvic lymph node dissection specimens, although there was consensus that all lymph nodes should be completely blocked as a minimum. There was also a consensus that a count of the number of lymph nodes harvested should be attempted. In view of recent evidence, there was consensus that the diameter of the largest lymph node metastasis should be measured. These consensus decisions will hopefully clarify the difficult areas of pathological assessment in radical prostatectomy evaluation and improve the concordance of research series to allow more accurate assessment of patient prognosis.

The Effect on Non-Normal Distributions on the Integrated Moving Average Model of Time-Series Analysis.

ERIC Educational Resources Information Center

Doerann-George, Judith

The Integrated Moving Average (IMA) model of time series, and the analysis of intervention effects based on it, assume random shocks which are normally distributed. To determine the robustness of the analysis to violations of this assumption, empirical sampling methods were employed. Samples were generated from three populations; normal,…

Accurate Size and Size-Distribution Determination of Polystyrene Latex Nanoparticles in Aqueous Medium Using Dynamic Light Scattering and Asymmetrical Flow Field Flow Fractionation with Multi-Angle Light Scattering

PubMed Central

Kato, Haruhisa; Nakamura, Ayako; Takahashi, Kayori; Kinugasa, Shinichi

2012-01-01

Accurate determination of the intensity-average diameter of polystyrene latex (PS-latex) by dynamic light scattering (DLS) was carried out through extrapolation of both the concentration of PS-latex and the observed scattering angle. Intensity-average diameter and size distribution were reliably determined by asymmetric flow field flow fractionation (AFFFF) using multi-angle light scattering (MALS) with consideration of band broadening in AFFFF separation. The intensity-average diameter determined by DLS and AFFFF-MALS agreed well within the estimated uncertainties, although the size distribution of PS-latex determined by DLS was less reliable in comparison with that determined by AFFFF-MALS. PMID:28348293

Delphi based consensus study into planning for chemical incidents.

PubMed

Crawford, I W F; Mackway-Jones, K; Russell, D R; Carley, S D

2004-01-01

To achieve consensus in all phases of chemical incident planning and response. A three round Delphi study was conducted using a panel of 39 experts from specialties involved in the management of chemical incidents. Areas that did not reach consensus in the Delphi study were presented as synopsis statements for discussion in four syndicate groups at a conference hosted by the Department of Health Emergency Planning Co-ordination Unit. A total of 183 of 322 statements had reached consensus upon completion of the Delphi study. This represented 56.8% of the total number of statements. Of these, 148 reached consensus at >94% and 35 reached consensus at >89%. The results of the process are presented as a series of synopsis consensus statements that cover all phases of chemical incident planning and response. The use of a Delphi study and subsequent syndicate group discussions achieved consensus in aspects of all phases of chemical incident planning and response that can be translated into practical guidance for use at regional prehospital and hospital level. Additionally, areas of non-consensus have been identified where further work is required.

Delphi based consensus study into planning for chemical incidents

PubMed Central

Crawford, I; Mackway-Jones, K; Russell, D; Carley, S

2004-01-01

Objective: To achieve consensus in all phases of chemical incident planning and response. Design: A three round Delphi study was conducted using a panel of 39 experts from specialties involved in the management of chemical incidents. Areas that did not reach consensus in the Delphi study were presented as synopsis statements for discussion in four syndicate groups at a conference hosted by the Department of Health Emergency Planning Co-ordination Unit. Results: A total of 183 of 322 statements had reached consensus upon completion of the Delphi study. This represented 56.8% of the total number of statements. Of these, 148 reached consensus at >94% and 35 reached consensus at >89%. The results of the process are presented as a series of synopsis consensus statements that cover all phases of chemical incident planning and response. Conclusions: The use of a Delphi study and subsequent syndicate group discussions achieved consensus in aspects of all phases of chemical incident planning and response that can be translated into practical guidance for use at regional prehospital and hospital level. Additionally, areas of non-consensus have been identified where further work is required. PMID:14734369

Augmentation plating in management of failed femoral nailing.

PubMed

Verma, Rahul; Sharma, Pulak; Gaur, Sanjiv

2017-08-01

Non-union following interlocking nailing is a troubling complication in treatment of shaft femur fractures. There is no clear consensus on the treatment of this problem. This research was undertaken to study the role of augmentation plating combined with exchange nailing in such cases. A prospective clinical study was undertaken from January 2010 to December 2015. Patients with aseptic femoral shaft non-union, with or without implant failure following intramedullary nailing were included in the study. Augmentation plating combined with Exchange Nailing with a 4.5mm LCP was done. Fifteen patients (nine male and six female) with an average age of 43.7 years (range 18-67 years) were treated. Average timing from the first surgery was 7.3 months. Complete clinical and radiological union was achieved in all cases in a mean duration of 5.2 months. Average duration of follow up was 12.6 months. All the patients retained the preoperative hip and knee range of motion till the last follow up. Augmentation plating combined with exchange nailing in non-unions following intramedullary nailing of femur shaft fractures is a reasonably good and effective procedure with a very high success rate. © 2017 Elsevier Ltd. All rights reserved.

Long Working Hours in Korea: Based on the 2014 Korean Working Conditions Survey.

PubMed

Park, Jungsun; Kim, Yangho; Han, Boyoung

2017-12-01

Long working hours adversely affect worker safety and health. In 2004, Korea passed legislation that limited the work week to 40 hours, in an effort to improve quality-of-life and increase business competitiveness. This regulation was implemented in stages, first for large businesses and then for small businesses, from 2004 to 2011. We previously reported that average weekly working hours decreased from 2006 to 2010, based on the Korean Working Conditions Survey. In the present study, we examine whether average weekly working hours continued to decrease in 2014 based on the 2014 Korean Working Conditions Survey. The results show that average weekly working hours among all groups of workers decreased in 2014 relative to previous years; however, self-employed individuals and employers (who are not covered by the new legislation) in the specific service sectors worked > 60 h/wk in 2014. The Korean government should prohibit employees from working excessive hours and should also attempt to achieve social and public consensus regarding work time reduction to improve the safety, health, and quality-of-life of all citizens, including those who are employers and self-employed.

Sampling probability distributions of lesions in mammograms

NASA Astrophysics Data System (ADS)

Looney, P.; Warren, L. M.; Dance, D. R.; Young, K. C.

2015-03-01

One approach to image perception studies in mammography using virtual clinical trials involves the insertion of simulated lesions into normal mammograms. To facilitate this, a method has been developed that allows for sampling of lesion positions across the cranio-caudal and medio-lateral radiographic projections in accordance with measured distributions of real lesion locations. 6825 mammograms from our mammography image database were segmented to find the breast outline. The outlines were averaged and smoothed to produce an average outline for each laterality and radiographic projection. Lesions in 3304 mammograms with malignant findings were mapped on to a standardised breast image corresponding to the average breast outline using piecewise affine transforms. A four dimensional probability distribution function was found from the lesion locations in the cranio-caudal and medio-lateral radiographic projections for calcification and noncalcification lesions. Lesion locations sampled from this probability distribution function were mapped on to individual mammograms using a piecewise affine transform which transforms the average outline to the outline of the breast in the mammogram. The four dimensional probability distribution function was validated by comparing it to the two dimensional distributions found by considering each radiographic projection and laterality independently. The correlation of the location of the lesions sampled from the four dimensional probability distribution function across radiographic projections was shown to match the correlation of the locations of the original mapped lesion locations. The current system has been implemented as a web-service on a server using the Python Django framework. The server performs the sampling, performs the mapping and returns the results in a javascript object notation format.

