Enrichment of Cross-Linked Peptides Using Charge-Based Fractional Diagonal Chromatography (ChaFRADIC).

PubMed

Tinnefeld, Verena; Venne, A Saskia; Sickmann, Albert; Zahedi, René P

2017-02-03

Chemical cross-linking of proteins is an emerging field with huge potential for the structural investigation of proteins and protein complexes. Owing to the often relatively low yield of cross-linking products, their identification in complex samples benefits from enrichment procedures prior to mass spectrometry analysis. So far, this is mainly accomplished by using biotin moieties in specific cross-linkers or by applying strong cation exchange chromatography (SCX) for a relatively crude enrichment. We present a novel workflow to enrich cross-linked peptides by utilizing charge-based fractional diagonal chromatography (ChaFRADIC). On the basis of two-dimensional diagonal SCX separation, we could increase the number of identified cross-linked peptides for samples of different complexity: pure cross-linked BSA, cross-linked BSA spiked into a simple protein mixture, and cross-linked BSA spiked into a HeLa lysate. We also compared XL-ChaFRADIC with size exclusion chromatography-based enrichment of cross-linked peptides. The XL-ChaFRADIC approach is straightforward, reproducible, and independent of the cross-linking chemistry and cross-linker properties.

Automatic Invocation Linking for Collaborative Web-Based Corpora

NASA Astrophysics Data System (ADS)

Gardner, James; Krowne, Aaron; Xiong, Li

Collaborative online encyclopedias or knowledge bases such as Wikipedia and PlanetMath are becoming increasingly popular because of their open access, comprehensive and interlinked content, rapid and continual updates, and community interactivity. To understand a particular concept in these knowledge bases, a reader needs to learn about related and underlying concepts. In this chapter, we introduce the problem of invocation linking for collaborative encyclopedia or knowledge bases, review the state of the art for invocation linking including the popular linking system of Wikipedia, discuss the problems and challenges of automatic linking, and present the NNexus approach, an abstraction and generalization of the automatic linking system used by PlanetMath.org. The chapter emphasizes both research problems and practical design issues through discussion of real world scenarios and hence is suitable for both researchers in web intelligence and practitioners looking to adopt the techniques. Below is a brief outline of the chapter.

Towards Linked Open Services and Processes

NASA Astrophysics Data System (ADS)

Krummenacher, Reto; Norton, Barry; Marte, Adrian

The combination of semantic technology and Web services in form of 'Semantic Web Services' has until now been oriented towards extension of the WS-* stack with ontology-based descriptions. The same time, there is a strong movement away from this stack - for which the 'Web' part is little more than branding - towards RESTful services. The Linked Open Data initiative is a keen adopter of this approach and exposes many datasets via SPARQL endpoints and RESTful services. Our developing approach of 'Linked Open Services', whose current state is described in this paper, accommodates such Linked Data endpoints and general RESTful services alongside WS-* stack-based services with descriptions based on RDF and SPARQL. This capitalises on the Linked Data Cloud and makes service description and comprehension more easy and direct to the growing Linked Data community. Along the way, we show how the existing link between service messaging and the semantic viewpoint, commonly called 'lifting and lowering', is usually unduly restricted to ontology-based classification and misses how the effect of a service contributes to the knowledge of its consumer. Our SPARQL-based approach helps also in the composition of services as knowledge-centric processes, and encourages the development and exposure of services that communicate RDF.

Interference Cognizant Network Scheduling

NASA Technical Reports Server (NTRS)

Hall, Brendan (Inventor); Bonk, Ted (Inventor); DeLay, Benjamin F. (Inventor); Varadarajan, Srivatsan (Inventor); Smithgall, William Todd (Inventor)

2017-01-01

Systems and methods for interference cognizant network scheduling are provided. In certain embodiments, a method of scheduling communications in a network comprises identifying a bin of a global timeline for scheduling an unscheduled virtual link, wherein a bin is a segment of the timeline; identifying a pre-scheduled virtual link in the bin; and determining if the pre-scheduled and unscheduled virtual links share a port. In certain embodiments, if the unscheduled and pre-scheduled virtual links don't share a port, scheduling transmission of the unscheduled virtual link to overlap with the scheduled transmission of the pre-scheduled virtual link; and if the unscheduled and pre-scheduled virtual links share a port: determining a start time delay for the unscheduled virtual link based on the port; and scheduling transmission of the unscheduled virtual link in the bin based on the start time delay to overlap part of the scheduled transmission of the pre-scheduled virtual link.

A satellite based telemetry link for a UAV application

NASA Technical Reports Server (NTRS)

Bloise, Anthony

1995-01-01

The requirements for a satellite based communication facility to service the needs of the Geographical Information System (GIS) data collection community are addressed in this paper. GIS data is supplied in the form of video imagery at sub-television rates in one or more spectral bands / polarizations laced with a position correlated data stream. The limitations and vicissitudes of using a terrestrial based telecommunications link to collect GIS data are illustrated from actual mission scenarios. The expectations from a satellite based communications link by the geophysical data collection community concerning satellite architecture, operating bands, bandwidth, footprint agility, up link and down link hardware configurations on the UAV, the Mobile Control Vehicle and at the Central Command and Data Collection Facility comprise the principle issues discussed in the first section of this paper. The final section of the paper discusses satellite based communication links would have an increased volume and scope of services the GIS data collection community could make available to the GIS user community, and the price the data collection community could afford to pay for access to the communication satellite described in the paper.

Implementing and testing a fiber-optic polarization-based intrusion detection system

NASA Astrophysics Data System (ADS)

Hajj, Rasha El; MacDonald, Gregory; Verma, Pramode; Huck, Robert

2015-09-01

We describe a layer-1-based intrusion detection system for fiber-optic-based networks. Layer-1-based intrusion detection represents a significant elevation in security as it prohibits an adversary from obtaining information in the first place (no cryptanalysis is possible). We describe the experimental setup of the intrusion detection system, which is based on monitoring the behavior of certain attributes of light both in unperturbed and perturbed optical fiber links. The system was tested with optical fiber links of various lengths and types, under different environmental conditions, and under changes in fiber geometry similar to what is experienced during tapping activity. Comparison of the results for perturbed and unperturbed links has shown that the state of polarization is more sensitive to intrusion activity than the degree of polarization or power of the received light. The testing was conducted in a simulated telecommunication network environment that included both underground and aerial links. The links were monitored for intrusion activity. Attempts to tap the link were easily detected with no apparent degradation in the visual quality of the real-time surveillance video.

Remote sensing using MIMO systems

DOEpatents

Bikhazi, Nicolas; Young, William F; Nguyen, Hung D

2015-04-28

A technique for sensing a moving object within a physical environment using a MIMO communication link includes generating a channel matrix based upon channel state information of the MIMO communication link. The physical environment operates as a communication medium through which communication signals of the MIMO communication link propagate between a transmitter and a receiver. A spatial information variable is generated for the MIMO communication link based on the channel matrix. The spatial information variable includes spatial information about the moving object within the physical environment. A signature for the moving object is generated based on values of the spatial information variable accumulated over time. The moving object is identified based upon the signature.

Constrained Active Learning for Anchor Link Prediction Across Multiple Heterogeneous Social Networks

PubMed Central

Zhu, Junxing; Zhang, Jiawei; Wu, Quanyuan; Jia, Yan; Zhou, Bin; Wei, Xiaokai; Yu, Philip S.

2017-01-01

Nowadays, people are usually involved in multiple heterogeneous social networks simultaneously. Discovering the anchor links between the accounts owned by the same users across different social networks is crucial for many important inter-network applications, e.g., cross-network link transfer and cross-network recommendation. Many different supervised models have been proposed to predict anchor links so far, but they are effective only when the labeled anchor links are abundant. However, in real scenarios, such a requirement can hardly be met and most anchor links are unlabeled, since manually labeling the inter-network anchor links is quite costly and tedious. To overcome such a problem and utilize the numerous unlabeled anchor links in model building, in this paper, we introduce the active learning based anchor link prediction problem. Different from the traditional active learning problems, due to the one-to-one constraint on anchor links, if an unlabeled anchor link a=(u,v) is identified as positive (i.e., existing), all the other unlabeled anchor links incident to account u or account v will be negative (i.e., non-existing) automatically. Viewed in such a perspective, asking for the labels of potential positive anchor links in the unlabeled set will be rewarding in the active anchor link prediction problem. Various novel anchor link information gain measures are defined in this paper, based on which several constraint active anchor link prediction methods are introduced. Extensive experiments have been done on real-world social network datasets to compare the performance of these methods with state-of-art anchor link prediction methods. The experimental results show that the proposed Mean-entropy-based Constrained Active Learning (MC) method can outperform other methods with significant advantages. PMID:28771201

Constrained Active Learning for Anchor Link Prediction Across Multiple Heterogeneous Social Networks.

PubMed

Zhu, Junxing; Zhang, Jiawei; Wu, Quanyuan; Jia, Yan; Zhou, Bin; Wei, Xiaokai; Yu, Philip S

2017-08-03

Nowadays, people are usually involved in multiple heterogeneous social networks simultaneously. Discovering the anchor links between the accounts owned by the same users across different social networks is crucial for many important inter-network applications, e.g., cross-network link transfer and cross-network recommendation. Many different supervised models have been proposed to predict anchor links so far, but they are effective only when the labeled anchor links are abundant. However, in real scenarios, such a requirement can hardly be met and most anchor links are unlabeled, since manually labeling the inter-network anchor links is quite costly and tedious. To overcome such a problem and utilize the numerous unlabeled anchor links in model building, in this paper, we introduce the active learning based anchor link prediction problem. Different from the traditional active learning problems, due to the one-to-one constraint on anchor links, if an unlabeled anchor link a = ( u , v ) is identified as positive (i.e., existing), all the other unlabeled anchor links incident to account u or account v will be negative (i.e., non-existing) automatically. Viewed in such a perspective, asking for the labels of potential positive anchor links in the unlabeled set will be rewarding in the active anchor link prediction problem. Various novel anchor link information gain measures are defined in this paper, based on which several constraint active anchor link prediction methods are introduced. Extensive experiments have been done on real-world social network datasets to compare the performance of these methods with state-of-art anchor link prediction methods. The experimental results show that the proposed Mean-entropy-based Constrained Active Learning (MC) method can outperform other methods with significant advantages.

Linking matrices in systems with periodic boundary conditions

NASA Astrophysics Data System (ADS)

Panagiotou, Eleni; Millett, Kenneth C.

2018-06-01

We study the linking matrix, a measure of entanglement for a collection of closed or open chains in 3-space based on the Gauss linking number. Periodic boundary conditions (PBC) are often used in the simulation of physical systems of filaments. To measure entanglement of closed or open chains in systems employing PBC we use the periodic linking matrix, based on the periodic linking number, defined in Panagiotou (2015 J. Comput. Phys. 300 533–73). We study the properties of the periodic linking matrix as a function of cell size. We provide analytical results concerning the eigenvalues of the periodic linking matrix and show that some of them are invariant of cell-size.

Predicting missing links in complex networks based on common neighbors and distance

PubMed Central

Yang, Jinxuan; Zhang, Xiao-Dong

2016-01-01

The algorithms based on common neighbors metric to predict missing links in complex networks are very popular, but most of these algorithms do not account for missing links between nodes with no common neighbors. It is not accurate enough to reconstruct networks by using these methods in some cases especially when between nodes have less common neighbors. We proposed in this paper a new algorithm based on common neighbors and distance to improve accuracy of link prediction. Our proposed algorithm makes remarkable effect in predicting the missing links between nodes with no common neighbors and performs better than most existing currently used methods for a variety of real-world networks without increasing complexity. PMID:27905526

To Cross-Link or Not to Cross-Link? Cross-Linking Associated Foreign Body Response of Collagen-Based Devices

PubMed Central

Delgado, Luis M.; Bayon, Yves; Pandit, Abhay

2015-01-01

Collagen-based devices, in various physical conformations, are extensively used for tissue engineering and regenerative medicine applications. Given that the natural cross-linking pathway of collagen does not occur in vitro, chemical, physical, and biological cross-linking methods have been assessed over the years to control mechanical stability, degradation rate, and immunogenicity of the device upon implantation. Although in vitro data demonstrate that mechanical properties and degradation rate can be accurately controlled as a function of the cross-linking method utilized, preclinical and clinical data indicate that cross-linking methods employed may have adverse effects on host response, especially when potent cross-linking methods are employed. Experimental data suggest that more suitable cross-linking methods should be developed to achieve a balance between stability and functional remodeling. PMID:25517923

Linking Item Parameters to a Base Scale

ERIC Educational Resources Information Center

Kang, Taehoon; Petersen, Nancy S.

2012-01-01

This paper compares three methods of item calibration--concurrent calibration, separate calibration with linking, and fixed item parameter calibration--that are frequently used for linking item parameters to a base scale. Concurrent and separate calibrations were implemented using BILOG-MG. The Stocking and Lord in "Appl Psychol Measure"…

Nonlinear optimization-based device-free localization with outlier link rejection.

PubMed

Xiao, Wendong; Song, Biao; Yu, Xiting; Chen, Peiyuan

2015-04-07

Device-free localization (DFL) is an emerging wireless technique for estimating the location of target that does not have any attached electronic device. It has found extensive use in Smart City applications such as healthcare at home and hospitals, location-based services at smart spaces, city emergency response and infrastructure security. In DFL, wireless devices are used as sensors that can sense the target by transmitting and receiving wireless signals collaboratively. Many DFL systems are implemented based on received signal strength (RSS) measurements and the location of the target is estimated by detecting the changes of the RSS measurements of the wireless links. Due to the uncertainty of the wireless channel, certain links may be seriously polluted and result in erroneous detection. In this paper, we propose a novel nonlinear optimization approach with outlier link rejection (NOOLR) for RSS-based DFL. It consists of three key strategies, including: (1) affected link identification by differential RSS detection; (2) outlier link rejection via geometrical positional relationship among links; (3) target location estimation by formulating and solving a nonlinear optimization problem. Experimental results demonstrate that NOOLR is robust to the fluctuation of the wireless signals with superior localization accuracy compared with the existing Radio Tomographic Imaging (RTI) approach.

Simple measurement-based admission control for DiffServ access networks

NASA Astrophysics Data System (ADS)

Lakkakorpi, Jani

2002-07-01

In order to provide good Quality of Service (QoS) in a Differentiated Services (DiffServ) network, a dynamic admission control scheme is definitely needed as an alternative to overprovisioning. In this paper, we present a simple measurement-based admission control (MBAC) mechanism for DiffServ-based access networks. Instead of using active measurements only or doing purely static bookkeeping with parameter-based admission control (PBAC), the admission control decisions are based on bandwidth reservations and periodically measured & exponentially averaged link loads. If any link load on the path between two endpoints is over the applicable threshold, access is denied. Link loads are periodically sent to Bandwidth Broker (BB) of the routing domain, which makes the admission control decisions. The information needed in calculating the link loads is retrieved from the router statistics. The proposed admission control mechanism is verified through simulations. Our results prove that it is possible to achieve very high bottleneck link utilization levels and still maintain good QoS.

MEMS-based beam-steerable free-space optical communication link for reconfigurable wireless data center

NASA Astrophysics Data System (ADS)

Deng, Peng; Kavehrad, Mohsen; Lou, Yan

2017-01-01

Flexible wireless datacenter networks based on free space optical communication (FSO) links are being considered as promising solutions to meet the future datacenter demands of high throughput, robustness to dynamic traffic patterns, cabling complexity and energy efficiency. Robust and precise steerable FSO links over dynamic traffic play a key role in the reconfigurable optical wireless datacenter inter-rack network. In this work, we propose and demonstrate a reconfigurable 10Gbps FSO system incorporated with smart beam acquisition and tracking mechanism based on gimballess two-axis MEMS micro-mirror and retro-reflective film marked aperture. The fast MEMS-based beam acquisition switches laser beam of FSO terminal from one rack to the next for reconfigurable networks, and the precise beam tracking makes FSO device auto-correct the misalignment in real-time. We evaluate the optical power loss and bit error rate performance of steerable FSO links at various directions. Experimental results suggest that the MEMS based beam steerable FSO links hold considerable promise for the future reconfigurable wireless datacenter networks.

Topology control algorithm for wireless sensor networks based on Link forwarding

NASA Astrophysics Data System (ADS)

Pucuo, Cairen; Qi, Ai-qin

2018-03-01

The research of topology control could effectively save energy and increase the service life of network based on wireless sensor. In this paper, a arithmetic called LTHC (link transmit hybrid clustering) based on link transmit is proposed. It decreases expenditure of energy by changing the way of cluster-node’s communication. The idea is to establish a link between cluster and SINK node when the cluster is formed, and link-node must be non-cluster. Through the link, cluster sends information to SINK nodes. For the sake of achieving the uniform distribution of energy on the network, prolongate the network survival time, and improve the purpose of communication, the communication will cut down much more expenditure of energy for cluster which away from SINK node. In the two aspects of improving the traffic and network survival time, we find that the LTCH is far superior to the traditional LEACH by experiments.

Predicting missing links via correlation between nodes

NASA Astrophysics Data System (ADS)

Liao, Hao; Zeng, An; Zhang, Yi-Cheng

2015-10-01

As a fundamental problem in many different fields, link prediction aims to estimate the likelihood of an existing link between two nodes based on the observed information. Since this problem is related to many applications ranging from uncovering missing data to predicting the evolution of networks, link prediction has been intensively investigated recently and many methods have been proposed so far. The essential challenge of link prediction is to estimate the similarity between nodes. Most of the existing methods are based on the common neighbor index and its variants. In this paper, we propose to calculate the similarity between nodes by the Pearson correlation coefficient. This method is found to be very effective when applied to calculate similarity based on high order paths. We finally fuse the correlation-based method with the resource allocation method, and find that the combined method can substantially outperform the existing methods, especially in sparse networks.

A One-System Theory Which is Not Propositional.

PubMed

Witnauer, James E; Urcelay, Gonzalo P; Miller, Ralph R

2009-04-01

We argue that the propositional and link-based approaches to human contingency learning represent different levels of analysis because propositional reasoning requires a basis, which is plausibly provided by a link-based architecture. Moreover, in their attempt to compare two general classes of models (link-based and propositional), Mitchell et al. have referred to only two generic models and ignore the large variety of different models within each class.

Link-Based Similarity Measures Using Reachability Vectors

PubMed Central

Yoon, Seok-Ho; Kim, Ji-Soo; Ryu, Minsoo; Choi, Ho-Jin

2014-01-01

We present a novel approach for computing link-based similarities among objects accurately by utilizing the link information pertaining to the objects involved. We discuss the problems with previous link-based similarity measures and propose a novel approach for computing link based similarities that does not suffer from these problems. In the proposed approach each target object is represented by a vector. Each element of the vector corresponds to all the objects in the given data, and the value of each element denotes the weight for the corresponding object. As for this weight value, we propose to utilize the probability of reaching from the target object to the specific object, computed using the “Random Walk with Restart” strategy. Then, we define the similarity between two objects as the cosine similarity of the two vectors. In this paper, we provide examples to show that our approach does not suffer from the aforementioned problems. We also evaluate the performance of the proposed methods in comparison with existing link-based measures, qualitatively and quantitatively, with respect to two kinds of data sets, scientific papers and Web documents. Our experimental results indicate that the proposed methods significantly outperform the existing measures. PMID:24701188

[Facial injections of hyaluronic acid-based fillers for malformations. Preliminary study regarding scar tissue improvement and cosmetic betterment].

PubMed

Franchi, G; Neiva-Vaz, C; Picard, A; Vazquez, M-P

2018-06-01

Cross-linked hyaluronic acid-based fillers have gained rapid acceptance for treating facial wrinkles, deep tissue folds and sunken areas due to aging. This study evaluates, in addition to space-filling properties, their effects on softness and elasticity as a secondary effect, following injection of 3 commercially available cross-linked hyaluronic acid-based fillers (15mg/mL, 17,5mg/mL and 20mg/mL) in patients presenting with congenital or acquired facial malformations. We started injecting gels of cross-linked hyaluronic acid-based fillers in those cases in 2013; we performed 46 sessions of injections in 32 patients, aged from 13-32. Clinical assessment was performed by the patient himself and by a plastic surgeon, 15 days after injections and 6-18 months later. Cross-linked hyaluronic acid-based fillers offered very subtle cosmetic results and supplemented surgery with a very high level of satisfaction of the patients. When injected in fibrosis, the first session enhanced softness and elasticity; the second session enhanced the volume. Cross-linked hyaluronic acid-based fillers fill sunken areas and better softness and elasticity of scar tissues. In addition to their well-understood space-filling function, as a secondary effect, the authors demonstrate that cross-linked hyaluronic acid-based fillers improve softness and elasticity of scarring tissues. Many experimental studies support our observations, showing that cross-linked hyaluronic acid stimulates the production of several extra-cellular matrix components, including dermal collagen and elastin. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Biomechanical Strengthening of the Human Cornea Induced by Nanoplatform-Based Transepithelial Riboflavin/UV-A Corneal Cross-Linking.

PubMed

Labate, Cristina; Lombardo, Marco; Lombardo, Giuseppe; De Santo, Maria Penelope

2017-01-01

The purpose of this study was to investigate the biomechanical stiffening effect induced by nanoplatform-based transepithelial riboflavin/UV-A cross-linking protocol using atomic force microscopy (AFM). Twelve eye bank donor human sclerocorneal tissues were investigated using a commercial atomic force microscope operated in force spectroscopy mode. Four specimens underwent transepithelial corneal cross-linking using a hypotonic solution of 0.1% riboflavin with biodegradable polymeric nanoparticles of 2-hydroxypropyl-β-cyclodextrin plus enhancers (trometamol and ethylenediaminetetraacetic acid) and UV-A irradiation with a 10 mW/cm2 device for 9 minutes. After treatment, the corneal epithelium was removed using the Amoils brush, and the Young's modulus of the most anterior stroma was quantified as a function of scan rate by AFM. The results were compared with those collected from four specimens that underwent conventional riboflavin/UV-A corneal cross-linking and four untreated specimens. The average Young's modulus of the most anterior stroma after the nanoplatform-based transepithelial and conventional riboflavin/UV-A corneal cross-linking treatments was 2.5 times (P < 0.001) and 1.7 times (P < 0.001) greater than untreated controls respectively. The anterior stromal stiffness was significantly different between the two corneal cross-linking procedures (P < 0.001). The indentation depth decreased after corneal cross-linking treatments, ranging from an average of 2.4 ± 0.3 μm in untreated samples to an average of 1.2 ± 0.1 μm and 1.8 ± 0.1 μm after nanoplatform-based transepithelial and conventional cross-linking, respectively. The present nanotechnology-based transepithelial riboflavin/UV-A corneal cross-linking was effective to improve the biomechanical strength of the most anterior stroma of the human cornea.

Homodyne BPSK-based optical inter-satellite communication links

NASA Astrophysics Data System (ADS)

Lange, Robert; Smutny, Berry

2007-02-01

Summer 2007, Tesat will verify laser communication terminals based on homodyne BPSK (binary phase shift keying) in-orbit. A 5.625 Gbps LEO-LEO laser communication link, established between the German satellite TerraSAR-X and the US satellite NFIRE, shall demonstrate the performance and advantages of laser communication. End of 2006, a further program has been kicked-off to demonstrate the performance of ~2 Gbps LEO-GEO laser communication links. The link is part of a data relais from the German LEO satellite TanDEM-X via a Geo satellite to ground. The LEO-to-GEO laser commmunication link can be extended to further ~2 Gpbs GEO-GEO, and GEO-to-ground links.

Linking Item Parameters to a Base Scale. ACT Research Report Series, 2009-2

ERIC Educational Resources Information Center

Kang, Taehoon; Petersen, Nancy S.

2009-01-01

This paper compares three methods of item calibration--concurrent calibration, separate calibration with linking, and fixed item parameter calibration--that are frequently used for linking item parameters to a base scale. Concurrent and separate calibrations were implemented using BILOG-MG. The Stocking and Lord (1983) characteristic curve method…

VCSEL-based fiber optic link for avionics: implementation and performance analyses

NASA Astrophysics Data System (ADS)

Shi, Jieqin; Zhang, Chunxi; Duan, Jingyuan; Wen, Huaitao

2006-11-01

A Gb/s fiber optic link with built-in test capability (BIT) basing on vertical-cavity surface-emitting laser (VCSEL) sources for military avionics bus for next generation has been presented in this paper. To accurately predict link performance, statistical methods and Bit Error Rate (BER) measurements have been examined. The results show that the 1Gb/s fiber optic link meets the BER requirement and values for link margin can reach up to 13dB. Analysis shows that the suggested photonic network may provide high performance and low cost interconnections alternative for future military avionics.

Link prediction based on local community properties

NASA Astrophysics Data System (ADS)

Yang, Xu-Hua; Zhang, Hai-Feng; Ling, Fei; Cheng, Zhi; Weng, Guo-Qing; Huang, Yu-Jiao

2016-09-01

The link prediction algorithm is one of the key technologies to reveal the inherent rule of network evolution. This paper proposes a novel link prediction algorithm based on the properties of the local community, which is composed of the common neighbor nodes of any two nodes in the network and the links between these nodes. By referring to the node degree and the condition of assortativity or disassortativity in a network, we comprehensively consider the effect of the shortest path and edge clustering coefficient within the local community on node similarity. We numerically show the proposed method provide good link prediction results.

The kinetics-based enzyme-linked immunosorbent assay for coronavirus antibodies in cats: calibration to the indirect immunofluorescence assay and computerized standardization of results through normalization to control values.

PubMed Central

Barlough, J E; Jacobson, R H; Downing, D R; Lynch, T J; Scott, F W

1987-01-01

The computer-assisted, kinetics-based enzyme-linked immunosorbent assay for coronavirus antibodies in cats was calibrated to the conventional indirect immunofluorescence assay by linear regression analysis and computerized interpolation (generation of "immunofluorescence assay-equivalent" titers). Procedures were developed for normalization and standardization of kinetics-based enzyme-linked immunosorbent assay results through incorporation of five different control sera of predetermined ("expected") titer in daily runs. When used with such sera and with computer assistance, the kinetics-based enzyme-linked immunosorbent assay minimized both within-run and between-run variability while allowing also for efficient data reduction and statistical analysis and reporting of results. PMID:3032390

The kinetics-based enzyme-linked immunosorbent assay for coronavirus antibodies in cats: calibration to the indirect immunofluorescence assay and computerized standardization of results through normalization to control values.

PubMed

Barlough, J E; Jacobson, R H; Downing, D R; Lynch, T J; Scott, F W

1987-01-01

The computer-assisted, kinetics-based enzyme-linked immunosorbent assay for coronavirus antibodies in cats was calibrated to the conventional indirect immunofluorescence assay by linear regression analysis and computerized interpolation (generation of "immunofluorescence assay-equivalent" titers). Procedures were developed for normalization and standardization of kinetics-based enzyme-linked immunosorbent assay results through incorporation of five different control sera of predetermined ("expected") titer in daily runs. When used with such sera and with computer assistance, the kinetics-based enzyme-linked immunosorbent assay minimized both within-run and between-run variability while allowing also for efficient data reduction and statistical analysis and reporting of results.

A class-based link prediction using Distance Dependent Chinese Restaurant Process

NASA Astrophysics Data System (ADS)

Andalib, Azam; Babamir, Seyed Morteza

2016-08-01

One of the important tasks in relational data analysis is link prediction which has been successfully applied on many applications such as bioinformatics, information retrieval, etc. The link prediction is defined as predicting the existence or absence of edges between nodes of a network. In this paper, we propose a novel method for link prediction based on Distance Dependent Chinese Restaurant Process (DDCRP) model which enables us to utilize the information of the topological structure of the network such as shortest path and connectivity of the nodes. We also propose a new Gibbs sampling algorithm for computing the posterior distribution of the hidden variables based on the training data. Experimental results on three real-world datasets show the superiority of the proposed method over other probabilistic models for link prediction problem.

Conjunctive Conceptual Clustering: A Methodology and Experimentation.

DTIC Science & Technology

1987-09-01

observing a typical restaurant table on vhich there are such objects as food on a plate, a salad, utensils, salt and pepper, napkins , a ase with flowers, a...colored graph has nodes and inks that match only if they have corre-ponding link-olor and node-color labelg 4w 80 [SEtexture sa lif ba p S M i e d If...LINK LINK LINK LINK LINK 9 0 1 OPENdRECT RECTLOD 1 2 CL 10 0 0 LINK LINK INK LINK LINK ,~ . 0.5. Input file for attribute-based clustering The

A DTN-Based Multiple Access Fast Forward Service for the NASA Space Network

NASA Technical Reports Server (NTRS)

Israel, David; Davis, Faith; Marquart. Jane

2011-01-01

The NASA Space Network provides a demand access return link service capable of providing users a space link "on demand". An equivalent service in the forward link direction is not possible due to Tracking and Data Relay Spacecraft (TDRS) constraints. A Disruption Tolerant Networking (DTN)-based Multiple Access Fast Forward (MAFF) service has been proposed to provide a forward link to a user as soon as possible. Previous concept studies have identified a basic architecture and implementation approach. This paper reviews the user scenarios and benefits of an MAFF service and proposes an implementation approach based on the use of DTN protocols.

Full-duplex radio over fiber link with colorless source-free base station based on single sideband optical mm-wave signal with polarization rotated optical carrier

NASA Astrophysics Data System (ADS)

Ma, Jianxin

2016-07-01

A full-duplex radio-over fiber (RoF) link scheme based on single sideband (SSB) optical millimeter (mm)-wave signal with polarization-rotated optical carrier is proposed to realize the source-free colorless base station (BS), in which a polarization beam splitter (PBS) is used to abstract part of the optical carrier for conveying the uplink data. Since the optical carrier for the uplink does not bear the downlink signal, no cross-talk from the downlink contaminates the uplink signal. The simulation results demonstrate that both down- and up-links maintain good performance. The mm-wave signal distribution network based on the proposed full duplex fiber link scheme can use the uniform source-free colorless BSs, which makes the access system very simpler.

Optimisation of UV irradiation as a binding site conserving method for crosslinking collagen-based scaffolds.

PubMed

Davidenko, Natalia; Bax, Daniel V; Schuster, Carlos F; Farndale, Richard W; Hamaia, Samir W; Best, Serena M; Cameron, Ruth E

2016-01-01

Short wavelength (λ = 254 nm) UV irradiation was evaluated over a range of intensities (0.06 to 0.96 J/cm(2)) as a means of cross-linking collagen- and gelatin-based scaffolds, to tailor their material characteristics whilst retaining biological functionality. Zero-link carbodiimide treatments are commonly applied to collagen-based materials, forming cross-links from carboxylate anions (for example the acidic E of GFOGER) that are an essential part of integrin binding sites on collagen. Cross-linking these amino acids therefore disrupts the bioactivity of collagen. In contrast, UV irradiation forms bonds from less important aromatic tyrosine and phenylalanine residues. We therefore hypothesised that UV cross-linking would not compromise collagen cell reactivity. Here, highly porous (~99 %) isotropic, collagen-based scaffolds were produced via ice-templating. A series of scaffolds (pore diameters ranging from 130-260 μm) with ascending stability in water was made from gelatin, two different sources of collagen I, or blends of these materials. Glucose, known to aid UV crosslinking of collagen, was added to some lower-stability formulations. These scaffolds were exposed to different doses of UV irradiation, and the scaffold morphology, dissolution stability in water, resistance to compression and cell reactivity was assessed. Stabilisation in aqueous media varied with both the nature of the collagen-based material employed and the UV intensity. Scaffolds made from the most stable materials showed the greatest stability after irradiation, although the levels of cross-linking in all cases were relatively low. Scaffolds made from pure collagen from the two different sources showed different optimum levels of irradiation, suggesting altered balance between stabilisation from cross-linking and destabilisation from denaturation. The introduction of glucose into the scaffold enhanced the efficacy of UV cross-linking. Finally, as hypothesized, cell attachment, spreading and proliferation on collagen materials were unaffected by UV cross-linking. UV irradiation may therefore be used to provide relatively low level cross-linking of collagen without loss of biological functionality.

A contact photo-cross-linking investigation of the active site of the 8-17 deoxyribozyme.

PubMed

Liu, Yong; Sen, Dipankar

2008-09-12

The small RNA-cleaving 8-17 deoxyribozyme (DNAzyme) has been the subject of extensive mechanistic and structural investigation, including a number of recent single-molecule studies of its global folding. Little detailed insight exists, however, into this DNAzyme's active site; for instance, the identity of specific nucleotides that are proximal to or in contact with the scissile site in the substrate. Here, we report a systematic replacement of a number of bases within the magnesium-folded DNAzyme-substrate complex with thio- and halogen-substituted base analogues, which were then photochemically activated to generate contact cross-links within the complex. Mapping of the cross-links revealed a striking pattern of DNAzyme-substrate cross-links but an absence of significant intra-DNAzyme cross-links. Notably, the two nucleotides directly flanking the scissile phosphodiester cross-linked strongly with functionally important elements within the DNAzyme, the thymine of a G.T wobble base pair, a WCGR bulge loop, and a terminal AGC loop. Mutation of the wobble base pair to a G-C pair led to a significant folding instability of the DNAzyme-substrate complex. The cross-linking patterns obtained were used to generate a model for the DNAzyme's active site that had the substrate's scissile phosphodiester sandwiched between the DNAzyme's wobble thymine and its AGC and WCGR loops.

Internet-Based Economic Education: The Case of EconEdLink

ERIC Educational Resources Information Center

VanFossen, Phillip J.; Herman-Ellison, Lisa C.

2006-01-01

The National Council on Economic Education's (NCEE) EconEdLink site provides lessons and classroom learning activities based on economics topics in the news, as well as access to real-time economic data. EconEdLink's content is designed to help integrate economic concepts across the curriculum as outlined in the Voluntary National Content…

Analysis of broadcasting satellite service feeder link power control and polarization

NASA Technical Reports Server (NTRS)

Sullivan, T. M.

1982-01-01

Statistical analyses of carrier to interference power ratios (C/Is) were performed in assessing 17.5 GHz feeder links using (1) fixed power and power control, and (2) orthogonal linear and orthogonal circular polarizations. The analysis methods and attenuation/depolarization data base were based on CCIR findings to the greatest possible extent. Feeder links using adaptive power control were found to neither cause or suffer significant C/I degradation relative to that for fixed power feeder links having similar or less stringent availability objectives. The C/Is for sharing between orthogonal linearly polarized feeder links were found to be significantly higher than those for circular polarization only in links to nominally colocated satellites from nominally colocated Earth stations in high attenuation environments.

Mining gene link information for survival pathway hunting.

PubMed

Jing, Gao-Jian; Zhang, Zirui; Wang, Hong-Qiang; Zheng, Hong-Mei

2015-08-01

This study proposes a gene link-based method for survival time-related pathway hunting. In this method, the authors incorporate gene link information to estimate how a pathway is associated with cancer patient's survival time. Specifically, a gene link-based Cox proportional hazard model (Link-Cox) is established, in which two linked genes are considered together to represent a link variable and the association of the link with survival time is assessed using Cox proportional hazard model. On the basis of the Link-Cox model, the authors formulate a new statistic for measuring the association of a pathway with survival time of cancer patients, referred to as pathway survival score (PSS), by summarising survival significance over all the gene links in the pathway, and devise a permutation test to test the significance of an observed PSS. To evaluate the proposed method, the authors applied it to simulation data and two publicly available real-world gene expression data sets. Extensive comparisons with previous methods show the effectiveness and efficiency of the proposed method for survival pathway hunting.

The combination of direct and paired link graphs can boost repetitive genome assembly

PubMed Central

Shi, Wenyu; Ji, Peifeng

2017-01-01

Abstract Currently, most paired link based scaffolding algorithms intrinsically mask the sequences between two linked contigs and bypass their direct link information embedded in the original de Bruijn assembly graph. Such disadvantage substantially complicates the scaffolding process and leads to the inability of resolving repetitive contig assembly. Here we present a novel algorithm, inGAP-sf, for effectively generating high-quality and continuous scaffolds. inGAP-sf achieves this by using a new strategy based on the combination of direct link and paired link graphs, in which direct link is used to increase graph connectivity and to decrease graph complexity and paired link is employed to supervise the traversing process on the direct link graph. Such advantage greatly facilitates the assembly of short-repeat enriched regions. Moreover, a new comprehensive decision model is developed to eliminate the noise routes accompanying with the introduced direct link. Through extensive evaluations on both simulated and real datasets, we demonstrated that inGAP-sf outperforms most of the genome scaffolding algorithms by generating more accurate and continuous assembly, especially for short repetitive regions. PMID:27924003

Link Correlated Military Data for Better Decision Support

DTIC Science & Technology

2011-06-01

automatically translated into URI based links, thus can greatly reduce man power cost on software development. 3 Linked Data Technique Tim Berners - Lee ...Linked Data - while Linked Data is usually considered as part of Semantic Web, or “the Semantic Web done right” as described by Tim himself - has been...Required data of automatic link construction mechanism on more kinds of correlations. References [1] B. L. Tim , “The next Web of open, linked data

Similarity indices based on link weight assignment for link prediction of unweighted complex networks

NASA Astrophysics Data System (ADS)

Liu, Shuxin; Ji, Xinsheng; Liu, Caixia; Bai, Yi

2017-01-01

Many link prediction methods have been proposed for predicting the likelihood that a link exists between two nodes in complex networks. Among these methods, similarity indices are receiving close attention. Most similarity-based methods assume that the contribution of links with different topological structures is the same in the similarity calculations. This paper proposes a local weighted method, which weights the strength of connection between each pair of nodes. Based on the local weighted method, six local weighted similarity indices extended from unweighted similarity indices (including Common Neighbor (CN), Adamic-Adar (AA), Resource Allocation (RA), Salton, Jaccard and Local Path (LP) index) are proposed. Empirical study has shown that the local weighted method can significantly improve the prediction accuracy of these unweighted similarity indices and that in sparse and weakly clustered networks, the indices perform even better.

Mining Missing Hyperlinks from Human Navigation Traces: A Case Study of Wikipedia.

PubMed

West, Robert; Paranjape, Ashwin; Leskovec, Jure

Hyperlinks are an essential feature of the World Wide Web. They are especially important for online encyclopedias such as Wikipedia: an article can often only be understood in the context of related articles, and hyperlinks make it easy to explore this context. But important links are often missing, and several methods have been proposed to alleviate this problem by learning a linking model based on the structure of the existing links. Here we propose a novel approach to identifying missing links in Wikipedia. We build on the fact that the ultimate purpose of Wikipedia links is to aid navigation. Rather than merely suggesting new links that are in tune with the structure of existing links, our method finds missing links that would immediately enhance Wikipedia's navigability. We leverage data sets of navigation paths collected through a Wikipedia-based human-computation game in which users must find a short path from a start to a target article by only clicking links encountered along the way. We harness human navigational traces to identify a set of candidates for missing links and then rank these candidates. Experiments show that our procedure identifies missing links of high quality.

Mining Missing Hyperlinks from Human Navigation Traces: A Case Study of Wikipedia

PubMed Central

West, Robert; Paranjape, Ashwin; Leskovec, Jure

2015-01-01

Hyperlinks are an essential feature of the World Wide Web. They are especially important for online encyclopedias such as Wikipedia: an article can often only be understood in the context of related articles, and hyperlinks make it easy to explore this context. But important links are often missing, and several methods have been proposed to alleviate this problem by learning a linking model based on the structure of the existing links. Here we propose a novel approach to identifying missing links in Wikipedia. We build on the fact that the ultimate purpose of Wikipedia links is to aid navigation. Rather than merely suggesting new links that are in tune with the structure of existing links, our method finds missing links that would immediately enhance Wikipedia's navigability. We leverage data sets of navigation paths collected through a Wikipedia-based human-computation game in which users must find a short path from a start to a target article by only clicking links encountered along the way. We harness human navigational traces to identify a set of candidates for missing links and then rank these candidates. Experiments show that our procedure identifies missing links of high quality. PMID:26634229

An NCME Instructional Module on Population Invariance in Linking and Equating

ERIC Educational Resources Information Center

Huggins, Anne C.; Penfield, Randall D.

2012-01-01

A goal for any linking or equating of two or more tests is that the linking function be invariant to the population used in conducting the linking or equating. Violations of population invariance in linking and equating jeopardize the fairness and validity of test scores, and pose particular problems for test-based accountability programs that…

Computerized training management system

DOEpatents

Rice, H.B.; McNair, R.C.; White, K.; Maugeri, T.

1998-08-04

A Computerized Training Management System (CTMS) is disclosed for providing a procedurally defined process that is employed to develop accreditable performance based training programs for job classifications that are sensitive to documented regulations and technical information. CTMS is a database that links information needed to maintain a five-phase approach to training-analysis, design, development, implementation, and evaluation independent of training program design. CTMS is designed using R-Base{trademark}, an-SQL compliant software platform. Information is logically entered and linked in CTMS. Each task is linked directly to a performance objective, which, in turn, is linked directly to a learning objective; then, each enabling objective is linked to its respective test items. In addition, tasks, performance objectives, enabling objectives, and test items are linked to their associated reference documents. CTMS keeps all information up to date since it automatically sorts, files and links all data; CTMS includes key word and reference document searches. 18 figs.

Computerized training management system

DOEpatents

Rice, Harold B.; McNair, Robert C.; White, Kenneth; Maugeri, Terry

1998-08-04

A Computerized Training Management System (CTMS) for providing a procedurally defined process that is employed to develop accreditable performance based training programs for job classifications that are sensitive to documented regulations and technical information. CTMS is a database that links information needed to maintain a five-phase approach to training-analysis, design, development, implementation, and evaluation independent of training program design. CTMS is designed using R-Base.RTM., an-SQL compliant software platform. Information is logically entered and linked in CTMS. Each task is linked directly to a performance objective, which, in turn, is linked directly to a learning objective; then, each enabling objective is linked to its respective test items. In addition, tasks, performance objectives, enabling objectives, and test items are linked to their associated reference documents. CTMS keeps all information up to date since it automatically sorts, files and links all data; CTMS includes key word and reference document searches.

Phase Transition in Biopolymer Hydrogels Based on Glycine (g), Valine (v), Proline (p), and Isoleucine (i)

NASA Astrophysics Data System (ADS)

Lee, Jonghwi; Urry, Dan W.; Macosko, Christopher W.

2000-03-01

Selectively modified elastic protein-based polymers demonstrate diverse energy conversions by means of the control of a phase transition resulting from the sensitivity to stimuli of the hydrophobic association. Among these polymers, poly(GVGVP), poly(GVGIP) and analogues of poly(GVGVP) containing carboxylic acid or amino functional groups as side chains were cross-linked and their swelling behavior was studied. Regardless of cross-linking method, reversible phase transitions can be observed in the swelling of all cross-linked polymers by changing temperature and pH, where relevant. Decreased cross-link density leads to increased swelling ratio as the transition becomes more pronounced. Fibers, chemically cross-linked after formation, exhibit anisotropic dimensional changes on changing the temperature. Gamma-irradiation cross-linked poly(GVGVP) exhibited a more distinct phase transition than modified poly(GVGVP) with ion pairs between side chains, which were partially converted to amide cross-links.

Enhanced correlation of received power-signal fluctuations in bidirectional optical links

NASA Astrophysics Data System (ADS)

Minet, Jean; Vorontsov, Mikhail A.; Polnau, Ernst; Dolfi, Daniel

2013-02-01

A study of the correlation between the power signals received at both ends of bidirectional free-space optical links is presented. By use of the quasi-optical approximation, we show that an ideal (theoretically 100%) power-signal correlation can be achieved in optical links with specially designed monostatic transceivers based on single-mode fiber collimators. The theoretical prediction of enhanced correlation is supported both by experiments conducted over a 7 km atmospheric path and wave optics numerical analysis of the corresponding bidirectional optical link. In the numerical simulations, we also compare correlation properties of received power signals for different atmospheric conditions and for optical links with monostatic and bistatic geometries based on single-mode fiber collimator and on power-in-the-bucket transceiver types. Applications of the observed phenomena for signal fading mitigation and turbulence-enhanced communication link security in free-space laser communication links are discussed.

Exploiting Information Diffusion Feature for Link Prediction in Sina Weibo

NASA Astrophysics Data System (ADS)

Li, Dong; Zhang, Yongchao; Xu, Zhiming; Chu, Dianhui; Li, Sheng

2016-01-01

The rapid development of online social networks (e.g., Twitter and Facebook) has promoted research related to social networks in which link prediction is a key problem. Although numerous attempts have been made for link prediction based on network structure, node attribute and so on, few of the current studies have considered the impact of information diffusion on link creation and prediction. This paper mainly addresses Sina Weibo, which is the largest microblog platform with Chinese characteristics, and proposes the hypothesis that information diffusion influences link creation and verifies the hypothesis based on real data analysis. We also detect an important feature from the information diffusion process, which is used to promote link prediction performance. Finally, the experimental results on Sina Weibo dataset have demonstrated the effectiveness of our methods.

Exploiting Information Diffusion Feature for Link Prediction in Sina Weibo.

PubMed

Li, Dong; Zhang, Yongchao; Xu, Zhiming; Chu, Dianhui; Li, Sheng

2016-01-28

The rapid development of online social networks (e.g., Twitter and Facebook) has promoted research related to social networks in which link prediction is a key problem. Although numerous attempts have been made for link prediction based on network structure, node attribute and so on, few of the current studies have considered the impact of information diffusion on link creation and prediction. This paper mainly addresses Sina Weibo, which is the largest microblog platform with Chinese characteristics, and proposes the hypothesis that information diffusion influences link creation and verifies the hypothesis based on real data analysis. We also detect an important feature from the information diffusion process, which is used to promote link prediction performance. Finally, the experimental results on Sina Weibo dataset have demonstrated the effectiveness of our methods.

Statistical similarity measures for link prediction in heterogeneous complex networks

NASA Astrophysics Data System (ADS)

Shakibian, Hadi; Charkari, Nasrollah Moghadam

2018-07-01

The majority of the link prediction measures in heterogeneous complex networks rely on the nodes connectivities while less attention has been paid to the importance of the nodes and paths. In this paper, we propose some new meta-path based statistical similarity measures to properly perform link prediction task. The main idea in the proposed measures is to drive some co-occurrence events in a number of co-occurrence matrices that are occurred between the visited nodes obeying a meta-path. The extracted co-occurrence matrices are analyzed in terms of the energy, inertia, local homogeneity, correlation, and information measure of correlation to determine various information theoretic measures. We evaluate the proposed measures, denoted as link energy, link inertia, link local homogeneity, link correlation, and link information measure of correlation, using a standard DBLP network data set. The results of the AUC score and Precision rate indicate the validity and accuracy of the proposed measures in comparison to the popular meta-path based similarity measures.

Packet based serial link realized in FPGA dedicated for high resolution infrared image transmission

NASA Astrophysics Data System (ADS)

Bieszczad, Grzegorz

2015-05-01

In article the external digital interface specially designed for thermographic camera built in Military University of Technology is described. The aim of article is to illustrate challenges encountered during design process of thermal vision camera especially related to infrared data processing and transmission. Article explains main requirements for interface to transfer Infra-Red or Video digital data and describes the solution which we elaborated based on Low Voltage Differential Signaling (LVDS) physical layer and signaling scheme. Elaborated link for image transmission is built using FPGA integrated circuit with built-in high speed serial transceivers achieving up to 2500Gbps throughput. Image transmission is realized using proprietary packet protocol. Transmission protocol engine was described in VHDL language and tested in FPGA hardware. The link is able to transmit 1280x1024@60Hz 24bit video data using one signal pair. Link was tested to transmit thermal-vision camera picture to remote monitor. Construction of dedicated video link allows to reduce power consumption compared to solutions with ASIC based encoders and decoders realizing video links like DVI or packed based Display Port, with simultaneous reduction of wires needed to establish link to one pair. Article describes functions of modules integrated in FPGA design realizing several functions like: synchronization to video source, video stream packeting, interfacing transceiver module and dynamic clock generation for video standard conversion.

The utilization of oncology web-based resources in Spanish-speaking Internet users.

PubMed

Simone, Charles B; Hampshire, Margaret K; Vachani, Carolyn; Metz, James M

2012-12-01

There currently are few web-based resources written in Spanish providing oncology-specific information. This study examines utilization of Spanish-language oncology web-based resources and evaluates oncology-related Internet browsing practices of Spanish-speaking patients. OncoLink (http://www.oncolink.org) is the oldest and among the largest Internet-based cancer information resources. In September 2005, OncoLink pioneered OncoLink en español (OEE) (http://es.oncolink.org), a Spanish translation of OncoLink. Internet utilization data on these sites for 2006 to 2007 were compared. Visits to OncoLink rose from 4,440,843 in 2006 to 5,125,952 in 2007. OEE had 204,578 unique visitors and 240,442 visits in 2006, and 351,228 visitors and 412,153 visits in 2007. Although there was no time predilection for viewing OncoLink, less relative browsing on OEE was conducted during weekends and early morning hours. Although OncoLink readers searched for information on the most common cancers in the United States, OEE readers most often search for gastric, vaginal, osteosarcoma, leukemia, penile, cervical, and testicular malignancies. Average visit duration on OEE was shorter, and fewer readers surveyed OEE more than 15 minutes (4.5% vs. 14.9%, P < 0.001). Spanish-speaking users of web-based oncology resources are increasingly using the Internet to supplement their cancer knowledge. Limited available resources written in Spanish contribute to disparities in information access and disease outcomes. Spanish-speaking oncology readers differ from English-speaking readers in day and time of Internet browsing, visit duration, Internet search patterns, and types of cancers searched. By acknowledging these differences, content of web-based oncology resources can be developed to best target the needs of Spanish-speaking viewers.

The Utilization of Oncology Web-based Resources in Spanish-speaking Internet Users

PubMed Central

Simone, Charles B.; Hampshire, Margaret K.; Vachani, Carolyn; Metz, James M.

2011-01-01

Objectives: There currently are few web-based resources written in Spanish providing oncology-specific information. This study examines utilization of Spanish-language oncology web-based resources and evaluates oncology-related Internet browsing practices of Spanish-speaking patients. Methods: OncoLink (http://www.oncolink.org) is the oldest and among the largest Internet-based cancer information resources. In 9/2005, OncoLink pioneered OncoLink en español (OEE) (http://es.oncolink.org), a Spanish translation of OncoLink. Internet utilization data on these sites for 2006-2007 were compared. Results: Visits to OncoLink rose from 4,440,843 in 2006 to 5,125,952 in 2007. OEE had 204,578 unique visitors and 240,442 visits in 2006, and 351,228 visitors and 412,153 visits in 2007. While there was no time predilection for viewing OncoLink, less relative browsing on OEE was conducted during weekends and early morning hours. While OncoLink readers searched for information on the most common cancers in the United States, OEE readers most often search for gastric, vaginal, osteosarcoma, leukemia, penile, cervical, and testicular malignancies. Average visit duration on OEE was shorter, and fewer readers surveyed OEE >15 minutes (4.5% vs. 14.9%, p<0.001). Conclusions: Spanish-speaking users of web-based oncology resources are increasingly using the Internet to supplement their cancer knowledge. Limited available resources written in Spanish contribute to disparities in information access and disease outcomes. Spanish-speaking oncology readers differ from English-speaking readers in day and time of Internet browsing, visit duration, Internet search patterns, and types of cancers searched. By acknowledging these differences, content of web-based oncology resources can be developed to best target the needs of Spanish-speaking viewers. PMID:21654312

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

Hayes, T.; Smith, K.S.; Severino, F.

A critical capability of the new RHIC low level rf (LLRF) system is the ability to synchronize signals across multiple locations. The 'Update Link' provides this functionality. The 'Update Link' is a deterministic serial data link based on the Xilinx RocketIO protocol that is broadcast over fiber optic cable at 1 gigabit per second (Gbps). The link provides timing events and data packets as well as time stamp information for synchronizing diagnostic data from multiple sources. The new RHIC LLRF was designed to be a flexible, modular system. The system is constructed of numerous independent RF Controller chassis. To providemore » synchronization among all of these chassis, the Update Link system was designed. The Update Link system provides a low latency, deterministic data path to broadcast information to all receivers in the system. The Update Link system is based on a central hub, the Update Link Master (ULM), which generates the data stream that is distributed via fiber optic links. Downstream chassis have non-deterministic connections back to the ULM that allow any chassis to provide data that is broadcast globally.« less

Content comparison of occupation-based instruments in adult rheumatology and musculoskeletal rehabilitation based on the International Classification of Functioning, Disability and Health.

PubMed

Stamm, Tanja A; Cieza, Alarcos; Machold, Klaus P; Smolen, Josef S; Stucki, Gerold

2004-12-15

To compare the content of clinical, occupation-based instruments that are used in adult rheumatology and musculoskeletal rehabilitation in occupational therapy based on the International Classification of Functioning, Disability and Health (ICF). Clinical instruments of occupational performance and occupation in adult rehabilitation and rheumatology were identified in a literature search. All items of these instruments were linked to the ICF categories according to 10 linking rules. On the basis of the linking, the content of these instruments was compared and the relationship between the capacity and performance component explored. The following 7 instruments were identified: the Canadian Occupational Performance Measure, the Assessment of Motor and Process Skills, the Sequential Occupational Dexterity Assessment, the Jebson Taylor Hand Function Test, the Moberg Picking Up Test, the Button Test, and the Functional Dexterity Test. The items of the 7 instruments were linked to 53 different ICF categories. Five items could not be linked to the ICF. The areas covered by the 7 occupation-based instruments differ importantly: The main focus of all 7 instruments is on the ICF component activities and participation. Body functions are covered by 2 instruments. Two instruments were linked to 1 single ICF category only. Clinicians and researchers who need to select an occupation-based instrument must be aware of the areas that are covered by this instrument and the potential areas that are not covered at all.

Bridging "The Gap"--Linking Workplace-Based and University-Based Learning in Preschool Teacher Education in Sweden

ERIC Educational Resources Information Center

Karlsson Lohmander, Maelis

2015-01-01

Professional experience in preschool settings comprises an important part of the education of preschool teachers. During their placements, students are expected to link theory to practice, to integrate university-based knowledge with workplace-based knowledge and skills essential for their future profession. They often refer to a perceived gap…

Effects of linking a soil-water-balance model with a groundwater-flow model

USGS Publications Warehouse

Stanton, Jennifer S.; Ryter, Derek W.; Peterson, Steven M.

2013-01-01

A previously published regional groundwater-flow model in north-central Nebraska was sequentially linked with the recently developed soil-water-balance (SWB) model to analyze effects to groundwater-flow model parameters and calibration results. The linked models provided a more detailed spatial and temporal distribution of simulated recharge based on hydrologic processes, improvement of simulated groundwater-level changes and base flows at specific sites in agricultural areas, and a physically based assessment of the relative magnitude of recharge for grassland, nonirrigated cropland, and irrigated cropland areas. Root-mean-squared (RMS) differences between the simulated and estimated or measured target values for the previously published model and linked models were relatively similar and did not improve for all types of calibration targets. However, without any adjustment to the SWB-generated recharge, the RMS difference between simulated and estimated base-flow target values for the groundwater-flow model was slightly smaller than for the previously published model, possibly indicating that the volume of recharge simulated by the SWB code was closer to actual hydrogeologic conditions than the previously published model provided. Groundwater-level and base-flow hydrographs showed that temporal patterns of simulated groundwater levels and base flows were more accurate for the linked models than for the previously published model at several sites, particularly in agricultural areas.

Internet-Based Approaches to Building Stakeholder Networks for Conservation and Natural Resource Management.

PubMed

Kreakie, B J; Hychka, K C; Belaire, J A; Minor, E; Walker, H A

2016-02-01

Social network analysis (SNA) is based on a conceptual network representation of social interactions and is an invaluable tool for conservation professionals to increase collaboration, improve information flow, and increase efficiency. We present two approaches to constructing internet-based social networks, and use an existing traditional (survey-based) case study to illustrate in a familiar context the deviations in methods and results. Internet-based approaches to SNA offer a means to overcome institutional hurdles to conducting survey-based SNA, provide unique insight into an institution's web presences, allow for easy snowballing (iterative process that incorporates new nodes in the network), and afford monitoring of social networks through time. The internet-based approaches differ in link definition: hyperlink is based on links on a website that redirect to a different website and relatedness links are based on a Google's "relatedness" operator that identifies pages "similar" to a URL. All networks were initiated with the same start nodes [members of a conservation alliance for the Calumet region around Chicago (n = 130)], but the resulting networks vary drastically from one another. Interpretation of the resulting networks is highly contingent upon how the links were defined.

Internet-Based Approaches to Building Stakeholder Networks for Conservation and Natural Resource Management

NASA Astrophysics Data System (ADS)

Kreakie, B. J.; Hychka, K. C.; Belaire, J. A.; Minor, E.; Walker, H. A.

2016-02-01

Social network analysis (SNA) is based on a conceptual network representation of social interactions and is an invaluable tool for conservation professionals to increase collaboration, improve information flow, and increase efficiency. We present two approaches to constructing internet-based social networks, and use an existing traditional (survey-based) case study to illustrate in a familiar context the deviations in methods and results. Internet-based approaches to SNA offer a means to overcome institutional hurdles to conducting survey-based SNA, provide unique insight into an institution's web presences, allow for easy snowballing (iterative process that incorporates new nodes in the network), and afford monitoring of social networks through time. The internet-based approaches differ in link definition: hyperlink is based on links on a website that redirect to a different website and relatedness links are based on a Google's "relatedness" operator that identifies pages "similar" to a URL. All networks were initiated with the same start nodes [members of a conservation alliance for the Calumet region around Chicago ( n = 130)], but the resulting networks vary drastically from one another. Interpretation of the resulting networks is highly contingent upon how the links were defined.

Utility-Based Link Recommendation in Social Networks

ERIC Educational Resources Information Center

Li, Zhepeng

2013-01-01

Link recommendation, which suggests links to connect currently unlinked users, is a key functionality offered by major online social networking platforms. Salient examples of link recommendation include "people you may know"' on Facebook and "who to follow" on Twitter. A social networking platform has two types of stakeholder:…

Link Prediction in Evolving Networks Based on Popularity of Nodes.

PubMed

Wang, Tong; He, Xing-Sheng; Zhou, Ming-Yang; Fu, Zhong-Qian

2017-08-02

Link prediction aims to uncover the underlying relationship behind networks, which could be utilized to predict missing edges or identify the spurious edges. The key issue of link prediction is to estimate the likelihood of potential links in networks. Most classical static-structure based methods ignore the temporal aspects of networks, limited by the time-varying features, such approaches perform poorly in evolving networks. In this paper, we propose a hypothesis that the ability of each node to attract links depends not only on its structural importance, but also on its current popularity (activeness), since active nodes have much more probability to attract future links. Then a novel approach named popularity based structural perturbation method (PBSPM) and its fast algorithm are proposed to characterize the likelihood of an edge from both existing connectivity structure and current popularity of its two endpoints. Experiments on six evolving networks show that the proposed methods outperform state-of-the-art methods in accuracy and robustness. Besides, visual results and statistical analysis reveal that the proposed methods are inclined to predict future edges between active nodes, rather than edges between inactive nodes.

A VGI data integration framework based on linked data model

NASA Astrophysics Data System (ADS)

Wan, Lin; Ren, Rongrong

2015-12-01

This paper aims at the geographic data integration and sharing method for multiple online VGI data sets. We propose a semantic-enabled framework for online VGI sources cooperative application environment to solve a target class of geospatial problems. Based on linked data technologies - which is one of core components of semantic web, we can construct the relationship link among geographic features distributed in diverse VGI platform by using linked data modeling methods, then deploy these semantic-enabled entities on the web, and eventually form an interconnected geographic data network to support geospatial information cooperative application across multiple VGI data sources. The mapping and transformation from VGI sources to RDF linked data model is presented to guarantee the unique data represent model among different online social geographic data sources. We propose a mixed strategy which combined spatial distance similarity and feature name attribute similarity as the measure standard to compare and match different geographic features in various VGI data sets. And our work focuses on how to apply Markov logic networks to achieve interlinks of the same linked data in different VGI-based linked data sets. In our method, the automatic generating method of co-reference object identification model according to geographic linked data is discussed in more detail. It finally built a huge geographic linked data network across loosely-coupled VGI web sites. The results of the experiment built on our framework and the evaluation of our method shows the framework is reasonable and practicable.

Similarity-based Regularized Latent Feature Model for Link Prediction in Bipartite Networks.

PubMed

Wang, Wenjun; Chen, Xue; Jiao, Pengfei; Jin, Di

2017-12-05

Link prediction is an attractive research topic in the field of data mining and has significant applications in improving performance of recommendation system and exploring evolving mechanisms of the complex networks. A variety of complex systems in real world should be abstractly represented as bipartite networks, in which there are two types of nodes and no links connect nodes of the same type. In this paper, we propose a framework for link prediction in bipartite networks by combining the similarity based structure and the latent feature model from a new perspective. The framework is called Similarity Regularized Nonnegative Matrix Factorization (SRNMF), which explicitly takes the local characteristics into consideration and encodes the geometrical information of the networks by constructing a similarity based matrix. We also develop an iterative scheme to solve the objective function based on gradient descent. Extensive experiments on a variety of real world bipartite networks show that the proposed framework of link prediction has a more competitive, preferable and stable performance in comparison with the state-of-art methods.

An indole-linked C8-deoxyguanosine nucleoside acts as a fluorescent reporter of Watson-Crick versus Hoogsteen base pairing.

PubMed

Schlitt, Katherine M; Millen, Andrea L; Wetmore, Stacey D; Manderville, Richard A

2011-03-07

Pyrrole- and indole-linked C(8)-deoxyguanosine nucleosides act as fluorescent reporters of H-bonding specificity. Their fluorescence is quenched upon Watson-Crick H-bonding to dC, while Hoogsteen H-bonding to G enhances emission intensity. The indole-linked probe is ∼ 10-fold brighter and shows promise as a fluorescent reporter of Hoogsteen base pairing.

Meta-path based heterogeneous combat network link prediction

NASA Astrophysics Data System (ADS)

Li, Jichao; Ge, Bingfeng; Yang, Kewei; Chen, Yingwu; Tan, Yuejin

2017-09-01

The combat system-of-systems in high-tech informative warfare, composed of many interconnected combat systems of different types, can be regarded as a type of complex heterogeneous network. Link prediction for heterogeneous combat networks (HCNs) is of significant military value, as it facilitates reconfiguring combat networks to represent the complex real-world network topology as appropriate with observed information. This paper proposes a novel integrated methodology framework called HCNMP (HCN link prediction based on meta-path) to predict multiple types of links simultaneously for an HCN. More specifically, the concept of HCN meta-paths is introduced, through which the HCNMP can accumulate information by extracting different features of HCN links for all the six defined types. Next, an HCN link prediction model, based on meta-path features, is built to predict all types of links of the HCN simultaneously. Then, the solution algorithm for the HCN link prediction model is proposed, in which the prediction results are obtained by iteratively updating with the newly predicted results until the results in the HCN converge or reach a certain maximum iteration number. Finally, numerical experiments on the dataset of a real HCN are conducted to demonstrate the feasibility and effectiveness of the proposed HCNMP, in comparison with 30 baseline methods. The results show that the performance of the HCNMP is superior to those of the baseline methods.

Atmospheric turbulence compensation in orbital angular momentum communications: Advances and perspectives

NASA Astrophysics Data System (ADS)

Li, Shuhui; Chen, Shi; Gao, Chunqing; Willner, Alan E.; Wang, Jian

2018-02-01

Orbital angular momentum (OAM)-carrying beams have recently generated considerable interest due to their potential use in communication systems to increase transmission capacity and spectral efficiency. For OAM-based free-space optical (FSO) links, a critical challenge is the atmospheric turbulence that will distort the helical wavefronts of OAM beams leading to the decrease of received power, introducing crosstalk between multiple channels, and impairing link performance. In this paper, we review recent advances in turbulence effects compensation techniques for OAM-based FSO communication links. First, basic concepts of atmospheric turbulence and theoretical model are introduced. Second, atmospheric turbulence effects on OAM beams are theoretically and experimentally investigated and discussed. Then, several typical turbulence compensation approaches, including both adaptive optics-based (optical domain) and signal processing-based (electrical domain) techniques, are presented. Finally, key challenges and perspectives of compensation of turbulence-distorted OAM links are discussed.

Inverted bulk-heterojunction solar cell with cross-linked hole-blocking layer

PubMed Central

Udum, Yasemin; Denk, Patrick; Adam, Getachew; Apaydin, Dogukan H.; Nevosad, Andreas; Teichert, Christian; S. White, Matthew.; S. Sariciftci, Niyazi.; Scharber, Markus C.

2014-01-01

We have developed a hole-blocking layer for bulk-heterojunction solar cells based on cross-linked polyethylenimine (PEI). We tested five different ether-based cross-linkers and found that all of them give comparable solar cell efficiencies. The initial idea that a cross-linked layer is more solvent resistant compared to a pristine PEI layer could not be confirmed. With and without cross-linking, the PEI layer sticks very well to the surface of the indium–tin–oxide electrode and cannot be removed by solvents used to process PEI or common organic semiconductors. The cross-linked PEI hole-blocking layer functions for multiple donor–acceptor blends. We found that using cross-linkers improves the reproducibility of the device fabrication process. PMID:24817837

Effect of the incidence angle to free space optical communication based on cat-eye modulating retro-reflector

NASA Astrophysics Data System (ADS)

Zhang, Lai-xian; Sun, Hua-yan; Zhao, Yan-zhong; Zheng, Yong-hui; Shan, Cong-miao

2013-08-01

Based on the cat-eye effect of optical system, free space optical communication based on cat-eye modulating retro-reflector can build communication link rapidly. Compared to classical free space optical communication system, system based on cat-eye modulating retro-reflector has great advantages such as building communication link more rapidly, a passive terminal is smaller, lighter and lower power consuming. The incident angle is an important factor of cat-eye effect, so it will affect the retro-reflecting communication link. In this paper, the principle and work flow of free space optical communication based on cat-eye modulating retro-reflector were introduced. Then, using the theory of geometric optics, the equivalent model of modulating retro-reflector with incidence angle was presented. The analytical solution of active area and retro-reflected light intensity of cat-eye modulating retro-reflector were given. Noise of PIN photodetector was analyzed, based on which, bit error rate of free space optical communication based on cat-eye modulating retro-reflector was presented. Finally, simulations were done to study the effect of incidence angle to the communication. The simulation results show that the incidence angle has little effect on active area and retro-reflected light intensity when the incidence beam is in the active field angle of cat-eye modulating retro-reflector. With certain system and condition, the communication link can rapidly be built when the incidence light beam is in the field angle, and the bit error rate increases greatly with link range. When link range is smaller than 35Km, the bit error rate is less than 10-16.

Teaching Inquiry with Linked Classes and Learning Communities

ERIC Educational Resources Information Center

Piercey, Victor; Cullen, Roxanne

2017-01-01

In order to improve problem-solving dispositions, a section of an inquiry-based math sequence for first-year business students was linked with a section of our general education English sequence. We describe how the linked classes worked and compare some preliminary results from linked and unlinked sections of the math sequence.

Unreported links between trial registrations and published articles were identified using document similarity measures in a cross-sectional analysis of ClinicalTrials.gov.

PubMed

Dunn, Adam G; Coiera, Enrico; Bourgeois, Florence T

2018-03-01

Trial registries can be used to measure reporting biases and support systematic reviews, but 45% of registrations do not provide a link to the article reporting on the trial. We evaluated the use of document similarity methods to identify unreported links between ClinicalTrials.gov and PubMed. We extracted terms and concepts from a data set of 72,469 ClinicalTrials.gov registrations and 276,307 PubMed articles and tested methods for ranking articles across 16,005 reported links and 90 manually identified unreported links. Performance was measured by the median rank of matching articles and the proportion of unreported links that could be found by screening ranked candidate articles in order. The best-performing concept-based representation produced a median rank of 3 (interquartile range [IQR] 1-21) for reported links and 3 (IQR 1-19) for the manually identified unreported links, and term-based representations produced a median rank of 2 (1-20) for reported links and 2 (IQR 1-12) in unreported links. The matching article was ranked first for 40% of registrations, and screening 50 candidate articles per registration identified 86% of the unreported links. Leveraging the growth in the corpus of reported links between ClinicalTrials.gov and PubMed, we found that document similarity methods can assist in the identification of unreported links between trial registrations and corresponding articles. Copyright © 2017 Elsevier Inc. All rights reserved.

Effectiveness evaluation of double-layered satellite network with laser and microwave hybrid links based on fuzzy analytic hierarchy process

NASA Astrophysics Data System (ADS)

Zhang, Wei; Rao, Qiaomeng

2018-01-01

In order to solve the problem of high speed, large capacity and limited spectrum resources of satellite communication network, a double-layered satellite network with global seamless coverage based on laser and microwave hybrid links is proposed in this paper. By analyzing the characteristics of the double-layered satellite network with laser and microwave hybrid links, an effectiveness evaluation index system for the network is established. And then, the fuzzy analytic hierarchy process, which combines the analytic hierarchy process and the fuzzy comprehensive evaluation theory, is used to evaluate the effectiveness of the double-layered satellite network with laser and microwave hybrid links. Furthermore, the evaluation result of the proposed hybrid link network is obtained by simulation. The effectiveness evaluation process of the proposed double-layered satellite network with laser and microwave hybrid links can help to optimize the design of hybrid link double-layered satellite network and improve the operating efficiency of the satellite system.

Design and modelling of a link monitoring mechanism for the Common Data Link (CDL)

NASA Astrophysics Data System (ADS)

Eichelberger, John W., III

1994-09-01

The Common Data Link (CDL) is a full duplex, point-to-point microwave communications system used in imagery and signals intelligence collection systems. It provides a link between two remote Local Area Networks (LAN's) aboard collection and surface platforms. In a hostile environment, there is an overwhelming need to dynamically monitor the link and thus, limit the impact of jamming. This work describes steps taken to design, model, and evaluate a link monitoring system suitable for the CDL. The monitoring system is based on features and monitoring constructs of the Link Control Protocol (LCP) in the Point-to-Point Protocol (PPP) suite. The CDL model is based on a system of two remote Fiber Distributed Data Interface (FDDI) LAN's. In particular, the policies and mechanisms associated with monitoring are described in detail. An implementation of the required mechanisms using the OPNET network engineering tool is described. Performance data related to monitoring parameters is reported. Finally, integration of the FDDI-CDL model with the OPNET Internet model is described.

Can Inquiry-Based Learning Strengthen the Links between Teaching and Disciplinary Research?

ERIC Educational Resources Information Center

Spronken-Smith, Rachel; Walker, Rebecca

2010-01-01

Inquiry-based learning has been promoted as a student-centred approach that can strengthen the links between teaching and research. This article examines the potential of inquiry-based learning to strengthen the teaching-research nexus by analysing three case studies: a "structured inquiry" third-year endocrinology medicine module, a…

FARVATX: FAmily-based Rare Variant Association Test for X-linked genes

PubMed Central

Choi, Sungkyoung; Lee, Sungyoung; Qiao, Dandi; Hardin, Megan; Cho, Michael H.; Silverman, Edwin K; Park, Taesung; Won, Sungho

2016-01-01

Although the X chromosome has many genes that are functionally related to human diseases, the complicated biological properties of the X chromosome have prevented efficient genetic association analyses, and only a few significantly associated X-linked variants have been reported for complex traits. For instance, dosage compensation of X-linked genes is often achieved via the inactivation of one allele in each X-linked variant in females; however, some X-linked variants can escape this X chromosome inactivation. Efficient genetic analyses cannot be conducted without prior knowledge about the gene expression process of X-linked variants, and misspecified information can lead to power loss. In this report, we propose new statistical methods for rare X-linked variant genetic association analysis of dichotomous phenotypes with family-based samples. The proposed methods are computationally efficient and can complete X-linked analyses within a few hours. Simulation studies demonstrate the statistical efficiency of the proposed methods, which were then applied to rare-variant association analysis of the X chromosome in chronic obstructive pulmonary disease (COPD). Some promising significant X-linked genes were identified, illustrating the practical importance of the proposed methods. PMID:27325607

FARVATX: Family-Based Rare Variant Association Test for X-Linked Genes.

PubMed

Choi, Sungkyoung; Lee, Sungyoung; Qiao, Dandi; Hardin, Megan; Cho, Michael H; Silverman, Edwin K; Park, Taesung; Won, Sungho

2016-09-01

Although the X chromosome has many genes that are functionally related to human diseases, the complicated biological properties of the X chromosome have prevented efficient genetic association analyses, and only a few significantly associated X-linked variants have been reported for complex traits. For instance, dosage compensation of X-linked genes is often achieved via the inactivation of one allele in each X-linked variant in females; however, some X-linked variants can escape this X chromosome inactivation. Efficient genetic analyses cannot be conducted without prior knowledge about the gene expression process of X-linked variants, and misspecified information can lead to power loss. In this report, we propose new statistical methods for rare X-linked variant genetic association analysis of dichotomous phenotypes with family-based samples. The proposed methods are computationally efficient and can complete X-linked analyses within a few hours. Simulation studies demonstrate the statistical efficiency of the proposed methods, which were then applied to rare-variant association analysis of the X chromosome in chronic obstructive pulmonary disease. Some promising significant X-linked genes were identified, illustrating the practical importance of the proposed methods. © 2016 WILEY PERIODICALS, INC.

UDE-based control of variable-speed wind turbine systems

NASA Astrophysics Data System (ADS)

Ren, Beibei; Wang, Yeqin; Zhong, Qing-Chang

2017-01-01

In this paper, the control of a PMSG (permanent magnet synchronous generator)-based variable-speed wind turbine system with a back-to-back converter is considered. The uncertainty and disturbance estimator (UDE)-based control approach is applied to the regulation of the DC-link voltage and the control of the RSC (rotor-side converter) and the GSC (grid-side converter). For the rotor-side controller, the UDE-based vector control is developed for the RSC with PMSG control to facilitate the application of the MPPT (maximum power point tracking) algorithm for the maximum wind energy capture. For the grid-side controller, the UDE-based vector control is developed to control the GSC with the power reference generated by a UDE-based DC-link voltage controller. Compared with the conventional vector control, the UDE-based vector control can achieve reliable current decoupling control with fast response. Moreover, the UDE-based DC-link voltage regulation can achieve stable DC-link voltage under model uncertainties and external disturbances, e.g. wind speed variations. The effectiveness of the proposed UDE-based control approach is demonstrated through extensive simulation studies in the presence of coupled dynamics, model uncertainties and external disturbances under varying wind speeds. The UDE-based control is able to generate more energy, e.g. by 5% for the wind profile tested.

Digital optical feeder links system for broadband geostationary satellite

NASA Astrophysics Data System (ADS)

Poulenard, Sylvain; Mège, Alexandre; Fuchs, Christian; Perlot, Nicolas; Riedi, Jerome; Perdigues, Josep

2017-02-01

An optical link based on a multiplex of wavelengths at 1.55μm is foreseen to be a valuable solution for the feeder link of the next generation of high-throughput geostationary satellite. The main satellite operator specifications for such link are an availability of 99.9% over the year, a capacity around 500Gbit/s and to be bent-pipe. Optical ground station networks connected to Terabit/s terrestrial fibers are proposed. The availability of the optical feeder link is simulated over 5 years based on a state-of-the-art cloud mask data bank and an atmospheric turbulence strength model. Yearly and seasonal optical feeder link availabilities are derived and discussed. On-ground and on-board terminals are designed to be compliant with 10Gbit/s per optical channel data rate taking into account adaptive optic systems to mitigate the impact of atmospheric turbulences on single-mode optical fiber receivers. The forward and return transmission chains, concept and implementation, are described. These are based on a digital transparent on-off keying optical link with digitalization of the DVB-S2 and DVB-RCS signals prior to the transmission, and a forward error correcting code. In addition, the satellite architecture is described taking into account optical and radiofrequency payloads as well as their interfaces.

Common neighbours and the local-community-paradigm for topological link prediction in bipartite networks

NASA Astrophysics Data System (ADS)

Daminelli, Simone; Thomas, Josephine Maria; Durán, Claudio; Vittorio Cannistraci, Carlo

2015-11-01

Bipartite networks are powerful descriptions of complex systems characterized by two different classes of nodes and connections allowed only across but not within the two classes. Unveiling physical principles, building theories and suggesting physical models to predict bipartite links such as product-consumer connections in recommendation systems or drug-target interactions in molecular networks can provide priceless information to improve e-commerce or to accelerate pharmaceutical research. The prediction of nonobserved connections starting from those already present in the topology of a network is known as the link-prediction problem. It represents an important subject both in many-body interaction theory in physics and in new algorithms for applied tools in computer science. The rationale is that the existing connectivity structure of a network can suggest where new connections can appear with higher likelihood in an evolving network, or where nonobserved connections are missing in a partially known network. Surprisingly, current complex network theory presents a theoretical bottle-neck: a general framework for local-based link prediction directly in the bipartite domain is missing. Here, we overcome this theoretical obstacle and present a formal definition of common neighbour index and local-community-paradigm (LCP) for bipartite networks. As a consequence, we are able to introduce the first node-neighbourhood-based and LCP-based models for topological link prediction that utilize the bipartite domain. We performed link prediction evaluations in several networks of different size and of disparate origin, including technological, social and biological systems. Our models significantly improve topological prediction in many bipartite networks because they exploit local physical driving-forces that participate in the formation and organization of many real-world bipartite networks. Furthermore, we present a local-based formalism that allows to intuitively implement neighbourhood-based link prediction entirely in the bipartite domain.

RAINLINK: Retrieval algorithm for rainfall monitoring employing microwave links from a cellular communication network

NASA Astrophysics Data System (ADS)

Uijlenhoet, R.; Overeem, A.; Leijnse, H.; Rios Gaona, M. F.

2017-12-01

The basic principle of rainfall estimation using microwave links is as follows. Rainfall attenuates the electromagnetic signals transmitted from one telephone tower to another. By measuring the received power at one end of a microwave link as a function of time, the path-integrated attenuation due to rainfall can be calculated, which can be converted to average rainfall intensities over the length of a link. Microwave links from cellular communication networks have been proposed as a promising new rainfall measurement technique for one decade. They are particularly interesting for those countries where few surface rainfall observations are available. Yet to date no operational (real-time) link-based rainfall products are available. To advance the process towards operational application and upscaling of this technique, there is a need for freely available, user-friendly computer code for microwave link data processing and rainfall mapping. Such software is now available as R package "RAINLINK" on GitHub (https://github.com/overeem11/RAINLINK). It contains a working example to compute link-based 15-min rainfall maps for the entire surface area of The Netherlands for 40 hours from real microwave link data. This is a working example using actual data from an extensive network of commercial microwave links, for the first time, which will allow users to test their own algorithms and compare their results with ours. The package consists of modular functions, which facilitates running only part of the algorithm. The main processings steps are: 1) Preprocessing of link data (initial quality and consistency checks); 2) Wet-dry classification using link data; 3) Reference signal determination; 4) Removal of outliers ; 5) Correction of received signal powers; 6) Computation of mean path-averaged rainfall intensities; 7) Interpolation of rainfall intensities ; 8) Rainfall map visualisation. Some applications of RAINLINK will be shown based on microwave link data from a temperate climate (the Netherlands), and from a subtropical climate (Brazil). We hope that RAINLINK will promote the application of rainfall monitoring using microwave links in poorly gauged regions around the world. We invite researchers to contribute to RAINLINK to make the code more generally applicable to data from different networks and climates.

Method and system for ultra-precision positioning

DOEpatents

Montesanti, Richard C.; Locke, Stanley F.; Thompson, Samuel L.

2005-01-11

An apparatus and method is disclosed for ultra-precision positioning. A slide base provides a foundational support. A slide plate moves with respect to the slide base along a first geometric axis. Either a ball-screw or a piezoelectric actuator working separate or in conjunction displaces the slide plate with respect to the slide base along the first geometric axis. A linking device directs a primary force vector into a center-line of the ball-screw. The linking device consists of a first link which directs a first portion of the primary force vector to an apex point, located along the center-line of the ball-screw, and a second link for directing a second portion of the primary force vector to the apex point. A set of rails, oriented substantially parallel to the center-line of the ball-screw, direct movement of the slide plate with respect to the slide base along the first geometric axis and are positioned such that the apex point falls within a geometric plane formed by the rails. The slide base, the slide plate, the ball-screw, and the linking device together form a slide assembly. Multiple slide assemblies can be distributed about a platform. In such a configuration, the platform may be raised and lowered, or tipped and tilted by jointly or independently displacing the slide plates.

Ultra-precision positioning assembly

DOEpatents

Montesanti, Richard C.; Locke, Stanley F.; Thompson, Samuel L.

2002-01-01

An apparatus and method is disclosed for ultra-precision positioning. A slide base provides a foundational support. A slide plate moves with respect to the slide base along a first geometric axis. Either a ball-screw or a piezoelectric actuator working separate or in conjunction displaces the slide plate with respect to the slide base along the first geometric axis. A linking device directs a primary force vector into a center-line of the ball-screw. The linking device consists of a first link which directs a first portion of the primary force vector to an apex point, located along the center-line of the ball-screw, and a second link for directing a second portion of the primary force vector to the apex point. A set of rails, oriented substantially parallel to the center-line of the ball-screw, direct movement of the slide plate with respect to the slide base along the first geometric axis and are positioned such that the apex point falls within a geometric plane formed by the rails. The slide base, the slide plate, the ball-screw, and the linking device together form a slide assembly. Multiple slide assemblies can be distributed about a platform. In such a configuration, the platform may be raised and lowered, or tipped and tilted by jointly or independently displacing the slide plates.

Investigation of grafted ETFE-based polymer membranes as alternative electrolyte for direct methanol fuel cells

NASA Astrophysics Data System (ADS)

Aricò, A. S.; Baglio, V.; Cretı̀, P.; Di Blasi, A.; Antonucci, V.; Brunea, J.; Chapotot, A.; Bozzi, A.; Schoemans, J.

Low cost ethylene-tetrafluoroethylene (ETFE)-based grafted membranes have been prepared by a process based on electron beam irradiation, subsequent grafting, cross-linking and sulfonation procedure. Two different grafted membranes varying by their grafting and cross-linking levels have been investigated for applications in direct methanol fuel cells (DMFCs) operating between 90 and 130 °C. DMFC assemblies based on these membranes showed cell resistance and performance values comparable to Nafion 117. Stable electrochemical performance was recorded during 1 month of cycled operation. Tailoring of grafting and cross-linking properties allows a significant reduction of methanol cross-over while maintaining suitable conductivity and performance levels.

The Potential of School-Linked Centers To Promote Adolescent Health and Development. Working Paper.

ERIC Educational Resources Information Center

Millstein, Susan G.

The future of school-linked adolescent health centers cannot be determined without further evaluation. The recent development of school-linked health centers stems from concerns about the special health needs of adolescents. Currently there are 125 school-based and school-linked centers in operation. Characteristics include the following: (1) most…

Cross-Linked Amylose Bio-Plastic: A Transgenic-Based Compostable Plastic Alternative

PubMed Central

Sagnelli, Domenico; Kemmer, Gerdi Christine; Holse, Mette; Hebelstrup, Kim H.; Bao, Jinsong; Stelte, Wolfgang; Bjerre, Anne-Belinda; Blennow, Andreas

2017-01-01

Bio-plastics and bio-materials are composed of natural or biomass derived polymers, offering solutions to solve immediate environmental issues. Polysaccharide-based bio-plastics represent important alternatives to conventional plastic because of their intrinsic biodegradable nature. Amylose-only (AO), an engineered barley starch with 99% amylose, was tested to produce cross-linked all-natural bioplastic using normal barley starch as a control. Glycerol was used as plasticizer and citrate cross-linking was used to improve the mechanical properties of cross-linked AO starch extrudates. Extrusion converted the control starch from A-type to Vh- and B-type crystals, showing a complete melting of the starch crystals in the raw starch granules. The cross-linked AO and control starch specimens displayed an additional wide-angle diffraction reflection. Phospholipids complexed with Vh-type single helices constituted an integrated part of the AO starch specimens. Gas permeability tests of selected starch-based prototypes demonstrated properties comparable to that of commercial Mater-Bi© plastic. The cross-linked AO prototypes had composting characteristics not different from the control, indicating that the modified starch behaves the same as normal starch. The data shows the feasibility of producing all-natural bioplastic using designer starch as raw material. PMID:28973963

A link prediction method for heterogeneous networks based on BP neural network

NASA Astrophysics Data System (ADS)

Li, Ji-chao; Zhao, Dan-ling; Ge, Bing-Feng; Yang, Ke-Wei; Chen, Ying-Wu

2018-04-01

Most real-world systems, composed of different types of objects connected via many interconnections, can be abstracted as various complex heterogeneous networks. Link prediction for heterogeneous networks is of great significance for mining missing links and reconfiguring networks according to observed information, with considerable applications in, for example, friend and location recommendations and disease-gene candidate detection. In this paper, we put forward a novel integrated framework, called MPBP (Meta-Path feature-based BP neural network model), to predict multiple types of links for heterogeneous networks. More specifically, the concept of meta-path is introduced, followed by the extraction of meta-path features for heterogeneous networks. Next, based on the extracted meta-path features, a supervised link prediction model is built with a three-layer BP neural network. Then, the solution algorithm of the proposed link prediction model is put forward to obtain predicted results by iteratively training the network. Last, numerical experiments on the dataset of examples of a gene-disease network and a combat network are conducted to verify the effectiveness and feasibility of the proposed MPBP. It shows that the MPBP with very good performance is superior to the baseline methods.

Cross-Linked Amylose Bio-Plastic: A Transgenic-Based Compostable Plastic Alternative.

PubMed

Sagnelli, Domenico; Hooshmand, Kourosh; Kemmer, Gerdi Christine; Kirkensgaard, Jacob J K; Mortensen, Kell; Giosafatto, Concetta Valeria L; Holse, Mette; Hebelstrup, Kim H; Bao, Jinsong; Stelte, Wolfgang; Bjerre, Anne-Belinda; Blennow, Andreas

2017-09-30

Bio-plastics and bio-materials are composed of natural or biomass derived polymers, offering solutions to solve immediate environmental issues. Polysaccharide-based bio-plastics represent important alternatives to conventional plastic because of their intrinsic biodegradable nature. Amylose-only (AO), an engineered barley starch with 99% amylose, was tested to produce cross-linked all-natural bioplastic using normal barley starch as a control. Glycerol was used as plasticizer and citrate cross-linking was used to improve the mechanical properties of cross-linked AO starch extrudates. Extrusion converted the control starch from A-type to Vh- and B-type crystals, showing a complete melting of the starch crystals in the raw starch granules. The cross-linked AO and control starch specimens displayed an additional wide-angle diffraction reflection. Phospholipids complexed with Vh-type single helices constituted an integrated part of the AO starch specimens. Gas permeability tests of selected starch-based prototypes demonstrated properties comparable to that of commercial Mater-Bi © plastic. The cross-linked AO prototypes had composting characteristics not different from the control, indicating that the modified starch behaves the same as normal starch. The data shows the feasibility of producing all-natural bioplastic using designer starch as raw material.

A link prediction approach to cancer drug sensitivity prediction.

PubMed

Turki, Turki; Wei, Zhi

2017-10-03

Predicting the response to a drug for cancer disease patients based on genomic information is an important problem in modern clinical oncology. This problem occurs in part because many available drug sensitivity prediction algorithms do not consider better quality cancer cell lines and the adoption of new feature representations; both lead to the accurate prediction of drug responses. By predicting accurate drug responses to cancer, oncologists gain a more complete understanding of the effective treatments for each patient, which is a core goal in precision medicine. In this paper, we model cancer drug sensitivity as a link prediction, which is shown to be an effective technique. We evaluate our proposed link prediction algorithms and compare them with an existing drug sensitivity prediction approach based on clinical trial data. The experimental results based on the clinical trial data show the stability of our link prediction algorithms, which yield the highest area under the ROC curve (AUC) and are statistically significant. We propose a link prediction approach to obtain new feature representation. Compared with an existing approach, the results show that incorporating the new feature representation to the link prediction algorithms has significantly improved the performance.

Power conversion distribution system using a resonant high-frequency AC link

NASA Technical Reports Server (NTRS)

Sood, P. K.; Lipo, T. A.

1986-01-01

Static power conversion systems based on a resonant high frequency (HF) link offers a significant reduction in the size and weight of the equipment over that achieved with conventional approaches, especially when multiple sources and loads are to be integrated. A faster system response and absence of audible noise are the other principal characteristics of such systems. A conversion configuration based on a HF link which is suitable for applications requiring distributed power is proposed.

Time Transfer Methodologies for International Atomic Time (TAI)

DTIC Science & Technology

2007-01-01

International Atomic Time (TAI) and Coordinated Universal Time (UTC) involve either GPS or Two Way Satellite Time and Frequency Transfer ( TWSTFT ). This paper...NRCan, provide real-time carrier-phase based time transfer as well [3,4] Beginning in 2000, time-transfer links using TWSTFT replaced some GPS...links as the primary operational link, and currently over half the clocks used for TAI-generation are linked to other sites via a direct TWSTFT link

An Optimal Schedule for Urban Road Network Repair Based on the Greedy Algorithm

PubMed Central

Lu, Guangquan; Xiong, Ying; Wang, Yunpeng

2016-01-01

The schedule of urban road network recovery caused by rainstorms, snow, and other bad weather conditions, traffic incidents, and other daily events is essential. However, limited studies have been conducted to investigate this problem. We fill this research gap by proposing an optimal schedule for urban road network repair with limited repair resources based on the greedy algorithm. Critical links will be given priority in repair according to the basic concept of the greedy algorithm. In this study, the link whose restoration produces the ratio of the system-wide travel time of the current network to the worst network is the minimum. We define such a link as the critical link for the current network. We will re-evaluate the importance of damaged links after each repair process is completed. That is, the critical link ranking will be changed along with the repair process because of the interaction among links. We repair the most critical link for the specific network state based on the greedy algorithm to obtain the optimal schedule. The algorithm can still quickly obtain an optimal schedule even if the scale of the road network is large because the greedy algorithm can reduce computational complexity. We prove that the problem can obtain the optimal solution using the greedy algorithm in theory. The algorithm is also demonstrated in the Sioux Falls network. The problem discussed in this paper is highly significant in dealing with urban road network restoration. PMID:27768732

Margins Associated with Loss of Assured Safety for Systems with Multiple Time-Dependent Failure Modes.

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

Helton, Jon C.; Brooks, Dusty Marie; Sallaberry, Cedric Jean-Marie.

Representations for margins associated with loss of assured safety (LOAS) for weak link (WL)/strong link (SL) systems involving multiple time-dependent failure modes are developed. The following topics are described: (i) defining properties for WLs and SLs, (ii) background on cumulative distribution functions (CDFs) for link failure time, link property value at link failure, and time at which LOAS occurs, (iii) CDFs for failure time margins defined by (time at which SL system fails) – (time at which WL system fails), (iv) CDFs for SL system property values at LOAS, (v) CDFs for WL/SL property value margins defined by (property valuemore » at which SL system fails) – (property value at which WL system fails), and (vi) CDFs for SL property value margins defined by (property value of failing SL at time of SL system failure) – (property value of this SL at time of WL system failure). Included in this presentation is a demonstration of a verification strategy based on defining and approximating the indicated margin results with (i) procedures based on formal integral representations and associated quadrature approximations and (ii) procedures based on algorithms for sampling-based approximations.« less

Application of an Externded CCSDS Telecommand Standard for All Mars In-Situ Telecommunication Links

NASA Technical Reports Server (NTRS)

Kazz, G.; Greenberg, E.; MacMedan, M.

1998-01-01

The purpose of this paper is to propose a link layer standard for bi-directional telecommunication for in-situ links for data transfer between landers, rovers, and orbiters based upon the CCSDS Telecommand Recommendation.

Exploring the link between clinical managers involvement in budgeting and performance: Insights from the Italian public health care sector.

PubMed

Macinati, Manuela S; Rizzo, Marco G

2016-01-01

The public health care sector has had an increase in initiatives, mostly inspired by New Public Management principles, aimed at assigning financial accountability to clinical managers. However, clinical managers might experience a scarce alignment between professional values and organizational requirements, which is a potentially important phenomena that may result in negative consequences on clinical managers' job performance. Building on Psychological Ownership Theory and adopting a psychology-based management accounting research approach, we focus on the managerial (nonmedical) role the clinical manager fulfills and explore the budgetary participation-performance link via the indirect effects of job-based psychological ownership, role clarity, and clinical managers' affective commitment toward managerial roles. The data were collected by a survey conducted in an Italian hospital. The research hypotheses were tested employing a path model. Our study revealed new insights that shed some light on underexplored processes through which mental states mediate the participation-performance link. Among these latter, the findings demonstrate that (a) budgetary participation has a direct effect on job-based psychological ownership; (b) role clarity mediates participation- and job-based psychological ownership link; (c) role clarity and job-based psychological ownership partially mediate the participation-commitment link; and (d) job-based psychological ownership, role clarity, and commitment fully mediate the participation-performance link. From a managerial viewpoint, an understanding of how clinical managers' feelings of ownership toward managerial roles could be enhanced is imperative in health care because ownership accounts for important attitudinal and organizational consequences. Results suggest that health care organizations that invest in budgetary participation will directly and indirectly affect clinical managers' psychological ownership, and this, along with role clarity, motivates clinical managers' managerial work attitudes and performance.

Adaptive laser link reconfiguration using constraint propagation

NASA Technical Reports Server (NTRS)

Crone, M. S.; Julich, P. M.; Cook, L. M.

1993-01-01

This paper describes Harris AI research performed on the Adaptive Link Reconfiguration (ALR) study for Rome Lab, and focuses on the application of constraint propagation to the problem of link reconfiguration for the proposed space based Strategic Defense System (SDS) Brilliant Pebbles (BP) communications system. According to the concept of operations at the time of the study, laser communications will exist between BP's and to ground entry points. Long-term links typical of RF transmission will not exist. This study addressed an initial implementation of BP's based on the Global Protection Against Limited Strikes (GPALS) SDI mission. The number of satellites and rings studied was representative of this problem. An orbital dynamics program was used to generate line-of-site data for the modeled architecture. This was input into a discrete event simulation implemented in the Harris developed COnstraint Propagation Expert System (COPES) Shell, developed initially on the Rome Lab BM/C3 study. Using a model of the network and several heuristics, the COPES shell was used to develop the Heuristic Adaptive Link Ordering (HALO) Algorithm to rank and order potential laser links according to probability of communication. A reduced set of links based on this ranking would then be used by a routing algorithm to select the next hop. This paper includes an overview of Constraint Propagation as an Artificial Intelligence technique and its embodiment in the COPES shell. It describes the design and implementation of both the simulation of the GPALS BP network and the HALO algorithm in COPES. This is described using a 59 Data Flow Diagram, State Transition Diagrams, and Structured English PDL. It describes a laser communications model and the heuristics involved in rank-ordering the potential communication links. The generation of simulation data is described along with its interface via COPES to the Harris developed View Net graphical tool for visual analysis of communications networks. Conclusions are presented, including a graphical analysis of results depicting the ordered set of links versus the set of all possible links based on the computed Bit Error Rate (BER). Finally, future research is discussed which includes enhancements to the HALO algorithm, network simulation, and the addition of an intelligent routing algorithm for BP.

Design and optimization of a fiber optic data link for new generation on-board SAR processing architectures

NASA Astrophysics Data System (ADS)

Ciminelli, Caterina; Dell'Olio, Francesco; Armenise, Mario N.; Iacomacci, Francesco; Pasquali, Franca; Formaro, Roberto

2017-11-01

A fiber optic digital link for on-board data handling is modeled, designed and optimized in this paper. Design requirements and constraints relevant to the link, which is in the frame of novel on-board processing architectures, are discussed. Two possible link configurations are investigated, showing their advantages and disadvantages. An accurate mathematical model of each link component and the entire system is reported and results of link simulation based on those models are presented. Finally, some details on the optimized design are provided.

LINKING THE CMAQ AND HYSPLIT MODELING SYSTEM INTERFACE PROGRAM AND EXAMPLE APPLICATION

EPA Science Inventory

A new software tool has been developed to link the Eulerian-based Community Multiscale Air Quality (CMAQ) modeling system with the Lagrangian-based HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory) model. Both models require many of the same hourly meteorological...

Implementation and Student Assessment of Intranet-Based Learning Resources.

ERIC Educational Resources Information Center

Sosabowski, Michael H.; Herson, Katie; Lloyd, Andrew W.

1998-01-01

The University of Brighton (England) pharmacy and biomedical sciences school developed an institutional intranet providing course information, Internet links, lecture notes, links to computer-assisted instructional packages, and worksheets. Electronic monitoring of usage and subsequent questionnaire-based evaluation showed the intranet to be a…

Performance of a radio link between a base station and a medical implant utilising the MICS standard.

PubMed

Johansson, Anders J

2004-01-01

Modern medical implants are of increasing complexity and with that, the need for fast and flexible communication with them grows. A wireless system is preferable and an inductive link is the most commonly used. But it has the drawback of a very short range, essentially limited to having the external transceiver touching the patient. The Medical Implant Communication System, MICS, is a standard aimed at improving the communication distance. It operates at a higher frequency band between 402 MHz and 405 MHz. We have by simulations and measurements investigated the channel properties of this band and calculated the link performance for a typical implant application. The result is a link speed between a base station and a bedridden patient of 600 kbit bits per second with a bit error rate of 2% in the downlink to the implant and 1 % in the uplink to the base station. Conclusions on the necessary complexity of the base station are also given.

Active Semi-Supervised Community Detection Based on Must-Link and Cannot-Link Constraints

PubMed Central

Cheng, Jianjun; Leng, Mingwei; Li, Longjie; Zhou, Hanhai; Chen, Xiaoyun

2014-01-01

Community structure detection is of great importance because it can help in discovering the relationship between the function and the topology structure of a network. Many community detection algorithms have been proposed, but how to incorporate the prior knowledge in the detection process remains a challenging problem. In this paper, we propose a semi-supervised community detection algorithm, which makes full utilization of the must-link and cannot-link constraints to guide the process of community detection and thereby extracts high-quality community structures from networks. To acquire the high-quality must-link and cannot-link constraints, we also propose a semi-supervised component generation algorithm based on active learning, which actively selects nodes with maximum utility for the proposed semi-supervised community detection algorithm step by step, and then generates the must-link and cannot-link constraints by accessing a noiseless oracle. Extensive experiments were carried out, and the experimental results show that the introduction of active learning into the problem of community detection makes a success. Our proposed method can extract high-quality community structures from networks, and significantly outperforms other comparison methods. PMID:25329660

A group evolving-based framework with perturbations for link prediction

NASA Astrophysics Data System (ADS)

Si, Cuiqi; Jiao, Licheng; Wu, Jianshe; Zhao, Jin

2017-06-01

Link prediction is a ubiquitous application in many fields which uses partially observed information to predict absence or presence of links between node pairs. The group evolving study provides reasonable explanations on the behaviors of nodes, relations between nodes and community formation in a network. Possible events in group evolution include continuing, growing, splitting, forming and so on. The changes discovered in networks are to some extent the result of these events. In this work, we present a group evolving-based characterization of node's behavioral patterns, and via which we can estimate the probability they tend to interact. In general, the primary aim of this paper is to offer a minimal toy model to detect missing links based on evolution of groups and give a simpler explanation on the rationality of the model. We first introduce perturbations into networks to obtain stable cluster structures, and the stable clusters determine the stability of each node. Then fluctuations, another node behavior, are assumed by the participation of each node to its own belonging group. Finally, we demonstrate that such characteristics allow us to predict link existence and propose a model for link prediction which outperforms many classical methods with a decreasing computational time in large scales. Encouraging experimental results obtained on real networks show that our approach can effectively predict missing links in network, and even when nearly 40% of the edges are missing, it also retains stationary performance.

Structural link between giant molybdenum oxide based ions and derived Keggin structure: modular assemblies based on the [BW11O39]9- ion and pentagonal {M'M5} units (M' = W; M = Mo,W).

PubMed

Leclerc-Laronze, Nathalie; Marrot, Jérôme; Thouvenot, René; Cadot, Emmanuel

2009-01-01

Linked to the Pentagon: The addition of molybdate to [HBW(11)O(39)](8-) ions leads to the formation of mixed pentagonal units {W(Mo(5))} and {W(WMo(4))} trapped as linkers in the resulting modular assemblies, thus establishing the first link between the conventional Keggin ion derivatives and the giant molybdenum oxide and keplerate ions.

Link-state-estimation-based transmission power control in wireless body area networks.

PubMed

Kim, Seungku; Eom, Doo-Seop

2014-07-01

This paper presents a novel transmission power control protocol to extend the lifetime of sensor nodes and to increase the link reliability in wireless body area networks (WBANs). We first experimentally investigate the properties of the link states using the received signal strength indicator (RSSI). We then propose a practical transmission power control protocol based on both short- and long-term link-state estimations. Both the short- and long-term link-state estimations enable the transceiver to adapt the transmission power level and target the RSSI threshold range, respectively, to simultaneously satisfy the requirements of energy efficiency and link reliability. Finally, the performance of the proposed protocol is experimentally evaluated in two experimental scenarios-body posture change and dynamic body motion-and compared with the typical WBAN transmission power control protocols, a real-time reactive scheme, and a dynamic postural position inference mechanism. From the experimental results, it is found that the proposed protocol increases the lifetime of the sensor nodes by a maximum of 9.86% and enhances the link reliability by reducing the packet loss by a maximum of 3.02%.

Link importance incorporated failure probability measuring solution for multicast light-trees in elastic optical networks

NASA Astrophysics Data System (ADS)

Li, Xin; Zhang, Lu; Tang, Ying; Huang, Shanguo

2018-03-01

The light-tree-based optical multicasting (LT-OM) scheme provides a spectrum- and energy-efficient method to accommodate emerging multicast services. Some studies focus on the survivability technologies for LTs against a fixed number of link failures, such as single-link failure. However, a few studies involve failure probability constraints when building LTs. It is worth noting that each link of an LT plays different important roles under failure scenarios. When calculating the failure probability of an LT, the importance of its every link should be considered. We design a link importance incorporated failure probability measuring solution (LIFPMS) for multicast LTs under independent failure model and shared risk link group failure model. Based on the LIFPMS, we put forward the minimum failure probability (MFP) problem for the LT-OM scheme. Heuristic approaches are developed to address the MFP problem in elastic optical networks. Numerical results show that the LIFPMS provides an accurate metric for calculating the failure probability of multicast LTs and enhances the reliability of the LT-OM scheme while accommodating multicast services.

Linking Project-Based Interdisciplinary Learning and Recommended Professional Competencies with Business Management, Digital Media, Distance Learning, Engineering Technology, and English

ERIC Educational Resources Information Center

Bender, Melinda; Fulwider, Miles; Stemkoski, Michael J.

2008-01-01

This paper encourages the investigation of real world problems by students and faculty and links recommended student competencies with project based learning. In addition to the traditional course objectives, project-based learning (PBL) uses real world problems for classroom instruction and fieldwork to connect students, instructors, and industry…

Link prediction based on local weighted paths for complex networks

NASA Astrophysics Data System (ADS)

Yao, Yabing; Zhang, Ruisheng; Yang, Fan; Yuan, Yongna; Hu, Rongjing; Zhao, Zhili

As a significant problem in complex networks, link prediction aims to find the missing and future links between two unconnected nodes by estimating the existence likelihood of potential links. It plays an important role in understanding the evolution mechanism of networks and has broad applications in practice. In order to improve prediction performance, a variety of structural similarity-based methods that rely on different topological features have been put forward. As one topological feature, the path information between node pairs is utilized to calculate the node similarity. However, many path-dependent methods neglect the different contributions of paths for a pair of nodes. In this paper, a local weighted path (LWP) index is proposed to differentiate the contributions between paths. The LWP index considers the effect of the link degrees of intermediate links and the connectivity influence of intermediate nodes on paths to quantify the path weight in the prediction procedure. The experimental results on 12 real-world networks show that the LWP index outperforms other seven prediction baselines.

Measuring the value of accurate link prediction for network seeding.

PubMed

Wei, Yijin; Spencer, Gwen

2017-01-01

The influence-maximization literature seeks small sets of individuals whose structural placement in the social network can drive large cascades of behavior. Optimization efforts to find the best seed set often assume perfect knowledge of the network topology. Unfortunately, social network links are rarely known in an exact way. When do seeding strategies based on less-than-accurate link prediction provide valuable insight? We introduce optimized-against-a-sample ([Formula: see text]) performance to measure the value of optimizing seeding based on a noisy observation of a network. Our computational study investigates [Formula: see text] under several threshold-spread models in synthetic and real-world networks. Our focus is on measuring the value of imprecise link information. The level of investment in link prediction that is strategic appears to depend closely on spread model: in some parameter ranges investments in improving link prediction can pay substantial premiums in cascade size. For other ranges, such investments would be wasted. Several trends were remarkably consistent across topologies.

Classifying quantum entanglement through topological links

NASA Astrophysics Data System (ADS)

Quinta, Gonçalo M.; André, Rui

2018-04-01

We propose an alternative classification scheme for quantum entanglement based on topological links. This is done by identifying a nonrigid ring to a particle, attributing the act of cutting and removing a ring to the operation of tracing out the particle, and associating linked rings to entangled particles. This analogy naturally leads us to a classification of multipartite quantum entanglement based on all possible distinct links for a given number of rings. To determine all different possibilities, we develop a formalism that associates any link to a polynomial, with each polynomial thereby defining a distinct equivalence class. To demonstrate the use of this classification scheme, we choose qubit quantum states as our example of physical system. A possible procedure to obtain qubit states from the polynomials is also introduced, providing an example state for each link class. We apply the formalism for the quantum systems of three and four qubits and demonstrate the potential of these tools in a context of qubit networks.

A constraint optimization based virtual network mapping method

NASA Astrophysics Data System (ADS)

Li, Xiaoling; Guo, Changguo; Wang, Huaimin; Li, Zhendong; Yang, Zhiwen

2013-03-01

Virtual network mapping problem, maps different virtual networks onto the substrate network is an extremely challenging work. This paper proposes a constraint optimization based mapping method for solving virtual network mapping problem. This method divides the problem into two phases, node mapping phase and link mapping phase, which are all NP-hard problems. Node mapping algorithm and link mapping algorithm are proposed for solving node mapping phase and link mapping phase, respectively. Node mapping algorithm adopts the thinking of greedy algorithm, mainly considers two factors, available resources which are supplied by the nodes and distance between the nodes. Link mapping algorithm is based on the result of node mapping phase, adopts the thinking of distributed constraint optimization method, which can guarantee to obtain the optimal mapping with the minimum network cost. Finally, simulation experiments are used to validate the method, and results show that the method performs very well.

Reversible TAD Chemistry as a Convenient Tool for the Design of (Re)processable PCL-Based Shape-Memory Materials.

PubMed

Defize, Thomas; Riva, Raphaël; Thomassin, Jean-Michel; Alexandre, Michaël; Herck, Niels Van; Prez, Filip Du; Jérôme, Christine

2017-01-01

A chemically cross-linked but remarkably (re)processable shape-memory polymer (SMP) is designed by cross-linking poly(ε-caprolactone) (PCL) stars via the efficient triazolinedione click chemistry, based on the very fast and reversible Alder-ene reaction of 1,2,4-triazoline-3,5-dione (TAD) with indole compounds. Typically, a six-arm star-shaped PCL functionalized by indole moieties at the chain ends is melt-blended with a bisfunctional TAD, directly resulting in a cross-linked PCL-based SMP without the need of post-curing treatment. As demonstrated by the stress relaxation measurement, the labile character of the TAD-indole adducts under stress allows for the solid-state plasticity reprocessing of the permanent shape at will by compression molding of the raw cross-linked material, while keeping excellent shape-memory properties. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Publication, discovery and interoperability of Clinical Decision Support Systems: A Linked Data approach.

PubMed

Marco-Ruiz, Luis; Pedrinaci, Carlos; Maldonado, J A; Panziera, Luca; Chen, Rong; Bellika, J Gustav

2016-08-01

The high costs involved in the development of Clinical Decision Support Systems (CDSS) make it necessary to share their functionality across different systems and organizations. Service Oriented Architectures (SOA) have been proposed to allow reusing CDSS by encapsulating them in a Web service. However, strong barriers in sharing CDS functionality are still present as a consequence of lack of expressiveness of services' interfaces. Linked Services are the evolution of the Semantic Web Services paradigm to process Linked Data. They aim to provide semantic descriptions over SOA implementations to overcome the limitations derived from the syntactic nature of Web services technologies. To facilitate the publication, discovery and interoperability of CDS services by evolving them into Linked Services that expose their interfaces as Linked Data. We developed methods and models to enhance CDS SOA as Linked Services that define a rich semantic layer based on machine interpretable ontologies that powers their interoperability and reuse. These ontologies provided unambiguous descriptions of CDS services properties to expose them to the Web of Data. We developed models compliant with Linked Data principles to create a semantic representation of the components that compose CDS services. To evaluate our approach we implemented a set of CDS Linked Services using a Web service definition ontology. The definitions of Web services were linked to the models developed in order to attach unambiguous semantics to the service components. All models were bound to SNOMED-CT and public ontologies (e.g. Dublin Core) in order to count on a lingua franca to explore them. Discovery and analysis of CDS services based on machine interpretable models was performed reasoning over the ontologies built. Linked Services can be used effectively to expose CDS services to the Web of Data by building on current CDS standards. This allows building shared Linked Knowledge Bases to provide machine interpretable semantics to the CDS service description alleviating the challenges on interoperability and reuse. Linked Services allow for building 'digital libraries' of distributed CDS services that can be hosted and maintained in different organizations. Copyright © 2016 Elsevier Inc. All rights reserved.

Finger-Based Numerical Skills Link Fine Motor Skills to Numerical Development in Preschoolers.

PubMed

Suggate, Sebastian; Stoeger, Heidrun; Fischer, Ursula

2017-12-01

Previous studies investigating the association between fine-motor skills (FMS) and mathematical skills have lacked specificity. In this study, we test whether an FMS link to numerical skills is due to the involvement of finger representations in early mathematics. We gave 81 pre-schoolers (mean age of 4 years, 9 months) a set of FMS measures and numerical tasks with and without a specific finger focus. Additionally, we used receptive vocabulary and chronological age as control measures. FMS linked more closely to finger-based than to nonfinger-based numerical skills even after accounting for the control variables. Moreover, the relationship between FMS and numerical skill was entirely mediated by finger-based numerical skills. We concluded that FMS are closely related to early numerical skill development through finger-based numerical counting that aids the acquisition of mathematical mental representations.

An Accurate Link Correlation Estimator for Improving Wireless Protocol Performance

PubMed Central

Zhao, Zhiwei; Xu, Xianghua; Dong, Wei; Bu, Jiajun

2015-01-01

Wireless link correlation has shown significant impact on the performance of various sensor network protocols. Many works have been devoted to exploiting link correlation for protocol improvements. However, the effectiveness of these designs heavily relies on the accuracy of link correlation measurement. In this paper, we investigate state-of-the-art link correlation measurement and analyze the limitations of existing works. We then propose a novel lightweight and accurate link correlation estimation (LACE) approach based on the reasoning of link correlation formation. LACE combines both long-term and short-term link behaviors for link correlation estimation. We implement LACE as a stand-alone interface in TinyOS and incorporate it into both routing and flooding protocols. Simulation and testbed results show that LACE: (1) achieves more accurate and lightweight link correlation measurements than the state-of-the-art work; and (2) greatly improves the performance of protocols exploiting link correlation. PMID:25686314

Sodium tripolyphosphate cross-linked chitosan based sensor for enhacing sensing properties towards acetone

NASA Astrophysics Data System (ADS)

Nasution, T. I.; Asrosa, R.; Nainggolan, I.; Balyan, M.; Indah, R.; Wahyudi, A.

2018-02-01

In this report, sensing properties of sodium tripolyphosphate (TPP) cross-linked chitosan based sensor has been successfully enhanced towards acetone. Chitosan solutions were cross-linked with sodium TPP in variation of 0.1%, 0.5%, 1% and 1.5% w/v, respectively. The sensors were fabricated in film form using an electrochemical deposition method. The sensing properties of the sensors were observed by exposing the pure chitosan and sodium TPP cross-linked chitosan sensors towards acetone concentrations of 5, 10, 50, 100 and 200 ppm. The measurement results revealed that the maximum response in output voltage value of pure chitosan sensor was 0.35 V while sodium TPP crosslinked chitosan sensors were above 0.35 V towards 5 ppm acetone concentration. When the sensors were exposed towards acetone concentration of 200 ppm, the maximum response of pure chitosan was 0.45 V while sodium TPP crosslinked chitosan sensors were above 0.45 V. Amongst the variation of sodium TPP, the maximum response of 1% sodium TPP was the highest since the maximum response was 0.4 V and 0.6 V towards 5 ppm and 200 ppm acetone concentration, respectively. While the maximum responses of other sodium TPP concentrations were under 0.4 V and 0.6 V towards 5 ppm and 200 ppm acetone concentration. Moreover, 1% sodium TPP cross-linked chitosan based sensor showed good reproducibility and outstanding lifetime. Therefore, 1% sodium TPP cross-linked chitosan based sensor has exhibited remarkable sensing properties as a novel acetone sensor.

ParentLink: A Model of Integration and Support for Parents.

ERIC Educational Resources Information Center

Mertensmeyer, Carol; Fine, Mark

2000-01-01

Discusses ParentLink, a collective of Missouri organizations and agencies striving to simplify parents' access to research-based information, services, and problem-solving support pertaining to parenting. It is based on systems theory, specifically the ecology of human development. A comprehensive array of technologies augments ParentLink…

The Maine Sealant Manual for School-Based and School-Linked Dental Sealant Programs.

ERIC Educational Resources Information Center

Hayward, Kneka, Ed.

This manual is designed for use by school personnel and dental personnel to aid in the development and maintenance of school-based or school-linked dental sealant programs. The sections include (1) "Introduction"; (2) "Guidelines" (school selection, school contacts, dental providers, target grades, and tooth selection…

Data preparation techniques for a perinatal psychiatric study based on linked data.

PubMed

Xu, Fenglian; Hilder, Lisa; Austin, Marie-Paule; Sullivan, Elizabeth A

2012-06-08

In recent years there has been an increase in the use of population-based linked data. However, there is little literature that describes the method of linked data preparation. This paper describes the method for merging data, calculating the statistical variable (SV), recoding psychiatric diagnoses and summarizing hospital admissions for a perinatal psychiatric study. The data preparation techniques described in this paper are based on linked birth data from the New South Wales (NSW) Midwives Data Collection (MDC), the Register of Congenital Conditions (RCC), the Admitted Patient Data Collection (APDC) and the Pharmaceutical Drugs of Addiction System (PHDAS). The master dataset is the meaningfully linked data which include all or major study data collections. The master dataset can be used to improve the data quality, calculate the SV and can be tailored for different analyses. To identify hospital admissions in the periods before pregnancy, during pregnancy and after birth, a statistical variable of time interval (SVTI) needs to be calculated. The methods and SPSS syntax for building a master dataset, calculating the SVTI, recoding the principal diagnoses of mental illness and summarizing hospital admissions are described. Linked data preparation, including building the master dataset and calculating the SV, can improve data quality and enhance data function.

Ecology in the information age: Patterns of use and attrition rates of internet-based citations in ESA journals, 1997–2005

USGS Publications Warehouse

Duda, Jeffrey J.; Camp, Richard J.

2008-01-01

As the amount of information available on the internet has increased, so too has the number of citations to network-accessible information in scholarly research. We searched all papers in four Ecological Society of America journals from 1997 to 2005 for articles containing a citation to material on the internet. We then tested the links to determine whether the information cited in the paper was still accessible. We identified 877 articles that contained at least one link to information on the internet and a total of 2100 unique links. The majority of these citations were based on an object's location (Uniform Resource Locator; 77%), whereas the rest were based on an object's identity (eg Digital Object Identifier, GenBank Accession number). We found that 19–30% of the location-based links were unavailable and that there was a positive relationship between the age of an article and the probability of the link being inactive. Using an internet search engine, we recovered 72–84% of the lost information, leaving a total of 6.2% of the total citations unavailable. Our results highlight the problem of persistence of information stored on the world wide web and we include recommendations for minimizing this problem.

Development of a clinician reputation metric to identify appropriate problem-medication pairs in a crowdsourced knowledge base.

PubMed

McCoy, Allison B; Wright, Adam; Rogith, Deevakar; Fathiamini, Safa; Ottenbacher, Allison J; Sittig, Dean F

2014-04-01

Correlation of data within electronic health records is necessary for implementation of various clinical decision support functions, including patient summarization. A key type of correlation is linking medications to clinical problems; while some databases of problem-medication links are available, they are not robust and depend on problems and medications being encoded in particular terminologies. Crowdsourcing represents one approach to generating robust knowledge bases across a variety of terminologies, but more sophisticated approaches are necessary to improve accuracy and reduce manual data review requirements. We sought to develop and evaluate a clinician reputation metric to facilitate the identification of appropriate problem-medication pairs through crowdsourcing without requiring extensive manual review. We retrieved medications from our clinical data warehouse that had been prescribed and manually linked to one or more problems by clinicians during e-prescribing between June 1, 2010 and May 31, 2011. We identified measures likely to be associated with the percentage of accurate problem-medication links made by clinicians. Using logistic regression, we created a metric for identifying clinicians who had made greater than or equal to 95% appropriate links. We evaluated the accuracy of the approach by comparing links made by those physicians identified as having appropriate links to a previously manually validated subset of problem-medication pairs. Of 867 clinicians who asserted a total of 237,748 problem-medication links during the study period, 125 had a reputation metric that predicted the percentage of appropriate links greater than or equal to 95%. These clinicians asserted a total of 2464 linked problem-medication pairs (983 distinct pairs). Compared to a previously validated set of problem-medication pairs, the reputation metric achieved a specificity of 99.5% and marginally improved the sensitivity of previously described knowledge bases. A reputation metric may be a valuable measure for identifying high quality clinician-entered, crowdsourced data. Copyright © 2013 Elsevier Inc. All rights reserved.

Development of a clinician reputation metric to identify appropriate problem-medication pairs in a crowdsourced knowledge base

PubMed Central

McCoy, Allison B.; Wright, Adam; Rogith, Deevakar; Fathiamini, Safa; Ottenbacher, Allison J.; Sittig, Dean F.

2014-01-01

Background Correlation of data within electronic health records is necessary for implementation of various clinical decision support functions, including patient summarization. A key type of correlation is linking medications to clinical problems; while some databases of problem-medication links are available, they are not robust and depend on problems and medications being encoded in particular terminologies. Crowdsourcing represents one approach to generating robust knowledge bases across a variety of terminologies, but more sophisticated approaches are necessary to improve accuracy and reduce manual data review requirements. Objective We sought to develop and evaluate a clinician reputation metric to facilitate the identification of appropriate problem-medication pairs through crowdsourcing without requiring extensive manual review. Approach We retrieved medications from our clinical data warehouse that had been prescribed and manually linked to one or more problems by clinicians during e-prescribing between June 1, 2010 and May 31, 2011. We identified measures likely to be associated with the percentage of accurate problem-medication links made by clinicians. Using logistic regression, we created a metric for identifying clinicians who had made greater than or equal to 95% appropriate links. We evaluated the accuracy of the approach by comparing links made by those physicians identified as having appropriate links to a previously manually validated subset of problem-medication pairs. Results Of 867 clinicians who asserted a total of 237,748 problem-medication links during the study period, 125 had a reputation metric that predicted the percentage of appropriate links greater than or equal to 95%. These clinicians asserted a total of 2464 linked problem-medication pairs (983 distinct pairs). Compared to a previously validated set of problem-medication pairs, the reputation metric achieved a specificity of 99.5% and marginally improved the sensitivity of previously described knowledge bases. Conclusion A reputation metric may be a valuable measure for identifying high quality clinician-entered, crowdsourced data. PMID:24321170

Application of a fast sorting algorithm to the assignment of mass spectrometric cross-linking data.

PubMed

Petrotchenko, Evgeniy V; Borchers, Christoph H

2014-09-01

Cross-linking combined with MS involves enzymatic digestion of cross-linked proteins and identifying cross-linked peptides. Assignment of cross-linked peptide masses requires a search of all possible binary combinations of peptides from the cross-linked proteins' sequences, which becomes impractical with increasing complexity of the protein system and/or if digestion enzyme specificity is relaxed. Here, we describe the application of a fast sorting algorithm to search large sequence databases for cross-linked peptide assignments based on mass. This same algorithm has been used previously for assigning disulfide-bridged peptides (Choi et al., ), but has not previously been applied to cross-linking studies. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Packet-Based Protocol Efficiency for Aeronautical and Satellite Communications

NASA Technical Reports Server (NTRS)

Carek, David A.

2005-01-01

This paper examines the relation between bit error ratios and the effective link efficiency when transporting data with a packet-based protocol. Relations are developed to quantify the impact of a protocol s packet size and header size relative to the bit error ratio of the underlying link. These relations are examined in the context of radio transmissions that exhibit variable error conditions, such as those used in satellite, aeronautical, and other wireless networks. A comparison of two packet sizing methodologies is presented. From these relations, the true ability of a link to deliver user data, or information, is determined. Relations are developed to calculate the optimal protocol packet size forgiven link error characteristics. These relations could be useful in future research for developing an adaptive protocol layer. They can also be used for sizing protocols in the design of static links, where bit error ratios have small variability.

Decoupling Identification for Serial Two-Link Two-Inertia System

NASA Astrophysics Data System (ADS)

Oaki, Junji; Adachi, Shuichi

The purpose of our study is to develop a precise model by applying the technique of system identification for the model-based control of a nonlinear robot arm, under taking joint-elasticity into consideration. We previously proposed a systematic identification method, called “decoupling identification,” for a “SCARA-type” planar two-link robot arm with elastic joints caused by the Harmonic-drive® reduction gears. The proposed method serves as an extension of the conventional rigid-joint-model-based identification. The robot arm is treated as a serial two-link two-inertia system with nonlinearity. The decoupling identification method using link-accelerometer signals enables the serial two-link two-inertia system to be divided into two linear one-link two-inertia systems. The MATLAB®'s commands for state-space model estimation are utilized in the proposed method. Physical parameters such as motor inertias, link inertias, joint-friction coefficients, and joint-spring coefficients are estimated through the identified one-link two-inertia systems using a gray-box approach. This paper describes accuracy evaluations using the two-link arm for the decoupling identification method under introducing closed-loop-controlled elements and varying amplitude-setup of identification-input. Experimental results show that the identification method also works with closed-loop-controlled elements. Therefore, the identification method is applicable to a “PUMA-type” vertical robot arm under gravity.

A Glider-Assisted Link Disruption Restoration Mechanism in Underwater Acoustic Sensor Networks.

PubMed

Jin, Zhigang; Wang, Ning; Su, Yishan; Yang, Qiuling

2018-02-07

Underwater acoustic sensor networks (UASNs) have become a hot research topic. In UASNs, nodes can be affected by ocean currents and external forces, which could result in sudden link disruption. Therefore, designing a flexible and efficient link disruption restoration mechanism to ensure the network connectivity is a challenge. In the paper, we propose a glider-assisted restoration mechanism which includes link disruption recognition and related link restoring mechanism. In the link disruption recognition mechanism, the cluster heads collect the link disruption information and then schedule gliders acting as relay nodes to restore the disrupted link. Considering the glider's sawtooth motion, we design a relay location optimization algorithm with a consideration of both the glider's trajectory and acoustic channel attenuation model. The utility function is established by minimizing the channel attenuation and the optimal location of glider is solved by a multiplier method. The glider-assisted restoration mechanism can greatly improve the packet delivery rate and reduce the communication energy consumption and it is more general for the restoration of different link disruption scenarios. The simulation results show that glider-assisted restoration mechanism can improve the delivery rate of data packets by 15-33% compared with cooperative opportunistic routing (OVAR), the hop-by-hop vector-based forwarding (HH-VBF) and the vector based forward (VBF) methods, and reduce communication energy consumption by 20-58% for a typical network's setting.

A Glider-Assisted Link Disruption Restoration Mechanism in Underwater Acoustic Sensor Networks

PubMed Central

Wang, Ning; Su, Yishan; Yang, Qiuling

2018-01-01

Underwater acoustic sensor networks (UASNs) have become a hot research topic. In UASNs, nodes can be affected by ocean currents and external forces, which could result in sudden link disruption. Therefore, designing a flexible and efficient link disruption restoration mechanism to ensure the network connectivity is a challenge. In the paper, we propose a glider-assisted restoration mechanism which includes link disruption recognition and related link restoring mechanism. In the link disruption recognition mechanism, the cluster heads collect the link disruption information and then schedule gliders acting as relay nodes to restore the disrupted link. Considering the glider’s sawtooth motion, we design a relay location optimization algorithm with a consideration of both the glider’s trajectory and acoustic channel attenuation model. The utility function is established by minimizing the channel attenuation and the optimal location of glider is solved by a multiplier method. The glider-assisted restoration mechanism can greatly improve the packet delivery rate and reduce the communication energy consumption and it is more general for the restoration of different link disruption scenarios. The simulation results show that glider-assisted restoration mechanism can improve the delivery rate of data packets by 15–33% compared with cooperative opportunistic routing (OVAR), the hop-by-hop vector-based forwarding (HH-VBF) and the vector based forward (VBF) methods, and reduce communication energy consumption by 20–58% for a typical network’s setting. PMID:29414898

Improving Website Hyperlink Structure Using Server Logs

PubMed Central

Paranjape, Ashwin; West, Robert; Zia, Leila; Leskovec, Jure

2016-01-01

Good websites should be easy to navigate via hyperlinks, yet maintaining a high-quality link structure is difficult. Identifying pairs of pages that should be linked may be hard for human editors, especially if the site is large and changes frequently. Further, given a set of useful link candidates, the task of incorporating them into the site can be expensive, since it typically involves humans editing pages. In the light of these challenges, it is desirable to develop data-driven methods for automating the link placement task. Here we develop an approach for automatically finding useful hyperlinks to add to a website. We show that passively collected server logs, beyond telling us which existing links are useful, also contain implicit signals indicating which nonexistent links would be useful if they were to be introduced. We leverage these signals to model the future usefulness of yet nonexistent links. Based on our model, we define the problem of link placement under budget constraints and propose an efficient algorithm for solving it. We demonstrate the effectiveness of our approach by evaluating it on Wikipedia, a large website for which we have access to both server logs (used for finding useful new links) and the complete revision history (containing a ground truth of new links). As our method is based exclusively on standard server logs, it may also be applied to any other website, as we show with the example of the biomedical research site Simtk. PMID:28345077

Generating and Executing Complex Natural Language Queries across Linked Data.

PubMed

Hamon, Thierry; Mougin, Fleur; Grabar, Natalia

2015-01-01

With the recent and intensive research in the biomedical area, the knowledge accumulated is disseminated through various knowledge bases. Links between these knowledge bases are needed in order to use them jointly. Linked Data, SPARQL language, and interfaces in Natural Language question-answering provide interesting solutions for querying such knowledge bases. We propose a method for translating natural language questions in SPARQL queries. We use Natural Language Processing tools, semantic resources, and the RDF triples description. The method is designed on 50 questions over 3 biomedical knowledge bases, and evaluated on 27 questions. It achieves 0.78 F-measure on the test set. The method for translating natural language questions into SPARQL queries is implemented as Perl module available at http://search.cpan.org/ thhamon/RDF-NLP-SPARQLQuery.

Ice templated and cross-linked xylan/nanocrystalline cellulose hydrogels

Treesearch

Tobias Köhnke; Thomas Elder; Hans Theliander; Arthur J. Ragauskas

2014-01-01

Structured xylan-based hydrogels, reinforced with cellulose nanocrystals (CNCs), have successfully been prepared from water suspensions by cross-linking during freeze-casting. In order to induce cross-linking during the solidification/sublimation operation, xylan was first oxidized using sodium periodate to introduce dialdehydes. The oxidized xylan was then mixed with...

A Comparison of Selective Pressures in Plant X-Linked and Autosomal Genes

PubMed Central

Krasovec, Marc; Filatov, Dmitry A.

2018-01-01

Selection is expected to work differently in autosomal and X-linked genes because of their ploidy difference and the exposure of recessive X-linked mutations to haploid selection in males. However, it is not clear whether these expectations apply to recently evolved sex chromosomes, where many genes retain functional X- and Y-linked gametologs. We took advantage of the recently evolved sex chromosomes in the plant Silene latifolia and its closely related species to compare the selective pressures between hemizygous and non-hemizygous X-linked genes as well as between X-linked genes and autosomal genes. Our analysis, based on over 1000 genes, demonstrated that, similar to animals, X-linked genes in Silene evolve significantly faster than autosomal genes—the so-called faster-X effect. Contrary to expectations, faster-X divergence was detectable only for non-hemizygous X-linked genes. Our phylogeny-based analyses of selection revealed no evidence for faster adaptation in X-linked genes compared to autosomal genes. On the other hand, partial relaxation of purifying selection was apparent on the X-chromosome compared to the autosomes, consistent with a smaller genetic diversity in S. latifolia X-linked genes (πx = 0.016; πaut = 0.023). Thus, the faster-X divergence in S. latifolia appears to be a consequence of the smaller effective population size rather than of a faster adaptive evolution on the X-chromosome. We argue that this may be a general feature of “young” sex chromosomes, where the majority of X-linked genes are not hemizygous, preventing haploid selection in heterogametic sex. PMID:29751495

A Comparison of Selective Pressures in Plant X-Linked and Autosomal Genes.

PubMed

Krasovec, Marc; Nevado, Bruno; Filatov, Dmitry A

2018-05-03

Selection is expected to work differently in autosomal and X-linked genes because of their ploidy difference and the exposure of recessive X-linked mutations to haploid selection in males. However, it is not clear whether these expectations apply to recently evolved sex chromosomes, where many genes retain functional X- and Y-linked gametologs. We took advantage of the recently evolved sex chromosomes in the plant Silene latifolia and its closely related species to compare the selective pressures between hemizygous and non-hemizygous X-linked genes as well as between X-linked genes and autosomal genes. Our analysis, based on over 1000 genes, demonstrated that, similar to animals, X-linked genes in Silene evolve significantly faster than autosomal genes—the so-called faster-X effect. Contrary to expectations, faster-X divergence was detectable only for non-hemizygous X-linked genes. Our phylogeny-based analyses of selection revealed no evidence for faster adaptation in X-linked genes compared to autosomal genes. On the other hand, partial relaxation of purifying selection was apparent on the X-chromosome compared to the autosomes, consistent with a smaller genetic diversity in S. latifolia X-linked genes (π x = 0.016; π aut = 0.023). Thus, the faster-X divergence in S. latifolia appears to be a consequence of the smaller effective population size rather than of a faster adaptive evolution on the X-chromosome. We argue that this may be a general feature of “young” sex chromosomes, where the majority of X-linked genes are not hemizygous, preventing haploid selection in heterogametic sex.

Efficient control-channel multifailure management mechanism in GMPLS-based optical networks

NASA Astrophysics Data System (ADS)

Muñoz, Raül; Martínez, Ricardo; Junyent, Gabriel

2006-12-01

In generalized multiprotocol label switching (GMPLS) architecture, the control channels between each pair of optical nodes are not forced to use the same physical link as the data/transport channels. The problem arises when, due to the fact of allowing the control channels to be physically diverse from the associated data links, there may not be any active control channels available while data channels are still in use. Control-channel faults should not have a service impact on the existing connections; that is, a link that is carrying data traffic must not be torn down because the control channel is no longer available. But, due to the lack of the control channel, the active traffic that is using the data link may no longer be guaranteed with the same level of recovery service (protection or restoration). Under these circumstances the link must be considered to be in a degraded state. This means that routing and signaling should be notified that new connections are not accepted and the link is advertised with no unreserved resources. For this purpose, here we propose a control-channel multifailure management mechanism involving routing, signaling, and link management with extended GMPLS-based protocol extensions to keep the same level of service (in terms of provisioning and recovery) when a link is in the degraded state.

Characterizing Deficiencies of Path-Based Routing for Wireless Multi-Hop Networks

DTIC Science & Technology

2017-05-01

called a “ hello ”) to all of its neighbors. If a series of hello messages are exchanged between two users, a link is considered to exist between them...A brief description of ETX is as follows. For a given window of time, the number of hello packets that a user receives from a neighbor is counted. A...cost is then assigned to the link based on how many hello messages were heard; a link that has fewer hellos successfully transmitted across it will be

Ubiquitousness of link-density and link-pattern communities in real-world networks

NASA Astrophysics Data System (ADS)

Šubelj, L.; Bajec, M.

2012-01-01

Community structure appears to be an intrinsic property of many complex real-world networks. However, recent work shows that real-world networks reveal even more sophisticated modules than classical cohesive (link-density) communities. In particular, networks can also be naturally partitioned according to similar patterns of connectedness among the nodes, revealing link-pattern communities. We here propose a propagation based algorithm that can extract both link-density and link-pattern communities, without any prior knowledge of the true structure. The algorithm was first validated on different classes of synthetic benchmark networks with community structure, and also on random networks. We have further applied the algorithm to different social, information, technological and biological networks, where it indeed reveals meaningful (composites of) link-density and link-pattern communities. The results thus seem to imply that, similarly as link-density counterparts, link-pattern communities appear ubiquitous in nature and design.

Overlapping Community Detection based on Network Decomposition

NASA Astrophysics Data System (ADS)

Ding, Zhuanlian; Zhang, Xingyi; Sun, Dengdi; Luo, Bin

2016-04-01

Community detection in complex network has become a vital step to understand the structure and dynamics of networks in various fields. However, traditional node clustering and relatively new proposed link clustering methods have inherent drawbacks to discover overlapping communities. Node clustering is inadequate to capture the pervasive overlaps, while link clustering is often criticized due to the high computational cost and ambiguous definition of communities. So, overlapping community detection is still a formidable challenge. In this work, we propose a new overlapping community detection algorithm based on network decomposition, called NDOCD. Specifically, NDOCD iteratively splits the network by removing all links in derived link communities, which are identified by utilizing node clustering technique. The network decomposition contributes to reducing the computation time and noise link elimination conduces to improving the quality of obtained communities. Besides, we employ node clustering technique rather than link similarity measure to discover link communities, thus NDOCD avoids an ambiguous definition of community and becomes less time-consuming. We test our approach on both synthetic and real-world networks. Results demonstrate the superior performance of our approach both in computation time and accuracy compared to state-of-the-art algorithms.

The Node Acquisition and Integration Technique: A Node-Link Based Teaching/Learning Strategy.

ERIC Educational Resources Information Center

Diekhoff, George M.

This paper presents the results of three experiments conducted in connection with development of a node-link based teaching/learning strategy. In experiment 1, subjects were instructed to either define concepts selected from a unit of introductory psychology or to describe the relationships existing between pairs of concepts. The cognitive…

Growth Points in Linking Representations of Function: A Research-Based Framework

ERIC Educational Resources Information Center

Ronda, Erlina

2015-01-01

This paper describes five growth points in linking representations of function developed from a study of secondary school learners. Framed within the cognitivist perspective and process-object conception of function, the growth points were identified and described based on linear and quadratic function tasks learners can do and their strategies…

Web-Based Knowledge Exchange through Social Links in the Workplace

ERIC Educational Resources Information Center

Filipowski, Tomasz; Kazienko, Przemyslaw; Brodka, Piotr; Kajdanowicz, Tomasz

2012-01-01

Knowledge exchange between employees is an essential feature of recent commercial organisations on the competitive market. Based on the data gathered by various information technology (IT) systems, social links can be extracted and exploited in knowledge exchange systems of a new kind. Users of such a system ask their queries and the system…

Hydrostatic Pressure Project: Linked-Class Problem-Based Learning in Engineering

ERIC Educational Resources Information Center

Davis, Freddie J.; Lockwood-Cooke, Pamela; Hunt, Emily M.

2011-01-01

Over the last few years, WTAMU Mathematics, Engineering and Science faculty has used interdisciplinary projects as the basis for implementation of a linked-class approach to Problem-Based Learning (PBL). A project that has significant relevance to engineering statics, fluid mechanics, and calculus is the Hydrostatic Pressure Project. This project…

MultiWaveLink: An interactive data base for the coordination of multiwavelength and multifacility observations

NASA Technical Reports Server (NTRS)

Cordova, F. A.

1993-01-01

MultiWaveLink is an interactive, computerized data base that was developed to facilitate a multi-wavelength approach to studying astrophysical sources. It can be used to access information about multiwavelenth resources (observers, telescopes, data bases and analysis facilities) or to organize observing campaigns that require either many telescopes operating in different spectral regimes or a network of similar telescopes circumspanning the Earth.

The use of molecular dynamics simulations to evaluate the DNA sequence-selectivity of G-A cross-linking PBD-duocarmycin dimers.

PubMed

Jackson, Paul J M; Rahman, Khondaker M; Thurston, David E

2017-01-01

The pyrrolobenzodiazepine (PBD) and duocarmycin families are DNA-interactive agents that covalently bond to guanine (G) and adenine (A) bases, respectively, and that have been joined together to create synthetic dimers capable of cross-linking G-G, A-A, and G-A bases. Three G-A alkylating dimers have been reported in publications to date, with defined DNA-binding sites proposed for two of them. In this study we have used molecular dynamics simulations to elucidate preferred DNA-binding sites for the three published molecular types. For the PBD-CPI dimer UTA-6026 (1), our simulations correctly predicted its favoured binding site (i.e., 5'-C(G)AATTA-3') as identified by DNA cleavage studies. However, for the PBD-CI molecule ('Compound 11', 3), we were unable to reconcile the results of our simulations with the reported preferred cross-linking sequence (5'-ATTTTCC(G)-3'). We found that the molecule is too short to span the five base pairs between the A and G bases as claimed, but should target instead a sequence such as 5'-ATTTC(G)-3' with two less base pairs between the reacting G and A residues. Our simulation results for this hybrid dimer are also in accord with the very low interstrand cross-linking and in vitro cytotoxicity activities reported for it. Although a preferred cross-linking sequence was not reported for the third hybrid dimer ('27eS', 2), our simulations predict that it should span two base pairs between covalently reacting G and A bases (e.g., 5'-GTAT(A)-3'). Copyright © 2016. Published by Elsevier Ltd.

Investigation of cross-linking characteristics of novel hole-transporting materials for solution-processed phosphorescent OLEDs

NASA Astrophysics Data System (ADS)

Lee, Jaemin; Ameen, Shahid; Lee, Changjin

2016-04-01

After the success of commercialization of the vacuum-evaporated organic light-emitting diodes (OLEDs), solutionprocessing or printing of OLEDs are currently attracting much research interests. However, contrary to various kinds of readily available vacuum-evaporable OLED materials, the solution-processable OLED materials are still relatively rare. Hole-transporting layer (HTL) materials for solution-processed OLEDs are especially limited, because they need additional characteristics such as cross-linking to realize multilayer structures in solution-processed OLEDs, as well as their own electrically hole-transporting characteristics. The presence of such cross-linking characteristics of solutionprocessable HTL materials therefore makes them more challenging in the development stage, and also makes them essence of solution-processable OLED materials. In this work, the structure-property relationships of thermally crosslinkable HTL materials were systematically investigated by changing styrene-based cross-linking functionalities and modifying the carbazole-based hole-transporting core structures. The temperature dependency of the cross-linking characteristics of the HTL materials was systematically investigated by the UV-vis. absorption spectroscopy. The new HTL materials were also applied to green phosphorescent OLEDs, and their device characteristics were also investigated based on the chemical structures of the HTL materials. The device configuration was [ITO / PEDOT:PSS / HTL / EML / ETL / CsF / Al]. We found out that the chemical structures of the cross-linking functionalities greatly affect not only the cross-linking characteristics of the resultant HTL materials, but also the resultant OLED device characteristics. The increase of the maximum luminance and efficiency of OLEDs was evident as the cross-linking temperature decreases from higher than 200°C to at around 150°C.

Modeling and control of a hydraulically actuated flexible-prismatic link robot

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

Love, L.; Kress, R.; Jansen, J.

1996-12-01

Most of the research related to flexible link manipulators to date has focused on single link, fixed length, single plane of vibration test beds. In addition, actuation has been predominantly based upon electromagnetic motors. Ironically, these elements are rarely found in the existing industrial long reach systems. This manuscript describes a new hydraulically actuated, long reach manipulator with a flexible prismatic link at Oak Ridge National Laboratory (ORNL). Focus is directed towards both modeling and control of hydraulic actuators as well as flexible links that have variable natural frequencies.

Network geometry inference using common neighbors

NASA Astrophysics Data System (ADS)

Papadopoulos, Fragkiskos; Aldecoa, Rodrigo; Krioukov, Dmitri

2015-08-01

We introduce and explore a method for inferring hidden geometric coordinates of nodes in complex networks based on the number of common neighbors between the nodes. We compare this approach to the HyperMap method, which is based only on the connections (and disconnections) between the nodes, i.e., on the links that the nodes have (or do not have). We find that for high degree nodes, the common-neighbors approach yields a more accurate inference than the link-based method, unless heuristic periodic adjustments (or "correction steps") are used in the latter. The common-neighbors approach is computationally intensive, requiring O (t4) running time to map a network of t nodes, versus O (t3) in the link-based method. But we also develop a hybrid method with O (t3) running time, which combines the common-neighbors and link-based approaches, and we explore a heuristic that reduces its running time further to O (t2) , without significant reduction in the mapping accuracy. We apply this method to the autonomous systems (ASs) Internet, and we reveal how soft communities of ASs evolve over time in the similarity space. We further demonstrate the method's predictive power by forecasting future links between ASs. Taken altogether, our results advance our understanding of how to efficiently and accurately map real networks to their latent geometric spaces, which is an important necessary step toward understanding the laws that govern the dynamics of nodes in these spaces, and the fine-grained dynamics of network connections.

Acid–base bifunctional shell cross-linked micelle nanoreactor for one-pot tandem reaction

DOE PAGES

Lee, Li -Chen; Lu, Jie; Weck, Marcus; ...

2015-12-29

In shell cross-linked micelles (SCMs) containing acid sites in the shell and base sites in the core are prepared from amphiphilic poly(2-oxazoline) triblock copolymers. These materials are utilized as two-chamber nanoreactors for a prototypical acid-base bifunctional tandem deacetalization-nitroaldol reaction. Furthermore, the acid and base sites are localized in different regions of the micelle, allowing the two steps in the reaction sequence to largely proceed in separate compartments, akin to the compartmentalization that occurs in biological systems.

CuAAC-Based Click Chemistry in Self-Healing Polymers.

PubMed

Döhler, Diana; Michael, Philipp; Binder, Wolfgang H

2017-10-17

Click chemistry has emerged as a significant tool for materials science, organic chemistry, and bioscience. Based on the initial concept of Barry Sharpless in 2001, the copper(I)-catalyzed azide/alkyne cycloaddition (CuAAC) reaction has triggered a plethora of chemical concepts for linking molecules and building blocks under ambient conditions, forming the basis for applications in autonomous cross-linking materials. Self-healing systems on the other hand are often based on mild cross-linking chemistries that are able to react either autonomously or upon an external trigger. In the ideal case, self-healing takes place efficiently at low temperatures, independent of the substrate(s) used, by forming strong and stable networks, binding to the newly generated (cracked) interfaces to restore the original material properties. The use of the CuAAC in self-healing systems, most of all the careful design of copper-based catalysts linked to additives as well as the chemical diversity of substrates, has led to an enormous potential of applications of this singular reaction. The implementation of click-based strategies in self-healing systems therefore is highly attractive, as here chemical (and physical) concepts of molecular reactivity, molecular design, and even metal catalysis are connected to aspects of materials science. In this Account, we will show how CuAAC reactions of multivalent components can be used as a tool for self-healing materials, achieving cross-linking at low temperatures (exploiting concepts of autocatalysis or internal chelation within the bulk CuAAC and systematic optimization of the efficiency of the used Cu(I) catalysts). Encapsulation strategies to separate the click components by micro- and nanoencapsulation are required in this context. Consequently, the examples reported here describe chemical concepts to realize more efficient and faster click reactions in self-healing polymeric materials. Thus, enhanced chain diffusion in (hyper)branched polymers, autocatalysis, or internal chelation concepts enable efficient click cross-linking already at 5 °C with a simultaneously reduced amount of Cu(I) catalyst and increased reaction rates, culminating in the first reported self-healing system based on click cycloaddition reactions. Via tailor-made nanocarbon/Cu(I) catalysts we can further improve the click cross-linking reaction in view of efficiency and kinetics, leading to the generation of self-healing graphene-based epoxy nanocomposites. Additionally, we have designed special CuAAC click methods for chemical reporting and visualization systems based on the detection of ruptured capsules via a fluorogenic click reaction, which can be combined with CuAAC cross-linking reactions to obtain simultaneous stress detection and self-healing within polymeric materials. In a similar concept, we have prepared polymeric Cu(I)-biscarbene complexes to detect (mechanical) stress within self-healing polymeric materials via a triggered fluorogenic reaction, thus using a destructive force for a constructive chemical response.

Competence-Based System Self-Study System for Suggesting Study Materials Links

ERIC Educational Resources Information Center

Nitchot, Athitaya; Gilbert, Lester; Wills, Gary B.

2014-01-01

The article proposes a self-study system which suggests web links to learners. The suggestions depend upon the learner's chosen competences selected from a competence structure for a particular knowledge domain. Three experiments were conducted, where the first compared the perceived usefulness and value of the links generated by different…

Real-time Author Co-citation Mapping for Online Searching.

ERIC Educational Resources Information Center

Lin, Xia; White, Howard D.; Buzydlowski, Jan

2003-01-01

Describes the design and implementation of a prototype visualization system, AuthorLink, to enhance author searching. AuthorLink is based on author co-citation analysis and visualization mapping algorithms. AuthorLink produces interactive author maps in real time from a database of 1.26 million records supplied by the Institute for Scientific…

Link performance model for filter bank based multicarrier systems

NASA Astrophysics Data System (ADS)

Petrov, Dmitry; Oborina, Alexandra; Giupponi, Lorenza; Stitz, Tobias Hidalgo

2014-12-01

This paper presents a complete link level abstraction model for link quality estimation on the system level of filter bank multicarrier (FBMC)-based networks. The application of mean mutual information per coded bit (MMIB) approach is validated for the FBMC systems. The considered quality measure of the resource element for the FBMC transmission is the received signal-to-noise-plus-distortion ratio (SNDR). Simulation results of the proposed link abstraction model show that the proposed approach is capable of estimating the block error rate (BLER) accurately, even when the signal is propagated through the channels with deep and frequent fades, as it is the case for the 3GPP Hilly Terrain (3GPP-HT) and Enhanced Typical Urban (ETU) models. The FBMC-related results of link level simulations are compared with cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) analogs. Simulation results are also validated through the comparison to reference publicly available results. Finally, the steps of link level abstraction algorithm for FBMC are formulated and its application for system level simulation of a professional mobile radio (PMR) network is discussed.

Heterogeneous Data Fusion Method to Estimate Travel Time Distributions in Congested Road Networks

PubMed Central

Lam, William H. K.; Li, Qingquan

2017-01-01

Travel times in congested urban road networks are highly stochastic. Provision of travel time distribution information, including both mean and variance, can be very useful for travelers to make reliable path choice decisions to ensure higher probability of on-time arrival. To this end, a heterogeneous data fusion method is proposed to estimate travel time distributions by fusing heterogeneous data from point and interval detectors. In the proposed method, link travel time distributions are first estimated from point detector observations. The travel time distributions of links without point detectors are imputed based on their spatial correlations with links that have point detectors. The estimated link travel time distributions are then fused with path travel time distributions obtained from the interval detectors using Dempster-Shafer evidence theory. Based on fused path travel time distribution, an optimization technique is further introduced to update link travel time distributions and their spatial correlations. A case study was performed using real-world data from Hong Kong and showed that the proposed method obtained accurate and robust estimations of link and path travel time distributions in congested road networks. PMID:29210978

Heterogeneous Data Fusion Method to Estimate Travel Time Distributions in Congested Road Networks.

PubMed

Shi, Chaoyang; Chen, Bi Yu; Lam, William H K; Li, Qingquan

2017-12-06

Travel times in congested urban road networks are highly stochastic. Provision of travel time distribution information, including both mean and variance, can be very useful for travelers to make reliable path choice decisions to ensure higher probability of on-time arrival. To this end, a heterogeneous data fusion method is proposed to estimate travel time distributions by fusing heterogeneous data from point and interval detectors. In the proposed method, link travel time distributions are first estimated from point detector observations. The travel time distributions of links without point detectors are imputed based on their spatial correlations with links that have point detectors. The estimated link travel time distributions are then fused with path travel time distributions obtained from the interval detectors using Dempster-Shafer evidence theory. Based on fused path travel time distribution, an optimization technique is further introduced to update link travel time distributions and their spatial correlations. A case study was performed using real-world data from Hong Kong and showed that the proposed method obtained accurate and robust estimations of link and path travel time distributions in congested road networks.

Turbulence mitigation scheme based on spatial diversity in orbital-angular-momentum multiplexed system

NASA Astrophysics Data System (ADS)

Zou, Li; Wang, Le; Zhao, Shengmei

2017-10-01

Atmospheric turbulence (AT) induced crosstalk can significantly impair the performance of free-space optical (FSO) communication link using orbital angular momentum (OAM) multiplexing. In this paper, we propose a spatial diversity (SD) turbulence mitigation scheme in an OAM-multiplexed FSO communication link. First, we present a SD mitigation model for the OAM-multiplexed FSO communication link under AT. Then we present a SD combining technique based on equal gain to enhance AT tolerance of the OAM-multiplexed FSO communication link. The numerical results show that performance of the OAM-multiplexed communication link has greatly improved by the proposed scheme. When the turbulence strength Cn2 is 5 × 10-15m - 2 / 3, the transmission distance is 1000 m and the channel signal-to-noise ratio (SNR) is 20 dB, the bit-error-rate (BER) performance of four spatial multiplexed OAM modes lm = + 1 , + 2 , + 3 , + 4 are 3 fold increase in comparison with those results without the proposed scheme. The proposed scheme is a promising direction for compensating the interference caused by AT in the OAM-multiplexed FSO communication link.

71-Mbit/s ultraviolet-B LED communication link based on 8-QAM-OFDM modulation.

PubMed

Sun, Xiaobin; Zhang, Zhenyu; Chaaban, Anas; Ng, Tien Khee; Shen, Chao; Chen, Rui; Yan, Jianchang; Sun, Haiding; Li, Xiaohang; Wang, Junxi; Li, Jinmin; Alouini, Mohamed-Slim; Ooi, Boon S

2017-09-18

A demonstration of ultraviolet-B (UVB) communication link is implemented utilizing quadrature amplitude modulation (QAM) orthogonal frequency-division multiplexing (OFDM). The demonstration is based on a 294-nm UVB-light-emitting-diode (UVB-LED) with a full-width at half-maximum (FWHM) of 9 nm and light output power of 190 μW, at 7 V, with a special silica gel lens on top of it. A -3-dB bandwidth of 29 MHz was measured and a high-speed near-solar-blind communication link with a data rate of 71 Mbit/s was achieved using 8-QAM-OFDM at perfect alignment. 23.6 Mbit/s using 2-QAM-OFDM when the angle subtended by the pointing directions of the UVB-LED and photodetector (PD) is 12 degrees, thus establishing a diffuse-line-of-sight (LOS) link. The measured bit-error rate (BER) of 2.8 ×10 -4 and 2.4 ×10 -4 , respectively, are well below the forward error correction (FEC) criterion of 3.8 ×10 -3 . The demonstrated high data-rate OFDM-based UVB communication link paves the way for realizing high-speed non-line-of-sight free-space optical communications.

Effect of Cross-Linking on Free Volume Properties of PEG Based Thiol-Ene Networks

NASA Astrophysics Data System (ADS)

Ramakrishnan, Ramesh; Vasagar, Vivek; Nazarenko, Sergei

According to the Fox and Loshaek theory, in elastomeric networks, free volume decreases linearly with the cross-link density increase. The aim of this study is to show whether the poly(ethylene glycol) (PEG) based multicomponent thiol-ene elastomeric networks demonstrate this model behavior? Networks with a broad cross-link density range were prepared by changing the ratio of the trithiol crosslinker to PEG dithiol and then UV cured with PEG diene while maintaining 1:1 thiol:ene stoichiometry. Pressure-volume-temperature (PVT) data of the networks was generated from the high pressure dilatometry experiments which was fit using the Simha-Somcynsky Equation-of-State analysis to obtain the fractional free volume of the networks. Using Positron Annihilation Lifetime Spectroscopy (PALS) analysis, the average free volume hole size of the networks was also quantified. The fractional free volume and the average free volume hole size showed a linear change with the cross-link density confirming that the Fox and Loshaek theory can be applied to this multicomponent system. Gas diffusivities of the networks showed a good correlation with free volume. A free volume based model was developed to describe the gas diffusivity trends as a function of cross-link density.

Progress on the Development of the UAS C2 Link and Supporting Spectrum - from LOS to BLOS

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Griner, James H.; Bishop, William D.; Matolak, David W.; Wilson, Jeffrey D.

2017-01-01

In order to provide for the safe integration of unmanned aircraft systems (UAS) into the National Airspace System, the control and non-payload communications (CNPC) link connecting the ground-based pilot with the unmanned aircraft must be highly reliable and robust, based upon standards that enable certification. Both line-of-sight (LOS) links using terrestrial-based communications and beyond-line-of-sight (BLOS) links using satellite communications are required to support UAS operations. The development of standards has been undertaken by RTCA Special Committee 228 (SC-228), with supporting technical data developed by NASA under the UAS in the National Airspace (NAS) Project. As a result of this work minimum operational performance standards (MOPS) have been completed and published for the LOS CNPC system. The second phase of work, for both NASA and RTCA involves the BLOS CNPC systems. The development of technical data to support MOPS development for UAS BLOS satellite-based CNPC links has now been initiated by NASA, and RTCA SC-228 has organized itself to begin the MOPS development process. This paper will provide an overview of the work that has been completed to date by the Communications Subproject in support of LOS C2 communications for UAS followed by an update of plans and progress for the BLOS phase of the project, with the focus on the UAS C2 spectrum aspects.

Fragment Linking and Optimization of Inhibitors of the Aspartic Protease Endothiapepsin: Fragment‐Based Drug Design Facilitated by Dynamic Combinatorial Chemistry

PubMed Central

Mondal, Milon; Radeva, Nedyalka; Fanlo‐Virgós, Hugo; Otto, Sijbren; Klebe, Gerhard

2016-01-01

Abstract Fragment‐based drug design (FBDD) affords active compounds for biological targets. While there are numerous reports on FBDD by fragment growing/optimization, fragment linking has rarely been reported. Dynamic combinatorial chemistry (DCC) has become a powerful hit‐identification strategy for biological targets. We report the synergistic combination of fragment linking and DCC to identify inhibitors of the aspartic protease endothiapepsin. Based on X‐ray crystal structures of endothiapepsin in complex with fragments, we designed a library of bis‐acylhydrazones and used DCC to identify potent inhibitors. The most potent inhibitor exhibits an IC50 value of 54 nm, which represents a 240‐fold improvement in potency compared to the parent hits. Subsequent X‐ray crystallography validated the predicted binding mode, thus demonstrating the efficiency of the combination of fragment linking and DCC as a hit‐identification strategy. This approach could be applied to a range of biological targets, and holds the potential to facilitate hit‐to‐lead optimization. PMID:27400756

Comparative Effects of Computer-Based Concept Maps, Refutational Texts, and Expository Texts on Science Learning

ERIC Educational Resources Information Center

Adesope, Olusola O.; Cavagnetto, Andy; Hunsu, Nathaniel J.; Anguiano, Carlos; Lloyd, Joshua

2017-01-01

This study used a between-subjects experimental design to examine the effects of three different computer-based instructional strategies (concept map, refutation text, and expository scientific text) on science learning. Concept maps are node-link diagrams that show concepts as nodes and relationships among the concepts as labeled links.…

New Blended Learning Strategy Based on Flipped-Learning for Vocational Work-Linked Training

ERIC Educational Resources Information Center

El Hajji, Mohamed; El Bouzaidi, Rachid Drissi; Douzi, Hassan; Khouya, El Hassane

2016-01-01

In a changing Moroccan educational landscape, Addressing teaching development needs is becoming a major issue in vocational work-linked Training. In this context, this paper present a new blended learning strategy based on the flipped classroom, using a social learning platform as support. Through this strategy, we increased the time dedicated to…

[superscript 1]H NMR Spectroscopy-Based Configurational Analysis of Mono- and Disaccharides and Detection of ß-Glucosidase Activity: An Undergraduate Biochemistry Laboratory

ERIC Educational Resources Information Center

Periyannan, Gopal R.; Lawrence, Barbara A.; Egan, Annie E.

2015-01-01

A [superscript 1]H NMR spectroscopy-based laboratory experiment explores mono- and disaccharide structural chemistry, and the enzyme-substrate specificity of glycosidic bond cleavage by ß-glucosidase towards cellobiose (ß-linked gluco-disaccharide) and maltose (a-linked gluco-disaccharide). Structural differences between cellobiose, maltose, and…

Examining the Characteristics of Student Postings That Are Liked and Linked in a CSCL Environment

ERIC Educational Resources Information Center

Makos, Alexandra; Lee, Kyungmee; Zingaro, Daniel

2015-01-01

This case study is the first iteration of a large-scale design-based research project to improve Pepper, an interactive discussion-based learning environment. In this phase, we designed and implemented two social features to scaffold positive learner interactivity behaviors: a "Like" button and linking tool. A mixed-methods approach was…

An AIEE fluorescent supramolecular cross-linked polymer network based on pillar[5]arene host-guest recognition: construction and application in explosive detection.

PubMed

Shao, Li; Sun, Jifu; Hua, Bin; Huang, Feihe

2018-05-08

Here a novel fluorescent supramolecular cross-linked polymer network with aggregation induced enhanced emission (AIEE) properties was constructed via pillar[5]arene-based host-guest recognition. Furthermore, the supramolecular polymer network can be used for explosive detection in both solution and thin films.

Project Link-Four: Pre-Vocational Education for Adults through Community Linkages.

ERIC Educational Resources Information Center

Stedman, Deborah S.

The Texas adult performance level (APL) project LINK-FOUR implemented a curriculum based on functional competencies at four sites (Austin, Texarkana, Texas City, and Abilene) and formed linkages with local organizations involved in adult vocational education. The concept on which the project was based was that a set of prevocational skills, plus a…

Data-Mining Techniques in Detecting Factors Linked to Academic Achievement

ERIC Educational Resources Information Center

Martínez Abad, Fernando; Chaparro Caso López, Alicia A.

2017-01-01

In light of the emergence of statistical analysis techniques based on data mining in education sciences, and the potential they offer to detect non-trivial information in large databases, this paper presents a procedure used to detect factors linked to academic achievement in large-scale assessments. The study is based on a non-experimental,…

A sensitive monoclonal antibody-based enzyme-linked immunosorbent assay for chlorpyrifos residue determination in Chinese agricultural smaples

USDA-ARS?s Scientific Manuscript database

A monoclonal antibody-based competitive antibody-coated enzyme-linked immunosorbent assay (ELISA) was developed and optimized for determining chlorpyrifos residue in agricultural products. The IC50 and IC10 of this ELISA were 3.3 ng/mL and 0.1 ng/mL respectively. The average recoveries recovery rate...

Technology, Data Bases and System Analysis for Space-to-Ground Optical Communications

NASA Technical Reports Server (NTRS)

Lesh, James

1995-01-01

Optical communications is becoming an ever-increasingly important option for designers of space-to- ground communications links, whether it be for government or commercial applications. In this paper the technology being developed by NASA for use in space-to-ground optical communications is presented. Next, a program which is collecting a long term data base of atmospheric visibility statistics for optical propagation through the atmosphere will be described. Finally, a methodology for utilizing the statistics of the atmospheric data base in the analysis of space-to-ground links will be presented. This methodology takes into account the effects of station availability, is useful when comparing optical communications with microwave systems, and provides a rationale establishing the recommended link margin.

The road not taken: Women’s life paths and gender-linked personality traits

PubMed Central

Newton, Nicky J.; Stewart, Abigail J.

2013-01-01

Key studies have established an association between women's social roles and their midlife personalities. The current research expands our understanding by examining personality traits in midlife women who followed normative or non-normative life paths. The normative/non-normative distinction was based on two kinds of social roles that college-educated women undertook until midlife: work and family. Gender-linked personality traits were compared between (1) women in high status professions and women in moderate status professions; (2) women without children and women with children; and (3) single mothers and married mothers. Composite measures of gender-linked traits, based on expert-identified Q-sort items, were used. Each non-normative social role group exhibited a different pattern of gender-linked personality traits inconsistent with conventional female gender roles. PMID:23559687

Prediction in complex systems: The case of the international trade network

NASA Astrophysics Data System (ADS)

Vidmer, Alexandre; Zeng, An; Medo, Matúš; Zhang, Yi-Cheng

2015-10-01

Predicting the future evolution of complex systems is one of the main challenges in complexity science. Based on a current snapshot of a network, link prediction algorithms aim to predict its future evolution. We apply here link prediction algorithms to data on the international trade between countries. This data can be represented as a complex network where links connect countries with the products that they export. Link prediction techniques based on heat and mass diffusion processes are employed to obtain predictions for products exported in the future. These baseline predictions are improved using a recent metric of country fitness and product similarity. The overall best results are achieved with a newly developed metric of product similarity which takes advantage of causality in the network evolution.

High-speed optical feeder-link system using adaptive optics

NASA Astrophysics Data System (ADS)

Arimoto, Yoshinori; Hayano, Yutaka; Klaus, Werner

1997-05-01

We propose a satellite laser communication system between a ground station and a geostationary satellite, named high- speed optical feeder link system. It is based on the application of (a) high-speed optical devices, which have been developed for ground-based high-speed fiber-optic communications, and (b) the adaptive optics which compensates wavefront distortions due to atmospheric turbulences using a real time feedback control. A link budget study shows that a system with 10-Gbps bit-rate are available assuming the state-of-the-art device performance of the Er-doped fiber amplifier. We further discuss preliminary measurement results of the atmospheric turbulence at the telescope site in Tokyo, and present current study on the design of the key components for the feeder-link laser transceiver.

Enhancement of the NMSU Channel Error Simulator to Provide User-Selectable Link Delays

NASA Technical Reports Server (NTRS)

Horan, Stephen; Wang, Ru-Hai

2000-01-01

This is the third in a continuing series of reports describing the development of the Space-to-Ground Link Simulator (SGLS) to be used for testing data transfers under simulated space channel conditions. The SGLS is based upon Virtual Instrument (VI) software techniques for managing the error generation, link data rate configuration, and, now, selection of the link delay value. In this report we detail the changes that needed to be made to the SGLS VI configuration to permit link delays to be added to the basic error generation and link data rate control capabilities. This was accomplished by modifying the rate-splitting VIs to include a buffer the hold the incoming data for the duration selected by the user to emulate the channel link delay. In sample tests of this configuration, the TCP/IP(sub ftp) service and the SCPS(sub fp) service were used to transmit 10-KB data files using both symmetric (both forward and return links set to 115200 bps) and unsymmetric (forward link set at 2400 bps and a return link set at 115200 bps) link configurations. Transmission times were recorded at bit error rates of 0 through 10(exp -5) to give an indication of the link performance. In these tests. we noted separate timings for the protocol setup time to initiate the file transfer and the variation in the actual file transfer time caused by channel errors. Both protocols showed similar performance to that seen earlier for the symmetric and unsymmetric channels. This time, the delays in establishing the file protocol also showed that these delays could double the transmission time and need to be accounted for in mission planning. Both protocols also showed a difficulty in transmitting large data files over large link delays. In these tests, there was no clear favorite between the TCP/IP(sub ftp) and the SCPS(sub fp). Based upon these tests, further testing is recommended to extend the results to different file transfer configurations.

TheatreLink: Wired to Make Plays Together at a Distance

ERIC Educational Resources Information Center

Shookhoff, David

2004-01-01

Now entering its eighth year, TheatreLink, Manhattan Theater Club's Internet-based distance-learning project remains the most exciting and most challenging initiative. MTC's Education Program had existed for seven years (since 1989 to be exact) before it started TheatreLink. During that early period MTC created an array of programs, all of them…

The role of social relationships in the link between olfactory dysfunction and mortality.

PubMed

Leschak, Carrianne J; Eisenberger, Naomi I

2018-01-01

Recent work suggests that olfactory dysfunction is a strong predictor of five-year mortality in older adults. Based on past work showing: 1) that olfactory dysfunction impairs social functioning and 2) that social ties are linked with mortality, the current work explored whether impairments in social life mediated the relationship between olfactory dysfunction and mortality. Additionally, based on work showing gender differences in the social consequences of olfactory dysfunction, gender was assessed as a potential moderator of this association. Social network size mediated the olfactory-mortality link for females. To probe what feature of social networks was driving this effect, we investigated two subcomponents of social life: emotional closeness (e.g., perceived social support, loneliness) and physical closeness (e.g., physical contact, in-person socializing with others). Physical closeness significantly mediated the olfactory-mortality link for females, even after controlling for social network size. Emotional closeness did not mediate this link. Possible mechanisms underlying this relationship are discussed.

Nessi: An EEG-Controlled Web Browser for Severely Paralyzed Patients

PubMed Central

Bensch, Michael; Karim, Ahmed A.; Mellinger, Jürgen; Hinterberger, Thilo; Tangermann, Michael; Bogdan, Martin; Rosenstiel, Wolfgang; Birbaumer, Niels

2007-01-01

We have previously demonstrated that an EEG-controlled web browser based on self-regulation of slow cortical potentials (SCPs) enables severely paralyzed patients to browse the internet independently of any voluntary muscle control. However, this system had several shortcomings, among them that patients could only browse within a limited number of web pages and had to select links from an alphabetical list, causing problems if the link names were identical or if they were unknown to the user (as in graphical links). Here we describe a new EEG-controlled web browser, called Nessi, which overcomes these shortcomings. In Nessi, the open source browser, Mozilla, was extended by graphical in-place markers, whereby different brain responses correspond to different frame colors placed around selectable items, enabling the user to select any link on a web page. Besides links, other interactive elements are accessible to the user, such as e-mail and virtual keyboards, opening up a wide range of hypertext-based applications. PMID:18350132

Mapping edge-based traffic measurements onto the internal links in MPLS network

NASA Astrophysics Data System (ADS)

Zhao, Guofeng; Tang, Hong; Zhang, Yi

2004-09-01

Applying multi-protocol label switching techniques to IP-based backbone for traffic engineering goals has shown advantageous. Obtaining a volume of load on each internal link of the network is crucial for traffic engineering applying. Though collecting can be available for each link, such as applying traditional SNMP scheme, the approach may cause heavy processing load and sharply degrade the throughput of the core routers. Then monitoring merely at the edge of the network and mapping the measurements onto the core provides a good alternative way. In this paper, we explore a scheme for traffic mapping with edge-based measurements in MPLS network. It is supposed that the volume of traffic on each internal link over the domain would be mapped onto by measurements available only at ingress nodes. We apply path-based measurements at ingress nodes without enabling measurements in the core of the network. We propose a method that can infer a path from the ingress to the egress node using label distribution protocol without collecting routing data from core routers. Based on flow theory and queuing theory, we prove that our approach is effective and present the algorithm for traffic mapping. We also show performance simulation results that indicate potential of our approach.

The mechanism of collagen cross-linking in diabetes: a puzzle nearing resolution.

PubMed

Monnier, V M; Glomb, M; Elgawish, A; Sell, D R

1996-07-01

Considerable interest has been focused in recent years on the mechanism of collagen cross-linking by high glucose in vitro and in vivo. Experiments in both diabetic humans and in animals have shown that over time collagen becomes less soluble, less digestible by collagenase, more stable to heat-induced denaturation, and more glycated. In addition, collagen becomes more modified by advanced products of the Maillard reaction, i.e., immunoreactive advanced glycation end products and the glycoxidation markers carboxymethyllysine and pentosidine. Mechanistic studies have shown that collagen cross-linking in vitro can be uncoupled from glycation by the use of antioxidants and chelating agents. Experiments in the authors' laboratory revealed that approximately 50% of carboxymethyllysine formed in vitro originates from pathways other than oxidation of Amadori products, i.e., most likely the oxidation of Schiff base-linked glucose. In addition, the increase in thermal stability of rat tail tendons exposed to high glucose in vitro or in vivo was found to strongly depend on H2O2 formation. The final missing piece of the puzzle is that of the structure of the major cross-link. We speculate that it is a nonfluorescent nonultraviolet active cross-link between two lysine residues, which includes a fragmentation product of glucose linked in a nonreducible bond labile to both strong acids and bases.

Consequences of population topology for studying gene flow using link-based landscape genetic methods.

PubMed

van Strien, Maarten J

2017-07-01

Many landscape genetic studies aim to determine the effect of landscape on gene flow between populations. These studies frequently employ link-based methods that relate pairwise measures of historical gene flow to measures of the landscape and the geographical distance between populations. However, apart from landscape and distance, there is a third important factor that can influence historical gene flow, that is, population topology (i.e., the arrangement of populations throughout a landscape). As the population topology is determined in part by the landscape configuration, I argue that it should play a more prominent role in landscape genetics. Making use of existing literature and theoretical examples, I discuss how population topology can influence results in landscape genetic studies and how it can be taken into account to improve the accuracy of these results. In support of my arguments, I have performed a literature review of landscape genetic studies published during the first half of 2015 as well as several computer simulations of gene flow between populations. First, I argue why one should carefully consider which population pairs should be included in link-based analyses. Second, I discuss several ways in which the population topology can be incorporated in response and explanatory variables. Third, I outline why it is important to sample populations in such a way that a good representation of the population topology is obtained. Fourth, I discuss how statistical testing for link-based approaches could be influenced by the population topology. I conclude the article with six recommendations geared toward better incorporating population topology in link-based landscape genetic studies.

Musical rhythm and reading development: does beat processing matter?

PubMed

Ozernov-Palchik, Ola; Patel, Aniruddh D

2018-05-20

There is mounting evidence for links between musical rhythm processing and reading-related cognitive skills, such as phonological awareness. This may be because music and speech are rhythmic: both involve processing complex sound sequences with systematic patterns of timing, accent, and grouping. Yet, there is a salient difference between musical and speech rhythm: musical rhythm is often beat-based (based on an underlying grid of equal time intervals), while speech rhythm is not. Thus, the role of beat-based processing in the reading-rhythm relationship is not clear. Is there is a distinct relation between beat-based processing mechanisms and reading-related language skills, or is the rhythm-reading link entirely due to shared mechanisms for processing nonbeat-based aspects of temporal structure? We discuss recent evidence for a distinct link between beat-based processing and early reading abilities in young children, and suggest experimental designs that would allow one to further methodically investigate this relationship. We propose that beat-based processing taps into a listener's ability to use rich contextual regularities to form predictions, a skill important for reading development. © 2018 New York Academy of Sciences.

Steps in Moving Evidence-Based Health Informatics from Theory to Practice.

PubMed

Rigby, Michael; Magrabi, Farah; Scott, Philip; Doupi, Persephone; Hypponen, Hannele; Ammenwerth, Elske

2016-10-01

To demonstrate and promote the importance of applying a scientific process to health IT design and implementation, and of basing this on research principles and techniques. A review by international experts linked to the IMIA Working Group on Technology Assessment and Quality Development. Four approaches are presented, linking to the creation of national professional expectations, adherence to research-based standards, quality assurance approaches to ensure safety, and scientific measurement of impact. Solely marketing- and aspiration-based approaches to health informatics applications are no longer ethical or acceptable when scientifically grounded evidence-based approaches are available and in use.

Realization of 10 GHz minus 30dB on-chip micro-optical links with Si-Ge RF bi-polar technology

NASA Astrophysics Data System (ADS)

Ogudo, Kingsley A.; Snyman, Lukas W.; Polleux, Jean-Luc; Viana, Carlos; Tegegne, Zerihun

2014-06-01

Si Avalanche based LEDs technology has been developed in the 650 -850nm wavelength regime [1, 2]. Correspondingly, small micro-dimensioned detectors with pW/μm2 sensitivity have been developed for the same wavelength range utilizing Si-Ge detector technology with detection efficiencies of up to 0.85, and with a transition frequencies of up to 80 GHz [3] A series of on-chip optical links of 50 micron length, utilizing 650 - 850 nm propagation wavelength have been designed and realized, utilizing a Si Ge radio frequency bipolar process. Micron dimensioned optical sources, waveguides and detectors were all integrated on the same chip to form a complete optical link on-chip. Avalanche based Si LEDs (Si Av LEDs), Schottky contacting, TEOS densification strategies, silicon nitride based waveguides, and state of the art Si-Ge bipolar detector technologies were used as key design strategies. Best performances show optical coupling from source to detector of up to 10GHz and - 40dBm total optical link budget loss with a potential transition frequency coupling of up to 40GHz utilizing Si Ge based LEDs. The technology is particularly suitable for application as on-chip optical links, optical MEMS and MOEMS, as well as for optical interconnects utilizing low loss, side surface, waveguide- to-optical fiber coupling. Most particularly is one of our designed waveguide which have a good core axis alignment with the optical source and yield 10GHz -30dB on-chip micro-optical links as shown in Fig 9 (c). The technology as developed has been appropriately IP protected.

LinkEHR-Ed: a multi-reference model archetype editor based on formal semantics.

PubMed

Maldonado, José A; Moner, David; Boscá, Diego; Fernández-Breis, Jesualdo T; Angulo, Carlos; Robles, Montserrat

2009-08-01

To develop a powerful archetype editing framework capable of handling multiple reference models and oriented towards the semantic description and standardization of legacy data. The main prerequisite for implementing tools providing enhanced support for archetypes is the clear specification of archetype semantics. We propose a formalization of the definition section of archetypes based on types over tree-structured data. It covers the specialization of archetypes, the relationship between reference models and archetypes and conformance of data instances to archetypes. LinkEHR-Ed, a visual archetype editor based on the former formalization with advanced processing capabilities that supports multiple reference models, the editing and semantic validation of archetypes, the specification of mappings to data sources, and the automatic generation of data transformation scripts, is developed. LinkEHR-Ed is a useful tool for building, processing and validating archetypes based on any reference model.

Image fusion algorithm based on energy of Laplacian and PCNN

NASA Astrophysics Data System (ADS)

Li, Meili; Wang, Hongmei; Li, Yanjun; Zhang, Ke

2009-12-01

Owing to the global coupling and pulse synchronization characteristic of pulse coupled neural networks (PCNN), it has been proved to be suitable for image processing and successfully employed in image fusion. However, in almost all the literatures of image processing about PCNN, linking strength of each neuron is assigned the same value which is chosen by experiments. This is not consistent with the human vision system in which the responses to the region with notable features are stronger than that to the region with nonnotable features. It is more reasonable that notable features, rather than the same value, are employed to linking strength of each neuron. As notable feature, energy of Laplacian (EOL) is used to obtain the value of linking strength in PCNN in this paper. Experimental results demonstrate that the proposed algorithm outperforms Laplacian-based, wavelet-based, PCNN -based fusion algorithms.

Frequency comb-based multiple-access ultrastable frequency dissemination with 7 × 10(-17) instability.

PubMed

Zhang, Shuangyou; Zhao, Jianye

2015-01-01

In this letter, we demonstrate frequency-comb-based multiple-access ultrastable frequency dissemination over a 10-km single-mode fiber link. First, we synchronize optical pulse trains from an Er-fiber frequency comb to the remote site by using a simple and robust phase-conjugate stabilization method. The fractional frequency-transfer instability at the remote site is 2.6×10(-14) and 4.9×10(-17) for averaging times of 1 and 10,000 s, respectively. Then, we reproduce the harmonic of the repetition rate from the disseminated optical pulse trains at an arbitrary point along the fiber link to test comb-based multiple-access performance, and demonstrate frequency instability of 4×10(-14) and 7×10(-17) at 1 and 10,000 s averaging time, respectively. The proposed comb-based multiple-access frequency dissemination can easily achieve highly stable wideband microwave extraction along the whole link.

Polymeric electrolytes based on hydrosilyation reactions

DOEpatents

Kerr, John Borland [Oakland, CA; Wang, Shanger [Fairfield, CA; Hou, Jun [Painted Post, NY; Sloop, Steven Edward [Berkeley, CA; Han, Yong Bong [Berkeley, CA; Liu, Gao [Oakland, CA

2006-09-05

New polymer electrolytes were prepared by in situ cross-linking of allyl functional polymers based on hydrosilation reaction using a multifunctional silane cross-linker and an organoplatinum catalyst. The new cross-linked electrolytes are insoluble in organic solvent and show much better mechanical strength. In addition, the processability of the polymer electrolyte is maintained since the casting is finished well before the gel formation.

Interdisciplinary Education and Critical Thinking in Religion and History: The Delivery of Two "Content-Based" Linked Courses

ERIC Educational Resources Information Center

McDougall, Roseanne; LaMonica, Jeffrey

2007-01-01

Primary sources in religion and history enable first year university students to connect "content-based" linked courses in the core curriculum. Fifty-four first year university students in three separate pairs of courses worked in teams to present oral critical reports on texts related to the Reformation, the Enlightenment, and the…

Links for Academic Learning (LAL): A Conceptual Model for Investigating Alignment of Alternate Assessments Based on Alternate Achievement Standards

ERIC Educational Resources Information Center

Flowers, Claudia; Wakeman, Shawnee; Browder, Diane M.; Karvonen, Meagan

2009-01-01

This article describes an alignment procedure, called Links for Academic Learning (LAL), for examining the degree of alignment of alternate assessments based on alternate achievement standards (AA-AAS) to grade-level content standards and instruction. Although some of the alignment criteria are similar to those used in general education…

Force reflecting hand controller

NASA Technical Reports Server (NTRS)

Mcaffee, Douglas A. (Inventor); Snow, Edward R. (Inventor); Townsend, William T. (Inventor)

1993-01-01

A universal input device for interfacing a human operator with a slave machine such as a robot or the like includes a plurality of serially connected mechanical links extending from a base. A handgrip is connected to the mechanical links distal from the base such that a human operator may grasp the handgrip and control the position thereof relative to the base through the mechanical links. A plurality of rotary joints is arranged to connect the mechanical links together to provide at least three translational degrees of freedom and at least three rotational degrees of freedom of motion of the handgrip relative to the base. A cable and pulley assembly for each joint is connected to a corresponding motor for transmitting forces from the slave machine to the handgrip to provide kinesthetic feedback to the operator and for producing control signals that may be transmitted from the handgrip to the slave machine. The device gives excellent kinesthetic feedback, high-fidelity force/torque feedback, a kinematically simple structure, mechanically decoupled motion in all six degrees of freedom, and zero backlash. The device also has a much larger work envelope, greater stiffness and responsiveness, smaller stowage volume, and better overlap of the human operator's range of motion than previous designs.

Circuit-level simulation of transistor lasers and its application to modelling of microwave photonic links

NASA Astrophysics Data System (ADS)

Iezekiel, Stavros; Christou, Andreas

2015-03-01

Equivalent circuit models of a transistor laser are used to investigate the suitability of this relatively new device for analog microwave photonic links. The three-terminal nature of the device enables transistor-based circuit design techniques to be applied to optoelectronic transmitter design. To this end, we investigate the application of balanced microwave amplifier topologies in order to enable low-noise links to be realized with reduced intermodulation distortion and improved RF impedance matching compared to conventional microwave photonic links.

Influence of an externally modulated photonic link on a microwave communications system

NASA Technical Reports Server (NTRS)

Yao, X. S.; Maleki, L.

1994-01-01

We analyze the influence of an externally modulated photonic link on the performance of a microwave communications system. From the analysis, we deduce limitations on the photocurrent, magnitude of the relaxation oscillation noise of the laser, third-order intercept point of the preamplifier, and other parameters in order for the photonic link to function according to the system specifications. Based on this, we outline a procedure for designing a photonic link that can be integrated in a system with minimal performance degradation.

Reversible Thermoset Adhesives

NASA Technical Reports Server (NTRS)

Mac Murray, Benjamin C. (Inventor); Tong, Tat H. (Inventor); Hreha, Richard D. (Inventor)

2016-01-01

Embodiments of a reversible thermoset adhesive formed by incorporating thermally-reversible cross-linking units and a method for making the reversible thermoset adhesive are provided. One approach to formulating reversible thermoset adhesives includes incorporating dienes, such as furans, and dienophiles, such as maleimides, into a polymer network as reversible covalent cross-links using Diels Alder cross-link formation between the diene and dienophile. The chemical components may be selected based on their compatibility with adhesive chemistry as well as their ability to undergo controlled, reversible cross-linking chemistry.

Advanced GPS-Based Time Link Calibration with PTB’s New GPS Calibration Setup

DTIC Science & Technology

2010-11-01

the BIPM to the Ku-band TWSTFT link. A deviation of 3.7 ns compared to the 2008 result was found. INTRODUCTION UTC generation and...adjustment made earlier by the BIPM to the Ku-band TWSTFT link. A deviation of 3.7 ns compared to the 2008 result was found. 15. SUBJECT TERMS 16...Frequency Transfer ( TWSTFT ) were in operation, with signals exchanged in X-band and in Ku-band, respectively. The links were repeatedly calibrated using

Geoscientific Vocabularies and Linked Data at The British Geological Survey - progress and pragmatism

NASA Astrophysics Data System (ADS)

McCormick, T.; Heaven, R.

2013-12-01

The British Geological Survey makes extensive use of controlled vocabularies to promote standardisation and interoperability between its databases and other digital information systems. Many of our vocabularies are published and searchable at http://www.bgs.ac.uk/data/vocabularies/home.html/. There is a movement to ';open up' government data in both the US and UK. In the UK this is promoted by data.gov.uk. Some view linked data as the best way to share and connect disparate data, information and knowledge, in order to develop a ';Web of Data'. Linked data facilitate connections between data sets, and lower the barriers to accessing data that must otherwise be discovered and exploited using other methods. Recently there has been a rapid increase in the rate of publication of linked data, this increase currently being estimated at 300% per year. In the past 2 years we have undertaken a pilot study to publish some of our authoritative vocabularies as linked data. This study has focussed primarily on publishing BGS' 1:625 000 scale geologic map data for the UK, supported by development of linked data sets for: Earth materials - based on the BGS Rock Classification Scheme; lithostratigraphy - based on the BGS Lexicon of Named Rock Units; and geochronology - based on the International Commission on Stratigraphy. The BGS linked data sets are published at data.bgs.ac.uk. We have learned a number of lessons about the potential and limitations of linked data and associated technologies. We do not envisage SPARQL endpoints being the primary route for public access to linked data because the user would require technical knowledge of the data structure, and because it can be a security threat. Rather, SPARQL may lie behind a user-friendly API. Federated SPARQL queries that can interrogate distributed data sources are in reality too slow, and in practise the data sets would likely be combined in a single store. The data sets in our pilot study are all reasonably static and we solve performance and security issues by serving the linked data as pre-generated static files in a range of formats rather than using a triple-store. This also allows the data to be indexed by search engines. Wherever possible it is good practice to use predicates from well-known published sources, for example RDFS, SKOS, or Dublin Core, in preference to inventing new ones. This promotes re-use of the linked data by as many potential users as possible. Linked data do not directly address logical inference, which is supposed to be one of the aims of the ';Semantic Web'. This sort of ';calculating with knowledge' must be implemented using additional, possibly human-based rather than mechanical, reasoning. Linked data come with all the same issues surrounding provenance and authority of the data that any web resource is subject to. There are issues surrounding versioning and permanence of URIs. Our work on publishing BGS' vocabularies as linked data is proceeding in parallel with our work with the Commission of Geoscience Information (CGI) Geoscience Terminology Working Group which is jointly developing multilingual vocabularies in range of knowledge domains.

A risk assessment method for multi-site damage

NASA Astrophysics Data System (ADS)

Millwater, Harry Russell, Jr.

This research focused on developing probabilistic methods suitable for computing small probabilities of failure, e.g., 10sp{-6}, of structures subject to multi-site damage (MSD). MSD is defined as the simultaneous development of fatigue cracks at multiple sites in the same structural element such that the fatigue cracks may coalesce to form one large crack. MSD is modeled as an array of collinear cracks with random initial crack lengths with the centers of the initial cracks spaced uniformly apart. The data used was chosen to be representative of aluminum structures. The structure is considered failed whenever any two adjacent cracks link up. A fatigue computer model is developed that can accurately and efficiently grow a collinear array of arbitrary length cracks from initial size until failure. An algorithm is developed to compute the stress intensity factors of all cracks considering all interaction effects. The probability of failure of two to 100 cracks is studied. Lower bounds on the probability of failure are developed based upon the probability of the largest crack exceeding a critical crack size. The critical crack size is based on the initial crack size that will grow across the ligament when the neighboring crack has zero length. The probability is evaluated using extreme value theory. An upper bound is based on the probability of the maximum sum of initial cracks being greater than a critical crack size. A weakest link sampling approach is developed that can accurately and efficiently compute small probabilities of failure. This methodology is based on predicting the weakest link, i.e., the two cracks to link up first, for a realization of initial crack sizes, and computing the cycles-to-failure using these two cracks. Criteria to determine the weakest link are discussed. Probability results using the weakest link sampling method are compared to Monte Carlo-based benchmark results. The results indicate that very small probabilities can be computed accurately in a few minutes using a Hewlett-Packard workstation.

A method for estimating the mass properties of a manipulator by measuring the reaction moments at its base

NASA Technical Reports Server (NTRS)

West, Harry; Papadopoulos, Evangelos; Dubowsky, Steven; Cheah, Hanson

1989-01-01

Emulating on earth the weightlessness of a manipulator floating in space requires knowledge of the manipulator's mass properties. A method for calculating these properties by measuring the reaction forces and moments at the base of the manipulator is described. A manipulator is mounted on a 6-DOF sensor, and the reaction forces and moments at its base are measured for different positions of the links as well as for different orientations of its base. A procedure is developed to calculate from these measurements some combinations of the mass properties. The mass properties identified are not sufficiently complete for computed torque and other dynamic control techniques, but do allow compensation for the gravitational load on the links, and for simulation of weightless conditions on a space emulator. The algorithm has been experimentally demonstrated on a PUMA 260 and used to measure the independent combinations of the 16 mass parameters of the base and three proximal links.

Development of CCSDS DCT to Support Spacecraft Dynamic Events

NASA Technical Reports Server (NTRS)

Sidhwa, Anahita F

2011-01-01

This report discusses the development of Consultative Committee for Space Data Systems (CCSDS) Design Control Table (DCT) to support spacecraft dynamic events. The Consultative Committee for Space Data Systems (CCSDS) Design Control Table (DCT) is a versatile link calculation tool to analyze different kinds of radio frequency links. It started out as an Excel-based program, and is now being evolved into a Mathematica-based link analysis tool. The Mathematica platform offers a rich set of advanced analysis capabilities, and can be easily extended to a web-based architecture. Last year the CCSDS DCT's for the uplink, downlink, two-way, and ranging models were developed as well as the corresponding input and output interfaces. Another significant accomplishment is the integration of the NAIF SPICE library into the Mathematica computation platform.

Power Quality Improvement by Unified Power Quality Conditioner Based on CSC Topology Using Synchronous Reference Frame Theory

PubMed Central

Dharmalingam, Rajasekaran; Dash, Subhransu Sekhar; Senthilnathan, Karthikrajan; Mayilvaganan, Arun Bhaskar; Chinnamuthu, Subramani

2014-01-01

This paper deals with the performance of unified power quality conditioner (UPQC) based on current source converter (CSC) topology. UPQC is used to mitigate the power quality problems like harmonics and sag. The shunt and series active filter performs the simultaneous elimination of current and voltage problems. The power fed is linked through common DC link and maintains constant real power exchange. The DC link is connected through the reactor. The real power supply is given by the photovoltaic system for the compensation of power quality problems. The reference current and voltage generation for shunt and series converter is based on phase locked loop and synchronous reference frame theory. The proposed UPQC-CSC design has superior performance for mitigating the power quality problems. PMID:25013854

Power quality improvement by unified power quality conditioner based on CSC topology using synchronous reference frame theory.

PubMed

Dharmalingam, Rajasekaran; Dash, Subhransu Sekhar; Senthilnathan, Karthikrajan; Mayilvaganan, Arun Bhaskar; Chinnamuthu, Subramani

2014-01-01

This paper deals with the performance of unified power quality conditioner (UPQC) based on current source converter (CSC) topology. UPQC is used to mitigate the power quality problems like harmonics and sag. The shunt and series active filter performs the simultaneous elimination of current and voltage problems. The power fed is linked through common DC link and maintains constant real power exchange. The DC link is connected through the reactor. The real power supply is given by the photovoltaic system for the compensation of power quality problems. The reference current and voltage generation for shunt and series converter is based on phase locked loop and synchronous reference frame theory. The proposed UPQC-CSC design has superior performance for mitigating the power quality problems.

Deep Space Quantum Link

NASA Astrophysics Data System (ADS)

Mohageg, M.; Strekalov, D.; Dolinar, S.; Shaw, M.; Yu, N.

2018-02-01

The Deep Space Quantum Link will test the effects of gravity on quantum systems, test the non-locality of quantum states at deep space distances, and perform long distance quantum teleportation to an Earth-based receiver.

Cross-linked polyelectrolyte for direct methanol fuel cells applications based on a novel sulfonated cross-linker

NASA Astrophysics Data System (ADS)

Li, Mingyu; Zhang, Gang; Xu, Shuai; Zhao, Chengji; Han, Miaomiao; Zhang, Liyuan; Jiang, Hao; Liu, Zhongguo; Na, Hui

2014-06-01

A novel type of cross-linked proton exchange membrane of lower methanol permeation and high proton conductivity is prepared, based on a newly synthesized sulfonated cross-linker: carboxyl terminated benzimidazole trimer bearing sulfonic acid groups (s-BI). Compared to membranes cross-linked with non-sulfonated cross-linker (BI), SPEEK/s-BI-n membranes show higher IEC values and proton conductivities. Meanwhile, oxidative stability and mechanical property of SPEEK/s-BI-n membranes are obviously improved. Among SPEEK/s-BI-n membranes, SPEEK/s-BI-2 exhibits high proton conductivity, low swelling ratio (0.122 S cm-1 and 15.2% at 60 °C, respectively) and low methanol permeability coefficient. These results imply that the cross-linked membranes prepared with the newly sulfonated cross-linker are promising for the direct methanol fuel cells (DMFCs) application.

A circular polarization converter based on in-linked loop antenna frequency selective surface

NASA Astrophysics Data System (ADS)

Wang, Shen-Yun; Liu, Wei; Geyi, Wen

2018-06-01

In this paper, we report the design, fabrication and measurement of a circular polarization converter based on an in-linked loop-antenna frequency selective surface. The building unit cell is the in-linked loop-antenna module, which consists of same front and back planar loop antennas in-linked by a pair of through-via holes passing through a sandwiched perforated metal ground plane. The proposed device can achieve transmission polarization conversions from right- or left-handed circularly polarized waves to left- or right-handed ones, respectively, or vice versa. Simulation and experimental results show that it has relative conversion ratio of near unity at resonant frequency and very low Joule insertion loss in the operating frequency band. The proposed circular polarization converter may be applied to wireless systems where circular polarization diversity is needed.

Carbon Nanofiber Incorporated Silica Based Aerogels with Di-Isocyanate Cross-Linking

NASA Technical Reports Server (NTRS)

Vivod, Stephanie L.; Meador, Mary Ann B.; Capadona, Lynn A.; Sullivan, Roy M.; Ghosn, Louis J.; Clark, Nicholas; McCorkle, Linda

2008-01-01

Lightweight materials with excellent thermal insulating properties are highly sought after for a variety of aerospace and aeronautic applications. (1) Silica based aerogels with their high surface area and low relative densities are ideal for applications in extreme environments such as insulators for the Mars Rover battery. (2) However, the fragile nature of aerogel monoliths prevents their widespread use in more down to earth applications. We have shown that the fragile aerogel network can be cross-linked with a di-isocyanate via amine decorated surfaces to form a conformal coating. (3) This coating reinforces the neck regions between secondary silica particles and significantly strengthens the aerogels with only a small effect on density or porosity. Scheme 1 depicts the cross-linking reaction with the di-isocyanate and exhibits the stages that result in polymer cross-linked aerogel monoliths.

Models, Strategies, and Tools: Theory in Implementing Evidence-Based Findings into Health Care Practice

PubMed Central

Sales, Anne; Smith, Jeffrey; Curran, Geoffrey; Kochevar, Laura

2006-01-01

This paper presents a case for careful consideration of theory in planning to implement evidence-based practices into clinical care. As described, theory should be tightly linked to strategic planning through careful choice or creation of an implementation framework. Strategies should be linked to specific interventions and/or intervention components to be implemented, and the choice of tools should match the interventions and overall strategy, linking back to the original theory and framework. The thesis advanced is that in most studies where there is an attempt to implement planned change in clinical processes, theory is used loosely. An example of linking theory to intervention design is presented from a Mental Health Quality Enhancement Research Initiative effort to increase appropriate use of antipsychotic medication among patients with schizophrenia in the Veterans Health Administration. PMID:16637960

Models, strategies, and tools. Theory in implementing evidence-based findings into health care practice.

PubMed

Sales, Anne; Smith, Jeffrey; Curran, Geoffrey; Kochevar, Laura

2006-02-01

This paper presents a case for careful consideration of theory in planning to implement evidence-based practices into clinical care. As described, theory should be tightly linked to strategic planning through careful choice or creation of an implementation framework. Strategies should be linked to specific interventions and/or intervention components to be implemented, and the choice of tools should match the interventions and overall strategy, linking back to the original theory and framework. The thesis advanced is that in most studies where there is an attempt to implement planned change in clinical processes, theory is used loosely. An example of linking theory to intervention design is presented from a Mental Health Quality Enhancement Research Initiative effort to increase appropriate use of antipsychotic medication among patients with schizophrenia in the Veterans Health Administration.

Noisy scale-free networks

NASA Astrophysics Data System (ADS)

Scholz, Jan; Dejori, Mathäus; Stetter, Martin; Greiner, Martin

2005-05-01

The impact of observational noise on the analysis of scale-free networks is studied. Various noise sources are modeled as random link removal, random link exchange and random link addition. Emphasis is on the resulting modifications for the node-degree distribution and for a functional ranking based on betweenness centrality. The implications for estimated gene-expressed networks for childhood acute lymphoblastic leukemia are discussed.

An Architecture Based on Linked Data Technologies for the Integration and Reuse of OER in MOOCs Context

ERIC Educational Resources Information Center

Piedra, Nelson; Chicaiza, Janneth Alexandra; López, Jorge; Tovar, Edmundo

2014-01-01

The Linked Data initiative is considered as one of the most effective alternatives for creating global shared information spaces, it has become an interesting approach for discovering and enriching open educational resources data, as well as achieving semantic interoperability and re-use between multiple OER repositories. The notion of Linked Data…

From Many Records to One Graph: Heterogeneity Conflicts in the Linked Data Restructuring Cycle

ERIC Educational Resources Information Center

Tallerås, Kim

2013-01-01

Introduction: During the last couple of years the library community has developed a number of comprehensive metadata standardization projects inspired by the idea of linked data, such as the BIBFRAME model. Linked data is a set of best practice principles of publishing and exposing data on the Web utilizing a graph based data model powered with…

Cotargeting the lncRNA-PIP3 Interaction and AKT/PI3K Signaling Axis: A Novel Paradigm for Treating Triple-Negative Breast Cancer

DTIC Science & Technology

2017-10-01

Model Core Facility at MD Anderson has generated a genomic deletion of LINK-A using CRISPR /Cas9 technology based on collaboration. The single...Generation of LINK-A deletion mutant using CRISPR /Cas9 technology. A, Illustration of genomic deletion region of LINK-A (Chr1: 238644075-238644134

A new mutually reinforcing network node and link ranking algorithm

PubMed Central

Wang, Zhenghua; Dueñas-Osorio, Leonardo; Padgett, Jamie E.

2015-01-01

This study proposes a novel Normalized Wide network Ranking algorithm (NWRank) that has the advantage of ranking nodes and links of a network simultaneously. This algorithm combines the mutual reinforcement feature of Hypertext Induced Topic Selection (HITS) and the weight normalization feature of PageRank. Relative weights are assigned to links based on the degree of the adjacent neighbors and the Betweenness Centrality instead of assigning the same weight to every link as assumed in PageRank. Numerical experiment results show that NWRank performs consistently better than HITS, PageRank, eigenvector centrality, and edge betweenness from the perspective of network connectivity and approximate network flow, which is also supported by comparisons with the expensive N-1 benchmark removal criteria based on network efficiency. Furthermore, it can avoid some problems, such as the Tightly Knit Community effect, which exists in HITS. NWRank provides a new inexpensive way to rank nodes and links of a network, which has practical applications, particularly to prioritize resource allocation for upgrade of hierarchical and distributed networks, as well as to support decision making in the design of networks, where node and link importance depend on a balance of local and global integrity. PMID:26492958

Design and evaluation of an advanced air-ground data-link system for air traffic control

NASA Technical Reports Server (NTRS)

Denbraven, Wim

1992-01-01

The design and evaluation of the ground-based portion of an air-ground data-link system for air traffic control (ATC) are described. The system was developed to support the 4D Aircraft/ATC Integration Study, a joint simulation experiment conducted at NASA's Ames and Langley Research Centers. The experiment focused on airborne and ground-based procedures for handling aircraft equipped with a 4D-Flight Management System (FMS) and the system requirements needed to ensure conflict-free traffic flow. The Center/TRACON Automation System (CTAS) at Ames was used for the ATC part of the experiment, and the 4D-FMS-equipped aircraft was simulated by the Transport Systems Research Vehicle (TSRV) simulator at Langley. The data-link system supported not only conventional ATC communications, but also the communications needed to accommodate the 4D-FMS capabilities of advanced aircraft. Of great significance was the synergism gained from integrating the data link with CTAS. Information transmitted via the data link was used to improve the monitoring and analysis capability of CTAS without increasing controller input workload. Conversely, CTAS was used to anticipate and create prototype messages, thus reducing the workload associated with the manual creation of data-link messages.

Frequency-tuning input-shaped manifold-based switching control for underactuated space robot equipped with flexible appendages

NASA Astrophysics Data System (ADS)

Kojima, Hirohisa; Ieda, Shoko; Kasai, Shinya

2014-08-01

Underactuated control problems, such as the control of a space robot without actuators on the main body, have been widely investigated. However, few studies have examined attitude control problems of underactuated space robots equipped with a flexible appendage, such as solar panels. In order to suppress vibration in flexible appendages, a zero-vibration input-shaping technique was applied to the link motion of an underactuated planar space robot. However, because the vibrational frequency depends on the link angles, simple input-shaping control methods cannot sufficiently suppress the vibration. In this paper, the dependency of the vibrational frequency on the link angles is measured experimentally, and the time-delay interval of the input shaper is then tuned based on the frequency estimated from the link angles. The proposed control method is referred to as frequency-tuning input-shaped manifold-based switching control (frequency-tuning IS-MBSC). The experimental results reveal that frequency-tuning IS-MBSC is capable of controlling the link angles and the main body attitude to maintain the target angles and that the vibration suppression performance of the proposed frequency-tuning IS-MBSC is better than that of a non-tuning IS-MBSC, which does not take the frequency variation into consideration.

Superlight Adsorbent Sponges Based on Graphene Oxide Cross-Linked with Poly(vinyl alcohol) for Continuous Flow Adsorption.

PubMed

Li, Xianfeng; Liu, Tao; Wang, Daohui; Li, Qing; Liu, Zhen; Li, Nana; Zhang, Yufeng; Xiao, Changfa; Feng, Xianshe

2018-06-12

In this study, superlight adsorbent sponges (bulk density 0.016-0.049 g·cm -3 ) were developed based on graphene oxide (GO) cross-linked with poly(vinyl alcohol) (PVA). The interlayer spacing of the GO nanosheets was increased by the insertion of PVA, and good mechanical integrity was attained by the cross-linked structure. They showed excellent continuous flow adsorption capacity (CFAC) when methylene blue (MB) was used as a model contaminant; a water flux of 396 L·m -2 ·h -1 through a 2 cm thick adsorbent sponge was achieved at a hydraulic head of only 10 cm water, with an almost complete retention of MB. They corresponded to a water permeability of 4.0 × 10 5 L·m -2 ·h -1 ·MPa -1 , which was several orders of magnitudes higher than GO-based membranes for similar applications reported in the literature. The GO nanosheets were completely immobilized in the sponge by cross-linking with PVA, and thus, there was no GO nanoparticle leaching or flushing out into the treated permeate water, which was another advantage over direct use of GO powders in water treatment. Because of the high water permeability and CFAC, the cross-linked GO/PVA sponges have a great potential for wastewater treatment.

Core dimensions of personality broadly account for the link from perceived social support to symptoms of depression and anxiety.

PubMed

Lewis, Gary J; Bates, Timothy C; Posthuma, Danielle; Polderman, Tinca J C

2014-08-01

Specific personality traits and poor social support are risk factors for anxiety and depression. Little work, however, has considered the effects of social support and personality on these aspects of psychopathology simultaneously. We examined whether perceived social support mediates the effects of core personality domains on symptoms of anxiety and depression. Measures of personality (based on the Five-Factor Model [FFM]), perceived social support, and symptoms of depression and anxiety were collected in a large Dutch adult population-based sample (n = 555), and, except for depression symptoms, in an independent U.S. adult population-based sample (n = 511). Path modeling was used to test the effects of FFM traits on symptoms of depression and anxiety, with and without the mediation of perceived social support. Social support showed no link to symptoms of anxiety and only modest links to symptoms of depression when controlling for the FFM traits. Neuroticism had the strongest effect on symptoms of both depression and anxiety, with Extraversion also showing links to symptoms of depression. Social support has limited influence on symptoms of depression, and no effects on anxiety, over and above the effects of personality. Links between social support and anxiety/depression may largely reflect influences of Neuroticism and Extraversion. © 2013 Wiley Periodicals, Inc.

Linking Quality and Spending to Measure Value for People with Serious Illness.

PubMed

Ryan, Andrew M; Rodgers, Phillip E

2018-03-01

Healthcare payment is rapidly evolving to reward value by measuring and paying for quality and spending performance. Rewarding value for the care of seriously ill patients presents unique challenges. To evaluate the state of current efforts to measure and reward value for the care of seriously ill patients. We performed a PubMed search of articles related to (1) measures of spending for people with serious illness and (2) linking spending and quality measures and rewarding performance for the care of people with serious illness. We limited our search to U.S.-based studies published in English between January 1, 1960, and March 31, 2017. We supplemented this search by identifying public programs and other known initiatives that linked quality and spending for the seriously ill and extracted key program elements. Our search related to linking spending and quality measures and rewarding performance for the care of people with serious illness yielded 277 articles. We identified three current public programs that currently link measures of quality and spending-or are likely to within the next few years-the Oncology Care Model; the Comprehensive End-Stage Renal Disease Model; and Home Health Value-Based Purchasing. Models that link quality and spending consist of four core components: (1) measuring quality, (2) measuring spending, (3) the payment adjustment model, and (4) the linking/incentive model. We found that current efforts to reward value for seriously ill patients are targeted for specific patient populations, do not broadly encourage the use of palliative care, and have not closely aligned quality and spending measures related to palliative care. We develop recommendations for policymakers and stakeholders about how measures of spending and quality can be balanced in value-based payment programs.

Linking Quality and Spending to Measure Value for People with Serious Illness

PubMed Central

Rodgers, Phillip E.

2018-01-01

Abstract Background: Healthcare payment is rapidly evolving to reward value by measuring and paying for quality and spending performance. Rewarding value for the care of seriously ill patients presents unique challenges. Objective: To evaluate the state of current efforts to measure and reward value for the care of seriously ill patients. Design: We performed a PubMed search of articles related to (1) measures of spending for people with serious illness and (2) linking spending and quality measures and rewarding performance for the care of people with serious illness. We limited our search to U.S.-based studies published in English between January 1, 1960, and March 31, 2017. We supplemented this search by identifying public programs and other known initiatives that linked quality and spending for the seriously ill and extracted key program elements. Results: Our search related to linking spending and quality measures and rewarding performance for the care of people with serious illness yielded 277 articles. We identified three current public programs that currently link measures of quality and spending—or are likely to within the next few years—the Oncology Care Model; the Comprehensive End-Stage Renal Disease Model; and Home Health Value-Based Purchasing. Models that link quality and spending consist of four core components: (1) measuring quality, (2) measuring spending, (3) the payment adjustment model, and (4) the linking/incentive model. We found that current efforts to reward value for seriously ill patients are targeted for specific patient populations, do not broadly encourage the use of palliative care, and have not closely aligned quality and spending measures related to palliative care. Conclusions: We develop recommendations for policymakers and stakeholders about how measures of spending and quality can be balanced in value-based payment programs. PMID:29091529

Data cleaning and management protocols for linked perinatal research data: a good practice example from the Smoking MUMS (Maternal Use of Medications and Safety) Study.

PubMed

Tran, Duong Thuy; Havard, Alys; Jorm, Louisa R

2017-07-11

Data cleaning is an important quality assurance in data linkage research studies. This paper presents the data cleaning and preparation process for a large-scale cross-jurisdictional Australian study (the Smoking MUMS Study) to evaluate the utilisation and safety of smoking cessation pharmacotherapies during pregnancy. Perinatal records for all deliveries (2003-2012) in the States of New South Wales (NSW) and Western Australia were linked to State-based data collections including hospital separation, emergency department and death data (mothers and babies) and congenital defect notifications (babies in NSW) by State-based data linkage units. A national data linkage unit linked pharmaceutical dispensing data for the mothers. All linkages were probabilistic. Twenty two steps assessed the uniqueness of records and consistency of items within and across data sources, resolved discrepancies in the linkages between units, and identified women having records in both States. State-based linkages yielded a cohort of 783,471 mothers and 1,232,440 babies. Likely false positive links relating to 3703 mothers were identified. Corrections of baby's date of birth and age, and parity were made for 43,578 records while 1996 records were flagged as duplicates. Checks for the uniqueness of the matches between State and national linkages detected 3404 ID clusters, suggestive of missed links in the State linkages, and identified 1986 women who had records in both States. Analysis of content data can identify inaccurate links that cannot be detected by data linkage units that have access to personal identifiers only. Perinatal researchers are encouraged to adopt the methods presented to ensure quality and consistency among studies using linked administrative data.

ROMP-based thermosetting polymers from modified castor oil with various cross-linking agents

NASA Astrophysics Data System (ADS)

Ding, Rui

Polymers derived from bio-renewable resources are finding an increase in global demand. In addition, polymers with distinctive functionalities are required in certain advanced fields, such as aerospace and civil engineering. In an attempt to meet both these needs, the goal of this work aims to develop a range of bio-based thermosetting matrix polymers for potential applications in multifunctional composites. Ring-opening metathesis polymerization (ROMP), which recently has been explored as a powerful method in polymer chemistry, was employed as a unique pathway to polymerize agricultural oil-based reactants. Specifically, a novel norbornyl-functionalized castor oil alcohol (NCA) was investigated to polymerize different cross-linking agents using ROMP. The effects of incorporating dicyclopentadiene (DCPD) and a norbornene-based crosslinker (CL) were systematically evaluated with respect to curing behavior and thermal mechanical properties of the polymers. Isothermal differential scanning calorimetry (DSC) was used to investigate the conversion during cure. Dynamic DSC scans at multiple heating rates revealed conversion-dependent activation energy by Ozawa-Flynn-Wall analysis. The glass transition temperature, storage modulus, and loss modulus for NCA/DCPD and NCA/CL copolymers with different cross-linking agent loading were compared using dynamic mechanical analysis. Cross-link density was examined to explain the very different dynamic mechanical behavior. Mechanical stress-strain curves were developed through tensile test, and thermal stability of the cross-linked polymers was evaluated by thermogravimetric analysis to further investigate the structure-property relationships in these systems.

Synthesis of new kojic acid based unnatural α-amino acid derivatives.

PubMed

Balakrishna, C; Payili, Nagaraju; Yennam, Satyanarayana; Uma Devi, P; Behera, Manoranjan

2015-11-01

An efficient method for the preparation of kojic acid based α-amino acid derivatives by alkylation of glycinate schiff base with bromokojic acids have been described. Using this method, mono as well as di alkylated kojic acid-amino acid conjugates have been prepared. This is the first synthesis of C-linked kojic acid-amino acid conjugate where kojic acid is directly linked to amino acid through a C-C bond. Copyright © 2015 Elsevier Ltd. All rights reserved.

PAM-4 Signaling over VCSELs with 0.13µm CMOS Chip Technology

NASA Astrophysics Data System (ADS)

Cunningham, J. E.; Beckman, D.; Zheng, Xuezhe; Huang, Dawei; Sze, T.; Krishnamoorthy, A. V.

2006-12-01

We present results for VCSEL based links operating PAM-4 signaling using a commercial 0.13µm CMOS technology. We perform a complete link analysis of the Bit Error Rate, Q factor, random and deterministic jitter by measuring waterfall curves versus margins in time and amplitude. We demonstrate that VCSEL based PAM 4 can match or even improve performance over binary signaling under conditions of a bandwidth limited, 100meter multi-mode optical link at 5Gbps. We present the first sensitivity measurements for optical PAM-4 and compare it with binary signaling. Measured benefits are reconciled with information theory predictions.

PAM-4 Signaling over VCSELs with 0.13microm CMOS Chip Technology.

PubMed

Cunningham, J E; Beckman, D; Zheng, Xuezhe; Huang, Dawei; Sze, T; Krishnamoorthy, A V

2006-12-11

We present results for VCSEL based links operating PAM-4 signaling using a commercial 0.13microm CMOS technology. We perform a complete link analysis of the Bit Error Rate, Q factor, random and deterministic jitter by measuring waterfall curves versus margins in time and amplitude. We demonstrate that VCSEL based PAM-4 can match or even improve performance over binary signaling under conditions of a bandwidth limited, 100meter multi-mode optical link at 5Gbps. We present the first sensitivity measurements for optical PAM-4 and compare it with binary signaling. Measured benefits are reconciled with information theory predictions.

Scintillation index and performance analysis of wireless optical links over non-Kolmogorov weak turbulence based on generalized atmospheric spectral model.

PubMed

Cang, Ji; Liu, Xu

2011-09-26

Based on the generalized spectral model for non-Kolmogorov atmospheric turbulence, analytic expressions of the scintillation index (SI) are derived for plane, spherical optical waves and a partially coherent Gaussian beam propagating through non-Kolmogorov turbulence horizontally in the weak fluctuation regime. The new expressions relate the SI to the finite turbulence inner and outer scales, spatial coherence of the source and spectral power-law and then used to analyze the effects of atmospheric condition and link length on the performance of wireless optical communication links. © 2011 Optical Society of America

Design and Development of a Linked Open Data-Based Health Information Representation and Visualization System: Potentials and Preliminary Evaluation

PubMed Central

Kauppinen, Tomi; Keßler, Carsten; Fritz, Fleur

2014-01-01

Background Healthcare organizations around the world are challenged by pressures to reduce cost, improve coordination and outcome, and provide more with less. This requires effective planning and evidence-based practice by generating important information from available data. Thus, flexible and user-friendly ways to represent, query, and visualize health data becomes increasingly important. International organizations such as the World Health Organization (WHO) regularly publish vital data on priority health topics that can be utilized for public health policy and health service development. However, the data in most portals is displayed in either Excel or PDF formats, which makes information discovery and reuse difficult. Linked Open Data (LOD)—a new Semantic Web set of best practice of standards to publish and link heterogeneous data—can be applied to the representation and management of public level health data to alleviate such challenges. However, the technologies behind building LOD systems and their effectiveness for health data are yet to be assessed. Objective The objective of this study is to evaluate whether Linked Data technologies are potential options for health information representation, visualization, and retrieval systems development and to identify the available tools and methodologies to build Linked Data-based health information systems. Methods We used the Resource Description Framework (RDF) for data representation, Fuseki triple store for data storage, and Sgvizler for information visualization. Additionally, we integrated SPARQL query interface for interacting with the data. We primarily use the WHO health observatory dataset to test the system. All the data were represented using RDF and interlinked with other related datasets on the Web of Data using Silk—a link discovery framework for Web of Data. A preliminary usability assessment was conducted following the System Usability Scale (SUS) method. Results We developed an LOD-based health information representation, querying, and visualization system by using Linked Data tools. We imported more than 20,000 HIV-related data elements on mortality, prevalence, incidence, and related variables, which are freely available from the WHO global health observatory database. Additionally, we automatically linked 5312 data elements from DBpedia, Bio2RDF, and LinkedCT using the Silk framework. The system users can retrieve and visualize health information according to their interests. For users who are not familiar with SPARQL queries, we integrated a Linked Data search engine interface to search and browse the data. We used the system to represent and store the data, facilitating flexible queries and different kinds of visualizations. The preliminary user evaluation score by public health data managers and users was 82 on the SUS usability measurement scale. The need to write queries in the interface was the main reported difficulty of LOD-based systems to the end user. Conclusions The system introduced in this article shows that current LOD technologies are a promising alternative to represent heterogeneous health data in a flexible and reusable manner so that they can serve intelligent queries, and ultimately support decision-making. However, the development of advanced text-based search engines is necessary to increase its usability especially for nontechnical users. Further research with large datasets is recommended in the future to unfold the potential of Linked Data and Semantic Web for future health information systems development. PMID:25601195

Design and development of a linked open data-based health information representation and visualization system: potentials and preliminary evaluation.

PubMed

Tilahun, Binyam; Kauppinen, Tomi; Keßler, Carsten; Fritz, Fleur

2014-10-25

Healthcare organizations around the world are challenged by pressures to reduce cost, improve coordination and outcome, and provide more with less. This requires effective planning and evidence-based practice by generating important information from available data. Thus, flexible and user-friendly ways to represent, query, and visualize health data becomes increasingly important. International organizations such as the World Health Organization (WHO) regularly publish vital data on priority health topics that can be utilized for public health policy and health service development. However, the data in most portals is displayed in either Excel or PDF formats, which makes information discovery and reuse difficult. Linked Open Data (LOD)-a new Semantic Web set of best practice of standards to publish and link heterogeneous data-can be applied to the representation and management of public level health data to alleviate such challenges. However, the technologies behind building LOD systems and their effectiveness for health data are yet to be assessed. The objective of this study is to evaluate whether Linked Data technologies are potential options for health information representation, visualization, and retrieval systems development and to identify the available tools and methodologies to build Linked Data-based health information systems. We used the Resource Description Framework (RDF) for data representation, Fuseki triple store for data storage, and Sgvizler for information visualization. Additionally, we integrated SPARQL query interface for interacting with the data. We primarily use the WHO health observatory dataset to test the system. All the data were represented using RDF and interlinked with other related datasets on the Web of Data using Silk-a link discovery framework for Web of Data. A preliminary usability assessment was conducted following the System Usability Scale (SUS) method. We developed an LOD-based health information representation, querying, and visualization system by using Linked Data tools. We imported more than 20,000 HIV-related data elements on mortality, prevalence, incidence, and related variables, which are freely available from the WHO global health observatory database. Additionally, we automatically linked 5312 data elements from DBpedia, Bio2RDF, and LinkedCT using the Silk framework. The system users can retrieve and visualize health information according to their interests. For users who are not familiar with SPARQL queries, we integrated a Linked Data search engine interface to search and browse the data. We used the system to represent and store the data, facilitating flexible queries and different kinds of visualizations. The preliminary user evaluation score by public health data managers and users was 82 on the SUS usability measurement scale. The need to write queries in the interface was the main reported difficulty of LOD-based systems to the end user. The system introduced in this article shows that current LOD technologies are a promising alternative to represent heterogeneous health data in a flexible and reusable manner so that they can serve intelligent queries, and ultimately support decision-making. However, the development of advanced text-based search engines is necessary to increase its usability especially for nontechnical users. Further research with large datasets is recommended in the future to unfold the potential of Linked Data and Semantic Web for future health information systems development.

Bit-error-rate testing of fiber optic data links for MMIC-based phased array antennas

NASA Technical Reports Server (NTRS)

Shalkhauser, K. A.; Kunath, R. R.; Daryoush, A. S.

1990-01-01

The measured bit-error-rate (BER) performance of a fiber optic data link to be used in satellite communications systems is presented and discussed. In the testing, the link was measured for its ability to carry high burst rate, serial-minimum shift keyed (SMSK) digital data similar to those used in actual space communications systems. The fiber optic data link, as part of a dual-segment injection-locked RF fiber optic link system, offers a means to distribute these signals to the many radiating elements of a phased array antenna. Test procedures, experimental arrangements, and test results are presented.

Mach-Zehnder Fiber-Optic Links for ICF Diagnostics

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

Miller, E. K., Hermann, H. W.

2012-11-01

This article describes the operation and evolution of Mach-Zehnder links for single-point detectors in inertial confinement fusion experimental facilities, based on the Gamma Reaction History (GRH) diagnostic at the National Ignition Facility.

Linking science and decision making to promote an ecology for the city: practices and opportunities

Treesearch

Morgan Grove; Daniel L. Childers; Michael Galvin; Sarah J. Hines; Tischa Munoz-Erickson; Erika S. Svendsen

2016-01-01

To promote urban sustainability and resilience, there is an increasing demand for actionable science that links science and decision making based on social–ecological knowledge. Approaches, frameworks, and practices for such actionable science are needed and have only begun to emerge. We propose that approaches based on the co- design and co- production of knowledge...

The Link between Basing Self-Worth on Academics and Student Performance Depends on Domain Identification and Academic Setting

ERIC Educational Resources Information Center

Lawrence, Jason S.; Charbonneau, Joseph

2009-01-01

Two studies showed that the link between how much students base their self-worth on academics and their math performance depends on whether their identification with math was statistically controlled and whether the task measured ability or not. Study 1 showed that, when math identification was uncontrolled and the task was ability-diagnostic,…

Investigation of the Public Library as a Linking Agent to Major Scientific, Educational, Social and Environmental Data Bases. Two-Year Interim Report.

ERIC Educational Resources Information Center

Summit, Roger K.; Firschein, Oscar

Eight public libraries participated in a two-year experiment to investigate the potential of the public library as a "linking agent" between the public and the many machine-readable data bases currently accessible using on line computer terminals. The investigation covered users of the service, impact on the library, conditions for…

Investigation of the Public Library as a Linking Agent to Major Scientific, Educational, Social, and Environmental Data Bases. Final Report.

ERIC Educational Resources Information Center

Lockheed Research Lab., Palo Alto, CA.

The DIALIB Project was a 3-year experiment that investigated the potential of the public library as a "linking agent" between the public and the many machine-readable data bases currently accessible via the telephone using online terminals. The study investigated the following questions: (1) Is online search of use to the patrons of a…

Reconstructing genome-wide regulatory network of E. coli using transcriptome data and predicted transcription factor activities

PubMed Central

2011-01-01

Background Gene regulatory networks play essential roles in living organisms to control growth, keep internal metabolism running and respond to external environmental changes. Understanding the connections and the activity levels of regulators is important for the research of gene regulatory networks. While relevance score based algorithms that reconstruct gene regulatory networks from transcriptome data can infer genome-wide gene regulatory networks, they are unfortunately prone to false positive results. Transcription factor activities (TFAs) quantitatively reflect the ability of the transcription factor to regulate target genes. However, classic relevance score based gene regulatory network reconstruction algorithms use models do not include the TFA layer, thus missing a key regulatory element. Results This work integrates TFA prediction algorithms with relevance score based network reconstruction algorithms to reconstruct gene regulatory networks with improved accuracy over classic relevance score based algorithms. This method is called Gene expression and Transcription factor activity based Relevance Network (GTRNetwork). Different combinations of TFA prediction algorithms and relevance score functions have been applied to find the most efficient combination. When the integrated GTRNetwork method was applied to E. coli data, the reconstructed genome-wide gene regulatory network predicted 381 new regulatory links. This reconstructed gene regulatory network including the predicted new regulatory links show promising biological significances. Many of the new links are verified by known TF binding site information, and many other links can be verified from the literature and databases such as EcoCyc. The reconstructed gene regulatory network is applied to a recent transcriptome analysis of E. coli during isobutanol stress. In addition to the 16 significantly changed TFAs detected in the original paper, another 7 significantly changed TFAs have been detected by using our reconstructed network. Conclusions The GTRNetwork algorithm introduces the hidden layer TFA into classic relevance score-based gene regulatory network reconstruction processes. Integrating the TFA biological information with regulatory network reconstruction algorithms significantly improves both detection of new links and reduces that rate of false positives. The application of GTRNetwork on E. coli gene transcriptome data gives a set of potential regulatory links with promising biological significance for isobutanol stress and other conditions. PMID:21668997

Fragment Linking and Optimization of Inhibitors of the Aspartic Protease Endothiapepsin: Fragment-Based Drug Design Facilitated by Dynamic Combinatorial Chemistry.

PubMed

Mondal, Milon; Radeva, Nedyalka; Fanlo-Virgós, Hugo; Otto, Sijbren; Klebe, Gerhard; Hirsch, Anna K H

2016-08-01

Fragment-based drug design (FBDD) affords active compounds for biological targets. While there are numerous reports on FBDD by fragment growing/optimization, fragment linking has rarely been reported. Dynamic combinatorial chemistry (DCC) has become a powerful hit-identification strategy for biological targets. We report the synergistic combination of fragment linking and DCC to identify inhibitors of the aspartic protease endothiapepsin. Based on X-ray crystal structures of endothiapepsin in complex with fragments, we designed a library of bis-acylhydrazones and used DCC to identify potent inhibitors. The most potent inhibitor exhibits an IC50 value of 54 nm, which represents a 240-fold improvement in potency compared to the parent hits. Subsequent X-ray crystallography validated the predicted binding mode, thus demonstrating the efficiency of the combination of fragment linking and DCC as a hit-identification strategy. This approach could be applied to a range of biological targets, and holds the potential to facilitate hit-to-lead optimization. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

A top-down design methodology and its implementation for VCSEL-based optical links design

NASA Astrophysics Data System (ADS)

Li, Jiguang; Cao, Mingcui; Cai, Zilong

2005-01-01

In order to find the optimal design for a given specification of an optical communication link, an integrated simulation of electronic, optoelectronic, and optical components of a complete system is required. It is very important to be able to simulate at both system level and detailed model level. This kind of model is feasible due to the high potential of Verilog-AMS language. In this paper, we propose an effective top-down design methodology and employ it in the development of a complete VCSEL-based optical links simulation. The principle of top-down methodology is that the development would proceed from the system to device level. To design a hierarchical model for VCSEL based optical links, the design framework is organized in three levels of hierarchy. The models are developed, and implemented in Verilog-AMS. Therefore, the model parameters are fitted to measured data. A sample transient simulation demonstrates the functioning of our implementation. Suggestions for future directions in top-down methodology used for optoelectronic systems technology are also presented.

Inductive power transmission to millimeter-sized biomedical implants using printed spiral coils.

PubMed

Ibrahim, Ahmed; Kiani, Mehdi

2016-08-01

The operation frequency (f) has been a key parameter in optimizing wireless power transmission links for biomedical implants with millimeter (mm) dimensions. This paper studies the feasibility of using printed spiral coils (PSCs) for powering mm-sized implants with high power transmission efficiency (PTE) at different fps. Compared to wire-wound coils (WWCs), using a PSC in the implant side allows batch fabrication on rigid or flexible substrates, which can also be used as a platform for integrating implant components. For powering an implant with 1 mm diameter, located 10 mm inside the tissue, the geometries of transmitter (Tx) and receiver (Rx) PSCs were optimized at different fPs of 50 MHz, 200 MHz, and 500 MHz using a commercial field solver (HFSS). In simulations, PSC- and WWC-based links achieved maximum PTE of 0.13% and 3.3%, and delivered power of 65.7 μW and 720 μW under specific absorption rate (SAR) constraints at the optimal fp of 50 MHz and 100 MHz, respectively, suggesting that the performance of the PSC-based link is significantly inferior to that of the WWC-based link.

Using expert knowledge for test linking.

PubMed

Bolsinova, Maria; Hoijtink, Herbert; Vermeulen, Jorine Adinda; Béguin, Anton

2017-12-01

Linking and equating procedures are used to make the results of different test forms comparable. In the cases where no assumption of random equivalent groups can be made some form of linking design is used. In practice the amount of data available to link the two tests is often very limited due to logistic and security reasons, which affects the precision of linking procedures. This study proposes to enhance the quality of linking procedures based on sparse data by using Bayesian methods which combine the information in the linking data with background information captured in informative prior distributions. We propose two methods for the elicitation of prior knowledge about the difference in difficulty of two tests from subject-matter experts and explain how these results can be used in the specification of priors. To illustrate the proposed methods and evaluate the quality of linking with and without informative priors, an empirical example of linking primary school mathematics tests is presented. The results suggest that informative priors can increase the precision of linking without decreasing the accuracy. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A Figure-of-Merit for Designing High-Performance Inductive Power Transmission Links

PubMed Central

Kiani, Mehdi; Ghovanloo, Maysam

2014-01-01

Power transfer efficiency (PTE) and power delivered to the load (PDL) are two key inductive link design parameters that relate to the power source and driver specs, power loss, transmission range, robustness against misalignment, variations in loading, and interference with other devices. Designers need to strike a delicate balance between these two because designing the link to achieve high PTE will degrade the PDL and vice versa. We are proposing a new figure-of-merit (FoM), which can help designers to find out whether a two-, three-, or four-coil link is appropriate for their particular application and guide them through an iterative design procedure to reach optimal coil geometries based on how they weigh the PTE versus PDL for that application. Three design examples at three different power levels have been presented based on the proposed FoM for implantable microelectronic devices, handheld mobile devices, and electric vehicles. The new FoM suggests that the two-coil links are suitable when the coils are strongly coupled, and a large PDL is needed. Three-coil links are the best when the coils are loosely coupled, the coupling distance varies considerably, and large PDL is necessary. Finally, four-coil links are optimal when the PTE is paramount, the coils are loosely coupled, and their relative distance and alignment are stable. Measurement results support the accuracy of the theoretical design procedure and conclusions. PMID:25382898

A Figure-of-Merit for Designing High-Performance Inductive Power Transmission Links.

PubMed

Kiani, Mehdi; Ghovanloo, Maysam

2012-11-16

Power transfer efficiency (PTE) and power delivered to the load (PDL) are two key inductive link design parameters that relate to the power source and driver specs, power loss, transmission range, robustness against misalignment, variations in loading, and interference with other devices. Designers need to strike a delicate balance between these two because designing the link to achieve high PTE will degrade the PDL and vice versa. We are proposing a new figure-of-merit (FoM), which can help designers to find out whether a two-, three-, or four-coil link is appropriate for their particular application and guide them through an iterative design procedure to reach optimal coil geometries based on how they weigh the PTE versus PDL for that application. Three design examples at three different power levels have been presented based on the proposed FoM for implantable microelectronic devices, handheld mobile devices, and electric vehicles. The new FoM suggests that the two-coil links are suitable when the coils are strongly coupled, and a large PDL is needed. Three-coil links are the best when the coils are loosely coupled, the coupling distance varies considerably, and large PDL is necessary. Finally, four-coil links are optimal when the PTE is paramount, the coils are loosely coupled, and their relative distance and alignment are stable. Measurement results support the accuracy of the theoretical design procedure and conclusions.

Research on Shore-Ship Photonic Link Performance for Two- Frequency-Band Signals

NASA Astrophysics Data System (ADS)

Zuo, Yanqin; Cong, Bo

2016-02-01

Ka and Ku bands links for shore-ship communications suffer limited bandwidth and high loss. In this paper, photonics-based links are proposed and modeled. The principle of phase modulation (PM) is elaborated and analyzed. It is showed that PM can effectively suppress high-order inter-modulation distortion (IMD), reduce the insert loss and improve the reliability of the system.

NASA's Plan for SDLS Testing

NASA Technical Reports Server (NTRS)

Bailey, Brandon

2015-01-01

The Space Data Link Security (SDLS) Protocol is a Consultative Committee for Space Data Systems (CCSDS) standard which extends the known Data Link protocols to secure data being sent over a space link by providing confidentiality and integrity services. This plan outlines the approach by National Aeronautics Space Administration (NASA) in performing testing of the SDLS protocol using a prototype based on an existing NASA missions simulator.

Analysis of an international collaboration for capacity building of human resources for eye care: case study of the college-college VISION 2020 LINK.

PubMed

Mwangi, Nyawira; Zondervan, Marcia; Bascaran, Covadonga

2017-03-14

There is an extreme health workforce shortage in Eastern, Central, and Southern Africa. Shortage of eye care workers impedes effective implementation of prevention of blindness programs. The World Health Organization has identified education, partnership, leadership, financing, and policy as intertwined interventions that are critical to resolving this crisis on the long term. The VISION 2020 LINK between the College of Ophthalmology of Eastern, Central, and Southern Africa and the Royal College of Ophthalmologists in the United Kingdom aims to increase the quantity and quality of eye care training in East, Central, and Southern Africa through a focus on five strategic areas: fellowship examination for ophthalmologists, training the trainers, curriculum development for residents in ophthalmology and ophthalmic clinical officers, continuous professional development (CPD), and mentoring program for young ophthalmologists. This study examined how education and partnership can be linked to improve eye care, through an evaluation of this north-south link based on its own targets and established frameworks to guide north-south links. An exploratory qualitative case study design was used. Twenty-nine link representatives were recruited through purposive sampling and snowballing. Face-to-face interviews were conducted using a semi-structured interview schedule that incorporated the components of a successful link from an existing framework. Documents pertaining to the link were also examined. Thematic analysis was used for data analysis. The findings revealed that the perception to the contribution of the link to eye care in the region is generally positive. Process indicators showed that the targets in three strategic objectives of the link have been achieved. Framework-based evaluation also showed that the link is successful. Mutual learning and development of friendships were the most commonly identified success factors. Inadequate awareness of the link by college members is a key challenge. The study concludes that the link is active and evolving and has achieved most of its targets. Further developments should be directed to influence health system strengthening in Eastern, Central, and Southern Africa more strategically. The study recommends expansion of the scope of collaboration to involve multiple health system building blocks.

Nanomechanics of layer-by-layer polyelectrolyte complexes: a manifestation of ionic cross-links and fixed charges.

PubMed

Han, Biao; Chery, Daphney R; Yin, Jie; Lu, X Lucas; Lee, Daeyeon; Han, Lin

2016-01-28

This study investigates the roles of two distinct features of ionically cross-linked polyelectrolyte networks - ionic cross-links and fixed charges - in determining their nanomechanical properties. The layer-by-layer assembled poly(allylamine hydrochloride)/poly(acrylic acid) (PAH/PAA) network is used as the model material. The densities of ionic cross-links and fixed charges are modulated through solution pH and ionic strength (IS), and the swelling ratio, elastic and viscoelastic properties are quantified via an array of atomic force microscopy (AFM)-based nanomechanical tools. The roles of ionic cross-links are underscored by the distinctive elastic and viscoelastic nanomechanical characters observed here. First, as ionic cross-links are highly sensitive to solution conditions, the instantaneous modulus, E0, exhibits orders-of-magnitude changes upon pH- and IS-governed swelling, distinctive from the rubber elasticity prediction based on permanent covalent cross-links. Second, ionic cross-links can break and self-re-form, and this mechanism dominates force relaxation of PAH/PAA under a constant indentation depth. In most states, the degree of relaxation is >90%, independent of ionic cross-link density. The importance of fixed charges is highlighted by the unexpectedly more elastic nature of the network despite low ionic cross-link density at pH 2.0, IS 0.01 M. Here, the complex is a net charged, loosely cross-linked, where the degree of relaxation is attenuated to ≈50% due to increased elastic contribution arising from fixed charge-induced Donnan osmotic pressure. In addition, this study develops a new method for quantifying the thickness of highly swollen polymer hydrogel films. It also underscores important technical considerations when performing nanomechanical tests on highly rate-dependent polymer hydrogel networks. These results provide new insights into the nanomechanical characters of ionic polyelectrolyte complexes, and lay the ground for further investigation of their unique time-dependent properties.

Precision and negative predictive value of links between ClinicalTrials.gov and PubMed.

PubMed

Huser, Vojtech; Cimino, James J

2012-01-01

One of the goals of translational science is to shorten the time from discovery to clinical use. Clinical trial registries were established to increase transparency in completed and ongoing clinical trials, and they support linking trials with resulting publications. We set out to investigate precision and negative predictive value (NPV) of links between ClinicalTrials.gov (CT.gov) and PubMed. CT.gov has been established to increase transparency in clinical trials and the link to PubMed is crucial for supporting a number of important functions, including ascertaining publication bias. We drew a random sample of trials downloaded from CT.gov and performed manual review of retrieved publications. We characterize two types of links between trials and publications (NCT-link originating from MEDLINE and PMID-link originating from CT.gov).The link precision is different based on type (NCT-link: 100%; PMID-link: 63% to 96%). In trials with no linked publication, we were able to find publications 44% of the time (NPV=56%) by searching PubMed. This low NPV shows that there are potentially numerous publications that should have been formally linked with the trials. Our results indicate that existing trial registry and publisher policies may not be fully enforced. We suggest some automated methods for improving link quality.

Proactive schema based link lifetime estimation and connectivity ratio.

PubMed

Bachir, Bouamoud; Ali, Ouacha; Ahmed, Habbani; Mohamed, Elkoutbi

2014-01-01

The radio link between a pair of wireless nodes is affected by a set of random factors such as transmission range, node mobility, and environment conditions. The properties of such radio links are continually experienced when nodes status balances between being reachable and being unreachable; thereby on completion of each experience the statistical distribution of link lifetime is updated. This aspect is emphasized in mobile ad hoc network especially when it is deployed in some fields that require intelligent processing of data information such as aerospace domain.

EPA ExpoBox Related Links

EPA Pesticide Factsheets

EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases,

Aspiration-based coevolution of link weight promotes cooperation in the spatial prisoner's dilemma game

PubMed Central

Shen, Chen; Chu, Chen; Shi, Lei

2018-01-01

In this article, we propose an aspiration-based coevolution of link weight, and explore how this set-up affects the evolution of cooperation in the spatial prisoner's dilemma game. In particular, an individual will increase the weight of its link to its neighbours only if the payoff received via this interaction exceeds a pre-defined aspiration. Conversely, if the received payoff is below this aspiration, the link weight with the corresponding neighbour will decrease. Our results show that an appropriate aspiration level leads to a high-cooperation plateau, whereas too high or too low aspiration will impede the evolution of cooperation. We explain these findings with a comprehensive analysis of transition points and with a systematic analysis of typical configuration patterns. The presented results provide further theoretical insights with regards to the impact of different aspiration levels on cooperation in human societies. PMID:29892454

Preparation and characterization of safe microparticles based on xylan.

PubMed

Cartaxo da Costa Urtiga, Silvana; Aquino Azevedo de Lucena Gabi, Camilla; Rodrigues de Araújo Eleamen, Giovanna; Santos Souza, Bartolomeu; Pessôa, Hilzeth de Luna Freire; Marcelino, Henrique Rodrigues; Afonso de Moura Mendonça, Elisângela; Egito, Eryvaldo Sócrates Tabosa do; Oliveira, Elquio Eleamen

2017-10-01

This work describes the preparation and evaluation of safe xylan-based microparticles prepared by cross-linking polymerization using sodium trimetaphosphate. The resulting microparticles were evaluated for morphology, particle size, polymer-cross-link agent interaction, and in vitro toxicity. The microparticles showed narrow monodisperse size distributions with their mean sizes being between 3.5 and 12.5 µm in dried state. FT-IR analyzes confirmed the interaction between sodium trimetaphosphate and xylan during the cross-linking process with formation of phosphate ester bonds. Additionally, the X-ray diffraction patterns and FT-IR analyzes suggested that little or no cross-linking agent remained inside the microparticles. Furthermore, the in-vitro studies using Artemia salina and human erythrocytes revealed that the microparticles are not toxic. Therefore, the overall results suggest that these xylan microparticles can be used as a platform for new drug delivery system.

Aspiration-based coevolution of link weight promotes cooperation in the spatial prisoner's dilemma game

NASA Astrophysics Data System (ADS)

Shen, Chen; Chu, Chen; Shi, Lei; Perc, Matjaž; Wang, Zhen

2018-05-01

In this article, we propose an aspiration-based coevolution of link weight, and explore how this set-up affects the evolution of cooperation in the spatial prisoner's dilemma game. In particular, an individual will increase the weight of its link to its neighbours only if the payoff received via this interaction exceeds a pre-defined aspiration. Conversely, if the received payoff is below this aspiration, the link weight with the corresponding neighbour will decrease. Our results show that an appropriate aspiration level leads to a high-cooperation plateau, whereas too high or too low aspiration will impede the evolution of cooperation. We explain these findings with a comprehensive analysis of transition points and with a systematic analysis of typical configuration patterns. The presented results provide further theoretical insights with regards to the impact of different aspiration levels on cooperation in human societies.

Ka-Band Phased Array System Characterization

NASA Technical Reports Server (NTRS)

Acosta, R.; Johnson, S.; Sands, O.; Lambert, K.

2001-01-01

Phased Array Antennas (PAAs) using patch-radiating elements are projected to transmit data at rates several orders of magnitude higher than currently offered with reflector-based systems. However, there are a number of potential sources of degradation in the Bit Error Rate (BER) performance of the communications link that are unique to PAA-based links. Short spacing of radiating elements can induce mutual coupling between radiating elements, long spacing can induce grating lobes, modulo 2 pi phase errors can add to Inter Symbol Interference (ISI), phase shifters and power divider network introduce losses into the system. This paper describes efforts underway to test and evaluate the effects of the performance degrading features of phased-array antennas when used in a high data rate modulation link. The tests and evaluations described here uncover the interaction between the electrical characteristics of a PAA and the BER performance of a communication link.

Covalent cross-linking as a strategy to generate novel materials based on layered (2D) and other low D structures.

PubMed

Rao, C N R; Pramoda, K; Kumar, Ram

2017-09-12

Covalent linking of 2D structures such as graphene, MoS 2 and C 3 N 4 by employing coupling reactions provides a strategy to generate a variety of materials with new or improved properties. These materials in a way provide the counter point based on covalent bonds to the van der Waals heterostructures. In this article, we describe materials obtained by linking graphene, MoS 2 and BN with other layered structures and also with one-dimensional nanotubes and zero-dimensional MOFs and MOPs. Novel properties of the materials relate not only to porosity, surface area and gas adsorption, but also to supercapacitor characterstics, mechanical properties and the hydrogen evolution reaction. It should be possible to discover many more interesting structures and materials by employing the cross-linking strategy described here.

Pricing of premiums for equity-linked life insurance based on joint mortality models

NASA Astrophysics Data System (ADS)

Riaman; Parmikanti, K.; Irianingsih, I.; Supian, S.

2018-03-01

Life insurance equity - linked is a financial product that not only offers protection, but also investment. The calculation of equity-linked life insurance premiums generally uses mortality tables. Because of advances in medical technology and reduced birth rates, it appears that the use of mortality tables is less relevant in the calculation of premiums. To overcome this problem, we use a combination mortality model which in this study is determined based on Indonesian Mortality table 2011 to determine the chances of death and survival. In this research, we use the Combined Mortality Model of the Weibull, Inverse-Weibull, and Gompertz Mortality Model. After determining the Combined Mortality Model, simulators calculate the value of the claim to be given and the premium price numerically. By calculating equity-linked life insurance premiums well, it is expected that no party will be disadvantaged due to the inaccuracy of the calculation result

The scheme of LLSST based on inter-satellite link for planet gravity field measurement in deep-space mission

NASA Astrophysics Data System (ADS)

Yang, Yikang; Li, Xue; Liu, Lei

2009-12-01

Gravity field measurement for the interested planets and their moos in solar system, such as Luna and Mars, is one important task in the next step of deep-space mission. In this paper, Similar to GRACE mission, LLSST and DOWR technology of common-orbit master-slave satellites around task planet is inherited in this scheme. Furthermore, by intersatellite 2-way UQPSK-DSSS link, time synchronization and data processing are implemented autonomously by masterslave satellites instead of GPS and ground facilities supporting system. Conclusion is derived that the ISL DOWR based on 2-way incoherent time synchronization has the same precise level to GRACE DOWR based on GPS time synchronization. Moreover, because of inter-satellite link, the proposed scheme is rather autonomous for gravity field measurement of the task planet in deep-space mission.

A Quarter Century of Participation in School-Based Extracurricular Activities: Inequalities by Race, Class, Gender and Age?

PubMed

Meier, Ann; Hartmann, Benjamin Swartz; Larson, Ryan

2018-06-01

Extracurricular activity participation is linked to positive development, but it is also a setting for inequality. Using a quarter century of data from Monitoring the Future (N = 593,979; 51% female; 65% non-Hispanic white; 13% non-Hispanic black; 12% Hispanic; 4% non-Hispanic Asian/Pacific Islander; 7% other race), this article documents patterns and trends in school-based extracurricular participation by race, social class, gender, and age, and their links to academic and substance use outcomes. Findings reveal differences by race and confirm a division by social class that has worsened over time. Further, girls are gaining on boys and surpass them in some types of school-based activities. Participation is linked to better academic outcomes and less substance use, affirming the importance of redressing the inequalities revealed.

U14 small nucleolar RNA makes multiple contacts with the pre-ribosomal RNA.

PubMed

Morrissey, J P; Tollervey, D

1997-06-01

The small nucleolar RNA (snoRNA) U14 has two regions of extended primary sequence complementarity to the 18S rRNA. The 3' region (domain B) shows the consensus structure for the methylation guide class of snoRNAs, whereas base-pairing between the 5' region (domain A) and the 18S rRNA sequence is required for the formation of functional ribosomes. Between domains A and B lies another essential region (domain Y). Here we report that yeast U14 can be cross-linked in vivo to the pre-rRNA; cross-linking is detected exclusively with the 35S primary transcript. Many nucleotides in U14 that lie outside of domains A and B are cross-linked to the pre-rRNA; in particular the essential domain Y region is cross-linked at several sites. U14 is, therefore, in far more extensive contact with the pre-rRNA than predicted from simple base-pairing models. Moreover, U14 can be cross-linked to other small RNA species. The functional interactions made by U14 during ribosome synthesis are likely to be very complex.

The degree-related clustering coefficient and its application to link prediction

NASA Astrophysics Data System (ADS)

Liu, Yangyang; Zhao, Chengli; Wang, Xiaojie; Huang, Qiangjuan; Zhang, Xue; Yi, Dongyun

2016-07-01

Link prediction plays a significant role in explaining the evolution of networks. However it is still a challenging problem that has been addressed only with topological information in recent years. Based on the belief that network nodes with a great number of common neighbors are more likely to be connected, many similarity indices have achieved considerable accuracy and efficiency. Motivated by the natural assumption that the effect of missing links on the estimation of a node's clustering ability could be related to node degree, in this paper, we propose a degree-related clustering coefficient index to quantify the clustering ability of nodes. Unlike the classical clustering coefficient, our new coefficient is highly robust when the observed bias of links is considered. Furthermore, we propose a degree-related clustering ability path (DCP) index, which applies the proposed coefficient to the link prediction problem. Experiments on 12 real-world networks show that our proposed method is highly accurate and robust compared with four common-neighbor-based similarity indices (Common Neighbors(CN), Adamic-Adar(AA), Resource Allocation(RA), and Preferential Attachment(PA)), and the recently introduced clustering ability (CA) index.

Link prediction in multiplex online social networks

NASA Astrophysics Data System (ADS)

Jalili, Mahdi; Orouskhani, Yasin; Asgari, Milad; Alipourfard, Nazanin; Perc, Matjaž

2017-02-01

Online social networks play a major role in modern societies, and they have shaped the way social relationships evolve. Link prediction in social networks has many potential applications such as recommending new items to users, friendship suggestion and discovering spurious connections. Many real social networks evolve the connections in multiple layers (e.g. multiple social networking platforms). In this article, we study the link prediction problem in multiplex networks. As an example, we consider a multiplex network of Twitter (as a microblogging service) and Foursquare (as a location-based social network). We consider social networks of the same users in these two platforms and develop a meta-path-based algorithm for predicting the links. The connectivity information of the two layers is used to predict the links in Foursquare network. Three classical classifiers (naive Bayes, support vector machines (SVM) and K-nearest neighbour) are used for the classification task. Although the networks are not highly correlated in the layers, our experiments show that including the cross-layer information significantly improves the prediction performance. The SVM classifier results in the best performance with an average accuracy of 89%.

Link prediction in multiplex online social networks.

PubMed

Jalili, Mahdi; Orouskhani, Yasin; Asgari, Milad; Alipourfard, Nazanin; Perc, Matjaž

2017-02-01

Online social networks play a major role in modern societies, and they have shaped the way social relationships evolve. Link prediction in social networks has many potential applications such as recommending new items to users, friendship suggestion and discovering spurious connections. Many real social networks evolve the connections in multiple layers (e.g. multiple social networking platforms). In this article, we study the link prediction problem in multiplex networks. As an example, we consider a multiplex network of Twitter (as a microblogging service) and Foursquare (as a location-based social network). We consider social networks of the same users in these two platforms and develop a meta-path-based algorithm for predicting the links. The connectivity information of the two layers is used to predict the links in Foursquare network. Three classical classifiers (naive Bayes, support vector machines (SVM) and K-nearest neighbour) are used for the classification task. Although the networks are not highly correlated in the layers, our experiments show that including the cross-layer information significantly improves the prediction performance. The SVM classifier results in the best performance with an average accuracy of 89%.

A non-heme iron-mediated chemical demethylation in DNA and RNA.

PubMed

Yi, Chengqi; Yang, Cai-Guang; He, Chuan

2009-04-21

DNA methylation is arguably one of the most important chemical signals in biology. However, aberrant DNA methylation can lead to cytotoxic or mutagenic consequences. A DNA repair protein in Escherichia coli, AlkB, corrects some of the unwanted methylations of DNA bases by a unique oxidative demethylation in which the methyl carbon is liberated as formaldehyde. The enzyme also repairs exocyclic DNA lesions--that is, derivatives in which the base is augmented with an additional heterocyclic subunit--by a similar mechanism. Two proteins in humans that are homologous to AlkB, ABH2 and ABH3, repair the same spectrum of lesions; another human homologue of AlkB, FTO, is linked to obesity. In this Account, we describe our studies of AlkB, ABH2, and ABH3, including our development of a general strategy to trap homogeneous protein-DNA complexes through active-site disulfide cross-linking. AlkB uses a non-heme mononuclear iron(II) and the cofactors 2-ketoglutarate (2KG) and dioxygen to effect oxidative demethylation of the DNA base lesions 1-methyladenine (1-meA), 3-methylcytosine (3-meC), 1-methylguanine (1-meG), and 3-methylthymine (3-meT). ABH3, like AlkB, works better on single-stranded DNA (ssDNA) and is capable of repairing damaged bases in RNA. Conversely, ABH2 primarily repairs lesions in double-stranded DNA (dsDNA); it is the main housekeeping enzyme that protects the mammalian genome from 1-meA base damage. The AlkB-family proteins have moderate affinities for their substrates and bind DNA in a non-sequence-specific manner. Knowing that these proteins flip the damaged base out from the duplex DNA and insert it into the active site for further processing, we first engineered a disulfide cross-link in the active site to stabilize the Michaelis complex. Based on the detailed structural information afforded by the active-site cross-linked structures, we can readily install a cross-link away from the active site to obtain the native-like structures of these complexes. The crystal structures show a distinct base-flipping feature in AlkB and establish ABH2 as a dsDNA repair protein. They also provide a molecular framework for understanding the demethylation reaction catalyzed by these proteins and help to explain their substrate preferences. The chemical cross-linking method demonstrated here can be applied to trap other labile protein-DNA interactions and can serve as a general strategy for exploring the structural and functional aspects of base-flipping proteins.

Characterising Extrinsic Challenges Linked to the Design and Implementation of Inquiry-Based Practical Work

NASA Astrophysics Data System (ADS)

Akuma, Fru Vitalis; Callaghan, Ronel

2017-11-01

Inquiry-based science education has been incorporated in science curricula internationally. In this regard, however, many teachers encounter challenges. The challenges have been characterised into those linked to the personal characteristics of these teachers (intrinsic challenges) and others associated with contextual factors (extrinsic challenges). However, this level of characterisation is inadequate in terms of appreciating the complexity of the challenges, tracking of their development, and discovering knowledge within specific categories. Against this background, the purpose of the research presented here was to characterise extrinsic challenges linked to the design and implementation of inquiry-based practical work. In order to do so, we used a conceptual framework of teaching challenges based on Bronfenbrenner's ecological theory of human development. The data gathered using a multi-method case study of practical work in two South African high schools, was analysed by combining the data-driven inductive approach and the deductive a priori template of codes approach in thematic analysis. On this basis, the extrinsic challenges linked to the design and implementation of inquiry-based practical work that participants are confronted with, were found to consist of macrosystem challenges (such as a restrictive curriculum) and microsystem challenges. At the latter level, the challenges are material-related (e.g., lack of science education equipment and materials) or non-material-related (such as time constraints and the lack of access to interactive computer simulations). We have discussed the theory-, practice- and research-based implications of these results in relation to the design and implementation of inquiry-based practical work in South Africa and internationally.

Social Networks and High Healthcare Utilization: Building Resilience Through Analysis

DTIC Science & Technology

2016-09-01

of Social Network Analysis Patients Developing targeted intervention programs based on the individual’s needs may potentially help improve the...network structure is found in the patterns of interconnection that develop between nodes. It is this linking through common nodes, “the AB link shares...transitivity is responsible for the clustering of nodes that form “communities” of people based on geography, common interests, or other group

Link predication based on matrix factorization by fusion of multi class organizations of the network.

PubMed

Jiao, Pengfei; Cai, Fei; Feng, Yiding; Wang, Wenjun

2017-08-21

Link predication aims at forecasting the latent or unobserved edges in the complex networks and has a wide range of applications in reality. Almost existing methods and models only take advantage of one class organization of the networks, which always lose important information hidden in other organizations of the network. In this paper, we propose a link predication framework which makes the best of the structure of networks in different level of organizations based on nonnegative matrix factorization, which is called NMF 3 here. We first map the observed network into another space by kernel functions, which could get the different order organizations. Then we combine the adjacency matrix of the network with one of other organizations, which makes us obtain the objective function of our framework for link predication based on the nonnegative matrix factorization. Third, we derive an iterative algorithm to optimize the objective function, which converges to a local optimum, and we propose a fast optimization strategy for large networks. Lastly, we test the proposed framework based on two kernel functions on a series of real world networks under different sizes of training set, and the experimental results show the feasibility, effectiveness, and competitiveness of the proposed framework.

A family with X-linked anophthalmia: exclusion of SOX3 as a candidate gene.

PubMed

Slavotinek, Anne; Lee, Stephen S; Hamilton, Steven P

2005-10-01

We report on a four-generation family with X-linked anophthalmia in four affected males and show that this family has LOD scores consistent with linkage to Xq27, the third family reported to be linked to the ANOP1 locus. We sequenced the SOX3 gene at Xq27 as a candidate gene for the X-linked anophthalmia based on the high homology of this gene to SOX2, a gene previously mutated in bilateral anophthlamia. However, no amino acid sequence alterations were identified in SOX3. We have improved the definition of the phenotype in males with anophthalmia linked to the ANOP1 locus, as microcephaly, ocular colobomas, and severe renal malformations have not been described in families linked to ANOP1. (c) 2005 Wiley-Liss, Inc.

Near Sun Free-Space Optical Communications from Space

NASA Technical Reports Server (NTRS)

Biswas, Abhijit; Khatri, F.; Boroson, D.

2006-01-01

Free-space optical communications offers expanded data return capacity, from probes distributed throughout the solar system and beyond. Space-borne and Earth-based optical transceivers used for communicating optically, will periodically encounter near Sun pointing. This will result in an increase in the scattered background light flux, often contributing to degraded link performance. The varying duration of near Sun pointing link operations relative to the location of space-probes, is discussed in this paper. The impact of near Sun pointing on link performance for a direct detection photon-counting communications system is analyzed for both ground- and space-based Earth receivers. Finally, impact of near Sun pointing on spaceborne optical transceivers is discussed.

Field-based Digital Mapping of the November 3, 2002 Susitna Glacier Fault Rupture - Integrating remotely sensed data, GIS, and photo-linking technologies

NASA Astrophysics Data System (ADS)

Staft, L. A.; Craw, P. A.

2003-12-01

In July 2003, the U.S. Geological Survey and the Alaska Division of Geological & Geophysical Surveys (DGGS) conducted field studies on the Susitna Glacier Fault (SGF), which ruptured on November 2002 during the M 7.9 Denali fault earthquake. The DGGS assumed responsibility for Geographic Information System (GIS) and data management, integrating remotely sensed imagery, GPS data, GIS, and photo-linking software to aid in planning and documentation of fieldwork. Pre-field preparation included acquisition of over 150, 1:6,000-scale true-color aerial photographs taken shortly after the SGF rupture, 1:63,360-scale color-infrared (CIR) 1980 aerial photographs, and digital geographic information including a 15-minute Digital Elevation Model (DEM), 1:63,360-scale Digital Raster Graphics (DRG), and LandSat 7 satellite imagery. Using Orthomapper software, we orthorectified and mosaiced seven CIRs, creating a georeferenced, digital photo base of the study area. We used this base to reference the 1:6,000-scale aerial photography, to view locations of field sites downloaded from GPS, and to locate linked digital photographs that were taken in the field. Photos were linked using GPS-Photo Link software which "links" digital photographs to GPS data by correlating time stamps from the GPS track log or waypoint file to those of the digital photos, using the correlated point data to create a photo location ESRI shape file. When this file is opened in ArcMap or ArcView with the GPS-Photo Link utility enabled, a thumbnail image of the linked photo appears when the cursor is over the photo location. Viewing photographed features and scarp-profile locations in GIS allowed us to evaluate data coverage of the rupture daily. Using remotely sensed imagery in the field with GIS gave us the versatility to display data on a variety of bases, including topographic maps, air photos, and satellite imagery, during fieldwork. In the field, we downloaded, processed, and reviewed data as it was collected, taking major steps toward final digital map production. Using the described techniques greatly enhanced our ability to analyze and interpret field data; the resulting digital data structure allows us to efficiently gather, disseminate, and archive critical field data.

LESS: Link Estimation with Sparse Sampling in Intertidal WSNs

PubMed Central

Ji, Xiaoyu; Chen, Yi-chao; Li, Xiaopeng; Xu, Wenyuan

2018-01-01

Deploying wireless sensor networks (WSN) in the intertidal area is an effective approach for environmental monitoring. To sustain reliable data delivery in such a dynamic environment, a link quality estimation mechanism is crucial. However, our observations in two real WSN systems deployed in the intertidal areas reveal that link update in routing protocols often suffers from energy and bandwidth waste due to the frequent link quality measurement and updates. In this paper, we carefully investigate the network dynamics using real-world sensor network data and find it feasible to achieve accurate estimation of link quality using sparse sampling. We design and implement a compressive-sensing-based link quality estimation protocol, LESS, which incorporates both spatial and temporal characteristics of the system to aid the link update in routing protocols. We evaluate LESS in both real WSN systems and a large-scale simulation, and the results show that LESS can reduce energy and bandwidth consumption by up to 50% while still achieving more than 90% link quality estimation accuracy. PMID:29494557

Cross-linking of type I collagen with microbial transglutaminase: identification of cross-linking sites.

PubMed

Stachel, Ines; Schwarzenbolz, Uwe; Henle, Thomas; Meyer, Michael

2010-03-08

Collagen is a popular biomaterial. To deal with its lack of thermal stability and its weak resistance to proteolytic degradation, collagen-based materials are stabilized via different cross-linking procedures. Regarding the potential toxicity of residual cross-linking agents, enzyme-mediated cross-linking would provide an alternative and nontoxic method for collagen stabilization. The results of this study show that type I collagen is a substrate for mTG. However, epsilon-(gamma-glutamyl)lysine cross-links are only incorporated at elevated temperatures when the protein is partially or completely denatured. A maximum number of 5.4 cross-links per collagen monomer were found for heat-denatured collagen. Labeling with the primary amine monodansylcadaverine revealed that at least half of the cross-links are located within the triple helical region of the collagen molecule. Because the triple helix is highly ordered in its native state, this finding might explain why the glutamine residues are inaccessible for mTG under nondenaturing conditions.

Tracking Data Acquisition System (TDAS) for the 1990's. Volume 6: TDAS navigation system architecture

NASA Technical Reports Server (NTRS)

Elrod, B. D.; Jacobsen, A.; Cook, R. A.; Singh, R. N. P.

1983-01-01

One-way range and Doppler methods for providing user orbit and time determination are examined. Forward link beacon tracking, with on-board processing of independent navigation signals broadcast continuously by TDAS spacecraft; forward link scheduled tracking; with on-board processing of navigation data received during scheduled TDAS forward link service intervals; and return link scheduled tracking; with ground-based processing of user generated navigation data during scheduled TDAS return link service intervals are discussed. A system level definition and requirements assessment for each alternative, an evaluation of potential navigation performance and comparison with TDAS mission model requirements is included. TDAS satellite tracking is also addressed for two alternatives: BRTS and VLBI tracking.

Polyvinyl alcohol membranes as alkaline battery separators

NASA Technical Reports Server (NTRS)

Sheibley, D. W.; Gonzalez-Sanabria, O.; Manzo, M. A.

1982-01-01

Polyvinly alcohol (PVA) cross-linked with aldehyde reagents yields membranes that demonstrate properties that make them suitable for use as alkaline battery separators. Film properties can be controlled by the choice of cross-linker, cross-link density and the method of cross-linking. Three methods of cross-linking and their effects on film properties are discussed. Film properties can also be modified by using a copolymer of vinyl alcohol and acrylic acid as the base for the separator and cross-linking it similarly to the PVA. Fillers can be incorporated into the films to further modify film properties. Results of separator screening tests and cell tests for several variations of PBA films are discussed.

Radio Science from an Optical Communications Signal

NASA Technical Reports Server (NTRS)

Moision, Bruce; Asmar, Sami; Oudrhiri, Kamal

2013-01-01

NASA is currently developing the capability to deploy deep space optical communications links. This creates the opportunity to utilize the optical link to obtain range, doppler, and signal intensity estimates. These may, in turn, be used to complement or extend the capabilities of current radio science. In this paper we illustrate the achievable precision in estimating range, doppler, and received signal intensity of an non-coherent optical link (the current state-of-the-art for a deep-space link). We provide a joint estimation algorithm with performance close to the bound. We draw comparisons to estimates based on a coherent radio frequency signal, illustrating that large gains in either precision or observation time are possible with an optical link.

Navigation API Route Fuel Saving Opportunity Assessment on Large-Scale Real-World Travel Data for Conventional Vehicles and Hybrid Electric Vehicles: Preprint

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

Zhu, Lei; Holden, Jacob; Gonder, Jeffrey D

The green routing strategy instructing a vehicle to select a fuel-efficient route benefits the current transportation system with fuel-saving opportunities. This paper introduces a navigation API route fuel-saving evaluation framework for estimating fuel advantages of alternative API routes based on large-scale, real-world travel data for conventional vehicles (CVs) and hybrid electric vehicles (HEVs). The navigation APIs, such Google Directions API, integrate traffic conditions and provide feasible alternative routes for origin-destination pairs. This paper develops two link-based fuel-consumption models stratified by link-level speed, road grade, and functional class (local/non-local), one for CVs and the other for HEVs. The link-based fuel-consumption modelsmore » are built by assigning travel from a large number of GPS driving traces to the links in TomTom MultiNet as the underlying road network layer and road grade data from a U.S. Geological Survey elevation data set. Fuel consumption on a link is calculated by the proposed fuel consumption model. This paper envisions two kinds of applications: 1) identifying alternate routes that save fuel, and 2) quantifying the potential fuel savings for large amounts of travel. An experiment based on a large-scale California Household Travel Survey GPS trajectory data set is conducted. The fuel consumption and savings of CVs and HEVs are investigated. At the same time, the trade-off between fuel saving and time saving for choosing different routes is also examined for both powertrains.« less

Long-term durability of HT-PEM fuel cells based on thermally cross-linked polybenzimidazole

NASA Astrophysics Data System (ADS)

Søndergaard, Tonny; Cleemann, Lars Nilausen; Becker, Hans; Aili, David; Steenberg, Thomas; Hjuler, Hans Aage; Seerup, Larisa; Li, Qingfeng; Jensen, Jens Oluf

2017-02-01

Long-term durability of high temperature polymer electrolyte membrane fuel cells based on thermally cross-linked polybenzimidazole membranes was studied and compared with reference membranes based on linear polybenzimidazole. The test was conducted at 160 °C under constant load currents of 200 mA cm-2 for periods of 1000, 4400, and 13,000 h. Extensive beginning-of-life (BoL) and end-of-test (EoT) characterisation was carried out, and disturbance of the steady state operated cells was minimised by limiting in-line diagnostics to the low-invasive technique of electrochemical impedance spectroscopy (EIS). Up until the operating time of 9200 h, the cell equipped with the cross-linked membrane showed an average degradation rate of 0.5 μV h-1, compared to 2.6 μV h-1 for the reference membrane, though parallel tests for a shorter period of time showed deviations, likely due to malfunctioning contact between layers or cell components. For the full test period of 13,000 h, the average voltage decay rate was about 1.4 and 4.6 μV h-1 for cells equipped with cross-linked and linear polybenzimidazole membranes, respectively. EIS and post-test analysis revealed that the cross-linked membrane showed better stability in terms of area specific resistance due to improved acid retention characteristics.

The sumLINK statistic for genetic linkage analysis in the presence of heterogeneity.

PubMed

Christensen, G B; Knight, S; Camp, N J

2009-11-01

We present the "sumLINK" statistic--the sum of multipoint LOD scores for the subset of pedigrees with nominally significant linkage evidence at a given locus--as an alternative to common methods to identify susceptibility loci in the presence of heterogeneity. We also suggest the "sumLOD" statistic (the sum of positive multipoint LOD scores) as a companion to the sumLINK. sumLINK analysis identifies genetic regions of extreme consistency across pedigrees without regard to negative evidence from unlinked or uninformative pedigrees. Significance is determined by an innovative permutation procedure based on genome shuffling that randomizes linkage information across pedigrees. This procedure for generating the empirical null distribution may be useful for other linkage-based statistics as well. Using 500 genome-wide analyses of simulated null data, we show that the genome shuffling procedure results in the correct type 1 error rates for both the sumLINK and sumLOD. The power of the statistics was tested using 100 sets of simulated genome-wide data from the alternative hypothesis from GAW13. Finally, we illustrate the statistics in an analysis of 190 aggressive prostate cancer pedigrees from the International Consortium for Prostate Cancer Genetics, where we identified a new susceptibility locus. We propose that the sumLINK and sumLOD are ideal for collaborative projects and meta-analyses, as they do not require any sharing of identifiable data between contributing institutions. Further, loci identified with the sumLINK have good potential for gene localization via statistical recombinant mapping, as, by definition, several linked pedigrees contribute to each peak.

Cost and Performance Comparison of an Earth-Orbiting Optical Communication Relay Transceiver and a Ground-Based Optical Receiver Subnet

NASA Technical Reports Server (NTRS)

Wilson, K. E.; Wright, M.; Cesarone, R.; Ceniceros, J.; Shea, K.

2003-01-01

Optical communications can provide high-data-rate telemetry from deep-space probes with subsystems that have lower mass, consume less power, and are smaller than their radio frequency (RF) counterparts. However, because optical communication is more a.ected by weather than is RF communication, it requires groundstation site diversity to mitigate the adverse e.ects of inclement weather on the link. An optical relay satellite is not a.ected by weather and can provide 24-hour coverage of deep-space probes. Using such a relay satellite for the deep-space link and an 8.4-GHz (X-band) link to a ground station would support high-data-rate links from small deep-space probes with very little link loss due to inclement weather. We have reviewed past JPL-funded work on RF and optical relay satellites, and on proposed clustered and linearly dispersed optical subnets. Cost comparisons show that the life cycle costs of a 7-m optical relay station based on the heritage of the Next Generation Space Telescope is comparable to that of an 8-station subnet of 10- m optical ground stations. This makes the relay link an attractive option vis- a-vis a ground-station network.

Cost and Performance Comparison of an Earth-Orbiting Optical Communication Relay Transceiver and a Ground-Based Optical Receiver Subnet

NASA Astrophysics Data System (ADS)

Wilson, K. E.; Wright, M.; Cesarone, R.; Ceniceros, J.; Shea, K.

2003-01-01

Optical communications can provide high-data-rate telemetry from deep-space probes with subsystems that have lower mass, consume less power, and are smaller than their radio frequency (RF) counterparts. However, because optical communication is more affected by weather than is RF communication, it requires ground station site diversity to mitigate the adverse effects of inclement weather on the link. An optical relay satellite is not affected by weather and can provide 24-hour coverage of deep-space probes. Using such a relay satellite for the deep-space link and an 8.4-GHz (X-band) link to a ground station would support high-data-rate links from small deep-space probes with very little link loss due to inclement weather. We have reviewed past JPL-funded work on RF and optical relay satellites, and on proposed clustered and linearly dispersed optical subnets. Cost comparisons show that the life cycle costs of a 7-m optical relay station based on the heritage of the Next Generation Space Telescope is comparable to that of an 8-station subnet of 10-m optical ground stations. This makes the relay link an attractive option vis-a-vis a ground station network.

Hybrid attacks on model-based social recommender systems

NASA Astrophysics Data System (ADS)

Yu, Junliang; Gao, Min; Rong, Wenge; Li, Wentao; Xiong, Qingyu; Wen, Junhao

2017-10-01

With the growing popularity of the online social platform, the social network based approaches to recommendation emerged. However, because of the open nature of rating systems and social networks, the social recommender systems are susceptible to malicious attacks. In this paper, we present a certain novel attack, which inherits characteristics of the rating attack and the relation attack, and term it hybrid attack. Furtherly, we explore the impact of the hybrid attack on model-based social recommender systems in multiple aspects. The experimental results show that, the hybrid attack is more destructive than the rating attack in most cases. In addition, users and items with fewer ratings will be influenced more when attacked. Last but not the least, the findings suggest that spammers do not depend on the feedback links from normal users to become more powerful, the unilateral links can make the hybrid attack effective enough. Since unilateral links are much cheaper, the hybrid attack will be a great threat to model-based social recommender systems.

Flight crew support for automated negotiation of descent and arrival clearances

DOT National Transportation Integrated Search

1997-01-01

This paper focuses on the application of data link for communication between air traffic management and FMS-equipped aircraft. Based on requirements and guidelines for data link usage, a general philosophy for automated data exchange and the distribu...

CEMERLL: The Propagation of an Atmosphere-Compensated Laser Beam to the Apollo 15 Lunar Array

NASA Technical Reports Server (NTRS)

Fugate, R. Q.; Leatherman, P. R.; Wilson, K. E.

1997-01-01

Adaptive optics techniques can be used to realize a robust low bit-error-rate link by mitigating the atmosphere-induced signal fades in optical communications links between ground-based transmitters and deep-space probes.

Linking Bibliographic Data Bases: A Discussion of the Battelle Technical Report.

ERIC Educational Resources Information Center

Jones, C. Lee

This document establishes the context, summarizes the contents, and discusses the Battelle technical report, noting certain constraints of the study. Further steps for the linking of bibliographic databases for use by academic and public libraries are suggested. (RAA)

Sub-picosecond timing fluctuation suppression in laser-based atmospheric transfer of microwave signal using electronic phase compensation

NASA Astrophysics Data System (ADS)

Chen, Shijun; Sun, Fuyu; Bai, Qingsong; Chen, Dawei; Chen, Qiang; Hou, Dong

2017-10-01

We demonstrated a timing fluctuation suppression in outdoor laser-based atmospheric radio-frequency transfer over a 110 m one-way free-space link using an electronic phase compensation technique. Timing fluctuations and Allan Deviation are both measured to characterize the instability of transferred frequency incurred during the transfer process. With transferring a 1 GHz microwave signal over a timing fluctuation suppressed transmission link, the total root-mean-square (rms) timing fluctuation was measured to be 920 femtoseconds in 5000 s, with fractional frequency instability on the order of 1 × 10-12 at 1 s, and order of 2 × 10-16 at 1000 s. This atmospheric frequency transfer scheme with the timing fluctuation suppression technique can be used to fast build an atomic clock-based frequency free-space transmission link since its stability is superior to a commercial Cs and Rb clock.

Ultra-wideband microwave photonic link based on single-sideband modulation

NASA Astrophysics Data System (ADS)

Li, Jingnan; Wang, Yunxin; Wang, Dayong; Zhou, Tao; Zhong, Xin; Xu, Jiahao; Yang, Dengcai; Rong, Lu

2017-10-01

Comparing with the conventional double-sideband (DSB) modulation in communication system, single-sideband (SSB) modulation only demands half bandwidth of DSB in transmission. Two common ways are employed to implement SSB modulation by using optical filter (OF) or electrical 90° phase shift, respectively. However, the bandwidth of above methods is limited by characteristics of current OF and electrical phase shift. To overcome this problem, an ultra-wideband microwave photonic link based on SSB modulation is proposed and demonstrated. The radio frequency (RF) signal modulates a single-drive dual-parallel Mach-Zehnder modulator, and the SSB modulation is realized by combining an electrical 90° hybrid coupler and an optical bandpass filter. The experimental results indicate that the system can achieve SSB modulation for RF signal from 2 to 40 GHz. The proposed microwave photonic link provides an ultra-wideband approach based on SSB modulation for radio-over-fiber system.

Real time markerless motion tracking using linked kinematic chains

DOEpatents

Luck, Jason P [Arvada, CO; Small, Daniel E [Albuquerque, NM

2007-08-14

A markerless method is described for tracking the motion of subjects in a three dimensional environment using a model based on linked kinematic chains. The invention is suitable for tracking robotic, animal or human subjects in real-time using a single computer with inexpensive video equipment, and does not require the use of markers or specialized clothing. A simple model of rigid linked segments is constructed of the subject and tracked using three dimensional volumetric data collected by a multiple camera video imaging system. A physics based method is then used to compute forces to align the model with subsequent volumetric data sets in real-time. The method is able to handle occlusion of segments and accommodates joint limits, velocity constraints, and collision constraints and provides for error recovery. The method further provides for elimination of singularities in Jacobian based calculations, which has been problematic in alternative methods.

The Formation Mechanism of Hydrogels.

PubMed

Lu, Liyan; Yuan, Shiliang; Wang, Jing; Shen, Yun; Deng, Shuwen; Xie, Luyang; Yang, Qixiang

2017-06-12

Hydrogels are degradable polymeric networks, in which cross-links play a vital role in structure formation and degradation. Cross-linking is a stabilization process in polymer chemistry that leads to the multi-dimensional extension of polymeric chains, resulting in network structures. By cross-linking, hydrogels are formed into stable structures that differ from their raw materials. Generally, hydrogels can be prepared from either synthetic or natural polymers. Based on the types of cross-link junctions, hydrogels can be categorized into two groups: the chemically cross-linked and the physically cross-linked. Chemically cross-linked gels have permanent junctions, in which covalent bonds are present between different polymer chains, thus leading to excellent mechanical strength. Although chemical cross-linking is a highly resourceful method for the formation of hydrogels, the cross-linkers used in hydrogel preparation should be extracted from the hydrogels before use, due to their reported toxicity, while, in physically cross-linked gels, dissolution is prevented by physical interactions, such as ionic interactions, hydrogen bonds or hydrophobic interactions. Physically cross-linked methods for the preparation of hydrogels are the alternate solution for cross-linker toxicity. Both methods will be discussed in this essay. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Centrality-based Selection of Semantic Resources for Geosciences

NASA Astrophysics Data System (ADS)

Cerba, Otakar; Jedlicka, Karel

2017-04-01

Semantical questions intervene almost in all disciplines dealing with geographic data and information, because relevant semantics is crucial for any way of communication and interaction among humans as well as among machines. But the existence of such a large number of different semantic resources (such as various thesauri, controlled vocabularies, knowledge bases or ontologies) makes the process of semantics implementation much more difficult and complicates the use of the advantages of semantics. This is because in many cases users are not able to find the most suitable resource for their purposes. The research presented in this paper introduces a methodology consisting of an analysis of identical relations in Linked Data space, which covers a majority of semantic resources, to find a suitable resource of semantic information. Identical links interconnect representations of an object or a concept in various semantic resources. Therefore this type of relations is considered to be crucial from the view of Linked Data, because these links provide new additional information, including various views on one concept based on different cultural or regional aspects (so-called social role of Linked Data). For these reasons it is possible to declare that one reasonable criterion for feasible semantic resources for almost all domains, including geosciences, is their position in a network of interconnected semantic resources and level of linking to other knowledge bases and similar products. The presented methodology is based on searching of mutual connections between various instances of one concept using "follow your nose" approach. The extracted data on interconnections between semantic resources are arranged to directed graphs and processed by various metrics patterned on centrality computing (degree, closeness or betweenness centrality). Semantic resources recommended by the research could be used for providing semantically described keywords for metadata records or as names of items in data models. Such an approach enables much more efficient data harmonization, integration, sharing and exploitation. * * * * This publication was supported by the project LO1506 of the Czech Ministry of Education, Youth and Sports. This publication was supported by project Data-Driven Bioeconomy (DataBio) from the ICT-15-2016-2017, Big Data PPP call.

Wireless optical transceiver design, link analisys and alignment control for mobile communication

NASA Astrophysics Data System (ADS)

Zhou, Dayong

Pointing, acquisition and tracking of a free-space optical node in a mobile network experiencing misalignment due to adverse factors including vibration, motion and atmospheric turbulence requires a different approach than traditional free-space optical transceivers. A recent fiber-bundle approach for beam steering at the transmitter was investigated to provide continuous beam coverage at the receiver without the application of mechanical devices. Utilizing multiple fibers-lenses sets at the receiver was also proposed to enhance the tolerance of optical link misalignment. In this work, both laboratory experiments and software simulation were implemented to evaluate the optical link performance for different fiber-bundle-based transceiver setups as the link parameters were varied. The performance was evaluated in terms of the coverage area at the receiver, which is a measure of misalignment tolerance and is dependent not only on wavelength but on other key parameters such as link length, transmitted power, the pattern of transmitters, beam divergence, and the receiver construction. The results showed that fiber-bindle-based transceivers reveal significant potential to maximize the up time of the link, and the results also provide guidance on the further development of the overall system. To incorporate the proposed transceiver designs, an alignment control system was developed and evaluated as well. The laboratory results show that the optical control system successfully recovered and maintained the link while the receiver was in motion and the signal coverage at the target area was enhanced significantly.

Communications terminal breadboard

NASA Technical Reports Server (NTRS)

1972-01-01

A baseline design is presented of a digital communications link between an advanced manned spacecraft (AMS) and an earth terminal via an Intelsat 4 type communications satellite used as a geosynchronous orbiting relay station. The fabrication, integration, and testing of terminal elements at each end of the link are discussed. In the baseline link design, the information carrying capacity of the link was estimated for both the forward direction (earth terminal to AMS) and the return direction, based upon orbital geometry, relay satellite characteristics, terminal characteristics, and the improvement that can be achieved by the use of convolutional coding/Viterbi decoding techniques.

Heterogeneity of link weight and the evolution of cooperation

NASA Astrophysics Data System (ADS)

Iwata, Manabu; Akiyama, Eizo

2016-04-01

In this paper, we investigate the effect of heterogeneity of link weight, heterogeneity of the frequency or amount of interactions among individuals, on the evolution of cooperation. Based on an analysis of the evolutionary prisoner's dilemma game on a weighted one-dimensional lattice network with intra-individual heterogeneity, we confirm that moderate level of link-weight heterogeneity can facilitate cooperation. Furthermore, we identify two key mechanisms by which link-weight heterogeneity promotes the evolution of cooperation: mechanisms for spread and maintenance of cooperation. We also derive the corresponding conditions under which the mechanisms can work through evolutionary dynamics.

A model for predicting propagation-related DSCS (Defense Communications Engineering Center) margin requirements

NASA Astrophysics Data System (ADS)

Shultheis, C. F.

1985-02-01

This technical report describes an analysis of the performance allocations for a satellite link, focusing specifically on a single-hop 7 to 8 GHz link of the Defense Satellite Communications System (DSCS). The analysis is performed for three primary reasons: (1) to reevaluate link power margin requirements for DSCS links based on digital signalling; (2) to analyze the implications of satellite availability and error rate allocations contained in proposed MIL-STD-188-323, system design and engineering standards for long haul digital transmission system performance; and (3) to standardize a methodology for determination of rain-related propagation constraints. The aforementioned methodology is then used to calculate the link margin requirements of typical DSCS binary/quaternary phase shift keying (BPSK/QPSK) links at 7 to 8 GHz for several different Earth terminal locations.

Anatomy of an experimental two-link flexible manipulator under end-point control

NASA Technical Reports Server (NTRS)

Oakley, Celia M.; Cannon, Robert H., Jr.

1990-01-01

The design and experimental implementation of an end-point controller for two-link flexible manipulators are presented. The end-point controller is based on linear quadratic Gaussian (LQG) theory and is shown to exhibit significant improvements in trajectory tracking over a conventional controller design. To understand the behavior of the manipulator structure under end-point control, a strobe sequence illustrating the link deflections during a typical slew maneuver is included.

A Development Testbed for ALPS-Based Systems

DTIC Science & Technology

1988-10-01

alloted to tile application because of size or power constraints). Given an underlying support ALPS architecture such as the d-ALPS architecture, a...resource on which it is assigned at runtime. A second representation problem is that most graph analysis algorithms treat either graphs with weighted links...subtask) associated with it but is treated like other links. In d-ALPS, as a priority precedence link, it would cause the binding of a pro- cessor: as a

Effect of fog on free-space optical links employing imaging receivers.

PubMed

Mahalati, Reza Nasiri; Kahn, Joseph M

2012-01-16

We analyze free-space optical links employing imaging receivers in the presence of misalignment and atmospheric effects, such as haze, fog or rain. We present a detailed propagation model based on the radiative transfer equation. We also compare the relative importance of two mechanisms by which these effects degrade link performance: signal attenuation and image blooming. We show that image blooming dominates over attenuation, except under medium-to-heavy fog conditions.

Room-Temperature Performance of Poly(Ethylene Ether Carbonate)-Based Solid Polymer Electrolytes for All-Solid-State Lithium Batteries.

PubMed

Jung, Yun-Chae; Park, Myung-Soo; Kim, Duck-Hyun; Ue, Makoto; Eftekhari, Ali; Kim, Dong-Won

2017-12-13

Amorphous poly(ethylene ether carbonate) (PEEC), which is a copolymer of ethylene oxide and ethylene carbonate, was synthesized by ring-opening polymerization of ethylene carbonate. This route overcame the common issue of low conductivity of poly(ethylene oxide)(PEO)-based solid polymer electrolytes at low temperatures, and thus the solid polymer electrolyte could be successfully employed at the room temperature. Introducing the ethylene carbonate units into PEEC improved the ionic conductivity, electrochemical stability and lithium transference number compared with PEO. A cross-linked solid polymer electrolyte was synthesized by photo cross-linking reaction using PEEC and tetraethyleneglycol diacrylate as a cross-linking agent, in the form of a flexible thin film. The solid-state Li/LiNi 0.6 Co 0.2 Mn 0.2 O 2 cell assembled with solid polymer electrolyte based on cross-linked PEEC delivered a high initial discharge capacity of 141.4 mAh g -1 and exhibited good capacity retention at room temperature. These results demonstrate the feasibility of using this solid polymer electrolyte in all-solid-state lithium batteries that can operate at ambient temperatures.

Academic health sciences library Website navigation: an analysis of forty-one Websites and their navigation tools.

PubMed

Brower, Stewart M

2004-10-01

The analysis included forty-one academic health sciences library (HSL) Websites as captured in the first two weeks of January 2001. Home pages and persistent navigational tools (PNTs) were analyzed for layout, technology, and links, and other general site metrics were taken. Websites were selected based on rank in the National Network of Libraries of Medicine, with regional and resource libraries given preference on the basis that these libraries are recognized as leaders in their regions and would be the most reasonable source of standards for best practice. A three-page evaluation tool was developed based on previous similar studies. All forty-one sites were evaluated in four specific areas: library general information, Website aids and tools, library services, and electronic resources. Metrics taken for electronic resources included orientation of bibliographic databases alphabetically by title or by subject area and with links to specifically named databases. Based on the results, a formula for determining obligatory links was developed, listing items that should appear on all academic HSL Web home pages and PNTs. These obligatory links demonstrate a series of best practices that may be followed in the design and construction of academic HSL Websites.

A New Freshwater Biodiversity Indicator Based on Fish Community Assemblages

PubMed Central

Clavel, Joanne; Poulet, Nicolas; Porcher, Emmanuelle; Blanchet, Simon; Grenouillet, Gaël; Pavoine, Sandrine; Biton, Anne; Seon-Massin, Nirmala; Argillier, Christine; Daufresne, Martin; Teillac-Deschamps, Pauline; Julliard, Romain

2013-01-01

Biodiversity has reached a critical state. In this context, stakeholders need indicators that both provide a synthetic view of the state of biodiversity and can be used as communication tools. Using river fishes as model, we developed community indicators that aim at integrating various components of biodiversity including interactions between species and ultimately the processes influencing ecosystem functions. We developed indices at the species level based on (i) the concept of specialization directly linked to the niche theory and (ii) the concept of originality measuring the overall degree of differences between a species and all other species in the same clade. Five major types of originality indices, based on phylogeny, habitat-linked and diet-linked morphology, life history traits, and ecological niche were analyzed. In a second step, we tested the relationship between all biodiversity indices and land use as a proxy of human pressures. Fish communities showed no significant temporal trend for most of these indices, but both originality indices based on diet- and habitat- linked morphology showed a significant increase through time. From a spatial point of view, all indices clearly singled out Corsica Island as having higher average originality and specialization. Finally, we observed that the originality index based on niche traits might be used as an informative biodiversity indicator because we showed it is sensitive to different land use classes along a landscape artificialization gradient. Moreover, its response remained unchanged over two other land use classifications at the global scale and also at the regional scale. PMID:24278356

The CTBTO Link to the database of the International Seismological Centre (ISC)

NASA Astrophysics Data System (ADS)

Bondar, I.; Storchak, D. A.; Dando, B.; Harris, J.; Di Giacomo, D.

2011-12-01

The CTBTO Link to the database of the International Seismological Centre (ISC) is a project to provide access to seismological data sets maintained by the ISC using specially designed interactive tools. The Link is open to National Data Centres and to the CTBTO. By means of graphical interfaces and database queries tailored to the needs of the monitoring community, the users are given access to a multitude of products. These include the ISC and ISS bulletins, covering the seismicity of the Earth since 1904; nuclear and chemical explosions; the EHB bulletin; the IASPEI Reference Event list (ground truth database); and the IDC Reviewed Event Bulletin. The searches are divided into three main categories: The Area Based Search (a spatio-temporal search based on the ISC Bulletin), the REB search (a spatio-temporal search based on specific events in the REB) and the IMS Station Based Search (a search for historical patterns in the reports of seismic stations close to a particular IMS seismic station). The outputs are HTML based web-pages with a simplified version of the ISC Bulletin showing the most relevant parameters with access to ISC, GT, EHB and REB Bulletins in IMS1.0 format for single or multiple events. The CTBTO Link offers a tool to view REB events in context within the historical seismicity, look at observations reported by non-IMS networks, and investigate station histories and residual patterns for stations registered in the International Seismographic Station Registry.

Retweets as a Predictor of Relationships among Users on Social Media.

PubMed

Tsugawa, Sho; Kito, Kosuke

2017-01-01

Link prediction is the problem of detecting missing links or predicting future link formation in a network. Application of link prediction to social media, such as Twitter and Facebook, is useful both for developing novel services and for sociological analyses. While most existing research on link prediction uses only the social network topology for the prediction, in social media, records of user activities such as posting, replying, and reposting are available. These records are expected to reflect user interest, and so incorporating them should improve link prediction. However, research into link prediction using the records of user activities is still in its infancy, and the effectiveness of such records for link prediction has not been fully explored. In this study, we focus in particular on records of reposting as a promising source that could be useful for link prediction, and investigate their effectiveness for link prediction on the popular social media platform Twitter. Our results show that (1) the prediction accuracy of techniques using reposting records is higher than that of popular topology-based techniques such as common neighbors and resource allocation for actively retweeting users, (2) the accuracy of link prediction techniques that use network topology alone can be improved by incorporating reposting records.

Retweets as a Predictor of Relationships among Users on Social Media

PubMed Central

Kito, Kosuke

2017-01-01

Link prediction is the problem of detecting missing links or predicting future link formation in a network. Application of link prediction to social media, such as Twitter and Facebook, is useful both for developing novel services and for sociological analyses. While most existing research on link prediction uses only the social network topology for the prediction, in social media, records of user activities such as posting, replying, and reposting are available. These records are expected to reflect user interest, and so incorporating them should improve link prediction. However, research into link prediction using the records of user activities is still in its infancy, and the effectiveness of such records for link prediction has not been fully explored. In this study, we focus in particular on records of reposting as a promising source that could be useful for link prediction, and investigate their effectiveness for link prediction on the popular social media platform Twitter. Our results show that (1) the prediction accuracy of techniques using reposting records is higher than that of popular topology-based techniques such as common neighbors and resource allocation for actively retweeting users, (2) the accuracy of link prediction techniques that use network topology alone can be improved by incorporating reposting records. PMID:28107489

A Simulation of X-Linked Inheritance.

ERIC Educational Resources Information Center

Harrell, Pamela Esprivalo

1997-01-01

Describes how to lead students through a classroom-based simulation to teach a variety of concepts such as X-linked traits, sex determination, and sex anomalies. The simulation utilizes inexpensive materials such as plastic eggs that twist apart to represent human eggs and sperm. (AIM)

LINKING EFFECTS OF PERSISTENT BIOACCUMULATIVE TOXICANTS TO CHEMICAL EXPOSURES IN AQUATIC ECOSYSTEMS

EPA Science Inventory

The critical step in characterization of ecological risks associated with exposures of fish and wildlife to persistent bioaccumulative toxicants (PBTs) is linking chemical residue based toxicological data to concentrations of PBTs in sediments, water, and biota. This is necessary...

Building a SuAVE browse interface to R2R's Linked Data

NASA Astrophysics Data System (ADS)

Clark, D.; Stocks, K. I.; Arko, R. A.; Zaslavsky, I.; Whitenack, T.

2017-12-01

The Rolling Deck to Repository program (R2R) is creating and evaluating a new browse portal based on the SuAVE platform and the R2R linked data graph. R2R manages the underway sensor data collected by the fleet of US academic research vessels, and provides a discovery and access point to those data at its website, www.rvdata.us. R2R has a database-driven search interface, but seeks a more capable and extensible browse interface that could be built off of the substantial R2R linked data resources. R2R's Linked Data graph organizes its data holdings around key concepts (e.g. cruise, vessel, device type, operator, award, organization, publication), anchored by persistent identifiers where feasible. The "Survey Analysis via Visual Exploration" or SuAVE platform (suave.sdsc.edu) is a system for online publication, sharing, and analysis of images and metadata. It has been implemented as an interface to diverse data collections, but has not been driven off of linked data in the past. SuAVE supports several features of interest to R2R, including faceted searching, collaborative annotations, efficient subsetting, Google maps-like navigation over an image gallery, and several types of data analysis. Our initial SuAVE-based implementation was through a CSV export from the R2R PostGIS-enabled PostgreSQL database. This served to demonstrate the utility of SuAVE but was static and required reloading as R2R data holdings grew. We are now working to implement a SPARQL-based ("RDF Query Language") service that directly leverages the R2R Linked Data graph and offers the ability to subset and/or customize output.We will show examples of SuAVE faceted searches on R2R linked data concepts, and discuss our experience to date with this work in progress.

Expectations and experiences of gamete donors and donor-conceived adults searching for genetic relatives using DNA linking through a voluntary register.

PubMed

van den Akker, O B A; Crawshaw, M A; Blyth, E D; Frith, L J

2015-01-01

What are the experiences of donor-conceived adults and donors who are searching for a genetic link through the use of a DNA-based voluntary register service? Donor-conceived adults and donors held positive beliefs about their search and although some concerns in relation to finding a genetically linked relative were reported, these were not a barrier to searching. Research with donor-conceived people has consistently identified their interest in learning about-and in some cases making contact with-their donor and other genetic relatives. However, donor-conceived individuals or donors rarely have the opportunity to act on these desires. A questionnaire was administered for online completion using Bristol Online Surveys. The survey was live for 3 months and responses were collected anonymously. The survey was completed by 65 donor-conceived adults, 21 sperm donors and 5 oocyte donors who had registered with a DNA-based voluntary contact register in the UK. The questionnaire included socio-demographic questions, questions specifically developed for the purposes of this study and the standardized Aspects of Identity Questionnaire (AIQ). Motivations for searching for genetic relatives were varied, with the most common reasons being curiosity and passing on information. Overall, participants who were already linked and those awaiting a link were positive about being linked and valued access to a DNA-based register. Collective identity (reflecting self-defining feelings of continuity and uniqueness), as assessed by the AIQ, was significantly lower for donor-conceived adults when compared with the donor groups (P < 0.05), but not significantly different between linked/not linked or length of time since disclosure of donor conception (all Ps > 0.05) for donor-conceived adults. Participants were members of a UK DNA-based registry which is unique. It was therefore not possible to determine how representative participants were of those who did not register for the service, those in other countries or of those who do not seek information exchange or contact. This is the first survey exploring the experiences of donor-conceived adults and donors using a DNA-based voluntary register to seek information about and contact with genetic relatives and the first to measure aspects of identity using standardized measures. Findings provide valuable information about patterns of expectations and experiences of searching through DNA linking, identity and of having contact in the context of donor conception that will inform future research, practice and policy development. No funding was obtained for this study. The authors have no competing interests to declare except for M.C. who was national adviser to UKDL from 2003-2013. Not applicable. © The Author 2014. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A method for modelling GP practice level deprivation scores using GIS

PubMed Central

Strong, Mark; Maheswaran, Ravi; Pearson, Tim; Fryers, Paul

2007-01-01

Background A measure of general practice level socioeconomic deprivation can be used to explore the association between deprivation and other practice characteristics. An area-based categorisation is commonly chosen as the basis for such a deprivation measure. Ideally a practice population-weighted area-based deprivation score would be calculated using individual level spatially referenced data. However, these data are often unavailable. One approach is to link the practice postcode to an area-based deprivation score, but this method has limitations. This study aimed to develop a Geographical Information Systems (GIS) based model that could better predict a practice population-weighted deprivation score in the absence of patient level data than simple practice postcode linkage. Results We calculated predicted practice level Index of Multiple Deprivation (IMD) 2004 deprivation scores using two methods that did not require patient level data. Firstly we linked the practice postcode to an IMD 2004 score, and secondly we used a GIS model derived using data from Rotherham, UK. We compared our two sets of predicted scores to "gold standard" practice population-weighted scores for practices in Doncaster, Havering and Warrington. Overall, the practice postcode linkage method overestimated "gold standard" IMD scores by 2.54 points (95% CI 0.94, 4.14), whereas our modelling method showed no such bias (mean difference 0.36, 95% CI -0.30, 1.02). The postcode-linked method systematically underestimated the gold standard score in less deprived areas, and overestimated it in more deprived areas. Our modelling method showed a small underestimation in scores at higher levels of deprivation in Havering, but showed no bias in Doncaster or Warrington. The postcode-linked method showed more variability when predicting scores than did the GIS modelling method. Conclusion A GIS based model can be used to predict a practice population-weighted area-based deprivation measure in the absence of patient level data. Our modelled measure generally had better agreement with the population-weighted measure than did a postcode-linked measure. Our model may also avoid an underestimation of IMD scores in less deprived areas, and overestimation of scores in more deprived areas, seen when using postcode linked scores. The proposed method may be of use to researchers who do not have access to patient level spatially referenced data. PMID:17822545

PubMedAlertMe - Standalone Windows-based PubMed SDI Software Application

PubMed Central

Ma’ayan, Avi

2008-01-01

PubMedAlertMe is a Windows-based software system for automatically receiving e-mail alert messages about recent publications listed on PubMed. The e-mail messages contain links to newly available abstracts listed on PubMed describing publications that were selectively returned from a specified list of queries. Links are also provided to directly export citations to EndNote, and links are provided to directly forward articles to colleagues. The program is standalone. Thus, it does not require a remote mail server or user registration. PubMedAlertMe is free software, and can be downloaded from: http://amp.pharm.mssm.edu/PubMedAlertMe/PubMedAlertMe_setup.zip PMID:18402930

An adaptive actuator failure compensation scheme for two linked 2WD mobile robots

NASA Astrophysics Data System (ADS)

Ma, Yajie; Al-Dujaili, Ayad; Cocquempot, Vincent; El Badaoui El Najjar, Maan

2017-01-01

This paper develops a new adaptive compensation control scheme for two linked mobile robots with actuator failurs. A configuration with two linked two-wheel drive (2WD) mobile robots is proposed, and the modelling of its kinematics and dynamics are given. An adaptive failure compensation scheme is developed to compensate actuator failures, consisting of a kinematic controller and a multi-design integration based dynamic controller. The kinematic controller is a virtual one, and based on which, multiple adaptive dynamic control signals are designed which covers all possible failure cases. By combing these dynamic control signals, the dynamic controller is designed, which ensures system stability and asymptotic tracking properties. Simulation results verify the effectiveness of the proposed adaptive failure compensation scheme.

Hydrothermal growth of cross-linked hyperbranched copper dendrites using copper oxalate complex

NASA Astrophysics Data System (ADS)

Truong, Quang Duc; Kakihana, Masato

2012-06-01

A facile and surfactant-free approach has been developed for the synthesis of cross-linked hyperbranched copper dendrites using copper oxalate complex as a precursor and oxalic acid as a reducing and structure-directing agent. The synthesized particles are composed of highly branched nanostructures with unusual cross-linked hierarchical networks. The formation of copper dendrites can be explained in view of both diffusion control and aggregation-based growth model accompanied by the chelation-assisted assembly. Oxalic acid was found to play dual roles as reducing and structure-directing agent based on the investigation results. The understanding on the crystal growth and the roles of oxalic acid provides clear insight into the formation mechanism of hyperbranched metal dendrites.

Claims-based studies of oral glucose-lowering medications can achieve balance in critical clinical variables only observed in electronic health records.

PubMed

Patorno, Elisabetta; Gopalakrishnan, Chandrasekar; Franklin, Jessica M; Brodovicz, Kimberly G; Masso-Gonzalez, Elvira; Bartels, Dorothee B; Liu, Jun; Schneeweiss, Sebastian

2018-04-01

To evaluate the extent to which balance in unmeasured characteristics of patients with type 2 diabetes (T2DM) was achieved in claims data, by comparing against more detailed information from linked electronic health records (EHR) data. Within a large US commercial insurance database and using a cohort design, we identified patients with T2DM initiating linagliptin or a comparator agent within class (ie, another dipeptidyl peptidase-4 inhibitor) or outside class (ie, pioglitazone or a sulphonylurea) between May 2011 and December 2012. We focused on comparators used at a similar stage of diabetes to linagliptin. For each comparison, 1:1 propensity score (PS) matching was used to balance >100 baseline claims-based characteristics, including proxies of diabetes severity and duration. Additional clinical data from EHR were available for a subset of patients. We assessed representativeness of the claims-EHR-linked subset, evaluated the balance of claims- and EHR-based covariates before and after PS-matching via standardized differences (SDs), and quantified the potential bias associated with observed imbalances. From a claims-based study population of 166 613 patients with T2DM, 7219 (4.3%) patients were linked to their EHR data. Claims-based characteristics in the EHR-linked and EHR-unlinked patients were similar (SD < 0.1), confirming the representativeness of the EHR-linked subset. The balance of claims-based and EHR-based patient characteristics appeared to be reasonable before PS-matching and generally improved in the PS-matched population, to be SD < 0.1 for most patient characteristics and SD < 0.2 for select laboratory results and body mass index categories, which was not large enough to cause meaningful confounding. In the context of pharmacoepidemiological research on diabetes therapy, choosing appropriate comparison groups paired with a new-user design and 1:1 PS matching on many proxies of diabetes severity and duration improves balance in covariates typically unmeasured in administrative claims datasets, to the extent that residual confounding is unlikely. © 2017 John Wiley & Sons Ltd.

Prefrontal and medial temporal contributions to episodic memory-based reasoning.

PubMed

Suzuki, Chisato; Tsukiura, Takashi; Mochizuki-Kawai, Hiroko; Shigemune, Yayoi; Iijima, Toshio

2009-03-01

Episodic memory retrieval and reasoning are fundamental psychological components of our daily lives. Although previous studies have investigated the brain regions associated with these processes separately, the neural mechanisms of reasoning based on episodic memory retrieval are largely unknown. Here, we investigated the neural correlates underlying episodic memory-based reasoning using functional magnetic resonance imaging (fMRI). During fMRI scanning, subjects performed three tasks: reasoning, episodic memory retrieval, and episodic memory-based reasoning. We identified dissociable activations related to reasoning, episodic memory retrieval, and linking processes between the two. Regions related to reasoning were identified in the left ventral prefrontal cortices (PFC), and those related to episodic memory retrieval were found in the right medial temporal lobe (MTL) regions. In addition, activations predominant in the linking process between the two were found in the left dorsal and right ventral PFC. These findings suggest that episodic memory-based reasoning is composed of at least three processes, i.e., reasoning, episodic memory retrieval, and linking processes between the two, and that activation of both the PFC and MTL is crucial in episodic memory-based reasoning. These findings are the first to demonstrate that PFC and MTL regions contribute differentially to each process in episodic memory-based reasoning.

Genetically encoded releasable photo-cross-linking strategies for studying protein-protein interactions in living cells.

PubMed

Yang, Yi; Song, Haiping; He, Dan; Zhang, Shuai; Dai, Shizhong; Xie, Xiao; Lin, Shixian; Hao, Ziyang; Zheng, Huangtao; Chen, Peng R

2017-10-01

Although protein-protein interactions (PPIs) have crucial roles in virtually all cellular processes, the identification of more transient interactions in their biological context remains challenging. Conventional photo-cross-linking strategies can be used to identify transient interactions, but these approaches often suffer from high background due to the cross-linked bait proteins. To solve the problem, we have developed membrane-permeable releasable photo-cross-linkers that allow for prey-bait separation after protein complex isolation and can be installed in proteins of interest (POIs) as unnatural amino acids. Here we describe the procedures for using two releasable photo-cross-linkers, DiZSeK and DiZHSeC, in both living Escherichia coli and mammalian cells. A cleavage after protein photo-cross-linking (CAPP ) strategy based on the photo-cross-linker DiZSeK is described, in which the prey protein pool is released from a POI after affinity purification. Prey proteins are analyzed using mass spectrometry or 2D gel electrophoresis for global comparison of interactomes from different experimental conditions. An in situ cleavage and mass spectrometry (MS)-label transfer after protein photo-cross-linking (IMAPP) strategy based on the photo-cross-linker DiZHSeC is also described. This strategy can be used for the identification of cross-linking sites to allow detailed characterization of PPI interfaces. The procedures for photo-cross-linker incorporation, photo-cross-linking of interaction partners and affinity purification of cross-linked complexes are similar for the two photo-cross-linkers. The final section of the protocol describes prey-bait separation (for CAPP) and MS-label transfer and identification (for IMAPP). After plasmid construction, the CAPP and IMAPP strategies can be completed within 6 and 7 d, respectively.

Epidemiological links between tuberculosis cases identified twice as efficiently by whole genome sequencing than conventional molecular typing: A population-based study.

PubMed

Jajou, Rana; de Neeling, Albert; van Hunen, Rianne; de Vries, Gerard; Schimmel, Henrieke; Mulder, Arnout; Anthony, Richard; van der Hoek, Wim; van Soolingen, Dick

2018-01-01

Patients with Mycobacterium tuberculosis isolates sharing identical DNA fingerprint patterns can be epidemiologically linked. However, municipal health services in the Netherlands are able to confirm an epidemiological link in only around 23% of the patients with isolates clustered by the conventional variable number of tandem repeat (VNTR) genotyping. This research aims to investigate whether whole genome sequencing (WGS) is a more reliable predictor of epidemiological links between tuberculosis patients than VNTR genotyping. VNTR genotyping and WGS were performed in parallel on all Mycobacterium tuberculosis complex isolates received at the Netherlands National Institute for Public Health and the Environment in 2016. Isolates were clustered by VNTR when they shared identical 24-loci VNTR patterns; isolates were assigned to a WGS cluster when the pair-wise genetic distance was ≤ 12 single nucleotide polymorphisms (SNPs). Cluster investigation was performed by municipal health services on all isolates clustered by VNTR in 2016. The proportion of epidemiological links identified among patients clustered by either method was calculated. In total, 535 isolates were genotyped, of which 25% (134/535) were clustered by VNTR and 14% (76/535) by WGS; the concordance between both typing methods was 86%. The proportion of epidemiological links among WGS clustered cases (57%) was twice as common than among VNTR clustered cases (31%). When WGS was applied, the number of clustered isolates was halved, while all epidemiologically linked cases remained clustered. WGS is therefore a more reliable tool to predict epidemiological links between tuberculosis cases than VNTR genotyping and will allow more efficient transmission tracing, as epidemiological investigations based on false clustering can be avoided.

Development and Application of a Saccharomyces cerevisiae-Expressed Nucleocapsid Protein-Based Enzyme-Linked Immunosorbent Assay for Detection of Antibodies against Infectious Bronchitis Virus

PubMed Central

Gibertoni, Aliandra M.; Montassier, Maria de Fátima S.; Sena, Janete A. D.; Givisiez, Patrícia E. N.; Furuyama, Cibele R. A. G.; Montassier, Hélio J.

2005-01-01

A Saccharomyces cerevisiae-expressed nucleocapsid (N) polypeptide of the M41 strain of infectious bronchitis virus (IBV) was used as antigen in a recombinant yeast-expressed N protein-based enzyme-linked immunosorbent assay (Y-N-ELISA). The Y-N-ELISA was rapid, sensitive, and specific for detecting chicken serum antibodies to IBV, and it compared favorably with a commercial ELISA. PMID:15815038

Cell therapy for basement membrane-linked diseases.

PubMed

Nyström, Alexander; Bornert, Olivier; Kühl, Tobias

2017-01-01

For most disorders caused by mutations in genes encoding basement membrane (BM) proteins, there are at present only limited treatment options available. Genetic BM-linked disorders can be viewed as especially suited for treatment with cell-based therapy approaches because the proteins that need to be restored are located in the extracellular space. In consequence, complete and permanent engraftment of cells does not necessarily have to occur to achieve substantial causal therapeutic effects. For these disorders cells can be used as transient vehicles for protein replacement. In addition, it is becoming evident that BM-linked genetic disorders are modified by secondary diseases mechanisms. Cell-based therapies have also the ability to target such disease modifying mechanisms. Thus, cell therapies can simultaneously provide causal treatment and symptomatic relief, and accordingly hold great potential for treatment of BM-linked disorders. However, this potential has for most applications and diseases so far not been realized. Here, we will present the state of cell therapies for BM-linked diseases. We will discuss use of both pluripotent and differentiated cells, the limitation of the approaches, their challenges, and the way forward to potential wider implementation of cell therapies in the clinics. Copyright © 2016 Elsevier B.V. All rights reserved.

Impairment assessment of orthogonal frequency division multiplexing over dispersion-managed links in backbone and backhaul networks

NASA Astrophysics Data System (ADS)

Tamilarasan, Ilavarasan; Saminathan, Brindha; Murugappan, Meenakshi

2016-04-01

The past decade has seen the phenomenal usage of orthogonal frequency division multiplexing (OFDM) in the wired as well as wireless communication domains, and it is also proposed in the literature as a future proof technique for the implementation of flexible resource allocation in cognitive optical networks. Fiber impairment assessment and adaptive compensation becomes critical in such implementations. A comprehensive analytical model for impairments in OFDM-based fiber links is developed. The proposed model includes the combined impact of laser phase fluctuations, fiber dispersion, self phase modulation, cross phase modulation, four-wave mixing, the nonlinear phase noise due to the interaction of amplified spontaneous emission with fiber nonlinearities, and the photodetector noises. The bit error rate expression for the proposed model is derived based on error vector magnitude estimation. The performance analysis of the proposed model is presented and compared for dispersion compensated and uncompensated backbone/backhaul links. The results suggest that OFDM would perform better for uncompensated links than the compensated links due to the negligible FWM effects and there is a need for flexible compensation. The proposed model can be employed in cognitive optical networks for accurate assessment of fiber-related impairments.

Preparation and characterization of a magneto-polymeric nanocomposite: Fe 3O 4 nanoparticles in a grafted, cross-linked and plasticized poly(vinyl chloride) matrix

NASA Astrophysics Data System (ADS)

Rodríguez-Fernández, Oliverio S.; Rodríguez-Calzadíaz, C. A.; Yáñez-Flores, Isaura G.; Montemayor, Sagrario M.

In this work two kind of materials: (1) grafted, cross-linked and plasticized poly(vinyl chloride) (PVC) "plastic films" and (2) magnetic plastic films "magneto-polymeric nanocomposites" were prepared. Precursor solutions or "plastisols" used to obtain the plastic films were obtained by mixing PVC (emulsion grade) as polymeric matrix, di(2-ethylhexyl)phthalate (DOP) as plasticizer, a thermal stabilizer based in Ca/Zn salts, and a cross-linking agent, 3-mercaptopropyltrimethoxysilane (MTMS) or 3-aminopropyltriethoxysilane (ATES), at several concentrations. Flexible films were obtained from the plastisols using static casting. The stress-strain behavior and the gel content (determined by Soxhlet extraction with boiling THF) of the flexible films were measured in order to evaluate the effect of the cross-linking agent and their content on the degree of cross-linking. The magneto-polymeric nanocomposites were obtained by mixing the optimum composition of the plastisols (analyzed previously) with magnetite (Fe 3O 4)-based ferrofluid and DOP. Later, flexible films were obtained by static casting of the plastisol/ferrofluid systems. The magnetic films were characterized by the above-mentioned techniques and X-ray diffraction, vibrating sample magnetometry and thermogravimetrical analysis.

Photoregulating RNA digestion using azobenzene linked dumbbell antisense oligodeoxynucleotides.

PubMed

Wu, Li; He, Yujian; Tang, Xinjing

2015-06-17

Introduction of 4,4'-bis(hydroxymethyl)-azobenzene (azo) to dumbbell hairpin oligonucleotides at the loop position was able to reversibly control the stability of the whole hairpin structure via UV or visible light irradiation. Here, we designed and synthesized a series of azobenzene linked dumbbell antisense oligodeoxynucleotides (asODNs) containing two terminal hairpins that are composed of an asODN and a short inhibitory sense strand. Thermal melting studies of these azobenzene linked dumbbell asODNs indicated that efficient trans to cis photoisomerization of azobenzene moieties induced large difference in thermal stability (ΔTm = 12.1-21.3 °C). In addition, photomodulation of their RNA binding abilities and RNA digestion by RNase H was investigated. The trans-azobenzene linked asODNs with the optimized base pairs between asODN strands and inhibitory sense strands could only bind few percentage of the target RNA, while it was able to recover their binding to the target RNA and degrade it by RNase H after light irradiation. Upon optimization, it is promising to use these azobenzene linked asODNs for reversible spatial and temporal regulation of antisense activities based on both steric binding and RNA digestion by RNase H.

Evaluation of inertial devices for the control of large, flexible, space-based telerobotic arms

NASA Technical Reports Server (NTRS)

Montgomery, Raymond C.; Kenny, Sean P.; Ghosh, Dave; Shenhar, Joram

1993-01-01

Inertial devices, including sensors and actuators, offer the potential of improving the tracking of telerobotic commands for space-based robots by smoothing payload motions and suppressing vibrations. In this paper, inertial actuators (specifically, torque-wheels and reaction-masses) are studied for that potential application. Batch simulation studies are presented which show that torque-wheels can reduce the overshoot in abrupt stop commands by 82 percent for a two-link arm. For man-in-the-loop evaluation, a real-time simulator has been developed which samples a hand-controller, solves the nonlinear equations of motion, and graphically displays the resulting motion on a computer workstation. Currently, two manipulator models, a two-link, rigid arm and a single-link, flexible arm, have been studied. Results are presented which show that, for a single-link arm, a reaction-mass/torque-wheel combination at the payload end can yield a settling time of 3 s for disturbances in the first flexible mode as opposed to 10 s using only a hub motor. A hardware apparatus, which consists of a single-link, highly flexible arm with a hub motor and a torque-wheel, has been assembled to evaluate the concept and is described herein.

Evaluation of inertial devices for the control of large, flexible, space-based telerobotic arms

NASA Astrophysics Data System (ADS)

Montgomery, Raymond C.; Kenny, Sean P.; Ghosh, Dave; Shenhar, Joram

1993-02-01

Inertial devices, including sensors and actuators, offer the potential of improving the tracking of telerobotic commands for space-based robots by smoothing payload motions and suppressing vibrations. In this paper, inertial actuators (specifically, torque-wheels and reaction-masses) are studied for that potential application. Batch simulation studies are presented which show that torque-wheels can reduce the overshoot in abrupt stop commands by 82 percent for a two-link arm. For man-in-the-loop evaluation, a real-time simulator has been developed which samples a hand-controller, solves the nonlinear equations of motion, and graphically displays the resulting motion on a computer workstation. Currently, two manipulator models, a two-link, rigid arm and a single-link, flexible arm, have been studied. Results are presented which show that, for a single-link arm, a reaction-mass/torque-wheel combination at the payload end can yield a settling time of 3 s for disturbances in the first flexible mode as opposed to 10 s using only a hub motor. A hardware apparatus, which consists of a single-link, highly flexible arm with a hub motor and a torque-wheel, has been assembled to evaluate the concept and is described herein.

Free-Space Quantum Key Distribution using Polarization Entangled Photons

NASA Astrophysics Data System (ADS)

Kurtsiefer, Christian

2007-06-01

We report on a complete experimental implementation of a quantum key distribution protocol through a free space link using polarization-entangled photon pairs from a compact parametric down-conversion source [1]. Based on a BB84-equivalent protocol, we generated without interruption over 10 hours a secret key free-space optical link distance of 1.5 km with a rate up to 950 bits per second after error correction and privacy amplification. Our system is based on two time stamp units and relies on no specific hardware channel for coincidence identification besides an IP link. For that, initial clock synchronization with an accuracy of better than 2 ns is achieved, based on a conventional NTP protocol and a tiered cross correlation of time tags on both sides. Time tags are used to servo a local clock, allowing a streamed measurement on correctly identified photon pairs. Contrary to the majority of quantum key distribution systems, this approach does not require a trusted large-bandwidth random number generator, but integrates that into the physical key generation process. We discuss our current progress of implementing a key distribution via an atmospherical link during daylight conditions, and possible attack scenarios on a physical timing information side channel to a entanglement-based key distribution system. [1] I. Marcikic, A. Lamas-Linares, C. Kurtsiefer, Appl. Phys. Lett. 89, 101122 (2006).

Link state relationships under incident conditions : using a CTM-based linear programming dynamic traffic assignment model.

DOT National Transportation Integrated Search

2010-03-01

Urban transportation networks, consisting of numerous links and nodes, experience traffic incidents such as accidents and road : maintenance work. A typical consequence of incidents is congestion which results in long queues and causes high travel ti...

Link State Relationships Under Incident Conditions: Using a CTM-Based Linear Programming Dynamic Traffic Assignment Model

DOT National Transportation Integrated Search

2010-03-01

Urban transportation networks, consisting of numerous links and nodes, experience traffic incidents such as accidents and road maintenance work. A typical consequence of incidents is congestion which results in long queues and causes high travel time...

Linking Ecosystem Services and Human Health: The Eco-Health Relationship Browser

EPA Science Inventory

Ecosystems provide multiple services associated with the provision of nature-based goods and services. Many of these ecosystem services have been linked to a range of positive health outcomes through buffering of pollutants, mitigation of natural hazards, and promotion of healthy...

Ways to estimate speeds for the purposes of air quality conformity analyses.

DOT National Transportation Integrated Search

2002-01-01

A speed post-processor refers to equations or lookup tables that can determine vehicle speeds on a particular roadway link using only the limited information available in a long-range planning model. An estimated link speed is usually based on volume...

Odd-Even Alternation in Tautomeric Porous Organic Cages with Exceptional Chemical Stability.

PubMed

Bera, Saibal; Basu, Arghya; Tothadi, Srinu; Garai, Bikash; Banerjee, Subhrashis; Vanka, Kumar; Banerjee, Rahul

2017-02-13

Amine-linked (C-NH) porous organic cages (POCs) are preferred over the imine-linked (C=N) POCs owing to their enhanced chemical stability. In general, amine-linked cages, obtained by the reduction of corresponding imines, are not shape-persistent in the crystalline form. Moreover, they require multistep synthesis. Herein, a one-pot synthesis of four new amine-linked organic cages by the reaction of 1,3,5-triformylphloroglucinol (Tp) with different analogues of alkanediamine is reported. The POCs resulting from the odd diamine (having an odd number of -CH 2 groups) is conformationally eclipsed, while the POCs constructed from even diamines adopt a gauche conformation. This odd-even alternation in the conformation of POCs has been supported by computational calculations. The synthetic strategy hinges on the concept of Schiff base condensation reaction followed by keto-enol tautomerization. This mechanism is the key for the exceptional chemical stability of cages and facilitates their resistance towards acids and bases. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cross-Linking/Mass Spectrometry for Studying Protein Structures and Protein-Protein Interactions: Where Are We Now and Where Should We Go from Here?

PubMed

Sinz, Andrea

2018-05-28

Structural mass spectrometry (MS) is gaining increasing importance for deriving valuable three-dimensional structural information on proteins and protein complexes, and it complements existing techniques, such as NMR spectroscopy and X-ray crystallography. Structural MS unites different MS-based techniques, such as hydrogen/deuterium exchange, native MS, ion-mobility MS, protein footprinting, and chemical cross-linking/MS, and it allows fundamental questions in structural biology to be addressed. In this Minireview, I will focus on the cross-linking/MS strategy. This method not only delivers tertiary structural information on proteins, but is also increasingly being used to decipher protein interaction networks, both in vitro and in vivo. Cross-linking/MS is currently one of the most promising MS-based approaches to derive structural information on very large and transient protein assemblies and intrinsically disordered proteins. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Working with previously anonymous gamete donors and donor-conceived adults: recent practice experiences of running the DNA-based voluntary information exchange and contact register, UK DonorLink.

PubMed

Crawshaw, Marilyn; Gunter, Christine; Tidy, Christine; Atherton, Freda

2013-03-01

This article describes recent practice experiences with donor conceived adults, donors, non-donor-conceived adult children of donors using the voluntary DNA-based register, UK DonorLink. It highlights additional complexities faced when using DNA rather than paper records for searching, in particular from the risk of false positives, low chances of success and potential inclusion of biological parents' DNA. Professionals' experiences in supporting those being "linked" suggest challenges as well as rewards. Registration carries the potential to be therapeutic for donor-conceived adults and donors and to enhance their political awareness regardless of links being made. Registrants value both peer and professional support, providing the latter can respond flexibly and be delivered by staff experienced in intermediary work. Given that the majority of those affected by donor conception internationally come from anonymous donation systems, these findings are highly pertinent and argue the need for political and moral debate about such service provision.

Image segmentation algorithm based on improved PCNN

NASA Astrophysics Data System (ADS)

Chen, Hong; Wu, Chengdong; Yu, Xiaosheng; Wu, Jiahui

2017-11-01

A modified simplified Pulse Coupled Neural Network (PCNN) model is proposed in this article based on simplified PCNN. Some work have done to enrich this model, such as imposing restrictions items of the inputs, improving linking inputs and internal activity of PCNN. A self-adaptive parameter setting method of linking coefficient and threshold value decay time constant is proposed here, too. At last, we realized image segmentation algorithm for five pictures based on this proposed simplified PCNN model and PSO. Experimental results demonstrate that this image segmentation algorithm is much better than method of SPCNN and OTSU.

Adaptive Reliable Routing Protocol Using Combined Link Stability Estimation for Mobile Ad hoc Networks

NASA Astrophysics Data System (ADS)

Vadivel, R.; Bhaskaran, V. Murali

2010-10-01

The main reason for packet loss in ad hoc networks is the link failure or node failure. In order to increase the path stability, it is essential to distinguish and moderate the failures. By knowing individual link stability along a path, path stability can be identified. In this paper, we develop an adaptive reliable routing protocol using combined link stability estimation for mobile ad hoc networks. The main objective of this protocol is to determine a Quality of Service (QoS) path along with prolonging the network life time and to reduce the packet loss. We calculate a combined metric for a path based on the parameters Link Expiration Time, Node Remaining Energy and Node Velocity and received signal strength to predict the link stability or lifetime. Then, a bypass route is established to retransmit the lost data, when a link failure occurs. By simulation results, we show that the proposed reliable routing protocol achieves high delivery ratio with reduced delay and packet drop.

The effect of inertial coupling in the dynamics and control of flexible robotic manipulators

NASA Technical Reports Server (NTRS)

Tesar, Delbert; Curran, Carol Cockrell; Graves, Philip Lee

1988-01-01

A general model of the dynamics of flexible robotic manipulators is presented, including the gross motion of the links, the vibrations of the links and joints, and the dynamic coupling between the gross motions and vibrations. The vibrations in the links may be modeled using lumped parameters, truncated modal summation, a component mode synthesis method, or a mixture of these methods. The local link inertia matrix is derived to obtain the coupling terms between the gross motion of the link and the vibrations of the link. Coupling between the motions of the links results from the kinematic model, which utilizes the method of kinematic influence. The model is used to simulate the dynamics of a flexible space-based robotic manipulator which is attached to a spacecraft, and is free to move with respect to the inertial reference frame. This model may be used to study the dynamic response of the manipulator to the motions of its joints, or to externally applied disturbances.

On the Reproducibility of Label-Free Quantitative Cross-Linking/Mass Spectrometry

NASA Astrophysics Data System (ADS)

Müller, Fränze; Fischer, Lutz; Chen, Zhuo Angel; Auchynnikava, Tania; Rappsilber, Juri

2018-02-01

Quantitative cross-linking/mass spectrometry (QCLMS) is an emerging approach to study conformational changes of proteins and multi-subunit complexes. Distinguishing protein conformations requires reproducibly identifying and quantifying cross-linked peptides. Here we analyzed the variation between multiple cross-linking reactions using bis[sulfosuccinimidyl] suberate (BS3)-cross-linked human serum albumin (HSA) and evaluated how reproducible cross-linked peptides can be identified and quantified by LC-MS analysis. To make QCLMS accessible to a broader research community, we developed a workflow that integrates the established software tools MaxQuant for spectra preprocessing, Xi for cross-linked peptide identification, and finally Skyline for quantification (MS1 filtering). Out of the 221 unique residue pairs identified in our sample, 124 were subsequently quantified across 10 analyses with coefficient of variation (CV) values of 14% (injection replica) and 32% (reaction replica). Thus our results demonstrate that the reproducibility of QCLMS is in line with the reproducibility of general quantitative proteomics and we establish a robust workflow for MS1-based quantitation of cross-linked peptides.

Identification of influential spreaders in online social networks using interaction weighted K-core decomposition method

NASA Astrophysics Data System (ADS)

Al-garadi, Mohammed Ali; Varathan, Kasturi Dewi; Ravana, Sri Devi

2017-02-01

Online social networks (OSNs) have become a vital part of everyday living. OSNs provide researchers and scientists with unique prospects to comprehend individuals on a scale and to analyze human behavioral patterns. Influential spreaders identification is an important subject in understanding the dynamics of information diffusion in OSNs. Targeting these influential spreaders is significant in planning the techniques for accelerating the propagation of information that is useful for various applications, such as viral marketing applications or blocking the diffusion of annoying information (spreading of viruses, rumors, online negative behaviors, and cyberbullying). Existing K-core decomposition methods consider links equally when calculating the influential spreaders for unweighted networks. Alternatively, the proposed link weights are based only on the degree of nodes. Thus, if a node is linked to high-degree nodes, then this node will receive high weight and is treated as an important node. Conversely, the degree of nodes in OSN context does not always provide accurate influence of users. In the present study, we improve the K-core method for OSNs by proposing a novel link-weighting method based on the interaction among users. The proposed method is based on the observation that the interaction of users is a significant factor in quantifying the spreading capability of user in OSNs. The tracking of diffusion links in the real spreading dynamics of information verifies the effectiveness of our proposed method for identifying influential spreaders in OSNs as compared with degree centrality, PageRank, and original K-core.

General Theory and Algorithms for the Non-Casual Inversion, Slewing and Control of Space-Based Articulated Structures

DTIC Science & Technology

1993-10-01

Structures: Simultaneous Trajectory Tracking and Vibration Reduction ... 10 3 . Buckling Control of a Flexible Beam Using Piezoelectric Actuators...bounded solution for the inverse dynamic torque has to be non-causal. Bayo, et. al. [ 3 ], extended the inverse dynamics to planar, multiple-link systems...presented by &ayo and Moulin [4] for the single link system, with provisions for 3 extension to multiple link systems. An equivalent time domain approach for

Analysis of the harmonic and intermodulation distortion in a multimode fiber optic link.

PubMed

Gasulla, I; Capmany, J

2007-07-23

We present an analytical evaluation of the harmonic and the intermodulation distortion effects produced in the transmission of an analog signal composed of various RF tones through a multimode fiber link. It is based on the electric field propagation model previously published by the authors. Results show the possibility of implementing subcarrier multiplexing techniques (SCM) with Composite Second Order (CSO) values below -50 dBc over short and middle reach multimode fiber links.

Leaders Are the Network: Applying the Kotter Model in Shaping Future Information Systems

DTIC Science & Technology

2010-01-01

common operational picture (COP) ( Hinson , 2009). Figure 3 demonstrates how CID combines Link 16 and FBCB2 feeds. The CID server polls different...Link 16 Info Exchange A B C S A D S Figure 3 FBCB2-Link 16 Information Exchange. Source: Created by author based on information derived from Hinson ...31552-new-army-leader-development-strategy- released/ (accessed July 30, 2010). Hinson , Jason and Summit, Bob, “Combat Identification Server: Blue

The Development of an Expert System for the Creative Design of Mechanisms

DTIC Science & Technology

1989-06-26

adjacelnt Link-1 Figue 41 B.Semntc newr-bae knowlede representto cee 25 4.3 Planning Control in Mechanism Design In a "plain", rule-based expert system...the contracted level, ensures the non-crossing feature. 2. Geometrical: handled at the monochrome level, manages the approximate size of links. 3...Ornamental: handled at the colored level, manages proper orientations between binary links and other miscellaneous appearance of the sketch. Each stage

The data sharing advantage in astrophysics

NASA Astrophysics Data System (ADS)

Dorch, Bertil F.; Drachen, Thea M.; Ellegaard, Ole

2016-10-01

We present here evidence for the existence of a citation advantage within astrophysics for papers that link to data. Using simple measures based on publication data from NASA Astrophysics Data System we find a citation advantage for papers with links to data receiving on the average significantly more citations per paper than papers without links to data. Furthermore, using INSPEC and Web of Science databases we investigate whether either papers of an experimental or theoretical nature display different citation behavior.

The vulnerability of the global container shipping network to targeted link disruption

NASA Astrophysics Data System (ADS)

Viljoen, Nadia M.; Joubert, Johan W.

2016-11-01

Using complex network theory to describe the relational geography of maritime networks has provided great insights regarding their hierarchy and evolution over the past two decades. Unlike applications in other transport fields, notably air transport, complex network theory has had limited application in studying the vulnerability of maritime networks. This study uses targeted link disruption to investigate the strategy specific vulnerability of the network. Although nodal infrastructure such as ports can render a network vulnerable as a result of labour strikes, trade embargoes or natural disasters, it is the shipping lines connecting the ports that are more probably disrupted, either from within the industry, or outside. In this paper, we apply and evaluate two link-based disruption strategies on the global container shipping network, one based on link betweenness, and the other on link salience, to emulate the impact of large-scale service reconfiguration affecting priority links. The results show that the network is by and large robust to such reconfiguration. Meanwhile the flexibility of the network is reduced by both strategies, but to a greater degree by betweenness, resulting in a reduction of transshipment and dynamic rerouting potential amongst the busiest port regions. The results further show that the salience strategy is highly effective in reducing the commonality of shortest path sets, thereby diminishing opportunities for freight consolidation and scale economies.

Linked Patient-Reported Outcomes Data From Patients With Multiple Sclerosis Recruited on an Open Internet Platform to Health Care Claims Databases Identifies a Representative Population for Real-Life Data Analysis in Multiple Sclerosis.

PubMed

Risson, Valery; Ghodge, Bhaskar; Bonzani, Ian C; Korn, Jonathan R; Medin, Jennie; Saraykar, Tanmay; Sengupta, Souvik; Saini, Deepanshu; Olson, Melvin

2016-09-22

An enormous amount of information relevant to public health is being generated directly by online communities. To explore the feasibility of creating a dataset that links patient-reported outcomes data, from a Web-based survey of US patients with multiple sclerosis (MS) recruited on open Internet platforms, to health care utilization information from health care claims databases. The dataset was generated by linkage analysis to a broader MS population in the United States using both pharmacy and medical claims data sources. US Facebook users with an interest in MS were alerted to a patient-reported survey by targeted advertisements. Eligibility criteria were diagnosis of MS by a specialist (primary progressive, relapsing-remitting, or secondary progressive), ≥12-month history of disease, age 18-65 years, and commercial health insurance. Participants completed a questionnaire including data on demographic and disease characteristics, current and earlier therapies, relapses, disability, health-related quality of life, and employment status and productivity. A unique anonymous profile was generated for each survey respondent. Each anonymous profile was linked to a number of medical and pharmacy claims datasets in the United States. Linkage rates were assessed and survey respondents' representativeness was evaluated based on differences in the distribution of characteristics between the linked survey population and the general MS population in the claims databases. The advertisement was placed on 1,063,973 Facebook users' pages generating 68,674 clicks, 3719 survey attempts, and 651 successfully completed surveys, of which 440 could be linked to any of the claims databases for 2014 or 2015 (67.6% linkage rate). Overall, no significant differences were found between patients who were linked and not linked for educational status, ethnicity, current or prior disease-modifying therapy (DMT) treatment, or presence of a relapse in the last 12 months. The frequencies of the most common MS symptoms did not differ significantly between linked patients and the general MS population in the databases. Linked patients were slightly younger and less likely to be men than those who were not linkable. Linking patient-reported outcomes data, from a Web-based survey of US patients with MS recruited on open Internet platforms, to health care utilization information from claims databases may enable rapid generation of a large population of representative patients with MS suitable for outcomes analysis.

Development of an air ground data exchange concept: Flight deck perspective

NASA Technical Reports Server (NTRS)

Flathers, G. W., II

1987-01-01

The planned modernization of the U.S. National Airspace System (NAS) includes the development and use of a digital data link as a means to exchange information between aircraft and ground-based facilities. This report presents an operationally-oriented concept on how data link could be used for applications related directly to air traffic control. The specific goal is to establish the role that data link could play in the air-ground communications. Due regard is given to the unique characteristics of data link and voice communications, current principles of air traffic control, operational procedures, human factors/man-machine interfaces, and the integration of data link with other air and ground systems. The resulting concept is illustrated in the form of a paper-and-pencil simulation in which data link and voice communications during the course of a hypothetical flight are described.

Modified gum arabic cross-linked gelatin scaffold for biomedical applications.

PubMed

Sarika, P R; Cinthya, Kuriakose; Jayakrishnan, A; Anilkumar, P R; James, Nirmala Rachel

2014-10-01

The present work deals with development of modified gum arabic cross-linked gelatin scaffold for cell culture. A new biocompatible scaffold was developed by cross-linking gelatin (Gel) with gum arabic, a polysaccharide. Gum arabic was subjected to periodate oxidation to obtain gum arabic aldehyde (GAA). GAA was reacted with gelatin under appropriate pH to prepare the cross-linked hydrogel. Cross-linking occurred due to Schiff's base reaction between aldehyde groups of oxidized gum arabic and amino groups of gelatin. The scaffold prepared from the hydrogel was characterized by swelling properties, degree of cross-linking, in vitro degradation and scanning electron microscopy (SEM). Cytocompatibility evaluation using L-929 and HepG2 cells confirmed non-cytotoxic and non-adherent nature of the scaffold. These properties are essential for generating multicellular spheroids and hence the scaffold is proposed to be a suitable candidate for spheroid cell culture. Copyright © 2014 Elsevier B.V. All rights reserved.

The NIF LinkOut broker: a web resource to facilitate federated data integration using NCBI identifiers.

PubMed

Marenco, Luis; Ascoli, Giorgio A; Martone, Maryann E; Shepherd, Gordon M; Miller, Perry L

2008-09-01

This paper describes the NIF LinkOut Broker (NLB) that has been built as part of the Neuroscience Information Framework (NIF) project. The NLB is designed to coordinate the assembly of links to neuroscience information items (e.g., experimental data, knowledge bases, and software tools) that are (1) accessible via the Web, and (2) related to entries in the National Center for Biotechnology Information's (NCBI's) Entrez system. The NLB collects these links from each resource and passes them to the NCBI which incorporates them into its Entrez LinkOut service. In this way, an Entrez user looking at a specific Entrez entry can LinkOut directly to related neuroscience information. The information stored in the NLB can also be utilized in other ways. A second approach, which is operational on a pilot basis, is for the NLB Web server to create dynamically its own Web page of LinkOut links for each NCBI identifier in the NLB database. This approach can allow other resources (in addition to the NCBI Entrez) to LinkOut to related neuroscience information. The paper describes the current NLB system and discusses certain design issues that arose during its implementation.

The NIF LinkOut Broker: A Web Resource to Facilitate Federated Data Integration using NCBI Identifiers

PubMed Central

Ascoli, Giorgio A.; Martone, Maryann E.; Shepherd, Gordon M.; Miller, Perry L.

2009-01-01

This paper describes the NIF LinkOut Broker (NLB) that has been built as part of the Neuroscience Information Framework (NIF) project. The NLB is designed to coordinate the assembly of links to neuroscience information items (e.g., experimental data, knowledge bases, and software tools) that are (1) accessible via the Web, and (2) related to entries in the National Center for Biotechnology Information’s (NCBI’s) Entrez system. The NLB collects these links from each resource and passes them to the NCBI which incorporates them into its Entrez LinkOut service. In this way, an Entrez user looking at a specific Entrez entry can LinkOut directly to related neuroscience information. The information stored in the NLB can also be utilized in other ways. A second approach, which is operational on a pilot basis, is for the NLB Web server to create dynamically its own Web page of LinkOut links for each NCBI identifier in the NLB database. This approach can allow other resources (in addition to the NCBI Entrez) to LinkOut to related neuroscience information. The paper describes the current NLB system and discusses certain design issues that arose during its implementation. PMID:18975149

Linking NCBI to Wikipedia: a wiki-based approach.

PubMed

Page, Roderic D M

2011-03-31

The NCBI Taxonomy underpins many bioinformatics and phyloinformatics databases, but by itself provides limited information on the taxa it contains. One readily available source of information on many taxa is Wikipedia. This paper describes iPhylo Linkout, a Semantic wiki that maps taxa in NCBI's taxonomy database onto corresponding pages in Wikipedia. Storing the mapping in a wiki makes it easy to edit, correct, or otherwise annotate the links between NCBI and Wikipedia. The mapping currently comprises some 53,000 taxa, and is available at http://iphylo.org/linkout. The links between NCBI and Wikipedia are also made available to NCBI users through the NCBI LinkOut service.

Shuttle Communications and Tracking Systems Modeling and TDRSS Link Simulations Studies

NASA Technical Reports Server (NTRS)

Chie, C. M.; Dessouky, K.; Lindsey, W. C.; Tsang, C. S.; Su, Y. T.

1985-01-01

An analytical simulation package (LinCsim) which allows the analytical verification of data transmission performance through TDRSS satellites was modified. The work involved the modeling of the user transponder, TDRS, TDRS ground terminal, and link dynamics for forward and return links based on the TDRSS performance specifications (4) and the critical design reviews. The scope of this effort has recently been expanded to include the effects of radio frequency interference (RFI) on the bit error rate (BER) performance of the S-band return links. The RFI environment and the modified TDRSS satellite and ground station hardware are being modeled in accordance with their description in the applicable documents.

Integrating First-Year Technology and Finite Mathematics Courses

ERIC Educational Resources Information Center

Shafii-Mousavi, Morteza; Kochanowski, Paul

2006-01-01

This paper describes an interdisciplinary project-based mathematics course linked to a computer technology course. The linkage encourages an appreciation of mathematics and technology as students see an immediate use for these skills in completing actual real-world projects. Linking mathematics and technology integrates subjects taught in…

Word Links: A Strategy for Developing Word Knowledge

ERIC Educational Resources Information Center

Yopp, Ruth Helen

2007-01-01

Word Links, an effective strategy for developing students' vocabulary, is based on four principles. It provides contextual and definitional information; offers repeated exposure to words and opportunities to practice them; encourages students to think about relationships among word meanings; and involves active engagement in learning tasks. Yopp…

Performance Assessment Links in Science.

ERIC Educational Resources Information Center

Quellmalz, Edys; Schank, Patricia; Hinojosa, Thomas; Padilla, Christine

1999-01-01

Describes work in progress at SRI International in the Performance Assessment Links in Science (PALS) project, which is developing an online, standards-based, interactive resource bank of science performance assessments. Coupled with the development of the resource bank is a program of research on effective use of these resources. (SLD)

FPGA-based fused smart sensor for dynamic and vibration parameter extraction in industrial robot links.

PubMed

Rodriguez-Donate, Carlos; Morales-Velazquez, Luis; Osornio-Rios, Roque Alfredo; Herrera-Ruiz, Gilberto; de Jesus Romero-Troncoso, Rene

2010-01-01

Intelligent robotics demands the integration of smart sensors that allow the controller to efficiently measure physical quantities. Industrial manipulator robots require a constant monitoring of several parameters such as motion dynamics, inclination, and vibration. This work presents a novel smart sensor to estimate motion dynamics, inclination, and vibration parameters on industrial manipulator robot links based on two primary sensors: an encoder and a triaxial accelerometer. The proposed smart sensor implements a new methodology based on an oversampling technique, averaging decimation filters, FIR filters, finite differences and linear interpolation to estimate the interest parameters, which are computed online utilizing digital hardware signal processing based on field programmable gate arrays (FPGA).

FPGA-Based Fused Smart Sensor for Dynamic and Vibration Parameter Extraction in Industrial Robot Links

PubMed Central

Rodriguez-Donate, Carlos; Morales-Velazquez, Luis; Osornio-Rios, Roque Alfredo; Herrera-Ruiz, Gilberto; de Jesus Romero-Troncoso, Rene

2010-01-01

Intelligent robotics demands the integration of smart sensors that allow the controller to efficiently measure physical quantities. Industrial manipulator robots require a constant monitoring of several parameters such as motion dynamics, inclination, and vibration. This work presents a novel smart sensor to estimate motion dynamics, inclination, and vibration parameters on industrial manipulator robot links based on two primary sensors: an encoder and a triaxial accelerometer. The proposed smart sensor implements a new methodology based on an oversampling technique, averaging decimation filters, FIR filters, finite differences and linear interpolation to estimate the interest parameters, which are computed online utilizing digital hardware signal processing based on field programmable gate arrays (FPGA). PMID:22319345

Linking data sources for measurement of effective coverage in maternal and newborn health: what do we learn from individual- vs ecological-linking methods?

PubMed

Willey, Barbara; Waiswa, Peter; Kajjo, Darious; Munos, Melinda; Akuze, Joseph; Allen, Elizabeth; Marchant, Tanya

2018-06-01

Improving maternal and newborn health requires improvements in the quality of facility-based care. This is challenging to measure: routine data may be unreliable; respondents in population surveys may be unable to accurately report on quality indicators; and facility assessments lack population level denominators. We explored methods for linking access to skilled birth attendance (SBA) from household surveys to data on provision of care from facility surveys with the aim of estimating population level effective coverage reflecting access to quality care. We used data from Mayuge District, Uganda. Data from household surveys on access to SBA were linked to health facility assessment census data on readiness to provide basic emergency obstetric and newborn care (BEmONC) in the same district. One individual- and two ecological-linking methods were applied. All methods used household survey reports on where care at birth was accessed. The individual-linking method linked this to data about facility readiness from the specific facility where each woman delivered. The first ecological-linking approach used a district-wide mean estimate of facility readiness. The second used an estimate of facility readiness adjusted by level of health facility accessed. Absolute differences between estimates derived from the different linking methods were calculated, and agreement examined using Lin's concordance correlation coefficient. A total of 1177 women resident in Mayuge reported a birth during 2012-13. Of these, 664 took place in facilities within Mayuge, and were eligible for linking to the census of the district's 38 facilities. 55% were assisted by a SBA in a facility. Using the individual-linking method, effective coverage of births that took place with an SBA in a facility ready to provide BEmONC was just 10% (95% confidence interval CI 3-17). The absolute difference between the individual- and ecological-level linking method adjusting for facility level was one percentage point (11%), and tests suggested good agreement. The ecological method using the district-wide estimate demonstrated poor agreement. The proportion of women accessing appropriately equipped facilities for care at birth is far lower than the coverage of facility delivery. To realise the life-saving potential of health services, countries need evidence to inform actions that address gaps in the provision of quality care. Linking household and facility-based information provides a simple but innovative method for estimating quality of care at the population level. These encouraging findings suggest that linking data sets can result in meaningful evidence even when the exact location of care seeking is not known.

Inter-Domain Roaming Mechanism Transparent to Mobile Nodes among PMIPv6 Networks

NASA Astrophysics Data System (ADS)

Park, Soochang; Lee, Euisin; Jin, Min-Sook; Kim, Sang-Ha

In Proxy Mobile IPv6 (PMIPv6), when a Mobile Node (MN) enters a PMIPv6 domain and attaches to an access link, the router on the access link detects attachment of the MN by the link-layer access. All elements of PMIPv6 including the router then provide network-based mobility management service for the MN. If the MN moves to another router in this PMIPv6 domain, the new router emulates attachment to the previous router by providing same network prefix to the MN. In other words, PMIPv6 provides rapid mobility management based on layer-2 attachment and transparent mobility support to the MN by emulating layer-3 attachment with respect to intra-domain roaming. However, when the MN moves to other PMIPv6 domains, although the domains also provide the network-based mobility management service, the MN should exploit the host-based mobility management protocol, i.e. Mobile IPv6 (MIPv6), for the inter-domain roaming. Hence, this letter proposes the rapid and transparent inter-domain roaming mechanism controlled by the networks adopting PMIPv6.

Development of a biomimetic enzyme-linked immunosorbent assay based on molecularly imprinted polymers on paper for the detection of carbaryl.

PubMed

Zhang, Can; Cui, Hanyu; Han, Yufeng; Yu, Fangfang; Shi, Xiaoman

2018-02-01

A biomimetic enzyme-linked immunosorbent assay (BELISA) which was based on molecularly imprinted polymers on paper (MIPs-paper) with specific recognition was developed. As a detector, the surface of paper was modified with γ-MAPS by hydrolytic action and anchored the MIP layer on γ-MAPS modified-paper by copolymerization to construct the artificial antibody Through a series of experimentation and verification, we successful got the MIPs-paper and established BELISA for the detection of carbaryl. The development of MIPs-paper based on BELISA was applied to detect carbaryl in real samples and validated by an enzyme-linked immunosorbent assay (ELISA) based on anti-carbaryl biological antibody. The results of these two methods (BELISA and ELISA) were well correlated (R 2 =0.944). The established method of MIPs-paper BELISA exhibits the advantages of low cost, higher stability and being re-generable, which can be applied as a convenient tool for the fast and efficient detection of carbaryl. Copyright © 2017. Published by Elsevier Ltd.

Phase change material based tunable reflectarray for free-space optical inter/intra chip interconnects.

PubMed

Zou, Longfang; Cryan, Martin; Klemm, Maciej

2014-10-06

The concept of phase change material (PCM) based optical antennas and antenna arrays is proposed for dynamic beam shaping and steering utilized in free-space optical inter/intra chip interconnects. The essence of this concept lies in the fact that the behaviour of PCM based optical antennas will change due to the different optical properties of the amorphous and crystalline state of the PCM. By engineering optical antennas or antenna arrays, it is feasible to design dynamic optical links in a desired manner. In order to illustrate this concept, a PCM based tunable reflectarray is proposed for a scenario of a dynamic optical link between a source and two receivers. The designed reflectarray is able to switch the optical link between two receivers by switching the two states of the PCM. Two types of antennas are employed in the proposed tunable reflectarray to achieve full control of the wavefront of the reflected beam. Numerical studies show the expected binary beam steering at the optical communication wavelength of 1.55 μm. This study suggests a new research area of PCM based optical antennas and antenna arrays for dynamic optical switching and routing.

A web-based system architecture for ontology-based data integration in the domain of IT benchmarking

NASA Astrophysics Data System (ADS)

Pfaff, Matthias; Krcmar, Helmut

2018-03-01

In the domain of IT benchmarking (ITBM), a variety of data and information are collected. Although these data serve as the basis for business analyses, no unified semantic representation of such data yet exists. Consequently, data analysis across different distributed data sets and different benchmarks is almost impossible. This paper presents a system architecture and prototypical implementation for an integrated data management of distributed databases based on a domain-specific ontology. To preserve the semantic meaning of the data, the ITBM ontology is linked to data sources and functions as the central concept for database access. Thus, additional databases can be integrated by linking them to this domain-specific ontology and are directly available for further business analyses. Moreover, the web-based system supports the process of mapping ontology concepts to external databases by introducing a semi-automatic mapping recommender and by visualizing possible mapping candidates. The system also provides a natural language interface to easily query linked databases. The expected result of this ontology-based approach of knowledge representation and data access is an increase in knowledge and data sharing in this domain, which will enhance existing business analysis methods.

Links SU-Sex: development of a screening tool for health-risk sexual behaviours related to substance use among men who have sex with men.

PubMed

Goyette, Mathieu; Flores-Aranda, Jorge; Bertrand, Karine; Pronovost, Frédérick; Aubut, Valérie; Ortiz, Roberto; Saint-Jacques, Marianne

2018-04-01

Background Men who have sex with men (MSM) have distinctive substance use (SU), which is more often linked to a sexual context than it is for their heterosexual peers. Screening of MSM's SU, its sexual contexts and the associated risks, is of clinical and public health concern. This paper aims to describe the preliminary development of a screening tool for health-risk sexual behaviours related to SU and to make recommendations for its potential use. Community-based participatory research and transdisciplinary approaches guided the development process. The Links SU-Sex screening tool is the result of the integration of findings from a scoping review and from four meetings among SU and sexual health experts (n=19), consisting of researchers, community stakeholders, as well as substance-using MSM. The Links SU-Sex questionnaire consists of 64 items divided into 13 components that focus on the links between SU and sexual health. It addresses the contexts in which SU occurs, its frequency, its perceived influence, as well as MSM's concerns about these various links. In accordance with current knowledge, the interpretation of the instrument offers feedback that is based on the respondents' answers to the various components assessed. The Links SU-Sex represents a potential screening tool that rests on a robust development process supporting its content validity that aims to identify MSM at risk or with concerns surrounding the influence of their SU on their sexual health. The psychometric qualities and the interpretation validity both remain to be established.

Gold nanorod linking to control plasmonic properties in solution and polymer nanocomposites.

PubMed

Ferrier, Robert C; Lee, Hyun-Su; Hore, Michael J A; Caporizzo, Matthew; Eckmann, David M; Composto, Russell J

2014-02-25

A novel, solution-based method is presented to prepare bifunctional gold nanorods (B-NRs), assemble B-NRs end-to-end in various solvents, and disperse linked B-NRs in a polymer matrix. The B-NRs have poly(ethylene glycol) grafted along its long axis and cysteine adsorbed to its ends. By controlling cysteine coverage, bifunctional ligands or polymer can be end-grafted to the AuNRs. Here, two dithiol ligands (C6DT and C9DT) are used to link the B-NRs in organic solvents. With increasing incubation time, the nanorod chain length increases linearly as the longitudinal surface plasmon resonance shifts toward lower adsorption wavelengths (i.e., red shift). Analogous to step-growth polymerization, the polydispersity in chain length also increases. Upon adding poly(ethylene glycol) or poly(methyl methacrylate) to chloroform solution with linked B-NR, the nanorod chains are shown to retain end-to-end linking upon spin-casting into PEO or PMMA films. Using quartz crystal microbalance with dissipation (QCM-D), the mechanism of nanorod linking is investigated on planar gold surfaces. At submonolayer coverage of cysteine, C6DT molecules can insert between cysteines and reach an areal density of 3.4 molecules per nm(2). To mimic the linking of Au NRs, this planar surface is exposed to cysteine-coated Au nanoparticles, which graft at 7 NPs per μm(2). This solution-based method to prepare, assemble, and disperse Au nanorods is applicable to other nanorod systems (e.g., CdSe) and presents a new strategy to assemble anisotropic particles in organic solvents and polymer coatings.

Gold Nanorod Linking to Control Plasmonic Properties in Solution and Polymer Nanocomposites

PubMed Central

2015-01-01

A novel, solution-based method is presented to prepare bifunctional gold nanorods (B-NRs), assemble B-NRs end-to-end in various solvents, and disperse linked B-NRs in a polymer matrix. The B-NRs have poly(ethylene glycol) grafted along its long axis and cysteine adsorbed to its ends. By controlling cysteine coverage, bifunctional ligands or polymer can be end-grafted to the AuNRs. Here, two dithiol ligands (C6DT and C9DT) are used to link the B-NRs in organic solvents. With increasing incubation time, the nanorod chain length increases linearly as the longitudinal surface plasmon resonance shifts toward lower adsorption wavelengths (i.e., red shift). Analogous to step-growth polymerization, the polydispersity in chain length also increases. Upon adding poly(ethylene glycol) or poly(methyl methacrylate) to chloroform solution with linked B-NR, the nanorod chains are shown to retain end-to-end linking upon spin-casting into PEO or PMMA films. Using quartz crystal microbalance with dissipation (QCM-D), the mechanism of nanorod linking is investigated on planar gold surfaces. At submonolayer coverage of cysteine, C6DT molecules can insert between cysteines and reach an areal density of 3.4 molecules per nm2. To mimic the linking of Au NRs, this planar surface is exposed to cysteine-coated Au nanoparticles, which graft at 7 NPs per μm2. This solution-based method to prepare, assemble, and disperse Au nanorods is applicable to other nanorod systems (e.g., CdSe) and presents a new strategy to assemble anisotropic particles in organic solvents and polymer coatings. PMID:24483622

A Complex Systems Model Approach to Quantified Mineral Resource Appraisal

USGS Publications Warehouse

Gettings, M.E.; Bultman, M.W.; Fisher, F.S.

2004-01-01

For federal and state land management agencies, mineral resource appraisal has evolved from value-based to outcome-based procedures wherein the consequences of resource development are compared with those of other management options. Complex systems modeling is proposed as a general framework in which to build models that can evaluate outcomes. Three frequently used methods of mineral resource appraisal (subjective probabilistic estimates, weights of evidence modeling, and fuzzy logic modeling) are discussed to obtain insight into methods of incorporating complexity into mineral resource appraisal models. Fuzzy logic and weights of evidence are most easily utilized in complex systems models. A fundamental product of new appraisals is the production of reusable, accessible databases and methodologies so that appraisals can easily be repeated with new or refined data. The data are representations of complex systems and must be so regarded if all of their information content is to be utilized. The proposed generalized model framework is applicable to mineral assessment and other geoscience problems. We begin with a (fuzzy) cognitive map using (+1,0,-1) values for the links and evaluate the map for various scenarios to obtain a ranking of the importance of various links. Fieldwork and modeling studies identify important links and help identify unanticipated links. Next, the links are given membership functions in accordance with the data. Finally, processes are associated with the links; ideally, the controlling physical and chemical events and equations are found for each link. After calibration and testing, this complex systems model is used for predictions under various scenarios.

Evolved Design, Integration, and Test of a Modular, Multi-Link, Spacecraft-Based Robotic Manipulator

DTIC Science & Technology

2016-06-01

of the MATLAB code, the SPART model [24]. The portions of the SPART model relevant to this thesis are contained in (Appendices E –P). While the SPART...the kinematics and the dynamics of the system must be modeled and simulated numerically to understand how the system will behave for a given number... simulators with multiple-link robotic arms has been ongoing. B . STATE OF THE ART 1. An Overarching Context Space-based manipulators and the experimental

Conformational analysis of a covalently cross-linked Watson-Crick base pair model.

PubMed

Jensen, Erik A; Allen, Benjamin D; Kishi, Yoshito; O'Leary, Daniel J

2008-11-15

Low-temperature NMR experiments and molecular modeling have been used to characterize the conformational behavior of a covalently cross-linked DNA base pair model. The data suggest that Watson-Crick or reverse Watson-Crick hydrogen bonding geometries have similar energies and can interconvert at low temperatures. This low-temperature process involves rotation about the crosslink CH(2)C(5') (psi) carbon-carbon bond, which is energetically preferred over the alternate CH(2)N(3) (phi) carbon-nitrogen bond rotation.

Long-Term Instability of GPS-Based Time Transfer and Proposals for Improvements

DTIC Science & Technology

2011-01-01

receiver, or use of a completely independent technique such as Two-Way Satellite Time and Frequency Transfer ( TWSTFT ), helps to identify which receiver...is generated using not only the PTB’s Two-Way Satellite Time and Frequency Transfer ( TWSTFT or TW) links, but also links based on other PTB GNSS...including the PTB by X WX [1,2]; delay variations in other PTB time transfer systems would have an additive effect whether they were TWSTFT or GNSS

Glycoprotein-Based Enzyme-Linked Immunosorbent Assays for Serodiagnosis of Infectious Laryngotracheitis

PubMed Central

Kanabagatte Basavarajappa, Mallikarjuna; Song, Haichen; Lamichhane, Chinta

2015-01-01

For detection of infectious laryngotracheitis virus (ILTV) antibody, glycoprotein B-, C-, and D-based enzyme-linked immunosorbent assays (B-, C-, and D-ELISAs, respectively) were developed. The B- and D-ELISAs showed enhanced detection of anti-ILTV antibodies in infected chickens compared to that of the commercial ELISA. Furthermore, the D-ELISA was efficient in detecting seroconversion with vectored vaccine, using recombinant Newcastle disease virus (rNDV) expressing glycoprotein D (gD) as the vaccine vector. PMID:25694519

Frequency comb-based time transfer over a 159 km long installed fiber network

NASA Astrophysics Data System (ADS)

Lessing, M.; Margolis, H. S.; Brown, C. T. A.; Marra, G.

2017-05-01

We demonstrate a frequency comb-based time transfer technique on a 159 km long installed fiber link. Timing information is superimposed onto the optical pulse train of an ITU-channel-filtered mode-locked laser using an intensity modulation scheme. The environmentally induced optical path length fluctuations are compensated using a round-trip phase noise cancellation technique. When the fiber link is stabilized, a time deviation of 300 fs at 5 s and an accuracy at the 100 ps level are achieved.

A comprehensive school-based/linked dental program: an essential piece of the California access to care puzzle.

PubMed

Fine, Jared I; Isman, Robert E; Grant, Catherine B

2012-03-01

California children suffer more from dental disease than any other chronic childhood disease. Disparities in access and oral health are disproportionately represented among children from minority and low-income families. A comprehensive school-based/linked dental program is one essential ingredient in addressing these problems. Described here are the goals, program elements, and challenges of building a seamless dental services system that could reduce barriers care, maximize resources, and employ best practices to improve oral health.

KOJAK Group Finder: Scalable Group Detection via Integrated Knowledge-Based and Statistical Reasoning

DTIC Science & Technology

2006-09-01

STELLA and PowerLoomn. These modules comunicate with a knowledge basec using KIF and stan(lardl relational database systelnis using either standard...groups ontology as well as a rule that infers additional seed members based on joint participation in a terrorism event. EDB schema files are a special... terrorism links from the Ali Baba EDB. Our interpretation of such links is that they KOJAK Manual E-42 encode that two people committed an act of

Identifying the Critical Links in Road Transportation Networks: Centrality-based approach utilizing structural properties

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

Chinthavali, Supriya

Surface transportation road networks share structural properties similar to other complex networks (e.g., social networks, information networks, biological networks, and so on). This research investigates the structural properties of road networks for any possible correlation with the traffic characteristics such as link flows those determined independently. Additionally, we define a criticality index for the links of the road network that identifies the relative importance in the network. We tested our hypotheses with two sample road networks. Results show that, correlation exists between the link flows and centrality measures of a link of the road (dual graph approach is followed) andmore » the criticality index is found to be effective for one test network to identify the vulnerable nodes.« less

High-speed fiber-optic links for distribution of satellite traffic

NASA Technical Reports Server (NTRS)

Daryoush, Afshin S.; Saedi, Reza; Ackerman, Edward; Kunath, Richard; Shalkhauser, Kurt

1990-01-01

Low-loss fiberoptic links are designed for distribution of data and the frequency reference in large-aperture phased-array antennas based on the transmit/receive-level data mixing architecture. In particular, design aspects of a fiberoptic link satisfying the distribution requirements of satellite data traffic are presented. The design is addressed in terms of reactively matched optical transmitter and receiver modules. Analog and digital characterization of a 50-m fiberoptic link realized using these modules indicates the applicability of this architecture as the only viable alternative for distribution of data signals inside a satellite at present. It is demonstrated that the design of a reactive matching modules enhances the link performance. A dynamic range of 88 dB/MHz was measured for analog data over a 500-1000-MHz bandwidth.

Nonequilibrium Chromosome Looping via Molecular Slip Links

NASA Astrophysics Data System (ADS)

Brackley, C. A.; Johnson, J.; Michieletto, D.; Morozov, A. N.; Nicodemi, M.; Cook, P. R.; Marenduzzo, D.

2017-09-01

We propose a model for the formation of chromatin loops based on the diffusive sliding of molecular slip links. These mimic the behavior of molecules like cohesin, which, along with the CTCF protein, stabilize loops which contribute to organizing the genome. By combining 3D Brownian dynamics simulations and 1D exactly solvable nonequilibrium models, we show that diffusive sliding is sufficient to account for the strong bias in favor of convergent CTCF-mediated chromosome loops observed experimentally. We also find that the diffusive motion of multiple slip links along chromatin is rectified by an intriguing ratchet effect that arises if slip links bind to the chromatin at a preferred "loading site." This emergent collective behavior favors the extrusion of loops which are much larger than the ones formed by single slip links.

Mapping N-linked Glycosylation Sites in the Secretome and Whole Cells of Aspergillus niger Using Hydrazide Chemistry and Mass Spectrometry

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

Wang, Lu; Aryal, Uma K.; Dai, Ziyu

2012-01-01

Protein glycosylation is known to play an essential role in both cellular functions and the secretory pathways; however, little information is available on the dynamics of glycosylated N-linked glycosites of fungi. Herein we present the first extensive mapping of glycosylated N-linked glycosites in industrial strain Aspergillus niger by applying an optimized solid phase enrichment of glycopeptide protocol using hydrazide modified magnetic beads. The enrichment protocol was initially optimized using mouse plasma and A. niger secretome samples, which was then applied to profile N-linked glycosites from both the secretome and whole cell lysates of A. niger. A total of 847 uniquemore » N-linked glycosites and 330 N-linked glycoproteins were confidently identified by LC-MS/MS. Based on gene ontology analysis, the identified N-linked glycoproteins in the whole cell lysate were primarily localized in the plasma membrane, endoplasmic reticulum, golgi apparatus, lysosome, and storage vacuoles. The identified N-linked glycoproteins are involved in a wide range of biological processes including gene regulation and signal transduction, protein folding and assembly, protein modification and carbohydrate metabolism. The extensive coverage of glycosylated N-linked glycosites along with identification of partial N-linked glycosylation in those enzymes involving in different biochemical pathways provide useful information for functional studies of N-linked glycosylation and their biotechnological applications in A. niger.« less

Modeling Protein Excited-state Structures from "Over-length" Chemical Cross-links.

PubMed

Ding, Yue-He; Gong, Zhou; Dong, Xu; Liu, Kan; Liu, Zhu; Liu, Chao; He, Si-Min; Dong, Meng-Qiu; Tang, Chun

2017-01-27

Chemical cross-linking coupled with mass spectroscopy (CXMS) provides proximity information for the cross-linked residues and is used increasingly for modeling protein structures. However, experimentally identified cross-links are sometimes incompatible with the known structure of a protein, as the distance calculated between the cross-linked residues far exceeds the maximum length of the cross-linker. The discrepancies may persist even after eliminating potentially false cross-links and excluding intermolecular ones. Thus the "over-length" cross-links may arise from alternative excited-state conformation of the protein. Here we present a method and associated software DynaXL for visualizing the ensemble structures of multidomain proteins based on intramolecular cross-links identified by mass spectrometry with high confidence. Representing the cross-linkers and cross-linking reactions explicitly, we show that the protein excited-state structure can be modeled with as few as two over-length cross-links. We demonstrate the generality of our method with three systems: calmodulin, enzyme I, and glutamine-binding protein, and we show that these proteins alternate between different conformations for interacting with other proteins and ligands. Taken together, the over-length chemical cross-links contain valuable information about protein dynamics, and our findings here illustrate the relationship between dynamic domain movement and protein function. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Analysis of Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol

NASA Technical Reports Server (NTRS)

Woo, Simon S.

2011-01-01

To synchronize clocks between spacecraft in proximity, the Proximity-1 Space Link Interleaved Time Synchronization (PITS) Protocol has been proposed. PITS is based on the NTP Interleaved On-Wire Protocol and is capable of being adapted and integrated into CCSDS Proximity-1 Space Link Protocol with minimal modifications. In this work, we will discuss the correctness and liveness of PITS. Further, we analyze and evaluate the performance of time synchronization latency with various channel error rates in different PITS operational modes.

Challenge: How Effective is Routing for Wireless Networking

DTIC Science & Technology

2017-03-03

sage (called a“ hello ”) to all of its neighbors. If a series of hello messages are exchanged between two users, a link is considered to exist between...these schemes. A brief description of ETX is as follows. For a given window of time, the number of hello packets that a user receives from a neighbor is...counted. A cost is then assigned to the link based on how many hello messages were heard; a link that has fewer hellos successfully transmitted across

Challenge: How Effective is Routing for Wireless Networking

DTIC Science & Technology

2015-09-07

sage (called a“ hello ”) to all of its neighbors. If a series of hello messages are exchanged between two users, a link is considered to exist between...these schemes. A brief description of ETX is as follows. For a given window of time, the number of hello packets that a user receives from a neighbor is...counted. A cost is then assigned to the link based on how many hello messages were heard; a link that has fewer hellos successfully transmitted across

Toward Continental-scale Rainfall Monitoring Using Commercial Microwave Links From Cellular Communication Networks

NASA Astrophysics Data System (ADS)

Uijlenhoet, R.; Leijnse, H.; Overeem, A.

2017-12-01

Accurate and timely surface precipitation measurements are crucial for water resources management, agriculture, weather prediction, climate research, as well as ground validation of satellite-based precipitation estimates. However, the majority of the land surface of the earth lacks such data, and in many parts of the world the density of surface precipitation gauging networks is even rapidly declining. This development can potentially be counteracted by using received signal level data from the enormous number of microwave links used worldwide in commercial cellular communication networks. Along such links, radio signals propagate from a transmitting antenna at one base station to a receiving antenna at another base station. Rain-induced attenuation and, subsequently, path-averaged rainfall intensity can be retrieved from the signal's attenuation between transmitter and receiver. We have previously shown how one such a network can be used to retrieve the space-time dynamics of rainfall for an entire country (The Netherlands, ˜35,500 km2), based on an unprecedented number of links (˜2,400) and a rainfall retrieval algorithm that can be applied in real time. This demonstrated the potential of such networks for real-time rainfall monitoring, in particular in those parts of the world where networks of dedicated ground-based rainfall sensors are often virtually absent. The presentation will focus on the potential for upscaling this technique to continental-scale rainfall monitoring in Europe. In addition, several examples of recent applications of this technique on other continents (South America, Africa, Asia and Australia) will be given.

Hybridisation-based resequencing of 17 X-linked intellectual disability genes in 135 patients reveals novel mutations in ATRX, SLC6A8 and PQBP1

PubMed Central

Jensen, Lars R; Chen, Wei; Moser, Bettina; Lipkowitz, Bettina; Schroeder, Christopher; Musante, Luciana; Tzschach, Andreas; Kalscheuer, Vera M; Meloni, Ilaria; Raynaud, Martine; van Esch, Hilde; Chelly, Jamel; de Brouwer, Arjan P M; Hackett, Anna; van der Haar, Sigrun; Henn, Wolfram; Gecz, Jozef; Riess, Olaf; Bonin, Michael; Reinhardt, Richard; Ropers, Hans-Hilger; Kuss, Andreas W

2011-01-01

X-linked intellectual disability (XLID), also known as X-linked mental retardation, is a highly genetically heterogeneous condition for which mutations in >90 different genes have been identified. In this study, we used a custom-made sequencing array based on the Affymetrix 50k platform for mutation screening in 17 known XLID genes in patients from 135 families and found eight single-nucleotide changes that were absent in controls. For four mutations affecting ATRX (p.1761M>T), PQBP1 (p.155R>X) and SLC6A8 (p.390P>L and p.477S>L), we provide evidence for a functional involvement of these changes in the aetiology of intellectual disability. PMID:21267006

Link prediction based on nonequilibrium cooperation effect

NASA Astrophysics Data System (ADS)

Li, Lanxi; Zhu, Xuzhen; Tian, Hui

2018-04-01

Link prediction in complex networks has become a common focus of many researchers. But most existing methods concentrate on neighbors, and rarely consider degree heterogeneity of two endpoints. Node degree represents the importance or status of endpoints. We describe the large-degree heterogeneity as the nonequilibrium between nodes. This nonequilibrium facilitates a stable cooperation between endpoints, so that two endpoints with large-degree heterogeneity tend to connect stably. We name such a phenomenon as the nonequilibrium cooperation effect. Therefore, this paper proposes a link prediction method based on the nonequilibrium cooperation effect to improve accuracy. Theoretical analysis will be processed in advance, and at the end, experiments will be performed in 12 real-world networks to compare the mainstream methods with our indices in the network through numerical analysis.

Mixed Transportation Network Design under a Sustainable Development Perspective

PubMed Central

Qin, Jin; Ni, Ling-lin; Shi, Feng

2013-01-01

A mixed transportation network design problem considering sustainable development was studied in this paper. Based on the discretization of continuous link-grade decision variables, a bilevel programming model was proposed to describe the problem, in which sustainability factors, including vehicle exhaust emissions, land-use scale, link load, and financial budget, are considered. The objective of the model is to minimize the total amount of resources exploited under the premise of meeting all the construction goals. A heuristic algorithm, which combined the simulated annealing and path-based gradient projection algorithm, was developed to solve the model. The numerical example shows that the transportation network optimized with the method above not only significantly alleviates the congestion on the link, but also reduces vehicle exhaust emissions within the network by up to 41.56%. PMID:23476142

Mixed transportation network design under a sustainable development perspective.

PubMed

Qin, Jin; Ni, Ling-lin; Shi, Feng

2013-01-01

A mixed transportation network design problem considering sustainable development was studied in this paper. Based on the discretization of continuous link-grade decision variables, a bilevel programming model was proposed to describe the problem, in which sustainability factors, including vehicle exhaust emissions, land-use scale, link load, and financial budget, are considered. The objective of the model is to minimize the total amount of resources exploited under the premise of meeting all the construction goals. A heuristic algorithm, which combined the simulated annealing and path-based gradient projection algorithm, was developed to solve the model. The numerical example shows that the transportation network optimized with the method above not only significantly alleviates the congestion on the link, but also reduces vehicle exhaust emissions within the network by up to 41.56%.

Linked Learning Communities. What Works Clearinghouse Intervention Report

ERIC Educational Resources Information Center

What Works Clearinghouse, 2014

2014-01-01

Linked learning communities in postsecondary education are programs defined by having social and curricular linkages that provide undergraduate students with intentional integration of the themes and concepts that they are learning. The theory behind these programs is that active learning in a community-based setting can improve academic outcomes…

A non-symmetric pillar[5]arene based on triazole-linked 8-oxyquinolines as a sequential sensor for thorium(IV) followed by fluoride ions.

PubMed

Fang, Yuyu; Li, Caixia; Wu, Lei; Bai, Bing; Li, Xing; Jia, Yiming; Feng, Wen; Yuan, Lihua

2015-09-07

A novel non-symmetric pillar[5]arene bearing triazole-linked 8-oxyquinolines at one rim was synthesized and demonstrated as a sequential fluorescence sensor for thorium(iv) followed by fluoride ions with high sensitivity and selectivity.

Data-Linking Requirements in Facilities Condition Audit RFPs.

ERIC Educational Resources Information Center

DeFranco, Randall W.

2002-01-01

Discusses why, when preparing a Request for Proposal (RFP) for Facilities Condition Audit (FCA)--including software-based delivery of findings--facilities managers should avoid complicating the bidding process with nondescript data-linking requirements. Presents ways to get an apples-to-apples comparison of bids for a proposed FCA project and…

Institutional Repositories in Universities in Nigeria: Desirability and Progress

ERIC Educational Resources Information Center

Oye, Peter Olorunlake; Oyeniyi, David Ajibola; Mahan, David Ezekiel

2017-01-01

The desire of academic institutions to link up to the virtual repository is a global phenomenon. Traditional scholarly publication through established journals characterized by peer review is being challenged by less formal net-based communication that links scholars essentially instantaneously. The contention is that universities need to preserve…

Linking Leadership to Student Learning

ERIC Educational Resources Information Center

Leithwood, Kenneth; Seashore-Louis, Karen

2011-01-01

"Linking Leadership to Student Learning" clearly shows how school leadership improves student achievement. The book is based on an ambitious five-year study on educational leadership that was sponsored by The Wallace Foundation. The authors studied 43 districts, across 9 states and 180 elementary, middle, and secondary schools. In this book,…

47 CFR 54.416 - Certification of consumer Qualification for Link Up.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 3 2010-10-01 2010-10-01 false Certification of consumer Qualification for... CARRIER SERVICES (CONTINUED) UNIVERSAL SERVICE Universal Service Support for Low-Income Consumers § 54.416 Certification of consumer Qualification for Link Up. Consumers qualifying under an income-based criterion must...

Sweet Rejuvenation: Linking In-Service and Teacher Induction.

ERIC Educational Resources Information Center

McNair, Veda; And Others

This paper describes a collaborative effort between a local education agency (LEA) and an institution of higher education to link inservice education with induction--teachers teaching teachers. The program, based on the Joyce coaching paradigm and recent cognitive development research, posits that long-term training conducted by trained teachers…

Gateway National Recreation Area, Jamaica Bay Unit : Jamaica Bay Greenway Missing Links Study.

DOT National Transportation Integrated Search

2010-09-24

Based on both a field site reconnaissance and workshop, this study developed a conceptual plan for the location and design of bicyle facilites to complete a "missing link" of the Jamaica Bay through the Rockaway region of Brooklyn and Queens in New Y...

The Natural Link between Teaching History and Computer Skills.

ERIC Educational Resources Information Center

Farnworth, George M.

1992-01-01

Suggests that, because both history and computers are information based, there is an natural link between the two. Argues that history teachers should exploit the technology to help students to understand history while they become computer literate. Points out uses for databases, word processing, desktop publishing, and telecommunications in…

A School-Linked Health Service for Adolescents in Jerusalem.

ERIC Educational Resources Information Center

Halevy, Ari; And Others

1995-01-01

Describes the Adolescent Health Service and its multidisciplinary, school-linked, community-based health clinic located in Jerusalem (Israel). Reviews of the files of the clinic's first 134 clients indicated that the clinic population was mainly female Jewish residents. Most referrals came from schools. Psychosocial issues and nutrition were the…

47 CFR 90.129 - Supplemental information to be routinely submitted with applications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES Applications and... communications. (n) All applications for renewal of base/mobile station licenses by licensees who also operate... of frequencies necessary for the link(s); (3) The name and phone number of the person(s) responsible...

The Eco-Health Relationship Browser: Linking Ecosystem Services and Human Health 11/6/13

EPA Science Inventory

Ecosystems provide multiple societal benefits from the production of nature-based goods and services. Many ecosystem services have been linked to a range of positive health outcomes through the buffering of pollutants and natural hazards and the promotion of healthy behaviors. A ...

A Systems Approach to the Estimation of Ecosystem and Human Health Stressors in Air, Land and Water

EPA Science Inventory

A model linkage paradigm, based on the nitrogen cascade, is introduced. This general paradigm is then adapted to specific multi-media nitrogen issues and specific models to be linked. An example linked modeling system addressing potential nitrogen responses to biofuel-driven co...

Extracting Macroscopic Information from Web Links.

ERIC Educational Resources Information Center

Thelwall, Mike

2001-01-01

Discussion of Web-based link analysis focuses on an evaluation of Ingversen's proposed external Web Impact Factor for the original use of the Web, namely the interlinking of academic research. Studies relationships between academic hyperlinks and research activities for British universities and discusses the use of search engines for Web link…

Super-resolution links vinculin localization to function in focal adhesions.

PubMed

Giannone, Grégory

2015-07-01

Integrin-based focal adhesions integrate biochemical and biomechanical signals from the extracellular matrix and the actin cytoskeleton. The combination of three-dimensional super-resolution imaging and loss- or gain-of-function protein mutants now links the nanoscale dynamic localization of proteins to their activation and function within focal adhesions.

47 CFR 54.416 - Certification of consumer Qualification for Link Up.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 3 2011-10-01 2011-10-01 false Certification of consumer Qualification for... CARRIER SERVICES (CONTINUED) UNIVERSAL SERVICE Universal Service Support for Low-Income Consumers § 54.416 Certification of consumer Qualification for Link Up. Consumers qualifying under an income-based criterion must...

High-resolution 3D laser imaging based on tunable fiber array link

NASA Astrophysics Data System (ADS)

Zhao, Sisi; Ruan, Ningjuan; Yang, Song

2017-10-01

Airborne photoelectric reconnaissance system with the bore sight down to the ground is an important battlefield situational awareness system, which can be used for reconnaissance and surveillance of complex ground scene. Airborne 3D imaging Lidar system is recognized as the most potential candidates for target detection under the complex background, and is progressing in the directions of high resolution, long distance detection, high sensitivity, low power consumption, high reliability, eye safe and multi-functional. However, the traditional 3D laser imaging system has the disadvantages of lower imaging resolutions because of the small size of the existing detector, and large volume. This paper proposes a high resolution laser 3D imaging technology based on the tunable optical fiber array link. The echo signal is modulated by a tunable optical fiber array link and then transmitted to the focal plane detector. The detector converts the optical signal into electrical signals which is given to the computer. Then, the computer accomplishes the signal calculation and image restoration based on modulation information, and then reconstructs the target image. This paper establishes the mathematical model of tunable optical fiber array signal receiving link, and proposes the simulation and analysis of the affect factors on high density multidimensional point cloud reconstruction.

[An evaluation of web-based information about Barrett's esophagus in Korea].

PubMed

Park, Sung Hyun; Lee, Jun Haeng; Kim, Kap Hyun; Kang, Ki Joo; Kim, Sang Jung; Lee, Seung Chul; Kim, Jin Yong; Rhee, Poong-Lyul; Kim, Jae J; Rhee, Jong Chul

2009-05-01

Internet has become an important source of medical information not only for doctors but also patients. However, information available in the Internet may provide wrong or even harmful knowledge to the public. The aim of this study was to evaluate the quality of Internet-based medical information about Barrett's esophagus in Korea. The first 50 Internet links were retrieved from the Google using the key word Barrett's esophagus. The quality of information from a total of 49 websites was evaluated using a checklist. Among total 49 sites related to Barrett's esophagus, only 4 sites (8.2%) were made by hospitals or clinics, and 11 sites (22.4%) were for patients. Of the 49 sites, only one web site (2.0%) had all HON CODE principles (authority, complementarity, confidentiality, attribution, justifiability, transparency of authorship, transparency of sponsorship, honesty in advertising and editorial policy). Sixteen Internet links (32.0%) had fair contents for the definition, and 24 links (48.0%) for the diagnosis, and 15 links (30.0%) for the treatment. Information about Barrett's esophagus was incomplete in the majority of medical web sites. It will bring about confusion in patients who want to get information about Barrett's esophagus from the Internet. There is a need for better evidence-based information about Barrett's esophagus on the web.

Academic health sciences library Website navigation: an analysis of forty-one Websites and their navigation tools

PubMed Central

Brower, Stewart M.

2004-01-01

Background: The analysis included forty-one academic health sciences library (HSL) Websites as captured in the first two weeks of January 2001. Home pages and persistent navigational tools (PNTs) were analyzed for layout, technology, and links, and other general site metrics were taken. Methods: Websites were selected based on rank in the National Network of Libraries of Medicine, with regional and resource libraries given preference on the basis that these libraries are recognized as leaders in their regions and would be the most reasonable source of standards for best practice. A three-page evaluation tool was developed based on previous similar studies. All forty-one sites were evaluated in four specific areas: library general information, Website aids and tools, library services, and electronic resources. Metrics taken for electronic resources included orientation of bibliographic databases alphabetically by title or by subject area and with links to specifically named databases. Results: Based on the results, a formula for determining obligatory links was developed, listing items that should appear on all academic HSL Web home pages and PNTs. Conclusions: These obligatory links demonstrate a series of best practices that may be followed in the design and construction of academic HSL Websites. PMID:15494756

To trade or not to trade: Link prediction in the virtual water network

NASA Astrophysics Data System (ADS)

Tuninetti, Marta; Tamea, Stefania; Laio, Francesco; Ridolfi, Luca

2017-12-01

In the international trade network, links express the (temporary) presence of a commercial exchange of goods between any two countries. Given the dynamical behaviour of the trade network, where links are created and dismissed every year, predicting the link activation/deactivation is an open research question. Through the international trade network of agricultural goods, water resources are 'virtually' transferred from the country of production to the country of consumption. We propose a novel methodology for link prediction applied to the network of virtual water trade. Starting from the assumption of having links between any two countries, we estimate the associated virtual water flows by means of a gravity-law model using country and link characteristics as drivers. We consider the links with estimated flows higher than 1000 m3/year as active links, while the others as non-active links. Flows traded along estimated active links are then re-estimated using a similar but differently-calibrated gravity-law model. We were able to correctly model 84% of the existing links and 93% of the non-existing links in year 2011. It is worth to note that the predicted active links carry 99% of the global virtual water flow; hence, missed links are mainly those where a minimum volume of virtual water is exchanged. Results indicate that, over the period from 1986 to 2011, population, geographical distances between countries, and agricultural efficiency (through fertilizers use) are the major factors driving the link activation and deactivation. As opposed to other (network-based) models for link prediction, the proposed method is able to reconstruct the network architecture without any prior knowledge of the network topology, using only the nodes and links attributes; it thus represents a general method that can be applied to other networks such as food or value trade networks.

WebTag: Web browsing into sensor tags over NFC.

PubMed

Echevarria, Juan Jose; Ruiz-de-Garibay, Jonathan; Legarda, Jon; Alvarez, Maite; Ayerbe, Ana; Vazquez, Juan Ignacio

2012-01-01

Information and Communication Technologies (ICTs) continue to overcome many of the challenges related to wireless sensor monitoring, such as for example the design of smarter embedded processors, the improvement of the network architectures, the development of efficient communication protocols or the maximization of the life cycle autonomy. This work tries to improve the communication link of the data transmission in wireless sensor monitoring. The upstream communication link is usually based on standard IP technologies, but the downstream side is always masked with the proprietary protocols used for the wireless link (like ZigBee, Bluetooth, RFID, etc.). This work presents a novel solution (WebTag) for a direct IP based access to a sensor tag over the Near Field Communication (NFC) technology for secure applications. WebTag allows a direct web access to the sensor tag by means of a standard web browser, it reads the sensor data, configures the sampling rate and implements IP based security policies. It is, definitely, a new step towards the evolution of the Internet of Things paradigm.

Broadband and fabrication-tolerant on-chip scalable mode-division multiplexing based on mode-evolution counter-tapered couplers.

PubMed

Wang, Jing; Xuan, Yi; Qi, Minghao; Huang, Haiyang; Li, You; Li, Ming; Chen, Xin; Sheng, Zhen; Wu, Aimin; Li, Wei; Wang, Xi; Zou, Shichang; Gan, Fuwan

2015-05-01

A broadband and fabrication-tolerant on-chip scalable mode-division multiplexing (MDM) scheme based on mode-evolution counter-tapered couplers is designed and experimentally demonstrated on a silicon-on-insulator (SOI) platform. Due to the broadband advantage offered by mode evolution, the two-mode MDM link exhibits a very large, -1  dB bandwidth of >180  nm, which is considerably larger than most of the previously reported MDM links whether they are based on mode-interference or evolution. In addition, the performance metrics remain stable for large-device width deviations from the designed valued by -60  nm to 40 nm, and for temperature variations from -25°C to 75°C. This MDM scheme can be readily extended to higher-order mode multiplexing and a three-mode MDM link is measured with less than -10  dB crosstalk from 1.46 to 1.64 μm wavelength range.

Evaluation of selective control information detection scheme in orthogonal frequency division multiplexing-based radio-over-fiber and visible light communication links

NASA Astrophysics Data System (ADS)

Dalarmelina, Carlos A.; Adegbite, Saheed A.; Pereira, Esequiel da V.; Nunes, Reginaldo B.; Rocha, Helder R. O.; Segatto, Marcelo E. V.; Silva, Jair A. L.

2017-05-01

Block-level detection is required to decode what may be classified as selective control information (SCI) such as control format indicator in 4G-long-term evolution systems. Using optical orthogonal frequency division multiplexing over radio-over-fiber (RoF) links, we report the experimental evaluation of an SCI detection scheme based on a time-domain correlation (TDC) technique in comparison with the conventional maximum likelihood (ML) approach. When compared with the ML method, it is shown that the TDC method improves detection performance over both 20 and 40 km of standard single mode fiber (SSMF) links. We also report a performance analysis of the TDC scheme in noisy visible light communication channel models after propagation through 40 km of SSMF. Experimental and simulation results confirm that the TDC method is attractive for practical orthogonal frequency division multiplexing-based RoF and fiber-wireless systems. Unlike the ML method, another key benefit of the TDC is that it requires no channel estimation.

Bio-Based Artificial Nacre with Excellent Mechanical and Barrier Properties Realized by a Facile In Situ Reduction and Cross-Linking Reaction.

PubMed

Shahzadi, Kiran; Mohsin, Imran; Wu, Lin; Ge, Xuesong; Jiang, Yijun; Li, Hui; Mu, Xindong

2017-01-24

Demands for high strength integrated materials have substantially increased across various kinds of industries. Inspired by the relationship of excellent integration of mechanical properties and hierarchical nano/microscale structure of the natural nacre, a simple and facile method to fabricate high strength integrated artificial nacre based on sodium carboxymethylcellulose (CMC) and borate cross-linked graphene oxide (GO) sheets has been developed. The tensile strength and toughness of cellulose-based hybrid material reached 480.5 ± 13.1 MPa and 11.8 ± 0.4 MJm -3 by a facile in situ reduction and cross-linking reaction between CMC and GO (0.7%), which are 3.55 and 6.55 times that of natural nacre. This hybrid film exhibits better thermal stability and flame retardancy. More interestingly, the hybrid material showed good water stability compared to that in the original water-soluble CMC. This type of hybrid has great potential applications in aerospace, artificial muscle, and tissue engineering.

WebTag: Web Browsing into Sensor Tags over NFC

PubMed Central

Echevarria, Juan Jose; Ruiz-de-Garibay, Jonathan; Legarda, Jon; Álvarez, Maite; Ayerbe, Ana; Vazquez, Juan Ignacio

2012-01-01

Information and Communication Technologies (ICTs) continue to overcome many of the challenges related to wireless sensor monitoring, such as for example the design of smarter embedded processors, the improvement of the network architectures, the development of efficient communication protocols or the maximization of the life cycle autonomy. This work tries to improve the communication link of the data transmission in wireless sensor monitoring. The upstream communication link is usually based on standard IP technologies, but the downstream side is always masked with the proprietary protocols used for the wireless link (like ZigBee, Bluetooth, RFID, etc.). This work presents a novel solution (WebTag) for a direct IP based access to a sensor tag over the Near Field Communication (NFC) technology for secure applications. WebTag allows a direct web access to the sensor tag by means of a standard web browser, it reads the sensor data, configures the sampling rate and implements IP based security policies. It is, definitely, a new step towards the evolution of the Internet of Things paradigm. PMID:23012511

Modelling and simulating decision processes of linked lives: An approach based on concurrent processes and stochastic race.

PubMed

Warnke, Tom; Reinhardt, Oliver; Klabunde, Anna; Willekens, Frans; Uhrmacher, Adelinde M

2017-10-01

Individuals' decision processes play a central role in understanding modern migration phenomena and other demographic processes. Their integration into agent-based computational demography depends largely on suitable support by a modelling language. We are developing the Modelling Language for Linked Lives (ML3) to describe the diverse decision processes of linked lives succinctly in continuous time. The context of individuals is modelled by networks the individual is part of, such as family ties and other social networks. Central concepts, such as behaviour conditional on agent attributes, age-dependent behaviour, and stochastic waiting times, are tightly integrated in the language. Thereby, alternative decisions are modelled by concurrent processes that compete by stochastic race. Using a migration model, we demonstrate how this allows for compact description of complex decisions, here based on the Theory of Planned Behaviour. We describe the challenges for the simulation algorithm posed by stochastic race between multiple concurrent complex decisions.

Eating out in Spain: Motivations, sociability and consumer contexts.

PubMed

Díaz-Méndez, Cecilia; García-Espejo, Isabel

2017-12-01

Eating out is a consumer practice which is difficult to define. The study of this practice has traditionally been based on the work/leisure dichotomy. However, in Spain this is not so clear. If we analyse profiles, motivations, places and relationships, we discover an eating-out food model which is specific to Spain and in which food is not limited by this dual link with work and leisure. Eating linked to work does not respond only to instrumental needs. Leisure eating is not always a choice based on preference. Both contain a strong element of sociability which acts as a motivator and are linked to the familisme of Spanish society, whilst at the same time de-routinizing daily life, both at home and at work. This study is based on a national survey carried out in 2014 and helps to understand this consumer practice and those elements which are specific to Spain. Copyright © 2017 Elsevier Ltd. All rights reserved.

Antioxidant films based on cross-linked methyl cellulose and native Chilean berry for food packaging applications.

PubMed

López de Dicastillo, Carol; Rodríguez, Francisco; Guarda, Abel; Galotto, Maria José

2016-01-20

Development of antioxidant and antimicrobial active food packaging materials based on biodegradable polymer and natural plant extracts has numerous advantages as reduction of synthetic additives into the food, reduction of plastic waste, and food protection against microorganisms and oxidation reactions. In this way, active films based on methylcellulose (MC) and maqui (Aristotelia chilensis) berry fruit extract, as a source of antioxidants agents, were studied. On the other hand, due to the high water affinity of MC, this polymer was firstly cross-linked with glutaraldehyde (GA) at different concentrations. The results showed that the addition of GA decreased water solubility, swelling, water vapor permeability of MC films, and the release of antioxidant substances from the active materials increased with the concentration of GA. Natural extract and active cross-linked films were characterized in order to obtain the optimal formulation with the highest antioxidant activity and the best physical properties for latter active food packaging application. Copyright © 2015 Elsevier Ltd. All rights reserved.

Availability of free-space optics (FSO) and hybrid FSO/RF systems

NASA Astrophysics Data System (ADS)

Kim, Isaac I.; Korevaar, Eric J.

2001-11-01

Free Space Optics (FSO) has become a viable, high-bandwidth wireless alternative to fiber optic cabling. The primary advantages of FSO over fiber are its rapid deployment time and significant cost savings. The disadvantage of FSO over fiber is that laser power attenuation through the atmosphere is variable and difficult to predict, since it is weather airports, the link availability as a function of distance can be predicted for any FSO system. These availability curves provide a good indication of the reasonable link distances for FSO systems in a particular geographical area. FSO link distances can vary greatly from desert areas like Las Vegas to heavy-fog cities like St. Johns NF. Another factor in determining FSO distance limitations is the link availability expectation of the application. For enterprise applications, link availability requirements are generally greater than 99%. This allows for longer FSO link ranges, based on the availability curves. The enterprise market is where the majority of FSO systems have been deployed. The carriers and ISPs are another potential large user of FSO systems, especially for last-mile metro access applications. If FSO systems are to be used in telecommunication applications, they will need to meet much higher availability requirements. Carrier-class availability is generally considered to be 99.999% (5 nines). An analysis of link budgets and visibility-limiting weather conditions indicates that to meet carrier-class availability, FSO links should normally be less than 140m (there are cities like Phoenix and Las Vegas where this 99.999% distance limitation increases significantly). This calculation is based on a 53 dB link budget. This concept is extended to the best possible FSO system, which would have a 10 W transmitter and a photocounting detector with a sensitivity of 1 nW. This FSO system would have a 100 dB link margin, which would only increase the 99.999% link distance to 286 m. A more practical solution to extending the high availability range would be to back up the FSO link with a lower data rate radio frequency (RF) link. This hybrid FSO/RF system would extend the 99.999% link range to longer distances and open up a much larger metro/access market to the carriers. It is important to realize that as the link range increases, there will be a slight decrease in overall bandwidth. To show the geographical dependence of FSO performance, the first map of FSO availabilities contoured over North America is presented. This map is the first step to developing an attenuation map for predicting FSO performance, which could be used in similar fashion to the International Telecommunication Union (ITU)/Crane maps for predicting microwave performance.

From Theory-Inspired to Theory-Based Interventions: A Protocol for Developing and Testing a Methodology for Linking Behaviour Change Techniques to Theoretical Mechanisms of Action.

PubMed

Michie, Susan; Carey, Rachel N; Johnston, Marie; Rothman, Alexander J; de Bruin, Marijn; Kelly, Michael P; Connell, Lauren E

2018-05-18

Understanding links between behaviour change techniques (BCTs) and mechanisms of action (the processes through which they affect behaviour) helps inform the systematic development of behaviour change interventions. This research aims to develop and test a methodology for linking BCTs to their mechanisms of action. Study 1 (published explicit links): Hypothesised links between 93 BCTs (from the 93-item BCT taxonomy, BCTTv1) and mechanisms of action will be identified from published interventions and their frequency, explicitness and precision documented. Study 2 (expert-agreed explicit links): Behaviour change experts will identify links between 61 BCTs and 26 mechanisms of action in a formal consensus study. Study 3 (integrated matrix of explicit links): Agreement between studies 1 and 2 will be evaluated and a new group of experts will discuss discrepancies. An integrated matrix of BCT-mechanism of action links, annotated to indicate strength of evidence, will be generated. Study 4 (published implicit links): To determine whether groups of co-occurring BCTs can be linked to theories, we will identify groups of BCTs that are used together from the study 1 literature. A consensus exercise will be used to rate strength of links between groups of BCT and theories. A formal methodology for linking BCTs to their hypothesised mechanisms of action can contribute to the development and evaluation of behaviour change interventions. This research is a step towards developing a behaviour change 'ontology', specifying relations between BCTs, mechanisms of action, modes of delivery, populations, settings and types of behaviour.

Consider the source: Children link the accuracy of text-based sources to the accuracy of the author.

PubMed

Vanderbilt, Kimberly E; Ochoa, Karlena D; Heilbrun, Jayd

2018-05-06

The present research investigated whether young children link the accuracy of text-based information to the accuracy of its author. Across three experiments, three- and four-year-olds (N = 231) received information about object labels from accurate and inaccurate sources who provided information both in text and verbally. Of primary interest was whether young children would selectively rely on information provided by more accurate sources, regardless of the form in which the information was communicated. Experiment 1 tested children's trust in text-based information (e.g., books) written by an author with a history of either accurate or inaccurate verbal testimony and found that children showed greater trust in books written by accurate authors. Experiment 2 replicated the findings of Experiment 1 and extended them by showing that children's selective trust in more accurate text-based sources was not dependent on experience trusting or distrusting the author's verbal testimony. Experiment 3 investigated this understanding in reverse by testing children's trust in verbal testimony communicated by an individual who had authored either accurate or inaccurate text-based information. Experiment 3 revealed that children showed greater trust in individuals who had authored accurate rather than inaccurate books. Experiment 3 also demonstrated that children used the accuracy of text-based sources to make inferences about the mental states of the authors. Taken together, these results suggest children do indeed link the reliability of text-based sources to the reliability of the author. Statement of Contribution Existing knowledge Children use sources' prior accuracy to predict future accuracy in face-to-face verbal interactions. Children who are just learning to read show increased trust in text bases (vs. verbal) information. It is unknown whether children consider authors' prior accuracy when judging the accuracy of text-based information. New knowledge added by this article Preschool children track sources' accuracy across communication mediums - from verbal to text-based modalities and vice versa. Children link the reliability of text-based sources to the reliability of the author. © 2018 The British Psychological Society.

Synthesis of carbohydrate-based surfactants

DOEpatents

Pemberton, Jeanne E.; Polt, Robin L.; Maier, Raina M.

2016-11-22

The present invention provides carbohydrate-based surfactants and methods for producing the same. Methods for producing carbohydrate-based surfactants include using a glycosylation promoter to link a carbohydrate or its derivative to a hydrophobic compound.

Cross-cultural differences in relationship- and group-based trust.

PubMed

Yuki, Masaki; Maddux, William W; Brewer, Marilynn B; Takemura, Kosuke

2005-01-01

Two experiments explored differences in depersonalized trust (trust toward a relatively unknown target person) across cultures. Based on a recent theoretical framework that postulates predominantly different bases for group behaviors in Western cultures versus Eastern cultures, it was predicted that Americans would tend to trust people primarily based on whether they shared category memberships; however, trust for Japanese was expected to be based on the likelihood of sharing direct or indirect interpersonal links. Results supported these predictions. In both Study 1 (questionnaire study) and Study 2 (online money allocation game), Americans trusted ingroup members more than outgroup members; however, the existence of a potential indirect relationship link increased trust for outgroup members more for Japanese than for Americans. Implications for understanding group processes across cultures are discussed.

Supporting inter-topic entity search for biomedical Linked Data based on heterogeneous relationships.

PubMed

Zong, Nansu; Lee, Sungin; Ahn, Jinhyun; Kim, Hong-Gee

2017-08-01

The keyword-based entity search restricts search space based on the preference of search. When given keywords and preferences are not related to the same biomedical topic, existing biomedical Linked Data search engines fail to deliver satisfactory results. This research aims to tackle this issue by supporting an inter-topic search-improving search with inputs, keywords and preferences, under different topics. This study developed an effective algorithm in which the relations between biomedical entities were used in tandem with a keyword-based entity search, Siren. The algorithm, PERank, which is an adaptation of Personalized PageRank (PPR), uses a pair of input: (1) search preferences, and (2) entities from a keyword-based entity search with a keyword query, to formalize the search results on-the-fly based on the index of the precomputed Individual Personalized PageRank Vectors (IPPVs). Our experiments were performed over ten linked life datasets for two query sets, one with keyword-preference topic correspondence (intra-topic search), and the other without (inter-topic search). The experiments showed that the proposed method achieved better search results, for example a 14% increase in precision for the inter-topic search than the baseline keyword-based search engine. The proposed method improved the keyword-based biomedical entity search by supporting the inter-topic search without affecting the intra-topic search based on the relations between different entities. Copyright © 2017 Elsevier Ltd. All rights reserved.

Artificial Intelligence-Based Models for the Optimal and Sustainable Use of Groundwater in Coastal Aquifers

NASA Astrophysics Data System (ADS)

Sreekanth, J.; Datta, Bithin

2011-07-01

Overexploitation of the coastal aquifers results in saltwater intrusion. Once saltwater intrusion occurs, it involves huge cost and long-term remediation measures to remediate these contaminated aquifers. Hence, it is important to have strategies for the sustainable use of coastal aquifers. This study develops a methodology for the optimal management of saltwater intrusion prone aquifers. A linked simulation-optimization-based management strategy is developed. The methodology uses genetic-programming-based models for simulating the aquifer processes, which is then linked to a multi-objective genetic algorithm to obtain optimal management strategies in terms of groundwater extraction from potential well locations in the aquifer.

Evaluation of a computer-assisted, kinetics-based enzyme-linked immunosorbent assay for detection of coronavirus antibodies in cats.

PubMed Central

Barlough, J E; Jacobson, R H; Downing, D R; Marcella, K L; Lynch, T J; Scott, F W

1983-01-01

A computer-assisted, kinetics-based enzyme-linked immunosorbent assay was adapted for the detection of coronavirus antibodies in feline serum. An alkaline antigen diluent (carbonate-bicarbonate buffer, pH 9.6) used in initial experiments produced diffuse, nonspecific color reactions in both viral and control antigen cuvettes which were correlated, paradoxically, with coronavirus antibody levels in test sera. These interfering reactions were minimized by use of lower-pH antigen diluents such as water and phosphate-buffered saline. Background kinetics-based enzyme-linked immunosorbent assay reactivity directed against a noncoronaviral component of antigen tissue culture fluids could then detected in numerous sera, particularly in samples with lower titers. Much of this reactivity was shown to be associated with bovine gamma globulins in cell culture fluid. It was not serum lot or species specific, since a variety of bovine serum lots as well as individual lots of serum from other mammalian and avian species reacted. Reactivity was markedly reduced when cells for antigen preparation were grown in gamma globulin-free bovine serum. Generation of corrected slope values from the kinetics-based enzyme-linked immunosorbent assay made it possible to correct for residual background reactivity in individual test sera and thus eliminate a potentially major source of false-positive reactions. Collectively, these studies indicated that the control of nonspecific reactivity in feline coronavirus serology is absolutely essential to obtain useful estimates of specific antibody responses. PMID:6300184

Evaluation of a computer-assisted, kinetics-based enzyme-linked immunosorbent assay for detection of coronavirus antibodies in cats.

PubMed

Barlough, J E; Jacobson, R H; Downing, D R; Marcella, K L; Lynch, T J; Scott, F W

1983-02-01

A computer-assisted, kinetics-based enzyme-linked immunosorbent assay was adapted for the detection of coronavirus antibodies in feline serum. An alkaline antigen diluent (carbonate-bicarbonate buffer, pH 9.6) used in initial experiments produced diffuse, nonspecific color reactions in both viral and control antigen cuvettes which were correlated, paradoxically, with coronavirus antibody levels in test sera. These interfering reactions were minimized by use of lower-pH antigen diluents such as water and phosphate-buffered saline. Background kinetics-based enzyme-linked immunosorbent assay reactivity directed against a noncoronaviral component of antigen tissue culture fluids could then detected in numerous sera, particularly in samples with lower titers. Much of this reactivity was shown to be associated with bovine gamma globulins in cell culture fluid. It was not serum lot or species specific, since a variety of bovine serum lots as well as individual lots of serum from other mammalian and avian species reacted. Reactivity was markedly reduced when cells for antigen preparation were grown in gamma globulin-free bovine serum. Generation of corrected slope values from the kinetics-based enzyme-linked immunosorbent assay made it possible to correct for residual background reactivity in individual test sera and thus eliminate a potentially major source of false-positive reactions. Collectively, these studies indicated that the control of nonspecific reactivity in feline coronavirus serology is absolutely essential to obtain useful estimates of specific antibody responses.

Heterogeneous wireless/wireline optical access networks with the R-EAT as backend component

NASA Astrophysics Data System (ADS)

Hagedorn, Klaus; Gindera, Ralf; Stohr, Andreas; Jager, Dieter

2004-09-01

A heterogeneous wireless/wireline optical transmission link using a reflection type electroabsorption transceiver (R-EAT) is presented. Simultaneous transmission of full-duplex broadband wireless LAN (WLAN) channels and 1Gb/s base band data is experimentally demonstrated. The system link employs sub-carrier multiplexing (SCM) and two optical channels for full duplex transmission of various analog WLAN channels and downlink digital base band data. The developed link architecture is suitable for simultaneous transmission of broadband wireline and wireless signals, it enables the coexistence and interoperability between wireline and wireless access technologies. The developed R-EAT component employed in this wireline/wireless access system, features "single-chip-component" base stations in access networks with star type topology where only a single optical fiber is used for bidirectional optical transmission. The R-EAT can be used within the optical C-band (1530- 1560nm) and is suitable for (D)WDM networks. Bit error rate measurements demonstrate the capabilities of the R-EAT for 1Gb/s base band transmission. The analog performance for WLAN transmission is characterised by a spurious free dynamic range (SFDR) of more than 75dB and 90dB for uplink and downlink transmission, respectively. The link gain for uplink and downlink transmission is -42dB and -37dB, respectively. The demonstrates the analog performances of the R-EAT for being used in wireless access networks such as W-LAN.

A genome-wide systems analysis reveals strong link between colorectal cancer and trimethylamine N-oxide (TMAO), a gut microbial metabolite of dietary meat and fat.

PubMed

Xu, Rong; Wang, QuanQiu; Li, Li

2015-01-01

Dietary intakes of red meat and fat are established risk factors for both colorectal cancer (CRC) and cardiovascular disease (CVDs). Recent studies have shown a mechanistic link between TMAO, an intestinal microbial metabolite of red meat and fat, and risk of CVDs. Data linking TMAO directly to CRC is, however, lacking. Here, we present an unbiased data-driven network-based systems approach to uncover a potential genetic relationship between TMAO and CRC. We constructed two different epigenetic interaction networks (EINs) using chemical-gene, disease-gene and protein-protein interaction data from multiple large-scale data resources. We developed a network-based ranking algorithm to ascertain TMAO-related diseases from EINs. We systematically analyzed disease categories among TMAO-related diseases at different ranking cutoffs. We then determined which genetic pathways were associated with both TMAO and CRC. We show that CVDs and their major risk factors were ranked highly among TMAO-related diseases, confirming the newly discovered mechanistic link between CVDs and TMAO, and thus validating our algorithms. CRC was ranked highly among TMAO-related disease retrieved from both EINs (top 0.02%, #1 out of 4,372 diseases retrieved based on Mendelian genetics and top 10.9% among 882 diseases based on genome-wide association genetics), providing strong supporting evidence for our hypothesis that TMAO is genetically related to CRC. We have also identified putative genetic pathways that may link TMAO to CRC, which warrants further investigation. Through systematic disease enrichment analysis, we also demonstrated that TMAO is related to metabolic syndromes and cancers in general. Our genome-wide analysis demonstrates that systems approaches to studying the epigenetic interactions among diet, microbiome metabolisms, and disease genetics hold promise for understanding disease pathogenesis. Our results show that TMAO is genetically associated with CRC. This study suggests that TMAO may be an important intermediate marker linking dietary meat and fat and gut microbiota metabolism to risk of CRC, underscoring opportunities for the development of new gut microbiome-dependent diagnostic tests and therapeutics for CRC.

Combined node and link partitions method for finding overlapping communities in complex networks

PubMed Central

Jin, Di; Gabrys, Bogdan; Dang, Jianwu

2015-01-01

Community detection in complex networks is a fundamental data analysis task in various domains, and how to effectively find overlapping communities in real applications is still a challenge. In this work, we propose a new unified model and method for finding the best overlapping communities on the basis of the associated node and link partitions derived from the same framework. Specifically, we first describe a unified model that accommodates node and link communities (partitions) together, and then present a nonnegative matrix factorization method to learn the parameters of the model. Thereafter, we infer the overlapping communities based on the derived node and link communities, i.e., determine each overlapped community between the corresponding node and link community with a greedy optimization of a local community function conductance. Finally, we introduce a model selection method based on consensus clustering to determine the number of communities. We have evaluated our method on both synthetic and real-world networks with ground-truths, and compared it with seven state-of-the-art methods. The experimental results demonstrate the superior performance of our method over the competing ones in detecting overlapping communities for all analysed data sets. Improved performance is particularly pronounced in cases of more complicated networked community structures. PMID:25715829

3D Bi2S3/TiO2 cross-linked heterostructure: An efficient strategy to improve charge transport and separation for high photoelectrochemical performance

NASA Astrophysics Data System (ADS)

Han, Minmin; Jia, Junhong

2016-10-01

A novel 3D cross-linked heterostructure of TiO2 nanorods connecting with each other via ultrathin Bi2S3 nanosheets is constructed by a facile and effective strategy. The growth mechanism has been investigated and proposed based on the evolution of microstructure by changing the reaction parameters. Benefiting from the unique cross-linked heterostructure, the as-prepared Bi2S3 nanosheets modified TiO2 nanorods arrays could achieve a high energy conversion efficiency of 3.29% which is the highest value to date for Bi2S3-only sensitized solar cells as the reported highest value is 2.23% and other reported values are less than 1%. Furthermore, the photoelectrochemical studies clearly reveal that the novel cross-linked heterostructure exhibits much better activity than 0D nanoparticles decorated TiO2 nanorods under visible light irradiation, which may be primarily ascribed to the efficient electron transfer from 2D ultrathin Bi2S3 nanosheets to 1D TiO2 nanorod arrays. The promising results in this work confirm the advantages of cross-linked heterostructure and also undoubtedly offer an attractive synthesis strategy to fabricate other nanorod-based hierarchical architecture as well as nano-devices for solar energy conversion.

An experimental study on digital predistortion for radio-over-fiber links

NASA Astrophysics Data System (ADS)

Vieira, Luis C.; Gomes, Nathan J.; Nkansah, Anthony

2010-12-01

Radio-over-fiber (RoF) has been proposed as an enabling technology for broadband networks, such as WiMAX and WiFi. Besides the inherent high bandwidth and reliability of RoF systems, they also allow the reduction of installation and maintenance cost of the remote antenna units (RAUs) and improvement in the coverage area of the base station/access point. However, the nonlinear distortion of the optical link, which stems mainly from the laser diode, may impose serious limitations on the system performance, especially when high PAPR, wideband signals are used. Thus, distortion compensation is a key issue in order to facilitate the application of the RoF technology for broadband networks. In this work, digital predistortion for directly modulated RoF links is experimentally investigated. A memory-polynomial- based predistorter model is identified from measurements of the baseband OFDM input-output signals and through the use of an indirect learning architecture. Then, a predistorted signal is generated and fed to the RoF link for comparing its output with that of the non-predistorted one. As a result of this compensation technique, an improvement of the static link linearity and the output constellation diagram has been found, with an EVM reduction of 1.73 %.

The social brain: scale-invariant layering of Erdős-Rényi networks in small-scale human societies.

PubMed

Harré, Michael S; Prokopenko, Mikhail

2016-05-01

The cognitive ability to form social links that can bind individuals together into large cooperative groups for safety and resource sharing was a key development in human evolutionary and social history. The 'social brain hypothesis' argues that the size of these social groups is based on a neurologically constrained capacity for maintaining long-term stable relationships. No model to date has been able to combine a specific socio-cognitive mechanism with the discrete scale invariance observed in ethnographic studies. We show that these properties result in nested layers of self-organizing Erdős-Rényi networks formed by each individual's ability to maintain only a small number of social links. Each set of links plays a specific role in the formation of different social groups. The scale invariance in our model is distinct from previous 'scale-free networks' studied using much larger social groups; here, the scale invariance is in the relationship between group sizes, rather than in the link degree distribution. We also compare our model with a dominance-based hierarchy and conclude that humans were probably egalitarian in hunter-gatherer-like societies, maintaining an average maximum of four or five social links connecting all members in a largest social network of around 132 people. © 2016 The Author(s).

Simultaneous wastewater treatment and bioelectricity production in microbial fuel cells using cross-linked chitosan-graphene oxide mixed-matrix membranes.

PubMed

Holder, Shima L; Lee, Ching-Hwa; Popuri, Srinivasa R

2017-05-01

Microbial fuel cells (MFCs) are emerging technology for wastewater treatment by chemical oxygen demand (COD) reduction and simultaneous bioelectricity production. Fabrication of an effective proton exchange membrane (PEM) is a vital component for MFC performance. In this work, green chitosan-based (CS) PEMs were fabricated with graphene oxide (GO) as filler material (CS-GO) and cross-linked with phosphoric acid (CS-GO-P(24)) or sulfuric acid (CS-GO-S(24)) to determine their effect on PEM properties. Interrogation of the physicochemical, thermal, and mechanical properties of the cross-linked CS-GO PEMs demonstrated that ionic cross-linking based on the incorporation of PO 4 3- groups in the CS-GO mixed-matrix composites, when compared with sulfuric acid cross-linking commonly used in proton exchange membrane fuel cell (PEMFC) studies, generated additional density of ionic cluster domains, rendered enhanced sorption properties, and augmented the thermal and mechanical stability of the composite structure. Consequently, bioelectricity performance analysis in MFC application showed that CS-GO-P(24) membrane produced 135% higher power density than the CS-GO-S(24) MFC system. Simultaneously, 89.52% COD removal of primary clarifier municipal wastewater was achieved in the MFC operated with the CS-GO-P(24) membrane.

Illuminate Knowledge Elements in Geoscience Literature

NASA Astrophysics Data System (ADS)

Ma, X.; Zheng, J. G.; Wang, H.; Fox, P. A.

2015-12-01

There are numerous dark data hidden in geoscience literature. Efficient retrieval and reuse of those data will greatly benefit geoscience researches of nowadays. Among the works of data rescue, a topic of interest is illuminating the knowledge framework, i.e. entities and relationships, embedded in documents. Entity recognition and linking have received extensive attention in news and social media analysis, as well as in bioinformatics. In the domain of geoscience, however, such works are limited. We will present our work on how to use knowledge bases on the Web, such as ontologies and vocabularies, to facilitate entity recognition and linking in geoscience literature. The work deploys an un-supervised collective inference approach [1] to link entity mentions in unstructured texts to a knowledge base, which leverages the meaningful information and structures in ontologies and vocabularies for similarity computation and entity ranking. Our work is still in the initial stage towards the detection of knowledge frameworks in literature, and we have been collecting geoscience ontologies and vocabularies in order to build a comprehensive geoscience knowledge base [2]. We hope the work will initiate new ideas and collaborations on dark data rescue, as well as on the synthesis of data and knowledge from geoscience literature. References: 1. Zheng, J., Howsmon, D., Zhang, B., Hahn, J., McGuinness, D.L., Hendler, J., and Ji, H. 2014. Entity linking for biomedical literature. In Proceedings of ACM 8th International Workshop on Data and Text Mining in Bioinformatics, Shanghai, China. 2. Ma, X. Zheng, J., 2015. Linking geoscience entity mentions to the Web of Data. ESIP 2015 Summer Meeting, Pacific Grove, CA.

Eco-friendly and biocompatible cross-linked carboxymethylcellulose hydrogels as adsorbents for the removal of organic dye pollutants for environmental applications.

PubMed

Capanema, Nádia S V; Mansur, Alexandra A P; Mansur, Herman S; de Jesus, Anderson C; Carvalho, Sandhra M; Chagas, Poliane; de Oliveira, Luiz C

2017-08-28

In this study, new eco-friendly hydrogel adsorbents were synthesized based on carboxymethylcellulose (CMC, degree of substitution [DS] = 0.7) chemically cross-linked with citric acid (CA) using a green process in aqueous solution and applied for the adsorption of methylene blue (MB). Spectroscopic analyses demonstrated the mechanism of cross-linking through the reaction of hydroxyl functional groups from CMC with CA. These CMC hydrogels showed very distinct morphological features dependent on the extension of cross-linking and their nanomechanical properties were drastically increased by approximately 300% after cross-linking with 20% CA (e.g. elastic moduli from 80 ± 15 to 270 ± 50 MPa). Moreover, they were biocompatible using an in vitro cell viability assay in contact with human osteosarcoma-derived cells (SAOS) for 24 h. These CMC-based hydrogels exhibited adsorption efficiency above 90% (24 h) and maximum removal capacity of MB from 5 to 25 mg g -1 depending on the dye concentration (from 100 to 500 mg L -1 ), which was used as the model cationic organic pollutant. The adsorption of process of MB was well-fit to the pseudo-second-order kinetics model. The desorption of MB by immersion in KCl solution (3 mol L -1 , 24 h) showed a typical recovery efficiency of over 60% with conceivable reuse of these CMC-based hydrogels. Conversely, CMC hydrogels repelled methyl orange dye used as model anionic pollutant, proving the mechanism of adsorption by the formation of charged polyelectrolyte/dye complexes.

Risk of future cardiovascular disease in women with prior preeclampsia: a focus group study.

PubMed

Seely, Ellen W; Rich-Edwards, Janet; Lui, Janet; Nicklas, Jacinda M; Saxena, Aditi; Tsigas, Eleni; Levkoff, Sue E

2013-12-21

A history of preeclampsia is a risk factor for the future development of hypertension and cardiovascular disease (CVD). The objective of this study was to assess, in women with prior preeclampsia, the level of knowledge regarding the link between preeclampsia and CVD, motivators for and barriers to lifestyle change and interest in a lifestyle modification program to decrease CVD risk following a pregnancy complicated by preeclampsia. Twenty women with a history of preeclampsia participated in 5 phone-based focus groups. Focus groups were recorded, transcribed, and analyzed. Qualitative content analysis was used to identify common themes across focus groups. Consensus was reached on a representative set of themes describing the data. Women with prior preeclampsia were in general unaware of the link between preeclampsia and future CVD but eager to learn about this link and motivated to achieve a healthy lifestyle. Major perceived barriers to lifestyle change were lack of time, cost of healthy foods and family responsibilities. Perceived facilitators included knowledge of the link between preeclampsia and CVD, a desire to stay healthy, and creating a healthy home for their children. Women with prior preeclampsia were interested in the idea of a web-based program focused on lifestyle strategies to decrease CVD risk in women. Women with prior preeclampsia were eager to learn about the link between preeclampsia and CVD and to take steps to reduce CVD risk. A web-based program to help women with prior preeclampsia adopt a healthy lifestyle may be an appropriate strategy for this population.

On-line capillary electrophoresis/laser-induced fluorescence/mass spectrometry analysis of glycans labeled with Teal™ fluorescent dye using an electrokinetic sheath liquid pump-based nanospray ion source.

PubMed

Khan, Shaheer; Liu, Jenkuei; Szabo, Zoltan; Kunnummal, Baburaj; Han, Xiaorui; Ouyang, Yilan; Linhardt, Robert J; Xia, Qiangwei

2018-06-15

N-linked glycan analysis of recombinant therapeutic proteins, such as monoclonal antibodies, Fc-fusion proteins, and antibody-drug conjugates, provides valuable information regarding protein therapeutics glycosylation profile. Both qualitative identification and quantitative analysis of N-linked glycans on recombinant therapeutic proteins are critical analytical tasks in the biopharma industry during the development of a biotherapeutic. Currently, such analyses are mainly carried out using capillary electrophoresis/laser-induced fluorescence (CE/LIF), liquid chromatography/fluorescence (LC/FLR), and liquid chromatography/fluorescence/mass spectrometry (LC/FLR/MS) technologies. N-linked glycans are first released from glycoproteins by enzymatic digestion, then labeled with fluorescence dyes for subsequent CE or LC separation, and LIF or MS detection. Here we present an on-line CE/LIF/MS N-glycan analysis workflow that incorporates the fluorescent Teal™ dye and an electrokinetic pump-based nanospray sheath liquid capillary electrophoresis/mass spectrometry (CE/MS) ion source. Electrophoresis running buffer systems using ammonium acetate and ammonium hydroxide were developed for the negative ion mode CE/MS analysis of fluorescence-labeled N-linked glycans. Results show that on-line CE/LIF/MS analysis can be readily achieved using this versatile CE/MS ion source on common CE/MS instrument platforms. This on-line CE/LIF/MS method using Teal™ fluorescent dye and electrokinetic pump-based nanospray sheath liquid CE/MS coupling technology holds promise for on-line quantitation and identification of N-linked glycans on recombinant therapeutic proteins. Copyright © 2018 John Wiley & Sons, Ltd.

An Internet-Based Real-Time Audiovisual Link for Dual MEG Recordings

PubMed Central

Zhdanov, Andrey; Nurminen, Jussi; Baess, Pamela; Hirvenkari, Lotta; Jousmäki, Veikko; Mäkelä, Jyrki P.; Mandel, Anne; Meronen, Lassi; Hari, Riitta; Parkkonen, Lauri

2015-01-01

Hyperscanning Most neuroimaging studies of human social cognition have focused on brain activity of single subjects. More recently, “two-person neuroimaging” has been introduced, with simultaneous recordings of brain signals from two subjects involved in social interaction. These simultaneous “hyperscanning” recordings have already been carried out with a spectrum of neuroimaging modalities, such as functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and functional near-infrared spectroscopy (fNIRS). Dual MEG Setup We have recently developed a setup for simultaneous magnetoencephalographic (MEG) recordings of two subjects that communicate in real time over an audio link between two geographically separated MEG laboratories. Here we present an extended version of the setup, where we have added a video connection and replaced the telephone-landline-based link with an Internet connection. Our setup enabled transmission of video and audio streams between the sites with a one-way communication latency of about 130 ms. Our software that allows reproducing the setup is publicly available. Validation We demonstrate that the audiovisual Internet-based link can mediate real-time interaction between two subjects who try to mirror each others’ hand movements that they can see via the video link. All the nine pairs were able to synchronize their behavior. In addition to the video, we captured the subjects’ movements with accelerometers attached to their index fingers; we determined from these signals that the average synchronization accuracy was 215 ms. In one subject pair we demonstrate inter-subject coherence patterns of the MEG signals that peak over the sensorimotor areas contralateral to the hand used in the task. PMID:26098628

Efficient network disintegration under incomplete information: the comic effect of link prediction

NASA Astrophysics Data System (ADS)

Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

2016-03-01

The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the “comic effect” of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized.

Improving the performance of transglutaminase-crosslinked microparticles for enteric delivery.

PubMed

Tello, Fernando; Prata, Ana S; Rodrigues, Rodney A F; Sartoratto, Adilson; Grosso, Carlos R F

2016-10-01

Various agents for cross-linking have been investigated for stabilizing and controlling the barrier properties of microparticles for enteric applications. Transglutaminase, in addition to being commercially available for human consumption, presents inferior cross-linking action compared to glutaraldehyde. In this study, the intensity of this enzymatic cross-linking was investigated in microparticles obtained by complex coacervation between gelatin and gum Arabic. The effectiveness of cross-linking in these microparticles was evaluated based on swelling, release of a model substance (parika oleoresin: colored and hydrophobic) and gastrointestinal assays. The cross-linked microparticles remained intact under gastric conditions, whereas the uncross-linked microparticles have been dissolved. However, all of the microparticles have been dissolved under intestinal conditions. The amount of oily core that was released decreased as the amount of transglutaminase increased. For the most efficient microparticles (50U/g of protein), the performance was improved by increasing the pH of cross-linking from 4.0 to 6.0, resulting in a release of 17.1% rather than 32.3% of the core material. These results were considerably closer to the 10.3% of core material released by glutaraldehyde-cross-linked microparticles (1mM/g of protein). Copyright © 2016 Elsevier Ltd. All rights reserved.

Rapid Y degeneration and dosage compensation in plant sex chromosomes

PubMed Central

Papadopulos, Alexander S. T.; Chester, Michael; Ridout, Kate; Filatov, Dmitry A.

2015-01-01

The nonrecombining regions of animal Y chromosomes are known to undergo genetic degeneration, but previous work has failed to reveal large-scale gene degeneration on plant Y chromosomes. Here, we uncover rapid and extensive degeneration of Y-linked genes in a plant species, Silene latifolia, that evolved sex chromosomes de novo in the last 10 million years. Previous transcriptome-based studies of this species missed unexpressed, degenerate Y-linked genes. To identify sex-linked genes, regardless of their expression, we sequenced male and female genomes of S. latifolia and integrated the genomic contigs with a high-density genetic map. This revealed that 45% of Y-linked genes are not expressed, and 23% are interrupted by premature stop codons. This contrasts with X-linked genes, in which only 1.3% of genes contained stop codons and 4.3% of genes were not expressed in males. Loss of functional Y-linked genes is partly compensated for by gene-specific up-regulation of X-linked genes. Our results demonstrate that the rate of genetic degeneration of Y-linked genes in S. latifolia is as fast as in animals, and that the evolutionary trajectories of sex chromosomes are similar in the two kingdoms. PMID:26438872

Efficient network disintegration under incomplete information: the comic effect of link prediction.

PubMed

Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

2016-03-10

The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the "comic effect" of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized.

Efficient network disintegration under incomplete information: the comic effect of link prediction

PubMed Central

Tan, Suo-Yi; Wu, Jun; Lü, Linyuan; Li, Meng-Jun; Lu, Xin

2016-01-01

The study of network disintegration has attracted much attention due to its wide applications, including suppressing the epidemic spreading, destabilizing terrorist network, preventing financial contagion, controlling the rumor diffusion and perturbing cancer networks. The crux of this matter is to find the critical nodes whose removal will lead to network collapse. This paper studies the disintegration of networks with incomplete link information. An effective method is proposed to find the critical nodes by the assistance of link prediction techniques. Extensive experiments in both synthetic and real networks suggest that, by using link prediction method to recover partial missing links in advance, the method can largely improve the network disintegration performance. Besides, to our surprise, we find that when the size of missing information is relatively small, our method even outperforms than the results based on complete information. We refer to this phenomenon as the “comic effect” of link prediction, which means that the network is reshaped through the addition of some links that identified by link prediction algorithms, and the reshaped network is like an exaggerated but characteristic comic of the original one, where the important parts are emphasized. PMID:26960247

Comparing Multi-Informant Assessment Measures of Parental Monitoring and Their Links with Adolescent Delinquent Behavior

PubMed Central

Augenstein, Tara M.; Thomas, Sarah A.; Ehrlich, Katherine B.; Daruwala, Samantha; Reyes, Shelby M.; Chrabaszcz, Jeffrey S.; De Los Reyes, Andres

2016-01-01

SYNOPSIS Objective Parents’ poor monitoring of adolescents’ whereabouts and activities is commonly linked to adolescents’ increased engagement in delinquent behaviors. Yet, different domains of parental monitoring (parental monitoring behaviors vs. parental knowledge) and reports from multiple informants (parent vs. adolescent) may vary in their links to delinquent behavior. Design Seventy-four parental caregivers and 74 adolescents completed survey measures of parental monitoring and knowledge, and adolescents completed self-report surveys of delinquent behavior. Results We observed low-to-moderate magnitudes of correspondence between parent- and adolescent-reports of parental monitoring behaviors and parental knowledge. Adolescent self-reported delinquent behavior related to parent and adolescent reports of parental monitoring behaviors and parental knowledge, with adolescents who self-reported engagement in delinquent behaviors evidencing lower levels of parental knowledge and higher levels of poor monitoring compared to adolescents who did not self-report engagement in delinquent behaviors. Adolescent self-reported engagement in delinquent behaviors evidenced stronger links to parental monitoring when based on adolescent reports of monitoring (relative to parent reports), whereas stronger links held between adolescent self-reported delinquent behavior and parental knowledge when based on parent reports of knowledge (relative to adolescent reports). Conclusions Links between monitoring and adolescents’ delinquent behavior vary by the kind of monitoring measure completed as well as the informant completing the measure. These findings inform measurement selection in research and clinical assessments of parental monitoring and adolescent delinquent behavior. PMID:27482171

Hypotheses generation as supervised link discovery with automated class labeling on large-scale biomedical concept networks

PubMed Central

2012-01-01

Computational approaches to generate hypotheses from biomedical literature have been studied intensively in recent years. Nevertheless, it still remains a challenge to automatically discover novel, cross-silo biomedical hypotheses from large-scale literature repositories. In order to address this challenge, we first model a biomedical literature repository as a comprehensive network of biomedical concepts and formulate hypotheses generation as a process of link discovery on the concept network. We extract the relevant information from the biomedical literature corpus and generate a concept network and concept-author map on a cluster using Map-Reduce frame-work. We extract a set of heterogeneous features such as random walk based features, neighborhood features and common author features. The potential number of links to consider for the possibility of link discovery is large in our concept network and to address the scalability problem, the features from a concept network are extracted using a cluster with Map-Reduce framework. We further model link discovery as a classification problem carried out on a training data set automatically extracted from two network snapshots taken in two consecutive time duration. A set of heterogeneous features, which cover both topological and semantic features derived from the concept network, have been studied with respect to their impacts on the accuracy of the proposed supervised link discovery process. A case study of hypotheses generation based on the proposed method has been presented in the paper. PMID:22759614

An intelligent anti-jamming network system of data link

NASA Astrophysics Data System (ADS)

Fan, Xiangrui; Lin, Jingyong; Liu, Jiarun; Zhou, Chunmei

2017-10-01

Data link is the key information system for the cooperation of weapons, single physical layer anti-jamming technology has been unable to meet its requirements. High dynamic precision-guided weapon nodes like missiles, anti-jamming design of data link system need to have stronger pertinence and effectiveness: the best anti-jamming communication mode can be selected intelligently in combat environment, in real time, guarantee the continuity of communication. We discuss an anti-jamming intelligent networking technology of data link based on interference awareness, put forward a model of intelligent anti-jamming system, and introduces the cognitive node protocol stack model and intelligent anti-jamming method, in order to improve the data chain of intelligent anti-jamming ability.

Enriching PubMed Related Article Search with Sentence Level Co-citations

PubMed Central

Tran, Nam; Alves, Pedro; Ma, Shuangge

2009-01-01

PubMed related article links identify closely related articles and enhance our ability to navigate the biomedical literature. They are derived by calculating the word similarity between two articles, relating articles with overlapping word content. In this paper, we propose to enrich PubMed with a new type of related article link based on citations within a single sentence (i.e. sentence level co-citations or SLCs). Using different similarity metrics, we demonstrated that articles linked by SLCs are highly related. We also showed that only half of SLCs are found among PubMed related article links. Additionally, we discuss how the citing sentence of an SLC explains the connection between two articles. PMID:20351935

Formaldehyde cross-linking and structural proteomics: Bridging the gap.

PubMed

Srinivasa, Savita; Ding, Xuan; Kast, Juergen

2015-11-01

Proteins are dynamic entities constantly moving and altering their structures based on their functions and interactions inside and outside the cell. Formaldehyde cross-linking combined with mass spectrometry can accurately capture interactions of these rapidly changing biomolecules while maintaining their physiological surroundings. Even with its numerous established uses in biology and compatibility with mass spectrometry, formaldehyde has not yet been applied in structural proteomics. However, formaldehyde cross-linking is moving toward analyzing tertiary structure, which conventional cross-linkers have already accomplished. The purpose of this review is to describe the potential of formaldehyde cross-linking in structural proteomics by highlighting its applications, characteristics and current status in the field. Copyright © 2015 Elsevier Inc. All rights reserved.

Leveraging Crowdsourcing and Linked Open Data for Geoscience Data Sharing and Discovery

NASA Astrophysics Data System (ADS)

Narock, T. W.; Rozell, E. A.; Hitzler, P.; Arko, R. A.; Chandler, C. L.; Wilson, B. D.

2013-12-01

Data citation standards can form the basis for increased incentives, recognition, and rewards for scientists. Additionally, knowing which data were utilized in a particular publication can enhance discovery and reuse. Yet, a lack of data citation information in existing publications as well as ambiguities across datasets can limit the accuracy of automated linking approaches. We describe a crowdsourcing approach, based on Linked Open Data, in which AGU abstracts are linked to the data used in those presentations. We discuss our efforts to incentivize participants through promotion of their research, the role that the Semantic Web can play in this effort, and how this work differs from existing platforms such as Mendeley and ResearchGate. Further, we discuss the benefits and challenges of Linked Open Data as a technical solution including the role of provenance, trust, and computational reasoning.

Business structure, ethnic shifts in labor markets, and violence: the link between company size, local labor markets, and non-Latino homicide.

PubMed

Barranco, Raymond E; Shihadeh, Edward S

2015-01-01

Combining several schools of thought, including the civic engagement thesis, we extend current research by linking three things at the county level; firm size, the ethnic composition of labor markets, and violent crime. Our results suggest that larger businesses (based on the average number of persons employed) are more likely to have an external orientation and long recruitment reach, and this is linked to ethnic shifts in labor markets toward Latino workers. Such shifts are in turn associated with high rates of homicide among non-Latinos. Through indirect effects modeling, we find that increases in Black homicide are linked to rises in concentrated poverty, while increases in White homicide are linked to changes in unemployment. We discuss the implications of our findings. Copyright © 2014 Elsevier Inc. All rights reserved.

A 400 Gbps/100 m free-space optical link

NASA Astrophysics Data System (ADS)

Lin, Chun-Yu; Lu, Hai-Han; Ho, Chun-Ming; Cheng, Ming-Te; Huang, Sheng-Jhe; Wang, Yun-Chieh; Chi, Jing-Kai

2017-02-01

A 400 Gbps/100 m free-space optical (FSO) link with dense-wavelength-division-multiplexing (DWDM)/space-division-multiplexing (SDM) techniques and a doublet lens scheme is proposed. To the best of our knowledge, this is the first time that a link adopting DWDM and SDM techniques and a doublet lens scheme has demonstrated a 400 Gbps/100 m FSO link. The experimental results show that the free-space transmission rate is significantly enhanced by the DWDM and SDM techniques, and the free-space transmission distance is greatly increased by the doublet lens scheme. A 16-channel FSO link with a total transmission rate of 400 Gbps (25 Gbps/λ  ×  16 λ  =  400 Gbps) over a 100 m free-space link is successfully demonstrated. Such a 400 Gbps/100 m DWDM/SDM FSO link provides the advantages of optical wireless communications for high transmission rates and long transmission distances, which is very useful for high-speed and long-haul light-based WiFi (LiFi) applications.

Integrated cockpit display and processor: the best solution for Link-16 applications

NASA Astrophysics Data System (ADS)

Smeyne, Alan L.; Savaya, John

2000-08-01

Link-16 Data Link systems are being added to current avionics systems to provide increased situational awareness and command data. By using a single intelligent display system, the impact to existing aircraft systems to implement Link-16 capabilities is minimized. Litton Guidance & Control Systems (G&CS), a military avionics supplier for more than forty years, provides Open System Architecture (OSA), large screen aircraft display systems. Based on a common set of plug-in modules, these Smart Multi-Function Displays (SMFD) are available in a variety of sizes and processing capabilities, any one of which can meet the Link-16 requirements. Using a single smart SMFD connected to a Link-16 subsystem has many advantages. With digital moving map capability, the SMFD can monitor and display air and ground tracks of both friendly and hostile forces while providing potential threat data to the operator. The SMFD can also monitor vehicle status and mission data to share between friendly air and surface forces. To support the integrated digital battlefield, Link-16 capability is required and the Litton G&CS SMFD provides the processing/display functionality to implement this capability.

Using Link Disconnection Entropy Disorder to Detect Fast Moving Nodes in MANETs.

PubMed

Alvarez, Carlos F; Palafox, Luis E; Aguilar, Leocundo; Sanchez, Mauricio A; Martinez, Luis G

2016-01-01

Mobile ad-hoc networks (MANETs) are dynamic by nature; this dynamism comes from node mobility, traffic congestion, and other transmission conditions. Metrics to evaluate the effects of those conditions shine a light on node's behavior in an ad-hoc network, helping to identify the node or nodes with better conditions of connection. In this paper, we propose a relative index to evaluate a single node reliability, based on the link disconnection entropy disorder using neighboring nodes as reference. Link disconnection entropy disorder is best used to identify fast moving nodes or nodes with unstable communications, this without the need of specialized sensors such as GPS. Several scenarios were studied to verify the index, measuring the effects of Speed and traffic density on the link disconnection entropy disorder. Packet delivery ratio is associated to the metric detecting a strong relationship, enabling the use of the link disconnection entropy disorder to evaluate the stability of a node to communicate with other nodes. To expand the utilization of the link entropy disorder, we identified nodes with higher speeds in network simulations just by using the link entropy disorder.

Toward link predictability of complex networks

PubMed Central

Lü, Linyuan; Pan, Liming; Zhou, Tao; Zhang, Yi-Cheng; Stanley, H. Eugene

2015-01-01

The organization of real networks usually embodies both regularities and irregularities, and, in principle, the former can be modeled. The extent to which the formation of a network can be explained coincides with our ability to predict missing links. To understand network organization, we should be able to estimate link predictability. We assume that the regularity of a network is reflected in the consistency of structural features before and after a random removal of a small set of links. Based on the perturbation of the adjacency matrix, we propose a universal structural consistency index that is free of prior knowledge of network organization. Extensive experiments on disparate real-world networks demonstrate that (i) structural consistency is a good estimation of link predictability and (ii) a derivative algorithm outperforms state-of-the-art link prediction methods in both accuracy and robustness. This analysis has further applications in evaluating link prediction algorithms and monitoring sudden changes in evolving network mechanisms. It will provide unique fundamental insights into the above-mentioned academic research fields, and will foster the development of advanced information filtering technologies of interest to information technology practitioners. PMID:25659742

LinkedOmics: analyzing multi-omics data within and across 32 cancer types.

PubMed

Vasaikar, Suhas V; Straub, Peter; Wang, Jing; Zhang, Bing

2018-01-04

The LinkedOmics database contains multi-omics data and clinical data for 32 cancer types and a total of 11 158 patients from The Cancer Genome Atlas (TCGA) project. It is also the first multi-omics database that integrates mass spectrometry (MS)-based global proteomics data generated by the Clinical Proteomic Tumor Analysis Consortium (CPTAC) on selected TCGA tumor samples. In total, LinkedOmics has more than a billion data points. To allow comprehensive analysis of these data, we developed three analysis modules in the LinkedOmics web application. The LinkFinder module allows flexible exploration of associations between a molecular or clinical attribute of interest and all other attributes, providing the opportunity to analyze and visualize associations between billions of attribute pairs for each cancer cohort. The LinkCompare module enables easy comparison of the associations identified by LinkFinder, which is particularly useful in multi-omics and pan-cancer analyses. The LinkInterpreter module transforms identified associations into biological understanding through pathway and network analysis. Using five case studies, we demonstrate that LinkedOmics provides a unique platform for biologists and clinicians to access, analyze and compare cancer multi-omics data within and across tumor types. LinkedOmics is freely available at http://www.linkedomics.org. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Improvement of desolvation and resilience of alginate binders for Si-based anodes in a lithium ion battery by calcium-mediated cross-linking.

PubMed

Yoon, Jihee; Oh, Dongyeop X; Jo, Changshin; Lee, Jinwoo; Hwang, Dong Soo

2014-12-14

Si-based anodes in lithium ion batteries (LIBs) have exceptionally high theoretical capacity, but the use of a Si-based anode in LIBs is problematic because the charging-discharging process can fracture the Si particles. Alginate and its derivatives show promise as Si particle binders in the anode. We show that calcium-mediated "egg-box" electrostatic cross-linking of alginate improves toughness, resilience, electrolyte desolvation of the alginate binder as a Si-binder for LIBs. Consequently, the improved mechanical properties of the calcium alginate binder compared to the sodium alginate binder and other commercial binders extend the lifetime and increase the capacity of Si-based anodes in LIBs.

Simultaneous transfer of optical frequency and time over 306 km long-haul optical fibre link

NASA Astrophysics Data System (ADS)

Hucl, Vaclav; Cizek, Martin; Pravdova, Lenka; Rerucha, Simon; Hrabina, Jan; Mikel, Bretislav; Smotlacha, Vladimir; Vojtech, Josef; Lazar, Josef; Cip, Ondrej

2016-12-01

Optical fibre links for distributing optical frequencies and time stamps were researched and experimentally tested in the past fifteen years. They have been used mainly for stability comparison of experimental optical clocks. But recent development puts demands on a technology transfer from laboratory experiments to the real industry. The remote calibration of interrogators of Fibre Bragg Grating strain sensory networks is one of important examples. The first step of the adoption the time and frequency broadcasting should be the drop-out free long-term operation of this technology between research laboratories connected via long-haul fibre links. We present a 306 km long-haul optical fibre link between the cities of Prague and Brno in the Czech Republic where a coherent transfer of stable optical frequency and a stable time signal has been firstly demonstrated. The link between ISI CAS Brno and CESNET Prague uses an internet communication fibre where a window of 1540-1546 nm is dedicated for the coherent transfer and 1PPS signal. The link is equipped with 6 bidirectional EDFA amplifiers. The optical frequency standard based on the highly-coherent laser Koheras Adjustik working at 1540.5 nm and stabilized with a saturation absorption spectroscopy technique was used for the coherent wave transfer. The suppression of the Doppler shift induced by the optical fibre was based on an accoustooptical modulator with a servo-loop including a fast PID controller processing the beat-note frequency given by mixing of the Adjustik laser (Brno) and the reflected frequency of this laser from the far end of 306 km long-haul fibre link (Prague). We verified the Doppler shift suppression for the coherent wave with a measuring method analysing the transport delay of the 1PPS signal.

A Link-Level Simulator of the cdma2000 Reverse-Link Physical Layer

PubMed Central

Gharavi, H.; Chin, F.; Ban, K.; Wyatt-Millington, R.

2003-01-01

The cdma2000 system is an evolutionary enhancement of the IS-95 standards which support 3G services defined by the International Telecommunications Union (ITU). cdma2000 comes in two phases: 1XRTT and 3XRTT (1X and 3X indicates the number of 1.25 MHz wide radio carrier channels used and RTT stands for Radio Transmission Technology). The cdma2000 1XRTT, which operates within a 1.25 MHz bandwidth, can be utilized in existing IS-95 CDMA channels as it uses the same bandwidth, while 3XRTT requires the commitment of 5 MHz bandwidth to support higher data rates. This paper describes a software model implementation of the cdma2000 reverse link and its application for evaluating the effect of rake receiver design parameters on the system performance under various multipath fading conditions. The cdma2000 models were developed at the National Institute of Standards and Technology (NIST), using SPW (Signal Processing Worksystem) commercial software tools. The model has been developed in a generic manner that includes all the reverse link six radio configurations and their corresponding data rates, according to cdma2000 specifications. After briefly reviewing the traffic channel characteristics of the cdma2000 reverse link (subscriber to base station), the paper discusses the rake receiver implementation including an ideal rake receiver. It then evaluates the performance of each receiver for a Spreading Rate 3 (3XRTT) operation, which is considered as a true “3G” cdma2000 technology. These evaluations are based on the vehicular IMT-2000 (International Mobile Telecommunication 2000) channel model using the link budget defined in cdma2000 specifications for the reverse link. PMID:27413613

Assessing Low-Intensity Relationships in Complex Networks

PubMed Central

Spitz, Andreas; Gimmler, Anna; Stoeck, Thorsten; Zweig, Katharina Anna; Horvát, Emőke-Ágnes

2016-01-01

Many large network data sets are noisy and contain links representing low-intensity relationships that are difficult to differentiate from random interactions. This is especially relevant for high-throughput data from systems biology, large-scale ecological data, but also for Web 2.0 data on human interactions. In these networks with missing and spurious links, it is possible to refine the data based on the principle of structural similarity, which assesses the shared neighborhood of two nodes. By using similarity measures to globally rank all possible links and choosing the top-ranked pairs, true links can be validated, missing links inferred, and spurious observations removed. While many similarity measures have been proposed to this end, there is no general consensus on which one to use. In this article, we first contribute a set of benchmarks for complex networks from three different settings (e-commerce, systems biology, and social networks) and thus enable a quantitative performance analysis of classic node similarity measures. Based on this, we then propose a new methodology for link assessment called z* that assesses the statistical significance of the number of their common neighbors by comparison with the expected value in a suitably chosen random graph model and which is a consistently top-performing algorithm for all benchmarks. In addition to a global ranking of links, we also use this method to identify the most similar neighbors of each single node in a local ranking, thereby showing the versatility of the method in two distinct scenarios and augmenting its applicability. Finally, we perform an exploratory analysis on an oceanographic plankton data set and find that the distribution of microbes follows similar biogeographic rules as those of macroorganisms, a result that rejects the global dispersal hypothesis for microbes. PMID:27096435

Assessing Low-Intensity Relationships in Complex Networks.

PubMed

Spitz, Andreas; Gimmler, Anna; Stoeck, Thorsten; Zweig, Katharina Anna; Horvát, Emőke-Ágnes

2016-01-01

Many large network data sets are noisy and contain links representing low-intensity relationships that are difficult to differentiate from random interactions. This is especially relevant for high-throughput data from systems biology, large-scale ecological data, but also for Web 2.0 data on human interactions. In these networks with missing and spurious links, it is possible to refine the data based on the principle of structural similarity, which assesses the shared neighborhood of two nodes. By using similarity measures to globally rank all possible links and choosing the top-ranked pairs, true links can be validated, missing links inferred, and spurious observations removed. While many similarity measures have been proposed to this end, there is no general consensus on which one to use. In this article, we first contribute a set of benchmarks for complex networks from three different settings (e-commerce, systems biology, and social networks) and thus enable a quantitative performance analysis of classic node similarity measures. Based on this, we then propose a new methodology for link assessment called z* that assesses the statistical significance of the number of their common neighbors by comparison with the expected value in a suitably chosen random graph model and which is a consistently top-performing algorithm for all benchmarks. In addition to a global ranking of links, we also use this method to identify the most similar neighbors of each single node in a local ranking, thereby showing the versatility of the method in two distinct scenarios and augmenting its applicability. Finally, we perform an exploratory analysis on an oceanographic plankton data set and find that the distribution of microbes follows similar biogeographic rules as those of macroorganisms, a result that rejects the global dispersal hypothesis for microbes.

Development of novel semi-conducting ortho-carborane based polymer films: Enhanced electronic and chemical properties

NASA Astrophysics Data System (ADS)

Pasquale, Frank L.

A novel class of semi-conducting ortho-carborane (B 10C2H12) based polymer films with enhanced electronic and chemical properties has been developed. The novel films are formed from electron-beam cross-linking of condensed B10C2H 12 and B10C2H12 co-condensed with aromatic linking units (Y) (Y=1,4-diaminobenzene (DAB), benzene (BNZ) and pyridine (PY)) at 110 K. The bonding and electronic properties of the novel films were investigated using X-ray photoelectron spectroscopy (XPS), UV photoelectron spectroscopy (UPS) and Mulliken charge analysis using density functional theory (DFT). These films exhibit site-specific cross-linking with bonding, in the pure B10C2HX films, occurring at B sites non-adjacent to C in the B10C2H12 icosahedra. The B10C2H12:Y films exhibit the same phenomena, with cross-linking that creates bonds primarily between B sites non-adjacent to C in the B10C2H12 icosahedra to C sites in the Y linking units. These novel B10C2HX: Y linked films exhibit significantly different electron structure when compared to pure B10C2HX films as seen in the UPS spectra. The valence band maxima (VBM) shift from - 4.3 eV below the Fermi level for pure B10C2HX to -2.6, -2.2, and -1.7 for B10C2HX:BNZ, B10C 2HX:PY, and B10C2HX:DAB, respectively. The top of the valence band is composed of states derived primarily from the Y linking units, suggesting that the bottom of the conduction band is composed of states primarily from B10C2H12. Consequently these B10C2HX:Y films may exhibit longer electron-hole separation lifetimes as compared to pure B10C 2HX films. This research should lead to an enhancement of boron carbide based neutron detectors, and is of potential significance for microelectronics, spintronics and photo-catalysis.

Biomine: predicting links between biological entities using network models of heterogeneous databases.

PubMed

Eronen, Lauri; Toivonen, Hannu

2012-06-06

Biological databases contain large amounts of data concerning the functions and associations of genes and proteins. Integration of data from several such databases into a single repository can aid the discovery of previously unknown connections spanning multiple types of relationships and databases. Biomine is a system that integrates cross-references from several biological databases into a graph model with multiple types of edges, such as protein interactions, gene-disease associations and gene ontology annotations. Edges are weighted based on their type, reliability, and informativeness. We present Biomine and evaluate its performance in link prediction, where the goal is to predict pairs of nodes that will be connected in the future, based on current data. In particular, we formulate protein interaction prediction and disease gene prioritization tasks as instances of link prediction. The predictions are based on a proximity measure computed on the integrated graph. We consider and experiment with several such measures, and perform a parameter optimization procedure where different edge types are weighted to optimize link prediction accuracy. We also propose a novel method for disease-gene prioritization, defined as finding a subset of candidate genes that cluster together in the graph. We experimentally evaluate Biomine by predicting future annotations in the source databases and prioritizing lists of putative disease genes. The experimental results show that Biomine has strong potential for predicting links when a set of selected candidate links is available. The predictions obtained using the entire Biomine dataset are shown to clearly outperform ones obtained using any single source of data alone, when different types of links are suitably weighted. In the gene prioritization task, an established reference set of disease-associated genes is useful, but the results show that under favorable conditions, Biomine can also perform well when no such information is available.The Biomine system is a proof of concept. Its current version contains 1.1 million entities and 8.1 million relations between them, with focus on human genetics. Some of its functionalities are available in a public query interface at http://biomine.cs.helsinki.fi, allowing searching for and visualizing connections between given biological entities.

Linking Extroversion and Proactive Personality to Career Success: The Role of Mentoring Received and Knowledge

ERIC Educational Resources Information Center

Turban, Daniel B.; Moake, Timothy R.; Wu, Sharon Yu-Hsien; Cheung, Yu Ha

2017-01-01

Although extroversion and proactive personality are related to career success, the mechanisms through which the relationships occur are unclear. Based on the contest- and sponsored-mobility processes, we examine a model linking extroversion and proactive personality to career success through the mediating effects of mentoring received and…

Pedagogical Staff in Children's Day Care Centres in Germany--Links between Working Conditions, Job Satisfaction, Commitment and Work-Related Stress

ERIC Educational Resources Information Center

Schreyer, Inge; Krause, Martin

2016-01-01

This article investigates links between staff working conditions in children's day care centres ("Kindertageseinrichtungen"--known as "Kitas" in Germany), job satisfaction, commitment and perceived stress at work. Data are based on the nationwide, representative questionnaire survey AQUA ("Arbeitsplatz und Qualität in…

Full Motion Flight Simulator in the Classroom

ERIC Educational Resources Information Center

Christensen, Brad

2005-01-01

Virtual flight can be very entertaining, and computer-based simulators can also be educational, if organized and used correctly. When Berea College decided to find a flight simulator suited to the school's educational goals, the faculty settled on an ANT-18 Link trainer. This article begins with a discussion of Link trainers' history, and then…

Intimate Partner Violence and Coparenting across the Transition to Parenthood

ERIC Educational Resources Information Center

Kan, Marni L.; Feinberg, Mark E.; Solmeyer, Anna R.

2012-01-01

Intimate partner violence (IPV) between parents has been linked to negative parenting and child maladjustment, yet the mechanisms underlying this association are not fully understood. Based on a theory that violence among parents disrupts the coparental alliance--which has been linked to parenting quality and child adjustment--the authors examined…

Linking the Organizational Health of Middle Grades Schools to Student Achievement

ERIC Educational Resources Information Center

Roney, Kathleen; Coleman, Howard; Schlichting, Kathleen A.

2007-01-01

The purpose of this study was to examine the relationship between student reading achievement and the organizational health of five middle grades schools in North Carolina. The theoretical framework was based upon Hoy and Feldman's definition of organizational health, which links healthy school climates to improved learning environments and…

Mastering the HRD Matrix: Generating ROI by Linking to Business Strategy. Innovative Session.

ERIC Educational Resources Information Center

Kalata, Erica D.; Satterfield, Mary Ellen; Klees, Phyllis

This innovative session provides a vehicle for facilitating dialogue and practical application of effective tools for linking human resource development (HRD) strategies with business/organizational strategies. The primary goal is to provide an increased understanding of and skill using practical, research-based approaches and techniques to build…

A Further Look at the Intergenerational Transmission of Violence: Witnessing Interparental Violence in Emerging Adulthood

ERIC Educational Resources Information Center

Black, David S.; Sussman, Steve; Unger, Jennifer B.

2010-01-01

The intergenerational transmission (IGT) of violence has been a main theoretical consideration to explain the link between interparental aggression in the family of origin and intimate partner violence (IPV) in subsequent intimate relationships. Studies have examined this theoretical link based on self reports of interparental violence witnessed…

The Power of Play: A Literature-based after School Sports Program for Urban Youth.

ERIC Educational Resources Information Center

Zierk, Tom

2000-01-01

A program that combines sports and literature can improve students' reading, writing, and comprehension skills, promoting links between children's personal development and self-esteem and forging links between sports, literature, and daily life. Describes one such program, Sports PLUS After School, noting: program goals, components, and structure;…

Use of Networked Collaborative Concept Mapping To Measure Team Processes and Team Outcomes.

ERIC Educational Resources Information Center

Chung, Gregory K. W. K.; O'Neil, Harold F., Jr.; Herl, Howard E.; Dennis, Robert A.

The feasibility of using a computer-based networked collaborative concept mapping system to measure teamwork skills was studied. A concept map is a node-link-node representation of content, where the nodes represent concepts and links represent relationships between connected concepts. Teamwork processes were examined for a group concept mapping…

Using exposure prediction tools to link exposure and dosimetry for risk based decisions: a case study with phthalates

EPA Science Inventory

The Population Life-course Exposure to Health Effects Modeling (PLETHEM) platform being developed provides a tool that links results from emerging toxicity testing tools to exposure estimates for humans as defined by the USEPA. A reverse dosimetry case study using phthalates was ...

Shared Semantics and the Use of Organizational Memories for E-Mail Communications.

ERIC Educational Resources Information Center

Schwartz, David G.

1998-01-01

Examines the use of shared semantics information to link concepts in an organizational memory to e-mail communications. Presents a framework for determining shared semantics based on organizational and personal user profiles. Illustrates how shared semantics are used by the HyperMail system to help link organizational memories (OM) content to…

AEC Experiment Establishes Computer Link Between California and Paris

Science.gov Websites

demonstrated that a terminal in Paris could search a computer in California and display the resulting (Copies) AEC EXPERIMENT ESTABLISHES COMPUTER LINK BETWEEN CALIFORNIA AND PARIS The feasibility of a worldwide information retrieval system which would tie a computer base of information to terminals on the

Eco-Health Linkages: evidence base and socio-economic considerations for linking ecosystem goods and services to human health

EPA Science Inventory

Ecosystem goods and services (EGS) are thought to play a role in protecting human health, but the empirical evidence directly linking EGS to human health outcomes is limited, and our ability to detect Eco-Health linkages is confounded by socio-economic factors. These limitations ...

ProXL (Protein Cross-Linking Database): A Platform for Analysis, Visualization, and Sharing of Protein Cross-Linking Mass Spectrometry Data

PubMed Central

2016-01-01

ProXL is a Web application and accompanying database designed for sharing, visualizing, and analyzing bottom-up protein cross-linking mass spectrometry data with an emphasis on structural analysis and quality control. ProXL is designed to be independent of any particular software pipeline. The import process is simplified by the use of the ProXL XML data format, which shields developers of data importers from the relative complexity of the relational database schema. The database and Web interfaces function equally well for any software pipeline and allow data from disparate pipelines to be merged and contrasted. ProXL includes robust public and private data sharing capabilities, including a project-based interface designed to ensure security and facilitate collaboration among multiple researchers. ProXL provides multiple interactive and highly dynamic data visualizations that facilitate structural-based analysis of the observed cross-links as well as quality control. ProXL is open-source, well-documented, and freely available at https://github.com/yeastrc/proxl-web-app. PMID:27302480

Tunable mechanical properties of green solid films based on deoxyribonucleic acids

NASA Astrophysics Data System (ADS)

Matsuno, Hisao; Morimitsu, Yuma; Ohta, Noboru; Sekiguchi, Hiroshi; Takahara, Atsushi; Tanaka, Keiji

Promoting green innovation to establish a worldwide low-carbon society is an urgent priority. We here show that solid films made from deoxyribonucleic acid (DNA) can be used as a structural material. The great advantage of DNA films over the ones made from synthetic polymers is that the mechanical properties are controllable, from glassy to rubbery, via semicrystalline by simply regulating the water content in the film. Why such unique mechanical properties can be manifested by the DNA films is determined from structural analyses using Fourier-transform infrared spectroscopy and wide-angle X-ray diffraction measurements. With increasing water content, the conformation of DNA was changed from A-form in an amorphous state to B-form in a partially packed one. DNA in the B-form became densely packed as the film was stretched. Also, DNAs were intermolecularly cross-linked using 2,5-hexanedione based on reductive amination induced by 2-picoline borane in aqueous phase. Cross-linking points were directly observed by atomic force microscopy. The tensile properties of cross-linked films were much better than those of non-cross-linked DNA films.

ProXL (Protein Cross-Linking Database): A Platform for Analysis, Visualization, and Sharing of Protein Cross-Linking Mass Spectrometry Data.

PubMed

Riffle, Michael; Jaschob, Daniel; Zelter, Alex; Davis, Trisha N

2016-08-05

ProXL is a Web application and accompanying database designed for sharing, visualizing, and analyzing bottom-up protein cross-linking mass spectrometry data with an emphasis on structural analysis and quality control. ProXL is designed to be independent of any particular software pipeline. The import process is simplified by the use of the ProXL XML data format, which shields developers of data importers from the relative complexity of the relational database schema. The database and Web interfaces function equally well for any software pipeline and allow data from disparate pipelines to be merged and contrasted. ProXL includes robust public and private data sharing capabilities, including a project-based interface designed to ensure security and facilitate collaboration among multiple researchers. ProXL provides multiple interactive and highly dynamic data visualizations that facilitate structural-based analysis of the observed cross-links as well as quality control. ProXL is open-source, well-documented, and freely available at https://github.com/yeastrc/proxl-web-app .

Rheological characterization of cataplasm bases composed of cross-linked partially neutralized polyacrylate hydrogel.

PubMed

Wang, Jian; Zhang, Hongqin; An, Dianyun; Yu, Jian; Li, Wei; Shen, Teng; Wang, Jianxin

2014-10-01

Viscoelasticity is a useful parameter for characterizing the intrinsic properties of the cross-linked polyacrylate hydrogel used in cataplasm bases. The aim of this study was to investigate the effects of various formulation parameters on the rheological characteristics of polyacrylate hydrogel. The hydrogel layers were formed using a partially neutralized polyacrylate (Viscomate(™)), which contained acrylic acid and sodium acrylate in different copolymerization ratios, as the cross-linked gel framework. Dihydroxyaluminum aminoacetate (DAAA), which produces aluminum ions, was used as the cross-linking agent. Rheological analyses were performed using a "stress amplitude sweep" and a "frequency sweep". The results showed that greater amounts of acrylic acid in the structure of Viscomate as well as higher concentrations of DAAA and Viscomate led to an increase in the elastic modulus (G'). However, greater amounts of acrylic acid in the structure of Viscomate and higher concentrations of DAAA had an opposite on the viscous modulus (G″); this might be owing to higher steric hindrance. The results of this study can serve as guidelines for the optimization of formulations for cataplasms.

IJS: An Intelligent Junction Selection Based Routing Protocol for VANET to Support ITS Services.

PubMed

Bhoi, Sourav Kumar; Khilar, Pabitra Mohan

2014-01-01

Selecting junctions intelligently for data transmission provides better intelligent transportation system (ITS) services. The main problem in vehicular communication is high disturbances of link connectivity due to mobility and less density of vehicles. If link conditions are predicted earlier, then there is a less chance of performance degradation. In this paper, an intelligent junction selection based routing protocol (IJS) is proposed to transmit the data in a quickest path, in which the vehicles are mostly connected and have less link connectivity problem. In this protocol, a helping vehicle is set at every junction to control the communication by predicting link failures or network gaps in a route. Helping vehicle at the junction produces a score for every neighboring junction to forward the data to the destination by considering the current traffic information and selects that junction which has minimum score. IJS protocol is implemented and compared with GyTAR, A-STAR, and GSR routing protocols. Simulation results show that IJS performs better in terms of average end-to-end delay, network gap encounter, and number of hops.

IJS: An Intelligent Junction Selection Based Routing Protocol for VANET to Support ITS Services

PubMed Central

Khilar, Pabitra Mohan

2014-01-01

Selecting junctions intelligently for data transmission provides better intelligent transportation system (ITS) services. The main problem in vehicular communication is high disturbances of link connectivity due to mobility and less density of vehicles. If link conditions are predicted earlier, then there is a less chance of performance degradation. In this paper, an intelligent junction selection based routing protocol (IJS) is proposed to transmit the data in a quickest path, in which the vehicles are mostly connected and have less link connectivity problem. In this protocol, a helping vehicle is set at every junction to control the communication by predicting link failures or network gaps in a route. Helping vehicle at the junction produces a score for every neighboring junction to forward the data to the destination by considering the current traffic information and selects that junction which has minimum score. IJS protocol is implemented and compared with GyTAR, A-STAR, and GSR routing protocols. Simulation results show that IJS performs better in terms of average end-to-end delay, network gap encounter, and number of hops. PMID:27433485

Regulation Mechanism of Salt Ions for Superlubricity of Hydrophilic Polymer Cross-Linked Networks on Ti6Al4V.

PubMed

Zhang, Caixia; Liu, Yuhong; Liu, Zhifeng; Zhang, Hongyu; Cheng, Qiang; Yang, Congbin

2017-03-07

Poly(vinylphosphonic acid) (PVPA) cross-linked networks on Ti 6 Al 4 V show superlubricity behavior when sliding against polytetrafluoroethylene in water-based lubricants. The superlubricity can occur but only with the existence of salt ions in the polymer cross-linked networks. This is different from the phenomenon in most polymer brushes. An investigation into the mechanism revealed that cations and anions in the lubricants worked together to yield the superlubricity even under harsh conditions. It is proposed that the preferential interactions of cations with PVPA molecules rather than water molecules are the main reason for the superlubricity in water-based lubricants. The interaction of anions with water molecules regulates the properties of the tribological interfaces, which influences the magnitude of the friction coefficient. Owing to the novel cross-linked networks and the interactions between cations and polymer molecules, their superlubricity can be maintained even at a high salt ion concentration of 5 M. These excellent properties make PVPA-modified Ti 6 Al 4 V a potential candidate for application in artificial implants.

Unsupervised Medical Entity Recognition and Linking in Chinese Online Medical Text

PubMed Central

Gan, Liang; Cheng, Mian; Wu, Quanyuan

2018-01-01

Online medical text is full of references to medical entities (MEs), which are valuable in many applications, including medical knowledge-based (KB) construction, decision support systems, and the treatment of diseases. However, the diverse and ambiguous nature of the surface forms gives rise to a great difficulty for ME identification. Many existing solutions have focused on supervised approaches, which are often task-dependent. In other words, applying them to different kinds of corpora or identifying new entity categories requires major effort in data annotation and feature definition. In this paper, we propose unMERL, an unsupervised framework for recognizing and linking medical entities mentioned in Chinese online medical text. For ME recognition, unMERL first exploits a knowledge-driven approach to extract candidate entities from free text. Then, the categories of the candidate entities are determined using a distributed semantic-based approach. For ME linking, we propose a collaborative inference approach which takes full advantage of heterogenous entity knowledge and unstructured information in KB. Experimental results on real corpora demonstrate significant benefits compared to recent approaches with respect to both ME recognition and linking. PMID:29849994

The Aeronautical Data Link: Taxonomy, Architectural Analysis, and Optimization

NASA Technical Reports Server (NTRS)

Morris, A. Terry; Goode, Plesent W.

2002-01-01

The future Communication, Navigation, and Surveillance/Air Traffic Management (CNS/ATM) System will rely on global satellite navigation, and ground-based and satellite based communications via Multi-Protocol Networks (e.g. combined Aeronautical Telecommunications Network (ATN)/Internet Protocol (IP)) to bring about needed improvements in efficiency and safety of operations to meet increasing levels of air traffic. This paper will discuss the development of an approach that completely describes optimal data link architecture configuration and behavior to meet the multiple conflicting objectives of concurrent and different operations functions. The practical application of the approach enables the design and assessment of configurations relative to airspace operations phases. The approach includes a formal taxonomic classification, an architectural analysis methodology, and optimization techniques. The formal taxonomic classification provides a multidimensional correlation of data link performance with data link service, information protocol, spectrum, and technology mode; and to flight operations phase and environment. The architectural analysis methodology assesses the impact of a specific architecture configuration and behavior on the local ATM system performance. Deterministic and stochastic optimization techniques maximize architectural design effectiveness while addressing operational, technology, and policy constraints.

The development of retrosynthetic glycan libraries to profile and classify the human serum N-linked glycome.

PubMed

Kronewitter, Scott R; An, Hyun Joo; de Leoz, Maria Lorna; Lebrilla, