WorldWideScience

Sample records for network loss characterization

  1. Loss Networks

    OpenAIRE

    Kelly, F. P.

    1991-01-01

    This paper describes work on the stochastic modelling of loss networks. Such systems have long been of interest to telephone engineers and are becoming increasingly important as models of computer and information systems. Throughout the century problems from this field have provided an impetus to the development of probability theory, pure and applied. This paper provides an introduction to the area and a review of recent work.

  2. Extending Stochastic Network Calculus to Loss Analysis

    Directory of Open Access Journals (Sweden)

    Chao Luo

    2013-01-01

    Full Text Available Loss is an important parameter of Quality of Service (QoS. Though stochastic network calculus is a very useful tool for performance evaluation of computer networks, existing studies on stochastic service guarantees mainly focused on the delay and backlog. Some efforts have been made to analyse loss by deterministic network calculus, but there are few results to extend stochastic network calculus for loss analysis. In this paper, we introduce a new parameter named loss factor into stochastic network calculus and then derive the loss bound through the existing arrival curve and service curve via this parameter. We then prove that our result is suitable for the networks with multiple input flows. Simulations show the impact of buffer size, arrival traffic, and service on the loss factor.

  3. A Network Coding Approach to Loss Tomography

    DEFF Research Database (Denmark)

    Sattari, Pegah; Markopoulou, Athina; Fragouli, Christina

    2013-01-01

    multicast and/or unicast end-to-end probes. Independently, recent advances in network coding have shown that there are several advantages from allowing intermediate nodes to process and combine, in addition to just forward, packets. In this paper, we pose the problem of loss tomography in networks that have...... network coding capabilities. We design a framework for estimating link loss rates, which leverages network coding capabilities and we show that it improves several aspects of tomography, including the identifiability of links, the tradeoff between estimation accuracy and bandwidth efficiency...... and multiple paths between sources and receivers. This work was the first to make the connection between active network tomography and network coding, and thus opened a new research direction....

  4. Loss Discrimination Algorithm for Wired/Wireless Networks

    OpenAIRE

    Liw J. Seng; Mohd N. Derahman; Azizol Abdullah

    2011-01-01

    Problem statement: Wireless technology has far growing with an increasing demand of the Wireless networking technologies recent years. The wireless access network and cellular networks are being used to support their need. It is usually connected to a wired backbone network. TCP is used to handle the congestion in wired network. However, it is not well suited for hybrid network consisting of wired and wireless networks. Packet loss occurs in wireless network mostly due to high bit error rate,...

  5. Individual Hearing Loss: Characterization, Modelling, Compensation Strategies

    DEFF Research Database (Denmark)

    Santurette, Sébastien; Dau, Torsten; Christensen-Dalsgaard, Jakob

    2016-01-01

    It is well-established that hearing loss does not only lead to a reduction of hearing sensitivity. Large individual differences are typically observed among listeners with hearing impairment in a wide range of suprathreshold auditory measures. In many cases, audiometric thresholds cannot fully...... account for such individual differences, which make it challenging to find adequate compensation strategies in hearing devices. How to characterize, model, and compensate for individual hearing loss were the main topics of the fifth International Symposium on Auditory and Audiological Research (ISAAR...

  6. Computation of loss allocation in electric power networks using loss ...

    African Journals Online (AJOL)

    This paper presents the computation of loss allocation that can be applied to sellers and buyers participating in electric power trade in a deregulated power market. The approach is based on the Jacobian and Hessian matrices of the power flow equations. The losses to be allocated are derived from load flow of a specified ...

  7. Minimizing heat loss in DC networks using batteries

    CERN Document Server

    Zocca, Alessandro

    2016-01-01

    Electricity transmission networks dissipate a non-negligible fraction of the power they transport due to the heat loss in the transmission lines. In this work we explore how the transport of energy can be more efficient by adding to the network multiple batteries that can coordinate their operations. Such batteries can both charge using the current excess in the network or discharge to meet the network current demand. Either way, the presence of batteries in the network can be leveraged to mitigate the intrinsic uncertainty in the power generation and demand and, hence, transport the energy more efficiently through the network. We consider a resistive DC network with stochastic external current injections or consumptions and show how the expected total heat loss depends on the network structure and on the batteries operations. Furthermore, in the case where the external currents are modeled by Ornstein-Uhlenbeck processes, we derive the dynamical optimal control for the batteries over a finite time interval.

  8. Entropy Characterization of Random Network Models

    Directory of Open Access Journals (Sweden)

    Pedro J. Zufiria

    2017-06-01

    Full Text Available This paper elaborates on the Random Network Model (RNM as a mathematical framework for modelling and analyzing the generation of complex networks. Such framework allows the analysis of the relationship between several network characterizing features (link density, clustering coefficient, degree distribution, connectivity, etc. and entropy-based complexity measures, providing new insight on the generation and characterization of random networks. Some theoretical and computational results illustrate the utility of the proposed framework.

  9. Loss optimization in distribution networks with distributed generation

    DEFF Research Database (Denmark)

    Pokhrel, Basanta Raj; Nainar, Karthikeyan; Bak-Jensen, Birgitte

    2017-01-01

    This paper presents a novel power loss minimization approach in distribution grids considering network reconfiguration, distributed generation and storage installation. Identification of optimum configuration in such scenario is one of the main challenges faced by distribution system operators in...

  10. On Extending Neural Networks with Loss Ensembles for Text Classification

    OpenAIRE

    Hajiabadi, Hamideh; Molla-Aliod, Diego; Monsefi, Reza

    2017-01-01

    Ensemble techniques are powerful approaches that combine several weak learners to build a stronger one. As a meta learning framework, ensemble techniques can easily be applied to many machine learning techniques. In this paper we propose a neural network extended with an ensemble loss function for text classification. The weight of each weak loss function is tuned within the training phase through the gradient propagation optimization method of the neural network. The approach is evaluated on...

  11. Minimizing heat loss in DC networks using batteries

    NARCIS (Netherlands)

    A. Zocca (Alessandro); A.P. Zwart (Bert)

    2016-01-01

    htmlabstractElectricity transmission networks dissipate a non-negligible fraction of the power they transport due to the heat loss in the transmission lines. In this work we explore how the transport of energy can be more efficient by adding to the network multiple batteries that can coordinate

  12. Mapping and characterization of LCA networks

    DEFF Research Database (Denmark)

    Bjørn, Anders; Owsianiak, Mikolaj; Laurent, Alexis

    2013-01-01

    Purpose: The aims of this study were to provide an up-todate overview of global, regional and local networks supporting life cycle thinking and to characterize them according to their structure and activities. Methods: Following a tentative life cycle assessment (LCA) network definition, a mapping...... was performed based on (1) a literature search, (2) a web search and (3) an inquiry to stakeholders distributed via the two largest LCA fora. Networks were characterized based on responses from a survey. Results and discussion: We identified 100 networks, of which 29 fulfilled all six criteria composing our...... tentative network definition (the remaining fulfilled four to five criteria). The networks are mainly located in Europe and the USA, whilst Africa, the Middle East and Central Asia are less covered regions. The survey results (from 25 network responses) indicate that LCA networks appear to be primarily...

  13. Triple Pulse Tester - Efficient Power Loss Characterization of Power Modules

    DEFF Research Database (Denmark)

    Trintis, Ionut; Poulsen, Thomas; Beczkowski, Szymon

    2015-01-01

    In this paper the triple pulse testing method and circuit for power loss characterization of power modules is introduced. The proposed test platform is able to accurately characterize both the switching and conduction losses of power modules in a single automated process. A configuration of a hal...

  14. Performance modeling, loss networks, and statistical multiplexing

    CERN Document Server

    Mazumdar, Ravi

    2009-01-01

    This monograph presents a concise mathematical approach for modeling and analyzing the performance of communication networks with the aim of understanding the phenomenon of statistical multiplexing. The novelty of the monograph is the fresh approach and insights provided by a sample-path methodology for queueing models that highlights the important ideas of Palm distributions associated with traffic models and their role in performance measures. Also presented are recent ideas of large buffer, and many sources asymptotics that play an important role in understanding statistical multiplexing. I

  15. Verifying cell loss requirements in high-speed communication networks

    Directory of Open Access Journals (Sweden)

    Kerry W. Fendick

    1998-01-01

    Full Text Available In high-speed communication networks it is common to have requirements of very small cell loss probabilities due to buffer overflow. Losses are measured to verify that the cell loss requirements are being met, but it is not clear how to interpret such measurements. We propose methods for determining whether or not cell loss requirements are being met. A key idea is to look at the stream of losses as successive clusters of losses. Often clusters of losses, rather than individual losses, should be regarded as the important “loss events”. Thus we propose modeling the cell loss process by a batch Poisson stochastic process. Successive clusters of losses are assumed to arrive according to a Poisson process. Within each cluster, cell losses do not occur at a single time, but the distance between losses within a cluster should be negligible compared to the distance between clusters. Thus, for the purpose of estimating the cell loss probability, we ignore the spaces between successive cell losses in a cluster of losses. Asymptotic theory suggests that the counting process of losses initiating clusters often should be approximately a Poisson process even though the cell arrival process is not nearly Poisson. The batch Poisson model is relatively easy to test statistically and fit; e.g., the batch-size distribution and the batch arrival rate can readily be estimated from cell loss data. Since batch (cluster sizes may be highly variable, it may be useful to focus on the number of batches instead of the number of cells in a measurement interval. We also propose a method for approximately determining the parameters of a special batch Poisson cell loss with geometric batch-size distribution from a queueing model of the buffer content. For this step, we use a reflected Brownian motion (RBM approximation of a G/D/1/C queueing model. We also use the RBM model to estimate the input burstiness given the cell loss rate. In addition, we use the RBM model to

  16. Characterizing multistationarity regimes in biochemical reaction networks

    OpenAIRE

    Irene Otero-Muras; Julio R. Banga; Alonso, Antonio A

    2012-01-01

    Switch like responses appear as common strategies in the regulation of cellular systems. Here we present a method to characterize bistable regimes in biochemical reaction networks that can be of use to both direct and reverse engineering of biological switches. In the design of a synthetic biological switch, it is important to study the capability for bistability of the underlying biochemical network structure. Chemical Reaction Network Theory (CRNT) may help at this level to decide whether a...

  17. On the Packet Loss Correlation in Wireless Mesh Networks

    DEFF Research Database (Denmark)

    Pahlevani, Peyman; Cabrera Guerrero, Juan Alberto; Roetter, Daniel Enrique Lucani

    2014-01-01

    /or multi-path routing approaches as well as network coding (NC) subgraph selection problems (routing in NC). This paper proposes simple channel models to incorporate the effect of correlation between receivers in a parametric fashion and supports them with a measurement campaign that leverages various......State-of-the-art analysis and protocols in wireless mesh networks typically assume an independent packet loss channel for each receiver of a transmission. Although this is usually transparent for single-path protocol design, this assumption may severely degrade the performance of opportunistic and...

  18. The MVAD pump: motor stator core loss characterization.

    Science.gov (United States)

    Mesa, Kelly J; Ferreira, Antonio; Castillo, Samir; Reyes, Carlos; Wolman, Justin; Casas, Fernando

    2015-01-01

    Investigation of the miniature ventricular assist device (MVAD) pump motor stator core loss behavior was conducted. During operation, the ferromagnetic core in the pump's motor is magnetized by alternating magnetic fields, which, in turn, create intrinsic energy losses in the core material; these losses are known as core losses. A core loss fixture and a method to characterize the magnetic behavior of the MVAD pump stator over a range of frequencies were developed. The MVAD pump motor design features a three phase brushless DC stator with ferromagnetic laminations and copper wire windings arranged in a six slot configuration. The stator's magnetic behavior is important because its core magnetic losses impact pump system efficiency. A system to measure the core loss of MVAD pump stators was developed using a custom core loss fixture consisting of 16 copper wire turns wound in a closed loop geometry bundle; the stator under test was then placed within this bundle. The instrumentation consisted of a signal generator, a power amplifier, and a power analyzer. Power analyzer parameters of current, voltage, and power were collected for several runs with a sinusoidal frequency sweep of 0 to 50 kHz; data were collected for the fixture with and without stators. The magnetic losses inherent to the fixture were characterized independently as a baseline presenting a flat frequency response. The core loss power measurements of individual stators yielded a characteristic bandpass frequency response morphology with a peak core loss found around 2.3 to 2.5 kHz. In conclusion, this method could be used to describe the transfer function of the stator's core magnetic behavior. It also has the potential to be used for future motor evaluation and for investigation of core loss performance variability between different stators during manufacturing operations. Investigational device. Limited by United States law to investigational use.

  19. Characterization of the Weatherization Assistance Program network

    Energy Technology Data Exchange (ETDEWEB)

    Mihlmester, P.E.; Koehler, W.C. Jr.; Beyer, M.A. (Aspen Systems Corp., Oak Ridge, TN (United States). Applied Management Sciences Div.); Brown, M.A. (Oak Ridge National Lab., TN (United States)); Beschen, D.A. Jr. (Department of Energy, Washington, DC (United States). Office of Weatherization Assistance Programs)

    1992-02-01

    The Characterization of the Weatherization Assistance Program (WAP) Network was designed to describe the national network of State and local agencies that provide WAP services to qualifying low-income households. The objective of this study was to profile the current WAP network. To achieve the objective, two national surveys were conducted: one survey collected data from 49 State WAP agencies (including the coterminous 48 States and the District of Columbia), and the second survey collected data from 920 (or 81 percent) of the local WAP agencies.

  20. Characterization and Modeling of Network Traffic

    DEFF Research Database (Denmark)

    Shawky, Ahmed; Bergheim, Hans; Ragnarsson, Olafur

    2011-01-01

    This paper attempts to characterize and model backbone network traffic, using a small number of statistics. In order to reduce cost and processing power associated with traffic analysis. The parameters affecting the behaviour of network traffic are investigated and the choice is that inter......-arrival time, IP addresses, port numbers and transport protocol are the only necessary parameters to model network traffic behaviour. In order to recreate this behaviour, a complex model is needed which is able to recreate traffic behaviour based on a set of statistics calculated from the parameters values....... The model investigates the traffic generation mechanisms, and grouping traffic into flows and applications....

  1. Microstructural characterization of stone wool fibre network

    DEFF Research Database (Denmark)

    Chapelle, Lucie; Brøndsted, Povl; Kusano, Yukihiro

    2014-01-01

    Understanding the mechanical properties of fibrous network as complex as stone wool materials requires a relevant description of their microstructure and architecture. In this study, different methods have been proposed to characterize the fibre orientation, diameter and length of fibres as well ...

  2. Correlated loss of ecosystem services in coupled mutualistic networks.

    Science.gov (United States)

    Albrecht, Jörg; Berens, Dana Gertrud; Jaroszewicz, Bogdan; Selva, Nuria; Brandl, Roland; Farwig, Nina

    2014-05-08

    Networks of species interactions promote biodiversity and provide important ecosystem services. These networks have traditionally been studied in isolation, but species are commonly involved in multiple, diverse types of interaction. Therefore, whether different types of species interaction networks coupled through shared species show idiosyncratic or correlated responses to habitat degradation is unresolved. Here we study the collective response of coupled mutualistic networks of plants and their pollinators and seed dispersers to the degradation of Europe's last relict of old-growth lowland forest (Białowieża, Poland). We show that logging of old-growth forests has correlated effects on the number of partners and interactions of plants in both mutualisms, and that these effects are mediated by shifts in plant densities on logged sites. These results suggest bottom-up-controlled effects of habitat degradation on plant-animal mutualistic networks, and predict that the conversion of primary old-growth forests to secondary habitats may cause a parallel loss of multiple animal-mediated ecosystem services.

  3. Characterizing multistationarity regimes in biochemical reaction networks.

    Directory of Open Access Journals (Sweden)

    Irene Otero-Muras

    Full Text Available Switch like responses appear as common strategies in the regulation of cellular systems. Here we present a method to characterize bistable regimes in biochemical reaction networks that can be of use to both direct and reverse engineering of biological switches. In the design of a synthetic biological switch, it is important to study the capability for bistability of the underlying biochemical network structure. Chemical Reaction Network Theory (CRNT may help at this level to decide whether a given network has the capacity for multiple positive equilibria, based on their structural properties. However, in order to build a working switch, we also need to ensure that the bistability property is robust, by studying the conditions leading to the existence of two different steady states. In the reverse engineering of biological switches, knowledge collected about the bistable regimes of the underlying potential model structures can contribute at the model identification stage to a drastic reduction of the feasible region in the parameter space of search. In this work, we make use and extend previous results of the CRNT, aiming not only to discriminate whether a biochemical reaction network can exhibit multiple steady states, but also to determine the regions within the whole space of parameters capable of producing multistationarity. To that purpose we present and justify a condition on the parameters of biochemical networks for the appearance of multistationarity, and propose an efficient and reliable computational method to check its satisfaction through the parameter space.

  4. Characterizing multistationarity regimes in biochemical reaction networks.

    Science.gov (United States)

    Otero-Muras, Irene; Banga, Julio R; Alonso, Antonio A

    2012-01-01

    Switch like responses appear as common strategies in the regulation of cellular systems. Here we present a method to characterize bistable regimes in biochemical reaction networks that can be of use to both direct and reverse engineering of biological switches. In the design of a synthetic biological switch, it is important to study the capability for bistability of the underlying biochemical network structure. Chemical Reaction Network Theory (CRNT) may help at this level to decide whether a given network has the capacity for multiple positive equilibria, based on their structural properties. However, in order to build a working switch, we also need to ensure that the bistability property is robust, by studying the conditions leading to the existence of two different steady states. In the reverse engineering of biological switches, knowledge collected about the bistable regimes of the underlying potential model structures can contribute at the model identification stage to a drastic reduction of the feasible region in the parameter space of search. In this work, we make use and extend previous results of the CRNT, aiming not only to discriminate whether a biochemical reaction network can exhibit multiple steady states, but also to determine the regions within the whole space of parameters capable of producing multistationarity. To that purpose we present and justify a condition on the parameters of biochemical networks for the appearance of multistationarity, and propose an efficient and reliable computational method to check its satisfaction through the parameter space.

  5. Loss of brain graph network efficiency in alcohol dependence.

    Science.gov (United States)

    Sjoerds, Zsuzsika; Stufflebeam, Steven M; Veltman, Dick J; Van den Brink, Wim; Penninx, Brenda W J H; Douw, Linda

    2017-03-01

    Alcohol dependence (AD) is characterized by corticostriatal impairments in individual brain areas such as the striatum. As yet however, complex brain network topology in AD and its association with disease progression are unknown. We applied graph theory to resting-state functional magnetic resonance imaging (RS-fMRI) to examine weighted global efficiency and local (clustering coefficient, degree and eigenvector centrality) network topology and the functional role of the striatum in 24 AD patients compared with 20 matched healthy controls (HCs), and their association with dependence characteristics. Graph analyses were performed based on Pearson's correlations between RS-fMRI time series, while correcting for age, gender and head motion. We found no significant group differences between AD patients and HCs in network topology. Notably, within the patient group, but not in HCs, the whole-brain network showed reduced average cluster coefficient with more severe alcohol use, whereas longer AD duration within the patient group was associated with a global decrease in efficiency, degree and clustering coefficient. Additionally, within four a-priori chosen bilateral striatal nodes, alcohol use severity was associated with lower clustering coefficient in the left caudate. Longer AD duration was associated with reduced clustering coefficient in caudate and putamen, and reduced degree in bilateral caudate, but with increased eigenvector centrality in left posterior putamen. Especially changes in global network topology and clustering coefficient in anterior striatum remained strikingly robust after exploratory variations in network weight. Our results show adverse effects of AD on overall network integration and possibly on striatal efficiency, putatively contributing to the increasing behavioral impairments seen in chronically addicted patients. © 2015 Society for the Study of Addiction.

  6. Toward economic flood loss characterization via hazard simulation

    Science.gov (United States)

    Czajkowski, Jeffrey; Cunha, Luciana K.; Michel-Kerjan, Erwann; Smith, James A.

    2016-08-01

    Among all natural disasters, floods have historically been the primary cause of human and economic losses around the world. Improving flood risk management requires a multi-scale characterization of the hazard and associated losses—the flood loss footprint. But this is typically not available in a precise and timely manner, yet. To overcome this challenge, we propose a novel and multidisciplinary approach which relies on a computationally efficient hydrological model that simulates streamflow for scales ranging from small creeks to large rivers. We adopt a normalized index, the flood peak ratio (FPR), to characterize flood magnitude across multiple spatial scales. The simulated FPR is then shown to be a key statistical driver for associated economic flood losses represented by the number of insurance claims. Importantly, because it is based on a simulation procedure that utilizes generally readily available physically-based data, our flood simulation approach has the potential to be broadly utilized, even for ungauged and poorly gauged basins, thus providing the necessary information for public and private sector actors to effectively reduce flood losses and save lives.

  7. Social Network Characteristics Associated with Weight Loss among Black and Hispanic Adults with Overweight and Obesity

    OpenAIRE

    Winston, Ginger; Phillips, Erica G.; Wethington, Elaine; Devine, Carol; Wells, Martin; Peterson, Janey C.; Hippolyte, Jessica; Ramos, Rosio; Martinez, Guillerma; Eldridge, Johanna; Charlson, Mary

    2015-01-01

    Objective To examine social network member characteristics associated with weight loss. Methods Cross-sectional examination of egocentric network data from 245 Black and Hispanic adults with BMI ? 25 kg/m2 enrolled in a small change weight loss study. The relationship between weight loss at 12 months and characteristics of helpful and harmful network members (relationship, contact frequency, living proximity and body size) were examined. Results There were 2,571 network members identified. Me...

  8. Social Network Characteristics Associated with Weight Loss among Black and Hispanic Adults with Overweight and Obesity

    Science.gov (United States)

    Winston, Ginger; Phillips, Erica G.; Wethington, Elaine; Devine, Carol; Wells, Martin; Peterson, Janey C.; Hippolyte, Jessica; Ramos, Rosio; Martinez, Guillerma; Eldridge, Johanna; Charlson, Mary

    2015-01-01

    Objective To examine social network member characteristics associated with weight loss. Methods Cross-sectional examination of egocentric network data from 245 Black and Hispanic adults with BMI ≥ 25 kg/m2 enrolled in a small change weight loss study. The relationship between weight loss at 12 months and characteristics of helpful and harmful network members (relationship, contact frequency, living proximity and body size) were examined. Results There were 2,571 network members identified. Mean weight loss was -4.8 (±11.3) lbs. among participants with network help and no harm with eating goals vs. +3.4 (±7.8) lbs. among participants with network harm alone. In a multivariable regression model, greater weight loss was associated with help from a child with eating goals (p=.0002) and coworker help with physical activity (p=.01). Weight gain was associated with having network members with obesity living in the home (p=.048) and increased network size (p=.002). Conclusions There was greater weight loss among participants with support from children and coworkers. Weight gain was associated with harmful network behaviors and having network members with obesity in the home. Incorporating child and co-worker support, and evaluating network harm and the body size of network members should be considered in future weight loss interventions. PMID:26179578

  9. Social network characteristics associated with weight loss among black and hispanic adults.

    Science.gov (United States)

    Winston, Ginger J; Phillips, Erica G; Wethington, Elaine; Devine, Carol; Wells, Martin; Peterson, Janey C; Hippolyte, Jessica; Ramos, Rosio; Martinez, Guillerma; Eldridge, Johanna; Charlson, Mary

    2015-08-01

    To examine social network member characteristics associated with weight loss. A cross-sectional examination included egocentric network data from 245 Black and Hispanic adults with BMI ≥ 25 kg/m(2) enrolled in a small change weight loss study. The relationships between weight loss at 12 months and characteristics of helpful and harmful network members (relationship, contact frequency, living proximity, and body size) were examined. There were 2,571 network members identified. Mean weight loss was -4.8 (±11.3) lbs. among participants with network help and no harm with eating goals vs. +3.4 (±7.8) lbs. among participants with network harm alone. In a multivariable regression model, greater weight loss was associated with help from a child with eating goals (P = 0.0002) and coworker help with physical activity (P = 0.01). Weight gain was associated with having network members with obesity living in the home (P = 0.048) and increased network size (P = 0.002). There was greater weight loss among participants with support from children and coworkers. Weight gain was associated with harmful network behaviors and having network members with obesity in the home. Incorporating child and coworker support and evaluating network harm and the body size of network members should be considered in future weight loss interventions. © 2015 The Obesity Society.

  10. The robustness of a network of ecological networks to habitat loss.

    Science.gov (United States)

    Evans, Darren M; Pocock, Michael J O; Memmott, Jane

    2013-07-01

    There have been considerable advances in our understanding of the tolerance of species interaction networks to sequential extinctions of plants and animals. However, communities of species exist in a mosaic of habitats, and the vulnerability of habitats to anthropogenic change varies. Here, we model the cascading effects of habitat loss, driven by plant extinctions, on the robustness of multiple animal groups. Our network is constructed from empirical observations of 11 animal groups in 12 habitats on farmland. We simulated sequential habitat removal scenarios: randomly; according to prior information; and with a genetic algorithm to identify best- and worst-case permutations of habitat loss. We identified two semi-natural habitats (waste ground and hedgerows together comprising < 5% of the total area of the farm) as disproportionately important to the integrity of the overall network. Our approach provides a new tool for network ecologists and for directing the management and restoration of multiple-habitat sites. © 2013 John Wiley & Sons Ltd/CNRS.

  11. Loss Performance Modeling for Hierarchical Heterogeneous Wireless Networks With Speed-Sensitive Call Admission Control

    DEFF Research Database (Denmark)

    Huang, Qian; Huang, Yue-Cai; Ko, King-Tim

    2011-01-01

    A hierarchical overlay structure is an alternative solution that integrates existing and future heterogeneous wireless networks to provide subscribers with better mobile broadband services. Traffic loss performance in such integrated heterogeneous networks is necessary for an operator's network...... dimensioning and planning. This paper investigates the computationally efficient loss performance modeling for multiservice in hierarchical heterogeneous wireless networks. A speed-sensitive call admission control (CAC) scheme is considered in our model to assign overflowed calls to appropriate tiers...

  12. Quantitative phosphoproteomics to characterize signaling networks

    DEFF Research Database (Denmark)

    Rigbolt, Kristoffer T G; Blagoev, Blagoy

    2012-01-01

    Reversible protein phosphorylation is involved in the regulation of most, if not all, major cellular processes via dynamic signal transduction pathways. During the last decade quantitative phosphoproteomics have evolved from a highly specialized area to a powerful and versatile platform for analy......Reversible protein phosphorylation is involved in the regulation of most, if not all, major cellular processes via dynamic signal transduction pathways. During the last decade quantitative phosphoproteomics have evolved from a highly specialized area to a powerful and versatile platform...... for analyzing protein phosphorylation at a system-wide scale and has become the intuitive strategy for comprehensive characterization of signaling networks. Contemporary phosphoproteomics use highly optimized procedures for sample preparation, mass spectrometry and data analysis algorithms to identify...... and quantify thousands of phosphorylations, thus providing extensive overviews of the cellular signaling networks. As a result of these developments quantitative phosphoproteomics have been applied to study processes as diverse as immunology, stem cell biology and DNA damage. Here we review the developments...

  13. Neural network analysis for hazardous waste characterization

    Energy Technology Data Exchange (ETDEWEB)

    Misra, M.; Pratt, L.Y.; Farris, C. [Colorado School of Mines, Golden, CO (United States)] [and others

    1995-12-31

    This paper is a summary of our work in developing a system for interpreting electromagnetic (EM) and magnetic sensor information from the dig face characterization experimental cell at INEL to determine the depth and nature of buried objects. This project contained three primary components: (1) development and evaluation of several geophysical interpolation schemes for correcting missing or noisy data, (2) development and evaluation of several wavelet compression schemes for removing redundancies from the data, and (3) construction of two neural networks that used the results of steps (1) and (2) to determine the depth and nature of buried objects. This work is a proof-of-concept study that demonstrates the feasibility of this approach. The resulting system was able to determine the nature of buried objects correctly 87% of the time and was able to locate a buried object to within an average error of 0.8 feet. These statistics were gathered based on a large test set and so can be considered reliable. Considering the limited nature of this study, these results strongly indicate the feasibility of this approach, and the importance of appropriate preprocessing of neural network input data.

  14. Characterization of hearing loss in aged type II diabetics

    Science.gov (United States)

    Frisina, Susan T.; Mapes, Frances; Kim, SungHee; Frisina, D. Robert; Frisina, Robert D.

    2009-01-01

    Presbycusis – age-related hearing loss – is the number one communicative disorder and a significant chronic medical condition of the aged. Little is known about how type II diabetes, another prevalent age-related medical condition, and presbycusis interact. The present investigation aimed to comprehensively characterize the nature of hearing impairment in aged type II diabetics. Hearing tests measuring both peripheral (cochlea) and central (brainstem and cortex) auditory processing were utilized. The majority of differences between the hearing abilities of the aged diabetics and their age-matched controls were found in measures of inner ear function. For example, large differences were found in pure-tone audiograms, wideband noise and speech reception thresholds, and otoacoustic emissions. The greatest deficits tended to be at low frequencies. In addition, there was a strong tendency for diabetes to affect the right ear more than the left. One possible interpretation is that as one develops presbycusis, the right ear advantage is lost, and this decline is accelerated by diabetes. In contrast, auditory processing tests that measure both peripheral and central processing showed fewer declines between the elderly diabetics and the control group. Consequences of elevated blood sugar levels as possible underlying physiological mechanisms for the hearing loss are discussed. PMID:16309862

  15. Acoustic signal propagation characterization of conduit networks

    Science.gov (United States)

    Khan, Muhammad Safeer

    may be intractable. A tractable approach is to develop an empirical model of the attenuation that has a stochastic component of a finite mean and variance to account for the random variable error akin to addition of a normally distributed random variable shadowing component in the path loss models of radio frequency (RF) wireless communication channels. This approach forms the crux of the present study. To develop an empirical model, a large number of measurements in conduit networks were made in the field and in a laboratory test set up to measure the variability of attenuation with variation in four parameters. These parameters include distance of the receiver from the source, frequency, numbers and lengths of side branches. Variation in signal attenuation with distance at each transmitted frequency is predicted by using linear regression through the scatter plot of the measured data. Variations in signal attenuation due to change in frequency, number and lengths of side branches are measured in the field and laboratory tests by comparing the reference transmitted pressure with the received pressure at either the open end or at some distance away from the source along the conduit length. Residuals between measured and predicted sound pressure levels are computed and tested for normal probability distribution through a graphical method as well as a statistical goodness of fit test for quantifiable results. The findings indicate that an empirical model of signal attenuation, which includes a normally distributed random variable component to account for random variable errors in the attenuation measurements, gives a more accurate prediction of received acoustic signal strength in a conduit compared to existing theoretical models.

  16. Loss of EEG Network Efficiency Is Related to Cognitive Impairment in Dementia With Lewy Bodies.

    Science.gov (United States)

    van Dellen, Edwin; de Waal, Hanneke; van der Flier, Wiesje M; Lemstra, Afina W; Slooter, Arjen J C; Smits, Lieke L; van Straaten, Elisabeth C W; Stam, Cornelis J; Scheltens, Philip

    2015-11-01

    The aim of this study was to test whether disturbed EEG resting-state functional connectivity and network organization are a potential neurophysiological substrate of cognitive impairment in dementia with Lewy bodies. EEG recordings were obtained in dementia with Lewy bodies patients, Alzheimer's disease patients and controls, matched for age and sex (N = 66 for each group; 14 [21%] female; mean age: 70 years). We analyzed functional connectivity of band-filtered EEG time series using the phase lag index. Functional brain network topology was analyzed with the minimum spanning tree. Mini-Mental State Examination, Trail Making Test A, and Visual Association Test were used as cognitive measures. Dementia with Lewy bodies patients showed lower connectivity strength in the alpha frequency band, compared to both controls and Alzheimer's disease patients (P dementia with Lewy bodies patients was less efficient and contained less hubs (P dementia with Lewy bodies patients, lower alpha band phase lag index correlated with Visual Association Test scores and Trail Making Test scores (ρ = 0.33 and ρ = 0.31, respectively), whereas leaf fraction (a measure of 'network efficiency') correlated with Visual Association Test scores (ρ = 0.29) and Mini-Mental State Examination scores (ρ = 0.27). Functional networks of dementia with Lewy bodies patients are characterized by decreased connectivity strength and a loss of network efficiency and hubs. Severity of these disturbances is related to cognitive impairment, suggesting that network disturbances mediate between neuropathology and the clinical syndrome in dementia with Lewy bodies. © 2015 International Parkinson and Movement Disorder Society.

  17. Networked data fusion with packet losses and variable delays.

    Science.gov (United States)

    Xia, Yuanqing; Shang, Jizong; Chen, Jie; Liu, Guo-Ping

    2009-10-01

    A novel networked multisensor data-fusion method is developed in this paper. A federated filter is employed to fuse the data transmitted over the network, which plays an important role in the data-processing center. The stability of filters under the network is considered; an algorithm to deal with the delayed data is introduced, and the principle for data fusion is presented. Finally, two numerical examples show the effectiveness of the proposed scheme.

  18. Characterization of Polymer Networks by Swelling

    DEFF Research Database (Denmark)

    Frankær, Sarah Maria; Jensen, Mette Krog; Bejenariu, Anca Gabriela

    2009-01-01

    The linear dynamic response of crosslinked PDMS samples with different stoichiometries, as well as the sol and network fractions, was investigated. It was found that all the networks showed similar properties after removal of the sol indicating only small deviations in the network structure upon ...

  19. ANALYSIS OF THE HARMONIC LOSSES WITH ARTIFICIAL NEURAL NETWORKS IN UNBALANCED SYSTEM LOSSES USING BALANCED ELECTRIC POWER SYSTEM DATA

    Directory of Open Access Journals (Sweden)

    Aslan İNAN

    2005-01-01

    Full Text Available The losses in the power systems should be low as possible as. Saving energy instead of loses (kWh in power utilities can supply much more energy to the consumers. The lower losses the more energy is saved and thus the power system becomes more economical. In recent years, the increasing number of applications and power ratings of the devices which have nonlinear voltage-current characteristics cause voltage waveform distortion and additional losses. While evaluating losses considering harmonics will provide more contribution to obtain more accurate results. In this study, Artificial Neural Networks (ANN method has been presented to predict the harmonic losses in unbalanced power systems by using the data from balanced power system with nonlinear loads.

  20. Habitat loss alters the architecture of plant--pollinator interaction networks.

    Science.gov (United States)

    Spiesman, Brian J; Inouye, Brian D

    2013-12-01

    Habitat loss can have a negative effect on the number, abundance, and composition of species in plant-pollinator communities. Although we have a general understanding of the negative consequences of habitat loss for biodiversity, much less is known about the resulting effects on the pattern of interactions in mutualistic networks. Ecological networks formed by mutualistic interactions often exhibit a highly nested architecture with low modularity, especially in comparison with antagonistic networks. These patterns of interaction are thought to confer stability on mutualistic communities. With the growing threat of environmental change, it is important to expand our understanding of the factors that affect biodiversity and the stability of the communities that provide critical ecosystem functions and services. We studied the effects of habitat loss on plant--pollinator network architecture and found that regional habitat loss contributes directly to species loss and indirectly to the reorganization of interspecific interactions in a local community. Networks became more highly connected and more modular with habitat loss. Species richness and abundance were the primary drivers of variation in network architecture, though species compositi n affected modularity. Theory suggests that an increase in modularity with habitat loss will threaten community stability, which may contribute to an extinction debt in communities already affected by habitat loss.

  1. Dynamic Data-Driven UAV Network for Plume Characterization

    Science.gov (United States)

    2016-05-23

    AFRL-AFOSR-VA-TR-2016-0203 Dynamic Data-Driven UAV Network for Plume Characterization Kamran Mohseni UNIVERSITY OF FLORIDA Final Report 05/23/2016...AND SUBTITLE Dynamic Data-Driven UAV Network for Plume Characterization 5a.  CONTRACT NUMBER 5b.  GRANT NUMBER FA9550-13-1-0090 5c.  PROGRAM ELEMENT...toxic plume characterization, Intelligence, Surveillance and Reconnaissance (ISR), environmental monitoring, weather forecasting, and disaster

  2. Loss of integrity and atrophy in cingulate structural covariance networks in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Laura J. de Schipper

    2017-01-01

    Conclusions: We identified loss of integrity and atrophy in the anterior and posterior cingulate networks in PD patients. Abnormalities of both networks were associated with predominantly non-dopaminergic features, specifically cognition and excessive daytime sleepiness. Our findings suggest that (components of the cingulate networks display a specific vulnerability to the pathobiology of PD and may operate as interfaces between networks involved in cognition and alertness.

  3. Characterizing auditory processing and perception in individual listeners with sensorineural hearing loss

    DEFF Research Database (Denmark)

    Jepsen, Morten Løve; Dau, Torsten

    2011-01-01

    This study considered consequences of sensorineural hearing loss in ten listeners. The characterization of individual hearing loss was based on psychoacoustic data addressing audiometric pure-tone sensitivity, cochlear compression, frequency selectivity, temporal resolution, and intensity discrim...

  4. Characterization of phylogenetic networks with NetTest

    Directory of Open Access Journals (Sweden)

    Valiente Gabriel

    2010-05-01

    Full Text Available Abstract Background Typical evolutionary events like recombination, hybridization or gene transfer make necessary the use of phylogenetic networks to properly depict the evolution of DNA and protein sequences. Although several theoretical classes have been proposed to characterize these networks, they make stringent assumptions that will likely not be met by the evolutionary process. We have recently shown that the complexity of simulated networks is a function of the population recombination rate, and that at moderate and large recombination rates the resulting networks cannot be categorized. However, we do not know whether these results extend to networks estimated from real data. Results We introduce a web server for the categorization of explicit phylogenetic networks, including the most relevant theoretical classes developed so far. Using this tool, we analyzed statistical parsimony phylogenetic networks estimated from ~5,000 DNA alignments, obtained from the NCBI PopSet and Polymorphix databases. The level of characterization was correlated to nucleotide diversity, and a high proportion of the networks derived from these data sets could be formally characterized. Conclusions We have developed a public web server, NetTest (freely available from the software section at http://darwin.uvigo.es, to formally characterize the complexity of phylogenetic networks. Using NetTest we found that most statistical parsimony networks estimated with the program TCS could be assigned to a known network class. The level of network characterization was correlated to nucleotide diversity and dependent upon the intra/interspecific levels, although no significant differences were detected among genes. More research on the properties of phylogenetic networks is clearly needed.

  5. DISTRIBUTION NETWORK RECONFIGURATION FOR POWER LOSS MINIMIZATION AND VOLTAGE PROFILE ENHANCEMENT USING ANT LION ALGORITHM

    Directory of Open Access Journals (Sweden)

    Maryam Shokouhi

    2017-06-01

    Full Text Available Distribution networks are designed as a ring and operated as a radial form. Therefore, the reconfiguration is a simple and cost-effective way to use existing facilities without the need for any new equipment in distribution networks to achieve various objectives such as: power loss reduction, feeder overload reduction, load balancing, voltage profile improvement, reducing the number of switching considering constraints that ultimately result in the power loss reduction. In this paper, a new method based on the Ant Lion algorithm (a modern meta-heuristic algorithm is provided for the reconfiguration of distribution networks. Considering the extension of the distribution networks and complexity of their communications networks, and the various parameters, using smart techniques is inevitable. The proposed approach is tested on the IEEE 33 & 69-bus radial standard distribution networks. The Evaluation of results in MATLAB software shows the effectiveness of the Ant Lion algorithm in the distribution network reconfiguration.

  6. Characterization of complex networks : Application to robustness analysis

    NARCIS (Netherlands)

    Jamakovic, A.

    2008-01-01

    This thesis focuses on the topological characterization of complex networks. It specifically focuses on those elementary graph measures that are of interest when quantifying topology-related aspects of the robustness of complex networks. This thesis makes the following contributions to the field of

  7. Strictly convex loss functions for port-Hamiltonian based optimization algorithm for MTDC networks

    NARCIS (Netherlands)

    Benedito, Ernest; del Puerto Flores, Dunstano; Doria-Cerezo, A.; van der Feltz, Olivier; Scherpen, Jacquelien M.A.

    2016-01-01

    In this work we propose a primal-dual method that can be cast in a port-Hamiltonian framework for minimizing the power losses in a multi-terminal DC network. The main contribution consists of proposing an alternative power loss function by means of a change of variables that translates the convex

  8. Up to what point is loss reduction environmentally friendly?: The LCA of loss reduction scenarios in drinking water networks.

    Science.gov (United States)

    Pillot, Julie; Catel, Laureline; Renaud, Eddy; Augeard, Bénédicte; Roux, Philippe

    2016-11-01

    In a context of increasing water shortage all over the world, water utilities must minimise losses in their distribution networks and draw up water loss reduction action plans. While leak reduction is clearly an important part of sustainable water management, its impacts have to be reconsidered in a broader objective of environmental protection than strictly the avoided losses in cubic metres of water. Reducing the volume of water abstracted reduces also environmental impacts associated to water production (the operation and infrastructure needed for abstraction, treatment, supply). In the mean time, activities for reducing water losses generate their own environmental impacts, notably as a result of the work, equipment, and infrastructures used for this purpose. In this study, Life Cycle Assessment (LCA) was used to assess and compare two sets of environmental impacts: those resulting from the production and supply of water which will never reach subscribers, and those caused by water loss reduction activities. This information can then be used to establish whether or not there is a point beyond which loss reduction is no longer effective in reducing the environmental impacts of drinking water supply. Results show that the improvement actions that start from a low water supply efficiency are clearly beneficial for ecosystems, human health and preservation of resources. When seeking to improve the efficiency beyond certain values (about 65%), the uncertainty makes it impossible to conclude for an environmental benefit on all impact categories. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Characterization of Early Cortical Neural Network ...

    Science.gov (United States)

    We examined the development of neural network activity using microelectrode array (MEA) recordings made in multi-well MEA plates (mwMEAs) over the first 12 days in vitro (DIV). In primary cortical cultures made from postnatal rats, action potential spiking activity was essentially absent on DIV 2 and developed rapidly between DIV 5 and 12. Spiking activity was primarily sporadic and unorganized at early DIV, and became progressively more organized with time in culture, with bursting parameters, synchrony and network bursting increasing between DIV 5 and 12. We selected 12 features to describe network activity and principal components analysis using these features demonstrated a general segregation of data by age at both the well and plate levels. Using a combination of random forest classifiers and Support Vector Machines, we demonstrated that 4 features (CV of within burst ISI, CV of IBI, network spike rate and burst rate) were sufficient to predict the age (either DIV 5, 7, 9 or 12) of each well recording with >65% accuracy. When restricting the classification problem to a binary decision, we found that classification improved dramatically, e.g. 95% accuracy for discriminating DIV 5 vs DIV 12 wells. Further, we present a novel resampling approach to determine the number of wells that might be needed for conducting comparisons of different treatments using mwMEA plates. Overall, these results demonstrate that network development on mwMEA plates is similar to

  10. Effect of placement of droop based generators in distribution network on small signal stability margin and network loss

    DEFF Research Database (Denmark)

    Dheer, D.K.; Doolla, S.; Bandyopadhyay, S.

    2017-01-01

    For a utility-connected system, issues related to small signal stability with Distributed Generators (DGs) are insignificant due to the presence of a very strong grid. Optimally placed sources in utility connected microgrid system may not be optimal/stable in islanded condition. Among others issues......, small signal stability margin is on the fore. The present research studied the effect of location of droop-controlled DGs on small signal stability margin and network loss on a modified IEEE 13 bus system, an IEEE 33-bus distribution system and a practical 22-bus radial distribution network. A complete...... dynamic model of an islanded microgrid was developed. From stability analysis, the study reports that both location of DGs and choice of droop coefficient have a significant effect on small signal stability, transient response of the system and network losses. The trade-off associated with the network...

  11. Characterization of Jos City Road Network, Nigeria

    Directory of Open Access Journals (Sweden)

    Olumide Akinwumi Oluwole

    2014-12-01

    Full Text Available ἀe performance of road network depends on its topological characteristics which help to deḀne its connectiv-ity. ἀis paper analyses the topological characteristic of Jos city road network and its bearing on traᴀc ᰀow situations. Simple graph theoretic measures oᬀered the framework on which the problem was approached. ἀe study requires the abstraction and analysis of the topological structure by selection of certain variables relating to the road connectivity. ἀese include the Beta, Gamma and Alpha index, the PI, Cyclomatic number, and the spread and density of the network. Information on these variables was obtained through the use of vector data model to abstract the road network graph from the Quick-bird satellite imagery used for the study. Results of the Ḁndings reveal that, the road network of Jos City Centre as a whole have achieved an average level of connectivity, showing Beta index values of 1.4049, Gamma index value of 47.06%, Alpha index Value of 20.63%; and a pi and cyclomatic number of 24.74 and 165 respectively, the spread of the network is moderate exhibiting a value of 23, even though some areas have more concentration of roads than the others; and has a road density of 52 links per km2. Based on these Ḁndings, the need for construction of new roads is imperative so as to improve the eᴀciency of connectivity and accessibility within the city.

  12. Characterizing naval team readiness through social network analysis

    NARCIS (Netherlands)

    Schraagen, J.M.C.; Post, W.M.

    2014-01-01

    Characterizing a team’s level of readiness in an efficient and objective way is important for organizations such as the military. Current methods to characterize real-time team interaction know limitations that may be addressed by social network analysis techniques. The purpose of the current field

  13. The disentangled bank: how loss of habitat fragments and disassembles ecological networks.

    Science.gov (United States)

    Gonzalez, Andrew; Rayfield, Bronwyn; Lindo, Zoë

    2011-03-01

    Habitat transformation is one of the leading causes of changes in biodiversity and the breakdown of ecosystem function and services. The impacts of habitat transformation on biodiversity are complex and can be difficult to test and demonstrate. Network approaches to biodiversity science have provided a powerful set of tools and models that are beginning to present new insight into the structural and functional effects of habitat transformation on complex ecological systems. We propose a framework for studying the ways in which habitat loss and fragmentation jointly affect biodiversity by altering both habitat and ecological interaction networks. That is, the explicit study of "networks of networks" is required to understand the impacts of habitat change on biodiversity. We conduct a broad review of network methods and results, with the aim of revealing the common approaches used by landscape ecology and community ecology. We find that while a lot is known about the consequences of habitat transformation for habitat network topology and for the structure and function of simple antagonistic and mutualistic interaction networks, few studies have evaluated the consequences for large interaction networks with complex and spatially explicit architectures. Moreover, almost no studies have been focused on the continuous feedback between the spatial structure and dynamics of the habitat network and the structure and dynamics of the interaction networks inhabiting the habitat network. We conclude that theory and experiments that tackle the ecology of networks of networks are needed to provide a deeper understanding of biodiversity change in fragmented landscapes.

  14. Impact of Loss Synchronization on Reliable High Speed Networks: A Model Based Simulation

    Directory of Open Access Journals (Sweden)

    Suman Kumar

    2014-01-01

    Full Text Available Contemporary nature of network evolution demands for simulation models which are flexible, scalable, and easily implementable. In this paper, we propose a fluid based model for performance analysis of reliable high speed networks. In particular, this paper aims to study the dynamic relationship between congestion control algorithms and queue management schemes, in order to develop a better understanding of the causal linkages between the two. We propose a loss synchronization module which is user configurable. We validate our model through simulations under controlled settings. Also, we present a performance analysis to provide insights into two important issues concerning 10 Gbps high speed networks: (i impact of bottleneck buffer size on the performance of 10 Gbps high speed network and (ii impact of level of loss synchronization on link utilization-fairness tradeoffs. The practical impact of the proposed work is to provide design guidelines along with a powerful simulation tool to protocol designers and network developers.

  15. Dynamic Network Model for Smart City Data-Loss Resilience Case Study: City-to-City Network for Crime Analytics.

    Science.gov (United States)

    Kotevska, Olivera; Kusne, A Gilad; Samarov, Daniel V; Lbath, Ahmed; Battou, Abdella

    2017-01-01

    Today's cities generate tremendous amounts of data, thanks to a boom in affordable smart devices and sensors. The resulting big data creates opportunities to develop diverse sets of context-aware services and systems, ensuring smart city services are optimized to the dynamic city environment. Critical resources in these smart cities will be more rapidly deployed to regions in need, and those regions predicted to have an imminent or prospective need. For example, crime data analytics may be used to optimize the distribution of police, medical, and emergency services. However, as smart city services become dependent on data, they also become susceptible to disruptions in data streams, such as data loss due to signal quality reduction or due to power loss during data collection. This paper presents a dynamic network model for improving service resilience to data loss. The network model identifies statistically significant shared temporal trends across multivariate spatiotemporal data streams and utilizes these trends to improve data prediction performance in the case of data loss. Dynamics also allow the system to respond to changes in the data streams such as the loss or addition of new information flows. The network model is demonstrated by city-based crime rates reported in Montgomery County, MD, USA. A resilient network is developed utilizing shared temporal trends between cities to provide improved crime rate prediction and robustness to data loss, compared with the use of single city-based auto-regression. A maximum improvement in performance of 7.8% for Silver Spring is found and an average improvement of 5.6% among cities with high crime rates. The model also correctly identifies all the optimal network connections, according to prediction error minimization. City-to-city distance is designated as a predictor of shared temporal trends in crime and weather is shown to be a strong predictor of crime in Montgomery County.

  16. Predicting Tooth Surface Loss Using Genetic Algorithms-Optimized Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Ali Al Haidan

    2014-01-01

    Full Text Available Our aim was to predict tooth surface loss in individuals without the need to conduct clinical examinations. Artificial neural networks (ANNs were used to construct a mathematical model. Input data consisted of age, smoker status, type of tooth brush, brushing, and consumption of pickled food, fizzy drinks, orange, apple, lemon, and dried seeds. Output data were the sum of tooth surface loss scores for selected teeth. The optimized constructed ANN consisted of 2-layer network with 15 neurons in the first layer and one neuron in the second layer. The data of 46 subjects were used to build the model, while the data of 15 subjects were used to test the model. Accepting an error of ±5 scores for all chosen teeth, the accuracy of the network becomes more than 80%. In conclusion, this study shows that modeling tooth surface loss using ANNs is possible and can be achieved with a high degree of accuracy.

  17. Predicting tooth surface loss using genetic algorithms-optimized artificial neural networks.

    Science.gov (United States)

    Al Haidan, Ali; Abu-Hammad, Osama; Dar-Odeh, Najla

    2014-01-01

    Our aim was to predict tooth surface loss in individuals without the need to conduct clinical examinations. Artificial neural networks (ANNs) were used to construct a mathematical model. Input data consisted of age, smoker status, type of tooth brush, brushing, and consumption of pickled food, fizzy drinks, orange, apple, lemon, and dried seeds. Output data were the sum of tooth surface loss scores for selected teeth. The optimized constructed ANN consisted of 2-layer network with 15 neurons in the first layer and one neuron in the second layer. The data of 46 subjects were used to build the model, while the data of 15 subjects were used to test the model. Accepting an error of ±5 scores for all chosen teeth, the accuracy of the network becomes more than 80%. In conclusion, this study shows that modeling tooth surface loss using ANNs is possible and can be achieved with a high degree of accuracy.

  18. A Visualization Methodology for Characterization of Network Scans

    Energy Technology Data Exchange (ETDEWEB)

    Muelder, C W; Ma, K; Bartoletti, A

    2005-12-15

    Many methods have been developed for monitoring network traffic, both using visualization and statistics. Most of these methods focus on the detection of suspicious or malicious activities. But what they often fail to do refine and exercise measures that contribute to the characterization of such activities and their sources, once they are detected. In particular, many tools exist that detect network scans or visualize them at a high level, but not very many tools exist that are capable of categorizing and analyzing network scans. This paper presents a means of facilitating the process of characterization by using visualization and statistics techniques to analyze the patterns found in the timing of network scans through a method of continuous improvement in measures that serve to separate the components of interest in the characterization so the user can control separately for the effects of attack tool employed, performance characteristics of the attack platform, and the effects of network routing in the arrival patterns of hostile probes. The end result is a system that allows large numbers of network scans to be rapidly compared and subsequently identified.

  19. Stabilization of a Wireless Networked Control System with Packet Loss and Time Delay: An ADS Approach

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2012-01-01

    Full Text Available The stabilization problem of a wireless networked control system is considered in this paper. Both time delay and packet loss exist simultaneously in the wireless network. The system is modeled as an asynchronous dynamic system (ADS with unstable subsystems. A sufficient condition for the system to be stable is presented. A numerical example is given to demonstrate the effectiveness of the proposed approach.

  20. A Paradox in a Queueing Network with State-Dependent Routing and Loss

    Directory of Open Access Journals (Sweden)

    Ilze Ziedins

    2007-01-01

    Full Text Available Consider a network of parallel finite tandem queues with two stages, where each arrival attempts to minimize its own cost due to loss. It is known that the user optimal and asymptotic system optimal policies may differ—we give examples showing that they may differ for finite systems and that as the service rate is increased at the second stage the user optimal policy may change in such a way that the total expected cost due to loss increases.

  1. Characterization of the Weatherization Assistance Program network. Weatherization Assistance Program

    Energy Technology Data Exchange (ETDEWEB)

    Mihlmester, P.E.; Koehler, W.C. Jr.; Beyer, M.A. [Aspen Systems Corp., Oak Ridge, TN (United States). Applied Management Sciences Div.; Brown, M.A. [Oak Ridge National Lab., TN (United States); Beschen, D.A. Jr. [Department of Energy, Washington, DC (United States). Office of Weatherization Assistance Programs

    1992-02-01

    The Characterization of the Weatherization Assistance Program (WAP) Network was designed to describe the national network of State and local agencies that provide WAP services to qualifying low-income households. The objective of this study was to profile the current WAP network. To achieve the objective, two national surveys were conducted: one survey collected data from 49 State WAP agencies (including the coterminous 48 States and the District of Columbia), and the second survey collected data from 920 (or 81 percent) of the local WAP agencies.

  2. An Experimental Exploration of the Impact of Network-Level Packet Loss on Network Intrusion Detection

    Science.gov (United States)

    2015-08-01

    packet loss is very common on the Internet. The Transmission Control Protocol ( TCP ) is specifically designed to account for general packet loss and uses...normal congestion control behavior”.4 Although generalized packet loss is not the focus of this research because it is assumed that the target and...datasets and generate and validate a general function. 10 6. References 1. Stevens WR. TCP slow start, congestion avoidance, fast retransmit, and

  3. Weight loss social support in 140 characters or less: use of an online social network in a remotely delivered weight loss intervention.

    Science.gov (United States)

    Turner-McGrievy, Gabrielle M; Tate, Deborah F

    2013-09-01

    Little is known about how online social networking can help enhance weight loss. To examine the types of online social support utilized in a behavioral weight loss intervention and relationship of posting and weight loss. A sub-analysis of the content and number of posts to Twitter among participants (n = 47) randomized to a mobile, social network arm as part of a 6-month trial among overweight adults, examining weight loss, use of Twitter, and type of social support (informational, tangible assistance, esteem, network, and emotional support). A number of Twitter posts were related to % weight loss at 6 months (p status update (n = 1,319). Engagement with Twitter was related to weight loss and participants mainly used Twitter to provide Information support to one another through status updates.

  4. Leakage Detection and Estimation Algorithm for Loss Reduction in Water Piping Networks

    Directory of Open Access Journals (Sweden)

    Kazeem B. Adedeji

    2017-10-01

    Full Text Available Water loss through leaking pipes constitutes a major challenge to the operational service of water utilities. In recent years, increasing concern about the financial loss and environmental pollution caused by leaking pipes has been driving the development of efficient algorithms for detecting leakage in water piping networks. Water distribution networks (WDNs are disperse in nature with numerous number of nodes and branches. Consequently, identifying the segment(s of the network and the exact leaking pipelines connected to this segment(s where higher background leakage outflow occurs is a challenging task. Background leakage concerns the outflow from small cracks or deteriorated joints. In addition, because they are diffuse flow, they are not characterised by quick pressure drop and are not detectable by measuring instruments. Consequently, they go unreported for a long period of time posing a threat to water loss volume. Most of the existing research focuses on the detection and localisation of burst type leakages which are characterised by a sudden pressure drop. In this work, an algorithm for detecting and estimating background leakage in water distribution networks is presented. The algorithm integrates a leakage model into a classical WDN hydraulic model for solving the network leakage flows. The applicability of the developed algorithm is demonstrated on two different water networks. The results of the tested networks are discussed and the solutions obtained show the benefits of the proposed algorithm. A noteworthy evidence is that the algorithm permits the detection of critical segments or pipes of the network experiencing higher leakage outflow and indicates the probable pipes of the network where pressure control can be performed. However, the possible position of pressure control elements along such critical pipes will be addressed in future work.

  5. Characterizing naval team readiness through social network analysis

    OpenAIRE

    Schraagen, J.M.C.; Post, W.M.

    2014-01-01

    Characterizing a team’s level of readiness in an efficient and objective way is important for organizations such as the military. Current methods to characterize real-time team interaction know limitations that may be addressed by social network analysis techniques. The purpose of the current field study was to investigate the usefulness of these techniques by applying them to two naval teams, one more experienced than the other. We observed how these teams responded during an actual training...

  6. Characterization of EGS Fracture Network Lifecycles

    Energy Technology Data Exchange (ETDEWEB)

    Gillian R. Foulger

    2008-03-31

    Geothermal energy is relatively clean, and is an important non-hydrocarbon source of energy. It can potentially reduce our dependence on fossil fuels and contribute to reduction in carbon emissions. High-temperature geothermal areas can be used for electricity generation if they contain permeable reservoirs of hot water or steam that can be extracted. The biggest challenge to achieving the full potential of the nation’s resources of this kind is maintaining and creating the fracture networks required for the circulation, heating, and extraction of hot fluids. The fundamental objective of the present research was to understand how fracture networks are created in hydraulic borehole injection experiments, and how they subsequently evolve. When high-pressure fluids are injected into boreholes in geothermal areas, they flow into hot rock at depth inducing thermal cracking and activating critically stressed pre-existing faults. This causes earthquake activity which, if monitored, can provide information on the locations of the cracks formed, their time-development and the type of cracking underway, e.g., whether shear movement on faults occurred or whether cracks opened up. Ultimately it may be possible to monitor the critical earthquake parameters in near-real-time so the information can be used to guide the hydraulic injection while it is in progress, e.g., how to adjust factors such as injectate pressure, volume and temperature. In order to achieve this, it is necessary to mature analysis techniques and software that were, at the start of this project, in an embryonic developmental state. Task 1 of the present project was to develop state-of-the-art techniques and software for calculating highly accurate earthquake locations, earthquake source mechanisms (moment tensors) and temporal changes in reservoir structure. Task 2 was to apply the new techniques to hydrofracturing (Enhanced Geothermal Systems, or “EGS”) experiments performed at the Coso geothermal field

  7. Parameter-free Network Sparsification and Data Reduction by Minimal Algorithmic Information Loss

    KAUST Repository

    Zenil, Hector

    2018-02-16

    The study of large and complex datasets, or big data, organized as networks has emerged as one of the central challenges in most areas of science and technology. Cellular and molecular networks in biology is one of the prime examples. Henceforth, a number of techniques for data dimensionality reduction, especially in the context of networks, have been developed. Yet, current techniques require a predefined metric upon which to minimize the data size. Here we introduce a family of parameter-free algorithms based on (algorithmic) information theory that are designed to minimize the loss of any (enumerable computable) property contributing to the object\\'s algorithmic content and thus important to preserve in a process of data dimension reduction when forcing the algorithm to delete first the least important features. Being independent of any particular criterion, they are universal in a fundamental mathematical sense. Using suboptimal approximations of efficient (polynomial) estimations we demonstrate how to preserve network properties outperforming other (leading) algorithms for network dimension reduction. Our method preserves all graph-theoretic indices measured, ranging from degree distribution, clustering-coefficient, edge betweenness, and degree and eigenvector centralities. We conclude and demonstrate numerically that our parameter-free, Minimal Information Loss Sparsification (MILS) method is robust, has the potential to maximize the preservation of all recursively enumerable features in data and networks, and achieves equal to significantly better results than other data reduction and network sparsification methods.

  8. A Recursive Solution for Power-Transmission Loss in DC-Powered Networks

    Directory of Open Access Journals (Sweden)

    Sehwan Kim

    2014-11-01

    Full Text Available This article presents a recursive solution to the power-transmission loss in DC-powered networks. In such a network, the load cannot be modeled as a fixed equivalent resistance value, since the switching regulator may draw more or less current based on the actual supply voltage to meet the power demand. Although the power-transmission loss itself is simply I2 RL, I, in turn, depends on the load’s supply voltage, which, in turn, depends on I, making it impossible to derive a closed-form solution by classical resistive network analysis in general. The proposed approach is to first derive a closed-form solution to I in the one-node topology using the quadratic formula. Next, we extend our solution to a locally daisy-chained (LDC network, where the network is readily decomposable into stages, such that the solution combines the closed-form formula for the current stage with the recursive solution for the subsequent stages. We then generalize the LDC topology to trees. In practice, the solution converges quickly after a small number of iterations. It has been validated on real-life networks, such as power over controller area network (PoCAN.

  9. Analysis of naming game over networks in the presence of memory loss

    Science.gov (United States)

    Fu, Guiyuan; Cai, Yunze; Zhang, Weidong

    2017-08-01

    In this paper, we study the dynamics of naming game where individuals are under the influence of memory loss. An extended naming game incorporating memory loss is proposed. Different from the existing naming game models, the individual in the proposed model would forget some words with a probability in his memory during interaction and keep his conveyed word unchanged until he reaches a local agreement. We analyze the dynamics of the proposed model through extensive and comprehensive simulations, where four typical networks with different configuration are employed. The influence of memory loss as well as the population size on the performance of the proposed model is investigated. The simulation results show that (i) the stronger memory loss, the larger convergence time; (ii) as the strength of memory loss becomes stronger, maximum number of total words will decrease, while the maximum number of different words among the population remains almost unchanged; (iii) the maximum number of different words increases linearly with the increase of the population size and coincides with each other under different strength of memory loss. The findings in the proposed model may give an insight to understand better the influence of memory loss on the transient dynamics of language evolution and opinion formation over networks.

  10. Optimizing the District Heating Primary Network from the Perspective of Economic-Specific Pressure Loss

    Directory of Open Access Journals (Sweden)

    Haichao Wang

    2017-07-01

    Full Text Available A district heating (DH system is one of the most important components of infrastructures in cold areas. Proper DH network design should balance the initial investment and the heat distribution cost of the DH network. Currently, this design is often based on a recommended value for specific pressure loss (R = ∆P/L in the main lines. This will result in a feasible network design, but probably not be optimal in most cases. The paper develops a novel optimization model to facilitate the design by considering the initial investment in the pipes and the heat distribution costs. The model will generate all possible network scenarios consisting of different series of diameters for each pipe in the flow direction of the network. Then, the annuity on the initial investment, the heat distribution cost, and the total annual cost will be calculated for each network scenario, taking into account the uncertainties of the material prices and the yearly operating time levels. The model is applied to a sample DH network and the results indicate that the model works quite well, clearly identifying the optimal network design and demonstrating that the heat distribution cost is more important than the initial investment in DH network design.

  11. Using Tutte polynomials to characterize sexual contact networks

    Science.gov (United States)

    Cadavid Muñoz, Juan José

    2014-06-01

    Tutte polynomials are used to characterize the dynamic and topology of the sexual contact networks, in which pathogens are transmitted as an epidemic. Tutte polynomials provide an algebraic characterization of the sexual contact networks and allow the projection of spread control strategies for sexual transmission diseases. With the usage of Tutte polynomials, it allows obtaining algebraic expressions for the basic reproductive number of different pathogenic agents. Computations are done using the computer algebra software Maple, and it's GraphTheory Package. The topological complexity of a contact network is represented by the algebraic complexity of the correspondent polynomial. The change in the topology of the contact network is represented as a change in the algebraic form of the associated polynomial. With the usage of the Tutte polynomials, the number of spanning trees for each contact network can be obtained. From the obtained results in the polynomial form, it can be said that Tutte polynomials are of great importance for designing and implementing control measures for slowing down the propagation of sexual transmitted pathologies. As a future research line, the analysis of weighted sexual contact networks using weighted Tutte polynomials is considered.

  12. Site characterization of the national seismic network of Italy

    Science.gov (United States)

    Bordoni, Paola; Pacor, Francesca; Cultrera, Giovanna; Casale, Paolo; Cara, Fabrizio; Di Giulio, Giuseppe; Famiani, Daniela; Ladina, Chiara; PIschiutta, Marta; Quintiliani, Matteo

    2017-04-01

    The national seismic network of Italy (Rete Sismica Nazionale, RSN) run by Istituto Nazionale di Geofisica e Vulcanologia (INGV) consists of more than 400 seismic stations connected in real time to the institute data center in order to locate earthquakes for civil defense purposes. A critical issue in the performance of a network is the characterization of site condition at the recording stations. Recently INGV has started addressing this subject through the revision of all available geological and geophysical data, the acquisition of new information by means of ad-hoc field measurements and the analysis of seismic waveforms. The main effort is towards building a database, integrated with the other INGV infrastructures, designed to archive homogeneous parameters through the seismic network useful for a complete site characterization, including housing, geological, seismological and geotechnical features as well as the site class according to the European and Italian building codes. Here we present the ongoing INGV activities.

  13. Geometrical characterization of interconnected phase networks in three dimensions

    DEFF Research Database (Denmark)

    Jørgensen, Peter Stanley; Hansen, Karin Vels; Larsen, Rasmus

    2011-01-01

    samples to be made. The methods characterize tortuosity, path diameters, the novel dead ends property and a particle shape independent alternative to a particle size distribution. The parameters are calculated by the computation of arrival time maps by the fast marching method. The methods are applied....... We present several general methods for quantitative characterization of network structures without prior assumptions of shape or application. The characterization is performed by extracting distributions of values rather than single value descriptions, thus allowing more detailed comparisons between...... to the analysis of each of the three phases in a solid oxide fuel cell sample....

  14. Damage and Loss Estimation for Natural Gas Networks: The Case of Istanbul

    Science.gov (United States)

    Çaktı, Eser; Hancılar, Ufuk; Şeşetyan, Karin; Bıyıkoǧlu, Hikmet; Şafak, Erdal

    2017-04-01

    Natural gas networks are one of the major lifeline systems to support human, urban and industrial activities. The continuity of gas supply is critical for almost all functions of modern life. Under natural phenomena such as earthquakes and landslides the damages to the system elements may lead to explosions and fires compromising human life and damaging physical environment. Furthermore, the disruption in the gas supply puts human activities at risk and also results in economical losses. This study is concerned with the performance of one of the largest natural gas distribution systems in the world. Physical damages to Istanbul's natural gas network are estimated under the most recent probabilistic earthquake hazard models available, as well as under simulated ground motions from physics based models. Several vulnerability functions are used in modelling damages to system elements. A first-order assessment of monetary losses to Istanbul's natural gas distribution network is also attempted.

  15. Observer-based H(infinity) control for networked nonlinear systems with random packet losses.

    Science.gov (United States)

    Li, Jian Guo; Yuan, Jing Qi; Lu, Jun Guo

    2010-01-01

    This paper investigates the observer-based H(infinity) control problem of networked nonlinear systems with global Lipschitz nonlinearities and random communication packet losses. The random packet loss is modelled as a Bernoulli distributed white sequence with a known conditional probability distribution. In the presence of random packet losses, sufficient conditions for the existence of an observer-based feedback controller are derived, such that the closed-loop networked nonlinear system is exponentially stable in the mean-square sense, and a prescribed H(infinity) disturbance-rejection-attenuation performance is also achieved. Then a linear matrix inequality (LMI) approach for designing such an observer-based H(infinity) controller is presented. Finally, a simulation example is used to demonstrate the effectiveness of the proposed method. 2009. Published by Elsevier Ltd.

  16. Application of Network Analysis for Characterizing Service Modularity

    DEFF Research Database (Denmark)

    Frandsen, Thomas

    2012-01-01

    The purpose of this paper is to explore the potential of the application of network analytical techniques to identify and characterize modularity of service processes. Services can be conceptualized as systems of interrelated components which can be decomposed in order to achieve a modular design....... The paper is based on a network theory perspective to the quantification and visualization of service process architectures. Metrics are considered in order to evaluate their usefulness for academics and practitioners interested in understanding service system design. The paper suggests a number of metrics...... of importance for evaluating components and their interrelationships in service systems....

  17. Impact of stand-by energy losses in electronic devices on smart network performance

    Directory of Open Access Journals (Sweden)

    Mandić-Lukić Jasmina S.

    2012-01-01

    Full Text Available Limited energy resources and environmental concerns due to ever increasing energy consumption, more and more emphasis is being put on energy savings. Smart networks are promoted worldwide as a powerful tool used to improve the energy efficiency through consumption management, as well as to enable the distributed power generation, primarily based on renewable energy sources, to be optimally explored. To make it possible for the smart networks to function, a large number of electronic devices is needed to operate or to be in their stand-by mode. The consumption of these devices is added to the consumption of many other electronic devices already in use in households and offices, thus giving rise to the overall power consumption and threatening to counteract the primary function of smart networks. This paper addresses the consumption of particular electronic devices, with an emphasis placed on their thermal losses when in stand-by mode and their total share in the overall power consumption in certain countries. The thermal losses of electronic devices in their stand-by mode are usually neglected, but it seems theoretically possible that a massive increase in their number can impact net performance of the future smart networks considerably so that above an optimum level of energy savings achieved by their penetration, total consumption begins to increase. Based on the current stand-by energy losses from the existing electronic devices, we propose that the future penetration of smart networks be optimized taking also into account losses from their own electronic devices, required to operate in stand-by mode.