Genome-wide SNP identification for the construction of a high-resolution genetic map of Japanese flounder (Paralichthys olivaceus): applications to QTL mapping of Vibrio anguillarum disease resistance and comparative genomic analysis.

PubMed

Shao, Changwei; Niu, Yongchao; Rastas, Pasi; Liu, Yang; Xie, Zhiyuan; Li, Hengde; Wang, Lei; Jiang, Yong; Tai, Shuaishuai; Tian, Yongsheng; Sakamoto, Takashi; Chen, Songlin

2015-04-01

High-resolution genetic maps are essential for fine mapping of complex traits, genome assembly, and comparative genomic analysis. Single-nucleotide polymorphisms (SNPs) are the primary molecular markers used for genetic map construction. In this study, we identified 13,362 SNPs evenly distributed across the Japanese flounder (Paralichthys olivaceus) genome. Of these SNPs, 12,712 high-confidence SNPs were subjected to high-throughput genotyping and assigned to 24 consensus linkage groups (LGs). The total length of the genetic linkage map was 3,497.29 cM with an average distance of 0.47 cM between loci, thereby representing the densest genetic map currently reported for Japanese flounder. Nine positive quantitative trait loci (QTLs) forming two main clusters for Vibrio anguillarum disease resistance were detected. All QTLs could explain 5.1-8.38% of the total phenotypic variation. Synteny analysis of the QTL regions on the genome assembly revealed 12 immune-related genes, among them 4 genes strongly associated with V. anguillarum disease resistance. In addition, 246 genome assembly scaffolds with an average size of 21.79 Mb were anchored onto the LGs; these scaffolds, comprising 522.99 Mb, represented 95.78% of assembled genomic sequences. The mapped assembly scaffolds in Japanese flounder were used for genome synteny analyses against zebrafish (Danio rerio) and medaka (Oryzias latipes). Flounder and medaka were found to possess almost one-to-one synteny, whereas flounder and zebrafish exhibited a multi-syntenic correspondence. The newly developed high-resolution genetic map, which will facilitate QTL mapping, scaffold assembly, and genome synteny analysis of Japanese flounder, marks a milestone in the ongoing genome project for this species. © The Author 2015. Published by Oxford University Press on behalf of Kazusa DNA Research Institute.

Dust layer effects on the atmospheric radiative budget and heating rate profiles

NASA Astrophysics Data System (ADS)

Perrone, Maria Rita; Tafuro, A. M.; Kinne, S.

2012-11-01

The effect of mineral aerosol optical properties and vertical distribution on clear-sky, instantaneous and daily-average aerosol direct radiative effects (DREs) and heating rates (HRs) is analyzed in the solar (S, 0.3-4 μm) and terrestrial (T, 4-80 μm) spectral domain, respectively. The used radiative transfer model is based on lidar, sun-sky photometer, and radiosonde measurements. The study focuses on the Sahara dust outbreak of July 16, 2009 which advected dust particles from north-western Africa over south-eastern Italy. Clear-sky, instantaneous aerosol DREs and HRs undergo large changes within few hours, for the variability of the dust aerosol properties and vertical distribution. The daily-average, clear-sky aerosol S-DRE is near -5 Wm-2 and -12 Wm-2 at the top of the atmosphere (ToA) and surface (sfc), respectively. The daily-average aerosol T-DRE offsets the S-DRE by about one third at the ToA and by about one half at the surface. The daily average aerosol HR integrated over the whole aerosol column is 0.5 and -0.3 K day-1 in the S and T domain, respectively. Thus, the all-wave integrated HR is 0.2 K day-1. These results highlight the importance of accounting for the interaction of dust particles with T and S radiation. Sensitivity tests indicate that the uncertainties of the aerosol refractive index, size distribution, and vertical distribution have on average a large impact on aerosol HRs in the S and T domain, respectively. Refractive index and aerosol size distribution uncertainties also have a large impact on S- and T-DREs. The aerosol vertical distribution that has a negligible impact on aerosol S-DREs, is important for aerosol T-DREs. It is also shown that aerosol HRs and DREs in the terrestrial domain are affected by the water vapour vertical distribution.

The Impact of Heterogeneity on Threshold-Limited Social Contagion, and on Crowd Decision-Making

NASA Astrophysics Data System (ADS)

Karampourniotis, Panagiotis Dimitrios

Recent global events and their poor predictability are often attributed to the complexity of the world event dynamics. A key factor generating the turbulence is human diversity. Here, we study the impact of heterogeneity of individuals on opinion formation and emergence of global biases. In the case of opinion formation, we focus on the heterogeneity of individuals' susceptibility to new ideas. In the case of global biases, we focus on the aggregated heterogeneity of individuals in a country. First, to capture the complex nature of social influencing we use a simple but classic model of contagion spreading in complex social systems, namely the threshold model. We investigate numerically and analytically the transition in the behavior of threshold-limited cascades in the presence of multiple initiators as the distribution of thresholds is varied between the two extreme cases of identical thresholds and a uniform distribution. We show that individuals' heterogeneity of susceptibility governs the dynamics, resulting in different sizes of initiators needed for consensus. Furthermore, given the impact of heterogeneity on the cascade dynamics, we investigate selection strategies for accelerating consensus. To this end, we introduce two new selection strategies for Influence Maximization. One of them focuses on finding the balance between targeting nodes which have high resistance to adoptions versus nodes positioned in central spots in networks. The second strategy focuses on the combination of nodes for reaching consensus, by targeting nodes which increase the group's influence. Our strategies outperform other existing strategies regardless of the susceptibility diversity and network degree assortativity. Finally, we study the aggregated biases of humans in a global setting. The emergence of technology and globalization gives raise to the debate on whether the world moves towards becoming flat, a world where preferential attachment does not govern economic growth. By studying the data from a global lending platform we discover that geographical proximity and cultural affinity are highly negatively correlated with levels of flatness of the world. Furthermore, we investigate the robustness of the flatness of the world against sudden catastrophic national events such as political disruptions, by removing countries (nodes) or connections (edges) between them.

