WorldWideScience

Sample records for network type effects

  1. THEORETICAL EVALUATION OF NONLINEAR EFFECTS ON OPTICAL WDM NETWORKS WITH VARIOUS FIBER TYPES

    Directory of Open Access Journals (Sweden)

    YASIN M. KARFAA

    2010-09-01

    Full Text Available A theoretical study is carried out to evaluate the performance of an opticalwavelength division multiplexing (WDM network transmission system in the presenceof crosstalk due to optical fiber nonlinearities. The most significant nonlinear effects inthe optical fiber which are Cross-Phase Modulation (XPM, Four-Wave Mixing (FWM,and Stimulated Raman Scattering (SRS are investigated. Four types of optical fiber areincluded in the analysis; these are: single-mode fiber (SMF, dispersion compensationfiber (DCF, non-zero dispersion fiber (NZDF, and non-zero dispersion shifted fiber(NZDSF. The results represent the standard deviation of nonlinearity induced crosstalknoise power due to FWM and SRS, XPM power penalty for SMF, DCF, NZDF, andNZDSF types of fiber, besides the Bit Error Rate (BER for the three nonlinear effectsusing standard fiber type (SMF. It is concluded that three significant fiber nonlinearitiesare making huge limitations against increasing the launched power which is desired,otherwise, lower values of launched power limit network expansion including length,distance, covered areas, and number of users accessing the WDM network, unlesssuitable precautions are taken to neutralize the nonlinear effects. Besides, various fibertypes are not behaving similarly towards network parameters.

  2. Adjustable hydrazine modulation of single-wall carbon nanotube network field effect transistors from p-type to n-type

    Science.gov (United States)

    Dai, Ruixuan; Xie, Dan; Xu, Jianlong; Sun, Yilin; Sun, MengXing; Zhang, Cheng; Li, Xian

    2016-11-01

    Single-wall carbon nanotube (SWCNT) network field effect transistors (FETs), which show decent p-type electronic properties, have been fabricated. The use of hydrazine as an aqueous solution and a strong n-type dopant for the SWCNTs is demonstrated in this paper. The electrical properties are obviously tuned by hydrazine treatment at different concentrations on the surface of the SWCNT network FETs. The transport behavior of SWCNTs can be modulated from p-type to n-type, demonstrating the controllable and adjustable doping effect of hydrazine. With a higher concentration of hydrazine, more electrons can be transferred from the hydrazine molecules to the SWCNT network films, thus resulting in a change of threshold voltage, carrier mobility and on-current. By cleaning the device, the hydrazine doping effects vanish, which indicates that the doping effects of hydrazine are reversible. Through x-ray photoelectron spectroscopy (XPS) characterization, the doping effects of hydrazine have also been studied.

  3. Network Degradation Effects on Different Codec Types and Characteristics of Video Streaming

    Directory of Open Access Journals (Sweden)

    Jaroslav Frnda

    2014-01-01

    Full Text Available Nowadays, there is a quickly growing demand for the transmission of voice, video and data over an IP based network. Multimedia, whether we are talking about broadcast, audio and video transmission and others, from a global perspective is growing exponentially with time. With incoming requests from users, new technologies for data transfer are continually developing. Data must be delivered reliably and with the fewest losses at such high speed. Video quality as part of multimedia technology has a very important role nowadays. It is influenced by several factors, where each of them can have many forms and processing. Network performance is the major degradation effect that influences the quality of resulting image. Poor network performance (lack of link capacity, high network load… causes data packet losses or different delivery time for each packet. This work focuses exactly on these network phenomena. It examines the impact of different delays and packet losses on the quality parameters of triple play services, to evaluate the results using objective methods. The aim of this work is to bring a detailed view on the performance of video streaming over IP-based networks.

  4. Percolating macropore networks in tilled topsoil: effects of sample size, minimum pore thickness and soil type

    Science.gov (United States)

    Jarvis, Nicholas; Larsbo, Mats; Koestel, John; Keck, Hannes

    2017-04-01

    The long-range connectivity of macropore networks may exert a strong control on near-saturated and saturated hydraulic conductivity and the occurrence of preferential flow through soil. It has been suggested that percolation concepts may provide a suitable theoretical framework to characterize and quantify macropore connectivity, although this idea has not yet been thoroughly investigated. We tested the applicability of percolation concepts to describe macropore networks quantified by X-ray scanning at a resolution of 0.24 mm in eighteen cylinders (20 cm diameter and height) sampled from the ploughed layer of four soils of contrasting texture in east-central Sweden. The analyses were performed for sample sizes ("regions of interest", ROI) varying between 3 and 12 cm in cube side-length and for minimum pore thicknesses ranging between image resolution and 1 mm. Finite sample size effects were clearly found for ROI's of cube side-length smaller than ca. 6 cm. For larger sample sizes, the results showed the relevance of percolation concepts to soil macropore networks, with a close relationship found between imaged porosity and the fraction of the pore space which percolated (i.e. was connected from top to bottom of the ROI). The percolating fraction increased rapidly as a function of porosity above a small percolation threshold (1-4%). This reflects the ordered nature of the pore networks. The percolation relationships were similar for all four soils. Although pores larger than 1 mm appeared to be somewhat better connected, only small effects of minimum pore thickness were noted across the range of tested pore sizes. The utility of percolation concepts to describe the connectivity of more anisotropic macropore networks (e.g. in subsoil horizons) should also be tested, although with current X-ray scanning equipment it may prove difficult in many cases to analyze sufficiently large samples that would avoid finite size effects.

  5. COMPARISON OF WIRELESS NETWORK OVER WIRED NETWORK AND ITS TYPE

    OpenAIRE

    Shikha Shukla; Meghana K M; Manjunath C R; SantoshNaik

    2017-01-01

    Wireless network has become one of the major requirements in today world. People expect wireless network in home, shopping mall, university etc. Nowadays, we cannot imagine the life without network. In this paper focuses on what the different types of networks are. Why wired network is preferred over wireless network. We will further compare the wired network with the wireless network and also present different type of wireless network. This paper provides the basic knowledge about Wired, Wir...

  6. Personality and personal network type

    NARCIS (Netherlands)

    Doeven-Eggens, Lilian; De Fruyt, Filip; Hendriks, A. A. Jolijn; Bosker, Roel J.; Van der Werf, Margaretha P. C.

    2008-01-01

    The association between personality and personal relationships is mostly studied within dyadic relationships. We examined these variables within the context of personal network types. We used Latent Class Analysis to identify groups Of Students with similar role relationships with three focal

  7. Network effects in railways

    DEFF Research Database (Denmark)

    Landex, Alex

    2012-01-01

    Railway operation is often affected by network effects as a change in one part of the network can influence other parts of the network. Network effects occur because the train runs may be quite long and since the railway system has a high degree of interdependencies as trains cannot cross....../overtake each other everywhere in the network. First this paper describes network effects in general (section 1). In section 2 the network effects for trains and how they can be measured by scheduled waiting time is described. When the trains are affected by network effects the passengers are also affected....... Therefore, sections 3 and 4 describe the network effects for passengers and how they can be measured using passenger delay models. Before the concluding remarks in section 6, section 5 discusses how the operation can be improved by examining network effects in the planning process. © 2012 WIT Press....

  8. The Effect of Navigation Map Types and Cognitive Styles on Learners' Performance in a Computer-Networked Hypertext Learning System.

    Science.gov (United States)

    Chou, Chien; Lin, Hua

    1998-01-01

    Describes a study of college freshmen that investigated the effects of navigation maps and learner cognitive styles on performance in searches for information, on cognitive map development, and on attitudes, within a hypertext learning system. Results indicate map type has significant effects on students' search steps, efficiency, and development…

  9. Distinct types of eigenvector localization in networks

    Science.gov (United States)

    Pastor-Satorras, Romualdo; Castellano, Claudio

    2016-01-01

    The spectral properties of the adjacency matrix provide a trove of information about the structure and function of complex networks. In particular, the largest eigenvalue and its associated principal eigenvector are crucial in the understanding of nodes’ centrality and the unfolding of dynamical processes. Here we show that two distinct types of localization of the principal eigenvector may occur in heterogeneous networks. For synthetic networks with degree distribution P(q) ~ q-γ, localization occurs on the largest hub if γ > 5/2 for γ centrality based on the non-backtracking matrix.

  10. Network-Based Effectiveness

    National Research Council Canada - National Science Library

    Friman, Henrik

    2006-01-01

    ... (extended from Leavitt, 1965). This text identifies aspects of network-based effectiveness that can benefit from a better understanding of leadership and management development of people, procedures, technology, and organizations...

  11. Convolution neural networks for ship type recognition

    Science.gov (United States)

    Rainey, Katie; Reeder, John D.; Corelli, Alexander G.

    2016-05-01

    Algorithms to automatically recognize ship type from satellite imagery are desired for numerous maritime applications. This task is difficult, and example imagery accurately labeled with ship type is hard to obtain. Convolutional neural networks (CNNs) have shown promise in image recognition settings, but many of these applications rely on the availability of thousands of example images for training. This work attempts to under- stand for which types of ship recognition tasks CNNs might be well suited. We report the results of baseline experiments applying a CNN to several ship type classification tasks, and discuss many of the considerations that must be made in approaching this problem.

  12. Types of social networks and the transition to parenthood

    Directory of Open Access Journals (Sweden)

    Daniel Lois

    2016-04-01

    Full Text Available Background: A growing body of literature acknowledges the importance of social interaction and ideational factors for generative behavior. Building on this research, the present study identifies specific types of social network and gauges their value for predicting fertility behavior. Methods: Based on data from the German Family Panel (N = 3,104 respondents aged 20 to 42, four types of ego-centric social networks were identified using cluster analyses. Clusters were used to prospectively predict the transition to parenthood using a discrete-time event history analysis. Results: In the event history analyses, the highest propensity to start a family was found for 'family-centered' social networks, which were characterized primarily by a high share of persons with young children, a high amount of network support in case of parenthood, and a high proportion of strong ties to members of the nuclear family. By contrast, respondents who were embedded in 'family-remote' networks had the lowest transition rate to parenthood. Family-remote networks were characterized by a high share of friends and acquaintances, a high proportion of weak ties, and a low amount of social support and social pressure. Regarding selection effects, a comparison of cluster affiliation over time does not consistently confirm that persons who start a family select themselves into 'fertility-promoting' network types. In sum, the results enhance our understanding of how mechanisms of social influence and structural features of ego-centric social networks are interlinked.

  13. Discriminating lysosomal membrane protein types using dynamic neural network.

    Science.gov (United States)

    Tripathi, Vijay; Gupta, Dwijendra Kumar

    2014-01-01

    This work presents a dynamic artificial neural network methodology, which classifies the proteins into their classes from their sequences alone: the lysosomal membrane protein classes and the various other membranes protein classes. In this paper, neural networks-based lysosomal-associated membrane protein type prediction system is proposed. Different protein sequence representations are fused to extract the features of a protein sequence, which includes seven feature sets; amino acid (AA) composition, sequence length, hydrophobic group, electronic group, sum of hydrophobicity, R-group, and dipeptide composition. To reduce the dimensionality of the large feature vector, we applied the principal component analysis. The probabilistic neural network, generalized regression neural network, and Elman regression neural network (RNN) are used as classifiers and compared with layer recurrent network (LRN), a dynamic network. The dynamic networks have memory, i.e. its output depends not only on the input but the previous outputs also. Thus, the accuracy of LRN classifier among all other artificial neural networks comes out to be the highest. The overall accuracy of jackknife cross-validation is 93.2% for the data-set. These predicted results suggest that the method can be effectively applied to discriminate lysosomal associated membrane proteins from other membrane proteins (Type-I, Outer membrane proteins, GPI-Anchored) and Globular proteins, and it also indicates that the protein sequence representation can better reflect the core feature of membrane proteins than the classical AA composition.

  14. Estimating Type Ia Supernova Metallicities Using Neural Networks

    Science.gov (United States)

    Villar, V. Ashley

    2017-01-01

    Normal Type Ia supernovae (SNe) can be used as standardizable candles because their progenitors, white dwarfs, are a fairly homogenous class of objects. However, intrinsic variability in these events arise from a number of factors, including metallicity. Recent studies have investigated the effects of metallicity on Type Ia SNe observables from both a theoretical approach, by tuning model metallicity to analyze spectral features, and an observational approach, by studying the effect of host metallicity on light curves. In this work, we take a new, data-driven approach to the problem. Inspired by the success of neural networks in the field of image processing, we aim to estimate the metallicities of Type Ia SNe progenitors from their near-maximum spectra using feed-forward neural networks. We first collect a sample of near-maximum Type Ia SNe spectra from the literature to be smoothed and down-sampled. We then estimate the metallicities of the SNe hosts using the B-band magnitudes. We build a multilayer perceptron to generate a model that takes as input the down-sampled spectra and returns a scalar metallicity. Finally, we discuss basic considerations to be taken when working with spectral (as opposed to image) data using neural networks.

  15. Social Network Types and Mental Health Among LGBT Older Adults.

    Science.gov (United States)

    Kim, Hyun-Jun; Fredriksen-Goldsen, Karen I; Bryan, Amanda E B; Muraco, Anna

    2017-02-01

    This study was designed to identify social network types among lesbian, gay, bisexual, and transgender (LGBT) older adults and examine the relationship between social network type and mental health. We analyzed the 2014 survey data of LGBT adults aged 50 and older (N = 2,450) from Aging with Pride: National Health, Aging, and Sexuality/Gender Study. Latent profile analyses were conducted to identify clusters of social network ties based on 11 indicators. Multiple regression analysis was performed to examine the association between social network types and mental health. We found five social network types. Ordered from greatest to least access to family, friend, and other non-family network ties, they were diverse, diverse/no children, immediate family-focused, friend-centered/restricted, and fully restricted. The friend-centered/restricted (33%) and diverse/no children network types (31%) were the most prevalent. Among individuals with the friend-centered/restricted type, access to social networks was limited to friends, and across both types children were not present. The least prevalent type was the fully restricted network type (6%). Social network type was significantly associated with mental health, after controlling for background characteristics and total social network size; those with the fully restricted type showed the poorest mental health. Unique social network types (diverse/no children and friend-centered/restricted) emerge among LGBT older adults. Moreover, individuals with fully restricted social networks are at particular risk due to heightened health needs and limited social resources. This study highlights the importance of understanding heterogeneous social relations and developing tailored interventions to promote social connectedness and mental health in LGBT older adults. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. An open network type DCME system

    Science.gov (United States)

    Kato, T.; Suga, K.; Hagi, K.; Ohtsuki, H.; Shinta, M.; Kinoshita, T.; Murata, K.

    1992-03-01

    The first open network-type digital circuit multiplication equipment (DCME) system, which complies with Intelsat IESS-501 (Rev.2), Eutelsat BS14-49E, CCITT Rec. G.723, G.721, and Rec. Q.50 specifications, has been developed. It provides an economical way to multiply circuit capacity by using DSI and variable bit rate adaptive differential pulse code modulation techniques. It is flexible enough to support a variety of operation modes such as Multidestination for up to four destinations, Multiclique for up to two destinations, Single destination, and Mixed Single-destination and Multidestination operations. In addition, it offers a wide range of possibilities in satellite, submarine, and terrestrial applications. The newly-developed DCME system utilizes a modified adaptive threshold activity detector and an accurate, robust data/speech discriminator in order to prevent false detection and false decisions in high background noise environment. In the DCME system, the Operation and Maintenance Center is used to monitor the operating conditions and to control the system functions.

  17. Effective professional networking.

    Science.gov (United States)

    Goolsby, Mary Jo; Knestrick, Joyce M

    2017-08-01

    The reasons for nurse practitioners to develop a professional network are boundless and are likely to change over time. Networking opens doors and creates relationships that support new opportunities, personal development, collaborative research, policy activism, evidence-based practice, and more. Successful professional networking involves shared, mutually beneficial interactions between individuals and/or individuals and groups, regardless of whether it occurs face to face or electronically. This article combines nuggets from the literature with guidance based on the authors' combined experience in networking activities at the local, national, and international levels. ©2017 American Association of Nurse Practitioners.

  18. The Network effects of Railway Investments

    DEFF Research Database (Denmark)

    Hansen, Sten; Landex, Alex; Kaas, Anders H.

    2006-01-01

    Network effects is when a change at one place in the railway network results in changes elsewhere in the network – maybe even far away from the original change. Railway investments have network effects, and therefore, this paper describes the network effects and how these network effects can be e...

  19. Synchronization properties of heterogeneous neuronal networks with mixed excitability type.

    Science.gov (United States)

    Leone, Michael J; Schurter, Brandon N; Letson, Benjamin; Booth, Victoria; Zochowski, Michal; Fink, Christian G

    2015-03-01

    We study the synchronization of neuronal networks with dynamical heterogeneity, showing that network structures with the same propensity for synchronization (as quantified by master stability function analysis) may develop dramatically different synchronization properties when heterogeneity is introduced with respect to neuronal excitability type. Specifically, we investigate networks composed of neurons with different types of phase response curves (PRCs), which characterize how oscillating neurons respond to excitatory perturbations. Neurons exhibiting type 1 PRC respond exclusively with phase advances, while neurons exhibiting type 2 PRC respond with either phase delays or phase advances, depending on when the perturbation occurs. We find that Watts-Strogatz small world networks transition to synchronization gradually as the proportion of type 2 neurons increases, whereas scale-free networks may transition gradually or rapidly, depending upon local correlations between node degree and excitability type. Random placement of type 2 neurons results in gradual transition to synchronization, whereas placement of type 2 neurons as hubs leads to a much more rapid transition, showing that type 2 hub cells easily "hijack" neuronal networks to synchronization. These results underscore the fact that the degree of synchronization observed in neuronal networks is determined by a complex interplay between network structure and the dynamical properties of individual neurons, indicating that efforts to recover structural connectivity from dynamical correlations must in general take both factors into account.

  20. Analysis of networking characteristics of different personality types

    OpenAIRE

    Charilaos, Mylonas

    2014-01-01

    The MBTI personality test and a personal facebook network were used in order to gain some insights on the relationship of social network centrality and path length measures and different personality types. Although the personality classification data were scarce, there were some intuitive quantitative results supporting anecdotal statements, based on empirical observations, about the expected social behavior of personality types.

  1. Characteristics of Effective Leadership Networks

    Science.gov (United States)

    Leithwood, Kenneth; Azah, Vera Ndifor

    2016-01-01

    Purpose: The purpose of this paper is to inquire about the characteristics of effective school leadership networks and the contribution of such networks to the development of individual leaders' professional capacities. Design/methodology/approach: The study used path-analytic techniques with survey data provided by 450 school and district leaders…

  2. Synergistic effects in threshold models on networks

    Science.gov (United States)

    Juul, Jonas S.; Porter, Mason A.

    2018-01-01

    Network structure can have a significant impact on the propagation of diseases, memes, and information on social networks. Different types of spreading processes (and other dynamical processes) are affected by network architecture in different ways, and it is important to develop tractable models of spreading processes on networks to explore such issues. In this paper, we incorporate the idea of synergy into a two-state ("active" or "passive") threshold model of social influence on networks. Our model's update rule is deterministic, and the influence of each meme-carrying (i.e., active) neighbor can—depending on a parameter—either be enhanced or inhibited by an amount that depends on the number of active neighbors of a node. Such a synergistic system models social behavior in which the willingness to adopt either accelerates or saturates in a way that depends on the number of neighbors who have adopted that behavior. We illustrate that our model's synergy parameter has a crucial effect on system dynamics, as it determines whether degree-k nodes are possible or impossible to activate. We simulate synergistic meme spreading on both random-graph models and networks constructed from empirical data. Using a heterogeneous mean-field approximation, which we derive under the assumption that a network is locally tree-like, we are able to determine which synergy-parameter values allow degree-k nodes to be activated for many networks and for a broad family of synergistic models.

  3. Effect of antidiabetic agents added to metformin on glycaemic control, hypoglycaemia and weight change in patients with type 2 diabetes: a network meta-analysis.

    Science.gov (United States)

    Liu, S-C; Tu, Y-K; Chien, M-N; Chien, K-L

    2012-09-01

    Most guidelines recommend metformin as first-line therapy in patients with type 2 diabetes. However, the choice of a second-line drug lacks consistent consensus. We aimed to assess available information of antidiabetic drugs added to metformin on the change in glycated haemoglobin A1c (A1C), risk of hypoglycaemia and change in body weight. PubMed and Cochrane Central Register of Controlled Trials were searched for randomized controlled trials (RCTs) written in English through December 2011. We analysed direct and indirect comparisons of different treatments using Bayesian network meta-analysis. Thirty-nine RCTs involving 17 860 individuals were included. Glucagon-like peptide-1 (GLP-1) analogues resulted in greater decrease in A1C compared with sulfonylureas, glinides, thiazolidinediones, α-glucosidase inhibitors and DPP-4 inhibitors [-0.20% (95% CI -0.34 to -0.04%), -0.31% (95% CI -0.61 to -0.02%), -0.20% (95% CI -0.38 to -0.00), -0.36% (95% CI -0.64 to -0.07%), -0.32% (95% CI -0.47 to -0.17%), respectively] and was comparable with basal insulin and biphasic insulin. A1C decrease was greater for sulfonylureas compared with DPP-4 inhibitors [-0.12% (-0.23 to -0.03%)], and for biphasic insulin compared with glinides (-0.36%; 95% CI -0.82 to -0.11%). Compared with placebo, the risk of hypoglycaemia was increased in the sulfonylureas, glinides, basal insulin and biphasic insulin. Weight increase was seen with sulfonylureas, glinides, thiazolidinediones, basal insulin and biphasic insulin, and weight loss was seen with α-glucosidase inhibitors and GLP-1 analogues. Biphasic insulin, GLP-1 analogues and basal insulin were ranked the top three drugs in terms of A1C reduction. GLP-1 analogues did not increase the risk of hypoglycaemia and resulted in a significant decrease in body weight. Most oral antidiabetic drugs had similar effects on A1C, but some agents had a lower risk of hypoglycaemia and body weight gain. © 2012 Blackwell Publishing Ltd.

  4. Network Effects Versus Strategic Discounting

    DEFF Research Database (Denmark)

    Zucchini, Leon; Claussen, Jörg; Trüg, Moritiz

    Mobile telecommunication operators routinely charge subscribers lower prices for calls on their own network than for calls to other networks (on-net discounts). Studies on tariff-mediated network effects suggest this is due to large operators using on-net discounts to damage smaller rivals....... Alternatively, research on strategic discounting suggests small operators use on-net discounts to advertise with low on-net prices. We test the relative strength of these effects using data on tariff setting in German mobile telecommunications between 2001 and 2009. We find that large operators are more likely...... to offer tariffs with on-net discounts but there is no consistently significant difference in the magnitude of discounts. Our results suggest that tariff-mediated network effects are the main cause of on-net discounts....

  5. Confidant network types and well-being among older europeans.

    Science.gov (United States)

    Litwin, Howard; Stoeckel, Kimberly J

    2014-10-01

    To derive a typology of confidant networks among older adults in Europe and to examine them in relation to country differences and well-being (CASP-12). The study population was composed of persons aged 65 and older in 16 countries from the 4th wave of the Survey of Health, Ageing and Retirement in Europe (N = 28,697). K-means cluster analysis was applied to data from a newly implemented name-generating network inventory. CASP-12 scores were regressed on network type controlling for country and potential sociodemographic and health confounders. Six prototypical confidant network types were discerned, including proximal and distal family-based networks of varying configurations, as well as friend-based and other-based network types. Regional country differences in network type constellations were observed. Better well-being was found to be associated with network types with greater social capital. Respondents with no named confidants had the lowest CASP-12 scores, and those embedded in "other" network types also exhibited a negative association with well-being. The study demonstrates the utility of name-generating network inventories in understanding the social capital of older persons. It also shows that accessible family ties are strong correlates of well-being in this population. Finally, it documents the importance of improving the means to detect the small but significant subgroup of isolated older people-those who have no confidants on whom they may rely. © The Author 2013. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  6. The Social Network, Socioeconomic Background, and School Type of Adolescent Smokers

    Science.gov (United States)

    Huisman, Chip; Bruggeman, Jeroen

    2012-01-01

    The aim of this study is to examine the role of Dutch second grade (age 13-14) high school peer networks in mediating socioeconomic background and school type effects on smoking behavior. This study is based on a longitudinal design with two measurement waves at five different high schools, of the complete networks of second grader friendships, as…

  7. Type-2 fuzzy neural networks and their applications

    CERN Document Server

    Aliev, Rafik Aziz

    2014-01-01

    This book deals with the theory, design principles, and application of hybrid intelligent systems using type-2 fuzzy sets in combination with other paradigms of Soft Computing technology such as Neuro-Computing and Evolutionary Computing. It provides a self-contained exposition of the foundation of type-2 fuzzy neural networks and presents a vast compendium of its applications to control, forecasting, decision making, system identification and other real problems. Type-2 Fuzzy Neural Networks and Their Applications is helpful for teachers and students of universities and colleges, for scientis

  8. Exploring Impact: Negative Effects of Social Networks

    OpenAIRE

    Egbert, Henrik; Sedlarski, Teodor

    2011-01-01

    he sociological literature on social networks emphasizes by and large positive network effects. Negative effects of such networks are discussed rather rarely. This paper tackles negative effects by applying economic theory, particularly neoclassical theory, new institutional theory and the results from experimental economics to the concept of social networks. In the paper it is assumed that social networks are exclusive and since exclusiveness affects the allocation of resources, negative ext...

  9. Resource Allocation in a Frequency Hopping PCS1900/GSM/DCS1800 Type of Network

    DEFF Research Database (Denmark)

    Nielsen, Thomas Toftegaard; Wigard, Jeroen; Michaelsen, Per-Henrik

    1999-01-01

    Resource allocation in a frequency hopping network is even more problematic than in a traditional network. The combined effect from all serving frequencies has to be considered directly in the allocation process. An algorithm doing this for a PCS1900/GSM/DCS1800 type of network is presented...

  10. An effective method for network module extraction from microarray data

    Directory of Open Access Journals (Sweden)

    Mahanta Priyakshi

    2012-08-01

    Full Text Available Abstract Background The development of high-throughput Microarray technologies has provided various opportunities to systematically characterize diverse types of computational biological networks. Co-expression network have become popular in the analysis of microarray data, such as for detecting functional gene modules. Results This paper presents a method to build a co-expression network (CEN and to detect network modules from the built network. We use an effective gene expression similarity measure called NMRS (Normalized mean residue similarity to construct the CEN. We have tested our method on five publicly available benchmark microarray datasets. The network modules extracted by our algorithm have been biologically validated in terms of Q value and p value. Conclusions Our results show that the technique is capable of detecting biologically significant network modules from the co-expression network. Biologist can use this technique to find groups of genes with similar functionality based on their expression information.

  11. Managing the Environment : Effects of network ambition on agency performance

    NARCIS (Netherlands)

    Akkerman, A.; Torenvlied, R.

    2011-01-01

    The literature on network management in the public sector reports positive effects of network activity on agency performance. Current studies show however no differences between specific types of contacts in an agency's environment. The present article adopts an explorative design to study the

  12. Selectively disrupted functional connectivity networks in type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Yaojing eChen

    2015-12-01

    Full Text Available Background: The high prevalence of type 2 diabetes mellitus (T2DM in individuals over 65 years old and cognitive deficits caused by T2DM have attracted broad attention. The pathophysiological mechanism of T2DM induced cognitive impairments, however, remains poorly understood. Previous studies have suggested that the cognitive impairments can be attributed not merely to local functional and structural abnormalities but also to specific brain networks. Thus, we aimed to investigate the changes of global networks selectively affected by T2DM. Methods: A resting state functional network analysis was conducted to investigate the intrinsic functional connectivity in 37 patients with diabetes and 40 healthy controls which were recruited from local communities in Beijing, China. Results: We found that patients with T2DM exhibited cognitive function declines and functional connectivity disruptions within the default mode network, left frontal parietal network, and sensorimotor network. More importantly, the fasting glucose level was correlated with abnormal functional connectivity.Conclusions: These findings could help to understand the neural mechanisms of cognitive impairments in T2DM and provide potential neuroimaging biomarkers that may be used for early diagnosis and intervention in cognitive decline.

  13. Synchronization of Lienard-Type Oscillators in Uniform Electrical Networks

    Energy Technology Data Exchange (ETDEWEB)

    Sinha, Mohit; Dorfler, Florian; Johnson, Brian B.; Dhople, Sairaj V.

    2016-08-01

    This paper presents a condition for global asymptotic synchronization of Lienard-type nonlinear oscillators in uniform LTI electrical networks with series R-L circuits modeling interconnections. By uniform electrical networks, we mean that the per-unit-length impedances are identical for the interconnecting lines. We derive conditions for global asymptotic synchronization for a particular feedback architecture where the derivative of the oscillator output current supplements the innate current feedback induced by simply interconnecting the oscillator to the network. Our proof leverages a coordinate transformation to a set of differential coordinates that emphasizes signal differences and the particular form of feedback permits the formulation of a quadratic Lyapunov function for this class of networks. This approach is particularly interesting since synchronization conditions are difficult to obtain by means of quadratic Lyapunov functions when only current feedback is used and for networks composed of series R-L circuits. Our synchronization condition depends on the algebraic connectivity of the underlying network, and reiterates the conventional wisdom from Lyapunov- and passivity-based arguments that strong coupling is required to ensure synchronization.

  14. Optogenetic stimulation effectively enhances intrinsically generated network synchrony

    Directory of Open Access Journals (Sweden)

    Ahmed eEl Hady

    2013-10-01

    Full Text Available Synchronized bursting is found in many brain areas and has also been implicated in the pathophysiology of neuropsychiatric disorders such as epilepsy, Parkinson’s disease and schizophrenia. Despite extensive studies of network burst synchronization, it is insufficiently understood how this type of network wide synchronization can be strengthened, reduced or even abolished. We combined electrical recording using multi-electrode array with optical stimulation of cultured channelrhodopsin-2 transducted hippocampal neurons to study and manipulate network burst synchronization. We found low frequency photo-stimulation protocols that are sufficient to induce potentiation of network bursting, modifying bursting dynamics and increasing interneuronal synchronization. Surprisingly, slowly fading-in light stimulation, which substantially delayed and reduced light driven spiking, was at least as effective in reorganizing network dynamics as much stronger pulsed light stimulation. Our study shows that mild stimulation protocols that do not enforce particular activity patterns onto the network can be highly effective inducers of network-level plasticity.

  15. SOCIAL NETWORK EFFECTS ON ROMANTIC RELATIONSHIP

    Directory of Open Access Journals (Sweden)

    Fatma CAN

    2015-06-01

    Full Text Available The main objective of the study was to obtain information about social network variables in order to predict the relational commitment of married individuals and people having dating relationships. For this purpose, social network analysis has been carried out on 134 people having dating relationship and 154 married individuals and then Relationship Stability Scale, Subjective Norm Scale and Social Network Feature Survey prepared by the researcher were used. The results indicated that the approval of the closest social network member and the level of enjoyment of each other’s social network members had the best predictive value for relationship satisfaction and the investment to the relationship. The results also demonstrated that, approval of the social network had a negative impact on the level of the quality of alternatives and it showed that social networks were seen as a barrier function to have alternative relationships. Furthermore, by dividing social network members into two groups, for the dating group, the approval of the social network was the most significant variable for commitment but in the married group, the need for social network approval was not an important criteria because of having their relatioship already confirmed legally. When social network members were categorised and examined, the closest social network members did not differ by sex, but were varied in terms of relationship types. In the flirt group, one of their friends among his/her social network and their partners’ social network was specified as the closest social network member whereas in the married group, the closest social network member among his/her social network was their mother while it was their sibling among partner’s social network.

  16. High-Dose Aspirin Is Required to Influence Plasma Fibrin Network Structure in Patients With Type 1 Diabetes

    OpenAIRE

    Tehrani, Sara; Antovic, Aleksandra; Mobarrez, Fariborz; Mageed, Koteiba; Lins, Per-Eric; Adamson, Ulf; Wall?n, H?kan N.; J?rneskog, Gun

    2012-01-01

    OBJECTIVE Patients with type 1 diabetes form a less permeable fibrin network, which could contribute to their increased risk of cardiovascular disease (CVD). Low-dose aspirin treatment is the standard in the management of CVD; however, the effect seems reduced in patients with diabetes. We investigated the effects of low- and high-dose aspirin treatment on fibrin network formation in patients with type 1 diabetes (primary aim) and the possible interaction between the treatment effects of aspi...

  17. Determination of Optimum Network Layout for Low-Energy District Heating Systems with Different Substation Types

    DEFF Research Database (Denmark)

    Tol, Hakan; Svendsen, Svend

    2011-01-01

    In this paper three different District Heating (DH) network types, which comprise substations with storage tank, and with instantaneous heat exchanger (each for domestic hot water production); and booster pumps installed in the beginning of each street at the latter network type, are pointed out...... temperature drop at supply in low heat demand conditions during summer months, are presented with the results of dynamic simulations, carried out in the Termis software with the input data of randomly generated heat demand of consumers in the basis of simultaneity factor effect in each pipe segment at the DH...

  18. Network effects on scientific collaborations.

    Directory of Open Access Journals (Sweden)

    Shahadat Uddin

    Full Text Available BACKGROUND: The analysis of co-authorship network aims at exploring the impact of network structure on the outcome of scientific collaborations and research publications. However, little is known about what network properties are associated with authors who have increased number of joint publications and are being cited highly. METHODOLOGY/PRINCIPAL FINDINGS: Measures of social network analysis, for example network centrality and tie strength, have been utilized extensively in current co-authorship literature to explore different behavioural patterns of co-authorship networks. Using three SNA measures (i.e., degree centrality, closeness centrality and betweenness centrality, we explore scientific collaboration networks to understand factors influencing performance (i.e., citation count and formation (tie strength between authors of such networks. A citation count is the number of times an article is cited by other articles. We use co-authorship dataset of the research field of 'steel structure' for the year 2005 to 2009. To measure the strength of scientific collaboration between two authors, we consider the number of articles co-authored by them. In this study, we examine how citation count of a scientific publication is influenced by different centrality measures of its co-author(s in a co-authorship network. We further analyze the impact of the network positions of authors on the strength of their scientific collaborations. We use both correlation and regression methods for data analysis leading to statistical validation. We identify that citation count of a research article is positively correlated with the degree centrality and betweenness centrality values of its co-author(s. Also, we reveal that degree centrality and betweenness centrality values of authors in a co-authorship network are positively correlated with the strength of their scientific collaborations. CONCLUSIONS/SIGNIFICANCE: Authors' network positions in co

  19. Network Security: Policies and Guidelines for Effective Network Management

    Directory of Open Access Journals (Sweden)

    Jonathan Gana KOLO

    2008-12-01

    Full Text Available Network security and management in Information and Communication Technology (ICT is the ability to maintain the integrity of a system or network, its data and its immediate environment. The various innovations and uses to which networks are being put are growing by the day and hence are becoming complex and invariably more difficult to manage by the day. Computers are found in every business such as banking, insurance, hospital, education, manufacturing, etc. The widespread use of these systems implies crime and insecurity on a global scale. In addition, the tremendous benefits brought about by Internet have also widened the scope of crime and insecurity at an alarming rate. Also, ICT has fast become a primary differentiator for institution/organization leaders as it offers effective and convenient means of interaction with each other across the globe. This upsurge in the population of organizations depending on ICT for business transaction has brought with it a growing number of security threats and attacks on poorly managed and secured networks primarily to steal personal data, particularly financial information and password.This paper therefore proposes some policies and guidelines that should be followed by network administrators in organizations to help them ensure effective network management and security of ICT facilities and data.

  20. Universal Approximation of a Class of Interval Type-2 Fuzzy Neural Networks in Nonlinear Identification

    Directory of Open Access Journals (Sweden)

    Oscar Castillo

    2013-01-01

    Full Text Available Neural networks (NNs, type-1 fuzzy logic systems (T1FLSs, and interval type-2 fuzzy logic systems (IT2FLSs have been shown to be universal approximators, which means that they can approximate any nonlinear continuous function. Recent research shows that embedding an IT2FLS on an NN can be very effective for a wide number of nonlinear complex systems, especially when handling imperfect or incomplete information. In this paper we show, based on the Stone-Weierstrass theorem, that an interval type-2 fuzzy neural network (IT2FNN is a universal approximator, which uses a set of rules and interval type-2 membership functions (IT2MFs for this purpose. Simulation results of nonlinear function identification using the IT2FNN for one and three variables and for the Mackey-Glass chaotic time series prediction are presented to illustrate the concept of universal approximation.

  1. Failure mitigation in software defined networking employing load type prediction

    KAUST Repository

    Bouacida, Nader

    2017-07-31

    The controller is a critical piece of the SDN architecture, where it is considered as the mastermind of SDN networks. Thus, its failure will cause a significant portion of the network to fail. Overload is one of the common causes of failure since the controller is frequently invoked by new flows. Even through SDN controllers are often replicated, the significant recovery time can be an overkill for the availability of the entire network. In order to overcome the problem of the overloaded controller failure in SDN, this paper proposes a novel controller offload solution for failure mitigation based on a prediction module that anticipates the presence of a harmful long-term load. In fact, the long-standing load would eventually overwhelm the controller leading to a possible failure. To predict whether the load in the controller is short-term or long-term load, we used three different classification algorithms: Support Vector Machine, k-Nearest Neighbors, and Naive Bayes. Our evaluation results demonstrate that Support Vector Machine algorithm is applicable for detecting the type of load with an accuracy of 97.93% in a real-time scenario. Besides, our scheme succeeded to offload the controller by switching between the reactive and proactive mode in response to the prediction module output.

  2. False Positive and False Negative Effects on Network Attacks

    Science.gov (United States)

    Shang, Yilun

    2017-11-01

    Robustness against attacks serves as evidence for complex network structures and failure mechanisms that lie behind them. Most often, due to detection capability limitation or good disguises, attacks on networks are subject to false positives and false negatives, meaning that functional nodes may be falsely regarded as compromised by the attacker and vice versa. In this work, we initiate a study of false positive/negative effects on network robustness against three fundamental types of attack strategies, namely, random attacks (RA), localized attacks (LA), and targeted attack (TA). By developing a general mathematical framework based upon the percolation model, we investigate analytically and by numerical simulations of attack robustness with false positive/negative rate (FPR/FNR) on three benchmark models including Erdős-Rényi (ER) networks, random regular (RR) networks, and scale-free (SF) networks. We show that ER networks are equivalently robust against RA and LA only when FPR equals zero or the initial network is intact. We find several interesting crossovers in RR and SF networks when FPR is taken into consideration. By defining the cost of attack, we observe diminishing marginal attack efficiency for RA, LA, and TA. Our finding highlights the potential risk of underestimating or ignoring FPR in understanding attack robustness. The results may provide insights into ways of enhancing robustness of network architecture and improve the level of protection of critical infrastructures.

  3. False Positive and False Negative Effects on Network Attacks

    Science.gov (United States)

    Shang, Yilun

    2018-01-01

    Robustness against attacks serves as evidence for complex network structures and failure mechanisms that lie behind them. Most often, due to detection capability limitation or good disguises, attacks on networks are subject to false positives and false negatives, meaning that functional nodes may be falsely regarded as compromised by the attacker and vice versa. In this work, we initiate a study of false positive/negative effects on network robustness against three fundamental types of attack strategies, namely, random attacks (RA), localized attacks (LA), and targeted attack (TA). By developing a general mathematical framework based upon the percolation model, we investigate analytically and by numerical simulations of attack robustness with false positive/negative rate (FPR/FNR) on three benchmark models including Erdős-Rényi (ER) networks, random regular (RR) networks, and scale-free (SF) networks. We show that ER networks are equivalently robust against RA and LA only when FPR equals zero or the initial network is intact. We find several interesting crossovers in RR and SF networks when FPR is taken into consideration. By defining the cost of attack, we observe diminishing marginal attack efficiency for RA, LA, and TA. Our finding highlights the potential risk of underestimating or ignoring FPR in understanding attack robustness. The results may provide insights into ways of enhancing robustness of network architecture and improve the level of protection of critical infrastructures.

  4. Fine-grained vehicle type recognition based on deep convolution neural networks

    Directory of Open Access Journals (Sweden)

    Hongcai CHEN

    2017-12-01

    Full Text Available Public security and traffic department put forward higher requirements for real-time performance and accuracy of vehicle type recognition in complex traffic scenes. Aiming at the problems of great plice forces occupation, low retrieval efficiency, and lacking of intelligence for dealing with false license, fake plate vehicles and vehicles without plates, this paper proposes a vehicle type fine-grained recognition method based GoogleNet deep convolution neural networks. The filter size and numbers of convolution neural network are designed, the activation function and vehicle type classifier are optimally selected, and a new network framework is constructed for vehicle type fine-grained recognition. The experimental results show that the proposed method has 97% accuracy for vehicle type fine-grained recognition and has greater improvement than the original GoogleNet model. Moreover, the new model effectively reduces the number of training parameters, and saves computer memory. Fine-grained vehicle type recognition can be used in intelligent traffic management area, and has important theoretical research value and practical significance.

  5. A Type of Low-Latency Data Gathering Method with Multi-Sink for Sensor Networks

    Directory of Open Access Journals (Sweden)

    Chao Sha

    2016-06-01

    Full Text Available To balance energy consumption and reduce latency on data transmission in Wireless Sensor Networks (WSNs, a type of low-latency data gathering method with multi-Sink (LDGM for short is proposed in this paper. The network is divided into several virtual regions consisting of three or less data gathering units and the leader of each region is selected according to its residual energy as well as distance to all of the other nodes. Only the leaders in each region need to communicate with the mobile Sinks which have effectively reduced energy consumption and the end-to-end delay. Moreover, with the help of the sleep scheduling and the sensing radius adjustment strategies, redundancy in network coverage could also be effectively reduced. Simulation results show that LDGM is energy efficient in comparison with MST as well as MWST and its time efficiency on data collection is higher than one Sink based data gathering methods.

  6. Social Network Type and Subjective Well-Being in a National Sample of Older Americans

    Science.gov (United States)

    Litwin, Howard; Shiovitz-Ezra, Sharon

    2011-01-01

    Purpose: The study considers the social networks of older Americans, a population for whom there have been few studies of social network type. It also examines associations between network types and well-being indicators: loneliness, anxiety, and happiness. Design and Methods: A subsample of persons aged 65 years and older from the first wave of…

  7. Equilibrium & Nonequilibrium Fluctuation Effects in Biopolymer Networks

    Science.gov (United States)

    Kachan, Devin Michael

    speculate that cells take advantage of this equilibrium effect by tuning near the transition point, where small changes in free cross-linker density will affect large structural rearrangements between free filament networks and networks of bundles. Cells are naturally found far from equilibrium, where the active influx of energy from ATP consumption controls the dynamics. Motor proteins actively generate forces within biopolymer networks, and one may ask how these differ from the random stresses characteristic of equilibrium fluctuations. Besides the trivial observation that the magnitude is independent of temperature, I find that the processive nature of the motors creates a temporally correlated, or colored, noise spectrum. I model the network with a nonlinear scalar elastic theory in the presence of active driving, and study the long distance and large scale properties of the system with renormalization group techniques. I find that there is a new critical point associated with diverging correlation time, and that the colored noise produces novel frequency dependence in the renormalized transport coefficients. Finally, I study marginally elastic solids which have vanishing shear modulus due to the presence of soft modes, modes with zero deformation cost. Although network coordination is a useful metric for determining the mechanical response of random spring networks in mechanical equilibrium, it is insufficient for describing networks under external stress. In particular, under-constrained networks which are fluid-like at zero load will dynamically stiffen at a critical strain, as observed in numerical simulations and experimentally in many biopolymer networks. Drawing upon analogies to the stress induced unjamming of emulsions, I develop a kinetic theory to explain the rigidity transition in spring and filament networks. Describing the dynamic evolution of non-affine deformation via a simple mechanistic picture, I recover the emergent nonlinear strain

  8. Dynamic Dilution Effects in Polymeric Networks

    DEFF Research Database (Denmark)

    Skov, Anne Ladegaard; Sommer-Larsen, Peter; Hassager, Ole

    2006-01-01

    processes, namely the reptation of linear species within the network and the arm withdrawal process of star arms in the sol fraction and of dangling single-chain ends attached to the network. The relaxation spectra are influenced by the stoichiometry to a large extent due to dynamic dilution effects caused...

  9. Effective teacher professionalization in networks?

    NARCIS (Netherlands)

    Hofman, R.H.; Dijkstra, B.J.

    Teacher professionalization has been focused to strongly on external experts and a one-size-fits-all set of solutions that often fail to distinguish between the needs of different teachers. This article describes a research into teacher networks that might be more successful vehicles for

  10. Scaling Effect In Trade Network

    Science.gov (United States)

    Konar, M.; Lin, X.; Rushforth, R.; Ruddell, B. L.; Reimer, J.

    2015-12-01

    Scaling is an important issue in the physical sciences. Economic trade is increasingly of interest to the scientific community due to the natural resources (e.g. water, carbon, nutrients, etc.) embodied in traded commodities. Trade refers to the spatial and temporal redistribution of commodities, and is typically measured annually between countries. However, commodity exchange networks occur at many different scales, though data availability at finer temporal and spatial resolution is rare. Exchange networks may prove an important adaptation measure to cope with future climate and economic shocks. As such, it is essential to understand how commodity exchange networks scale, so that we can understand opportunities and roadblocks to the spatial and temporal redistribution of goods and services. To this end, we present an empirical analysis of trade systems across three spatial scales: global, sub-national in the United States, and county-scale in the United States. We compare and contrast the network properties, the self-sufficiency ratio, and performance of the gravity model of trade for these three exchange systems.

  11. Diagnosis of three types of constant faults in read-once contact networks over finite bases

    KAUST Repository

    Busbait, Monther I.

    2016-03-24

    We study the depth of decision trees for diagnosis of three types of constant faults in read-once contact networks over finite bases containing only indecomposable networks. For each basis and each type of faults, we obtain a linear upper bound on the minimum depth of decision trees depending on the number of edges in networks. For bases containing networks with at most 10 edges, we find sharp coefficients for linear bounds.

  12. Effects of three injectable antidiabetic agents on glycaemic control, weight change and drop-out in type 2 diabetes suboptimally controlled with metformin and/or a sulfonylurea: A network meta-analysis.

    Science.gov (United States)

    Zhong, Xihua; Zhang, Tianyi; Liu, Yuzhou; Wei, Xin; Zhang, Xinji; Qin, Yingyi; Jin, Zhichao; Chen, Qi; Ma, Xiuqiang; Wang, Rui; He, Jia

    2015-09-01

    The objective of this review was to assess glucagon-like peptide-1 receptor agonists (GLP-1 RAs), basal insulin, and premixed insulin among participants with type 2 diabetes inadequately controlled with metformin and/or a sulfonylurea. We searched PubMed, EmBase, and the Cochrane Library to identify eligible randomized controlled trials (RCTs) for a network meta-analysis. A total of 17 RCTs involving 5874 adult individuals were included. Compared with placebo, all three therapies showed a significant effect on achieving target glycated hemoglobin (HbA1c) (GLP-1 RAs: 31.7%, 95% CI, 24.7-38.6%; premixed insulin: 31.1%, 95% CI, 20.4-41.8%; basal insulin: 26.0%, 95% CI, 16.4-35.7%). However, there was no significant difference between the three therapies. A similar result was found in HbA1c reduction. The use of GLP-1 RAs resulted in significant body weight loss (-3.73 kg, 95% CI, -4.52 to -2.95 kg vs. basal insulin and -5.27 kg, 95% CI, -6.17 to -4.36 kg vs. premixed insulin) but there was a higher drop-out rate of participants. Premixed insulin seemed associated with more severe hypoglycemic episodes. The three injectables had similar impact on glycemic control but other differentiating features relevant to the management of type 2 diabetes with GLP-1 RAs having the most favorable profile. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  13. Network system effects of mileage fee.

    Science.gov (United States)

    2015-08-01

    This project presents a comprehensive investigation about the network effects of MF to facilitate the : developments of proper MF policies. After a practice scan and a review of the recent literature on MF, a multi-class mathematical programming with...

  14. Social Network Effects and Green Consumerism

    OpenAIRE

    Hauck, Dominic; Ansink, Erik; Bouma, Jetske; van Soest, Daan

    2014-01-01

    One of the drivers of green consumerism are social network externalities that are associated with buying 'green' because green consumerism is fashionable, or because of reputation effects. We analyze how the strength of this social network effect impacts green consumerism, environmental externalities and total welfare. We discuss a model where products are differentiated according to their environmental quality, where the production of green products generates positive externalities to all, a...

  15. Dissecting the logical types of network control in gene expression profiles

    Directory of Open Access Journals (Sweden)

    Geertz Marcel

    2008-02-01

    Full Text Available Abstract Background In the bacterium Escherichia coli the transcriptional regulation of gene expression involves both dedicated regulators binding specific DNA sites with high affinity and also global regulators – abundant DNA architectural proteins of the bacterial nucleoid binding multiple sites with a wide range of affinities and thus modulating the superhelical density of DNA. The first form of transcriptional regulation is predominantly pairwise and specific, representing digitial control, while the second form is (in strength and distribution continuous, representing analog control. Results Here we look at the properties of effective networks derived from significant gene expression changes under variation of the two forms of control and find that upon limitations of one type of control (caused e.g. by mutation of a global DNA architectural factor the other type can compensate for compromised regulation. Mutations of global regulators significantly enhance the digital control, whereas in the presence of global DNA architectural proteins regulation is mostly of the analog type, coupling spatially neighboring genomic loci. Taken together our data suggest that two logically distinct – digital and analog – types of control are balancing each other. Conclusion By revealing two distinct logical types of control, our approach provides basic insights into both the organizational principles of transcriptional regulation and the mechanisms buffering genetic flexibility. We anticipate that the general concept of distinguishing logical types of control will apply to many complex biological networks.

  16. Social Network Data Validity: The Example of the Social Network of Caregivers of Older Persons with Alzheimer-Type Dementia

    Science.gov (United States)

    Carpentier, Normand

    2007-01-01

    This article offers reflection on the validity of relational data such as used in social network analysis. Ongoing research on the transformation of the support network of caregivers of persons with an Alzheimer-type disease provides the data to fuel the debate on the validity of participant report. More specifically, we sought to understand the…

  17. Development of Network-type Archaeological Investigation System

    Science.gov (United States)

    Chiba, F.; Yokokoyama, S.; Kaneda, A.; Konno, K.

    2015-08-01

    The Great East Japan Earthquake on March 11, 2011 is said to be a once-in-1000-year catastrophic quake. The Tsunami triggered by the earthquake destroyed broad coastal areas in northeast Japan. As recovery from the earthquake proceeds, the demand for new road construction, housing hill development, and residential construction is rapidly increasing. Culture plays a critical role in the district's recovery. For that reason, before development, cultural properties in the corresponding districts must be urgently investigated. This is a must, although balancing cultural recovery with rapid economic recovery is no easy task. With this in mind, we have developed a new system focusing on speedy archaeological investigation and adequate documentation. The authors reexamined the existing investigation process to categorize tasks into two types: those that must be done only at archaeological sites (site A) and ones available at other places (site B). We then formulated a scheme where the tasks on both sites are performed simultaneously in parallel over the network. Experiments are ongoing. This presentation reports the process and issues of our research and development.

  18. Synergistic effect of repulsive inhibition in synchronization of excitatory networks

    Science.gov (United States)

    Belykh, Igor; Reimbayev, Reimbay; Zhao, Kun

    2015-06-01

    We show that the addition of pairwise repulsive inhibition to excitatory networks of bursting neurons induces synchrony, in contrast to one's expectations. Through stability analysis, we reveal the mechanism underlying this purely synergistic phenomenon and demonstrate that it originates from the transition between different types of bursting, caused by excitatory-inhibitory synaptic coupling. This effect is generic and observed in different models of bursting neurons and fast synaptic interactions. We also find a universal scaling law for the synchronization stability condition for large networks in terms of the number of excitatory and inhibitory inputs each neuron receives, regardless of the network size and topology. This general law is in sharp contrast with linearly coupled networks with positive (attractive) and negative (repulsive) coupling where the placement and structure of negative connections heavily affect synchronization.

  19. Family and Friends: Which Types of Personal Relationships Go Together in a Network?

    Science.gov (United States)

    Rözer, Jesper; Mollenhorst, Gerald; Poortman, Anne-Rigt

    We examine the link between family and personal networks. Using arguments about meeting opportunities, competition and social influence, we hypothesise how the presence of specific types of family members (i.e., a partner, children, parents and siblings) and non-family members (i.e., friends, neighbours and colleagues) in the network mutually affect one another. In addition, we propose that-beyond their mere presence-the active role of family members in the network strongly affects the presence of non-family members in the network. Data from the third wave of the Survey on the Social Networks of the Dutch, collected in 2012 and 2013, show that active involvement is of key importance; more than merely having family members present in one's personal network, the active involvement of specific types of family members in the personal network is associated with having disproportionally more other family members and having somewhat fewer non-family members in the network.

  20. System markets: Indirect network effects in action, or inaction?

    NARCIS (Netherlands)

    J.L.G. Binken (Jeroen)

    2010-01-01

    textabstractIn this dissertation, I empirically examine system markets up close. More specifically I examine indirect network effects, both demand-side and supply-side indirect network effects. Indirect network effects are the source of positive feedback in system markets, or so network effect

  1. Learning to trust : network effects through time.

    NARCIS (Netherlands)

    Barrera, D.; Bunt, G. van de

    2009-01-01

    This article investigates the effects of information originating from social networks on the development of interpersonal trust relations in the context of a dialysis department of a Dutch medium-sized hospital. Hypotheses on learning effects are developed from existing theories and tested using

  2. Learning to trust: network effects through time

    NARCIS (Netherlands)

    Barrera, D.; van de Bunt, G

    2009-01-01

    This article investigates the effects of information originating from social networks on the development of interpersonal trust relations in the context of a dialysis department of a Dutch medium-sized hospital. Hypotheses on learning effects are developed from existing theories and tested using

  3. Understanding types of organizational networking behaviors in the UK manufacturing sector

    OpenAIRE

    Thornton, Sabrina C.; Henneberg, Stephan C.; Naudé, Peter

    2013-01-01

    This research is aimed at understanding firms' different types of ‘networking behaviors’, i.e., how and why firms affect their strategic network position by activities/routines/practices aimed not just at their business partners, but beyond such direct relationships. Thus, we adopt a network perspective to examine how firms exploit their webs of direct and indirect business relationships in order to assess and embrace the potential opportunities and constraints in the network. Based on the in...

  4. Autocorrelation in queuing network-type production systems - revisited

    DEFF Research Database (Denmark)

    Nielsen, Erland Hejn

    2007-01-01

    In managing production systems, a strong emphasis is placed on the reduction of variance in specific transformation processes (e.g. for quality control purposes) and on controlling the level of variability in general, as for instance with the Bullwhip effect. However, the possible disturbing......, either production managers are missing important aspects in production planning, or the 'realistic' autocorrelation patterns inherent in actual production setups are not like those considered in the literature. In this paper, relevant and 'realistic' types of autocorrelation schemes are characterised...

  5. Early Cerebellar Network Shifting in Spinocerebellar Ataxia Type 6.

    Science.gov (United States)

    Falcon, M I; Gomez, C M; Chen, E E; Shereen, A; Solodkin, A

    2016-07-01

    Spinocerebellar ataxia 6 (SCA6), an autosomal dominant degenerative disease, is characterized by diplopia, gait ataxia, and incoordination due to severe progressive degeneration of Purkinje cells in the vestibulo- and spinocerebellum. Ocular motor deficits are common, including difficulty fixating on moving objects, nystagmus and disruption of smooth pursuit movements. In presymptomatic SCA6, there are alterations in saccades and smooth-pursuit movements. We sought to assess functional and structural changes in cerebellar connectivity associated with a visual task, hypothesizing that gradual changes would parallel disease progression. We acquired functional magnetic resonance imaging and diffusion tensor imaging data during a passive smooth-pursuit task in 14 SCA6 patients, representing a range of disease duration and severity, and performed a cross-sectional comparison of cerebellar networks compared with healthy controls. We identified a shift in activation from vermis in presymptomatic individuals to lateral cerebellum in moderate-to-severe cases. Concomitantly, effective connectivity between regions of cerebral cortex and cerebellum was at its highest in moderate cases, and disappeared in severe cases. Finally, we noted structural differences in the cerebral and cerebellar peduncles. These unique results, spanning both functional and structural domains, highlight widespread changes in SCA6 and compensatory mechanisms associated with cerebellar physiology that could be utilized in developing new therapies. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  6. Network Metamodeling: Effect of Correlation Metric Choice on Phylogenomic and Transcriptomic Network Topology.

    Science.gov (United States)

    Weighill, Deborah A; Jacobson, Daniel

    We explore the use of a network meta-modeling approach to compare the effects of similarity metrics used to construct biological networks on the topology of the resulting networks. This work reviews various similarity metrics for the construction of networks and various topology measures for the characterization of resulting network topology, demonstrating the use of these metrics in the construction and comparison of phylogenomic and transcriptomic networks.

  7. Towards Resilient Critical Infrastructures: Application of Type-2 Fuzzy Logic in Embedded Network Security Cyber Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Ondrej Linda; Todd Vollmer; Jim Alves-Foss; Milos Manic

    2011-08-01

    Resiliency and cyber security of modern critical infrastructures is becoming increasingly important with the growing number of threats in the cyber-environment. This paper proposes an extension to a previously developed fuzzy logic based anomaly detection network security cyber sensor via incorporating Type-2 Fuzzy Logic (T2 FL). In general, fuzzy logic provides a framework for system modeling in linguistic form capable of coping with imprecise and vague meanings of words. T2 FL is an extension of Type-1 FL which proved to be successful in modeling and minimizing the effects of various kinds of dynamic uncertainties. In this paper, T2 FL provides a basis for robust anomaly detection and cyber security state awareness. In addition, the proposed algorithm was specifically developed to comply with the constrained computational requirements of low-cost embedded network security cyber sensors. The performance of the system was evaluated on a set of network data recorded from an experimental cyber-security test-bed.

  8. The African Field Epidemiology Network - Networking for effective ...

    African Journals Online (AJOL)

    Networks are a catalyst for promoting common goals and objectives of their membership. Public Health networks in Africa are crucial, because of the severe resource limitations that nations face in dealing with priority public health problems. For a long time, networks have existed on the continent and globally, but many of ...

  9. Social network types among older Korean adults: Associations with subjective health.

    Science.gov (United States)

    Sohn, Sung Yun; Joo, Won-Tak; Kim, Woo Jung; Kim, Se Joo; Youm, Yoosik; Kim, Hyeon Chang; Park, Yeong-Ran; Lee, Eun

    2017-01-01

    With population aging now a global phenomenon, the health of older adults is becoming an increasingly important issue. Because the Korean population is aging at an unprecedented rate, preparing for public health problems associated with old age is particularly salient in this country. As the physical and mental health of older adults is related to their social relationships, investigating the social networks of older adults and their relationship to health status is important for establishing public health policies. The aims of this study were to identify social network types among older adults in South Korea and to examine the relationship of these social network types with self-rated health and depression. Data from the Korean Social Life, Health, and Aging Project were analyzed. Model-based clustering using finite normal mixture modeling was conducted to identify the social network types based on ten criterion variables of social relationships and activities: marital status, number of children, number of close relatives, number of friends, frequency of attendance at religious services, attendance at organized group meetings, in-degree centrality, out-degree centrality, closeness centrality, and betweenness centrality. Multivariate regression analysis was conducted to examine associations between the identified social network types and self-rated health and depression. The model-based clustering analysis revealed that social networks clustered into five types: diverse, family, congregant, congregant-restricted, and restricted. Diverse or family social network types were significantly associated with more favorable subjective mental health, whereas the restricted network type was significantly associated with poorer ratings of mental and physical health. In addition, our analysis identified unique social network types related to religious activities. In summary, we developed a comprehensive social network typology for older Korean adults. Copyright © 2016

  10. Cohort Differences in Received Social Support in Later Life: The Role of Network Type.

    Science.gov (United States)

    Suanet, Bianca; Antonucci, Toni C

    2017-07-01

    The objective is to assess cohort differences in received emotional and instrumental support in relation to network types. The main guiding hypothesis is that due to increased salience of non-kin with recent social change, those in friend-focused and diverse network types receive more support in later birth cohorts than earlier birth cohorts. Data from the Longitudinal Aging Study Amsterdam are employed. We investigate cohort differences in total received emotional and instrumental support in a series of linear regression models comparing birth cohorts aged 55-64, 65-74, 75-84, and 85-94 across three time periods (1992, 2002, and 2012). Four network types (friend, family, restricted, and diverse) are identified. Friend-focused networks are more common in later birth cohorts, restrictive networks less common. Those in friend-focused networks in later cohorts report receiving more emotional and instrumental support. No differences in received support are evident upon diverse networks. The increased salience of non-kin is reflected in an increase in received emotional and instrumental support in friend-focused networks in later birth cohorts. The preponderance of non-kin in networks should not be perceived as a deficit model for social relationships as restrictive networks are declining across birth cohorts.