  18. Characterizing complex networks through statistics of Möbius transformations

    Science.gov (United States)

    Jaćimović, Vladimir; Crnkić, Aladin

    2017-04-01

    It is well-known now that dynamics of large populations of globally (all-to-all) coupled oscillators can be reduced to low-dimensional submanifolds (WS transformation and OA ansatz). Marvel et al. (2009) described an intriguing algebraic structure standing behind this reduction: oscillators evolve by the action of the group of Möbius transformations. Of course, dynamics in complex networks of coupled oscillators is highly complex and not reducible. Still, closer look unveils that even in complex networks some (possibly overlapping) groups of oscillators evolve by Möbius transformations. In this paper, we study properties of the network by identifying Möbius transformations in the dynamics of oscillators. This enables us to introduce some new (statistical) concepts that characterize the network. In particular, the notion of coherence of the network (or subnetwork) is proposed. This conceptual approach is meaningful for the broad class of networks, including those with time-delayed, noisy or mixed interactions. In this paper, several simple (random) graphs are studied illustrating the meaning of the concepts introduced in the paper.

  19. Calculation of transmission system losses for the Taiwan Power Company by the artificial neural network with time decayed weight

    Energy Technology Data Exchange (ETDEWEB)

    Chu, W.C.; Chen, B.K.; Mo, P.C. [Tatung Inst. of Tech., Taipei (Taiwan, Province of China)

    1995-12-31

    For energy conservation and improvement of power system operation efficiency, how to reduce the transmission system losses becomes an important topic of grave concern. To understand the cause, and to evaluate the amount, of the losses are the prior steps to diminish them. To simplify the evaluation procedure without losing too much accuracy, this paper adopts the artificial neural network, which is a model free network, to analyze the transmission system losses. As the artificial neural network with time decayed weight has the capability of learning, memorizing, and forgetting, it is more suitable for a power system with gradually changing characteristics. By using this artificial neural network, the estimation of transmission system losses will be more precise. In this paper, comparison will be made between the results of artificial neural network analysis and polynomial loss equations analysis.

  20. Loss of integrity and atrophy in cingulate structural covariance networks in Parkinson's disease.

    Science.gov (United States)

    de Schipper, Laura J; van der Grond, Jeroen; Marinus, Johan; Henselmans, Johanna M L; van Hilten, Jacobus J

    2017-01-01

    In Parkinson's disease (PD), the relation between cortical brain atrophy on MRI and clinical progression is not straightforward. Determination of changes in structural covariance networks - patterns of covariance in grey matter density - has shown to be a valuable technique to detect subtle grey matter variations. We evaluated how structural network integrity in PD is related to clinical data. 3 Tesla MRI was performed in 159 PD patients. We used nine standardized structural covariance networks identified in 370 healthy subjects as a template in the analysis of the PD data. Clinical assessment comprised motor features (Movement Disorder Society-Unified Parkinson's Disease Rating Scale; MDS-UPDRS motor scale) and predominantly non-dopaminergic features (SEverity of Non-dopaminergic Symptoms in Parkinson's Disease; SENS-PD scale: postural instability and gait difficulty, psychotic symptoms, excessive daytime sleepiness, autonomic dysfunction, cognitive impairment and depressive symptoms). Voxel-based analyses were performed within networks significantly associated with PD. The anterior and posterior cingulate network showed decreased integrity, associated with the SENS-PD score, p = 0.001 (β = - 0.265, ηp2 = 0.070) and p = 0.001 (β = - 0.264, ηp2 = 0.074), respectively. Of the components of the SENS-PD score, cognitive impairment and excessive daytime sleepiness were associated with atrophy within both networks. We identified loss of integrity and atrophy in the anterior and posterior cingulate networks in PD patients. Abnormalities of both networks were associated with predominantly non-dopaminergic features, specifically cognition and excessive daytime sleepiness. Our findings suggest that (components of) the cingulate networks display a specific vulnerability to the pathobiology of PD and may operate as interfaces between networks involved in cognition and alertness.

  1. Neural-network-based single-sided non-enwrapping power loss tester

    CERN Document Server

    Passadis, K; Beckley, P

    2003-01-01

    It is preferable to be able to assess the power loss of electrical steels during production. When a single-sided tester is used, flux sensing is undertaken from one side only and hence some leakage flux above the strip may not captured by the sensing coils. Therefore, the disadvantage of a single-sided non-enwrapping tester lies in the measurement of the flux density in the material. A neural network was successfully used to 'predict' the correct level of flux density for accurate assessment of power loss.

  2. Validation of Tilt Gain under Realistic Path Loss Model and Network Scenario

    DEFF Research Database (Denmark)

    Nguyen, Huan Cong; Rodriguez, Ignacio; Sørensen, Troels Bundgaard

    2013-01-01

    Despite being a simple and commonly-applied radio optimization technique, the impact on practical network performance from base station antenna downtilt is not well understood. Most published studies based on empirical path loss models report tilt angles and performance gains that are far higher...... than practical experience suggests. We motivate in this paper, based on a practical LTE scenario, that the discrepancy partly lies in the path loss model, and shows that a more detailed semi-deterministic model leads to both lower gains in terms of SINR, outage probability and downlink throughput...... and lower optimum tilt settings. Furthermore, we show that a simple geometrically based tilt optimization algorithm can outperform other tilt profiles, including the setting applied by the cellular operator in the specific case. In general, the network performance is not highly sensitive to the tilt...

  3. Specialization and rarity predict nonrandom loss of interactions from mutualist networks.

    Science.gov (United States)

    Aizen, Marcelo A; Sabatino, Malena; Tylianakis, Jason M

    2012-03-23

    The loss of interactions from mutualistic networks could foreshadow both plant and animal species extinctions. Yet, the characteristics of interactions that predispose them to disruption are largely unknown. We analyzed 12 pollination webs from isolated hills ("sierras"), in Argentina, ranging from tens to thousands of hectares. We found evidence of nonrandom loss of interactions with decreasing sierra size. Low interaction frequency and high specialization between interacting partners contributed additively to increase the vulnerability of interactions to disruption. Interactions between generalists in the largest sierras were ubiquitous across sierras, but many of them lost their central structural role in the smallest sierras. Thus, particular configurations of interaction networks, along with unique ecological relations and evolutionary pathways, could be lost forever after habitat reduction.

  4. The loss of efficiency caused by agents' uncoordinated routing in transport networks.

    Directory of Open Access Journals (Sweden)

    Zhongzhi Xu

    Full Text Available Large-scale daily commuting data were combined with detailed geographical information system (GIS data to analyze the loss of transport efficiency caused by drivers' uncoordinated routing in urban road networks. We used Price of Anarchy (POA to quantify the loss of transport efficiency and found that both volume and distribution of human mobility demand determine the POA. In order to reduce POA, a small number of highways require considerable decreases in traffic, and their neighboring arterial roads need to attract more traffic. The magnitude of the adjustment in traffic flow can be estimated using the fundamental measure traffic flow only, which is widely available and easy to collect. Surprisingly, the most congested roads or the roads with largest traffic flow were not those requiring the most reduction of traffic. This study can offer guidance for the optimal control of urban traffic and facilitate improvements in the efficiency of transport networks.

  5. TCP-ADaLR: TCP with adaptive delay and loss response for broadband GEO satellite networks

    OpenAIRE

    Omueti, Modupe Omogbohun

    2007-01-01

    Transmission Control Protocol (TCP) performance degrades in broadband geostationary satellite networks due to long propagation delays and high bit error rates. In this thesis, we propose TCP with algorithm modifications for adaptive delay and loss response (TCP-ADaLR) to improve TCP performance. TCP-ADaLR incorporates delayed acknowledgement mechanism recommended for Internet hosts. We evaluate and compare the performance of TCP-ADaLR, TCP SACK, and TCP NewReno, with and without delayed ackno...

  6. Development and Efficacy Testing of a Social Network-Based Competitive Application for Weight Loss.

    Science.gov (United States)

    Lee, Jisan; Kim, Jeongeun

    2016-05-01

    Although a lot of people continuously try to lose weight, the obesity rate has remained high: 36.9% of males and 38.0% of females worldwide in 2013. This suggests the need for a new intervention. In this study, we designed a smartphone application, With U, to aid weight loss by using an offline social network of friends and an online social network, Facebook. To determine the effects of With U, this study was designed as a one-group pretest-posttest design. Overweight, obese, and severely obese adults 20-40 years old, along with their friends, participated in this study. A total of 10 pairs attempted to lose weight for 4 weeks. We used a questionnaire to measure general characteristics, motivation, and intent to continue to use With U, and the Inbody720 (Biospace, Seoul, Republic of Korea) body composition analyzer was used to measure physical characteristics. In addition, we briefly interviewed the participants about their experience. We observed statistically significant effects in terms of motivation to lose weight and the amount of weight loss. Changes in physical characteristics beyond weight loss also showed positive trends. Also, we discovered some interesting facts during the interviews. The weight loss effect was greater when the team members met more and the relationship between the challengers was more direct and intimate. The application With U, designed and developed to allow friends to challenge each other to lose weight, affected both motivation to lose weight and the amount of weight loss. In the future, effects of smartphone applications for health management with social networks need to be studied further.

  7. Impact of indoor environment on path loss in body area networks.

    Science.gov (United States)

    Hausman, Sławomir; Januszkiewicz, Łukasz

    2014-10-20

    In this paper the influence of an example indoor environment on narrowband radio channel path loss for body area networks operating around 2.4 GHz is investigated using computer simulations and on-site measurements. In contrast to other similar studies, the simulation model included both a numerical human body phantom and its environment-room walls, floor and ceiling. As an example, radio signal attenuation between two different configurations of transceivers with dipole antennas placed in a direct vicinity of a human body (on-body scenario) is analyzed by computer simulations for several types of reflecting environments. In the analyzed case the propagation environments comprised a human body and office room walls. As a reference environment for comparison, free space with only a conducting ground plane, modelling a steel mesh reinforced concrete floor, was chosen. The transmitting and receiving antennas were placed in two on-body configurations chest-back and chest-arm. Path loss vs. frequency simulation results obtained using Finite Difference Time Domain (FDTD) method and a multi-tissue anthropomorphic phantom were compared to results of measurements taken with a vector network analyzer with a human subject located in an average-size empty cuboidal office room. A comparison of path loss values in different environments variants gives some qualitative and quantitative insight into the adequacy of simplified indoor environment model for the indoor body area network channel representation.

  8. Impact of Indoor Environment on Path Loss in Body Area Networks

    Science.gov (United States)

    Hausman, Sławomir; Januszkiewicz, Łukasz

    2014-01-01

    In this paper the influence of an example indoor environment on narrowband radio channel path loss for body area networks operating around 2.4 GHz is investigated using computer simulations and on-site measurements. In contrast to other similar studies, the simulation model included both a numerical human body phantom and its environment—room walls, floor and ceiling. As an example, radio signal attenuation between two different configurations of transceivers with dipole antennas placed in a direct vicinity of a human body (on-body scenario) is analyzed by computer simulations for several types of reflecting environments. In the analyzed case the propagation environments comprised a human body and office room walls. As a reference environment for comparison, free space with only a conducting ground plane, modelling a steel mesh reinforced concrete floor, was chosen. The transmitting and receiving antennas were placed in two on-body configurations chest–back and chest–arm. Path loss vs. frequency simulation results obtained using Finite Difference Time Domain (FDTD) method and a multi-tissue anthropomorphic phantom were compared to results of measurements taken with a vector network analyzer with a human subject located in an average-size empty cuboidal office room. A comparison of path loss values in different environments variants gives some qualitative and quantitative insight into the adequacy of simplified indoor environment model for the indoor body area network channel representation. PMID:25333289

  9. Impact of Indoor Environment on Path Loss in Body Area Networks

    Directory of Open Access Journals (Sweden)

    Sławomir Hausman

    2014-10-01

    Full Text Available In this paper the influence of an example indoor environment on narrowband radio channel path loss for body area networks operating around 2.4 GHz is investigated using computer simulations and on-site measurements. In contrast to other similar studies, the simulation model included both a numerical human body phantom and its environment—room walls, floor and ceiling. As an example, radio signal attenuation between two different configurations of transceivers with dipole antennas placed in a direct vicinity of a human body (on-body scenario is analyzed by computer simulations for several types of reflecting environments. In the analyzed case the propagation environments comprised a human body and office room walls. As a reference environment for comparison, free space with only a conducting ground plane, modelling a steel mesh reinforced concrete floor, was chosen. The transmitting and receiving antennas were placed in two on-body configurations chest–back and chest–arm. Path loss vs. frequency simulation results obtained using Finite Difference Time Domain (FDTD method and a multi-tissue anthropomorphic phantom were compared to results of measurements taken with a vector network analyzer with a human subject located in an average-size empty cuboidal office room. A comparison of path loss values in different environments variants gives some qualitative and quantitative insight into the adequacy of simplified indoor environment model for the indoor body area network channel representation.

  10. On the Highly Stable Performance of Loss-Free Optical Burst Switching Networks

    Directory of Open Access Journals (Sweden)

    Milos Kozak

    2016-01-01

    Full Text Available Increase of bandwidth demand in data networks, driven by the continuous growth of the Internet and the increase of bandwidth greedy applications, raise the issue of how to support all the bandwidth requirements in the near future. Three optical switching paradigms have been defined and are being investigated: Optical Circuit Switching (OCS; Optical Packet Switching (OPS; and Optical Burst Switching (OBS. Among these paradigms, OBS is seen as the most appropriate solution today. However, OBS suffers from high burst loss as a result of contention in the bufferless mode of operation. This issue was investigated by Coutelen et al., 2009 who proposed the loss-free CAROBS framework whereby signal convertors of the optical signal to the electrical domain ensure electrical buffering. Convertors increase the network price which must be minimized to reduce the installation and operating costs of the CAROBS framework. An analysis capturing convertor requirements, with respect to the number of merging flows and CAROBS node offered load, was carried out. We demonstrated the convertor location significance, which led to an additional investigation of the shared wavelength convertors scenario. Shared wavelength convertors significantly decrease the number of required convertors and show great promise for CAROBS. Based on this study we can design a CAROBS network to contain a combination of simple and complex nodes that include none or some convertors respectively, a vital feature of network throughput efficiency and cost.

  11. Impact of the load curve on losses In the power supply network of the company

    Directory of Open Access Journals (Sweden)

    Я. Э. Шклярский

    2016-12-01

    Full Text Available In the recent years, the researchers and experts in the field of energetics often mention in their publications a need to reduce power transmission losses. Among different ways to accomplish this goal the method of the company load leveling stands out due to its simplicity, accessibility and efficiency. The paper proposes a new assessment factor for additional power losses in distribution network. It is known that dispersion of the load curve correlates with the amount of power losses, which is why the proposed factor is put in a position of dependency on the shape of the load curve of the company. It is demonstrated that the proposed factor can help to identify without any strain a need in technical measures for levelling the load curve of the company and to assess efficiency thereof.

  12. Geometrical characterization of interconnected phase networks in three dimensions.

    Science.gov (United States)

    Jørgensen, P S; Hansen, K V; Larsen, R; Bowen, J R

    2011-10-01

    In electrochemical devices such as fuel cells or batteries the microstructure is a determining factor for the performance of the device. To be able to optimize the microstructure it is important to be able to quantitatively measure key structural parameters, such that systematic studies can be made. We present several general methods for quantitative characterization of network structures without prior assumptions of shape or application. The characterization is performed by extracting distributions of values rather than single value descriptions, thus allowing more detailed comparisons between samples to be made. The methods characterize tortuosity, path diameters, the novel dead ends property and a particle shape independent alternative to a particle size distribution. The parameters are calculated by the computation of arrival time maps by the fast marching method. The methods are applied to the analysis of each of the three phases in a solid oxide fuel cell sample. © 2011 The Authors Journal of Microscopy © 2011 The Royal Microscopical Society.

  13. The effect of mild-to-moderate hearing loss on auditory and emotion processing networks

    Directory of Open Access Journals (Sweden)

    Fatima T Husain

    2014-02-01

    Full Text Available We investigated the impact of hearing loss on emotional processing using task- and rest-based functional magnetic resonance imaging. Two age-matched groups of middle-aged participants were recruited: one with bilateral high-frequency hearing loss (HL and a control group with normal hearing (NH. During the task-based portion of the experiment, participants were instructed to rate affective stimuli from the International Affective Digital Sounds database as pleasant, unpleasant, or neutral. In the resting state experiment, participants were told to fixate on a '+' sign on a screen for five minutes. The results of both the task-based and resting state studies suggest that NH and HL patients differ in their emotional response. Specifically, in the task-based study, we found slower response to affective but not neutral sounds by the HL group compared to the NH group. This was reflected in the brain activation patterns, with the NH group employing the expected limbic and auditory regions including the left amygdala, left parahippocampus, right middle temporal gyrus and left superior temporal gyrus to a greater extent in processing affective stimuli when compared to the HL group. In the resting state study, we observed no significant differences in connectivity of the auditory network between the groups. In the dorsal attention network, HL patients exhibited decreased connectivity between seed regions and left insula and left postcentral gyrus compared to controls. The default mode network was also altered, showing increased connectivity between seeds and left middle frontal gyrus in the HL group. Further targeted analysis revealed increased intrinsic connectivity between the right middle temporal gyrus and the right precentral gyrus. The results from both studies suggest neuronal reorganization as a consequence of hearing loss, most notably in networks responding to emotional sounds.

  14. Is Social Network Diversity Associated with Tooth Loss among Older Japanese Adults?

    Directory of Open Access Journals (Sweden)

    Jun Aida

    Full Text Available We sought to examine social network diversity as a potential determinant of oral health, considering size and contact frequency of the social network and oral health behaviors.Our cross-sectional study was based on data from the 2010 Japan Gerontological Evaluation Study. Data from 19,756 community-dwelling individuals aged 65 years or older were analyzed. We inquired about diversity of friendships based on seven types of friends. Ordered logistic regression models were developed to determine the association between the diversity of social networks and number of teeth (categorized as ≥20, 10-19, 1-9, and 0.Of the participants, 54.1% were women (mean age, 73.9 years; standard deviation, 6.2. The proportion of respondents with ≥20 teeth was 34.1%. After adjusting for age, sex, socioeconomic status (income, education, and occupation, marital status, health status (diabetes and mental health, and size and contact frequency of the social network, an increase in the diversity of social networks was significantly associated with having more teeth (odds ratio = 1.08; 95% confidence interval, 1.04-1.11. Even adjusted for oral health behaviors (smoking, curative/preventive dental care access, use of dental floss/fluoride toothpaste, significant association was still observed (odds ratio = 1.05 (95% confidence interval, 1.02-1.08.Social connectedness among people from diverse backgrounds may increase information channels and promote the diffusion of oral health behaviors and prevent tooth loss.

  15. Drooping as a simple characterization tool for extraction efficiency and optical losses in light emitting diodes

    Science.gov (United States)

    Oksanen, Jani; Tulkki, Jukka

    2010-09-01

    We extend the previous droop models developed for InGaN light emitting diodes (LEDs) by accounting for the light extraction and show that drooping can be used to quantify both the extraction efficiency and the optical losses in LEDs. Our model allows very simple characterization of LEDs by an integrating sphere and therefore provides an attractive characterization tool to measure the most important loss parameters of various LED structures. In particular, the approach allows evaluation of the effects of various optical losses and photon recycling on the efficiency and consequently allows more efficient optimization of the LED structures. As an additional benefit, our measurement method does not necessarily require any fitting of the data.

  16. Fracture network topology and characterization of structural permeability

    Science.gov (United States)

    Hansberry, Rowan; King, Rosalind; Holford, Simon

    2017-04-01

    other permeability indicators such as drilling fluid losses, and pore pressure measurements. Initial work with these techniques has led to new developments in our ability to image subsurface faults and fractures at a variety of scales from independent datasets. We establish a strong relationship between features identified using seismic attribute analysis and interpreted natural fractures. However, care must be taken to use these methods in a case-by-case basis, as controls on fracture distribution and orientation can vary significantly with both regional and local influences. These results outline and effective method by which structural permeability can be assessed with existing petroleum datasets. However, unlike the broad stress field, mapping fracture orientation and characteristics within the Australian Continent is complicated as the distribution, geometry, areal extent and connectivity of fracture networks can vary significantly.

  17. Multi-Relational Characterization of Dynamic Social Network Communities

    Science.gov (United States)

    Lin, Yu-Ru; Sundaram, Hari; Kelliher, Aisling

    The emergence of the mediated social web - a distributed network of participants creating rich media content and engaging in interactive conversations through Internet-based communication technologies - has contributed to the evolution of powerful social, economic and cultural change. Online social network sites and blogs, such as Facebook, Twitter, Flickr and LiveJournal, thrive due to their fundamental sense of "community". The growth of online communities offers both opportunities and challenges for researchers and practitioners. Participation in online communities has been observed to influence people's behavior in diverse ways ranging from financial decision-making to political choices, suggesting the rich potential for diverse applications. However, although studies on the social web have been extensive, discovering communities from online social media remains challenging, due to the interdisciplinary nature of this subject. In this article, we present our recent work on characterization of communities in online social media using computational approaches grounded on the observations from social science.

  18. Strong Attractors in Stochastic Adaptive Networks: Emergence and Characterization

    CERN Document Server

    Santos, Augusto Almeida; Krishnan, Ramayya; Moura, José M F

    2016-01-01

    We propose a family of models to study the evolution of ties in a network of interacting agents by reinforcement and penalization of their connections according to certain local laws of interaction. The family of stochastic dynamical systems, on the edges of a graph, exhibits \\emph{good} convergence properties, in particular, we prove a strong-stability result: a subset of binary matrices or graphs -- characterized by certain compatibility properties -- is a global almost sure attractor of the family of stochastic dynamical systems. To illustrate finer properties of the corresponding strong attractor, we present some simulation results that capture, e.g., the conspicuous phenomenon of emergence and downfall of leaders in social networks.

  19. Ammonia and greenhouse gases losses from mechanically turned cattle manure windrows: A regional composting network.

    Science.gov (United States)

    Arriaga, Haritz; Viguria, Maialen; López, Diana M; Merino, Pilar

    2017-12-01

    An on-farm composting network operates in the Basque Country (northern Spain), in which solid manure produced in livestock farms (mostly dairy and beef cattle) is composted through windrow turning. This network aims to produce a valuable resource (compost) for the farmers whereas the volume of the solid manure was reduced at farm level The objective of the study was to assess the gaseous losses (NH 3 and GHG) from 6 on-farm composting windrows (either deep litter systems or solid fraction after slurry separation) after turning operations. Monitored turning events occurred 1 to 4 months after establishing the heaps on the field. Ammonia and greenhouse gas (GHG) losses were estimated by the open and close chamber techniques, respectively. Results showed overall low emission rates related to the long degradation period of the windrows. Maximum NH 3 release was at 2.0 mg m -2 d -1 after the second/third turning events. Baseline N 2 O losses were below 50 mg m -2 d -1 , with maximum rates close to 500 mg m -2 d -1 some days after turning works. Methane emissions were mostly below 100 mg m -2 d -1 , while CO 2 losses were lower than 25 g m -2 d -1 . Carbon dioxide peaks (≈250 g m -2 d -1 ) were reached after the second/third turnings. Overall, gaseous N and C losses accounted for 0.1 and 1% of the initial N and C content of the windrows, respectively. The present study concluded that two/three turning operations in aged solid manure-derived compost windrows do not have significant effects on NH 3 and GHG losses. The magnitude of the gaseous losses from on-farm composting systems is dependent on the manure management practices at farm level (e.g. moment of windrow stacking). Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Quantifying the impact of road capacity loss on urban electrified transportation networks: An optimization based approach

    Directory of Open Access Journals (Sweden)

    Wei Wei

    2016-12-01

    Full Text Available The proliferation of electric vehicles and commercialization of public charging facilities have inspired the emerging trend of transportation electrification, which creates an urgent demand for systematic methodologies to analyze the performance of electrified transportation networks (ETNs while taking the interdependency across the transportation network and the power distribution network into account. This paper introduces a comprehensive mathematical formulation of the ETN from a system-level perspective, in which the steady-state distribution of the traffic flow is described by Wardrop user equilibrium, while the operating status of the power grid is characterized by a linearized branch power flow model. Moreover, this paper investigates the impact of road capacity degradation on the transportation network, which is quantified by the total vehicle travel time, as well as the power distribution network, which is quantified by the operating cost. The former gives rise to a nonlinear programming problem with complementarity constraints (NPCC, which is reformulated as a mixed integer linear program, thereby the global optimal solution can be found with moderate computational effort. The latter yields a max–min NPCC, which is transformed into an equivalent single-level NPCC; thus a commercial nonlinear solver is applicable to find a local solution. A derivative-free searching algorithm which relies on convex optimization is also suggested. Numerical case studies on a test system demonstrate the necessity of considering the intrinsic interdependency of the transportation and electricity infrastructures in designing and operating the ETN.

  1. Characterization of leadership styles by analyzing social networks

    Directory of Open Access Journals (Sweden)

    Enrique Saravia Vergara

    2015-12-01

    Full Text Available The study presents an analysis of networks to characterize the leadership styles in an institution volunteer, complementary or alternative to classic questionnaires to measure leadership. The study raises test questions to identify friendly relations and prominent leaders in the leadership dimensions of transformational, transactional and passive / avoidant and analyzes, for each of them, the metrics of the network structure as a whole and the role each individual actor. The study exploratory level, based on the opinion of 9 members of a specific project, allowed to show the benefits of network analysis applied to the subject of leadership: (i identified that the climate of "respect and trust", "enthusiasm" and "concern for the welfare of the people" dominate the organization; and (ii the individual role of each leader was identified. Three leaders who are considered as the best friends and care about the welfare of others were identified, but one of them stands for broadcasting "greater respect and trust" and is "an example to follow"; while the other two leaders stand out as being more "enthusiastic and optimistic" and "promote innovation and creativity," among other findings.

  2. Associations between sensory loss and social networks, participation, support, and loneliness: Analysis of the Canadian Longitudinal Study on Aging.

    Science.gov (United States)

    Mick, Paul; Parfyonov, Maksim; Wittich, Walter; Phillips, Natalie; Kathleen Pichora-Fuller, M

    2018-01-01

    To determine if hearing loss, vision loss, and dual sensory loss were associated with social network diversity, social participation, availability of social support, and loneliness, respectively, in a population-based sample of older Canadians and to determine whether age or sex modified the associations. Cross-sectional population-based study. Canada. The sample included 21 241 participants in the Canadian Longitudinal Study on Aging tracking cohort. The sample was nationally representative of English- and French-speaking, non-institutionalized 45- to 89-year-old Canadians who did not live on First Nations reserves and who had normal cognition. Participants with missing data for any of the variables in the multivariable regression models were excluded from analysis. Hearing and vision loss were determined by self-report. Dual sensory loss was defined as reporting both hearing and vision loss. Univariate analyses were performed to assess cross-sectional associations between hearing, vision, and dual sensory loss, and social, demographic, and medical variables. Multivariable regression models were used to analyze cross-sectional associations between each type of sensory loss and social network diversity, social participation, availability of social support, and loneliness. Vision loss (in men) and dual sensory loss (in 65- to 85-year-olds) were independently associated with reduced social network diversity. Vision loss and dual sensory loss (in 65- to 85-year-olds) were each independently associated with reduced social participation. All forms of sensory loss were associated with both low availability of social support and loneliness. Sensory impairment is associated with reduced social function in older Canadians. Interventions and research that address the social needs of older individuals with sensory loss are needed. Copyright© the College of Family Physicians of Canada.

  3. Synchrotron-Based in Situ Characterization of the Scaffold Mass Loss from Erosion Degradation

    Directory of Open Access Journals (Sweden)

    Nahshon K. Bawolin

    2016-07-01

    Full Text Available The mass loss behavior of degradable tissue scaffolds is critical to their lifespan and other degradation-related properties including mechanical strength and mass transport characteristics. This paper presents a novel method based on synchrotron imaging to characterize the scaffold mass loss from erosion degradation in situ, or without the need of extracting scaffolds once implanted. Specifically, the surface-eroding degradation of scaffolds in a degrading medium was monitored in situ by synchrotron-based imaging; and the time-dependent geometry of scaffolds captured by images was then employed to estimate their mass loss with time, based on the mathematical model that was adopted from the literature of surface erosion with the experimentally-identified model parameters. Acceptable agreement between experimental results and model predictions was observed for scaffolds in a cylindrical shape, made from poly(lactic-co-glycolic acid (PLGA and polycaprolactone (PCL. This study illustrates that geometry evaluation by synchrotron-based imaging is an effective means to in situ characterize the scaffold mass loss as well as possibly other degradation-related properties.

  4. Characterization of the dominant loss mechanisms in superconducting coplanar waveguide resonators

    Science.gov (United States)

    Calusine, Greg; Melville, Alexander; Woods, Wayne; Kim, David K.; Miloshi, Xhovalin; Sevi, Arjan; Yoder, Jonilyn; Oliver, William D.

    The characterization of losses in superconducting coplanar waveguide (CPW) resonators is commonly used as a surrogate means to probe relaxation in superconducting qubit capacitor structures. However, this method is complicated by device-to-device variations that result from a sensitivity to variations in fabrication processes, packaging, and measurement methods. We present results on characterizing ensembles of aluminum, niobium, and titanium nitride superconducting CPW resonators to determine the statistical significance of the effects of fabrication process changes on resonator intrinsic quality factor. Furthermore, we report progress on experiments aimed at determining the impact of other competing loss mechanisms such as vortex trapping, package coupling, and substrate loss. These results are then applied to the study of relaxation in superconducting qubits and investigations into the microscopic origins of surface losses. This research was funded in part by the Intelligence Advanced Research Projects Activity (IARPA). The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of IARPA or the US Government.

  5. Face-to-Face and Online Networks: College Students' Experiences in a Weight-Loss Trial.

    Science.gov (United States)

    Merchant, Gina; Weibel, Nadir; Pina, Laura; Griswold, William G; Fowler, James H; Ayala, Guadalupe X; Gallo, Linda C; Hollan, James; Patrick, Kevin

    2017-01-01

    This study aimed to understand how college students participating in a 2-year randomized controlled trial (Project SMART: Social and Mobile Approach to Reduce Weight; N = 404) engaged their social networks and used social and mobile technologies to try and lose weight. Participants in the present study (n = 20 treatment, n = 18 control) were approached after a measurement visit and administered semi-structured interviews. Interviews were analyzed using principles from grounded theory. Treatment group participants appreciated the timely support provided by the study and the integration of content across multiple technologies. Participants in both groups reported using non-study-designed apps to help them lose weight, and many participants knew one another outside of the study. Individuals talked about weight-loss goals with their friends face to face and felt accountable to follow through with their intentions. Although seeing others' success online motivated many, there was a range of perceived acceptability in talking about personal health-related information on social media. The findings from this qualitative study can inform intervention trials using social and mobile technologies to promote weight loss. For example, weight-loss trials should measure participants' use of direct-to-consumer technologies and interconnectivity so that treatment effects can be isolated and cross-contamination accounted for.

  6. Revisiting the Characterization of the Losses in Piezoelectric Materials from Impedance Spectroscopy at Resonance

    Directory of Open Access Journals (Sweden)

    Amador M. González

    2016-01-01

    Full Text Available Electronic devices using the piezoelectric effect contain piezoelectric materials: often crystals, but in many cases poled ferroelectric ceramics (piezoceramics, polymers or composites. On the one hand, these materials exhibit non-negligible losses, not only dielectric, but also mechanical and piezoelectric. In this work, we made simulations of the effect of the three types of losses in piezoelectric materials on the impedance spectrum at the resonance. We analyze independently each type of loss and show the differences among them. On the other hand, electrical and electronic engineers include piezoelectric sensors in electrical circuits to build devices and need electrical models of the sensor element. Frequently, material scientists and engineers use different languages, and the characteristic material coefficients do not have a straightforward translation to those specific electrical circuit components. To connect both fields of study, we propose the use of accurate methods of characterization from impedance measurements at electromechanical resonance that lead to determination of all types of losses, as an alternative to current standards. We introduce a simplified equivalent circuit model with electrical parameters that account for piezoceramic losses needed for the modeling and design of industrial applications.

  7. 3D characterization of rolling contact fatigue crack networks

    DEFF Research Database (Denmark)

    Jessop, Casey; Ahlström, Johan; Hammar, Lars

    2016-01-01

    , metallography, X-ray tomography, and topography measurements. The experiments were performed on squats from rail sections taken from the field. In the first method, high-resolution and high-energy X-ray images exposed through the entire rail head from a range of angles were combined using a semi-automated image...... was investigated by X-ray tomography after extraction of a section of the rail head. A third squat was opened by careful cutting, which gave full access to the crack faces, and the topography was measured by stylus profilometry. The high-energy X-ray, 3D reconstruction method showed accurate main crack geometry......-destructive detection techniques. After cutting out damaged sections of rail, there are a number of options to characterize the damage. The aim of this study was to evaluate different methods to geometrically describe squat crack networks; through X-ray radiography complemented with geometrical reconstruction...

  8. Characterization of Energy Availability in RF Energy Harvesting Networks

    Directory of Open Access Journals (Sweden)

    Daniela Oliveira

    2016-01-01

    Full Text Available The multiple nodes forming a Radio Frequency (RF Energy Harvesting Network (RF-EHN have the capability of converting received electromagnetic RF signals in energy that can be used to power a network device (the energy harvester. Traditionally the RF signals are provided by high power transmitters (e.g., base stations operating in the neighborhood of the harvesters. Admitting that the transmitters are spatially distributed according to a spatial Poisson process, we start by characterizing the distribution of the RF power received by an energy harvester node. Considering Gamma shadowing and Rayleigh fading, we show that the received RF power can be approximated by the sum of multiple Gamma distributions with different scale and shape parameters. Using the distribution of the received RF power, we derive the probability of a node having enough energy to transmit a packet after a given amount of charging time. The RF power distribution and the probability of a harvester having enough energy to transmit a packet are validated through simulation. The numerical results obtained with the proposed analysis are close to the ones obtained through simulation, which confirms the accuracy of the proposed analysis.

  9. Efficient Characterization of Parametric Uncertainty of Complex (Biochemical Networks.

    Directory of Open Access Journals (Sweden)

    Claudia Schillings

    2015-08-01

    Full Text Available Parametric uncertainty is a particularly challenging and relevant aspect of systems analysis in domains such as systems biology where, both for inference and for assessing prediction uncertainties, it is essential to characterize the system behavior globally in the parameter space. However, current methods based on local approximations or on Monte-Carlo sampling cope only insufficiently with high-dimensional parameter spaces associated with complex network models. Here, we propose an alternative deterministic methodology that relies on sparse polynomial approximations. We propose a deterministic computational interpolation scheme which identifies most significant expansion coefficients adaptively. We present its performance in kinetic model equations from computational systems biology with several hundred parameters and state variables, leading to numerical approximations of the parametric solution on the entire parameter space. The scheme is based on adaptive Smolyak interpolation of the parametric solution at judiciously and adaptively chosen points in parameter space. As Monte-Carlo sampling, it is "non-intrusive" and well-suited for massively parallel implementation, but affords higher convergence rates. This opens up new avenues for large-scale dynamic network analysis by enabling scaling for many applications, including parameter estimation, uncertainty quantification, and systems design.

  10. Characterizing Social Interaction in Tobacco-Oriented Social Networks: An Empirical Analysis

    National Research Council Canada - National Science Library

    Liang, Yunji; Zheng, Xiaolong; Zeng, Daniel Dajun; Zhou, Xingshe; Leischow, Scott James; Chung, Wingyan

    2015-01-01

    .... To reveal the impact of tobacco-related user-generated content, this paper characterizes user interaction and social influence utilizing social network analysis and information theoretic approaches...

  11. Loss of functional diversity and network modularity in introduced plant-fungal symbioses.

    Science.gov (United States)

    Dickie, Ian A; Cooper, Jerry A; Bufford, Jennifer L; Hulme, Philip E; Bates, Scott T

    2016-12-30

    The introduction of alien plants into a new range can result in the loss of co-evolved symbiotic organisms, such as mycorrhizal fungi, that are essential for normal plant physiological functions. Prior studies of mycorrhizal associations in alien plants have tended to focus on individual plant species on a case-by-case basis. This approach limits broad scale understanding of functional shifts and changes in interaction network structure that may occur following introduction. Here we use two extensive datasets of plant-fungal interactions derived from fungal sporocarp observations and recorded plant hosts in two island archipelago nations: New Zealand (NZ) and the United Kingdom (UK). We found that the NZ dataset shows a lower functional diversity of fungal hyphal foraging strategies in mycorrhiza of alien as compared with native trees. Across species this resulted in fungal foraging strategies associated with alien trees being much more variable in functional composition compared with native trees, which had a strikingly similar functional composition. The UK data showed no functional difference in fungal associates of alien and native plant genera. Notwithstanding this, both the NZ and UK data showed a substantial difference in interaction network structure of alien trees compared with native trees. In both cases, fungal associates of native trees showed strong modularity, while fungal associates of alien trees generally integrated into a single large module. The results suggest a lower functional diversity (in one dataset) and a simplification of network structure (in both) as a result of introduction, potentially driven by either limited symbiont co-introductions or disruption of habitat as a driver of specificity due to nursery conditions, planting, or plant edaphic-niche expansion. Recognizing these shifts in function and network structure has important implications for plant invasions and facilitation of secondary invasions via shared mutualist populations

  12. RF Path and Absorption Loss Estimation for Underwater Wireless Sensor Networks in Different Water Environments.

    Science.gov (United States)

    Qureshi, Umair Mujtaba; Shaikh, Faisal Karim; Aziz, Zuneera; Shah, Syed M Zafi S; Sheikh, Adil A; Felemban, Emad; Qaisar, Saad Bin

    2016-06-16

    Underwater Wireless Sensor Network (UWSN) communication at high frequencies is extremely challenging. The intricacies presented by the underwater environment are far more compared to the terrestrial environment. The prime reason for such intricacies are the physical characteristics of the underwater environment that have a big impact on electromagnetic (EM) signals. Acoustics signals are by far the most preferred choice for underwater wireless communication. Because high frequency signals have the luxury of large bandwidth (BW) at shorter distances, high frequency EM signals cannot penetrate and propagate deep in underwater environments. The EM properties of water tend to resist their propagation and cause severe attenuation. Accordingly, there are two questions that need to be addressed for underwater environment, first what happens when high frequency EM signals operating at 2.4 GHz are used for communication, and second which factors affect the most to high frequency EM signals. To answer these questions, we present real-time experiments conducted at 2.4 GHz in terrestrial and underwater (fresh water) environments. The obtained results helped in studying the physical characteristics (i.e., EM properties, propagation and absorption loss) of underwater environments. It is observed that high frequency EM signals can propagate in fresh water at a shallow depth only and can be considered for a specific class of applications such as water sports. Furthermore, path loss, velocity of propagation, absorption loss and the rate of signal loss in different underwater environments are also calculated and presented in order to understand why EM signals cannot propagate in sea water and oceanic water environments. An optimal solk6ution for underwater communication in terms of coverage distance, bandwidth and nature of communication is presented, along with possible underwater applications of UWSNs at 2.4 GHz.

  13. RF Path and Absorption Loss Estimation for Underwater Wireless Sensor Networks in Different Water Environments

    Directory of Open Access Journals (Sweden)

    Umair Mujtaba Qureshi

    2016-06-01

    Full Text Available Underwater Wireless Sensor Network (UWSN communication at high frequencies is extremely challenging. The intricacies presented by the underwater environment are far more compared to the terrestrial environment. The prime reason for such intricacies are the physical characteristics of the underwater environment that have a big impact on electromagnetic (EM signals. Acoustics signals are by far the most preferred choice for underwater wireless communication. Because high frequency signals have the luxury of large bandwidth (BW at shorter distances, high frequency EM signals cannot penetrate and propagate deep in underwater environments. The EM properties of water tend to resist their propagation and cause severe attenuation. Accordingly, there are two questions that need to be addressed for underwater environment, first what happens when high frequency EM signals operating at 2.4 GHz are used for communication, and second which factors affect the most to high frequency EM signals. To answer these questions, we present real-time experiments conducted at 2.4 GHz in terrestrial and underwater (fresh water environments. The obtained results helped in studying the physical characteristics (i.e., EM properties, propagation and absorption loss of underwater environments. It is observed that high frequency EM signals can propagate in fresh water at a shallow depth only and can be considered for a specific class of applications such as water sports. Furthermore, path loss, velocity of propagation, absorption loss and the rate of signal loss in different underwater environments are also calculated and presented in order to understand why EM signals cannot propagate in sea water and oceanic water environments. An optimal solk6ution for underwater communication in terms of coverage distance, bandwidth and nature of communication is presented, along with possible underwater applications of UWSNs at 2.4 GHz.

  14. Honey characterization using computer vision system and artificial neural networks.

    Science.gov (United States)

    Shafiee, Sahameh; Minaei, Saeid; Moghaddam-Charkari, Nasrollah; Barzegar, Mohsen

    2014-09-15

    This paper reports the development of a computer vision system (CVS) for non-destructive characterization of honey based on colour and its correlated chemical attributes including ash content (AC), antioxidant activity (AA), and total phenolic content (TPC). Artificial neural network (ANN) models were applied to transform RGB values of images to CIE L*a*b* colourimetric measurements and to predict AC, TPC and AA from colour features of images. The developed ANN models were able to convert RGB values to CIE L*a*b* colourimetric parameters with low generalization error of 1.01±0.99. In addition, the developed models for prediction of AC, TPC and AA showed high performance based on colour parameters of honey images, as the R(2) values for prediction were 0.99, 0.98, and 0.87, for AC, AA and TPC, respectively. The experimental results show the effectiveness and possibility of applying CVS for non-destructive honey characterization by the industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. A linear model for characterization of synchronization frequencies of neural networks.

    Science.gov (United States)

    Lv, Peili; Hu, Xintao; Lv, Jinglei; Han, Junwei; Guo, Lei; Liu, Tianming

    2014-02-01

    The synchronization frequency of neural networks and its dynamics have important roles in deciphering the working mechanisms of the brain. It has been widely recognized that the properties of functional network synchronization and its dynamics are jointly determined by network topology, network connection strength, i.e., the connection strength of different edges in the network, and external input signals, among other factors. However, mathematical and computational characterization of the relationships between network synchronization frequency and these three important factors are still lacking. This paper presents a novel computational simulation framework to quantitatively characterize the relationships between neural network synchronization frequency and network attributes and input signals. Specifically, we constructed a series of neural networks including simulated small-world networks, real functional working memory network derived from functional magnetic resonance imaging, and real large-scale structural brain networks derived from diffusion tensor imaging, and performed synchronization simulations on these networks via the Izhikevich neuron spiking model. Our experiments demonstrate that both of the network synchronization strength and synchronization frequency change according to the combination of input signal frequency and network self-synchronization frequency. In particular, our extensive experiments show that the network synchronization frequency can be represented via a linear combination of the network self-synchronization frequency and the input signal frequency. This finding could be attributed to an intrinsically-preserved principle in different types of neural systems, offering novel insights into the working mechanism of neural systems.

  16. Application of neural networks for the calculation of technical losses of electric energy in air power lines 6-35 kV

    Directory of Open Access Journals (Sweden)

    Володимир Леонідович Бакулевський

    2015-11-01

    Full Text Available A model for the calculation of technical losses of electricity in the air lines with voltage of 6-35 kV based on neural networks with due regard to meteorological factors has been worked out; the main components of the model have been considered and researched; the best ones being selected, that is: a set of input variables, volume of excerpts (training, control and testing, architecture and network activation function, network learning algorithm was proposed. Simulation was conducted in OS STATISTICA Neural Networks. Input variables are: transmission line (TL active load, transmission line rated voltage, transmission line cross section and length of wire, average air temperature, wind speed, rainfall availability; output variable – that is technical losses in electric transmission line. To select the optimal input vector model the data selection methods were used: variables testing using trial and error method, variables stepped inclusion and exclusion algorithm. It has been proved that the most important variables are TL active load and average air temperature. all input variables under review should be included in the created artificial neural network (ANN. It was determined that the optimal volume for ANN training set given parameters made 250 observations, control and test excerpts volume were respectively 250 and 332 observations. It has been proved that the best type of architecture is multilayer perceptron ANN that being compared to radial basis functions and generalized regression network is characterized by minimal errors and complexity of the network. ANN of the following architecture: multilayer perceptron, 7 neurons in the input layer, 5 neurons in the hidden layer, 1 output neuron, logistics as activation function – has been taken optimal

  17. Loss of Intra- and Inter-Network Resting State Functional Connections with Alzheimer’s Disease Progression

    Science.gov (United States)

    Brier, Mathew; Thomas, Jewell B.; Snyder, Abraham Z.; Benzinger, Tammie L.; Zhang, Dongyang; Raichle, Marcus E.; Holtzman, David M.; Morris, John C.; Ances, Beau M.

    2012-01-01

    Alzheimer’s disease (AD) is the most common cause of dementia. Much is known concerning AD pathophysiology but our understanding of the disease at the systems level remains incomplete. Previous AD research has used resting state functional connectivity magnetic resonance imaging (rs-fcMRI) to assess the integrity of functional networks within the brain. Most studies have focused on the default-mode network (DMN), a primary locus of AD pathology. However, other brain regions are inevitably affected with disease progression. We studied rs-fcMRI in five functionally defined brain networks within a large cohort of human participants of either gender (n=510) that ranged in AD severity from unaffected (clinical dementia rating, CDR 0) to very mild (CDR 0.5) to mild AD (CDR 1). We observed loss of correlations within not only the DMN but other networks at CDR 0.5. Within the salience network (SAL), increases were seen between CDR 0 and CDR 0.5. However, at CDR 1, all networks, including SAL, exhibited reduced correlations. Specific networks were preferentially affected at certain CDR stages. In addition, cross-network relations were consistently lost with increasing AD severity. Our results demonstrate that AD is associated with widespread loss of both intra- and inter-network correlations. These results provide insight into AD pathophysiology and reinforce an integrative view of the brain’s functional organization. PMID:22745490

  18. Characterization of the loss of the dislocation-free growth during Czochralski silicon pulling

    Science.gov (United States)

    Lanterne, Adeline; Gaspar, Guilherme; Hu, Yu; Øvrelid, Eivind; Di Sabatino, Marisa

    2017-01-01

    The loss of the dislocation-free growth (structure loss) during Czochralski (Cz) silicon pulling can have a strong negative impact on the production yield of the Cz photovoltaic industry. As almost no publication has been dedicated to this phenomenon in the past, this paper aims at investigate in detail the loss of the dislocation-free growth and its origin by characterizing an industrial-scale n-type Cz silicon ingot exhibiting such issue. After the occurrence of a perturbation, generation and propagation of slip dislocations in the already grown crystal have been observed. These dislocations, generated over the whole ingot cross-section, propagate with the solidification front during further growth. Additional small perturbations seem then to be responsible for their multiplication together with the transition to a multicrystalline structure. Investigations were conducted to find the perturbation causing the structure loss in the ingot. A pinhole, small gas bubble of 0.5 mm diameter, was identified as the main cause for the generation of dislocations.

  19. Cross-Characterization for Imaging Parasitic Resistive Losses in Thin-Film Photovoltaic Modules

    Directory of Open Access Journals (Sweden)

    Archana Sinha

    2016-08-01

    Full Text Available Thin-film photovoltaic (PV modules often suffer from a variety of parasitic resistive losses in transparent conductive oxide (TCO and absorber layers that significantly affect the module electrical performance. This paper presents the holistic investigation of resistive effects due to TCO lateral sheet resistance and shunts in amorphous-silicon (a-Si thin-film PV modules by simultaneous use of three different imaging techniques, electroluminescence (EL, lock-in thermography (LIT and light beam induced current (LBIC, under different operating conditions. Results from individual techniques have been compared and analyzed for particular type of loss channel, and combination of these techniques has been used to obtain more detailed information for the identification and classification of these loss channels. EL and LIT techniques imaged the TCO lateral resistive effects with different spatial sensitivity across the cell width. For quantification purpose, a distributed diode modeling and simulation approach has been exploited to estimate TCO sheet resistance from EL intensity pattern and effect of cell width on module efficiency. For shunt investigation, LIT provided better localization of severe shunts, while EL and LBIC given good localization of weak shunts formed by the scratches. The impact of shunts on the photocurrent generation capability of individual cells has been assessed by li-LBIC technique. Results show that the cross-characterization by different imaging techniques provides additional information, which aids in identifying the nature and severity of loss channels with more certainty, along with their relative advantages and limitations in particular cases.

  20. Characterizing and Predicting the Robustness of Power-law Networks

    CERN Document Server

    LaRocca, Sarah

    2013-01-01

    Power-law networks such as the Internet, terrorist cells, species relationships, and cellular metabolic interactions are susceptible to node failures, yet maintaining network connectivity is essential for network functionality. Disconnection of the network leads to fragmentation and, in some cases, collapse of the underlying system. However, the influences of the topology of networks on their ability to withstand node failures are poorly understood. Based on a study of the response of 2,000 power-law networks to node failures, we find that networks with higher nodal degree and clustering coefficient, lower betweenness centrality, and lower variability in path length and clustering coefficient maintain their cohesion better during such events. We also find that network robustness, i.e., the ability to withstand node failures, can be accurately predicted a priori for power-law networks across many fields. These results provide a basis for designing new, more robust networks, improving the robustness of existing...

  1. Loss of regional accent after damage to the speech production network

    Directory of Open Access Journals (Sweden)

    Marcelo L Berthier

    2015-11-01

    Full Text Available Lesion-symptom mapping studies reveal that selective damage to one or more components of the speech production network can be associated with foreign accent syndrome, changes in regional accent (e.g., from Parisian accent to Alsatian accent, stronger regional accent, or re-emergence of a previously learned and dormant regional accent. Here, we report loss of regional accent after rapidly regressive Broca’s aphasia in three Argentinean patients who had suffered unilateral or bilateral focal lesions in components of the speech production network. All patients were monolingual speakers with three different native Spanish accents (Cordobés or central, Guaranítico or northeast, and Bonaerense. Samples of speech production from the patient with native Córdoba’s accent were compared with previous recordings of his voice, whereas data from the patient with native Guaranítico´s accent were compared with speech samples from one healthy control matched for age, gender, and native accent. Speech samples from the patient with native Buenos Aires’s accent were compared with data obtained from four healthy control subjects with the same accent. Analysis of speech production revealed discrete slowing in speech rate, inappropriate long pauses, and monotonous intonation. Phonemic production remained similar to those of healthy Spanish speakers, but phonetic variants peculiar to each accent (e.g.,

  2. Computational simulations of frictional losses in pipe networks confirmed in experimental apparatusses designed by honors students

    Science.gov (United States)

    Pohlman, Nicholas A.; Hynes, Eric; Kutz, April

    2015-11-01

    Lectures in introductory fluid mechanics at NIU are a combination of students with standard enrollment and students seeking honors credit for an enriching experience. Most honors students dread the additional homework problems or an extra paper assigned by the instructor. During the past three years, honors students of my class have instead collaborated to design wet-lab experiments for their peers to predict variable volume flow rates of open reservoirs driven by gravity. Rather than learn extra, the honors students learn the Bernoulli head-loss equation earlier to design appropriate systems for an experimental wet lab. Prior designs incorporated minor loss features such as sudden contraction or multiple unions and valves. The honors students from Spring 2015 expanded the repertoire of available options by developing large scale set-ups with multiple pipe networks that could be combined together to test the flexibility of the student team's computational programs. The engagement of bridging the theory with practice was appreciated by all of the students such that multiple teams were able to predict performance within 4% accuracy. The challenges, schedules, and cost estimates of incorporating the experimental lab into an introductory fluid mechanics course will be reported.

  3. Variable Scheduling to Mitigate Channel Losses in Energy-Efficient Body Area Networks

    Directory of Open Access Journals (Sweden)

    Lavy Libman

    2012-11-01

    Full Text Available We consider a typical body area network (BAN setting in which sensor nodes send data to a common hub regularly on a TDMA basis, as defined by the emerging IEEE 802.15.6 BAN standard. To reduce transmission losses caused by the highly dynamic nature of the wireless channel around the human body, we explore variable TDMA scheduling techniques that allow the order of transmissions within each TDMA round to be decided on the fly, rather than being fixed in advance. Using a simple Markov model of the wireless links, we devise a number of scheduling algorithms that can be performed by the hub, which aim to maximize the expected number of successful transmissions in a TDMA round, and thereby significantly reduce transmission losses as compared with a static TDMA schedule. Importantly, these algorithms do not require a priori knowledge of the statistical properties of the wireless channels, and the reliability improvement is achieved entirely via shuffling the order of transmissions among devices, and does not involve any additional energy consumption (e.g., retransmissions. We evaluate these algorithms directly on an experimental set of traces obtained from devices strapped to human subjects performing regular daily activities, and confirm that the benefits of the proposed variable scheduling algorithms extend to this practical setup as well.

  4. Variable scheduling to mitigate channel losses in energy-efficient body area networks.

    Science.gov (United States)

    Tselishchev, Yuriy; Boulis, Athanassios; Libman, Lavy

    2012-11-02

    We consider a typical body area network (BAN) setting in which sensor nodes send data to a common hub regularly on a TDMA basis, as defined by the emerging IEEE 802.15.6 BAN standard. To reduce transmission losses caused by the highly dynamic nature of the wireless channel around the human body, we explore variable TDMA scheduling techniques that allow the order of transmissions within each TDMA round to be decided on the fly, rather than being fixed in advance. Using a simple Markov model of the wireless links, we devise a number of scheduling algorithms that can be performed by the hub, which aim to maximize the expected number of successful transmissions in a TDMA round, and thereby significantly reduce transmission losses as compared with a static TDMA schedule. Importantly, these algorithms do not require a priori knowledge of the statistical properties of the wireless channels, and the reliability improvement is achieved entirely via shuffling the order of transmissions among devices, and does not involve any additional energy consumption (e.g., retransmissions). We evaluate these algorithms directly on an experimental set of traces obtained from devices strapped to human subjects performing regular daily activities, and confirm that the benefits of the proposed variable scheduling algorithms extend to this practical setup as well.

  5. Statistical Modeling of Large-Scale Signal Path Loss in Underwater Acoustic Networks

    Directory of Open Access Journals (Sweden)

    Manuel Perez Malumbres

    2013-02-01

    Full Text Available In an underwater acoustic channel, the propagation conditions are known to vary in time, causing the deviation of the received signal strength from the nominal value predicted by a deterministic propagation model. To facilitate a large-scale system design in such conditions (e.g., power allocation, we have developed a statistical propagation model in which the transmission loss is treated as a random variable. By applying repetitive computation to the acoustic field, using ray tracing for a set of varying environmental conditions (surface height, wave activity, small node displacements around nominal locations, etc., an ensemble of transmission losses is compiled and later used to infer the statistical model parameters. A reasonable agreement is found with log-normal distribution, whose mean obeys a log-distance increases, and whose variance appears to be constant for a certain range of inter-node distances in a given deployment location. The statistical model is deemed useful for higher-level system planning, where simulation is needed to assess the performance of candidate network protocols under various resource allocation policies, i.e., to determine the transmit power and bandwidth allocation necessary to achieve a desired level of performance (connectivity, throughput, reliability, etc..

  6. Quantification and characterization of glyphosate use and loss in a residential area.

    Science.gov (United States)

    Tang, Ting; Boënne, Wesley; Desmet, Nele; Seuntjens, Piet; Bronders, Jan; van Griensven, Ann

    2015-06-01

    Urban runoff can be a significant source of pesticides in urban streams. However, quantification of this source has been difficult because pesticide use by urban residents (e.g., on pavements or in gardens) is often unknown, particularly at the scale of a residential catchment. Proper quantification and characterization of pesticide loss via urban runoff require sound information on the use and occurrence of pesticides at hydrologically-relevant spatial scales, involving various hydrological conditions. We conducted a monitoring study in a residential area (9.5 ha, Flanders, Belgium) to investigate the use and loss of a widely-used herbicide (glyphosate) and its major degradation product (aminomethylphosphonic acid, AMPA). The study covered 13 rainfall events over 67 days. Overall, less than 0.5% of glyphosate applied was recovered from the storm drain outflow in the catchment. Maximum detected concentrations were 6.1 μg/L and 5.8 μg/L for glyphosate and AMPA, respectively, both of which are below the predicted no-effect concentration for surface water proposed by the Flemish environmental agency (10 μg/L), but are above the EU drinking water standard (0.1 μg/L). The measured concentrations and percentage loss rates can be attributed partially to the strong sorption capacity of glyphosate and low runoff potential in the study area. However, glyphosate loss varied considerably among rainfall events and event load of glyphosate mass was mainly controlled by rainfall amount, according to further statistical analyses. To obtain urban pesticide management insights, robust tools are required to investigate the loss and occurrence of pesticides influenced by various factors, particularly the hydrological and spatial factors. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Characterization of critical network components of coupled oscillators

    Science.gov (United States)

    Holifield, Gregory A.

    This dissertation analyzes the fundamental limits for the determination of the network structure of loosely coupled oscillators based on observing the behavior of the network, specifically, node synchronization. The determination of the requisite characteristics and underlying behaviors necessary for the application of a theoretical mechanism for determining the underlying network topology in a network of loosely coupled natural oscillators are the desired outcome. To that end, this effort defines an analytical framework where key components of networks of coupled oscillators are isolated in order to determine the relationships between the various components. The relationship between the number of nodes in a network, the number of connections in the network, the number of connections of a given node, the distribution of the phases of the network, and the resolution of measurement of the components of the network, and system noise is investigated.

  8. Stochastic Characterization of Communication Network Latency for Wide Area Grid Control Applications.

    Energy Technology Data Exchange (ETDEWEB)

    Ameme, Dan Selorm Kwami [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Guttromson, Ross [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-10-01

    This report characterizes communications network latency under various network topologies and qualities of service (QoS). The characterizations are probabilistic in nature, allowing deeper analysis of stability for Internet Protocol (IP) based feedback control systems used in grid applications. The work involves the use of Raspberry Pi computers as a proxy for a controlled resource, and an ns-3 network simulator on a Linux server to create an experimental platform (testbed) that can be used to model wide-area grid control network communications in smart grid. Modbus protocol is used for information transport, and Routing Information Protocol is used for dynamic route selection within the simulated network.

  9. Fabrication and Mechanical Characterization of Hydrogel Infused Network Silk Scaffolds

    Directory of Open Access Journals (Sweden)

    Lakshminath Kundanati

    2016-09-01

    Full Text Available Development and characterization of porous scaffolds for tissue engineering and regenerative medicine is of great importance. In recent times, silk scaffolds were developed and successfully tested in tissue engineering and drug release applications. We developed a novel composite scaffold by mechanical infusion of silk hydrogel matrix into a highly porous network silk scaffold. The mechanical behaviour of these scaffolds was thoroughly examined for their possible use in load bearing applications. Firstly, unconfined compression experiments show that the denser composite scaffolds displayed significant enhancement in the elastic modulus as compared to either of the components. This effect was examined and further explained with the help of foam mechanics principles. Secondly, results from confined compression experiments that resemble loading of cartilage in confinement, showed nonlinear material responses for all scaffolds. Finally, the confined creep experiments were performed to calculate the hydraulic permeability of the scaffolds using soil mechanics principles. Our results show that composite scaffolds with some modifications can be a potential candidate for use of cartilage like applications. We hope such approaches help in developing novel scaffolds for tissue engineering by providing an understanding of the mechanics and can further be used to develop graded scaffolds by targeted infusion in specific regions.

  10. ELASTICITY:Topological characterization of robustness in complex networks

    NARCIS (Netherlands)

    Sydney, A.; Scoglio, C.; Schumm, P.; Kooij, R.E.

    2008-01-01

    Just as a herd of animals relies on its robust social structure to survive in the wild, similarly robustness is a crucial characteristic for the survival of a complex network under attack. The capacity to measure robustness in complex networks defines a network's survivability in the advent of

  11. Measurement based analysis of active and reactive power losses in a distribution network with wind farms and CHPs

    DEFF Research Database (Denmark)

    Lund, Torsten

    2007-01-01

    The paper presents an investigation of the active and reactive power losses in a distribution network with wind turbines and combined heat and power plants. The investigation is based on 15 min average power measurements and load flow calculations in the power system simulation tool Power......Factory®. Based on the measurements and simulations, a regressive model for calculation and allocation of active and reactive power losses has been derived. The influence of the covariance between load and production on the system losses is investigated separately....

  12. [Loss of anesthesia records during network failure of anesthesia management information system: a case of malfunction of backup system].

    Science.gov (United States)

    Fujii, Seishi; Moriwaki, Katsuyuki; Sanuki, Mikako; Tajima, Minoru; Kurita, Shigeaki; Shiroyama, Kazuhisa; Hashimoto, Ken

    2014-05-01

    We report a case of an accidental loss of anesthesia records through network failure of an anesthesia information management system (AIMS). The backup data were not kept in the anesthesia workstations or the server during the failure. Accordingly, anesthesia records of five patients were lost for one hour. Our AIMS has a network redundancy where the server keeps anesthesia monitoring data via two pathways: one via the monitoring server to the AIMS server and the other via anesthesia workstation to the server. Despite the redundant pathways, transient power failures of network switches caused interruptions in both pathways. Our case indicates that, to improve the robustness of the AIMS as electronic medical records, every network apparatus of AIMS, should be supplied with an uninterrupted power supply. Furthermore, each anesthesia workstation should function independently as an anesthesia record keeping client when network failure occurs.

  13. Using complex networks to characterize international business cycles.

    Directory of Open Access Journals (Sweden)

    Petre Caraiani

    Full Text Available BACKGROUND: There is a rapidly expanding literature on the application of complex networks in economics that focused mostly on stock markets. In this paper, we discuss an application of complex networks to study international business cycles. METHODOLOGY/PRINCIPAL FINDINGS: We construct complex networks based on GDP data from two data sets on G7 and OECD economies. Besides the well-known correlation-based networks, we also use a specific tool for presenting causality in economics, the Granger causality. We consider different filtering methods to derive the stationary component of the GDP series for each of the countries in the samples. The networks were found to be sensitive to the detrending method. While the correlation networks provide information on comovement between the national economies, the Granger causality networks can better predict fluctuations in countries' GDP. By using them, we can obtain directed networks allows us to determine the relative influence of different countries on the global economy network. The US appears as the key player for both the G7 and OECD samples. CONCLUSION: The use of complex networks is valuable for understanding the business cycle comovements at an international level.

  14. Using complex networks to characterize international business cycles.

    Science.gov (United States)

    Caraiani, Petre

    2013-01-01

    There is a rapidly expanding literature on the application of complex networks in economics that focused mostly on stock markets. In this paper, we discuss an application of complex networks to study international business cycles. We construct complex networks based on GDP data from two data sets on G7 and OECD economies. Besides the well-known correlation-based networks, we also use a specific tool for presenting causality in economics, the Granger causality. We consider different filtering methods to derive the stationary component of the GDP series for each of the countries in the samples. The networks were found to be sensitive to the detrending method. While the correlation networks provide information on comovement between the national economies, the Granger causality networks can better predict fluctuations in countries' GDP. By using them, we can obtain directed networks allows us to determine the relative influence of different countries on the global economy network. The US appears as the key player for both the G7 and OECD samples. The use of complex networks is valuable for understanding the business cycle comovements at an international level.

  15. Conservation Measures and Loss of Ecosystem Services: A Study Concerning the Sardinian Natura 2000 Network

    Directory of Open Access Journals (Sweden)

    Federica Leone

    2016-10-01

    Full Text Available The seeming dichotomy between the protection of biodiversity and the supply of ecosystem services (ESs represents an outstanding field of research that requires a structured and detailed analysis. The paper analyzes and discusses the role of ESs within spatial planning and strategic environmental assessment (SEA procedures through the content analysis methodology and a logical framework (LF implemented into the SEA of municipal masterplans (MMPs. We discuss the role of ESs as factors that improve the effectiveness of SEA-based processes related to management plans (MPs of sites that belong to the Sardinian Natura 2000 Network with reference to their positive impacts on environmental quality. The empirical outcomes put in evidence the inconsistencies between MMPs and MPs in terms of sustainability-oriented objectives and potential losses of the ESs productive output due to measures adopted by the MPs in order to protect habitats and species. The scant attention paid to ESs in the operational context of MMPs, MPs and SEA reports, particularly as regards their regulative framework, entails that the issue of the protection of ESs has to be carefully taken into account within the process of the definition and establishment of MPs through an SEA report that integrates the MPs and MMPs LFs.

  16. Association patterns in saproxylic insect networks in three Iberian Mediterranean woodlands and their resistance to microhabitat loss.

    Directory of Open Access Journals (Sweden)

    Javier Quinto

    Full Text Available The assessment of the relationship between species diversity, species interactions and environmental characteristics is indispensable for understanding network architecture and ecological distribution in complex networks. Saproxylic insect communities inhabiting tree hollow microhabitats within Mediterranean woodlands are highly dependent on woodland configuration and on microhabitat supply they harbor, so can be studied under the network analysis perspective. We assessed the differences in interacting patterns according to woodland site, and analysed the importance of functional species in modelling network architecture. We then evaluated their implications for saproxylic assemblages' persistence, through simulations of three possible scenarios of loss of tree hollow microhabitat. Tree hollow-saproxylic insect networks per woodland site presented a significant nested pattern. Those woodlands with higher complexity of tree individuals and tree hollow microhabitats also housed higher species/interactions diversity and complexity of saproxylic networks, and exhibited a higher degree of nestedness, suggesting that a higher woodland complexity positively influences saproxylic diversity and interaction complexity, thus determining higher degree of nestedness. Moreover, the number of insects acting as key interconnectors (nodes falling into the core region, using core/periphery tests was similar among woodland sites, but the species identity varied on each. Such differences in insect core composition among woodland sites suggest the functional role they depict at woodland scale. Tree hollows acting as core corresponded with large tree hollows near the ground and simultaneously housing various breeding microsites, whereas core insects were species mediating relevant ecological interactions within saproxylic communities, e.g. predation, competitive or facilitation interactions. Differences in network patterns and tree hollow characteristics among

  17. Association patterns in saproxylic insect networks in three Iberian Mediterranean woodlands and their resistance to microhabitat loss.

    Science.gov (United States)

    Quinto, Javier; Marcos-García, María de los Ángeles; Díaz-Castelazo, Cecilia; Rico-Gray, Víctor; Galante, Eduardo; Micó, Estefanía

    2015-01-01

    The assessment of the relationship between species diversity, species interactions and environmental characteristics is indispensable for understanding network architecture and ecological distribution in complex networks. Saproxylic insect communities inhabiting tree hollow microhabitats within Mediterranean woodlands are highly dependent on woodland configuration and on microhabitat supply they harbor, so can be studied under the network analysis perspective. We assessed the differences in interacting patterns according to woodland site, and analysed the importance of functional species in modelling network architecture. We then evaluated their implications for saproxylic assemblages' persistence, through simulations of three possible scenarios of loss of tree hollow microhabitat. Tree hollow-saproxylic insect networks per woodland site presented a significant nested pattern. Those woodlands with higher complexity of tree individuals and tree hollow microhabitats also housed higher species/interactions diversity and complexity of saproxylic networks, and exhibited a higher degree of nestedness, suggesting that a higher woodland complexity positively influences saproxylic diversity and interaction complexity, thus determining higher degree of nestedness. Moreover, the number of insects acting as key interconnectors (nodes falling into the core region, using core/periphery tests) was similar among woodland sites, but the species identity varied on each. Such differences in insect core composition among woodland sites suggest the functional role they depict at woodland scale. Tree hollows acting as core corresponded with large tree hollows near the ground and simultaneously housing various breeding microsites, whereas core insects were species mediating relevant ecological interactions within saproxylic communities, e.g. predation, competitive or facilitation interactions. Differences in network patterns and tree hollow characteristics among woodland sites clearly

  18. Improved Safety Margin Characterization of Risk from Loss of Offsite Power

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Paul [Texas A & M Univ., College Station, TX (United States)

    2017-11-07

    Original intent: The original intent of this task was “support of the Risk-Informed Safety Margin Characteristic (RISMC) methodology in order” “to address … efficiency of computation so that more accurate and cost-effective techniques can be used to address safety margin characterizations” (S. M. Hess et al., “Risk-Informed Safety Margin Characterization,” Procs. ICONE17, Brussels, July 2009, CD format). It was intended that “in Task 1 itself this improvement will be directed toward upon the very important issue of Loss of Offsite Power (LOOP) events,” more specifically toward the challenge of efficient computation of the multidimensional nonrecovery integral that has been discussed by many previous contributors to the theory of nuclear safety. It was further envisioned that “three different computational approaches will be explored,” corresponding to the three subtasks listed below; deliverables were tied to the individual subtasks.

  19. Characterization of Static/Dynamic Topological Routing For Grid Networks

    DEFF Research Database (Denmark)

    Gutierrez Lopez, Jose Manuel; Cuevas, Ruben; Riaz, M. Tahir

    2009-01-01

    Grid or 2D Mesh structures are becoming one of the most attractive network topologies to study. They can be used in many different fields raging from future broadband networks to multiprocessors structures. In addition, the high requirements of future services and applications demand more flexible...

  20. Indoor positioning in wireless local area networks with online path-loss parameter estimation.

    Science.gov (United States)

    Bruno, Luigi; Addesso, Paolo; Restaino, Rocco

    2014-01-01

    Location based services are gathering an even wider interest also in indoor environments and urban canyons, where satellite systems like GPS are no longer accurate. A much addressed solution for estimating the user position exploits the received signal strengths (RSS) in wireless local area networks (WLANs), which are very common nowadays. However, the performances of RSS based location systems are still unsatisfactory for many applications, due to the difficult modeling of the propagation channel, whose features are affected by severe changes. In this paper we propose a localization algorithm which takes into account the nonstationarity of the working conditions by estimating and tracking the key parameters of RSS propagation. It is based on a Sequential Monte Carlo realization of the optimal Bayesian estimation scheme, whose functioning is improved by exploiting the Rao-Blackwellization rationale. Two key statistical models for RSS characterization are deeply analyzed, by presenting effective implementations of the proposed scheme and by assessing the positioning accuracy by extensive computer experiments. Many different working conditions are analyzed by simulated data and corroborated through the validation in a real world scenario.

  1. On Evaluating Power Loss with HATSGA Algorithm for Power Network Reconfiguration in the Smart Grid

    OpenAIRE

    Calhau, Flavio Galvão; Pezzutti, Alysson; Martins, Joberto S. B.

    2017-01-01

    This paper presents the power network reconfig-uration algorithm HATSGA with a " R " modeling approach and evaluates its behavior in computing new reconfiguration topologies for the power network in the Smart Grid context. The modelling of the power distribution network with the language " R " is used to represent the network and support computation of distinct algorithm configurations towards the evaluation of new reconfiguration topologies. The HATSGA algorithm adopts hybrid Tabu Search and...