Development of a portfolio of learning for postgraduate family medicine training in South Africa: a Delphi study

PubMed Central

2012-01-01

Background Within the 52 health districts in South Africa, the family physician is seen as the clinical leader within a multi-professional district health team. Family physicians must be competent to meet 90% of the health needs of the communities in their districts. The eight university departments of Family Medicine have identified five unit standards, broken down into 85 training outcomes, for postgraduate training. The family medicine registrar must prove at the end of training that all the required training outcomes have been attained. District health managers must be assured that the family physician is competent to deliver the expected service. The Colleges of Medicine of South Africa (CMSA) require a portfolio to be submitted as part of the uniform assessment of all registrars applying to write the national fellowship examinations. This study aimed to achieve a consensus on the contents and principles of the first national portfolio for use in family medicine training in South Africa. Methods A workshop held at the WONCA Africa Regional Conference in 2009 explored the purpose and broad contents of the portfolio. The 85 training outcomes, ideas from the WONCA workshop, the literature, and existing portfolios in the various universities were used to develop a questionnaire that was tested for content validity by a panel of 31 experts in family medicine in South Africa, via the Delphi technique in four rounds. Eighty five content items (national learning outcomes) and 27 principles were tested. Consensus was defined as 70% agreement. For those items that the panel thought should be included, they were also asked how to provide evidence for the specific item in the portfolio, and how to assess that evidence. Results Consensus was reached on 61 of the 85 national learning outcomes. The panel recommended that 50 be assessed by the portfolio and 11 should not be. No consensus could be reached on the remaining 24 outcomes and these were also omitted from the portfolio. The panel recommended that various types of evidence be included in the portfolio. The panel supported 26 of the 27 principles, but could not reach consensus on whether the portfolio should reflect on the relationship between the supervisor and registrar. Conclusion A portfolio was developed and distributed to the eight departments of Family Medicine in South Africa, and the CMSA, to be further tested in implementation. PMID:22385468

Development of a portfolio of learning for postgraduate family medicine training in South Africa: a Delphi study.

PubMed

Jenkins, Louis; Mash, Bob; Derese, Anselme

2012-03-03

Within the 52 health districts in South Africa, the family physician is seen as the clinical leader within a multi-professional district health team. Family physicians must be competent to meet 90% of the health needs of the communities in their districts. The eight university departments of Family Medicine have identified five unit standards, broken down into 85 training outcomes, for postgraduate training. The family medicine registrar must prove at the end of training that all the required training outcomes have been attained. District health managers must be assured that the family physician is competent to deliver the expected service. The Colleges of Medicine of South Africa (CMSA) require a portfolio to be submitted as part of the uniform assessment of all registrars applying to write the national fellowship examinations. This study aimed to achieve a consensus on the contents and principles of the first national portfolio for use in family medicine training in South Africa. A workshop held at the WONCA Africa Regional Conference in 2009 explored the purpose and broad contents of the portfolio. The 85 training outcomes, ideas from the WONCA workshop, the literature, and existing portfolios in the various universities were used to develop a questionnaire that was tested for content validity by a panel of 31 experts in family medicine in South Africa, via the Delphi technique in four rounds. Eighty five content items (national learning outcomes) and 27 principles were tested. Consensus was defined as 70% agreement. For those items that the panel thought should be included, they were also asked how to provide evidence for the specific item in the portfolio, and how to assess that evidence. Consensus was reached on 61 of the 85 national learning outcomes. The panel recommended that 50 be assessed by the portfolio and 11 should not be. No consensus could be reached on the remaining 24 outcomes and these were also omitted from the portfolio. The panel recommended that various types of evidence be included in the portfolio. The panel supported 26 of the 27 principles, but could not reach consensus on whether the portfolio should reflect on the relationship between the supervisor and registrar. A portfolio was developed and distributed to the eight departments of Family Medicine in South Africa, and the CMSA, to be further tested in implementation.

Fluctuation Dynamics of Exchange Rates on Indian Financial Market

NASA Astrophysics Data System (ADS)

Sarkar, A.; Barat, P.

Here we investigate the scaling behavior and the complexity of the average daily exchange rate returns of the Indian Rupee against four foreign currencies namely US Dollar, Euro, Great Britain Pound and Japanese Yen. Our analysis revealed that the average daily exchange rate return of the Indian Rupee against the US Dollar exhibits a persistent scaling behavior and follow Levy stable distribution. On the contrary the average daily exchange rate returns of the other three foreign currencies show randomness and follow Gaussian distribution. Moreover, it is seen that the complexity of the average daily exchange rate return of the Indian Rupee against US Dollar is less than the other three exchange rate returns.

Improving Flood Prediction By the Assimilation of Satellite Soil Moisture in Poorly Monitored Catchments.

NASA Astrophysics Data System (ADS)

Alvarez-Garreton, C. D.; Ryu, D.; Western, A. W.; Crow, W. T.; Su, C. H.; Robertson, D. E.

2014-12-01

Flood prediction in poorly monitored catchments is among the greatest challenges faced by hydrologists. To address this challenge, an increasing number of studies in the last decade have explored methods to integrate various existing observations from ground and satellites. One approach in particular, is the assimilation of satellite soil moisture (SM-DA) into rainfall-runoff models. The rationale is that satellite soil moisture (SSM) can be used to correct model soil water states, enabling more accurate prediction of catchment response to precipitation and thus better streamflow. However, there is still no consensus on the most effective SM-DA scheme and how this might depend on catchment scale, climate characteristics, runoff mechanisms, model and SSM products used, etc. In this work, an operational SM-DA scheme was set up in the poorly monitored, large (>40,000 km2), semi-arid Warrego catchment situated in eastern Australia. We assimilated passive and active SSM products into the probability distributed model (PDM) using an ensemble Kalman filter. We explored factors influencing the SM-DA framework, including relatively new techniques to remove model-observation bias, estimate observation errors and represent model errors. Furthermore, we explored the advantages of accounting for the spatial distribution of forcing and channel routing processes within the catchment by implementing and comparing lumped and semi-distributed model setups. Flood prediction is improved by SM-DA (Figure), with a 30% reduction of the average root-mean-squared difference of the ensemble prediction, a 20% reduction of the false alarm ratio and a 40% increase of the ensemble mean Nash-Sutcliffe efficiency. SM-DA skill does not significantly change with different observation error assumptions, but the skill strongly depends on the observational bias correction technique used, and more importantly, on the performance of the open-loop model before assimilation. Our findings imply that proper pre-processing of SSM is important for the efficacy of the SM-DA and assimilation performance is critically affected by the quality of model calibration. We therefore recommend focusing efforts on these two factors, while further evaluating the trade-offs between model complexity and data availability.

New Methodologies Applied to Seismic Hazard Assessment in Southern Calabria (Italy)

NASA Astrophysics Data System (ADS)

Console, R.; Chiappini, M.; Speranza, F.; Carluccio, R.; Greco, M.