  11. Significant Deregulated Pathways in Diabetes Type II Complications Identified through Expression Based Network Biology

    Science.gov (United States)

    Ukil, Sanchaita; Sinha, Meenakshee; Varshney, Lavneesh; Agrawal, Shipra

    Type 2 Diabetes is a complex multifactorial disease, which alters several signaling cascades giving rise to serious complications. It is one of the major risk factors for cardiovascular diseases. The present research work describes an integrated functional network biology approach to identify pathways that get transcriptionally altered and lead to complex complications thereby amplifying the phenotypic effect of the impaired disease state. We have identified two sub-network modules, which could be activated under abnormal circumstances in diabetes. Present work describes key proteins such as P85A and SRC serving as important nodes to mediate alternate signaling routes during diseased condition. P85A has been shown to be an important link between stress responsive MAPK and CVD markers involved in fibrosis. MAPK8 has been shown to interact with P85A and further activate CTGF through VEGF signaling. We have traced a novel and unique route correlating inflammation and fibrosis by considering P85A as a key mediator of signals. The next sub-network module shows SRC as a junction for various signaling processes, which results in interaction between NF-kB and beta catenin to cause cell death. The powerful interaction between these important genes in response to transcriptionally altered lipid metabolism and impaired inflammatory response via SRC causes apoptosis of cells. The crosstalk between inflammation, lipid homeostasis and stress, and their serious effects downstream have been explained in the present analyses.

  12. Reconstruction of genome-scale active metabolic networks for 69 human cell types and 16 cancer types using INIT.

    Directory of Open Access Journals (Sweden)

    Rasmus Agren

    Full Text Available Development of high throughput analytical methods has given physicians the potential access to extensive and patient-specific data sets, such as gene sequences, gene expression profiles or metabolite footprints. This opens for a new approach in health care, which is both personalized and based on system-level analysis. Genome-scale metabolic networks provide a mechanistic description of the relationships between different genes, which is valuable for the analysis and interpretation of large experimental data-sets. Here we describe the generation of genome-scale active metabolic networks for 69 different cell types and 16 cancer types using the INIT (Integrative Network Inference for Tissues algorithm. The INIT algorithm uses cell type specific information about protein abundances contained in the Human Proteome Atlas as the main source of evidence. The generated models constitute the first step towards establishing a Human Metabolic Atlas, which will be a comprehensive description (accessible online of the metabolism of different human cell types, and will allow for tissue-level and organism-level simulations in order to achieve a better understanding of complex diseases. A comparative analysis between the active metabolic networks of cancer types and healthy cell types allowed for identification of cancer-specific metabolic features that constitute generic potential drug targets for cancer treatment.

  13. Net benefits: assessing the effectiveness of clinical networks in Australia through qualitative methods

    Science.gov (United States)

    2012-01-01

    Background In the 21st century, government and industry are supplementing hierarchical, bureaucratic forms of organization with network forms, compatible with principles of devolved governance and decentralization of services. Clinical networks are employed as a key health policy approach to engage clinicians in improving patient care in Australia. With significant investment in such networks in Australia and internationally, it is important to assess their effectiveness and sustainability as implementation mechanisms. Methods In two purposively selected, musculoskeletal clinical networks, members and stakeholders were interviewed to ascertain their perceptions regarding key factors relating to network effectiveness and sustainability. We adopted a three-level approach to evaluating network effectiveness: at the community, network, and member levels, across the network lifecycle. Results Both networks studied are advisory networks displaying characteristics of the ‘enclave’ type of non-hierarchical network. They are hybrids of the mandated and natural network forms. In the short term, at member level, both networks were striving to create connectivity and collaboration of members. Over the short to medium term, at network level, both networks applied multi-disciplinary engagement in successfully developing models of care as key outputs, and disseminating information to stakeholders. In the long term, at both community and network levels, stakeholders would measure effectiveness by the broader statewide influence of the network in changing and improving practice. At community level, in the long term, stakeholders acknowledged both networks had raised the profile, and provided a ‘voice’ for musculoskeletal conditions, evidencing some progress with implementation of the network mission while pursuing additional implementation strategies. Conclusions This research sheds light on stakeholders’ perceptions of assessing clinical network effectiveness at

  14. Net benefits: assessing the effectiveness of clinical networks in Australia through qualitative methods

    Directory of Open Access Journals (Sweden)

    Cunningham Frances C

    2012-11-01

    Full Text Available Abstract Background In the 21st century, government and industry are supplementing hierarchical, bureaucratic forms of organization with network forms, compatible with principles of devolved governance and decentralization of services. Clinical networks are employed as a key health policy approach to engage clinicians in improving patient care in Australia. With significant investment in such networks in Australia and internationally, it is important to assess their effectiveness and sustainability as implementation mechanisms. Methods In two purposively selected, musculoskeletal clinical networks, members and stakeholders were interviewed to ascertain their perceptions regarding key factors relating to network effectiveness and sustainability. We adopted a three-level approach to evaluating network effectiveness: at the community, network, and member levels, across the network lifecycle. Results Both networks studied are advisory networks displaying characteristics of the ‘enclave’ type of non-hierarchical network. They are hybrids of the mandated and natural network forms. In the short term, at member level, both networks were striving to create connectivity and collaboration of members. Over the short to medium term, at network level, both networks applied multi-disciplinary engagement in successfully developing models of care as key outputs, and disseminating information to stakeholders. In the long term, at both community and network levels, stakeholders would measure effectiveness by the broader statewide influence of the network in changing and improving practice. At community level, in the long term, stakeholders acknowledged both networks had raised the profile, and provided a ‘voice’ for musculoskeletal conditions, evidencing some progress with implementation of the network mission while pursuing additional implementation strategies. Conclusions This research sheds light on stakeholders’ perceptions of assessing clinical

  15. Neural Network-Based Passive Filtering for Delayed Neutral-Type Semi-Markovian Jump Systems.

    Science.gov (United States)

    Shi, Peng; Li, Fanbiao; Wu, Ligang; Lim, Cheng-Chew

    2017-09-01

    This paper investigates the problem of exponential passive filtering for a class of stochastic neutral-type neural networks with both semi-Markovian jump parameters and mixed time delays. Our aim is to estimate the states by designing a Luenberger-type observer, such that the filter error dynamics are mean-square exponentially stable with an expected decay rate and an attenuation level. Sufficient conditions for the existence of passive filters are obtained, and a convex optimization algorithm for the filter design is given. In addition, a cone complementarity linearization procedure is employed to cast the nonconvex feasibility problem into a sequential minimization problem, which can be readily solved by the existing optimization techniques. Numerical examples are given to demonstrate the effectiveness of the proposed techniques.

  16. Distinct behavioural and network correlates of two interneuron types in prefrontal cortex.

    Science.gov (United States)

    Kvitsiani, D; Ranade, S; Hangya, B; Taniguchi, H; Huang, J Z; Kepecs, A

    2013-06-20

    Neurons in the prefrontal cortex exhibit diverse behavioural correlates, an observation that has been attributed to cell-type diversity. To link identified neuron types with network and behavioural functions, we recorded from the two largest genetically defined inhibitory interneuron classes, the perisomatically targeting parvalbumin (PV) and the dendritically targeting somatostatin (SOM) neurons in anterior cingulate cortex of mice performing a reward foraging task. Here we show that PV and a subtype of SOM neurons form functionally homogeneous populations showing a double dissociation between both their inhibitory effects and behavioural correlates. Out of several events pertaining to behaviour, a subtype of SOM neurons selectively responded at reward approach, whereas PV neurons responded at reward leaving and encoded preceding stay duration. These behavioural correlates of PV and SOM neurons defined a behavioural epoch and a decision variable important for foraging (whether to stay or to leave), a crucial function attributed to the anterior cingulate cortex. Furthermore, PV neurons could fire in millisecond synchrony, exerting fast and powerful inhibition on principal cell firing, whereas the inhibitory effect of SOM neurons on firing output was weak and more variable, consistent with the idea that they respectively control the outputs of, and inputs to, principal neurons. These results suggest a connection between the circuit-level function of different interneuron types in regulating the flow of information and the behavioural functions served by the cortical circuits. Moreover, these observations bolster the hope that functional response diversity during behaviour can in part be explained by cell-type diversity.

  17. Definition of Type of Single-Phase Fault in Overhead Power Distribution Networks with Isolated Neutral

    Directory of Open Access Journals (Sweden)

    E. Kalentionok

    2012-01-01

    Full Text Available The paper considers the distinctive features of different types of single-phase damage in the distribution networks. By results of researches the algorithm is developed for definition of type of single-phase damage on the basis of the information on emergency operation parameters.The results can be used in devices of microprocessor relay protection when implementing a function fault location in distribution power networks.

  18. Social Network Type and Long-Term Condition Management Support: A Cross-Sectional Study in Six European Countries

    NARCIS (Netherlands)

    Vassilev, I.; Rogers, A.; Kennedy, A.; Wensing, M.; Koetsenruijter, J.; Orlando, R.; Portillo, M.C.; Culliford, D.

    2016-01-01

    BACKGROUND: Network types and characteristics have been linked to the capacity of inter-personal environments to mobilise and share resources. The aim of this paper is to examine personal network types in relation to long-term condition management in order to identify the properties of network types

  19. High-dose aspirin is required to influence plasma fibrin network structure in patients with type 1 diabetes.

    Science.gov (United States)

    Tehrani, Sara; Antovic, Aleksandra; Mobarrez, Fariborz; Mageed, Koteiba; Lins, Per-Eric; Adamson, Ulf; Wallén, Håkan N; Jörneskog, Gun

    2012-02-01

    Patients with type 1 diabetes form a less permeable fibrin network, which could contribute to their increased risk of cardiovascular disease (CVD). Low-dose aspirin treatment is the standard in the management of CVD; however, the effect seems reduced in patients with diabetes. We investigated the effects of low- and high-dose aspirin treatment on fibrin network formation in patients with type 1 diabetes (primary aim) and the possible interaction between the treatment effects of aspirin on fibrin network permeability and glycemic control in these patients (secondary aim). Forty-eight patients (24 subjects with good [HbA(1c) 8.4%] glycemic control) were randomly assigned to treatment with 75 or 320 mg/day aspirin during 4 weeks in a crossover fashion. A 4-week washout period separated the treatment periods. The plasma fibrin network was assessed by determination of the permeability coefficient (K(s)). Treatment with 75 mg aspirin did not influence fibrin network permeability (K(s)). However, K(s) increased significantly during treatment with 320 mg aspirin (P = 0.004), and a significant treatment effect was seen compared with treatment with 75 mg aspirin (P = 0.009). The increase in K(s) during high-dose aspirin treatment was significant in patients with poor glycemic control (P = 0.02), whereas K(s) only tended to increase in patients with good glycemic control (P = 0.06). A high dose of aspirin is required to influence fibrin network permeability in patients with type 1 diabetes. The observed lack of effect with low-dose aspirin may contribute to aspirin treatment failure in diabetes.

  20. Adolescent Social Networks and Alcohol Use: Variability by Gender and Type.

    Science.gov (United States)

    Jacobs, Wura; Goodson, Patricia; Barry, Adam E; McLeroy, Kenneth R; McKyer, E Lisako J; Valente, Thomas W

    2017-03-21

    Scientists have established that social networks influence adolescents' substance use behavior, an influence that varies by gender. However, the role of gender in this mechanism of influence remains poorly understood. Particularly, the role an adolescent's gender, alongside the gender composition of his/her network, plays in facilitating or constraining alcohol use is still unclear. This study examined the associations among the gender composition of adolescents' networks, select network characteristics, intrapersonal and interpersonal factors, and alcohol use among a sample of adolescents in the United States. We assessed cross-sectional data from a 2010 study of 1,523 high school students from a school district in Los Angeles. Analyses of adolescents' network characteristics were conducted using UCINET 6; and logistic regression analyses testing the associations between gender composition of the network and alcohol use were conducted using SPSS 20. Our results indicate that the gender composition of adolescents' networks in our sample is associated with alcohol use. Adolescents in predominantly female or predominantly male friendship networks were less likely to report alcohol use compared to adolescents in an equal/balanced network. In addition, depending upon the context/type of network, intrapersonal and interpersonal factors varied in their association with alcohol use. Conclusions/Importance: Based on these findings, we make several recommendations for the future research. We call for researchers to further examine gender as a risk factor for alcohol abuse, particularly within the complex interplay between gender and network contexts.

  1. A Deployment Strategy for Multiple Types of Requirements in Wireless Sensor Networks.

    Science.gov (United States)

    Liu, Xuxun

    2015-10-01

    Node deployment is one of the most crucial issues in wireless sensor networks, and it is of realistic significance to complete the deployment task with multiple types of application requirements. In this paper, we propose a deployment strategy for multiple types of requirements to solve the problem of deterministic and grid-based deployment. This deployment strategy consists of three deployment algorithms, which are for different deployment objectives. First, instead of general random search, we put forward a deterministic search mechanism and the related cost-based deployment algorithm, in which nodes are assigned to different groups which are connected by near-shortest paths, and realize significant reduction of path length and deployment cost. Second, rather than ordinary nondirection deployment, we present a notion of counterflow and the related delay-based deployment algorithm, in which the profit of deployment cost and loss of transmission delay are evaluated, and achieve much diminishing of transmission path length and transmission delay. Third, instead of conventional uneven deployment based on the distances to the sink, we propose a concept of node load level and the related lifetime-based deployment algorithm, in which node distribution is determined by the actual load levels and extra nodes are deployed only where really necessary. This contributes to great improvement of network lifetime. Last, extensive simulations are used to test and verify the effectiveness and superiority of our findings.

  2. Hybrid Generalised Additive Type-2 Fuzzy-Wavelet-Neural Network in Dynamic Data Mining

    Directory of Open Access Journals (Sweden)

    Bodyanskiy Yevgeniy

    2015-12-01

    Full Text Available In the paper, a new hybrid system of computational intelligence is proposed. This system combines the advantages of neuro-fuzzy system of Takagi-Sugeno-Kang, type-2 fuzzy logic, wavelet neural networks and generalised additive models of Hastie-Tibshirani. The proposed system has universal approximation properties and learning capability based on the experimental data sets which pertain to the neural networks and neuro-fuzzy systems; interpretability and transparency of the obtained results due to the soft computing systems and, first of all, due to type-2 fuzzy systems; possibility of effective description of local signal and process features due to the application of systems based on wavelet transform; simplicity and speed of learning process due to generalised additive models. The proposed system can be used for solving a wide class of dynamic data mining tasks, which are connected with non-stationary, nonlinear stochastic and chaotic signals. Such a system is sufficiently simple in numerical implementation and is characterised by a high speed of learning and information processing.

  3. Auditing the Assignments of Top-Level Semantic Types in the UMLS Semantic Network to UMLS Concepts.

    Science.gov (United States)

    He, Zhe; Perl, Yehoshua; Elhanan, Gai; Chen, Yan; Geller, James; Bian, Jiang

    2017-11-01

    The Unified Medical Language System (UMLS) is an important terminological system. By the policy of its curators, each concept of the UMLS should be assigned the most specific Semantic Types (STs) in the UMLS Semantic Network (SN). Hence, the Semantic Types of most UMLS concepts are assigned at or near the bottom (leaves) of the UMLS Semantic Network. While most ST assignments are correct, some errors do occur. Therefore, Quality Assurance efforts of UMLS curators for ST assignments should concentrate on automatically detected sets of UMLS concepts with higher error rates than random sets. In this paper, we investigate the assignments of top-level semantic types in the UMLS semantic network to concepts, identify potential erroneous assignments, define four categories of errors, and thus provide assistance to curators of the UMLS to avoid these assignments errors. Human experts analyzed samples of concepts assigned 10 of the top-level semantic types and categorized the erroneous ST assignments into these four logical categories. Two thirds of the concepts assigned these 10 top-level semantic types are erroneous. Our results demonstrate that reviewing top-level semantic type assignments to concepts provides an effective way for UMLS quality assurance, comparing to reviewing a random selection of semantic type assignments.

  4. Network analysis of pig movements: Loyalty patterns and contact chains of different holding types in Denmark

    DEFF Research Database (Denmark)

    Schulz, Jana; Boklund, Anette; Hisham Beshara Halasa, Tariq

    2017-01-01

    Understanding animal movements is an important factor for the development of meaningful surveillance and control programs, but also for the development of disease spread models. We analysed the Danish pig movement network using static and temporal network analysis tools to provide deeper insight......, the number of registered movements and the number of pigs moved. To identify holdings and holding types with potentially higher risk for introduction or spread of diseases via pig movements, we determined loyalty patterns, annual network components and contact chains for the 24 registered holding types...... potential of spreading diseases and thus limit the outbreak size or support control or eradication of the considered pathogen....

  5. Different types of laughter modulate connectivity within distinct parts of the laughter perception network.

    Directory of Open Access Journals (Sweden)

    Dirk Wildgruber

    Full Text Available Laughter is an ancient signal of social communication among humans and non-human primates. Laughter types with complex social functions (e.g., taunt and joy presumably evolved from the unequivocal and reflex-like social bonding signal of tickling laughter already present in non-human primates. Here, we investigated the modulations of cerebral connectivity associated with different laughter types as well as the effects of attention shifts between implicit and explicit processing of social information conveyed by laughter using functional magnetic resonance imaging (fMRI. Complex social laughter types and tickling laughter were found to modulate connectivity in two distinguishable but partially overlapping parts of the laughter perception network irrespective of task instructions. Connectivity changes, presumably related to the higher acoustic complexity of tickling laughter, occurred between areas in the prefrontal cortex and the auditory association cortex, potentially reflecting higher demands on acoustic analysis associated with increased information load on auditory attention, working memory, evaluation and response selection processes. In contrast, the higher degree of socio-relational information in complex social laughter types was linked to increases of connectivity between auditory association cortices, the right dorsolateral prefrontal cortex and brain areas associated with mentalizing as well as areas in the visual associative cortex. These modulations might reflect automatic analysis of acoustic features, attention direction to informative aspects of the laughter signal and the retention of those in working memory during evaluation processes. These processes may be associated with visual imagery supporting the formation of inferences on the intentions of our social counterparts. Here, the right dorsolateral precentral cortex appears as a network node potentially linking the functions of auditory and visual associative sensory cortices

  6. Models of Hopfield-type quaternion neural networks and their energy functions.

    Science.gov (United States)

    Yoshida, Mitsuo; Kuroe, Yasuaki; Mori, Takehiro

    2005-01-01

    Recently models of neural networks that can directly deal with complex numbers, complex-valued neural networks, have been proposed and several studies on their abilities of information processing have been done. Furthermore models of neural networks that can deal with quaternion numbers, which is the extension of complex numbers, have also been proposed. However they are all multilayer quaternion neural networks. This paper proposes models of fully connected recurrent quaternion neural networks, Hopfield-type quaternion neural networks. Since quaternion numbers are non-commutative on multiplication, some different models can be considered. We investigate dynamics of these proposed models from the point of view of the existence of an energy function and derive their conditions for existence.

  7. Physics of soft hyaluronic acid-collagen type II double network gels

    Science.gov (United States)

    Morozova, Svetlana; Muthukumar, Murugappan

    2015-03-01

    Many biological hydrogels are made up of multiple interpenetrating, charged components. We study the swelling, elastic diffusion, mechanical, and optical behaviors of 100 mol% ionizable hyaluronic acid (HA) and collagen type II fiber networks. Dilute, 0.05-0.5 wt% hyaluronic acid networks are extremely sensitive to solution salt concentration, but are stable at pH above 2. When swelled in 0.1M NaCl, single-network hyaluronic acid gels follow scaling laws relevant to high salt semidilute solutions; the elastic shear modulus G' and diffusion constant D scale with the volume fraction ϕ as G' ~ϕ 9 / 4 and D ~ϕ 3 / 4 , respectively. With the addition of a collagen fiber network, we find that the hyaluronic acid network swells to suspend the rigid collagen fibers, providing extra strength to the hydrogel. Results on swelling equilibria, elasticity, and collective diffusion on these double network hydrogels will be presented.

  8. Neural Networks For Electrohydrodynamic Effect Modelling

    Directory of Open Access Journals (Sweden)

    Wiesław Wajs

    2004-01-01

    Full Text Available This paper presents currently achieved results concerning methods of electrohydrodynamiceffect used in geophysics simulated with feedforward networks trained with backpropagation algorithm, radial basis function networks and generalized regression networks.

  9. Atmospheric icing status and type of southwest China networks

    Directory of Open Access Journals (Sweden)

    Li Yawei

    2016-01-01

    Full Text Available Transmission line disconnection, tower collapse and insulator flashover caused by icing seriously threaten power system security. Ice type and state of transmission lines, which vary a lot with terrain and climate, in typical areas such as Daqing-ridge, Yak Mountain and Erlang Mountain in Sichuan Province in South China were investigated in this paper. It is shown that mixed-phase ice with obvious layered structure, low density, strong adhesive force and windward-side growth is the main type of ice threatening the security of transmission lines and insulators. There is more ice on the ends of insulators than other areas in severe cases, where all sheds of the insulator is bridged by ice. Besides, temperature, humidity and precipitation intensity are main factors influencing the icing process. As a result, terrain and climate play a leading role in determination of icing type and severity.

  10. Effects of network node consolidation in optical access and aggregation networks on costs and power consumption

    Science.gov (United States)

    Lange, Christoph; Hülsermann, Ralf; Kosiankowski, Dirk; Geilhardt, Frank; Gladisch, Andreas

    2010-01-01

    The increasing demand for higher bit rates in access networks requires fiber deployment closer to the subscriber resulting in fiber-to-the-home (FTTH) access networks. Besides higher access bit rates optical access network infrastructure and related technologies enable the network operator to establish larger service areas resulting in a simplified network structure with a lower number of network nodes. By changing the network structure network operators want to benefit from a changed network cost structure by decreasing in short and mid term the upfront investments for network equipment due to concentration effects as well as by reducing the energy costs due to a higher energy efficiency of large network sites housing a high amount of network equipment. In long term also savings in operational expenditures (OpEx) due to the closing of central office (CO) sites are expected. In this paper different architectures for optical access networks basing on state-of-the-art technology are analyzed with respect to network installation costs and power consumption in the context of access node consolidation. Network planning and dimensioning results are calculated for a realistic network scenario of Germany. All node consolidation scenarios are compared against a gigabit capable passive optical network (GPON) based FTTH access network operated from the conventional CO sites. The results show that a moderate reduction of the number of access nodes may be beneficial since in that case the capital expenditures (CapEx) do not rise extraordinarily and savings in OpEx related to the access nodes are expected. The total power consumption does not change significantly with decreasing number of access nodes but clustering effects enable a more energyefficient network operation and optimized power purchase order quantities leading to benefits in energy costs.

  11. Network effects of deep brain stimulation.

    Science.gov (United States)

    Alhourani, Ahmad; McDowell, Michael M; Randazzo, Michael J; Wozny, Thomas A; Kondylis, Efstathios D; Lipski, Witold J; Beck, Sarah; Karp, Jordan F; Ghuman, Avniel S; Richardson, R Mark

    2015-10-01

    The ability to differentially alter specific brain functions via deep brain stimulation (DBS) represents a monumental advance in clinical neuroscience, as well as within medicine as a whole. Despite the efficacy of DBS in the treatment of movement disorders, for which it is often the gold-standard therapy when medical management becomes inadequate, the mechanisms through which DBS in various brain targets produces therapeutic effects is still not well understood. This limited knowledge is a barrier to improving efficacy and reducing side effects in clinical brain stimulation. A field of study related to assessing the network effects of DBS is gradually emerging that promises to reveal aspects of the underlying pathophysiology of various brain disorders and their response to DBS that will be critical to advancing the field. This review summarizes the nascent literature related to network effects of DBS measured by cerebral blood flow and metabolic imaging, functional imaging, and electrophysiology (scalp and intracranial electroencephalography and magnetoencephalography) in order to establish a framework for future studies. Copyright © 2015 the American Physiological Society.

  12. Сhoosing the best type neural network jet contour diagnostics engines

    Directory of Open Access Journals (Sweden)

    О.С. Якушенко

    2006-01-01

    Full Text Available  In the paper the  choice problems of neurons  type for neural network is considered. The neurons types has to be , optimal from the point of work stability, training speed and quality of gas turbine engine  technical condition class recognition by work process parameters. Results of researches are given.

  13. Aberrant functional connectivity of default-mode network in type 2 diabetes patients

    Energy Technology Data Exchange (ETDEWEB)

    Cui, Ying; Jiao, Yun; Chen, Hua-Jun; Ding, Jie; Luo, Bing; Peng, Cheng-Yu; Ju, Sheng-Hong; Teng, Gao-Jun [Medical School of Southeast University, Jiangsu Key Laboratory of Molecular and Functional Imaging, Department of Radiology, Zhongda Hospital, Nanjing, Jiangsu (China)

    2015-11-15

    Type 2 diabetes mellitus is associated with increased risk for dementia. Patients with impaired cognition often show default-mode network disruption. We aimed to investigate the integrity of a default-mode network in diabetic patients by using independent component analysis, and to explore the relationship between network abnormalities, neurocognitive performance and diabetic variables. Forty-two patients with type 2 diabetes and 42 well-matched healthy controls were included and underwent resting-state functional MRI in a 3 Tesla unit. Independent component analysis was adopted to extract the default-mode network, including its anterior and posterior components. Z-maps of both sub-networks were compared between the two groups and correlated with each clinical variable. Patients showed increased connectivity around the medial prefrontal cortex in the anterior sub-network, but decreased connectivity around the posterior cingulate cortex in the posterior sub-network. The decreased connectivity in the posterior part was significantly correlated with the score on Complex Figure Test-delay recall test (r = 0.359, p = 0.020), the time spent on Trail-Making Test-part B (r = -0.346, p = 0.025) and the insulin resistance level (r = -0.404, p = 0.024). Dissociation pattern in the default-mode network was found in diabetic patients, which might provide powerful new insights into the neural mechanisms that underlie the diabetes-related cognitive decline. (orig.)

  14. Effect of synapse dilution on the memory retrieval in structured attractor neural networks

    Science.gov (United States)

    Brunel, N.

    1993-08-01

    We investigate a simple model of structured attractor neural network (ANN). In this network a module codes for the category of the stored information, while another group of neurons codes for the remaining information. The probability distribution of stabilities of the patterns and the prototypes of the categories are calculated, for two different synaptic structures. The stability of the prototypes is shown to increase when the fraction of neurons coding for the category goes down. Then the effect of synapse destruction on the retrieval is studied in two opposite situations : first analytically in sparsely connected networks, then numerically in completely connected ones. In both cases the behaviour of the structured network and that of the usual homogeneous networks are compared. When lesions increase, two transitions are shown to appear in the behaviour of the structured network when one of the patterns is presented to the network. After the first transition the network recognizes the category of the pattern but not the individual pattern. After the second transition the network recognizes nothing. These effects are similar to syndromes caused by lesions in the central visual system, namely prosopagnosia and agnosia. In both types of networks (structured or homogeneous) the stability of the prototype is greater than the stability of individual patterns, however the first transition, for completely connected networks, occurs only when the network is structured.

  15. Social Network Type and Long-Term Condition Management Support: A Cross-Sectional Study in Six European Countries.

    Science.gov (United States)

    Vassilev, Ivaylo; Rogers, Anne; Kennedy, Anne; Wensing, Michel; Koetsenruijter, Jan; Orlando, Rosanna; Portillo, Maria Carmen; Culliford, David

    2016-01-01

    Network types and characteristics have been linked to the capacity of inter-personal environments to mobilise and share resources. The aim of this paper is to examine personal network types in relation to long-term condition management in order to identify the properties of network types most likely to provide support for those with a long-term condition. A cross-sectional observational survey of people with type 2 diabetes using interviews and questionnaires was conducted between April and October 2013 in six European countries: Greece, Spain, Bulgaria, Norway, United Kingdom, and Netherlands. 1862 people with predominantly lower socio-economic status were recruited from each country. We used k-means clustering analysis to derive the network types, and one-way analysis of variance and multivariate logistic regression analysis to explore the relationship between network type socio-economic characteristics, self-management monitoring and skills, well-being, and network member work. Five network types of people with long-term conditions were identified: restricted, minimal family, family, weak ties, and diverse. Restricted network types represented those with the poorest self-management skills and were associated with limited support from social network members. Restricted networks were associated with poor indicators across self-management capacity, network support, and well-being. Diverse networks were associated with more enhanced self-management skills amongst those with a long-term condition and high level of emotional support. It was the three network types which had a large number of network members (diverse, weak ties, and family) where healthcare utilisation was most likely to correspond to existing health needs. Our findings suggest that type of increased social involvement is linked to greater self-management capacity and potentially lower formal health care costs indicating that diverse networks constitute the optimal network type as a policy in terms of

  16. Novel Robust Exponential Stability of Markovian Jumping Impulsive Delayed Neural Networks of Neutral-Type with Stochastic Perturbation

    Directory of Open Access Journals (Sweden)

    Yang Fang

    2016-01-01

    Full Text Available The robust exponential stability problem for a class of uncertain impulsive stochastic neural networks of neutral-type with Markovian parameters and mixed time-varying delays is investigated. By constructing a proper exponential-type Lyapunov-Krasovskii functional and employing Jensen integral inequality, free-weight matrix method, some novel delay-dependent stability criteria that ensure the robust exponential stability in mean square of the trivial solution of the considered networks are established in the form of linear matrix inequalities (LMIs. The proposed results do not require the derivatives of discrete and distributed time-varying delays to be 0 or smaller than 1. Moreover, the main contribution of the proposed approach compared with related methods lies in the use of three types of impulses. Finally, two numerical examples are worked out to verify the effectiveness and less conservativeness of our theoretical results over existing literature.

  17. Almost Sure Asymptotical Adaptive Synchronization for Neutral-Type Neural Networks with Stochastic Perturbation and Markovian Switching

    Directory of Open Access Journals (Sweden)

    Wuneng Zhou

    2014-01-01

    Full Text Available The problem of almost sure (a.s. asymptotic adaptive synchronization for neutral-type neural networks with stochastic perturbation and Markovian switching is researched. Firstly, we proposed a new criterion of a.s. asymptotic stability for a general neutral-type stochastic differential equation which extends the existing results. Secondly, based upon this stability criterion, by making use of Lyapunov functional method and designing an adaptive controller, we obtained a condition of a.s. asymptotic adaptive synchronization for neutral-type neural networks with stochastic perturbation and Markovian switching. The synchronization condition is expressed as linear matrix inequality which can be easily solved by Matlab. Finally, we introduced a numerical example to illustrate the effectiveness of the method and result obtained in this paper.

  18. Nonlinear dynamic systems identification using recurrent interval type-2 TSK fuzzy neural network - A novel structure.

    Science.gov (United States)

    El-Nagar, Ahmad M

    2017-10-31

    In this study, a novel structure of a recurrent interval type-2 Takagi-Sugeno-Kang (TSK) fuzzy neural network (FNN) is introduced for nonlinear dynamic and time-varying systems identification. It combines the type-2 fuzzy sets (T2FSs) and a recurrent FNN to avoid the data uncertainties. The fuzzy firing strengths in the proposed structure are returned to the network input as internal variables. The interval type-2 fuzzy sets (IT2FSs) is used to describe the antecedent part for each rule while the consequent part is a TSK-type, which is a linear function of the internal variables and the external inputs with interval weights. All the type-2 fuzzy rules for the proposed RIT2TSKFNN are learned on-line based on structure and parameter learning, which are performed using the type-2 fuzzy clustering. The antecedent and consequent parameters of the proposed RIT2TSKFNN are updated based on the Lyapunov function to achieve network stability. The obtained results indicate that our proposed network has a small root mean square error (RMSE) and a small integral of square error (ISE) with a small number of rules and a small computation time compared with other type-2 FNNs. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  19. Topological effects of network structure on long-term social network dynamics in a wild mammal.

    Science.gov (United States)

    Ilany, Amiyaal; Booms, Andrew S; Holekamp, Kay E

    2015-07-01

    Social structure influences ecological processes such as dispersal and invasion, and affects survival and reproductive success. Recent studies have used static snapshots of social networks, thus neglecting their temporal dynamics, and focused primarily on a limited number of variables that might be affecting social structure. Here, instead we modelled effects of multiple predictors of social network dynamics in the spotted hyena, using observational data collected during 20 years of continuous field research in Kenya. We tested the hypothesis that the current state of the social network affects its long-term dynamics. We employed stochastic agent-based models that allowed us to estimate the contribution of multiple factors to network changes. After controlling for environmental and individual effects, we found that network density and individual centrality affected network dynamics, but that social bond transitivity consistently had the strongest effects. Our results emphasise the significance of structural properties of networks in shaping social dynamics. © 2015 John Wiley & Sons Ltd/CNRS.

  20. Coexisting Behaviors of Asymmetric Attractors in Hyperbolic-Type Memristor based Hopfield Neural Network

    Directory of Open Access Journals (Sweden)

    Bocheng Bao

    2017-08-01

    Full Text Available A new hyperbolic-type memristor emulator is presented and its frequency-dependent pinched hysteresis loops are analyzed by numerical simulations and confirmed by hardware experiments. Based on the emulator, a novel hyperbolic-type memristor based 3-neuron Hopfield neural network (HNN is proposed, which is achieved through substituting one coupling-connection weight with a memristive synaptic weight. It is numerically shown that the memristive HNN has a dynamical transition from chaotic, to periodic, and further to stable point behaviors with the variations of the memristor inner parameter, implying the stabilization effect of the hyperbolic-type memristor on the chaotic HNN. Of particular interest, it should be highly stressed that for different memristor inner parameters, different coexisting behaviors of asymmetric attractors are emerged under different initial conditions, leading to the existence of multistable oscillation states in the memristive HNN. Furthermore, by using commercial discrete components, a nonlinear circuit is designed and PSPICE circuit simulations and hardware experiments are performed. The results simulated and captured from the realization circuit are consistent with numerical simulations, which well verify the facticity of coexisting asymmetric attractors' behaviors.

  1. Diagnosis of Cervical Cancer Using the Median M-Type Radial Basis Function (MMRBF) Neural Network

    Science.gov (United States)

    Gómez-Mayorga, Margarita E.; Gallegos-Funes, Francisco J.; de-La-Rosa-Vázquez, José M.; Cruz-Santiago, Rene; Ponomaryov, Volodymyr

    The automatic analysis of Pap smear microscopic images is one of the most interesting fields in biomedical image processing. In this paper we present the capability of the Median M-Type Radial Basis Function (MMRBF) neural network in the classification of cervical cancer cells. From simulation results we observe that the MMRBF neural network has better classification capabilities in comparison with the Median RBF algorithm used as comparative.

  2. Bayesian estimation inherent in a Mexican-hat-type neural network

    Science.gov (United States)

    Takiyama, Ken

    2016-05-01

    Brain functions, such as perception, motor control and learning, and decision making, have been explained based on a Bayesian framework, i.e., to decrease the effects of noise inherent in the human nervous system or external environment, our brain integrates sensory and a priori information in a Bayesian optimal manner. However, it remains unclear how Bayesian computations are implemented in the brain. Herein, I address this issue by analyzing a Mexican-hat-type neural network, which was used as a model of the visual cortex, motor cortex, and prefrontal cortex. I analytically demonstrate that the dynamics of an order parameter in the model corresponds exactly to a variational inference of a linear Gaussian state-space model, a Bayesian estimation, when the strength of recurrent synaptic connectivity is appropriately stronger than that of an external stimulus, a plausible condition in the brain. This exact correspondence can reveal the relationship between the parameters in the Bayesian estimation and those in the neural network, providing insight for understanding brain functions.

  3. Bayesian estimation inherent in a Mexican-hat-type neural network.

    Science.gov (United States)

    Takiyama, Ken

    2016-05-01

    Brain functions, such as perception, motor control and learning, and decision making, have been explained based on a Bayesian framework, i.e., to decrease the effects of noise inherent in the human nervous system or external environment, our brain integrates sensory and a priori information in a Bayesian optimal manner. However, it remains unclear how Bayesian computations are implemented in the brain. Herein, I address this issue by analyzing a Mexican-hat-type neural network, which was used as a model of the visual cortex, motor cortex, and prefrontal cortex. I analytically demonstrate that the dynamics of an order parameter in the model corresponds exactly to a variational inference of a linear Gaussian state-space model, a Bayesian estimation, when the strength of recurrent synaptic connectivity is appropriately stronger than that of an external stimulus, a plausible condition in the brain. This exact correspondence can reveal the relationship between the parameters in the Bayesian estimation and those in the neural network, providing insight for understanding brain functions.

  4. The nature and types of network relations in distribution of metallurgical products

    Directory of Open Access Journals (Sweden)

    2010-12-01

    Full Text Available The article analyses the motives for establishing cooperation within a company supply network as division points in a supplies chain of metallurgical products. The division points were defined and identified at the level of service centres in the investigated chain. The analysis took into consideration various types of inter-organisational bonds, which are placed in the network relations classification matrix. The study concerns a complex distribution system. The analysed distribution network combines flows characteristic for both flexible and narrow supply chains.

  5. Variations in Social Network Type Membership Among Older African Americans, Caribbean Blacks, and Non-Hispanic Whites.

    Science.gov (United States)

    Nguyen, Ann W

    2017-07-01

    This study examined race differences in the probability of belonging to a specific social network typology of family, friends, and church members. Samples of African Americans, Caribbean blacks, and non-Hispanic whites aged 55+ were drawn from the National Survey of American Life. Typology indicators related to social integration and negative interactions with family, friendship, and church networks were used. Latent class analysis was used to identify typologies, and latent class multinomial logistic regression was used to assess the influence of race, and interactions between race and age, and race and education on typology membership. Four network typologies were identified: optimal (high social integration, low negative interaction), family-centered (high social integration within primarily the extended family network, low negative interaction), strained (low social integration, high negative interaction), and ambivalent (high social integration and high negative interaction). Findings for race and age and race and education interactions indicated that the effects of education and age on typology membership varied by race. Overall, the findings demonstrate how race interacts with age and education to influence the probability of belonging to particular network types. A better understanding of the influence of race, education, and age on social network typologies will inform future research and theoretical developments in this area.

  6. Enriching an effect calculus with linear types

    DEFF Research Database (Denmark)

    Egger, Jeff; Møgelberg, Rasmus Ejlers; Simpson, Alex

    2009-01-01

    We define an ``enriched effect calculus'' by conservatively extending  a type theory for computational effects with primitives from linear logic. By doing so, we obtain a generalisation of linear type theory, intended as a formalism for expressing linear aspects of effects. As a worked example, we...... formulate  linearly-used continuations in the enriched effect calculus. These are captured by a fundamental translation of the enriched effect calculus into itself, which extends existing call-by-value and call-by-name linearly-used CPS translations. We show that our translation is involutive. Full...... completeness results for the various linearly-used CPS translations  follow. Our main results, the conservativity of enriching the effect calculus with linear primitives, and the involution property of the fundamental translation, are proved using a category-theoretic semantics for the enriched effect calculus...

  7. New backpropagation algorithm with type-2 fuzzy weights for neural networks

    CERN Document Server

    Gaxiola, Fernando; Valdez, Fevrier

    2016-01-01

    In this book a neural network learning method with type-2 fuzzy weight adjustment is proposed. The mathematical analysis of the proposed learning method architecture and the adaptation of type-2 fuzzy weights are presented. The proposed method is based on research of recent methods that handle weight adaptation and especially fuzzy weights. The internal operation of the neuron is changed to work with two internal calculations for the activation function to obtain two results as outputs of the proposed method. Simulation results and a comparative study among monolithic neural networks, neural network with type-1 fuzzy weights and neural network with type-2 fuzzy weights are presented to illustrate the advantages of the proposed method. The proposed approach is based on recent methods that handle adaptation of weights using fuzzy logic of type-1 and type-2. The proposed approach is applied to a cases of prediction for the Mackey-Glass (for ô=17) and Dow-Jones time series, and recognition of person with iris bi...

  8. The Effect of Road Transport Network on Agricultural Produce ...

    African Journals Online (AJOL)

    The study focused on the effects of road transport network on agricultural produce marketing in Giwa Local Government Area of Kaduna state. It took a critical look at the development of road network connectivity and the development of markets with a view to understand the level to which this network components affected ...

  9. Damage spreading on networks: Clustering effects

    Indian Academy of Sciences (India)

    The damage spreading of the Ising model on three kinds of networks is studied with Glauber dynamics. One of the networks is generated by evolving the hexagonal lattice with the star-triangle transformation. Another kind of network is constructed by connecting the midpoints of the edges of the topological hexagonal lattice.

  10. Social network types and functional dependency in older adults in Mexico

    Directory of Open Access Journals (Sweden)

    Espinosa-Alarcón Patricia

    2010-02-01

    Full Text Available Abstract Background Social networks play a key role in caring for older adults. A better understanding of the characteristics of different social networks types (TSNs in a given community provides useful information for designing policies to care for this age group. Therefore this study has three objectives: 1 To derive the TSNs among older adults affiliated with the Mexican Institute of Social Security; 2 To describe the main characteristics of the older adults in each TSN, including the instrumental and economic support they receive and their satisfaction with the network; 3 To determine the association between functional dependency and the type of social network. Methods Secondary data analysis of the 2006 Survey of Autonomy and Dependency (N = 3,348. The TSNs were identified using the structural approach and cluster analysis. The association between functional dependency and the TSNs was evaluated with Poisson regression with robust variance analysis in which socio-demographic characteristics, lifestyle and medical history covariates were included. Results We identified five TSNs: diverse with community participation (12.1%, diverse without community participation (44.3%; widowed (32.0%; nonfriends-restricted (7.6%; nonfamily-restricted (4.0%. Older adults belonging to widowed and restricted networks showed a higher proportion of dependency, negative self-rated health and depression. Older adults with functional dependency more likely belonged to a widowed network (adjusted prevalence ratio 1.5; 95%CI: 1.1-2.1. Conclusion The derived TSNs were similar to those described in developed countries. However, we identified the existence of a diverse network without community participation and a widowed network that have not been previously described. These TSNs and restricted networks represent a potential unmet need of social security affiliates.

  11. Bartlett-type corrections and bootstrap adjustments of likelihood-based inference methods for network meta-analysis.

    Science.gov (United States)

    Noma, Hisashi; Nagashima, Kengo; Maruo, Kazushi; Gosho, Masahiko; Furukawa, Toshi A

    2017-12-18

    In network meta-analyses that synthesize direct and indirect comparison evidence concerning multiple treatments, multivariate random effects models have been routinely used for addressing between-studies heterogeneities. Although their standard inference methods depend on large sample approximations (eg, restricted maximum likelihood estimation) for the number of trials synthesized, the numbers of trials are often moderate or small. In these situations, standard estimators cannot be expected to behave in accordance with asymptotic theory; in particular, confidence intervals cannot be assumed to exhibit their nominal coverage probabilities (also, the type I error probabilities of the corresponding tests cannot be retained). The invalidity issue may seriously influence the overall conclusions of network meta-analyses. In this article, we develop several improved inference methods for network meta-analyses to resolve these problems. We first introduce 2 efficient likelihood-based inference methods, the likelihood ratio test-based and efficient score test-based methods, in a general framework of network meta-analysis. Then, to improve the small-sample inferences, we developed improved higher-order asymptotic methods using Bartlett-type corrections and bootstrap adjustment methods. The proposed methods adopt Monte Carlo approaches using parametric bootstraps to effectively circumvent complicated analytical calculations of case-by-case analyses and to permit flexible application to various statistical models network meta-analyses. These methods can also be straightforwardly applied to multivariate meta-regression analyses and to tests for the evaluation of inconsistency. In numerical evaluations via simulations, the proposed methods generally performed well compared with the ordinary restricted maximum likelihood-based inference method. Applications to 2 network meta-analysis datasets are provided. Copyright © 2017 John Wiley & Sons, Ltd.

  12. Nonreciprocal effects and their applications in fiber optic networks

    OpenAIRE

    Fang, Xiaojun

    1996-01-01

    Nonreciprocity is a fundamental property of networks. Unlike electronic networks theory, optical network theory is still a field to be investigated. Lightwave systems, including fiber optic and integrated optic, are becoming more and more complex, new function blocks ( or components) and networking strategies are very important for future highly integrated lightwave circuits. Several common nonreciprocal optical effects studied in this disseration and several basic applications...

  13. The ecological and evolutionary implications of merging different types of networks

    NARCIS (Netherlands)

    Fontaine, C.; Guimaraes, P.R.; Kefi, S.; Loeuille, N.; Memmott, J.; Van der Putten, W.H.; Van Veen, F.J.F.; Thebault, E.

    2011-01-01

    Interactions among species drive the ecological and evolutionary processes in ecological communities. These interactions are effectively key components of biodiversity. Studies that use a network approach to study the structure and dynamics of communities of interacting species have revealed many

  14. Modeling multi-typed structurally viewed chemicals with the UMLS Refined Semantic Network.

    Science.gov (United States)

    Chen, Ling; Morrey, C Paul; Gu, Huanying; Halper, Michael; Perl, Yehoshua

    2009-01-01

    Chemical concepts assigned multiple "Chemical Viewed Structurally" semantic types (STs) in the Unified Medical Language System (UMLS) are subject to ambiguous interpretation. The multiple assignments may denote the fact that a specific represented chemical (combination) is a conjugate, derived via a chemical reaction of chemicals of the different types, or a complex, composed of a mixture of such chemicals. The previously introduced Refined Semantic Network (RSN) is modified to properly model these varied multi-typed chemical combinations. The RSN was previously introduced as an enhanced abstraction of the UMLS's concepts. It features new types, called intersection semantic types (ISTs), each of which explicitly captures a unique combination of ST assignments in one abstract unit. The ambiguous ISTs of different "Chemical Viewed Structurally" ISTs of the RSN are replaced with two varieties of new types, called conjugate types and complex types, which explicitly denote the nature of the chemical interactions. Additional semantic relationships help further refine that new portion of the RSN rooted at the ST "Chemical Viewed Structurally." The number of new conjugate and complex types and the amount of changes to the type assignment of chemical concepts are presented. The modified RSN, consisting of 35 types and featuring 22 new conjugate and complex types, is presented. A total of 800 (about 98%) chemical concepts representing multi-typed chemical combinations from "Chemical Viewed Structurally" STs are uniquely assigned one of the new types. An additional benefit is the identification of a number of illegal ISTs and ST assignment errors, some of which are direct violations of exclusion rules defined by the UMLS Semantic Network. The modified RSN provides an enhanced abstract view of the UMLS's chemical content. Its array of conjugate and complex types provides a more accurate model of the variety of combinations involving chemicals viewed structurally. This

  15. Classification of epilepsy types through global network analysis of scalp electroencephalograms

    Science.gov (United States)

    Lee, Uncheol; Kim, Seunghwan; Jung, Ki-Young

    2006-04-01

    Epilepsy is a dynamic disease in which self-organization and emergent structures occur dynamically at multiple levels of neuronal integration. Therefore, the transient relationship within multichannel electroencephalograms (EEGs) is crucial for understanding epileptic processes. In this paper, we show that the global relationship within multichannel EEGs provides us with more useful information in classifying two different epilepsy types than pairwise relationships such as cross correlation. To demonstrate this, we determine the global network structure within channels of the scalp EEG based on the minimum spanning tree method. The topological dissimilarity of the network structures from different types of temporal lobe epilepsy is described in the form of the divergence rate and is computed for 11 patients with left (LTLE) and right temporal lobe epilepsy (RTLE). We find that patients with LTLE and RTLE exhibit different large scale network structures, which emerge at the epoch immediately before the seizure onset, not in the preceding epochs. Our results suggest that patients with the two different epilepsy types display distinct large scale dynamical networks with characteristic epileptic network structures.

  16. Modular Neural Networks and Type-2 Fuzzy Systems for Pattern Recognition

    CERN Document Server

    Melin, Patricia

    2012-01-01

    This book describes hybrid intelligent systems using type-2 fuzzy logic and modular neural networks for pattern recognition applications. Hybrid intelligent systems combine several intelligent computing paradigms, including fuzzy logic, neural networks, and bio-inspired optimization algorithms, which can be used to produce powerful pattern recognition systems. Type-2 fuzzy logic is an extension of traditional type-1 fuzzy logic that enables managing higher levels of uncertainty in complex real world problems, which are of particular importance in the area of pattern recognition. The book is organized in three main parts, each containing a group of chapters built around a similar subject. The first part consists of chapters with the main theme of theory and design algorithms, which are basically chapters that propose new models and concepts, which are the basis for achieving intelligent pattern recognition. The second part contains chapters with the main theme of using type-2 fuzzy models and modular neural ne...

  17. Psychological type profile of Lead Elders within the Newfrontiers network of churches in the United Kingdom

    OpenAIRE

    Francis, Leslie J.; Gubb, Sean; Robbins, Mandy

    2009-01-01

    This study set out to examine the psychological type profile of Lead Elders within the Newfrontiers network of churches in the United Kingdom and to compare this profile with the established profile of clergymen in the Church of England. A sample of 134 Lead Elders completed the Francis Psychological Type Scales. The study shows that Newfrontiers Lead Elders display slight preferences for extraversion over introversion, for sensing over intuition, and for thinking over feeling, and a strong p...

  18. Comparing various artificial neural network types for water temperature prediction in rivers

    Science.gov (United States)

    Piotrowski, Adam P.; Napiorkowski, Maciej J.; Napiorkowski, Jaroslaw J.; Osuch, Marzena

    2015-10-01

    A number of methods have been proposed for the prediction of streamwater temperature based on various meteorological and hydrological variables. The present study shows a comparison of few types of data-driven neural networks (multi-layer perceptron, product-units, adaptive-network-based fuzzy inference systems and wavelet neural networks) and nearest neighbour approach for short time streamwater temperature predictions in two natural catchments (mountainous and lowland) located in temperate climate zone, with snowy winters and hot summers. To allow wide applicability of such models, autoregressive inputs are not used and only easily available measurements are considered. Each neural network type is calibrated independently 100 times and the mean, median and standard deviation of the results are used for the comparison. Finally, the ensemble aggregation approach is tested. The results show that simple and popular multi-layer perceptron neural networks are in most cases not outperformed by more complex and advanced models. The choice of neural network is dependent on the way the models are compared. This may be a warning for anyone who wish to promote own models, that their superiority should be verified in different ways. The best results are obtained when mean, maximum and minimum daily air temperatures from the previous days are used as inputs, together with the current runoff and declination of the Sun from two recent days. The ensemble aggregation approach allows reducing the mean square error up to several percent, depending on the case, and noticeably diminishes differences in modelling performance obtained by various neural network types.

  19. Effect of inhibitory firing pattern on coherence resonance in random neural networks

    Science.gov (United States)

    Yu, Haitao; Zhang, Lianghao; Guo, Xinmeng; Wang, Jiang; Cao, Yibin; Liu, Jing

    2018-01-01

    The effect of inhibitory firing patterns on coherence resonance (CR) in random neuronal network is systematically studied. Spiking and bursting are two main types of firing pattern considered in this work. Numerical results show that, irrespective of the inhibitory firing patterns, the regularity of network is maximized by an optimal intensity of external noise, indicating the occurrence of coherence resonance. Moreover, the firing pattern of inhibitory neuron indeed has a significant influence on coherence resonance, but the efficacy is determined by network property. In the network with strong coupling strength but weak inhibition, bursting neurons largely increase the amplitude of resonance, while they can decrease the noise intensity that induced coherence resonance within the neural system of strong inhibition. Different temporal windows of inhibition induced by different inhibitory neurons may account for the above observations. The network structure also plays a constructive role in the coherence resonance. There exists an optimal network topology to maximize the regularity of the neural systems.

  20. Family and Friends: Which Types of Personal Relationships Go Together in a Network?

    NARCIS (Netherlands)

    Rözer, J.; Mollenhorst, G.; Poortman, A.R.

    2015-01-01

    We examine the link between family and personal networks. Using arguments about meeting opportunities, competition and social influence, we hypothesise how the presence of specific types of family members (i.e., a partner, children, parents and siblings) and non-family members (i.e., friends,

  1. Family and Friends : Which Types of Personal Relationships Go Together in a Network?

    NARCIS (Netherlands)

    Rözer, Jesper; Mollenhorst, Gerald; Poortman, Anne Rigt

    We examine the link between family and personal networks. Using arguments about meeting opportunities, competition and social influence, we hypothesise how the presence of specific types of family members (i.e., a partner, children, parents and siblings) and non-family members (i.e., friends,

  2. Identification of children's activity type with accelerometer-based neural networks

    NARCIS (Netherlands)

    Vries, S.I. de; Engels, M.; Garre, F.G.

    2011-01-01

    Purpose: The study's purpose was to identify children's physical activity type using artificial neural network (ANN) models based on uniaxial or triaxial accelerometer data from the hip or the ankle. Methods: Fifty-eight children (31 boys and 27 girls, age range = 9-12 yr) performed the following

  3. Evaluation of neural networks to identify types of activity using accelerometers

    NARCIS (Netherlands)

    Vries, S.I. de; Garre, F.G.; Engbers, L.H.; Hildebrandt, V.H.; Buuren, S. van

    2011-01-01

    Purpose: To develop and evaluate two artificial neural network (ANN) models based on single-sensor accelerometer data and an ANN model based on the data of two accelerometers for the identification of types of physical activity in adults. Methods: Forty-nine subjects (21 men and 28 women; age range

  4. Robust giant magnetoresistive effect type multilayer sensor

    NARCIS (Netherlands)

    Lenssen, K.M.H.; Kuiper, A.E.T.; Roozeboom, F.

    2002-01-01

    A robust Giant Magneto Resistive effect type multilayer sensor comprising a free and a pinned ferromagnetic layer, which can withstand high temperatures and strong magnetic fields as required in automotive applications. The GMR multi-layer has an asymmetric magneto-resistive curve and enables

  5. Dissemination Patterns and Associated Network Effects of Sentiments in Social Networks

    DEFF Research Database (Denmark)

    Hillmann, Robert; Trier, Matthias

    2012-01-01

    with textual messages classified according to embedded positive and negative sentiments. Based on this data, sub-networks are extracted and analyzed with a dynamic network motif analysis to determine dissemination patterns and associated network effects. Results indicate that the emergence of digital social......Communication in online social networks has been analyzed for some time regarding the expression of sentiments. So far, very little is known about the relationship between sentiments and network emergence, dissemination patterns and possible differences between positive and negative sentiments...... networks exhibits a strong tendency towards reciprocity, followed by the dominance of hierarchy as an intermediate step leading to social clustering with hubs and transitivity effects for both positive and negative sentiments to the same extend. Sentiments embedded in exchanged textual messages do only...

  6. How Effective is Routing for Wireless Networking

    Science.gov (United States)

    2016-03-05

    world examples of multi-hop wireless networks. Today, almost all of our wireless devices communicate directly with a base station (such as WiFi or...a link towards the next waypoint. Since routing Distribution A: Public Release. This work is sponsored by the Defense Advanced Research Program...prevents these schemes from working well in a wireless environment. The idea of a link is borrowed from wired networks. In a wireless network, there is no

  7. Social Capital, Network Effects and Savings in Rural Vietnam

    DEFF Research Database (Denmark)

    Newman, Carol; Tarp, Finn; Van Den Broeck, Katleen

    social networks in rural Vietnam can play a role in increasing formal savings where knowledge gaps exist. Networks are defined as active membership of women’s unions and the quality of networks is measured by the level of formal savings observed among group members. We find that membership of high...... quality networks leads to higher levels of saving in formal financial institutions and to higher levels of saving for productive investments as compared with other precautionary or lifecycle motives. Our results suggest that transmitting financial information through formal networks could be effective...... in increasing formal savings at grassroots level. We also conclude that ensuring information disseminated by networks is both accurate and desirable as well as important given that behavioural effects are also found in low-quality networks....

  8. Assembly effect of groups in online social networks

    Science.gov (United States)

    Fan, W.; Yeung, K. H.; Wong, K. Y.

    2013-03-01

    Due to the popularity and growth of online social networks, security in these networks becomes a critical problem. Previous works have proved that a virus can spread effectively in social networks. In this paper, groups in social networks are studied. We notice that groups on social network services sites can assemble people with similar characteristics, which may promote virus propagation in these networks. After our analysis, it is found that the use of groups can shorten the distance among users, and hence it would cause faster virus spread. We propose a virus propagation model and simulate it in a group network to show the assembly effect of groups. Our result shows that even with only one random attack, a virus can still spread rapidly, and the direct contact among group members is the reason for fast spreading.

  9. Analyzing Bullwhip Effect in Supply Networks under Exogenous Uncertainty

    Directory of Open Access Journals (Sweden)

    Mitra Darvish

    2014-05-01

    Full Text Available This paper explains a model for analyzing and measuring the propagation of order amplifications (i.e. bullwhip effect for a single-product supply network topology considering exogenous uncertainty and linear and time-invariant inventory management policies for network entities. The stream of orders placed by each entity of the network is characterized assuming customer demand is ergodic. In fact, we propose an exact formula in order to measure the bullwhip effect in the addressed supply network topology considering the system in Markovian chain framework and presenting a matrix of network member relationships and relevant order sequences. The formula turns out using a mathematical method called frequency domain analysis. The major contribution of this paper is analyzing the bullwhip effect considering exogenous uncertainty in supply networks and using the Fourier transform in order to simplify the relevant calculations. We present a number of numerical examples to assess the analytical results accuracy in quantifying the bullwhip effect.

  10. Gender and Peer Effects on Performance in Social Networks

    OpenAIRE

    Beugnot, Julie; Fortin, Bernard; Lacroix, Guy; Villeval, Marie Claire

    2017-01-01

    We investigate whether peer effects at work differ by gender and whether gender differences in peer effects -if any- depend on work organization. We develop a social network model with gender heterogeneity that we test in a real-effort laboratory experiment. We compare sequential networks in which information flows from peers to the worker and simultaneous networks where it disseminates bi-directionally. We identify strong gender differences as females disregard their peers’ performance in si...

  11. Challenge: How Effective is Routing for Wireless Networking

    Science.gov (United States)

    2017-03-03

    Approved for Public Release, Distribution Unlimited Challenge: How Effective is Routing for Wireless Networking ? Greg Kuperman, Scott Moore, Bow-Nan...paper, we examine the question of how effective rout- ing is for reliably and efficiently delivering data in a wireless network . With the emergence of the...Internet of Things, there is a renewed focus on multi-hop wireless networking to con- nect these systems of smart-devices. Many of the proposals to

  12. Social networks as mediators of the effect of Alcoholics Anonymous.

    Science.gov (United States)

    Kaskutas, Lee Ann; Bond, Jason; Humphreys, Keith

    2002-07-01

    This study tested the hypothesis that the relationship between Alcoholics Anonymous (AA) involvement and reduced substance use is partially explained (or 'mediated') by changes in social networks. This is a naturalistic longitudinal study of the course of alcohol problems. Study sites were the 10 largest public and private alcohol treatment programs in a northern California county. Three hundred and seventy-seven men and 277 women were recruited upon seeking treatment at study sites. At baseline and 1-year follow-up, we assessed alcohol consequences and dependence symptoms, consumption, social support for abstinence, pro-drinking social influences and AA involvement. In the structural equation model, AA involvement was a significant predictor of lower alcohol consumption and fewer related problems. The size of this effect decreased by 36% when network size and support for drinking were included as mediators. In logistic regression models predicting abstinence at follow-up, AA remained highly significant after including social network variables but was again reduced in magnitude. Thirty-day abstinence was predicted by AA involvement (OR=2.9), not having pro-drinking influences in one's network (OR=0.7) and having support for reducing consumption from people met in AA (versus no support; OR=3.4). In contrast, having support from non-AA members was not a significant predictor of abstinence. For alcohol-related outcomes other than abstinence, significant relationships were found for both AA-based and non-AA-based support. The type of social support specifically given by AA members, such as 24-hour availability, role modeling and experientially based advice for staying sober, may help to explain AA's mechanism of action. Results highlight the value of focusing on outcomes reflective of AA's goals (such as abstinence) when studying how AA works.

  13. A Dependable Localization Algorithm for Survivable Belt-Type Sensor Networks.

    Science.gov (United States)

    Zhu, Mingqiang; Song, Fei; Xu, Lei; Seo, Jung Taek; You, Ilsun

    2017-11-29

    As the key element, sensor networks are widely investigated by the Internet of Things (IoT) community. When massive numbers of devices are well connected, malicious attackers may deliberately propagate fake position information to confuse the ordinary users and lower the network survivability in belt-type situation. However, most existing positioning solutions only focus on the algorithm accuracy and do not consider any security aspects. In this paper, we propose a comprehensive scheme for node localization protection, which aims to improve the energy-efficient, reliability and accuracy. To handle the unbalanced resource consumption, a node deployment mechanism is presented to satisfy the energy balancing strategy in resource-constrained scenarios. According to cooperation localization theory and network connection property, the parameter estimation model is established. To achieve reliable estimations and eliminate large errors, an improved localization algorithm is created based on modified average hop distances. In order to further improve the algorithms, the node positioning accuracy is enhanced by using the steepest descent method. The experimental simulations illustrate the performance of new scheme can meet the previous targets. The results also demonstrate that it improves the belt-type sensor networks' survivability, in terms of anti-interference, network energy saving, etc.

  14. Sex differences in the association of social network satisfaction and the risk for type 2 diabetes

    Directory of Open Access Journals (Sweden)

    K. Lukaschek

    2017-05-01

    Full Text Available Abstract Background The role of an individual’s social network satisfaction (SNS in the association of social isolation or living alone and incident type 2 diabetes (T2D is unclear. We assessed the association of SNS with incident T2D and analysed potential modifications of the SNS-T2D association by social isolation or living alone. Methods The study population (N = 6839 aged 25–74 years without diabetes at baseline derived from the prospective population-based MONICA/KORA study (1989–2009. Social network satisfaction was assessed by a single item. Cox regression was used to estimate hazard ratios (HR for SNS separately in men and women. Results In men with low SNS, risk for incident T2D increased significantly (HR: 2.15, 95% CI: 1.33–3.48, p value 0.002. After additional adjustments for social isolation or living alone, the risk for incident T2D was still significant, albeit less pronounced (HRs 1.85 or 2.05, p values 0.001 or 0.004. The interaction analysis showed an increased T2D risk effect for low SNS compared to high SNS in women living in a partnership (HR: 2.11, 95% CI: 1.00–4.44, p value for interaction: 0.047 and for moderate SNS compared to high SNS in socially connected women (1.56, 1.01–2.39, 0.010. Conclusions Further research is needed to address the complexities of the perception of social relationships and social interactions, or interdependence, especially when another major public health issue such as T2D is concerned.

  15. Combatting Global Infectious Diseases: A Network Effect of Specimen Referral Systems.

    Science.gov (United States)

    Fonjungo, Peter N; Alemnji, George A; Kebede, Yenew; Opio, Alex; Mwangi, Christina; Spira, Thomas J; Beard, R Suzanne; Nkengasong, John N

    2017-02-13

    The recent Ebola virus outbreak in West Africa clearly demonstrated the critical role of laboratory systems and networks in responding to epidemics. Because of the huge challenges in establishing functional laboratories at all tiers of health systems in developing countries, strengthening specimen referral networks is critical. In this review article, we propose a platform strategy for developing specimen referral networks based on 2 models: centralized and decentralized laboratory specimen referral networks. These models have been shown to be effective in patient management in programs in resource-limited settings. Both models lead to reduced turnaround time and retain flexibility for integrating different specimen types. In Haiti, decentralized specimen referral systems resulted in a 182% increase in patients enrolling in human immunodeficiency virus treatment programs within 6 months. In Uganda, cost savings of up to 62% were observed with a centralized model. A platform strategy will create a network effect that will benefit multiple disease programs.

  16. Evolution of technology convergence networks in Korea: Characteristics of temporal changes in R&D according to institution type

    Science.gov (United States)

    Choi, Jae Young; Jeong, Seongkyoon

    2018-01-01

    This study investigates the temporal changes in development of technology convergence networks by institution type, i.e., public research institute (PRI), university and industry. Using the co-classification of technological domains of patents, we identified technology convergence of Korean patents, which were filed at Korea Intellectual Properties Office (KIPO) from 1997 to 2011. We conducted a network analysis at the technology level to search for the key technology fields and frequent instances of technology convergence. The results show that technology convergence networks have grown significantly in the recent period regardless of the institution type. While industries started to conspicuously engage in technology convergence in the late 1990s, universities or PRIs did not do so until the mid-2000s. This discrepancy in the phase of technology convergence is attributed to the temporal difference in R&D stage (e.g., basic research and commercial product development). Our findings imply that corporal and governmental R&D management decision on promising technology fields will be more effective if the decision makers carefully consider the type of R&D entity in analyzing technological landscapes. PMID:29420574

  17. Enhancing Classroom Effectiveness through Social Networking Tools

    Science.gov (United States)

    Kurthakoti, Raghu; Boostrom, Robert E., Jr.; Summey, John H.; Campbell, David A.

    2013-01-01

    To determine the usefulness of social networking Web sites such as Ning.com as a communication tool in marketing courses, a study was designed with special concern for social network use in comparison to Blackboard. Students from multiple marketing courses were surveyed. Assessments of Ning.com and Blackboard were performed both to understand how…

  18. Types of Non-kin Networks and Their Association With Survival in Late Adulthood: A Latent Class Approach.

    Science.gov (United States)

    Ellwardt, Lea; Aartsen, Marja; van Tilburg, Theo

    2017-07-01

    Integration into social networks is an important determinant of health and survival in late adulthood. We first identify different types of non-kin networks among older adults and second, investigate the association of these types with survival rates. Official register information on mortality is combined with data from the Longitudinal Aging Study Amsterdam (LASA). The sample includes 2,440 Dutch respondents aged 54-85 at baseline in 1992 and six follow-ups covering a time span of 20 years. Using latent class analysis, respondents are classified into distinct types of non-kin networks, based on differences in number and variation of non-kin relations, social support received from non-kin, and contact frequency with non-kin. Next, membership in network types is related to mortality in a Cox proportional hazard regression model. There are four latent types of non-kin networks that vary in network size and support. These types differ in their associations with mortality, independent of sociodemographic and health confounders. Older adults integrated into networks high in both number and variation of supportive non-kin contacts have higher chances of survival than older adults embedded in networks low in either amount or variation of support or both. A combination of structural and functional network characteristics should be taken into account when developing intervention programs aiming at increasing social integration outside the family network.

  19. Revealing effective classifiers through network comparison

    Science.gov (United States)

    Gallos, Lazaros K.; Fefferman, Nina H.

    2014-11-01

    The ability to compare complex systems can provide new insight into the fundamental nature of the processes captured, in ways that are otherwise inaccessible to observation. Here, we introduce the n-tangle method to directly compare two networks for structural similarity, based on the distribution of edge density in network subgraphs. We demonstrate that this method can efficiently introduce comparative analysis into network science and opens the road for many new applications. For example, we show how the construction of a “phylogenetic tree” across animal taxa according to their social structure can reveal commonalities in the behavioral ecology of the populations, or how students create similar networks according to the University size. Our method can be expanded to study many additional properties, such as network classification, changes during time evolution, convergence of growth models, and detection of structural changes during damage.

  20. Revealing effective classifiers through network comparison

    CERN Document Server

    Gallos, Lazaros K

    2014-01-01

    The ability to compare complex systems can provide new insight into the fundamental nature of the processes captured in ways that are otherwise inaccessible to observation. Here, we introduce the $n$-tangle method to directly compare two networks for structural similarity, based on the distribution of edge density in network subgraphs. We demonstrate that this method can efficiently introduce comparative analysis into network science and opens the road for many new applications. For example, we show how the construction of a phylogenetic tree across animal taxa according to their social structure can reveal commonalities in the behavioral ecology of the populations, or how students create similar networks according to the University size. Our method can be expanded to study a multitude of additional properties, such as network classification, changes during time evolution, convergence of growth models, and detection of structural changes during damage.

  1. Novel Cross-Type Network for Wide-Tuning-Range Reconfigurable Multiband Antennas

    Directory of Open Access Journals (Sweden)

    Chieh-Sen Lee

    2014-01-01

    Full Text Available This paper presents a cross-type network design with a novel reconfigurable functionality to realize a tunable multiband antenna. By attaching a reconfigurable network at the feeding port of a broadband antenna, multi-input impedance adjustment enables the production of multimatching operating bands. Each band can be independently controlled by a single component with a considerably wide tuning range and high selectivity. The experiments in this study involved using an ultra-wideband (UWB antenna connected to the proposed cross-type network. The tunable antenna operates in a dual band of fL (1.39 to 2.34 GHz and fH (2.1 to 3.6 GHz with tunable frequency ratios of 168% and 132%, respectively. The average bandwidths at fL and fH are approximately 50 MHz and 148 MHz, respectively, implying narrowband operation. The measured radiation pattern revealed that the tunable antenna exhibits a nearly omnidirectional radiation pattern at both 1.8 and 3.5 GHz. The network circuit architecture can be extended to the multiband function type by adopting this matching approach. The amount of shunt matches determines the number of operation bands.

  2. The Effect of Social Network Diagrams on a Virtual Network of Practice: A Korean Case

    Science.gov (United States)

    Jo, Il-Hyun

    2009-01-01

    This study investigates the effect of the presentation of social network diagrams on virtual team members' interaction behavior via e-mail. E-mail transaction data from 22 software developers in a Korean IT company was analyzed and depicted as diagrams by social network analysis (SNA), and presented to the members as an intervention. Results…

  3. Identification of Nonlinear Dynamic Systems Using Hammerstein-Type Neural Network

    Directory of Open Access Journals (Sweden)

    Hongshan Yu

    2014-01-01

    Full Text Available Hammerstein model has been popularly applied to identify the nonlinear systems. In this paper, a Hammerstein-type neural network (HTNN is derived to formulate the well-known Hammerstein model. The HTNN consists of a nonlinear static gain in cascade with a linear dynamic part. First, the Lipschitz criterion for order determination is derived. Second, the backpropagation algorithm for updating the network weights is presented, and the stability analysis is also drawn. Finally, simulation results show that HTNN identification approach demonstrated identification performances.

  4. Modeling and Optimization of M/G/1-Type Queueing Networks: An Efficient Sensitivity Analysis Approach

    Directory of Open Access Journals (Sweden)

    Liang Tang

    2010-01-01

    Full Text Available A mathematical model for M/G/1-type queueing networks with multiple user applications and limited resources is established. The goal is to develop a dynamic distributed algorithm for this model, which supports all data traffic as efficiently as possible and makes optimally fair decisions about how to minimize the network performance cost. An online policy gradient optimization algorithm based on a single sample path is provided to avoid suffering from a “curse of dimensionality”. The asymptotic convergence properties of this algorithm are proved. Numerical examples provide valuable insights for bridging mathematical theory with engineering practice.

  5. Game Theoretical Analysis on Cooperation Stability and Incentive Effectiveness in Community Networks.

    Directory of Open Access Journals (Sweden)

    Kaida Song

    Full Text Available Community networks, the distinguishing feature of which is membership admittance, appear on P2P networks, social networks, and conventional Web networks. Joining the network costs money, time or network bandwidth, but the individuals get access to special resources owned by the community in return. The prosperity and stability of the community are determined by both the policy of admittance and the attraction of the privileges gained by joining. However, some misbehaving users can get the dedicated resources with some illicit and low-cost approaches, which introduce instability into the community, a phenomenon that will destroy the membership policy. In this paper, we analyze on the stability using game theory on such a phenomenon. We propose a game-theoretical model of stability analysis in community networks and provide conditions for a stable community. We then extend the model to analyze the effectiveness of different incentive policies, which could be used when the community cannot maintain its members in certain situations. Then we verify those models through a simulation. Finally, we discuss several ways to promote community network's stability by adjusting the network's properties and give some proposal on the designs of these types of networks from the points of game theory and stability.

  6. Topological Effects and Performance Optimization in Transportation Continuous Network Design

    Directory of Open Access Journals (Sweden)

    Jianjun Wu

    2014-01-01

    Full Text Available Because of the limitation of budget, in the planning of road works, increased efforts should be made on links that are more critical to the whole traffic system. Therefore, it would be helpful to model and evaluate the vulnerability and reliability of the transportation network when the network design is processing. This paper proposes a bilevel transportation network design model, in which the upper level is to minimize the performance of the network under the given budgets, while the lower level is a typical user equilibrium assignment problem. A new solution approach based on particle swarm optimization (PSO method is presented. The topological effects on the performance of transportation networks are studied with the consideration of three typical networks, regular lattice, random graph, and small-world network. Numerical examples and simulations are presented to demonstrate the proposed model.

  7. Prediction of drugs having opposite effects on disease genes in a directed network.

    Science.gov (United States)

    Yu, Hasun; Choo, Sungji; Park, Junseok; Jung, Jinmyung; Kang, Yeeok; Lee, Doheon

    2016-01-11

    Developing novel uses of approved drugs, called drug repositioning, can reduce costs and times in traditional drug development. Network-based approaches have presented promising results in this field. However, even though various types of interactions such as activation or inhibition exist in drug-target interactions and molecular pathways, most of previous network-based studies disregarded this information. We developed a novel computational method, Prediction of Drugs having Opposite effects on Disease genes (PDOD), for identifying drugs having opposite effects on altered states of disease genes. PDOD utilized drug-drug target interactions with 'effect type', an integrated directed molecular network with 'effect type' and 'effect direction', and disease genes with regulated states in disease patients. With this information, we proposed a scoring function to discover drugs likely to restore altered states of disease genes using the path from a drug to a disease through the drug-drug target interactions, shortest paths from drug targets to disease genes in molecular pathways, and disease gene-disease associations. We collected drug-drug target interactions, molecular pathways, and disease genes with their regulated states in the diseases. PDOD is applied to 898 drugs with known drug-drug target interactions and nine diseases. We compared performance of PDOD for predicting known therapeutic drug-disease associations with the previous methods. PDOD outperformed other previous approaches which do not exploit directional information in molecular network. In addition, we provide a simple web service that researchers can submit genes of interest with their altered states and will obtain drugs seeming to have opposite effects on altered states of input genes at http://gto.kaist.ac.kr/pdod/index.php/main . Our results showed that 'effect type' and 'effect direction' information in the network based approaches can be utilized to identify drugs having opposite effects on

  8. Effective Protocols for Mobile Communications and Networking

    Energy Technology Data Exchange (ETDEWEB)

    Espinoza, J.; Sholander, P.; Van Leeuwen, B,

    1998-12-01

    This report examines methods of mobile communications with an emphasis on mobile computing and wireless communications. Many of the advances in communications involve the use of Internet Protocol (IP), Asynchronous Transfer Mode (ATM), and ad hoc network protocols. However, many of the advances in these protocols have been focused on wired communications. Recently much focus has been directed at advancing communication technology in the area of mobile wireless networks. This report discusses various protocols used in mobile communications and proposes a number of extensions to existing protocols. A detailed discussion is also included on desirable protocol characteristics and evaluation criteria. In addition, the report includes a discussion on several network simulation tools that maybe used to evaluate network protocols.

  9. Dry unit weight of compacted soils prediction using GMDH-type neural network

    Science.gov (United States)

    Hassanlourad, Mahmoud; Ardakani, Alireza; Kordnaeij, Afshin; Mola-Abasi, Hossein

    2017-08-01

    Dry unit weight ( {γ}_d of soils is usually determined by in situ tests, such as rubber balloon, sand cone, nuclear density measurements, etc. The elastic wave method using compressional wave has been broadly used to determine various geotechnical parameters. In the present paper, the polynomial neural network (NN) is used to estimate the {γ}_d of compacted soils indirectly depending on P -wave velocity ( V_p , moisture content ( ω and plasticity index ( PI as well as fine-grained particles (FC). Eight natural soil samples (88 data) were applied for developing a polynomial representation of model. To determine the performance of the proposed model, a comparison was carried out between the predicted and experimentally measured values. The results show that the developed GMDH-type NN has a great ability (R^2=0.942) to predict the {γ}_d of the compacted soils and is more efficient (53% to 73% improvement) than the previous reported methods. Finally, the derived model sensitivity analysis has been performed to evaluate the effect of each input variable on the proposed model output and shows that the P -wave velocity is the most influential parameter on the predicted {γ}_d.

  10. A mathematics for medicine: The Network Effect

    OpenAIRE

    West, Bruce J.

    2014-01-01

    The theory of medicine and its complement systems biology are intended to explain the workings of the large number of mutually interdependent complex physiologic networks in the human body and to apply that understanding to maintaining the functions for which nature designed them. Therefore, when what had originally been made as a simplifying assumption or a working hypothesis becomes foundational to understanding the operation of physiologic networks it is in the best interests of science to...

  11. Towards Effective Intra-flow Network Coding in Software Defined Wireless Mesh Networks

    Directory of Open Access Journals (Sweden)

    Donghai Zhu

    2016-01-01

    Full Text Available Wireless Mesh Networks (WMNs have potential to provide convenient broadband wireless Internet access to mobile users.With the support of Software-Defined Networking (SDN paradigm that separates control plane and data plane, WMNs can be easily deployed and managed. In addition, by exploiting the broadcast nature of the wireless medium and the spatial diversity of multi-hop wireless networks, intra-flow network coding has shown a greater benefit in comparison with traditional routing paradigms in data transmission for WMNs. In this paper, we develop a novel OpenCoding protocol, which combines the SDN technique with intra-flow network coding for WMNs. Our developed protocol can simplify the deployment and management of the network and improve network performance. In OpenCoding, a controller that works on the control plane makes routing decisions for mesh routers and the hop-by-hop forwarding function is replaced by network coding functions in data plane. We analyze the overhead of OpenCoding. Through a simulation study, we show the effectiveness of the OpenCoding protocol in comparison with existing schemes. Our data shows that OpenCoding outperforms both traditional routing and intra-flow network coding schemes.

  12. A Simulation Study Comparing Epidemic Dynamics on Exponential Random Graph and Edge-Triangle Configuration Type Contact Network Models

    Science.gov (United States)

    Rolls, David A.; Wang, Peng; McBryde, Emma; Pattison, Philippa; Robins, Garry

    2015-01-01

    We compare two broad types of empirically grounded random network models in terms of their abilities to capture both network features and simulated Susceptible-Infected-Recovered (SIR) epidemic dynamics. The types of network models are exponential random graph models (ERGMs) and extensions of the configuration model. We use three kinds of empirical contact networks, chosen to provide both variety and realistic patterns of human contact: a highly clustered network, a bipartite network and a snowball sampled network of a “hidden population”. In the case of the snowball sampled network we present a novel method for fitting an edge-triangle model. In our results, ERGMs consistently capture clustering as well or better than configuration-type models, but the latter models better capture the node degree distribution. Despite the additional computational requirements to fit ERGMs to empirical networks, the use of ERGMs provides only a slight improvement in the ability of the models to recreate epidemic features of the empirical network in simulated SIR epidemics. Generally, SIR epidemic results from using configuration-type models fall between those from a random network model (i.e., an Erdős-Rényi model) and an ERGM. The addition of subgraphs of size four to edge-triangle type models does improve agreement with the empirical network for smaller densities in clustered networks. Additional subgraphs do not make a noticeable difference in our example, although we would expect the ability to model cliques to be helpful for contact networks exhibiting household structure. PMID:26555701

  13. Relationship between social network, social support and health behaviour in people with type 1 and type 2 diabetes: cross-sectional studies

    OpenAIRE

    Hempler, Nana F.; Joensen, Lene E; Willaing, Ingrid

    2016-01-01

    Background Psychosocial and behavioural aspects of diabetes may differ according to diabetes type. This study compared people with type 1 and type 2 diabetes with respect to social relations (cohabitation status, contact with the social network and social support) and health behaviours (diet and physical activity). Furthermore, we examined whether potential differences in health behaviour between people with type 1 and type 2 diabetes were influenced by education level and social relations. M...

  14. A Dependable Localization Algorithm for Survivable Belt-Type Sensor Networks

    Directory of Open Access Journals (Sweden)

    Mingqiang Zhu

    2017-11-01

    Full Text Available As the key element, sensor networks are widely investigated by the Internet of Things (IoT community. When massive numbers of devices are well connected, malicious attackers may deliberately propagate fake position information to confuse the ordinary users and lower the network survivability in belt-type situation. However, most existing positioning solutions only focus on the algorithm accuracy and do not consider any security aspects. In this paper, we propose a comprehensive scheme for node localization protection, which aims to improve the energy-efficient, reliability and accuracy. To handle the unbalanced resource consumption, a node deployment mechanism is presented to satisfy the energy balancing strategy in resource-constrained scenarios. According to cooperation localization theory and network connection property, the parameter estimation model is established. To achieve reliable estimations and eliminate large errors, an improved localization algorithm is created based on modified average hop distances. In order to further improve the algorithms, the node positioning accuracy is enhanced by using the steepest descent method. The experimental simulations illustrate the performance of new scheme can meet the previous targets. The results also demonstrate that it improves the belt-type sensor networks’ survivability, in terms of anti-interference, network energy saving, etc.

  15. Beware of Selfies: The Impact of Photo Type on Impression Formation Based on Social Networking Profiles.

    Science.gov (United States)

    Krämer, Nicole C; Feurstein, Markus; Kluck, Jan P; Meier, Yannic; Rother, Marius; Winter, Stephan

    2017-01-01

    Users of social networking sites such as Facebook frequently post self-portraits on their profiles. While research has begun to analyze the motivations for posting such pictures, less is known about how selfies are evaluated by recipients. Although producers of selfies typically aim to create a positive impression, selfies may also be regarded as narcissistic and therefore fail to achieve the intended goal. The aim of this study is to examine the potentially ambivalent reception of selfies compared to photos taken by others based on the Brunswik lens model Brunswik (1956). In a between-subjects online experiment (N = 297), Facebook profile mockups were shown which differed with regard to picture type (selfie vs. photo taken by others), gender of the profile owner (female vs. male), and number of individuals within a picture (single person vs. group). Results revealed that selfies were indeed evaluated more negatively than photos taken by others. Persons in selfies were rated as less trustworthy, less socially attractive, less open to new experiences, more narcissistic and more extroverted than the same persons in photos taken by others. In addition, gender differences were observed in the perception of pictures. Male profile owners were rated as more narcissistic and less trustworthy than female profile owners, but there was no significant interaction effect of type of picture and gender. Moreover, a mediation analysis of presumed motives for posting selfies revealed that negative evaluations of selfie posting individuals were mainly driven by the perceived motivation of impression management. Findings suggest that selfies are likely to be evaluated less positively than producers of selfies might suppose.

  16. Beware of Selfies: The Impact of Photo Type on Impression Formation Based on Social Networking Profiles

    Science.gov (United States)

    Krämer, Nicole C.; Feurstein, Markus; Kluck, Jan P.; Meier, Yannic; Rother, Marius; Winter, Stephan

    2017-01-01

    Users of social networking sites such as Facebook frequently post self-portraits on their profiles. While research has begun to analyze the motivations for posting such pictures, less is known about how selfies are evaluated by recipients. Although producers of selfies typically aim to create a positive impression, selfies may also be regarded as narcissistic and therefore fail to achieve the intended goal. The aim of this study is to examine the potentially ambivalent reception of selfies compared to photos taken by others based on the Brunswik lens model Brunswik (1956). In a between-subjects online experiment (N = 297), Facebook profile mockups were shown which differed with regard to picture type (selfie vs. photo taken by others), gender of the profile owner (female vs. male), and number of individuals within a picture (single person vs. group). Results revealed that selfies were indeed evaluated more negatively than photos taken by others. Persons in selfies were rated as less trustworthy, less socially attractive, less open to new experiences, more narcissistic and more extroverted than the same persons in photos taken by others. In addition, gender differences were observed in the perception of pictures. Male profile owners were rated as more narcissistic and less trustworthy than female profile owners, but there was no significant interaction effect of type of picture and gender. Moreover, a mediation analysis of presumed motives for posting selfies revealed that negative evaluations of selfie posting individuals were mainly driven by the perceived motivation of impression management. Findings suggest that selfies are likely to be evaluated less positively than producers of selfies might suppose. PMID:28261129

  17. Moderating Effects of Sales Promotion Types

    Directory of Open Access Journals (Sweden)

    Fernando de Oliveira Santini

    2015-04-01

    Full Text Available This paper aims to analyze the influence sales promotion types have on the relationship between perception of financial risk and perception of utilitarian and hedonic value on consumer purchase intentions. To this end, an experiment was conducted involving 589 participants divided into two groups defined by distinct scenarios in which the sales promotion type (monetary vs. non-monetary was manipulated. The working hypotheses predicted a direct and positive relationship between the perception of (hedonic and utilitarian consumption value and purchase intention for a promoted product and a negative relationship between the perception of consumption value and the perception of financial risk. In addition, it was supposed that the sales promotion type would moderate these direct relationships and that a monetary promotion would have a stronger effect on the relationship between purchase intention and perceived product utility, whereas a non-monetary promotion would have a stronger effect on the other relationships (hedonic value and financial risk perceptions. Analysis of the outcomes supported the proposed hypotheses.

  18. Network-based Type-2 Fuzzy System with Water Flow Like Algorithm for System Identification and Signal Processing

    Directory of Open Access Journals (Sweden)

    Che-Ting Kuo

    2015-02-01

    Full Text Available This paper introduces a network-based interval type-2 fuzzy inference system (NT2FIS with a dynamic solution agent algorithm water flow like algorithm (WFA, for nonlinear system identification and blind source separation (BSS problem. The NT2FIS consists of interval type-2 asymmetric fuzzy membership functions and TSK-type consequent parts to enhance the performance. The proposed scheme is optimized by a new heuristic learning algorithm, WFA, with dynamic solution agents. The proposed WFA is inspired by the natural behavior of water flow. Splitting, moving, merging, evaporation, and precipitation have all been introduced for optimization. Some modifications, including new moving strategies, such as the application of tabu searching and gradient-descent techniques, are proposed to enhance the performance of the WFA in training the NT2FIS systems. Simulation and comparison results for nonlinear system identification and blind signal separation are presented to illustrate the performance and effectiveness of the proposed approach.

  19. LEARNING ALGORITHM EFFECT ON MULTILAYER FEED FORWARD ARTIFICIAL NEURAL NETWORK PERFORMANCE IN IMAGE CODING

    Directory of Open Access Journals (Sweden)

    OMER MAHMOUD

    2007-08-01

    Full Text Available One of the essential factors that affect the performance of Artificial Neural Networks is the learning algorithm. The performance of Multilayer Feed Forward Artificial Neural Network performance in image compression using different learning algorithms is examined in this paper. Based on Gradient Descent, Conjugate Gradient, Quasi-Newton techniques three different error back propagation algorithms have been developed for use in training two types of neural networks, a single hidden layer network and three hidden layers network. The essence of this study is to investigate the most efficient and effective training methods for use in image compression and its subsequent applications. The obtained results show that the Quasi-Newton based algorithm has better performance as compared to the other two algorithms.

  20. Cell type specific alterations in interchromosomal networks across the cell cycle.

    Directory of Open Access Journals (Sweden)

    Andrew J Fritz

    2014-10-01

    Full Text Available The interchromosomal organization of a subset of human chromosomes (#1, 4, 11, 12, 16, 17, and 18 was examined in G1 and S phase of human WI38 lung fibroblast and MCF10A breast epithelial cells. Radial positioning of the chromosome territories (CTs was independent of gene density, but size dependent. While no changes in radial positioning during the cell cycle were detected, there were stage-specific differences between cell types. Each CT was in close proximity (interaction with a similar number of other CT except the gene rich CT17 which had significantly more interactions. Furthermore, CT17 was a member of the highest pairwise CT combinations with multiple interactions. Major differences were detected in the pairwise interaction profiles of MCF10A versus WI38 including cell cycle alterations from G1 to S. These alterations in interaction profiles were subdivided into five types: overall increase, overall decrease, switching from 1 to ≥2 interactions, vice versa, or no change. A global data mining program termed the chromatic median determined the most probable overall association network for the entire subset of CT. This probabilistic interchromosomal network was nearly completely different between the two cell lines. It was also strikingly altered across the cell cycle in MCF10A, but only slightly in WI38. We conclude that CT undergo multiple and preferred interactions with other CT in the nucleus and form preferred -albeit probabilistic- interchromosomal networks. This network of interactions is altered across the cell cycle and between cell types. It is intriguing to consider the relationship of these alterations to the corresponding changes in the gene expression program across the cell cycle and in different cell types.

  1. Machine-Type-Communication (MTC) Device Grouping Algorithm for Congestion Avoidance of MTC Oriented LTE Network

    Science.gov (United States)

    Jung, Kwang-Ryul; Park, Aesoon; Lee, Sungwon

    Machine-Type-Communication (MTC) is a new paradigm in mobile wireless network domains such as Mobile WiMAX (IEEE 802.16e) and 3GPP LTE (3rd Generation Partnership Project Long Term Evolution). We explain the background for MTC environments, and its key issues. Then we focus on the uplink traffic aggressiveness characteristics in major applications such as Smart Grid. Then, we propose a new congestion avoidance algorithm to reduce the congestion of the uplink intensive applications.

  2. Two types of well followed users in the followership networks of Twitter.

    Directory of Open Access Journals (Sweden)

    Kodai Saito

    Full Text Available In the Twitter blogosphere, the number of followers is probably the most basic and succinct quantity for measuring popularity of users. However, the number of followers can be manipulated in various ways; we can even buy follows. Therefore, alternative popularity measures for Twitter users on the basis of, for example, users' tweets and retweets, have been developed. In the present work, we take a purely network approach to this fundamental question. First, we find that two relatively distinct types of users possessing a large number of followers exist, in particular for Japanese, Russian, and Korean users among the seven language groups that we examined. A first type of user follows a small number of other users. A second type of user follows approximately the same number of other users as the number of follows that the user receives. Then, we compare local (i.e., egocentric followership networks around the two types of users with many followers. We show that the second type, which is presumably uninfluential users despite its large number of followers, is characterized by high link reciprocity, a large number of friends (i.e., those whom a user follows for the followers, followers' high link reciprocity, large clustering coefficient, large fraction of the second type of users among the followers, and a small PageRank. Our network-based results support that the number of followers used alone is a misleading measure of user's popularity. We propose that the number of friends, which is simple to measure, also helps us to assess the popularity of Twitter users.

  3. Two Types of Well Followed Users in the Followership Networks of Twitter

    Science.gov (United States)

    Saito, Kodai; Masuda, Naoki

    2014-01-01

    In the Twitter blogosphere, the number of followers is probably the most basic and succinct quantity for measuring popularity of users. However, the number of followers can be manipulated in various ways; we can even buy follows. Therefore, alternative popularity measures for Twitter users on the basis of, for example, users' tweets and retweets, have been developed. In the present work, we take a purely network approach to this fundamental question. First, we find that two relatively distinct types of users possessing a large number of followers exist, in particular for Japanese, Russian, and Korean users among the seven language groups that we examined. A first type of user follows a small number of other users. A second type of user follows approximately the same number of other users as the number of follows that the user receives. Then, we compare local (i.e., egocentric) followership networks around the two types of users with many followers. We show that the second type, which is presumably uninfluential users despite its large number of followers, is characterized by high link reciprocity, a large number of friends (i.e., those whom a user follows) for the followers, followers' high link reciprocity, large clustering coefficient, large fraction of the second type of users among the followers, and a small PageRank. Our network-based results support that the number of followers used alone is a misleading measure of user's popularity. We propose that the number of friends, which is simple to measure, also helps us to assess the popularity of Twitter users. PMID:24416209

  4. Dynamics and nature of support in the personal networks of people with type 2 diabetes living in Europe: qualitative analysis of network properties.

    Science.gov (United States)

    Kennedy, Anne; Rogers, Anne; Vassilev, Ivaylo; Todorova, Elka; Roukova, Poli; Foss, Christina; Knutsen, Ingrid; Portillo, Mari Carmen; Mujika, Agurtzane; Serrano-Gil, Manuel; Lionis, Christos; Angelaki, Agapi; Ratsika, Nikoleta; Koetsenruijter, Jan; Wensing, Michel

    2015-12-01

    Living with and self-managing a long-term condition implicates a diversity of networked relationships. This qualitative study examines the personal communities of support of people with type 2 diabetes. We conducted 170 biographical interviews in six European countries (Bulgaria, Greece, the Netherlands, Norway, Spain and UK) to explore social support and networks. Analysis was framed with reference to three predetermined social support mechanisms: the negotiation of support enabling engagement with healthy practices, navigation to sources of support and collective efficacy. Each interview was summarized to describe navigation and negotiation of participants' networks and the degree of collective efficacy. Analysis highlighted the similarities and differences between countries and provided insights into capacities of networks to support self-management. The network support mechanisms were identified in all interviews, and losses and gains in networks impacted on diabetes management. There were contextual differences between countries, most notably the impact of financial austerity on network dynamics. Four types of network are suggested: generative, diverse and beneficial to individuals; proxy, network members undertook diabetes management work; avoidant, support not engaged with; and struggling, diabetes management a struggle or not prioritized. It is possible to differentiate types of network input to living with and managing diabetes. Recognizing the nature of active, generative aspects of networks support is likely to have relevance for self-management support interventions either through encouraging continuing development and maintenance of these contacts or intervening to address struggling networks through introducing the means to connect people to additional sources of support. © 2014 John Wiley & Sons Ltd.

  5. Interviewer Effects on a Network-Size Filter Question

    Directory of Open Access Journals (Sweden)

    Josten Michael

    2016-06-01

    Full Text Available There is evidence that survey interviewers may be tempted to manipulate answers to filter questions in a way that minimizes the number of follow-up questions. This becomes relevant when ego-centered network data are collected. The reported network size has a huge impact on interview duration if multiple questions on each alter are triggered. We analyze interviewer effects on a network-size question in the mixed-mode survey “Panel Study ‘Labour Market and Social Security’” (PASS, where interviewers could skip up to 15 follow-up questions by generating small networks. Applying multilevel models, we find almost no interviewer effects in CATI mode, where interviewers are paid by the hour and frequently supervised. In CAPI, however, where interviewers are paid by case and no close supervision is possible, we find strong interviewer effects on network size. As the area-specific network size is known from telephone mode, where allocation to interviewers is random, interviewer and area effects can be separated. Furthermore, a difference-in-difference analysis reveals the negative effect of introducing the follow-up questions in Wave 3 on CAPI network size. Attempting to explain interviewer effects we neither find significant main effects of experience within a wave, nor significantly different slopes between interviewers.

  6. The effects of traffic structure on application and network performance

    CERN Document Server

    Aikat, Jay; Smith, F Donelson

    2012-01-01

    Over the past three decades, the Internet's rapid growth has spurred the development of new applications in mobile computing, digital music, online video, gaming and social networks. These applications rely heavily upon various underlying network protocols and mechanisms to enable, maintain and enhance their Internet functionalityThe Effects of Traffic Structure on Application and Network Performance provides the necessary tools for maximizing the network efficiency of any Internet application, and presents ground-breaking research that will influence how these applications are built in the fu

  7. Type-II superlattice hole effective masses

    Science.gov (United States)

    Ting, David Z.; Soibel, Alexander; Gunapala, Sarath D.

    2017-08-01

    A long wavelength infrared (LWIR) type-II superlattice (T2SL) is typically characterized by a very large valence-band-edge curvature effective mass, which is often assumed to lead to poor hole mobility. A detailed examination of the LWIR T2SL heavy-hole 1 (hh1) band structure reveals that a hole with non-zero in-plane momentum (k‖ ≠ 0) can move with a much larger group velocity component along the growth direction than one at the band edge (k‖ = 0), and that the hh1 miniband width can exhibit a very strong dependence on the in-plane wavevector k‖ . To distill the band structure effects relevant to hole transport into a simple quantity, we describe a formulation for computing the thermally averaged conductivity effective mass. We show that the LWIR T2SL hole conductivity effective masses along the growth direction can be orders of magnitude smaller than the corresponding band-edge curvature effective masses. We compare the conductivities effective masses of InAs/GaSb T2SL and InAs/InAsSb T2SL grown pseudomorphically on GaSb substrate, as well as the metamorphic bulk InAsSb and InAs/InAsSb T2SL.

  8. IDENTIFICATION OF THE TYPE OF AGRICULTURE SUITED FOR APPLICATION OF WIRELESS SENSOR NETWORKS

    Directory of Open Access Journals (Sweden)

    Ahsan Abdullah

    2012-12-01

    Full Text Available The world's population is expected to double by 2050; world food supply is unlikely to double by doubling the area under cultivation or by doubling the availability of water. There are other challenges too, such as decline in the number of farms and a decline in the number of agriculture workforce. Climate change is expected to further aggravate the existing situation. Therefore, for the humanity to survive agriculture has to become smart - one way is by integrating Wireless Sensor Networks (WSN in agriculture. In this paper, we will present the application of WSN in agriculture and discuss different types of sensors, different types of WSN and their application in 13 different types of traditional agriculture. We identify the type of agriculture most suited for WSN in terms of applications. We will also review some recent applications of WSN in agriculture; identify challenges and present possible future directions.

  9. Relationship between social network, social support and health behaviour in people with type 1 and type 2 diabetes: cross-sectional studies

    Directory of Open Access Journals (Sweden)

    Nana F. Hempler

    2016-02-01

    Full Text Available Abstract Background Psychosocial and behavioural aspects of diabetes may differ according to diabetes type. This study compared people with type 1 and type 2 diabetes with respect to social relations (cohabitation status, contact with the social network and social support and health behaviours (diet and physical activity. Furthermore, we examined whether potential differences in health behaviour between people with type 1 and type 2 diabetes were influenced by education level and social relations. Methods We conducted two cross-sectional surveys consisting of people with type 2 diabetes (N = 1081 and type 1 diabetes (N = 2419 from a specialist diabetes clinic. Gender-stratified stepwise multiple regression models assessed differences by diabetes type and other variables of interest. Results Significant associations were found between diabetes type and social network, social support and health behaviour. No differences were observed regarding cohabitation status. People with type 2 diabetes were less physically active, less likely to follow recommended diet (men, had fewer contacts with family and friends and were less certain of counting on help in case of severe illness than people with type 1 diabetes. No impact of education level, social network and social support were observed concerning differences in health behaviours by diabetes type; however, in women, the association between physical activity and diabetes type was not significant after adjustment for social relations and education level. Conclusions People with type 2 diabetes had less contact with the social network, less certainty about support in case of severe illness and fewer healthy behaviours than people with type 1 diabetes. It may be important to draw attention to differences in health behaviours and social relations between people with type 1 and type 2 diabetes in diabetes care, patient education and support initiatives.

  10. Relationship between social network, social support and health behaviour in people with type 1 and type 2 diabetes: cross-sectional studies.

    Science.gov (United States)

    Hempler, Nana F; Joensen, Lene E; Willaing, Ingrid

    2016-02-29

    Psychosocial and behavioural aspects of diabetes may differ according to diabetes type. This study compared people with type 1 and type 2 diabetes with respect to social relations (cohabitation status, contact with the social network and social support) and health behaviours (diet and physical activity). Furthermore, we examined whether potential differences in health behaviour between people with type 1 and type 2 diabetes were influenced by education level and social relations. We conducted two cross-sectional surveys consisting of people with type 2 diabetes (N = 1081) and type 1 diabetes (N = 2419) from a specialist diabetes clinic. Gender-stratified stepwise multiple regression models assessed differences by diabetes type and other variables of interest. Significant associations were found between diabetes type and social network, social support and health behaviour. No differences were observed regarding cohabitation status. People with type 2 diabetes were less physically active, less likely to follow recommended diet (men), had fewer contacts with family and friends and were less certain of counting on help in case of severe illness than people with type 1 diabetes. No impact of education level, social network and social support were observed concerning differences in health behaviours by diabetes type; however, in women, the association between physical activity and diabetes type was not significant after adjustment for social relations and education level. People with type 2 diabetes had less contact with the social network, less certainty about support in case of severe illness and fewer healthy behaviours than people with type 1 diabetes. It may be important to draw attention to differences in health behaviours and social relations between people with type 1 and type 2 diabetes in diabetes care, patient education and support initiatives.

  11. Solidarity through networks : The effects of task and informal interdependence on cooperation within teams

    NARCIS (Netherlands)

    Koster, F.; Stokman, F.N.; Hodson, R.; Sanders, K.

    2007-01-01

    PURPOSE – The aim of this paper is to investigate the effects of task and informal networks and their interaction on cooperative types of employee behaviour. DESIGN/METHODOLOGY/APPROACH – Two studies are used to examine the research question. The first dataset consists of book-length ethnographies

  12. Price Competition in Two-Sided Markets with Heterogeneous Consumers and Network Effects

    NARCIS (Netherlands)

    Filistrucchi, L.; Klein, T.J.

    We model a two-sided market with heterogeneous customers and two heterogeneous network effects. In our model, customers on each market side care differently about both the number and the type of customers on the other side. Examples of two-sided markets are online platforms or daily newspapers. In

  13. Effects of Social Networking on Adolescent Education

    Science.gov (United States)

    Miah, Muhammed; Omar, Adnan; Allison-Golding, Monique

    2013-01-01

    In recent years, the use of social networking sites has grown tremendously especially among the teens and high school students. However, very little is known about the scale of use, the purpose, how students use these sites and, more specifically, whether these sites help or hurt their academic progress. This study investigates how high school…

  14. Detecting and Predicting Muscle Fatigue during Typing By SEMG Signal Processing and Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Elham Ghoochani

    2011-03-01

    Full Text Available Introduction: Repetitive strain injuries are one of the most prevalent problems in occupational diseases. Repetition, vibration and bad postures of the extremities are physical risk factors related to work that can cause chronic musculoskeletal disorders. Repetitive work on a computer with low level contraction requires the posture to be maintained for a long time, which can cause muscle fatigue. Muscle fatigue in shoulders and neck is one of the most prevalent problems reported with computer users especially during typing. Surface electromyography (SEMG signals are used for detecting muscle fatigue as a non-invasive method. Material and Methods: Nine healthy females volunteered for signal recoding during typing. EMG signals were recorded from the trapezius muscle, which is subjected to muscle fatigue during typing.  After signal analysis and feature extraction, detecting and predicting muscle fatigue was performed by using the MLP artificial neural network. Results: Recorded signals were analyzed in time and frequency domains for feature extraction. Results of classification showed that the MLP neural network can detect and predict muscle fatigue during typing with 80.79 % ± 1.04% accuracy. Conclusion: Intelligent classification and prediction of muscle fatigue can have many applications in human factors engineering (ergonomics, rehabilitation engineering and biofeedback equipment for mitigating the injuries of repetitive works.

  15. Meta-analysis reveals conserved cell cycle transcriptional network across multiple human cell types.

    Science.gov (United States)

    Giotti, Bruno; Joshi, Anagha; Freeman, Tom C

    2017-01-05

    Cell division is central to the physiology and pathology of all eukaryotic organisms. The molecular machinery underpinning the cell cycle has been studied extensively in a number of species and core aspects of it have been found to be highly conserved. Similarly, the transcriptional changes associated with this pathway have been studied in different organisms and different cell types. In each case hundreds of genes have been reported to be regulated, however there seems to be little consensus in the genes identified across different studies. In a recent comparison of transcriptomic studies of the cell cycle in different human cell types, only 96 cell cycle genes were reported to be the same across all studies examined. Here we perform a systematic re-examination of published human cell cycle expression data by using a network-based approach to identify groups of genes with a similar expression profile and therefore function. Two clusters in particular, containing 298 transcripts, showed patterns of expression consistent with cell cycle occurrence across the four human cell types assessed. Our analysis shows that there is a far greater conservation of cell cycle-associated gene expression across human cell types than reported previously, which can be separated into two distinct transcriptional networks associated with the G 1 /S-S and G 2 -M phases of the cell cycle. This work also highlights the benefits of performing a re-analysis on combined datasets.

  16. Bi-stability in type 2 diabetes mellitus multi-organ signalling network.

    Directory of Open Access Journals (Sweden)

    Shubhankar Kulkarni

    Full Text Available Type 2 diabetes mellitus (T2DM is believed to be irreversible although no component of the pathophysiology is irreversible. We show here with a network model that the apparent irreversibility is contributed by the structure of the network of inter-organ signalling. A network model comprising all known inter-organ signals in T2DM showed bi-stability with one insulin sensitive and one insulin resistant attractor. The bi-stability was made robust by multiple positive feedback loops suggesting an evolved allostatic system rather than a homeostatic system. In the absence of the complete network, impaired insulin signalling alone failed to give a stable insulin resistant or hyperglycemic state. The model made a number of correlational predictions many of which were validated by empirical data. The current treatment practice targeting obesity, insulin resistance, beta cell function and normalization of plasma glucose failed to reverse T2DM in the model. However certain behavioural and neuro-endocrine interventions ensured a reversal. These results suggest novel prevention and treatment approaches which need to be tested empirically.

  17. The African Field Epidemiology Network--networking for effective field epidemiology capacity building and service delivery.

    Science.gov (United States)

    Gitta, Sheba Nakacubo; Mukanga, David; Babirye, Rebecca; Dahlke, Melissa; Tshimanga, Mufuta; Nsubuga, Peter

    2011-01-01

    Networks are a catalyst for promoting common goals and objectives of their membership. Public Health networks in Africa are crucial, because of the severe resource limitations that nations face in dealing with priority public health problems. For a long time, networks have existed on the continent and globally, but many of these are disease-specific with a narrow scope. The African Field Epidemiology Network (AFENET) is a public health network established in 2005 as a non-profit networking alliance of Field Epidemiology and Laboratory Training Programs (FELTPs) and Field Epidemiology Training Programs (FETPs) in Africa. AFENET is dedicated to helping ministries of health in Africa build strong, effective and sustainable programs and capacity to improve public health systems by partnering with global public health experts. The Network's goal is to strengthen field epidemiology and public health laboratory capacity to contribute effectively to addressing epidemics and other major public health problems in Africa. AFENET currently networks 12 FELTPs and FETPs in sub-Saharan Africa with operations in 20 countries. AFENET has a unique tripartite working relationship with government technocrats from human health and animal sectors, academicians from partner universities, and development partners, presenting the Network with a distinct vantage point. Through the Network, African nations are making strides in strengthening their health systems. Members are able to: leverage resources to support field epidemiology and public health laboratory training and service delivery notably in the area of outbreak investigation and response as well as disease surveillance; by-pass government bureaucracies that often hinder and frustrate development partners; and consolidate efforts of different partners channelled through the FELTPs by networking graduates through alumni associations and calling on them to offer technical support in various public health capacities as the need arises

  18. The African Field Epidemiology Network-Networking for effective field epidemiology capacity building and service delivery

    Science.gov (United States)

    Gitta, Sheba Nakacubo; Mukanga, David; Babirye, Rebecca; Dahlke, Melissa; Tshimanga, Mufuta; Nsubuga, Peter

    2011-01-01

    Networks are a catalyst for promoting common goals and objectives of their membership. Public Health networks in Africa are crucial, because of the severe resource limitations that nations face in dealing with priority public health problems. For a long time, networks have existed on the continent and globally, but many of these are disease-specific with a narrow scope. The African Field Epidemiology Network (AFENET) is a public health network established in 2005 as a non-profit networking alliance of Field Epidemiology and Laboratory Training Programs (FELTPs) and Field Epidemiology Training Programs (FETPs) in Africa. AFENET is dedicated to helping ministries of health in Africa build strong, effective and sustainable programs and capacity to improve public health systems by partnering with global public health experts. The Network's goal is to strengthen field epidemiology and public health laboratory capacity to contribute effectively to addressing epidemics and other major public health problems in Africa. AFENET currently networks 12 FELTPs and FETPs in sub-Saharan Africa with operations in 20 countries. AFENET has a unique tripartite working relationship with government technocrats from human health and animal sectors, academicians from partner universities, and development partners, presenting the Network with a distinct vantage point. Through the Network, African nations are making strides in strengthening their health systems. Members are able to: leverage resources to support field epidemiology and public health laboratory training and service delivery notably in the area of outbreak investigation and response as well as disease surveillance; by-pass government bureaucracies that often hinder and frustrate development partners; and consolidate efforts of different partners channelled through the FELTPs by networking graduates through alumni associations and calling on them to offer technical support in various public health capacities as the need arises

  19. The Connect Effect Building Strong Personal, Professional, and Virtual Networks

    CERN Document Server

    Dulworth, Michael

    2008-01-01

    Entrepreneur and executive development expert Mike Dulworth's THE CONNECT EFFECT provides readers with a simple framework and practical tools for developing that crucial competitive advantage: a high-quality personal, professional/organizational and virtual network.

  20. Integrated metabolic modelling reveals cell-type specific epigenetic control points of the macrophage metabolic network.

    Science.gov (United States)

    Pacheco, Maria Pires; John, Elisabeth; Kaoma, Tony; Heinäniemi, Merja; Nicot, Nathalie; Vallar, Laurent; Bueb, Jean-Luc; Sinkkonen, Lasse; Sauter, Thomas

    2015-10-19

    The reconstruction of context-specific metabolic models from easily and reliably measurable features such as transcriptomics data will be increasingly important in research and medicine. Current reconstruction methods suffer from high computational effort and arbitrary threshold setting. Moreover, understanding the underlying epigenetic regulation might allow the identification of putative intervention points within metabolic networks. Genes under high regulatory load from multiple enhancers or super-enhancers are known key genes for disease and cell identity. However, their role in regulation of metabolism and their placement within the metabolic networks has not been studied. Here we present FASTCORMICS, a fast and robust workflow for the creation of high-quality metabolic models from transcriptomics data. FASTCORMICS is devoid of arbitrary parameter settings and due to its low computational demand allows cross-validation assays. Applying FASTCORMICS, we have generated models for 63 primary human cell types from microarray data, revealing significant differences in their metabolic networks. To understand the cell type-specific regulation of the alternative metabolic pathways we built multiple models during differentiation of primary human monocytes to macrophages and performed ChIP-Seq experiments for histone H3 K27 acetylation (H3K27ac) to map the active enhancers in macrophages. Focusing on the metabolic genes under high regulatory load from multiple enhancers or super-enhancers, we found these genes to show the most cell type-restricted and abundant expression profiles within their respective pathways. Importantly, the high regulatory load genes are associated to reactions enriched for transport reactions and other pathway entry points, suggesting that they are critical regulatory control points for cell type-specific metabolism. By integrating metabolic modelling and epigenomic analysis we have identified high regulatory load as a common feature of metabolic

  1. Distributed flow optimization and cascading effects in weighted complex networks

    OpenAIRE

    Asztalos, Andrea; Sreenivasan, Sameet; Szymanski, Boleslaw K.; Korniss, G.

    2011-01-01

    We investigate the effect of a specific edge weighting scheme $\\sim (k_i k_j)^{\\beta}$ on distributed flow efficiency and robustness to cascading failures in scale-free networks. In particular, we analyze a simple, yet fundamental distributed flow model: current flow in random resistor networks. By the tuning of control parameter $\\beta$ and by considering two general cases of relative node processing capabilities as well as the effect of bandwidth, we show the dependence of transport efficie...

  2. Effect of the missing nodes in a bidirectional network

    Science.gov (United States)

    Gemao, Beverly; Lai, Pik-Yin

    2017-08-01

    Complex networks have attracted studies from various fields of science due to their relevance in many real systems. As not all nodes are measured in real-systems, this paper explores the effect of the missing nodes on the observed nodes of a bidirectional network with Gaussian noises. Here, it is shown that the collective effect of the missing nodes on the observed nodes may be viewed as a colored noise with exponentially decaying time correlations.

  3. Genetic interaction network of the Saccharomyces cerevisiae type 1 phosphatase Glc7

    Directory of Open Access Journals (Sweden)

    Neszt Michael

    2008-07-01

    Full Text Available Abstract Background Protein kinases and phosphatases regulate protein phosphorylation, a critical means of modulating protein function, stability and localization. The identification of functional networks for protein phosphatases has been slow due to their redundant nature and the lack of large-scale analyses. We hypothesized that a genome-scale analysis of genetic interactions using the Synthetic Genetic Array could reveal protein phosphatase functional networks. We apply this approach to the conserved type 1 protein phosphatase Glc7, which regulates numerous cellular processes in budding yeast. Results We created a novel glc7 catalytic mutant (glc7-E101Q. Phenotypic analysis indicates that this novel allele exhibits slow growth and defects in glucose metabolism but normal cell cycle progression and chromosome segregation. This suggests that glc7-E101Q is a hypomorphic glc7 mutant. Synthetic Genetic Array analysis of glc7-E101Q revealed a broad network of 245 synthetic sick/lethal interactions reflecting that many processes are required when Glc7 function is compromised such as histone modification, chromosome segregation and cytokinesis, nutrient sensing and DNA damage. In addition, mitochondrial activity and inheritance and lipid metabolism were identified as new processes involved in buffering Glc7 function. An interaction network among 95 genes genetically interacting with GLC7 was constructed by integration of genetic and physical interaction data. The obtained network has a modular architecture, and the interconnection among the modules reflects the cooperation of the processes buffering Glc7 function. Conclusion We found 245 genes required for the normal growth of the glc7-E101Q mutant. Functional grouping of these genes and analysis of their physical and genetic interaction patterns bring new information on Glc7-regulated processes.

  4. Tariff-Mediated Network Effects Versus Strategic Disounting

    DEFF Research Database (Denmark)

    Zucchini, Leon; Claussen, Jörg; Trüg, Moritz

    2013-01-01

    Mobile telecommunication operators routinely charge subscribers lower prices for calls on their own network than for calls to other networks (on-net discounts). Studies on tariff-mediated network effects suggest this is due to large operators using on-net discounts to damage smaller rivals....... Alternatively, research on strategic discounting suggests that small operators use on-net discounts to advertise with low on-net prices. We test the relative strength of these effects using data on tariff setting in German mobile telecommunications between 2001 and 2009. We find that large operators are more...... likely to offer tariffs with on-net discounts but there is no consistently significant difference in the magnitude of discounts. Our results suggest that tariff-mediated network effects are the main cause of on-net discounts....

  5. Development of a neural network for prediction of glucose concentration in type 1 diabetes patients.

    Science.gov (United States)

    Pappada, Scott M; Cameron, Brent D; Rosman, Paul M

    2008-09-01

    A major difficulty in the management of diabetes is the optimization of insulin therapies to avoid occurrences of hypoglycemia and hyperglycemia. Many factors impact glucose fluctuations in diabetes patients, such as insulin dosage, nutritional intake, daily activities and lifestyle (e.g., sleep-wake cycles and exercise), and emotional states (e.g., stress). The overall effect of these factors has not been fully quantified to determine the impact on subsequent glycemic trends. Recent advances in diabetes technology such as continuous glucose monitoring (CGM) provides significant sources of data, such that quantification may be possible. Depending on the CGM technology utilized, the sampling frequency ranges from 1-5 min. In this study, an intensive electronic diary documenting the factors previously described was created. This diary was utilized by 18 patients with insulin-dependent diabetes mellitus in conjunction with CGM. Utilizing this dataset, various neural network models were constructed to predict glucose in these diabetes patients while varying the predictive window from 50-180 min. The predictive capability of each neural network within the fully trained dataset was analyzed as well as the predictive capabilities of the neural networks on unseen data. Neural network models were created using NeuroSolutions software with variable predictive windows of 50, 75, 100, 120, 150, and 180 min. Neural network models were trained using patient datasets ranging from 11-17 patients and evaluated on patient data not included in the neural network formulation. Performance analysis was completed for the neural network models using MATLAB. Performance measures include the calculation of the mean absolute difference percent overall and at hypoglycemic and hyperglycemic extremes, and the percentage of hypoglycemic and hyperglycemic occurrences were predicted. Overall, the neural network models perform adequately at predicting at normal (>70 and or =180 mg/dl); however

  6. Social networks and trade of services: modelling interregional flows with spatial and network autocorrelation effects

    Science.gov (United States)

    de la Mata, Tamara; Llano, Carlos

    2013-07-01

    Recent literature on border effect has fostered research on informal barriers to trade and the role played by network dependencies. In relation to social networks, it has been shown that intensity of trade in goods is positively correlated with migration flows between pairs of countries/regions. In this article, we investigate whether such a relation also holds for interregional trade of services. We also consider whether interregional trade flows in services linked with tourism exhibit spatial and/or social network dependence. Conventional empirical gravity models assume the magnitude of bilateral flows between regions is independent of flows to/from regions located nearby in space, or flows to/from regions related through social/cultural/ethic network connections. With this aim, we provide estimates from a set of gravity models showing evidence of statistically significant spatial and network (demographic) dependence in the bilateral flows of the trade of services considered. The analysis has been applied to the Spanish intra- and interregional monetary flows of services from the accommodation, restaurants and travel agencies for the period 2000-2009, using alternative datasets for the migration stocks and definitions of network effects.

  7. A Comparative Study on Substation Types and Network Layouts in Connection with Low-Energy District Heating Systems

    DEFF Research Database (Denmark)

    Tol, Hakan; Svendsen, Svend

    2012-01-01

    The study deals with low-energy district heating (DH) networks operating in low temperatures such as 55 °C in terms of supply and 25 °C in terms of return. The network layout, additional booster pumps, and different substation types such as storage tanks either equipped or not equipped in domestic...

  8. Hierarchical Group Based Mutual Authentication and Key Agreement for Machine Type Communication in LTE and Future 5G Networks

    Directory of Open Access Journals (Sweden)

    Probidita Roychoudhury

    2017-01-01

    Full Text Available In view of the exponential growth in the volume of wireless data communication among heterogeneous devices ranging from smart phones to tiny sensors across a wide range of applications, 3GPP LTE-A has standardized Machine Type Communication (MTC which allows communication between entities without any human intervention. The future 5G cellular networks also envisage massive deployment of MTC Devices (MTCDs which will increase the total number of connected devices hundredfold. This poses a huge challenge to the traditional cellular system processes, especially the traditional Mutual Authentication and Key Agreement (AKA mechanism currently used in LTE systems, as the signaling load caused by the increasingly large number of devices may have an adverse effect on the regular Human to Human (H2H traffic. A solution in the literature has been the use of group based architecture which, while addressing the authentication traffic, has their share of issues. This paper introduces Hierarchical Group based Mutual Authentication and Key Agreement (HGMAKA protocol to address those issues and also enables the small cell heterogeneous architecture in line with 5G networks to support MTC services. The aggregate Message Authentication Code based approach has been shown to be lightweight and significantly efficient in terms of resource usage compared to the existing protocols, while being robust to authentication message failures, and scalable to heterogeneous network architectures.

  9. The Social Name-Letter Effect on Online Social Networks

    OpenAIRE

    Kooti, Farshad; Magno, Gabriel; Weber, Ingmar

    2014-01-01

    The Name-Letter Effect states that people have a preference for brands, places, and even jobs that start with the same letter as their own first name. So Sam might like Snickers and live in Seattle. We use social network data from Twitter and Google+ to replicate this effect in a new environment. We find limited to no support for the Name-Letter Effect on social networks. We do, however, find a very robust Same-Name Effect where, say, Michaels would be more likely to link to other Michaels th...

  10. Gravity Effects on Information Filtering and Network Evolving

    Science.gov (United States)

    Liu, Jin-Hu; Zhang, Zi-Ke; Chen, Lingjiao; Liu, Chuang; Yang, Chengcheng; Wang, Xueqi

    2014-01-01

    In this paper, based on the gravity principle of classical physics, we propose a tunable gravity-based model, which considers tag usage pattern to weigh both the mass and distance of network nodes. We then apply this model in solving the problems of information filtering and network evolving. Experimental results on two real-world data sets, Del.icio.us and MovieLens, show that it can not only enhance the algorithmic performance, but can also better characterize the properties of real networks. This work may shed some light on the in-depth understanding of the effect of gravity model. PMID:24622162

  11. Creating an Effective Network: The GRACEnet Example

    Science.gov (United States)

    Follett, R. F.; Del Grosso, S.

    2008-12-01

    Networking activities require time, work, and nurturing. The objective of this presentation is to share the experience gained from The Greenhouse gas Reduction through Agricultural Carbon Enhancement network (GRACEnet). GRACEnet, formally established in 2005 by the ARS/USDA, resulted from workshops, teleconferences, and other activities beginning in at least 2002. Critical factors for its formation were to develop and formalize a common vision, goals, and objectives, which was accomplished in a 2005 workshop. The 4-person steering committee (now 5) was charged with coordinating the part-time (0.05- to 0.5 SY/location) efforts across 30 ARS locations to develop four products; (1) a national database, (2) regional/national guidelines of management practices, (3) computer models, and (4) "state-of-knowledge" summary publications. All locations are asked to contribute to the database from their field studies. Communication with everyone and periodic meeting are extremely important. Required to populate the database has to be a common vision of sharing, format, and trust. Based upon the e-mail list, GRACEnet has expanded from about 30 to now nearly 70 participants. Annual reports and a new website help facilitate this activity.