  2. Magnitude Characterization Using Complex Networks in Central Chile

    Science.gov (United States)

    Pasten, D.; Comte, D.; Munoz, V.

    2013-12-01

    Studies using complex networks are applied to many systems, like traffic, social networks, internet and earth science. In this work we make an analysis using complex networks applied to magnitude of seismicity in the central zone of Chile, we use the preferential attachment in order to construct a seismic network using local magnitudes and the hypocenters of a seismic data set in central Chile. In order to work with a complete catalogue in magnitude, the data associated with the linear part of the Gutenberg-Richter law, with magnitudes greater than 2.7, were taken. We then make a grid in space, so that each seismic event falls into a certain cell, depending on the location of its hypocenter. Now the network is constructed: the first node corresponds to the cell where the first seismic event occurs. The node has an associated number which is the magnitude of the event which occured in it, and a probability is assigned to the node. The probability is a nonlinear mapping of the magnitude (a Gaussian function was taken), so that nodes with lower magnitude events are more likely to be attached to. Each time a new node is added to the network, it is attached to the previous node which has the larger probability; the link is directed from the previous node to the new node. In this way, a directed network is constructed, with a ``preferential attachment''-like growth model, using the magnitudes as the parameter to determine the probability of attachment to future nodes. Several events could occur in the same node. In this case, the probability is calculated using the average of the magnitudes of the events occuring in that node. Once the directed network is finished, the corresponding undirected network is constructed, by making all links symmetric, and eliminating the loops which may appear when two events occur in the same cell. The resulting directed network is found to be scale free (with very low values of the power-law distribution exponent), whereas the undirected

  3. Loss of variation of state detected in soybean metabolic and human myelomonocytic leukaemia cell transcriptional networks under external stimuli

    KAUST Repository

    Sakata, Katsumi

    2016-10-24

    Soybean (Glycine max) is sensitive to flooding stress, and flood damage at the seedling stage is a barrier to growth. We constructed two mathematical models of the soybean metabolic network, a control model and a flooded model, from metabolic profiles in soybean plants. We simulated the metabolic profiles with perturbations before and after the flooding stimulus using the two models. We measured the variation of state that the system could maintain from a state–space description of the simulated profiles. The results showed a loss of variation of state during the flooding response in the soybean plants. Loss of variation of state was also observed in a human myelomonocytic leukaemia cell transcriptional network in response to a phorbol-ester stimulus. Thus, we detected a loss of variation of state under external stimuli in two biological systems, regardless of the regulation and stimulus types. Our results suggest that a loss of robustness may occur concurrently with the loss of variation of state in biological systems. We describe the possible applications of the quantity of variation of state in plant genetic engineering and cell biology. Finally, we present a hypothetical “external stimulus-induced information loss” model of biological systems.

  4. Geochemical characterization of oceanic basalts using artificial neural network

    Digital Repository Service at National Institute of Oceanography (India)

    Das, P.; Iyer, S.D.

    method is specifically needed to identify the OFB as normal (N-MORB), enriched (E-MORB) and ocean island basalts (OIB). Artificial Neural Network (ANN) technique as a supervised Learning Vector Quantisation (LVQ) is applied to identify the inherent...

  5. Characterization of Background Traffic in Hybrid Network Simulation

    National Research Council Canada - National Science Library

    Lauwens, Ben; Scheers, Bart; Van de Capelle, Antoine

    2006-01-01

    .... Two approaches are common: discrete event simulation and fluid approximation. A discrete event simulation generates a huge amount of events for a full-blown battlefield communication network resulting in a very long runtime...

  6. Characterization of differentially expressed genes using high-dimensional co-expression networks

    DEFF Research Database (Denmark)

    Coelho Goncalves de Abreu, Gabriel; Labouriau, Rodrigo S.

    2010-01-01

    We present a technique to characterize differentially expressed genes in terms of their position in a high-dimensional co-expression network. The set-up of Gaussian graphical models is used to construct representations of the co-expression network in such a way that redundancy and the propagation...

  7. A new convolution algorithm for loss probablity analysis in multiservice networks

    DEFF Research Database (Denmark)

    Huang, Qian; Ko, King-Tim; Iversen, Villy Bæk

    2011-01-01

    present a new Permutational Convolution Algorithm (PCA) for loss probability approximation in multiservice systems with trunk reservation. This method extends the application of the convolution algorithm and overcomes the problems of approximation accuracy in systems with a large number of traffic flows......Performance analysis in multiservice loss systems generally focuses on accurate and efficient calculation methods for traffic loss probability. Convolution algorithm is one of the existing efficient numerical methods. Exact loss probabilities are obtainable from the convolution algorithm in systems....... It is verified that the loss probabilities obtained by PCA are very close to the exact solutions obtained by Markov chain models, and the accuracy outperforms the ACA approximation....

  8. Efficient amorphous silicon solar cells: characterization, optimization, and optical loss analysis

    Directory of Open Access Journals (Sweden)

    Wayesh Qarony

    Full Text Available Hydrogenated amorphous silicon (a-Si:H has been effectively utilized as photoactive and doped layers for quite a while in thin-film solar applications but its energy conversion efficiency is limited due to thinner absorbing layer and light degradation issue. To overcome such confinements, it is expected to adjust better comprehension of device structure, material properties, and qualities since a little enhancement in the photocurrent significantly impacts on the conversion efficiency. Herein, some numerical simulations were performed to characterize and optimize different configuration of amorphous silicon-based thin-film solar cells. For the optical simulation, two-dimensional finite-difference time-domain (FDTD technique was used to analyze the superstrate (p-i-n planar amorphous silicon solar cells. Besides, the front transparent contact layer was also inquired by using SnO2:F and ZnO:Al materials to improve the photon absorption in the photoactive layer. The cell was studied for open-circuit voltage, external quantum efficiency, and short-circuit current density, which are building blocks for solar cell conversion efficiency. The optical simulations permit investigating optical losses at the individual layers. The enhancement in both short-circuit current density and open-circuit voltage prompts accomplishing more prominent power conversion efficiency. A maximum short-circuit current density of 15.32 mA/cm2 and an energy conversion efficiency of 11.3% were obtained for the optically optimized cell which is the best in class amorphous solar cell. Keywords: Superstrate p-i-n, Power loss, Quantum efficiency, Short circuit current, FDTD

  9. Examining Social Influence on Participation and Outcomes among a Network of Behavioral Weight-Loss Intervention Enrollees

    OpenAIRE

    Carson, T. L.; Eddings, K. E.; Krukowski, R. A.; Love, S. J.; Harvey-Berino, J. R.; West, D. S.

    2013-01-01

    Research suggests that social networks, social support, and social influence are associated with weight trajectories among treatment- and non-treatment-seeking individuals. This study examined the impact of having a social contact who participated in the same group behavioral weight-control intervention in the absence of specific social support training on women engaged in a weight-loss program. Participants (n = 92; 100% female; 54% black; mean age: 46 ? 10 years; mean BMI: 38 ? 6) were grou...

  10. Characterizing interactions in online social networks during exceptional events

    CERN Document Server

    Omodei, Elisa; Arenas, Alex

    2015-01-01

    Nowadays, millions of people interact on a daily basis on online social media like Facebook and Twitter, where they share and discuss information about a wide variety of topics. In this paper, we focus on a specific online social network, Twitter, and we analyze multiple datasets each one consisting of individuals' online activity before, during and after an exceptional event in terms of volume of the communications registered. We consider important events that occurred in different arenas that range from policy to culture or science. For each dataset, the users' online activities are modeled by a multilayer network in which each layer conveys a different kind of interaction, specifically: retweeting, mentioning and replying. This representation allows us to unveil that these distinct types of interaction produce networks with different statistical properties, in particular concerning the degree distribution and the clustering structure. These results suggests that models of online activity cannot discard the...

  11. A STUDY OF VARIABLES CHARACTERIZING DRAINAGE PATTERNS IN RIVER NETWORKS

    Directory of Open Access Journals (Sweden)

    L. Zhang

    2012-07-01

    Full Text Available In GIS and in terrain analysis, drainage systems are important components. Due to local topography and subsurface geology, a drainage system achieves a particular drainage pattern based on the form and texture of its network of stream channels and tributaries. Drainage pattern recognition helps to provide a qualitative description of the terrain for analysis and classification and is useful for terrain modelling and visualization and applications in environment. Much research has been done on the description of drainage patterns in geography and hydrology. However automatic drainage pattern recognition in river networks is not well developed. This paper introduces a method based on geometric quantitative indicators to recognize drainage patterns in a river network automatically. Experiment results are presented and discussed.

  12. Characterizing disease states from topological properties of transcriptional regulatory networks

    Directory of Open Access Journals (Sweden)

    Kluger Harriet M

    2006-05-01

    Full Text Available Abstract Background High throughput gene expression experiments yield large amounts of data that can augment our understanding of disease processes, in addition to classifying samples. Here we present new paradigms of data Separation based on construction of transcriptional regulatory networks for normal and abnormal cells using sequence predictions, literature based data and gene expression studies. We analyzed expression datasets from a number of diseased and normal cells, including different types of acute leukemia, and breast cancer with variable clinical outcome. Results We constructed sample-specific regulatory networks to identify links between transcription factors (TFs and regulated genes that differentiate between healthy and diseased states. This approach carries the advantage of identifying key transcription factor-gene pairs with differential activity between healthy and diseased states rather than merely using gene expression profiles, thus alluding to processes that may be involved in gene deregulation. We then generalized this approach by studying simultaneous changes in functionality of multiple regulatory links pointing to a regulated gene or emanating from one TF (or changes in gene centrality defined by its in-degree or out-degree measures, respectively. We found that samples can often be separated based on these measures of gene centrality more robustly than using individual links. We examined distributions of distances (the number of links needed to traverse the path between each pair of genes in the transcriptional networks for gene subsets whose collective expression profiles could best separate each dataset into predefined groups. We found that genes that optimally classify samples are concentrated in neighborhoods in the gene regulatory networks. This suggests that genes that are deregulated in diseased states exhibit a remarkable degree of connectivity. Conclusion Transcription factor-regulated gene links and

  13. Characterizing dynamic changes in the human blood transcriptional network.

    Directory of Open Access Journals (Sweden)

    Jun Zhu

    2010-02-01

    Full Text Available Gene expression data generated systematically in a given system over multiple time points provides a source of perturbation that can be leveraged to infer causal relationships among genes explaining network changes. Previously, we showed that food intake has a large impact on blood gene expression patterns and that these responses, either in terms of gene expression level or gene-gene connectivity, are strongly associated with metabolic diseases. In this study, we explored which genes drive the changes of gene expression patterns in response to time and food intake. We applied the Granger causality test and the dynamic Bayesian network to gene expression data generated from blood samples collected at multiple time points during the course of a day. The simulation result shows that combining many short time series together is as powerful to infer Granger causality as using a single long time series. Using the Granger causality test, we identified genes that were supported as the most likely causal candidates for the coordinated temporal changes in the network. These results show that PER1 is a key regulator of the blood transcriptional network, in which multiple biological processes are under circadian rhythm regulation. The fasted and fed dynamic Bayesian networks showed that over 72% of dynamic connections are self links. Finally, we show that different processes such as inflammation and lipid metabolism, which are disconnected in the static network, become dynamically linked in response to food intake, which would suggest that increasing nutritional load leads to coordinate regulation of these biological processes. In conclusion, our results suggest that food intake has a profound impact on the dynamic co-regulation of multiple biological processes, such as metabolism, immune response, apoptosis and circadian rhythm. The results could have broader implications for the design of studies of disease association and drug response in clinical

  14. Quantifying the impact of road capacity loss on urban electrified transportation networks: An optimization based approach

    OpenAIRE

    Wei Wei; Jianhui Wang; Lei Wu

    2016-01-01

    The proliferation of electric vehicles and commercialization of public charging facilities have inspired the emerging trend of transportation electrification, which creates an urgent demand for systematic methodologies to analyze the performance of electrified transportation networks (ETNs) while taking the interdependency across the transportation network and the power distribution network into account. This paper introduces a comprehensive mathematical formulation of the ETN from a system-l...

  15. How to Enhance the Efficiency of Loss-Less Optical Burst Switching Networks with the Streamline Effect

    Directory of Open Access Journals (Sweden)

    Milos Kozak

    2015-01-01

    Full Text Available With the ongoing steady traffic increase in the Internet, the wavelength usage of the supporting optical networks is a critical network efficiency parameter. Therefore, this paper suggests a way how to efficiently and economically achieve this goal in the context of optical burst switching, a very promising technology that has been proposed to overcome the shortcomings of conventional WDM deployment, such as lack of fine bandwidth granularity in wavelength routing and electronic speed bottlenecks in the presence of bursty traffic. In order to mitigate the burst loss and achieve high network efficiency we adapt the loss-less paradigm defined by Coutelen et al. (2010, i.e., the CAROBS framework. In classical OBS networks, the streamline effect ensures a very low level of contention, i.e., efficient transmission, hence we define a routing guided only by the streamline effect. The resulting routing problem is formulated as an optimization model which is solved using a decomposition technique to increase the scalability of the solution process.

  16. An Efficience Scheme to Reduce Burst Loss Rate and Supporting Differentiated Services in All-Optical Networks

    Science.gov (United States)

    Garg, Amit Kumar

    2011-06-01

    Due to their one-way resource reservation mechanism, Optical Burst Switching (OBS) networks experience high bursts (thus packets) loss rate. In OBS networks, the contention is resolved either by dropping one of the contending bursts or more efficiently by dropping from one of the contending bursts only the parts that overlap with the other bursts. In both situations, only one data source will suffer the data loss in favor to the other. In this paper, an efficient scheme to reduce burst loss rate has been proposed in conjunction with an appropriate mechanism to provide differentiated service in order to support the quality of service (QoS) requirements of different applications. Simulation results show that the performance of the proposed scheme is better than existing mechanisms in terms of reducing burst (packets) loss. Numerical results show that the proposed scheme provides an accurate fit for the performance of the highest traffic class and lower bounds for the other traffic classes that are tighter than earlier known results.

  17. Characterization of the Network of Protected Areas in Puerto Rico

    Science.gov (United States)

    J. Castro-Prieto; Maya Quinones; William Gould

    2016-01-01

    Our goal was to describe the biodiversity and associated landscape diversity and forest cover characteristics within the network of terrestrial protected areas in Puerto Rico. We conducted spatial analysis to quantify different indicators of diversity at these sites. We found that protected areas in Puerto Rico overlap the most species-rich regions on the island,...

  18. Characterizing the sustainable forestry issue network in thc United States

    Science.gov (United States)

    Steverson O. Moffat; Frederick W. Cubbage; Thomas P. Holmes; Elizabethann O' Sullivan

    2001-01-01

    Issue network analysis techniques were applied to the issue sustainable forestry in the United States to identify potential public and private outcomes for the issue. A quantitative approach based on work by Laumann and Knoke [(The Organizational State (1987)] was utilized in conjunction with the Delphi method. Results suggest that the parity in the distribution of...

  19. Characterizing interactions in online social networks during exceptional events

    Science.gov (United States)

    Omodei, Elisa; De Domenico, Manlio; Arenas, Alex

    2015-08-01

    Nowadays, millions of people interact on a daily basis on online social media like Facebook and Twitter, where they share and discuss information about a wide variety of topics. In this paper, we focus on a specific online social network, Twitter, and we analyze multiple datasets each one consisting of individuals' online activity before, during and after an exceptional event in terms of volume of the communications registered. We consider important events that occurred in different arenas that range from policy to culture or science. For each dataset, the users' online activities are modeled by a multilayer network in which each layer conveys a different kind of interaction, specifically: retweeting, mentioning and replying. This representation allows us to unveil that these distinct types of interaction produce networks with different statistical properties, in particular concerning the degree distribution and the clustering structure. These results suggests that models of online activity cannot discard the information carried by this multilayer representation of the system, and should account for the different processes generated by the different kinds of interactions. Secondly, our analysis unveils the presence of statistical regularities among the different events, suggesting that the non-trivial topological patterns that we observe may represent universal features of the social dynamics on online social networks during exceptional events.

  20. Characterizing the Path Coverage of Random Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Moslem Noori

    2010-01-01

    Full Text Available Wireless sensor networks are widely used in security monitoring applications to sense and report specific activities in a field. In path coverage, for example, the network is in charge of monitoring a path and discovering any intruder trying to cross it. In this paper, we investigate the path coverage properties of a randomly deployed wireless sensor network when the number of sensors and also the length of the path are finite. As a consequence, Boolean model, which has been widely used previously, is not applicable. Using results from geometric probability, we determine the probability of full path coverage, distribution of the number of uncovered gaps over the path, and the probability of having no uncovered gaps larger than a specific size. We also find the cumulative distribution function (cdf of the covered part of the path. Based on our results on the probability of full path coverage, we derive a tight upper bound for the number of nodes guaranteeing the full path coverage with a desired reliability. Through computer simulations, it is verified that for networks with nonasymptotic size, our analysis is accurate where the Boolean model can be inaccurate.

  1. Characterizing the intrinsic correlations of scale-free networks

    CERN Document Server

    de Brito, J B; Moreira, A A; Andrade, J S

    2015-01-01

    Very often, when studying topological or dynamical properties of random scale-free networks, it is tacitly assumed that degree-degree correlations are not present. However, simple constraints, such as the absence of multiple edges and self-loops, can give rise to intrinsic correlations in these structures. In the same way that Fermionic correlations in thermodynamic systems are relevant only in the limit of low temperature, the intrinsic correlations in scale-free networks are relevant only when the extreme values for the degrees grow faster than the square-root of the network size. In this situation, these correlations can significantly affect the dependence of the average degree of the nearest neighbors of a given vertice on this vertices's degree. Here, we introduce an analytical approach that is capable to predict the functional form of this property. Moreover, our results indicate that random scale-free networks models are not self-averaging, that is, the second moment of their degree distribution may va...

  2. NFP: An R Package for Characterizing and Comparing of Annotated Biological Networks.

    Science.gov (United States)

    Cao, Yang; Xu, Wenjian; Niu, Chao; Bo, Xiaochen; Li, Fei

    2017-01-01

    Large amounts of various biological networks exist for representing different types of interaction data, such as genetic, metabolic, gene regulatory, and protein-protein relationships. Recent approaches on biological network study are based on different mathematical concepts. It is necessary to construct a uniform framework to judge the functionality of biological networks. We recently introduced a knowledge-based computational framework that reliably characterized biological networks in system level. The method worked by making systematic comparisons to a set of well-studied "basic networks," measuring both the functional and topological similarities. A biological network could be characterized as a spectrum-like vector consisting of similarities to basic networks. Here, to facilitate the application, development, and adoption of this framework, we present an R package called NFP. This package extends our previous pipeline, offering a powerful set of functions for Network Fingerprint analysis. The software shows great potential in biological network study. The open source NFP R package is freely available under the GNU General Public License v2.0 at CRAN along with the vignette.

  3. NFP: An R Package for Characterizing and Comparing of Annotated Biological Networks

    Directory of Open Access Journals (Sweden)

    Yang Cao

    2017-01-01

    Full Text Available Large amounts of various biological networks exist for representing different types of interaction data, such as genetic, metabolic, gene regulatory, and protein-protein relationships. Recent approaches on biological network study are based on different mathematical concepts. It is necessary to construct a uniform framework to judge the functionality of biological networks. We recently introduced a knowledge-based computational framework that reliably characterized biological networks in system level. The method worked by making systematic comparisons to a set of well-studied “basic networks,” measuring both the functional and topological similarities. A biological network could be characterized as a spectrum-like vector consisting of similarities to basic networks. Here, to facilitate the application, development, and adoption of this framework, we present an R package called NFP. This package extends our previous pipeline, offering a powerful set of functions for Network Fingerprint analysis. The software shows great potential in biological network study. The open source NFP R package is freely available under the GNU General Public License v2.0 at CRAN along with the vignette.

  4. Estimation of furrow irrigation sediment loss using an artificial neural network

    Science.gov (United States)

    The area irrigated by furrow irrigation in the U.S. has been steadily decreasing but still represents about 20% of the total irrigated area in the U.S. Furrow irrigation sediment loss is a major water quality issue and a method for estimating sediment loss is needed to quantify the environmental imp...

  5. REFINED ALGORITHMS OF ELECTRICAL ENERGY LOSSES CALCULATION IN 0,38 KV NETWORKS IN REAL TIME

    Directory of Open Access Journals (Sweden)

    Miroshnyk A.

    2010-08-01

    Full Text Available An approach for closer definition of electrical energy losses size in air lines due to the accounting of environment temperature influence and flowing current size on the wire resistance is offered. Multifunctional microprocessor devices for energy losses calculation are elaborated.

  6. Single-subject morphological brain networks: connectivity mapping, topological characterization and test-retest reliability.

    Science.gov (United States)

    Wang, Hao; Jin, Xiaoqing; Zhang, Ye; Wang, Jinhui

    2016-04-01

    Structural MRI has long been used to characterize local morphological features of the human brain. Coordination patterns of the local morphological features among regions, however, are not well understood. Here, we constructed individual-level morphological brain networks and systematically examined their topological organization and long-term test-retest reliability under different analytical schemes of spatial smoothing, brain parcellation, and network type. This study included 57 healthy participants and all participants completed two MRI scan sessions. Individual morphological brain networks were constructed by estimating interregional similarity in the distribution of regional gray matter volume in terms of the Kullback-Leibler divergence measure. Graph-based global and nodal network measures were then calculated, followed by the statistical comparison and intra-class correlation analysis. The morphological brain networks were highly reproducible between sessions with significantly larger similarities for interhemispheric connections linking bilaterally homotopic regions. Further graph-based analyses revealed that the morphological brain networks exhibited nonrandom topological organization of small-worldness, high parallel efficiency and modular architecture regardless of the analytical choices of spatial smoothing, brain parcellation and network type. Moreover, several paralimbic and association regions were consistently revealed to be potential hubs. Nonetheless, the three studied factors particularly spatial smoothing significantly affected quantitative characterization of morphological brain networks. Further examination of long-term reliability revealed that all the examined network topological properties showed fair to excellent reliability irrespective of the analytical strategies, but performing spatial smoothing significantly improved reliability. Interestingly, nodal centralities were positively correlated with their reliabilities, and nodal degree

  7. Seismic Site Characterizations and Earthquake Loss Estimation Analyses for K-12 Schools in Washington State

    Science.gov (United States)

    Cakir, R.; Walsh, T. J.; Hayashi, K.; Norman, D. K.; Lau, T.; Scott, S.

    2016-12-01

    Washington State has the second-highest earthquake risk in the U.S. after only California, and major earthquakes in western Washington in 1946, 1949, 1965, and 2001 killed 15 people and caused billions of dollars' worth of property damage. Washington State has not been exempt from earthquake damage to school buildings. The mission of The Washington Department of Natural Resources-Division of Geology and Earth Resources is to "reduce or eliminate risks to life and property from natural hazards." We conducted active and passive seismic surveys, and estimated shear-wave velocity (Vs) profiles, then determined NEHRP soil classifications using calculated Vs30m values at public schools in Thurston, Grays Harbor, Walla Walla, Chelan and Okanogan counties, Washington. We used active and passive seismic surveys: 1D and 2D MASW and MAM, P- and S-wave refraction, horizontal-to-vertical spectral ratio (H/V), and 2-Station SPAC (2ST-SPAC) surveys to measure Vs and Vp at shallow (0-70m) and Vs at greater (10 to 500 or 10 -3000 meters) depths at the sites, respectively. We then ran Ground Penetrating Radar (GPR) surveys along each seismic line to check possible horizontal subsurface variations between the survey line and the actual location of the school buildings. These survey results were then used for calculations of Vs30m to determine the NEHRP site classifications at school sites. These site classes were also used for determining soil amplification effects on the ground motions affecting structural damage estimations of the school buildings. These seismic site characterization results associated with structural engineering evaluations were then used as inputs in FEMA Hazus-Advanced Engineering Building Module (AEBM) analysis to provide estimated casualties, nonstructural, and structural losses. The final AEBM loss estimation along with the more detailed structural evaluations will help school districts assess the earthquake performance of school buildings in order to

  8. Outward Accessibility in Urban Street Networks: Characterization and Improvements

    OpenAIRE

    Travençolo, Bruno Augusto Nassif; Costa, Luciano da Fontoura

    2008-01-01

    The dynamics of transportation through towns and cities is strongly affected by the topology of the connections and routes. The current work describes an approach combining complex networks and self-avoiding random walk dynamics in order to quantify in objective and accurate manner, along a range of spatial scales, the accessibility of places in towns and cities. The transition probabilities are estimated for several lengths of the walks and used to calculate the outward accessibility of each...

  9. Mesoscale Characterization of Supramolecular Transient Networks Using SAXS and Rheology

    Directory of Open Access Journals (Sweden)

    A. C. H. Pape

    2014-01-01

    Full Text Available Hydrogels and, in particular, supramolecular hydrogels show promising properties for application in regenerative medicine because of their ability to adapt to the natural environment these materials are brought into. However, only few studies focus on the structure-property relationships in supramolecular hydrogels. Here, we study in detail both the structure and the mechanical properties of such a network, composed of poly(ethylene glycol, end-functionalized with ureido-pyrimidinone fourfold hydrogen bonding units. This network is responsive to triggers such as concentration, temperature and pH. To obtain more insight into the sol-gel transition of the system, both rheology and small-angle X-ray scattering (SAXS are used. We show that the sol-gel transitions based on these three triggers, as measured by rheology, coincide with the appearance of a structural feature in SAXS. We attribute this feature to the presence of hydrophobic domains where cross-links are formed. These results provide more insight into the mechanism of network formation in these materials, which can be exploited for tailoring their behavior for biomedical applications, where one of the triggers discussed might be used.

  10. A hybrid ART-GRNN online learning neural network with a epsilon -insensitive loss function.

    Science.gov (United States)

    Yap, Keem Siah; Lim, Chee Peng; Abidin, Izham Zainal

    2008-09-01

    In this brief, a new neural network model called generalized adaptive resonance theory (GART) is introduced. GART is a hybrid model that comprises a modified Gaussian adaptive resonance theory (MGA) and the generalized regression neural network (GRNN). It is an enhanced version of the GRNN, which preserves the online learning properties of adaptive resonance theory (ART). A series of empirical studies to assess the effectiveness of GART in classification, regression, and time series prediction tasks is conducted. The results demonstrate that GART is able to produce good performances as compared with those of other methods, including the online sequential extreme learning machine (OSELM) and sequential learning radial basis function (RBF) neural network models.

  11. The Localized Discovery and Recovery for Query Packet Losses in Wireless Sensor Networks with Distributed Detector Clusters

    Directory of Open Access Journals (Sweden)

    Ryu Miura

    2013-06-01

    Full Text Available An essential application of wireless sensor networks is to successfully respond to user queries. Query packet losses occur in the query dissemination due to wireless communication problems such as interference, multipath fading, packet collisions, etc. The losses of query messages at sensor nodes result in the failure of sensor nodes reporting the requested data. Hence, the reliable and successful dissemination of query messages to sensor nodes is a non-trivial problem. The target of this paper is to enable highly successful query delivery to sensor nodes by localized and energy-efficient discovery, and recovery of query losses. We adopt local and collective cooperation among sensor nodes to increase the success rate of distributed discoveries and recoveries. To enable the scalability in the operations of discoveries and recoveries, we employ a distributed name resolution mechanism at each sensor node to allow sensor nodes to self-detect the correlated queries and query losses, and then efficiently locally respond to the query losses. We prove that the collective discovery of query losses has a high impact on the success of query dissemination and reveal that scalability can be achieved by using the proposed approach. We further study the novel features of the cooperation and competition in the collective recovery at PHY and MAC layers, and show that the appropriate number of detectors can achieve optimal successful recovery rate. We evaluate the proposed approach with both mathematical analyses and computer simulations. The proposed approach enables a high rate of successful delivery of query messages and it results in short route lengths to recover from query losses. The proposed approach is scalable and operates in a fully distributed manner.

  12. The localized discovery and recovery for query packet losses in wireless sensor networks with distributed detector clusters.

    Science.gov (United States)

    Teng, Rui; Leibnitz, Kenji; Miura, Ryu

    2013-06-07

    An essential application of wireless sensor networks is to successfully respond to user queries. Query packet losses occur in the query dissemination due to wireless communication problems such as interference, multipath fading, packet collisions, etc. The losses of query messages at sensor nodes result in the failure of sensor nodes reporting the requested data. Hence, the reliable and successful dissemination of query messages to sensor nodes is a non-trivial problem. The target of this paper is to enable highly successful query delivery to sensor nodes by localized and energy-efficient discovery, and recovery of query losses. We adopt local and collective cooperation among sensor nodes to increase the success rate of distributed discoveries and recoveries. To enable the scalability in the operations of discoveries and recoveries, we employ a distributed name resolution mechanism at each sensor node to allow sensor nodes to self-detect the correlated queries and query losses, and then efficiently locally respond to the query losses. We prove that the collective discovery of query losses has a high impact on the success of query dissemination and reveal that scalability can be achieved by using the proposed approach. We further study the novel features of the cooperation and competition in the collective recovery at PHY and MAC layers, and show that the appropriate number of detectors can achieve optimal successful recovery rate. We evaluate the proposed approach with both mathematical analyses and computer simulations. The proposed approach enables a high rate of successful delivery of query messages and it results in short route lengths to recover from query losses. The proposed approach is scalable and operates in a fully distributed manner.

  13. Efficient randomization of biological networks while preserving functional characterization of individual nodes.

    Science.gov (United States)

    Iorio, Francesco; Bernardo-Faura, Marti; Gobbi, Andrea; Cokelaer, Thomas; Jurman, Giuseppe; Saez-Rodriguez, Julio

    2016-12-20

    Networks are popular and powerful tools to describe and model biological processes. Many computational methods have been developed to infer biological networks from literature, high-throughput experiments, and combinations of both. Additionally, a wide range of tools has been developed to map experimental data onto reference biological networks, in order to extract meaningful modules. Many of these methods assess results' significance against null distributions of randomized networks. However, these standard unconstrained randomizations do not preserve the functional characterization of the nodes in the reference networks (i.e. their degrees and connection signs), hence including potential biases in the assessment. Building on our previous work about rewiring bipartite networks, we propose a method for rewiring any type of unweighted networks. In particular we formally demonstrate that the problem of rewiring a signed and directed network preserving its functional connectivity (F-rewiring) reduces to the problem of rewiring two induced bipartite networks. Additionally, we reformulate the lower bound to the iterations' number of the switching-algorithm to make it suitable for the F-rewiring of networks of any size. Finally, we present BiRewire3, an open-source Bioconductor package enabling the F-rewiring of any type of unweighted network. We illustrate its application to a case study about the identification of modules from gene expression data mapped on protein interaction networks, and a second one focused on building logic models from more complex signed-directed reference signaling networks and phosphoproteomic data. BiRewire3 it is freely available at https://www.bioconductor.org/packages/BiRewire/ , and it should have a broad application as it allows an efficient and analytically derived statistical assessment of results from any network biology tool.

  14. New hybrid frequency reuse method for packet loss minimization in LTE network.

    Science.gov (United States)

    Ali, Nora A; El-Dakroury, Mohamed A; El-Soudani, Magdi; ElSayed, Hany M; Daoud, Ramez M; Amer, Hassanein H

    2015-11-01

    This paper investigates the problem of inter-cell interference (ICI) in Long Term Evolution (LTE) mobile systems, which is one of the main problems that causes loss of packets between the base station and the mobile station. Recently, different frequency reuse methods, such as soft and fractional frequency reuse, have been introduced in order to mitigate this type of interference. In this paper, minimizing the packet loss between the base station and the mobile station is the main concern. Soft Frequency Reuse (SFR), which is the most popular frequency reuse method, is examined and the amount of packet loss is measured. In order to reduce packet loss, a new hybrid frequency reuse method is implemented. In this method, each cell occupies the same bandwidth of the SFR, but the total system bandwidth is greater than in SFR. This will provide the new method with a lot of new sub-carriers from the neighboring cells to reduce the ICI which represents a big problem in many applications and causes a lot of packets loss. It is found that the new hybrid frequency reuse method has noticeable improvement in the amount of packet loss compared to SFR method in the different frequency bands. Traffic congestion management in Intelligent Transportation system (ITS) is one of the important applications that is affected by the packet loss due to the large amount of traffic that is exchanged between the base station and the mobile node. Therefore, it is used as a studied application for the proposed frequency reuse method and the improvement in the amount of packet loss reached 49.4% in some frequency bands using the new hybrid frequency reuse method.

  15. Calorimetric Measuring Systems for Characterizing High Frequency Power Losses in Power Electronic Components and Systems

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Pedersen, John Kim; Ritchie, Andrew Ewen

    2002-01-01

    High frequency power losses in power electronic components and systems are very difficult to measure. The same applies to the efficiency of high-efficiency systems and components. An important method to measure losses with high accuracy is the calorimetric measuring systems. This paper describes...... two different calorimetric measuring systems, one for power losses up to 50 W and one for power losses up to 1500 W. These differ in size and also the systems which can be analysed. The basic concept of calorimetry is discussed and the overall performance of the two systems is specified. Methods...

  16. Characterization of Sound Transmission Loss of Laminated Glass with Analytical and Experimental Approaches

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xin; Simmons, Kevin L.; Khaleel, Mohammad A.

    2005-11-30

    In this project, we have developed the general formation for calculating transmission loss of sound waves through multi-layered structures. Full factorial design method has also been used to investigate the relative effect of various geometric and material parameters on the transmission loss. It was found that within the range of practical interest, the most effect way of increasing transmission loss is by increasing either the glass thickness or increasing the inner layer mass density. Experimental measurements of sound transmission loss (in decibels) for four laminated glass samples have been made in accordance to SAE J1400, in third-octave bands between 125 Hz and 8 kHz.

  17. Cultured Neural Networks: Optimization of Patterned Network Adhesiveness and Characterization of their Neural Activity

    Directory of Open Access Journals (Sweden)

    W. L. C. Rutten

    2006-01-01

    Full Text Available One type of future, improved neural interface is the “cultured probe”. It is a hybrid type of neural information transducer or prosthesis, for stimulation and/or recording of neural activity. It would consist of a microelectrode array (MEA on a planar substrate, each electrode being covered and surrounded by a local circularly confined network (“island” of cultured neurons. The main purpose of the local networks is that they act as biofriendly intermediates for collateral sprouts from the in vivo system, thus allowing for an effective and selective neuron–electrode interface. As a secondary purpose, one may envisage future information processing applications of these intermediary networks. In this paper, first, progress is shown on how substrates can be chemically modified to confine developing networks, cultured from dissociated rat cortex cells, to “islands” surrounding an electrode site. Additional coating of neurophobic, polyimide-coated substrate by triblock-copolymer coating enhances neurophilic-neurophobic adhesion contrast. Secondly, results are given on neuronal activity in patterned, unconnected and connected, circular “island” networks. For connected islands, the larger the island diameter (50, 100 or 150 μm, the more spontaneous activity is seen. Also, activity may show a very high degree of synchronization between two islands. For unconnected islands, activity may start at 22 days in vitro (DIV, which is two weeks later than in unpatterned networks.

  18. Geochemical characterization of oceanic basalts using Artificial Neural Network.

    Science.gov (United States)

    Das, Pranab; Iyer, Sridhar D

    2009-12-23

    The geochemical discriminate diagrams help to distinguish the volcanics recovered from different tectonic settings but these diagrams tend to group the ocean floor basalts (OFB) under one class i.e., as mid-oceanic ridge basalts (MORB). Hence, a method is specifically needed to identify the OFB as normal (N-MORB), enriched (E-MORB) and ocean island basalts (OIB). We have applied Artificial Neural Network (ANN) technique as a supervised Learning Vector Quantisation (LVQ) to identify the inherent geochemical signatures present in the Central Indian Ocean Basin (CIOB) basalts. A range of N-MORB, E-MORB and OIB dataset was used for training and testing of the network. Although the identification of the characters as N-MORB, E-MORB and OIB is completely dependent upon the training data set for the LVQ, but to a significant extent this method is found to be successful in identifying the characters within the CIOB basalts. The study helped to geochemically delineate the CIOB basalts as N-MORB with perceptible imprints of E-MORB and OIB characteristics in the form of moderately enriched rare earth and incompatible elements. Apart from the fact that the magmatic processes are difficult to be deciphered, the architecture performs satisfactorily.

  19. Geochemical characterization of oceanic basalts using Artificial Neural Network

    Directory of Open Access Journals (Sweden)

    Iyer Sridhar D

    2009-12-01

    Full Text Available Abstract The geochemical discriminate diagrams help to distinguish the volcanics recovered from different tectonic settings but these diagrams tend to group the ocean floor basalts (OFB under one class i.e., as mid-oceanic ridge basalts (MORB. Hence, a method is specifically needed to identify the OFB as normal (N-MORB, enriched (E-MORB and ocean island basalts (OIB. We have applied Artificial Neural Network (ANN technique as a supervised Learning Vector Quantisation (LVQ to identify the inherent geochemical signatures present in the Central Indian Ocean Basin (CIOB basalts. A range of N-MORB, E-MORB and OIB dataset was used for training and testing of the network. Although the identification of the characters as N-MORB, E-MORB and OIB is completely dependent upon the training data set for the LVQ, but to a significant extent this method is found to be successful in identifying the characters within the CIOB basalts. The study helped to geochemically delineate the CIOB basalts as N-MORB with perceptible imprints of E-MORB and OIB characteristics in the form of moderately enriched rare earth and incompatible elements. Apart from the fact that the magmatic processes are difficult to be deciphered, the architecture performs satisfactorily.

  20. Templated synthesis, characterization, and sensing application of macroscopic platinum nanowire network electrodes

    DEFF Research Database (Denmark)

    Wang, D. H.; Kou, R.; Gil, M. P.

    2005-01-01

    Abstract: Novel platinum nanowire network electrodes have been fabricated through electrodeposition using mesoporous silica thin films as templates. These electrodes were characterized by X-ray diffraction, transmission electron microscope, and scanning electron microscope. The electrochemical...... properties of the electrodes, such as electrochemical active area and methanol oxidation, have also been studied. Compared with conventional polycrystalline Pt electrodes, these novel nanowire network electrodes possess high electrochemical active areas and demonstrate higher current densities and a lower...

  1. Optimizing real power loss and voltage stability limit of a large transmission network using firefly algorithm

    Directory of Open Access Journals (Sweden)

    P. Balachennaiah

    2016-06-01

    Full Text Available This paper proposes a Firefly algorithm based technique to optimize the control variables for simultaneous optimization of real power loss and voltage stability limit of the transmission system. Mathematically, this issue can be formulated as nonlinear equality and inequality constrained optimization problem with an objective function integrating both real power loss and voltage stability limit. Transformers taps, unified power flow controller and its parameters have been included as control variables in the problem formulation. The effectiveness of the proposed algorithm has been tested on New England 39-bus system. Simulation results obtained with the proposed algorithm are compared with the real coded genetic algorithm for single objective of real power loss minimization and multi-objective of real power loss minimization and voltage stability limit maximization. Also, a classical optimization method known as interior point successive linear programming technique is considered here to compare the results of firefly algorithm for single objective of real power loss minimization. Simulation results confirm the potentiality of the proposed algorithm in solving optimization problems.

  2. Further characterization of diabetes mellitus and body weight loss in males of the congenic mouse strain DDD.Cg-Ay

    OpenAIRE

    Suto, Jun-ichi; Satou, Kunio

    2014-01-01

    The Ay allele at the agouti locus causes obesity and promotes linear growth in mice. However, body weight gain stops between 16 and 17 weeks after birth, and then, body weight decreases gradually in DDD.Cg-Ay male mice. Body weight loss is a consequence of diabetes mellitus, which is genetically controlled mainly by a quantitative trait locus (QTL) on chromosome 4. This study aimed to further characterize diabetes mellitus and body weight loss in DDD.Cg-Ay males. The number of ?-cells was mar...

  3. Characterization of low loss microstrip resonators as a building block for circuit QED in a 3D waveguide

    Science.gov (United States)

    Zoepfl, D.; Muppalla, P. R.; Schneider, C. M. F.; Kasemann, S.; Partel, S.; Kirchmair, G.

    2017-08-01

    Here we present the microwave characterization of microstrip resonators, made from aluminum and niobium, inside a 3D microwave waveguide. In the low temperature, low power limit internal quality factors of up to one million were reached. We found a good agreement to models predicting conductive losses and losses to two level systems for increasing temperature. The setup presented here is appealing for testing materials and structures, as it is free of wire bonds and offers a well controlled microwave environment. In combination with transmon qubits, these resonators serve as a building block for a novel circuit QED architecture inside a rectangular waveguide.

  4. Efficiency Loss of Mixed Equilibrium Associated with Altruistic Users and Logit-based Stochastic Users in Transportation Network

    Directory of Open Access Journals (Sweden)

    Xiao-Jun Yu

    2014-02-01

    Full Text Available The efficiency loss of mixed equilibrium associated with two categories of users is investigated in this paper. The first category of users are altruistic users (AU who have the same altruism coefficient and try to minimize their own perceived cost that assumed to be a linear combination of selfish com­ponent and altruistic component. The second category of us­ers are Logit-based stochastic users (LSU who choose the route according to the Logit-based stochastic user equilib­rium (SUE principle. The variational inequality (VI model is used to formulate the mixed route choice behaviours associ­ated with AU and LSU. The efficiency loss caused by the two categories of users is analytically derived and the relations to some network parameters are discussed. The numerical tests validate our analytical results. Our result takes the re­sults in the existing literature as its special cases.

  5. Interference Path Loss Prediction in A319/320 Airplanes Using Modulated Fuzzy Logic and Neural Networks

    Science.gov (United States)

    Jafri, Madiha J.; Ely, Jay J.; Vahala, Linda L.

    2007-01-01

    In this paper, neural network (NN) modeling is combined with fuzzy logic to estimate Interference Path Loss measurements on Airbus 319 and 320 airplanes. Interference patterns inside the aircraft are classified and predicted based on the locations of the doors, windows, aircraft structures and the communication/navigation system-of-concern. Modeled results are compared with measured data. Combining fuzzy logic and NN modeling is shown to improve estimates of measured data over estimates obtained with NN alone. A plan is proposed to enhance the modeling for better prediction of electromagnetic coupling problems inside aircraft.

  6. Functional characterization of GABAA receptor-mediated modulation of cortical neuron network activity in microelectrode array recordings

    National Research Council Canada - National Science Library

    Benjamin M Bader; Anne Steder; Anders Bue Klein; Bente Frølund; Olaf H U Schroeder; Anders A Jensen

    2017-01-01

    .... In this study we have investigated GABAAR-mediated modulation of the spontaneous activity patterns of primary neuronal networks from murine frontal cortex by characterizing the effects induced...

  7. Reliable Multi-Fractal Characterization of Weighted Complex Networks: Algorithms and Implications.

    Science.gov (United States)

    Xue, Yuankun; Bogdan, Paul

    2017-08-08

    Through an elegant geometrical interpretation, the multi-fractal analysis quantifies the spatial and temporal irregularities of the structural and dynamical formation of complex networks. Despite its effectiveness in unweighted networks, the multi-fractal geometry of weighted complex networks, the role of interaction intensity, the influence of the embedding metric spaces and the design of reliable estimation algorithms remain open challenges. To address these challenges, we present a set of reliable multi-fractal estimation algorithms for quantifying the structural complexity and heterogeneity of weighted complex networks. Our methodology uncovers that (i) the weights of complex networks and their underlying metric spaces play a key role in dictating the existence of multi-fractal scaling and (ii) the multi-fractal scaling can be localized in both space and scales. In addition, this multi-fractal characterization framework enables the construction of a scaling-based similarity metric and the identification of community structure of human brain connectome. The detected communities are accurately aligned with the biological brain connectivity patterns. This characterization framework has no constraint on the target network and can thus be leveraged as a basis for both structural and dynamic analysis of networks in a wide spectrum of applications.

  8. Using Discrete Loss Functions and Weighted Kappa for Classification: An Illustration Based on Bayesian Network Analysis

    Science.gov (United States)

    Zwick, Rebecca; Lenaburg, Lubella

    2009-01-01

    In certain data analyses (e.g., multiple discriminant analysis and multinomial log-linear modeling), classification decisions are made based on the estimated posterior probabilities that individuals belong to each of several distinct categories. In the Bayesian network literature, this type of classification is often accomplished by assigning…

  9. Quantitative thermography and methods for in-situ determination of heat losses from district heating networks

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, B. [ed.

    1996-11-01

    The course and seminar summarizing application of infrared thermography in district heating systems control gathered Danish specialists with 5 contributions on the subject. Maintenance of the heat distribution pipelines and thermographic inspection of the systems are essential in order to avoid heat losses. (EG)

  10. Assessing Losses of Power and Electrical Energy in Unbalanced Medium Voltage Distribution Networks

    Directory of Open Access Journals (Sweden)

    Toader C.

    2016-12-01

    Full Text Available The work is dedicated to calculating electricity losses related to power lines average voltage overhead or underground, which in terms of construction can be three-phase (three or four wire in unbalanced sinusoidal harmonic, determining energy efficiency indicators (such as positive and negative factors of unbalance thereof. It examines a case study and argues the results.

  11. Application of neural networks for the calculation of technical losses of electric energy in air power lines 6-35 kV

    OpenAIRE

    Володимир Леонідович Бакулевський

    2015-01-01

    A model for the calculation of technical losses of electricity in the air lines with voltage of 6-35 kV based on neural networks with due regard to meteorological factors has been worked out; the main components of the model have been considered and researched; the best ones being selected, that is: a set of input variables, volume of excerpts (training, control and testing), architecture and network activation function, network learning algorithm was proposed. Simulation was conducted in OS ...

  12. Can't wait to lose weight? Characterizing temporal discounting parameters for weight-loss.

    Science.gov (United States)

    Lim, Seung-Lark; Bruce, Amanda S

    2015-02-01

    Obesity is often related to steeper temporal discounting, that is, higher decision impulsivity for immediate rewards over delayed rewards. However, previous studies have measured temporal discounting parameters through monetary rewards. The aim of this study was to develop a temporal discounting measure based on weight-loss rewards, which may help to understand decision-making mechanisms more closely related to body weight regulation. After having their heights and weights measured, healthy young adults completed the Monetary Choice Questionnaire (MCQ), and an adapted version of the MCQ, with weight-loss as a reward. Participants also completed self-reports that measure obesity-related cognitive variables. For 42 participants who expressed a desire to lose weight, weight-loss rewards were discounted over time and had a positive correlation with temporal discounting for monetary rewards. Higher temporal discounting for weight loss rewards (i.e., preference for immediate weight loss) showed correlations with beliefs that obesity is under obese persons' control and largely due to lack of willpower, while temporal discounting parameters for monetary rewards did not. Taken together, our weight loss temporal discounting measure demonstrated both convergent and divergent validity, which can be utilized for future obesity research and interventions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Exploratory Literature Meta-Analysis to Characterize the Relationship Between Early and Longer Term Body Weight Loss for Antiobesity Compounds.

    Science.gov (United States)

    Plock, Nele; Bax, Leon; Lee, Douglas; DeManno, Deborah; Lahu, Gezim; Pfister, Marc

    2017-01-01

    The presented analysis was performed to characterize the relationship between treatment-related early (week 4) and longer term (3-6 months) weight loss to understand the potential utility of 4-week proof-of-mechanism studies in the early decision-making process during clinical development of new antiobesity compounds. A regression-based meta-analysis was performed leveraging publically available clinical outcomes data to (1) characterize the within-trial relationship between treatment-related early and longer term body weight loss and (2) identify and quantify key covariate effects on this relationship. Data from 89 randomized clinical trials with 209 treatment arms, representing observations from 54 461 patients and 9 treatments, were available for the meta-analysis. Results indicated that (1) there is a correlation between treatment-related early and longer term body weight loss (r > 0.9), (2) baseline body weight influences the relationship between early and longer term weight loss, whereas comorbidity such as type 2 diabetes mellitus, class of drugs including GLP-1 analogues and the antiobesity compounds lorcaserin or phentermine/topiramate showed no significant effects on this relationship. The model was externally evaluated with data from the investigational compound beloranib, for which longer term weight loss could be successfully predicted based on early response data. Based on these results, the identified strong relationship between treatment-related early and longer term weight loss appears to be independent of mechanism of action. Thus, findings from this analysis can optimize design of clinical studies and facilitate development of new anti-obesity compounds. © 2016, The American College of Clinical Pharmacology.

  14. Loss of 'small-world' networks in Alzheimer's disease: graph analysis of FMRI resting-state functional connectivity.

    Directory of Open Access Journals (Sweden)

    Ernesto J Sanz-Arigita

    Full Text Available BACKGROUND: Local network connectivity disruptions in Alzheimer's disease patients have been found using graph analysis in BOLD fMRI. Other studies using MEG and cortical thickness measures, however, show more global long distance connectivity changes, both in functional and structural imaging data. The form and role of functional connectivity changes thus remains ambiguous. The current study shows more conclusive data on connectivity changes in early AD using graph analysis on resting-state condition fMRI data. METHODOLOGY/PRINCIPAL FINDINGS: 18 mild AD patients and 21 healthy age-matched control subjects without memory complaints were investigated in resting-state condition with MRI at 1.5 Tesla. Functional coupling between brain regions was calculated on the basis of pair-wise synchronizations between regional time-series. Local (cluster coefficient and global (path length network measures were quantitatively defined. Compared to controls, the characteristic path length of AD functional networks is closer to the theoretical values of random networks, while no significant differences were found in cluster coefficient. The whole-brain average synchronization does not differ between Alzheimer and healthy control groups. Post-hoc analysis of the regional synchronization reveals increased AD synchronization involving the frontal cortices and generalized decreases located at the parietal and occipital regions. This effectively translates in a global reduction of functional long-distance links between frontal and caudal brain regions. CONCLUSIONS/SIGNIFICANCE: We present evidence of AD-induced changes in global brain functional connectivity specifically affecting long-distance connectivity. This finding is highly relevant for it supports the anterior-posterior disconnection theory and its role in AD. Our results can be interpreted as reflecting the randomization of the brain functional networks in AD, further suggesting a loss of global information

  15. Loss of 'small-world' networks in Alzheimer's disease: graph analysis of FMRI resting-state functional connectivity.

    Science.gov (United States)

    Sanz-Arigita, Ernesto J; Schoonheim, Menno M; Damoiseaux, Jessica S; Rombouts, Serge A R B; Maris, Erik; Barkhof, Frederik; Scheltens, Philip; Stam, Cornelis J

    2010-11-01

    Local network connectivity disruptions in Alzheimer's disease patients have been found using graph analysis in BOLD fMRI. Other studies using MEG and cortical thickness measures, however, show more global long distance connectivity changes, both in functional and structural imaging data. The form and role of functional connectivity changes thus remains ambiguous. The current study shows more conclusive data on connectivity changes in early AD using graph analysis on resting-state condition fMRI data. 18 mild AD patients and 21 healthy age-matched control subjects without memory complaints were investigated in resting-state condition with MRI at 1.5 Tesla. Functional coupling between brain regions was calculated on the basis of pair-wise synchronizations between regional time-series. Local (cluster coefficient) and global (path length) network measures were quantitatively defined. Compared to controls, the characteristic path length of AD functional networks is closer to the theoretical values of random networks, while no significant differences were found in cluster coefficient. The whole-brain average synchronization does not differ between Alzheimer and healthy control groups. Post-hoc analysis of the regional synchronization reveals increased AD synchronization involving the frontal cortices and generalized decreases located at the parietal and occipital regions. This effectively translates in a global reduction of functional long-distance links between frontal and caudal brain regions. We present evidence of AD-induced changes in global brain functional connectivity specifically affecting long-distance connectivity. This finding is highly relevant for it supports the anterior-posterior disconnection theory and its role in AD. Our results can be interpreted as reflecting the randomization of the brain functional networks in AD, further suggesting a loss of global information integration in disease.

  16. An X-band waveguide measurement technique for the accurate characterization of materials with low dielectric loss permittivity.

    Science.gov (United States)

    Allen, Kenneth W; Scott, Mark M; Reid, David R; Bean, Jeffrey A; Ellis, Jeremy D; Morris, Andrew P; Marsh, Jeramy M

    2016-05-01

    In this work, we present a new X-band waveguide (WR90) measurement method that permits the broadband characterization of the complex permittivity for low dielectric loss tangent material specimens with improved accuracy. An electrically long polypropylene specimen that partially fills the cross-section is inserted into the waveguide and the transmitted scattering parameter (S21) is measured. The extraction method relies on computational electromagnetic simulations, coupled with a genetic algorithm, to match the experimental S21 measurement. The sensitivity of the technique to sample length was explored by simulating specimen lengths from 2.54 to 15.24 cm, in 2.54 cm increments. Analysis of our simulated data predicts the technique will have the sensitivity to measure loss tangent values on the order of 10(-3) for materials such as polymers with relatively low real permittivity values. The ability to accurately characterize low-loss dielectric material specimens of polypropylene is demonstrated experimentally. The method was validated by excellent agreement with a free-space focused-beam system measurement of a polypropylene sheet. This technique provides the material measurement community with the ability to accurately extract material properties of low-loss material specimen over the entire X-band range. This technique could easily be extended to other frequency bands.

  17. Characterizing individual differences in reward sensitivity from the brain networks involved in response inhibition.

    Science.gov (United States)

    Fuentes-Claramonte, Paola; Ávila, César; Rodríguez-Pujadas, Aina; Costumero, Víctor; Ventura-Campos, Noelia; Bustamante, Juan Carlos; Rosell-Negre, Patricia; Barrós-Loscertales, Alfonso

    2016-01-01

    A "disinhibited" cognitive profile has been proposed for individuals with high reward sensitivity, characterized by increased engagement in goal-directed responses and reduced processing of negative or unexpected cues, which impairs adequate behavioral regulation after feedback in these individuals. This pattern is manifested through deficits in inhibitory control and/or increases in RT variability. In the present work, we aimed to test whether this profile is associated with the activity of functional networks during a stop-signal task using independent component analysis (ICA). Sixty-one participants underwent fMRI while performing a stop-signal task, during which a manual response had to be inhibited. ICA was used to mainly replicate the functional networks involved in the task (Zhang and Li, 2012): two motor networks involved in the go response, the left and right fronto-parietal networks for stopping, a midline error-processing network, and the default-mode network (DMN), which was further subdivided into its anterior and posterior parts. Reward sensitivity was mainly associated with greater activity of motor networks, reduced activity in the midline network during correct stop trials and, behaviorally, increased RT variability. All these variables explained 36% of variance of the SR scores. This pattern of associations suggests that reward sensitivity involves greater motor engagement in the dominant response, more distractibility and reduced processing of salient or unexpected events, which may lead to disinhibited behavior. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. A hybrid framework for reservoir characterization using fuzzy ranking and an artificial neural network

    Science.gov (United States)

    Wang, Baijie; Wang, Xin; Chen, Zhangxin

    2013-08-01

    Reservoir characterization refers to the process of quantitatively assigning reservoir properties using all available field data. Artificial neural networks (ANN) have recently been introduced to solve reservoir characterization problems dealing with the complex underlying relationships inherent in well log data. Despite the utility of ANNs, the current limitation is that most existing applications simply focus on directly implementing existing ANN models instead of improving/customizing them to fit the specific reservoir characterization tasks at hand. In this paper, we propose a novel intelligent framework that integrates fuzzy ranking (FR) and multilayer perceptron (MLP) neural networks for reservoir characterization. FR can automatically identify a minimum subset of well log data as neural inputs, and the MLP is trained to learn the complex correlations from the selected well log data to a target reservoir property. FR guarantees the selection of the optimal subset of representative data from the overall well log data set for the characterization of a specific reservoir property; and, this implicitly improves the modeling and predication accuracy of the MLP. In addition, a growing number of industrial agencies are implementing geographic information systems (GIS) in field data management; and, we have designed the GFAR solution (GIS-based FR ANN Reservoir characterization solution) system, which integrates the proposed framework into a GIS system that provides an efficient characterization solution. Three separate petroleum wells from southwestern Alberta, Canada, were used in the presented case study of reservoir porosity characterization. Our experiments demonstrate that our method can generate reliable results.

  19. Improved Robust Stability Criterion of Networked Control Systems with Transmission Delays and Packet Loss

    Directory of Open Access Journals (Sweden)

    Shenping Xiao

    2014-01-01

    Full Text Available The problem of stability analysis for a class of networked control systems (NCSs with network-induced delay and packet dropout is investigated in this paper. Based on the working mechanism of zero-order holder, the closed-loop NCS is modeled as a continuous-time linear system with input delay. By introducing a novel Lyapunov-Krasovskii functional which splits both the lower and upper bounds of the delay into two subintervals, respectively, and utilizes reciprocally convex combination technique, a new stability criterion is derived in terms of linear matrix inequalities. Compared with previous results in the literature, the obtained stability criterion is less conservative. Numerical examples demonstrate the validity and feasibility of the proposed method.

  20. Reservoir characterization using artificial neural network; Neural network wo mochiita choryuso tokusei kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Shimada, N.; Kozawa, T. [Japan National Oil Corp., Tokyo (Japan); Nishikawa, N.; Tani, A. [Fuji Research Institute Corp., Tokyo (Japan)

    1997-05-27

    Neural network is used for the prediction of porosity and permeability using logging data as reservoir characteristics, and the validity of this method is verified. For the prediction of reservoir characteristics by the use of seismic survey data, composite seismic survey records obtained by density logging and acoustic logging are used to experiment the prediction of porosity and permeability continuous along lines of wells. A 3-output back propagation network is used for analysis. There is a possibility that this technique when optimized will improve on prediction accuracy. Furthermore, in the case of characteristics mapping, 3-dimensional seismic data is applied to a carbonate rock reservoir for predicting spatial porosity and permeability. This technique facilitates the comprehensive analysis of core data, well data, and seismic survey data, enabling the derivation of a high-precision spatial distribution of reservoir characteristics. Efforts will continue for further improvement on prediction accuracy. 6 refs., 7 figs., 3 tabs.

  1. Dual-frequency characterization of bending loss in hollow flexible terahertz waveguides

    Science.gov (United States)

    Doradla, Pallavi; Giles, Robert H.

    2014-03-01

    Low-loss, hollow, flexible, metal-coated waveguides were designed and fabricated for the maximal transmission of terahertz radiation. Since recent terahertz skin, colon, and breast cancer studies showed a contrast between normal and diseased tissues between 500 to 600GHz frequencies, flexible metal-coated waveguides with various bore diameters were studied at both 584GHz and 1.4THz frequencies for endoscopic applications. Attenuation characteristics of 2μm thick silver-coated waveguides with 99% reflective inner surface were measured as a function of wavelength, bore diameter, bending angle and bend radius. Though the theoretical attenuation coefficient in metal-coated waveguide varies directly as square of wavelength, the propagation loss was found to be smaller at higher wavelengths. This study demonstrates that flexible waveguides with bore diameters less-than 10λ preserve the linearly polarized mode and hence exhibit low bending losses even at smaller bend radii. Also, in contrast to the lower propagation losses in larger bore tubes, the analysis shows higher transmission in smaller bore tubes at larger bending angles. Finally, the dual-frequency investigation of bending and modal characteristics confirms the feasibility of using these metal-coated flexible waveguides at various terahertz frequencies, to obtain low transmission losses even at greater flexures, in addition to the Gaussian mode preservation.

  2. A Flexible Load Control Strategy for Distribution Network to Reduce the Line Losses and to Eliminate the Transmission Congestion

    Directory of Open Access Journals (Sweden)

    Beibei Wang

    2017-01-01

    Full Text Available There are many uncertain factors in the modern distribution network, including the access of renewable energy sources and the heavy load level. The existence of these factors has brought challenges to the stability of the power distribution network, as well as increasing the risk of exceeding transmission capacity of distribution lines. The appearance of flexible load control technology provides a new idea to solve the above problems. Air conditioners (ACs account for a great proportion of all loads. In this paper, the model of dispatching AC loads in the regional power grid is constructed, and the direct load control (DLC method is adopted to reduce the load of ACs. An improved tabu search technique is proposed to solve the problem of network dispatch in distribution systems in order to reduce the resistive line losses and to eliminate the transmission congestion in lines under normal operating conditions. The optimal node solution is obtained to find the best location and reduction capacity of ACs for load control. To demonstrate the validity and effectiveness of the proposed method, a test system is studied. The numerical results are also given in this article, which reveal that the proposed method is promising.

  3. Characterization of hairless (Hr) and FGF5 genes provides insights into the molecular basis of hair loss in cetaceans.

    Science.gov (United States)

    Chen, Zhuo; Wang, Zhengfei; Xu, Shixia; Zhou, Kaiya; Yang, Guang

    2013-02-09

    Hair is one of the main distinguishing characteristics of mammals and it has many important biological functions. Cetaceans originated from terrestrial mammals and they have evolved a series of adaptations to aquatic environments, which are of evolutionary significance. However, the molecular mechanisms underlying their aquatic adaptations have not been well explored. This study provided insights into the evolution of hair loss during the transition from land to water by investigating and comparing two essential regulators of hair follicle development and hair follicle cycling, i.e., the Hairless (Hr) and FGF5 genes, in representative cetaceans and their terrestrial relatives. The full open reading frame sequences of the Hr and FGF5 genes were characterized in seven cetaceans. The sequence characteristics and evolutionary analyses suggested the functional loss of the Hr gene in cetaceans, which supports the loss of hair during their full adaptation to aquatic habitats. By contrast, positive selection for the FGF5 gene was found in cetaceans where a series of positively selected amino acid residues were identified. This is the first study to investigate the molecular basis of the hair loss in cetaceans. Our investigation of Hr and FGF5, two indispensable regulators of the hair cycle, provide some new insights into the molecular basis of hair loss in cetaceans. The results suggest that positive selection for the FGF5 gene might have promoted the termination of hair growth and early entry into the catagen stage of hair follicle cycling. Consequently, the hair follicle cycle was disrupted and the hair was lost completely due to the loss of the Hr gene function in cetaceans. This suggests that cetaceans have evolved an effective and complex mechanism for hair loss.

  4. Chromosome 3p loss of heterozygosity is associated with a unique metabolic network in clear cell renal carcinoma

    Science.gov (United States)

    Gatto, Francesco; Nookaew, Intawat; Nielsen, Jens

    2014-01-01

    Several common oncogenic pathways have been implicated in the emergence of renowned metabolic features in cancer, which in turn are deemed essential for cancer proliferation and survival. However, the extent to which different cancers coordinate their metabolism to meet these requirements is largely unexplored. Here we show that even in the heterogeneity of metabolic regulation a distinct signature encompassed most cancers. On the other hand, clear cell renal cell carcinoma (ccRCC) strongly deviated in terms of metabolic gene expression changes, showing widespread down-regulation. We observed a metabolic shift that associates differential regulation of enzymes in one-carbon metabolism with high tumor stage and poor clinical outcome. A significant yet limited set of metabolic genes that explained the partial divergence of ccRCC metabolism correlated with loss of von Hippel-Lindau tumor suppressor (VHL) and a potential activation of signal transducer and activator of transcription 1. Further network-dependent analyses revealed unique defects in nucleotide, one-carbon, and glycerophospholipid metabolism at the transcript and protein level, which contrasts findings in other tumors. Notably, this behavior is recapitulated by recurrent loss of heterozygosity in multiple metabolic genes adjacent to VHL. This study therefore shows how loss of heterozygosity, hallmarked by VHL deletion in ccRCC, may uniquely shape tumor metabolism. PMID:24550497

  5. Discrete Fracture Network Characterization of Fractured Shale Reservoirs with Implications to Hydraulic Fracturing Optimization

    Science.gov (United States)

    Jin, G.

    2016-12-01

    Shales are important petroleum source rocks and reservoir seals. Recent developments in hydraulic fracturing technology have facilitated high gas production rates from shale and have had a strong impact on the U.S. gas supply and markets. Modeling of effective permeability for fractured shale reservoirs has been challenging because the presence of a fracture network significantly alters the reservoir hydrologic properties. Due to the frequent occurrence of fracture networks, it is of vital importance to characterize fracture networks and to investigate how these networks can be used to optimize the hydraulic fracturing. We have conducted basic research on 3-D fracture permeability characterization and compartmentization analyses for fractured shale formations, which takes the advantages of the discrete fracture networks (DFN). The DFN modeling is a stochastic modeling approach using the probabilistic density functions of fractures. Three common scenarios of DFN models have been studied for fracture permeability mapping using our previously proposed techniques. In DFN models with moderately to highly concentrated fractures, there exists a representative element volume (REV) for fracture permeability characterization, which indicates that the fractured reservoirs can be treated as anisotropic homogeneous media. Hydraulic fracturing will be most effective if the orientation of the hydraulic fracture is perpendicular to the mean direction of the fractures. A DFN model with randomized fracture orientations, on the other hand, lacks an REV for fracture characterization. Therefore, a fracture permeability tensor has to be computed from each element. Modeling of fracture interconnectivity indicates that there exists no preferred direction for hydraulic fracturing to be most effective oweing to the interconnected pathways of the fracture network. 3-D fracture permeability mapping has been applied to the Devonian Chattanooga Shale in Alabama and the results suggest that an

  6. Family factors that characterize adolescents with severe obesity and their role in weight loss surgery outcomes.

    Science.gov (United States)

    Zeller, Meg H; Hunsaker, Sanita; Mikhail, Carmen; Reiter-Purtill, Jennifer; McCullough, Mary Beth; Garland, Beth; Austin, Heather; Washington, Gia; Baughcum, Amy; Rofey, Dana; Smith, Kevin

    2016-12-01

    To comprehensively assess family characteristics of adolescents with severe obesity and whether family factors impact weight loss outcomes following weight loss surgery (WLS). Multisite prospective data from 138 adolescents undergoing WLS and primary caregivers (adolescent: Mage  = 16.9; MBMI = 51.5 kg/m(2) ; caregiver: Mage  = 44.5; 93% female) and 83 nonsurgical comparators (NSComp: adolescent: Mage  = 16.1; MBMI = 46.9 kg/m(2) ; caregiver: Mage  = 43.9; 94% female) were collected using standardized measures at presurgery/baseline and at 1 and 2 years. The majority (77.3%) of caregivers had obesity, with rates of caregiver WLS significantly higher in the WLS (23.8%) versus NSComp group (3.7%, P < 0.001). Family dysfunction was prevalent (≈1 in every two to three families), with rates higher for NSComp than the WLS group. For the WLS group, preoperative family factors (i.e., caregiver BMI or WLS history, dysfunction, social support) were not significant predictors of adolescent weight loss at 1 and 2 years postoperatively, although change in family functioning over time emerged as a significant correlate of percent weight loss. Rates of severe obesity in caregivers as well as family dysfunction were clinically noteworthy, although not related to adolescent weight loss success following WLS. However, change in family communication and emotional climate over time emerged as potential targets to optimize weight loss outcomes. © 2016 The Obesity Society.

  7. Spatiotemporal alterations of cortical network activity by selective loss of NOS-expressing interneurons .

    Directory of Open Access Journals (Sweden)

    Dan eShlosberg

    2012-02-01

    Full Text Available Deciphering the role of GABAergic neurons in large neuronal networks such as the neocortex forms a particularly complex task as they comprise a highly diverse population. The neuronal isoform of the enzyme nitric oxide synthase (nNOS is expressed in the neocortex by specific subsets of GABAergic neurons. These neurons can be identified in live brain slices by the nitric oxide (NO fluorescent indicator DAF-2DA. However, this indicator was found to be highly toxic to the stained neurons. We used this feature to induce acute phototoxic damage to NO-producing neurons in cortical slices, and measured subsequent alterations in parameters of cellular and network activity.Neocortical slices were briefly incubated in DAF-2DA and then illuminated through the 4X objective. Histochemistry for NADPH diaphorase, a marker for nNOS activity, revealed elimination of staining in the illuminated areas following treatment. Whole cell recordings from several neuronal types before, during and after illumination confirmed the selective damage to non fast-spiking interneurons. Treated slices displayed mild disinhibition. The reversal potential of compound synaptic events on pyramidal neurons became more positive, and their decay time constant was elongated, substantiating the removal of an inhibitory conductance. The horizontal decay of local field potentials (LFPs was significantly reduced at distances of 300-400 m from the stimulation, but not when inhibition was non-selectively weakened with the GABAA blocker picrotoxin. Finally, whereas the depression of LFPs along short trains of 40 Hz stimuli was linearly reduced with distance or initial amplitude in control slices, this ordered relationship was disrupted in DAF-treated slices. These results reveal that NO-producing interneurons in the neocortex convey lateral inhibition to neighboring columns, and shape the spatiotemporal dynamics of the network's activity.

  8. Initial Characterization of Optical Communications with Disruption-Tolerant Network Protocols

    Science.gov (United States)

    Schoolcraft, Joshua; Wilson, Keith

    2011-01-01

    Disruption-tolerant networks (DTNs) are groups of network assets connected with a suite of communication protocol technologies designed to mitigate the effects of link delay and disruption. Application of DTN protocols to diverse groups of network resources in multiple sub-networks results in an overlay network-of-networks with autonomous data routing capability. In space environments where delay or disruption is expected, performance of this type of architecture (such as an interplanetary internet) can increase with the inclusion of new communications mediums and techniques. Space-based optical communication links are therefore an excellent building block of space DTN architectures. When compared to traditional radio frequency (RF) communications, optical systems can provide extremely power-efficient and high bandwidth links bridging sub-networks. Because optical links are more susceptible to link disruption and experience the same light-speed delays as RF, optical-enabled DTN architectures can lessen potential drawbacks and maintain the benefits of autonomous optical communications over deep space distances. These environment-driven expectations - link delay and interruption, along with asymmetric data rates - are the purpose of the proof-of-concept experiment outlined herein. In recognizing the potential of these two technologies, we report an initial experiment and characterization of the performance of a DTN-enabled space optical link. The experiment design employs a point-to-point free-space optical link configured to have asymmetric bandwidth. This link connects two networked systems running a DTN protocol implementation designed and written at JPL for use on spacecraft, and further configured for higher bandwidth performance. Comparing baseline data transmission metrics with and without periodic optical link interruptions, the experiment confirmed the DTN protocols' ability to handle real-world unexpected link outages while maintaining capability of

  9. Characterization of the Neisseria gonorrhoeae Iron and Fur Regulatory Network.

    Science.gov (United States)

    Yu, Chunxiao; McClure, Ryan; Nudel, Kathleen; Daou, Nadine; Genco, Caroline Attardo

    2016-08-15

    The Neisseria gonorrhoeae ferric uptake regulator (Fur) protein controls expression of iron homeostasis genes in response to intracellular iron levels. In this study, using transcriptome sequencing (RNA-seq) analysis of an N. gonorrhoeae fur strain, we defined the gonococcal Fur and iron regulons and characterized Fur-controlled expression of an ArsR-like DNA binding protein. We observed that 158 genes (8% of the genome) showed differential expression in response to iron in an N. gonorrhoeae wild-type or fur strain, while 54 genes exhibited differential expression in response to Fur. The Fur regulon was extended to additional regulators, including NrrF and 13 other small RNAs (sRNAs), and two transcriptional factors. One transcriptional factor, coding for an ArsR-like regulator (ArsR), exhibited increased expression under iron-replete conditions in the wild-type strain but showed decreased expression across iron conditions in the fur strain, an effect that was reversed in a fur-complemented strain. Fur was shown to bind to the promoter region of the arsR gene downstream of a predicted σ(70) promoter region. Electrophoretic mobility shift assay (EMSA) analysis confirmed binding of the ArsR protein to the norB promoter region, and sequence analysis identified two additional putative targets, NGO1411 and NGO1646. A gonococcal arsR strain demonstrated decreased survival in human endocervical epithelial cells compared to that of the wild-type and arsR-complemented strains, suggesting that the ArsR regulon includes genes required for survival in host cells. Collectively, these results demonstrate that the N. gonorrhoeae Fur functions as a global regulatory protein to repress or activate expression of a large repertoire of genes, including additional transcriptional regulatory proteins. Gene regulation in bacteria in response to environmental stimuli, including iron, is of paramount importance to both bacterial replication and, in the case of pathogenic bacteria

  10. Spectral characterization of hierarchical network modularity and limits of modularity detection.

    Science.gov (United States)

    Sarkar, Somwrita; Henderson, James A; Robinson, Peter A

    2013-01-01

    Many real world networks are reported to have hierarchically modular organization. However, there exists no algorithm-independent metric to characterize hierarchical modularity in a complex system. The main results of the paper are a set of methods to address this problem. First, classical results from random matrix theory are used to derive the spectrum of a typical stochastic block model hierarchical modular network form. Second, it is shown that hierarchical modularity can be fingerprinted using the spectrum of its largest eigenvalues and gaps between clusters of closely spaced eigenvalues that are well separated from the bulk distribution of eigenvalues around the origin. Third, some well-known results on fingerprinting non-hierarchical modularity in networks automatically follow as special cases, threreby unifying these previously fragmented results. Finally, using these spectral results, it is found that the limits of detection of modularity can be empirically established by studying the mean values of the largest eigenvalues and the limits of the bulk distribution of eigenvalues for an ensemble of networks. It is shown that even when modularity and hierarchical modularity are present in a weak form in the network, they are impossible to detect, because some of the leading eigenvalues fall within the bulk distribution. This provides a threshold for the detection of modularity. Eigenvalue distributions of some technological, social, and biological networks are studied, and the implications of detecting hierarchical modularity in real world networks are discussed.

  11. Changes of the directional brain networks related with brain plasticity in patients with long-term unilateral sensorineural hearing loss.

    Science.gov (United States)

    Zhang, G-Y; Yang, M; Liu, B; Huang, Z-C; Li, J; Chen, J-Y; Chen, H; Zhang, P-P; Liu, L-J; Wang, J; Teng, G-J

    2016-01-28

    Previous studies often report that early auditory deprivation or congenital deafness contributes to cross-modal reorganization in the auditory-deprived cortex, and this cross-modal reorganization limits clinical benefit from cochlear prosthetics. However, there are inconsistencies among study results on cortical reorganization in those subjects with long-term unilateral sensorineural hearing loss (USNHL). It is also unclear whether there exists a similar cross-modal plasticity of the auditory cortex for acquired monaural deafness and early or congenital deafness. To address this issue, we constructed the directional brain functional networks based on entropy connectivity of resting-state functional MRI and researched changes of the networks. Thirty-four long-term USNHL individuals and seventeen normally hearing individuals participated in the test, and all USNHL patients had acquired deafness. We found that certain brain regions of the sensorimotor and visual networks presented enhanced synchronous output entropy connectivity with the left primary auditory cortex in the left long-term USNHL individuals as compared with normally hearing individuals. Especially, the left USNHL showed more significant changes of entropy connectivity than the right USNHL. No significant plastic changes were observed in the right USNHL. Our results indicate that the left primary auditory cortex (non-auditory-deprived cortex) in patients with left USNHL has been reorganized by visual and sensorimotor modalities through cross-modal plasticity. Furthermore, the cross-modal reorganization also alters the directional brain functional networks. The auditory deprivation from the left or right side generates different influences on the human brain. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  12. Carbon induced extreme ultraviolet (EUV) reflectance loss characterized using visible-light ellipsometry

    NARCIS (Netherlands)

    Chen, Juequan; Chen, Juequan; Louis, Eric; Louis, Eric; Wormeester, Herbert; Harmsen, Rob; van de Kruijs, Robbert Wilhelmus Elisabeth; Lee, Christopher James; van Schaik, Willem; Bijkerk, Frederik

    2011-01-01

    Carbon deposition on extreme ultraviolet (EUV) optics was observed due to photon-induced dissociation of hydrocarbons in a EUV lithography environment. The reflectance loss of the multilayer mirror is determined by the carbon layer thickness and density. To study the influence of various forms of

  13. Reason's Enemy Is Not Emotion: Engagement of Cognitive Control Networks Explains Biases in Gain/Loss Framing.

    Science.gov (United States)

    Li, Rosa; Smith, David V; Clithero, John A; Venkatraman, Vinod; Carter, R McKell; Huettel, Scott A

    2017-03-29

    In the classic gain/loss framing effect, describing a gamble as a potential gain or loss biases people to make risk-averse or risk-seeking decisions, respectively. The canonical explanation for this effect is that frames differentially modulate emotional processes, which in turn leads to irrational choice behavior. Here, we evaluate the source of framing biases by integrating functional magnetic resonance imaging data from 143 human participants performing a gain/loss framing task with meta-analytic data from >8000 neuroimaging studies. We found that activation during choices consistent with the framing effect were most correlated with activation associated with the resting or default brain, while activation during choices inconsistent with the framing effect was most correlated with the task-engaged brain. Our findings argue against the common interpretation of gain/loss framing as a competition between emotion and control. Instead, our study indicates that this effect results from differential cognitive engagement across decision frames. SIGNIFICANCE STATEMENT The biases frequently exhibited by human decision makers have often been attributed to the presence of emotion. Using a large fMRI sample and analysis of whole-brain networks defined with the meta-analytic tool Neurosynth, we find that neural activity during frame-biased decisions was more significantly associated with default behaviors (and the absence of executive control) than with emotion. These findings point to a role for neuroscience in shaping long-standing psychological theories in decision science. Copyright © 2017 the authors 0270-6474/17/373588-11$15.00/0.

  14. Integrated workflow for characterizing and modeling fracture network in unconventional reservoirs using microseismic data

    Science.gov (United States)

    Ayatollahy Tafti, Tayeb

    We develop a new method for integrating information and data from different sources. We also construct a comprehensive workflow for characterizing and modeling a fracture network in unconventional reservoirs, using microseismic data. The methodology is based on combination of several mathematical and artificial intelligent techniques, including geostatistics, fractal analysis, fuzzy logic, and neural networks. The study contributes to scholarly knowledge base on the characterization and modeling fractured reservoirs in several ways; including a versatile workflow with a novel objective functions. Some the characteristics of the methods are listed below: 1. The new method is an effective fracture characterization procedure estimates different fracture properties. Unlike the existing methods, the new approach is not dependent on the location of events. It is able to integrate all multi-scaled and diverse fracture information from different methodologies. 2. It offers an improved procedure to create compressional and shear velocity models as a preamble for delineating anomalies and map structures of interest and to correlate velocity anomalies with fracture swarms and other reservoir properties of interest. 3. It offers an effective way to obtain the fractal dimension of microseismic events and identify the pattern complexity, connectivity, and mechanism of the created fracture network. 4. It offers an innovative method for monitoring the fracture movement in different stages of stimulation that can be used to optimize the process. 5. Our newly developed MDFN approach allows to create a discrete fracture network model using only microseismic data with potential cost reduction. It also imposes fractal dimension as a constraint on other fracture modeling approaches, which increases the visual similarity between the modeled networks and the real network over the simulated volume.

  15. Nanoscale Chemical Evolution of Silicon Negative Electrodes Characterized by Low-Loss STEM-EELS

    CERN Document Server

    Boniface, Maxime; Danet, Julien; Guyomard, Dominique; Moreau, Philippe; Bayle-Guillemaud, Pascale

    2016-01-01

    Continuous solid electrolyte interface (SEI) formation remains the limiting factor of the lifetime of silicon nanoparticles (SiNPs) based negative electrodes. Methods that could provide clear diagnosis of the electrode degradation are of utmost necessity to streamline further developments. We demonstrate that electron energy-loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM) can be used to quickly map SEI components and quantify LixSi alloys from single experiments, with resolutions down to 5 nm. Exploiting the low-loss part of the EEL spectrum allowed us to circumvent the degradation phenomena that have so far crippled the application of this technique on such beam-sensitive compounds. Our results provide unprecedented insight into silicon aging mechanisms in full cell configuration. We observe the morphology of the SEI to be extremely heterogeneous at the particle scale but with clear chemical evolutions with extended cycling coming from both SEI accumulation and a transition fro...

  16. Characterization of physiological networks in sleep apnea patients using artificial neural networks for Granger causality computation

    Science.gov (United States)

    Cárdenas, Jhon; Orjuela-Cañón, Alvaro D.; Cerquera, Alexander; Ravelo, Antonio

    2017-11-01

    Different studies have used Transfer Entropy (TE) and Granger Causality (GC) computation to quantify interconnection between physiological systems. These methods have disadvantages in parametrization and availability in analytic formulas to evaluate the significance of the results. Other inconvenience is related with the assumptions in the distribution of the models generated from the data. In this document, the authors present a way to measure the causality that connect the Central Nervous System (CNS) and the Cardiac System (CS) in people diagnosed with obstructive sleep apnea syndrome (OSA) before and during treatment with continuous positive air pressure (CPAP). For this purpose, artificial neural networks were used to obtain models for GC computation, based on time series of normalized powers calculated from electrocardiography (EKG) and electroencephalography (EEG) signals recorded in polysomnography (PSG) studies.

  17. Characterizing momentum change and viscous loss of a hemodynamic endpoint in assessment of coronary lesions.

    Science.gov (United States)

    Banerjee, Rupak K; Sinha Roy, Abhijit; Back, Lloyd H; Back, Martin R; Khoury, Saeb F; Millard, Ronald W

    2007-01-01

    Myocardial fractional flow reserve (FFR(myo)) and coronary flow reserve (CFR), measured with guidewire, and quantitative angiography (QA) are widely used in combination to distinguish ischemic from non-ischemic coronary stenoses. Recent studies have shown that simultaneous measurements of FFR(myo) and CFR are recommended to dissociate conduit epicardial coronary stenoses from distal resistance microvascular disease. In this study, a more comprehensive diagnostic parameter, named as lesion flow coefficient, c, is proposed. The coefficient, c, which accounts for mean pressure drop, Delta p, mean coronary flow, Q, and percentage area stenosis, can be used to assess the hemodynamic severity of a coronary artery stenoses. Importantly, the contribution of viscous loss and loss due to momentum change for several lesion sizes can be distinguished using c. FFR(myo), CFR and c were calculated for pre-angioplasty, intermediate and post-angioplasty epicardial lesions, without microvascular disease. While hyperemic c decreased from 0.65 for pre-angioplasty to 0.48 for post-angioplasty lesion with guidewire of size 0.35 mm, FFR(myo) increased from 0.52 to 0.87, and CFR increased from 1.72 to 3.45, respectively. Thus, reduced loss produced by momentum change due to lower percentage area stenosis decreased c. For post-angioplasty lesion, c decreased from 0.55 to 0.48 with the insertion of guidewire. Hence, increased viscous loss due to the presence of guidewire decreased c compared with a lesion without guidewire. Further, c showed a linear relationship with FFR(myo), CFR and percentage area stenosis for pre-angioplasty, intermediate and post-angioplasty lesion. These baseline values of c were developed from fluid dynamics fundamentals for focal lesions, and provided a single hemodynamic endpoint to evaluate coronary stenosis severity.

  18. Characterization of solidified gas thin film targets via alpha particle energy loss

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, M.C. [British Columbia Univ., Vancouver, BC (Canada). Dept. of Phys. and Astron.; Beer, G.A.; Douglas, J.L.; Knowles, P.E.; Maier, M.; Mason, G.R.; Porcelli, T.A. [Department of Physics and Astronomy, University of Victoria, Victoria, BC, V8W 2Y2 (Canada); Beveridge, J.L.; Marshall, G.M.; Mulhauser, F.; Olin, A. [TRIUMF, Vancouver, BC, V6T 2A3 (Canada); Huber, T.M. [Department of Physics, Gustavus Adolphus College, St.Peter, MN 56082 (United States); Jacot-Guillarmod, R. [Physics Institute, Universite de Fribourg, CH-1700 Fribourg (Switzerland); Kim, S.K. [Department of Physics, Jeonbuk National University, Jeonju City 560-756 (Korea, Republic of); Kunselman, A.R. [Department of Physics, University of Wyoming, Laramie, WY 82071 (United States); Petitjean, C. [Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Zmeskal, J. [Austrian Academy of Sciences, A-1090 Wien (Austria); TRIUMF Collaboration

    1997-08-11

    A method is reported for measuring the thickness and uniformity of thin films of solidified gas targets. The energy of {alpha} particles traversing the film is measured and the energy loss is converted to thickness using the range. The uniformity is determined by measuring the thickness at different positions with an array of sources. Monte Carlo simulations have been performed to study the film deposition mechanism. Thickness calibrations for a TRIUMF solid hydrogen target system are presented. (orig.).

  19. Artificial Neural Networks for reconstruction of energy losses in dead materials between barrel LAr and Tile calorimeters exploration and results

    CERN Document Server

    Budagov, Yu A; Kulchitskii, Yu A; Rusakovitch, N A; Shigaev, V N; Tsiareshka, P V

    2008-01-01

    In the course of computational experiments with Monte-Carlo events for ATLAS Combined Test Beam 2004 setup Artificial Neural Networks (ANN) technique was applied for reconstruction of energy losses in dead materials between barrel LAr and Tile calorimeters (Edm). The constructed ANN procedures exploit as their input vectors the information content of different sets of variables (parameters) which describe particular features of the hadronic shower of an event in ATLAS calorimeters. It was shown that application of ANN procedures allows one to reach 40% reduction of the Edm reconstruction error compared to the conventional procedure used in ATLAS collaboration. Impact of various features of a shower on the precision of $Edm$ reconstruction is presented in detail. It was found that longitudinal shower profile information brings greater improvement in $Edm$ reconstruction accuracy than cell energies information in LAr3 and Tile1 samplings.

  20. ATHENA (Advanced Thermal Hydraulic Energy Network Analyzer) simulation of a loss of coolant accident in a space reactor

    Energy Technology Data Exchange (ETDEWEB)

    Roth, P.A.; Shumway, R.W.

    1988-01-01

    The Advanced Thermal Hydraulic Energy Network Analyzer (ATHENA) code was used to simulate a loss-of-coolant accident (LOCA) in a conceptual space reactor design. ATHENA provides the capability of simulating the thermal-hydraulic behavior of the wide variety of systems which are being considered for use in space reactors. Flow loops containing any one of several available working fluids may interact through thermal connections with other loops containing the same or a different working fluid. The code can be used to model special systems such as: heat pipes, point reactor kinetics, plant control systems, turbines, valves, and pumps. This work demonstrates the application of the thermal radiation model which has been recently incorporated into ATHENA and verifies the need for supplemental reactor cooling to prevent reactor fuel damage in the event of a LOCA.

  1. Examining Social Influence on Participation and Outcomes among a Network of Behavioral Weight-Loss Intervention Enrollees

    Directory of Open Access Journals (Sweden)

    T. L. Carson

    2013-01-01

    Full Text Available Research suggests that social networks, social support, and social influence are associated with weight trajectories among treatment- and non-treatment-seeking individuals. This study examined the impact of having a social contact who participated in the same group behavioral weight-control intervention in the absence of specific social support training on women engaged in a weight-loss program. Participants (n=92; 100% female; 54% black; mean age: 46±10 years; mean BMI: 38±6 were grouped based upon whether or not they reported a social contact enrolled previously/concurrently in our behavioral weight-control studies. Primary outcomes were 6-month weight change and treatment adherence (session attendance and self-monitoring. Half of the participants (53% indicated that they had a social contact; black women were more likely to report a social contact than white women (67.3% versus 39.5%; P<0.01. Among participants with a social contact, 67% reported at least one contact as instrumental in the decision to enroll in the program. Those with a contact lost more weight (5.9 versus 3.7 kg; P=0.04, attended more group sessions (74% versus 54%; P<0.01, and submitted more self-monitoring journals (69% versus 54%; P=0.01 than those without a contact. Participants' weight change was inversely associated with social contacts' weight change (P=0.04. There was no association between participant and contact’s group attendance or self-monitoring. Social networks may be a promising vehicle for recruiting and engaging women in a behavioral weight-loss program, particularly black women. The role of a natural social contact deserves further investigation.

  2. Design and characterization of chemical space networks for different compound data sets.

    Science.gov (United States)

    Zwierzyna, Magdalena; Vogt, Martin; Maggiora, Gerald M; Bajorath, Jürgen

    2015-02-01

    Chemical Space Networks (CSNs) are generated for different compound data sets on the basis of pairwise similarity relationships. Such networks are thought to complement and further extend traditional coordinate-based views of chemical space. Our proof-of-concept study focuses on CSNs based upon fingerprint similarity relationships calculated using the conventional Tanimoto similarity metric. The resulting CSNs are characterized with statistical measures from network science and compared in different ways. We show that the homophily principle, which is widely considered in the context of social networks, is a major determinant of the topology of CSNs of bioactive compounds, designed as threshold networks, typically giving rise to community structures. Many properties of CSNs are influenced by numerical features of the conventional Tanimoto similarity metric and largely dominated by the edge density of the networks, which depends on chosen similarity threshold values. However, properties of different CSNs with constant edge density can be directly compared, revealing systematic differences between CSNs generated from randomly collected or bioactive compounds.

  3. Evolutionary conservation and network structure characterize genes of phenotypic relevance for mitosis in human.

    Directory of Open Access Journals (Sweden)

    Marek Ostaszewski

    Full Text Available The impact of gene silencing on cellular phenotypes is difficult to establish due to the complexity of interactions in the associated biological processes and pathways. A recent genome-wide RNA knock-down study both identified and phenotypically characterized a set of important genes for the cell cycle in HeLa cells. Here, we combine a molecular interaction network analysis, based on physical and functional protein interactions, in conjunction with evolutionary information, to elucidate the common biological and topological properties of these key genes. Our results show that these genes tend to be conserved with their corresponding protein interactions across several species and are key constituents of the evolutionary conserved molecular interaction network. Moreover, a group of bistable network motifs is found to be conserved within this network, which are likely to influence the network stability and therefore the robustness of cellular functioning. They form a cluster, which displays functional homogeneity and is significantly enriched in genes phenotypically relevant for mitosis. Additional results reveal a relationship between specific cellular processes and the phenotypic outcomes induced by gene silencing. This study introduces new ideas regarding the relationship between genotype and phenotype in the context of the cell cycle. We show that the analysis of molecular interaction networks can result in the identification of genes relevant to cellular processes, which is a promising avenue for future research.

  4. Further characterization of diabetes mellitus and body weight loss in males of the congenic mouse strain DDD.Cg-Ay

    Science.gov (United States)

    SUTO, Jun-ichi; SATOU, Kunio

    2014-01-01

    The Ay allele at the agouti locus causes obesity and promotes linear growth in mice. However, body weight gain stops between 16 and 17 weeks after birth, and then, body weight decreases gradually in DDD.Cg-Ay male mice. Body weight loss is a consequence of diabetes mellitus, which is genetically controlled mainly by a quantitative trait locus (QTL) on chromosome 4. This study aimed to further characterize diabetes mellitus and body weight loss in DDD.Cg-Ay males. The number of β-cells was markedly reduced, and plasma insulin levels were very low in the DDD.Cg-Ay males. Using a backcross progeny of DDD × (B6 × DDD.Cg-Ay) F1-Ay, we identified one significant QTL for plasma insulin levels on distal chromosome 4, which was coincidental with QTL for hyperglycemia and lower body weight. The DDD allele was associated with decreased plasma insulin levels. When the DDD.Cg-Ay males were housed under three different housing conditions [group housing (4 or 5 DDD.Cg-Ay and DDD males), individual housing (single DDD.Cg-Ay male) and single male housing with females (single DDD.Cg-Ay male with DDD.Cg-Ay or DDD females)], diabetes mellitus and body weight loss were most severely expressed in individually housed mice. Thus, the severity of diabetes and body weight loss in the DDD.Cg-Ay males was strongly influenced by the housing conditions. These results demonstrate that both genetic and nongenetic environmental factors are involved in the development of diabetes mellitus and body weight loss in the DDD.Cg-Ay males. PMID:25373882

  5. Characterization of the Usage of the Serine Metabolic Network in Human Cancer

    Directory of Open Access Journals (Sweden)

    Mahya Mehrmohamadi

    2014-11-01

    Full Text Available The serine, glycine, one-carbon (SGOC metabolic network is implicated in cancer pathogenesis, but its general functions are unknown. We carried out a computational reconstruction of the SGOC network and then characterized its expression across thousands of cancer tissues. Pathways including methylation and redox metabolism exhibited heterogeneous expression indicating a strong context dependency of their usage in tumors. From an analysis of coexpression, simultaneous up- or downregulation of nucleotide synthesis, NADPH, and glutathione synthesis was found to be a common occurrence in all cancers. Finally, we developed a method to trace the metabolic fate of serine using stable isotopes, high-resolution mass spectrometry, and a mathematical model. Although the expression of single genes didn’t appear indicative of flux, the collective expression of several genes in a given pathway allowed for successful flux prediction. Altogether, these findings identify expansive and heterogeneous functions for the SGOC metabolic network in human cancer.

  6. Preparation and characterization of interpenetrating networks based on polyacrylates and poly(lactic acid

    Directory of Open Access Journals (Sweden)

    H. Kaczmarek

    2012-01-01

    Full Text Available Three different, multifunctional acrylic monomers were photopolymerized in a matrix of poly(lactic acid, PLA, using 2-hydroxy-2-methyl-1-phenyl-propan-1-one as a photoinitiator. The kinetics of the photopolymerization of monomers in PLA, studied with Fourier Transform Infrared Spectroscopy, has been compared to analogous processes of pure monomers under the same conditions (room temperature, air atmosphere. Additionally, poly(ethylene glycol was added to acrylate/PLA blends as plasticizer.The highly crosslinked networks obtained were characterized by FTIR and optical microscopy. The amount of insoluble gel has been estimated gravimetrically. It was found that the studied systems are characterized by very high polymerization rate, moreover, efficient grafting of polyacrylates on PLA takes place. The observed morphology indicates the heterogeneity of formed networks. The glass transition temperature of PLA in studied blends has been determined by differential scanning calorimetry.

  7. Characterization of scintillator materials for fast-ion loss detectors in nuclear fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Jiménez-Ramos, M.C., E-mail: mcyjr@us.es [Centro Nacional de Aceleradores (U. Sevilla, J. Andalucia, CSIC), Av. Thomas A. Edison 7, Isla de la Cartuja, 41902 Seville (Spain); García López, J.; García-Muñoz, M. [Centro Nacional de Aceleradores (U. Sevilla, J. Andalucia, CSIC), Av. Thomas A. Edison 7, Isla de la Cartuja, 41902 Seville (Spain); Dpto. Física Atómica, Molecular y Nuclear, Universidad de Sevilla, 41080 Sevilla (Spain); Rodríguez-Ramos, M.; Carmona Gázquez, M. [Centro Nacional de Aceleradores (U. Sevilla, J. Andalucia, CSIC), Av. Thomas A. Edison 7, Isla de la Cartuja, 41902 Seville (Spain); Zurro, B. [Laboratorio Nacional de Fusión, Asociación Euratom-CIEMAT, Av. Complutense 22, E-28040, Madrid (Spain)

    2014-08-01

    In fusion plasma reactors, fast ion generated by heating systems and fusion born particles must be well confined. The presence of magnetohydrodynamic (MHD) instabilities can lead to a significant loss of these ions, which may reduce drastically the heating efficiency and may cause damage to plasma facing components in the vacuum vessel. In order to understand the physics underlying the fast ion loss mechanism, scintillator based detectors have been installed in several fusion devices. In this work we present the absolute photon yield and its degradation with ion fluence in terms of the number of photons emitted per incident ion of several scintillators thin coatings: SrGa{sub 2}S{sub 4}:Eu{sup 2+} (TG-Green), Y{sub 3}Al{sub 5}O{sub 12}:Ce{sup 3+} (P46) and Y{sub 2}O{sub 3}:Eu{sup 3+} (P56) when irradiated with light ions of different masses (deuterium ions, protons and α-particles) at energies between approximately 575 keV and 3 MeV. The photon yield will be discussed in terms of the energy deposited by the particles into the scintillator. For that, the actual composition and thickness of the thin layers were determined by Rutherford Backscattering Spectrometry (RBS)

  8. Stimulus-response paradigm for characterizing the loss of resilience in homeostatic regulation associated with frailty.

    Science.gov (United States)

    Varadhan, R; Seplaki, C L; Xue, Q L; Bandeen-Roche, K; Fried, L P

    2008-11-01

    Frailty is a state of health signified by an increased vulnerability to adverse health outcomes in the face of stressors (e.g. infection). There is emerging consensus that research on both the theory and measurement of frailty must focus on the dynamic interactions within and across systems underlying the frailty syndrome. In this paper, we propose a dynamical systems modeling approach, based on the stimulus-response experimental paradigm, to propel future advances in the study of frailty. Our proposal is novel in that it provides a quantitative framework to operationalize and test the core notion underlying frailty that it signifies a loss of resilience in homeostatic regulation. The proposed framework offers many important benefits, including (a) insights into whether and how homeostatic regulation differs between frail and non-frail older adults, (b) identification of critical regulatory systems, if they exist, that could function as sentinel systems for screening and early detection of frailty, (c) establishment of the value of provocative tests that can provide maximal information on the integrity of systems identified in (b), and (d) evaluation and unification of diverse empirical descriptions of frailty by providing a mathematical framework anchored in quantifying the loss of resilience, an essential property of frailty.

  9. A Formal Approach to the Selection by Minimum Error and Pattern Method for Sensor Data Loss Reduction in Unstable Wireless Sensor Network Communications.

    Science.gov (United States)

    Kim, Changhwa; Shin, DongHyun

    2017-05-12

    There are wireless networks in which typically communications are unsafe. Most terrestrial wireless sensor networks belong to this category of networks. Another example of an unsafe communication network is an underwater acoustic sensor network (UWASN). In UWASNs in particular, communication failures occur frequently and the failure durations can range from seconds up to a few hours, days, or even weeks. These communication failures can cause data losses significant enough to seriously damage human life or property, depending on their application areas. In this paper, we propose a framework to reduce sensor data loss during communication failures and we present a formal approach to the Selection by Minimum Error and Pattern (SMEP) method that plays the most important role for the reduction in sensor data loss under the proposed framework. The SMEP method is compared with other methods to validate its effectiveness through experiments using real-field sensor data sets. Moreover, based on our experimental results and performance comparisons, the SMEP method has been validated to be better than others in terms of the average sensor data value error rate caused by sensor data loss.

  10. Characterizing Social Interaction in Tobacco-Oriented Social Networks: An Empirical Analysis

    OpenAIRE

    Yunji Liang; Xiaolong Zheng; Daniel Dajun Zeng; Xingshe Zhou; Scott James Leischow; Wingyan Chung

    2015-01-01

    Social media is becoming a new battlefield for tobacco ?wars?. Evaluating the current situation is very crucial for the advocacy of tobacco control in the age of social media. To reveal the impact of tobacco-related user-generated content, this paper characterizes user interaction and social influence utilizing social network analysis and information theoretic approaches. Our empirical studies demonstrate that the exploding pro-tobacco content has long-lasting effects with more active users a...

  11. Co-citation, bibliographic coupling and a characterization of lattice citation networks

    OpenAIRE

    Egghe, Leo; Rousseau, Ronald

    2002-01-01

    In this article we study directed, acyclic graphs. We introduce the head and tail order relations and study some of their properties. Recalling the notions of generalized bibliographic coupling and generalized co-citation, and introducing a new property, called the l - property, we come to a characterization of lattices. As document citation networks are concrete realizations of directed acyclic graphs all our results are directly applicable to citation analysis. bibliographic coupling; co...

  12. Algorithm and Program for Calculation and Analysis of Modes and Losses of Electric Energy in Electricity Distribution Networks of 6–20 kV

    Directory of Open Access Journals (Sweden)

    M. Fursanov

    2013-01-01

    Full Text Available A refined mathematical model and algorithm for operative control of the modes and detection of energy loss sites in electricity distribution networks of 6–20 kV have been developed in the paper. The developed software program can be used for testing other technical solutions and computer programs pertaining to the area of research and it is considered as one of the most important components applied for creation of intellectual electric networks.

  13. A computational model for path loss in wireless sensor networks in orchard environments.

    Science.gov (United States)

    Anastassiu, Hristos T; Vougioukas, Stavros; Fronimos, Theodoros; Regen, Christian; Petrou, Loukas; Zude, Manuela; Käthner, Jana

    2014-03-12

    A computational model for radio wave propagation through tree orchards is presented. Trees are modeled as collections of branches, geometrically approximated by cylinders, whose dimensions are determined on the basis of measurements in a cherry orchard. Tree canopies are modeled as dielectric spheres of appropriate size. A single row of trees was modeled by creating copies of a representative tree model positioned on top of a rectangular, lossy dielectric slab that simulated the ground. The complete scattering model, including soil and trees, enhanced by periodicity conditions corresponding to the array, was characterized via a commercial computational software tool for simulating the wave propagation by means of the Finite Element Method. The attenuation of the simulated signal was compared to measurements taken in the cherry orchard, using two ZigBee receiver-transmitter modules. Near the top of the tree canopies (at 3 m), the predicted attenuation was close to the measured one-just slightly underestimated. However, at 1.5 m the solver underestimated the measured attenuation significantly, especially when leaves were present and, as distances grew longer. This suggests that the effects of scattering from neighboring tree rows need to be incorporated into the model. However, complex geometries result in ill conditioned linear systems that affect the solver's convergence.

  14. The LCO Follow-up and Characterization Network and AgentNEO Citizen Science Project

    Science.gov (United States)

    Lister, Tim; Greenstreet, Sarah; Gomez, Edward; Christensen, Eric J.; Larson, Stephen M.

    2017-10-01

    The LCO NEO Follow-up Network is using the telescopes of the Las Cumbres Observatory (LCO) and a web-based target selection, scheduling and data reduction system to confirm NEO candidates and characterize radar-targeted known NEOs. Starting in July 2014, the LCO NEO Follow-up Network has observed over 4,500 targets and reported more than 25,000 astrometric and photometric measurements to the Minor Planet Center.The LCO NEO Follow-up Network's main aims are to perform confirming follow-up of the large number of NEO candidates and to perform characterization measurements of radar targets to obtain light curves and rotation rates. The NEO candidates come from the NEO surveys such as Catalina, PanSTARRS, ATLAS, NEOWISE and others. In particular, we are targeting objects in the Southern Hemisphere, where the LCO NEO Follow-up Network is the largest resource for NEO observations.The first phase of the LCO Network comprises nine 1-meter and seven 0.4-meter telescopes at site at McDonald Observatory (Texas), Cerro Tololo (Chile), SAAO (South Africa) and Siding Spring Observatory (Australia). The network has been fully operational since 2014 May, and observations are being executed remotely and robotically. Additional 0.4-meter telescopes will be deployed in 2017 and 2x1-meter telescopes for a site at Ali Observatory, Tibet are planned for 2018-2019.We have developed web-based software called NEOexchange which automatically downloads and aggregates NEO candidates from the Minor Planet Center's NEO Confirmation Page, the Arecibo and Goldstone radar target lists and the NASA lists. NEOexchange allows the planning and scheduling of observations on the LCO Telescope Network and the tracking of the resulting blocks and generated data. We have extended the NEOexchange software to include automated scheduling and moving object detection, with the results presented to the user via the website.We will present results from the LCO NEO Follow-up Network and from the development of the

  15. Loss-of-flow transient characterization in carbide-fueled LMFBRs

    Science.gov (United States)

    Rothrock, R. B.; Morgan, M. M.; Baars, R. E.; Elson, J. S.; Wray, M. L.

    One of the benefits derived from the use of carbide fuel in advanced liquid metal fast breeder reactors (LMFBRs) is a decreased vulnerability to certaiin accidents. This can be achieved through the combination of advanced fuel performance with the enhanced reactivity feedback effects and passive shutdown cooling systems characteristic of the current inherently safe plant concepts. The calculated core response to an unprotected loss of flow (ULOF) accident has frequently been used as a benchmark test of these designs, and the advantages of a high-conductivity fuel in relation to this type of transient have been noted in previous analyses. To evaluate this benefit in carbide-fueled LMFBRs incorporating representative current plant design features, limited calculations have been made of a ULOF transient in a small (modular) carbide-fueled LMFBR.

  16. Characterizing the weathering induced haze formation and gloss loss of poly(ethylene-terephthalate) via MaPd:RTS spectroscopy

    Science.gov (United States)

    Gordon, Devin A.; Gok, Abdulkerim; Meyer, Corey W.; Fagerholm, Cara L.; Sweet, Noah W.; DeNoyer, Lin; Bruckman, Laura S.; French, Roger H.

    2016-09-01

    Poly(ethylene-terephthalate) (PET) film is a widely used material in photovoltaic module backsheets, for its dielectric breakdown strength, and in optical displays for its excellent combination of properties, notably optical clarity. However, PET degrades and loses optical clarity under environmental stressors of heat, moisture, and ultraviolet irradiance. Stabilizers are often included in PET formulation to increase its longevity; however, even these are subject to degradation and further reduce optical clarity. In a previous study, it was found that material yellowing is dominant with UV light exposures while moisture mostly causes hazing of the samples. Lifetime service prediction models were developed for PET from yellowing and hazing responses. To study the loss of optical clarity in PET films, samples of a UV-stabilized grade of PET were exposed to heat, moisture, and UV irradiance as prescribed by ASTM-G154 Cycle 4 and their optical properties were studied over time. Surface gloss loss and bulk haze formation were observed as primary material responses to degradation; after the first 168 hour exposure step an initial three-fold increase in bulk haze and a two-fold reduction in gloss were observed. Multi-Angle, Polarization-Dependent, Reflection, Transmission, and Scattering (MaPd:RTS) spectroscopy was employed to fully characterize the haze formation and gloss loss of the PET films under exposure.

  17. Characterization of the loss of SUMO pathway function on cancer cells and tumor proliferation.

    Directory of Open Access Journals (Sweden)

    Xingyue He

    Full Text Available SUMOylation is a post-translational ubiquitin-like protein modification pathway that regulates important cellular processes including chromosome structure, kinetochore function, chromosome segregation, nuclear and sub-nuclear organization, transcription and DNA damage repair. There is increasing evidence that the SUMO pathway is dysregulated in cancer, raising the possibility that modulation of this pathway may have therapeutic potential. To investigate the importance of the SUMO pathway in the context of cancer cell proliferation and tumor growth, we applied lentivirus-based short hairpin RNAs (shRNA to knockdown SUMO pathway genes in human cancer cells. shRNAs for SAE2 and UBC9 reduced SUMO conjugation activity and inhibited proliferation of human cancer cells. To expand upon these observations, we generated doxycycline inducible conditional shRNA cell lines for SAE2 to achieve acute and reversible SAE2 knockdown. Conditional SAE2 knockdown in U2OS and HCT116 cells slowed cell growth in vitro, and SAE2 knockdown induced multiple terminal outcomes including apoptosis, endoreduplication and senescence. Multinucleated cells became senescent and stained positive for the senescence marker, SA-β Gal, and displayed elevated levels of p53 and p21. In an attempt to explain these phenotypes, we confirmed that loss of SUMO pathway activity leads to a loss of SUMOylated Topoisomerase IIα and the appearance of chromatin bridges which can impair proper cytokinesis and lead to multinucleation. Furthermore, knockdown of SAE2 induces disruption of PML nuclear bodies which may further promote apoptosis or senescence. In an in vivo HCT116 xenograft tumor model, conditional SAE2 knockdown strongly impaired tumor growth. These data demonstrate that the SUMO pathway is required for cancer cell proliferation in vitro and tumor growth in vivo, implicating the SUMO pathway as a potential cancer therapeutic target.

  18. Feasibility of a network of excellence postharvest food losses : combining knowledge and competences to reduce food losses in developing and emerging economies

    NARCIS (Netherlands)

    Gogh, van J.B.; Aramyan, L.H.; Sluis, van der A.A.; Soethoudt, J.M.; Scheer, F.P.

    2013-01-01

    Motivation: food security & postharvest losses Fruits and vegetables supply chains in developing countries are characterised by relatively high losses between harvest and consumption. In general, the postharvest system includes all stages in the chain where the activity/service is intended to

  19. Expeditious Calculations of Electric Power Losses in 0.38–10 kV Electric Networks of Belarusian United Energy Systems

    Directory of Open Access Journals (Sweden)

    M. Fursanov

    2013-01-01

    Full Text Available An algorithmized methodology for expedi­tious calculations of technical losses in 0.38–10 kV electric networks of the Belarusian United Energy Systems has been developed on the basis of performance information which is formed by modern intellectual devices for registration and accumulation of data. The methodology allows to increase the accuracy in calculation of losses using more exact distribution of loadings between consumers of transformer substations and analyze an incremental value of  losses due to their asymmetrical connection of consumers and circuit asymmetry.

  20. Brain network characterization of high-risk preterm-born school-age children

    Directory of Open Access Journals (Sweden)

    Elda Fischi-Gomez

    2016-01-01

    Full Text Available Higher risk for long-term cognitive and behavioral impairments is one of the hallmarks of extreme prematurity (EP and pregnancy-associated fetal adverse conditions such as intrauterine growth restriction (IUGR. While neurodevelopmental delay and abnormal brain function occur in the absence of overt brain lesions, these conditions have been recently associated with changes in microstructural brain development. Recent imaging studies indicate changes in brain connectivity, in particular involving the white matter fibers belonging to the cortico-basal ganglia-thalamic loop. Furthermore, EP and IUGR have been related to altered brain network architecture in childhood, with reduced network global capacity, global efficiency and average nodal strength. In this study, we used a connectome analysis to characterize the structural brain networks of these children, with a special focus on their topological organization. On one hand, we confirm the reduced averaged network node degree and strength due to EP and IUGR. On the other, the decomposition of the brain networks in an optimal set of clusters remained substantially different among groups, talking in favor of a different network community structure. However, and despite the different community structure, the brain networks of these high-risk school-age children maintained the typical small-world, rich-club and modularity characteristics in all cases. Thus, our results suggest that brain reorganizes after EP and IUGR, prioritizing a tight modular structure, to maintain the small-world, rich-club and modularity characteristics. By themselves, both extreme prematurity and IUGR bear a similar risk for neurocognitive and behavioral impairment, and the here defined modular network alterations confirm similar structural changes both by IUGR and EP at school age compared to control. Interestingly, the combination of both conditions (IUGR + EP does not result in a worse outcome. In such cases, the alteration

  1. Brain network characterization of high-risk preterm-born school-age children.

    Science.gov (United States)

    Fischi-Gomez, Elda; Muñoz-Moreno, Emma; Vasung, Lana; Griffa, Alessandra; Borradori-Tolsa, Cristina; Monnier, Maryline; Lazeyras, François; Thiran, Jean-Philippe; Hüppi, Petra S

    2016-01-01

    Higher risk for long-term cognitive and behavioral impairments is one of the hallmarks of extreme prematurity (EP) and pregnancy-associated fetal adverse conditions such as intrauterine growth restriction (IUGR). While neurodevelopmental delay and abnormal brain function occur in the absence of overt brain lesions, these conditions have been recently associated with changes in microstructural brain development. Recent imaging studies indicate changes in brain connectivity, in particular involving the white matter fibers belonging to the cortico-basal ganglia-thalamic loop. Furthermore, EP and IUGR have been related to altered brain network architecture in childhood, with reduced network global capacity, global efficiency and average nodal strength. In this study, we used a connectome analysis to characterize the structural brain networks of these children, with a special focus on their topological organization. On one hand, we confirm the reduced averaged network node degree and strength due to EP and IUGR. On the other, the decomposition of the brain networks in an optimal set of clusters remained substantially different among groups, talking in favor of a different network community structure. However, and despite the different community structure, the brain networks of these high-risk school-age children maintained the typical small-world, rich-club and modularity characteristics in all cases. Thus, our results suggest that brain reorganizes after EP and IUGR, prioritizing a tight modular structure, to maintain the small-world, rich-club and modularity characteristics. By themselves, both extreme prematurity and IUGR bear a similar risk for neurocognitive and behavioral impairment, and the here defined modular network alterations confirm similar structural changes both by IUGR and EP at school age compared to control. Interestingly, the combination of both conditions (IUGR + EP) does not result in a worse outcome. In such cases, the alteration in network

  2. Loss of Intrinsic Organization of Cerebellar Networks in Spinocerebellar Ataxia Type 1: Correlates with Disease Severity and Duration

    Science.gov (United States)

    Peri, Eitan; Chen, E. Elinor; Ben-Jacob, Eshel; Gomez, Christopher M.

    2011-01-01

    The spinocerebellar ataxias (SCAs) are a genetically heterogeneous group of cerebellar degenerative disorders, characterized by progressive gait unsteadiness, hand incoordination, and dysarthria. The mutational mechanism in SCA1, a dominantly inherited form of SCA, consists of an expanded trinucleotide CAG repeat. In SCA1, there is loss of Purkinje cells, neuronal loss in dentate nucleus, olives, and pontine nuclei. In the present study, we sought to apply intrinsic functional connectivity analysis combined with diffusion tensor imaging to define the state of cerebellar connectivity in SCA1. Our results on the intrinsic functional connectivity in lateral cerebellum and thalamus showed progressive organizational changes in SCA1 noted as a progressive increase in the absolute value of the correlation coefficients. In the lateral cerebellum, the anatomical organization of functional clusters seen as parasagittal bands in controls is lost, changing to a patchy appearance in SCA1. Lastly, only fractional anisotropy in the superior peduncle and changes in functional organization in thalamus showed a linear dependence to duration and severity of disease. The present pilot work represents an initial effort describing connectivity biomarkers of disease progression in SCA1. The functional changes detected with intrinsic functional analysis and diffusion tensor imaging suggest that disease progression can be analyzed as a disconnection syndrome. PMID:20886327

  3. Does the turgor loss point characterize drought response in dryland plants?

    Science.gov (United States)

    Farrell, Claire; Szota, Christopher; Arndt, Stefan K

    2017-08-01

    The water potential at turgor loss point (Ψtlp ) has been suggested as a key functional trait for determining plant drought tolerance, because of its close relationship with stomatal closure. Ψtlp may indicate drought tolerance as plants, which maintain gas exchange at lower midday water potentials as soil water availability declines also have lower Ψtlp . We evaluated 17 species from seasonally dry habitats, representing a range of life-forms, under well-watered and drought conditions, to determine how Ψtlp relates to stomatal sensitivity (pre-dawn water potential at stomatal closure: Ψgs0 ) and drought strategy (degree of isohydry or anisohydry; ΔΨMD between well-watered conditions and stomatal closure). Although Ψgs0 was related to Ψtlp , Ψgs0 was better related to drought strategy (ΔΨMD ). Drought avoiders (isohydric) closed stomata at water potentials higher than their Ψtlp ; whereas, drought tolerant (anisohydric) species maintained stomatal conductance at lower water potentials than their Ψtlp and were more dehydration tolerant. There was no significant relationship between Ψtlp and ΔΨMD . While Ψtlp has been related to biome water availability, we found that Ψtlp did not relate strongly to stomatal closure or drought strategy, for either drought avoiders or tolerators. We therefore suggest caution in using Ψtlp to predict vulnerability to drought. © 2017 John Wiley & Sons Ltd.

  4. Gene Network Polymorphism Illuminates Loss and Retention of Novel RNAi Silencing Components in the Cryptococcus Pathogenic Species Complex.

    Directory of Open Access Journals (Sweden)

    Marianna Feretzaki

    2016-03-01

    Full Text Available RNAi is a ubiquitous pathway that serves central functions throughout eukaryotes, including maintenance of genome stability and repression of transposon expression and movement. However, a number of organisms have lost their RNAi pathways, including the model yeast Saccharomyces cerevisiae, the maize pathogen Ustilago maydis, the human pathogen Cryptococcus deuterogattii, and some human parasite pathogens, suggesting there may be adaptive benefits associated with both retention and loss of RNAi. By comparing the RNAi-deficient genome of the Pacific Northwest Outbreak C. deuterogattii strain R265 with the RNAi-proficient genomes of the Cryptococcus pathogenic species complex, we identified a set of conserved genes that were lost in R265 and all other C. deuterogattii isolates examined. Genetic and molecular analyses reveal several of these lost genes play roles in RNAi pathways. Four novel components were examined further. Znf3 (a zinc finger protein and Qip1 (a homolog of N. crassa Qip were found to be essential for RNAi, while Cpr2 (a constitutive pheromone receptor and Fzc28 (a transcription factor are involved in sex-induced but not mitosis-induced silencing. Our results demonstrate that the mitotic and sex-induced RNAi pathways rely on the same core components, but sex-induced silencing may be a more specific, highly induced variant that involves additional specialized or regulatory components. Our studies further illustrate how gene network polymorphisms involving known components of key cellular pathways can inform identification of novel elements and suggest that RNAi loss may have been a core event in the speciation of C. deuterogattii and possibly contributed to its pathogenic trajectory.

  5. Cell-to-module optical loss/gain analysis for various photovoltaic module materials through systematic characterization

    Science.gov (United States)

    Hsian Saw, Min; Khoo, Yong Sheng; Singh, Jai Prakash; Wang, Yan

    2017-08-01

    Reducing levelized cost of electricity (LCOE) is important for solar photovoltaics to compete against other energy sources. Thus, the focus should not only be on improving the solar cell efficiency, but also on continuously reducing the losses (or achieving gain) in the cell-to-module process. This can be achieved by choosing the appropriate module material and design. This paper presents a detailed and systematic characterization of various photovoltaic (PV) module materials (encapsulants, tabbing ribbons, and backsheets) and an evaluation of their impact on the output power of silicon wafer-based PV modules. Various characterization tools/techniques, such as UV-vis (reflectance) measurement, external quantum efficiency (EQE) measurement and EQE line-scan are used. Based on the characterization results, we use module materials with the best-evaluated optical performance to build “optimized modules”. Compared to the standard mini-module, an optical gain of more than 5% is achievable for the “optimized module” with selected module materials.

  6. Characterization of a mouse model with complete RPE loss and its use for RPE cell transplantation.

    Science.gov (United States)

    Carido, Madalena; Zhu, Yu; Postel, Kai; Benkner, Boris; Cimalla, Peter; Karl, Mike O; Kurth, Thomas; Paquet-Durand, François; Koch, Edmund; Münch, Thomas A; Tanaka, Elly M; Ader, Marius

    2014-08-07

    Age-related macular degeneration (AMD) is a major leading cause of visual impairment and blindness with no cure currently established. Cell replacement of RPE is discussed as a potential therapy for AMD. Previous studies were performed in animal models with severe limitations in recapitulating the disease progression. In detail, we describe the effect of systemic injection of sodium iodate in the mouse retina. We further evaluate the usefulness of this animal model to analyze cell-specific effects following transplantation of human embryonic stem cell (hESC)-derived RPE cells. Morphologic, functional, and behavioral changes following sodium iodate injection were monitored by histology, gene expression analysis, electroretinography, and optokinetic head tracking. Human embryonic stem cell-derived RPE cells were transplanted 1 week after sodium iodate injection and experimental retinae were analyzed 3 weeks later. Injection of sodium iodate caused complete RPE cell loss, photoreceptor degeneration, and altered gene and protein expression in outer and inner nuclear layers. Retinal function was severely affected by day 3 and abolished from day 14. Following transplantation, donor hESC-derived RPE cells formed extensive monolayers that displayed wild-type RPE cell morphology, organization, and function, including phagocytosis of host photoreceptor outer segments. Systemic injection of sodium iodate has considerable effects on RPE, photoreceptors, and inner nuclear layer neurons, and provides a model to assay reconstitution and maturation of RPE cell transplants. The availability of an RPE-free Bruch's membrane in this model likely allows the unprecedented formation of extensive polarized cell monolayers from donor hESC-derived RPE cell suspensions. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  7. Global Integration of the Hot-State Brain Network of Appetite Predicts Short Term Weight Loss in Older Adult

    Directory of Open Access Journals (Sweden)

    Brielle M Paolini

    2015-05-01

    Full Text Available Obesity is a public health crisis in North America. While lifestyle interventions for weight loss (WL remain popular, the rate of success is highly variable. Clearly, self-regulation of eating behavior is a challenge and patterns of activity across the brain may be an important determinant of success. The current study prospectively examined whether integration across the Hot-State Brain Network of Appetite (HBN-A predicts WL after 6-months of treatment in older adults. Our metric for network integration was global efficiency (GE. The present work is a sub-study (n = 56 of an ongoing randomized clinical trial involving WL. Imaging involved a baseline food-cue visualization functional MRI (fMRI scan following an overnight fast. Using graph theory to build functional brain networks, we demonstrated that regions of the HBN-A (insula, anterior cingulate cortex (ACC, superior temporal pole, amygdala and the parahippocampal gyrus were highly integrated as evidenced by the results of a principal component analysis. After accounting for known correlates of WL (baseline weight, age, sex, and self-regulatory efficacy and treatment condition, which together contributed 36.9% of the variance in WL, greater GE in the HBN-A was associated with an additional 19% of the variance. The ACC of the HBN-A was the primary driver of this effect, accounting for 14.5% of the variance in WL when entered in a stepwise regression following the covariates, p = 0.0001. The HBN-A is comprised of limbic regions important in the processing of emotions and visceral sensations and the ACC is key for translating such processing into behavioral consequences. The improved integration of these regions may enhance awareness of body and emotional states leading to more successful self-regulation and to greater WL. This is the first study among older adults to prospectively demonstrate that, following an overnight fast, GE of the HBN-A during a food visualization task is predictive of

  8. Characterization of Schizophrenia Adverse Drug Interactions through a Network Approach and Drug Classification

    Directory of Open Access Journals (Sweden)

    Jingchun Sun

    2013-01-01

    Full Text Available Antipsychotic drugs are medications commonly for schizophrenia (SCZ treatment, which include two groups: typical and atypical. SCZ patients have multiple comorbidities, and the coadministration of drugs is quite common. This may result in adverse drug-drug interactions, which are events that occur when the effect of a drug is altered by the coadministration of another drug. Therefore, it is important to provide a comprehensive view of these interactions for further coadministration improvement. Here, we extracted SCZ drugs and their adverse drug interactions from the DrugBank and compiled a SCZ-specific adverse drug interaction network. This network included 28 SCZ drugs, 241 non-SCZs, and 991 interactions. By integrating the Anatomical Therapeutic Chemical (ATC classification with the network analysis, we characterized those interactions. Our results indicated that SCZ drugs tended to have more adverse drug interactions than other drugs. Furthermore, SCZ typical drugs had significant interactions with drugs of the “alimentary tract and metabolism” category while SCZ atypical drugs had significant interactions with drugs of the categories “nervous system” and “antiinfectives for systemic uses.” This study is the first to characterize the adverse drug interactions in the course of SCZ treatment and might provide useful information for the future SCZ treatment.

  9. Networking our science to characterize the state, vulnerabilities, and management opportunities of soil organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Harden, J.W.; Hugelius, Gustaf; Ahlstrom, A.; Blankinship, J. C.; Bond-Lamberty, Benjamin; Lawrence, C.; Loisel, Julie; Malhotra, Avni; Jackson, R. B.; Ogle, Stephen; Phillips, C.; Ryals, Rebecca; Todd-Brown, Katherine EO; Vargas, R.; Vergara, Sintana; Cotrufo, Francesca; Keiluweit, M.; Heckman, K. A.; Crow, Susan; Silver, Whendee; Delonge, Marcia; Nave, Lucas

    2018-02-01

    Soil organic matter supports the Earth’s ability to sustain terrestrial ecosystems, provide food and fiber, and retain the largest pool of actively cycling carbon (C). Over 75% ofthe soil organic carbon (SOC) in the top meter of soil is directly affected by human land use. Large land areas have lost SOC as a result of land use practices, yet there are compensatory opportunities to enhance land productivity and SOC storage in degraded lands through improved management practices. Large areas with and without intentional management are also being subjected to rapid changes in climate, making many SOC stocks vulnerable to losses by decomposition or disturbance. In order to quantify potential SOC losses or sequestration at field, regional, and global scales, measurements for detecting changes in SOC are needed. Such measurements and soil-management best practices should be based on well-established and emerging scientific understanding of processes of C stabilization and destabilization over various timescales, soil types, and spatial scales. As newly engaged members of the International Soil Carbon Network, we have identified gaps in data, modeling, and communication that underscore the need for an open, shared network to frame and guide the study of soil organic matter and C and their management for sustained production and climate regulation.

  10. Networking our science to characterize the state, vulnerabilities, and management opportunities of soil organic matter.

    Science.gov (United States)

    Harden, Jennifer W; Hugelius, Gustaf; Ahlström, Anders; Blankinship, Joseph C; Bond-Lamberty, Ben; Lawrence, Corey R; Loisel, Julie; Malhotra, Avni; Jackson, Robert B; Ogle, Stephen; Phillips, Claire; Ryals, Rebecca; Todd-Brown, Katherine; Vargas, Rodrigo; Vergara, Sintana E; Cotrufo, M Francesca; Keiluweit, Marco; Heckman, Katherine A; Crow, Susan E; Silver, Whendee L; DeLonge, Marcia; Nave, Lucas E

    2018-02-01

    Soil organic matter (SOM) supports the Earth's ability to sustain terrestrial ecosystems, provide food and fiber, and retains the largest pool of actively cycling carbon. Over 75% of the soil organic carbon (SOC) in the top meter of soil is directly affected by human land use. Large land areas have lost SOC as a result of land use practices, yet there are compensatory opportunities to enhance productivity and SOC storage in degraded lands through improved management practices. Large areas with and without intentional management are also being subjected to rapid changes in climate, making many SOC stocks vulnerable to losses by decomposition or disturbance. In order to quantify potential SOC losses or sequestration at field, regional, and global scales, measurements for detecting changes in SOC are needed. Such measurements and soil-management best practices should be based on well established and emerging scientific understanding of processes of C stabilization and destabilization over various timescales, soil types, and spatial scales. As newly engaged members of the International Soil Carbon Network, we have identified gaps in data, modeling, and communication that underscore the need for an open, shared network to frame and guide the study of SOM and SOC and their management for sustained production and climate regulation. © 2017 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

  11. Networking our science to characterize the state, vulnerabilities, and management opportunities of soil organic matter

    Science.gov (United States)

    Harden, Jennifer W.; Hugelius, Gustaf; Ahlström, Anders; Blankinship, Joseph C.; Bond-Lamberty, Ben; Lawrence, Corey; Loisel, Julie; Malhotra, Avni; Jackson, Robert B.; Ogle, Stephen M.; Phillips, Claire; Ryals, Rebecca; Todd-Brown, Katherine; Vargas, Rodrigo; Vergara, Sintana E.; Cotrufo, M. Francesca; Keiluweit, Marco; Heckman, Katherine; Crow, Susan E.; Silver, Whendee L.; DeLonge, Marcia; Nave, Lucas E.

    2018-01-01

    Soil organic matter (SOM) supports the Earth's ability to sustain terrestrial ecosystems, provide food and fiber, and retains the largest pool of actively cycling carbon. Over 75% of the soil organic carbon (SOC) in the top meter of soil is directly affected by human land use. Large land areas have lost SOC as a result of land use practices, yet there are compensatory opportunities to enhance productivity and SOC storage in degraded lands through improved management practices. Large areas with and without intentional management are also being subjected to rapid changes in climate, making many SOC stocks vulnerable to losses by decomposition or disturbance. In order to quantify potential SOC losses or sequestration at field, regional, and global scales, measurements for detecting changes in SOC are needed. Such measurements and soil-management best practices should be based on well established and emerging scientific understanding of processes of C stabilization and destabilization over various timescales, soil types, and spatial scales. As newly engaged members of the International Soil Carbon Network, we have identified gaps in data, modeling, and communication that underscore the need for an open, shared network to frame and guide the study of SOM and SOC and their management for sustained production and climate regulation.

  12. Flooded area characterization and losses estimation for water balance and hydrological functioning over the Niger inland delta, Mali

    Science.gov (United States)

    Moussa, Ibrahim; Dominik, Wisser; Abdou, Ali; Ousmane, Seidou; Adama, Mariko; Abel, Afouda

    2015-04-01

    Water availability is an ongoing challenge for West African countries in general and Niger River basin in particular. Niger Inland Delta undergone an annual flood events from the Niger and Bani Rivers. During such events the flooded area can overs a surface of about 40,000 km2 and extends around 350 km in length and 100 km width in Mali. The processes that occur in NID are not fully incorporated in the conceptual development of many hydrological models under Niger Basin runoff. While these processes in NID can have considerable influence on downstream flow regimes due water losses impacting significantly the water availability. Although several studies in this region developed conceptual models to represent hydrological processes in that system. But the models have been criticized for their limitation and simplicity in conception for representing explicitly all the hydrological processes. This paper presents an attempt to assess the hydrological processes by taking into account more physical knowledge of the NID system. This is in view of incorporating wetland processes into an existing hydrological model to improve model simulations on the basin. The approach is mainly water balance based on large units that account for the system over the NID. Digital elevation model (DEM), satellite data, observed climate and hydrological parameters allowed the assessment of spatiotemporal variations of the flooded area, and then the quantification of evaporative and infiltration fluxes. Characterization of the extent of the flooded area is obtained from monthly-scale inflow data and remote sensing derived flood maps within a non-linear regression Model based. The modelization of the spatiotemporal extension of the flooding of the NID show that the flooded areas vary between 25 000 km2 in wet period and 2 000 km2 in dry period. Time series of input water volumes in the Niger Inland delta and of the water losses through the NID show that the percentage of volume of annual water

  13. A Research on Test Platform of Energy-Saving and Loss-Reducing Experiment for Distribution Network

    Science.gov (United States)

    Jiang, Li-Min; Yan, Hua-Guang; Meng, Jun-Xia; Yin, Zhong-Dong; Wei, Wen-Si

    2017-05-01

    Based on the study of quantitative energy consumption reduction model, a test platform was established to test and verify the theoretical method. In the experiment, a power supply device with different power quality disturbances is required. This paper proposes a series multi-objective VQDG which can generate typical voltage disturbance, such as flicker, sag or swell, harmonics, unbalance and their superimposition applied to testing load. In the application, the cascade H-bridges inverter is seriesly connected between the gird source and the testing load. The device has two advantages: the output disturbance voltage level is low and the power absorbed by load is mostly provided by grid. Compared with those devices with high power rating, the size of the capacitor of VQDG will be decreased remarkably. The device is designed and physical tests are performed to demonstrate the variety of functions. Therefore, it can provide the power quality disturbance signal for the simulation experiment platform of energy saving and loss reduction of distribution network.

  14. Definition and characterization of an extended social-affective default network.

    Science.gov (United States)

    Amft, Maren; Bzdok, Danilo; Laird, Angela R; Fox, Peter T; Schilbach, Leonhard; Eickhoff, Simon B

    2015-03-01

    Recent evidence suggests considerable overlap between the default mode network (DMN) and regions involved in social, affective and introspective processes. We considered these overlapping regions as the social-affective part of the DMN. In this study, we established a robust mapping of the underlying brain network formed by these regions and those strongly connected to them (the extended social-affective default network). We first seeded meta-analytic connectivity modeling and resting-state analyses in the meta-analytically defined DMN regions that showed statistical overlap with regions associated with social and affective processing. Consensus connectivity of each seed was subsequently delineated by a conjunction across both connectivity analyses. We then functionally characterized the ensuing regions and performed several cluster analyses. Among the identified regions, the amygdala/hippocampus formed a cluster associated with emotional processes and memory functions. The ventral striatum, anterior cingulum, subgenual cingulum and ventromedial prefrontal cortex formed a heterogeneous subgroup associated with motivation, reward and cognitive modulation of affect. Posterior cingulum/precuneus and dorsomedial prefrontal cortex were associated with mentalizing, self-reference and autobiographic information. The cluster formed by the temporo-parietal junction and anterior middle temporal sulcus/gyrus was associated with language and social cognition. Taken together, the current work highlights a robustly interconnected network that may be central to introspective, socio-affective, that is, self- and other-related mental processes.

  15. Characterizing Social Interaction in Tobacco-Oriented Social Networks: An Empirical Analysis.

    Science.gov (United States)

    Liang, Yunji; Zheng, Xiaolong; Zeng, Daniel Dajun; Zhou, Xingshe; Leischow, Scott James; Chung, Wingyan

    2015-06-19

    Social media is becoming a new battlefield for tobacco "wars". Evaluating the current situation is very crucial for the advocacy of tobacco control in the age of social media. To reveal the impact of tobacco-related user-generated content, this paper characterizes user interaction and social influence utilizing social network analysis and information theoretic approaches. Our empirical studies demonstrate that the exploding pro-tobacco content has long-lasting effects with more active users and broader influence, and reveal the shortage of social media resources in global tobacco control. It is found that the user interaction in the pro-tobacco group is more active, and user-generated content for tobacco promotion is more successful in obtaining user attention. Furthermore, we construct three tobacco-related social networks and investigate the topological patterns of these tobacco-related social networks. We find that the size of the pro-tobacco network overwhelms the others, which suggests a huge number of users are exposed to the pro-tobacco content. These results indicate that the gap between tobacco promotion and tobacco control is widening and tobacco control may be losing ground to tobacco promotion in social media.

  16. Segmentation of nanotomographic cortical bone images for quantitative characterization of the osteoctyte lacuno-canalicular network

    Energy Technology Data Exchange (ETDEWEB)

    Ciani, A.; Kewish, C. M. [Synchrotron Soleil, L’Orme des Merisiers, 91192 Saint-Aubin (France); Guizar-Sicairos, M.; Diaz, A.; Holler, M. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Pallu, S.; Achiou, Z.; Jennane, R.; Toumi, H.; Lespessailles, E. [Univ Orléans, I3MTO, Ea 4708, 45000 Orléans (France)

    2016-01-28

    A newly developed data processing method able to characterize the osteocytes lacuno-canalicular network (LCN) is presented. Osteocytes are the most abundant cells in the bone, living in spaces called lacunae embedded inside the bone matrix and connected to each other with an extensive network of canals that allows for the exchange of nutrients and for mechanotransduction functions. The geometrical three-dimensional (3D) architecture is increasingly thought to be related to the macroscopic strength or failure of the bone and it is becoming the focus for investigating widely spread diseases such as osteoporosis. To obtain 3D LCN images non-destructively has been out of reach until recently, since tens-of-nanometers scale resolution is required. Ptychographic tomography was validated for bone imaging in [1], showing clearly the LCN. The method presented here was applied to 3D ptychographic tomographic images in order to extract morphological and geometrical parameters of the lacuno-canalicular structures.

  17. Demonstration of the feasibility of a complete ellipsometric characterization method based on an artificial neural network.

    Science.gov (United States)

    Battie, Yann; Robert, Stéphane; Gereige, Issam; Jamon, Damien; Stchakovsky, Michel

    2009-10-01

    Ellipsometry is an optical technique that is widely used for determining optical and geometrical properties of optical thin films. These properties are in general extracted from the ellipsometric measurement by solving an inverse problem. Classical methods like the Levenberg-Marquardt algorithm are generally too long, depending on direct calculation and are very sensitive to local minima. In this way, the neural network has proved to be an efficient tool for solving these kinds of problems in a very short time. Indeed, it is rapid and less sensitive to local minima than the classical inversion method. We suggest a complete neural ellipsometric characterization method for determining the index dispersion law and the thickness of a simple SiO(2) or photoresist thin layer on Si, SiO(2), and BK7 substrates. The influence of the training couples on the artificial neural network performance is also discussed.

  18. Characterization of a patch-clamp microchannel array towards neuronal networks analysis

    DEFF Research Database (Denmark)

    Alberti, Massimo; Snakenborg, Detlef; Lopacinska, Joanna M.

    2010-01-01

    for simultaneous patch clamping of cultured cells or neurons in the same network. A disposable silicon/silicon dioxide (Si/SiO2) chip with a microhole array was integrated in a microfluidic system for cell handling, perfusion and electrical recording. Fluidic characterization showed that our PC mu CA can work...... theory, but the capacitance is still too high for high resolution recording. The system was tested on HeLa cells: successful cell trapping with a sealing of 40 M Omega was recorded. Modification of the Si/SiO2 chip is needed in order to achieve a better sealing and long-term cell culturing in the PC mu...

  19. Characterizing Design Process Interfaces as Organization Networks: Insights for Engineering Systems Management

    DEFF Research Database (Denmark)

    Ruiz, Pedro Parraguez; Eppinger, Steven; Maier, Anja

    2016-01-01

    The engineering design literature has provided guidance on how to identify and analyze design activities and their information dependencies. However, a systematic characterization of process interfaces between engineering design activities is missing, and the impact of structural and compositional...... and interpret the effect of those characteristics on interface problems. As a result, we show how structural and compositional aspects of the organization networks between information-dependent activities provide valuable insights to better manage complex engineering design processes. The proposed approach...... and organization architectures, the systematic identification of key performance metrics associated with interface problems, and improved support for engineering managers by means of a better overview of information flows between activities....

  20. Characterization of contact offenders and child exploitation material trafficking on five peer-to-peer networks.

    Science.gov (United States)

    Bissias, George; Levine, Brian; Liberatore, Marc; Lynn, Brian; Moore, Juston; Wallach, Hanna; Wolak, Janis

    2016-02-01

    We provide detailed measurement of the illegal trade in child exploitation material (CEM, also known as child pornography) from mid-2011 through 2014 on five popular peer-to-peer (P2P) file sharing networks. We characterize several observations: counts of peers trafficking in CEM; the proportion of arrested traffickers that were identified during the investigation as committing contact sexual offenses against children; trends in the trafficking of sexual images of sadistic acts and infants or toddlers; the relationship between such content and contact offenders; and survival rates of CEM. In the 5 P2P networks we examined, we estimate there were recently about 840,000 unique installations per month of P2P programs sharing CEM worldwide. We estimate that about 3 in 10,000 Internet users worldwide were sharing CEM in a given month; rates vary per country. We found an overall month-to-month decline in trafficking of CEM during our study. By surveying law enforcement we determined that 9.5% of persons arrested for P2P-based CEM trafficking on the studied networks were identified during the investigation as having sexually offended against children offline. Rates per network varied, ranging from 8% of arrests for CEM trafficking on Gnutella to 21% on BitTorrent. Within BitTorrent, where law enforcement applied their own measure of content severity, the rate of contact offenses among peers sharing the most-severe CEM (29%) was higher than those sharing the least-severe CEM (15%). Although the persistence of CEM on the networks varied, it generally survived for long periods of time; e.g., BitTorrent CEM had a survival rate near 100%. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Artificial Neural Networks-Based Software for Measuring Heat Collection Rate and Heat Loss Coefficient of Water-in-Glass Evacuated Tube Solar Water Heaters.

    Science.gov (United States)

    Liu, Zhijian; Liu, Kejun; Li, Hao; Zhang, Xinyu; Jin, Guangya; Cheng, Kewei

    2015-01-01

    Measurements of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, conventional measurement requires expensive detection devices and undergoes a series of complicated procedures. To simplify the measurement and reduce the cost, software based on artificial neural networks for measuring heat collection rate and heat loss coefficient of water-in-glass evacuated tube solar water heaters was developed. Using multilayer feed-forward neural networks with back-propagation algorithm, we developed and tested our program on the basis of 915 measured samples of water-in-glass evacuated tube solar water heaters. This artificial neural networks-based software program automatically obtained accurate heat collection rate and heat loss coefficient using simply "portable test instruments" acquired parameters, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, angle between tubes and ground and final temperature. Our results show that this software (on both personal computer and Android platforms) is efficient and convenient to predict the heat collection rate and heat loss coefficient due to it slow root mean square errors in prediction. The software now can be downloaded from http://t.cn/RLPKF08.

  2. The impact of an online social network with wireless monitoring devices on physical activity and weight loss.

    Science.gov (United States)

    Greene, Jessica; Sacks, Rebecca; Piniewski, Brigitte; Kil, David; Hahn, Jin S

    2013-07-01

    Online social networks (OSNs) are a new, promising approach for catalyzing health-related behavior change. To date, the empirical evidence on their impact has been limited. Using a randomized trial, we assessed the impact of a health-oriented OSN with accelerometer and scales on participant's physical activity, weight, and clinical indicators. A sample of 349 PeaceHealth Oregon employees and family members were randomized to the iWell OSN or a control group and followed for 6 months in 2010-2011. The iWell OSN enabled participants to connect with "friends," make public postings, view contacts' postings, set goals, download the number of their steps from an accelerometer and their weight from a scale, view trends in physical activity and weight, and compete against others in physical activity. Both control and intervention participants received traditional education material on diet and physical activity. Laboratory data on weight and clinical indicators (triglycerides, high-density lipoprotein, or low-density lipoprotein), and self-reported data on physical activity, were collected at baseline, 3 months, and 6 months. At 6 months, the intervention group increased leisure walking minutes by 164% compared with 47% in the control group. The intervention group also lost more weight than the controls (5.2 pounds compared with 1.5 pounds). There were no observed significant differences in vigorous exercise or clinical indicators between the 2 groups. Among intervention participants, greater OSN use, as measured by number of private messages sent, was associated with a greater increase in leisure walking and greater weight reduction over the study period. The study provides evidence that interventions using OSNs can successfully promote increases in physical activity and weight loss.

  3. Bioinformatics, interaction network analysis, and neural networks to characterize gene expression of radicular cyst and periapical granuloma.

    Science.gov (United States)

    Poswar, Fabiano de Oliveira; Farias, Lucyana Conceição; Fraga, Carlos Alberto de Carvalho; Bambirra, Wilson; Brito-Júnior, Manoel; Sousa-Neto, Manoel Damião; Santos, Sérgio Henrique Souza; de Paula, Alfredo Maurício Batista; D'Angelo, Marcos Flávio Silveira Vasconcelos; Guimarães, André Luiz Sena

    2015-06-01

    Bioinformatics has emerged as an important tool to analyze the large amount of data generated by research in different diseases. In this study, gene expression for radicular cysts (RCs) and periapical granulomas (PGs) was characterized based on a leader gene approach. A validated bioinformatics algorithm was applied to identify leader genes for RCs and PGs. Genes related to RCs and PGs were first identified in PubMed, GenBank, GeneAtlas, and GeneCards databases. The Web-available STRING software (The European Molecular Biology Laboratory [EMBL], Heidelberg, Baden-Württemberg, Germany) was used in order to build the interaction map among the identified genes by a significance score named weighted number of links. Based on the weighted number of links, genes were clustered using k-means. The genes in the highest cluster were considered leader genes. Multilayer perceptron neural network analysis was used as a complementary supplement for gene classification. For RCs, the suggested leader genes were TP53 and EP300, whereas PGs were associated with IL2RG, CCL2, CCL4, CCL5, CCR1, CCR3, and CCR5 genes. Our data revealed different gene expression for RCs and PGs, suggesting that not only the inflammatory nature but also other biological processes might differentiate RCs and PGs. Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  4. Multitype Network-Guided Target Controllability in Phenotypically Characterized Osteosarcoma: Role of Tumor Microenvironment

    Directory of Open Access Journals (Sweden)

    Ankush Sharma

    2017-07-01

    Full Text Available This study highlights the relevance of network-guided controllability analysis as a precision oncology tool. Target controllability through networks is potentially relevant to cancer research for the identification of therapeutic targets. With reference to a recent study on multiple phenotypes from 22 osteosarcoma (OS cell lines characterized both in vitro and in vivo, we found that a variety of critical proteins in OS regulation circuits were in part phenotype specific and in part shared. To generalize our inference approach and match cancer phenotypic heterogeneity, we employed multitype networks and identified targets in correspondence with protein sub-complexes. Therefore, we established the relevance for diagnostic and therapeutic purposes of inspecting interactive targets, namely those enriched by significant connectivity patterns in protein sub-complexes. Emerging targets appeared with reference to the OS microenvironment, and relatively to small leucine-rich proteoglycan members and D-type cyclins, among other collagen, laminin, and keratin proteins. These described were evidences shared across all phenotypes; instead, specific evidences were provided by critical proteins including IGFBP7 and PDGFRA in the invasive phenotype, and FGFR3 and THBS1 in the colony forming phenotype.

  5. Complex Network Analysis for Characterizing Global Value Chains in Equipment Manufacturing.

    Directory of Open Access Journals (Sweden)

    Hao Xiao

    Full Text Available The rise of global value chains (GVCs characterized by the so-called "outsourcing", "fragmentation production", and "trade in tasks" has been considered one of the most important phenomena for the 21st century trade. GVCs also can play a decisive role in trade policy making. However, due to the increasing complexity and sophistication of international production networks, especially in the equipment manufacturing industry, conventional trade statistics and the corresponding trade indicators may give us a distorted picture of trade. This paper applies various network analysis tools to the new GVC accounting system proposed by Koopman et al. (2014 and Wang et al. (2013 in which gross exports can be decomposed into value-added terms through various routes along GVCs. This helps to divide the equipment manufacturing-related GVCs into some sub-networks with clear visualization. The empirical results of this paper significantly improve our understanding of the topology of equipment manufacturing-related GVCs as well as the interdependency of countries in these GVCs that is generally invisible from the traditional trade statistics.

  6. Complex Network Analysis for Characterizing Global Value Chains in Equipment Manufacturing

    Science.gov (United States)

    Meng, Bo; Cheng, Lihong

    2017-01-01

    The rise of global value chains (GVCs) characterized by the so-called “outsourcing”, “fragmentation production”, and “trade in tasks” has been considered one of the most important phenomena for the 21st century trade. GVCs also can play a decisive role in trade policy making. However, due to the increasing complexity and sophistication of international production networks, especially in the equipment manufacturing industry, conventional trade statistics and the corresponding trade indicators may give us a distorted picture of trade. This paper applies various network analysis tools to the new GVC accounting system proposed by Koopman et al. (2014) and Wang et al. (2013) in which gross exports can be decomposed into value-added terms through various routes along GVCs. This helps to divide the equipment manufacturing-related GVCs into some sub-networks with clear visualization. The empirical results of this paper significantly improve our understanding of the topology of equipment manufacturing-related GVCs as well as the interdependency of countries in these GVCs that is generally invisible from the traditional trade statistics. PMID:28081201

  7. Characterization of Genes for Beef Marbling Based on Applying Gene Coexpression Network

    Directory of Open Access Journals (Sweden)

    Dajeong Lim

    2014-01-01

    Full Text Available Marbling is an important trait in characterization beef quality and a major factor for determining the price of beef in the Korean beef market. In particular, marbling is a complex trait and needs a system-level approach for identifying candidate genes related to the trait. To find the candidate gene associated with marbling, we used a weighted gene coexpression network analysis from the expression value of bovine genes. Hub genes were identified; they were topologically centered with large degree and BC values in the global network. We performed gene expression analysis to detect candidate genes in M. longissimus with divergent marbling phenotype (marbling scores 2 to 7 using qRT-PCR. The results demonstrate that transmembrane protein 60 (TMEM60 and dihydropyrimidine dehydrogenase (DPYD are associated with increasing marbling fat. We suggest that the network-based approach in livestock may be an important method for analyzing the complex effects of candidate genes associated with complex traits like marbling or tenderness.

  8. Complex Network Analysis for Characterizing Global Value Chains in Equipment Manufacturing.

    Science.gov (United States)

    Xiao, Hao; Sun, Tianyang; Meng, Bo; Cheng, Lihong

    2017-01-01

    The rise of global value chains (GVCs) characterized by the so-called "outsourcing", "fragmentation production", and "trade in tasks" has been considered one of the most important phenomena for the 21st century trade. GVCs also can play a decisive role in trade policy making. However, due to the increasing complexity and sophistication of international production networks, especially in the equipment manufacturing industry, conventional trade statistics and the corresponding trade indicators may give us a distorted picture of trade. This paper applies various network analysis tools to the new GVC accounting system proposed by Koopman et al. (2014) and Wang et al. (2013) in which gross exports can be decomposed into value-added terms through various routes along GVCs. This helps to divide the equipment manufacturing-related GVCs into some sub-networks with clear visualization. The empirical results of this paper significantly improve our understanding of the topology of equipment manufacturing-related GVCs as well as the interdependency of countries in these GVCs that is generally invisible from the traditional trade statistics.

  9. Resident Space Object Characterization and Behavior Understanding via Machine Learning and Ontology-based Bayesian Networks

    Science.gov (United States)

    Furfaro, R.; Linares, R.; Gaylor, D.; Jah, M.; Walls, R.

    2016-09-01

    In this paper, we present an end-to-end approach that employs machine learning techniques and Ontology-based Bayesian Networks (BN) to characterize the behavior of resident space objects. State-of-the-Art machine learning architectures (e.g. Extreme Learning Machines, Convolutional Deep Networks) are trained on physical models to learn the Resident Space Object (RSO) features in the vectorized energy and momentum states and parameters. The mapping from measurements to vectorized energy and momentum states and parameters enables behavior characterization via clustering in the features space and subsequent RSO classification. Additionally, Space Object Behavioral Ontologies (SOBO) are employed to define and capture the domain knowledge-base (KB) and BNs are constructed from the SOBO in a semi-automatic fashion to execute probabilistic reasoning over conclusions drawn from trained classifiers and/or directly from processed data. Such an approach enables integrating machine learning classifiers and probabilistic reasoning to support higher-level decision making for space domain awareness applications. The innovation here is to use these methods (which have enjoyed great success in other domains) in synergy so that it enables a "from data to discovery" paradigm by facilitating the linkage and fusion of large and disparate sources of information via a Big Data Science and Analytics framework.

  10. Characterizing the Networks of Digital Information that Support Collaborative Adaptive Forest Management in Sierra Nevada Forests.

    Science.gov (United States)

    Lei, Shufei; Iles, Alastair; Kelly, Maggi

    2015-07-01

    Some of the factors that can contribute to the success of collaborative adaptive management--such as social learning, open communication, and trust--are built upon a foundation of the open exchange of information about science and management between participants and the public. Despite the importance of information transparency, the use and flow of information in collaborative adaptive management has not been characterized in detail in the literature, and currently there exist opportunities to develop strategies for increasing the exchange of information, as well as to track information flow in such contexts. As digital information channels and networks have been increased over the last decade, powerful new information monitoring tools have also been evolved allowing for the complete characterization of information products through their production, transport, use, and monitoring. This study uses these tools to investigate the use of various science and management information products in a case study--the Sierra Nevada Adaptive Management Project--using a mixed method (citation analysis, web analytics, and content analysis) research approach borrowed from the information processing and management field. The results from our case study show that information technologies greatly facilitate the flow and use of digital information, leading to multiparty collaborations such as knowledge transfer and public participation in science research. We conclude with recommendations for expanding information exchange in collaborative adaptive management by taking advantage of available information technologies and networks.

  11. Parkinson's disease-related network topographies characterized with resting state functional MRI.

    Science.gov (United States)

    Vo, An; Sako, Wataru; Fujita, Koji; Peng, Shichun; Mattis, Paul J; Skidmore, Frank M; Ma, Yilong; Uluğ, Aziz M; Eidelberg, David

    2017-02-01

    Spatial covariance mapping can be used to identify and measure the activity of disease-related functional brain networks. While this approach has been widely used in the analysis of cerebral blood flow and metabolic PET scans, it is not clear whether it can be reliably applied to resting state functional MRI (rs-fMRI) data. In this study, we present a novel method based on independent component analysis (ICA) to characterize specific network topographies associated with Parkinson's disease (PD). Using rs-fMRI data from PD and healthy subjects, we used ICA with bootstrap resampling to identify a PD-related pattern that reliably discriminated the two groups. This topography, termed rs-MRI PD-related pattern (fPDRP), was similar to previously characterized disease-related patterns identified using metabolic PET imaging. Following pattern identification, we validated the fPDRP by computing its expression in rs-fMRI testing data on a prospective case basis. Indeed, significant increases in fPDRP expression were found in separate sets of PD and control subjects. In addition to providing a similar degree of group separation as PET, fPDRP values correlated with motor disability and declined toward normal with levodopa administration. Finally, we used this approach in conjunction with neuropsychological performance measures to identify a separate PD cognition-related pattern in the patients. This pattern, termed rs-fMRI PD cognition-related pattern (fPDCP), was topographically similar to its PET-derived counterpart. Subject scores for the fPDCP correlated with executive function in both training and testing data. These findings suggest that ICA can be used in conjunction with bootstrap resampling to identify and validate stable disease-related network topographies in rs-fMRI. Hum Brain Mapp 38:617-630, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  12. Genotype-phenotype correlation for DFNA22: characterization of non-syndromic, autosomal dominant, progressive sensorineural hearing loss due to MYO6 mutations

    DEFF Research Database (Denmark)

    Topsakal, Vedat; Hilgert, Nele; van Dinther, Joost

    2010-01-01

    Clinical and audiological examination was done in 2 Belgian families with autosomal dominant sensorineural hearing loss (SNHL) linked to DFNA22. Nineteen subjects in family 1 had mild to moderate SNHL starting in the third decade. The hearing loss was characterized by a flat audiogram affecting a...... reported DFNA22 families with mutations in the MYO6 gene have been studied and compared. It seems that genetic defects that spare the motor domain of the myosin VI protein have a milder phenotype....

  13. Systematically characterizing and prioritizing chemosensitivity related gene based on Gene Ontology and protein interaction network

    Directory of Open Access Journals (Sweden)

    Chen Xin

    2012-10-01

    Full Text Available Abstract Background The identification of genes that predict in vitro cellular chemosensitivity of cancer cells is of great importance. Chemosensitivity related genes (CRGs have been widely utilized to guide clinical and cancer chemotherapy decisions. In addition, CRGs potentially share functional characteristics and network features in protein interaction networks (PPIN. Methods In this study, we proposed a method to identify CRGs based on Gene Ontology (GO and PPIN. Firstly, we documented 150 pairs of drug-CCRG (curated chemosensitivity related gene from 492 published papers. Secondly, we characterized CCRGs from the perspective of GO and PPIN. Thirdly, we prioritized CRGs based on CCRGs’ GO and network characteristics. Lastly, we evaluated the performance of the proposed method. Results We found that CCRG enriched GO terms were most often related to chemosensitivity and exhibited higher similarity scores compared to randomly selected genes. Moreover, CCRGs played key roles in maintaining the connectivity and controlling the information flow of PPINs. We then prioritized CRGs using CCRG enriched GO terms and CCRG network characteristics in order to obtain a database of predicted drug-CRGs that included 53 CRGs, 32 of which have been reported to affect susceptibility to drugs. Our proposed method identifies a greater number of drug-CCRGs, and drug-CCRGs are much more significantly enriched in predicted drug-CRGs, compared to a method based on the correlation of gene expression and drug activity. The mean area under ROC curve (AUC for our method is 65.2%, whereas that for the traditional method is 55.2%. Conclusions Our method not only identifies CRGs with expression patterns strongly correlated with drug activity, but also identifies CRGs in which expression is weakly correlated with drug activity. This study provides the framework for the identification of signatures that predict in vitro cellular chemosensitivity and offers a valuable

  14. Synthesis and characterizations of high permittivity ultraviolet cured soft elastomeric networks and composites applicable as dielectric electroactive polymer

    DEFF Research Database (Denmark)

    Goswami, Kaustav

    siloxane) (PDMS) and polyurethanes are designed with the requirements specific for DEAPs. Thus there is a need to develop elastomers with low elastic modulus, low viscous and dielectric losses and high relative permittivity. Interpenetrating networks and fumed silica reinforced composites of poly...

  15. Atomic scale characterization of the origin of mobility loss at the silicon carbide/silicon dioxide interface

    Science.gov (United States)

    Biggerstaff, Trinity Leigh

    Silicon carbide (SiC) is a wide band gap semiconductor with material properties which make it ideally suited for high temperature, high frequency, and high power metal oxide semiconductor field effect transistor (MOSFET) applications. The wide scale commercial development of these devices has been hindered due to disappointing electron mobility when compared to properties of the bulk material. This mobility loss has been associated with the interface between SiC and the native oxide formed (SiO2). Many improvements in mobility have been realized, but it is currently still significantly less than that of the bulk material. The work in this dissertation is aimed at understanding the origin of this mobility loss from an atomic perspective. Analytical electron microscopy techniques including scanning transmission electron microscopy (STEM), Z-contrast imaging, electron energy loss spectroscopy (EELS), and convergent beam electron diffraction (CBED) are used in this study to characterize the 4HSiC/SiO2 interface. The effect of aluminum implantation, nitric oxide annealing, oxidation rate, and activation annealing temperature on the interface was examined. We found a carbon rich transition layer present on the SiC side of the interface which varies in thickness depending on processing conditions. The thickness of this transition region is linearly related to the electron mobility. We were also able to determine that this transition region occurs as a result of the oxidation process. During oxidation, carbon interstitials are emitted on both sides of the interface, causing a carbon pileup on the SiC side of the interface, which we detect as a transition region. The rate of oxidation is also very important as oxidizing at a fast rate leads to greater carbon pileup. The extra carbon in this transition region acts as electron scattering centers, which ultimately lead to a reduced electron mobility. This study is able to directly correlate the microstructure on an atomic

  16. Selective logging in tropical forests decreases the robustness of liana–tree interaction networks to the loss of host tree species

    Science.gov (United States)

    Magrach, Ainhoa; Senior, Rebecca A.; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F.; Santamaria, Luis; Edwards, David P.

    2016-01-01

    Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the ‘health’ and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana–tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of ‘extinction debt’. PMID:26936241

  17. Selective logging in tropical forests decreases the robustness of liana-tree interaction networks to the loss of host tree species.

    Science.gov (United States)

    Magrach, Ainhoa; Senior, Rebecca A; Rogers, Andrew; Nurdin, Deddy; Benedick, Suzan; Laurance, William F; Santamaria, Luis; Edwards, David P

    2016-03-16

    Selective logging is one of the major drivers of tropical forest degradation, causing important shifts in species composition. Whether such changes modify interactions between species and the networks in which they are embedded remain fundamental questions to assess the 'health' and ecosystem functionality of logged forests. We focus on interactions between lianas and their tree hosts within primary and selectively logged forests in the biodiversity hotspot of Malaysian Borneo. We found that lianas were more abundant, had higher species richness, and different species compositions in logged than in primary forests. Logged forests showed heavier liana loads disparately affecting slow-growing tree species, which could exacerbate the loss of timber value and carbon storage already associated with logging. Moreover, simulation scenarios of host tree local species loss indicated that logging might decrease the robustness of liana-tree interaction networks if heavily infested trees (i.e. the most connected ones) were more likely to disappear. This effect is partially mitigated in the short term by the colonization of host trees by a greater diversity of liana species within logged forests, yet this might not compensate for the loss of preferred tree hosts in the long term. As a consequence, species interaction networks may show a lagged response to disturbance, which may trigger sudden collapses in species richness and ecosystem function in response to additional disturbances, representing a new type of 'extinction debt'. © 2016 The Author(s).

  18. The robustness of pollination networks to the loss of species and interactions: a quantitative approach incorporating pollinator behaviour.

    Science.gov (United States)

    Kaiser-Bunbury, Christopher N; Muff, Stefanie; Memmott, Jane; Müller, Christine B; Caflisch, Amedeo

    2010-04-01

    Species extinctions pose serious threats to the functioning of ecological communities worldwide. We used two qualitative and quantitative pollination networks to simulate extinction patterns following three removal scenarios: random removal and systematic removal of the strongest and weakest interactors. We accounted for pollinator behaviour by including potential links into temporal snapshots (12 consecutive 2-week networks) to reflect mutualists' ability to 'switch' interaction partners (re-wiring). Qualitative data suggested a linear or slower than linear secondary extinction while quantitative data showed sigmoidal decline of plant interaction strength upon removal of the strongest interactor. Temporal snapshots indicated greater stability of re-wired networks over static systems. Tolerance of generalized networks to species extinctions was high in the random removal scenario, with an increase in network stability if species formed new interactions. Anthropogenic disturbance, however, that promote the extinction of the strongest interactors might induce a sudden collapse of pollination networks.

  19. Finite mixture models to characterize and refine air quality monitoring networks.

    Science.gov (United States)

    Gómez-Losada, Álvaro; Lozano-García, Antonio; Pino-Mejías, Rafael; Contreras-González, Juan

    2014-07-01

    Existing air quality monitoring programs are, on occasion, not updated according to local, varying conditions and as such the monitoring programs become non-informative over time, under-detecting new sources of pollutants or duplicating information. Furthermore, inadequate maintenance may cause the monitoring equipment to be utterly deficient in providing information. To deal with these issues, a combination of formal statistical methods is used to optimize resources for monitoring and to characterize the monitoring networks, introducing new criteria for their refinement. Monitoring data were obtained on key pollutants such as carbon monoxide (CO), nitrogen dioxide (NO2), ozone (O3), particulate matter (PM10) and sulfur dioxide (SO2) from 12 air quality monitoring sites in Seville (Spain) during 2012. A total of 49 data sets were fit to mixture models of Gaussian distribution using the expectation-maximization (EM) algorithm. To summarize these 49 models, the mean and coefficient of variation were calculated for each mixture and carried out a hierarchical clustering analysis (HCA) to study the grouping of the sites according to these statistics. To handle the lack of observational data from the sites with unmonitored pollutants, the missing statistical values were imputed by applying the random forests technique and then later, a principal component analysis (PCA) was carried out to better understand the relationship between the level of pollution and the classification of monitoring sites. All of the techniques were applied using free, open-source, statistical software. One example of source attribution and contribution is analyzed using mixture models and the potential for mixture models is posed in characterizing pollution trends. The mixture statistics have proven to be a fingerprint for every model and this work presents a novel use of them and represents a promising approach to characterizing mixture models in the air quality management discipline. The

  20. Development and Characterization of Novel Interpenetrating Network (IPN Foams from Epoxy Ester and Aliphatic Epoxy Resin

    Directory of Open Access Journals (Sweden)

    Kanuprasad Patel

    2009-01-01

    Full Text Available Diglycidyl ether of bisphenol-A (DGEBA was reacted with acrylate monomer at variable molar ratios. The reaction between glycerine and epichlorohydrine form glycidyl ether of polyol aliphatic epoxy resin. The resultant resins were characterized duly. Both the resins were mixed at different ratios with constant high shear stirring. The obtained mixture and suitable additives were heated at 150oC for one and half hour. The so called Interpenetrating Network (IPN transformed into foams. The performance of foams was evaluated by testing for compression in both parallel and perpendicular to rise direction. The tests were carried out at room temperature and at the elevated temperature. The compression properties showed a decreasing trend for increasing amounts of glycerine resin. The density and thermal properties of epoxy foams were also evaluated. The relation between the composition, density and properties of the foam was analyzed.

  1. Incorporating space, time, and magnitude measures in a network characterization of earthquake events

    Science.gov (United States)

    Janer, Ciara D.; Biton, Dionessa C.; Batac, Rene C.

    2017-11-01

    We investigate the structural properties of a spatio-temporal network of earthquake events that incorporates magnitude information between the connected events. The network creates temporally directed links from an origin event towards a later event if it breaks the record closest distance from the origin among all the events in the catalog so far. Additionally, the links are conditionally classified based on the magnitude difference between connected events: "up" ("down") connections point from a weaker (stronger) to a stronger (weaker) event. Using earthquake records from the Philippines from 1973 to 2012 and southern California from 1982 to 2012, we observe that the out-degree distributions show slight deviations from the corresponding Poisson distribution of the same mean. The space and time separations of connected earthquakes both show power-law regimes, suggesting spatio-temporal (self-)organization. More importantly, the conditional distributions of "up" and "down" connections in space, time, and network structure point to a higher likelihood of a stronger event triggering a nearby weaker event for the first few connections, as in the case of aftershocks. The results are captured by a sandpile-based model where a small but finite probability of preferentially targeting the most susceptible grid site is introduced. Our analysis, coupled with the discrete model analog, provides a quantitative picture of the spatio-temporal and magnitude organization of seismicity beyond just the successive events. The technique may be extended to further characterize similar long-period earthquake records to yield a more complete picture of the underlying processes involved in seismicity.

  2. Incorporating space, time, and magnitude measures in a network characterization of earthquake events

    Science.gov (United States)

    Janer, Ciara D.; Biton, Dionessa C.; Batac, Rene C.

    2017-12-01

    We investigate the structural properties of a spatio-temporal network of earthquake events that incorporates magnitude information between the connected events. The network creates temporally directed links from an origin event towards a later event if it breaks the record closest distance from the origin among all the events in the catalog so far. Additionally, the links are conditionally classified based on the magnitude difference between connected events: "up" ("down") connections point from a weaker (stronger) to a stronger (weaker) event. Using earthquake records from the Philippines from 1973 to 2012 and southern California from 1982 to 2012, we observe that the out-degree distributions show slight deviations from the corresponding Poisson distribution of the same mean. The space and time separations of connected earthquakes both show power-law regimes, suggesting spatio-temporal (self-)organization. More importantly, the conditional distributions of "up" and "down" connections in space, time, and network structure point to a higher likelihood of a stronger event triggering a nearby weaker event for the first few connections, as in the case of aftershocks. The results are captured by a sandpile-based model where a small but finite probability of preferentially targeting the most susceptible grid site is introduced. Our analysis, coupled with the discrete model analog, provides a quantitative picture of the spatio-temporal and magnitude organization of seismicity beyond just the successive events. The technique may be extended to further characterize similar long-period earthquake records to yield a more complete picture of the underlying processes involved in seismicity.

  3. Nonlinear aeroacoustic characterization of Helmholtz resonators with a local-linear neuro-fuzzy network model

    Science.gov (United States)

    Förner, K.; Polifke, W.

    2017-10-01

    The nonlinear acoustic behavior of Helmholtz resonators is characterized by a data-based reduced-order model, which is obtained by a combination of high-resolution CFD simulation and system identification. It is shown that even in the nonlinear regime, a linear model is capable of describing the reflection behavior at a particular amplitude with quantitative accuracy. This observation motivates to choose a local-linear model structure for this study, which consists of a network of parallel linear submodels. A so-called fuzzy-neuron layer distributes the input signal over the linear submodels, depending on the root mean square of the particle velocity at the resonator surface. The resulting model structure is referred to as an local-linear neuro-fuzzy network. System identification techniques are used to estimate the free parameters of this model from training data. The training data are generated by CFD simulations of the resonator, with persistent acoustic excitation over a wide range of frequencies and sound pressure levels. The estimated nonlinear, reduced-order models show good agreement with CFD and experimental data over a wide range of amplitudes for several test cases.

  4. Efficient Characterization of Parametric Uncertainty of Complex (Bio)chemical Networks.

    Science.gov (United States)

    Schillings, Claudia; Sunnåker, Mikael; Stelling, Jörg; Schwab, Christoph

    2015-08-01

    Parametric uncertainty is a particularly challenging and relevant aspect of systems analysis in domains such as systems biology where, both for inference and for assessing prediction uncertainties, it is essential to characterize the system behavior globally in the parameter space. However, current methods based on local approximations or on Monte-Carlo sampling cope only insufficiently with high-dimensional parameter spaces associated with complex network models. Here, we propose an alternative deterministic methodology that relies on sparse polynomial approximations. We propose a deterministic computational interpolation scheme which identifies most significant expansion coefficients adaptively. We present its performance in kinetic model equations from computational systems biology with several hundred parameters and state variables, leading to numerical approximations of the parametric solution on the entire parameter space. The scheme is based on adaptive Smolyak interpolation of the parametric solution at judiciously and adaptively chosen points in parameter space. As Monte-Carlo sampling, it is "non-intrusive" and well-suited for massively parallel implementation, but affords higher convergence rates. This opens up new avenues for large-scale dynamic network analysis by enabling scaling for many applications, including parameter estimation, uncertainty quantification, and systems design.

  5. Efficient Characterization of Parametric Uncertainty of Complex (Bio)chemical Networks

    Science.gov (United States)

    Schillings, Claudia; Sunnåker, Mikael; Stelling, Jörg; Schwab, Christoph

    2015-01-01

    Parametric uncertainty is a particularly challenging and relevant aspect of systems analysis in domains such as systems biology where, both for inference and for assessing prediction uncertainties, it is essential to characterize the system behavior globally in the parameter space. However, current methods based on local approximations or on Monte-Carlo sampling cope only insufficiently with high-dimensional parameter spaces associated with complex network models. Here, we propose an alternative deterministic methodology that relies on sparse polynomial approximations. We propose a deterministic computational interpolation scheme which identifies most significant expansion coefficients adaptively. We present its performance in kinetic model equations from computational systems biology with several hundred parameters and state variables, leading to numerical approximations of the parametric solution on the entire parameter space. The scheme is based on adaptive Smolyak interpolation of the parametric solution at judiciously and adaptively chosen points in parameter space. As Monte-Carlo sampling, it is “non-intrusive” and well-suited for massively parallel implementation, but affords higher convergence rates. This opens up new avenues for large-scale dynamic network analysis by enabling scaling for many applications, including parameter estimation, uncertainty quantification, and systems design. PMID:26317784

  6. Characterization and preparation of p(U-MMA-An) interpenetrating polymer network damping and absorbing material.

    Science.gov (United States)

    Liu, Jun; Li, Qingshan; Zhuo, Yuguo; Hong, Wei; Lv, Wenfeng; Xing, Guangzhong

    2014-06-01

    P(U-MMA-ANI) interpenetrating polymer network (IPN) damping and absorbing material is successfully synthesized by PANI particles served as an absorbing agent with the microemulsion polymerization and P(U-MMA) foam IPN network structure for substrate materials with foaming way. P(U-MMA-ANI) IPN is characterized by the compression mechanical performance testing, TG-DSC, and DSC. The results verify that the P(U-MMA) IPN foam damping material has a good compressive strength and compaction cycle property, and the optimum content of PMMA was 40% (mass) with which the SEM graphs do not present the phase separation on the macro level between PMMA and PU, while the phase separation was observed on the micro level. The DTG curve indicates that because of the formation of P(U-MMA) IPN, the decomposition temperature of PMMA and the carbamate in PU increases, while that of the polyol segment in PU has almost no change. P(U-MMA-ANI) IPN foam damping and absorbing material is obtained by PANI particles served as absorbing agent in the form of filler, and PMMA in the form of micro area in substrate material. When the content of PANI was up to 2.0% (mass), the dissipation factor of composites increased, and with the increasing of frequency the dissipation factor increased in a straight line.

  7. Surface and thermomechanical characterization of polyurethane networks based on poly(dimethylsiloxane and hyperbranched polyester

    Directory of Open Access Journals (Sweden)

    M. V. Pergal

    2013-10-01

    Full Text Available Two series of polyurethane (PU networks based on Boltorn® hyperbranched polyester (HBP and hydroxyethoxy propyl terminated poly(dimethylsiloxane (EO-PDMS or hydroxy propyl terminated poly(dimethylsiloxane (HPPDMS, were synthesized. The effect of the type of soft PDMS segment on the properties of PUs was investigated by Fourier transform infrared spectroscopy (FTIR, contact angle measurements, surface free energy determination, X-ray photoelectron spectroscopy (XPS, scanning electron microscopy (SEM, atomic force microscopy (AFM, dynamic mechanical thermal analysis (DMTA and differential scanning calorimetry (DSC. The surface characterization of PUs showed existence of slightly amphiphilic character and it revealed that PUs based on HP-PDMS have lower surface free energy, more hydrophobic surface and better waterproof performances than PUs based on EO-PDMS. PUs based on HPPDMS had higher crosslinking density than PUs based on EO-PDMS. DSC and DMTA results revealed that these newlysynthesized PUs exhibit the glass transition temperatures of the soft and hard segments. DMTA, SEM and AFM results confirmed existence of microphase separated morphology. The results obtained in this work indicate that PU networks based on HBP and PDMS have improved surface and thermomechanical properties.

  8. Functional characterization of novel loss-of-function mutations in the vasopressin type 2 receptor gene causing nephrogenic diabetes insipidus.

    Science.gov (United States)

    Böselt, Iris; Tramma, Despoina; Kalamitsou, Serafia; Niemeyer, Thomas; Nykänen, Päivi; Gräf, Klaus-Jürgen; Krude, Heiko; Marenzi, Karen Sabrina; Di Candia, Stefania; Schöneberg, Torsten; Schulz, Angela

    2012-04-01

    X-linked nephrogenic diabetes insipidus (NDI) is a rare polyuric disorder caused by inactivating mutations in the arginine vasopressin receptor Type 2 (AVPR2) gene. NDI patients from six unrelated families were subjected to mutational analysis of the AVPR2 gene. In-depth in vitro characterization of novel AVPR2 mutants by a combination of functional and immunological techniques provided further insight into molecular mechanisms causing receptor dysfunction. Mutational analysis revealed four novel (A89P, G107R, Q174R, W208X) and three recurrent (V277A, R337X, ΔR247-G250) mutations within the AVPR2 gene. One family carried the missense mutation R337X and a 12-bp deletion (ΔR247-G250), corresponding to a fragment in the third intracellular loop (ICL3), which was not genetically linked to R337X. The functionally tested missense mutations A89P, G107R and Q174R led to reduced receptor cell surface expression in transfected COS-7 cells, most probably due to misfolding and intracellular retention, and consequently to reduction or loss of agonist-mediated cyclic adenosine monophosphate formation. Deletion of R247-G250 had no effect on receptor function in vitro. Comparison with other mammalian AVPR2 orthologs showed that this part of the ICL3 is structurally not conserved and, therefore, less relevant for receptor function. In contrast, all missense mutations (A89P, G107R, Q174R, V277A) affect receptor positions that were fully preserved during mammalian evolution. Our results provide valuable information about residues critical for AVPR2 folding, trafficking and function and proof that these mutations are responsible for causing NDI in the affected subjects.

  9. Exhaustively characterizing feasible logic models of a signaling network using Answer Set Programming.

    Science.gov (United States)

    Guziolowski, Carito; Videla, Santiago; Eduati, Federica; Thiele, Sven; Cokelaer, Thomas; Siegel, Anne; Saez-Rodriguez, Julio

    2013-09-15

    Logic modeling is a useful tool to study signal transduction across multiple pathways. Logic models can be generated by training a network containing the prior knowledge to phospho-proteomics data. The training can be performed using stochastic optimization procedures, but these are unable to guarantee a global optima or to report the complete family of feasible models. This, however, is essential to provide precise insight in the mechanisms underlaying signal transduction and generate reliable predictions. We propose the use of Answer Set Programming to explore exhaustively the space of feasible logic models. Toward this end, we have developed caspo, an open-source Python package that provides a powerful platform to learn and characterize logic models by leveraging the rich modeling language and solving technologies of Answer Set Programming. We illustrate the usefulness of caspo by revisiting a model of pro-growth and inflammatory pathways in liver cells. We show that, if experimental error is taken into account, there are thousands (11 700) of models compatible with the data. Despite the large number, we can extract structural features from the models, such as links that are always (or never) present or modules that appear in a mutual exclusive fashion. To further characterize this family of models, we investigate the input-output behavior of the models. We find 91 behaviors across the 11 700 models and we suggest new experiments to discriminate among them. Our results underscore the importance of characterizing in a global and exhaustive manner the family of feasible models, with important implications for experimental design. caspo is freely available for download (license GPLv3) and as a web service at http://caspo.genouest.org/. Supplementary materials are available at Bioinformatics online. santiago.videla@irisa.fr.

  10. Stream-gage locations where streamflow gains/losses were quantified along the Central Valley surface-water network

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This digital dataset contains the name and location for the diversions from the surface-water network for the Central Valley Hydrologic Model (CVHM). The Central...

  11. A Flexible Load Control Strategy for Distribution Network to Reduce the Line Losses and to Eliminate the Transmission Congestion

    National Research Council Canada - National Science Library

    Beibei Wang; Xiaoqing Hu; Peifeng Shen; Wenlu Ji; Yang Cao; Jiaping Tang

    2017-01-01

    .... The existence of these factors has brought challenges to the stability of the power distribution network, as well as increasing the risk of exceeding transmission capacity of distribution lines...

  12. Loss of functional connectivity is greater outside the default mode network in nonfamilial early-onset Alzheimer's disease variants.

    Science.gov (United States)

    Lehmann, Manja; Madison, Cindee; Ghosh, Pia M; Miller, Zachary A; Greicius, Michael D; Kramer, Joel H; Coppola, Giovanni; Miller, Bruce L; Jagust, William J; Gorno-Tempini, Maria L; Seeley, William W; Rabinovici, Gil D

    2015-10-01

    The common and specific involvement of brain networks in clinical variants of Alzheimer's disease (AD) is not well understood. We performed task-free ("resting-state") functional imaging in 60 nonfamilial AD patients, including 20 early-onset AD (age at onset functional connectivity is greatest in networks outside the DMN in early-onset and nonamnestic AD variants and may thus be a better biomarker in these patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Power system reconfiguration in a radial distribution network for reducing losses and to improve voltage profile using modified plant growth simulation algorithm with Distributed Generation (DG

    Directory of Open Access Journals (Sweden)

    R. Rajaram

    2015-11-01

    Full Text Available Network reconfiguration which is constrained non linear optimization problem has been solved for loss minimization, load balancing, etc. for last two decades using various heuristic search evolutionary algorithms like binary particle swarm optimization, neuro-fuzzy techniques, etc. The contribution of this paper lies in considering distributed generation which are smaller power sources like solar photovoltaic cells or wind turbines connected in the customer roof top. This new connection in the radial network has made unidirectional current flow to become bidirectional there by increasing the efficiency but sometimes reducing stability of the system. Modified plant growth simulation algorithm has been applied here successfully to minimize real power loss because it does not require barrier factors or cross over rates because the objectives and constraints are dealt separately. The main advantage of this algorithm is continuous guiding search along with changing objective function because power from distributed generation is continuously varying so this can be applied for real time applications with required modifications. This algorithm here is tested for a standard 33 bus radial distribution system for loss minimization and test results here shows that this algorithm is efficient and suitable for real time applications.

  14. Major depressive disorder is characterized by greater reward network activation to monetary than pleasant image rewards.

    Science.gov (United States)

    Smoski, Moria J; Rittenberg, Alison; Dichter, Gabriel S

    2011-12-30

    Anhedonia, the loss of interest or pleasure in normally rewarding activities, is a hallmark feature of unipolar Major Depressive Disorder (MDD). A growing body of literature has identified frontostriatal dysfunction during reward anticipation and outcomes in MDD. However, no study to date has directly compared responses to different types of rewards such as pleasant images and monetary rewards in MDD. To investigate the neural responses to monetary and pleasant image rewards in MDD, a modified Monetary Incentive Delay task was used during functional magnetic resonance imaging to assess neural responses during anticipation and receipt of monetary and pleasant image rewards. Participants included nine adults with MDD and 13 affectively healthy controls. The MDD group showed lower activation than controls when anticipating monetary rewards in right orbitofrontal cortex and subcallosal cortex, and when anticipating pleasant image rewards in paracingulate and supplementary motor cortex. The MDD group had relatively greater activation in right putamen when anticipating monetary versus pleasant image rewards, relative to the control group. Results suggest reduced reward network activation in MDD when anticipating rewards, as well as relatively greater hypoactivation to pleasant image than monetary rewards. 2011 Elsevier Ireland Ltd. All rights reserved.

  15. Characterizing Intra-Urban Air Quality Gradients with a Spatially-Distributed Network

    Science.gov (United States)

    Zimmerman, N.; Ellis, A.; Schurman, M. I.; Gu, P.; Li, H.; Snell, L.; Gu, J.; Subramanian, R.; Robinson, A. L.; Apte, J.; Presto, A. A.

    2016-12-01

    City-wide air pollution measurements have typically relied on regulatory or research monitoring sites with low spatial density to assess population-scale exposure. However, air pollutant concentrations exhibit significant spatial variability depending on local sources and features of the built environment, which may not be well captured by the existing monitoring regime. To better understand urban spatial and temporal pollution gradients at 1 km resolution, a network of 12 real-time air quality monitoring stations was deployed beginning July 2016 in Pittsburgh, PA. The stations were deployed at sites along an urban-rural transect and in urban locations with a range of traffic, restaurant, and tall building densities to examine the impact of various modifiable factors. Measurements from the stationary monitoring stations were further supported by mobile monitoring, which provided higher spatial resolution pollutant measurements on nearby roadways and enabled routine calibration checks. The stationary monitoring measurements comprise ultrafine particle number (Aerosol Dynamics "MAGIC" CPC), PM2.5 (Met One Neighborhood PM Monitor), black carbon (Met One BC 1050), and a new low-cost air quality monitor, the Real-time Affordable Multi-Pollutant (RAMP) sensor package for measuring CO, NO2, SO2, O3, CO2, temperature and relative humidity. High time-resolution (sub-minute) measurements across the distributed monitoring network enable insight into dynamic pollutant behaviour. Our preliminary findings show that our instruments are sensitive to PM2.5 gradients exceeding 2 micro-grams per cubic meter and ultrafine particle gradients exceeding 1000 particles per cubic centimeter. Additionally, we have developed rigorous calibration protocols to characterize the RAMP sensor response and drift, as well as multiple linear regression models to convert sensor response into pollutant concentrations that are comparable to reference instrumentation.

  16. The poultry-associated microbiome: network analysis and farm-to-fork characterizations.

    Directory of Open Access Journals (Sweden)

    Brian B Oakley

    Full Text Available Microbial communities associated with agricultural animals are important for animal health, food safety, and public health. Here we combine high-throughput sequencing (HTS, quantitative-PCR assays, and network analysis to profile the poultry-associated microbiome and important pathogens at various stages of commercial poultry production from the farm to the consumer. Analysis of longitudinal data following two flocks from the farm through processing showed a core microbiome containing multiple sequence types most closely related to genera known to be pathogenic for animals and/or humans, including Campylobacter, Clostridium, and Shigella. After the final stage of commercial poultry processing, taxonomic richness was ca. 2-4 times lower than the richness of fecal samples from the same flocks and Campylobacter abundance was significantly reduced. Interestingly, however, carcasses sampled at 48 hr after processing harboured the greatest proportion of unique taxa (those not encountered in other samples, significantly more than expected by chance. Among these were anaerobes such as Prevotella, Veillonella, Leptrotrichia, and multiple Campylobacter sequence types. Retail products were dominated by Pseudomonas, but also contained 27 other genera, most of which were potentially metabolically active and encountered in on-farm samples. Network analysis was focused on the foodborne pathogen Campylobacter and revealed a majority of sequence types with no significant interactions with other taxa, perhaps explaining the limited efficacy of previous attempts at competitive exclusion of Campylobacter. These data represent the first use of HTS to characterize the poultry microbiome across a series of farm-to-fork samples and demonstrate the utility of HTS in monitoring the food supply chain and identifying sources of potential zoonoses and interactions among taxa in complex communities.

  17. Network discovery, characterization, and prediction : a grand challenge LDRD final report.

    Energy Technology Data Exchange (ETDEWEB)

    Kegelmeyer, W. Philip, Jr.

    2010-11-01

    This report is the final summation of Sandia's Grand Challenge LDRD project No.119351, 'Network Discovery, Characterization and Prediction' (the 'NGC') which ran from FY08 to FY10. The aim of the NGC, in a nutshell, was to research, develop, and evaluate relevant analysis capabilities that address adversarial networks. Unlike some Grand Challenge efforts, that ambition created cultural subgoals, as well as technical and programmatic ones, as the insistence on 'relevancy' required that the Sandia informatics research communities and the analyst user communities come to appreciate each others needs and capabilities in a very deep and concrete way. The NGC generated a number of technical, programmatic, and cultural advances, detailed in this report. There were new algorithmic insights and research that resulted in fifty-three refereed publications and presentations; this report concludes with an abstract-annotated bibliography pointing to them all. The NGC generated three substantial prototypes that not only achieved their intended goals of testing our algorithmic integration, but which also served as vehicles for customer education and program development. The NGC, as intended, has catalyzed future work in this domain; by the end it had already brought in, in new funding, as much funding as had been invested in it. Finally, the NGC knit together previously disparate research staff and user expertise in a fashion that not only addressed our immediate research goals, but which promises to have created an enduring cultural legacy of mutual understanding, in service of Sandia's national security responsibilities in cybersecurity and counter proliferation.

  18. Camera characterization using back-propagation artificial neutral network based on Munsell system

    Science.gov (United States)

    Liu, Ye; Yu, Hongfei; Shi, Junsheng

    2008-02-01

    The camera output RGB signals do not directly corresponded to the tristimulus values based on the CIE standard colorimetric observer, i.e., it is a device-independent color space. For achieving accurate color information, we need to do color characterization, which can be used to derive a transformation between camera RGB values and CIE XYZ values. In this paper we set up a Back-Propagation (BP) artificial neutral network to realize the mapping from camera RGB to CIE XYZ. We used the Munsell Book of Color with total number 1267 as color samples. Each patch of the Munsell Book of Color was recorded by camera, and the RGB values could be obtained. The Munsell Book of Color were taken in a light booth and the surround was kept dark. The viewing/illuminating geometry was 0/45 using D 65 illuminate. The lighting illuminating the reference target needs to be as uniform as possible. The BP network was a 5-layer one and (3-10-10-10-3), which was selected through our experiments. 1000 training samples were selected randomly from the 1267 samples, and the rest 267 samples were as the testing samples. Experimental results show that the mean color difference between the reproduced colors and target colors is 0.5 CIELAB color-difference unit, which was smaller than the biggest acceptable color difference 2 CIELAB color-difference unit. The results satisfy some applications for the more accurate color measurements, such as medical diagnostics, cosmetics production, the color reappearance of different media, etc.

  19. Salt-bridge networks within globular and disordered proteins: characterizing trends for designable interactions.

    Science.gov (United States)

    Basu, Sankar; Mukharjee, Debasish

    2017-07-01

    There has been considerable debate about the contribution of salt bridges to the stabilization of protein folds, in spite of their participation in crucial protein functions. Salt bridges appear to contribute to the activity-stability trade-off within proteins by bringing high-entropy charged amino acids into close contacts during the course of their functions. The current study analyzes the modes of association of salt bridges (in terms of networks) within globular proteins and at protein-protein interfaces. While the most common and trivial type of salt bridge is the isolated salt bridge, bifurcated salt bridge appears to be a distinct salt-bridge motif having a special topology and geometry. Bifurcated salt bridges are found ubiquitously in proteins and interprotein complexes. Interesting and attractive examples presenting different modes of interaction are highlighted. Bifurcated salt bridges appear to function as molecular clips that are used to stitch together large surface contours at interacting protein interfaces. The present work also emphasizes the key role of salt-bridge-mediated interactions in the partial folding of proteins containing long stretches of disordered regions. Salt-bridge-mediated interactions seem to be pivotal to the promotion of "disorder-to-order" transitions in small disordered protein fragments and their stabilization upon binding. The results obtained in this work should help to guide efforts to elucidate the modus operandi of these partially disordered proteins, and to conceptualize how these proteins manage to maintain the required amount of disorder even in their bound forms. This work could also potentially facilitate explorations of geometrically specific designable salt bridges through the characterization of composite salt-bridge networks. Graphical abstract ᅟ.

  20. Assembly, characterization and swelling kinetics of Ag nanoparticles in PDMAA-g-PVA hydrogel networks

    Energy Technology Data Exchange (ETDEWEB)

    Luo Yanling, E-mail: luoyanl@snnu.edu.cn [Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, No. 199, South Chang' an Road, Xi' an 710062 (China); Wei Qingbo [Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, No. 199, South Chang' an Road, Xi' an 710062 (China); Xu Feng, E-mail: fengxu@snnu.edu.cn [Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, No. 199, South Chang' an Road, Xi' an 710062 (China); Chen Yashao; Fan Lihua; Zhang Changhu [Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry and Materials Science, Shaanxi Normal University, No. 199, South Chang' an Road, Xi' an 710062 (China)

    2009-12-15

    A series of poly(N,N-dimethylacrylamide)-g-poly(vinyl alcohol) (PDMAA-g-PVA) graft hydrogel networks were designed and prepared via a free radical polymerization route initiated by a PVA-(NH{sub 4}){sub 2}Ce(NO{sub 3}){sub 6} redox reaction. Silver nanoparticles with high stability and good distribution behavior have been self-assembled by using these hydrogel networks as a nanoreactor and in situ reducing system. Meanwhile the PDMAA or PVA chains can efficiently act as stabilizing agents for the Ag nanoparticles in that Ag{sup +} would form complex via oxygen atom and nitrogen atom, and form weak coordination bonds, thus astricting Ag{sup +}. The structure of the PDMAA-g-PVA/Ag was characterized by a Fourier transform infrared spectroscope (FTIR). The morphologies of pure PDMAA-g-PVA hydrogels and PDMAA-g-PVA/Ag nanocomposite ones were observed by a scanning electron microscopy (SEM) and transmission electron microscope (TEM). TEM micrographs revealed the presence of nearly spherical and well-separated Ag nanoparticles with diameters ranging from 10 to 20 nm, depending on their reduction routes. XRD results showed all relevant Bragg's reflection for crystal structure of Ag nanoparticles. UV-vis studies apparently showed the characteristic surface plasmon band at 410-440 nm for the existence of Ag nanoparticles within the hydrogel matrix. The swelling kinetics demonstrated that the transport mechanism belongs to non-Fickian mode for the PDMAA-g-PVA hydrogels and PDMAA-g-PVA/Ag nanocomposite ones. With increasing the DMAA proportion, the r{sub 0} and S{sub {infinity} }are enhanced for each system. The assembly of Ag nanoparticles and the swelling behavior may be controlled and modulated by means of the compositional ratios of PVA to DMAA and reduction systems.

  1. Application of circular consensus sequencing and network analysis to characterize the bovine IgG repertoire

    Directory of Open Access Journals (Sweden)

    Larsen Peter A

    2012-09-01

    Full Text Available Abstract Background Vertebrate immune systems generate diverse repertoires of antibodies capable of mediating response to a variety of antigens. Next generation sequencing methods provide unique approaches to a number of immuno-based research areas including antibody discovery and engineering, disease surveillance, and host immune response to vaccines. In particular, single-molecule circular consensus sequencing permits the sequencing of antibody repertoires at previously unattainable depths of coverage and accuracy. We approached the bovine immunoglobulin G (IgG repertoire with the objective of characterizing diversity of expressed IgG transcripts. Here we present single-molecule real-time sequencing data of expressed IgG heavy-chain repertoires of four individual cattle. We describe the diversity observed within antigen binding regions and visualize this diversity using a network-based approach. Results We generated 49,945 high quality cDNA sequences, each spanning the entire IgG variable region from four Bos taurus calves. From these sequences we identified 49,521 antigen binding regions using the automated Paratome web server. Approximately 9% of all unique complementarity determining 2 (CDR2 sequences were of variable lengths. A bimodal distribution of unique CDR3 sequence lengths was observed, with common lengths of 5–6 and 21–25 amino acids. The average number of cysteine residues in CDR3s increased with CDR3 length and we observed that cysteine residues were centrally located in CDR3s. We identified 19 extremely long CDR3 sequences (up to 62 amino acids in length within IgG transcripts. Network analyses revealed distinct patterns among the expressed IgG antigen binding repertoires of the examined individuals. Conclusions We utilized circular consensus sequencing technology to provide baseline data of the expressed bovine IgG repertoire that can be used for future studies important to livestock research. Somatic mutation resulting in

  2. On the Synthesis and Optical Characterization of Zero-Dimensional-Networked Perovskites

    KAUST Repository

    Almutlaq, Jawaher

    2017-04-26

    The three-dimensional perovskites are known for their wide range of interesting properties including spectral tunability, charge carrier mobility, solution-based synthesis and many others. Such properties make them good candidates for photovoltaics and photodetectors. Low-dimensional perovskites, on the other hand, are good as light emitters due to the quantum confinement originating from their nanoparticle size. Another class of low-dimensional perovskites, also called low-dimensional-networked perovskites (L-DN), is recently reemerging. Those interesting materials combine the advantages of the nanocrystals and the stability of the bulk. For example, zero-dimensional-networked perovskite (0-DN), a special class of perovskites and the focus of this work, consists of building blocks of isolated lead-halide octahedra that could be synthesized into mm-size single crystal without losing their confinement. This thesis focuses on the synthesis and investigation of the optical properties of the 0-DN perovskites through experimental, theoretical and computational tools. The recent discovery of the retrograde solubility of the perovskites family (ABX3), the basis of the inverse temperature crystallization (ITC), inspired the reinvestigation of the low-dimensional-networked perovskites. The results of the optical characterization showed that the absorption and the corresponding PL spectra were successfully tuned to cover the visible spectrum from 410 nm for Cs4PbCl6, to 520 nm and 700 m for Cs4PbBr6 and Cs4PbI6, respectively. Interestingly, the exciton binding energies (Eb) of the 0-DNs were found to be in the order of few hundred meV(s), at least five times larger than their three-dimensional counterpart. Such high Eb is coupled with a few nanoseconds lifetime and ultimately yielded a high photoluminesce quantum yield (PLQY). In fact, the PLQY of Cs4PbBr6 powder showed a record of 45%, setting a new benchmark for solid-state luminescent perovskites. Computational methods

  3. Analysis of wireless sensor network topology and estimation of optimal network deployment by deterministic radio channel characterization.

    Science.gov (United States)

    Aguirre, Erik; Lopez-Iturri, Peio; Azpilicueta, Leire; Astrain, José Javier; Villadangos, Jesús; Falcone, Francisco

    2015-02-05

    One of the main challenges in the implementation and design of context-aware scenarios is the adequate deployment strategy for Wireless Sensor Networks (WSNs), mainly due to the strong dependence of the radiofrequency physical layer with the surrounding media, which can lead to non-optimal network designs. In this work, radioplanning analysis for WSN deployment is proposed by employing a deterministic 3D ray launching technique in order to provide insight into complex wireless channel behavior in context-aware indoor scenarios. The proposed radioplanning procedure is validated with a testbed implemented with a Mobile Ad Hoc Network WSN following a chain configuration, enabling the analysis and assessment of a rich variety of parameters, such as received signal level, signal quality and estimation of power consumption. The adoption of deterministic radio channel techniques allows the design and further deployment of WSNs in heterogeneous wireless scenarios with optimized behavior in terms of coverage, capacity, quality of service and energy consumption.

  4. Fluvial particle characterization using artificial neural network and spectral image processing

    Science.gov (United States)

    Shrestha, Bim Prasad; Gautam, Bijaya; Nagata, Masateru

    2008-03-01

    Sand, chemical waste, microbes and other solid materials flowing with the water bodies are of great significance to us as they cause substantial impact to different sectors including drinking water management, hydropower generation, irrigation, aquatic life preservation and various other socio-ecological factors. Such particles can't completely be avoided due to the high cost of construction and maintenance of the waste-treatment methods. A detailed understanding of solid particles in surface water system can have benefit in effective, economic, environmental and social management of water resources. This paper describes an automated system of fluvial particle characterization based on spectral image processing that lead to the development of devices for monitoring flowing particles in river. Previous research in coherent field has shown that it is possible to automatically classify shapes and sizes of solid particles ranging from 300-400 μm using artificial neural networks (ANN) and image processing. Computer facilitated with hyper spectral and multi spectral images using ANN can further classify fluvial materials into organic, inorganic, biodegradable, bio non degradable and microbes. This makes the method attractive for real time monitoring of particles, sand and microorganism in water bodies at strategic locations. Continuous monitoring can be used to determine the effect of socio-economic activities in upstream rivers, or to monitor solid waste disposal from treatment plants and industries or to monitor erosive characteristic of sand and its contribution to degradation of efficiency of hydropower plant or to identify microorganism, calculate their population and study the impact of their presence. Such system can also be used to characterize fluvial particles for planning effective utilization of water resources in micro-mega hydropower plant, irrigation, aquatic life preservation etc.

  5. Characterization of Mason Gully (H5): The second recovered fall from the Desert Fireball Network

    Science.gov (United States)

    Dyl, Kathryn A.; Benedix, Gretchen K.; Bland, Phil A.; Friedrich, Jon M.; Spurný, Pavel; Towner, Martin C.; O'Keefe, Mary Claire; Howard, Kieren; Greenwood, Richard; Macke, Robert J.; Britt, Daniel T.; Halfpenny, Angela; Thostenson, James O.; Rudolph, Rebecca A.; Rivers, Mark L.; Bevan, Alex W. R.

    2016-03-01

    Mason Gully, the second meteorite recovered using the Desert Fireball Network (DFN), is characterized using petrography, mineralogy, oxygen isotopes, bulk chemistry, and physical properties. Geochemical data are consistent with its classification as an H5 ordinary chondrite. Several properties distinguish it from most other H chondrites. Its 10.7% porosity is predominantly macroscopic, present as intergranular void spaces rather than microscopic cracks. Modal mineralogy (determined via PS-XRD, element mapping via energy dispersive spectroscopy [EDS], and X-ray tomography [for sulfide, metal, and porosity volume fractions]) consistently gives an unusually low olivine/orthopyroxene ratio (0.67-0.76 for Mason Gully versus ~1.3 for typical H5 ordinary chondrites). Widespread "silicate darkening" is observed. In addition, it contains a bright green crystalline object at the surface of the recovered stone (diameter ≈ 1.5 mm), which has a tridymite core with minor α-quartz and a rim of both low- and high-Ca pyroxene. The mineralogy allows the calculation of the temperatures and ƒ(O2) characterizing thermal metamorphism on the parent body using both the two-pyroxene and the olivine-chromite geo-oxybarometers. These indicate that MG experienced a peak metamorphic temperature of ~900 °C and had a similar ƒ(O2) to Kernouvé (H6) that was buffered by the reaction between olivine, metal, and pyroxene. There is no evidence for shock, consistent with the observed porosity structure. Thus, while Mason Gully has some unique properties, its geochemistry indicates a similar thermal evolution to other H chondrites. The presence of tridymite, while rare, is seen in other OCs and likely exogenous; however, the green object itself may result from metamorphism.

  6. Loss of 'Small-World' Networks in Alzheimer's Disease: Graph Analysis of fMRI Resting-State Functional Connectivity

    NARCIS (Netherlands)

    Sanz-Arigita, E.J.; Schoonheim, M.M.; Damoiseaux, J.S.; Rombouts, S.A.R.B.; Maris, E.; Barkhof, F.; Scheltens, P.; Stam, C.J.

    2010-01-01

    Background: Local network connectivity disruptions in Alzheimer's disease patients have been found using graph analysis in BOLD fMRI. Other studies using MEG and cortical thickness measures, however, show more global long distance connectivity changes, both in functional and structural imaging data.

  7. Projected climate-induced habitat loss for salmonids in the John Day River network, Oregon, U.S.A.

    Science.gov (United States)

    Ruesch, Aaron S.; Torgersen, Christian E.; Lawler, Joshua J.; Olden, Julian D.; Peterson, Erin E.; Volk, Carol J.; Lawrence, David J.

    2012-01-01

    Climate change will likely have profound effects on cold-water species of freshwater fishes. As temperatures rise, cold-water fish distributions may shift and contract in response. Predicting the effects of projected stream warming in stream networks is complicated by the generally poor correlation between water temperature and air temperature. Spatial dependencies in stream networks are complex because the geography of stream processes is governed by dimensions of flow direction and network structure. Therefore, forecasting climate-driven range shifts of stream biota has lagged behind similar terrestrial modeling efforts. We predicted climate-induced changes in summer thermal habitat for 3 cold-water fish species—juvenile Chinook salmon, rainbow trout, and bull trout (Oncorhynchus tshawytscha, O. mykiss, and Salvelinus confluentus, respectively)—in the John Day River basin, northwestern United States. We used a spatially explicit statistical model designed to predict water temperature in stream networks on the basis of flow and spatial connectivity. The spatial distribution of stream temperature extremes during summers from 1993 through 2009 was largely governed by solar radiation and interannual extremes of air temperature. For a moderate climate change scenario, estimated declines by 2100 in the volume of habitat for Chinook salmon, rainbow trout, and bull trout were 69–95%, 51–87%, and 86–100%, respectively. Although some restoration strategies may be able to offset these projected effects, such forecasts point to how and where restoration and management efforts might focus.

  8. Does social network site use buffer against well-being loss when older adults face reduced functional ability?

    NARCIS (Netherlands)

    van Ingen, Erik; Rains, Stephen A; Wright, Kevin B

    2017-01-01

    We examine the role of the Internet in dealing with problems in later life by analyzing whether direct and buffering models of social support can be applied to social network site (SNS) use. Whereas the direct model implies a positive effect of time spent using SNSs on subjective well-being, and a

  9. Assessing loss event frequencies of smart grid cyber threats: Encoding flexibility into FAIR using Bayesian network approach

    NARCIS (Netherlands)

    Le, Anhtuan; Chen, Yue; Chai, Kok Keong; Vasenev, Alexandr; Montoya, L.

    Assessing loss event frequencies (LEF) of smart grid cyber threats is essential for planning cost-effective countermeasures. Factor Analysis of Information Risk (FAIR) is a well-known framework that can be applied to consider threats in a structured manner by using look-up tables related to a

  10. A wireless sensor network for urban traffic characterization and trend monitoring.

    Science.gov (United States)

    Fernández-Lozano, J J; Martín-Guzmán, Miguel; Martín-Ávila, Juan; García-Cerezo, A

    2015-10-15

    Sustainable mobility requires a better management of the available infrastructure resources. To achieve this goal, it is necessary to obtain accurate data about road usage, in particular in urban areas. Although a variety of sensor alternates for urban traffic exist, they usually require extensive investments in the form of construction works for installation, processing means, etc. Wireless Sensor Networks (WSN) are an alternative to acquire urban traffic data, allowing for flexible, easy deployment. Together with the use of the appropriate sensors, like Bluetooth identification, and associate processing, WSN can provide the means to obtain in real time data like the origin-destination matrix, a key tool for trend monitoring which previously required weeks or months to be completed. This paper presents a system based on WSN designed to characterize urban traffic, particularly traffic trend monitoring through the calculation of the origin-destination matrix in real time by using Bluetooth identification. Additional sensors are also available integrated in different types of nodes. Experiments in real conditions have been performed, both for separate sensors (Bluetooth, ultrasound and laser), and for the whole system, showing the feasibility of this approach.

  11. Performance characterization and transmission schemes for instantly decodable network coding in wireless broadcast

    Science.gov (United States)

    Yu, Mingchao; Sadeghi, Parastoo; Aboutorab, Neda

    2015-12-01

    We consider broadcasting a block of packets to multiple wireless receivers under random packet erasures using instantly decodable network coding (IDNC). The sender first broadcasts each packet uncoded once, then generates coded packets according to receivers' feedback about their missing packets. We focus on strict IDNC (S-IDNC), where each coded packet includes at most one missing packet of every receiver. But, we will also study its relation with generalized IDNC (G-IDNC), where this condition is relaxed. We characterize two fundamental performance limits of S-IDNC: (1) the number of transmissions to complete the broadcast, which measures throughput and (2) average packet decoding delay, which measures how fast each packet is decoded at each receiver on average. We derive a closed-form expression for the expected minimum number of transmissions in terms of the number of packets and receivers and the erasure probability. We prove that it is NP-hard to minimize the average packet decoding delay of S-IDNC. We also prove that the graph models of S- and G-IDNC share the same chromatic number. Next, we design efficient S-IDNC transmission schemes and coding algorithms with full/intermittent receiver feedback. We present simulation results to corroborate the developed theory and compare our schemes with existing ones.

  12. Radio Characterization for ISM 2.4 GHz Wireless Sensor Networks for Judo Monitoring Applications

    Directory of Open Access Journals (Sweden)

    Peio Lopez-Iturri

    2014-12-01

    Full Text Available In this work, the characterization of the radio channel for ISM 2.4GHz Wireless Sensor Networks (WSNs for judo applications is presented. The environments where judo activity is held are usually complex indoor scenarios in terms of radiopropagation due to their morphology, the presence of humans and the electromagnetic interference generated by personal portable devices, wireless microphones and other wireless systems used by the media. For the assessment of the impact that the topology and the morphology of these environments have on electromagnetic propagation, an in-house developed 3D ray-launching software has been used in this study. Time domain results as well as estimations of received power level have been obtained for the complete volume of a training venue of a local judo club’s facilities with a contest area with the dimensions specified by the International Judo Federation (IJF for international competitions. The obtained simulation results have been compared with measurements, which have been carried out deploying ZigBee-compliant XBee Pro modules at presented scenario, using approved Judogis (jacket, trousers and belt. The analysis is completed with the inclusion of an in-house human body computational model. Such analysis has allowed the design and development of an in house application devoted to monitor the practice of judo, in order to aid referee activities, training routines and to enhance spectator experience.

  13. Radio Characterization for ISM 2.4 GHz Wireless Sensor Networks for Judo Monitoring Applications

    Science.gov (United States)

    Lopez-Iturri, Peio; Aguirre, Erik; Azpilicueta, Leire; Astrain, José J.; Villadangos, Jesús; Falcone, Francisco

    2014-01-01

    In this work, the characterization of the radio channel for ISM 2.4GHz Wireless Sensor Networks (WSNs) for judo applications is presented. The environments where judo activity is held are usually complex indoor scenarios in terms of radiopropagation due to their morphology, the presence of humans and the electromagnetic interference generated by personal portable devices, wireless microphones and other wireless systems used by the media. For the assessment of the impact that the topology and the morphology of these environments have on electromagnetic propagation, an in-house developed 3D ray-launching software has been used in this study. Time domain results as well as estimations of received power level have been obtained for the complete volume of a training venue of a local judo club's facilities with a contest area with the dimensions specified by the International Judo Federation (IJF) for international competitions. The obtained simulation results have been compared with measurements, which have been carried out deploying ZigBee-compliant XBee Pro modules at presented scenario, using approved Judogis (jacket, trousers and belt). The analysis is completed with the inclusion of an in-house human body computational model. Such analysis has allowed the design and development of an in house application devoted to monitor the practice of judo, in order to aid referee activities, training routines and to enhance spectator experience. PMID:25615735

  14. Directed weighted network structure analysis of complex impedance measurements for characterizing oil-in-water bubbly flow

    Science.gov (United States)

    Gao, Zhong-Ke; Dang, Wei-Dong; Xue, Le; Zhang, Shan-Shan

    2017-03-01

    Characterizing the flow structure underlying the evolution of oil-in-water bubbly flow remains a contemporary challenge of great interests and complexity. In particular, the oil droplets dispersing in a water continuum with diverse size make the study of oil-in-water bubbly flow really difficult. To study this issue, we first design a novel complex impedance sensor and systematically conduct vertical oil-water flow experiments. Based on the multivariate complex impedance measurements, we define modalities associated with the spatial transient flow structures and construct modality transition-based network for each flow condition to study the evolution of flow structures. In order to reveal the unique flow structures underlying the oil-in-water bubbly flow, we filter the inferred modality transition-based network by removing the edges with small weight and resulting isolated nodes. Then, the weighted clustering coefficient entropy and weighted average path length are employed for quantitatively assessing the original network and filtered network. The differences in network measures enable to efficiently characterize the evolution of the oil-in-water bubbly flow structures.

  15. Strain-dependent characterization of electrode and polymer network of electrically activated polymer actuators

    Science.gov (United States)

    Töpper, Tino; Osmani, Bekim; Weiss, Florian M.; Winterhalter, Carla; Wohlfender, Fabian; Leung, Vanessa; Müller, Bert

    2015-04-01

    Fecal incontinence describes the involuntary loss of bowel content and affects about 45 % of retirement home residents and overall more than 12 % of the adult population. Artificial sphincter implants for treating incontinence are currently based on mechanical systems with failure rates resulting in revision after three to five years. To overcome this drawback, artificial muscle sphincters based on bio-mimetic electro-active polymer (EAP) actuators are under development. Such implants require polymer films that are nanometer-thin, allowing actuation below 24 V, and electrodes that are stretchable, remaining conductive at strains of about 10 %. Strain-dependent resistivity measurements reveal an enhanced conductivity of 10 nm compared to 30 nm sputtered Au on silicone for strains higher than 5 %. Thus, strain-dependent morphology characterization with optical microscopy and atomic force microscopy could demonstrate these phenomena. Cantilever bending measurements are utilized to determine elastic/viscoelastic properties of the EAP films as well as their long-term actuation behavior. Controlling these properties enables the adjustment of growth parameters of nanometer-thin EAP actuators.

  16. Site characterization of the Romanian Seismic Network stations: a national initiative and its first preliminary results

    Science.gov (United States)

    Grecu, Bogdan; Zahria, Bogdan; Manea, Elena; Neagoe, Cristian; Borleanu, Felix; Diaconescu, Mihai; Constantinescu, Eduard; Bala, Andrei

    2017-04-01

    The seismic activity in Romania is dominated by the intermediate-depth earthquakes occurring in Vrancea region, although weak to moderate crustal earthquakes are produced regularly in different areas of the country. The National Institute for Earth Physics (NIEP) built in the last years an impressive infrastructure for monitoring this activity, known as the Romanian Seismic Network (RSN). At present, RSN consists of 122 seismic stations, of which 70 have broadband velocity sensors and 42 short period sensors. One hundred and eleven stations out of 122 have accelerometer sensors collocated with velocity sensors and only 10 stations have only accelerometers. All the stations record continuously the ground motion and the data are transmitted in real-time to the Romanian National Data Center (RoNDC), in Magurele. Last year, NIEP has started a national project that addresses the characterization of all real-time seismic stations that constitute the RSN. We present here the steps that were undertaken and the preliminary results obtained since the beginning the project. The first two activities consisted of collecting all the existent technical and geological data, with emphasize on the latter. Then, we performed station noise investigations and analyses in order to characterize the noise level and estimate the resonances of the sites. The computed H/V ratios showed clear resonant peaks at different frequencies which correlate relatively well with the thickness of the sedimentary package beneath the stations. The polarization analysis of the H/V ratios indicates for some stations a strong directivity of the resonance peak which suggests possible topographic effects at the stations. At the same time, special attention was given to the estimation of the site amplification from earthquake data. The spectral ratios obtained from the analysis of more than 50 earthquakes with magnitudes (Mw) larger than 4.1 are characterized by similar resonance peaks as those obtained from

  17. Characterization of IP Flows Eligible for Lambda-Connections in Optical Networks

    NARCIS (Netherlands)

    Fioreze, Tiago; Oude Wolbers, Mattijs; van de Meent, R.; Pras, Aiko

    2008-01-01

    The advance on data transmission in optical networks has allowed data forwarding decisions to be taken at multiple levels in the protocol stack (e.g., at network and optical levels). With such capability, big IP flows can be moved from the network level and switched completely at the optical level

  18. Characterizing Deep Brain Stimulation effects in computationally efficient neural network models.

    Science.gov (United States)

    Latteri, Alberta; Arena, Paolo; Mazzone, Paolo

    2011-04-15

    Recent studies on the medical treatment of Parkinson's disease (PD) led to the introduction of the so called Deep Brain Stimulation (DBS) technique. This particular therapy allows to contrast actively the pathological activity of various Deep Brain structures, responsible for the well known PD symptoms. This technique, frequently joined to dopaminergic drugs administration, replaces the surgical interventions implemented to contrast the activity of specific brain nuclei, called Basal Ganglia (BG). This clinical protocol gave the possibility to analyse and inspect signals measured from the electrodes implanted into the deep brain regions. The analysis of these signals led to the possibility to study the PD as a specific case of dynamical synchronization in biological neural networks, with the advantage to apply the theoretical analysis developed in such scientific field to find efficient treatments to face with this important disease. Experimental results in fact show that the PD neurological diseases are characterized by a pathological signal synchronization in BG. Parkinsonian tremor, for example, is ascribed to be caused by neuron populations of the Thalamic and Striatal structures that undergo an abnormal synchronization. On the contrary, in normal conditions, the activity of the same neuron populations do not appear to be correlated and synchronized. To study in details the effect of the stimulation signal on a pathological neural medium, efficient models of these neural structures were built, which are able to show, without any external input, the intrinsic properties of a pathological neural tissue, mimicking the BG synchronized dynamics.We start considering a model already introduced in the literature to investigate the effects of electrical stimulation on pathologically synchronized clusters of neurons. This model used Morris Lecar type neurons. This neuron model, although having a high level of biological plausibility, requires a large computational effort

  19. Synthesis, characterization, swelling and drug release behavior of semi-interpenetrating network hydrogels of sodium alginate and polyacrylamide.

    Science.gov (United States)

    Samanta, Himadri Sekhar; Ray, Samit Kumar

    2014-01-01

    Several semi interpenetrating network (SIPN) type hydrogels were synthesized by in-situ free radical crosslink copolymerization of acrylamide and crosslinker N,N'-methylene bisacrylamide (MBA) in aqueous solution of sodium alginate (SA).These SIPN hydrogels were characterized by FTIR, NMR SEM, DTA-TGA, XRD, PZC and also by swelling characteristics and network parameters. Adsorption (loading) and release of acetaminophen drug were studied with these hydrogels. Solution pH, crosslinker concentration and monomer to SA weight ratio of the hydrogels were found to have a strong effect on adsorption and in vitro release profile of the drug from the gel matrix. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. An Erlang Loss Queue with Time-Phased Batch Arrivals as a Model for Traffic Control in Communication Networks

    Directory of Open Access Journals (Sweden)

    Moon Ho Lee

    2008-01-01

    Full Text Available A multiserver queueing model that does not have a buffer but has batch arrival of customers is considered. In contrast to the standard batch arrival, in which the entire batch arrives at the system during a single epoch, we assume that the customers of a batch (flow arrive individually in exponentially distributed times. The service time is exponentially distributed. Flows arrive according to a stationary Poisson arrival process. The flow size distribution is geometric. The number of flows that can be simultaneously admitted to the system is under control. The loss of any customer from an admitted flow, with a fixed probability, implies termination of the flow arrival. Analysis of the sojourn time and loss probability of an arbitrary flow is performed.

  1. Analysis of Wireless Sensor Network Topology and Estimation of Optimal Network Deployment by Deterministic Radio Channel Characterization

    Directory of Open Access Journals (Sweden)

    Erik Aguirre

    2015-02-01

    Full Text Available One of the main challenges in the implementation and design of context-aware scenarios is the adequate deployment strategy for Wireless Sensor Networks (WSNs, mainly due to the strong dependence of the radiofrequency physical layer with the surrounding media, which can lead to non-optimal network designs. In this work, radioplanning analysis for WSN deployment is proposed by employing a deterministic 3D ray launching technique in order to provide insight into complex wireless channel behavior in context-aware indoor scenarios. The proposed radioplanning procedure is validated with a testbed implemented with a Mobile Ad Hoc Network WSN following a chain configuration, enabling the analysis and assessment of a rich variety of parameters, such as received signal level, signal quality and estimation of power consumption. The adoption of deterministic radio channel techniques allows the design and further deployment of WSNs in heterogeneous wireless scenarios with optimized behavior in terms of coverage, capacity, quality of service and energy consumption.

  2. Multi-TID detection and characterization in a dense Global Navigation Satellite System receiver network

    Science.gov (United States)

    Yang, Heng; Monte-Moreno, Enrique; Hernández-Pajares, Manuel

    2017-09-01

    The medium-scale traveling ionospheric disturbances (MSTIDs) constitute the most frequent ionospheric wave signatures. We propose a method for detecting the number of simultaneous MSTIDs from a time series of high-pass-filtered Vertical Total Electron Content (VTEC) maps and their parameters. The method is tested on the VTEC map corresponding to a simulated realistic scenario and on actual data from dual-frequency Global Positioning System (GPS) measurements gathered by +1200 GPS receivers of the GPS Earth Observation Network (GEONET) in Japan. The contribution consists of the detection of the number of independent MSTIDs from a nonuniform sampling of the ionospheric pierce points. The problem is set as a sparse decomposition on elements of a dictionary of atoms that span a linear space of possible MSTIDs. These atoms consist of plane waves characterized by a wavelength, direction, and phase on a surface defined, the part of the ionosphere sounded by the GEONET (i.e., 25°N to 50°N of latitude and 125°E to 155°E of longitude). The technique is related to the atomic decomposition and least absolute shrinkage and selection operator. The geophysical contribution of this paper is showing (a) the detection of several simultaneous MSTIDs of different characteristics, with a continuous change in the velocity; (b) detection of circular MSTID waves compatible by time and center with a specific earthquake; (c) simultaneous superposition of two distinct MSTIDs, with almost the same azimuth; and (d) the presence at nighttime of MSTIDs with velocities in the range 400-600 m/s.

  3. Approaching zero cellulose loss in cellulose nanocrystal (CNC) production: recovery and characterization of cellulosic solid residues (CSR) and CNC

    Science.gov (United States)

    Q.Q. Wang; J.Y. Zhu; R.S. Reiner; S.P. Verrill; U. Baxa; S.E. McNeil

    2012-01-01

    This study demonstrated the potential of simultaneously recovering cellulosic solid residues (CSR) and producing cellulose nanocrystals (CNCs) by strong sulfuric acid hydrolysis to minimize cellulose loss to near zero. A set of slightly milder acid hydrolysis conditions than that considered as “optimal” were used to significantly minimize the degradation of cellulose...

  4. Use of a Real-Time Remote Monitoring Network (RTRM) to Characterize the Guadalquivir Estuary (Spain)

    OpenAIRE

    Isabel Caballero; Victoria López-Rodas; Javier Ruiz; Laura Prieto; Susana Flecha; Manuel Díez-Minguito; Eduardo Costas; Gabriel Navarro; Isabel Emma Huertas

    2012-01-01

    The temporal variability of hydrological variables in the Guadalquivir estuary was examined during three years through a real-time remote monitoring network (RTRM). The network was developed with the aim of studying the influence of hydrodynamical and hydrological features within the estuary on the functioning of the pelagic ecosystem. Completing this data-gathering network, monthly cruises were performed in order to measure biogeochemical variables that are indicative of the trophic status o...

  5. Electrical network method for the thermal or structural characterization of a conducting material sample or structure

    Science.gov (United States)

    Ortiz, Marco G.

    1993-01-01

    A method for modeling a conducting material sample or structure system, as an electrical network of resistances in which each resistance of the network is representative of a specific physical region of the system. The method encompasses measuring a resistance between two external leads and using this measurement in a series of equations describing the network to solve for the network resistances for a specified region and temperature. A calibration system is then developed using the calculated resistances at specified temperatures. This allows for the translation of the calculated resistances to a region temperature. The method can also be used to detect and quantify structural defects in the system.

  6. Pharmacological characterization of cultivated neuronal networks: relevance to synaptogenesis and synaptic connectivity.

    Science.gov (United States)

    Verstraelen, Peter; Pintelon, Isabel; Nuydens, Rony; Cornelissen, Frans; Meert, Theo; Timmermans, Jean-Pierre

    2014-07-01

    Mental disorders, such as schizophrenia or Alzheimer's disease, are associated with impaired synaptogenesis and/or synaptic communication. During development, neurons assemble into neuronal networks, the primary supracellular mediators of information processing. In addition to the orchestrated activation of genetic programs, spontaneous electrical activity and associated calcium signaling have been shown to be critically involved in the maturation of such neuronal networks. We established an in vitro model that recapitulates the maturation of neuronal networks, including spontaneous electrical activity. Upon plating, mouse primary hippocampal neurons grow neurites and interconnect via synapses to form a dish-wide neuronal network. Via live cell calcium imaging, we identified a limited period of time in which the spontaneous activity synchronizes across neurons, indicative of the formation of a functional network. After establishment of network activity, the neurons grow dendritic spines, the density of which was used as a morphological readout for neuronal maturity and connectivity. Hence, quantification of neurite outgrowth, synapse density, spontaneous neuronal activity, and dendritic spine density allowed to study neuronal network maturation from the day of plating until the presence of mature neuronal networks. Via acute pharmacological intervention, we show that synchronized network activity is mediated by the NMDA-R. The balance between kynurenic and quinolinic acid, both neuro-active intermediates in the tryptophan/kynurenine pathway, was shown to be decisive for the maintenance of network activity. Chronic modulation of the neurotrophic support influenced the network formation and revealed the extreme sensitivity of calcium imaging to detect subtle alterations in neuronal physiology. Given the reproducible cultivation in a 96-well setup in combination with fully automated analysis of the calcium recordings, this approach can be used to build a high

  7. Comparative genomics of the bacterial genus Listeria: Genome evolution is characterized by limited gene acquisition and limited gene loss

    Science.gov (United States)

    2010-01-01

    Background The bacterial genus Listeria contains pathogenic and non-pathogenic species, including the pathogens L. monocytogenes and L. ivanovii, both of which carry homologous virulence gene clusters such as the prfA cluster and clusters of internalin genes. Initial evidence for multiple deletions of the prfA cluster during the evolution of Listeria indicates that this genus provides an interesting model for studying the evolution of virulence and also presents practical challenges with regard to definition of pathogenic strains. Results To better understand genome evolution and evolution of virulence characteristics in Listeria, we used a next generation sequencing approach to generate draft genomes for seven strains representing Listeria species or clades for which genome sequences were not available. Comparative analyses of these draft genomes and six publicly available genomes, which together represent the main Listeria species, showed evidence for (i) a pangenome with 2,032 core and 2,918 accessory genes identified to date, (ii) a critical role of gene loss events in transition of Listeria species from facultative pathogen to saprotroph, even though a consistent pattern of gene loss seemed to be absent, and a number of isolates representing non-pathogenic species still carried some virulence associated genes, and (iii) divergence of modern pathogenic and non-pathogenic Listeria species and strains, most likely circa 47 million years ago, from a pathogenic common ancestor that contained key virulence genes. Conclusions Genome evolution in Listeria involved limited gene loss and acquisition as supported by (i) a relatively high coverage of the predicted pan-genome by the observed pan-genome, (ii) conserved genome size (between 2.8 and 3.2 Mb), and (iii) a highly syntenic genome. Limited gene loss in Listeria did include loss of virulence associated genes, likely associated with multiple transitions to a saprotrophic lifestyle. The genus Listeria thus provides

  8. Corona helps curb losses

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-11-01

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

  9. Graph analytic characterization of resting state networks in post-stroke aphasia

    Directory of Open Access Journals (Sweden)

    Swathi Kiran

    2014-04-01

    Relative to controls, these results indicate inefficiencies in the post-stroke resting-state network, with greater shifts in network hubs in PWA dependent on the site and size of lesion. Such graph analytic results may prove informative in advancing individual-specific therapies.

  10. The Trees and the Forest : Characterization of complex brain networks with minimum spanning trees

    NARCIS (Netherlands)

    Stam, C.J.; Tewarie, P.; Van Dellen, E.; Van Straaten, E.C.W.; Hillebrand, A.; Van Mieghem, P.

    2014-01-01

    In recent years there has been a shift in focus from the study of local, mostly task-related activation to the exploration of the organization and functioning of large-scale structural and functional complex brain networks. Progress in the interdisciplinary field of modern network science has

  11. The trees and the forest: Characterization of complex brain networks with minimum spanning trees

    NARCIS (Netherlands)

    Stam, C.J.; Tewarie, P.; van Dellen, E.; van Straaten, E.C.W.; Hillebrand, A.; Van Mieghem, P.

    2014-01-01

    In recent years there has been a shift in focus from the study of local, mostly task-related activation to the exploration of the organization and functioning of large-scale structural and functional complex brain networks. Progress in the interdisciplinary field of modern network science has

  12. Epidemic Survivability: Characterizing Networks Under Epidemic-like Failure Propagation Scenarios

    DEFF Research Database (Denmark)

    Manzano, Marc; Calle, Eusebi; Ripoll, Jordi

    2013-01-01

    in telecommunication networks has not been extensively considered, nowadays, with the increasing computation capacity and complexity of operating systems of modern network devices (routers, switches, etc.), the study of possible epidemic-like failure scenarios must be taken into account. When epidemics occur......, such as in other multiple failure scenarios, identifying the level of vulnerability offered by a network is one of the main challenges. In this paper, we present epidemic survivability, a new network measure that describes the vulnerability of each node of a network under a specific epidemic intensity. Moreover......, this metric is able to identify the set of nodes which are more vulnerable under an epidemic attack. In addition, two applications of epidemic survivability are provided. First, we introduce epidemic criticality, a novel robustness metric for epidemic failure scenarios. A case study shows the utility...

  13. Identifying and characterizing key nodes among communities based on electrical-circuit networks.

    Directory of Open Access Journals (Sweden)

    Fenghui Zhu

    Full Text Available Complex networks with community structures are ubiquitous in the real world. Despite many approaches developed for detecting communities, we continue to lack tools for identifying overlapping and bridging nodes that play crucial roles in the interactions and communications among communities in complex networks. Here we develop an algorithm based on the local flow conservation to effectively and efficiently identify and distinguish the two types of nodes. Our method is applicable in both undirected and directed networks without a priori knowledge of the community structure. Our method bypasses the extremely challenging problem of partitioning communities in the presence of overlapping nodes that may belong to multiple communities. Due to the fact that overlapping and bridging nodes are of paramount importance in maintaining the function of many social and biological networks, our tools open new avenues towards understanding and controlling real complex networks with communities accompanied with the key nodes.

  14. Identifying and characterizing key nodes among communities based on electrical-circuit networks.

    Science.gov (United States)

    Zhu, Fenghui; Wang, Wenxu; Di, Zengru; Fan, Ying

    2014-01-01

    Complex networks with community structures are ubiquitous in the real world. Despite many approaches developed for detecting communities, we continue to lack tools for identifying overlapping and bridging nodes that play crucial roles in the interactions and communications among communities in complex networks. Here we develop an algorithm based on the local flow conservation to effectively and efficiently identify and distinguish the two types of nodes. Our method is applicable in both undirected and directed networks without a priori knowledge of the community structure. Our method bypasses the extremely challenging problem of partitioning communities in the presence of overlapping nodes that may belong to multiple communities. Due to the fact that overlapping and bridging nodes are of paramount importance in maintaining the function of many social and biological networks, our tools open new avenues towards understanding and controlling real complex networks with communities accompanied with the key nodes.

  15. Biophysical characterization of the short QT mutation hERG-N588K reveals a mixed gain-and loss-of-function

    DEFF Research Database (Denmark)

    Grunnet, M.; Diness, T.G.; Hansen, R.S.

    2008-01-01

    The short QT syndrome is a newly discovered pro-arrhythmic condition, which may cause ventricular fibrillation and sudden death. Short QT can originate from the apparent gain-of-function mutation N588K in the hERG potassium channel that conducts repolarising I(Kr) current. The present study...... describes a profound biophysical characterization of HERG-N588K revealing both loss-of-function and gain-of-function properties of the mutant. Experiments were conducted after heterologous expression in both Xenopus laevis oocytes and mammalian cells and at both room temperature and at 37 degrees C. Also...... the impact of the beta-subunits KCNE2 was investigated. The most prominent loss-of-function property of HERG-N588K was reduced tail currents but also the activation properties was compromised. Based on these biophysical results we suggest that the general view of HERG-N588K being a gain...

  16. Characterization of the Gut Microbial Community of Obese Patients Following a Weight-Loss Intervention Using Whole Metagenome Shotgun Sequencing.

    Directory of Open Access Journals (Sweden)

    Sandrine Louis

    Full Text Available Cross-sectional studies suggested that obesity is promoted by the gut microbiota. However, longitudinal data on taxonomic and functional changes in the gut microbiota of obese patients are scarce. The aim of this work is to study microbiota changes in the course of weight loss therapy and the following year in obese individuals with or without co-morbidities, and to asses a possible predictive value of the gut microbiota with regard to weight loss maintenance.Sixteen adult patients, who followed a 52-week weight-loss program comprising low calorie diet, exercise and behavioral therapy, were selected according to their weight-loss course. Over two years, anthropometric and metabolic parameters were assessed and microbiota from stool samples was functionally and taxonomically analyzed using DNA shotgun sequencing.Overall the microbiota responded to the dietetic and lifestyle intervention but tended to return to the initial situation both at the taxonomical and functional level at the end of the intervention after one year, except for an increase in Akkermansia abundance which remained stable over two years (12.7x103 counts, 95%CI: 322-25100 at month 0; 141x103 counts, 95%CI: 49-233x103 at month 24; p = 0.005. The Firmicutes/Bacteroidetes ratio was higher in obese subjects with metabolic syndrome (0.64, 95%CI: 0.34-0.95 than in the "healthy obese" (0.27, 95%CI: 0.08-0.45, p = 0.04. Participants, who succeeded in losing their weight consistently over the two years, had at baseline a microbiota enriched in Alistipes, Pseudoflavonifractor and enzymes of the oxidative phosphorylation pathway compared to patients who were less successful in weight reduction.Successful weight reduction in the obese is accompanied with increased Akkermansia numbers in feces. Metabolic co-morbidities are associated with a higher Firmicutes/Bacteroidetes ratio. Most interestingly, microbiota differences might allow discrimination between successful and unsuccessful weight

  17. Real-time Monitoring Network to Characterize Anthropogenic and Natural Events Affecting the Hudson River, NY

    Science.gov (United States)

    Islam, M. S.; Bonner, J. S.; Fuller, C.; Kirkey, W.; Ojo, T.

    2011-12-01

    The Hudson River watershed spans 34,700 km2 predominantly in New York State, including agricultural, wilderness, and urban areas. The Hudson River supports many activities including shipping, supplies water for municipal, commercial, and agricultural uses, and is an important recreational resource. As the population increases within this watershed, so does the anthropogenic impact on this natural system. To address the impacts of anthropogenic and natural activities on this ecosystem, the River and Estuary Observatory Network (REON) is being developed through a joint venture between the Beacon Institute, Clarkson University, General Electric Inc. and IBM Inc. to monitor New York's Hudson and Mohawk Rivers in real-time. REON uses four sensor platform types with multiple nodes within the network to capture environmentally relevant episodic events. Sensor platform types include: 1) fixed robotic vertical profiler (FRVP); 2) mobile robotic undulating platform (MRUP); 3) fixed acoustic Doppler current profiler (FADCP) and 4) Autonomous Underwater Vehicle (AUV). The FRVP periodically generates a vertical profile with respect to water temperature, salinity, dissolved oxygen, particle concentration and size distribution, and fluorescence. The MRUP utilizes an undulating tow-body tethered behind a research vessel to measure the same set of water parameters as the FRVP, but does so 'synchronically' over a highly-resolved spatial regime. The fixed ADCP provides continuous water current profiles. The AUV maps four-dimensional (time, latitude, longitude, depth) variation of water quality, water currents and bathymetry along a pre-determined transect route. REON data can be used to identify episodic events, both anthropogenic and natural, that impact the Hudson River. For example, a strong heat signature associated with cooling water discharge from the Indian Point nuclear power plant was detected with the MRUP. The FRVP monitoring platform at Beacon, NY, located in the

  18. Characterization of biomarkers in stroke based on ego-networks and pathways.

    Science.gov (United States)

    Li, Haixia; Guo, Qianqian

    2017-12-01

    To explore potential biomarkers in stroke based on ego-networks and pathways. EgoNet method was applied to search for the underlying biomarkers in stroke using transcription profiling of E-GEOD-58294 and protein-protein interaction (PPI) data. Eight ego-genes were identified from PPI network according to the degree characteristics at the criteria of top 5% ranked z-sore and degree >1. Eight candidate ego-networks with classification accuracy ≥0.9 were selected. After performed randomization test, seven significant ego-networks with adjusted p value ego-networks to search for the significant pathways. Finally, two significant pathways were identified, and six of seven ego-networks were enriched to "3'-UTR-mediated translational regulation" pathway, indicating that this pathway performs an important role in the development of stroke. Seven ego-networks were constructed using EgoNet and two significant enriched by pathways were identified. These may provide new insights into the potential biomarkers for the development of stroke.

  19. Identification and characterization of the leaf specific networks of inner and rosette leaves in Brassica rapa.

    Science.gov (United States)

    Kim, Man-Sun; Hong, Seongmin; Devaraj, Sangeeth Prasath; Im, Subin; Kim, Jeong-Rae; Lim, Yong Pyo

    2017-08-26

    Inner and rosette leaves of Chinese cabbage (Brassica rapa) have different characteristics in terms of nutritional value, appearance, taste, color and texture. Many researchers have utilized differentially expressed genes for exploring the difference between inner and rosette leaves of Brassica rapa. The functional characteristics of a gene, however, is determined by complex interactions between genes. Hence, a noble network approach is required for elucidating such functional difference that is not captured by gene expression profiles alone. In this study, we measured gene expression in the standard cabbage genome by RNA-Sequencing and constructed rosette and inner leaf networks based on the gene expression profiles. Furthermore, we compared the topological and functional characteristics of these networks. We found significant functional difference between the rosette and inner leaf networks. Specifically, we found that the genes in the rosette leaf network were associated with homeostasis and response to external stimuli whereas the genes in the inner leaf network were mainly related to the glutamine biosynthesis processes and developmental processes with hormones. Overall, the network approach provides an insight into the functional difference of the two leaves. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Brain network dynamics characterization in epileptic seizures. Joint directed graph and pairwise synchronization measures

    Science.gov (United States)

    Rodrigues, A. C.; Machado, B. S.; Florence, G.; Hamad, A. P.; Sakamoto, A. C.; Fujita, A.; Baccalá, L. A.; Amaro, E.; Sameshima, K.

    2014-12-01

    Here we propose and evaluate a new approach to analyse multichannel mesial temporal lobe epilepsy EEG data from eight patients through complex network and synchronization theories. The method employs a Granger causality test to infer the directed connectivity graphs and a wavelet transform based phase synchronization measure whose characteristics allow studying dynamical transitions during epileptic seizures. We present a new combined graph measure that quantifies the level of network hub formation, called network hub out-degree, which closely reflects the level of synchronization observed during the ictus.

  1. Attenuated improvements in adiponectin and fat loss characterize type 2 diabetes non-remission status following bariatric surgery

    Science.gov (United States)

    Malin, Steven K.; Bena, James; Abood, Beth; Pothier, Claire E.; Bhatt, Deepak L; Nissen, Steven; Brethauer, Stacy A.; Schauer, Philip R.; Kirwan, John P.; Kashyap, Sangeeta R.

    2014-01-01

    Aim Bariatric surgery improves glycemic control, but not all patients achieve type 2 diabetes (T2D) remission. Thus, we aimed to identify metabolic determinants of T2D non-remission status following bariatric surgery at 12 and 24 months (m). Methods Forty adults (BMI: 36±3kg/m2, Age: 48±9y, HbA1c: 9.7±2%) undergoing bariatric surgery (i.e. RYGB or SG) were enrolled in STAMPEDE. T2D remission was defined as HbA1c Bariatric surgery-induced 40% and 27% T2D remission rates at 12 and 24m, respectively. Total fat/abdominal fat loss, insulin secretion, insulin sensitivity, and β-cell function (C-peptide0–120/Glucose0–120 × Matsuda index) improved more in remitters at 12 and 24m than non-remitters. Incretin levels were unrelated to T2D remission, but, compared to non-remitters, hs-CRP decreased and adiponectin increased more in remitters. Only baseline adiponectin predicted lower HbA1c at 12 and 24m, and elevated adiponectin correlated with enhanced β-cell function, lower triglycerides and fat loss. Conclusions Smaller rises in adiponectin, a mediator of insulin action and adipose mass, depict T2D non-remission up to 2 years after bariatric surgery. Adjunctive strategies promoting greater fat loss and/or raising adiponectin may be key for higher T2D remission rates after bariatric surgery. PMID:25132119

  2. Further characterization of diabetes mellitus and body weight loss in males of the congenic mouse strain DDD.Cg-A(y.).

    Science.gov (United States)

    Suto, Jun-ichi; Satou, Kunio

    2015-02-01

    The A(y) allele at the agouti locus causes obesity and promotes linear growth in mice. However, body weight gain stops between 16 and 17 weeks after birth, and then, body weight decreases gradually in DDD.Cg-A(y) male mice. Body weight loss is a consequence of diabetes mellitus, which is genetically controlled mainly by a quantitative trait locus (QTL) on chromosome 4. This study aimed to further characterize diabetes mellitus and body weight loss in DDD.Cg-A(y) males. The number of β-cells was markedly reduced, and plasma insulin levels were very low in the DDD.Cg-A(y) males. Using a backcross progeny of DDD × (B6 × DDD.Cg-A(y)) F1-A(y), we identified one significant QTL for plasma insulin levels on distal chromosome 4, which was coincidental with QTL for hyperglycemia and lower body weight. The DDD allele was associated with decreased plasma insulin levels. When the DDD.Cg-A(y) males were housed under three different housing conditions [group housing (4 or 5 DDD.Cg-A(y) and DDD males), individual housing (single DDD.Cg-A(y) male) and single male housing with females (single DDD.Cg-A(y) male with DDD.Cg-A(y) or DDD females)], diabetes mellitus and body weight loss were most severely expressed in individually housed mice. Thus, the severity of diabetes and body weight loss in the DDD.Cg-A(y) males was strongly influenced by the housing conditions. These results demonstrate that both genetic and nongenetic environmental factors are involved in the development of diabetes mellitus and body weight loss in the DDD.Cg-A(y) males.

  3. Characterization of lipid profile by nuclear magnetic resonance spectroscopy (1H NMR) of metabolically healthy obese women after weight loss with Mediterranean diet and physical exercise.

    Science.gov (United States)

    Rodriguez-Garcia, Enrique; Ruiz-Nava, Josefina; Santamaria-Fernandez, Sonia; Fernandez-Garcia, Jose Carlos; Vargas-Candela, Antonio; Yahyaoui, Raquel; Tinahones, Francisco J; Bernal-Lopez, Maria Rosa; Gomez-Huelgas, Ricardo

    2017-07-01

    Obesity is associated with an atherogenic lipid profile. No data exists on lipoprotein particle profiles in metabolically healthy obese (MHO) individuals. Our aim is to characterize lipoprotein size, particle, and subclass concentrations in MHO women after 3 months of weight loss through dietary restriction and physical exercise.A total of 115 nondiabetic women (aged 35-55 years) with a body mass index (BMI) of 30 to 40 kg/m and ≤1 of the following criteria: blood pressure ≤135/85 mm Hg, fasting plasma glucose ≤100 mg/dL, HDL-cholesterol ≤50 mg/dL, and triglycerides ≤150 mg/dL were included. After 3 months of intensive lifestyle modification (Mediterranean diet and physical exercise), they were classified according to their weight loss: women (age: 44.4 ± 3.7 years, BMI: 36.3 ± 4.7 kg/m), of whom 47 (45.2%), 27 (26%), and 30 (28.8%) lost weight, respectively. All participants experienced significant weight loss and decreases in BMI. The lipid profiles showed an increase in small, medium, and large very low density lipoprotein (VLDL) particles in all groups of study with the exception of small VLDL particles in women with ≥10% of weight loss, in which it decreased. The number of VLDL particles decreased in women who had ≥10% weight loss. On the other hand, we detected a decrease in all low density lipoprotein (cLDL) and high density lipoprotein (cHDL) concentrations.These results indicate that intensive lifestyle modification alters lipid profiles. In particular, it decreases small LDL and HDL particle numbers and does not increase medium or large HDL particles numbers.

  4. Characterizing cartilage microarchitecture on phase-contrast x-ray computed tomography using deep learning with convolutional neural networks

    Science.gov (United States)

    Deng, Botao; Abidin, Anas Z.; D'Souza, Adora M.; Nagarajan, Mahesh B.; Coan, Paola; Wismüller, Axel

    2017-03-01

    The effectiveness of phase contrast X-ray computed tomography (PCI-CT) in visualizing human patellar cartilage matrix has been demonstrated due to its ability to capture soft tissue contrast on a micrometer resolution scale. Recent studies have shown that off-the-shelf Convolutional Neural Network (CNN) features learned from a nonmedical data set can be used for medical image classification. In this paper, we investigate the ability of features extracted from two different CNNs for characterizing chondrocyte patterns in the cartilage matrix. We obtained features from 842 regions of interest annotated on PCI-CT images of human patellar cartilage using CaffeNet and Inception-v3 Network, which were then used in a machine learning task involving support vector machines with radial basis function kernel to classify the ROIs as healthy or osteoarthritic. Classification performance was evaluated using the area (AUC) under the Receiver Operating Characteristic (ROC) curve. The best classification performance was observed with features from Inception-v3 network (AUC = 0.95), which outperforms features extracted from CaffeNet (AUC = 0.91). These results suggest that such characterization of chondrocyte patterns using features from internal layers of CNNs can be used to distinguish between healthy and osteoarthritic tissue with high accuracy.

  5. Cognitive Network Modeling as a Basis for Characterizing Human Communication Dynamics and Belief Contagion in Technology Adoption

    Science.gov (United States)

    Hutto, Clayton; Briscoe, Erica; Trewhitt, Ethan

    2012-01-01

    Societal level macro models of social behavior do not sufficiently capture nuances needed to adequately represent the dynamics of person-to-person interactions. Likewise, individual agent level micro models have limited scalability - even minute parameter changes can drastically affect a model's response characteristics. This work presents an approach that uses agent-based modeling to represent detailed intra- and inter-personal interactions, as well as a system dynamics model to integrate societal-level influences via reciprocating functions. A Cognitive Network Model (CNM) is proposed as a method of quantitatively characterizing cognitive mechanisms at the intra-individual level. To capture the rich dynamics of interpersonal communication for the propagation of beliefs and attitudes, a Socio-Cognitive Network Model (SCNM) is presented. The SCNM uses socio-cognitive tie strength to regulate how agents influence--and are influenced by--one another's beliefs during social interactions. We then present experimental results which support the use of this network analytical approach, and we discuss its applicability towards characterizing and understanding human information processing.

  6. Multielemental characterization of sediments from rivers and reservoirs of a sediment quality monitoring network of Sao Paulo state, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Walace A.A.; Quinaglia, Gilson A., E-mail: wasoares@sp.gov.br, E-mail: gquinaglia@sp.gov.br [Companhia Ambiental do Estado de Sao Paulo (CETESB), SP (Brazil). Setor de Analises Toxicologicas; Favaro, Deborah I.T., E-mail: defavaro@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (LAN/CRPq/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Lab. de Analise por Ativacao Neutronica

    2013-07-01

    The Environment Company of the State of Sao Paulo (CETESB) by means of its quality monitoring network does, systematically, the assessment of water and sediment quality in rivers and reservoirs in the Sao Paulo state. The quality evaluation is done by means 50 parameters in water and 63 for sediment that are considered the more representative for CETESB monitoring. In 2011 the network monitoring analyzed 420 points being 24 in sediments. In the present study the multielemental characterization (total concentration) of 13 sediment samples from 24 rivers and reservoirs belonging to the CETESB monitoring network were analyzed by instrumental neutron activation analysis (INAA). The analytical validation according to precision and accuracy was checked through certified reference materials analyzes BEN (Basalt-IWG-GIT), SL-1 (Lake Sediment - IAEA) and Soil-5 (IAEA), that presents certified concentration values for all elements analyzed. The results obtained for multielemental characterization were compared to NASC values (North American Shale Composite) and the enrichment factor (EF) by using Sc as a normalizer element was calculated. The results showed higher enrichment values for As, Br, Cr, Hf, Ta, Th , U and Zn and rare earth elements (REE) Ce, Eu, La, Nd, Sm, Tb and Yb in many of the tested sediment samples indicating that there may be an anthropogenic contribution for these elements. The multielemental results were also compared to the granulometric composition of the sediment samples. Factorial and Cluster Analysis were applied and indicated that the elements distribution is controlled, mainly by the granulometric fractions of the sediments. (author)

  7. Statistical Modelling and Characterization of Experimental mm-Wave Indoor Channels for Future 5G Wireless Communication Networks

    Science.gov (United States)

    Al-Samman, A. M.; Rahman, T. A.; Azmi, M. H.; Hindia, M. N.; Khan, I.; Hanafi, E.

    2016-01-01

    This paper presents an experimental characterization of millimeter-wave (mm-wave) channels in the 6.5 GHz, 10.5 GHz, 15 GHz, 19 GHz, 28 GHz and 38 GHz frequency bands in an indoor corridor environment. More than 4,000 power delay profiles were measured across the bands using an omnidirectional transmitter antenna and a highly directional horn receiver antenna for both co- and cross-polarized antenna configurations. This paper develops a new path-loss model to account for the frequency attenuation with distance, which we term the frequency attenuation (FA) path-loss model and introduce a frequency-dependent attenuation factor. The large-scale path loss was characterized based on both new and well-known path-loss models. A general and less complex method is also proposed to estimate the cross-polarization discrimination (XPD) factor of close-in reference distance with the XPD (CIX) and ABG with the XPD (ABGX) path-loss models to avoid the computational complexity of minimum mean square error (MMSE) approach. Moreover, small-scale parameters such as root mean square (RMS) delay spread, mean excess (MN-EX) delay, dispersion factors and maximum excess (MAX-EX) delay parameters were used to characterize the multipath channel dispersion. Multiple statistical distributions for RMS delay spread were also investigated. The results show that our proposed models are simpler and more physically-based than other well-known models. The path-loss exponents for all studied models are smaller than that of the free-space model by values in the range of 0.1 to 1.4 for all measured frequencies. The RMS delay spread values varied between 0.2 ns and 13.8 ns, and the dispersion factor values were less than 1 for all measured frequencies. The exponential and Weibull probability distribution models best fit the RMS delay spread empirical distribution for all of the measured frequencies in all scenarios. PMID:27654703

  8. The impact of spin coupling signal loss on fat content characterization in multi-echo acquisitions with different echo spacing.

    Science.gov (United States)

    Nikiforaki, K; Manikis, G C; Boursianis, T; Marias, K; Karantanas, A; Maris, T G

    2017-05-01

    This study aimed to assess the effect of echo spacing in transverse magnetization (T2) signal decay of gel and fat (oil) samples. Additionally, we assess the feasibility of using spin coupling as a determinant of fat content. Phantoms of known T2 values, as well as vegetable oil phantoms, were scanned at 1.5T scanner with a multi echo FSE sequence of variable echo spacing above and below the empirical threshold of 20ms for echo train signal modulation (6.7, 13.6, 26.8, and 40ms). T2 values were calculated from monoexponential fitting of the data. Relative signal loss between the four acquisitions of different echo spacing was calculated. Agreement in the T2 values of water gel phantom was observed in all acquisitions as opposed to fat phantom (oil) samples. Relative differences in signal intensity between two successive sequences of different echo spacing on composite fat/water regions of interest was found to be linearly correlated to fat fraction of the ROI. The sample specific degree of signal loss that was observed between different fat samples (vegetable oils) can be attributed to the composition of each sample in J coupled fat components. Hence, spin coupling may be used as a determinant of fat content. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Exploring triad-rich substructures by graph-theoretic characterizations in complex networks

    OpenAIRE

    Jia, Songwei; Gao, Lin; Gao, Yong; Nastos, James; Wen, Xiao; Zhang, Xindong; Wang, Haiyang

    2016-01-01

    One of the most important problems in complex networks is how to detect metadata groups accurately. The main challenge lies in the fact that traditional structural communities do not always capture the intrinsic features of metadata groups. Motivated by the observation that metadata groups in PPI networks tend to consist of an abundance of interacting triad motifs, we define a 2-club substructure with diameter 2 which possessing triad-rich property to describe a metadata group. Based on the t...

  10. Capacity of Byzantine Agreement: Complete Characterization of Four-Node Networks

    Science.gov (United States)

    2010-04-06

    network. Technical Report, CSL, UIUC, February 2010. [18] N. A. Lynch. Distributed algorithms. Morgan Kaufmann Publishers, 1995. [19] T. Mizrahi and Y...Moses. Continuous consensus via common knowledge. In TARK’05, 2005. [20] T. Mizrahi and Y. Moses. Continuous consensus with ambiguous failures...Distributed Computing and Networking (Lecture Notes in Computer Science), 4904/2008:73–85, 2008. [21] T. Mizrahi and Y. Moses. Continuous consensus with

  11. Characterizing structure connectivity correlation with the default mode network in Alzheimer's patients and normal controls

    Science.gov (United States)

    Guo, Jia; Xu, Peng; Song, Chao; Yao, Li; Zhao, Xiaojie

    2012-03-01

    Magnetic resonance diffusion tensor imaging (DTI) is a kind of effective measure to do non-invasive investigation on brain fiber structure at present. Studies of fiber tracking based on DTI showed that there was structural connection of white matter fiber among the nodes of resting-state functional network, denoting that the connection of white matter was the basis of gray matter regions in functional network. Nevertheless, relationship between these structure connectivity regions and functional network has not been clearly indicated. Moreover, research of fMRI found that activation of default mode network (DMN) in Alzheimer's disease (AD) was significantly descended, especially in hippocampus and posterior cingulated cortex (PCC). The relationship between this change of DMN activity and structural connection among functional networks needs further research. In this study, fast marching tractography (FMT) algorithm was adopted to quantitative calculate fiber connectivity value between regions, and hippocampus and PCC which were two important regions in DMN related with AD were selected to compute white matter connection region between them in elderly normal control (NC) and AD patient. The fiber connectivity value was extracted to do the correlation analysis with activity intensity of DMN. Results showed that, between PCC and hippocampus of NC, there exited region with significant high connectivity value of white matter fiber whose performance has relatively strong correlation with the activity of DMN, while there was no significant white matter connection region between them for AD patient which might be related with reduced network activation in these two regions of AD.

  12. Characterization of the Virtual Water Commodity Network of Major U.S. Cities

    Science.gov (United States)

    Garcia, S.; Ahams, I. C.; Ruddell, B. L.; Mejia, A.

    2016-12-01

    Cities, through their socioeconomic power and consumption patterns, drive an intricate web of commodity flows that gives rise to an underlying network of indirect transfers of energy and water. The virtual water content of a commodity represents the water embedded in its production. It can serve as a measure of city water consumption that, along with direct, metabolic consumption, exposes the dependence of cities on distant regions and the potential vulnerabilities of the network to shocks and stresses. Using the U.S. network of commodities flows, together with their associated virtual water content, we use network theory to analyze first-order and higher-order topological properties of virtual water flows for major U.S. cities, defined by their metropolitan boundaries. They are represented as nodes and weighted directed links, symbolizing the volume and direction of the virtual water flows associated with the transfer of agricultural, livestock and industrial commodities. We find that network properties, generally, vary across commodities and reveal complex structures such as the appearance of hubs like Chicago, Houston, and New Orleans for industrial commodities and the formation of communities (megaregions). Additionally, using scaling arguments, we find that increasing city size makes larger cities more water efficient and hydroeconomically productive than smaller ones. This work represents an initial step towards understanding the role played by cities in the U.S. commodity network and food-energy-water (FEW) nexus.

  13. Interhemispheric Connectivity Characterizes Cortical Reorganization in Motor-Related Networks After Cerebellar Lesions.

    Science.gov (United States)

    De Vico Fallani, Fabrizio; Clausi, Silvia; Leggio, Maria; Chavez, Mario; Valencia, Miguel; Maglione, Anton Giulio; Babiloni, Fabio; Cincotti, Febo; Mattia, Donatella; Molinari, Marco

    2017-04-01

    Although cerebellar-cortical interactions have been studied extensively in animal models and humans using modern neuroimaging techniques, the effects of cerebellar stroke and focal lesions on cerebral cortical processing remain unknown. In the present study, we analyzed the large-scale functional connectivity at the cortical level by combining high-density electroencephalography (EEG) and source imaging techniques to evaluate and quantify the compensatory reorganization of brain networks after cerebellar damage. The experimental protocol comprised a repetitive finger extension task by 10 patients with unilateral focal cerebellar lesions and 10 matched healthy controls. A graph theoretical approach was used to investigate the functional reorganization of cortical networks. Our patients, compared with controls, exhibited significant differences at global and local topological level of their brain networks. An abnormal rise in small-world network efficiency was observed in the gamma band (30-40 Hz) during execution of the task, paralleled by increased long-range connectivity between cortical hemispheres. Our findings show that a pervasive reorganization of the brain network is associated with cerebellar focal damage and support the idea that the cerebellum boosts or refines cortical functions. Clinically, these results suggest that cortical changes after cerebellar damage are achieved through an increase in the interactions between remote cortical areas and that rehabilitation should aim to reshape functional activation patterns. Future studies should determine whether these hypotheses are limited to motor tasks or if they also apply to cerebro-cerebellar dysfunction in general.

  14. Use of a real-time remote monitoring network (RTRM) to characterize the Guadalquivir estuary (Spain).

    Science.gov (United States)

    Navarro, Gabriel; Huertas, Isabel Emma; Costas, Eduardo; Flecha, Susana; Díez-Minguito, Manuel; Caballero, Isabel; López-Rodas, Victoria; Prieto, Laura; Ruiz, Javier

    2012-01-01

    The temporal variability of hydrological variables in the Guadalquivir estuary was examined during three years through a real-time remote monitoring network (RTRM). The network was developed with the aim of studying the influence of hydrodynamical and hydrological features within the estuary on the functioning of the pelagic ecosystem. Completing this data-gathering network, monthly cruises were performed in order to measure biogeochemical variables that are indicative of the trophic status of the aquatic environment. The results showed that several sources of physical forcing, such as wind, tide-associated currents and river discharge were responsible for the spatio-temporal patterns of dissolved oxygen, salinity and turbidity in the estuary. The analysis was conducted under tidal and flood regime, which allowed us to identify river discharge as the main forcing agent of the hydrology inside the estuary. In particular, episodes of elevated turbidity detected by the network, together with episodes of low salinity and dissolved oxygen were closely related to the increase in water supply from a dam located upstream. The network installed provided accurate data that can be rapidly used for research or educational applications and by policy-makers or agencies in charge of the management of the coastal area.

  15. Use of a Real-Time Remote Monitoring Network (RTRM to Characterize the Guadalquivir Estuary (Spain

    Directory of Open Access Journals (Sweden)

    Isabel Caballero

    2012-02-01

    Full Text Available The temporal variability of hydrological variables in the Guadalquivir estuary was examined during three years through a real-time remote monitoring network (RTRM. The network was developed with the aim of studying the influence of hydrodynamical and hydrological features within the estuary on the functioning of the pelagic ecosystem. Completing this data-gathering network, monthly cruises were performed in order to measure biogeochemical variables that are indicative of the trophic status of the aquatic environment. The results showed that several sources of physical forcing, such as wind, tide-associated currents and river discharge were responsible for the spatio-temporal patterns of dissolved oxygen, salinity and turbidity in the estuary. The analysis was conducted under tidal and flood regime, which allowed us to identify river discharge as the main forcing agent of the hydrology inside the estuary. In particular, episodes of elevated turbidity detected by the network, together with episodes of low salinity and dissolved oxygen were closely related to the increase in water supply from a dam located upstream. The network installed provided accurate data that can be rapidly used for research or educational applications and by policy-makers or agencies in charge of the management of the coastal area.

  16. Characterization of Antimicrobial Resistance Dissemination across Plasmid Communities Classified by Network Analysis

    Directory of Open Access Journals (Sweden)

    Akifumi Yamashita

    2014-04-01

    Full Text Available The global clustering of gene families through network analysis has been demonstrated in whole genome, plasmid, and microbiome analyses. In this study, we carried out a plasmidome network analysis of all available complete bacterial plasmids to determine plasmid associations. A blastp clustering search at 100% aa identity cut-off and sharing at least one gene between plasmids, followed by a multilevel community network analysis revealed that a surprisingly large number of the plasmids were connected by one largest connected component (LCC, with dozens of community sub-groupings. The LCC consisted mainly of Bacilli and Gammaproteobacteria plasmids. Intriguingly, horizontal gene transfer (HGT was noted between different phyla (i.e., Staphylococcus and Pasteurellaceae, suggesting that Pasteurellaceae can acquire antimicrobial resistance (AMR genes from closely contacting Staphylococcus spp., which produce the external supplement of V-factor (NAD. Such community network analysis facilitate displaying possible recent HGTs like a class 1 integron, str and tet resistance markers between communities. Furthermore, the distribution of the Inc replicon type and AMR genes, such as the extended-spectrum ß-lactamase (ESBL CTX-M or the carbapenemases KPC NDM-1, implies that such genes generally circulate within limited communities belonging to typical bacterial genera. Thus, plasmidome network analysis provides a remarkable discriminatory power for plasmid-related HGT and evolution.

  17. DFNModeler: an efficient discrete fracture network modeler and its application to fracture characterization in Black Warrior basin, Alabama

    Science.gov (United States)

    Jin, G.; Pashin, J. C.

    2009-12-01

    Discrete fracture network (DFN) models are stochastic representations of natural fracture systems that incorporate statistical scaling rules derived from analysis of fracture length, height, spacing, orientation, and aperture, and have been used increasingly in coalbed methane reservoir characterization. The DFN technique has been applied in a number of areas such as hydraulic fluid transport, carbon sequestration modeling, and fracture reservoir characterization, etc. The goal of DFN modeling is to represent the important aspects of natural fractures within the mathematical framework of numerical simulation and engineering calculations. DFN models are important vehicles for the simulation of flow and solute transport in a fractured rock mass, thus DFN modeling techniques have become important and powerful tools for fractured reservoir characterization and CO2 sequestration studies. We have developed a computer software package called DFNModeler, which is designed for the realization, visualization, and analysis of discrete fracture network models. Computerized analysis of fracture networks is important because fractures are abundant in reservoirs and aquifers and can have a strong effect on fluid flow patterns and compartmentalization. DFNModeler has four major functionalities: 1) edit and input information on the statistical properties of fracture networks; 2) realize the DFN model using derived stochastic populations; 3) analyze fracture compartmentalization and fluid migration pathways; and 4) visualize the DFN model. These functionalities are provided through user-friendly, menu-driven interfaces. Accuracy, efficiency, and reliability are three important factors that guided software development. The DFNModeler has been applied to the fracture reservoir characterization of the Lower Pennsylvanian-age Pottsville Formation in the Black Warrior basin, Alabama. The Pottsville Formation constitutes a thick succession of shale, sandstone, and coal. Coalbed methane

  18. A physical sciences network characterization of non-tumorigenic and metastatic cells

    Science.gov (United States)

    Physical Sciences-Oncology Centers Network; Agus, David B.; Alexander, Jenolyn F.; Arap, Wadih; Ashili, Shashanka; Aslan, Joseph E.; Austin, Robert H.; Backman, Vadim; Bethel, Kelly J.; Bonneau, Richard; Chen, Wei-Chiang; Chen-Tanyolac, Chira; Choi, Nathan C.; Curley, Steven A.; Dallas, Matthew; Damania, Dhwanil; Davies, Paul C. W.; Decuzzi, Paolo; Dickinson, Laura; Estevez-Salmeron, Luis; Estrella, Veronica; Ferrari, Mauro; Fischbach, Claudia; Foo, Jasmine; Fraley, Stephanie I.; Frantz, Christian; Fuhrmann, Alexander; Gascard, Philippe; Gatenby, Robert A.; Geng, Yue; Gerecht, Sharon; Gillies, Robert J.; Godin, Biana; Grady, William M.; Greenfield, Alex; Hemphill, Courtney; Hempstead, Barbara L.; Hielscher, Abigail; Hillis, W. Daniel; Holland, Eric C.; Ibrahim-Hashim, Arig; Jacks, Tyler; Johnson, Roger H.; Joo, Ahyoung; Katz, Jonathan E.; Kelbauskas, Laimonas; Kesselman, Carl; King, Michael R.; Konstantopoulos, Konstantinos; Kraning-Rush, Casey M.; Kuhn, Peter; Kung, Kevin; Kwee, Brian; Lakins, Johnathon N.; Lambert, Guillaume; Liao, David; Licht, Jonathan D.; Liphardt, Jan T.; Liu, Liyu; Lloyd, Mark C.; Lyubimova, Anna; Mallick, Parag; Marko, John; McCarty, Owen J. T.; Meldrum, Deirdre R.; Michor, Franziska; Mumenthaler, Shannon M.; Nandakumar, Vivek; O'Halloran, Thomas V.; Oh, Steve; Pasqualini, Renata; Paszek, Matthew J.; Philips, Kevin G.; Poultney, Christopher S.; Rana, Kuldeepsinh; Reinhart-King, Cynthia A.; Ros, Robert; Semenza, Gregg L.; Senechal, Patti; Shuler, Michael L.; Srinivasan, Srimeenakshi; Staunton, Jack R.; Stypula, Yolanda; Subramanian, Hariharan; Tlsty, Thea D.; Tormoen, Garth W.; Tseng, Yiider; van Oudenaarden, Alexander; Verbridge, Scott S.; Wan, Jenny C.; Weaver, Valerie M.; Widom, Jonathan; Will, Christine; Wirtz, Denis; Wojtkowiak, Jonathan; Wu, Pei-Hsun

    2013-04-01

    To investigate the transition from non-cancerous to metastatic from a physical sciences perspective, the Physical Sciences-Oncology Centers (PS-OC) Network performed molecular and biophysical comparative studies of the non-tumorigenic MCF-10A and metastatic MDA-MB-231 breast epithelial cell lines, commonly used as models of cancer metastasis. Experiments were performed in 20 laboratories from 12 PS-OCs. Each laboratory was supplied with identical aliquots and common reagents and culture protocols. Analyses of these measurements revealed dramatic differences in their mechanics, migration, adhesion, oxygen response, and proteomic profiles. Model-based multi-omics approaches identified key differences between these cells' regulatory networks involved in morphology and survival. These results provide a multifaceted description of cellular parameters of two widely used cell lines and demonstrate the value of the PS-OC Network approach for integration of diverse experimental observations to elucidate the phenotypes associated with cancer metastasis.

  19. Complex Evolutionary and Genetic Patterns Characterize the Loss of Scleral Ossification in the Blind Cavefish Astyanax mexicanus

    Science.gov (United States)

    O’Quin, Kelly E.; Doshi, Pooja; Lyon, Anastasia; Hoenemeyer, Emma; Yoshizawa, Masato; Jeffery, William R.

    2015-01-01

    The sclera is the tough outer covering of the eye that provides structural support and helps maintain intraocular pressure. In some fishes, reptiles, and birds, the sclera is reinforced with an additional ring of hyaline cartilage or bone that forms from scleral ossicles. Currently, the evolutionary and genetic basis of scleral ossification is poorly understood, especially in teleost fishes. We assessed scleral ossification among several groups of the Mexican tetra (Astyanax mexicanus), which exhibit both an eyed and eyeless morph. Although eyed Astyanax surface fish have bony sclera similar to other teleosts, the ossicles of blind Astyanax cavefish generally do not form. We first sampled cavefish from multiple independent populations and used ancestral character state reconstructions to determine how many times scleral ossification has been lost. We then confirmed these results by assessing complementation of scleral ossification among the F1 hybrid progeny of two cavefish populations. Finally, we quantified the number of scleral ossicles present among the F2 hybrid progeny of a cross between surface fish and cavefish, and used this information to identify quantitative trait loci (QTL) responsible for this trait. Our results indicate that the loss of scleral ossification is common–but not ubiquitous–among Astyanax cavefish, and that this trait has been convergently lost at least three times. The presence of wild-type, ossified sclera among the F1 hybrid progeny of a cross between different cavefish populations confirms the convergent evolution of this trait. However, a strongly skewed distribution of scleral ossicles found among surface fish x cavefish F2 hybrids suggests that scleral ossification is a threshold trait with a complex genetic basis. Quantitative genetic mapping identified a single QTL for scleral ossification on Astyanax linkage group 1. We estimate that the threshold for this trait is likely determined by at least three genetic factors which

  20. Characterization and assessment of voltage and power constraints of DFIG WT connected to a weak network

    DEFF Research Database (Denmark)

    Abulanwar, Elsayed; Hu, Weihao; Iov, Florin

    2014-01-01

    of common coupling, PCC, and maximize the wind power penetration into weak networks. As a basis of investigation, a simplified system model is utilized and the respective PCC voltage, active and reactive power stability issues are identified. Besides, a steady-state study for DFIG WT connected to a weak......This article thoroughly investigates the challenges and constraints raised by the integration of a Doubly-fed Induction generator wind turbine, DFIG WT, into an ac network of extensively varying parameters and very weak conditions. The objective is to mitigate the voltage variations at the point...

  1. Synthesis and Characterization of Low Loss Dielectric Ceramics Prepared from Composite of Titanate Nanosheets with Barium Ions

    Directory of Open Access Journals (Sweden)

    Aleksandra Wypych-Puszkarz

    2017-01-01

    Full Text Available We report a strategy for preparing barium titanate precursor, being the composite of titanate nanosheets (TN with barium ions (Ba-TN, which subjected to step sintering allows obtaining TiO2 rich barium titanate ceramics of stoichiometry BaTi4O9 or Ba2Ti9O20. These compounds are important in modern electronics due to their required dielectric properties and grains’ size that can be preserved in nanometric range. The morphology studies, structural characterization, and dielectric investigations were performed simultaneously in each step of Ba-TN calcinations in order to properly characterize type of obtained ceramic, its grains’ morphology, and dielectric properties. The Ba-TN precursor can be sintered at given temperatures, so that its dielectric permittivity can be tuned between 25 and 42 with controlled temperature coefficients that change from negative 32 ppm/°C for Ba-TN sintered at 900°C up to positive 37 ppm/°C after calcination at 1300°C. XRD analysis and Raman investigations performed for the Ba-TN in the temperature range of 900÷1250°C showed that below 1100°C we obtained as a main phase BaTi4O9, whereas the higher calcinations temperature transformed Ba-TN into Ba2Ti9O20. Taking into account trend of device miniaturization and nanoscopic size requirements, temperatures of 900°C and 1100°C seem to be an optimal condition for Ba-TN precursor calcinations that guarantee the satisfactory value of dielectric permittivity (ε=26 and 32 and ceramic grains with a mean size of ~180 nm and ~550 nm, respectively.

  2. Characterization of Early Cortical Neural Network Development in Multiwell Microelectrode Array Plates

    Science.gov (United States)

    We examined the development of neural network activity using microelectrode array (MEA) recordings made in multi-well MEA plates (mwMEAs) over the first 12 days in vitro (DIV). In primary cortical cultures made from postnatal rats, action potential spiking activity was essentiall...

  3. Characterization of computer network events through simultaneous feature selection and clustering of intrusion alerts

    Science.gov (United States)

    Chen, Siyue; Leung, Henry; Dondo, Maxwell

    2014-05-01

    As computer network security threats increase, many organizations implement multiple Network Intrusion Detection Systems (NIDS) to maximize the likelihood of intrusion detection and provide a comprehensive understanding of intrusion activities. However, NIDS trigger a massive number of alerts on a daily basis. This can be overwhelming for computer network security analysts since it is a slow and tedious process to manually analyse each alert produced. Thus, automated and intelligent clustering of alerts is important to reveal the structural correlation of events by grouping alerts with common features. As the nature of computer network attacks, and therefore alerts, is not known in advance, unsupervised alert clustering is a promising approach to achieve this goal. We propose a joint optimization technique for feature selection and clustering to aggregate similar alerts and to reduce the number of alerts that analysts have to handle individually. More precisely, each identified feature is assigned a binary value, which reflects the feature's saliency. This value is treated as a hidden variable and incorporated into a likelihood function for clustering. Since computing the optimal solution of the likelihood function directly is analytically intractable, we use the Expectation-Maximisation (EM) algorithm to iteratively update the hidden variable and use it to maximize the expected likelihood. Our empirical results, using a labelled Defense Advanced Research Projects Agency (DARPA) 2000 reference dataset, show that the proposed method gives better results than the EM clustering without feature selection in terms of the clustering accuracy.

  4. Biophysical and Structural Characterization of the Centriolar Protein Cep104 Interaction Network

    NARCIS (Netherlands)

    Rezabkova, Lenka; Kraatz, Sebastian H W; Akhmanova, Anna; Steinmetz, Michel O; Kammerer, Richard A

    2016-01-01

    Dysfunction of cilia is associated with common genetic disorders termed ciliopathies. Knowledge on the interaction networks of ciliary proteins is therefore key for understanding the processes that are underlying these severe diseases and the mechanisms of ciliogenesis in general. Cep104 has

  5. Identification and characterization of starch and inulin modifying network of Aspergillus niger by functional genomics

    NARCIS (Netherlands)

    Yuan, Xiao-Lian

    2008-01-01

    Aspergillus niger produces a wide variety of carbohydrate hydrolytic enzymes which have potential applications in the baking, starch, textile, food and feed industries. The goal of this thesis is to unravel the molecular mechanisms of starch and inulin modifying network of A. niger, in order to

  6. Structural, magnetic characterization (dependencies of coercivity and loss with the frequency) of magnetic cores based in Finemet

    Science.gov (United States)

    Osinalde, M.; Infante, P.; Domínguez, L.; Blanco, J. M.; del Val, J. J.; Chizhik, A.; González, J.

    2017-12-01

    We report changes of coercivity, induced magnetic anisotropy, magneto-optical domain structure and frequency dependencies of coercivity and energy loss (up to 10 MHz) associated with the structural modifications produced by thermal treatments under applied magnetic field (field annealing) in toroidal wound cores of Fe73.5Cu1Nb3Si15.5B7 amorphous alloy. The thermal treatment (535 °C, 1 h) leads to the typical nanocrystalline structure of α-Fe(Si) nanograins (60-65% relative volume, 10-20 nm average grain size embedded in a residual amorphous matrix, while the magnetic field with the possibility to be applied in two directions to the toroidal core axis, that is in transverse (which is equivalent to the transverse direction of the ribbon) or longitudinal (equivalent to the longitudinal direction of the ribbon), develops a macroscopic uniaxial magnetic anisotropy in the transverse (around 245 J/m3) or longitudinal (around 85 J/m3) direction of the ribbon, respectively. It is remarkable the quasi-unhysteretic character of the cores with these two kinds of field annealing as comparing with that of the as-quenched one. Magneto-optical study by Kerr-effect of the ribbons provides useful information on the domain structure of the surface in agreement with the direction and intensity of the induced magnetic anisotropy. This induced uniaxial magnetic anisotropy plays a very important role on the Hc(f) and EL(f) curves, (f: frequency), being drastic the presence and direction of the induced magnetic anisotropy. In addition, these frequency dependencies show a significant change at the frequency around 100 Hz.

  7. Hearing loss

    Science.gov (United States)

    Decreased hearing; Deafness; Loss of hearing; Conductive hearing loss; Sensorineural hearing loss; Presbycusis ... Symptoms of hearing loss may include: Certain sounds seeming too loud Difficulty following conversations when two or more people are talking ...

  8. Characterizing Radiation-Aged Polysiloxane-Silica Composites: Identifying Changes in Network Topology via 1H NMR

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, B; Chinn, S C; Maxwell, R S; Reimer, J

    2008-11-03

    Characterizing and quantifying changes in elastomeric materials upon exposure to harsh environments is important in the estimation of device lifetimes. Nuclear magnetic resonance (NMR) spectroscopy has been used effectively in the analysis of such materials and has proved to be both sensitive to micro- and macroscopic changes associated with material 'aging'. Traditional analyses, however, rely on empirical formulae containing a large number of (often arbitrary) independent variables. This ambiguity can be circumvented largely by developing models of NMR observables that are based on basic polymer physics. We compare two such models, one previously published and one derived herein, along with empirical expressions that describe the proton transverse magnetization decay associated with complex polymer networks. One particular extracted parameter, the proton-proton residual dipolar coupling (RDC), can be directly related to network topology, and a comparison of the extracted RDCs reveals high consistency among the models. An expression derived from the properties of a static Gaussian chain can minimize the number of parameters necessarily to describe the solid-like, networked proton population to a single independent parameter, the average residual dipolar coupling, D{sub avg}.

  9. One-step synthesis and characterization of polyaniline nanofiber/silver nanoparticle composite networks as antibacterial agents.

    Science.gov (United States)

    Poyraz, Selcuk; Cerkez, Idris; Huang, Tung Shi; Liu, Zhen; Kang, Litao; Luo, Jujie; Zhang, Xinyu

    2014-11-26

    Through a facile and effective seeding polymerization reaction via a one-step redox/complexation process, which took place in aqueous medium at ambient temperature, silver nanoparticles (Ag NPs) embedded polyaniline nanofiber (PANI NF) networks were synthesized as antibacterial agents. During the reaction, not only NF morphology formation of the resulting conducting polymers (CPs) but also amplification of the aqueous silver nitrate (AgNO3) solutions' oxidative potentials were managed by vanadium pentoxide (V2O5) sol-gel nanofibers, which acted as well-known nanofibrous seeding agents and the auxiliary oxidative agent at the same time. The PANI/Ag nanocomposites were proven to exhibit excellent antibacterial property against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. Antibacterial property performance and average life span of the nanocomposite network were optimized through the homogeneous distribution/embedment of Ag NPs within one-dimensional (1-D) PANI NF matrix. The antibacterial efficacy tests and nanocomposite material characterization results further indicated that the sole components of PANI/Ag have a synergistic effect to each other in terms of antibacterial property. Thus, this well-known catalytic seeding approach via a one-step oxidative polymerization reaction can be considered as a general methodology and a substantial fabrication tool to synthesize Ag NP decorated nanofibrillar PANI networks as advanced antibacterial agents.

  10. Statistical metrics for the characterization of karst network geometry and topology

    Science.gov (United States)

    Collon, Pauline; Bernasconi, David; Vuilleumier, Cécile; Renard, Philippe

    2017-04-01

    Statistical metrics can be used to analyse the morphology of natural or simulated karst systems; they allow describing, comparing, and quantifying their geometry and topology. In this paper, we present and discuss a set of such metrics. We study their properties and their usefulness based on a set of more than 30 karstic networks mapped by speleologists. The data set includes some of the largest explored cave systems in the world and represents a broad range of geological and speleogenetic conditions allowing us to test the proposed metrics, their variability, and their usefulness for the discrimination of different morphologies. All the proposed metrics require that the topographical survey of the caves are first converted to graphs consisting of vertices and edges. This data preprocessing includes several quality check operations and some corrections to ensure that the karst is represented as accurately as possible. The statistical parameters relating to the geometry of the system are then directly computed on the graphs, while the topological parameters are computed on a reduced version of the network focusing only on its structure. Among the tested metrics, we include some that were previously proposed such as tortuosity or the Howard's coefficients. We also investigate the possibility to use new metrics derived from graph theory. In total, 21 metrics are introduced, discussed in detail, and compared on the basis of our data set. This work shows that orientation analysis and, in particular, the entropy of the orientation data can help to detect the existence of inception features. The statistics on branch length are useful to describe the extension of the conduits within the network. Rather surprisingly, the tortuosity does not vary very significantly. It could be heavily influenced by the survey methodology. The degree of interconnectivity of the network, related to the presence of maze patterns, can be measured using different metrics such as the Howard

  11. Characterization of WRKY co-regulatory networks in rice and Arabidopsis

    Directory of Open Access Journals (Sweden)

    Kikuchi Shoshi

    2009-09-01

    Full Text Available Abstract Background The WRKY transcription factor gene family has a very ancient origin and has undergone extensive duplications in the plant kingdom. Several studies have pointed out their involvement in a range of biological processes, revealing that a large number of WRKY genes are transcriptionally regulated under conditions of biotic and/or abiotic stress. To investigate the existence of WRKY co-regulatory networks in plants, a whole gene family WRKYs expression study was carried out in rice (Oryza sativa. This analysis was extended to Arabidopsis thaliana taking advantage of an extensive repository of gene expression data. Results The presented results suggested that 24 members of the rice WRKY gene family (22% of the total were differentially-regulated in response to at least one of the stress conditions tested. We defined the existence of nine OsWRKY gene clusters comprising both phylogenetically related and unrelated genes that were significantly co-expressed, suggesting that specific sets of WRKY genes might act in co-regulatory networks. This hypothesis was tested by Pearson Correlation Coefficient analysis of the Arabidopsis WRKY gene family in a large set of Affymetrix microarray experiments. AtWRKYs were found to belong to two main co-regulatory networks (COR-A, COR-B and two smaller ones (COR-C and COR-D, all including genes belonging to distinct phylogenetic groups. The COR-A network contained several AtWRKY genes known to be involved mostly in response to pathogens, whose physical and/or genetic interaction was experimentally proven. We also showed that specific co-regulatory networks were conserved between the two model species by identifying Arabidopsis orthologs of the co-expressed OsWRKY genes. Conclusion In this work we identified sets of co-expressed WRKY genes in both rice and Arabidopsis that are functionally likely to cooperate in the same signal transduction pathways. We propose that, making use of data from co

  12. Characterization of lipid profile by nuclear magnetic resonance spectroscopy (1H NMR) of metabolically healthy obese women after weight loss with Mediterranean diet and physical exercise

    Science.gov (United States)

    Rodriguez-Garcia, Enrique; Ruiz-Nava, Josefina; Santamaria-Fernandez, Sonia; Fernandez-Garcia, Jose Carlos; Vargas-Candela, Antonio; Yahyaoui, Raquel; Tinahones, Francisco J.; Bernal-Lopez, Maria Rosa; Gomez-Huelgas, Ricardo

    2017-01-01

    Abstract Obesity is associated with an atherogenic lipid profile. No data exists on lipoprotein particle profiles in metabolically healthy obese (MHO) individuals. Our aim is to characterize lipoprotein size, particle, and subclass concentrations in MHO women after 3 months of weight loss through dietary restriction and physical exercise. A total of 115 nondiabetic women (aged 35–55 years) with a body mass index (BMI) of 30 to 40 kg/m2 and ≤1 of the following criteria: blood pressure ≤135/85 mm Hg, fasting plasma glucose ≤100 mg/dL, HDL-cholesterol ≤50 mg/dL, and triglycerides ≤150 mg/dL were included. After 3 months of intensive lifestyle modification (Mediterranean diet and physical exercise), they were classified according to their weight loss: <5%, ≥5% to <10%, and ≥10%. Lipoprotein size, particle, and subclass concentrations were measured using 1H NMR. The final sample, after dropouts, comprised 104 women (age: 44.4 ± 3.7 years, BMI: 36.3 ± 4.7 kg/m2), of whom 47 (45.2%), 27 (26%), and 30 (28.8%) lost <5%, ≥5% to <10%, and ≥10% of baseline body weight, respectively. All participants experienced significant weight loss and decreases in BMI. The lipid profiles showed an increase in small, medium, and large very low density lipoprotein (VLDL) particles in all groups of study with the exception of small VLDL particles in women with ≥10% of weight loss, in which it decreased. The number of VLDL particles decreased in women who had ≥10% weight loss. On the other hand, we detected a decrease in all low density lipoprotein (cLDL) and high density lipoprotein (cHDL) concentrations. These results indicate that intensive lifestyle modification alters lipid profiles. In particular, it decreases small LDL and HDL particle numbers and does not increase medium or large HDL particles numbers. PMID:28682864

  13. Prediction and characterization of enzymatic activities guided by sequence similarity and genome neighborhood networks.

    Science.gov (United States)

    Zhao, Suwen; Sakai, Ayano; Zhang, Xinshuai; Vetting, Matthew W; Kumar, Ritesh; Hillerich, Brandan; San Francisco, Brian; Solbiati, Jose; Steves, Adam; Brown, Shoshana; Akiva, Eyal; Barber, Alan; Seidel, Ronald D; Babbitt, Patricia C; Almo, Steven C; Gerlt, John A; Jacobson, Matthew P

    2014-06-30

    Metabolic pathways in eubacteria and archaea often are encoded by operons and/or gene clusters (genome neighborhoods) that provide important clues for assignment of both enzyme functions and metabolic pathways. We describe a bioinformatic approach (genome neighborhood network; GNN) that enables large scale prediction of the in vitro enzymatic activities and in vivo physiological functions (metabolic pathways) of uncharacterized enzymes in protein families. We demonstrate the utility of the GNN approach by predicting in vitro activities and in vivo functions in the proline racemase superfamily (PRS; InterPro IPR008794). The predictions were verified by measuring in vitro activities for 51 proteins in 12 families in the PRS that represent ∼85% of the sequences; in vitro activities of pathway enzymes, carbon/nitrogen source phenotypes, and/or transcriptomic studies confirmed the predicted pathways. The synergistic use of sequence similarity networks3 and GNNs will facilitate the discovery of the components of novel, uncharacterized metabolic pathways in sequenced genomes.

  14. Characterization of Network Structure of Polyacrylamide Based Hydrogels Prepared By Radiation Induced Polymerization

    Science.gov (United States)

    Mahmudi, Naim; Şen, Murat; Güven, Olgun; Rendevski, Stojan

    2007-04-01

    In this study network structure of polyacrylamide based hydrogels prepared by radiation induced polymerization has been investigated. Polyacrylamide based hydrogels in the rod form were prepared by copolymerization of acrylamide(AAm) with hydroxyl ethyl methacrylate(HEMA) and methyl acrylamide(MAAm) in the presence of cross-linking agent and water by gamma rays at ambient temperature. Molecular weight between cross-links and effective cross-link density of hydrogels were calculated from swelling as well as shear modulus data obtained from compression tests. The results have shown that simple compression analyses can be used for the determination of effective cross-link density of hydrogels without any need to some polymer-solvent based parameters as in the case of swelling based determinations. Diffusion of water into hydrogels was examined by analyzing water absorption kinetics and the effect of network, structure on the diffusion type and coefficient was discussed.