2016-12-01

Although it is generally recognized that the M7+ 1783 and 1908 Calabria earthquakes were caused by normal faults rupturing the upper crust of the southern Calabria-Peloritani area, no consensus exists on seismogenic source location and orientation. A recent high-resolution low-altitude aeromagnetic survey of southern Calabria and Messina straits suggested that the sources of the 1783 and 1908 earthquakes are en echelon faults belonging to the same NW dipping normal fault system straddling the whole southern Calabria. The application of a newly developed physics-based earthquake simulator to the active fault system modeled by the data obtained from the aeromagnetic survey and other recent geological studies has allowed the production of catalogs lasting 100,000 years and containing more than 25,000 events of magnitudes ≥ 4.0. The algorithm on which this simulator is based is constrained by several physical elements as: (a) an average slip rate due to tectonic loading for every single segment in the investigated fault system, (b) the process of rupture growth and termination, leading to a self-organized earthquake magnitude distribution, and (c) interaction between earthquake sources, including small magnitude events. Events nucleated in one segment are allowed to expand into neighboring segments, if they are separated by a given maximum range of distance. The application of our simulation algorithm to Calabria region provides typical features in time, space and magnitude behaviour of the seismicity, which can be compared with those of the real observations. These features include long-term pseudo-periodicity and clustering of strong earthquakes, and a realistic earthquake magnitude distribution departing from the Gutenberg-Richter distribution in the moderate and higher magnitude range. Lastly, as an example of a possible use of synthetic catalogs, an attenuation law has been applied to all the events reported in the synthetic catalog for the production of maps showing the exceedence probability of given values of peak acceleration (PGA) on the territory under investigation. These maps can be compared with the existing hazard maps that are presently used in the national seismic building regulations.

Mapping the Characteristics of Critical Care Facilities: Assessment, Distribution, and Level of Critical Care Facilities from Central India.

PubMed

Saigal, Saurabh; Sharma, Jai Prakash; Pakhare, Abhijit; Bhaskar, Santosh; Dhanuka, Sanjay; Kumar, Sanjay; Sabde, Yogesh; Bhattacharya, Pradip; Joshi, Rajnish

2017-10-01

In low- and middle-income countries such as India, where health systems are weak, the number of available Critical Care Unit (Intensive Care Unit [ICU]) beds is expected to be low. There is no study from the Indian subcontinent that has reported the characteristics and distribution of existing ICUs. We performed this study to understand the characteristics and distribution of ICUs in Madhya Pradesh (MP) state of Central India. We also aimed to develop a consensus scoring system and internally validate it to define levels of care and to improve health system planning and to strengthen referral networks in the state. We obtained a list of potential ICU facilities from various sources and then performed a cross-sectional survey by visiting each facility and determining characteristics for each facility. We collected variables with respect to infrastructure, human resources, equipment, support services, procedures performed, training courses conducted, and in-place policies or standard operating procedure documents. We identified a total of 123 ICUs in MP. Of 123 ICUs, 35 were level 1 facilities, 74 were level 2 facilities, and only 14 were level 3 facilities. Overall, there were 0.17 facilities per 100,000 population (95* confidence interval [CI] 0.14-0.20 per 100,000 populations). There were a total of 1816 ICU beds in the state, with an average of 2.5 beds per 100,000 population (95* CI 2.4-2.6 per 100,000 population). Of the total number of ICU beds, 250 are in level 1, 1141 are in level 2, and 425 are in level 3 facilities. This amounts to 0.34, 1.57, and 0.59 ICU beds per 100,000 population for levels 1, 2, and 3, respectively. This study could just be an eye opener for our healthcare authorities at both state and national levels to estimate the proportion of ICU beds per lac population. Similar mapping of intensive care services from other States will generate national data that is hitherto unknown.

The Human Resources for Health Effort Index: a tool to assess and inform Strategic Health Workforce Investments.

PubMed

Fort, Alfredo L; Deussom, Rachel; Burlew, Randi; Gilroy, Kate; Nelson, David

2017-07-19

Despite its importance, the field of human resources for health (HRH) has lagged in developing methods to measure its status and progress in low- and middle-income countries suffering a workforce crisis. Measures of professional health worker densities and distribution are purely numerical, unreliable, and do not represent the full spectrum of workers providing health services. To provide more information on the multi-dimensional characteristics of human resources for health, in 2013-2014, the global USAID-funded CapacityPlus project, led by IntraHealth International, developed and tested a 79-item HRH Effort Index modeled after the widely used Family Planning Effort Index. The index includes seven recognized HRH dimensions: Leadership and Advocacy; Policy and Governance; Finance; Education and Training; Recruitment, Distribution, and Retention; Human Resources Management; and Monitoring, Evaluation, and Information Systems. Each item is scored from 1 to 10 and scores are averaged with equal weights for each dimension and overall. The questionnaire is applied to knowledgeable informants from public, nongovernmental organization, and private sectors in each country. A pilot test among 49 respondents in Kenya and Nigeria provided useful information to improve, combine, and streamline questions. CapacityPlus applied the revised 50-item questionnaire in 2015 in Burkina Faso, Dominican Republic, Ghana, and Mali, among 92 respondents. Additionally, the index was applied subnationally in the Dominican Republic (16 respondents) and in a consensus-building meeting in Mali (43 respondents) after the national application. The results revealed a range of scores between 3.7 and 6.2 across dimensions, for overall scores between 4.8 and 5.5. Dimensions with lower scores included Recruitment, Distribution, and Retention, while Leadership and Advocacy had higher scores. The tool proved to be well understood and provided key qualitative information on the health workforce to assist in health systems strengthening. It is expected that subsequent applications should provide more information for comparison purposes, to refine aspects of the questionnaire and to correlate scores with measures of service outputs and outcomes.

A Self-Categorization Explanation for Opinion Consensus Perceptions

ERIC Educational Resources Information Center

Zhang, Jinguang; Reid, Scott A.

2013-01-01

The public expression of opinions (and related communicative activities) hinges upon the perception of opinion consensus. Current explanations for opinion consensus perceptions typically focus on egocentric and other biases, rather than functional cognitions. Using self-categorization theory we showed that opinion consensus perceptions flow from…

Opinion formation on adaptive networks with intensive average degree

NASA Astrophysics Data System (ADS)

Schmittmann, B.; Mukhopadhyay, Abhishek

2010-12-01

We study the evolution of binary opinions on a simple adaptive network of N nodes. At each time step, a randomly selected node updates its state (“opinion”) according to the majority opinion of the nodes that it is linked to; subsequently, all links are reassigned with probability p˜ (q˜) if they connect nodes with equal (opposite) opinions. In contrast to earlier work, we ensure that the average connectivity (“degree”) of each node is independent of the system size (“intensive”), by choosing p˜ and q˜ to be of O(1/N) . Using simulations and analytic arguments, we determine the final steady states and the relaxation into these states for different system sizes. We find two absorbing states, characterized by perfect consensus, and one metastable state, characterized by a population split evenly between the two opinions. The relaxation time of this state grows exponentially with the number of nodes, N . A second metastable state, found in the earlier studies, is no longer observed.

Anxiety-related visits to New Jersey emergency departments after September 11, 2001.

PubMed

Adinaro, David J; Allegra, John R; Cochrane, Dennis G; Cable, Gregory

2008-04-01

The purpose of this study was to examine the effect of September 11, 2001 on anxiety-related visits to selected Emergency Departments (EDs). We performed a retrospective analysis of consecutive patients seen by emergency physicians in 15 New Jersey EDs located within a 50-mile radius of the World Trade Center from July 11 through December 11 in each of 6 years, 1996--2001. We chose by consensus all ICD-9 (International Classification of Diseases, 9th revision) codes related to anxiety. We used graphical methods, Box-Jenkins modeling, and time series regression to determine the effect of September 11 to 14 on daily rates of anxiety-related visits. We found that the daily rate of anxiety-related visits just after September 11th was 93% higher (p < 0.0001) than the average for the remaining 150 days for 2001. This represents, on average, one additional daily visit for anxiety at each ED. We concluded that there was an increase in anxiety-related ED visits after September 11, 2001.

Muon simulations for Super-Kamiokande, KamLAND, and CHOOZ

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

Tang, Alfred; Horton-Smith, Glenn; Kudryavtsev, Vitaly A.

2006-09-01

Muon backgrounds at Super-Kamiokande, KamLAND, and CHOOZ are calculated using MUSIC. A modified version of the Gaisser sea-level muon distribution and a well-tested Monte Carlo integration method are introduced. Average muon energy, flux, and rate are tabulated. Plots of average energy and angular distributions are given. Implications for muon tracker design in future experiments are discussed.

Communicating and countering misconceptions about the scientific consensus on human-caused global warming

NASA Astrophysics Data System (ADS)

Cook, J.

2016-12-01

A number of studies have sought to quantify the level of agreement among climate scientists on human-caused global warming. This has included surveys of the scientific community, analyses of public declarations about climate change and analyses of peer-reviewed climate papers. This body of research has found that the level of consensus increases with expertise in climate science, culminating in 97% agreement among publishing climate scientists. Despite this robust finding, there is a significant gap between public perception of scientific consensus and the overwhelming agreement among climate scientists. This "consensus gap" is due in large part to a persistent, focused campaign to manufacture doubt about the scientific consensus by opponents of climate action. This campaign has employed non-expert spokespeople, magnified the small minority of dissenting scientists and exploited the journalistic norm of balance to generate the impression of an equal debate among scientists. Given the importance of perceived consensus as a "gateway belief" influencing a number of climate beliefs and attitudes, it is imperative that climate communicators close the consensus gap. This can be achieved by communicating the 97% consensus and explaining the techniques used to cast doubt on the consensus.

Evaluating the Performance of the Pediatric Acute Lung Injury Consensus Conference Definition of Acute Respiratory Distress Syndrome.

PubMed

Parvathaneni, Kaushik; Belani, Sanjay; Leung, Dennis; Newth, Christopher J L; Khemani, Robinder G

2017-01-01

The Pediatric Acute Lung Injury Consensus Conference has developed a pediatric-specific definition of acute respiratory distress syndrome, which is a significant departure from both the Berlin and American European Consensus Conference definitions. We sought to test the external validity and potential impact of the Pediatric Acute Lung Injury Consensus Conference definition by comparing the number of cases of acute respiratory distress syndrome and mortality rates among children admitted to a multidisciplinary PICU when classified by Pediatric Acute Lung Injury Consensus Conference, Berlin, and American European Consensus Conference criteria. Retrospective cohort study. Tertiary care, university-affiliated PICU. All patients admitted between March 2009 and April 2013 who met inclusion criteria for acute respiratory distress syndrome. None. Of 4,764 patients admitted to the ICU, 278 (5.8%) met Pediatric Acute Lung Injury Consensus Conference pediatric acute respiratory distress syndrome criteria with a mortality rate of 22.7%. One hundred forty-three (32.2% mortality) met Berlin criteria, and 134 (30.6% mortality) met American European Consensus Conference criteria. All patients who met American European Consensus Conference criteria and 141 (98.6%) patients who met Berlin criteria also met Pediatric Acute Lung Injury Consensus Conference criteria. The 137 patients who met Pediatric Acute Lung Injury Consensus Conference but not Berlin criteria had an overall mortality rate of 13.1%, but 29 had severe acute respiratory distress syndrome with 31.0% mortality. At acute respiratory distress syndrome onset, there was minimal difference in mortality between mild or moderate acute respiratory distress syndrome by both Berlin (32.4% vs 25.0%, respectively) and Pediatric Acute Lung Injury Consensus Conference (16.7% vs 18.6%, respectively) criteria, but higher mortality for severe acute respiratory distress syndrome (Berlin, 43.6%; Pediatric Acute Lung Injury Consensus Conference, 37.0%). Twenty-four hours after acute respiratory distress syndrome onset, the presence of severe acute respiratory distress syndrome (using either Berlin or Pediatric Acute Lung Injury Consensus Conference) was associated with nearly 50% mortality. Applying the Pediatric Acute Lung Injury Consensus Conference definition of acute respiratory distress syndrome has the potential to significantly increase the number of acute respiratory distress syndrome patients identified, with a lower overall mortality rate. However, severe acute respiratory distress syndrome is associated with extremely high mortality, particularly if present at 24 hours after initial diagnosis.

Discordant identification of pediatric severe sepsis by research and clinical definitions in the SPROUT international point prevalence study.

PubMed

Weiss, Scott L; Fitzgerald, Julie C; Maffei, Frank A; Kane, Jason M; Rodriguez-Nunez, Antonio; Hsing, Deyin D; Franzon, Deborah; Kee, Sze Ying; Bush, Jenny L; Roy, Jason A; Thomas, Neal J; Nadkarni, Vinay M

2015-09-16

Consensus criteria for pediatric severe sepsis have standardized enrollment for research studies. However, the extent to which critically ill children identified by consensus criteria reflect physician diagnosis of severe sepsis, which underlies external validity for pediatric sepsis research, is not known. We sought to determine the agreement between physician diagnosis and consensus criteria to identify pediatric patients with severe sepsis across a network of international pediatric intensive care units (PICUs). We conducted a point prevalence study involving 128 PICUs in 26 countries across 6 continents. Over the course of 5 study days, 6925 PICU patients <18 years of age were screened, and 706 with severe sepsis defined either by physician diagnosis or on the basis of 2005 International Pediatric Sepsis Consensus Conference consensus criteria were enrolled. The primary endpoint was agreement of pediatric severe sepsis between physician diagnosis and consensus criteria as measured using Cohen's κ. Secondary endpoints included characteristics and clinical outcomes for patients identified using physician diagnosis versus consensus criteria. Of the 706 patients, 301 (42.6%) met both definitions. The inter-rater agreement (κ ± SE) between physician diagnosis and consensus criteria was 0.57 ± 0.02. Of the 438 patients with a physician's diagnosis of severe sepsis, only 69% (301 of 438) would have been eligible to participate in a clinical trial of pediatric severe sepsis that enrolled patients based on consensus criteria. Patients with physician-diagnosed severe sepsis who did not meet consensus criteria were younger and had lower severity of illness and lower PICU mortality than those meeting consensus criteria or both definitions. After controlling for age, severity of illness, number of comorbid conditions, and treatment in developed versus resource-limited regions, patients identified with severe sepsis by physician diagnosis alone or by consensus criteria alone did not have PICU mortality significantly different from that of patients identified by both physician diagnosis and consensus criteria. Physician diagnosis of pediatric severe sepsis achieved only moderate agreement with consensus criteria, with physicians diagnosing severe sepsis more broadly. Consequently, the results of a research study based on consensus criteria may have limited generalizability to nearly one-third of PICU patients diagnosed with severe sepsis.

Attitude Importance and the False Consensus Effect.

ERIC Educational Resources Information Center

Fabrigar, Leandre R.; Krosnick, Jon A.

1995-01-01

Explores the possibility that importance may regulate the magnitude of the false consensus effect. Analysis revealed a strong false consensus effect but no reliable relation between its magnitude and attitude importance. Results contradict assumptions that the false consensus effect arises from attitudes that directly or indirectly influence…

1st International consensus guidelines for advanced breast cancer (ABC 1).

PubMed

Cardoso, F; Costa, A; Norton, L; Cameron, D; Cufer, T; Fallowfield, L; Francis, P; Gligorov, J; Kyriakides, S; Lin, N; Pagani, O; Senkus, E; Thomssen, C; Aapro, M; Bergh, J; Di Leo, A; El Saghir, N; Ganz, P A; Gelmon, K; Goldhirsch, A; Harbeck, N; Houssami, N; Hudis, C; Kaufman, B; Leadbeater, M; Mayer, M; Rodger, A; Rugo, H; Sacchini, V; Sledge, G; van't Veer, L; Viale, G; Krop, I; Winer, E

2012-06-01

The 1st international Consensus Conference for Advanced Breast Cancer (ABC 1) took place on November 2011, in Lisbon. Consensus guidelines for the management of this disease were developed. This manuscript summarizes these international consensus guidelines. Copyright © 2012 Elsevier Ltd. All rights reserved.

Correlates of syringe coverage for heroin injection in 35 large metropolitan areas in the US in which heroin is the dominant injected drug

PubMed Central

Tempalski, Barbara; Cooper, Hannah L.; Friedman, Samuel R.; Des Jarlais, Don C.; Brady, Joanne; Gostnell, Karla

2009-01-01

Background Scientific consensus holds that if, at the outset of the HIV/AIDS epidemic, injection drug users (IDUs) had had better access to sterile syringes, much of the epidemic among IDUs in the U.S. could have been prevented. In the context of preventing infectious diseases, 100% syringe coverage—that is, one sterile syringe per injector for each injection—is a public health goal. Notably, we know little about variations in syringe coverage within the U.S. and elsewhere, or about the social and political factors that might determine this coverage. Methods Using data from Holmberg (AJPH, 1996), the 1990 United States Census, the 2000 Beth Israel National Syringe Exchange Survey (n=72), and estimates of IDUs in metropolitan areas (MSAs); (Friedman et al., 2004), we explore the impact of (1) political factors (ACT UP, outreach, early syringe exchange programme (SEP) presence, men who have sex with men (MSM) per capita, drug arrests, and police per capita); (2) local resources for SEPs; and (3) indicators of socioeconomic inequality on SEP coverage. We define “syringe coverage” as the ratio of syringes distributed at SEPs to the number of syringes heroin injectors need in a year. We calculated the number of syringes heroin injectors need in a year by multiplying an estimate of the number of IDUs in each MSA by an estimate of the average number of times heroin injectors inject heroin per year (2.8 times per day times 365 days). In this analysis, the sample was limited to 35 MSAs in which the primary drug of choice among injectors was heroin. Results SEP coverage varies greatly across MSAs, with an average of 3 syringes distributed per 100 injection events (std dev = 0.045; range: 2 syringes per 10 injection events, to 3 syringes per 10,000 injection events). In bivariate regression analyses, a 1 unit difference in the proportion of the population that was MSM per 1,000 was associated with a difference of 0.002 in SEP coverage (p=0.052); early SEP presence was associated with a difference of 0.038 in coverage (p=0.012); and having government funding was associated with a 0.040 difference in SEP coverage (p=0.021). Conclusions This analysis suggests that longer duration of SEP presence may increase syringe distribution and enhance successful programme utilization. Furthermore, MSAs with greater proportions of MSM tend to have better SEP coverage, perhaps providing further evidence that grassroots activism plays an important role in programme implementation and successful SEP coverage. This research provides evidence that government funding for SEPs contributes to better syringe coverage. PMID:18295468

Competition Among Reputations in the 2D Sznajd Model: Spontaneous Emergence of Democratic States

NASA Astrophysics Data System (ADS)

Crokidakis, Nuno; Forgerini, Fabricio L.

2012-04-01

We propose a modification in the Sznajd sociophysics model defined on the square lattice. For this purpose, we consider reputation—a mechanism limiting the agents' persuasive power. The reputation is introduced as a time-dependent score, which can be positive or negative. This mechanism avoids dictatorship (full consensus, all spins parallel) for a wide range of model parameters. We consider two different situations: case 1, in which the agents' reputation increases for each persuaded neighbor, and case 2, in which the agents' reputation increases for each persuasion and decreases when a neighbor keeps his opinion. Our results show that the introduction of reputation avoids full consensus even for initial densities of up spins greater than 1/2. The relaxation times follow a log-normal-like distribution in both cases, but they are larger in case 2 due to the competition among reputations. In addition, we show that the usual phase transition occurs and depends on the initial concentration d of individuals with the same opinion, but the critical points d c in the two cases are different.

Molecular dynamics study of the phosphorylation effect on the conformational states of the C-terminal domain of RNA polymerase II.

PubMed

Yonezawa, Yasushige

2014-05-01

The carboxyl-terminal domain (CTD) of RNA polymerase II in eukaryotes regulates mRNA processing processes by recruiting various regulation factors. A main function of the CTD relies on the heptad consensus sequence (YSPTSPS). The CTD dynamically changes its conformational state to recognize and bind different regulation factors. The dynamical conformation changes are caused by modifications, mainly phosphorylation and dephosphorylation, to the serine residues. In this study, we investigate the conformational states of the unit consensus CTD peptide with various phosphorylation patterns of the serine residues by extended ensemble simulations. The results show that the CTD without phosphorylation has a flexible disordered structure distributed between twisted and extended states, but phosphorylation tends to reduce the conformational space. It was found that phosphorylation induces a β-turn around the phosphorylated serine residue and the cis conformation of the proline residue significantly inhibits the β-turn formation. The β-turn should contribute to specific CTD binding of the different regulation factors by changing the conformation propensity combined with induced fit.

Climate Impacts of CALIPSO-Guided Corrections to Black Carbon Aerosol Vertical Distributions in a Global Climate Model

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

Kovilakam, Mahesh; Mahajan, Salil; Saravanan, R.

Here, we alleviate the bias in the tropospheric vertical distribution of black carbon aerosols (BC) in the Community Atmosphere Model (CAM4) using the Cloud-Aerosol and Infrared Pathfinder Satellite Observations (CALIPSO)-derived vertical profiles. A suite of sensitivity experiments are conducted with 1x, 5x, and 10x the present-day model estimated BC concentration climatology, with (corrected, CC) and without (uncorrected, UC) CALIPSO-corrected BC vertical distribution. The globally averaged top of the atmosphere radiative flux perturbation of CC experiments is ~8–50% smaller compared to uncorrected (UC) BC experiments largely due to an increase in low-level clouds. The global average surface temperature increases, the globalmore » average precipitation decreases, and the ITCZ moves northward with the increase in BC radiative forcing, irrespective of the vertical distribution of BC. Further, tropical expansion metrics for the poleward extent of the Northern Hemisphere Hadley cell (HC) indicate that simulated HC expansion is not sensitive to existing model biases in BC vertical distribution.« less

Climate Impacts of CALIPSO-Guided Corrections to Black Carbon Aerosol Vertical Distributions in a Global Climate Model

DOE PAGES

Kovilakam, Mahesh; Mahajan, Salil; Saravanan, R.; ...

2017-09-13

Here, we alleviate the bias in the tropospheric vertical distribution of black carbon aerosols (BC) in the Community Atmosphere Model (CAM4) using the Cloud-Aerosol and Infrared Pathfinder Satellite Observations (CALIPSO)-derived vertical profiles. A suite of sensitivity experiments are conducted with 1x, 5x, and 10x the present-day model estimated BC concentration climatology, with (corrected, CC) and without (uncorrected, UC) CALIPSO-corrected BC vertical distribution. The globally averaged top of the atmosphere radiative flux perturbation of CC experiments is ~8–50% smaller compared to uncorrected (UC) BC experiments largely due to an increase in low-level clouds. The global average surface temperature increases, the globalmore » average precipitation decreases, and the ITCZ moves northward with the increase in BC radiative forcing, irrespective of the vertical distribution of BC. Further, tropical expansion metrics for the poleward extent of the Northern Hemisphere Hadley cell (HC) indicate that simulated HC expansion is not sensitive to existing model biases in BC vertical distribution.« less

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.

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.

Consensus statement on the multidisciplinary management of patients with recurrent and primary rectal cancer beyond total mesorectal excision planes.

PubMed

2013-07-01

The management of primary rectal cancer beyond total mesorectal excision planes (PRC-bTME) and recurrent rectal cancer (RRC) is challenging. There is global variation in standards and no guidelines exist. To achieve cure most patients require extended, multivisceral, exenterative surgery, beyond conventional total mesorectal excision planes. The aim of the Beyond TME Group was to achieve consensus on the definitions and principles of management, and to identify areas of research priority. Delphi methodology was used to achieve consensus. The Group consisted of invited experts from surgery, radiology, oncology and pathology. The process included two international dedicated discussion conferences, formal feedback, three rounds of editing and two rounds of anonymized web-based voting. Consensus was achieved with more than 80 per cent agreement; less than 80 per cent agreement indicated low consensus. During conferences held in September 2011 and March 2012, open discussion took place on areas in which there is a low level of consensus. The final consensus document included 51 voted statements, making recommendations on ten key areas of PRC-bTME and RRC. Consensus agreement was achieved on the recommendations of 49 statements, with 34 achieving consensus in over 95 per cent. The lowest level of consensus obtained was 76 per cent. There was clear identification of the need for referral to a specialist multidisciplinary team for diagnosis, assessment and further management. The consensus process has provided guidance for the management of patients with PRC-bTME or RRC, taking into account global variations in surgical techniques and technology. It has further identified areas of research priority.

Consensus Building: A Key to School Transformation

ERIC Educational Resources Information Center

Baron, Daniel

2008-01-01

Consensus-based decision making can turn faculty meetings into meaningful and productive work sessions in which faculty members know that their input is respected and valued and important decisions are made. Reaching consensus has different meanings in different contexts. Decisions are made "by consensus" when the decision affects the entire…

aerosol radiative effects and forcing: spatial and temporal distributions

NASA Astrophysics Data System (ADS)

Kinne, Stefan

2014-05-01

A monthly climatology for aerosol optical properties based on a synthesis from global modeling and observational data has been applied to illustrate spatial distributions and global averages of aerosol radiative impacts. With the help of a pre-industrial reference for aerosol optical properties from global modeling, also the aerosol direct forcing (ca -0.35W/m2 globally and annual averaged) and their spatial and seasonal distributions and contributions by individual aerosol components are estimated. Finally, CCN and IN concentrations associated with this climatology are applied to estimate aerosol indirect effects and forcing.

Populism vs. elitism: social consensus and social status as bases of attitude certainty.

PubMed

Prislin, Radmila; Shaffer, Emily; Crowder, Marisa

2012-01-01

This study examined the effects of social consensus and social status on attitude certainty that is conceptualized multi-dimensionally as perceived clarity and correctness of one's attitude. In a mock opinion exchange about a social issue, participants were either supported (high consensus) or opposed (low consensus) by most of the confederates. They were informed that their opinion (high status) or their opponents' opinion (low status) had the alleged psychological significance indicative of future success. Post-experimental attitude clarity was significantly greater when attitudinal position was associated with high rather than low status. Attitude correctness was interactively affected by social status and social consensus. Supporting the compensatory effect hypothesis, attitude correctness was comparable across the levels of social consensus as long as they were associated with high status, and across the levels of social status as long as they were associated with high social consensus.

Cofactor specificity switch in Shikimate dehydrogenase by rational design and consensus engineering.

PubMed

García-Guevara, Fernando; Bravo, Iris; Martínez-Anaya, Claudia; Segovia, Lorenzo

2017-08-01

Consensus engineering has been used to design more stable variants using the most frequent amino acid at each site of a multiple sequence alignment; sometimes consensus engineering modifies function, but efforts have mainly been focused on studying stability. Here we constructed a consensus Rossmann domain for the Shikimate dehydrogenase enzyme; separately we decided to switch the cofactor specificity through rational design in the Escherichia coli Shikimate dehydrogenase enzyme and then analyzed the effect of consensus mutations on top of our design. We found that consensus mutations closest to the 2' adenine moiety increased the activity in our design. Consensus engineering has been shown to result in more stable proteins and our findings suggest it could also be used as a complementary tool for increasing or modifying enzyme activity during design. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A consensus definition and core competencies for being an advocate for pharmacy.

PubMed

Bzowyckyj, Andrew S; Janke, Kristin K

2013-03-12

To develop a consensus definition for "advocacy for the profession of pharmacy" and core competencies for doctor of pharmacy (PharmD) graduates to be effective advocates for the profession. A 3-round modified Delphi process was conducted using a panel of 9 experts. Participants revised a definition for "advocacy for the profession" and ultimately rated their agreement using a 5-point Likert scale. Competency statements were developed and subsequently rated for importance for being an advocate and importance to address in PharmD curricula. A consensus-derived definition was developed. Two competency statements achieved consensus for both measures of importance. Four competency statements achieved consensus for only 1 measure and another 4 did not reach consensus for either measure. A consensus-derived definition was developed describing advocacy for the profession of pharmacy and began laying the groundwork for the knowledge and skills necessary to be an effective advocate for the profession of pharmacy.

On the Control of Consensus Networks: Theory and Applications

NASA Astrophysics Data System (ADS)

Hudoba de Badyn, Mathias

Signed networks allow the study of positive and negative interactions between agents. In this thesis, three papers are presented that address controllability of networked dynamics. First, controllability of signed consensus networks is approached from a symmetry perspective, for both linear and nonlinear consensus protocols. It is shown that the graph-theoretic property of signed networks known as structural balance renders the consensus protocol uncontrollable when coupled with a certain type of symmetry. Stabilizability and output controllability of signed linear consensus is also examined, as well as a data-driven approach to finding bipartite consensus stemming from structural balance for signed nonlinear consensus. Second, an algorithm is constructed that allows one to grow a network while preserving controllability, and some generalizations of this algorithm are presented. Submodular optimization is used to analyze a second algorithm that adds nodes to a network to maximize the network connectivity.

Peruvian and globally reported amino acid substitutions on the Mycobacterium tuberculosis pyrazinamidase suggest a conserved pattern of mutations associated to pyrazinamide resistance

PubMed Central

Zimic, Mirko; Sheen, Patricia; Quiliano, Miguel; Gutierrez, Andrés; Gilman, Robert H.

2010-01-01

Resistance to pyrazinamide in Mycobacterium tuberculosis is usually associated with a reduction of pyrazinamidase activity caused by mutations in pncA, the pyrazinamidase coding gene. Pyrazinamidase is a hydrolase that converts pyrazinamide, the antituberculous drug against the latent stage, to the active compound, pyrazinoic acid. To better understand the relationship between pncA mutations and pyrazinamide-resistance, it is necessary to analyze the distribution of pncA mutations from pyrazinamide resistant strains. We determined the distribution of Peruvian and globally reported pncA missense mutations from M. tuberculosis clinical isolates resistant to pyrazinamide. The distributions of the single amino acid substitutions were compared at the secondary-structure-domains level. The distribution of the Peruvian mutations followed a similar pattern as the mutations reported globally. A consensus clustering of mutations was observed in hot-spot regions located in the metal coordination site and to a lesser extent in the active site of the enzyme. The data was not able to reject the null hypothesis that both distributions are similar, suggesting that pncA mutations associated to pyrazinamide resistance in M. tuberculosis, follow a conserved pattern responsible to impair the pyrazinamidase activity. PMID:19963078

EDDA: An Efficient Distributed Data Replication Algorithm in VANETs.

PubMed

Zhu, Junyu; Huang, Chuanhe; Fan, Xiying; Guo, Sipei; Fu, Bin

2018-02-10

Efficient data dissemination in vehicular ad hoc networks (VANETs) is a challenging issue due to the dynamic nature of the network. To improve the performance of data dissemination, we study distributed data replication algorithms in VANETs for exchanging information and computing in an arbitrarily-connected network of vehicle nodes. To achieve low dissemination delay and improve the network performance, we control the number of message copies that can be disseminated in the network and then propose an efficient distributed data replication algorithm (EDDA). The key idea is to let the data carrier distribute the data dissemination tasks to multiple nodes to speed up the dissemination process. We calculate the number of communication stages for the network to enter into a balanced status and show that the proposed distributed algorithm can converge to a consensus in a small number of communication stages. Most of the theoretical results described in this paper are to study the complexity of network convergence. The lower bound and upper bound are also provided in the analysis of the algorithm. Simulation results show that the proposed EDDA can efficiently disseminate messages to vehicles in a specific area with low dissemination delay and system overhead.

EDDA: An Efficient Distributed Data Replication Algorithm in VANETs

PubMed Central

Zhu, Junyu; Huang, Chuanhe; Fan, Xiying; Guo, Sipei; Fu, Bin

2018-01-01

Efficient data dissemination in vehicular ad hoc networks (VANETs) is a challenging issue due to the dynamic nature of the network. To improve the performance of data dissemination, we study distributed data replication algorithms in VANETs for exchanging information and computing in an arbitrarily-connected network of vehicle nodes. To achieve low dissemination delay and improve the network performance, we control the number of message copies that can be disseminated in the network and then propose an efficient distributed data replication algorithm (EDDA). The key idea is to let the data carrier distribute the data dissemination tasks to multiple nodes to speed up the dissemination process. We calculate the number of communication stages for the network to enter into a balanced status and show that the proposed distributed algorithm can converge to a consensus in a small number of communication stages. Most of the theoretical results described in this paper are to study the complexity of network convergence. The lower bound and upper bound are also provided in the analysis of the algorithm. Simulation results show that the proposed EDDA can efficiently disseminate messages to vehicles in a specific area with low dissemination delay and system overhead. PMID:29439443

29 CFR Appendix B to Subpart L of... - National Consensus Standards

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 5 2010-07-01 2010-07-01 false National Consensus Standards B Appendix B to Subpart L of... Appendix B to Subpart L of Part 1910—National Consensus Standards The following table contains a cross-reference listing of those current national consensus standards which contains information and guidelines...

Food Security: The Elaboration of Contested Claims to a Consensus Frame

ERIC Educational Resources Information Center

Mooney, Patrick H.; Hunt, Scott A.

2009-01-01

This article demonstrates Gamson's claim that behind the apparent agreement implied by "consensus frames" lies considerable dissensus. Ironically, the very potency of consensus frames may generate contested claims to the ownership of a social problem. Food security is a potent consensus frame that has generated at least three distinct collective…

Stationary Fuel Cell System Composite Data Products | Hydrogen and Fuel

Science.gov Websites

Capacity by Equipment Type CDP STAT 14, 10/21/15 Average Eligible Cost by Equipment Type, including Other Distributed Generation CDP STAT 15, 10/21/15 Average Eligible Cost for Biogas Sources CDP STAT 16, 10/21/15 Capacity and Eligible Cost (CHP Fuel Cells) CDP STAT 22, 10/21/15 Distribution of Eligible Cost with and

Internet information on colorectal cancer: commercialization and lack of quality control.

PubMed

Sajid, M S; Iftikhar, M; Monteiro, R S; Miles, A F W; Woods, W G A; Baig, M K

2008-05-01

The objective of this study was to evaluate the effectiveness of the internet as a source of information for colorectal cancer (CRC). Six of the most common search engines (Yahoo, Google, MSN search, Alta Vista, Excite and Lycos) were used for the search of the generic term 'CRC'. First 300 links were analysed and classified by information type, provider, readership and commercial orientation. The average time delay was 1.70 s before matches were located. A total of 3.2827 million matches on CRC were found using the six search engines ranging from 700 (Excite) to 1 417 000 (Lycos) websites. Approximately 50% of the links were based on information from textbooks or governmental websites. Commercial companies giving information about private hospitals and products provided over 50% of the websites on CRC. The distribution of target readers was uneven, although a majority of websites were delivering CRC information to public and patients. Readability of information was difficult to comprehend by the public. The internet is becoming an essential tool for disseminating information about CRC to consumers. Half of the links on CRC are commercially oriented, containing information on goods or private health services. Less than 1% information is being provided by professional societies. To provide relevant CRC information, key consensus criteria for evaluating healthcare-related websites have to be established. There is an urgent need for CRC information on the internet to be regulated through the establishment of government-funded organizations (e.g. NHS) or professional societies (e.g. ACPGBI).