  12. Cost Effective Rumor Containment in Social Networks

    CERN Document Server

    Kotnis, Bhushan

    2014-01-01

    The spread of rumors through social media and online social networks can not only disrupt the daily lives of citizens but also result in loss of life and property. A rumor spreads when individuals, who are unable decide the authenticity of the information, mistake the rumor as genuine information and pass it on to their acquaintances. We propose a solution where a set of individuals (based on their degree) in the social network are trained and provided resources to help them distinguish a rumor from genuine information. By formulating an optimization problem we calculate the optimum set of individuals, who must undergo training, and the quality of training that minimizes the expected training cost and ensures an upper bound on the size of the rumor outbreak. Our primary contribution is that although the optimization problem turns out to be non convex, we show that the problem is equivalent to solving a set of linear programs. This result also allows us to solve the problem of minimizing the size of rumor outb...

  13. A New Type of Photo-Thermo Staged-Responsive Shape-Memory Polyurethanes Network

    Directory of Open Access Journals (Sweden)

    Jinghao Yang

    2017-07-01

    Full Text Available In this paper, we developed a photo-thermo staged-responsive shape-memory polymer network which has a unique ability of being spontaneously photo-responsive deformable and thermo-responsive shape recovery. This new type of shape-memory polyurethane network (A-SMPUs was successfully synthesized with 4,4-azodibenzoic acid (Azoa, hexamethylenediisocyanate (HDI and polycaprolactone (PCL, followed by chemical cross-linking with glycerol (Gl. The structures, morphology, and shape-memory properties of A-SMPUs have been carefully investigated. The results demonstrate that the A-SMPUs form micro-phase separation structures consisting of a semi-crystallized PCL soft phase and an Azoa amorphous hard phase that could influence the crystallinity of PCL soft phases. The chemical cross-linking provided a stable network and good thermal stability to the A-SMPUs. All A-SMPUs exhibited good triple-shape-memory properties with higher than 97% shape fixity ratio and 95% shape recovery ratio. Additionally, the A-SMPUs with higher Azoa content exhibited interesting photo-thermo two-staged responsiveness. A pre-processed film with orientated Azoa structure exhibited spontaneous curling deformation upon exposing to ultraviolet (UV light, and curling deformation is constant even under Vis light. Finally, the curling deformation can spontaneously recover to the original shape by applying a thermal stimulus. This work demonstrates new synergistically multi-responsive SMPUs that will have many applications in smart science and technology.

  14. Network analysis of pig movements: Loyalty patterns and contact chains of different holding types in Denmark.

    Science.gov (United States)

    Schulz, Jana; Boklund, Anette; Halasa, Tariq H B; Toft, Nils; Lentz, Hartmut H K

    2017-01-01

    Understanding animal movements is an important factor for the development of meaningful surveillance and control programs, but also for the development of disease spread models. We analysed the Danish pig movement network using static and temporal network analysis tools to provide deeper insight in the connection between holdings dealing with pigs, such as breeding and multiplier herds, production herds, slaughterhouses or traders. Pig movements, which occurred between 1st January 2006 and 31st December 2015 in Denmark, were summarized to investigate temporal trends such as the number of active holdings, the number of registered movements and the number of pigs moved. To identify holdings and holding types with potentially higher risk for introduction or spread of diseases via pig movements, we determined loyalty patterns, annual network components and contact chains for the 24 registered holding types. The total number of active holdings as well as the number of pig movements decreased during the study period while the holding sizes increased. Around 60-90% of connections between two pig holdings were present in two consecutive years and around one third of the connections persisted within the considered time period. Weaner herds showed the highest level of in-loyalty, whereas we observed an intermediate level of in-loyalty for all breeding sites and for production herds. Boar stations, production herds and trade herds showed a high level of out-loyalty. Production herds constituted the highest proportion of holdings in the largest strongly connected component. All production sites showed low levels of in-going contact chains and we observed a high level of out-going contact chain for breeding and multiplier herds. Except for livestock auctions, all transit sites also showed low levels of out-going contact chains. Our results reflect the pyramidal structure of the underlying network. Based on the considered disease, the time frame for the calculation of network

  15. Analysis of Linkage Effects among Currency Networks Using REER Data

    Directory of Open Access Journals (Sweden)

    Haishu Qiao

    2015-01-01

    Full Text Available We modeled the currency networks through the use of REER (real effective exchange rate instead of a bilateral exchange rate in order to overcome the confusion in selecting base currencies. Based on the MST (minimum spanning tree approach and the rolling-window method, we constructed time-varying and correlation-based networks with which we investigate the linkage effects among different currencies. In particular, and as the source of empirical data, we chose the monthly REER data for a set of 61 major currencies during the period from 1994 to 2014. The study demonstrated that obvious linkage effects existed among currency networks and the euro (EUR was confirmed as the predominant world currency. Additionally, we used the rolling-window method to investigate the stability of linkage effects, doing so by calculating the mean correlations and mean distances as well as the normalized tree length and degrees of those currencies. The results showed that financial crises during the study period had a great effect on the currency network’s topology structure and led to more clustered currency networks. Our results suggested that it is more appropriate to estimate the linkage effects among currency networks through the use of REER data.

  16. Planning the City Logistics Terminal Location by Applying the Green p-Median Model and Type-2 Neurofuzzy Network.

    Science.gov (United States)

    Pamučar, Dragan; Vasin, Ljubislav; Atanasković, Predrag; Miličić, Milica

    2016-01-01

    The paper herein presents green p-median problem (GMP) which uses the adaptive type-2 neural network for the processing of environmental and sociological parameters including costs of logistics operators and demonstrates the influence of these parameters on planning the location for the city logistics terminal (CLT) within the discrete network. CLT shows direct effects on increment of traffic volume especially in urban areas, which further results in negative environmental effects such as air pollution and noise as well as increased number of urban populations suffering from bronchitis, asthma, and similar respiratory infections. By applying the green p-median model (GMM), negative effects on environment and health in urban areas caused by delivery vehicles may be reduced to minimum. This model creates real possibilities for making the proper investment decisions so as profitable investments may be realized in the field of transport infrastructure. The paper herein also includes testing of GMM in real conditions on four CLT locations in Belgrade City zone.

  17. Planning the City Logistics Terminal Location by Applying the Green p-Median Model and Type-2 Neurofuzzy Network

    Directory of Open Access Journals (Sweden)

    Dragan Pamučar

    2016-01-01

    Full Text Available The paper herein presents green p-median problem (GMP which uses the adaptive type-2 neural network for the processing of environmental and sociological parameters including costs of logistics operators and demonstrates the influence of these parameters on planning the location for the city logistics terminal (CLT within the discrete network. CLT shows direct effects on increment of traffic volume especially in urban areas, which further results in negative environmental effects such as air pollution and noise as well as increased number of urban populations suffering from bronchitis, asthma, and similar respiratory infections. By applying the green p-median model (GMM, negative effects on environment and health in urban areas caused by delivery vehicles may be reduced to minimum. This model creates real possibilities for making the proper investment decisions so as profitable investments may be realized in the field of transport infrastructure. The paper herein also includes testing of GMM in real conditions on four CLT locations in Belgrade City zone.

  18. Planning the City Logistics Terminal Location by Applying the Green p-Median Model and Type-2 Neurofuzzy Network

    Science.gov (United States)

    Pamučar, Dragan; Vasin, Ljubislav; Atanasković, Predrag; Miličić, Milica

    2016-01-01

    The paper herein presents green p-median problem (GMP) which uses the adaptive type-2 neural network for the processing of environmental and sociological parameters including costs of logistics operators and demonstrates the influence of these parameters on planning the location for the city logistics terminal (CLT) within the discrete network. CLT shows direct effects on increment of traffic volume especially in urban areas, which further results in negative environmental effects such as air pollution and noise as well as increased number of urban populations suffering from bronchitis, asthma, and similar respiratory infections. By applying the green p-median model (GMM), negative effects on environment and health in urban areas caused by delivery vehicles may be reduced to minimum. This model creates real possibilities for making the proper investment decisions so as profitable investments may be realized in the field of transport infrastructure. The paper herein also includes testing of GMM in real conditions on four CLT locations in Belgrade City zone. PMID:27195005

  19. The streetlight effect in type 1 diabetes.

    Science.gov (United States)

    Battaglia, Manuela; Atkinson, Mark A

    2015-04-01

    In the nearly 100 years since the discovery of therapeutic insulin, significant research efforts have been directed at finding the underlying cause of type 1 diabetes (T1D) and developing a "cure" for the disease. While progress has clearly been made toward each of these goals, neither vision has been fulfilled. With increasing pressure from both public and private funders of diabetes research, growing impatience of those with T1D at the lack of practical discoveries, increased competition for research funds, uncertainties on the reproducibility of published scientific data, and questions regarding the value of animal models, the current research environment has become extraordinarily difficult to traverse from the perspective of investigators. As a result, there is an increasing pressure toward performance of what might be considered "safe" research, where the aim is to affirm existing dogmas rather than to pioneer efforts involving unconventional thought. Psychologists refer to this practice as "observational bias" while cartoonists label the process the "streetlight effect." In this Perspective, we consider notions in T1D research that should be subject to bold question and provide additional concepts, many somewhat orphan to research efforts, whose investigation could lead to a means for truly identifying the cause of and a cure for T1D. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  20. The optimal number, type and location of devices in automation of electrical distribution networks

    Directory of Open Access Journals (Sweden)

    Popović Željko N.

    2015-01-01

    Full Text Available This paper presents the mixed integer linear programming based model for determining optimal number, type and location of remotely controlled and supervised devices in distribution networks in the presence of distributed generators. The proposed model takes into consideration a number of different devices simultaneously (remotely controlled circuit breakers/reclosers, sectionalizing switches, remotely supervised and local fault passage indicators along with the following: expected outage cost to consumers and producers due to momentary and long-term interruptions, automated device expenses (capital investment, installation, and annual operation and maintenance costs, number and expenses of crews involved in the isolation and restoration process. Furthermore, the other possible benefits of each of automated device are also taken into account (e.g., benefits due to decreasing the cost of switching operations in normal conditions. The obtained numerical results emphasize the importance of consideration of different types of automation devices simultaneously. They also show that the proposed approach have a potential to improve the process of determining of the best automation strategy in real life distribution networks.

  1. Effect of planning for connectivity on linear reserve networks.

    Science.gov (United States)

    Lentini, Pia E; Gibbons, Philip; Carwardine, Josie; Fischer, Joern; Drielsma, Michael; Martin, Tara G

    2013-08-01

    Although the concept of connectivity is decades old, it remains poorly understood and defined, and some argue that habitat quality and area should take precedence in conservation planning instead. However, fragmented landscapes are often characterized by linear features that are inherently connected, such as streams and hedgerows. For these, both representation and connectivity targets may be met with little effect on the cost, area, or quality of the reserve network. We assessed how connectivity approaches affect planning outcomes for linear habitat networks by using the stock-route network of Australia as a case study. With the objective of representing vegetation communities across the network at a minimal cost, we ran scenarios with a range of representation targets (10%, 30%, 50%, and 70%) and used 3 approaches to account for connectivity (boundary length modifier, Euclidean distance, and landscape-value [LV]). We found that decisions regarding the target and connectivity approach used affected the spatial allocation of reserve systems. At targets ≥50%, networks designed with the Euclidean distance and LV approaches consisted of a greater number of small reserves. Hence, by maximizing both representation and connectivity, these networks compromised on larger contiguous areas. However, targets this high are rarely used in real-world conservation planning. Approaches for incorporating connectivity into the planning of linear reserve networks that account for both the spatial arrangement of reserves and the characteristics of the intervening matrix highlight important sections that link the landscape and that may otherwise be overlooked. © 2013 Society for Conservation Biology.

  2. Effects of behavioral patterns and network topology structures on Parrondo’s paradox

    Science.gov (United States)

    Ye, Ye; Cheong, Kang Hao; Cen, Yu-Wan; Xie, Neng-Gang

    2016-11-01

    A multi-agent Parrondo’s model based on complex networks is used in the current study. For Parrondo’s game A, the individual interaction can be categorized into five types of behavioral patterns: the Matthew effect, harmony, cooperation, poor-competition-rich-cooperation and a random mode. The parameter space of Parrondo’s paradox pertaining to each behavioral pattern, and the gradual change of the parameter space from a two-dimensional lattice to a random network and from a random network to a scale-free network was analyzed. The simulation results suggest that the size of the region of the parameter space that elicits Parrondo’s paradox is positively correlated with the heterogeneity of the degree distribution of the network. For two distinct sets of probability parameters, the microcosmic reasons underlying the occurrence of the paradox under the scale-free network are elaborated. Common interaction mechanisms of the asymmetric structure of game B, behavioral patterns and network topology are also revealed.

  3. On the Directionality Test of Peer Effects in Social Networks

    Science.gov (United States)

    An, Weihua

    2016-01-01

    One interesting idea in social network analysis is the directionality test that utilizes the directions of social ties to help identify peer effects. The null hypothesis of the test is that if contextual factors are the only force that affects peer outcomes, the estimated peer effects should not differ, if the directions of social ties are…

  4. Implementation of Internet Protocol Network Architecture for Effective ...

    African Journals Online (AJOL)

    Implementation of Internet Protocol Network Architecture for Effective bandwidth Allocation in a Multiparty, Multimedia Conferencing. ... as M/G/∞ input processes and divided into several classes, with the constraint that the aggregate effective bandwidth is within the link capacity times a prescribed utilization threshold.

  5. A Study of Rank Defect and Network Effect in Processing the CMONOC Network on Bernese

    Directory of Open Access Journals (Sweden)

    Weiwei Wu

    2018-02-01

    Full Text Available High-precision GPS data processing on Bernese has been employed to routinely resolve daily position solutions of GPS stations in the Crustal Movement Observation Network of China (CMONOC. The rank-deficient problems of the normal equation (NEQ system and the network effect on the frame alignment of NEQs in the processing of CMONOC data on Bernese still present difficulties. In this study, we diagnose the rank-deficient problems of the original NEQ, review the efficiency of the controlled datum removal (CDR method in filtering out the three frame-origin-related datum contents, investigate the reliabilities of the inherited frame orientation and scale information from the fixation of the GPS satellite orbits and the Earth rotation parameters in establishing the NEQ of the CMONOC network on Bernese, and analyze the impact of the network effect on the position time series of GPS stations. Our results confirm the nonsingularity of the original NEQ and the efficiency of the CDR filtering in resolving the rank-deficient problems; show that the frame origin parameters are weakly defined and should be stripped off, while the frame orientation and scale parameters should be retained due to their insufficient redefinition from the minimal constraint (MC implementation through inhomogeneous and asymmetrical fiducial networks; and reveal the superiority of a globally distributed fiducial network for frame alignment of the reconstructed NEQs via No-Net-Translation (NNT MC conditions. Finally, we attribute the two apparent discontinuities in the position time series to the terrestrial reference frame (TRF conversions of the GPS satellite orbits, and identify it as the orbit TRF effect.

  6. Contrasting effects of invasive plants in plant-pollinator networks.

    Science.gov (United States)

    Bartomeus, Ignasi; Vilà, Montserrat; Santamaría, Luís

    2008-04-01

    The structural organization of mutualism networks, typified by interspecific positive interactions, is important to maintain community diversity. However, there is little information available about the effect of introduced species on the structure of such networks. We compared uninvaded and invaded ecological communities, to examine how two species of invasive plants with large and showy flowers (Carpobrotus affine acinaciformis and Opuntia stricta) affect the structure of Mediterranean plant-pollinator networks. To attribute differences in pollination to the direct presence of the invasive species, areas were surveyed that contained similar native plant species cover, diversity and floral composition, with or without the invaders. Both invasive plant species received significantly more pollinator visits than any native species and invaders interacted strongly with pollinators. Overall, the pollinator community richness was similar in invaded and uninvaded plots, and only a few generalist pollinators visited invasive species exclusively. Invasive plants acted as pollination super generalists. The two species studied were visited by 43% and 31% of the total insect taxa in the community, respectively, suggesting they play a central role in the plant-pollinator networks. Carpobrotus and Opuntia had contrasting effects on pollinator visitation rates to native plants: Carpobrotus facilitated the visit of pollinators to native species, whereas Opuntia competed for pollinators with native species, increasing the nestedness of the plant-pollinator network. These results indicate that the introduction of a new species to a community can have important consequences for the structure of the plant-pollinator network.

  7. Internet use among urban Malaysians: Network diversity effects

    Directory of Open Access Journals (Sweden)

    De Rycker Antoon

    2017-01-01

    Full Text Available This study examines social network diversity in urban areas relative to residents’ usage of information and communication technologies (ICTs. Individual-level variation in social network diversity was measured using position generator data collected as part of a survey conducted in Malaysia’s Klang Valley (N = 808. Regression analyses were performed to assess the extent to which network diversity is related to ICTs. We find that most ICTs have a negative effect on diversity. Only frequent use of the Internet at work, mobile access to the Internet, and reading online news or blogs contribute positively to diversity. Findings support both a tendency toward ‘networked individualism’ and the more recent ‘glocalization’ thesis that some ICTs may also afford participation within local space rather than only across distant space.

  8. Heterogeneous Deployment Analysis for Cost-Effective Mobile Network Evolution

    DEFF Research Database (Denmark)

    Coletti, Claudio

    2013-01-01

    -powered base stations is a promising cost-effective solution to considerably enhance user experience. In such a network topology, which is denoted as heterogeneous deployment, the macro layer is expected to provide wider coverage but lower average data speeds whereas small cells are targeted at extending...... network coverage and boosting network capacity in traffic hot-spot areas. The thesis deals with the deployment of both outdoor small cells and indoor femto cells. Amongst the outdoor solution, particular emphasis is put on relay base stations as backhaul costs can be reduced by utilizing LTE spectrum...... statistical models of deployment areas, the performance analysis is carried out in the form of operator case studies for large-scale deployment scenarios, including realistic macro network layouts and inhomogeneous spatial traffic distributions. Deployment of small cells is performed by means of proposed...

  9. Meta-Analysis Approach identifies Candidate Genes and associated Molecular Networks for Type-2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Herwig Ralf

    2008-06-01

    Full Text Available Abstract Background Multiple functional genomics data for complex human diseases have been published and made available by researchers worldwide. The main goal of these studies is the detailed analysis of a particular aspect of the disease. Complementary, meta-analysis approaches try to extract supersets of disease genes and interaction networks by integrating and combining these individual studies using statistical approaches. Results Here we report on a meta-analysis approach that integrates data of heterogeneous origin in the domain of type-2 diabetes mellitus (T2DM. Different data sources such as DNA microarrays and, complementing, qualitative data covering several human and mouse tissues are integrated and analyzed with a Bootstrap scoring approach in order to extract disease relevance of the genes. The purpose of the meta-analysis is two-fold: on the one hand it identifies a group of genes with overall disease relevance indicating common, tissue-independent processes related to the disease; on the other hand it identifies genes showing specific alterations with respect to a single study. Using a random sampling approach we computed a core set of 213 T2DM genes across multiple tissues in human and mouse, including well-known genes such as Pdk4, Adipoq, Scd, Pik3r1, Socs2 that monitor important hallmarks of T2DM, for example the strong relationship between obesity and insulin resistance, as well as a large fraction (128 of yet barely characterized novel candidate genes. Furthermore, we explored functional information and identified cellular networks associated with this core set of genes such as pathway information, protein-protein interactions and gene regulatory networks. Additionally, we set up a web interface in order to allow users to screen T2DM relevance for any – yet non-associated – gene. Conclusion In our paper we have identified a core set of 213 T2DM candidate genes by a meta-analysis of existing data sources. We have

  10. The effects of music on brain functional networks: a network analysis.

    Science.gov (United States)

    Wu, J; Zhang, J; Ding, X; Li, R; Zhou, C

    2013-10-10

    The human brain can dynamically adapt to the changing surroundings. To explore this issue, we adopted graph theoretical tools to examine changes in electroencephalography (EEG) functional networks while listening to music. Three different excerpts of Chinese Guqin music were played to 16 non-musician subjects. For the main frequency intervals, synchronizations between all pair-wise combinations of EEG electrodes were evaluated with phase lag index (PLI). Then, weighted connectivity networks were created and their organizations were characterized in terms of an average clustering coefficient and characteristic path length. We found an enhanced synchronization level in the alpha2 band during music listening. Music perception showed a decrease of both normalized clustering coefficient and path length in the alpha2 band. Moreover, differences in network measures were not observed between musical excerpts. These experimental results demonstrate an increase of functional connectivity as well as a more random network structure in the alpha2 band during music perception. The present study offers support for the effects of music on human brain functional networks with a trend toward a more efficient but less economical architecture. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  11. Moderating Effects of Sales Promotion Types

    OpenAIRE

    Fernando de Oliveira Santini; Cláudio Hoffmann Sampaio; Marcelo Gattermann Perin; Lelis Balestrin Espartel; Wagner Junior Ladeira

    2015-01-01

    This paper aims to analyze the influence sales promotion types have on the relationship between perception of financial risk and perception of utilitarian and hedonic value on consumer purchase intentions. To this end, an experiment was conducted involving 589 participants divided into two groups defined by distinct scenarios in which the sales promotion type (monetary vs. non-monetary) was manipulated. The working hypotheses predicted a direct and positive relationship between th...

  12. Metabolic network topology reveals transcriptional regulatory signatures of type 2 diabetes.

    Directory of Open Access Journals (Sweden)

    Aleksej Zelezniak

    2010-04-01

    Full Text Available Type 2 diabetes mellitus (T2DM is a disorder characterized by both insulin resistance and impaired insulin secretion. Recent transcriptomics studies related to T2DM have revealed changes in expression of a large number of metabolic genes in a variety of tissues. Identification of the molecular mechanisms underlying these transcriptional changes and their impact on the cellular metabolic phenotype is a challenging task due to the complexity of transcriptional regulation and the highly interconnected nature of the metabolic network. In this study we integrate skeletal muscle gene expression datasets with human metabolic network reconstructions to identify key metabolic regulatory features of T2DM. These features include reporter metabolites--metabolites with significant collective transcriptional response in the associated enzyme-coding genes, and transcription factors with significant enrichment of binding sites in the promoter regions of these genes. In addition to metabolites from TCA cycle, oxidative phosphorylation, and lipid metabolism (known to be associated with T2DM, we identified several reporter metabolites representing novel biomarker candidates. For example, the highly connected metabolites NAD+/NADH and ATP/ADP were also identified as reporter metabolites that are potentially contributing to the widespread gene expression changes observed in T2DM. An algorithm based on the analysis of the promoter regions of the genes associated with reporter metabolites revealed a transcription factor regulatory network connecting several parts of metabolism. The identified transcription factors include members of the CREB, NRF1 and PPAR family, among others, and represent regulatory targets for further experimental analysis. Overall, our results provide a holistic picture of key metabolic and regulatory nodes potentially involved in the pathogenesis of T2DM.

  13. Dynamics and control of infections on social networks of population types.

    Science.gov (United States)

    Williams, Brian G; Dye, Christopher

    2017-10-26

    Random mixing in host populations has been a convenient simplifying assumption in the study of epidemics, but neglects important differences in contact rates within and between population groups. For HIV/AIDS, the assumption of random mixing is inappropriate for epidemics that are concentrated in groups of people at high risk, including female sex workers (FSW) and their male clients (MCF), injecting drug users (IDU) and men who have sex with men (MSM). To find out who transmits infection to whom and how that affects the spread and containment of infection remains a major empirical challenge in the epidemiology of HIV/AIDS. Here we develop a technique, based on the routine sampling of infection in linked population groups (a social network of population types), which shows how an HIV/AIDS epidemic in Can Tho Province of Vietnam began in FSW, was propagated mainly by IDU, and ultimately generated most cases among the female partners of MCF (FPM). Calculation of the case reproduction numbers within and between groups, and for the whole network, provides insights into control that cannot be deduced simply from observations on the prevalence of infection. Specifically, the per capita rate of HIV transmission was highest from FSW to MCF, and most HIV infections occurred in FPM, but the number of infections in the whole network is best reduced by interrupting transmission to and from IDU. This analysis can be used to guide HIV/AIDS interventions using needle and syringe exchange, condom distribution and antiretroviral therapy. The method requires only routine data and could be applied to infections in other populations. Copyright © 2017. Published by Elsevier B.V.

  14. Bottle-neck type of neural network as a mapping device towards food specifications.

    Science.gov (United States)

    Novic, Marjana; Groselj, Neva

    2009-09-01

    A novel methodology is proposed for food specifications associated with the origin of food. The methodology was tested on honey samples collected within the TRACE EU project. The data were sampled in various regions in Europe and analysed for the trace elements content. The sampling sites were characterized by different geological origins, such as limestone, shale, or magmatic. We have chosen 14 elements, B, Na, Mg, A, K, Ca, Mn, Co, Ni, Cu, Zn, Rb, Sr, and Ba, due to their influence on the separation of samples regarding the geology of the sampling sites. A special architecture of an error back-propagation neural network, so called bottle-neck type of neural network was used to project the data into a 2D plane. The data were fed into the 14-nodes input layer and then transferred through the 2-nodes hidden layer (compared to a bottle-neck) to the 14-nodes output layer. The two hidden nodes representing the two coordinates of the projection plane enable us to map the samples used for training of the bottle-neck network. With the knowledge about the classes of individual samples we determine the clusters in the projection plane and consequently obtain the coordinates of the centroid (gravity point) of a particular cluster. The clusters are characterized with an ellipse shape borders spanning the length of up to 3sigma in each dimension. Since the data were classified as regard to the geology, three main clusters were sought: (i) limestone, (ii) shale/mudstone/clay/loess, and (iii) acid-magmatic origin of honey samples. The novel methodology proposed for food specifications was demonstrated on a reduced set of samples, which shows good clustering of all three classes in the projection plane, and on the third class of the original data set.

  15. Routing optimization for multi-type containerships in a hub-and-spoke network

    Directory of Open Access Journals (Sweden)

    Mingjun Ji

    2015-10-01

    Full Text Available This paper considers the ship routing optimization problem in a hub-and-spoke network. A routing optimization model for multi-type containerships with time deadlines is established, and the target is to minimize the total cost, which consists of the total travelling cost, total service cost and total waiting cost. The model is set up through an improved genetic algorithm. The study data are from the Pearl River Delta region of China, which include 1 hub port and 29 feeder ports and have a population of 30 million. Result shows that when the iteration time reaches 190, the total cost comes to 521 thousand yuan near the optimal value. There are 6 routes, including 3 containerships of 100 TEU, 2 containerships of 150 TEU and 1 containership of 200 TEU. At the same time, in the single-type containerships case, there are 7 routes, and when the iteration time reaches 120, the total cost comes to 573 thousand yuan, which is close to the optimal value. Comparing the two cases, it shows that the model for multi-type containerships with time deadlines is reasonable, and the algorithm is practicable. In the last, three factors, which may affect the total cost to carry out sensitivity analysis are chosen. It shows that time deadline, containership capacity and cargo handling capacity of each port have significant influence on the total cost. It is also shown that the total cost for multi-type containerships is always less than that for the single-type containerships.

  16. The Moderating Effect of Network Centrality on the Relationship Between Work Experience Variables and Organizational Commitment

    Science.gov (United States)

    2013-03-01

    network can be personal or social ( Ibarra & Andrews, 1993). While formal networks show the official rules and workings of an organization...THE MODERATING EFFECT OF NETWORK CENTRALITY ON THE RELATIONSHIP BETWEEN WORK EXPERIENCE VARIABLES...

  17. Computer vision-based limestone rock-type classification using probabilistic neural network

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Patel

    2016-01-01

    Full Text Available Proper quality planning of limestone raw materials is an essential job of maintaining desired feed in cement plant. Rock-type identification is an integrated part of quality planning for limestone mine. In this paper, a computer vision-based rock-type classification algorithm is proposed for fast and reliable identification without human intervention. A laboratory scale vision-based model was developed using probabilistic neural network (PNN where color histogram features are used as input. The color image histogram-based features that include weighted mean, skewness and kurtosis features are extracted for all three color space red, green, and blue. A total nine features are used as input for the PNN classification model. The smoothing parameter for PNN model is selected judicially to develop an optimal or close to the optimum classification model. The developed PPN is validated using the test data set and results reveal that the proposed vision-based model can perform satisfactorily for classifying limestone rock-types. Overall the error of mis-classification is below 6%. When compared with other three classification algorithms, it is observed that the proposed method performs substantially better than all three classification algorithms.

  18. Designability of Aromatic Interaction Networks at E. coli Bacterioferritin B-Type Channels

    Directory of Open Access Journals (Sweden)

    Yu Zhang

    2017-12-01

    Full Text Available The bacterioferritin from E. coli (BFR, a maxi-ferritin made of 24 subunits, has been utilized as a model to study the fundamentals of protein folding and self-assembly. Through structural and computational analyses, two amino acid residues at the B-site interface of BFR were chosen to investigate the role they play in the self-assembly of nano-cage formation, and the possibility of building aromatic interaction networks at B-type protein–protein interfaces. Three mutants were designed, expressed, purified, and characterized using transmission electron microscopy, size exclusion chromatography, native gel electrophoresis, and temperature-dependent circular dichroism spectroscopy. All of the mutants fold into α-helical structures and possess lowered thermostability. The double mutant D132W/N34W was 12 °C less stable than the wild type, and was also the only mutant for which cage-like nanostructures could not be detected in the dried, surface-immobilized conditions of transmission electron microscopy. Two mutants—N34W and D132W/N34W—only formed dimers in solution, while mutant D132W favored the 24-mer even more robustly than the wild type, suggesting that we were successful in designing proteins with enhanced assembly properties. This investigation into the structure of this important class of proteins could help to understand the self-assembly of proteins in general.

  19. Design of proportional-derivative-type state feedback controllers for congestion control of transmission control protocol networks

    Science.gov (United States)

    Azadegan, Masoumeh; Beheshti, Mohammad T. H.; Tavassoli, Babak

    2015-07-01

    A new proportional-derivative-type state feedback controller is proposed for congestion control of transmission control protocol (TCP) networks. An analytical TCP model is adopted. In the proposed control scheme, it is possible to efficiently control the TCP traffic using only the queue length at the router without the need to know the TCP window size which is not available locally. The results are presented in terms of delay-dependent linear matrix inequality. The proposed method is verified by simulation examples using NS software, and the effectiveness and superiority of our method over other control schemes, such as the proportional-integral, random early detection and generalised minimum variancemethods, are also shown.

  20. Merging DNA typing and network analysis to assess the transmission of paratuberculosis between farms.

    Science.gov (United States)

    Marquetoux, N; Heuer, C; Wilson, P; Ridler, A; Stevenson, M

    2016-11-01

    Paratuberculosis, a chronic enteric infection caused by Mycobacterium subsp. paratuberculosis (MAP), is endemic in all farmed ruminant species in New Zealand. The use of genotyping in combination with network analysis of livestock movement events from one farm location to another has the potential to contribute to our understanding of between-farm transmission events. We studied a population of 122 farms from a corporate commercial livestock enterprise in New Zealand, trading with each other in near isolation from other commercial farms. The data consisted of longitudinal movements to and from these farms between 2006 and 2010, as well as the results of cross-sectional MAP screening and genotyping performed in 2010. We explored associations between past livestock movements and current strain type distribution in this population of farms using quadratic assignment procedure. Our results show that measures of farm clustering within the movement network were significantly associated with sharing of MAP strains. For example, farms closely related by trade were twice as likely to share the same strains of MAP (p=0.033). Other covariates were also associated with the probability of sharing the same strains of MAP, such as being located on the same island (OR=5.8 to 8.7, p<0.01), farming the same livestock species and Euclidian distance between farms. The novel approach we used supports the hypothesis that livestock movement is indeed a significant contributor to farm-to-farm transmission of MAP. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Collective helping and bystander effects in coevolving helping networks

    Science.gov (United States)

    Jo, Hang-Hyun; Lee, Hyun Keun; Park, Hyunggyu

    2010-06-01

    We study collective helping behavior and bystander effects in a coevolving helping network model. A node and a link of the network represents an agent who renders or receives help and a friendly relation between agents, respectively. A helping trial of an agent depends on relations with other involved agents and its result (success or failure) updates the relation between the helper and the recipient. We study the network link dynamics and its steady states analytically and numerically. The full phase diagram is presented with various kinds of active and inactive phases and the nature of phase transitions are explored. We find various interesting bystander effects, consistent with the field study results, of which the underlying mechanism is proposed.

  2. Spatiotemporal Scaling Effect on Rainfall Network Design Using Entropy

    Directory of Open Access Journals (Sweden)

    Chiang Wei

    2014-08-01

    Full Text Available Because of high variation in mountainous areas, rainfall data at different spatiotemporal scales may yield potential uncertainty for network design. However, few studies focus on the scaling effect on both the spatial and the temporal scale. By calculating the maximum joint entropy of hourly typhoon events, monthly, six dry and wet months and annual rainfall between 1992 and 2012 for 1-, 3-, and 5-km grids, the relocated candidate rain gauges in the National Taiwan University Experimental Forest of Central Taiwan are prioritized. The results show: (1 the network exhibits different locations for first prioritized candidate rain gauges for different spatiotemporal scales; (2 the effect of spatial scales is insignificant compared to temporal scales; and (3 a smaller number and a lower percentage of required stations (PRS reach stable joint entropy for a long duration at finer spatial scale. Prioritized candidate rain gauges provide key reference points for adjusting the network to capture more accurate information and minimize redundancy.

  3. Dynamic biosignal management and transmission during telemedicine incidents handled by Mobile Units over diverse network types.

    Science.gov (United States)

    Mandellos, George J; Koutelakis, George V; Panagiotakopoulos, Theodor C; Koukias, Andreas M; Koukias, Mixalis N; Lymberopoulos, Dimitrios K

    2008-01-01

    Early and specialized pre-hospital patient treatment improves outcome in terms of mortality and morbidity, in emergency cases. This paper focuses on the design and implementation of a telemedicine system that supports diverse types of endpoints including moving transports (MT) (ambulances, ships, planes, etc.), handheld devices and fixed units, using diverse communication networks. Target of the above telemedicine system is the pre-hospital patient treatment. While vital sign transmission is prior to other services provided by the telemedicine system (videoconference, remote management, voice calls etc.), a predefined algorithm controls provision and quality of the other services. A distributed database system controlled by a central server, aims to manage patient attributes, exams and incidents handled by different Telemedicine Coordination Centers (TCC).

  4. A Bayesian network model for predicting type 2 diabetes risk based on electronic health records

    Science.gov (United States)

    Xie, Jiang; Liu, Yan; Zeng, Xu; Zhang, Wu; Mei, Zhen

    2017-07-01

    An extensive, in-depth study of diabetes risk factors (DBRF) is of crucial importance to prevent (or reduce) the chance of suffering from type 2 diabetes (T2D). Accumulation of electronic health records (EHRs) makes it possible to build nonlinear relationships between risk factors and diabetes. However, the current DBRF researches mainly focus on qualitative analyses, and the inconformity of physical examination items makes the risk factors likely to be lost, which drives us to study the novel machine learning approach for risk model development. In this paper, we use Bayesian networks (BNs) to analyze the relationship between physical examination information and T2D, and to quantify the link between risk factors and T2D. Furthermore, with the quantitative analyses of DBRF, we adopt EHR and propose a machine learning approach based on BNs to predict the risk of T2D. The experiments demonstrate that our approach can lead to better predictive performance than the classical risk model.

  5. Learning from adaptive neural network output feedback control of a unicycle-type mobile robot.

    Science.gov (United States)

    Zeng, Wei; Wang, Qinghui; Liu, Fenglin; Wang, Ying

    2016-03-01

    This paper studies learning from adaptive neural network (NN) output feedback control of nonholonomic unicycle-type mobile robots. The major difficulties are caused by the unknown robot system dynamics and the unmeasurable states. To overcome these difficulties, a new adaptive control scheme is proposed including designing a new adaptive NN output feedback controller and two high-gain observers. It is shown that the stability of the closed-loop robot system and the convergence of tracking errors are guaranteed. The unknown robot system dynamics can be approximated by radial basis function NNs. When repeating same or similar control tasks, the learned knowledge can be recalled and reused to achieve guaranteed stability and better control performance, thereby avoiding the tremendous repeated training process of NNs. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Effect of Soil Types and Phosphorus Fertilizer Interaction on the ...

    African Journals Online (AJOL)

    Effect of Soil Types and Phosphorus Fertilizer Interaction on the Growth and Yield of Maize ( Zea mays .L) ... This yield at varying phosphorus levels is an indication that soil types do have an effect on the yield of crops. Since all the soils are used in planting maize one soil type cannot be said to be better than the other, ...

  7. Membership in a diabetes-care network and adherence to clinical practice guidelines for treating type 2 diabetes among general practitioners: A four-year follow-up.

    Science.gov (United States)

    Casanova, Ludovic; Bocquier, Aurélie; Cortaredona, Sébastien; Nauleau, Stève; Sauze, Laurent; Sciortino, Vincent; Villani, Patrick; Verger, Pierre

    2016-10-01

    To assess whether private general practitioners (GPs) belonging to a diabetes-care network adhered more closely to clinical practice guidelines for diabetes care than GPs not in such a network, for all their patients with type 2 diabetes treated with medication (patients with diabetes), regardless of whether they received care through a network (that is, whether a halo effect occurred). The study, based on health insurance reimbursement databases in southeastern France, included 468 GPs in two networks and 468 non-network GPs in the same geographical area, matched one-to-one by propensity scores. We followed up their patients with diabetes (n=22,808) from 2008 through 2011, conducting multivariate time-to-event analyses (Cox models) that took the matching design into account to evaluate time from inclusion until performance of the given number of each of six recommended examinations/tests. GPs belonging to a diabetes-care network adhered more closely to clinical practice guidelines but our result were slightly pronounced. Hazard ratios (HR) were significantly higher for patients of network GPs for the implementation of 3 HbA1C assays (HRa=1.13; [95%CI=1.10-1.16]), or 1 microalbuminuria assay (1.4 [1.35-1.45]); they were lower for LDL-cholesterol assays (1.04 [1.01-1.07]) and ophthalmological checkups (1.07 [1.04-1.10]), and not significant for creatinemia or cardiac monitoring. Network GPs had better diabetes monitoring practices for all their patients with diabetes than the other GPs, especially for the most diabetes-specific tests. Further research is needed in other settings to confirm the existence of this halo effect. Copyright © 2016 Primary Care Diabetes Europe. Published by Elsevier Ltd. All rights reserved.

  8. Decentralized event-triggered synchronization of uncertain Markovian jumping neutral-type neural networks with mixed delays.

    Science.gov (United States)

    Senan, Sibel; Syed Ali, M; Vadivel, R; Arik, Sabri

    2017-02-01

    In this study, we present an approach for the decentralized event-triggered synchronization of Markovian jumping neutral-type neural networks with mixed delays. We present a method for designing decentralized event-triggered synchronization, which only utilizes locally available information, in order to determine the time instants for transmission from sensors to a central controller. By applying a novel Lyapunov-Krasovskii functional, as well as using the reciprocal convex combination method and some inequality techniques such as Jensen's inequality, we obtain several sufficient conditions in terms of a set of linear matrix inequalities (LMIs) under which the delayed neural networks are stochastically stable in terms of the error systems. Finally, we conclude that the drive systems synchronize stochastically with the response systems. We show that the proposed stability criteria can be verified easily using the numerically efficient Matlab LMI toolbox. The effectiveness and feasibility of the results obtained are verified by numerical examples. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Evaluating collaborations in comparative effectiveness research: opportunities and challenges for social network analysis.

    Science.gov (United States)

    Zickafoose, Joseph S; Kimmey, Laura D; Tomas, Amber; Esposito, Dominick; Rich, Eugene

    2014-11-01

    Multidisciplinary, multi-institutional collaboration has become a key feature of comparative effectiveness research (CER), and CER funders have made promotion of these types of collaboration an implicit, and sometimes explicit, goal of funding. An important challenge in evaluating CER programs is understanding if and how different forms of collaboration are associated with successful CER projects. This article explores the potential use of social network analysis to address research questions about the associations between collaboration and the success of CER projects.

  10. Interval algebra - an effective means of scheduling surveillance radar networks

    CSIR Research Space (South Africa)

    Focke, RW

    2015-05-01

    Full Text Available Interval Algebra provides an effective means to schedule surveillance radar networks, as it is a temporal ordering constraint language. Thus it provides a solution to a part of resource management, which is included in the revised Data Fusion...

  11. The effect of network degradation on speech recognition

    CSIR Research Space (South Africa)

    Joubert, G

    2005-11-01

    Full Text Available The authors describe a system, based on open-source tools, that was developed in order to study the effect of network degenerations in Voice-over-Internet-Protocol applications on speech-recognition accuracy. Sophisticated play-out algorithms...

  12. Effect of online social networking on employee productivity

    Directory of Open Access Journals (Sweden)

    A. Ferreira

    2009-02-01

    Full Text Available The popularity of social networking sites is relatively recent and the effect of online social networking (OSN on employee productivity has not received much scholarly attention. The reason most likely lies in the social nature of social networking sites and OSN, which is assumed to have a negative effect on employee productivity and not bear organisational benefit. This reseach investigated recent Internet developments as seen in the social Web and specifically investigated the effect of OSN on employee productivity and what some of the consequences would be if employees were allowed unrestricted access to these networks. The findings concerning the nature of employees' OSN activities, employees' attitude or perceptions with regard to OSN in the workplace and how OSN can contribute or affect the productivity of employees are discussed in this article. Some of the basic misconceptions regarding OSN are highlighted and it is concluded that this technology can be used to increase collaboration between individuals who share a common interest or goal. Increased collaboration will stimulate knowledge sharing between individuals, with the possible effect of increased productivity. However, the risks associated with OSN should be noted, such as loss of privacy, bandwidth and storage consumption, exposure to malware and lower employee productivity.

  13. The effect of the earthquake on the water distribution network ...

    African Journals Online (AJOL)

    ... and in some areas they pass necessarily from areas with fault lines. Thus studying the pipelines in earthquake-prone areas is of utmost importance. In this paper, the effect of the earthquake on the water distribution network has been discussed. Keywords: Water Foundations, Earthquake, Vibrations, Connections, Pipes ...

  14. Social Network Sites Effectiveness from EFL Students' Viewpoints

    Science.gov (United States)

    Alnujaidi, Sulaiman

    2017-01-01

    This study investigated the relationship between EFL students' experience, attitudes, perceptions, and expectations toward the effectiveness of Social Network Sites (SNS), namely, Facebook, Twitter, YouTube, Instagram, Flickr, Classmates, Academica, MySpace, English baby, and Google+, in English language learning. A survey of 103 participants from…

  15. The effect of music-induced mood on attentional networks.

    Science.gov (United States)

    Jiang, Jun; Scolaro, Ashley J; Bailey, Kira; Chen, Antao

    2011-06-01

    Attention network theory suggests that there are three separate neural networks that execute the discrete functions of alerting, orienting, and executive attention. Previous research on the influence of mood on attention has shown subtle and inconsistent results. The attention network theory may aid in clarifying the influence of mood on attention. The present study investigated the influence of mood on attentional networks in a normal population. Participants performed the Attention Network Test (ANT), which provides functional measures of alerting, orienting, and executive attention. Positive or negative mood was induced by listening to music with a positive or negative valence, respectively; neutral mood was induced by reading a collection of basic facts about China. The results revealed that negative mood led to a significantly higher alerting efficiency relative to other moods, while there were no significant mood effects on orienting or executive attention efficiency. According to the algorithm underlying the ANT, the higher alerting efficiency in the negative mood condition can be attributed to relatively greater benefits of cueing effects. The findings are discussed in the context of the noradrenergic system and of evolutionary significance. Specifically, the increase in the alerting function during negative mood states may be due to the modulation effect of negative mood on the noradrenergic system, and/or to the survival benefit resulting from an increase in automatic vigilance towards negative information. The current results suggest that as the influence of negative mood on attention appears to specifically consist in an enhanced alerting function, it may not be found in studies where the three attentional networks are not dissociated.

  16. Understanding Farmers Information Network Implication For Effective Extension Delivery In Akwa Ibom State

    Directory of Open Access Journals (Sweden)

    Odoemelam

    2015-01-01

    Full Text Available ABSTRACT Appropriateness of information is a critical factor needed to stimulate the right knowledge and attitude of farmers towards sustainable transformation of agriculture. The study investigated the information network that exists among rural communities in Akwa-Ibom States and its implication for effective extension delivery. Even though AKADEPAkwa-Ibom State Agricultural Development Programmes are highly involved in the dissemination process it is important to analyze the information networks of the farmers to improve exchange of information with the following specific objectives identify the different wealth groups in the study area ascertain the information networks that exists in the area analyze the different information types and assess the strength and weakness of the information sources. Data were generated through Focus Group Discussion and Participatory Observation employing different methodologies like wealth ranking information diagram and linkage matrix analysis using Likerts scale type. Data generated were analyzed with simple descriptive statistics and means. Major results show that in wealth ranking two groups of respondents were identified the female households with mean score between 1.9 and male headed household with mean score of 2.00 2.99. on information network farmer to farmer with 21 market 14 church 15 were highest source of their information network. On perceived weakness and strength of the information network the information quality frequency of use timeliness of information flow and link up of information were adequate while reliability of information was not adequate. The results show that intra community information flow was suitable and accessible to rich farmers while inaccessible and often irrelevant to poor farmers. Therefore in the face of threat to food insecurity prevalent in the country it is important to put in place a platform that will afford farmers to ask questions and get substantive responses

  17. Application of new type of distributed multimedia databases to networked electronic museum

    Science.gov (United States)

    Kuroda, Kazuhide; Komatsu, Naohisa; Komiya, Kazumi; Ikeda, Hiroaki

    1999-01-01

    Recently, various kinds of multimedia application systems have actively been developed based on the achievement of advanced high sped communication networks, computer processing technologies, and digital contents-handling technologies. Under this background, this paper proposed a new distributed multimedia database system which can effectively perform a new function of cooperative retrieval among distributed databases. The proposed system introduces a new concept of 'Retrieval manager' which functions as an intelligent controller so that the user can recognize a set of distributed databases as one logical database. The logical database dynamically generates and performs a preferred combination of retrieving parameters on the basis of both directory data and the system environment. Moreover, a concept of 'domain' is defined in the system as a managing unit of retrieval. The retrieval can effectively be performed by cooperation of processing among multiple domains. Communication language and protocols are also defined in the system. These are used in every action for communications in the system. A language interpreter in each machine translates a communication language into an internal language used in each machine. Using the language interpreter, internal processing, such internal modules as DBMS and user interface modules can freely be selected. A concept of 'content-set' is also introduced. A content-set is defined as a package of contents. Contents in the content-set are related to each other. The system handles a content-set as one object. The user terminal can effectively control the displaying of retrieved contents, referring to data indicating the relation of the contents in the content- set. In order to verify the function of the proposed system, a networked electronic museum was experimentally built. The results of this experiment indicate that the proposed system can effectively retrieve the objective contents under the control to a number of distributed

  18. Negotiating Diet in Networks: A Cross-European Study of the Experiences of Managing Type 2 Diabetes.

    Science.gov (United States)

    Knutsen, Ingrid Ruud; Foss, I Christina; Todorova, Elka; Roukova, Poli; Kennedy, Anne; Portillo, Mari Carmen; Regaira, Elena; Serrano-Gil, Manuel; Lionis, Christos; Angelaki, Agapi; Rogers, Anne

    2017-02-01

    Food and diet are central aspects of diabetes self-management but the relevance of social networks for the way people are supported in their management of type 2 diabetes is often under-acknowledged. In this article, we aimed to explore the coalescences between these two phenomena among people with type 2 diabetes to increase knowledge of interactions within social network related to daily diet. The article is based on 125 qualitative interviews with individuals with type 2 diabetes from five European countries. Based on assumptions that people with chronic illnesses reshape relationships through negotiation, we analyzed negotiations of food at different levels of network. The respondents' reflections indicate that there are complex negotiations that influence self-management and food, including support, knowledge, and relationships within families; attention and openness in social situations; and the premises and norms of society.

  19. Effect of type 2 diabetes mellitus on pulmonary function.

    Science.gov (United States)

    Huang, H; Guo, Q; Li, L; Lin, S; Lin, Y; Gong, X; Yao, J; Liang, J; Lin, L; Wen, J; Chen, G

    2014-06-01

    Type 2 diabetes mellitus (T2DM) is a metabolic disease with debilitating effects on multiple organs. The alveolar-capillary network in the lung is a large microvascular unit which may be affected by T2DM-associated microangiopathy. This retrospective study investigated whether type 2 diabetes mellitus (T2DM) affected pulmonary function. Of the 584 patients enrolled in the study, 292 had T2DM and 292 did not. Forced expiratory volume in one second (FEV₁), forced vital capacity (FVC), maximum voluntary ventilation (MVV) and total lung capacity (TLC) are values as percent of predicted, as well as FEV₁/FVC ratio which were values measured. FEV₁, FVC, FEV₁/FVC ratio, MVV, and TLC were significantly lower in T2DM than in non-T2DM (P-values Multiple linear regression analysis found that for the entire study population fasting plasma glucose levels was negatively associated with FEV₁, FVC, FEV₁/FVC ratio and maximum voluntary ventilation (P-values Multiple linear regression analysis found for patients with T2DM that fasting plasma glucose was negatively associated with FEV₁, FVC, FEV₁/FVC ratio and maximum voluntary ventilation (P-values < 0.020). In T2DM patient, height was negatively correlated with FEV₁ and FVC (all P-values < 0.020), triglycerides were negatively correlated with FEV₁/FVC ratio (P-values = 0.048), and creatinine was negatively correlated with total lung capacity (P-values = 0.017). In summary, T2DM is associated with impaired pulmonary function consistent with obstructive ventilation pattern and fasting plasma glucose is an independent risk factor of reduced pulmonary function. © Georg Thieme Verlag KG Stuttgart · New York.

  20. The cost of sensitive response and accurate adaptation in networks with an incoherent type-1 feed-forward loop.

    Science.gov (United States)

    Lan, Ganhui; Tu, Yuhai

    2013-10-06

    The incoherent type-1 feed-forward loop (I1-FFL) is ubiquitous in biological regulatory circuits. Although much is known about the functions of the I1-FFL motif, the energy cost incurred in the network and how it affects the performance of the network have not been investigated. Here, we study a generic I1-FFL enzymatic reaction network modelled after the GEF-GAP-Ras pathway responsible for chemosensory adaptation in eukaryotic cells. Our analysis shows that the I1-FFL network always operates out of equilibrium. Continuous energy dissipation is necessary to drive an internal phosphorylation-dephosphorylation cycle that is crucial in achieving strong short-time response and accurate long-time adaptation. In particular, we show quantitatively that the energy dissipated in the I1-FFL network is used (i) to increase the system's initial response to the input signals; (ii) to enhance the adaptation accuracy at steady state; and (iii) to expand the range of such accurate adaptation. Moreover, we find that the energy dissipation rate, the catalytic speed and the maximum adaptation accuracy in the I1-FFL network satisfy the same energy-speed-accuracy relationship as in the negative-feedback-loop (NFL) networks. Because the I1-FFL and NFL are the only two basic network motifs that enable accurate adaptation, our results suggest that a universal cost-performance trade-off principle may underlie all cellular adaptation processes independent of the detailed biochemical circuit architecture.

  1. Pavement type and wear condition classification from tire cavity acoustic measurements with artificial neural networks.

    Science.gov (United States)

    Masino, Johannes; Foitzik, Michael-Jan; Frey, Michael; Gauterin, Frank

    2017-06-01

    Tire road noise is the major contributor to traffic noise, which leads to general annoyance, speech interference, and sleep disturbances. Standardized methods to measure tire road noise are expensive, sophisticated to use, and they cannot be applied comprehensively. This paper presents a method to automatically classify different types of pavement and the wear condition to identify noisy road surfaces. The methods are based on spectra of time series data of the tire cavity sound, acquired under normal vehicle operation. The classifier, an artificial neural network, correctly predicts three pavement types, whereas there are few bidirectional mis-classifications for two pavements, which have similar physical characteristics. The performance measures of the classifier to predict a new or worn out condition are over 94.6%. One could create a digital map with the output of the presented method. On the basis of these digital maps, road segments with a strong impact on tire road noise could be automatically identified. Furthermore, the method can estimate the road macro-texture, which has an impact on the tire road friction especially on wet conditions. Overall, this digital map would have a great benefit for civil engineering departments, road infrastructure operators, and for advanced driver assistance systems.

  2. Automated Classification of Lung Cancer Types from Cytological Images Using Deep Convolutional Neural Networks

    Directory of Open Access Journals (Sweden)

    Atsushi Teramoto

    2017-01-01

    Full Text Available Lung cancer is a leading cause of death worldwide. Currently, in differential diagnosis of lung cancer, accurate classification of cancer types (adenocarcinoma, squamous cell carcinoma, and small cell carcinoma is required. However, improving the accuracy and stability of diagnosis is challenging. In this study, we developed an automated classification scheme for lung cancers presented in microscopic images using a deep convolutional neural network (DCNN, which is a major deep learning technique. The DCNN used for classification consists of three convolutional layers, three pooling layers, and two fully connected layers. In evaluation experiments conducted, the DCNN was trained using our original database with a graphics processing unit. Microscopic images were first cropped and resampled to obtain images with resolution of 256 × 256 pixels and, to prevent overfitting, collected images were augmented via rotation, flipping, and filtering. The probabilities of three types of cancers were estimated using the developed scheme and its classification accuracy was evaluated using threefold cross validation. In the results obtained, approximately 71% of the images were classified correctly, which is on par with the accuracy of cytotechnologists and pathologists. Thus, the developed scheme is useful for classification of lung cancers from microscopic images.

  3. On effectiveness of network sensor-based defense framework

    Science.gov (United States)

    Zhang, Difan; Zhang, Hanlin; Ge, Linqiang; Yu, Wei; Lu, Chao; Chen, Genshe; Pham, Khanh

    2012-06-01

    Cyber attacks are increasing in frequency, impact, and complexity, which demonstrate extensive network vulnerabilities with the potential for serious damage. Defending against cyber attacks calls for the distributed collaborative monitoring, detection, and mitigation. To this end, we develop a network sensor-based defense framework, with the aim of handling network security awareness, mitigation, and prediction. We implement the prototypical system and show its effectiveness on detecting known attacks, such as port-scanning and distributed denial-of-service (DDoS). Based on this framework, we also implement the statistical-based detection and sequential testing-based detection techniques and compare their respective detection performance. The future implementation of defensive algorithms can be provisioned in our proposed framework for combating cyber attacks.

  4. On the Effects of Heterogeneous Packet Lengths on Network Coding

    DEFF Research Database (Denmark)

    Compta, Pol Torres; Fitzek, Frank; Roetter, Daniel Enrique Lucani

    2014-01-01

    Random linear network coding (RLNC) has been shown to provide increased throughput, security and robustness for the transmission of data through the network. Most of the analysis and the demonstrators have focused on the study of data packets with the same size (number of bytes). This constitutes...... a best case scenario as coded packets will incur little overhead to handle such packets. However, packet lengths are quite heterogeneous in real networks, which can cause a high overhead or, alternatively, a high delay in the transmission of data packets. As we show, this can have a severe effect...... on a variety of applications. This paper proposes a series of mechanisms to manage heterogeneous packet lengths and analyzes the induced overhead of those mechanisms using real packet length distributions provided by CAIDA and own measurements using video content. Our results show that an appropriate...

  5. Effects of active links on epidemic transmission over social networks

    Science.gov (United States)

    Zhu, Guanghu; Chen, Guanrong; Fu, Xinchu

    2017-02-01

    A new epidemic model with two infection periods is developed to account for the human behavior in social network, where newly infected individuals gradually restrict most of future contacts or are quarantined, causing infectivity change from a degree-dependent form to a constant. The corresponding dynamics are formulated by a set of ordinary differential equations (ODEs) via mean-field approximation. The effects of diverse infectivity on the epidemic dynamics ​are examined, with a behavioral interpretation of the basic reproduction number. Results show that such simple adaptive reactions largely determine the impact of network structure on epidemics. Particularly, a theorem proposed by Lajmanovich and Yorke in 1976 is generalized, so that it can be applied for the analysis of the epidemic models with multi-compartments especially network-coupled ODE systems.

  6. Effect of chain rigidity on network architecture and deformation behavior of glassy polymer networks

    Science.gov (United States)

    Knowles, Kyler Reser

    Processing carbon fiber composite laminates creates molecular-level strains in the thermoset matrix upon curing and cooling which can lead to failures such as geometry deformations, micro-cracking, and other issues. It is known strain creation is attributed to the significant volume and physical state changes undergone by the polymer matrix throughout the curing process, though storage and relaxation of cure-induced strains remain poorly understood. This dissertation establishes two approaches to address the issue. The first establishes testing methods to simultaneously measure key volumetric properties of a carbon fiber composite laminate and its polymer matrix. The second approach considers the rigidity of the polymer matrix in regards to strain storage and relaxation mechanisms which ultimately control composite performance throughout manufacturing and use. Through the use of a non-contact, full-field strain measurement technique known as digital image correlation (DIC), we describe and implement useful experiments which quantify matrix and composite parameters necessary for simulation efforts and failure models. The methods are compared to more traditional techniques and show excellent correlation. Further, we established relationships which represent matrix-fiber compatibility in regards to critical processing constraints. The second approach involves a systematic study of epoxy-amine networks which are chemically-similar but differ in chain segment rigidity. Prior research has investigated the isomer effect of glassy polymers, showing sizeable differences in thermal, volumetric, physical, and mechanical properties. This work builds on these themes and shows the apparent isomer effect is rather an effect of chain rigidity. Indeed, it was found that structurally-dissimilar polymer networks exhibit very similar properties as a consequence of their shared average network rigidity. Differences in chain packing, as a consequence of chain rigidity, were shown to

  7. Artificial Neural Networks to Detect Risk of Type 2 Diabetes | Baha ...

    African Journals Online (AJOL)

    A multilayer feedforward architecture with backpropagation algorithm was designed using Neural Network Toolbox of Matlab. The network was trained using batch mode backpropagation with gradient descent and momentum. Best performed network identified during the training was 2 hidden layers of 6 and 3 neurons, ...

  8. Investigating the effects of virtual social networks on entrepreneurial marketing

    Directory of Open Access Journals (Sweden)

    Kambeiz Talebi

    2014-10-01

    Full Text Available This paper presents an empirical investigation to study the effects of virtual social networks on entrepreneurial marketing. The study designs a questionnaire in Likert scale based on a model originally developed by Morris et al. (2002 [Morris, M. H., Schindehutte, M., & LaForge, R. W. (2002. Entrepreneurial marketing: a construct for integrating emerging entrepreneurship and marketing perspectives. Journal of Marketing Theory and Practice, 10(4, 1-19.]. The study considers the effects of three components of virtual social network (VSN; namely structural VSN, interaction VSN and functional VSN on entrepreneurial marketing. Using structural equation modeling, the study has determined positive and meaningful effects of all three VSN components on entrepreneurial marketing.

  9. How democratic are Networks?- A framework for Assessing the Democratic Effects of Networks

    DEFF Research Database (Denmark)

    Agger, Annika; Löfgren, Karl

    by an underlying idea of enhancing public participation and mobilising the citizens, thereby strengthening local democracy. Even though much is written about these initiatives, the actual democratic effects of these activities have been notably overlooked in the literature. Both among scholars, as well......: How can we assess the democratic effects of formal network mobilisation?  The article will present a tentative framework deriving criteria from both traditional democratic theory, as well as new theories on democratic governance and collaborative planning, which can be deployed for empirical studies...

  10. Relative potencies of Type I and Type II pyrethroids for inhibition of spontaneous firing in neuronal networks.

    Science.gov (United States)

    Pyrethroids insecticides commonly used in pest control disrupt the normal function of voltage-sensitive sodium channels. We have previously demonstrated that permethrin (a Type I pyrethroid) and deltamethrin (a Type II pyrethroid) inhibit sodium channel-dependent spontaneous netw...

  11. Obtaining Arbitrary Prescribed Mean Field Dynamics for Recurrently Coupled Networks of Type-I Spiking Neurons with Analytically Determined Weights

    Directory of Open Access Journals (Sweden)

    Wilten eNicola

    2016-02-01

    Full Text Available A fundamental question in computational neuroscience is how to connect a network of spiking neurons to produce desired macroscopic or mean field dynamics. One possible approach is through the Neural Engineering Framework (NEF. The NEF approach requires quantities called decoders which are solved through an optimization problem requiring large matrix inversion. Here, we show how a decoder can be obtained analytically for type I and certain type II firing rates as a function of the heterogeneity of its associated neuron. These decoders generate approximants for functions that converge to the desired function in mean-squared error like 1/N, where N is the number of neurons in the network. We refer to these decoders as scale-invariant decoders due to their structure. These decoders generate weights for a network of neurons through the NEF formula for weights. These weights force the spiking network to have arbitrary and prescribed mean field dynamics. The weights generated with scale-invariant decoders all lie on low dimensional hypersurfaces asymptotically. We demonstrate the applicability of these scale-invariant decoders and weight surfaces by constructing networks of spiking theta neurons that replicate the dynamics of various well known dynamical systems such as the neural integrator, Van der Pol system and the Lorenz system. As these decoders are analytically determined and non-unique, the weights are also analytically determined and non-unique. We discuss the implications for measured weights of neuronal networks

  12. The importance of delineating networks by activity type in bottlenose dolphins (Tursiops truncatus) in Cedar Key, Florida.

    Science.gov (United States)

    Gazda, Stefanie; Iyer, Swami; Killingback, Timothy; Connor, Richard; Brault, Solange

    2015-03-01

    Network analysis has proved to be a valuable tool for studying the behavioural patterns of complex social animals. Often such studies either do not distinguish between different behavioural states of the organisms or simply focus attention on a single behavioural state to the exclusion of all others. In either of these approaches it is impossible to ascertain how the behavioural patterns of individuals depend on the type of activity they are engaged in. Here we report on a network-based analysis of the behavioural associations in a population of bottlenose dolphins (Tursiops truncatus) in Cedar Key, Florida. We consider three distinct behavioural states-socializing, travelling and foraging-and analyse the association networks corresponding to each activity. Moreover, in constructing the different activity networks we do not simply record a spatial association between two individuals as being either present or absent, but rather quantify the degree of any association, thus allowing us to construct weighted networks describing each activity. The results of these weighted activity networks indicate that networks can reveal detailed patterns of bottlenose dolphins at the population level; dolphins socialize in large groups with preferential associations; travel in small groups with preferential associates; and spread out to forage in very small, weakly connected groups. There is some overlap in the socialize and travel networks but little overlap between the forage and other networks. This indicates that the social bonds maintained in other activities are less important as they forage on dispersed, solitary prey. The overall network, not sorted by activity, does not accurately represent any of these patterns.

  13. Epileptogenic networks of type II focal cortical dysplasia: a stereo-EEG study.

    Science.gov (United States)

    Varotto, Giulia; Tassi, Laura; Franceschetti, Silvana; Spreafico, Roberto; Panzica, Ferruccio

    2012-07-02

    In the context of focal and drug-resistant epilepsy, surgical resection of the epileptogenic zone may be the only therapeutic option for reducing or suppressing seizures. In many such patients, intracranial stereo-EEG recordings remain the gold standard for the epilepsy surgery work-up. Assessing the extent of the epileptogenic zone and its organisation is a crucial objective, and requires advanced methods of signal processing. Over the last ten years, considerable efforts have been made to develop signal analysis techniques for characterising the connectivity between spatially distributed regions. The aim of this study was to evaluate the changes in dynamic connectivity pattern under inter-ictal, pre-ictal and ictal conditions using signals derived from stereo-EEG recordings of 10 patients with Taylor-type focal cortical dysplasia. A causal linear multivariate method - partial directed coherence - and indices derived from graph theory were used to characterise the synchronisation property of the lesional zone (corresponding to the epileptogenic zone in our patients) and to distinguish it from other regions involved in ictal activity or not. The results show that a significantly different connectivity pattern (mainly in the gamma band) distinguishes the epileptogenic zone from other cortical regions not only during the ictal event, but also during the inter- and pre-ictal periods. This indicates that the lesional nodes play a leading role in generating and propagating ictal EEG activity by acting as the hubs of the epileptic network originating and sustaining seizures. Our findings also indicate that the cortical regions beyond the dysplasia involved in the ictal activity essentially act as "secondary" generators of synchronous activity. The leading role of the lesional zone may account for the good post-surgical outcome of patients with type II focal cortical dysplasia as resecting the dysplasia removes the epileptogenic zone responsible for seizure organisation

  14. Effects of aquatic vegetation type on denitrification

    NARCIS (Netherlands)

    Veraart, A.J.; Bruijne, de W.J.J.; Peeters, E.T.H.M.; Klein, de J.J.M.; Scheffer, M.

    2011-01-01

    In a microcosm 15N enrichment experiment we tested the effect of floating vegetation (Lemna sp.) and submerged vegetation (Elodea nuttallii) on denitrification rates, and compared it to systems without macrophytes. Oxygen concentration, and thus photosynthesis, plays an important role in regulating

  15. Fluctuation relations between hierarchical kinetically equivalent networks with Arrhenius-type transitions and their roles in systems and structural biology

    Science.gov (United States)

    Deng, De-Ming; Lu, Yi-Ta; Chang, Cheng-Hung

    2017-06-01

    The legality of using simple kinetic schemes to determine the stochastic properties of a complex system depends on whether the fluctuations generated from hierarchical equivalent schemes are consistent with one another. To analyze this consistency, we perform lumping processes on the stochastic differential equations and the generalized fluctuation-dissipation theorem and apply them to networks with the frequently encountered Arrhenius-type transition rates. The explicit Langevin force derived from those networks enables us to calculate the state fluctuations caused by the intrinsic and extrinsic noises on the free energy surface and deduce their relations between kinetically equivalent networks. In addition to its applicability to wide classes of network related systems, such as those in structural and systems biology, the result sheds light on the fluctuation relations for general physical variables in Keizer's canonical theory.

  16. Social networks : Effects on Identification, Performance and Satisfaction Effects on identification, performance and satisfaction

    NARCIS (Netherlands)

    Stormbroek-Burgers, van R.G.B.M.; Montfort, van K.; Sluis, van der E.C. (Lidewey)

    2011-01-01

    This study contributes to research on the impact of social networks on organizational outcomes in the context of the increasing number of professionals in the Netherlands. The aim of this study was to get insight into the characteristics of professionals’ social networks and to examine the effect of

  17. Mechanisms of Self-Sustained Oscillatory States in Hierarchical Modular Networks with Mixtures of Electrophysiological Cell Types.

    Science.gov (United States)

    Tomov, Petar; Pena, Rodrigo F O; Roque, Antonio C; Zaks, Michael A

    2016-01-01

    In a network with a mixture of different electrophysiological types of neurons linked by excitatory and inhibitory connections, temporal evolution leads through repeated epochs of intensive global activity separated by intervals with low activity level. This behavior mimics "up" and "down" states, experimentally observed in cortical tissues in absence of external stimuli. We interpret global dynamical features in terms of individual dynamics of the neurons. In particular, we observe that the crucial role both in interruption and in resumption of global activity is played by distributions of the membrane recovery variable within the network. We also demonstrate that the behavior of neurons is more influenced by their presynaptic environment in the network than by their formal types, assigned in accordance with their response to constant current.

  18. Pluralized leadership in complex organizations : exploring the cross network effects between leadership influence and informal network relations

    OpenAIRE

    White, Leroy; Lockett, Andy; Currie, Graeme

    2016-01-01

    Understanding the connection between leadership and informal social network structures is important in advancing understanding of the enactment of pluralized leadership. in this article we explore how the enactment of pluralized leadership is shaped by leadership influence and informal (advice and support) networks and the interactions between the two. building on recent developments in exponential random graph modeling, we empirically model the cross network effects across three leadership n...

  19. Landscape effects on pollination networks in Mediterranean gypsum islands.

    Science.gov (United States)

    Santamaría, S; Sánchez, A M; López-Angulo, J; Ornosa, C; Mola, I; Escudero, A

    2017-07-17

    Habitat fragmentation is a major driver of global change that has operated historically on Mediterranean ecosystems. However, more needs to be understood about how fragmentation influences ecological interactions, particularly pollination. Gypsum outcrops are historically fragmented Mediterranean habitats and settings for the evolution of many endangered soil-specialist plants with narrow ranges. In this study, we aimed to determine how fragmentation (area and connectivity) affects: (i) pollinator community composition and (ii) structural properties of pollination networks; and whether there are differences in the effects of fragmentation on: (iii) the number of interactions and visits among pollinator functional groups; and (iv) the number of interactions and specialisation degree between soil-specialist and soil-generalist plants. We characterised the degree of fragmentation and the pollination network structures in 12 gypsum habitat fragments embedded in a cropland matrix during two consecutive years. We found significant relationships between fragmentation and network structure. The effects of fragmentation differed among pollinator functional groups, but not between soil-specialist and soil-generalist plants, in terms of number of interactions. However, the relatively higher pollinator specialisation of soil-specialist plants suggested greater dependence on pollinators. Inter-annual variations in the network structures demonstrated the importance of temporal replication. The observed patterns related to the landscape structure and pollination at both the network and species levels provide insights into the key ecological processes in gypsum islands. These findings may help to identify the potential drivers of species persistence, especially for endangered soil-specialist plants with narrow ranges in a changing scenario with exacerbated habitat fragmentation. © 2017 German Botanical Society and The Royal Botanical Society of the Netherlands.

  20. Effect of Family Type on Secondary School Students\\' Performance ...

    African Journals Online (AJOL)

    This study investigated the effect of family type on Secondary School students\\' performance in physics in Ilorin metropolis. The sample comprised one hundred Senior Secondary II students from four schools in Ilorin metropolis. The instrument for the study titled \\"Effect of Family type on Students\\' Performance in Physics ...

  1. Effects of network structure on the synchronizability of nonlinearly coupled Hindmarsh–Rose neurons

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chun-Hsien, E-mail: chli@nknucc.nknu.edu.tw [Department of Mathematics, National Kaohsiung Normal University, Yanchao District, Kaohsiung City 82444, Taiwan (China); Yang, Suh-Yuh, E-mail: syyang@math.ncu.edu.tw [Department of Mathematics, National Central University, Jhongli District, Taoyuan City 32001, Taiwan (China)

    2015-10-23

    This work is devoted to investigate the effects of network structure on the synchronizability of nonlinearly coupled dynamical network of Hindmarsh–Rose neurons with a sigmoidal coupling function. We mainly focus on the networks that exhibit the small-world character or scale-free property. By checking the first nonzero eigenvalue of the outer-coupling matrix, which is closely related to the synchronization threshold, the synchronizabilities of three specific network ensembles with prescribed network structures are compared. Interestingly, we find that networks with more connections will not necessarily result in better synchronizability. - Highlights: • We investigate the effects of network structure on the synchronizability of nonlinearly coupled Hindmarsh–Rose neurons. • We mainly consider the networks that exhibit the small-world character or scale-free property. • The synchronizability of three specific network ensembles with prescribed network structures are compared. • Networks with more connections will not necessarily result in better synchronizability.

  2. Analysis of social networks supporting the self-management of type 2 diabetes for people with mental illness.

    Science.gov (United States)

    Crotty, Mikaila M; Henderson, Julie; Ward, Paul R; Fuller, Jeffrey; Rogers, Anne; Kralik, Debbie; Gregory, Sue

    2015-07-04

    People with mental illness have been identified as being more likely to experience type 2 diabetes and the complications arising from this, necessitating more complex chronic illness self-management. Social support has been identified as a significant factor in the successful adoption of lifestyle change for people with type 2 diabetes, however people with mental illness often have impoverished social networks leading to greater reliance upon professional care givers. This study maps the support provided by formal (paid and professional carers) and informal networks to people with mental illness and type 2 diabetes, comparing the experiences of people with a spouse with those without one. Interviews were conducted with 29 clients of a community nursing service with mental health problems who receive professional support to self-manage type 2 diabetes. Participants were asked to complete an egocentric social network map which involved mapping the people and services who support them to manage their health. Demographic data was collected as was data about co-morbidities and service use within the last 6 months. Network maps were supplemented by a series of open-ended questions about self-management practices, who supports these practices and what support they provide. Participants identified small social networks with few friendship ties. These networks had diminished due to illness. For people with a spouse, this person provided significant support for chronic illness self-management performing a range of daily care and illness management tasks. People without a spouse were more reliant on professional and paid care givers for daily care and illness management. People without a spouse also demonstrated greater reliance upon weak social ties for emotional support and social connection and often developed friendships with formal caregivers. Spousal support reduces the need for professional services. In the absence of a spouse, participants were more reliant upon paid

  3. What's in a face? : the use and effects of types of endorsers with types of products

    NARCIS (Netherlands)

    Meijer, E.

    2010-01-01

    In international literature, persons who recommend products or services in advertisements are often called ‘endorsers’. Also apparent from the literature is that the effectiveness of endorsers in advertisements particularly depends on two factors: the type of endorser and the type of product.

  4. Effects of individual popularity on information spreading in complex networks

    Science.gov (United States)

    Gao, Lei; Li, Ruiqi; Shu, Panpan; Wang, Wei; Gao, Hui; Cai, Shimin

    2018-01-01

    In real world, human activities often exhibit preferential selection mechanism based on the popularity of individuals. However, this mechanism is seldom taken into account by previous studies about spreading dynamics on networks. Thus in this work, an information spreading model is proposed by considering the preferential selection based on individuals' current popularity, which is defined as the number of individuals' cumulative contacts with informed neighbors. A mean-field theory is developed to analyze the spreading model. Through systematically studying the information spreading dynamics on uncorrelated configuration networks as well as real-world networks, we find that the popularity preference has great impacts on the information spreading. On the one hand, the information spreading is facilitated, i.e., a larger final prevalence of information and a smaller outbreak threshold, if nodes with low popularity are preferentially selected. In this situation, the effective contacts between informed nodes and susceptible nodes are increased, and nodes almost have uniform probabilities of obtaining the information. On the other hand, if nodes with high popularity are preferentially selected, the final prevalence of information is reduced, the outbreak threshold is increased, and even the information cannot outbreak. In addition, the heterogeneity of the degree distribution and the structure of real-world networks do not qualitatively affect the results. Our research can provide some theoretical supports for the promotion of spreading such as information, health related behaviors, and new products, etc.

  5. Effective learning in recurrent max-min neural networks.

    Science.gov (United States)

    Loe, Kia Fock; Teow, Loo Nin

    1998-04-01

    Max and min operations have interesting properties that facilitate the exchange of information between the symbolic and real-valued domains. As such, neural networks that employ max-min activation functions have been a subject of interest in recent years. Since max-min functions are not strictly differentiable, we propose a mathematically sound learning method based on using Fourier convergence analysis of side-derivatives to derive a gradient descent technique for max-min error functions. We then propose a novel recurrent max-min neural network model that is trained to perform grammatical inference as an application example. Comparisons made between this model and recurrent sigmoidal neural networks show that our model not only performs better in terms of learning speed and generalization, but that its final weight configuration allows a deterministic finite automation (DFA) to be extracted in a straightforward manner. In essence, we are able to demonstrate that our proposed gradient descent technique does allow max-min neural networks to learn effectively.

  6. Effects of Hospital Workers’ Friendship Networks on Job Stress

    Science.gov (United States)

    Shin, Sung Yae; Lee, Sang Gyu

    2016-01-01

    Background This study attempted to identify the sources of job stress according to job position and investigate how friendship networks affect job stress. Methods Questionnaires based on The Health Professions Stress Inventory (HPSI) developed by Wolfgang experienced by healthcare providers were collected from 420 nurses, doctors and radiological technologists in two general hospitals in Korea by a multistage cluster sampling method. Multiple regression analysis was used to examine the effects of friendship networks on job stress after controlling for other factors. Results The severity of job stress differed according to level of job demands (p = .006); radiologic technologists experienced the least stress (45.4), nurses experienced moderate stress (52.4), and doctors experienced the most stress (53.6). Those with long-term friendships characterized by strong connections reported lower levels of stress than did those with weak ties to friends among nurses (1.3, p job stress experienced by nurses (8.2, p job stress (9.2, p job stress. Conclusion The strength and density of such friendship networks were related to job stress. Life information support from their friendship network was the primary positive contributor to control of job stress. PMID:26900945

  7. Multiplex networks in metropolitan areas: generic features and local effects.

    Science.gov (United States)

    Strano, Emanuele; Shai, Saray; Dobson, Simon; Barthelemy, Marc

    2015-10-06

    Most large cities are spanned by more than one transportation system. These different modes of transport have usually been studied separately: it is however important to understand the impact on urban systems of coupling different modes and we report in this paper an empirical analysis of the coupling between the street network and the subway for the two large metropolitan areas of London and New York. We observe a similar behaviour for network quantities related to quickest paths suggesting the existence of generic mechanisms operating beyond the local peculiarities of the specific cities studied. An analysis of the betweenness centrality distribution shows that the introduction of underground networks operate as a decentralizing force creating congestion in places located at the end of underground lines. Also, we find that increasing the speed of subways is not always beneficial and may lead to unwanted uneven spatial distributions of accessibility. In fact, for London—but not for New York—there is an optimal subway speed in terms of global congestion. These results show that it is crucial to consider the full, multimodal, multilayer network aspects of transportation systems in order to understand the behaviour of cities and to avoid possible negative side-effects of urban planning decisions. © 2015 The Author(s).

  8. Effects of Implementing Adaptable Channelization in Wi-Fi Networks

    Directory of Open Access Journals (Sweden)

    Abid Hussain

    2016-01-01

    Full Text Available The unprecedented increase of wireless devices is now facing a serious threat of spectrum scarcity. The situation becomes even worse due to inefficient frequency distribution protocols, deployed in trivial Wi-Fi networks. The primary source of this inefficiency is static channelization used in wireless networks. In this work, we investigate the use of dynamic and flexible channelization, for optimal spectrum utilization in Wi-Fi networks. We propose optimal spectrum sharing algorithm (OSSA and analyze its effect on exhaustive list of essential network performance measuring parameters. The elementary concept of the proposed algorithm lies in the fact that frequency spectrum should be assigned to any access point (AP based on its current requirement. The OSSA algorithm assigns channels with high granularity, thus maximizing spectrum utilization by more than 20% as compared to static width channel allocation. This optimum spectrum utilization, in turn, increases throughput by almost 30% in many deployment scenarios. The achieved results depict considerable decrease in interference, while simultaneously increasing range. Similarly signal strength values at relatively longer distances improve significantly at narrower channel widths while simultaneously decreasing bit error rates. We found that almost 25% reduction in interference is possible in certain scenarios through proposed algorithm.

  9. Uncovering the relationship and mechanisms of Tartary buckwheat (Fagopyrum tataricum and Type II diabetes, hypertension, and hyperlipidemia using a network pharmacology approach

    Directory of Open Access Journals (Sweden)

    Chao-Long Lu

    2017-11-01

    Full Text Available Background Tartary buckwheat (TB, a crop rich in protein, dietary fiber, and flavonoids, has been reported to have an effect on Type II diabetes (T2D, hypertension (HT, and hyperlipidemia (HL. However, limited information is available about the relationship between Tartary buckwheat and these three diseases. The mechanisms of how TB impacts these diseases are still unclear. Methods In this study, network pharmacology was used to investigate the relationship between the herb as well as the diseases and the mechanisms of how TB might impact these diseases. Results A total of 97 putative targets of 20 compounds found in TB were obtained. Then, an interaction network of 97 putative targets for these compounds and known therapeutic targets for the treatment of the three diseases was constructed. Based on the constructed network, 28 major nodes were identified as the key targets of TB due to their importance in network topology. The targets of ATK2, IKBKB, RAF1, CHUK, TNF, JUN, and PRKCA were mainly involved in fluid shear stress and the atherosclerosis and PI3K-Akt signaling pathways. Finally, molecular docking simulation showed that 174 pairs of chemical components and the corresponding key targets had strong binding efficiencies. Conclusion For the first time, a comprehensive systemic approach integrating drug target prediction, network analysis, and molecular docking simulation was developed to reveal the relationships and mechanisms between the putative targets in TB and T2D, HT, and HL.

  10. Altered temporal features of intrinsic connectivity networks in boys with combined type of attention deficit hyperactivity disorder

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xun-Heng, E-mail: xhwang@hdu.edu.cn [College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); School of Biological Science and Medical Engineering, Southeast University, Nanjing 210096 (China); Li, Lihua [College of Life Information Science and Instrument Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China)

    2015-05-15

    Highlights: • Temporal patterns within ICNs provide new way to investigate ADHD brains. • ADHD exhibits enhanced temporal activities within and between ICNs. • Network-wise ALFF influences functional connectivity between ICNs. • Univariate patterns within ICNs are correlated to behavior scores. - Abstract: Purpose: Investigating the altered temporal features within and between intrinsic connectivity networks (ICNs) for boys with attention-deficit/hyperactivity disorder (ADHD); and analyzing the relationships between altered temporal features within ICNs and behavior scores. Materials and methods: A cohort of boys with combined type of ADHD and a cohort of age-matched healthy boys were recruited from ADHD-200 Consortium. All resting-state fMRI datasets were preprocessed and normalized into standard brain space. Using general linear regression, 20 ICNs were taken as spatial templates to analyze the time-courses of ICNs for each subject. Amplitude of low frequency fluctuations (ALFFs) were computed as univariate temporal features within ICNs. Pearson correlation coefficients and node strengths were computed as bivariate temporal features between ICNs. Additional correlation analysis was performed between temporal features of ICNs and behavior scores. Results: ADHD exhibited more activated network-wise ALFF than normal controls in attention and default mode-related network. Enhanced functional connectivities between ICNs were found in ADHD. The network-wise ALFF within ICNs might influence the functional connectivity between ICNs. The temporal pattern within posterior default mode network (pDMN) was positively correlated to inattentive scores. The subcortical network, fusiform-related DMN and attention-related networks were negatively correlated to Intelligence Quotient (IQ) scores. Conclusion: The temporal low frequency oscillations of ICNs in boys with ADHD were more activated than normal controls during resting state; the temporal features within ICNs could

  11. Understanding the effect of n-type and p-type doping in the channel ...

    Indian Academy of Sciences (India)

    GNRFET) with diffe- rent doping concentrations in different ... Further, we introduced step-doping profile in the graphene nanoribbon (GNR) channel and found that the device ... for any type of metal-semiconductor contact. The effect of. Figure 1.

  12. The effect of faulty local detectors on a detection network.

    CERN Document Server

    Mirjalily, G

    2002-01-01

    Distributed detection theory has received increasing attention recently. Development of multiple sensors for signal detection results in improved performance and increased reliability. in a detection network, each local sensor decides locally whether a signal is detected or not. The local decisions are sent to the fusion center, where the final decision is made. In this paper, a theoretic approach is considered to data fusion when one of the sensors is faulty. If the fusion center does not have any knowledge of this fault, the performance of the system is different than its normal performance. The changes in the error probabilities depend on the type of the fault and on the threshold value of the fission center test. We derived some expressions of the changes in the values of error probabilities. For some type of faults, the system false alarm probability increases significantly, whereas for some other faults, the system detection probability decreases significantly. To illustrate the results, a numerical exa...

  13. Data-Driven Networked Optimal Iterative Learning Control for Discrete Linear Time-Varying Systems with One-Operation Bernoulli-Type Communication Delays

    Directory of Open Access Journals (Sweden)

    Yan Geng

    2017-01-01

    Full Text Available This paper develops a type of data-driven networked optimal iterative learning control strategy for a class of discrete linear time-varying systems with one-operation Bernoulli-type communication delays. In terms of the stochastic Bernoulli-type one-operation communication delayed inputs and outputs, the previous-iteration synchronous compensations are adopted. By means of deriving gradients of two types of objective functions that express the optimal approximation of the system matrix and the minimal tracking error, the strategy approximates the system matrix and upgrades the control inputs in an interact mode as the iteration evolves. By taking advantage of matrix theory and statistical technique, it is derived that the approximation discrepancy of the system matrix is bounded and the mathematical expectation of the tracking error vanishes as the iteration goes on. Numerical simulations manifest the validity and effectiveness.

  14. Networks as a type of social entrepreneurship to advance population health.

    Science.gov (United States)

    Wei-Skillern, Jane

    2010-11-01

    A detailed case study from the field of social entrepreneurship is used to illustrate the network approach, which does not require more resources but rather makes better use of existing resources. Leaders in public health can use networks to overcome some of the barriers that inhibit the widespread adoption of a population health approach to community health. Public health leaders who embrace social entrepreneurship may be better able to accomplish their missions by building their networks rather than just their organizations.

  15. NETWORKING COMPANY AS A MODERN TYPE OF FIRM IN CONTEMPORARY ECONOMY

    Directory of Open Access Journals (Sweden)

    Дмитрий Юрьевич Усов

    2014-02-01

    Full Text Available Despite the increase of popularity of network business forms, there is no common unified approach towards understanding of the nature of the network company and definition of its specific features in comparison with traditional (hierarchical firm and purely market mechanism of regulation of interaction between companies. The analysis of Russian and foreign scholarly publications on the problems of networking companies supports this conclusion.This is why the goal of the present research is to amend the definition of the network company. In order to reach this goal the following problems should be solved:-            An analysis of existing definitions of networking company;-            A comparative analysis of functioning of traditional and networking companies;-            A unified list of distinctive features that can be used to oppose networking companies to traditional ones;The research resulted in the following formulation of the nature of the networking company: the networking company is a group of firms, based on coopetition and providing its members with access to each other resources.DOI: http://dx.doi.org/10.12731/2218-7405-2013-12-3

  16. Effects of Hospital Workers' Friendship Networks on Job Stress.

    Directory of Open Access Journals (Sweden)

    Sung Yae Shin

    Full Text Available This study attempted to identify the sources of job stress according to job position and investigate how friendship networks affect job stress.Questionnaires based on The Health Professions Stress Inventory (HPSI developed by Wolfgang experienced by healthcare providers were collected from 420 nurses, doctors and radiological technologists in two general hospitals in Korea by a multistage cluster sampling method. Multiple regression analysis was used to examine the effects of friendship networks on job stress after controlling for other factors.The severity of job stress differed according to level of job demands (p = .006; radiologic technologists experienced the least stress (45.4, nurses experienced moderate stress (52.4, and doctors experienced the most stress (53.6. Those with long-term friendships characterized by strong connections reported lower levels of stress than did those with weak ties to friends among nurses (1.3, p < .05 and radiological technologists (11.4, p < .01. The degree of cohesion among friends had a positive impact on the level of job stress experienced by nurses (8.2, p < .001 and radiological technologists (14.6, p < .1. Doctors who participated in workplace alumni meetings scored higher than those who did not. However, those who participated in alumni meetings outside the workplace showed the opposite tendency, scoring 9.4 (p < .05 lower than those who did not. The resources from their friendship network include both information and instrumental support. As most radiological technologists were male, their instrumental support positively affected their job stress (9.2, p < .05. Life information support was the primary positive contributor to control of nurses' (4.1, p < .05, radiological technologists' (8.0, p < .05 job stress.The strength and density of such friendship networks were related to job stress. Life information support from their friendship network was the primary positive contributor to control of job

  17. Leverage Between the Buffering Effect and the Bystander Effect in Social Networking.

    Science.gov (United States)

    Chiu, Yu-Ping; Chang, Shu-Chen

    2015-08-01

    This study examined encouraged and inhibited social feedback behaviors based on the theories of the buffering effect and the bystander effect. A system program was used to collect personal data and social feedback from a Facebook data set to test the research model. The results revealed that the buffering effect induced a positive relationship between social network size and feedback gained from friends when people's social network size was under a certain cognitive constraint. For people with a social network size that exceeds this cognitive constraint, the bystander effect may occur, in which having more friends may inhibit social feedback. In this study, two social psychological theories were applied to explain social feedback behavior on Facebook, and it was determined that social network size and social feedback exhibited no consistent linear relationship.

  18. [Medical error: analysis of their type, their consequences and impact of the mortality and morbidity meetings in midwifery (APERIF network maternities)].

    Science.gov (United States)

    Nazac, A; Poudensan, P; Barraquet, A; Dufour, M; Godreau, M; Larre, C; Jathière, F; Leguluche, L

    2015-03-01

    The medical error begins to be estimated by mortality and morbidity meetings (MMM). They concern all the medical professions among which the midwives. One of the themes of the congress of APERIF networks in 2013 concerned the evaluation of the medical errors of the midwives. We sounded the midwives of the network to know the type of medical errors, their frequencies, their consequences and the proposed corrective measures. A workgroup was set up who allowed to establish a questionnaire of evaluation which was diffused to midwives of the maternities of the network. The questionnaire analysed the population and the existing organizations in the departments regarding staff and MMM. The questionnaire also analyzed the type of committed errors, their mode of revelation, the medical and psychological consequences. The last part of the questionnaire concerned the effective corrective measures and those wished by the midwives. The rate of answer in spite of brakes to the distribution of questionnaires was satisfactory for this type of behavioural research. We noticed that the errors are very frequent and that they have an important impact in the professional life of the midwives. The MMM is little known by midwives and they are badly informed about their existence. The medical error is inevitable, it has important consequences which are underestimated and consequently without real targeted corrective measures. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  19. Spanish Network on Effects of Wildfires on Soils. The view after 5 years of networking

    Science.gov (United States)

    Jordán, Antonio; Mataix-Solera, Jorge; Cerdà, Artemi

    2013-04-01

    1. WHAT IS FUEGORED? The Spanish Thematic Network "Effects of Wildfires on Soils" (FUEGORED, http://grupo.us.es/fuegored) has been working for over 5 years at becoming a point of reference for the study of fire-affected soils and restoration strategies. FUEGORED started in 2007, originally scheduled to run three years, as a result of the interest of Spanish researchers for developing better strategies and scientific interchange of ideas, people and collaboration between research groups. The first steps towards the establishment of a working group were a series of fieldtrips through Spain (2003), USA (2004) and Portugal (2005), where discussions about problems and research strategies arised. In its early years the network was supported by the former Ministry of Science and Innovation. This is a project to review scientific knowledge developed to date and discuss and propose future developments in scientific research about the effects of wildfires on soils. The objectives of the network are to promote and disseminate scientific research findings, provide technical and management information, and facilitate transference of knowledge between scientists, forest managers, students and society. 2. WHO IS IN THE NETWORK? The research group consists of the leading names of Spanish science in the topic and young talents, which are currently developing the most innovative research lines. Currently, the network is formed by 245 members, researchers from over 30 Spanish universities and research centers to provide the experience of decades of scientific and technical work in areas affected by forest fires and outstanding foreign researchers from Europe, Australia and America, including countries such as Australia, Italy, Lithuania, Portugal, UK, USA and others. Forest managers and technicians from various institutions are also present. 3. MAIN ACHIEVEMENTS Four international congresses have been promoted by the network in Valencia, 2008, Seville, 2009, Santiago de Compostela

  20. Interval type-2 fuzzy neural network controller for a multivariable anesthesia system based on a hardware-in-the-loop simulation.

    Science.gov (United States)

    El-Nagar, Ahmad M; El-Bardini, Mohammad

    2014-05-01

    This manuscript describes the use of a hardware-in-the-loop simulation to simulate the control of a multivariable anesthesia system based on an interval type-2 fuzzy neural network (IT2FNN) controller. The IT2FNN controller consists of an interval type-2 fuzzy linguistic process as the antecedent part and an interval neural network as the consequent part. It has been proposed that the IT2FNN controller can be used for the control of a multivariable anesthesia system to minimize the effects of surgical stimulation and to overcome the uncertainty problem introduced by the large inter-individual variability of the patient parameters. The parameters of the IT2FNN controller were trained online using a back-propagation algorithm. Three experimental cases are presented. All of the experimental results show good performance for the proposed controller over a wide range of patient parameters. Additionally, the results show better performance than the type-1 fuzzy neural network (T1FNN) controller under the effect of surgical stimulation. The response of the proposed controller has a smaller settling time and a smaller overshoot compared with the T1FNN controller and the adaptive interval type-2 fuzzy logic controller (AIT2FLC). The values of the performance indices for the proposed controller are lower than those obtained for the T1FNN controller and the AIT2FLC. The IT2FNN controller is superior to the T1FNN controller for the handling of uncertain information due to the structure of type-2 fuzzy logic systems (FLSs), which are able to model and minimize the numerical and linguistic uncertainties associated with the inputs and outputs of the FLSs. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Quantifying stochastic effects in biochemical reaction networks using partitioned leaping.

    Science.gov (United States)

    Harris, Leonard A; Piccirilli, Aaron M; Majusiak, Emily R; Clancy, Paulette

    2009-05-01

    "Leaping" methods show great promise for significantly accelerating stochastic simulations of complex biochemical reaction networks. However, few practical applications of leaping have appeared in the literature to date. Here, we address this issue using the "partitioned leaping algorithm" (PLA) [L. A. Harris and P. Clancy, J. Chem. Phys. 125, 144107 (2006)], a recently introduced multiscale leaping approach. We use the PLA to investigate stochastic effects in two model biochemical reaction networks. The networks that we consider are simple enough so as to be accessible to our intuition but sufficiently complex so as to be generally representative of real biological systems. We demonstrate how the PLA allows us to quantify subtle effects of stochasticity in these systems that would be difficult to ascertain otherwise as well as not-so-subtle behaviors that would strain commonly used "exact" stochastic methods. We also illustrate bottlenecks that can hinder the approach and exemplify and discuss possible strategies for overcoming them. Overall, our aim is to aid and motivate future applications of leaping by providing stark illustrations of the benefits of the method while at the same time elucidating obstacles that are often encountered in practice.

  2. A Bayesian Network View on Nested Effects Models

    Directory of Open Access Journals (Sweden)

    Fröhlich Holger

    2009-01-01

    Full Text Available Nested effects models (NEMs are a class of probabilistic models that were designed to reconstruct a hidden signalling structure from a large set of observable effects caused by active interventions into the signalling pathway. We give a more flexible formulation of NEMs in the language of Bayesian networks. Our framework constitutes a natural generalization of the original NEM model, since it explicitly states the assumptions that are tacitly underlying the original version. Our approach gives rise to new learning methods for NEMs, which have been implemented in the /Bioconductor package nem. We validate these methods in a simulation study and apply them to a synthetic lethality dataset in yeast.

  3. Angular Velocity's Neural Network Observer of the Electric Drive of TVR - IM Type Implemented in Software Environment LabVIEW

    Science.gov (United States)

    Kozlova, L.; Bolovin, E.; Payuk, L.

    2016-06-01

    One of the common ways to manage a smooth starting and stopping of asynchronous motors are soft-start system. For this provision is necessary to use a closed speed asynchronous electric drive of tiristor voltage regulator - induction motor (TVR-IM) type. Using real sensors significantly increases the cost of installation and also introduces a number of inconveniences in the operation of the actuator. Observer has clear advantages that are created on artificial neural network. Creating a neural network observer in program graphic programming LabVIEW will allow to evaluate the speed of rotation of the asynchronous electric.

  4. Development of a privacy and security policy framework for a multistate comparative effectiveness research network.

    Science.gov (United States)

    Kim, Katherine K; McGraw, Deven; Mamo, Laura; Ohno-Machado, Lucila

    2013-08-01

    Comparative effectiveness research (CER) conducted in distributed research networks (DRNs) is subject to different state laws and regulations as well as institution-specific policies intended to protect privacy and security of health information. The goal of the Scalable National Network for Effectiveness Research (SCANNER) project is to develop and demonstrate a scalable, flexible technical infrastructure for DRNs that enables near real-time CER consistent with privacy and security laws and best practices. This investigation began with an analysis of privacy and security laws and state health information exchange (HIE) guidelines applicable to SCANNER participants from California, Illinois, Massachusetts, and the Federal Veteran's Administration. A 7-member expert panel of policy and technical experts reviewed the analysis and gave input into the framework during 5 meetings held in 2011-2012. The state/federal guidelines were applied to 3 CER use cases: safety of new oral hematologic medications; medication therapy management for patients with diabetes and hypertension; and informational interventions for providers in the treatment of acute respiratory infections. The policy framework provides flexibility, beginning with a use-case approach rather than a one-size-fits-all approach. The policies may vary depending on the type of patient data shared (aggregate counts, deidentified, limited, and fully identified datasets) and the flow of data. The types of agreements necessary for a DRN may include a network-level and data use agreements. The need for flexibility in the development and implementation of policies must be balanced with responsibilities of data stewardship.

  5. Expression-based network biology identifies alteration in key regulatory pathways of type 2 diabetes and associated risk/complications.

    Directory of Open Access Journals (Sweden)

    Urmi Sengupta

    Full Text Available Type 2 diabetes mellitus (T2D is a multifactorial and genetically heterogeneous disease which leads to impaired glucose homeostasis and insulin resistance. The advanced form of disease causes acute cardiovascular, renal, neurological and microvascular complications. Thus there is a constant need to discover new and efficient treatment against the disease by seeking to uncover various novel alternate signalling mechanisms that can lead to diabetes and its associated complications. The present study allows detection of molecular targets by unravelling their role in altered biological pathways during diabetes and its associated risk factors and complications. We have used an integrated functional networks concept by merging co-expression network and interaction network to detect the transcriptionally altered pathways and regulations involved in the disease. Our analysis reports four novel significant networks which could lead to the development of diabetes and other associated dysfunctions. (a The first network illustrates the up regulation of TGFBRII facilitating oxidative stress and causing the expression of early transcription genes via MAPK pathway leading to cardiovascular and kidney related complications. (b The second network demonstrates novel interactions between GAPDH and inflammatory and proliferation candidate genes i.e., SUMO4 and EGFR indicating a new link between obesity and diabetes. (c The third network portrays unique interactions PTPN1 with EGFR and CAV1 which could lead to an impaired vascular function in diabetic nephropathy condition. (d Lastly, from our fourth network we have inferred that the interaction of beta-catenin with CDH5 and TGFBR1 through Smad molecules could contribute to endothelial dysfunction. A probability of emergence of kidney complication might be suggested in T2D condition. An experimental investigation on this aspect may further provide more decisive observation in drug target identification and better

  6. Do Specific Types of Networking Predict Specific Mobility Outcomes? A Two-Year Prospective Study

    Science.gov (United States)

    Wolff, Hans-Georg; Moser, Klaus

    2010-01-01

    Previous research has established a general relation between networking and career outcomes, as postulated by theories on protean careers and career self management. We suggest that specific facets of networking behavior differentially affect specific career mobility outcomes over time. In a 2-year prospective study, we examined the impact of six…

  7. The effect of personality type on denture satisfaction.

    Science.gov (United States)

    Ozdemir, Ali Kemal; Ozdemir, Hatice Deniz; Polat, Nilüfer Tülin; Turgut, Mehmet; Sezer, Hafize

    2006-01-01

    The aim of this study was to determine the correlation between personality type and denture satisfaction of totally and partially edentulous patients. Two hundred thirty-nine patients (107 women and 132 men) aged 31 to 78 years (mean, 51.87) using removable dentures (165 maxillary and mandibular partial, 51 maxillary and mandibular complete, and 23 maxillary complete and mandibular partial) were asked to fill out a questionnaire on their satisfaction with their dentures with regard to esthetics, speaking ability, and masticatory function. Personality types were evaluated using both the responses to this questionnaire and the Type A Behavior Pattern Test. Chi-square test and logistic regression analysis were used to compare the denture satisfaction scores of the groups (Type A, Type B, and Type AB). The level of statistical significance was set at P = .05. Denture satisfaction of the patients with regard to esthetics, speaking ability, and masticatory function was affected by personality type. Statistically significant differences were found between Type A and types B and AB, as well as between types B and AB. The personality type of the patients had an effect on their satisfaction with dentures. The lowest denture satisfaction values were observed in the Type A patients.

  8. From Social Integration to Social Isolation: The Relationship Between Social Network Types and Perceived Availability of Social Support in a National Sample of Older Canadians.

    Science.gov (United States)

    Harasemiw, Oksana; Newall, Nancy; Shooshtari, Shahin; Mackenzie, Corey; Menec, Verena

    2017-01-01

    It is well-documented that social isolation is detrimental to health and well-being. What is less clear is what types of social networks allow older adults to get the social support they need to promote health and well-being. In this study, we identified social network types in a national sample of older Canadians and explored whether they are associated with perceived availability of different types of social support (affectionate, emotional, or tangible, and positive social interactions). Data were drawn from the baseline questionnaire of the Canadian Longitudinal Study on Aging for participants aged 65-85 (unweighted n = 8,782). Cluster analyses revealed six social network groups. Social support generally declined as social networks became more restricted; however, different patterns of social support availability emerged for different social network groups. These findings suggest that certain types of social networks place older adults at risk of not having met specific social support needs.

  9. Effect of Fertilizer Type and Method of Application on Nutrient ...

    African Journals Online (AJOL)

    The effects of fertilizer types and methods of application on the nutritive value and in situ rumen degradability of maize straw were assessed. The fertilizer types were; Low analysis fertilizer (LAF), with nutrient contents of less than 41% and High analysis fertilizer (HAF), with nutrient contents greater than 41%. The methods of ...

  10. A neural network model of ventriloquism effect and aftereffect.

    Directory of Open Access Journals (Sweden)

    Elisa Magosso

    Full Text Available Presenting simultaneous but spatially discrepant visual and auditory stimuli induces a perceptual translocation of the sound towards the visual input, the ventriloquism effect. General explanation is that vision tends to dominate over audition because of its higher spatial reliability. The underlying neural mechanisms remain unclear. We address this question via a biologically inspired neural network. The model contains two layers of unimodal visual and auditory neurons, with visual neurons having higher spatial resolution than auditory ones. Neurons within each layer communicate via lateral intra-layer synapses; neurons across layers are connected via inter-layer connections. The network accounts for the ventriloquism effect, ascribing it to a positive feedback between the visual and auditory neurons, triggered by residual auditory activity at the position of the visual stimulus. Main results are: i the less localized stimulus is strongly biased toward the most localized stimulus and not vice versa; ii amount of the ventriloquism effect changes with visual-auditory spatial disparity; iii ventriloquism is a robust behavior of the network with respect to parameter value changes. Moreover, the model implements Hebbian rules for potentiation and depression of lateral synapses, to explain ventriloquism aftereffect (that is, the enduring sound shift after exposure to spatially disparate audio-visual stimuli. By adaptively changing the weights of lateral synapses during cross-modal stimulation, the model produces post-adaptive shifts of auditory localization that agree with in-vivo observations. The model demonstrates that two unimodal layers reciprocally interconnected may explain ventriloquism effect and aftereffect, even without the presence of any convergent multimodal area. The proposed study may provide advancement in understanding neural architecture and mechanisms at the basis of visual-auditory integration in the spatial realm.

  11. Mapping effective connectivity within cortical networks with diffuse optical tomography.

    Science.gov (United States)

    Hassanpour, Mahlega S; Eggebrecht, Adam T; Peelle, Jonathan E; Culver, Joseph P

    2017-10-01

    Understanding how cortical networks interact in response to task demands is important both for providing insight into the brain's processing architecture and for managing neurological diseases and mental disorders. High-density diffuse optical tomography (HD-DOT) is a neuroimaging technique that offers the significant advantages of having a naturalistic, acoustically controllable environment and being compatible with metal implants, neither of which is possible with functional magnetic resonance imaging. We used HD-DOT to study the effective connectivity and assess the modulatory effects of speech intelligibility and syntactic complexity on functional connections within the cortical speech network. To accomplish this, we extend the use of a generalized psychophysiological interaction (PPI) analysis framework. In particular, we apply PPI methods to event-related HD-DOT recordings of cortical oxyhemoglobin activity during auditory sentence processing. We evaluate multiple approaches for selecting cortical regions of interest and for modeling interactions among these regions. Our results show that using subject-based regions has minimal effect on group-level connectivity maps. We also demonstrate that incorporating an interaction model based on estimated neural activity results in significantly stronger effective connectivity. Taken together our findings support the use of HD-DOT with PPI methods for noninvasively studying task-related modulations of functional connectivity.

  12. Removal of batch effects using distribution-matching residual networks.

    Science.gov (United States)

    Shaham, Uri; Stanton, Kelly P; Zhao, Jun; Li, Huamin; Raddassi, Khadir; Montgomery, Ruth; Kluger, Yuval

    2017-08-15

    Sources of variability in experimentally derived data include measurement error in addition to the physical phenomena of interest. This measurement error is a combination of systematic components, originating from the measuring instrument and random measurement errors. Several novel biological technologies, such as mass cytometry and single-cell RNA-seq (scRNA-seq), are plagued with systematic errors that may severely affect statistical analysis if the data are not properly calibrated. We propose a novel deep learning approach for removing systematic batch effects. Our method is based on a residual neural network, trained to minimize the Maximum Mean Discrepancy between the multivariate distributions of two replicates, measured in different batches. We apply our method to mass cytometry and scRNA-seq datasets, and demonstrate that it effectively attenuates batch effects. our codes and data are publicly available at https://github.com/ushaham/BatchEffectRemoval.git. yuval.kluger@yale.edu. Supplementary data are available at Bioinformatics online.

  13. Social Networks Across Common Cancer Types: The Evidence, Gaps, and Areas of Potential Impact.

    Science.gov (United States)

    Rice, L J; Halbert, C H

    2017-01-01

    Although the association between social context and health has been demonstrated previously, much less is known about network interactions by gender, race/ethnicity, and sociodemographic characteristics. Given the variability in cancer outcomes among groups, research on these relationships may have important implications for addressing cancer health disparities. We examined the literature on social networks and cancer across the cancer continuum among adults. Relevant studies (N=16) were identified using two common databases: PubMed and Google Scholar. Most studies used a prospective cohort study design (n=9), included women only (n=11), and were located in the United States (n=14). Seventy-five percent of the studies reviewed used a validated scale or validated items to measure social networks (n=12). Only one study examined social network differences by race, 57.1% (n=8) focused on breast cancer alone, 14.3% (n=2) explored colorectal cancer or multiple cancers simultaneously, and 7.1% (n=1) only prostate cancer. More than half of the studies included multiple ethnicities in the sample, while one study included only low-income subjects. Despite findings of associations between social networks and cancer survival, risk, and screening, none of the studies utilized social networks as a mechanism for reducing health disparities; however, such an approach has been utilized for infectious disease control. Social networks and the support provided within these networks have important implications for health behaviors and ultimately cancer disparities. This review serves as the first step toward dialog on social networks as a missing component in the social determinants of cancer disparities literature that could move the needle upstream to target adverse cancer outcomes among vulnerable populations. © 2017 Elsevier Inc. All rights reserved.

  14. Sealing type effect on corn silage quality in bunker silos

    National Research Council Canada - National Science Library

    Mikael Neumann; Guilherme Fernando Mattos Leão; Eloize Jaqueline Askel; Fabiano Marafon; Danúbia Nogueira Figueira; Mailson Poczynek

    .... Thus, the aim of the present study was to evaluate the effect of two sealing types on dry matter recovery rate, aerobic stability, nutritional composition, and in vitro digestibility of corn silage in bunker silos...

  15. Effects of coagulating enzyme types (commercial calf rennet ...

    African Journals Online (AJOL)

    Effects of coagulating enzyme types (commercial calf rennet, Aspergillus niger var. awamori as recombinant chymosin and rhizomucor miehei as microbial rennet) on the chemical and sensory characteristics of white pickled cheese.

  16. How can the functioning and effectiveness of networks in the settings approach of health promotion be understood, achieved and researched?

    Science.gov (United States)

    Dietscher, Christina

    2017-02-01

    Networks in health promotion (HP) have, after the launch of WHO's Ottawa Charter [(World Health Organization (WHO) (eds). (1986) Ottawa Charter on Health Promotion. Towards A New Public Health. World Health Organization, Geneva], become a widespread tool to disseminate HP especially in conjunction with the settings approach. Despite their allegedly high importance for HP practice and more than two decades of experiences with networking so far, a sound theoretical basis to support effective planning, formation, coordination and strategy development for networks in the settings approach of HP (HPSN) is still widely missing. Brößkamp-Stone's multi-facetted interorganizational network assessment framework (2004) provides a starting point but falls short of specifying the outcomes that can be reasonably expected from the specific network type of HPSN, and the specific processes/strategies and structures that are needed to achieve them. Based on outcome models in HP, on social, managerial and health science theories of networks, settings and organizations, a sociological systems theory approach and the capacity approach in HP, this article points out why existing approaches to studying networks are insufficient for HPSN, what can be understood by their functioning and effectiveness, what preconditions there are for HPSN effectiveness and how an HPSN functioning and effectiveness framework proposed on these grounds can be used for researching networks in practice, drawing on experiences from the ‘Project on an Internationally Comparative Evaluation Study of the International Network of Health Promoting Hospitals and Health Services’ (PRICES-HPH), which was coordinated by the WHO Collaborating Centre for Health Promotion in Hospitals and Health Services (Vienna WHO-CC) from 2008 to 2012.

  17. Cell-type deconvolution with immune pathways identifies gene networks of host defense and immunopathology in leprosy

    Science.gov (United States)

    Inkeles, Megan S.; Teles, Rosane M.B.; Pouldar, Delila; Andrade, Priscila R.; Madigan, Cressida A.; Ambrose, Mike; Sarno, Euzenir N.; Rea, Thomas H.; Ochoa, Maria T.; Iruela-Arispe, M. Luisa; Swindell, William R.; Ottenhoff, Tom H.M.; Geluk, Annemieke; Bloom, Barry R.

    2016-01-01

    Transcriptome profiles derived from the site of human disease have led to the identification of genes that contribute to pathogenesis, yet the complex mixture of cell types in these lesions has been an obstacle for defining specific mechanisms. Leprosy provides an outstanding model to study host defense and pathogenesis in a human infectious disease, given its clinical spectrum, which interrelates with the host immunologic and pathologic responses. Here, we investigated gene expression profiles derived from skin lesions for each clinical subtype of leprosy, analyzing gene coexpression modules by cell-type deconvolution. In lesions from tuberculoid leprosy patients, those with the self-limited form of the disease, dendritic cells were linked with MMP12 as part of a tissue remodeling network that contributes to granuloma formation. In lesions from lepromatous leprosy patients, those with disseminated disease, macrophages were linked with a gene network that programs phagocytosis. In erythema nodosum leprosum, neutrophil and endothelial cell gene networks were identified as part of the vasculitis that results in tissue injury. The present integrated computational approach provides a systems approach toward identifying cell-defined functional networks that contribute to host defense and immunopathology at the site of human infectious disease. PMID:27699251

  18. Comb-Type Grafted Hydrogels of PNIPAM and PDMAEMA with Reversed Network-Graft Architectures from Controlled Radical Polymerizations

    Directory of Open Access Journals (Sweden)

    Sheng-Qi Chen

    2016-02-01

    Full Text Available Dual thermo- and pH-responsive comb-type grafted hydrogels of poly(N,N-dimethylaminoethyl methacrylate (PDMAEMA and poly(N-isopropylacrylamide (PNIPAM with reversed network-graft architectures were synthesized by the combination of atom transfer radical polymerization (ATRP, reversible addition-fragmentation chain transfer (RAFT polymerization and click chemistry. Two kinds of macro-cross-linkers with two azido groups at one chain-end and different chain length [PNIPAM–(N32 and PDMAEMA–(N32] were prepared with N,N-di(β-azidoethyl 2-halocarboxylamide as the ATRP initiator. Through RAFT copolymerization of DMAEMA or NIPAM with propargyl acrylate (ProA using dibenzyltrithiocarbonate as a chain transfer agent, two network precursors with different content of alkynyl side-groups [P(DMAEMA-co-ProA and P(NIPAM-co-ProA] were obtained. The subsequent azido-alkynyl click reaction of macro-cross-linkers and network precursors led to the formation of the network-graft hydrogels. These dual stimulus-sensitive hydrogels exhibited rapid response, high swelling ratio and reproducible swelling/de-swelling cycles under different temperatures and pH values. The influences of cross-linkage density and network-graft architecture on the properties of the hydrogels were investigated. The release of ceftriaxone sodium from these hydrogels showed both thermal- and pH-dependence, suggesting the feasibility of these hydrogels as thermo- and pH-dependent drug release devices.

  19. Effects of Competition and Cooperation Interaction between Agents on Networks in Presence of a "Market Capacity"

    CERN Document Server

    Sonubi, A; Stefani, S; Ausloos, M

    2016-01-01

    A network effect is introduced taking into account competition, cooperation and mixed-type interaction amongst agents along a generalized Verhulst-Lotka-Volterra model. It is also argued that the presence of a market capacity enforces an indubious limit on the agent's size growth. The state stability of triadic agents, i.e., the most basic network plaquette, is investigated analytically for possible scenarios, through a fixed point analysis. It is discovered that: (i) \\market" demand is only satisfied for full competition when one agent monopolizes the market; (ii) growth of agent size is encouraged in full cooperation; (iii) collaboration amongst agents to compete against one single agent may result in the disappearance of this single agent out of the market, and (iv) cooperating with two rivals may become a growth strategy for an intelligent agent.

  20. EFFECTIVE BANDWIDTH FOR SELF-SIMILAR TRAFFIC IN ATM NETWORK

    Directory of Open Access Journals (Sweden)

    Linawati Linawati

    2009-05-01

    Full Text Available This paper proposes a new approach to estimate the effective bandwidth for self-similar traffic in ATM network. In this approach we use the tail distribution of queue length based on FBM model. This approach is derived from the inequalities for Mills’ ratio. Then a comparison with Norros and Trinh&Miki schemes are analysed. The results demonstrate reasonable agreement between numerical and simulation results and between all schemes. Their bandwidth estimation tends closer for CLP improvement.

  1. Labor Mobility, Social Network Effects, and Innovative Activity

    DEFF Research Database (Denmark)

    Kongsted, Hans Christian; Rønde, Thomas; Kaiser, Ulrich

    . This relationship is stronger if workers join from innovative firms. We also find evidence for positive feedback from workers who leave for an innovative firm, presumably because the worker who left stays in contact with their former colleagues. This implies that the positive feedback (“social network effects......We study the mapping between labor mobility and industrial innovative activity for the population of R&D active Danish firms observed between 1999 and 2004. Our study documents a positive relationship between the number of workers who join a firm and the firm’s innovative activity...

  2. Globally fixed-time synchronization of coupled neutral-type neural network with mixed time-varying delays

    Science.gov (United States)

    2018-01-01

    This paper mainly studies the globally fixed-time synchronization of a class of coupled neutral-type neural networks with mixed time-varying delays via discontinuous feedback controllers. Compared with the traditional neutral-type neural network model, the model in this paper is more general. A class of general discontinuous feedback controllers are designed. With the help of the definition of fixed-time synchronization, the upper right-hand derivative and a defined simple Lyapunov function, some easily verifiable and extensible synchronization criteria are derived to guarantee the fixed-time synchronization between the drive and response systems. Finally, two numerical simulations are given to verify the correctness of the results. PMID:29370248

  3. Identification of direct and indirect social network effects in the pathophysiology of insulin resistance in obese human subjects.

    Science.gov (United States)

    Henning, Christian H C A; Zarnekow, Nana; Hedtrich, Johannes; Stark, Sascha; Türk, Kathrin; Laudes, Matthias

    2014-01-01

    The aim of the present study was to examine to what extent different social network mechanisms are involved in the pathogenesis of obesity and insulin-resistance. We used nonparametric and parametric regression models to analyse whether individual BMI and HOMA-IR are determined by social network characteristics. A total of 677 probands (EGO) and 3033 social network partners (ALTER) were included in the study. Data gathered from the probands include anthropometric measures, HOMA-IR index, health attitudes, behavioural and socio-economic variables and social network data. We found significant treatment effects for ALTERs frequent dieting (pnetwork effect also on EGO's insulin resistance. Most importantly, we also found significant direct social network effects on EGO's insulin resistance, evidenced by an effect of ALTERs frequent dieting (p = 0.033) and ALTERs sport activities (p = 0.041) to decrease EGO's HOMA-IR index independently of EGO's BMI. Social network phenomena appear not only to be relevant for the spread of obesity, but also for the spread of insulin resistance as the basis for type 2 diabetes. Attitudes and behaviour of peer groups influence EGO's health status not only via social mechanisms, but also via socio-biological mechanisms, i.e. higher brain areas might be influenced not only by biological signals from the own organism, but also by behaviour and knowledge from different human individuals. Our approach allows the identification of peer group influence controlling for potential homophily even when using cross-sectional observational data.

  4. Effects of budget constraints on conservation network design for biodiversity and ecosystem services

    NARCIS (Netherlands)

    Remme, Roy P.; Schröter, Matthias

    2016-01-01

    Limited budgets and budget cuts hamper the development of effective biodiversity conservation networks. Optimizing the spatial configuration of conservation networks given such budget constraints remains challenging. Systematic conservation planning addresses this challenge. Systematic

  5. Developing Evidence to Inform Decisions about Effectiveness (DeCIDE) Network

    Science.gov (United States)

    The Developing Evidence to Inform Decisions about Effectiveness Network is a network of research centers that the Agency for Healthcare Research and Quality created to conduct practical studies about health care items and services.

  6. Verification of the authenticity of handwritten signature using structure neural-network-type OCON

    Science.gov (United States)

    Molina, M. L.; Arias, N. A.; Gualdron, Oscar

    2004-10-01

    A method in order to carry out the verification of handwritten signatures is described. The method keeps in mind global features and local features that encode the shape and the dynamics of the signatures. Signatures are recorded with a digital tablet that can read the position and pressure of the pen. Input patterns are considered time and space dependent. Before extracting the information of the static features such as total length or height/width ratio, and the dynamic features such as speed or acceleration, the signature is normalized for position, size and orientation using its Fourier Descriptors. The comparison stage is carried out for algorithms of neurals networks. For each one of the sets of features a special two stage Perceptron OCON (one-class-one-network) classification structure has been implemented. In the first stage networks multilayer perceptron with few neurons are used. The classifier combines the decision results of the neural networks and the Euclidean distance obtained using the two feature sets. The results of the first-stage classifier feed a second-stage radial basis function (RBF) neural network structure, which makes the final decision. The entire system was extensively tested, 160 neurals networks has been implemented.

  7. Simulating the effects of social networks on a population's hurricane evacuation participation

    Science.gov (United States)

    Widener, Michael J.; Horner, Mark W.; Metcalf, Sara S.

    2013-04-01

    Scientists have noted that recent shifts in the earth's climate have resulted in more extreme weather events, like stronger hurricanes. Such powerful storms disrupt societal function and result in a tremendous number of casualties, as demonstrated by recent hurricane experience in the US Planning for and facilitating evacuations of populations forecast to be impacted by hurricanes is perhaps the most effective strategy for reducing risk. A potentially important yet relatively unexplored facet of people's evacuation decision-making involves the interpersonal communication processes that affect whether at-risk residents decide to evacuate. While previous research has suggested that word-of-mouth effects are limited, data supporting these assertions were collected prior to the widespread adoption of digital social media technologies. This paper argues that the influence of social network effects on evacuation decisions should be revisited given the potential of new social media for impacting and augmenting information dispersion through real-time interpersonal communication. Using geographic data within an agent-based model of hurricane evacuation in Bay County, Florida, we examine how various types of social networks influence participation in evacuation. It is found that strategies for encouraging evacuation should consider the social networks influencing individuals during extreme events, as it can be used to increase the number of evacuating residents.

  8. Temperature Effect on Capacitive Humidity Sensors and its Compensation Using Artificial Neural Networks

    Directory of Open Access Journals (Sweden)

    Tarikul ISLAM

    2015-08-01

    Full Text Available This paper represents the study of the effect of temperature on different capacitive humidity sensors used in practice. Capacitance of the humidity sensor, which is a function of concentration of water vapor, also depends on ambient temperature. This variation of ambient temperature causes error in the performance of sensor outputs and its compensation is essential. In this paper, we have used an artificial neural network to compensate the effect of ambient temperature error. The proposed artificial neural network technique is based on inverse model of the sensor. The technique is applicable for compensation of linear or nonlinear temperature effect of humidity sensor. It can also compensate the nonlinearity of the capacitive humidity response which is an issue for all most all types of humidity sensor. Our simulation studies show the sensor output and artificial neural network model output matches closely. Even though sensor characteristics change with temperature, the proposed model performs well irrespective of any change in temperature. It can be extended for the temperature compensation of other sensors. The maximum error for nonlinearity using the ANN technique are 0.2 % and temperature error of 0.08 % for temperature range between 10 0C to 60 0C of Sensor 3 and 0.01 % for temperature range between 25 0C to 85 0C of Sensor 4 respectively.

  9. A trans-acting locus regulates an anti-viral expression network and type 1 diabetes risk

    Czech Academy of Sciences Publication Activity Database

    Heinig, M.; Petretto, E.; Wallace, C.; Bottolo, L.; Rotival, M.; Lu, H.; Li, Y.; Sarwar, R.; Langley, S. R.; Bauerfeind, A.; Hummel, O.; Lee, Y. A.; Paskas, S.; Rintisch, C.; Saar, K.; Cooper, J.; Buchan, R.; Gray, C. C.; Cyster, J. G.; Erdmann, J.; Hengstenberg, C.; Maouche, S.; Ouwehand, W. H.; Rice, C. M.; Samani, N. J.; Schunkert, H.; Goodall, A. H.; Schulz, H.; Roider, H. G.; Vingron, M.; Blankenberg, S.; Münzel, T.; Zeller, T.; Szymczak, S.; Ziegler, A.; Tiret, L.; Smyth, D. J.; Pravenec, Michal; Aitman, T. J.; Cambien, F.; Clayton, D.; Todd, J. A.; Hubner, N.; Cook, S.A.

    2010-01-01

    Roč. 467, č. 7314 (2010), s. 460-464 ISSN 0028-0836 R&D Projects: GA MŠk(CZ) 1M0520; GA ČR GAP301/10/0290 Institutional research plan: CEZ:AV0Z50110509 Keywords : IRF7 driven inflammatory network * Ebi2 * type 1 diabetes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 36.101, year: 2010

  10. Angular Velocity's Neural Network Observer of the Electric Drive of TVR - IM Type Implemented in Software Environment LabVIEW

    OpenAIRE

    Kozlova, Liudmila Evgenevna; Bolovin, Evgeny Vladimirovich; Payuk, Lyubov Anatoljevna

    2016-01-01

    One of the common ways to manage a smooth starting and stopping of asynchronous motors are soft-start system. For this provision is necessary to use a closed speed asynchronous electric drive of tiristor voltage regulator - induction motor (TVR-IM) type. Using real sensors significantly increases the cost of installation and also introduces a number of inconveniences in the operation of the actuator. Observer has clear advantages that are created on artificial neural network. Creating a neura...

  11. Oil-collecting bee–flower interaction network: do bee size and anther type influence the use of pollen sources?

    OpenAIRE

    Rabelo, Laíce S.; Vilhena, Alice M. G. F.; Bastos, Esther M. A. F.; Aguiar, Cândida M.L.; Augusto, Solange Cristina

    2015-01-01

    International audience; AbstractPollination is an ecosystem service sustained by a differentiated use of resources among sympatric species. The bee size can influence the similarity in the use of resources, and poricidal anthers limit the access to pollen. Therefore, we evaluated the influence of body size and the anther type of pollen sources in Centridini–flower interaction network. We expected that the low niche overlap, promoted by these morphological parameters, would result in the forma...

  12. Articulation points in complex networks

    Science.gov (United States)

    Tian, Liang; Bashan, Amir; Shi, Da-Ning; Liu, Yang-Yu

    2017-01-01

    An articulation point in a network is a node whose removal disconnects the network. Those nodes play key roles in ensuring connectivity of many real-world networks, from infrastructure networks to protein interaction networks and terrorist communication networks. Despite their fundamental importance, a general framework of studying articulation points in complex networks is lacking. Here we develop analytical tools to study key issues pertinent to articulation points, such as the expected number of them and the network vulnerability against their removal, in an arbitrary complex network. We find that a greedy articulation point removal process provides us a different perspective on the organizational principles of complex networks. Moreover, this process results in a rich phase diagram with two fundamentally different types of percolation transitions. Our results shed light on the design of more resilient infrastructure networks and the effective destruction of terrorist communication networks.

  13. Serial position effects in dementia of the Alzheimer type.

    Science.gov (United States)

    Burkart, M; Heun, R; Benkert, O

    1998-01-01

    The aim of the present study was to analyse serial position effects for immediate and delayed free recall in patients with dementia of the Alzheimer type and controls. EXPERIMENT 1: 44 patients with dementia of the Alzheimer-type and 24 non-demented controls were asked for immediate and delayed free recall of 12 schematic drawings of common objects presented at the rate of 10 s/picture. Steep primacy effects were obtained at all delays in controls. By contrast, primacy effects were significantly impaired in patients with dementia at all delays of recall. Small immediate and delayed recall recency effects were found in both, patients and controls. EXPERIMENT 2: 19 patients with dementia of the Alzheimer type and 21 controls were asked for immediate and delayed free picture recall with presentation rates of 10, 5 and 1 s/picture. Again, primacy effects were significantly impaired in demented patients versus controls. With shorter presentation times, immediate recall recency effects were more pronounced than with longer presentation times, and no delayed recall recency effects were found. Primacy effect is impaired for immediate and delayed recall in dementia of the Alzheimer type. By contrast, immediate recall recency effect and possibly also long-term recency effect are preserved. The loss of the primacy effect contributes to the impairment of episodic memory in dementia of the Alzheimer type. Therefore further research is warranted into pharmacological and psychological interventions that might re-establish the primacy effect. Possibly, the orientation of demented patients might be improved by psychological techniques that rely on long-term recency effect.

  14. Protective effects of social networks on disability among older adults in Spain.

    Science.gov (United States)

    Escobar-Bravo, Miguel-Ángel; Puga-González, Dolores; Martín-Baranera, Monserrat

    2012-01-01

    The loss of autonomy at advanced ages is not only associated with ageing, but also with the characteristics of the physical and social environment. Recent investigations have shown that social networks, social engagement and participation act like predictors of disability among the elderly. The aim of this study is to determine whether social networks are related to the development and progression of disability in the early years of old age. The source of data is the first wave of the survey "Processes of Vulnerability among Spanish Elderly", carried out in 2005 to a sample of 1244 individuals. The population object of study is the cohort aged 70-74 years in metropolitan areas (Madrid and Barcelona) and not institutionalized. Disability is measured by the development of basic activities of daily life (ADL), and instrumental activities of daily life (IADL). The structural aspects of the social relationships are measured through the diversity of social networks and participation. We used the social network index (SNI). For each point over the SNI, the risk of developing any type of disability decreased by 49% (HR=0.51, 95%CI=0.31-0.82). The SNI was a decisive factor in all forecasting models constructed with some hazard ratios (HR) that ranged from 0.29 (95%CI=0.14-0.59) in the first model to 0.43 (95%CI 0.20-0.90) in the full model. The results of the present study showed a strong association between an active social life, emotional support provided by friends and confidents and disability. These findings suggest a protective effect of social networks on disability. Also, these results indicate that some family and emotional ties have a significant effect on both the prevalence and the incidence of disability. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  15. A cost-effective measurement-device-independent quantum key distribution system for quantum networks

    Science.gov (United States)

    Valivarthi, Raju; Zhou, Qiang; John, Caleb; Marsili, Francesco; Verma, Varun B.; Shaw, Matthew D.; Nam, Sae Woo; Oblak, Daniel; Tittel, Wolfgang

    2017-12-01

    We experimentally realize a measurement-device-independent quantum key distribution (MDI-QKD) system. It is based on cost-effective and commercially available hardware such as distributed feedback lasers and field-programmable gate arrays that enable time-bin qubit preparation and time-tagging, and active feedback systems that allow for compensation of time-varying properties of photons after transmission through deployed fiber. We examine the performance of our system, and conclude that its design does not compromise performance. Our demonstration paves the way for MDI-QKD-based quantum networks in star-type topology that extend over more than 100 km distance.

  16. Lag synchronization of unknown chaotic delayed Yang-Yang-type fuzzy neural networks with noise perturbation based on adaptive control and parameter identification.

    Science.gov (United States)

    Xia, Yonghui; Yang, Zijiang; Han, Maoan

    2009-07-01

    This paper considers the lag synchronization (LS) issue of unknown coupled chaotic delayed Yang-Yang-type fuzzy neural networks (YYFCNN) with noise perturbation. Separate research work has been published on the stability of fuzzy neural network and LS issue of unknown coupled chaotic neural networks, as well as its application in secure communication. However, there have not been any studies that integrate the two. Motivated by the achievements from both fields, we explored the benefits of integrating fuzzy logic theories into the study of LS problems and applied the findings to secure communication. Based on adaptive feedback control techniques and suitable parameter identification, several sufficient conditions are developed to guarantee the LS of coupled chaotic delayed YYFCNN with or without noise perturbation. The problem studied in this paper is more general in many aspects. Various problems studied extensively in the literature can be treated as special cases of the findings of this paper, such as complete synchronization (CS), effect of fuzzy logic, and noise perturbation. This paper presents an illustrative example and uses simulated results of this example to show the feasibility and effectiveness of the proposed adaptive scheme. This research also demonstrates the effectiveness of application of the proposed adaptive feedback scheme in secure communication by comparing chaotic masking with fuzziness with some previous studies. Chaotic signal with fuzziness is more complex, which makes unmasking more difficult due to the added fuzzy logic.

  17. Scattering Analysis of a Compact Dipole Array with Series and Parallel Feed Network including Mutual Coupling Effect

    Directory of Open Access Journals (Sweden)

    H. L. Sneha

    2013-01-01

    Full Text Available The current focus in defense arena is towards the stealth technology with an emphasis to control the radar cross-section (RCS. The scattering from the antennas mounted over the platform is of prime importance especially for a low-observable aerospace vehicle. This paper presents the analysis of the scattering cross section of a uniformly spaced linear dipole array. Two types of feed networks, that is, series and parallel feed networks, are considered. The total RCS of phased array with either kind of feed network is obtained by following the signal as it enters through the aperture and travels through the feed network. The RCS estimation of array is done including the mutual coupling effect between the dipole elements in three configurations, that is, side-by-side, collinear, and parallel-in-echelon. The results presented can be useful while designing a phased array with optimum performance towards low observability.

  18. USING BAYESIAN NETWORKS TO UNDERSTAND RELATIONSHIPS AMONG MATH ANXIETY, GENDERS, PERSONALITY TYPES, AND STUDY HABITS AT A UNIVERSITY IN JORDAN

    Directory of Open Access Journals (Sweden)

    Linda Smail

    2016-12-01

    Full Text Available Mathematics is the foundation of all sciences, but most students have problems learning math. Although students’ success in life related to their success in learning, many would not take a math course unless it is their university’s core requirements. Multiple reasons exist for students’ poor performance in mathematics, but one prevalent variable worth consideration is the personality type. This work seeks to uncover relationships, if any, between students’ math anxiety and the students’ learning type in learning math and preparing for exams and tests. We use Bayesian networks to link those different variables and detect possible relationships among these variables. The data was obtained from population of 468 students during spring in 2009 at a U.S. institution in Jordan. Not many researches have been performed in the area of math study and personality types so we undertook this study to add to this area of knowledge. The study reveals that math anxiety related to gender, personality type, and study habits among this group of university students. Keywords: Mathematics Anxiety, MBTI, Personality Types, Bayesian Networks DOI: http://dx.doi.org/10.22342/jme.8.1.3405.17-34

  19. The Effects of Electronic Glossing Types on Foreign Language Vocabulary Learning: Different Types of Format and Glossary Information

    National Research Council Canada - National Science Library

    Lee, Hansol; Lee, Jang Ho

    2015-01-01

    This study investigated the effects of three different types of electronic textual glosses, tooltip-type glossing, frame-type glossing, and concordance glossing on foreign language vocabulary learning...

  20. Effect of Transcranial Magnetic Stimulation on Neuronal Networks

    Science.gov (United States)

    Unsal, Ahmet; Hadimani, Ravi; Jiles, David

    2013-03-01

    The human brain contains around 100 billion nerve cells controlling our day to day activities. Consequently, brain disorders often result in impairments such as paralysis, loss of coordination and seizure. It has been said that 1 in 5 Americans suffer some diagnosable mental disorder. There is an urgent need to understand the disorders, prevent them and if possible, develop permanent cure for them. As a result, a significant amount of research activities is being directed towards brain research. Transcranial Magnetic Stimulation (TMS) is a promising tool for diagnosing and treating brain disorders. It is a non-invasive treatment method that produces a current flow in the brain which excites the neurons. Even though TMS has been verified to have advantageous effects on various brain related disorders, there have not been enough studies on the impact of TMS on cells. In this study, we are investigating the electrophysiological effects of TMS on one dimensional neuronal culture grown in a circular pathway. Electrical currents are produced on the neuronal networks depending on the directionality of the applied field. This aids in understanding how neuronal networks react under TMS treatment.

  1. 29 CFR 779.329 - Effect of type of customer and type of goods or services.

    Science.gov (United States)

    2010-07-01

    ... FAIR LABOR STANDARDS ACT AS APPLIED TO RETAILERS OF GOODS OR SERVICES Exemptions for Certain Retail or Service Establishments ârecognizedâ As Retail âin the Particular Industryâ § 779.329 Effect of type of... as retail in the particular industry. In other industries a sale or service may be recognized as...

  2. 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...

  3. A General Model for Representing Arbitrary Unsymmetries in Various Types of Network Analysis

    DEFF Research Database (Denmark)

    Rønne-Hansen, Jan

    1997-01-01

    When dealing with unsymmetric faults various proposals have been put forward. In general they have been characterized by specific treatment of the single fault in accordance with the structure and impedances involved. The model presented is based on node equations and was originally developed...... for transient stability studies in order to allow for an arbitrary fault representation as seen from the positive sequence network. The method results in impedances -or admittances-combining the negative sequence and zero sequence representation for the symmetrical network with the structure and electrical...... constants of the unsymmetry involving one or more buses. These impedances are introduced in the positive sequence network in the nodes involved in the unsymmetrical conditions. In addition the model can be used for static fault current analysis and presents also in this connection a general method...

  4. A Bayesian Network View on Nested Effects Models

    Directory of Open Access Journals (Sweden)

    Achim Tresch

    2009-01-01

    Full Text Available Nested effects models (NEMs are a class of probabilistic models that were designed to reconstruct a hidden signalling structure from a large set of observable effects caused by active interventions into the signalling pathway. We give a more flexible formulation of NEMs in the language of Bayesian networks. Our framework constitutes a natural generalization of the original NEM model, since it explicitly states the assumptions that are tacitly underlying the original version. Our approach gives rise to new learning methods for NEMs, which have been implemented in the R/Bioconductor package nem. We validate these methods in a simulation study and apply them to a synthetic lethality dataset in yeast.

  5. The Effect of Type-1 Error on Deterrence

    DEFF Research Database (Denmark)

    Lando, Henrik; Mungan, Murat C.

    A traditional view of law and economics holds that an increase in the probability with which a court will convict an innocent defendant (type-1 error) lowers deterrence as much as an increase in the probability with which the court will acquit a guilty defendant (type-2 error). We demonstrate...... when he acts lawfully; there can e.g. then be no adjudication and hence no type-1 error when the sanction is harm-based and when the lawful act precludes harm. For mistake of identity, the potential offender may be falsely convicted of a crime committed by someone else whether or not he himself acts...... lawfully, and hence such type-1 error does not exert any direct effect on deterrence. Moreover, any indirect effect on deterrence is likely to be small because when the potential offender abides by the law, his risk of being subject to adjudication is generally shared with many other innocent people....

  6. Noise Sources, Effects and Countermeasures in Narrowband Power-Line Communications Networks: A Practical Approach

    Directory of Open Access Journals (Sweden)

    Gregorio López

    2017-08-01

    Full Text Available The integration of Distributed Generation, Electric Vehicles, and storage without compromising the quality of the power delivery requires the deployment of a communications overlay that allows monitoring and controlling low voltage networks in almost real time. Power Line Communications are gaining momentum for this purpose since they present a great trade-off between economic and technical features. However, the power lines also represent a harsh communications medium which presents different problems such as noise, which is indeed affected by Distributed Generation, Electric Vehicles, and storage. This paper provides a comprehensive overview of the types of noise that affects Narrowband Power Line Communications, including normative noises, noises coming from common electronic devices measured in actual operational power distribution networks, and noises coming from photovoltaic inverters and electric vehicle charging spots measured in a controlled environment. The paper also reviews several techniques to mitigate the effects of noise, paying special attention to passive filtering, as for being one of the most widely used solution to avoid this kind of problems in the field. In addition, the paper presents a set of tests carried out to evaluate the impact of some representative noises on Narrowband Power Line Communications network performance, as well as the effectiveness of different passive filter configurations to mitigate such an impact. In addition, the considered sources of noise can also bring value to further improve PLC communications in the new scenarios of the Smart Grid as an input to theoretical models or simulations.

  7. Modified AC Wheatstone Bridge Network for Accurate Measurement of Pressure Using Strain Gauge Type Pressure Sensor

    Directory of Open Access Journals (Sweden)

    Subrata CHATTOPADHYAY

    2012-01-01

    Full Text Available In order to achieve high quality of products at lesser cost, accurate measurement of different process variables is of vital importance in any industry. There are different well-established techniques of measurement and control instrumentations of these variables. In the resistive transducer like strain gauge, the small resistance generally changes linearly with a process variable like pressure but their measurement by usual AC Wheatstone bridge circuit may suffer from errors due to the effect of stray capacitance between bridge nodal points and ground and stray inductance on the strain gauge grid respectively. Though the conventional Wagner-Earth technique may be used to reduced the error but not suitable for continuous measurement. In the present paper, a modified operational amplifier based AC Wheatstone bridge measurement technique has been proposed in which the effect of stray capacitance and inductance is minimized. This bridge performance has been studied experimentally with the strain gauge type pressure transducer. The linear characteristics over a wide range of pressure with good repeatability, linearity and variable sensitivity have been described.

  8. An on-chip cardiomyocyte cell network assay for stable drug screening regarding community effect of cell network size.

    Science.gov (United States)

    Kaneko, Tomoyuki; Kojima, Kensuke; Yasuda, Kenji

    2007-09-01

    We investigate the effect of haloperidol on a four-cell and nine-cell cardiomyocyte network on an agarose microchamber array chip to evaluate a cell-based model for drug screening. Using a network of cardiomyocytes whose beating intervals were stable and relatively uniform (they only fluctuated 10% from the mean beating interval), we easily observed the effect of haloperidol on the cell network beating interval 5 min after administering it. We also observed the beating interval returned to its original state 10 min after the haloperidol was washed out of the chip. Although the four-cell network showed the unstable recovery of its beating rhythm after washout of haloperidol, the nine-cell network recovered completely to the stable original beating rhythm even after a second administration of haloperidol. The results indicate the importance of the community size in cell networks used in the stable cell-based screening model. Moreover, they indicate the advantage of using direct cell-based measurements in which the amount of drug administered and the time course over which it is administered are strictly controlled for evaluating the quantitative chemical effects of drugs on cells.

  9. Resting-state functional magnetic resonance imaging shows altered brain network topology in Type 2 diabetic patients without cognitive impairment.

    Science.gov (United States)

    Chen, Guan-Qun; Zhang, Xin; Xing, Yue; Wen, Dong; Cui, Guang-Bin; Han, Ying

    2017-11-28

    We analyzed topology of brain functional networks in type 2 diabetes mellitus (T2DM) patients without mild cognitive impairment. We recruited T2DM patients without mild cognitive impairment (4 males and 8 females) and healthy control subjects (8 males and 16 females) to undergo cognitive testing and resting-state functional magnetic resonance imaging. Graph theoretical analysis of functional brain networks revealed abnormal small-world architecture in T2DM patients as compared to control subjects. The functional brain networks of T2DM patients showed increased path length, decreased global efficiency and disrupted long-distance connections. Moreover, reduced nodal characteristics were distributed in the frontal, parietal and temporal lobes, while increased nodal characteristics were distributed in the frontal, occipital lobes, and basal ganglia in the T2DM patients. The disrupted topological properties correlated with cognitive performance of T2DM patients. These findings demonstrate altered topological organization of functional brain networks in T2DM patients without mild cognitive impairment.

  10. Clay mineral type effect on bacterial enteropathogen survival in soil.

    Science.gov (United States)

    Brennan, Fiona P; Moynihan, Emma; Griffiths, Bryan S; Hillier, Stephen; Owen, Jason; Pendlowski, Helen; Avery, Lisa M

    2014-01-15

    Enteropathogens released into the environment can represent a serious risk to public health. Soil clay content has long been known to have an important effect on enteropathogen survival in soil, generally enhancing survival. However, clay mineral composition in soils varies, and different clay minerals have specific physiochemical properties that would be expected to impact differentially on survival. This work investigated the effect of clay materials, with a predominance of a particular mineral type (montmorillonite, kaolinite, or illite), on the survival in soil microcosms over 96 days of Listeria monocytogenes, Salmonella Dublin, and Escherichia coli O157. Clay mineral addition was found to alter a number of physicochemical parameters in soil, including cation exchange capacity and surface area, and this was specific to the mineral type. Clay mineral addition enhanced enteropathogen survival in soil. The type of clay mineral was found to differentially affect enteropathogen survival and the effect was enteropathogen-specific. © 2013.

  11. Substituted Polyacetylenes Prepared with Rh Catalysts: From Linear to Network-Type Conjugated Polymers

    Czech Academy of Sciences Publication Activity Database

    Sedláček, J.; Balcar, Hynek

    2017-01-01

    Roč. 57, č. 1 (2017), s. 31-51 ISSN 1558-3724 Institutional support: RVO:61388955 Keywords : conjugated polymers * polyacetylenes * conjugated polymer networks Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 6.459, year: 2016

  12. The effect of mobility on local service discovery in the Ahoy ad-hoc network system

    NARCIS (Netherlands)

    Goering, P.T.H.; Heijenk, Geert; Haverkort, Boudewijn R.H.M.; Haarman, Robbert

    2007-01-01

    Ahoy, a protocol to perform local service discovery in ad-hoc networks is described in this paper. The protocol has been implemented in a discreteevent simulator to study its performance in case of a multihop mobile ad-hoc network. Especially the effect of mobility on the network load and the

  13. The Effect of Teachers' Social Networks on Teaching Practices and Class Composition

    Science.gov (United States)

    Kim, Chong Min

    2011-01-01

    Central to this dissertation was an examination of the role teachers' social networks play in schools as living organizations through three studies. The first study investigated the impact of teachers' social networks on teaching practices. Recent evidence suggests that teachers' social networks have a significant effect on teachers' norms,…

  14. A comparison of two types of neural network for weld quality prediction in small scale resistance spot welding

    Science.gov (United States)

    Wan, Xiaodong; Wang, Yuanxun; Zhao, Dawei; Huang, YongAn

    2017-09-01

    Our study aims at developing an effective quality monitoring system in small scale resistance spot welding of titanium alloy. The measured electrical signals were interpreted in combination with the nugget development. Features were extracted from the dynamic resistance and electrode voltage curve. A higher welding current generally indicated a lower overall dynamic resistance level. A larger electrode voltage peak and higher change rate of electrode voltage could be detected under a smaller electrode force or higher welding current condition. Variation of the extracted features and weld quality was found more sensitive to the change of welding current than electrode force. Different neural network model were proposed for weld quality prediction. The back propagation neural network was more proper in failure load estimation. The probabilistic neural network model was more appropriate to be applied in quality level classification. A real-time and on-line weld quality monitoring system may be developed by taking advantages of both methods.

  15. Effect of Amphiphiles on the Rheology of Triglyceride Networks

    Science.gov (United States)

    Seth, Jyoti

    2014-11-01

    Networks of aggregated crystallites form the structural backbone of many products from the food, cosmetic and pharmaceutical industries. Such materials are generally formulated by cooling a saturated solution to yield the desired solid fraction. Crystal nucleation and growth followed by aggregation leads to formation of a space percolating fractal-network. It is understood that microstructural hierarchy and particle-particle interactions determine material behavior during processing, storage and use. In this talk, rheology of suspensions of triglycerides (TAG, like tristearin) will be explored. TAGs exhibit a rich assortment of polymorphs and form suspensions that are evidently sensitive to surface modifying additives like surfactants and polymers. Here, a theoretical framework will be presented for suspensions containing TAG crystals interacting via pairwise potentials. The work builds on existing models of fractal aggregates to understand microstructure and its correlation with material rheology. Effect of amphiphilic additives is derived through variation of particle-particle interactions. Theoretical predictions for storage modulus will be compared against experimental observations and data from the literature and micro structural predictions against microscopy. Such a theory may serve as a step towards predicting short and long-term behavior of aggregated suspensions formulated via crystallization.

  16. Gait features analysis using artificial neural networks - testing the footwear effect.

    Science.gov (United States)

    Wang, Jikun; Zielińska, Teresa

    2017-01-01

    The aim of this paper is to provide the methods for automatic detection of the difference in gait features depending on a footwear. Artificial neural networks were applied in the study. The gait data were recorded during the walk with different footwear for testing and validation of the proposed method. The gait properties were analyzed considering EMG (electromyography) signals and using two types of artificial neural networks: the learning vector quantization (LVQ) classifying network, and the clustering competitive network. Obtained classification and clustering results were discussed. For comparative studies, velocities of the leg joint trajectories, and accelerations were used. The features indicated by neural networks were compared with the conclusions formulated analyzing the above mentioned trajectories for ankle and knee joints. The matching between experimentally recorded joint trajectories and the results given by neural networks was studied. It was indicated what muscles are most influenced by the footwear, the relation between the footwear type and the muscles work was concluded.

  17. Towards effective visual analytics on multiplex and multilayer networks

    DEFF Research Database (Denmark)

    Rossi, Luca; Magnani, Matteo

    2015-01-01

    In this article we discuss visualisation strategies for multiplex networks. Since Moreno’s early works on network analysis, visualisation has been one of the main ways to understand networks thanks to its ability to summarise a complex structure into a single representation highlighting multiple ...

  18. modeling the effect of bandwidth allocation on network performance

    African Journals Online (AJOL)

    Keywords: Coverage capacity, CDMA, mobile network, network throughput. INTRODUCTION. Wireless network is one of the rapidly growing aspects in today's communication technology. Advances in interactive multimedia applications such as audio phone, movie/video on demand, video conferencing, video gaming, etc., ...

  19. Choice Of Computer Networking Cables And Their Effect On Data ...

    African Journals Online (AJOL)

    Computer networking is the order of the day in this Information and Communication Technology (ICT) age. Although a network can be through a wireless device most local connections are done using cables. There are three main computer-networking cables namely coaxial cable, unshielded twisted pair cable and the optic ...

  20. MERLiN: Mixture Effect Recovery in Linear Networks

    Science.gov (United States)

    Weichwald, Sebastian; Grosse-Wentrup, Moritz; Gretton, Arthur

    2016-10-01

    Causal inference concerns the identification of cause-effect relationships between variables, e.g. establishing whether a stimulus affects activity in a certain brain region. The observed variables themselves often do not constitute meaningful causal variables, however, and linear combinations need to be considered. In electroencephalographic studies, for example, one is not interested in establishing cause-effect relationships between electrode signals (the observed variables), but rather between cortical signals (the causal variables) which can be recovered as linear combinations of electrode signals. We introduce MERLiN (Mixture Effect Recovery in Linear Networks), a family of causal inference algorithms that implement a novel means of constructing causal variables from non-causal variables. We demonstrate through application to EEG data how the basic MERLiN algorithm can be extended for application to different (neuroimaging) data modalities. Given an observed linear mixture, the algorithms can recover a causal variable that is a linear effect of another given variable. That is, MERLiN allows us to recover a cortical signal that is affected by activity in a certain brain region, while not being a direct effect of the stimulus. The Python/Matlab implementation for all presented algorithms is available on https://github.com/sweichwald/MERLiN

  1. Effective seeding strategy in evolutionary prisoner's dilemma games on online social networks

    Science.gov (United States)

    Xu, Bo; Shi, Huibin; Wang, Jianwei; Huang, Yun

    2015-04-01

    This paper explores effective seeding strategies in prisoner's dilemma game (PDG) on online social networks, i.e. the optimal strategy to obtain global cooperation with minimum cost. Three distinct seeding strategies are compared by performing computer simulations on real online social network datasets. Our finding suggests that degree centrality seeding outperforms other strategies regardless of the initial payoff setting or network size. Celebrities of online social networks play key roles in preserving cooperation.

  2. Power, Status and Network Perceptions: The Effects of Network Bias on Organizational Outcomes

    Science.gov (United States)

    2012-09-01

    to have achieved. Extending social comparison theory ( Festinger 1954) and cognitive network comparison research (e.g., Burt 1982) to this case, we...Faust, K. 2007. Very local structure in social networks. Sociological Methodology. 37 209-256. Festinger , L. 1954. A theory of social comparison

  3. Scale effects of nitrate sinks and sources in stream networks

    Science.gov (United States)

    Schuetz, Tobias; Weiler, Markus; Gascuel-Odoux, Chantal

    2014-05-01

    Increasing N-fertilizer applications in agricultural catchments are considered as one of the major sources for dissolved nitrate-nitrogen (NO3-N) in surface water. While NO3-N mobilization pathways depend on catchment's pedological and hydrogeological characteristics and its runoff generation processes, in-stream retention and removal processes depend on local/reach-scale conditions such as weather, discharge, channel morphology, vegetation, shading or hyporheic exchange and others. However, knowledge is still limited to scale up locally observable retention and removal processes to larger stream networks to understand the spatial and temporal dynamics of in-stream NO3-N concentrations. Relevant processes to consider explicitly are the effects of 'hot spots', dominant NO3-N sources (e.g. sub-catchments, 'critical source areas') or specific NO3-N sinks (e.g. riparian wetlands and stream reaches with high biogeochemical activity). We studied these processes in a 1.7 km2 agricultural headwater catchment, where distinct locations of groundwater inflow (a dense artificial drainage network) and a predominantly impervious streambed allowed separating mixing and dilution processes as well as in-stream retention and removal processes. During two summer seasons we conducted a set (25) of stream network wide (stream water and drainage water) synoptic sampling campaigns including climate parameters, discharge, channel geomorphology, vegetation, stream water chemistry and physical water parameters (dissolved oxygen concentration, water temperatures, electrical conductivity, pH). Analyzing these data sets we were able to determine a) time variant NO3-N concentrations and loads for all sub-catchments (sources), b) time variant in-stream removal rates for all stream reaches (sinks) and c) the hierarchical order of all contributing NO3-N sinks and sources and their time variant influence on total NO3-N export. Climate parameters, discharge, channel geomorphology, vegetation, stream

  4. Antimicrobial effect of different types of honey on Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Saad B. Almasaudi

    2017-09-01

    Full Text Available Honey exhibits antimicrobial activities against a wide range of bacteria in different milieu. This study aims to compare the effects of five types of honey (both imported and local Saudi honey against Staphylococcus aureus. The five types of honey (Manuka Honey UMF +20, Manuka Honey UMF +16, Active +10 Manuka Honey, Sidr honey and Nigella sativa honey were evaluated for their bactericidal/bacteriostatic activities against both methicillin resistant and sensitive S. aureus. The inhibitory effect of honey on bacterial growth was evident at concentrations of 20% and 10% (v/v. Manuka Honey showed the best results. Manuka Honey UMF +20 had a bactericidal effect on both methicillin resistant and sensitive S. aureus. However, Sidr and N. sativa honey exerted only a bacteriostatic effect. The efficacy of different types of honey against S. aureus was dependent on the type of honey and the concentration at which it was administered. Manuka Honey had the best bactericidal activity. Future experiments should be conducted to evaluate the effects of honey on bacterial resistance.

  5. Mechanisms of self-sustained oscillatory states in hierarchical modular networks with mixtures of electrophysiological cell types

    Directory of Open Access Journals (Sweden)

    Petar eTomov

    2016-03-01

    Full Text Available In a network with a mixture of different electrophysiologicaltypes of neurons linked by excitatory and inhibitory connections,temporal evolution leads through repeated epochs of intensive global activity separated by intervals with low activity level. This behavior mimics ``up'' and ``down'' states, experimentally observed in cortical tissues in absence of external stimuli. We interpret global dynamical features interms of individual dynamics of the neurons. In particular, weobserve that the crucial role both in interruption and in resumptionof global activity is played by distributions of the membrane recovery variable within the network. We also demonstrate that the behavior of neurons is moreinfluenced by their presynaptic environment in the networkthan by their formal types,assigned in accordance with their response to constant current.

  6. Log-periodic oscillations due to discrete effects in complex networks

    Science.gov (United States)

    Sienkiewicz, Julian; Fronczak, Piotr; Hołyst, Janusz A.

    2007-06-01

    We show how discretization affects two major characteristics in complex networks: internode distances (measured as the shortest number of edges between network sites) and average path length, and as a result there are log-periodic oscillations of the above quantities. The effect occurs both in numerical network models as well as in such real systems as coauthorship, language, food, and public transport networks. Analytical description of these oscillations fits well numerical simulations. We consider a simple case of the network optimization problem, arguing that discrete effects can lead to a nontrivial solution.

  7. An effective convolutional neural network model for Chinese sentiment analysis

    Science.gov (United States)

    Zhang, Yu; Chen, Mengdong; Liu, Lianzhong; Wang, Yadong

    2017-06-01

    Nowadays microblog is getting more and more popular. People are increasingly accustomed to expressing their opinions on Twitter, Facebook and Sina Weibo. Sentiment analysis of microblog has received significant attention, both in academia and in industry. So far, Chinese microblog exploration still needs lots of further work. In recent years CNN has also been used to deal with NLP tasks, and already achieved good results. However, these methods ignore the effective use of a large number of existing sentimental resources. For this purpose, we propose a Lexicon-based Sentiment Convolutional Neural Networks (LSCNN) model focus on Weibo's sentiment analysis, which combines two CNNs, trained individually base on sentiment features and word embedding, at the fully connected hidden layer. The experimental results show that our model outperforms the CNN model only with word embedding features on microblog sentiment analysis task.

  8. Cell-type-specific predictive network yields novel insights into mouse embryonic stem cell self-renewal and cell fate.

    Directory of Open Access Journals (Sweden)

    Karen G Dowell

    Full Text Available Self-renewal, the ability of a stem cell to divide repeatedly while maintaining an undifferentiated state, is a defining characteristic of all stem cells. Here, we clarify the molecular foundations of mouse embryonic stem cell (mESC self-renewal by applying a proven Bayesian network machine learning approach to integrate high-throughput data for protein function discovery. By focusing on a single stem-cell system, at a specific developmental stage, within the context of well-defined biological processes known to be active in that cell type, we produce a consensus predictive network that reflects biological reality more closely than those made by prior efforts using more generalized, context-independent methods. In addition, we show how machine learning efforts may be misled if the tissue specific role of mammalian proteins is not defined in the training set and circumscribed in the evidential data. For this study, we assembled an extensive compendium of mESC data: ∼2.2 million data points, collected from 60 different studies, under 992 conditions. We then integrated these data into a consensus mESC functional relationship network focused on biological processes associated with embryonic stem cell self-renewal and cell fate determination. Computational evaluations, literature validation, and analyses of predicted functional linkages show that our results are highly accurate and biologically relevant. Our mESC network predicts many novel players involved in self-renewal and serves as the foundation for future pluripotent stem cell studies. This network can be used by stem cell researchers (at http://StemSight.org to explore hypotheses about gene function in the context of self-renewal and to prioritize genes of interest for experimental validation.

  9. Cell-type-specific predictive network yields novel insights into mouse embryonic stem cell self-renewal and cell fate.

    Science.gov (United States)

    Dowell, Karen G; Simons, Allen K; Wang, Zack Z; Yun, Kyuson; Hibbs, Matthew A

    2013-01-01

    Self-renewal, the ability of a stem cell to divide repeatedly while maintaining an undifferentiated state, is a defining characteristic of all stem cells. Here, we clarify the molecular foundations of mouse embryonic stem cell (mESC) self-renewal by applying a proven Bayesian network machine learning approach to integrate high-throughput data for protein function discovery. By focusing on a single stem-cell system, at a specific developmental stage, within the context of well-defined biological processes known to be active in that cell type, we produce a consensus predictive network that reflects biological reality more closely than those made by prior efforts using more generalized, context-independent methods. In addition, we show how machine learning efforts may be misled if the tissue specific role of mammalian proteins is not defined in the training set and circumscribed in the evidential data. For this study, we assembled an extensive compendium of mESC data: ∼2.2 million data points, collected from 60 different studies, under 992 conditions. We then integrated these data into a consensus mESC functional relationship network focused on biological processes associated with embryonic stem cell self-renewal and cell fate determination. Computational evaluations, literature validation, and analyses of predicted functional linkages show that our results are highly accurate and biologically relevant. Our mESC network predicts many novel players involved in self-renewal and serves as the foundation for future pluripotent stem cell studies. This network can be used by stem cell researchers (at http://StemSight.org) to explore hypotheses about gene function in the context of self-renewal and to prioritize genes of interest for experimental validation.

  10. Strategies to Make Ramadan Fasting Safer in Type 2 Diabetics: A Systematic Review and Network Meta-analysis of Randomized Controlled Trials and Observational Studies.

    Science.gov (United States)

    Lee, Shaun Wen Huey; Lee, Jun Yang; Tan, Christina San San; Wong, Chee Piau

    2016-01-01

    Ramadan is the holy month for Muslims whereby they fast from predawn to after sunset and is observed by all healthy Muslim adults as well as a large population of type 2 diabetic Muslims.To determine the comparative effectiveness of various strategies that have been used for type 2 diabetic Muslim who fast during Ramadan.A systematic review and network meta-analysis of randomized controlled studies (RCT) as well as observational studies for patients with type 2 diabetes who fasted during Ramadan was conducted. Eight databases were searched from January 1980 through October 2015 for relevant studies. Two reviewers independently screened and assessed study for eligibility, assessed the risk of bias, and extracted relevant data. A network meta-analysis for each outcome was fitted separately, combining direct and indirect evidence for each comparison.Twenty-nine studies, 16 RCTs and 13 observational studies each met the inclusion criteria. The most common strategy used was drug changes during the Ramadan period, which found that the use of DPP-4 (Dipeptidyl peptidase inhibitor -4) inhibitors were associated with a reduction in incidence of experiencing hypoglycemia during Ramadan in both RCTs (pooled relative risk: 0.56; 95% confidence interval: 0.44-0.72) as well as in observational studies (pooled relative risk: 0.27; 0.09-0.75). Ramadan-focused education was shown to be beneficial in reducing hypoglycemia in observational studies but not RCTs (0.25 versus 1.00). Network meta-analyses suggest that incretin mimetics can reduce the risk of hypoglycemia by nearly 1.5 times.The newer antidiabetic agents appear to lower the risk of hypoglycemia and improved glycemic control when compared with sulfonylureas. Ramadan-focused education shows to be a promising strategy but more rigorous examination from RCTs are required.

  11. Complex Network Analysis of Resting State EEG in Amnestic Mild Cognitive Impairment Patients with Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Ke eZeng

    2015-10-01

    Full Text Available Purpose: Diabetes is a great risk factor for dementia and mild cognitive impairment. This study inves-tigates whether complex network-derived features in resting state EEG (rsEEG could be applied as a biomarker to distinguish amnestic mild cognitive impairment (aMCI from normal cognitive function in subjects with type 2 diabetes. Method: In this study, EEG was recorded in 28 patients with type 2 diabetes (16 aMCI patients and 12 controls during a no-task eyes-closed resting state. Pair-wise synchronization of rsEEG signals were assessed in six frequency bands (delta, theta, lower alpha, upper alpha, beta, and gamma using phase lag index (PLI and grouped into long distance (intra- and inter-hemispheric and short distance inter-actions. PLI-weighted connectivity networks were also constructed, and characterized by mean clus-tering coefficient and path length. The correlation of these features and Montreal Cognitive Assess-ment (MoCA scores was assessed.Results: Main findings of this study were as follows: (1 In comparison with controls, patients with aMCI had a significant decrease of global mean PLI in lower alpha, upper alpha, and beta bands. Lower functional connection at short and long intra-hemispheric distance mainly appeared on the left hemisphere. (2 In the lower alpha band, clustering coefficient was significantly lower in aMCI group, and the path length significantly increased. (3 Cognitive status measured by MoCA had a significant positive correlation with cluster coefficient and negative correlation with path length in lower alpha band. Conclusions: The brain network of aMCI patients displayed a disconnection syndrome and a loss of small-world architecture. The correlation between cognitive states and network characteristics sug-gested that the more in deterioration of the diabetes patients’ cognitive state, the less optimal the net-work organization become. Hence, the complex network-derived biomarkers based on EEG could be employed

  12. Determination of type and concentration of DNA nitrogenous bases by Raman spectroscopy using artificial neural networks

    Science.gov (United States)

    Laptinskiy, Kirill A.; Burikov, Sergey A.; Sarmanova, Olga E.; Dolenko, Sergey A.; Dolenko, Tatiana A.

    2016-04-01

    In this article the results of solution of two-parametrical inverse problems of laser Raman spectroscopy of identification and determination of concentration of DNA nitrogenous bases in two-component solutions are presented. Elaboration of methods of control of reactions with DNA strands in remote real-time mode is necessary for solution of one of the basic problems of creation of biocomputers - increase of reliability of molecular DNA-computations. The comparative analysis of two used methods of solution of stated problems has demonstrated convincing advantages of technique of artificial neural networks. Use of artificial neural networks allowed to reach the accuracy of determination of concentration of each base in two-component solutions 0.2-0.3 g/l.

  13. The effect of sentencing types on singlehood and relationship dissolution

    DEFF Research Database (Denmark)

    Fallesen, Peter; Andersen, Lars Højsgaard

    Prior research shows that imprisonment may matter for the risk of experiencing divorce or other types of relationship dissolution, as imprisonment implies separation and the social stigma of criminal conviction. Despite these straightforward theoretical mechanisms, we currently lack empirical...... knowledge on the causal effect of sentencing types on relationship dissolution. This study fills this gap in the literature by examining how a noncustodial alternatives to imprisonment—electronic monitoring—affects the risk of relationship dissolution in Denmark. While imprisonment might disrupt contacts...... between spouses or partners, and restrains single convicted men from interacted with other for significant periods, electronic monitoring allows felons to serve time without severing ties to their partner and community. To obtain uncontaminated estimates of the effect of sentencing types on relationship...

  14. Beware of Selfies: The Impact of Photo Type on Impression Formation Based on Social Networking Profiles

    OpenAIRE

    Krämer, Nicole C.; Feurstein, Markus; Kluck, Jan P.; Meier, Yannic; Rother, Marius; Winter, Stephan

    2017-01-01

    Users of social networking sites such as Facebook frequently post self-portraits on their profiles. While research has begun to analyze the motivations for posting such pictures, less is known about how selfies are evaluated by recipients. Although producers of selfies typically aim to create a positive impression, selfies may also be regarded as narcissistic and therefore fail to achieve the intended goal. The aim of this study is to examine the potentially ambivalent reception of selfies co...

  15. Distinct functional connectivity of limbic network in the washing type obsessive-compulsive disorder.

    Science.gov (United States)

    Jhung, Kyungun; Ku, Jeonghun; Kim, Se Joo; Lee, Hyeongrae; Kim, Kyung Ran; An, Suk Kyoon; Kim, Sun I; Yoon, Kang-Jun; Lee, Eun

    2014-08-04

    Neurobiological models of obsessive-compulsive disorder (OCD) emphasize disturbances of the corticostriatal circuit, but it remains unclear as to how these complex network dysfunctions correspond to heterogeneous OCD phenotypes. We aimed to investigate corticostriatal functional connectivity alterations distinct to OCD characterized predominantly by contamination/washing symptoms. Functional connectivity strengths of the striatal seed regions with remaining brain regions during the resting condition and the contamination symptom provocation condition were compared among 13 OCD patients with predominant contamination/washing symptoms (CON), 13 OCD patients without these symptoms (NCON), and 18 healthy controls. The CON group showed distinctively altered functional connectivity between the ventral striatum and the insula during both the resting and symptom-provoking conditions. Also, the connectivity strength between the ventral striatum and the insula significantly correlated with contamination/washing symptom severity. As common connectivity alterations of the whole OCD subjects, corticostriatal circuits involving the orbitofrontal and temporal cortices were again confirmed. To our knowledge, this is the first study that examined specific abnormalities in functional connectivity of contamination/washing symptom dimension OCD. The findings suggest limbic network dysfunctions to play a pivotal role in contamination/washing symptoms, possibly associated with emotionally salient error awareness. Our study sample allowed us to evaluate the corticostriatal network dysfunction underlying the contamination/washing symptom dimension, which leaves other major symptom dimensions to be explored in the future. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Life Cycle Cost Analysis of Three Types of Power Lines in 10 kV Distribution Network

    Directory of Open Access Journals (Sweden)

    Zhenyu Zhu

    2016-10-01

    Full Text Available There are three types of power lines in the 10 kV distribution network in China, i.e., copper power cables, overhead power conductors and aluminum alloy power cables. It is necessary to give a comprehensive evaluation to choose the type of power line in some delicate practical engineering. This paper presents a life cycle cost (LCC-based analysis method for the three types of power lines. An LCC model of the power line in the 10 kV distribution network is established, which considers four parts: investment cost, operation and maintenance cost, failure cost and discard cost. A detailed calculation model for the four parts is presented, and to calculate the failure cost, the Monte Carlo algorithm is employed to simulate the values of expected energy not supplied (EENS. Two practical 10 kV power line projects in Fujian Province in China were analyzed based on the proposed LLC model and corresponding developed software, which has helped the power company select the appropriate power line successfully.

  17. The Effect of Text Types on Reading Comprehension

    Science.gov (United States)

    Sahin, Ayfer

    2013-01-01

    Aim of this study is to determine the effect of narrative and informative text types on Reading Comprehension levels of Primary Education 4th and 5th grade students. Application was fulfilled in 2011-2012 academic year with 134 students in a primary education school in Province Kirsehir. Reading comprehension tests prepared according to text types…

  18. Effects of different crop associations and fertilizer types on weed ...

    African Journals Online (AJOL)

    Experiments were conducted at the Teaching and Research Farm of the University of Ibadan in 1998/1999 and 1999/2000 cropping seasons to determine the effects of different crop associations and fertilizer types on the weed biomass. The results showed that crop associations did not significantly affect weed density and ...

  19. Effects of fertilizer types and different companion crops on the ...

    African Journals Online (AJOL)

    A field experiment was conducted in 2002 and 2003 cropping seasons, at the University of Ibadan Teaching and Research Farm to evaluate the effects of fertilizer types and different companion crops on the performance of sweet potato. The results obtained showed that the growth and yield of sweet potato were ...

  20. The effect of anesthesia type on stress hormone response ...

    African Journals Online (AJOL)

    Aim: The aim of this study was to investigate the effect of different types of anesthesia on stress hormones. Materials and Methods: The study was included 60 ASAI-II cases scheduled for major lower extremity surgery. The cases were randomized into 2 groups: The EA group was administered epidural anesthesia and the ...

  1. Effect of two types of methionine supplement on performance of ...

    African Journals Online (AJOL)

    An experiment was carried out to determine the effect of two types of synthetic methionine supplement (Dl methionine and MHA FA; Methionine Hydroxyl Analogue Free Acid, also known as Alimet) on performance of finisher broiler. Two hundred and thirty four (234) day old Hubbard Flex broilerschicks were allotted to six ...

  2. The effect of breed type and lactation status on reproductive ...

    African Journals Online (AJOL)

    p2492989

    Abstract. This study was conducted to evaluate the effect of breed types and lactation status on reproductive performance of hormonally-treated Awassi ewes. A total of 282 ewes were treated with intravaginal progestagen sponges and equine chorionic gonadotropin. Ewes were mated with fertile rams following sponge ...

  3. Modulatory effect of polymer type and composition on drug release ...

    African Journals Online (AJOL)

    The purpose of this study was to investigate the effects of polymer type and composition on drug release from the matrix of diclofenac sodium sustained release tablets formulated using three different granulation methods. Ten (10) batches of diclofenac sodium tablets (F01 - F10) were prepared by melt granulation, ...

  4. The effect of breed type and lactation status on reproductive ...

    African Journals Online (AJOL)

    This study was conducted to evaluate the effect of breed types and lactation status on reproductive performance of hormonally-treated Awassi ewes. A total of 282 ewes were treated with intravaginal progestagen sponges and equine chorionic gonadotropin. Ewes were mated with fertile rams following sponge removal.

  5. Effect of tetrahydrocurcumin on insulin receptor status in type 2 ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR G

    Effect of tetrahydrocurcumin on insulin receptor status in type 2 diabetic rats: studies on insulin binding to erythrocytes 63. J. Biosci. 33(1), March 2008. 1. Introduction. A number of recent studies have shown that human erythrocytes can be used as a cellular model for assessing the status of insulin receptors in diabetes ...

  6. The effect of breed type and lactation status on reproductive ...

    African Journals Online (AJOL)

    p2492989

    progestagen sponges and equine chorionic gonadotropin. Ewes were mated with fertile rams following sponge removal. Lambing rate was similar between brown- and ... fertility, prolificacy and milk production). For this reason, this study was conducted to evaluate the effect of breed type (black-faced vs. brown-faced Awassi ...

  7. Transcriptome atlas of eight liver cell types uncovers effects of ...

    Indian Academy of Sciences (India)

    Eight liver cell types were isolated using the methods of Percoll density gradient centrifugation and immunomagnetic beads to explore effects of histidine catabolites on rat liver regeneration. Rat Genome 230 2.0 Array was used to detect the expression profiles of genes associated with metabolism of histidine and its ...

  8. Effect of individualized diabetes education for type 2 diabetes ...

    African Journals Online (AJOL)

    Background: To evaluate the effect of individualized education for patients with type 2 diabetes mellitus (T2DM). Methods: A total of 280 patients (158 males, mean age 63 ± 10 years) with T2DM were randomly divided into study and control group. Eysenck Personality questionnaire was used to assess the personality of the ...

  9. Effect of Soil Types and Phosphorus Fertilizer Interaction on the ...

    African Journals Online (AJOL)

    A pot experiment was conducted to examine the effect of soil types and phosphorus fertilizer application on maize (variety DMR-L-SR) growth and yield in the rain forest zone of Nigeria. This was done at the Teaching and Research Farm, Ladoke Akintola University of Technology, Ogbomoso. The experimental treatments ...

  10. Microwave Faraday effect in n-type germanium

    NARCIS (Netherlands)

    Bouwknegt, A.; Volger, J.

    The Faraday rotation, ellipticity and the accompanying magneto-absorption were determined from measurements with the crossed wave guide coupler device, at room temperature, at 24.9 GHz. The complex conductivity tensor elements of n-type germanium were deduced from this complete Faraday effect, with

  11. Gastrointestinal Adverse Events of Dipeptidyl Peptidase 4 Inhibitors in Type 2 Diabetes: A Systematic Review and Network Meta-analysis.

    Science.gov (United States)

    Wu, Shanshan; Chai, Sanbao; Yang, Jun; Cai, Ting; Xu, Yang; Yang, Zhirong; Zhang, Yuan; Ji, Linong; Sun, Feng; Zhan, Siyan

    2017-09-01

    The purpose of this study was to systematically evaluate the effect of dipeptidyl peptidase 4 inhibitors on gastrointestinal adverse events in patients with type 2 diabetes. MEDLINE, Embase, the Cochrane Library, and ClinicalTrials.gov were searched from inception through April 28, 2016. Randomized controlled trials that compared dipeptidyl peptidase 4 inhibitor-based therapies with placebo and other hypoglycemic agents in type 2 diabetes were included. The duration of studies was at least 4 weeks. A total of 165 randomized controlled trials and 122,072 patients were included in the study. Dipeptidyl peptidase 4 inhibitors did not increase the incidence of gastrointestinal adverse events after the treatment with alogliptin (odds ratio [OR] = 0.83; 95% CI, 0.59-1.15), linagliptin (OR = 1.11; 95% CI, 0.92-1.35), saxagliptin (OR = 0.96; 95% CI, 0.80-1.15), sitagliptin (OR = 0.95; 95% CI, 0.64-1.14), teneligliptin (OR = 1.50; 95% CI, 0.81-2.77), and vildagliptin (OR = 0.80; 95% CI, 0.63-1.01) compared with placebo. Compared with glucagon-like peptide 1 receptor agonists, dipeptidyl peptidase 4 inhibitors significantly decreased the incidence of gastrointestinal adverse events with alogliptin (OR = 0.26; 95% CI, 0.15-0.44), linagliptin (OR = 0.43; 95% CI, 0.25-0.74), saxagliptin (OR = 0.28; 95% CI, 0.17-0.46), sitagliptin (OR = 0.24; 95% CI, 0.17-0.35), and vildagliptin (OR = 0.27; 95% CI, 0.18-0.41). Dipeptidyl peptidase 4 inhibitors were not associated with an increased risk of gastrointestinal adverse events relative to metformin and α-glucosidase inhibitors, respectively. The network meta-analysis found that compared with glucagon-like peptide 1 receptor agonists, metformin, and α-glucosidase inhibitor, dipeptidyl peptidase 4 inhibitors are associated with a lower incidence of gastrointestinal adverse events. Copyright © 2017 Elsevier HS Journals, Inc. All rights reserved.

  12. Abnormal brain activation in neurofibromatosis type 1: a link between visual processing and the default mode network.

    Directory of Open Access Journals (Sweden)

    Inês R Violante

    Full Text Available Neurofibromatosis type 1 (NF1 is one of the most common single gene disorders affecting the human nervous system with a high incidence of cognitive deficits, particularly visuospatial. Nevertheless, neurophysiological alterations in low-level visual processing that could be relevant to explain the cognitive phenotype are poorly understood. Here we used functional magnetic resonance imaging (fMRI to study early cortical visual pathways in children and adults with NF1. We employed two distinct stimulus types differing in contrast and spatial and temporal frequencies to evoke relatively different activation of the magnocellular (M and parvocellular (P pathways. Hemodynamic responses were investigated in retinotopically-defined regions V1, V2 and V3 and then over the acquired cortical volume. Relative to matched control subjects, patients with NF1 showed deficient activation of the low-level visual cortex to both stimulus types. Importantly, this finding was observed for children and adults with NF1, indicating that low-level visual processing deficits do not ameliorate with age. Moreover, only during M-biased stimulation patients with NF1 failed to deactivate or even activated anterior and posterior midline regions of the default mode network. The observation that the magnocellular visual pathway is impaired in NF1 in early visual processing and is specifically associated with a deficient deactivation of the default mode network may provide a neural explanation for high-order cognitive deficits present in NF1, particularly visuospatial and attentional. A link between magnocellular and default mode network processing may generalize to neuropsychiatric disorders where such deficits have been separately identified.

  13. Effects of traffic generation patterns on the robustness of complex networks

    Science.gov (United States)

    Wu, Jiajing; Zeng, Junwen; Chen, Zhenhao; Tse, Chi K.; Chen, Bokui

    2018-02-01

    Cascading failures in communication networks with heterogeneous node functions are studied in this paper. In such networks, the traffic dynamics are highly dependent on the traffic generation patterns which are in turn determined by the locations of the hosts. The data-packet traffic model is applied to Barabási-Albert scale-free networks to study the cascading failures in such networks and to explore the effects of traffic generation patterns on network robustness. It is found that placing the hosts at high-degree nodes in a network can make the network more robust against both intentional attacks and random failures. It is also shown that the traffic generation pattern plays an important role in network design.

  14. Measurement of company effectiveness using analytic network process method

    Directory of Open Access Journals (Sweden)

    Goran Janjić

    2017-07-01

    Full Text Available The sustainable development of an organisation is monitored through the organisation’s performance, which beforehand incorporates all stakeholders’ requirements in its strategy. The strategic management concept enables organisations to monitor and evaluate their effectiveness along with efficiency by monitoring of the implementation of set strategic goals. In the process of monitoring and measuring effectiveness, an organisation can use multiple-criteria decision-making methods as help. This study uses the method of analytic network process (ANP to define the weight factors of the mutual influences of all the important elements of an organisation’s strategy. The calculation of an organisation’s effectiveness is based on the weight factors and the degree of fulfilment of the goal values of the strategic map measures. New business conditions influence the changes in the importance of certain elements of an organisation’s business in relation to competitive advantage on the market, and on the market, increasing emphasis is given to non-material resources in the process of selection of the organisation’s most important measures.

  15. Measurement of company effectiveness using analytic network process method

    Science.gov (United States)

    Goran, Janjić; Zorana, Tanasić; Borut, Kosec

    2017-07-01

    The sustainable development of an organisation is monitored through the organisation's performance, which beforehand incorporates all stakeholders' requirements in its strategy. The strategic management concept enables organisations to monitor and evaluate their effectiveness along with efficiency by monitoring of the implementation of set strategic goals. In the process of monitoring and measuring effectiveness, an organisation can use multiple-criteria decision-making methods as help. This study uses the method of analytic network process (ANP) to define the weight factors of the mutual influences of all the important elements of an organisation's strategy. The calculation of an organisation's effectiveness is based on the weight factors and the degree of fulfilment of the goal values of the strategic map measures. New business conditions influence the changes in the importance of certain elements of an organisation's business in relation to competitive advantage on the market, and on the market, increasing emphasis is given to non-material resources in the process of selection of the organisation's most important measures.

  16. Preventing the progression to type 2 diabetes mellitus in adults at high risk: a systematic review and network meta-analysis of lifestyle, pharmacological and surgical interventions.

    Science.gov (United States)

    Stevens, John W; Khunti, Kamlesh; Harvey, Rebecca; Johnson, Maxine; Preston, Louise; Woods, Helen Buckley; Davies, Melanie; Goyder, Elizabeth

    2015-03-01

    Individuals with impaired fasting glucose (IFG) or impaired glucose tolerance (IGT) have an increased risk of progression to Type 2 diabetes mellitus. The objective of this review was to quantify the effectiveness of lifestyle, pharmacological and surgical interventions in reducing the progression to Type 2 diabetes mellitus in people with IFG or IGT. A systematic review was carried out. A network meta-analysis (NMA) of log-hazard ratios was performed. Results are presented as hazard ratios and the probabilities of treatment rankings. 30 studies were included in the NMA. There was a reduced hazard of progression to Type 2 diabetes mellitus associated with all interventions versus standard lifestyle advice; glipizide, diet plus pioglitazone, diet plus exercise plus metformin plus rosiglitazone, diet plus exercise plus orlistat, diet plus exercise plus pedometer, rosiglitazone, orlistat and diet plus exercise plus voglibose produced the greatest effects. Lifestyle and some pharmacological interventions are beneficial in reducing the risk of progression to Type 2 diabetes mellitus. Lifestyle interventions require significant behaviour changes that may be achieved through incentives such as the use of pedometers. Adverse events and cost of pharmacological interventions should be taken into account when considering potential risks and benefits. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  17. Identification of direct and indirect social network effects in the pathophysiology of insulin resistance in obese human subjects.

    Directory of Open Access Journals (Sweden)

    Christian H C A Henning

    Full Text Available OBJECTIVE: The aim of the present study was to examine to what extent different social network mechanisms are involved in the pathogenesis of obesity and insulin-resistance. DESIGN: We used nonparametric and parametric regression models to analyse whether individual BMI and HOMA-IR are determined by social network characteristics. SUBJECTS AND METHODS: A total of 677 probands (EGO and 3033 social network partners (ALTER were included in the study. Data gathered from the probands include anthropometric measures, HOMA-IR index, health attitudes, behavioural and socio-economic variables and social network data. RESULTS: We found significant treatment effects for ALTERs frequent dieting (p<0.001 and ALTERs health oriented nutritional attitudes (p<0.001 on EGO's BMI, establishing a significant indirect network effect also on EGO's insulin resistance. Most importantly, we also found significant direct social network effects on EGO's insulin resistance, evidenced by an effect of ALTERs frequent dieting (p = 0.033 and ALTERs sport activities (p = 0.041 to decrease EGO's HOMA-IR index independently of EGO's BMI. CONCLUSIONS: Social network phenomena appear not only to be relevant for the spread of obesity, but also for the spread of insulin resistance as the basis for type 2 diabetes. Attitudes and behaviour of peer groups influence EGO's health status not only via social mechanisms, but also via socio-biological mechanisms, i.e. higher brain areas might be influenced not only by biological signals from the own organism, but also by behaviour and knowledge from different human individuals. Our approach allows the identification of peer group influence controlling for potential homophily even when using cross-sectional observational data.

  18. Investigating the Effects of Imputation Methods for Modelling Gene Networks Using a Dynamic Bayesian Network from Gene Expression Data

    Science.gov (United States)

    CHAI, Lian En; LAW, Chow Kuan; MOHAMAD, Mohd Saberi; CHONG, Chuii Khim; CHOON, Yee Wen; DERIS, Safaai; ILLIAS, Rosli Md

    2014-01-01

    Background: Gene expression data often contain missing expression values. Therefore, several imputation methods have been applied to solve the missing values, which include k-nearest neighbour (kNN), local least squares (LLS), and Bayesian principal component analysis (BPCA). However, the effects of these imputation methods on the modelling of gene regulatory networks from gene expression data have rarely been investigated and analysed using a dynamic Bayesian network (DBN). Methods: In the present study, we separately imputed datasets of the Escherichia coli S.O.S. DNA repair pathway and the Saccharomyces cerevisiae cell cycle pathway with kNN, LLS, and BPCA, and subsequently used these to generate gene regulatory networks (GRNs) using a discrete DBN. We made comparisons on the basis of previous studies in order to select the gene network with the least error. Results: We found that BPCA and LLS performed better on larger networks (based on the S. cerevisiae dataset), whereas kNN performed better on smaller networks (based on the E. coli dataset). Conclusion: The results suggest that the performance of each imputation method is dependent on the size of the dataset, and this subsequently affects the modelling of the resultant GRNs using a DBN. In addition, on the basis of these results, a DBN has the capacity to discover potential edges, as well as display interactions, between genes. PMID:24876803

  19. Transparency effect in the emergence of monopolies in social networks

    CERN Document Server

    Shirazi, A H; Roohi, A A; Jafari, G R

    2013-01-01

    Power law degree distribution was shown in many complex networks. However, in most real systems, deviation from power-law behavior is observed in social and economical networks and emergence of giant hubs is obvious in real network structures far from the tail of power law. We propose a model based on the information transparency (transparency means how much the information is obvious to others). This model can explain power structure in societies with non-transparency in information delivery. The emergence of ultra powerful nodes is explained as a direct result of censorship. Based on these assumptions, we define four distinct transparency regions: perfect non-transparent, low transparent, perfect transparent and exaggerated regions. We observe the emergence of some ultra powerful (very high degree) nodes in low transparent networks, in accordance with the economical and social systems. We show that the low transparent networks are more vulnerable to attacks and the controllability of low transparent network...

  20. The properties of genome conformation and spatial gene interaction and regulation networks of normal and malignant human cell types.

    Directory of Open Access Journals (Sweden)

    Zheng Wang

    Full Text Available The spatial conformation of a genome plays an important role in the long-range regulation of genome-wide gene expression and methylation, but has not been extensively studied due to lack of genome conformation data. The recently developed chromosome conformation capturing techniques such as the Hi-C method empowered by next generation sequencing can generate unbiased, large-scale, high-resolution chromosomal interaction (contact data, providing an unprecedented opportunity to investigate the spatial structure of a genome and its applications in gene regulation, genomics, epigenetics, and cell biology. In this work, we conducted a comprehensive, large-scale computational analysis of this new stream of genome conformation data generated for three different human leukemia cells or cell lines by the Hi-C technique. We developed and applied a set of bioinformatics methods to reliably generate spatial chromosomal contacts from high-throughput sequencing data and to effectively use them to study the properties of the genome structures in one-dimension (1D and two-dimension (2D. Our analysis demonstrates that Hi-C data can be effectively applied to study tissue-specific genome conformation, chromosome-chromosome interaction, chromosomal translocations, and spatial gene-gene interaction and regulation in a three-dimensional genome of primary tumor cells. Particularly, for the first time, we constructed genome-scale spatial gene-gene interaction network, transcription factor binding site (TFBS - TFBS interaction network, and TFBS-gene interaction network from chromosomal contact information. Remarkably, all these networks possess the properties of scale-free modular networks.

  1. The effect of network template from normal subjects in the detection of network impairment.

    Science.gov (United States)

    Chun-Chao, Huang; Shang-Hua, Lin; Ching-Po, Lin; Disease Neuroimaging Initiative, The Alzheimer's

    2016-01-01

    This study aimed to provide a simple way to approach group differences by independent component analysis when researching functional connectivity changes of resting-state network in brain disorders. We used baseline resting state functional magnetic resonance imaging from the Alzheimer's disease neuroimaging initiative dataset and performed independent component analysis based on different kinds of subject selection, by including two downloaded templates and single-subject independent component analysis method. All conditions were used to calculate the functional connectivity of the default mode network, and to test group differences and evaluate correlation with cognitive measurements and hippocampal volume. The default mode network functional connectivity results most fitting clinical evaluations were from templates based on young healthy subjects and the worst results were from heterogeneous or more severe disease groups or single-subject independent component analysis method. Using independent component analysis network maps derived from normal young subjects to extract all individual functional connectivities provides significant correlations with clinical evaluations.

  2. The Contagion Effects of Repeated Activation in Social Networks

    OpenAIRE

    Piedrahita, Pablo; Borge-Holthoefer, Javier; Moreno, Yamir; González-Bailón, Sandra

    2017-01-01

    Demonstrations, protests, riots, and shifts in public opinion respond to the coordinating potential of communication networks. Digital technologies have turned interpersonal networks into massive, pervasive structures that constantly pulsate with information. Here, we propose a model that aims to analyze the contagion dynamics that emerge in networks when repeated activation is allowed, that is, when actors can engage recurrently in a collective effort. We analyze how the structure of communi...

  3. The effects of stressor type on projected coping.

    Science.gov (United States)

    Bjorck, J P; Klewicki, L L

    1997-07-01

    Previous analog research (Bjorck & Cohen, 1993), in which Caucasian college students' projected coping responses to major stressors differed as a function of stressor type (threat, loss, or challenge), was replicated with an ethnoculturally diverse sample. Because Bjorck and Cohen's findings might have been confounded by participants' prior life experiences and/or differing perceptions of event controllability, these two dimensions were also assessed. Even after statistically controlling for these two potential confounds, however, projected coping again differed as a function of stressor type. Effects of both controllability and prior experience were also found. Results are discussed in terms of their application to coping processes in general and to coping with trauma in particular.

  4. Radiation effects on science instruments in Grand Tour type missions

    Science.gov (United States)

    Parker, R. H.

    1972-01-01

    The extent of the radiation effects problem is delineated, along with the status of protective designs for 15 representative science instruments. Designs for protecting science instruments from radiation damage is discussed for the various instruments to be employed in the Grand Tour type missions. A literature search effort was undertaken to collect science instrument components damage/interference effects data on the various sensitive components such as Si detectors, vidicon tubes, etc. A small experimental effort is underway to provide verification of the radiation effects predictions.

  5. Potential Use of a Bayesian Network for Discriminating Flash Type from Future GOES-R Geostationary Lightning Mapper (GLM) data

    Science.gov (United States)

    Solakiewiz, Richard; Koshak, William

    2008-01-01

    Continuous monitoring of the ratio of cloud flashes to ground flashes may provide a better understanding of thunderstorm dynamics, intensification, and evolution, and it may be useful in severe weather warning. The National Lighting Detection Network TM (NLDN) senses ground flashes with exceptional detection efficiency and accuracy over most of the continental United States. A proposed Geostationary Lightning Mapper (GLM) aboard the Geostationary Operational Environmental Satellite (GOES-R) will look at the western hemisphere, and among the lightning data products to be made available will be the fundamental optical flash parameters for both cloud and ground flashes: radiance, area, duration, number of optical groups, and number of optical events. Previous studies have demonstrated that the optical flash parameter statistics of ground and cloud lightning, which are observable from space, are significantly different. This study investigates a Bayesian network methodology for discriminating lightning flash type (ground or cloud) using the lightning optical data and ancillary GOES-R data. A Directed Acyclic Graph (DAG) is set up with lightning as a "root" and data observed by GLM as the "leaves." This allows for a direct calculation of the joint probability distribution function for the lighting type and radiance, area, etc. Initially, the conditional probabilities that will be required can be estimated from the Lightning Imaging Sensor (LIS) and the Optical Transient Detector (OTD) together with NLDN data. Directly manipulating the joint distribution will yield the conditional probability that a lightning flash is a ground flash given the evidence, which consists of the observed lightning optical data [and possibly cloud data retrieved from the GOES-R Advanced Baseline Imager (ABI) in a more mature Bayesian network configuration]. Later, actual GLM and NLDN data can be used to refine the estimates of the conditional probabilities used in the model; i.e., the Bayesian

  6. Linear-Optics-Based Entanglement Concentration of Four-Photon χ-type States for Quantum Communication Network

    Science.gov (United States)

    Li, Tao; Deng, Fu-Guo

    2014-09-01

    We present an efficient entanglement concentration protocol (ECP) for partially entangled four-photon χ-type states in the first time with only linear optical elements and single-photon detectors. Without any ancillary particles, the parties in quantum communication network can obtain a subset of four-photon systems in the standard | χ 00> state from a set of four-photon systems in a partially entangled χ-type state with the parameter-splitting method developed by Ren et al. (Phys. Rev. A 88:012302, 2013). The present ECP has the optimal success probability which is determined by the component with the minimal probability amplitude in the initial state. Moreover, it is easy to implement this ECP in experiment.

  7. Labor Mobility, Social Network Effects, and Innovative Activity

    DEFF Research Database (Denmark)

    Kaiser, Ulrich; Kongsted, H.C.; Rønde, Thomas

    We study the mapping between labor mobility and industrial innovative activity for the population of R&D active Danish firms observed between 1999 and 2004. Our study documents a positive relationship between the number of workers who join a firm and the firm’s innovative activity. This relations......We study the mapping between labor mobility and industrial innovative activity for the population of R&D active Danish firms observed between 1999 and 2004. Our study documents a positive relationship between the number of workers who join a firm and the firm’s innovative activity....... This relationship is stronger if workers join from innovative firms. We also find evidence for positive feedback from workers who leave for an innovative firm, presumably because the worker who left stays in contact with their former colleagues. This implies that the positive feedback (“social network effects......”) that has been found by other studies not only exists but even outweighs the disruption and loss of knowledge occurring to the previous employer from the worker leaving. Summing up the effects of joining and leaving workers, we find ample evidence for mobility to be associated with an increase in total...

  8. Larval Connectivity in an Effective Network of Marine Protected Areas

    Science.gov (United States)

    Christie, Mark R.; Tissot, Brian N.; Albins, Mark A.; Beets, James P.; Jia, Yanli; Ortiz, Delisse M.; Thompson, Stephen E.; Hixon, Mark A.

    2010-01-01

    Acceptance of marine protected areas (MPAs) as fishery and conservation tools has been hampered by lack of direct evidence that MPAs successfully seed unprotected areas with larvae of targeted species. For the first time, we present direct evidence of large-scale population connectivity within an existing and effective network of MPAs. A new parentage analysis identified four parent-offspring pairs from a large, exploited population of the coral-reef fish Zebrasoma flavescens in Hawai'i, revealing larval dispersal distances ranging from 15 to 184 km. In two cases, successful dispersal was from an MPA to unprotected sites. Given high adult abundances, the documentation of any parent-offspring pairs demonstrates that ecologically-relevant larval connectivity between reefs is substantial. All offspring settled at sites to the north of where they were spawned. Satellite altimetry and oceanographic models from relevant time periods indicated a cyclonic eddy that created prevailing northward currents between sites where parents and offspring were found. These findings empirically demonstrate the effectiveness of MPAs as useful conservation and management tools and further highlight the importance of coupling oceanographic, genetic, and ecological data to predict, validate and quantify larval connectivity among marine populations. PMID:21203576

  9. Larval connectivity in an effective network of marine protected areas.

    Directory of Open Access Journals (Sweden)

    Mark R Christie

    Full Text Available Acceptance of marine protected areas (MPAs as fishery and conservation tools has been hampered by lack of direct evidence that MPAs successfully seed unprotected areas with larvae of targeted species. For the first time, we present direct evidence of large-scale population connectivity within an existing and effective network of MPAs. A new parentage analysis identified four parent-offspring pairs from a large, exploited population of the coral-reef fish Zebrasoma flavescens in Hawai'i, revealing larval dispersal distances ranging from 15 to 184 km. In two cases, successful dispersal was from an MPA to unprotected sites. Given high adult abundances, the documentation of any parent-offspring pairs demonstrates that ecologically-relevant larval connectivity between reefs is substantial. All offspring settled at sites to the north of where they were spawned. Satellite altimetry and oceanographic models from relevant time periods indicated a cyclonic eddy that created prevailing northward currents between sites where parents and offspring were found. These findings empirically demonstrate the effectiveness of MPAs as useful conservation and management tools and further highlight the importance of coupling oceanographic, genetic, and ecological data to predict, validate and quantify larval connectivity among marine populations.

  10. The effects of cultural learning in populations of neural networks.

    Science.gov (United States)

    Curran, Dara; O'Riordan, Colm

    2007-01-01

    Population learning can be described as the iterative Darwinian process of fitness-based selection and genetic transfer of information leading to populations of higher fitness and is often simulated using genetic algorithms. Cultural learning describes the process of information transfer between individuals in a population through non-genetic means. Cultural learning has been simulated by combining genetic algorithms and neural networks using a teacher-pupil scenario where highly fit individuals are selected as teachers and instruct the next generation. By examining the innate fitness of a population (i.e., the fitness of the population measured before any cultural learning takes place), it is possible to examine the effects of cultural learning on the population's genetic makeup. Our model explores the effect of cultural learning on a population and employs three benchmark sequential decision tasks as the evolutionary task for the population: connect-four, tic-tac-toe, and blackjack. Experiments are conducted with populations employing population learning alone and populations combining population and cultural learning. The article presents results showing the gradual transfer of knowledge from genes to the cultural process, illustrated by the simultaneous decrease in the population's innate fitness and the increase of its acquired fitness measured after learning takes place.

  11. Critical tipping point distinguishing two types of transitions in modular network structures.

    Science.gov (United States)

    Shai, Saray; Kenett, Dror Y; Kenett, Yoed N; Faust, Miriam; Dobson, Simon; Havlin, Shlomo

    2015-12-01

    Modularity is a key organizing principle in real-world large-scale complex networks. The relatively sparse interactions between modules are critical to the functionality of the system and are often the first to fail. We model such failures as site percolation targeting interconnected nodes, those connecting between modules. We find, using percolation theory and simulations, that they lead to a "tipping point" between two distinct regimes. In one regime, removal of interconnected nodes fragments the modules internally and causes the system to collapse. In contrast, in the other regime, while only attacking a small fraction of nodes, the modules remain but become disconnected, breaking the entire system. We show that networks with broader degree distribution might be highly vulnerable to such attacks since only few nodes are needed to interconnect the modules, consequently putting the entire system at high risk. Our model has the potential to shed light on many real-world phenomena, and we briefly consider its implications on recent advances in the understanding of several neurocognitive processes and diseases.

  12. A Network of Three Types of Filaments Organizes Synaptic Vesicles for Storage, Mobilization, and Docking.

    Science.gov (United States)

    Cole, Andy A; Chen, Xiaobing; Reese, Thomas S

    2016-03-16

    Synaptic transmission between neurons requires precise management of synaptic vesicles. While individual molecular components of the presynaptic terminal are well known, exactly how the molecules are organized into a molecular machine serving the storage and mobilization of synaptic vesicles to the active zone remains unclear. Here we report three filament types associated with synaptic vesicles in glutamatergic synapses revealed by electron microscope tomography in unstimulated, dissociated rat hippocampal neurons. One filament type, likely corresponding to the SNAREpin complex, extends from the active zone membrane and surrounds docked vesicles. A second filament type contacts all vesicles throughout the active zone and pairs vesicles together. On the third filament type, vesicles attach to side branches extending from the long filament core and form vesicle clusters that are distributed throughout the vesicle cloud and along the active zone membrane. Detailed analysis of presynaptic structure reveals how each of the three filament types interacts with synaptic vesicles, providing a means to traffic reserved and recycled vesicles from the cloud of vesicles into the docking position at the active zone. The formation and release of synaptic vesicles has been extensively investigated. Explanations of the release of synaptic vesicles generally begin with the movement of vesicles from the cloud into the synaptic active zone. However, the presynaptic terminal is filled with filamentous material that would appear to limit vesicular diffusion. Here, we provide a systematic description of three filament types connecting synaptic vesicles. A picture emerges illustrating how the cooperative attachment and release of these three filament types facilitate the movement of vesicles to the active zone to become docked in preparation for release. Copyright © 2016 the authors 0270-6474/16/363222-09$15.00/0.

  13. Selection in the social network: effects of chronic diseases.

    NARCIS (Netherlands)

    Tijhuis, M.A.R.; Flap, H.D.; Foets, M.; Groenewegen, P.P.

    1998-01-01

    Background: this article deals with the consequences of disease for someone's personal social network. It is hypothesized that the duration of a socially severe disease will affect the social network in such a way that the proportions of women, kin, long-standing relationships and people living

  14. The Effect of Employer Networks on Workplace Innovation and Training.

    Science.gov (United States)

    Erickson, Christopher L.; Jacoby, Sanford M.

    2003-01-01

    Multivariate analyses of data from the California Workplace Survey suggested that managers' participation in networks, especially professional and community organizations and internal networks, positively influenced the probability and intensity of adoption of high-performance work practices and training. Multiple affiliations increased the…

  15. Effect of mean network coordination number on dispersivity characteristics

    NARCIS (Netherlands)

    Vasilyev, L.; Raoof, A.; Nordbotten, J.M.

    2012-01-01

    In this study, we investigate the role of topology on the macroscopic (centimeter scale) dispersion characteristics derived from pore-network models.We consider 3D random porous networks extracted from a regular cubic lattice with coordination number distributed in accordance with real porous

  16. Mediation Effects of Internet Addiction on Shame and Social Networking

    Science.gov (United States)

    Dogan, Ugur; Kaya, Sinem

    2016-01-01

    A survey of 488 college students was conducted in Turkey to investigate the relationship between social network usage, shame and Internet addiction. It was hypothesized that a relationship between shame and social network usage was mediated by Internet addiction. First of all, according to simple regression analysis, it was found that shame…

  17. Effective Network Management via System-Wide Coordination and Optimization

    Science.gov (United States)

    2010-08-01

    capacity of ISPs and socializes the performance benefits to all end-to-end traffic [30]. However, extending single-vantage solutions to a network-wide...O. Spatscheck, and V. Shkapenyuk. Gigascope: A stream database for network applications. In Proc. ACM SIGMOD, 2003. 185 [42] C. Kruegel, F. Valeur

  18. Effect of environmental air pollution on type 2 diabetes mellitus.

    Science.gov (United States)

    Meo, S A; Memon, A N; Sheikh, S A; Rouq, F A; Usmani, A Mahmood; Hassan, A; Arian, S A

    2015-01-01

    Air pollution is a novel risk factor for insulin resistance and occurrence of type 2 diabetes mellitus (T2DM), but the evidence is limited and diverse. Therefore, the aim of this study was to assess the effect of environmental air pollution on incidence of type 2 diabetes mellitus. In this study, we identified 102 published studies through a systematic data base search including ISI-Web of Science, EMBASE and PubMed. We searched the related literature by using the key terms including diabetes mellitus, air pollution, occupational and environmental pollution, gaseous, NO2, particulate matter pollutants PM2.5, and PM10. Studies in which diabetes mellitus, insulin resistance, air pollution, occupational and environmental pollution was discussed were included in the study. No confines on publication status, study design or language of publication were considered. Descriptive and quantitative information were extracted from the selected literature. Finally we included 21 publications and remaining studies were excluded. Air pollution is a leading cause of insulin resistance and incidence of type 2 diabetes mellitus. The association between air pollution and diabetes is stronger for traffic associated pollutants, gaseous, nitrogen dioxide, tobacco smoke and particulate matter. Exposure to air pollutants is significantly associated with increased risk of type 2 diabetes mellitus. It is suggested that, environmental protection officials must take high priority steps to minimize the air pollution, hence to decrease the incidence of type 2 diabetes mellitus.

  19. Effect of shoe type on descending a curb.

    Science.gov (United States)

    George, Juff; Heller, Michelle; Kuzel, Michael

    2012-01-01

    The aim of this study was to evaluate the effect of shoe type on the performance of women during curb descent. Performance during curb stepping may be explained by biomechanical research that has evaluated the kinematics of overground walking and stair ascent and descent. Studies have reported that women exhibit performance differences when wearing high heels, flip flops and sneakers during overground walking and stair ascent and descent. Thus, in addition to features of the curb, the type of shoe being worn may also affect performance. Although several studies have investigated curb stepping, no known studies have investigated the effects of different types of footwear on curb descent performance. This research was conducted in a real-world environment where participants wore three different types of shoes and performed a series of activities that involved curb stepping. The subjects were videotaped while descending a curb, allowing for observation of changes in gait parameters. Results of this study indicate that wearing high heels leads to performance differences as compared to wearing flip flops or sneakers.

  20. Verification of failover effects from distributed control system communication networks in digitalized nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Min, Moon Gi; Lee, Jae Ki; Lee, Kwang Hyun; Lee, Dong Il; Lim, Hee Taek [Korea Hydro and Nuclear Power Co., Ltd, Daejeon (Korea, Republic of)

    2017-08-15

    Distributed Control System (DCS) communication networks, which use Fast Ethernet with redundant networks for the transmission of information, have been installed in digitalized nuclear power plants. Normally, failover tests are performed to verify the reliability of redundant networks during design and manufacturing phases; however, systematic integrity tests of DCS networks cannot be fully performed during these phases because all relevant equipment is not installed completely during these two phases. In additions, practical verification tests are insufficient, and there is a need to test the actual failover function of DCS redundant networks in the target environment. The purpose of this study is to verify that the failover functions works correctly in certain abnormal conditions during installation and commissioning phase and identify the influence of network failover on the entire DCS. To quantify the effects of network failover in the DCS, the packets (Protocol Data Units) must be collected and resource usage of the system has to be monitored and analyzed. This study introduces the use of a new methodology for verification of DCS network failover during the installation and commissioning phases. This study is expected to provide insight into verification methodology and the failover effects from DCS redundant networks. It also provides test results of network performance from DCS network failover in digitalized domestic nuclear power plants (NPPs)

  1. Effective information spreading based on local information in correlated networks

    CERN Document Server

    Gao, Lei; Pan, Liming; Tang, Ming; Zhang, Hai-Feng

    2016-01-01

    Using network-based information to facilitate information spreading is an essential task for spreading dynamics in complex networks, which will benefit the promotion of technical innovations, healthy behaviors, new products, etc. Focusing on degree correlated networks, we propose a preferential contact strategy based on the local network structure and local informed density to promote the information spreading. During the spreading process, an informed node will preferentially select a contact target among its neighbors, basing on their degrees or local informed densities. By extensively implementing numerical simulations in synthetic and empirical networks, we find that when only consider the local structure information, the convergence time of information spreading will be remarkably reduced if low-degree neighbors are favored as contact targets. Meanwhile, the minimum convergence time depends non-monotonically on degree-degree correlation, and moderate correlation coefficients result in most efficient info...

  2. NETWORKING TOOLS FOR SHOPPING MALLS: HOW TO IMPLEMENT THEM AND MEASURE THEIR EFFECTIVENESS

    Directory of Open Access Journals (Sweden)

    Evgeniya Vasilevna Elistratova

    2017-10-01

    Full Text Available Despite the importance of shopping malls for the contemporary society and their network nature there is no algorithmic basis for support of implementation of networking tools in the business activity of shopping malls. The goal of the present paper is to develop this basis. The paper contains an algorithm of implementation of networking tools which includes five stages. For each stage detailed comments and recommendations are given. A list of indexes of effectiveness of networking tools is proposed. A method for evaluation of the effectiveness of measures of implementation of networking tools is described. A diagnostic matrix which can be used for evaluation of the effectiveness of the company during the proccess of implementation of networking tools is given.

  3. Antihyperglycemic effects of stevioside in type 2 diabetic subjects

    DEFF Research Database (Denmark)

    Gregersen, Søren; Jeppesen, Per B; Holst, Jens Juul

    2004-01-01

    Stevioside is present in the plant Stevia rebaudiana Bertoni (SrB). Extracts of SrB have been used for the treatment of diabetes in, for example, Brazil, although a positive effect on glucose metabolism has not been unequivocally demonstrated. We studied the acute effects of stevioside in type 2...... diabetic patients. We hypothesize that supplementation with stevioside to a test meal causes a reduction in postprandial blood glucose. Twelve type 2 diabetic patients were included in an acute, paired cross-over study. A standard test meal was supplemented with either 1 g of stevioside or 1 g of maize...... starch (control). Blood samples were drawn at 30 minutes before and for 240 minutes after ingestion of the test meal. Compared to control, stevioside reduced the incremental area under the glucose response curve by 18% (P =.013). The insulinogenic index (AUC(i,insulin)/AUC(i,glucose)) was increased...

  4. Stormwater management network effectiveness and implications for urban watershed function: A critical review

    Science.gov (United States)

    Jefferson, Anne J.; Bhaskar, Aditi S.; Hopkins, Kristina G.; Fanelli, Rosemary; Avellaneda, Pedro M.; McMillan, Sara K.

    2017-01-01

    Deleterious effects of urban stormwater are widely recognized. In several countries, regulations have been put into place to improve the conditions of receiving water bodies, but planning and engineering of stormwater control is typically carried out at smaller scales. Quantifying cumulative effectiveness of many stormwater control measures on a watershed scale is critical to understanding how small-scale practices translate to urban river health. We review 100 empirical and modelling studies of stormwater management effectiveness at the watershed scale in diverse physiographic settings. Effects of networks with stormwater control measures (SCMs) that promote infiltration and harvest have been more intensively studied than have detention-based SCM networks. Studies of peak flows and flow volumes are common, whereas baseflow, groundwater recharge, and evapotranspiration have received comparatively little attention. Export of nutrients and suspended sediments have been the primary water quality focus in the United States, whereas metals, particularly those associated with sediments, have received greater attention in Europe and Australia. Often, quantifying cumulative effects of stormwater management is complicated by needing to separate its signal from the signal of urbanization itself, innate watershed characteristics that lead to a range of hydrologic and water quality responses, and the varying functions of multiple types of SCMs. Biases in geographic distribution of study areas, and size and impervious surface cover of watersheds studied also limit our understanding of responses. We propose hysteretic trajectories for how watershed function responds to increasing imperviousness and stormwater management. Even where impervious area is treated with SCMs, watershed function may not be restored to its predevelopment condition because of the lack of treatment of all stormwater generated from impervious surfaces; non-additive effects of individual SCMs; and

  5. Beyond Space For Spatial Networks

    CERN Document Server

    Expert, Paul; Blondel, Vincent D; Lambiotte, Renaud

    2010-01-01

    Many complex systems are organized in the form of a network embedded in space. Important examples include the physical Internet infrastucture, road networks, flight connections, brain functional networks and social networks. The effect of space on network topology has recently come under the spotlight because of the emergence of pervasive technologies based on geo-localization, which constantly fill databases with people's movements and thus reveal their trajectories and spatial behaviour. Extracting patterns and regularities from the resulting massive amount of human mobility data requires the development of appropriate tools for uncovering information in spatially-embedded networks. In contrast with most works that tend to apply standard network metrics to any type of network, we argue in this paper for a careful treatment of the constraints imposed by space on network topology. In particular, we focus on the problem of community detection and propose a modularity function adapted to spatial networks. We sh...

  6. The Effectiveness of Using Social Communications Networks in Mathematics Teachers' Professional Development

    Science.gov (United States)

    Hussein, Hisham Barakat

    2013-01-01

    The study aims to determine the effectiveness of using social communications networks in mathematics teachers' professional development. The main research questions was: what is the effectiveness of using social communications networks in mathematics teachers' professional development. The sub questions were: (1) what are the standards of…

  7. An optimal general type-2 fuzzy controller for Urban Traffic Network

    DEFF Research Database (Denmark)

    Khooban, Mohammad Hassan; Vafamand, Navid; Liaghat, Alireza

    2017-01-01

    , a combination of the general type-2 fuzzy logic sets and the Modified Backtracking Search Algorithm (MBSA) techniques are used in order to control the traffic signal scheduling and phase succession so as to guarantee a smooth flow of traffic with the least wait times and average queue length. The parameters...... of input and output membership functions are optimized simultaneously by the novel heuristic algorithm MBSA. A comparison is made between the achieved results with those of optimal and conventional type-1 fuzzy logic controllers....

  8. Experimental calibration of forward and inverse neural networks for rotary type magnetorheological damper

    DEFF Research Database (Denmark)

    Bhowmik, Subrata; Weber, Felix; Høgsberg, Jan Becker

    2013-01-01

    This paper presents a systematic design and training procedure for the feed-forward backpropagation neural network (NN) modeling of both forward and inverse behavior of a rotary magnetorheological (MR) damper based on experimental data. For the forward damper model, with damper force as output...... an optimization procedure demonstrates accurate training of the NN architecture with only current and velocity as input states. For the inverse damper model, with current as output, the absolute value of velocity and force are used as input states to avoid negative current spikes when tracking a desired damper...... force. The forward and inverse damper models are trained and validated experimentally, combining a limited number of harmonic displacement records, and constant and half-sinusoidal current records. In general the validation shows accurate results for both forward and inverse damper models, where...

  9. Two-Level Effects of Interorganizational Network Collaboration on Graduate Satisfaction: A Comparison of Five Intercollege Networks in Dutch Higher Education

    NARCIS (Netherlands)

    Akkerman, A.; Torenvlied, R.; Schalk, J.

    2012-01-01

    In the public management literature, network effects are studied primarily at two levels: (a) the level of the interorganizational network as a whole and (b) the level of individual organizations’ networking behavior. This article combines the two levels within one theoretical framework and derives

  10. Antihyperglycemic effects of stevioside in type 2 diabetic subjects.

    Science.gov (United States)

    Gregersen, Søren; Jeppesen, Per B; Holst, Jens J; Hermansen, Kjeld

    2004-01-01

    Stevioside is present in the plant Stevia rebaudiana Bertoni (SrB). Extracts of SrB have been used for the treatment of diabetes in, for example, Brazil, although a positive effect on glucose metabolism has not been unequivocally demonstrated. We studied the acute effects of stevioside in type 2 diabetic patients. We hypothesize that supplementation with stevioside to a test meal causes a reduction in postprandial blood glucose. Twelve type 2 diabetic patients were included in an acute, paired cross-over study. A standard test meal was supplemented with either 1 g of stevioside or 1 g of maize starch (control). Blood samples were drawn at 30 minutes before and for 240 minutes after ingestion of the test meal. Compared to control, stevioside reduced the incremental area under the glucose response curve by 18% (P =.013). The insulinogenic index (AUC(i,insulin)/AUC(i,glucose)) was increased by approximately 40% by stevioside compared to control (P diabetic patients, indicating beneficial effects on the glucose metabolism. Stevioside may be advantageous in the treatment of type 2 diabetes.

  11. Cardiovascular effects of the angiotensin type 2 receptor.

    Science.gov (United States)

    Faria-Costa, Gabriel; Leite-Moreira, Adelino; Henriques-Coelho, Tiago

    2014-01-01

    The angiotensin type 2 receptor, AT2R, has been described as having opposite effects to the angiotensin type 1 receptor, AT1R. Although the quantities of the AT2R found in the adult are low, its expression rises in pathological situations. The AT2R has three major signaling pathways: activation of serine/threonine phosphatases (promoting apoptosis and antioxidant effects), activation of the bradykinin/NO/cGMP pathway (promoting vasodilation), and activation of phospholipase A2 (associated with regulation of potassium currents). The AT2R appears to have effects in vascular remodeling, atherosclerosis prevention and blood pressure lowering (when associated with an AT1R inhibitor). After myocardial infarction, the AT2R appears to decrease infarct size, cardiac hypertrophy and fibrosis, and to improve cardiac function. However, its role in the heart is controversial. In the kidney, the AT2R promotes natriuresis. Until now, treatment directed at the renin-angiotensin-aldosterone system has been based on angiotensin-converting enzyme inhibitors or angiotensin type 1 receptor blockers. The study of the AT2R has been revolutionized by the discovery of a direct agonist, C21, which promises to become part of the treatment of cardiovascular disease. Copyright © 2013 Sociedade Portuguesa de Cardiologia. Published by Elsevier España. All rights reserved.

  12. Effect of Fiber Crimp on the Elasticity of Random Fiber Networks With and Without Embedding Matrices.

    Science.gov (United States)

    Ban, Ehsan; Barocas, Victor H; Shephard, Mark S; Picu, Catalin R

    2016-04-01

    Fiber networks are assemblies of one-dimensional elements representative of materials with fibrous microstructures such as collagen networks and synthetic nonwovens. The mechanics of random fiber networks has been the focus of numerous studies. However, fiber crimp has been explicitly represented only in few cases. In the present work, the mechanics of cross-linked networks with crimped athermal fibers, with and without an embedding elastic matrix, is studied. The dependence of the effective network stiffness on the fraction of nonstraight fibers and the relative crimp amplitude (or tortuosity) is studied using finite element simulations of networks with sinusoidally curved fibers. A semi-analytic model is developed to predict the dependence of network modulus on the crimp amplitude and the bounds of the stiffness reduction associated with the presence of crimp. The transition from the linear to the nonlinear elastic response of the network is rendered more gradual by the presence of crimp, and the effect of crimp on the network tangent stiffness decreases as strain increases. If the network is embedded in an elastic matrix, the effect of crimp becomes negligible even for very small, biologically relevant matrix stiffness values. However, the distribution of the maximum principal stress in the matrix becomes broader in the presence of crimp relative to the similar system with straight fibers, which indicates an increased probability of matrix failure.

  13. Effects of maximum node degree on computer virus spreading in scale-free networks

    Science.gov (United States)

    Bamaarouf, O.; Ould Baba, A.; Lamzabi, S.; Rachadi, A.; Ez-Zahraouy, H.

    2017-10-01

    The increase of the use of the Internet networks favors the spread of viruses. In this paper, we studied the spread of viruses in the scale-free network with different topologies based on the Susceptible-Infected-External (SIE) model. It is found that the network structure influences the virus spreading. We have shown also that the nodes of high degree are more susceptible to infection than others. Furthermore, we have determined a critical maximum value of node degree (Kc), below which the network is more resistible and the computer virus cannot expand into the whole network. The influence of network size is also studied. We found that the network with low size is more effective to reduce the proportion of infected nodes.

  14. Understanding the effects of administrative boundary in sampling spatially embedded networks

    Science.gov (United States)

    Chi, Guanghua; Liu, Yu; Shi, Li; Gao, Yong

    2017-01-01

    When analyzing spatially embedded networks, networks consisting of nodes and connections within an administrative boundary are commonly analyzed directly without considering possible errors or biases due to lost connections to nodes outside the network. However, connections exist not only within administrative boundaries but also to nodes outside of the boundaries. This study empirically analyzed the geographical boundary problem using a mobile communication network constructed based on mobile phone data collected in Heilongjiang province, China. We find that although many connections outside of the administrative boundary are lost, sampled networks based on administrative boundaries perform relatively well in terms of degree and clustering coefficient. We find that the mechanisms behind the reliability of these sampled networks include the effects of distance decay and cohesion strength in administrative regions on spatially embedded networks.

  15. Metabolic Network Topology Reveals Transcriptional Regulatory Signatures of Type 2 Diabetes

    DEFF Research Database (Denmark)

    Zelezniak, Aleksej; Pers, Tune Hannes; Pinho Soares, Simao Pedro

    2010-01-01

    Type 2 diabetes mellitus (T2DM) is a disorder characterized by both insulin resistance and impaired insulin secretion. Recent transcriptomics studies related to T2DM have revealed changes in expression of a large number of metabolic genes in a variety of tissues. Identification of the molecular...

  16. Place of Origin, Types of Ties, and Support Networks in Mexico-U.S. Migration

    Science.gov (United States)

    Flores-Yeffal, Nadia Y.; Aysa-Lastra, Maria

    2011-01-01

    Previous studies explored how urban or rural place of origin influences the source of social capital. There remains a need to consider how the place of origin affects the type of ties--family, friends, or "paisanos" (countrymen)--with those who provide support to migrants. We use data from the Mexican Migration Project (MMP128) and…

  17. Impact of acoustic coordinated reset neuromodulation on effective connectivity in a neural network of phantom sound.

    Science.gov (United States)

    Silchenko, Alexander N; Adamchic, Ilya; Hauptmann, Christian; Tass, Peter A

    2013-08-15

    Chronic subjective tinnitus is an auditory phantom phenomenon characterized by abnormal neuronal synchrony in the central auditory system. As recently shown in a proof of concept clinical trial, acoustic coordinated reset (CR) neuromodulation causes a significant relief of tinnitus symptoms combined with a significant decrease of pathological oscillatory activity in a network comprising auditory and non-auditory brain areas. The objective of the present study was to analyze whether CR therapy caused an alteration of the effective connectivity in a tinnitus related network of localized EEG brain sources. To determine which connections matter, in a first step, we considered a larger network of brain sources previously associated with tinnitus. To that network we applied a data-driven approach, combining empirical mode decomposition and partial directed coherence analysis, in patients with bilateral tinnitus before and after 12 weeks of CR therapy as well as in healthy controls. To increase the signal-to-noise ratio, we focused on the good responders, classified by a reliable-change-index (RCI). Prior to CR therapy and compared to the healthy controls, the good responders showed a significantly increased connectivity between the left primary cortex auditory cortex and the posterior cingulate cortex in the gamma and delta bands together with a significantly decreased effective connectivity between the right primary auditory cortex and the dorsolateral prefrontal cortex in the alpha band. Intriguingly, after 12 weeks of CR therapy most of the pathological interactions were gone, so that the connectivity patterns of good responders and healthy controls became statistically indistinguishable. In addition, we used dynamic causal modeling (DCM) to examine the types of interactions which were altered by CR therapy. Our DCM results show that CR therapy specifically counteracted the imbalance of excitation and inhibition. CR significantly weakened the excitatory connection

  18. Bubbling effect in the electro-optic delayed feedback oscillator coupled network

    Science.gov (United States)

    Liu, Lingfeng; Lin, Jun; Miao, Suoxia

    2017-03-01

    Synchronization in the optical systems coupled network always suffers from bubbling events. In this paper, we numerically investigate the statistical properties of the synchronization characteristics and bubbling effects in the electro-optic delayed feedback oscillator coupled network with different coupling strength, delay time and gain coefficient. Furthermore, we compare our results with the synchronization properties of semiconductor laser (SL) coupled network, which indicates that the electro-optic delayed feedback oscillator can be better to suppress the bubbling effects in the synchronization of coupled network under the same conditions.

  19. Classes of antihypertensive agents and mortality in hypertensive patients with type 2 diabetes-Network meta-analysis of randomized trials.

    Science.gov (United States)

    Remonti, Luciana R; Dias, Sofia; Leitão, Cristiane B; Kramer, Caroline K; Klassman, Lucas P; Welton, Nicky J; Ades, A E; Gross, Jorge L

    2016-08-01

    The aim of this study was to evaluate the effects of antihypertensive drug classes in mortality in patients with type 2 diabetes. MEDLINE, EMBASE, Clinical Trials and Cochrane Library were searched for randomized trials comparing thiazides, beta-blockers, calcium channel blockers (CCBs), angiotensin-converting inhibitors (ACEi) and angiotensin-receptor blockers (ARBs), alone or in combination for hypertension treatment in patients with type 2 diabetes. Outcomes were overall and cardiovascular mortality. Network meta-analysis was used to obtain pooled effect estimate. A total of 27 studies, comprising 49,418 participants, 5647 total and 1306 cardiovascular deaths were included. No differences in total or cardiovascular mortality were observed with isolated antihypertensive drug classes compared to each other or placebo. The ACEi and CCB combination showed evidence of reduction in cardiovascular mortality comparing to placebo [median HR, 95% credibility intervals: 0.16, 0.01-0.82], betablockers (0.20, 0.02-0.98), CCBs (0.21, 0.02-0.97) and ARBs (0.18, 0.02-0.91). In included trials, this combination was the treatment that most consistently achieved both lower systolic and diastolic end of study blood pressure. There is no benefit of a single antihypertensive class in reduction of mortality in hypertensive patients with type 2 diabetes. Reduction of cardiovascular mortality observed in patients treated with ACEi and CCB combination may be related to lower blood pressure levels. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Network Theory and Effects of Transcranial Brain Stimulation Methods on the Brain Networks

    Directory of Open Access Journals (Sweden)

    Sema Demirci

    2014-12-01

    Full Text Available In recent years, there has been a shift from classic localizational approaches to new approaches where the brain is considered as a complex system. Therefore, there has been an increase in the number of studies involving collaborations with other areas of neurology in order to develop methods to understand the complex systems. One of the new approaches is graphic theory that has principles based on mathematics and physics. According to this theory, the functional-anatomical connections of the brain are defined as a network. Moreover, transcranial brain stimulation techniques are amongst the recent research and treatment methods that have been commonly used in recent years. Changes that occur as a result of applying brain stimulation techniques on physiological and pathological networks help better understand the normal and abnormal functions of the brain, especially when combined with techniques such as neuroimaging and electroencephalography. This review aims to provide an overview of the applications of graphic theory and related parameters, studies conducted on brain functions in neurology and neuroscience, and applications of brain stimulation systems in the changing treatment of brain network models and treatment of pathological networks defined on the basis of this theory.

  1. Humanitarian Information Management Network Effectiveness: An Analysis at the Organizational and Network Levels

    Science.gov (United States)

    Ngamassi Tchouakeu, Louis-Marie

    2011-01-01

    Massive international response to humanitarian crises such as the South Asian Tsunami in 2004, the Hurricane Katrina in 2005 and the Haiti earthquake in 2010 highlights the importance of humanitarian inter-organizational collaboration networks, especially in information management and exchange. Despite more than a decade old call for more research…

  2. Overdominant Effect of a CHRNA4 Polymorphism on Cingulo-Opercular Network Activity and Cognitive Control.

    Science.gov (United States)

    Sadaghiani, Sepideh; Ng, Bernard; Altmann, Andre; Poline, Jean-Baptiste; Banaschewski, Tobias; Bokde, Arun L W; Bromberg, Uli; Büchel, Christian; Burke Quinlan, Erin; Conrod, Patricia; Desrivières, Sylvane; Flor, Herta; Frouin, Vincent; Garavan, Hugh; Gowland, Penny; Gallinat, Jürgen; Heinz, Andreas; Ittermann, Bernd; Martinot, Jean-Luc; Paillère Martinot, Marie-Laure; Lemaitre, Hervé; Nees, Frauke; Papadopoulos Orfanos, Dimitri; Paus, Tomáš; Poustka, Luise; Millenet, Sabina; Fröhner, Juliane H; Smolka, Michael N; Walter, Henrik; Whelan, Robert; Schumann, Gunter; Napolioni, Valerio; Greicius, Michael

    2017-10-04

    The nicotinic system plays an important role in cognitive control and is implicated in several neuropsychiatric conditions. However, the contributions of genetic variability in this system to individuals' cognitive control abilities are poorly understood and the brain processes that mediate such genetic contributions remain largely unidentified. In this first large-scale neuroimaging genetics study of the human nicotinic receptor system (two cohorts, males and females, fMRI total N = 1586, behavioral total N = 3650), we investigated a common polymorphism of the high-affinity nicotinic receptor α4β2 (rs1044396 on the CHRNA4 gene) previously implicated in behavioral and nicotine-related studies (albeit with inconsistent major/minor allele impacts). Based on our prior neuroimaging findings, we expected this polymorphism to affect neural activity in the cingulo-opercular (CO) network involved in core cognitive control processes including maintenance of alertness. Consistent across the cohorts, all cortical areas of the CO network showed higher activity in heterozygotes compared with both types of homozygotes during cognitive engagement. This inverted U-shaped relation reflects an overdominant effect; that is, allelic interaction (cumulative evidence p = 1.33 * 10(-5)). Furthermore, heterozygotes performed more accurately in behavioral tasks that primarily depend on sustained alertness. No effects were observed for haplotypes of the surrounding CHRNA4 region, supporting a true overdominant effect at rs1044396. As a possible mechanism, we observed that this polymorphism is an expression quantitative trait locus modulating CHRNA4 expression levels. This is the first report of overdominance in the nicotinic system. These findings connect CHRNA4 genotype, CO network activation, and sustained alertness, providing insights into how genetics shapes individuals' cognitive control abilities.SIGNIFICANCE STATEMENT The nicotinic acetylcholine system plays a central role in

  3. The robustness and restoration of a network of ecological networks.

    Science.gov (United States)

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

    2012-02-24

    Understanding species' interactions and the robustness of interaction networks to species loss is essential to understand the effects of species' declines and extinctions. In most studies, different types of networks (such as food webs, parasitoid webs, seed dispersal networks, and pollination networks) have been studied separately. We sampled such multiple networks simultaneously in an agroecosystem. We show that the networks varied in their robustness; networks including pollinators appeared to be particularly fragile. We show that, overall, networks did not strongly covary in their robustness, which suggests that ecological restoration (for example, through agri-environment schemes) benefitting one functional group will not inevitably benefit others. Some individual plant species were disproportionately well linked to many other species. This type of information can be used in restoration management, because it identifies the plant taxa that can potentially lead to disproportionate gains in biodiversity.

  4. Effects of social environment and personality on communication in male Siamese fighting fish in an artificial network

    DEFF Research Database (Denmark)

    Matessi, Giuliano; Matos, Ricardo Jorge Santa Clara; Peake, Tom M.

    2010-01-01

    Individuals of the same species, sex, age and size may differ in suites of behaviour traits in a consistent manner across time and may thus represent different personalities. In a communication context, the personality of an individual may both affect and be affected by the behaviour...... of the individuals surrounding it within a network. We investigated the effects of a change of local social environment on two behavioural types, ‘persistent' versus ‘sporadic' signaller, in Siamese fighting fish, Betta splendens. Males visually interacted for 1 day in a communication network of seven fish in tanks...... arranged in a hexagonal grid, while we recorded space use and signalling data. We then exchanged the positions of two males with different behavioural types and observed them interacting the following day. ‘Persistent' signallers were unaffected by the treatment, while ‘sporadic' signallers increased...

  5. Expression Profiling of Human Genetic and Protein Interaction Networks in Type 1 Diabetes

    DEFF Research Database (Denmark)

    Brunak, Søren; Bergholdt, R; Brorsson, C

    2009-01-01

    Proteins contributing to a complex disease are often members of the same functional pathways. Elucidation of such pathways may provide increased knowledge about functional mechanisms underlying disease. By combining genetic interactions in Type 1 Diabetes (T1D) with protein interaction data we have...... stress, regulation of transcription and apoptosis. To understand biological systems, integration of genetic and functional information is necessary, and the current study has used this approach to improve understanding of T1D and the underlying biological mechanisms....

  6. Mitigating Adverse Effects of Using Online Social Networks

    OpenAIRE

    Paul, Thomas

    2016-01-01

    Online Social Networks (OSNs), such as Facebook and Google+, are network-based communication systems. They allow their users to create persistent digital representations of themselves, called user profiles, and to establish explicit connections to other user profiles within a bounded system. OSNs have become popular services that attract more than one billion users. The ubiquity of mobile devices, which support accessing OSNs from anywhere, causes OSNs to be powerful communication tools that ...

  7. The effects of redundancy and information manipulation on traffic networks

    OpenAIRE

    Özel, Berk; Ozel, Berk

    2014-01-01

    Traffic congestion is one of the most frequently encountered problems in real life. It is not only a scientific concern of scholars, but also an inevitable issue for most of the individuals living in urban areas. Since every driver in traffic networks tries to minimize own journey length, and volume of the traffic prevents coordination between individuals, a cooperative behavior will not be provided spontaneously in order to decrease the total cost of the network and the time spent on traffic...

  8. Demand Based Effective Energy Utilization in Mobile Ad Hoc Networks

    OpenAIRE

    Bhuvaneswari, R.; Viswanathan, M

    2012-01-01

    Mobile Ad Hoc Networks (MANET) are the collection of mobile nodes without any centralized infrastructure. The underlying assumption is that the intermediate nodes cooperate in forwarding packets. Mobile nodes collects the route information through overhearing and stores these information in route caches with the use of Dynamic Source Routing (DSR) Protocol. These nodes consume power unnecessarily due to overhearing the transmissions of their neighbors. Due to this, the network performance is ...

  9. Stochastic effects as a force to increase the complexity of signaling networks

    KAUST Repository

    Kuwahara, Hiroyuki

    2013-07-29

    Cellular signaling networks are complex and appear to include many nonfunctional elements. Recently, it was suggested that nonfunctional interactions of proteins cause signaling noise, which, perhaps, shapes the signal transduction mechanism. However, the conditions under which molecular noise influences cellular information processing remain unclear. Here, we explore a large number of simple biological models of varying network sizes to understand the architectural conditions under which the interactions of signaling proteins can exhibit specific stochastic effects - called deviant effects - in which the average behavior of a biological system is substantially altered in the presence of molecular noise. We find that a small fraction of these networks does exhibit deviant effects and shares a common architectural feature whereas most of the networks show only insignificant levels of deviations. Interestingly, addition of seemingly unimportant interactions into protein networks gives rise to deviant effects.

  10. Developing a Framework for Effective Network Capacity Planning

    Science.gov (United States)

    Yaprak, Ece

    2005-01-01

    As Internet traffic continues to grow exponentially, developing a clearer understanding of, and appropriately measuring, network's performance is becoming ever more critical. An important challenge faced by the Information Resources Directorate (IRD) at the Johnson Space Center in this context remains not only monitoring and maintaining a secure network, but also better understanding the capacity and future growth potential boundaries of its network. This requires capacity planning which involves modeling and simulating different network alternatives, and incorporating changes in design as technologies, components, configurations, and applications change, to determine optimal solutions in light of IRD's goals, objectives and strategies. My primary task this summer was to address this need. I evaluated network-modeling tools from OPNET Technologies Inc. and Compuware Corporation. I generated a baseline model for Building 45 using both tools by importing "real" topology/traffic information using IRD's various network management tools. I compared each tool against the other in terms of the advantages and disadvantages of both tools to accomplish IRD's goals. I also prepared step-by-step "how to design a baseline model" tutorial for both OPNET and Compuware products.

  11. Monitoring air quality in mountains: Designing an effective network

    Science.gov (United States)

    Peterson, D.L.

    2000-01-01

    A quantitatively robust yet parsimonious air-quality monitoring network in mountainous regions requires special attention to relevant spatial and temporal scales of measurement and inference. The design of monitoring networks should focus on the objectives required by public agencies, namely: 1) determine if some threshold has been exceeded (e.g., for regulatory purposes), and 2) identify spatial patterns and temporal trends (e.g., to protect natural resources). A short-term, multi-scale assessment to quantify spatial variability in air quality is a valuable asset in designing a network, in conjunction with an evaluation of existing data and simulation-model output. A recent assessment in Washington state (USA) quantified spatial variability in tropospheric ozone distribution ranging from a single watershed to the western third of the state. Spatial and temporal coherence in ozone exposure modified by predictable elevational relationships ( 1.3 ppbv ozone per 100 m elevation gain) extends from urban areas to the crest of the Cascade Range. This suggests that a sparse network of permanent analyzers is sufficient at all spatial scales, with the option of periodic intensive measurements to validate network design. It is imperative that agencies cooperate in the design of monitoring networks in mountainous regions to optimize data collection and financial efficiencies.

  12. Effect of edge pruning on structural controllability and observability of complex networks

    Science.gov (United States)

    Mengiste, Simachew Abebe; Aertsen, Ad; Kumar, Arvind

    2015-12-01

    Controllability and observability of complex systems are vital concepts in many fields of science. The network structure of the system plays a crucial role in determining its controllability and observability. Because most naturally occurring complex systems show dynamic changes in their network connectivity, it is important to understand how perturbations in the connectivity affect the controllability of the system. To this end, we studied the control structure of different types of artificial, social and biological neuronal networks (BNN) as their connections were progressively pruned using four different pruning strategies. We show that the BNNs are more similar to scale-free networks than to small-world networks, when comparing the robustness of their control structure to structural perturbations. We introduce a new graph descriptor, ‘the cardinality curve’, to quantify the robustness of the control structure of a network to progressive edge pruning. Knowing the susceptibility of control structures to different pruning methods could help design strategies to destroy the control structures of dangerous networks such as epidemic networks. On the other hand, it could help make useful networks more resistant to edge attacks.

  13. Effect and Analysis of Sustainable Cell Rate using MPEG video Traffic in ATM Networks

    Directory of Open Access Journals (Sweden)

    Sakshi Kaushal

    2006-04-01

    Full Text Available The broadband networks inhibit the capability to carry multiple types of traffic – voice, video and data, but these services need to be controlled according to the traffic contract negotiated at the time of the connection to maintain desired Quality of service. Such control techniques use traffic descriptors to evaluate its performance and effectiveness. In case of Variable Bit Rate (VBR services, Peak Cell Rate (PCR and its Cell Delay Variation Tolerance (CDVTPCR are mandatory descriptors. In addition to these, ATM Forum proposed Sustainable Cell Rate (SCR and its Cell delay variation tolerance (CDVTSCR. In this paper, we evaluated the impact of specific SCR and CDVTSCR values on the Usage Parameter Control (UPC performance in case of measured MPEG traffic for improving the efficiency

  14. Modeling the effects of social impact on epidemic spreading in complex networks

    Science.gov (United States)

    Ni, Shunjiang; Weng, Wenguo; Zhang, Hui

    2011-11-01

    We investigate by mean-field analysis and extensive simulations the effects of social impact on epidemic spreading in various typical networks with two types of nodes: active nodes and passive nodes, of which the behavior patterns are modeled according to the social impact theory. In this study, nodes are not only the media to spread the virus, but also disseminate their opinions on the virus-whether there is a need for certain self-protection measures to be taken to reduce the risk of being infected. Our results indicate that the interaction between epidemic spreading and opinion dynamics can have significant influences on the spreading of infectious diseases and related applications, such as the implementation of prevention and control measures against the infectious diseases.

  15. Effect of diet on type 2 diabetes mellitus: a review.

    Science.gov (United States)

    Khazrai, Y M; Defeudis, G; Pozzilli, P

    2014-03-01

    Type 2 diabetes mellitus is one of the fastest growing diseases; the number of people affected by diabetes will soon reach 552 million worldwide, with associated increases in complications and healthcare expenditure. Lifestyle and medical nutrition therapy are considered the keystones of type 2 diabetes prevention and treatment, but there is no definite consensus on how to treat this disease with these therapies. The American Diabetes Association has made several recommendations regarding the medical nutrition therapy of diabetes; these emphasize the importance of minimizing macrovascular and microvascular complications in people with diabetes. Four types of diets were reviewed for their effects on diabetes: the Mediterranean diet, a low-carbohydrate/high-protein diet, a vegan diet and a vegetarian diet. Each of the four types of diet has been shown to improve metabolic conditions, but the degree of improvement varies from patient to patient. Therefore, it is necessary to evaluate a patient's pathophysiological characteristics in order to determine the diet that will achieve metabolic improvement in each individual. Many dietary regimens are available for patients with type 2 diabetes to choose from, according to personal taste and cultural tradition. It is important to provide a tailor-made diet wherever possible in order to maximize the efficacy of the diet on reducing diabetes symptoms and to encourage patient adherence. Additional randomized studies, both short term (to analyse physiological responses) and long term, could help reduce the multitude of diets currently recommended and focus on a shorter list of useful regimens. Copyright © 2013 John Wiley & Sons, Ltd.

  16. Understanding Challenges, Strategies, and the Role of Support Networks in Medication Self-management Among Patients With Type 2 Diabetes.

    Science.gov (United States)

    Bernhard, Gerda; Ose, Dominik; Baudendistel, Ines; Seidling, Hanna M; Stützle, Marion; Szecsenyi, Joachim; Wensing, Michel; Mahler, Cornelia

    2017-04-01

    Purpose The purpose of this qualitative study was to investigate the challenges and strategies of patients with type 2 diabetes mellitus (T2DM) regarding daily management of their medication regimen focusing on the role of their support networks. Methods A purposeful sample of 25 patients with T2DM was recruited from local self-help groups, general practitioner practices, and a university hospital in southwestern Germany. Four semi-structured focus groups were conducted to identify the challenges patients experienced, the strategies they used, and their collaboration with support networks to assist them in self-managing their medication regimen. Sessions were audio- and video-recorded, fully transcribed, and subjected to computer-aided qualitative content analysis, guided by the Self- and Family Management Framework (SFMF). Results Patients with T2DM experienced numerous challenges affecting medication self-management arising from their personal situation, health status and resources, characteristics of their regimen, and how health care is currently organized. Patients' self-initiated strategies included activating health care, community, social, and online resources; taking ownership of medication-related needs; and integrating medication-taking into daily life. Patients drew on self-help groups, family, and friends to discuss concerns regarding medication safety and receive experience-based information and advice for navigating within the health care system as well as practical hands-on support with daily medication self-management. Conclusions Understanding the challenges and building on strategies patients with T2DM devised help diabetes educators to better address patients' needs and priorities and guide patient-centered interventions to support patients' self-management activities. Community and social support networks operating in patients' lives need to be engaged in the self-management support.

  17. Social networking and understanding alcohol-associated risk for people with type 1 diabetes: friend or foe?

    Science.gov (United States)

    Jones, Emma; Sinclair, Julia M A; Holt, Richard I G; Barnard, Katharine D

    2013-04-01

    Online communication has become popular in recent years, especially for young people. Limited research exists into how people with type 1 diabetes mellitus (T1DM) discuss risks about diabetes. Alcohol use by people with T1DM, as in the rest of society, is common and may adversely affect diabetes management. This study reviewed the literature on social networking as a communication tool and conducted a systematic search of social networking sites to determine whether people with T1DM use them to discuss risks associated with diabetes and alcohol consumption. Systematic literature review was performed followed by an Internet search and forum identification relating to T1DM and alcohol. Qualitative coding and thematic analysis of publicly available data retrieved from social networking sites were undertaken. In the literature review, 292 articles were identified, of which six met the inclusion criteria. Widespread use of social media for medical advice pertaining to diabetes was reported. The quality and safety of online advice were reported as variable. Ten Web sites with 247 individual postings about alcohol and diabetes were selected for analysis, which revealed six themes ranging from safety and seeking and provision of advice to wider views about behaviors, opinions, and experiences of people with T1DM and alcohol. No specific professional health information was identified on any sites, and inaccurate information was common. Online resources are used by people with T1DM to find information about diabetes and alcohol consumption. Easily signposted and accessible professional online resources would ensure people can access appropriate advice to minimize risks of alcohol use.

  18. Changes in MEG resting-state networks are related to cognitive decline in type 1 diabetes mellitus patients.

    Science.gov (United States)

    Demuru, Matteo; van Duinkerken, Eelco; Fraschini, Matteo; Marrosu, Francesco; Snoek, Frank J; Barkhof, Frederik; Klein, Martin; Diamant, Michaela; Hillebrand, Arjan

    2014-01-01

    Integrity of resting-state functional brain networks (RSNs) is important for proper cognitive functioning. In type 1 diabetes mellitus (T1DM) cognitive decrements are commonly observed, possibly due to alterations in RSNs, which may vary according to microvascular complication status. Thus, we tested the hypothesis that functional connectivity in RSNs differs according to clinical status and correlates with cognition in T1DM patients, using an unbiased approach with high spatio-temporal resolution functional network. Resting-state magnetoencephalographic (MEG) data for T1DM patients with (n = 42) and without (n = 41) microvascular complications and 33 healthy participants were recorded. MEG time-series at source level were reconstructed using a recently developed atlas-based beamformer. Functional connectivity within classical frequency bands, estimated by the phase lag index (PLI), was calculated within eight commonly found RSNs. Neuropsychological tests were used to assess cognitive performance, and the relation with RSNs was evaluated. Significant differences in terms of RSN functional connectivity between the three groups were observed in the lower alpha band, in the default-mode (DMN), executive control (ECN) and sensorimotor (SMN) RSNs. T1DM patients with microvascular complications showed the weakest functional connectivity in these networks relative to the other groups. For DMN, functional connectivity was higher in patients without microangiopathy relative to controls (all p cognitive performance for both patient groups was worse compared with healthy controls. Lower DMN alpha band functional connectivity correlated with poorer general cognitive ability in patients with microvascular complications. Altered RSN functional connectivity was found in T1DM patients depending on clinical status. Lower DMN functional connectivity was related to poorer cognitive functioning. These results indicate that functional connectivity may play a key role in T1DM

  19. Intrinsic connectivity networks from childhood to late adolescence: Effects of age and sex

    Directory of Open Access Journals (Sweden)

    Cristina Solé-Padullés

    2016-02-01

    Full Text Available There is limited evidence on the effects of age and sex on intrinsic connectivity of networks underlying cognition during childhood and adolescence. Independent component analysis was conducted in 113 subjects aged 7–18; the default mode, executive control, anterior salience, basal ganglia, language and visuospatial networks were identified. The effect of age was examined with multiple regression, while sex and ‘age × sex’ interactions were assessed by dividing the sample according to age (7–12 and 13–18 years. As age increased, connectivity in the dorsal and ventral default mode network became more anterior and posterior, respectively, while in the executive control network, connectivity increased within frontoparietal regions. The basal ganglia network showed increased engagement of striatum, thalami and precuneus. The anterior salience network showed greater connectivity in frontal areas and anterior cingulate, and less connectivity of orbitofrontal, middle cingulate and temporoparietal regions. The language network presented increased connectivity of inferior frontal and decreased connectivity within the right middle frontal and left inferior parietal cortices. The visuospatial network showed greater engagement of inferior parietal and frontal cortices. No effect of sex, nor age by sex interactions was observed. These findings provide evidence of strengthening of cortico-cortical and cortico-subcortical networks across childhood and adolescence.

  20. Dopamine-dependent effects on basal and glutamate stimulated network dynamics in cultured hippocampal neurons.

    Science.gov (United States)

    Li, Yan; Chen, Xin; Dzakpasu, Rhonda; Conant, Katherine

    2017-02-01

    Oscillatory activity occurs in cortical and hippocampal networks with specific frequency ranges thought to be critical to working memory, attention, differentiation of neuronal precursors, and memory trace replay. Synchronized activity within relatively large neuronal populations is influenced by firing and bursting frequency within individual cells, and the latter is modulated by changes in intrinsic membrane excitability and synaptic transmission. Published work suggests that dopamine, a potent modulator of learning and memory, acts on dopamine receptor 1-like dopamine receptors to influence the phosphorylation and trafficking of glutamate receptor subunits, along with long-term potentiation of excitatory synaptic transmission in striatum and prefrontal cortex. Prior studies also suggest that dopamine can influence voltage gated ion channel function and membrane excitability in these regions. Fewer studies have examined dopamine's effect on related endpoints in hippocampus, or potential consequences in terms of network burst dynamics. In this study, we record action potential activity using a microelectrode array system to examine the ability of dopamine to modulate baseline and glutamate-stimulated bursting activity in an in vitro network of cultured murine hippocampal neurons. We show that dopamine stimulates a dopamine type-1 receptor-dependent increase in number of overall bursts within minutes of its application. Notably, however, at the concentration used herein, dopamine did not increase the overall synchrony of bursts between electrodes. Although the number of bursts normalizes by 40 min, bursting in response to a subsequent glutamate challenge is enhanced by dopamine pretreatment. Dopamine-dependent potentiation of glutamate-stimulated bursting was not observed when the two modulators were administered concurrently. In parallel, pretreatment of murine hippocampal cultures with dopamine stimulated lasting increases in the phosphorylation of the

  1. Altered power spectral density in the resting-state sensorimotor network in patients with myotonic dystrophy type 1.

    Science.gov (United States)

    Park, Jin-Sung; Seo, Jeehye; Cha, Hyunsil; Song, Hui-Jin; Lee, Sang-Hoon; Jang, Kyung Eun; Lee, Hui Joong; Park, Juyoung; Lee, Ho-Won; Chang, Yongmin

    2018-01-17

    Myotonic dystrophy type 1 (DM1) is a multisystemic disease that involves the brain with several neurological symptoms. Although there were few imaging studies on DM1, no studies have investigated functional alterations in the sensorimotor network at rest in patients with DM1. In the current study, a power spectral density (PSD) analysis of resting-state fMRI data was performed to assess possible alteration in spontaneous neural activity of the sensorimotor network in patients with DM1. Compared to healthy controls, patients with DM1 showed higher PSD responses in the orbitofrontal cortex, parahippocampus and basal ganglia (corrected P < 0.05). Patients with DM1 showed higher PSD responses in white matter structures associated with motor function (corrected P < 0.05). Furthermore, correlation analysis indicated that the brain regions showing PSD differences were correlated with measures of motor performance (P < 0.05). In gray matter, our findings suggest that motor disability in DM1 is not an isolated deterioration of the motor power but a multimodal dysfunction that also involves the visual system. In addition, the widespread PSD alteration in white matter structures suggest that motor deficits in DM1 involve motor movement structures as well as structures important for its coordination and regulation.

  2. Effect of Heterogeneity on Decorrelation Mechanisms in Spiking Neural Networks: A Neuromorphic-Hardware Study

    Directory of Open Access Journals (Sweden)

    Thomas Pfeil

    2016-05-01

    Full Text Available High-level brain function, such as memory, classification, or reasoning, can be realized by means of recurrent networks of simplified model neurons. Analog neuromorphic hardware constitutes a fast and energy-efficient substrate for the implementation of such neural computing architectures in technical applications and neuroscientific research. The functional performance of neural networks is often critically dependent on the level of correlations in the neural activity. In finite networks, correlations are typically inevitable due to shared presynaptic input. Recent theoretical studies have shown that inhibitory feedback, abundant in biological neural networks, can actively suppress these shared-input correlations and thereby enable neurons to fire nearly independently. For networks of spiking neurons, the decorrelating effect of inhibitory feedback has so far been explicitly demonstrated only for homogeneous networks of neurons with linear subthreshold dynamics. Theory, however, suggests that the effect is a general phenomenon, present in any system with sufficient inhibitory feedback, irrespective of the details of the network structure or the neuronal and synaptic properties. Here, we investigate the effect of network heterogeneity on correlations in sparse, random networks of inhibitory neurons with nonlinear, conductance-based synapses. Emulations of these networks on the analog neuromorphic-hardware system Spikey allow us to test the efficiency of decorrelation by inhibitory feedback in the presence of hardware-specific heterogeneities. The configurability of the hardware substrate enables us to modulate the extent of heterogeneity in a systematic manner. We selectively study the effects of shared input and recurrent connections on correlations in membrane potentials and spike trains. Our results confirm that shared-input correlations are actively suppressed by inhibitory feedback also in highly heterogeneous networks exhibiting broad

  3. Accelerating rate calorimetry study on the thermal stability of interpenetrating network type poly(siloxane-g-ethylene oxide) polymer electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Bookeun; Hyung, Yoo-Eup; Vissers, Donald R.; Amine, Khalil

    2003-06-30

    Safety study regarding an exothermic reaction at elevated temperature of comb-shaped siloxane polymer and its interpenetrating network type solid polymer electrolyte (SPE) are investigated. Accelerating rate calorimetry (ARC) is used to examine exothermic reactions. The thermal stability of the polymer electrolyte in the presence of charged electrodes is also monitored. Resulting data were compared with those of 1.0 M LiPF{sub 6} in ethylene carbonate:ethyl methyl carbonate (3:7 by wt.) electrolyte. The self-heating exothermic reaction of mono comb-shaped siloxane polymer electrolyte starts at approximately 300 deg. C. Comparison of the heat generation profiles from ARC tests indicates that SPE reduces the intensity of exothermic reactions resulting from charged electrodes and electrolyte.

  4. A neural network based computational model to predict the output power of different types of photovoltaic cells.

    Directory of Open Access Journals (Sweden)

    WenBo Xiao

    Full Text Available In this article, we introduced an artificial neural network (ANN based computational model to predict the output power of three types of photovoltaic cells, mono-crystalline (mono-, multi-crystalline (multi-, and amorphous (amor- crystalline. The prediction results are very close to the experimental data, and were also influenced by numbers of hidden neurons. The order of the solar generation power output influenced by the external conditions from smallest to biggest is: multi-, mono-, and amor- crystalline silicon cells. In addition, the dependences of power prediction on the number of hidden neurons were studied. For multi- and amorphous crystalline cell, three or four hidden layer units resulted in the high correlation coefficient and low MSEs. For mono-crystalline cell, the best results were achieved at the hidden layer unit of 8.

  5. A neural network based computational model to predict the output power of different types of photovoltaic cells.

    Science.gov (United States)

    Xiao, WenBo; Nazario, Gina; Wu, HuaMing; Zhang, HuaMing; Cheng, Feng

    2017-01-01

    In this article, we introduced an artificial neural network (ANN) based computational model to predict the output power of three types of photovoltaic cells, mono-crystalline (mono-), multi-crystalline (multi-), and amorphous (amor-) crystalline. The prediction results are very close to the experimental data, and were also influenced by numbers of hidden neurons. The order of the solar generation power output influenced by the external conditions from smallest to biggest is: multi-, mono-, and amor- crystalline silicon cells. In addition, the dependences of power prediction on the number of hidden neurons were studied. For multi- and amorphous crystalline cell, three or four hidden layer units resulted in the high correlation coefficient and low MSEs. For mono-crystalline cell, the best results were achieved at the hidden layer unit of 8.

  6. Cost effectiveness of type 2 diabetes screening: A systematic review.

    Science.gov (United States)

    Najafi, Behzad; Farzadfar, Farshad; Ghaderi, Hossein; Hadian, Mohammad

    2016-01-01

    Although studies reported diabetes mellitus screening cost effective, the mass screening for type2 diabetes remains controversial. In this study we reviewed the recently evidence about the cost effectiveness of mass screening systematically. We reviewed the MEDLINE, Scopus, Web of Science (WOS), and Cochrane library databases by MeSH terms to identify relevant studies from 2000 to 2013. We had 4 inclusion and 6 exclusion criteria and used the Drummond's checklist for appraising the quality of studies. The initial search yielded 358 potentially related studies from selected databases. 6 studies met our inclusion and exclusion criteria and included in final review. 3 and 2 of them were conducted in Europe and America and only one of them in Asia. Quality-adjusted life year (QALY) was the main outcome to appraise the effectiveness in the studies. Incremental cost effectiveness ratio (ICER) was computed in range from $516.33 to $126,238 per QALY in the studies. A review of previous diabetes screening cost effectiveness analysis showed that the studies varied in some aspects but reached similar conclusions. They concluded that the screening may be cost effective, however further studies is required to support the diabetes mass screening.

  7. Cost effectiveness of type 2 diabetes screening: A systematic review

    Science.gov (United States)

    Najafi, Behzad; Farzadfar, Farshad; Ghaderi, Hossein; Hadian, Mohammad

    2016-01-01

    Background: Although studies reported diabetes mellitus screening cost effective, the mass screening for type2 diabetes remains controversial. In this study we reviewed the recently evidence about the cost effectiveness of mass screening systematically. Methods: We reviewed the MEDLINE, Scopus, Web of Science (WOS), and Cochrane library databases by MeSH terms to identify relevant studies from 2000 to 2013. We had 4 inclusion and 6 exclusion criteria and used the Drummond’s checklist for appraising the quality of studies. Results: The initial search yielded 358 potentially related studies from selected databases. 6 studies met our inclusion and exclusion criteria and included in final review. 3 and 2 of them were conducted in Europe and America and only one of them in Asia. Quality-adjusted life year (QALY) was the main outcome to appraise the effectiveness in the studies. Incremental cost effectiveness ratio (ICER) was computed in range from $516.33 to $126,238 per QALY in the studies. Conclusion: A review of previous diabetes screening cost effectiveness analysis showed that the studies varied in some aspects but reached similar conclusions. They concluded that the screening may be cost effective, however further studies is required to support the diabetes mass screening. PMID:27390696

  8. Tissue and cell-type co-expression networks of transcription factors and wood component genes in Populus trichocarpa.

    Science.gov (United States)

    Shi, Rui; Wang, Jack P; Lin, Ying-Chung; Li, Quanzi; Sun, Ying-Hsuan; Chen, Hao; Sederoff, Ronald R; Chiang, Vincent L

    2017-05-01

    Co-expression networks based on transcriptomes of Populus trichocarpa major tissues and specific cell types suggest redundant control of cell wall component biosynthetic genes by transcription factors in wood formation. We analyzed the transcriptomes of five tissues (xylem, phloem, shoot, leaf, and root) and two wood forming cell types (fiber and vessel) of Populus trichocarpa to assemble gene co-expression subnetworks associated with wood formation. We identified 165 transcription factors (TFs) that showed xylem-, fiber-, and vessel-specific expression. Of these 165 TFs, 101 co-expressed (correlation coefficient, r > 0.7) with the 45 secondary cell wall cellulose, hemicellulose, and lignin biosynthetic genes. Each cell wall component gene co-expressed on average with 34 TFs, suggesting redundant control of the cell wall component gene expression. Co-expression analysis showed that the 101 TFs and the 45 cell wall component genes each has two distinct groups (groups 1 and 2), based on their co-expression patterns. The group 1 TFs (44 members) are predominantly xylem and fiber specific, and are all highly positively co-expressed with the group 1 cell wall component genes (30 members), suggesting their roles as major wood formation regulators. Group 1 TFs include a lateral organ boundary domain gene (LBD) that has the highest number of positively correlated cell wall component genes (36) and TFs (47). The group 2 TFs have 57 members, including 14 vessel-specific TFs, and are generally less correlated with the cell wall component genes. An exception is a vessel-specific basic helix-loop-helix (bHLH) gene that negatively correlates with 20 cell wall component genes, and may function as a key transcriptional suppressor. The co-expression networks revealed here suggest a well-structured transcriptional homeostasis for cell wall component biosynthesis during wood formation.

  9. Effects of global gas flows on type I migration

    Science.gov (United States)

    Ogihara, Masahiro; Kokubo, Eiichiro; Suzuki, Takeru K.; Morbidelli, Alessandro; Crida, Aurélien

    2017-12-01

    Context. Magnetically-driven disk winds would alter the surface density slope of gas in the inner region of a protoplanetary disk (r ≲ 1 au). This in turn affects planet formation. Recently, the effect of disk wind torque has been considered with the suggestion that it would carve out the surface density of the disk from inside and would induce global gas flows (wind-driven accretion). Aims: We aim to investigate effects of global gas flows on type I migration and also examine planet formation. Methods: A simplified approach was taken to address this issue, and N-body simulations with isolation-mass planets were also performed. Results: In previous studies, the effect of gas flow induced by turbulence-driven accretion has been taken into account for its desaturation effect of the corotation torque. If more rapid gas flows (e.g., wind-driven accretion) are considered, the desaturation effect can be modified. In MRI-inactive disks, in which the wind-driven accretion dominates the disk evolution, the gas flow at the midplane plays an important role. If this flow is fast, the corotation torque is efficiently desaturated. Then, the fact that the surface density slope can be positive in the inner region due to the wind torque can generate an outward migration region extended to super-Earth mass planets. In this case, we observe that no planets fall onto the central star in N-body simulations with migration forces imposed to reproduce such migration pattern. We also see that super-Earth mass planets can undergo outward migration. Conclusions: Relatively rapid gas flows affects type I migration and thus the formation of close-in planets.

  10. Network effects across the earnings distribution: payoffs to visible and invisible job finding assistance.

    Science.gov (United States)

    McDonald, Steve

    2015-01-01

    This study makes three critical contributions to the "Do Contacts Matter?" debate. First, the widely reported null relationship between informal job searching and wages is shown to be mostly the artifact of a coding error and sample selection restrictions. Second, previous analyses examined only active informal job searching without fully considering the benefits derived from unsolicited network assistance (the "invisible hand of social capital") - thereby underestimating the network effect. Third, wage returns to networks are examined across the earnings distribution. Longitudinal data from the NLSY reveal significant wage returns for network-based job finding over formal job searching, especially for individuals who were informally recruited into their jobs (non-searchers). Fixed effects quantile regression analyses show that contacts generate wage premiums among middle and high wage jobs, but not low wage jobs. These findings challenge conventional wisdom on contact effects and advance understanding of how social networks affect wage attainment and inequality. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Activity and High-Order Effective Connectivity Alterations in Sanfilippo C Patient-Specific Neuronal Networks

    Directory of Open Access Journals (Sweden)

    Isaac Canals

    2015-10-01

    Full Text Available Induced pluripotent stem cell (iPSC technology has been successfully used to recapitulate phenotypic traits of several human diseases in vitro. Patient-specific iPSC-based disease models are also expected to reveal early functional phenotypes, although this remains to be proved. Here, we generated iPSC lines from two patients with Sanfilippo type C syndrome, a lysosomal storage disorder with inheritable progressive neurodegeneration. Mature neurons obtained from patient-specific iPSC lines recapitulated the main known phenotypes of the disease, not present in genetically corrected patient-specific iPSC-derived cultures. Moreover, neuronal networks organized in vitro from mature patient-derived neurons showed early defects in neuronal activity, network-wide degradation, and altered effective connectivity. Our findings establish the importance of iPSC-based technology to identify early functional phenotypes, which can in turn shed light on the pathological mechanisms occurring in Sanfilippo syndrome. This technology also has the potential to provide valuable readouts to screen compounds, which can prevent the onset of neurodegeneration.

  12. Flat electronic bands in fractal-kagomé network and the effect of perturbation

    Energy Technology Data Exchange (ETDEWEB)

    Nandy, Atanu, E-mail: atanunandy1989@gmail.com; Chakrabarti, Arunava, E-mail: arunava-chakrabarti@yahoo.co.in [Department of Physics, University of Kalyani, Kalyani, West Bengal - 741235 (India)

    2016-05-06

    We demonstrate an analytical prescription of demonstrating the flat band [FB] states in a fractal incorporated kagomé type network that can give rise to a countable infinity of flat non-dispersive eigenstates with a multitude of localization area. The onset of localization can, in principle, be delayed in space by an appropriate choice of energy regime. The length scale, at which the onset of localization for each mode occurs, can be tuned at will following the formalism developed within the framework of real space renormalization group. This scheme leads to an exact determination of energy eigenvalue for which one can have dispersionless flat electronic bands. Furthermore, we have shown the effect ofuniform magnetic field for the same non-translationally invariant network model that has ultimately led to an‘apparent invisibility’ of such staggered localized states and to generate absolutely continuous sub-bands in the energy spectrum and again an interesting re-entrant behavior of those FB states.

  13. Effect of salinity on regulation mechanism of neuroendocrine-immunoregulatory network in Litopenaeus vannamei.

    Science.gov (United States)

    Zhao, Qun; Pan, Luqing; Ren, Qin; Wang, Lin; Miao, Jingjing

    2016-02-01

    The effects of low salinity (transferred from 31‰ to 26‰, 21‰, and 16‰) on the regulation pathways of neuroendocrine-immunoregulatory network were investigated in Litopenaeus vannamei. The results showed that the hormones (corticotrophin-releasing hormone, adrenocorticotropic hormone) and biogenic amines (dopamine, noradrenaline, 5-hydroxytryptamine) concentrations in lower salinity groups increased significantly within 12 h. The gene expression of biogenic amine receptors showed that dopamine receptor D4 and α2 adrenergic receptor in lower salinity groups decreased significantly within 12 h, whereas the 5-HT7 receptor significantly increased within 1d. The second messenger synthetases (adenylyl cyclase, phospholipase C) and the second messengers (cyclic adenosine monophosphate, cyclic guanosine monophosphate) of lower salinity groups shared a similar trend in which adenylyl cyclase and cyclic adenosine monophosphate reached the maximum at 12 h, whereas phospholipase C and cyclic guanosine monophosphate reached the minimum. The immune parameters (total hemocyte count, phenoloxidase activity, phagocytic activity, crustin expression, antibacterial activity, C-type lectin expression, hemagglutinating activity) in lower salinity groups decreased significantly within 12 h. Except for the total hemocyte count, all the parameters recovered to the control levels afterwards. Therefore, it may be concluded that the neuroendocrine-immunoregulatory network plays a principal role in adapting to salinity changes as the main center for sensing the stress and causes immune response in L. vannamei. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Establishing a network of specialist Porphyria centres - effects on diagnostic activities and services.

    Science.gov (United States)

    Tollånes, Mette C; Aarsand, Aasne K; Villanger, Jørild Haugen; Støle, Egil; Deybach, Jean-Charles; Marsden, Joanne; To-Figueras, Jordi; Sandberg, Sverre

    2012-12-10

    The porphyrias are a heterogeneous group of rare metabolic diseases. The full spectrum of porphyria diagnostics is usually performed by specialized porphyria laboratories or centres. The European Porphyria Initiative (EPI), a collaborative network of porphyria centres formed in 2001, evolved in 2007 into the European Porphyria Network (EPNET), where participating centres are required to adhere to agreed quality criteria. The aim of this study was to examine the state and distribution of porphyria diagnostic services in 2009 and to explore potential effects of increased international collaboration in the field of these rare diseases in the period 2006-2009. Data on laboratory, diagnostic and clinical activities and services reported to EPI/EPNET in yearly activity reports during 2006 through 2009 were compared between reporting centres, and possible time trends explored. Thirty-five porphyria centres from 22 countries, five of which were non-European associate EPNET members, filed one or more activity reports to EPI/EPNET during the study period. Large variations between centres were observed in the analytical repertoire offered, numbers of analyses performed and type and number of staff engaged. The proportion of centres fulfilling the minimum criteria set by EPNET to be classified as a specialist porphyria centre increased from 80% to 94% during the study period. Porphyria services are unevenly distributed, and some areas are probably still lacking in specialized porphyria services altogether. However, improvements in the quality of diagnostic services provided by porphyria centres participating in EPI/EPNET were observed during 2006 through 2009.

  15. The effect of awareness on networked SIS epidemics

    KAUST Repository

    Paarporn, Keith

    2017-01-05

    We study an SIS epidemic model over an arbitrary fixed network topology where the n agents, or nodes of the network, have partial information about the epidemic state. The agents react by distancing themselves from their neighbors when they believe the epidemic is currently prevalent. An agent\\'s awareness is weighted from three sources of information: the fraction of infected neighbors in their contact network, their social network, and a global broadcast of the fraction of infected nodes in the entire network. The dynamics of the benchmark (no awareness) and awareness models are described by discrete-time 2-state Markov chains. Through a coupling technique, we establish monotonicity properties between the benchmark and awareness models. Particularly, we show that the expectation of any increasing random variable on the space of sample paths, e.g. eradication time or total infections, is lower for the awareness model. In addition, we give a characterization for this difference of expectations in terms of the coupling distribution. In simulations, we evaluate how different sources of information affect the spread of an epidemic.

  16. Effect Of Diet Counseling On Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Kusumaneela Bolla

    2015-08-01

    Full Text Available Abstract Diabetes is a metabolic disorder. Metabolism is the way the uses digested food for growth amp energy. Importance of diet in diabetes can be treated back to the days of the ancient ayurvedic physician Sushreeta. Type of diabetes age of the patient body weight severity of the hyperglycemia associated complications and mode of treatment being followed determine the exact allowance and type of diet. This needs to be worked out for each individual diabetic. Dietary management is the corn stone of diabetes treatment and should receive the almost consideration by the patient and by the treating physician. Objective To assess The Nutritional Status and To Study the Effect Of Diet Counseling on Type II Diabetic Patients. Methodology For this study from diabetic hospital in Vijayawada were selected. In this study 40 samples age 30 to 60 years. They belong to age between 30 to 60 years. Preparation of Questionnaire to collect the General information age sex past history of subjects Anthropometric data Biochemical information Dietary information. Conclusion There is significant changes in the blood sugar levels after the diet counseling. Intake of the high amounts of the fiber low glycemic foods and functional foods helps to reduce the blood sugar levels randomly.

  17. Integrated Analysis of Environment-driven Operational Effects in Sensor Networks

    Energy Technology Data Exchange (ETDEWEB)

    Park, Alfred J [ORNL; Perumalla, Kalyan S [ORNL

    2007-07-01

    There is a rapidly growing need to evaluate sensor network functionality and performance in the context of the larger environment of infrastructure and applications in which the sensor network is organically embedded. This need, which is motivated by complex applications related to national security operations, leads to a paradigm fundamentally different from that of traditional data networks. In the sensor networks of interest to us, the network dynamics depend strongly on sensor activity, which in turn is triggered by events in the environment. Because the behavior of sensor networks is sensitive to these driving phenomena, the integrity of the sensed observations, measurements and resource usage by the network can widely vary. It is therefore imperative to accurately capture the environmental phenomena, and drive the simulation of the sensor network operation by accounting fully for the environment effects. In this paper, we illustrate the strong, intimate coupling between the sensor network operation and the driving phenomena in their applications with an example sensor network designed to detect and track gaseous plumes.

  18. The effect of tracking network configuration on GPS baseline estimates for the CASA Uno experiment

    Science.gov (United States)

    Wolf, S. Kornreich; Dixon, T. H.; Freymueller, J. T.

    1990-01-01

    The effect of the tracking network on long (greater than 100 km) GPS baseline estimates was estimated using various subsets of the global tracking network initiated by the first Central and South America (CASA Uno) experiment. It was found that best results could be obtained with a global tacking network consisting of three U.S. stations, two sites in the southwestern Pacific, and two sites in Europe. In comparison with smaller subsets, this global network improved the baseline repeatability, the resolution of carrier phase cycle ambiguities, and formal errors of the orbit estimates.

  19. Efficient Data Forwarding for Machine Type Communications in Internet of Things Networks

    Directory of Open Access Journals (Sweden)

    Yujin Lim

    2017-01-01

    Full Text Available The MTC (Machine Type Communications system is one of the most promising technologies to provide IoT (Internet of Things applications. The MTC system suffers from congestion due to limited data transmission capacity and burst traffic. The congestion disturbs data delivery, results in an increase of energy consumption due to data retransmission, and finally poses a threat to the providers of IoT applications. In this paper, we focus on the congestion problem and present an efficient data forwarding mechanism to regulate the burst channel access from a large number of MTC devices. To regulate the communication channel access from the devices, we predict the number of devices by separating traffic load into the prediction of the number of devices that newly attempt to have access and the prediction of the number of devices that retry to access the channel. Through simulations, we show that our mechanism improves access success probability and reduces collision probability and access delay.

  20. The Effects of Financial Education and Networks on Business Students' Financial Literacy

    Science.gov (United States)

    Chung, Yunhyung; Park, Youngkyun

    2014-01-01

    This study investigates the joint effects of financial education and educational networks on students' financial literacy. With a sample (N = 105) of senior students in a business college, the study finds that not only financial education, but also strong networks with professors, are positively related to the financial literacy of business…

  1. Effect of chain flexibility in the network structure on the viscoelasticity of epoxy thermosets

    NARCIS (Netherlands)

    Nakka, J.S.; Jansen, K.M.B.; Ernst, L.J.

    2011-01-01

    In this paper a detailed study in investigating the effect of the chain flexibility in epoxy-amine crosslinked network is done. In order to introduce flexibility into the crosslinked network a homologous series of four aliphatic diamine curing agents varying only in the chain length and having a

  2. The effects of familiarity and similarity on compliance in social networks

    NARCIS (Netherlands)

    Kaptein, M.C.; Nass, C.; Markopoulos, P.

    2014-01-01

    Advertisers on social network sites often use recommendations by others in a user's networks to endorse products. While these familiar others are hypothesised to be more effective in influencing users than unfamiliar others, there is a catch: familiarity does not necessarily ensure similarity to the

  3. Research on Acceptance Effect of Ideological and Political Education among College Students Based on Network Media

    National Research Council Canada - National Science Library

    Jia Li; Huichuan Zhang; Xinli Lu

    2016-01-01

    ... the realistic significance of research on acceptance effect of ideological and political education among college students based on network media by starting from analyzing the practical problems and through checking literature material from summarizing the meaning, features and current development situation of network media. At the same time, ...

  4. Effects of Spike Anticipation on the Spiking Dynamics of Neural Networks

    Directory of Open Access Journals (Sweden)

    Daniel ede Santos-Sierra

    2015-11-01

    Full Text Available Synchronization is one of the central phenomena involved in information processing in living systems. It is known that the nervous system requires the coordinated activity of both local and distant neural populations. Such an interplay allows to merge different information modalities in a whole processing supporting high-level mental skills as understanding, memory, abstraction, etc. Though the biological processes underlying synchronization in the brain are not fully understood there have been reported a variety of mechanisms supporting different types of synchronization both at theoretical and experimental level. One of the more intriguing of these phenomena is the anticipating synchronization, which has been recently reported in a pair of unidirectionally coupled artificial neurons under simple conditions cite{Pyragas}, where the slave neuron is able to anticipate in time the behaviour of the master one. In this paper we explore the effect of spike anticipation over the information processing performed by a neural network at functional and structural level. We show that the introduction of intermediary neurons in the network enhances spike anticipation and analyse how these variations in spike anticipation can significantly change the firing regime of the neural network according to its functional and structural properties. In addition we show that the interspike interval (ISI, one of the main features of the neural response associated to the information coding, can be closely related to spike anticipation by each spike, and how synaptic plasticity can be modulated through that relationship. This study has been performed through numerical simulation of a coupled system of Hindmarsh-Rose neurons.

  5. Simulation study on effects of signaling network structure on the developmental increase in complexity

    Energy Technology Data Exchange (ETDEWEB)

    Keranen, Soile V.E.

    2003-04-02

    The developmental increase in structural complexity in multicellular life forms depends on local, often non-periodic differences in gene expression. These depend on a network of gene-gene interactions coded within the organismal genome. To better understand how genomic information generates complex expression patterns, I have modeled the pattern forming behavior of small artificial genomes in virtual blastoderm embryos. I varied several basic properties of these genomic signaling networks, such as the number of genes, the distributions of positive (inductive) and negative (repressive) interactions, and the strengths of gene-gene interactions, and analyzed their effects on developmental pattern formation. The results show how even simple genomes can generate complex non-periodic patterns under suitable conditions. They also show how the frequency of complex patterns depended on the numbers and relative arrangements of positive and negative interactions. For example, negative co-regulation of signaling pathway components increased the likelihood of (complex) patterns relative to differential negative regulation of the pathway components. Interestingly, neither quantitative differences either in strengths of signaling interactions nor multiple response thresholds to signal concentration (as in morphogen gradients) were essential for formation of multiple, spatially unique cell types. Thus, with combinatorial code of gene regulation and hierarchical signaling interactions, it is theoretically possible to organize metazoan embryogenesis with just a small fraction of the metazoan genome. Because even small networks can generate complex patterns when they contain a suitable set of connections, evolution of metazoan complexity may have depended more on selection for favourable configurations of signaling interactions than on the increase in numbers of regulatory genes.

  6. Biomechanical Performances of Networked Polyethylene Glycol Diacrylate: Effect of Photoinitiator Concentration, Temperature, and Incubation Time

    Directory of Open Access Journals (Sweden)

    Morshed Khandaker

    2016-01-01

    Full Text Available Nutrient conduit networks can be introduced within the Polyethylene Glycol Diacrylate (PEGDA tissue construct to enable cells to survive in the scaffold. Nutrient conduit networks can be created on PEGDA by macrochannel to nanochannel fabrication techniques. Such networks can influence the mechanical and cell activities of PEGDA scaffold. There is no study conducted to evaluate the effect of nutrient conduit networks on the maximum tensile stress and cell activities of the tissue scaffold. The study aimed to explore the influence of the network architecture on the maximum tensile stress of PEGDA scaffold and compared with the nonnetworked PEGDA scaffold. Our study found that there are 1.78 and 2.23 times decrease of maximum tensile stress due to the introduction of nutrient conduit networks to the PEGDA scaffold at 23°C and 37°C temperature conditions, respectively. This study also found statistically significant effect of network architecture, PI concentration, temperature, and wait time on the maximum failure stress of PEGDA samples (P value < 0.05. Cell viability results demonstrated that networked PEGDA hydrogels possessed increased viability compared to nonnetworked and decreased viability with increased photoinitiator concentrations. The results of this study can be used for the design of PEGDA scaffold with macrosize nutrient conduit network channels.

  7. Enhanced Effective Filtering Approach (eEFA for Improving HSR Network Performance in Smart Grids

    Directory of Open Access Journals (Sweden)

    Nguyen Xuan Tien

    2018-01-01

    Full Text Available The effective filtering approach (EFA is one of the most effective approaches for improving the network traffic performance of high-availability seamless redundancy (HSR networks. However, because EFA uses port locking (PL for detecting nondestination doubly-attached nodes with HSR protocol (DANH rings in HSR networks, it forwards the first sent frame to all DANH rings in the network. In addition, it uses a control message for discovering passive QuadBox rings in both unidirectional and bidirectional communications. In this study, we propose an enhanced version of EFA called enhanced-EFA (eEFA that does not forward unicast frames to nondestination DANH rings. eEFA does not use any control message to discover passive QuadBox rings in bidirectional communications. eEFA thus reduces the network traffic in HSR networks compared with EFA. Analytical and simulation results for a sample network show that the traffic reduction of eEFA was 4–26% and 2–20% for unidirectional and bidirectional communications, respectively, compared to EFA. eEFA, thus, clearly saves network bandwidth and improves the network performance.

  8. Effects of sampling completeness on the structure of plant-pollinator networks.

    Science.gov (United States)

    Rivera-Hutinel, A; Bustamante, R O; Marín, V H; Medel, R

    2012-07-01

    Plant-animal interaction networks provide important information on community organization. One of the most critical assumptions of network analysis is that the observed interaction patterns constitute an adequate sample of the set of interactions present in plant-animal communities. In spite of its importance, few studies have evaluated this assumption, and in consequence, there is no consensus on the sensitivity of network metrics to sampling methodological shortcomings. In this study we examined how variation in sampling completeness influences the estimation of six network metrics frequently used in the literature (connectance, nestedness, modularity, robustness to species loss, path length, and centralization). We analyzed data of 186 flowering plants and 336 pollinator species in 10 networks from a forest-fragmented system in central Chile. Using species-based accumulation curves, we estimated the deviation of network metrics in undersampled communities with respect to exhaustively sampled communities and the effect of network size and sampling evenness on network metrics. Our results indicate that: (1) most metrics were affected by sampling completeness but differed in their sensitivity to sampling effort; (2) nestedness, modularity, and robustness to species loss were less influenced by insufficient sampling than connectance, path length, and centralization; (3) robustness was mildly influenced by sampling evenness. These results caution studies that summarize information from databases with high, or unknown, heterogeneity in sampling effort per species and should stimulate researchers to report sampling intensity to standardize its effects in the search for broad patterns in plant-pollinator networks.

  9. Effects of Actor-Network Theory in Accounting Research

    DEFF Research Database (Denmark)

    Justesen, Lise Nederland; Mouritsen, Jan

    2011-01-01

    of a critical literature review and discussion. Findings – Since the early 1990s, actor-network theory, particularly the work of Bruno Latour, has inspired accounting researchers and led to a number of innovative studies of accounting phenomena. In particular, Latour's book, Science in Action, has been...... number of accounting papers that apply actor-network theory. A different sample might have given a somewhat different picture. Furthermore, it focuses on the influence of Latour's work and refrains from discussing how the writings of Michel Callon, John Law or other thinkers within the actor......Purpose – This paper aims to discuss how Bruno Latour's version of actor-network theory has influenced accounting research. It also seeks to show that Latour's writings contain unexplored potential that may inspire future accounting research. Design/methodology/approach – The paper takes the form...

  10. Effectiveness of frequency relays on networks with multiple distributed generation

    Directory of Open Access Journals (Sweden)

    A.A.M. Hassan

    2015-05-01

    Full Text Available Distributed generation (DG has gained a vital role in distribution utilities. So, it is important to correctly detect islanding of DG units. Frequency relays are one of the most commonly used loss of mains detection method. However, distribution utilities may be faced by concern related to false operation of these frequency relays. The commercially available frequency relays reported considering standard tight setting. This paper investigates some factors related to relays internal algorithm that contribute to their different operating responses. The factors that will be investigated are frequency measuring techniques, measuring windows, time delays and under voltage interlock function. With the increasing penetration of DG into the network, it is becoming common to have multiple DG units connected at the same network location. Two generators connected at the same location and employing frequency relays with the same setting but different characteristics were simulated. When subjected to the same network disturbances the possible interference between the two relays is analyzed.

  11. Mobility and social network effects on extremist opinions.

    Science.gov (United States)

    Martins, André C R

    2008-09-01

    Understanding the emergence of extreme opinions and in what kind of environment they might become less extreme is a central theme in our modern globalized society. A model combining continuous opinions and observed discrete actions (CODA) capable of addressing the important issue of measuring how extreme opinions might be has been recently proposed. In this paper I show extreme opinions to arise in a ubiquitous manner in the CODA model for a multitude of social network structures. Depending on network details reducing extremism seems to be possible. However, a large number of agents with extreme opinions is always observed. A significant decrease in the number of extremists can be observed by allowing agents to change their positions in the network.

  12. Topological effects of data incompleteness of gene regulatory networks

    CERN Document Server

    Sanz, J; Borge-Holthoefer, J; Moreno, Y

    2012-01-01

    The topological analysis of biological networks has been a prolific topic in network science during the last decade. A persistent problem with this approach is the inherent uncertainty and noisy nature of the data. One of the cases in which this situation is more marked is that of transcriptional regulatory networks (TRNs) in bacteria. The datasets are incomplete because regulatory pathways associated to a relevant fraction of bacterial genes remain unknown. Furthermore, direction, strengths and signs of the links are sometimes unknown or simply overlooked. Finally, the experimental approaches to infer the regulations are highly heterogeneous, in a way that induces the appearance of systematic experimental-topological correlations. And yet, the quality of the available data increases constantly. In this work we capitalize on these advances to point out the influence of data (in)completeness and quality on some classical results on topological analysis of TRNs, specially regarding modularity at different level...

  13. Multiplex networks in metropolitan areas: generic features and local effects

    CERN Document Server

    Strano, Emanuele; Dobson, Simon; Barthelemy, Marc

    2015-01-01

    Most large cities are spanned by more than one transportation system. These different modes of transport have usually been studied separately: it is however important to understand the impact on urban systems of the coupling between them and we report in this paper an empirical analysis of the coupling between the street network and the subway for the two large metropolitan areas of London and New York. We observe a similar behaviour for network quantities related to quickest paths suggesting the existence of generic mechanisms operating beyond the local peculiarities of the specific cities studied. An analysis of the betweenness centrality distribution shows that the introduction of underground networks operate as a decentralising force creating congestions in places located at the end of underground lines. Also, we find that increasing the speed of subways is not always beneficial and may lead to unwanted uneven spatial distributions of accessibility. In fact, for London -- but not for New York -- there is ...

  14. Effects of Network Capabilities on Firm Performance across Cultures

    Directory of Open Access Journals (Sweden)

    Papastamatelou Julie

    2016-03-01

    Full Text Available The purpose of this study is to identify key factors related to network capabilities that enhance the performance of Chinese, Turkish and German firms. Chinese (n = 107, Turkish (n = 129 and German (n = 109 MBA-students completed a questionnaire, based on an earlier version developed by Kenny [2009], which included questions on the respective firm, its performance and network capabilities. The predictors of firm performance varied by country: in China “information sharing” and “trust” were important, in Turkey “network coordination” and in Germany “human capital resources.” In addition, each country had its own specific drivers of firm performance. The findings of this paper should enhance understanding of the cross-cultural differences and assist managers when planning to join foreign corporations.

  15. D-effects in Toroidally Compactified Type II String Theory

    CERN Document Server

    Pioline, B

    1999-01-01

    We review exact results obtained for R^4 couplings in maximally supersymmetric type II string theories. These couplings offer a privileged scene to understand the rules of semiclassical calculus in string theory. Upon expansion in weak string coupling, they reveal an infinite sum of non-perturbative e^{-1/g} effects that can be imputed to euclidean D-branes wrapped on cycles of the compactification manifolds. They also shed light on the relation between Dp-branes and D-(p-2)branes, D-strings and (p,q) strings, instanton sums and soliton loops. The latter interpretation takes over in D<=6 in order to account for the e^{-1/g^2} effects, still mysterious from the point of view of instanton calculus. [To appear in the proceedings of the conference "Quantum Aspects of Gauge Theories, Supersymmetry and Unification" held at Neuchatel University, Switzerland, 18-23 September 1997.

  16. The Complexity of the Business Network Context and Its Effect on Subsidiary Relational (Over-) Embeddedness

    DEFF Research Database (Denmark)

    Nell, Phillip Christopher; Andersson, Ulf

    2012-01-01

    Many studies have focused on the effects of MNC subsidiaries’ external relational embeddedness. Little attention has been given to its antecedents and especially to the potential effect that the business network context might have. We try to fill this gap and attempt to explain variation among...... subsidiaries’ degree of relational embeddedness. Our results show a strong and robust effect of the business network context – i.e. the network context in which the direct business relationships between the subsidiary and its partners are embedded – on the degree of relational embeddedness. However, contrary...

  17. The Complexity of the Business Network Context and Its Effect on Subsidiary Relational (Over-) Embeddedness

    DEFF Research Database (Denmark)

    Nell, Phillip Christopher; Andersson, Ulf

    Many studies have focused on the effects of MNC subsidiaries’ external relational embeddedness. Little attention has been given to its antecedents and especially to the potential effect that the business network context might have. We try to fill this gap and attempt to explain variation among...... subsidiaries’ degree of relational embeddedness. Our results show a strong and robust effect of the business network context -- i.e. the network context in which the direct business relationships between the subsidiary and its partners are embedded -- on the degree of relational embeddedness. However, contrary...

  18. Combining Slater-type orbitals and effective core potentials

    Science.gov (United States)

    Lesiuk, Michał; Tucholska, Aleksandra M.; Moszynski, Robert

    2017-05-01

    We present a general methodology to evaluate matrix elements of the effective core potentials (ECPs) within a one-electron basis set of Slater-type orbitals (STOs). The scheme is based on translation of individual STO distributions in the framework of the Barnett-Coulson method. We discuss different types of integrals which naturally appear and reduce them to a few basic quantities which can be calculated recursively or purely numerically. Additionally, we consider evaluation of the STOs matrix elements involving the core polarization potentials and effective spin-orbit potentials. Construction of the STOs basis sets designed specifically for use with ECPs is discussed and differences in comparison with all-electron basis sets are briefly summarized. We verify the validity of the present approach by calculating excitation energies, static dipole polarizabilities, and valence orbital energies for the alkaline-earth metals (Ca, Sr, and Ba). Finally, we evaluate interaction energies, permanent dipole moments, and ionization energies for barium and strontium hydrides, and compare them with the best available experimental and theoretical data.

  19. Integrated Network Analysis and Effective Tools in Plant Systems Biology

    Directory of Open Access Journals (Sweden)

    Atsushi eFukushima

    2014-11-01

    Full Text Available One of the ultimate goals in plant systems biology is to elucidate the genotype-phenotype relationship in plant cellular systems. Integrated network analysis that combines omics data with mathematical models has received particular attention. Here we focus on the latest cutting-edge computational advances that facilitate their combination. We highlight (1 network visualization tools, (2 pathway analyses, (3 genome-scale metabolic reconstruction, and (4 the integration of high-throughput experimental data and mathematical models. Multi-omics data that contain the genome, transcriptome, proteome, and metabolome and mathematical models are expected to integrate and expand our knowledge of complex plant metabolisms.

  20. Effect of size heterogeneity on community identification in complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Danon, L.; Diaz-Guilera, A.; Arenas, A.

    2008-01-01

    Identifying community structure can be a potent tool in the analysis and understanding of the structure of complex networks. Up to now, methods for evaluating the performance of identification algorithms use ad-hoc networks with communities of equal size. We show that inhomogeneities in community sizes can and do affect the performance of algorithms considerably, and propose an alternative method which takes these factors into account. Furthermore, we propose a simple modification of the algorithm proposed by Newman for community detection (Phys. Rev. E 69 066133) which treats communities of different sizes on an equal footing, and show that it outperforms the original algorithm while retaining its speed.

  1. High-performance dispenser printed MA p-type Bi(0.5)Sb(1.5)Te(3) flexible thermoelectric generators for powering wireless sensor networks.

    Science.gov (United States)

    Madan, Deepa; Wang, Zuoqian; Chen, Alic; Wright, Paul K; Evans, James W

    2013-11-27

    This work presents a novel method to synthesize p-type composite thermoelectric materials to print scalable thermoelectric generator (TEG) devices in a cost-effective way. A maximum ZT of 0.2 was achieved for mechanically alloyed (MA) p-type Bi0.5Sb1.5Te3 (8 wt % extra Te additive)-epoxy composite films cured at 250 °C. A 50% increase in Seebeck coefficient as a result of adding 8 wt % extra Te in stoichiometric Bi0.5Sb1.5Te3 contributed to the increase in ZT. To demonstrate cost-effective and scalable manufacturing, we fabricated a sixty element thermoelectric generator prototype with 5.0 mm × 600 μm × 120 μm printed dimensions on a custom designed polyimide substrate with thick metal contacts. The prototype TEG device produced a power output of 20.5 μW at 0.15 mA and 130 mV for a temperature difference of 20 K resulting in a device areal power density of 152 μW/cm(2). This power is sufficient for low power applications such as wireless sensor network (WSN) devices.

  2. On the development of online cities and neighborhoods: an exploration of cumulative and segmentive network effects in social media

    NARCIS (Netherlands)

    Maris, I.; Huizinga, A; Bouman, W.; Tuunainen, V.K.; Rossi, M.; Nandhakumar, J.

    2011-01-01

    This paper outlines a research in progress set to study network effects in social media. The focus is on outlining the theoretical framework in which this study is embedded. The concepts of cumulative network effects and segmentive network effects are introduced to explain the processes by which

  3. Mechanisms of migration development at the community level: Migrant networks and types of links

    Directory of Open Access Journals (Sweden)

    Mónica Serban

    2014-11-01

    Full Text Available The paper approaches the problem of the development mechanism of international migration at community level.Some empirical observations cumulated during several researches,at origin and destination area, regarding Romanian migration to Spain constitute the starting points. Appealing to the distinction introduced by Mark Granovetter in 1976 between weak and strongties, we find that, if initially migration develops almost exclusively based on social relations that could be assimilated to strong ties,there is a moment in the process of development when the departures on the base of weak ties, with important consequences on the migrant’s situation at destination, increase.The paper tries to clarify, preponderantly invoking theoretical arguments,in what measure the departures based on weak ties between migrant and non migrant are normal in the process of international migration development at community level. The study concludes that, because of cumulative effects, migration evolution to a phase when the departure is possible based on weak ties is explainable.Two mechanisms mainly contribute to this result: enhancement of incentives to migrate (because of quantitative and qualitative information increase; visibility of migration effects in the origin area;changes of relative deprivation at community level and migration costs and risk lowering, with the consequence of reduction of effective support that a non-migrant needs from one migrant in order to migrate.

  4. Turbofan engine diagnostics neuron network size optimization method which takes into account overlaerning effect

    Directory of Open Access Journals (Sweden)

    О.С. Якушенко

    2010-01-01

    Full Text Available  The article is devoted to the problem of gas turbine engine (GTE technical state class automatic recognition with operation parameters by neuron networks. The one of main problems for creation the neuron networks is determination of their optimal structures size (amount of layers in network and count of neurons in each layer.The method of neuron network size optimization intended for classification of GTE technical state is considered in the article. Optimization is cared out with taking into account of overlearning effect possibility when a learning network loses property of generalization and begins strictly describing educational data set. To determinate a moment when overlearning effect is appeared in learning neuron network the method  of three data sets is used. The method is based on the comparison of recognition quality parameters changes which were calculated during recognition of educational and control data sets. As the moment when network overlearning effect is appeared the moment when control data set recognition quality begins deteriorating but educational data set recognition quality continues still improving is used. To determinate this moment learning process periodically is terminated and simulation of network with education and control data sets is fulfilled. The optimization of two-, three- and four-layer networks is conducted and some results of optimization are shown. Also the extended educational set is created and shown. The set describes 16 GTE technical state classes and each class is represented with 200 points (200 possible technical state class realizations instead of 20 points using in the former articles. It was done to increase representativeness of data set.In the article the algorithm of optimization is considered and some results which were obtained with it are shown. The results of experiments were analyzed to determinate most optimal neuron network structure. This structure provides most high-quality GTE

  5. The challenge of sustaining effectiveness over time: the case of the global network to stop tuberculosis

    Science.gov (United States)

    Quissell, Kathryn; Walt, Gill

    2016-01-01

    Where once global health decisions were largely the domain of national governments and the World Health Organization, today networks of international organizations, governments, private philanthropies and other entities are actively shaping public policy. However, there is still limited understanding of how global networks form, how they create institutions, how they promote and sustain collective action, and how they adapt to changes in the policy environment. Understanding these processes is crucial to understanding their effectiveness: whether and how global networks influence policy and public health outcomes. This study seeks to address these gaps through the examination of the global network to stop tuberculosis (TB) and the factors influencing its effectiveness over time. Drawing from ∼200 document sources and 16 interviews with key informants, we trace the development of the Global Partnership to Stop TB and its work over the past decade. We find that having a centralized core group and a strategic brand helped the network to coalesce around a primary intervention strategy, directly observed treatment short course. This strategy was created before the network was formalized, and helped bring in donors, ministries of health and other organizations committed to fighting TB—growing the network. Adaptations to this strategy, the creation of a consensus-based Global Plan, and the creation of a variety of participatory venues for discussion, helped to expand and sustain the network. Presently, however, tensions have become more apparent within the network as it struggles with changing internal political dynamics and the evolution of the disease. While centralization and stability helped to launch and grow the network, the institutionalization of governance and strategy may have constrained adaptation. Institutionalization and centralization may, therefore, facilitate short-term success for networks, but may end up complicating longer-term effectiveness. PMID

  6. Adolescent peer networks and the potential for the diffusion of intervention effects.

    Science.gov (United States)

    Rulison, Kelly L; Gest, Scott D; Osgood, D Wayne

    2015-01-01

    Many evaluation studies assess the direct effect of an intervention on individuals, but there is an increasing interest in clarifying how interventions can impact larger social settings. One process that can lead to these setting-level effects is diffusion, in which intervention effects spread from participants to non-participants. Diffusion may be particularly important when intervention participation rates are low, as they often are in universal family based prevention programs. We drew on socialization and diffusion theories to articulate how features of peer networks may promote the diffusion of intervention effects. Then, we tested the measurement properties of ten social network analytic (SNA) measures of diffusion potential. Data were from 42 networks (n = 5,784 students) involved in the PROSPER intervention trial. All families of sixth-grade students were invited to participate in a family based substance use prevention program, and 17 % of the families attended at least one session. We identified two dimensions of network structure--social integration and location of intervention participants in their peer network--that might promote diffusion. Analyses demonstrated that these SNA measures varied across networks and were distinct from traditional analytic measures that do not require social network analysis (i.e., participation rate, how representative participants are of the broader population). Importantly, several SNA measures and the global network index predicted diffusion over and above the effect of participation rate and representativeness. We conclude by recommending which SNA measures may be the most promising for studying how networks promote the diffusion of intervention effects and lead to setting-level effects.

  7. Effect of mobility models on infrastructure based wireless networks ...

    African Journals Online (AJOL)

    The tremendous demand is pushing the development of wireless mobile communications faster than ever before. Handoff management has widely been recognized as one of the most important and challenging problems for a seamless access to wireless network and mobile services. Mobility Models plays an important ...

  8. Effects of Network Segregation in Intergroup Conflict : An Experimental Analysis

    NARCIS (Netherlands)

    Takács, Károly

    2006-01-01

    Dense in-group and scarce out-group relations (network segregation) often support the emergence of conflicts between groups. A key underlying mechanism is social control that helps to overcome the collective action problem within groups, but contributes to harmful conflicts among them in segregated

  9. Effects of social networks on innovation diffusion and marketing dynamics

    NARCIS (Netherlands)

    Delre, Sebastiano Alessio

    2007-01-01

    The main goal of this thesis is to incorporate part of the flourishing literature on network structures in a marketing context. Most of the results we have obtained and presented generate several implications. First of all we hope that the reader, after going through these chapters is convinced that

  10. Effects of network resolution on topological properties of human neocortex

    DEFF Research Database (Denmark)

    Romero-Garcia, Rafael; Atienza, Mercedes; Clemmensen, Line Katrine Harder

    2012-01-01

    networks and the number of cortical regions included in the scale. Results revealed that schemes comprising 540–599 regions (surface areas spanning between 250 and 275mm2) at sparsities below 10% showed a superior balance between small-world organization and the size of the cortical scale employed...

  11. Toward effective strategies for energy efficient network management

    NARCIS (Netherlands)

    Vreeswijk, Jacob Dirk; van Berkum, Eric C.; van Arem, Bart; van Vliet, H.; Abadi, A.; Bauer e.a., D.

    2010-01-01

    Trade-offs in efficiency, equity and acceptability arise as a central feature in traffic management. Today's urban traffic network management strategies focus on overall system performance and often overlook the interests of the individual road user. In addition, the emphasis is on travel time

  12. Building the process-drug–side effect network to discover the relationship between biological Processes and side effects

    Science.gov (United States)

    2011-01-01

    Background Side effects are unwanted responses to drug treatment and are important resources for human phenotype information. The recent development of a database on side effects, the side effect resource (SIDER), is a first step in documenting the relationship between drugs and their side effects. It is, however, insufficient to simply find the association of drugs with biological processes; that relationship is crucial because drugs that influence biological processes can have an impact on phenotype. Therefore, knowing which processes respond to drugs that influence the phenotype will enable more effective and systematic study of the effect of drugs on phenotype. To the best of our knowledge, the relationship between biological processes and side effects of drugs has not yet been systematically researched. Methods We propose 3 steps for systematically searching relationships between drugs and biological processes: enrichment scores (ES) calculations, t-score calculation, and threshold-based filtering. Subsequently, the side effect-related biological processes are found by merging the drug-biological process network and the drug-side effect network. Evaluation is conducted in 2 ways: first, by discerning the number of biological processes discovered by our method that co-occur with Gene Ontology (GO) terms in relation to effects extracted from PubMed records using a text-mining technique and second, determining whether there is improvement in performance by limiting response processes by drugs sharing the same side effect to frequent ones alone. Results The multi-level network (the process-drug-side effect network) was built by merging the drug-biological process network and the drug-side effect network. We generated a network of 74 drugs-168 side effects-2209 biological process relation resources. The preliminary results showed that the process-drug-side effect network was able to find meaningful relationships between biological processes and side effects in an

  13. Socioeconomic analysis of patient-centric networks: effects of patients and hospitals' characteristics and network structure on hospitalization costs.

    Science.gov (United States)

    Abbasi, Alireza; Uddin, Shahadat; Hossain, Liaquat

    2012-06-01

    Improving operations and delivery of cost-effective healthcare services is considered to be an important area of investigation due to the challenges in allocation of resources in meeting the increasing cost of health care for the twenty-first century. To date, appropriate mechanisms for systematic evaluation of hospital operations and its impact of the delivery of cost-effective healthcare services are lacking. This is, perhaps, the first study, which focuses on using large insurance claims data to develop a social network-based model for exploring the effect of patient-doctor tie strength and patient socio-demographic factors for exploring the social structure of operations and delivery of cost-effective healthcare services. We suggest that delivery of cost-effective healthcare services and operation is embedded within the social structure of hospitals. By exploring the mode of hospital operations in terms of their patient-centric care network, we are able to develop a better understanding of the operation and delivery of cost-effective healthcare services.

  14. Structure of triadic relations in multiplex networks

    Science.gov (United States)

    Cozzo, Emanuele; Kivelä, Mikko; De Domenico, Manlio; Solé-Ribalta, Albert; Arenas, Alex; Gómez, Sergio; Porter, Mason A.; Moreno, Yamir

    2015-07-01

    Recent advances in the study of networked systems have highlighted that our interconnected world is composed of networks that are coupled to each other through different ‘layers’ that each represent one of many possible subsystems or types of interactions. Nevertheless, it is traditional to aggregate multilayer networks into a single weighted network in order to take advantage of existing tools. This is admittedly convenient, but it is also extremely problematic, as important information can be lost as a result. It is therefore important to develop multilayer generalizations of network concepts. In this paper, we analyze triadic relations and generalize the idea of transitivity to multiplex networks. By focusing on triadic relations, which yield the simplest type of transitivity, we generalize the concept and computation of clustering coefficients to multiplex networks. We show how the layered structure of such networks introduces a new degree of freedom that has a fundamental effect on transitivity. We compute multiplex clustering coefficients for several real multiplex networks and illustrate why one must take great care when generalizing standard network concepts to multiplex networks. We also derive analytical expressions for our clustering coefficients for ensemble averages of networks in a family of random multiplex networks. Our analysis illustrates that social networks have a strong tendency to promote redundancy by closing triads at every layer and that they thereby have a different type of multiplex transitivity from transportation networks, which do not exhibit such a tendency. These insights are invisible if one only studies aggregated networks.

  15. Which stocks are profitable? A network method to investigate the effects of network structure on stock returns

    Science.gov (United States)

    Chen, Kun; Luo, Peng; Sun, Bianxia; Wang, Huaiqing

    2015-10-01

    According to asset pricing theory, a stock's expected returns are determined by its exposure to systematic risk. In this paper, we propose a new method for analyzing the interaction effects among industries and stocks on stock returns. We construct a complex network based on correlations of abnormal stock returns and use centrality and modularity, two popular measures in social science, to determine the effect of interconnections on industry and stock returns. Supported by previous studies, our findings indicate that a relationship exists between inter-industry closeness and industry returns and between stock centrality and stock returns. The theoretical and practical contributions of these findings are discussed.

  16. Effect of using peer tutoring to support knowledge sharing in Learning Networks: A cognitive load perspective

    NARCIS (Netherlands)

    Hsiao, Amy; Brouns, Francis; Sloep, Peter

    2010-01-01

    Hsiao, Y. P., Brouns, F., & Sloep, P. B. (2010, 4 November). Effect of using peer tutoring to support knowledge sharing in Learning Networks: A cognitive load perspective. Presentation at ICO-Toogdag, Amstelveen, The Netherlands: VU Amsterdam.

  17. Effect of using peer tutoring to support knowledge sharing in Learning Networks: A cognitive load perspective

    NARCIS (Netherlands)

    Hsiao, Amy; Brouns, Francis; Sloep, Peter

    2010-01-01

    Hsiao, Y. P., Brouns, F., & Sloep, P. B. (2010). Effect of using peer tutoring to support knowledge sharing in Learning Networks: A cognitive load perspective. ICO-Toogdag. November, 4, 2010, Amstelveen, The Netherlands: VU Amsterdam.

  18. 76 FR 23812 - Reliability and Continuity of Communications Networks, Including Broadband Technologies; Effects...

    Science.gov (United States)

    2011-04-28

    ... they begin to deploy Smart Grid. Hospitals and healthcare providers can leverage broadband technologies... COMMISSION Reliability and Continuity of Communications Networks, Including Broadband Technologies; Effects... broadband technologies. 4. Today's increasingly interconnected world is one in which communications services...

  19. Effects of different types of refractive errors on bilateral amblyopia

    Directory of Open Access Journals (Sweden)

    Mücella Arıkan Yorgun

    2012-12-01

    Full Text Available Objectives: Identifying effects of different types of refractiveerrors on final visual acuity and stereopsis levels inpatients with bilateral amblyopia.Materials and methods: Patients with bilateral amblyopialower than ≥1.5 D anisometropia were included. Thepatients were classified according to the level of sphericalequivalent (0-4 D and >4 D of hypermetropia, the levelof astigmatism (below and above 2D in positive cylinderand type of composed refractive error [ 4 D of hypermetropiaand 2 D of astigmatism (group III]. Initialand final binocular best corrected visual acuities (BCVAwere compared between groups.Results: The initial binocular BCVA levels were significantlylower in patients with > 4 D of hypermetropia(p=0.028, without correction after treatment (p=0.235.The initial binocular BCVA was not different betweenastigmatism groups, but final BCVA levels were significantlylower in 4-6D of astigmatism compared with 2-4D of astigmatism (p=0.001. During comparison of composedrefractive errors, only the initial binocular BCVAwas significantly lower in group I compared to group II(p=0.015. The final binocular BCVA levels were not differentbetween groups I and III (p>0.05.Conclusions: Although the initial BCVA is lower in patientswith higher levels of hypermetropia, the response ofpatients to treatment with glasses is good. The responseof patients with high levels of astigmatism seems to belimited. J Clin Exp Invest 2012; 3(4: 467-471Key words: Amblyopia, isoametropic amblyopia, hypermetropia,refractive amblyopia, visual acuity

  20. Cardioprotective effects of magnesium valproate in type 2 diabetes mellitus.

    Science.gov (United States)

    Patel, Bhoomika M; Raghunathan, Suchi; Porwal, Urvashi

    2014-04-05

    We have evaluated the effect of magnesium valproate (210 mg/kg/day, p.o.) in type 2 diabetes induced cardiovascular complications induced by streptozotocin (STZ, 90 mg/kg, i.p.) in neonatal wistar rats. Various biochemical, cardiovascular and hemodynamic parameters were measured at the end of 8 weeks of treatment. STZ produced significant hyperglycaemia, hypoinsulinemia and dyslipidemia, which was prevented by magnesium valproate treatment. STZ produced increase in Creatinine Kinase, C-reactive protein and lactate dehydrogenase levels and treatment with magnesium valproate produced reduction in these levels. STZ produced increase in cardiac and LV hypertrophy index, LV/RV ratio, LV collagen deposition and LV cardiomyocyte diameter which were decreased by magnesium valproate treatment. Magnesium valproate also prevented STZ induced hemodynamic alterations and oxidative stress. These results were further supported by histopathological studies in which magnesium valproate showed marked reduction in fibrosis and cardiac fiber disarray. In conclusion, our data suggests that magnesium valproate is beneficial as an anti-diabetic agent in type-2 diabetes mellitus and also prevents its cardiac complications. Copyright © 2014 Elsevier B.V. All rights reserved.