  15. Spatial Characterization of the Uplink Inter-Cell Interference in Polygonal-Shaped Wireless Networks

    Directory of Open Access Journals (Sweden)

    K. B. Baltzis

    2013-04-01

    Full Text Available The uplink inter-cell interference is a major impairment in wireless systems. In this paper, we provide a geometrical-based framework for its analysis in networks with convex polygonal coverage area. Algebraic expressions for the Angle-of-Arrival (AoA statistics of the uplink interfering signals are obtained. Simulation results validate the model. Representative examples show the dependence of the AoA on system geometry and demonstrate the relation between uplink interference and the radiation pattern of the receiver antenna. The proposed model is a generalization of previous studies in simpler geometries. It is a useful tool for the design, simulation and performance evaluation of wireless communication systems. The obtained expressions simplify the analysis of wireless networks and reduce the complexity and computational cost of their modeling and simulation.

  16. Performance characterization of game recommendation algorithms on online social network sites

    OpenAIRE

    Leroux, Philip; Dhoedt, Bart; Demeester, Piet; Turck, Filip De

    2012-01-01

    Since years, online social networks have evolved from profile and communication websites to online portals where people interact with each other, share and consume multimedia-enriched data and play different types of games. Due to the immense popularity of these online games and their huge revenue potential, the number of these games increases every day, resulting in a current offering of thousands of online social games. In this paper, the applicability of neighborhood-based collaborative fi...

  17. A Novel Characterization of Distributed Sensor Networks within the DoD

    Science.gov (United States)

    2012-02-03

    hop or broadcast communication systems . The study also provides factors that influence sensor network design. These factors include fault tolerance ...is underway to explore the role that robust Byzantine Fault Tolerance (BFT) has to play in the design and operation of DSNs. The authors believe that...strikes. An important non-kinetic application of synchrony is fault tolerance . As cyber warfare continues to grow and become a part of the modern day

  18. Is CoV(t)-based Modeling Sufficient for Traffic Characterization in Network Links ?

    OpenAIRE

    Noirie, Ludovic; Post, Georg

    2008-01-01

    http://euronf.enst.fr/archive/164/EuroNFDeliverableDSEA641.pdf; International audience; For performance evaluation and dimensioning of packet-based networks, engineers need simple, efficient and realistic traffic models. The traffic volume on a packet link, observed at different time scales t, has previously been modeled as a stationary stochastic process based on the Coefficient of Variation CoV(t). In this paper we try to supply the missing information about the shape of the distribution fu...

  19. Characterizing SMS spam in a large cellular network via mining victim spam reports

    OpenAIRE

    Skudlark, Ann

    2015-01-01

    In this paper a study of SMS messages in a large US based cellular carrier utilizing both customer reported SMS spam and network Call Detail Records (CDRs) is conducted to develop a comprehensive understanding of SMS spam in order to develop strategies and approaches to detect and control SMS spam activity. The analysis provides insights into content classification of spam campaigns as well as spam characteristics based on sending patterns, tenure and geolocation.

  20. A characterization of internet dating network structures among nordic men who have sex with men.

    Directory of Open Access Journals (Sweden)

    Antonella Villani

    Full Text Available BACKGROUND: The Internet has become an important venue for seeking sexual partners and may facilitate transmission of sexually transmitted infections. METHODS: We examined a 64-day data log of flirt messages expressing sexual interest among MSM within the Qruiser.com community. We used logistic regression to analyze characteristics of MSM sending and receiving flirt messages and negative binomial regression to examine individual activity and popularity. The structural properties, including the core structure of the flirt network, were analyzed. RESULTS: The MSM population consisted of approximately 40% homosexuals and 37% bisexuals, while the remaining 23% included men who identified as heterosexual but searched for sex with men and "experimental". MSM were more likely to send flirt messages if they were homosexual and aged 40+ years; young people aged < 30 years were more likely to receive a flirt. Possession of a webcam was strongly associated with both sending flirt messages and being a flirt target. The distributions of flirts sent (max k(out = 2162 and received (max k(in = 84 were highly heterogeneous. Members in central cores were more likely homosexuals, singles, and aged 31-40 years. The probability of a matched flirt (flirt returned from target increased from 1% in the outer core to 18% in the central core (core size = 4. DISCUSSION: The flirt network showed high degree heterogeneity similar to the structural properties of real sexual contact networks with a single central core. Further studies are needed to explore use of webcam for Internet dating.

  1. Characterization of Salt-Induced Epigenetic Segregation by Genome-Wide Loss of Heterozygosity and its Association with Salt Tolerance in Rice (Oryza sativa L.

    Directory of Open Access Journals (Sweden)

    Min Li

    2017-06-01

    Full Text Available In a breeding effort to develop salt tolerant (ST rice varieties by designed QTL pyramiding, large numbers of progenies derived from four crosses between salt- or drought- tolerant BC2F5 IR64 introgression lines, were subjected to severe salt stress, resulting in 422 ST plants. The progeny testing of the selected F3 lines under more severe salt stress resulted in identification of 16 promising homozygous lines with high levels of ST. Genetic characterization of the 422 ST F3 progeny and 318 random F2 plants from the same four crosses using 105 segregating SSR markers lead to three interesting discoveries: (1 salt stress can induce genome-wide epigenetic segregation (ES characterized by complete loss of heterozygosity (LOH and nearly complete loss of an allele (LOA in the F3 progenies of four rice populations in a single generation; (2 ∼25% of the stress-induced ES loci were transgenerational and inherited from their salt- and drought- selected parents; and (3 the salt-induced LOH and LOA loci (regions appeared to contain genes/alleles associated with ST and/or drought tolerance. 32 genomic regions that showed one or more types of salt-induced ES in the random and salt-selected progenies from these crosses. The same or different types of ES were detected with two large genomic regions on chromosomes 1 and 6 where more and the strongest ES were found across different populations. 14 genomic regions were found where the salt-induced ES regions were overlapping with QTL affecting ST related traits. The discovery of the three types of salt-induced ES showed several interesting characteristics and had important implications in evolution and future breeding for developing stress-resilient rice and crops.

  2. Loss of bone strength in HLA-B27 transgenic rats is characterized by a high bone turnover and is mainly osteoclast-driven.

    Science.gov (United States)

    Rauner, Martina; Thiele, Sylvia; Fert, Ingrid; Araujo, Luiza M; Layh-Schmitt, Gerlinde; Colbert, Robert A; Hofbauer, Christine; Bernhardt, Ricardo; Bürki, Alexander; Schwiedrzik, Jakob; Zysset, Philippe K; Pietschmann, Peter; Taurog, Joel D; Breban, Maxime; Hofbauer, Lorenz C

    2015-06-01

    Although osteopenia is frequent in spondyloarthritis (SpA), the underlying cellular mechanisms and association with other symptoms are poorly understood. This study aimed to characterize bone loss during disease progression, determine cellular alterations, and assess the contribution of inflammatory bowel disease (IBD) to bone loss in HLA-B27 transgenic rats. Bones of 2-, 6-, and 12-month-old non-transgenic, disease-free HLA-B7 and disease-associated HLA-B27 transgenic rats were examined using peripheral quantitative computed tomography, μCT, and nanoindentation. Cellular characteristics were determined by histomorphometry and ex vivo cultures. The impact of IBD was determined using [21-3 x 283-2]F1 rats, which develop arthritis and spondylitis, but not IBD. HLA-B27 transgenic rats continuously lost bone mass with increasing age and had impaired bone material properties, leading to a 3-fold decrease in bone strength at 12 months of age. Bone turnover was increased in HLA-B27 transgenic rats, as evidenced by a 3-fold increase in bone formation and a 6-fold increase in bone resorption parameters. Enhanced osteoclastic markers were associated with a larger number of precursors in the bone marrow and a stronger osteoclastogenic response to RANKL or TNFα. Further, IBD-free [21-3 x 283-2]F1 rats also displayed decreased total and trabecular bone density. HLA-B27 transgenic rats lose an increasing amount of bone density and strength with progressing age, which is primarily mediated via increased bone remodeling in favor of bone resorption. Moreover, IBD and bone loss seem to be independent features of SpA in HLA-B27 transgenic rats. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Correlated Sources in Distributed Networks--Data Transmission, Common Information Characterization and Inferencing

    Science.gov (United States)

    Liu, Wei

    2011-01-01

    Correlation is often present among observations in a distributed system. This thesis deals with various design issues when correlated data are observed at distributed terminals, including: communicating correlated sources over interference channels, characterizing the common information among dependent random variables, and testing the presence of…

  4. Functional and structural neural network characterization of serotonin transporter knockout rats.

    Directory of Open Access Journals (Sweden)

    Kajo van der Marel

    Full Text Available Brain serotonin homeostasis is crucially maintained by the serotonin transporter (5-HTT, and its down-regulation has been linked to increased vulnerability for anxiety- and depression-related behavior. Studies in 5-HTT knockout (5-HTT(-/- rodents have associated inherited reduced functional expression of 5-HTT with increased sensitivity to adverse as well as rewarding environmental stimuli, and in particular cocaine hyperresponsivity. 5-HTT down-regulation may affect normal neuronal wiring of implicated corticolimbic cerebral structures. To further our understanding of its contribution to potential alterations in basal functional and structural properties of neural network configurations, we applied resting-state functional MRI (fMRI, pharmacological MRI of cocaine-induced activation, and diffusion tensor imaging (DTI in 5-HTT(-/- rats and wild-type controls (5-HTT(+/+. We found that baseline functional connectivity values and cocaine-induced neural activity within the corticolimbic network was not significantly altered in 5-HTT(-/- versus 5-HTT(+/+ rats. Similarly, DTI revealed mostly intact white matter structural integrity, except for a reduced fractional anisotropy in the genu of the corpus callosum of 5-HTT(-/- rats. At the macroscopic level, analyses of complex graphs constructed from either functional connectivity values or structural DTI-based tractography results revealed that key properties of brain network organization were essentially similar between 5-HTT(+/+ and 5-HTT(-/- rats. The individual tests for differences between 5-HTT(+/+ and 5-HTT(-/- rats were capable of detecting significant effects ranging from 5.8% (fractional anisotropy to 26.1% (pharmacological MRI and 29.3% (functional connectivity. Tentatively, lower fractional anisotropy in the genu of the corpus callosum could indicate a reduced capacity for information integration across hemispheres in 5-HTT(-/- rats. Overall, the comparison of 5-HTT(-/- and wild-type rats

  5. Characterizing Offshore Earthquakes at Hawaii Recorded by the First PLUME Temporary Ocean-Bottom Seismometer Network

    Science.gov (United States)

    Anchieta, M. C.; Wolfe, C. J.; Laske, G.; Collins, J. A.; Solomon, S. C.; Detrick, R. S.; Orcutt, J. A.; Bercovici, D. A.; Hauri, E. H.; Pavlis, G. L.; Eakins, J. A.; Vernon, F. L.

    2007-12-01

    In 2005-2006 and again in 2006-2007, the Plume-Lithosphere Undersea Melt Experiment (PLUME) deployed successive networks of ocean-bottom seismometers (OBSs) around the Hawaiian Islands. The experiment consisted of a 2-year deployment of broadband land seismometers and two year-long deployments of broadband OBSs, the first with a station spacing of about 75 km centered on the island of Hawaii and the second with larger spacing of about 200 km. PLUME's major objective was to determine the mantle structure beneath the Hawaiian hotspot and swell; however, these unique data are also potentially valuable to the study of small offshore earthquakes. The Hawaiian Islands are marked by significant and continuous seismic activity. In addition to the thousands of microearthquakes that are detected and located by the USGS Hawaiian Volcano Observatory (HVO) seismic network each year, Hawaii also experiences occasional large, damaging earthquakes. Several of these large events occurred in Hawaii's offshore region (e.g., the 1871 Lanai earthquake, the 1938 Maui earthquake, and the 2006 Kiholo Bay earthquake), and such events pose a significant seismic hazard for the state. We assess whether data from the first PLUME OBS deployment and land data can improve the detection and location of offshore microearthquakes around Hawaii. We are particularly interested in whether the PLUME data set may reveal offshore fault zones not detected to date by the HVO seismic network. Initial tests indicate that many offshore earthquakes already in the HVO catalog produce detectable P and S waves on the PLUME three- component seismometers, and earthquake detection rates are improved when seismograms are high-pass filtered above about 5 Hz to reduce the seismic noise from wind-generated waves. Differential pressure gauge data yield far fewer detectable events (with the exception of a swarm of Loihi earthquakes in December 2005) and appear less promising for improving our knowledge of offshore

  6. Network-based characterization of brain functional connectivity in Zen practitioners

    Directory of Open Access Journals (Sweden)

    Phebe Brenne Kemmer

    2015-05-01

    Full Text Available In the last decade, a number of neuroimaging studies have investigated the neurophysiological effects associated with contemplative practices. Meditation-related changes in resting state functional connectivity (rsFC have been previously reported, particularly in the default mode network, frontoparietal (FP attentional circuits, saliency-related regions, and primary sensory cortices. We collected fMRI data from a sample of 12 experienced Zen meditators and 12 meditation-naïve matched controls during a basic attention-to-breathing protocol, together with behavioral performance outside the scanner on a set of computerized neuropsychological tests. We adopted a network system of 209 nodes, classified into 9 functional modules, and a multi-stage approach to identify rsFC differences in meditators and controls. Between-group comparisons of modulewise FC, summarized by the first principal component of the relevant set of edges, revealed important connections of FP circuits with early visual and executive control areas. We also identified several group differences in positive and negative edgewise FC, often involving the visual or FP regions. Multivariate pattern analysis of modulewise FC, using Support Vector Machine (SVM, classified meditators and controls with 79% accuracy and selected 10 modulewise connections that were jointly prominent in distinguishing meditators and controls; a similar SVM procedure based on the subjects' scores on the neuropsychological battery yielded a slightly weaker accuracy (75%. Finally, we observed a good correlation between the across-subject variation in strength of modulewise connections among FP, executive, and visual circuits, on the one hand, and in the performance on a rapid visual information processing (RVIP test of sustained attention, on the other. Taken together, these findings highlight the usefulness of employing network analysis techniques in investigating the neural correlates of contemplative practices.

  7. Mobility Network and Safety

    Directory of Open Access Journals (Sweden)

    Adriana Galderisi

    2010-04-01

    Full Text Available Mobility network is crucial for ensuring territorial safety with respect to natural and technological hazards. They represent a basic support to community’s everyday life although being exposed elements often characterized by high vulnerability to different hazards and, in the meanwhile, strategic equipments for emergency management. Physical damages or the lack in functioning of those networks may greatly increase the loss of human lives caused by hazardous events as well as produce relevant economic damages at medium and long term. Although the relevance of the mobility networks in assuring territorial safety is at present largely recognized, risk analyses have been long focused on buildings’ vulnerability or, even where they have paid attention to mobility network, they have been mainly focused on the physical damages that a given hazard could may induce on individual elements of such network. It is recent the awareness that mobility network represents a system, characterized by relevant interdependences both among its elements and among network infrastructures and urban systems. Based on these assumptions, this paper points out the heterogeneous aspects of the mobility network vulnerability and their relevance in increasing the overall territorial or urban vulnerability to hazardous events. Therefore, an in-depth investigation of the concept of mobility network vulnerability is provided, in order to highlight the aspects mostly investigated and more recent research perspectives. Finally, a case study in the Campania Region is presented in order to point out how traditional risk analyses, generally referred to individual hazards, can sometimes led to invest in the mobility network improvement or development which, targeted to increase the security of a territory result, on the opposite, in an increase of the territorial vulnerability.

  8. Characterizing Deficiencies of Path-Based Routing for Wireless Multi-Hop Networks

    Science.gov (United States)

    2017-05-01

    Transactions on, vol. 46, no. 2, pp. 388–404, 2000. [39] S. Guo, L. He, Y. Gu, B. Jiang, and T. He, “Opportunistic flood - ing in low-duty- cycle wireless sensor...a route to another user only when it has data destined for that user. To find a route, a control packet is flooded across the network that identifies...link exists until no set of control packets are exchanged for the length of a timeout period, which is typically a cycle of 2 or 3 hello messages

  9. Synthesis and Structural Characterization of Magnesium Based Coordination Networks in Different Solvents

    Energy Technology Data Exchange (ETDEWEB)

    D Banerjee; J Finkelstein; A Smirnov; P Forster; L Borkowski; S Teat; J Parise

    2011-12-31

    Three magnesium based metal-organic frameworks, Mg{sub 3}(3,5-PDC){sub 3}(DMF){sub 3} {center_dot} DMF [1], Mg(3,5-PDC)(H{sub 2}O) {center_dot} (H{sub 2}O) [3], and Mg{sub 4}(3,5-PDC){sub 4}(DMF){sub 2}(H{sub 2}O){sub 2} {center_dot} 2DMF {center_dot} 4.5H{sub 2}O [4], and a 2-D coordination polymer, [Mg(3,5-PDC)(H{sub 2}O){sub 2}] [2] [PDC = pyridinedicarboxylate], were synthesized using a combination of DMF, methanol, ethanol, and water. Compound 1 [space group P2{sub 1}/n, a = 12.3475(5) {angstrom}, b = 11.1929(5) {angstrom}, c = 28.6734(12) {angstrom}, {beta} = 98.8160(10){sup o}, V = 3916.0(3) {angstrom}{sup 3}] consists of a combination of isolated and corner-sharing magnesium octahedra connected by the organic linkers to form a 3-D network with a 12.2 {angstrom} x 4.6 {angstrom} 1-D channel. The channel contains coordinated and free DMF molecules. In compound 2 [space group C2/c, a = 9.964(5) {angstrom}, b = 12.0694(6) {angstrom}, c = 7.2763(4) {angstrom}, {beta} = 106.4970(6){sup o}, V = 836.70(6) {angstrom}{sup 3}], PDC connects isolated seven coordinated magnesium polyhedra into a layered structure. Compound 3 [space group P6{sub 1}22, a = 11.479(1) {angstrom}, c = 14.735(3) {angstrom}, V = 1681.7(4) {angstrom}{sup 3}] (previously reported) contains isolated magnesium octahedra connected by the organic linker with each other forming a 3D network. Compound 4 [space group P2{sub 1}/c, a = 13.7442(14) {angstrom}, b = 14.2887(15) {angstrom}, c = 14.1178(14) {angstrom}, {beta} = 104.912(2){sup o}, V = 2679.2(5) {angstrom}{sup 3}] also exhibits a 3D network based on isolated magnesium octahedra with square cavities containing both disordered DMF and water molecules. The structural topologies originate due to the variable coordination ability of solvent molecules with the metal center. Water molecules coordinate with the magnesium metal centers preferably over other polar solvents (DMF, methanol, ethanol) used to synthesize the coordination networks. Despite

  10. Simultaneous characterization of elemental segregation and cementite networks in high carbon steel products by spatially-resolved laser-induced breakdown spectroscopy

    Science.gov (United States)

    Boué-Bigne, Fabienne

    2014-06-01

    The reliable characterization of the level of elemental segregation and of the extent of grain-boundary cementite networks in high carbon steel products is a prerequisite for checking product quality, for the purpose of product release to customers, and to investigate the presence of defects that may have led to mechanical property failure of the product. Current methods for the characterization of segregation and cementite networks rely on two different methods of sample etching followed by visual observation, where quality scores are given based on human perception and judgment. With the continuous demand on increasing quality, some of the conventional characterization methods and their associated scoring boards have lost relevance for the precision of characterization that is required today to distinguish between a product that will perform well and one that will not. In order to move away from a qualitative, human perception based situation for the scoring of the severity of segregation and cementite networks, a new method of data evaluation based on spatially-resolved LIBS measurements was developed to provide quantitative and simultaneous characterization of both types of defects. The quantitative assessment of segregation and cementite networks is based on the acquisition of carbon concentration maps. The ability to produce rapid scanning measurements of micro and macro-scale features with adequate spatial resolution makes LIBS the measurement method of preference for this purpose. The characterization of both different defects is extracted simultaneously and from the same carbon concentration map following a series of statistical treatment and data extraction rules. LIBS results were validated against recognized methods and were applied to a significant number of routine samples. The new LIBS method offers a step change improvement in reliability for the characterization of segregation and cementite networks in steel products over the conventional methods

  11. Preparation and characterization of shape memory composite foams with interpenetrating polymer networks

    Science.gov (United States)

    Yao, Yongtao; Zhou, Tianyang; Yang, Cheng; Liu, Yanju; Leng, Jinsong

    2016-03-01

    The present study reports a feasible approach of fabricating shape memory composite foams with an interpenetrating polymer network (IPN) based on polyurethane (PU) and shape memory epoxy resin (SMER) via a simultaneous polymerization technique. The PU component is capable of constructing a foam structure and the SMER is grafted on the PU network to offer its shape memory property in the final IPN foams. A series of IPN foams without phase separation were produced due to good compatibility and a tight chemical interaction between PU and SMER components. The relationships of the geometry of the foam cell were investigated via varying compositions of PU and SMER. The physical property and shape memory property were also evaluated. The stimulus temperature of IPN shape memory composite foams, glass temperature (Tg), could be tunable by varying the constituents and Tg of PU and SMER. The mechanism of the shape memory effect of IPN foams has been proposed. The shape memory composite foam with IPN developed in this study has the potential to extend its application field.

  12. Water Relationships in the U.S. Southwest: Characterizing Water Management Networks Using Natural Language Processing

    Directory of Open Access Journals (Sweden)

    John T. Murphy

    2014-06-01

    Full Text Available Natural language processing (NLP and named entity recognition (NER techniques are applied to collections of newspaper articles from four cities in the U.S. Southwest. The results are used to generate a network of water management institutions that reflect public perceptions of water management and the structure of water management in these areas. This structure can be highly centralized or fragmented; in the latter case, multiple peer institutions exist that may cooperate or be in conflict. This is reflected in the public discourse of the water consumers in these areas and can, we contend, impact the potential responses of management agencies to challenges of water supply and quality and, in some cases, limit their effectiveness. Flagstaff, AZ, Tucson, AZ, Las Vegas, NV, and the Grand Valley, CO, are examined, including more than 110,000 articles from 2004–2012. Documents are scored by association with water topics, and phrases likely to be institutions are extracted via custom NLP and NER algorithms; those institutions associated with water-related documents are used to form networks via document co-location. The Grand Valley is shown to have a markedly different structure, which we contend reflects the different historical trajectory of its development and its current state, which includes multiple institutions of roughly equal scope and size. These results demonstrate the utility of using NLP and NER methods to understanding the structure and variation of water management systems.

  13. Structural Health Monitoring and Impact Detection Using Neural Networks for Damage Characterization

    Science.gov (United States)

    Ross, Richard W.

    2006-01-01

    Detection of damage due to foreign object impact is an important factor in the development of new aerospace vehicles. Acoustic waves generated on impact can be detected using a set of piezoelectric transducers, and the location of impact can be determined by triangulation based on the differences in the arrival time of the waves at each of the sensors. These sensors generate electrical signals in response to mechanical motion resulting from the impact as well as from natural vibrations. Due to electrical noise and mechanical vibration, accurately determining these time differentials can be challenging, and even small measurement inaccuracies can lead to significant errors in the computed damage location. Wavelet transforms are used to analyze the signals at multiple levels of detail, allowing the signals resulting from the impact to be isolated from ambient electromechanical noise. Data extracted from these transformed signals are input to an artificial neural network to aid in identifying the moment of impact from the transformed signals. By distinguishing which of the signal components are resultant from the impact and which are characteristic of noise and normal aerodynamic loads, the time differentials as well as the location of damage can be accurately assessed. The combination of wavelet transformations and neural network processing results in an efficient and accurate approach for passive in-flight detection of foreign object damage.

  14. Characterization of dynamical systems under noise using recurrence networks: Application to simulated and EEG data

    Energy Technology Data Exchange (ETDEWEB)

    Puthanmadam Subramaniyam, Narayan, E-mail: npsubramaniyam@gmail.com [Department of Electronics and Communications, Tampere University of Technology, Tampere (Finland); BioMediTech, Tampere (Finland); Hyttinen, Jari [Department of Electronics and Communications, Tampere University of Technology, Tampere (Finland); BioMediTech, Tampere (Finland)

    2014-10-24

    In this letter, we study the influence of observational noise on recurrence network (RN) measures, the global clustering coefficient (C) and average path length (L) using the Rössler system and propose the application of RN measures to analyze the structural properties of electroencephalographic (EEG) data. We find that for an appropriate recurrence rate (RR>0.02) the influence of noise on C can be minimized while L is independent of RR for increasing levels of noise. Indications of structural complexity were found for healthy EEG, but to a lesser extent than epileptic EEG. Furthermore, C performed better than L in case of epileptic EEG. Our results show that RN measures can provide insights into the structural properties of EEG in normal and pathological states. - Highlights: • We study the influence of noise on the recurrence network measures C and L. • We propose the application of C and L to healthy and epileptic EEG data. • The influence of noise can be minimized by increasing the recurrence rate. • Measures C and L can describe the structural complexity of EEG data. • In case of epileptic EEG, C performs better than L.

  15. Synthesis and Structural Characterization of Carboxylate-Based Metal-Organic Frameworks and Coordination Networks

    Science.gov (United States)

    Calderone, Paul

    Coordination networks (CNs) and metal-organic frameworks (MOFs) are crystalline materials composed of metal ions linked by multifunctional organic ligands. From these connections, infinite arrays of one-, two-, or three-dimensional networks can be formed. Exploratory synthesis and research of novel CNs and MOFs is of current interest because of their many possible industrial applications including gas storage, catalysis, magnetism, and luminescence. A variety of metal centers and organic ligands can be used to synthesize MOFs and CNs under a range of reaction conditions, leading to extraordinary structural diversity. The characteristics of the metals and linkers, such as properties and coordination preferences, play the biggest role in determining the structure and properties of the resulting network. Thus, the choice of metal and linker is dictated by the desired traits of the target network. The pervasive use of transition metal centers in MOF synthesis stems from their well-known coordination behavior with carboxylate-based linkers, thus facilitating design strategies. Conversely, CNs and MOFs based on s-block and lanthanide metals are less studied because each group presents unique challenges to structure prediction. Lanthanide metals have variable coordination spheres capable of accommodating up to twelve atoms, while the bonding in s-block metals takes on a mainly ionic character. In spite of these obstacles, lanthanide and s-block CNs are worthwhile synthetic targets because of their unique properties. Interesting photoluminescent and sensing materials can be developed using lanthanide metals, whereas low atomic weight s-block metals may afford an advantage in gravimetric advantages for gas storage applications. The aim of this research was to expand the current understanding of carboxylate-based CN and MOF synthesis by varying the metals, solvents, and temperatures used. To this end, magnesium-based CNs were examined using a variety of aromatic carboxylate

  16. On the importance of social network sites in the transitions which characterize ‘emerging adulthood’

    Directory of Open Access Journals (Sweden)

    Gianluca Frozzi

    2011-09-01

    Full Text Available Modern-day economic and socio-cultural developments require people to be ever more specialized and mobile in their educational and professional choices. This is particularly relevant for ‘emerging adults’, that is to say, those who find themselves at that stage of life when their scholastic or university education ends, and they begin to make choices regarding their professional working life. Transitions between different activity systems, and changes of residence which they entail, make ‘emerging adulthood’ a particularly unstable period in which young people continually dissolve, create and recreate relationship networks of varying degrees of importance which are able to support them through these changes. Beginning with empirical evidence and theoretical starting points typical of the psychology of education and development, this contribution proposes a theoretical reflection which attempts to analyze the efficacy of Social Network Sites in facilitating and supporting emerging adults during their education and vocational training and the important transitions which they have to face as they develop.

  17. Novel Method for Measuring the Heat Collection Rate and Heat Loss Coefficient of Water-in-Glass Evacuated Tube Solar Water Heaters Based on Artificial Neural Networks and Support Vector Machine

    Directory of Open Access Journals (Sweden)

    Zhijian Liu

    2015-08-01

    Full Text Available The determinations of heat collection rate and heat loss coefficient are crucial for the evaluation of in service water-in-glass evacuated tube solar water heaters. However, the direct determination requires complex detection devices and a series of standard experiments, which also wastes too much time and manpower. To address this problem, we propose machine learning models including artificial neural networks (ANNs and support vector machines (SVM to predict the heat collection rate and heat loss coefficient without a direct determination. Parameters that can be easily obtained by “portable test instruments” were set as independent variables, including tube length, number of tubes, tube center distance, heat water mass in tank, collector area, final temperature and angle between tubes and ground, while the heat collection rate and heat loss coefficient determined by the detection device were set as dependent variables respectively. Nine hundred fifteen samples from in-service water-in-glass evacuated tube solar water heaters were used for training and testing the models. Results show that the multilayer feed-forward neural network (MLFN with 3 nodes is the best model for the prediction of heat collection rate and the general regression neural network (GRNN is the best model for the prediction of heat loss coefficient due to their low root mean square (RMS errors, short training times, and high prediction accuracies (under the tolerances of 30%, 20%, and 10%, respectively.

  18. Synthesis and characterization of UV photocrosslinkable hydrogels with poly(N-vinyl-2-pyrrolidone): Determination of the network mesh size distribution

    DEFF Research Database (Denmark)

    Marizza, Paolo; Abrami, M.; Keller, Stephan Sylvest

    2016-01-01

    Hydrogels of poly(n-vinyl-2-pyrrolidone) were produced by UV irradiation of aqueous solutions of the polymer in presence of hydrogen peroxide, used as initiator. The mechanical and the nanostructural properties of the gels were characterized by a combination of experimental techniques including r...... of the gel polymeric network. Moreover, a novel correlation model was developed based on Chui and Scherer theories for the interpretation of LF-NMR dataset of polymer solutions and networks....

  19. Characterizing Transcriptional Networks in Male Rainbow Darter (Etheostoma caeruleum that Regulate Testis Development over a Complete Reproductive Cycle.

    Directory of Open Access Journals (Sweden)

    Paulina A Bahamonde

    Full Text Available Intersex is a condition that has been associated with exposure to sewage effluents in male rainbow darter (Etheostoma caeruleum. To better understand changes in the transcriptome that are associated with intersex, we characterized annual changes in the testis transcriptome in wild, unexposed fish. Rainbow darter males were collected from the Grand River (Ontario, Canada in May (spawning, August (post-spawning, October (recrudescence, January (developing and March (pre-spawning. Histology was used to determine the proportion of spermatogenic cell types that were present during each period of testicular maturation. Regression analysis determined that the proportion of spermatozoa versus spermatocytes in all stages of development (R2 ≥ 0.58 were inversely related; however this was not the case when males were in the post-spawning period. Gene networks that were specific to the transition from developing to pre-spawning stages included nitric oxide biosynthesis, response to wounding, sperm cell function, and stem cell maintenance. The pre-spawning to spawning transition included gene networks related to amino acid import, glycogenesis, Sertoli cell proliferation, sperm capacitation, and sperm motility. The spawning to post-spawning transition included unique gene networks associated with chromosome condensation, ribosome biogenesis and assembly, and mitotic spindle assembly. Lastly, the transition from post-spawning to recrudescence included gene networks associated with egg activation, epithelial to mesenchymal transition, membrane fluidity, and sperm cell adhesion. Noteworthy was that there were a significant number of gene networks related to immune system function that were differentially expressed throughout reproduction, suggesting that immune network signalling has a prominent role in the male testis. Transcripts in the testis of post-spawning individuals showed patterns of expression that were most different for the majority of transcripts

  20. Synthesis and characterization of semi-interpenetrating networks of chitosan and poly(N-vinyl-2-pyrrolidone

    Directory of Open Access Journals (Sweden)

    Milosavljević Nedeljko B.

    2010-01-01

    Full Text Available A semi-interpenetrating networks (semi-IPNs based on chitosan and poly(N-vinyl-2-pyrrolidone were prepared in order to achieve better mechanical properties. The samples were characterized by FTIR, SEM, DMA analysis and the swelling behavior at different pHs (2.0-8.0. The semi-IPNs composition was found to have a great impact the hydrogel structure, mechanical properties, morphology and swelling kinetics. The gels demonstrated substantial change in buffer absorbency with the change of pH, high for acid buffers and lower for pH values above 6 where the swelling was considerably slow. Incorporation of PVP led to better mechanical strength of semi-IPNs keeping satisfactory degree of swelling which make them suitable for various applications.

  1. Characterization of dynamical systems under noise using recurrence networks: Application to simulated and EEG data

    Science.gov (United States)

    Puthanmadam Subramaniyam, Narayan; Hyttinen, Jari

    2014-10-01

    In this letter, we study the influence of observational noise on recurrence network (RN) measures, the global clustering coefficient (C) and average path length (L) using the Rössler system and propose the application of RN measures to analyze the structural properties of electroencephalographic (EEG) data. We find that for an appropriate recurrence rate (RR>0.02) the influence of noise on C can be minimized while L is independent of RR for increasing levels of noise. Indications of structural complexity were found for healthy EEG, but to a lesser extent than epileptic EEG. Furthermore, C performed better than L in case of epileptic EEG. Our results show that RN measures can provide insights into the structural properties of EEG in normal and pathological states.

  2. Networking our science to characterize the state, vulnerabilities, and management opportunities of soil organic matter

    Energy Technology Data Exchange (ETDEWEB)

    Harden, Jennifer W.; Hugelius, Gustaf; Ahlstrom, Anders; Blankinship, Joseph; Bond-Lamberty, Benjamin; Lawrence, Corey; Loisel, Julie; Malhotra, Avni; Jackson, Robert B.; Ogle, S.M.; Phillips, Claire; Ryals, Rebecca; Todd-Brown, Katherine EO; Vargas, Rodrigo; Vergara, Sintana; Cotrufo, Francesca; Keiluweit, M.; Heckman, Katherine; Crow, Susan; Silver, Whendee; Delonge, Marcia; Nave, Lucas

    2018-02-01

    Over 75% of soil organic carbon (C) in the upper meter of earth’s terrestrial surface has been subjected to cropping, grazing, forestry, or urbanization. As a result, terrestrial C cycling cannot be studied out of land use context. Meanwhile, amendments by soil organic matter demonstrate reliable methodologies to restore and improve soils to a more productive state, therefore soil health and productivity cannot be understood without reference to soil C. Measurements for detecting changes in soil C are needed to constrain and monitor best practices and must reflect processes of C stabilization and destabilization over various timescales, soil types, and spatial scales in order to quantify C sequestration at regional to global scales. We have identified gaps in data, modeling, and communication that underscore the need for an open, shared network to frame and guide the study of soil carbon and its management for sustained production and climate regulation.

  3. A study using a Monte Carlo method of the optimal configuration of a distribution network in terms of power loss sensing.

    Science.gov (United States)

    Moon, Hyun Ho; Lee, Jong Joo; Choi, Sang Yule; Cha, Jae Sang; Kang, Jang Mook; Kim, Jong Tae; Shin, Myong Chul

    2011-01-01

    Recently there have been many studies of power systems with a focus on "New and Renewable Energy" as part of "New Growth Engine Industry" promoted by the Korean government. "New And Renewable Energy"-especially focused on wind energy, solar energy and fuel cells that will replace conventional fossil fuels-is a part of the Power-IT Sector which is the basis of the SmartGrid. A SmartGrid is a form of highly-efficient intelligent electricity network that allows interactivity (two-way communications) between suppliers and consumers by utilizing information technology in electricity production, transmission, distribution and consumption. The New and Renewable Energy Program has been driven with a goal to develop and spread through intensive studies, by public or private institutions, new and renewable energy which, unlike conventional systems, have been operated through connections with various kinds of distributed power generation systems. Considerable research on smart grids has been pursued in the United States and Europe. In the United States, a variety of research activities on the smart power grid have been conducted within EPRI's IntelliGrid research program. The European Union (EU), which represents Europe's Smart Grid policy, has focused on an expansion of distributed generation (decentralized generation) and power trade between countries with improved environmental protection. Thus, there is current emphasis on a need for studies that assesses the economic efficiency of such distributed generation systems. In this paper, based on the cost of distributed power generation capacity, calculations of the best profits obtainable were made by a Monte Carlo simulation. Monte Carlo simulations that rely on repeated random sampling to compute their results take into account the cost of electricity production, daily loads and the cost of sales and generate a result faster than mathematical computations. In addition, we have suggested the optimal design, which considers

  4. Importance of RIFLE (Risk, Injury, Failure, Loss, and End-Stage Renal Failure) and AKIN (Acute Kidney Injury Network) in Hemodialysis Initiation and Intensive Care Unit Mortality.

    Science.gov (United States)

    Kara, Iskender; Yildirim, Fatma; Kayacan, Esra; Bilaloğlu, Burcu; Turkoglu, Melda; Aygencel, Gülbin

    2017-07-01

    Our study evaluated the differences between early and late hemodialysis (HD) initiation in the intensive care unit (ICU) according to the RIFLE (Risk, Injury, Failure, Loss, and End-stage renal failure) and AKIN (Acute Kidney Injury Network) classifications. On the assumption that early initiation of HD in critical patients according to the RIFLE and AKIN criteria decreases mortality, we retrospectively evaluated the medical records of 68 patients in our medical ICU and divided the patients into 2 groups: Those undergoing HD in no risk, risk, or injury stage according to RIFLE and in stage 0, I, or II according to AKIN were defined as early HD and those in failure stage according to RIFLE and in stage III according to AKIN were defined as late HD. The median age of the patients was 66.5 years, and 56.5% were male. HD was started in 25% and 39.7% of the patients in the early stage in the RIFLE and AKIN classification, respectively. According to RIFLE, HD was started in 61.5% of the surviving patients in the early stage; this rate was 16.4% in the deceased patients (P=0.001). HD was commenced in 69.2% of the surviving patients in AKIN stages 0, I, and II and in 32.7% of the deceased patients (P=0.026). Sepsis (61.5% vs. 94.5%; P=0.001) and mechanical ventilation (30.8% vs. 87.3%; P<0.001) during HD increased ICU mortality, whereas HD initiation in the early stages according to RIFLE decreased ICU mortality (61.5% vs. 16.4%; P=0.001). In conclusion, in critically ill patients, HD initiation in the early stages according to the RIFLE classification decreased our ICU mortality.

  5. Characterizing steady states of genome-scale metabolic networks in continuous cell cultures.

    Directory of Open Access Journals (Sweden)

    Jorge Fernandez-de-Cossio-Diaz

    2017-11-01

    Full Text Available In the continuous mode of cell culture, a constant flow carrying fresh media replaces culture fluid, cells, nutrients and secreted metabolites. Here we present a model for continuous cell culture coupling intra-cellular metabolism to extracellular variables describing the state of the bioreactor, taking into account the growth capacity of the cell and the impact of toxic byproduct accumulation. We provide a method to determine the steady states of this system that is tractable for metabolic networks of arbitrary complexity. We demonstrate our approach in a toy model first, and then in a genome-scale metabolic network of the Chinese hamster ovary cell line, obtaining results that are in qualitative agreement with experimental observations. We derive a number of consequences from the model that are independent of parameter values. The ratio between cell density and dilution rate is an ideal control parameter to fix a steady state with desired metabolic properties. This conclusion is robust even in the presence of multi-stability, which is explained in our model by a negative feedback loop due to toxic byproduct accumulation. A complex landscape of steady states emerges from our simulations, including multiple metabolic switches, which also explain why cell-line and media benchmarks carried out in batch culture cannot be extrapolated to perfusion. On the other hand, we predict invariance laws between continuous cell cultures with different parameters. A practical consequence is that the chemostat is an ideal experimental model for large-scale high-density perfusion cultures, where the complex landscape of metabolic transitions is faithfully reproduced.

  6. Characterization of Impulse Radio Intrabody Communication System for Wireless Body Area Networks.

    Science.gov (United States)

    Cai, Zibo; Seyedi, MirHojjat; Zhang, Weiwei; Rivet, Francois; Lai, Daniel T H

    2017-01-01

    Intrabody communication (IBC) is a promising data communication technique for body area networks. This short-distance communication approach uses human body tissue as the medium of signal propagation. IBC is defined as one of the physical layers for the new IEEE 802.15.6 or wireless body area network (WBAN) standard, which can provide a suitable data rate for real-time physiological data communication while consuming lower power compared to that of radio-frequency protocols such as Bluetooth. In this paper, impulse radio (IR) IBC (IR-IBC) is examined using a field-programmable gate array (FPGA) implementation of an IBC system. A carrier-free pulse position modulation (PPM) scheme is implemented using an IBC transmitter in an FPGA board. PPM is a modulation technique that uses time-based pulse characteristics to encode data based on IR concepts. The transmission performance of the scheme was evaluated through signal propagation measurements of the human arm using 4- and 8-PPM transmitters, respectively. 4 or 8 is the number of symbols during modulations. It was found that the received signal-to-noise ratio (SNR) decreases approximately 8.0 dB for a range of arm distances (5-50 cm) between the transmitter and receiver electrodes with constant noise power and various signal amplitudes. The SNR for the 4-PPM scheme is approximately 2 dB higher than that for the 8-PPM one. In addition, the bit error rate (BER) is theoretically analyzed for the human body channel with additive white Gaussian noise. The 4- and 8-PPM IBC systems have average BER values of 10(-5) and 10(-10), respectively. The results indicate the superiority of the 8-PPM scheme compared to the 4-PPM one when implementing the IBC system. The performance evaluation of the proposed IBC system will improve further IBC transceiver design.

  7. Characterizing genes with distinct methylation patterns in the context of protein-protein interaction network: application to human brain tissues.

    Science.gov (United States)

    Li, Yongsheng; Xu, Juan; Chen, Hong; Zhao, Zheng; Li, Shengli; Bai, Jing; Wu, Aiwei; Jiang, Chunjie; Wang, Yuan; Su, Bin; Li, Xia

    2013-01-01

    DNA methylation is an essential epigenetic mechanism involved in transcriptional control. However, how genes with different methylation patterns are assembled in the protein-protein interaction network (PPIN) remains a mystery. In the present study, we systematically dissected the characterization of genes with different methylation patterns in the PPIN. A negative association was detected between the methylation levels in the brain tissues and topological centralities. By focusing on two classes of genes with considerably different methylation levels in the brain tissues, namely the low methylated genes (LMGs) and high methylated genes (HMGs), we found that their organizing principles in the PPIN are distinct. The LMGs tend to be the center of the PPIN, and attacking them causes a more deleterious effect on the network integrity. Furthermore, the LMGs express their functions in a modular pattern and substantial differences in functions are observed between the two types of genes. The LMGs are enriched in the basic biological functions, such as binding activity and regulation of transcription. More importantly, cancer genes, especially recessive cancer genes, essential genes, and aging-related genes were all found more often in the LMGs. Additionally, our analysis presented that the intra-classes communications are enhanced, but inter-classes communications are repressed. Finally, a functional complementation was revealed between methylation and miRNA regulation in the human genome. We have elucidated the assembling principles of genes with different methylation levels in the context of the PPIN, providing key insights into the complex epigenetic regulation mechanisms.

  8. Non pecuniary losses

    NARCIS (Netherlands)

    S.D. Lindenbergh (Siewert); P.M. Kippersluis (Peter)

    2009-01-01

    textabstractNon pecuniary losses can be characterized as losses that are suffered by damaging goods or interests which have in themselves no economic price or value on a financial market. Examples are damage to goods with a primarily sentimental value, such as an album of wedding photos, pain and

  9. Losses compensation; Compensation des pertes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    One mission of RTE (Electric Power Transportation), is to watch over the losses compensation resulting from the power transport on the electric power network. Since january 2001, RTE makes good the electric losses by the purchase of energy. To choose the marketers, a consultation has been realized by RTE. This document presents the rules concerning these losses compensation. (A.L.B.)

  10. Whole-Building Airflow Network Characterization by a Many-Pressure-States (MPS) Technique

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Peter R.; Hadley, Donald L.; Stenner, Robert D.; Janus, Michael C.

    2001-06-01

    Applications of multi-zone airflow and contaminant dispersion models to specific buildings include air quality diagnosis, weatherization, smoke control, and pressure balancing for lab-hood safety. Research applications may involve energy and air quality impacts of infiltration, ventilation, and development of associated standards. The benefits of these applications are not being fully realized because of uncertainties in model inputs. An economical test method that is as accurate but less intrusive and faster than incremental or component-by-component blower door testing is needed. Existing methods of measuring inter-zone flows by tracers and flow-pressure network parameters by pressurization tests are reviewed. A method based on simultaneous measurement of all zone pressures within a given control volume and flow measurements on a few selected inter-zonal paths is presented. Flow rates at a subset of flow measuring locations are controlled during testing to take on two or more values. Constrained, nonlinear least squares analysis produces the power law parameters (flow coefficient and exponent) for each set of two-port aggregate flow paths within the topology. Testing cost and effort are reduced by relying mainly on zone pressure measurements and a rich set of HVAC- or blower-door-induced flow-pressure excitation states with relatively few flow measuring stationsements. Results of applying the method to a two-story test building are reported. Potential application to fault detection, acceptance testing, continuous commissioning, smoke dispersion and other problems of building performance and operation are outlined.

  11. Characterization of New PEEK/HA Composites with 3D HA Network Fabricated by Extrusion Freeforming.

    Science.gov (United States)

    Vaezi, Mohammad; Black, Cameron; Gibbs, David M R; Oreffo, Richard O C; Brady, Mark; Moshrefi-Torbati, Mohamed; Yang, Shoufeng

    2016-05-26

    Addition of bioactive materials such as calcium phosphates or Bioglass, and incorporation of porosity into polyetheretherketone (PEEK) has been identified as an effective approach to improve bone-implant interfaces and osseointegration of PEEK-based devices. In this paper, a novel production technique based on the extrusion freeforming method is proposed that yields a bioactive PEEK/hydroxyapatite (PEEK/HA) composite with a unique configuration in which the bioactive phase (i.e., HA) distribution is computer-controlled within a PEEK matrix. The 100% interconnectivity of the HA network in the biocomposite confers an advantage over alternative forms of other microstructural configurations. Moreover, the technique can be employed to produce porous PEEK structures with controlled pore size and distribution, facilitating greater cellular infiltration and biological integration of PEEK composites within patient tissue. The results of unconfined, uniaxial compressive tests on these new PEEK/HA biocomposites with 40% HA under both static and cyclic mode were promising, showing the composites possess yield and compressive strength within the range of human cortical bone suitable for load bearing applications. In addition, preliminary evidence supporting initial biological safety of the new technique developed is demonstrated in this paper. Sufficient cell attachment, sustained viability in contact with the sample over a seven-day period, evidence of cell bridging and matrix deposition all confirmed excellent biocompatibility.

  12. Characterization of New PEEK/HA Composites with 3D HA Network Fabricated by Extrusion Freeforming

    Directory of Open Access Journals (Sweden)

    Mohammad Vaezi

    2016-05-01

    Full Text Available Addition of bioactive materials such as calcium phosphates or Bioglass, and incorporation of porosity into polyetheretherketone (PEEK has been identified as an effective approach to improve bone-implant interfaces and osseointegration of PEEK-based devices. In this paper, a novel production technique based on the extrusion freeforming method is proposed that yields a bioactive PEEK/hydroxyapatite (PEEK/HA composite with a unique configuration in which the bioactive phase (i.e., HA distribution is computer-controlled within a PEEK matrix. The 100% interconnectivity of the HA network in the biocomposite confers an advantage over alternative forms of other microstructural configurations. Moreover, the technique can be employed to produce porous PEEK structures with controlled pore size and distribution, facilitating greater cellular infiltration and biological integration of PEEK composites within patient tissue. The results of unconfined, uniaxial compressive tests on these new PEEK/HA biocomposites with 40% HA under both static and cyclic mode were promising, showing the composites possess yield and compressive strength within the range of human cortical bone suitable for load bearing applications. In addition, preliminary evidence supporting initial biological safety of the new technique developed is demonstrated in this paper. Sufficient cell attachment, sustained viability in contact with the sample over a seven-day period, evidence of cell bridging and matrix deposition all confirmed excellent biocompatibility.

  13. Characterization of the proneural gene regulatory network during mouse telencephalon development

    Directory of Open Access Journals (Sweden)

    Parker Joel S

    2008-03-01

    Full Text Available Abstract Background The proneural proteins Mash1 and Ngn2 are key cell autonomous regulators of neurogenesis in the mammalian central nervous system, yet little is known about the molecular pathways regulated by these transcription factors. Results Here we identify the downstream effectors of proneural genes in the telencephalon using a genomic approach to analyze the transcriptome of mice that are either lacking or overexpressing proneural genes. Novel targets of Ngn2 and/or Mash1 were identified, such as members of the Notch and Wnt pathways, and proteins involved in adhesion and signal transduction. Next, we searched the non-coding sequence surrounding the predicted proneural downstream effector genes for evolutionarily conserved transcription factor binding sites associated with newly defined consensus binding sites for Ngn2 and Mash1. This allowed us to identify potential novel co-factors and co-regulators for proneural proteins, including Creb, Tcf/Lef, Pou-domain containing transcription factors, Sox9, and Mef2a. Finally, a gene regulatory network was delineated using a novel Bayesian-based algorithm that can incorporate information from diverse datasets. Conclusion Together, these data shed light on the molecular pathways regulated by proneural genes and demonstrate that the integration of experimentation with bioinformatics can guide both hypothesis testing and hypothesis generation.

  14. Characterizing two-phase flow relative permeabilities in chemicalflooding using a pore-scale network model

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Qingjie; Shen, Pingping; Wu, Yu-Shu

    2004-03-15

    A dynamic pore-scale network model is presented for investigating the effects of interfacial tension and oil-water viscosity on relative permeability during chemical flooding. This model takes into account both viscous and capillary forces in analyzing the impact of chemical properties on flow behavior or displacement configuration, as opposed to the conventional or invasion percolation algorithm which incorporates capillary pressure only. The study results indicate that both water and oil relative-permeability curves are dependent strongly on interfacial tension as well as an oil-water viscosity ratio. In particular, water and oil relative-permeability curves are both found to shift upward as interfacial tension is reduced, and they both tend to become linear versus saturation once interfacial tension is at low values. In addition, the oil-water viscosity ratio appears to have only a small effect under conditions of high interfacial tension. When the interfacial tension is low, however, water relative permeability decreases more rapidly (with the increase in the aqueous-phase viscosity) than oil relative permeability. The breakthrough saturation of the aqueous phase during chemical flooding tends to decrease with the reduction of interfacial tension and may also be affected by the oil-water viscosity ratio.

  15. Using deep belief network modelling to characterize differences in brain morphometry in schizophrenia

    Science.gov (United States)

    Pinaya, Walter H. L.; Gadelha, Ary; Doyle, Orla M.; Noto, Cristiano; Zugman, André; Cordeiro, Quirino; Jackowski, Andrea P.; Bressan, Rodrigo A.; Sato, João R.

    2016-12-01

    Neuroimaging-based models contribute to increasing our understanding of schizophrenia pathophysiology and can reveal the underlying characteristics of this and other clinical conditions. However, the considerable variability in reported neuroimaging results mirrors the heterogeneity of the disorder. Machine learning methods capable of representing invariant features could circumvent this problem. In this structural MRI study, we trained a deep learning model known as deep belief network (DBN) to extract features from brain morphometry data and investigated its performance in discriminating between healthy controls (N = 83) and patients with schizophrenia (N = 143). We further analysed performance in classifying patients with a first-episode psychosis (N = 32). The DBN highlighted differences between classes, especially in the frontal, temporal, parietal, and insular cortices, and in some subcortical regions, including the corpus callosum, putamen, and cerebellum. The DBN was slightly more accurate as a classifier (accuracy = 73.6%) than the support vector machine (accuracy = 68.1%). Finally, the error rate of the DBN in classifying first-episode patients was 56.3%, indicating that the representations learned from patients with schizophrenia and healthy controls were not suitable to define these patients. Our data suggest that deep learning could improve our understanding of psychiatric disorders such as schizophrenia by improving neuromorphometric analyses.

  16. Synthesis and characterization of ionic polymer networks in a room-temperature ionic liquid.

    Science.gov (United States)

    Stanzione, Joseph F; Jensen, Robert E; Costanzo, Philip J; Palmese, Giuseppe R

    2012-11-01

    Ionic liquid gels (ILGs) for potential use in ion transport and separation applications were generated via a free radical copolymerization of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) and N,N'-methylene(bis)acrylamide (MBA) using 1-ethyl-3-methylimidazolium ethylsulfate (IL) as a room temperature ionic liquid solvent medium. The AMPS and MBA monomer solubility window in the IL in the temperature range of 25 to 65 °C was determined. In situ ATR-FTIR showed near complete conversion of monomers to a cross-linked polymer network. ILGs with glass transition temperatures (T(g)s) near -50 °C were generated with T(g) decreasing with increasing IL content. The elastic moduli in compression (200 to 6600 kPa) decreased with increasing IL content and increasing AMPS content while the conductivities (0.35 to 2.14 mS cm⁻¹) increased with increasing IL content and decreasing MBA content. The polymer-IL interaction parameter (χ) (0.48 to 0.55) was determined via a modified version of the Bray and Merrill equation.

  17. Network films of conducting polymer-linked polyoxometalate-modified gold nanoparticles: Preparation and electrochemical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, Andrzej Z. [Department of Chemistry, University of Warsaw, Pasteura 1, PL-02-093 Warsaw (Poland); Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056 (United States); Zoladek, Sylwia [Department of Chemistry, University of Warsaw, Pasteura 1, PL-02-093 Warsaw (Poland); Wiaderek, Kamila [Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056 (United States); Cox, James A. [Department of Chemistry and Biochemistry, Miami University, Oxford, OH 45056 (United States)], E-mail: coxja@muohio.edu; Kolary-Zurowska, Aneta; Miecznikowski, Krzysztof [Department of Chemistry, University of Warsaw, Pasteura 1, PL-02-093 Warsaw (Poland); Kulesza, Pawel J. [Department of Chemistry, University of Warsaw, Pasteura 1, PL-02-093 Warsaw (Poland)], E-mail: pkulesza@chem.uw.edu.pl

    2008-04-20

    The ability of Keggin-type phosphododecamolybdate (PMo{sub 12}O{sub 40}{sup 3-}, PMo{sub 12}) to undergo chemisorption on solid surfaces (including gold) is explored here to convert (by ligand place-exchange and phase transfer to aqueous solution) the alkanothiolate-modified Au nanoparticles of controlled size (prepared in toluene) into a stable colloidal solution of PMo{sub 12}-protected gold nanoparticles, PMo{sub 12}-AuNPs, the sizes of which are ca. 4-5 nm as determined by transmission electron microscopy. By dip-coating, PMo{sub 12}-AuNPs were assembled on carbon electrode substrates. The step-by-step assembly, by which alternate exposures to the solutions of PMo{sub 12}-AuNPs and either anilinium cations or pyrrole monomers, was utilized to grow in controlled manner hybrid network films in which the negatively charged PMo{sub 12}-AuNP deposits were linked, or electrostatically attracted, by ultra-thin, positively charged conducting polymer (polyaniline or polypyrrole) structures. The three-dimensionally distributed PMo{sub 12}-AuNPs immobilized within the polypyrrole-based composite film exhibited some electrocatalytic reactivity towards reduction of hydrogen peroxide.

  18. Functional and gene network analyses of transcriptional signatures characterizing pre-weaned bovine mammary parenchyma or fat pad uncovered novel inter-tissue signaling networks during development

    Directory of Open Access Journals (Sweden)

    Lewin Harris A

    2010-05-01

    Full Text Available Abstract Background The neonatal bovine mammary fat pad (MFP surrounding the mammary parenchyma (PAR is thought to exert proliferative effects on the PAR through secretion of local modulators of growth induced by systemic hormones. We used bioinformatics to characterize transcriptomics differences between PAR and MFP from ~65 d old Holstein heifers. Data were mined to uncover potential crosstalk through the analyses of signaling molecules preferentially expressed in one tissue relative to the other. Results Over 9,000 differentially expressed genes (DEG; False discovery rate ≤ 0.05 were found of which 1,478 had a ≥1.5-fold difference between PAR and MFP. Within the DEG highly-expressed in PAR vs. MFP (n = 736 we noted significant enrichment of functions related to cell cycle, structural organization, signaling, and DNA/RNA metabolism. Only actin cytoskeletal signaling was significant among canonical pathways. DEG more highly-expressed in MFP vs. PAR (n = 742 belong to lipid metabolism, signaling, cell movement, and immune-related functions. Canonical pathways associated with metabolism and signaling, particularly immune- and metabolism-related were significantly-enriched. Network analysis uncovered a central role of MYC, TP53, and CTNNB1 in controlling expression of DEG highly-expressed in PAR vs. MFP. Similar analysis suggested a central role for PPARG, KLF2, EGR2, and EPAS1 in regulating expression of more highly-expressed DEG in MFP vs. PAR. Gene network analyses revealed putative inter-tissue crosstalk between cytokines and growth factors preferentially expressed in one tissue (e.g., ANGPTL1, SPP1, IL1B in PAR vs. MFP; ADIPOQ, IL13, FGF2, LEP in MFP vs. PAR with DEG preferentially expressed in the other tissue, particularly transcription factors or pathways (e.g., MYC, TP53, and actin cytoskeletal signaling in PAR vs. MFP; PPARG and LXR/RXR Signaling in MFP vs. PAR. Conclusions Functional analyses underscored a reciprocal influence in

  19. Communication Network Architectures Based on Ethernet Passive Optical Network for Offshore Wind Power Farms

    Directory of Open Access Journals (Sweden)

    Mohamed A. Ahmed

    2016-03-01

    Full Text Available Nowadays, with large-scale offshore wind power farms (WPFs becoming a reality, more efforts are needed to maintain a reliable communication network for WPF monitoring. Deployment topologies, redundancy, and network availability are the main items to enhance the communication reliability between wind turbines (WTs and control centers. Traditional communication networks for monitoring and control (i.e., supervisory control and data acquisition (SCADA systems using switched gigabit Ethernet will not be sufficient for the huge amount of data passing through the network. In this paper, the optical power budget, optical path loss, reliability, and network cost of the proposed Ethernet Passive Optical Network (EPON-based communication network for small-size offshore WPFs have been evaluated for five different network architectures. The proposed network model consists of an optical network unit device (ONU deployed on the WT side for collecting data from different internal networks. All ONUs from different WTs are connected to a central optical line terminal (OLT, placed in the control center. There are no active electronic elements used between the ONUs and the OLT, which reduces the costs and complexity of maintenance and deployment. As fiber access networks without any protection are characterized by poor reliability, three different protection schemes have been configured, explained, and discussed. Considering the cost of network components, the total implementation expense of different architectures with, or without, protection have been calculated and compared. The proposed network model can significantly contribute to the communication network architecture for next generation WPFs.

  20. Digital recovery management: Characterizing recovery-specific social network site participation and perceived benefit.

    Science.gov (United States)

    Bergman, Brandon G; Kelly, Nathaniel W; Hoeppner, Bettina B; Vilsaint, Corrie L; Kelly, John F

    2017-06-01

    Research shows that digital social network sites (SNSs) may be valuable platforms to effect health behavior change. Little is known specifically about their ability to help address alcohol and other drug problems. This gap is noteworthy, given that individuals are already participating in existing, recovery-specific SNSs (hereafter referred to as recovery SNSs): online communities with the functionality of conventional SNSs (e.g., Facebook) that focus on substance use disorder (SUD) recovery. For example, InTheRooms.com (ITR) is a large, well-known recovery SNS that is available for free 24 hr/day via website and mobile smartphone applications. It offers recovery tools within a digital social milieu for over 430,000 registered users. To augment the knowledge base on recovery SNS platforms, we conducted an online survey of 123 ITR participants (M = 50.8 years old; 56.9% female; 93.5% White; M = 7.3 years of abstinence, range of 0-30 years; 65% cited alcohol as their primary substance). Respondents engaged with ITR, on average, for about 30 min/day several times each week. Daily meditation prompts and live online video meetings were the most commonly utilized resources. Participants generally endorsed ITR as a helpful platform, particularly with respect to increased abstinence/recovery motivation and self-efficacy. Compared to individuals abstinent for 1 or more years, those abstinent less than 1 year (including nonabstinent individuals) showed similar rates of engagement with ITR activities and similar levels of perceived benefit. Our findings suggest that longitudinal studies are warranted to examine the clinical utility of ITR and other recovery SNSs as SUD treatment adjuncts and/or recovery self-management tools. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  1. GPS receiver phase biases estimable in PPP-RTK networks: dynamic characterization and impact analysis

    Science.gov (United States)

    Zhang, Baocheng; Liu, Teng; Yuan, Yunbin

    2017-11-01

    The integer ambiguity resolution enabled precise point positioning (PPP-RTK) has been proven advantageous in a wide range of applications. The realization of PPP-RTK concerns the isolation of satellite phase biases (SPBs) and other corrections from a network of Global Positioning System (GPS) reference receivers. This is generally based on Kalman filter in order to achieve real-time capability, in which proper modeling of the dynamics of various types of unknowns remains crucial. This paper seeks to gain insight into how to reasonably deal with the dynamic behavior of the estimable receiver phase biases (RPBs). Using dual-frequency GPS data collected at six colocated receivers over days 50-120 of 2015, we analyze the 30-s epoch-by-epoch estimates of L1 and wide-lane (WL) RPBs for each receiver pair. The dynamics observed in these estimates are a combined effect of three factors, namely the random measurement noise, the multipath and the ambient temperature. The first factor can be overcome by turning to a real-time filter and the second by considering the use of a sidereal filtering. The third factor has an effect only on the WL, and this effect appears to be linear. After accounting for these three factors, the low-pass-filtered, sidereal-filtered, epoch-by-epoch estimates of L1 RPBs follow a random walk process, whereas those of WL RPBs are constant over time. Properly modeling the dynamics of RPBs is vital, as it ensures the best convergence of the Kalman-filtered, between-satellite single-differenced SPB estimates to their correct values and, in turn, shortens the time-to-first-fix at user side.

  2. ACCOUNTING OF REACTIVE POWER COMPENSATION LEVEL AT PAYMENT CALCULATION OF TECHNOLOGICAL CONSUMPTION (LOSSES OF ELECTRIC POWER FOR ITS TRANSMISSION IN POWER NETWORK

    Directory of Open Access Journals (Sweden)

    E. P. Zabello

    2005-01-01

    Full Text Available The method is proposed to make a correction in payment for consumption of reactive energy and power which is attributed to deviation of actual activation energy losses for reactive power compensation from their standard value. It is recommended to calculate standard loss values for every voltage level and actual loss values are to be determined with the help of application of remote electronic accounting means in the current mode of power consumption.

  3. A Study Using a Monte Carlo Method of the Optimal Configuration of a Distribution Network in Terms of Power Loss Sensing

    Science.gov (United States)

    Moon, Hyun Ho; Lee, Jong Joo; Choi, Sang Yule; Cha, Jae Sang; Kang, Jang Mook; Kim, Jong Tae; Shin, Myong Chul

    2011-01-01

    Recently there have been many studies of power systems with a focus on “New and Renewable Energy” as part of “New Growth Engine Industry” promoted by the Korean government. “New And Renewable Energy”—especially focused on wind energy, solar energy and fuel cells that will replace conventional fossil fuels—is a part of the Power-IT Sector which is the basis of the SmartGrid. A SmartGrid is a form of highly-efficient intelligent electricity network that allows interactivity (two-way communications) between suppliers and consumers by utilizing information technology in electricity production, transmission, distribution and consumption. The New and Renewable Energy Program has been driven with a goal to develop and spread through intensive studies, by public or private institutions, new and renewable energy which, unlike conventional systems, have been operated through connections with various kinds of distributed power generation systems. Considerable research on smart grids has been pursued in the United States and Europe. In the United States, a variety of research activities on the smart power grid have been conducted within EPRI’s IntelliGrid research program. The European Union (EU), which represents Europe’s Smart Grid policy, has focused on an expansion of distributed generation (decentralized generation) and power trade between countries with improved environmental protection. Thus, there is current emphasis on a need for studies that assesses the economic efficiency of such distributed generation systems. In this paper, based on the cost of distributed power generation capacity, calculations of the best profits obtainable were made by a Monte Carlo simulation. Monte Carlo simulations that rely on repeated random sampling to compute their results take into account the cost of electricity production, daily loads and the cost of sales and generate a result faster than mathematical computations. In addition, we have suggested the optimal

  4. A Study Using a Monte Carlo Method of the Optimal Configuration of a Distribution Network in Terms of Power Loss Sensing

    Directory of Open Access Journals (Sweden)

    Jae Sang Cha

    2011-08-01

    Full Text Available Recently there have been many studies of power systems with a focus on “New and Renewable Energy” as part of “New Growth Engine Industry” promoted by the Korean government. “New And Renewable Energy”—especially focused on wind energy, solar energy and fuel cells that will replace conventional fossil fuels—is a part of the Power-IT Sector which is the basis of the SmartGrid. A SmartGrid is a form of highly-efficient intelligent electricity network that allows interactivity (two-way communications between suppliers and consumers by utilizing information technology in electricity production, transmission, distribution and consumption. The New and Renewable Energy Program has been driven with a goal to develop and spread through intensive studies, by public or private institutions, new and renewable energy which, unlike conventional systems, have been operated through connections with various kinds of distributed power generation systems. Considerable research on smart grids has been pursued in the United States and Europe. In the United States, a variety of research activities on the smart power grid have been conducted within EPRI's IntelliGrid research program. The European Union (EU, which represents Europe’s Smart Grid policy, has focused on an expansion of distributed generation (decentralized generation and power trade between countries with improved environmental protection. Thus, there is current emphasis on a need for studies that assesses the economic efficiency of such distributed generation systems. In this paper, based on the cost of distributed power generation capacity, calculations of the best profits obtainable were made by a Monte Carlo simulation. Monte Carlo simulations that rely on repeated random sampling to compute their results take into account the cost of electricity production, daily loads and the cost of sales and generate a result faster than mathematical computations. In addition, we have suggested

  5. EEG-MEG Integration Enhances the Characterization of Functional and Effective Connectivity in the Resting State Network

    Science.gov (United States)

    Mideksa, Kidist Gebremariam; Anwar, Abdul Rauf; Stephani, Ulrich; Deuschl, Günther; Freitag, Christine M.; Siniatchkin, Michael

    2015-01-01

    At the sensor level many aspects, such as spectral power, functional and effective connectivity as well as relative-power-ratio ratio (RPR) and spatial resolution have been comprehensively investigated through both electroencephalography (EEG) and magnetoencephalography (MEG). Despite this, differences between both modalities have not yet been systematically studied by direct comparison. It remains an open question as to whether the integration of EEG and MEG data would improve the information obtained from the above mentioned parameters. Here, EEG (64-channel system) and MEG (275 sensor system) were recorded simultaneously in conditions with eyes open (EO) and eyes closed (EC) in 29 healthy adults. Spectral power, functional and effective connectivity, RPR, and spatial resolution were analyzed at five different frequency bands (delta, theta, alpha, beta and gamma). Networks of functional and effective connectivity were described using a spatial filter approach called the dynamic imaging of coherent sources (DICS) followed by the renormalized partial directed coherence (RPDC). Absolute mean power at the sensor level was significantly higher in EEG than in MEG data in both EO and EC conditions. At the source level, there was a trend towards a better performance of the combined EEG+MEG analysis compared with separate EEG or MEG analyses for the source mean power, functional correlation, effective connectivity for both EO and EC. The network of coherent sources and the spatial resolution were similar for both the EEG and MEG data if they were analyzed separately. Results indicate that the combined approach has several advantages over the separate analyses of both EEG and MEG. Moreover, by a direct comparison of EEG and MEG, EEG was characterized by significantly higher values in all measured parameters in both sensor and source level. All the above conclusions are specific to the resting state task and the specific analysis used in this study to have general

  6. Proteomics-based network analysis characterizes biological processes and pathways activated by preconditioned mesenchymal stem cells in cardiac repair mechanisms.

    Science.gov (United States)

    Di Silvestre, Dario; Brambilla, Francesca; Scardoni, Giovanni; Brunetti, Pietro; Motta, Sara; Matteucci, Marco; Laudanna, Carlo; Recchia, Fabio A; Lionetti, Vincenzo; Mauri, Pierluigi

    2017-05-01

    We have demonstrated that intramyocardial delivery of human mesenchymal stem cells preconditioned with a hyaluronan mixed ester of butyric and retinoic acid (MSCp+) is more effective in preventing the decay of regional myocardial contractility in a swine model of myocardial infarction (MI). However, the understanding of the role of MSCp+ in proteomic remodeling of cardiac infarcted tissue is not complete. We therefore sought to perform a comprehensive analysis of the proteome of infarct remote (RZ) and border zone (BZ) of pigs treated with MSCp+ or unconditioned stem cells. Heart tissues were analyzed by MudPIT and differentially expressed proteins were selected by a label-free approach based on spectral counting. Protein profiles were evaluated by using PPI networks and their topological analysis. The proteomic remodeling was largely prevented in MSCp+ group. Extracellular proteins involved in fibrosis were down-regulated, while energetic pathways were globally up-regulated. Cardioprotectant pathways involved in the production of keto acid metabolites were also activated. Additionally, we found that new hub proteins support the cardioprotective phenotype characterizing the left ventricular BZ treated with MSCp+. In fact, the up-regulation of angiogenic proteins NCL and RAC1 can be explained by the increase of capillary density induced by MSCp+. Our results show that angiogenic pathways appear to be uniquely positioned to integrate signaling with energetic pathways involving cardiac repair. Our findings prompt the use of proteomics-based network analysis to optimize new approaches preventing the post-ischemic proteomic remodeling that may underlie the limited self-repair ability of adult heart. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Functional characterization of FLT3 receptor signaling deregulation in acute myeloid leukemia by single cell network profiling (SCNP.

    Directory of Open Access Journals (Sweden)

    David B Rosen

    Full Text Available BACKGROUND: Molecular characterization of the FMS-like tyrosine kinase 3 receptor (FLT3 in cytogenetically normal acute myeloid leukemia (AML has recently been incorporated into clinical guidelines based on correlations between FLT3 internal tandem duplications (FLT3-ITD and decreased disease-free and overall survival. These mutations result in constitutive activation of FLT3, and FLT3 inhibitors are currently undergoing trials in AML patients selected on FLT3 molecular status. However, the transient and partial responses observed suggest that FLT3 mutational status alone does not provide complete information on FLT3 biological activity at the individual patient level. Examination of variation in cellular responsiveness to signaling modulation may be more informative. METHODOLOGY/PRINCIPAL FINDINGS: Using single cell network profiling (SCNP, cells were treated with extracellular modulators and their functional responses were quantified by multiparametric flow cytometry. Intracellular signaling responses were compared between healthy bone marrow myeloblasts (BMMb and AML leukemic blasts characterized as FLT3 wild type (FLT3-WT or FLT3-ITD. Compared to healthy BMMb, FLT3-WT leukemic blasts demonstrated a wide range of signaling responses to FLT3 ligand (FLT3L, including elevated and sustained PI3K and Ras/Raf/Erk signaling. Distinct signaling and apoptosis profiles were observed in FLT3-WT and FLT3-ITD AML samples, with more uniform signaling observed in FLT3-ITD AML samples. Specifically, increased basal p-Stat5 levels, decreased FLT3L induced activation of the PI3K and Ras/Raf/Erk pathways, decreased IL-27 induced activation of the Jak/Stat pathway, and heightened apoptotic responses to agents inducing DNA damage were observed in FLT3-ITD AML samples. Preliminary analysis correlating these findings with clinical outcomes suggests that classification of patient samples based on signaling profiles may more accurately reflect FLT3 signaling

  8. Determination of temperate bird-flower interactions as entangled mutualistic and antagonistic sub-networks: characterization at the network and species levels.

    Science.gov (United States)

    Yoshikawa, Tetsuro; Isagi, Yuji

    2014-05-01

    Most network studies on biological interactions consider only a single interaction type. However, individual species are simultaneously positioned in various types of interactions. The ways in which different network types are merged and entangled, and the variations in network structures between different sympatric networks, require full elucidation. Incorporating interaction types and disentangling complex networks is crucial, because the integration of various network architectures has the potential to alter the stability and co-evolutionary dynamics of the whole network. To reveal how different types of interaction networks are entangled, we focused on the interaction between birds and flowers of temperate plants in Japan, where flower-feeding birds are mainly generalist passerines, acting as pollinators and predators of flowers. Using long-term monitoring data, we investigated the flower-feeding episodes of birds. We constructed the whole network (WN) between birds and plants, separating the network into mutualistic and antagonistic sub-networks (MS and AS, respectively). We investigated structural properties of the three quantified networks and species-level characteristics of the main bird species. For bird species, we evaluated dietary similarity, dietary specialization and shifts of feeding behaviour relative to plant traits. Our results indicate that WN comprises entangled MS and AS, sharing considerable proportions of bird and plant assemblages. We observed distinctive differences in the network structural properties between the two sub-networks. In comparison with AS, MS had lower numbers of bird and plant species, showed lower specialization and modularity and exhibited higher nestedness. At the species level, the Japanese white-eye acted as pollinator, while the brown-eared bulbul acted as both pollinator and predator for large numbers of flowers, based on its behavioural plasticity. Overall, the pattern of avian feeding behaviour was influenced by

  9. Characterization of the semi-interpenetrated network based on collagen and poly(N-isopropyl acrylamide-co-diethylene glycol diacrylate).

    Science.gov (United States)

    Nistor, Manuela T; Chiriac, Aurica P; Nita, Loredana E; Vasile, Cornelia

    2013-08-16

    The study is devoted to the characterization of the semi-interpenetrating polymeric network (semi-IPN) structures, prepared as dual sensitive networks, based on poly(N-isopropyl acrylamide-co-diethylene glycol diacrylate) inserted into a collagen porous membrane with potential biomedical-applications. The pharmaceutical applications are related to the possibility of using the semi-synthetic networks for inclusion, retention, transportation and release of drug molecules. The insertion and the homogeneity distribution of the drug into the polymeric network were evaluated by near infrared-chemical imaging (NIR-CI) technique. The drug release was investigated from the kinetically viewpoint in simulated biological environment by using UV-vis spectrophotometric technique. The zeta potential measurement results showed meaningful change of the electric potential of the network surface at the interfacial double layer with the environment in the interdependence with the network composition and environment characteristics. The biodegradable character of the semi-synthetic network, also presented, undergoes with tissue engineering request for achievement of tissue substituents. Texture analysis of the semi-IPN was realized in order to evidence the potential applications of the prepared compounds in tissue engineering. The adhesion properties reveal the possibility to control the surface adhesion by: network composition, the ratio between the polymer types, and the crosslinking degree of polymeric networks. The evaluation of the semi-IPN characteristics in medical terms, concerned the surface electrical charge, the loading, retention and release properties of an active compound, the adhesion properties and the effect of collagenase enzyme over the collagen fibres as component in semi-IPN, and from the pharmaceutical terms emphasizes the potential applications of the new polymeric semi-IPN networks. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. A Bayesian network and heuristic approach for systematic characterization of radiotherapy receipt after breast-conservation surgery.

    Science.gov (United States)

    Soto-Ferrari, Milton; Prieto, Diana; Munene, Gitonga

    2017-06-28

    Breast-conservation surgery with radiotherapy is a treatment highly recommended by the guidelines from the National Comprehensive Cancer Network. However, several variables influence the final receipt of radiotherapy and it might not be administered to breast cancer patients. Our objective is to propose a systematic framework to identify the clinical and non-clinical variables that influence the receipt of unexpected radiotherapy treatment by means of Bayesian networks and a proposed heuristic approach. We used cancer registry data of Detroit, San Francisco-Oakland, and Atlanta from years 2007-2012 downloaded from the Surveillance, Epidemiology, and End Results Program. The samples had patients diagnosed with in situ and early invasive cancer with 14 clinical and non-clinical variables. Bayesian networks were fitted to the data of each region and systematically analyzed through the proposed Zoom-in heuristic. A comparative analysis with logistic regressions is also presented. For Detroit, patients under stage 0, grade undetermined, histology lobular carcinoma in situ, and age between 26-50 were found more likely to receive breast-conservation surgery without radiotherapy. For stages I, IIA, and IIB patients with age between 51-75, and grade II were found to be more likely to receive breast-conservation surgery with radiotherapy. For San Francisco-Oakland, patients under stage 0, grade undetermined, and age >75 are more likely to receive BCS. For stages I, IIA, and IIB patients with age >75 are more likely to receive breast-conservation surgery without radiotherapy. For Atlanta, patients under stage 0, grade undetermined, year 2011, and primary site C509 are more likely to receive breast-conservation surgery without radiotherapy. For stages I, IIA, and IIB patients in year 2011, and grade III are more likely to receive breast-conservation surgery without radiotherapy. For in situ breast cancer and early invasive breast cancer, the results are in accordance with the

  11. Memory loss

    Science.gov (United States)

    ... amnesia (sudden, temporary loss of memory) of unclear cause Transient ischemic attack (TIA) or stroke Hydrocephalus (fluid collection in the brain) Sometimes, memory loss occurs with mental health problems, such as: After a major, traumatic or stressful ...

  12. Hair Loss

    Science.gov (United States)

    ... overall hair thinning and not bald patches. Full-body hair loss. Some conditions and medical treatments, such as ... in the loss of hair all over your body. The hair usually grows back. Patches of scaling that spread ...

  13. Initial Characterization of Osteoblast Differentiation and Loss of RUNX2 Stability in the Newly Established SK11 Human Embryonic Stem Cell-Derived Cell Line

    Science.gov (United States)

    YU, JIA-LI; ADISETIYO, HELTY; LITTLE, GILLIAN H.; VANGSNESS, C. THOMAS; JIANG, JIANJIE; STERNBERG, HAL; WEST, MICHAEL D.; FRENKEL, BARUCH

    2018-01-01

    We describe a novel model for investigation of genetically normal human osteoblasts in culture. SK11 is a clonal progenitor cell line derived from human embryonic stem cells. Initially selected based on the expression of chondrogenic markers when differentiated in micromass culture, SK11 cells display typical mRNA expression patterns of bone phenotypic genes under osteogenic conditions. These include osterix, α1(I) collagen, alkaline phosphatase, osteonectin, osteopontin, and osteocalcin. Similar to well-characterized murine osteoblast cultures, the osteoblast master regulator RUNX2 was present during the first few days after plating, but the protein disappeared during the first week of culture. Loss of RUNX2 expression is considered an important regulatory feature for osteoblast maturation. Indeed, following ~2 weeks of differentiation, SK11 cultures exhibited robust calcium deposition, evidenced by alizarin red staining. We also introduced a lentiviral vector encoding doxycycline (dox)-inducible FLAG-tagged RUNX2 into SK11 cells. Dox-mediated enhancement of RUNX2 expression resulted in accelerated mineralization, which was further increased by co-treatment with BMP-2. Like the endogenous RUNX2, expression of the virally coded FLAG-RUNX2 was lost during the first week of culture despite persistent dox treatment. By following RUNX2 decay after dox withdrawal from day-5 versus day-3 cultures, we demonstrated a developmentally regulated decrease in RUNX2 stability. Availability of culture models for molecular investigation of genetically normal human osteoblasts is important because differences between murine and human osteoblasts, demonstrated here by the regulation of matrix Gla Protein, may have significant biomedical implications. PMID:25160731

  14. Experiencing Loss

    DEFF Research Database (Denmark)

    Kristiansen, Maria; Younis, Tarek; Hassani, Amani

    2015-01-01

    , who narrates her experience of losing herhusband to lung cancer. By drawing on a religious framework, Aisha creates meaning fromher loss, which enables her to incorporate this loss into her life history and sustain agency.Her narrative invites wider audiences to witness her tale of overcoming loss...

  15. Microstructural Characterization of Dislocation Networks During Harper-Dorn Creep of fcc, bcc, and hcp Metals and Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Przystupa, Marek A.

    2007-12-13

    Harper-Dorn (H-D) creep is observed in metals and geological materials exposed to very low stresses at temperatures close to the melting point. It is one of several types of creep processes wherein the steady-state strain rate is proportional to the applied stress, Nabarro-Herring creep and Coble creep being two other important processes. H-D creep can be somewhat insidious because the creep rates are much larger than those expected for Nabarro-Herring or Coble creep. Since the working conditions of structural components of power plants and propulsion systems, as well as the motion of the earth’s mantle all involve very low stresses, an understanding of the factors controlling H-D creep is critical in preventing failures associated with those higher-than-expected creep rates. The purpose of this investigation was to obtain missing microstructural information on the evolution of the dislocation structures during static annealing of materials with fcc, bcc and hcp structure and use obtained results to test predictive capabilities of the dislocation network theory of H-D creep. In our view the evolutionary processes during static annealing and during Harper-Dorn creep are intimately related. The materials used in this study were fcc aluminum, hcp zinc and bcc tin. All characterizations of dislocation structures, densities and dislocation link length distributions were carried out using the etch pit method. To obtain quantitative information on the evolution of the dislocation networks during annealing the pure fcc aluminum samples were pre-deformed by creep at 913 and 620 K and then annealed. The higher deformation temperature was selected to generate starting dislocation networks similar to those forming during Harper-Dorn creep and the lower, to obtain higher dislocation densities suitable for reliable estimates of the parameters of the network growth law. The measured experimental link length distribution were, after scaling, (1) the same for all annealing

  16. A Study on the Rate of Events and Water Loss in Water Distribution Network of Azna, Lorstan, Iran during 2008-2014 and Its Associated Factors

    Directory of Open Access Journals (Sweden)

    Mohammad Adeli

    2016-12-01

    Full Text Available Introduction and purpose: One of the problems of water distribution systems is loss of large volumes of water due to the occurrence of various events, which incurs a huge financial loss. Regarding this, the aim of the present study was to investigate the rate of events and water loss in the water distribution system and its related factors in Azna, Lorestan province, Iran, during 2008-2014. Methods: This cross-sectional study was conducted using census method, surveys, and field data collection. The amount of water production and consumption, the volumes of water loss, the number of accidents, type of pipe, pressure zone, as well as the age and length of the pipes recorded during 2008- 2014 were studied and analyzed. Results: According to the results, the highest (34.48% and lowest (20.57% amount of water losses happened in 2008 and 2014, respectively. High pressures in water systems had significant relationship with the number of events as well as the amount of water loss and water consumption. In addition, higher length and age of the pipes had a direct correlation with increased number of events and water loss. Furthermore, the maximum number of events were found to occur in the pipe embranchment and galvanized pipes. Conclusion: This study showed that of events was directly related to the length and age of the pipes, the water pressure, and number of branches. Also water loss quantity can be reduced by applying suitable management techniques in different sections. Furthermore, the water loss can be significantly controlled by taking such measures as reducing the pressure in the high-pressure zones, timely replacement of old and inappropriate pipes, appropriate fixing of the pipes, replacement of the galvanized pipe, and standard implementation of pipes and fittings.

  17. Connections among soil, ground, and surface water chemistries characterize nitrogen loss from an agricultural landscape in the upper Missouri River Basin

    Science.gov (United States)

    Sigler, W. Adam; Ewing, Stephanie A.; Jones, Clain A.; Payn, Robert A.; Brookshire, E. N. Jack; Klassen, Jane K.; Jackson-Smith, Douglas; Weissmann, Gary S.

    2018-01-01

    Elevated nitrate in shallow aquifers is common in agricultural areas and remediation requires an understanding of nitrogen (N) leaching at a variety of spatial scales. Characterization of the drivers of nitrate leaching at the mesoscale level (102-103 km2) is needed to bridge from field-scale observations to the landscape-scale context, allowing informed water resource management decisions. Here we explore patterns in nitrate leaching rates across a depositional landform in the northern Great Plains within the Upper Missouri Basin, where the predominant land use is non-irrigated small grain production, and nitrate-N concentrations above 10 mg L-1 are common. The shallow Moccasin terrace (260 km2) aquifer is bounded in vertical extent by underlying shale and is isolated from mountain front stream recharge, such that aquifer recharge is dominated by infiltration of precipitation through agricultural soils. This configuration presents a simple landform-scale water balance that we leveraged to estimate leaching rates using groundwater nitrate concentrations and surface water discharge, and quantify uncertainty using a Monte Carlo approach based on spatial variation in observations of groundwater nitrate concentrations. A participatory research approach allowed local farmer knowledge of the landscape to be incorporated into the study design, improved selection of and access to sample sites, and enhanced prospects for addressing nitrate leaching through collaborative understanding of system hydrology. Mean landform-scale nitrate-N leaching rates were 11 and 18 kg ha-1 yr-1 during the 2012-2014 study for the two largest catchments draining the terrace. Over a standard three-year crop rotation, these leaching rates represent 19-31% of typical fertilizer N application rates; however, leaching losses are likely derived not only from fertilizer but also from soil organic N mineralization, and are apparently higher during the post-fallow phase of the crop rotation. Groundwater

  18. Characterization of voids formed during liquid impregnation of nonwoven multifilament glass networks as related to composite processing

    Science.gov (United States)

    Mahale, Anant D.; Prudhomme, Robert K.; Rebenfeld, Ludwig

    1993-01-01

    A technique based on matching the refractive index of an invading liquid to that of a fiber mat was used to study entrapment of air ('voids') that occurs during forced in-plane radial flow into nonwoven multifilament glass networks. The usefulness of this technique is demonstrated in quantifying and mapping the air pockets. Experiments with a series of fluids with surface tensions varying from 28 x 10(exp -3) to 36 x 10(exp -3) N/m, viscosities from 45 x 10(exp -3) to 290 x 10(exp -3) Pa.s, and inlet flow rates from 0.15 x 10(exp -6) to 0.75 x 10(exp -6) m(exp 3)/s, showed that void content is a function of the capillary number characterizing the flow process. A critical value of capillary number, Ca = 2.5 x 10(exp -3), identifies a zone below which void content increases exponentially with decreasing capillary number. Above this critical value, negligible entrapment of voids is observed. Similar experiments carried out on surface treated nonwoven mats spanning a range of equilibrium contact angles from 20 deg to 78 deg showed that there is a critical contact angle above which negligible entrapment is observed. Below this value, there is no apparent effect of contact angle on the void fraction - capillary number relationship described earlier. Studies on the effect of filament wettability, and fluid velocity and viscosity on the size of the entrapment (voids) were also carried out. These indicate that larger sized entrapments which envelop more than one pore are favored by a low capillary number in comparison to smaller, pore level bubbles. Experiments were carried out on deformed mats - imposing high permeability spots at regular intervals on a background of low permeability. The effect of these spatial fluctuations in heterogeneity of the mat on entrapment is currently being studied.

  19. on the correctness of load loss factor correctness of load loss factor ...

    African Journals Online (AJOL)

    eobe

    JACOBS ENGINEERING INC/BRUNEL UNIVERSITY LONDON,UNITED KINGDOM ... distribution network involves estimating the active power (MW) losses .... Distribution Network Control Centre, if available, in calculating the LLF. This will ensure a better evaluation of the technical losses in any distribution network. 5.

  20. Electrical responses and spontaneous activity of human iPS-derived neuronal networks characterized for three-month culture with 4096-electrode arrays

    Directory of Open Access Journals (Sweden)

    Hayder eAmin

    2016-03-01

    Full Text Available The recent availability of human induced pluripotent stem cells (hiPSCs holds great promise as a novel source of human-derived neurons for cell and tissue therapies as well as for in vitro drug screenings that might replace the use of animal models. However, there is still a considerable lack of knowledge on the functional properties of hiPSC-derived neuronal networks, thus limiting their application. Here, upon optimization of cell culture protocols, we demonstrate that both spontaneous and evoked electrical spiking activities of these networks can be characterized on-chip by taking advantage of the resolution provided by CMOS multielectrode arrays (CMOS-MEAs. These devices feature a large and closely-spaced array of 4096 simultaneously recording electrodes and multi-site on-chip electrical stimulation. Our results show that networks of human-derived neurons can respond to electrical stimulation with a physiological repertoire of spike waveforms after three months of cell culture, a period of time during which the network undergoes the expression of developing patterns of spontaneous spiking activity. To achieve this, we have investigated the impact on the network formation and on the emerging network-wide functional properties induced by different biochemical substrates, i.e. poly-dl-ornithine (PDLO, poly-l-ornithine (PLO, and polyethylenimine (PEI, that were used as adhesion promoters for the cell culture. Interestingly, we found that neuronal networks grown on PDLO coated substrates show significantly higher spontaneous firing activity, reliable responses to low-frequency electrical stimuli, and an appropriate level of PSD-95 that may denote a physiological neuronal maturation profile and synapse stabilization. However, our results also suggest that even three-month culture might not be sufficient for human-derived neuronal network maturation. Taken together, our results highlight the tight relationship existing between substrate coatings

  1. Electrical Responses and Spontaneous Activity of Human iPS-Derived Neuronal Networks Characterized for 3-month Culture with 4096-Electrode Arrays.

    Science.gov (United States)

    Amin, Hayder; Maccione, Alessandro; Marinaro, Federica; Zordan, Stefano; Nieus, Thierry; Berdondini, Luca

    2016-01-01

    The recent availability of human induced pluripotent stem cells (hiPSCs) holds great promise as a novel source of human-derived neurons for cell and tissue therapies as well as for in vitro drug screenings that might replace the use of animal models. However, there is still a considerable lack of knowledge on the functional properties of hiPSC-derived neuronal networks, thus limiting their application. Here, upon optimization of cell culture protocols, we demonstrate that both spontaneous and evoked electrical spiking activities of these networks can be characterized on-chip by taking advantage of the resolution provided by CMOS multielectrode arrays (CMOS-MEAs). These devices feature a large and closely-spaced array of 4096 simultaneously recording electrodes and multi-site on-chip electrical stimulation. Our results show that networks of human-derived neurons can respond to electrical stimulation with a physiological repertoire of spike waveforms after 3 months of cell culture, a period of time during which the network undergoes the expression of developing patterns of spontaneous spiking activity. To achieve this, we have investigated the impact on the network formation and on the emerging network-wide functional properties induced by different biochemical substrates, i.e., poly-dl-ornithine (PDLO), poly-l-ornithine (PLO), and polyethylenimine (PEI), that were used as adhesion promoters for the cell culture. Interestingly, we found that neuronal networks grown on PDLO coated substrates show significantly higher spontaneous firing activity, reliable responses to low-frequency electrical stimuli, and an appropriate level of PSD-95 that may denote a physiological neuronal maturation profile and synapse stabilization. However, our results also suggest that even 3-month culture might not be sufficient for human-derived neuronal network maturation. Taken together, our results highlight the tight relationship existing between substrate coatings and emerging network

  2. Uplift rates from a new high-density GPS network in Palmer Land indicate significant late Holocene ice loss in the southwestern Weddell Sea

    NARCIS (Netherlands)

    Wolstencroft, M.; King, M.A.; Whitehouse, P.L.; Bentley, M.J.; Nield, G.A.; King, E.C.; McMillan, M.; Shepherd, A.; Barletta, V.; Bordoni, A.; Riva, R.E.M.; Didova, O.; Gunter, B.C.

    2015-01-01

    The measurement of ongoing ice-mass loss and associated melt water contribution to sea-level change from regions such as West Antarctica is dependent on a combination of remote sensing methods. A key method, the measurement of changes in Earth's gravity via the GRACE satellite mission, requires a

  3. Wireless Networks

    OpenAIRE

    Samaka, Mohammed; Khan, Khaled M.D.

    2007-01-01

    Wireless communication is the fastest-growing field in the telecommunication industry. Wireless networks have grown significantly as an important segment of the communications industry. They have become popular networks with the potential to provide high-speed, high-quality information exchange between two or more portable devices without any wire or conductors. Wireless networks can simply be characterized as the technology that provides seamless access to information, anywhere, anyplace, an...

  4. Few-mode fiber, splice and SDM component characterization by spatially-diverse optical vector network analysis

    DEFF Research Database (Denmark)

    Rommel, Simon; Mendinueta, José Manuel Delgado; Klaus, Werner

    2017-01-01

    photonic lantern spatial multiplexer, coupled to a 36-core 3-mode fiber, is experimentally demonstrated, extracting the full impulse response and complex transfer function matrices as well as insertion loss (IL) and mode-dependent loss (MDL) data. Moreover, the mode-mixing behavior of fiber splices...

  5. Intelligent Classification and Visualization of Network Scans

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L; Muelder, C; Ma, K; Bartoletti, A

    2007-03-01

    Network scans are a common first step in a network intrusion attempt. In order to gain information about a potential network intrusion, it is beneficial to analyze these network scans. Statistical methods such as wavelet scalogram analysis have been used along with visualization techniques in previous methods. However, applying these statistical methods to reduce the data causes a substantial amount of data loss. This paper presents a study of using associative memory learning techniques to directly compare network scans in order to create a classification which can be used by itself or in conjunction with existing visualization techniques to better characterize the sources of these scans. This produces an integrated system of visual and intelligent analysis which is applicable to real world data.

  6. Characterization of transcription factor networks involved in umbilical cord blood CD34+ stem cells-derived erythropoiesis.

    Directory of Open Access Journals (Sweden)

    Biaoru Li

    Full Text Available Fetal stem cells isolated from umbilical cord blood (UCB possess a great capacity for proliferation and differentiation and serve as a valuable model system to study gene regulation. Expanded knowledge of the molecular control of hemoglobin synthesis will provide a basis for rational design of therapies for β-hemoglobinopathies. Transcriptome data are available for erythroid progenitors derived from adult stem cells, however studies to define molecular mechanisms controlling globin gene regulation during fetal erythropoiesis are limited. Here, we utilize UCB-CD34+ stem cells induced to undergo erythroid differentiation to characterize the transcriptome and transcription factor networks (TFNs associated with the γ/β-globin switch during fetal erythropoiesis. UCB-CD34+ stem cells grown in the one-phase liquid culture system displayed a higher proliferative capacity than adult CD34+ stem cells. The γ/β-globin switch was observed after day 42 during fetal erythropoiesis in contrast to adult progenitors where the switch occurred around day 21. To gain insights into transcription factors involved in globin gene regulation, microarray analysis was performed on RNA isolated from UCB-CD34+ cell-derived erythroid progenitors harvested on day 21, 42, 49 and 56 using the HumanHT-12 Expression BeadChip. After data normalization, Gene Set Enrichment Analysis identified transcription factors (TFs with significant changes in expression during the γ/β-globin switch. Forty-five TFs were silenced by day 56 (Profile-1 and 30 TFs were activated by day 56 (Profile-2. Both GSEA datasets were analyzed using the MIMI Cytoscape platform, which discovered TFNs centered on KLF4 and GATA2 (Profile-1 and KLF1 and GATA1 for Profile-2 genes. Subsequent shRNA studies in KU812 leukemia cells and human erythroid progenitors generated from UCB-CD34+ cells supported a negative role of MAFB in γ-globin regulation. The characteristics of erythroblasts derived from UCB-CD34

  7. Uplift rates from a new high-density GPS network in Palmer Land indicate significant late Holocene ice loss in the southwestern Weddell Sea

    DEFF Research Database (Denmark)

    Wolstencroft, Martin; King, Matt A.; Whitehouse, Pippa L

    2015-01-01

    The measurement of ongoing ice-mass loss and associated melt water contribution to sea-level change from regions such as West Antarctica is dependent on a combination of remote sensing methods. A key method, the measurement of changes in Earth's gravity via the GRACE satellite mission, requires...... a potentially large correction to account for the isostatic response of the solid Earth to ice-load changes since the Last Glacial Maximum. In this study, we combine glacial isostatic adjustment modelling with a new GPS dataset of solid Earth deformation for the southern Antarctic Peninsula to test the current...... understanding of ice history in this region. A sufficiently complete history of past ice-load change is required for glacial isostatic adjustment models to accurately predict the spatial variation of ongoing solid Earth deformation, once the independently-constrained effects of present-day ice mass loss have...

  8. Illness Severity and Work Productivity Loss Among Working Adults With Medically Attended Acute Respiratory Illnesses: US Influenza Vaccine Effectiveness Network 2012-2013.

    Science.gov (United States)

    Petrie, Joshua G; Cheng, Caroline; Malosh, Ryan E; VanWormer, Jeffrey J; Flannery, Brendan; Zimmerman, Richard K; Gaglani, Manjusha; Jackson, Michael L; King, Jennifer P; Nowalk, Mary Patricia; Benoit, Joyce; Robertson, Anne; Thaker, Swathi N; Monto, Arnold S; Ohmit, Suzanne E

    2016-02-15

    Influenza causes significant morbidity and mortality, with considerable economic costs, including lost work productivity. Influenza vaccines may reduce the economic burden through primary prevention of influenza and reduction in illness severity. We examined illness severity and work productivity loss among working adults with medically attended acute respiratory illnesses and compared outcomes for subjects with and without laboratory-confirmed influenza and by influenza vaccination status among subjects with influenza during the 2012-2013 influenza season. Illnesses laboratory-confirmed as influenza (ie, cases) were subjectively assessed as more severe than illnesses not caused by influenza (ie, noncases) based on multiple measures, including current health status at study enrollment (≤7 days from illness onset) and current activity and sleep quality status relative to usual. Influenza cases reported missing 45% more work hours (20.5 vs 15.0; P productivity as impeded to a greater degree (6.0 vs 5.4; P productivity loss were noted for vaccinated subjects. Influenza illnesses were more severe and resulted in more missed work hours and productivity loss than illnesses not confirmed as influenza. Modest reductions in illness severity for vaccinated cases were observed. These findings highlight the burden of influenza illnesses and illustrate the importance of laboratory confirmation of influenza outcomes in evaluations of vaccine effectiveness. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  9. Characterizing Breast Deformities After Massive Weight Loss: Utilizing the Pittsburgh Rating Scale to Examine Factors Affecting Severity Score and Surgical Decision Making in a Retrospective Series.

    Science.gov (United States)

    Pang, John Henry; Coombs, Demetrius M; James, Isaac; Fishman, Jordan; Rubin, J Peter; Gusenoff, Jeffrey A

    2018-03-01

    Massive weight loss (MWL) can result in variable contour deformities of the breasts. The Pittsburgh Rating Scale (PRS) was designed to describe the multitude of deformities after MWL and recommends operations to consider for surgical improvement. We present the first comprehensive description of breast deformities in a large sample of MWL patients, examine factors affecting the severity of deformities, and report the correlation between PRS score and surgical decision making. A retrospective review of all MWL patients presenting for breast surgery at our institution's Life After Weight Loss program from 2004 to 2015 was performed. Information including demographics, body mass indices (BMIs), method of weight loss, and type of surgical intervention was collected. Preoperative breast photographs were blinded and scored according to the PRS. A total of 204 MWL patients were identified; 26% (53) scored 1, 34% (69) scored 2, and 40% (82) scored 3 on the PRS. Greater deformities were seen after weight loss from bariatric surgery versus diet and exercise alone (P = 0.031), in mastopexy versus augmentation/mastopexy (P = 0.001), and in breast reduction versus augmentation/mastopexy patients (P > 0.0001). Patients who underwent reduction mammaplasty had the greatest maximum BMI compared with other procedures (P = 0.016). The PRS scores were positively correlated to maximum BMI (P < 0.001), delta BMI (P < 0.001), and current BMI (P < 0.001). Massive weight loss patients have variable, and often severe, breast deformities, and the PRS remains a valuable classification tool. Severity scores correlate with BMI, procedure, and weight loss mechanism. Similar scores between mastopexy-only and reduction mammaplasty patients may reflect a composite of personal cosmetic expectations and cost. The PRS scale should also be expanded to include breast reduction as a surgical remedy for PRS grade 3 breast deformities. Understanding breast deformities in this unique population has

  10. Hair Loss

    Science.gov (United States)

    ... to treat acne, bipolar disorder, and ADHD. Diet pills that contain amphetamines also can cause hair loss. Alopecia areata (pronounced: al-uh-PEE-shuh air-ee-AH-tuh) . This skin disease causes hair ...

  11. Methodology and tools for improving competence of a chemical plant characterized by a complex Supply Chain network

    OpenAIRE

    LEOFANTI, GUIDO

    2012-01-01

    Supply chain performance is strongly influenced by its design, chosen architecture, logistic network and types of finished product that made their marketplace. Sometimes environmental reasons like site location due to deals between government administration and companies may cause changes in logical design and hence increase logistic network complexity and become in a strategic Supply Chain constraint. Our case study addresses a geographic place of a chemical manufacturing plant inside i...

  12. Organic Molecules and Network Polymers of Intrinsic Microporosity: Structural Characterization via X-ray Scattering and Simulations

    Science.gov (United States)

    McDermott, Amanda G.; Abbott, Lauren J.; Del Regno, Annalaura; Msayib, Kadhum J.; Ghanem, Bader S.; Taylor, Rupert; Carta, Mariolino; McKeown, Neil B.; Budd, Peter M.; Siperstein, Flor R.; Colina, Coray M.; Runt, James

    2011-03-01

    Like polymers of intrinsic microporosity (PIMs), organic molecules of intrinsic microporosity (OMIMs) are glassy solids featuring a large concentration of pores smaller than 2 nm and large internal surface area as measured by gas sorption experiments. OMIMs are oligomers designed to fill space inefficiently, consisting of several rigid segments joined at one vertex to produce concave faces. Both X-ray scattering patterns and simulations provide insight into the packing geometry and short-range order of these molecules. We also discuss the interpretation of scattering patterns from two- and three-dimensional network PIMs. Supported by NSF/Materials World Network/EPSRC and the NSF Graduate Research Fellowship Program.

  13. Social networks for improving healthy weight loss behaviors for overweight and obese adults: A randomized clinical trial of the social pounds off digitally (Social POD) mobile app.

    Science.gov (United States)

    Hales, Sarah; Turner-McGrievy, Gabrielle M; Wilcox, Sara; Fahim, Arjang; Davis, Rachel E; Huhns, Michael; Valafar, Homayoun

    2016-10-01

    To test the efficacy of a weight loss mobile app based on recommender systems and developed by experts in health promotion and computer science to target social support and self-monitoring of diet, physical activity (PA), and weight (Social POD app), compared to a commercially available diet and PA tracking app (standard). Overweight adults [N=51] were recruited and randomly assigned to either the experimental group [n=26; theory-based podcasts (TBP)+Social POD app] or the comparison group (n=25; TBP+standard app). The Social POD app issued notifications to encourage users to self-monitor and send theory-based messages to support users who had not self-monitored in the previous 48h. Independent samples t-test were used to examine group differences in kilograms lost and change in BMI. Analysis of covariance was used to analyze secondary outcomes while controlling for baseline values. Participant attrition was 12% (n=3 experimental and n=3 comparison). Experimental group participants lost significantly more weight (-5.3kg, CI: -7.5, -3.0) than comparison group (-2.23kg, CI: -3.6, -1.0; d=0.8, r=0.4, p=0.02) and had a greater reduction in BMI (p=0.02). While there were significant differences in positive outcome expectations between groups (p=0.04) other secondary outcomes (e.g., caloric intake and social support) were not significant. Use of the Social POD app resulted in significantly greater weight loss than use of a commercially available tracking app. This mobile health intervention has the potential to be widely disseminated to reduce the risk of chronic disease associated with overweight and obesity. Published by Elsevier Ireland Ltd.

  14. Hair Loss

    Science.gov (United States)

    ... hair if you have certain diseases, such as thyroid problems, diabetes, or lupus. If you take certain medicines or have chemotherapy for cancer, you may also lose your hair. Other causes are stress, a low protein diet, a family history, or poor nutrition. Treatment for hair loss depends ...

  15. Hearing Loss

    Science.gov (United States)

    ... birth defects and other medical conditions run in families, and how they can affect your health and your baby's health. There are ... Too Soon Global Map Premature birth report card Careers Archives ... Family health & safety Complications & Loss Pregnancy complications Preterm labor & ...

  16. Functional characterization of GABAA receptor-mediated modulation of cortical neuron network activity in microelectrode array recordings

    DEFF Research Database (Denmark)

    Bader, Benjamin M; Steder, Anne; Klein, Anders Bue

    2017-01-01

    The numerous γ-aminobutyric acid type A receptor (GABAAR) subtypes are differentially expressed and mediate distinct functions at neuronal level. In this study we have investigated GABAAR-mediated modulation of the spontaneous activity patterns of primary neuronal networks from murine frontal...

  17. Characterization of the CLASP2 Protein Interaction Network Identifies SOGA1 as a Microtubule-Associated Protein

    DEFF Research Database (Denmark)

    Sørensen, Rikke Kruse; Krantz, James; Barker, Natalie

    2017-01-01

    and built a CLASP2 protein network in 3T3-L1 adipocytes. Using two different commercially available antibodies for CLASP2 and an antibody for epitope-tagged, overexpressed CLASP2, we performed multiple affinity purification coupled with mass spectrometry (AP-MS) experiments in combination with label...

  18. Characterization of synthesized NANO-encapsulated drug for bone loss on hind limb suspension rat model by NMR and micro-CT.

    Science.gov (United States)

    Ni, Qingwen; Dixon, Hong; Gutierrez, Gloria; Bi, Long; Qin, Yi-Xian

    2013-06-01

    A formulation of nano-encapsulated enantiomer of (+) promethazine with desired release rate has been synthesized for establish a localized drug delivery system. It was tested on a hind limb suspension (HLS) disuse rat model, and by using a non-destructive Nuclear Magnetic Resonance (NMR) relaxation technique, and micro computed tomography (Micro-CT) analysis technique to qualitatively evaluate the effectiveness of the new bone formations as well as to compare the current commercial anti-bone loss drug Alendeonate. Our studies suggest that nano-encapsulated (+) promethazine in controlled release formulations conjugating bone-targeting functional groups are effective in promoting bone growth in a disuse rat model.

  19. Achievement of Weight Loss and Other Requirements of the Diabetes Prevention and Recognition Program: A National Diabetes Prevention Program Network Based on Nationally Certified Diabetes Self-management Education Programs.

    Science.gov (United States)

    DiBenedetto, Joanna Craver; Blum, Natalie M; O'Brian, Catherine A; Kolb, Leslie E; Lipman, Ruth D

    2016-12-01

    The purpose of this report is (1) to describe the use of the American Association of Diabetes Educators' (AADE's) model of implementation of the National Diabetes Prevention Program through nationally certified diabetes self-management education (DSME) programs and (2) to report the aggregated program outcomes as defined by the Diabetes Prevention and Recognition Program standards of the Centers for Disease Control and Prevention (CDC). In 2012, the AADE worked with the CDC to select 30 certified DSME programs for National Diabetes Prevention Program delivery. For the following 3 years, the AADE continued to work with 25 of the 30 original programs. Results for all CDC recognition standards have been collected from these 25 programs and analyzed as aggregated data over the course of 36 months. At the end of the full-year program, average percentage body weight loss for participants across all 25 programs exceeded the CDC's minimum requirement of 5% weight loss. All programs on average met the CDC requirements for program attendance. Increasing access to the National Diabetes Prevention Program, through an array of networks, including certified DSME programs, will better ensure that people are able to engage in an effective approach to reducing their risk of diabetes. © 2016 The Author(s).

  20. Micro- and nano-X-ray computed-tomography: A step forward in the characterization of the pore network of a leached cement paste

    Energy Technology Data Exchange (ETDEWEB)

    Bossa, Nathan, E-mail: bossanathan@gmail.com [Aix-Marseille Université (AMU), CNRS, IRD, CEREGE UM34, BP 80, 13545 Aix-en-Provence, Cedex 4 (France); INERIS, Parc Technologique Alata, BP2, 60550 Verneuil-en-Halatte (France); iCEINT, CNRS, Duke Univ. International Consortium for the Environmental Implications of Nanotechnology, Aix-en-Provence (France); Chaurand, Perrine [Aix-Marseille Université (AMU), CNRS, IRD, CEREGE UM34, BP 80, 13545 Aix-en-Provence, Cedex 4 (France); iCEINT, CNRS, Duke Univ. International Consortium for the Environmental Implications of Nanotechnology, Aix-en-Provence (France); Vicente, Jérôme [Aix-Marseille Université, CNRS, IUSTI UMR 7343, 13013 Marseille (France); Borschneck, Daniel; Levard, Clément [Aix-Marseille Université (AMU), CNRS, IRD, CEREGE UM34, BP 80, 13545 Aix-en-Provence, Cedex 4 (France); iCEINT, CNRS, Duke Univ. International Consortium for the Environmental Implications of Nanotechnology, Aix-en-Provence (France); Aguerre-Chariol, Olivier [INERIS, Parc Technologique Alata, BP2, 60550 Verneuil-en-Halatte (France); Rose, Jérôme [Aix-Marseille Université (AMU), CNRS, IRD, CEREGE UM34, BP 80, 13545 Aix-en-Provence, Cedex 4 (France); iCEINT, CNRS, Duke Univ. International Consortium for the Environmental Implications of Nanotechnology, Aix-en-Provence (France)

    2015-01-15

    Pore structure of leached cement pastes (w/c = 0.5) was studied for the first time from micro-scale down to the nano-scale by combining micro- and nano-X-ray computed tomography (micro- and nano-CT). This allowed assessing the 3D heterogeneity of the pore network along the cement profile (from the core to the altered layer) of almost the entire range of cement pore size, i.e. from capillary to gel pores. We successfully quantified an increase of porosity in the altered layer at both resolutions. Porosity is increasing from 1.8 to 6.1% and from 18 to 58% at the micro-(voxel = 1.81 μm) and nano-scale (voxel = 63.5 nm) respectively. The combination of both CT allowed to circumvent weaknesses inherent of both investigation scales. In addition the connectivity and the channel size of the pore network were also evaluated to obtain a complete 3D pore network characterization at both scales.

  1. IP, ethernet and MPLS networks resource and fault management

    CERN Document Server

    Perez, André

    2013-01-01

    This book summarizes the key Quality of Service technologies deployed in telecommunications networks: Ethernet, IP, and MPLS. The QoS of the network is made up of two parts: fault and resource management. Network operation quality is among the functions to be fulfilled in order to offer QoS to the end user. It is characterized by four parameters: packet loss, delay, jitter or the variation of delay over time, and availability. Resource management employs mechanisms that enable the first three parameters to be guaranteed or optimized. Fault management aims to ensure continuity of service.

  2. Optimal location of distributed generation for loss minimization in ...

    African Journals Online (AJOL)

    Accurate loss minimization is the critical component for efficient electrical power flow. The introduction of distributed generation (DG) in networks is bound to have significant effect in network losses. Such dispersed generators can reduce distribution system loss by appropriate allocation. With the integration of DG into an ...

  3. Feasibility of real-time soil state and flux characterization for wastewater reuse using an embedded sensor network data assimilation approach

    Science.gov (United States)

    Wu, Che-Chuan; Margulis, Steven A.

    2011-03-01

    SummaryWastewater reuse via irrigation provides the potential for significant increases in water use efficiency; however, excessive solutes from wastewater can pollute the groundwater beneath the irrigated lands. To avoid this adverse impact and provide a mechanism for informing optimal management practices, this study develops a monitoring and modeling system to assimilate embedded sensor network measurements into a hydrologic model to provide real-time soil state and flux estimates. The feasibility of soil characterization with a data assimilation algorithm is investigated through a series of observing system simulation experiments (OSSEs) at a wastewater reuse testbed in Palmdale, California. Results show that state (i.e. soil moisture) estimation in isolation can lead to significant errors if flux estimates are a primary objective of the estimation framework and parameters are not well characterized. Overall, the OSSEs indicate that with sufficient measurement information, the system is capable of providing an accurate characterization of real-time soil state, model parameter, and flux estimates (even in the presence of biases) that could be useful in managing wastewater irrigation to avoid hazardous contamination of the underlying groundwater system.

  4. Comprehensive Power Losses Model for Electronic Power Transformer

    DEFF Research Database (Denmark)

    Yue, Quanyou; Li, Canbing; Cao, Yijia

    2018-01-01

    The electronic power transformer (EPT) has highe rpower losses than the conventional transformer. However, the EPT can correct the power factor, compensate the unbalanced current and reduce the line power losses in the distribution network.Therefore, the higher losses of the EPT and the consequent......-losses and considering the impact of the non-unity power factor and the three-phase unbalanced current, the overall power losses in the distribution network when using the EPT to replace the conventional transformer is analyzed, and the conditions in which the application of the EPT can cause less power losses...... reduced power losses in the distribution network require a comprehensive consideration when comparing the power losses of theEPT and conventional transformer. In this paper, a comprehensive power losses analysis model for the EPT in distribution networks is proposed. By analyzing the EPT self...

  5. Historical photographs revisited: A case study for dating and characterizing recent loss of coral cover on the inshore Great Barrier Reef.

    Science.gov (United States)

    Clark, Tara R; Leonard, Nicole D; Zhao, Jian-Xin; Brodie, Jon; McCook, Laurence J; Wachenfeld, David R; Duc Nguyen, Ai; Markham, Hannah L; Pandolfi, John M

    2016-01-27

    Long-term data with high-precision chronology are essential to elucidate past ecological changes on coral reefs beyond the period of modern-day monitoring programs. In 2012 we revisited two inshore reefs within the central Great Barrier Reef, where a series of historical photographs document a loss of hard coral cover between c.1890-1994 AD. Here we use an integrated approach that includes high-precision U-Th dating specifically tailored for determining the age of extremely young corals to provide a robust, objective characterisation of ecological transition. The timing of mortality for most of the dead in situ corals sampled from the historical photograph locations was found to coincide with major flood events in 1990-1991 at Bramston Reef and 1970 and 2008 at Stone Island. Evidence of some recovery was found at Bramston Reef with living coral genera similar to what was described in c.1890 present in 2012. In contrast, very little sign of coral re-establishment was found at Stone Island suggesting delayed recovery. These results provide a valuable reference point for managers to continue monitoring the recovery (or lack thereof) of coral communities at these reefs.

  6. Characterization of thermal-hydraulic and ignition phenomena in prototypic, full-length boiling water reactor spent fuel pool assemblies after a complete loss-of-coolant accident.

    Energy Technology Data Exchange (ETDEWEB)

    Lindgren, Eric Richard; Durbin, Samuel G

    2007-04-01

    The objective of this project was to provide basic thermal-hydraulic data associated with a SFP complete loss-of-coolant accident. The accident conditions of interest for the SFP were simulated in a full-scale prototypic fashion (electrically-heated, prototypic assemblies in a prototypic SFP rack) so that the experimental results closely represent actual fuel assembly responses. A major impetus for this work was to facilitate code validation (primarily MELCOR) and reduce questions associated with interpretation of the experimental results. It was necessary to simulate a cluster of assemblies to represent a higher decay (younger) assembly surrounded by older, lower-power assemblies. Specifically, this program provided data and analysis confirming: (1) MELCOR modeling of inter-assembly radiant heat transfer, (2) flow resistance modeling and the natural convective flow induced in a fuel assembly as it heats up in air, (3) the potential for and nature of thermal transient (i.e., Zircaloy fire) propagation, and (4) mitigation strategies concerning fuel assembly management.

  7. Characterization of mutations and loss of heterozygosity of p53 and K-ras2 in pancreatic cancer cell lines by immobilized polymerase chain reaction

    Directory of Open Access Journals (Sweden)

    Edwards Jeremy

    2003-07-01

    Full Text Available Abstract Background The identification of known mutations in a cell population is important for clinical applications and basic cancer research. In this work an immobilized form of the polymerase chain reaction, referred to as polony technology, was used to detect mutations as well as gene deletions, resulting in loss of heterozygosity (LOH, in cancer cell lines. Specifically, the mutational hotspots in p53, namely codons 175, 245, 248, 249, 273, and 282, and K-ras2, codons 12, 13 and 61, were genotyped in the pancreatic cell line, Panc-1. In addition LOH analysis was also performed for these same two genes in Panc-1 by quantifying the relative gene copy number of p53 and K-ras2. Results Using polony technology, Panc-1 was determined to possess only one copy of p53, which possessed a mutation in codon 273, and two copies of K-ras2, one wildtype and one with a mutation in codon 12. To further demonstrate the general approach of this method, polonies were also used to detect K-ras2 mutations in the pancreatic cell lines, AsPc-1 and CAPAN-1. Conclusions In conclusion, we have developed an assay that can detect mutations in hotspots of p53 and K-ras2 as well as diagnose LOH in these same genes.

  8. Atmosphere Impact Losses

    Science.gov (United States)

    Schlichting, Hilke E.; Mukhopadhyay, Sujoy

    2018-02-01

    Determining the origin of volatiles on terrestrial planets and quantifying atmospheric loss during planet formation is crucial for understanding the history and evolution of planetary atmospheres. Using geochemical observations of noble gases and major volatiles we determine what the present day inventory of volatiles tells us about the sources, the accretion process and the early differentiation of the Earth. We further quantify the key volatile loss mechanisms and the atmospheric loss history during Earth's formation. Volatiles were accreted throughout the Earth's formation, but Earth's early accretion history was volatile poor. Although nebular Ne and possible H in the deep mantle might be a fingerprint of this early accretion, most of the mantle does not remember this signature implying that volatile loss occurred during accretion. Present day geochemistry of volatiles shows no evidence of hydrodynamic escape as the isotopic compositions of most volatiles are chondritic. This suggests that atmospheric loss generated by impacts played a major role during Earth's formation. While many of the volatiles have chondritic isotopic ratios, their relative abundances are certainly not chondritic again suggesting volatile loss tied to impacts. Geochemical evidence of atmospheric loss comes from the {}3He/{}^{22}Ne, halogen ratios (e.g., F/Cl) and low H/N ratios. In addition, the geochemical ratios indicate that most of the water could have been delivered prior to the Moon forming impact and that the Moon forming impact did not drive off the ocean. Given the importance of impacts in determining the volatile budget of the Earth we examine the contributions to atmospheric loss from both small and large impacts. We find that atmospheric mass loss due to impacts can be characterized into three different regimes: 1) Giant Impacts, that create a strong shock transversing the whole planet and that can lead to atmospheric loss globally. 2) Large enough impactors (m_{cap} ≳ √{2

  9. Streamflow gains and losses along San Francisquito Creek and characterization of surface-water and ground-water quality, southern San Mateo and northern Santa Clara counties, California, 1996-97

    Science.gov (United States)

    Metzger, Loren F.

    2002-01-01

    -level measurements from nearby wells indicate that the regional water table may coincide with the channel bottom along this reach of San Francisquito Creek, particularly during the winter and early spring when water levels usually reach their maximum. Streamflow losses resumed below the 1200 block of Woodland Avenue, extending downstream to Newell Road. Discharge from a large storm drain between Newell Road and East Bayshore Road may account for the streamflow gains measured between these sites. Streamflow gains were measured between East Bayshore Road and the Palo Alto Municipal Golf Course, but this reach is difficult to characterize because of the probable influence of high tides.Estimated average streamflow losses totaled approximately 1,050 acre-feet per year for the reaches between USGS stream gage 11164500 at Stanford University (upstream of Junipero Serra Boulevard) and the Palo Alto Municipal Golf Course, including approximately 595 acre-feet per year for the 1.8-mile section between San Mateo Drive and Middlefield Road. Approximately 58 percent, or 550 acre-feet, of the total estimated average annual recharge from San Francisquito Creek occurs between the San Mateo Drive and Middlefield Road sites.The chemical composition of San Francisquito Creek water varies as a function of seasonal changes in hydrologic conditions. Measurements of specific conductance indicate that during dry weather and low flow, the dissolved-solids concentrations tends to be high, and during wet weather, the concentration tends to be low owing to dilution by surface water. Compared with water samples from upstream sites at USGS stream gage 11164500 and San Mateo Drive, the samples from the downstream sites at Alma Street and Woodland Avenue had low specific conductance; low concentrations of magnesium, sodium, sulfate, chloride, boron, and total dissolved solids; high nutrient concentrations; and light isotopic compositions indicating that urban runoff constitutes most of the streamflow

  10. Regional Characterization of Tokyo Metropolitan area using a highly-dense seismic network (MeSO-net)

    Science.gov (United States)

    Hirata, Naoshi; Nakagawa, Shigeki; Sakai, Shin'ichi; Panayotopoulos, Yannis; Ishikawa, Masahiro; Ishibe, Takeo; Kimura, Hisanori; Honda, Ryou

    2015-04-01

    We have developed a dense seismic network, MeSO-net (Metropolitan Seismic Observation network), which consists of about 300 seismic stations, since 2007 in the greater Tokyo urban region(Hirata et al., 2009). Using MeSO-net data, we obtain P- and S- wave velocity tomograms (Nakagawa et al., 2010) and Qp, Qs tomograms (Panayotopoulos et al., 2014) which show a clear image of Philippine Sea Plate (PSP) and PAcific Plate (PAP). A depth to the top of PSP, 20 to 30 km beneath northern part of Tokyo bay, is about 10 km shallower than previous estimates based on the hypocenter distribution (Ishida, 1992). Based on elastic wave velocities of rocks and minerals, we constructed a petrologic model. The Vp steps in subducting Izu forearc crust occurs at a depth of 30km (blueschist or greenschist to garnet amphibolite transformation) and a depth of 50km (garnet amphibolite to eclogite transformation). Both temperatures are estimated to be 500 and 600 degree C, respectively. The high Vp/Vs anomaly (>1.9) implies large amounts of fluid H2O released by garnet amphibolite to eclogite dehydration reactions. This study is supported by MEXT Japan under the Special Project for Reducing Vulnerability for Urban Mega Earthquake Disasters.

  11. Characterizing acupuncture de qi in mild cognitive impairment: relations with small-world efficiency of functional brain networks.

    Science.gov (United States)

    Bai, Lijun; Zhang, Ming; Chen, Shangjie; Ai, Lin; Xu, Maosheng; Wang, Dan; Wang, Fei; Liu, Lihua; Wang, Fang; Lao, Lixing

    2013-01-01

    As an intermediate state between normal aging and dementia, mild cognitive impairment (MCI) became a hot topic and early treatments can improve disease prognosis. Acupuncture is shown to have possible effect in improving its cognitive defect. However, the underlying neural mechanism of acupuncture and relations between De Qi and different needling depths are still elusive. The present study aimed to explore how acupuncture can exert effect on the reorganization of MCI and to what extent needling depths, associating with De Qi sensations, can influence the acupuncture effects for MCI treatment. Our results presented that MCI patients exhibited losses of small-world attributes indicated by longer characteristic path lengths and larger clustering coefficients, compared with healthy controls. In addition, acupuncture with deep needling can induce much stronger and a wide range of De Qi sensations both in intensity and prevalence. Acupuncture with deep needling showed modulatory effect to compensate the losses of small-world attributes existed in MCI patients while acupuncture with superficial needling did not. Furthermore, acupuncture with deep needling enhanced the nodal centrality primarily in the abnormal regions of MCI including the hippocampus, postcentral cortex as well as anterior cingulate cortex. This study provides evidence to understand neural mechanism underlying acupuncture and the key role of De Qi for MCI treatment.

  12. Characterizing Acupuncture De Qi in Mild Cognitive Impairment: Relations with Small-World Efficiency of Functional Brain Networks

    Directory of Open Access Journals (Sweden)

    Lijun Bai

    2013-01-01

    Full Text Available As an intermediate state between normal aging and dementia, mild cognitive impairment (MCI became a hot topic and early treatments can improve disease prognosis. Acupuncture is shown to have possible effect in improving its cognitive defect. However, the underlying neural mechanism of acupuncture and relations between De Qi and different needling depths are still elusive. The present study aimed to explore how acupuncture can exert effect on the reorganization of MCI and to what extent needling depths, associating with De Qi sensations, can influence the acupuncture effects for MCI treatment. Our results presented that MCI patients exhibited losses of small-world attributes indicated by longer characteristic path lengths and larger clustering coefficients, compared with healthy controls. In addition, acupuncture with deep needling can induce much stronger and a wide range of De Qi sensations both in intensity and prevalence. Acupuncture with deep needling showed modulatory effect to compensate the losses of small-world attributes existed in MCI patients while acupuncture with superficial needling did not. Furthermore, acupuncture with deep needling enhanced the nodal centrality primarily in the abnormal regions of MCI including the hippocampus, postcentral cortex as well as anterior cingulate cortex. This study provides evidence to understand neural mechanism underlying acupuncture and the key role of De Qi for MCI treatment.

  13. Loss of sex and age driven differences in the gut microbiome characterize arthritis-susceptible 0401 mice but not arthritis-resistant 0402 mice.

    Directory of Open Access Journals (Sweden)

    Andres Gomez

    Full Text Available BACKGROUND: HLA-DRB1 0401 is associated with susceptibility, while HLA-DRB1 0402 is associated with resistance to developing rheumatoid arthritis (RA and collagen-induced arthritis in humans and transgenic mice respectively. The influence of gut-joint axis has been suggested in RA, though not yet proven. METHODOLOGY/PRINCIPAL FINDINGS: We have used HLA transgenic mice carrying arthritis susceptible and -resistant HLA-DR genes to explore if genetic factors and their interaction with gut flora gut can be used to predict susceptibility to develop arthritis. Pyrosequencing of the 16S rRNA gene from the fecal microbiomes of DRB1 0401 and DRB1 0402 transgenic mice revealed that the guts of 0401 mice is dominated by a Clostridium-like bacterium, whereas the guts of 0402 mice are enriched for members of the Porphyromonadaceae family and Bifidobacteria. DRB1 0402 mice harbor a dynamic sex and age-influenced gut microbiome while DRB1 0401 mice did not show age and sex differences in gut microbiome even though they had altered gut permeability. Cytokine transcripts, measured by rtPCR, in jejuna showed differential TH17 regulatory network gene transcripts in 0401 and 0402 mice. CONCLUSIONS/SIGNIFICANCE: We have demonstrated for the first time that HLA genes in association with the gut microbiome may determine the immune environment and that the gut microbiome might be a potential biomarker as well as contributor for susceptibility to arthritis. Identification of pathogenic commensal bacteria would provide new understanding of disease pathogenesis, thereby leading to novel approaches for therapy.

  14. Application of artificial neural networks on the characterization of radioactive waste drums; Aplicacao de redes neurais artificiais na caracterizacao de tambores de rejeito radioativo

    Energy Technology Data Exchange (ETDEWEB)

    Potiens Junior, Ademar Jose; Hiromoto, Goro, E-mail: apotiens@ipen.b, E-mail: hiromoto@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-10-26

    The methodology consist of system simulation of drum-detector by Monte Carlo for obtention of counting efficiency. The obtained data were treated and a neural artificial network (RNA) were constructed for evaluation of total activity of drum. For method evaluation measurements were performed in ten position parallel to the drum axis and the results submitted to the RNA. The developed methodology showed to be effective for isotopic characterization of gamma emitter radioactive wastes distributed in a heterogeneous way in a 200 litters drum. The objective of this work as to develop a methodology of analyse for quantification and localization of radionuclides not homogeneous distributed in a 200 liters drum based on the mathematical techniques

  15. Mathematical characterization of values of rheological variables during the networking reaction of rubber mixtures based on SBR

    Science.gov (United States)

    Seliga, E.; Bošák, O.; Rusnáková, S.; Minárik, S.; Tóth, M.

    2015-04-01

    The article presents an analysis of cross-linking reaction using measurements of time dependencies of torque at constant temperature from the range 100 up to 200 °C. The measured results obtained on sample based on styrene - butadiene (SBS) prepared in the laboratory show the behaviour which can be well described by equations of chemical reactions of first-order kinetics. It is possible mathematically describe significant constants of the kinetics of networking reaction (induction period, reaction rate coefficient) by the solution of differential equations and by mathematical approximation. Constants are exponentially dependent on the temperature of vulcanization, while dependencies are Arrhenius like. Math description allows describe the progress of the vulcanization reaction also in the temperature range outside of the monitoring interval, i.e. in the area of extremely long times required for the realization of the cross-linking reaction.

  16. Face Recognition Using MLP and RBF Neural Network with Gabor and Discrete Wavelet Transform Characterization: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Fatma Zohra Chelali

    2015-01-01

    Full Text Available Face recognition has received a great attention from a lot of researchers in computer vision, pattern recognition, and human machine computer interfaces in recent years. Designing a face recognition system is a complex task due to the wide variety of illumination, pose, and facial expression. A lot of approaches have been developed to find the optimal space in which face feature descriptors are well distinguished and separated. Face representation using Gabor features and discrete wavelet has attracted considerable attention in computer vision and image processing. We describe in this paper a face recognition system using artificial neural networks like multilayer perceptron (MLP and radial basis function (RBF where Gabor and discrete wavelet based feature extraction methods are proposed for the extraction of features from facial images using two facial databases: the ORL and computer vision. Good recognition rate was obtained using Gabor and DWT parameterization with MLP classifier applied for computer vision dataset.

  17. Characterization of the pairwise correlations in different quantum networks consisting of four-wave mixers and beamsplitters

    Science.gov (United States)

    Qi, Jian; Xin, Jun; Wang, Hai-Long; Jing, Jie-Tai

    2017-06-01

    Not Available Project supported by the National Natural Science Foundation of China (Grants Nos. 91436211, 11374104, and 10974057), the Natural Science Foundation of Shanghai, China (Grant No. 17ZR1442900), the Specialized Research Fund for the Doctoral Program of Higher Education, China (Grant No. 20130076110011), the Program for Professor of Special Appointment (Eastern Scholar) at Shanghai Institutions of Higher Learning, the Program for New Century Excellent Talents in University, China (Grant No. NCET-10-0383), the Shu Guang Project supported by Shanghai Municipal Education Commission and Shanghai Education Development Foundation, China (Grant No. 11SG26), the Shanghai Pujiang Program, China (Grant No. 09PJ1404400), the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry, National Basic Research Program of China (Grant No. 2016YFA0302103), and the Program of State Key Laboratory of Advanced 207 Optical Communication Systems and Networks, China (Grant No. 2016GZKF0JT003).

  18. Characterization of long-range functional connectivity in epileptic networks by neuronal spike-triggered local field potentials

    Science.gov (United States)

    Lopour, Beth A.; Staba, Richard J.; Stern, John M.; Fried, Itzhak; Ringach, Dario L.

    2016-04-01

    Objective. Quantifying the relationship between microelectrode-recorded multi-unit activity (MUA) and local field potentials (LFPs) in distinct brain regions can provide detailed information on the extent of functional connectivity in spatially widespread networks. These methods are common in studies of cognition using non-human animal models, but are rare in humans. Here we applied a neuronal spike-triggered impulse response to electrophysiological recordings from the human epileptic brain for the first time, and we evaluate functional connectivity in relation to brain areas supporting the generation of seizures. Approach. Broadband interictal electrophysiological data were recorded from microwires adapted to clinical depth electrodes that were implanted bilaterally using stereotactic techniques in six presurgical patients with medically refractory epilepsy. MUA and LFPs were isolated in each microwire, and we calculated the impulse response between the MUA on one microwire and the LFPs on a second microwire for all possible MUA/LFP pairs. Results were compared to clinical seizure localization, including sites of seizure onset and interictal epileptiform discharges. Main results. We detected significant interictal long-range functional connections in each subject, in some cases across hemispheres. Results were consistent between two independent datasets, and the timing and location of significant impulse responses reflected anatomical connectivity. However, within individual subjects, the spatial distribution of impulse responses was unique. In two subjects with clear seizure localization and successful surgery, the epileptogenic zone was associated with significant impulse responses. Significance. The results suggest that the spike-triggered impulse response can provide valuable information about the neuronal networks that contribute to seizures using only interictal data. This technique will enable testing of specific hypotheses regarding functional connectivity

  19. Characterization of long-range functional connectivity in epileptic networks by neuronal spike-triggered local field potentials.

    Science.gov (United States)

    Lopour, Beth A; Staba, Richard J; Stern, John M; Fried, Itzhak; Ringach, Dario L

    2016-04-01

    Quantifying the relationship between microelectrode-recorded multi-unit activity (MUA) and local field potentials (LFPs) in distinct brain regions can provide detailed information on the extent of functional connectivity in spatially widespread networks. These methods are common in studies of cognition using non-human animal models, but are rare in humans. Here we applied a neuronal spike-triggered impulse response to electrophysiological recordings from the human epileptic brain for the first time, and we evaluate functional connectivity in relation to brain areas supporting the generation of seizures. Broadband interictal electrophysiological data were recorded from microwires adapted to clinical depth electrodes that were implanted bilaterally using stereotactic techniques in six presurgical patients with medically refractory epilepsy. MUA and LFPs were isolated in each microwire, and we calculated the impulse response between the MUA on one microwire and the LFPs on a second microwire for all possible MUA/LFP pairs. Results were compared to clinical seizure localization, including sites of seizure onset and interictal epileptiform discharges. We detected significant interictal long-range functional connections in each subject, in some cases across hemispheres. Results were consistent between two independent datasets, and the timing and location of significant impulse responses reflected anatomical connectivity. However, within individual subjects, the spatial distribution of impulse responses was unique. In two subjects with clear seizure localization and successful surgery, the epileptogenic zone was associated with significant impulse responses. The results suggest that the spike-triggered impulse response can provide valuable information about the neuronal networks that contribute to seizures using only interictal data. This technique will enable testing of specific hypotheses regarding functional connectivity in epilepsy and the relationship between

  20. Congenital diaphragmatic hernia interval on chromosome 8p23.1 characterized by genetics and protein interaction networks

    DEFF Research Database (Denmark)

    Longoni, Mauro; Hansen, Kasper Lage; Russell, Meaghan K.

    2012-01-01

    expressed in the E11.5–12.5 primordial mouse diaphragm, the developmental stage at which CDH is thought to occur. This combination of bioinformatics and expression studies can be applied to other chromosomal hotspots, as well as private microdeletions or microduplications, to identify causative genes......Chromosome 8p23.1 is a common hotspot associated with major congenital malformations, including congenital diaphragmatic hernia (CDH) and cardiac defects. We present findings from high‐resolution arrays in patients who carry a loss (n = 18) or a gain (n = 1) of sub‐band 8p23.1. We confirm a region....... Sequence analysis of these genes in 226 chromosomally normal CDH patients, as well as in a small number of deletion 8p23.1 patients, showed rare unreported variants in the coding region; these may be contributing to the diaphragmatic phenotype. We also demonstrated that two of these three genes were...

  1. A Systems Biology Approach to Reveal Putative Host-Derived Biomarkers of Periodontitis by Network Topology Characterization of MMP-REDOX/NO and Apoptosis Integrated Pathways.

    Science.gov (United States)

    Zeidán-Chuliá, Fares; Gürsoy, Mervi; Neves de Oliveira, Ben-Hur; Özdemir, Vural; Könönen, Eija; Gürsoy, Ulvi K

    2015-01-01

    Periodontitis, a formidable global health burden, is a common chronic disease that destroys tooth-supporting tissues. Biomarkers of the early phase of this progressive disease are of utmost importance for global health. In this context, saliva represents a non-invasive biosample. By using systems biology tools, we aimed to (1) identify an integrated interactome between matrix metalloproteinase (MMP)-REDOX/nitric oxide (NO) and apoptosis upstream pathways of periodontal inflammation, and (2) characterize the attendant topological network properties to uncover putative biomarkers to be tested in saliva from patients with periodontitis. Hence, we first generated a protein-protein network model of interactions ("BIOMARK" interactome) by using the STRING 10 database, a search tool for the retrieval of interacting genes/proteins, with "Experiments" and "Databases" as input options and a confidence score of 0.400. Second, we determined the centrality values (closeness, stress, degree or connectivity, and betweenness) for the "BIOMARK" members by using the Cytoscape software. We found Ubiquitin C (UBC), Jun proto-oncogene (JUN), and matrix metalloproteinase-14 (MMP14) as the most central hub- and non-hub-bottlenecks among the 211 genes/proteins of the whole interactome. We conclude that UBC, JUN, and MMP14 are likely an optimal candidate group of host-derived biomarkers, in combination with oral pathogenic bacteria-derived proteins, for detecting periodontitis at its early phase by using salivary samples from patients. These findings therefore have broader relevance for systems medicine in global health as well.

  2. Characterization of Sequential Collagen-Poly(ethylene glycol) Diacrylat Interpenetrating Networks and Initial Assessment of their Potential for Vascular Tissue Engineering

    Science.gov (United States)

    Munoz-Pinto, Dany J.; Jimenez-Vergara, Andrea Carolina; Gharat, Tanmay; Hahn, Mariah S.

    2014-01-01

    Collagen hydrogels have been widely investigated as scaffolds for vascular tissue engineering due in part to the capacity of collagen to promote robust cell adhesion and elongation. However, collagen hydrogels display relatively low stiffness and strength, are thrombogenic, and are highly susceptible to cell-mediated contraction. In the current work, we develop and characterize a sequentially-formed interpenetrating network (IPN) that retains the benefits of collagen, but which displays enhanced mechanical stiffness and strength, improved thromboresistance, high physical stability and resistance to contraction. In this strategy, we first form a collagen hydrogel, infuse this hydrogel with poly(ethylene glycol) diacrylate (PEGDA), and subsequently crosslink the PEGDA by exposure to longwave UV light. These collagen-PEGDA IPNs allow for cell encapsulation during the fabrication process with greater than 90% cell viability via inclusion of cells within the collagen hydrogel precursor solution. Furthermore, the degree of cell spreading within the IPNs can be tuned from rounded to fully elongated by varying the time delay between the formation of the cell-laden collagen hydrogel and the formation of the PEGDA network. We also demonstrate that these collagen-PEGDA IPNs are able to support the initial stages of smooth muscle cell lineage progression by elongated human mesenchymal stems cells. PMID:25433604

  3. Weight-loss medicines

    Science.gov (United States)

    Prescription weight loss drugs; Diabetes - weight loss drugs; Obesity - weight loss drugs; Overweight - weight loss drugs ... are not approved by the FDA to treat weight-loss. So you should not take them if you do not have diabetes.

  4. Individual Hearing Loss

    Directory of Open Access Journals (Sweden)

    Sébastien Santurette

    2016-06-01

    Full Text Available It is well-established that hearing loss does not only lead to a reduction of hearing sensitivity. Large individual differences are typically observed among listeners with hearing impairment in a wide range of suprathreshold auditory measures. In many cases, audiometric thresholds cannot fully account for such individual differences, which make it challenging to find adequate compensation strategies in hearing devices. How to characterize, model, and compensate for individual hearing loss were the main topics of the fifth International Symposium on Auditory and Audiological Research (ISAAR, held in Nyborg, Denmark, in August 2015. The following collection of papers results from some of the work that was presented and discussed at the symposium.

  5. Significant Need for a French Network of Expert Centers Enabling a Better Characterization and Management of Treatment-Resistant Depression (Fondation FondaMental

    Directory of Open Access Journals (Sweden)

    Antoine Yrondi

    2017-11-01

    Full Text Available BackgroundMajor depression is characterized by (i a high lifetime prevalence of 16–17% in the general population; (ii a high frequency of treatment resistance in around 20–30% of cases; (iii a recurrent or chronic course; (iv a negative impact on the general functioning and quality of life; and (v a high level of comorbidity with various psychiatric and non-psychiatric disorders, high occurrence of completed suicide, significant burden along with the personal, societal, and economic costs. In this context, there is an important need for the development of a network of expert centers for treatment-resistant depression (TRD, as performed under the leadership of the Fondation FondaMental.MethodsThe principal mission of this national network is to establish a genuine prevention, screening, and diagnosis policy for TRD to offer a systematic, comprehensive, longitudinal, and multidimensional evaluation of cases. A shared electronic medical file is used referring to a common exhaustive and standardized set of assessment tools exploring psychiatric, non-psychiatric, metabolic, biological, and cognitive dimensions of TRD. This is paralleled by a medico-economic evaluation to examine the global economic burden of the disease and related health-care resource utilization. In addition, an integrated biobank has been built by the collection of serum and DNA samples for the measurement of several biomarkers that could further be associated with the treatment resistance in the recruited depressed patients. A French observational long-term follow-up cohort study is currently in progress enabling the extensive assessment of resistant depressed patients. In those unresponsive cases, each expert center proposes relevant therapeutic options that are classically aligned to the international guidelines referring to recognized scientific societies.DiscussionThis approach is expected to improve the overall clinical assessments and to provide evidence

  6. Resistive Network Optimal Power Flow: Uniqueness and Algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Tan, CW; Cai, DWH; Lou, X

    2015-01-01

    The optimal power flow (OPF) problem minimizes the power loss in an electrical network by optimizing the voltage and power delivered at the network buses, and is a nonconvex problem that is generally hard to solve. By leveraging a recent development on the zero duality gap of OPF, we propose a second-order cone programming convex relaxation of the resistive network OPF, and study the uniqueness of the optimal solution using differential topology, especially the Poincare-Hopf Index Theorem. We characterize the global uniqueness for different network topologies, e.g., line, radial, and mesh networks. This serves as a starting point to design distributed local algorithms with global behaviors that have low complexity, are computationally fast, and can run under synchronous and asynchronous settings in practical power grids.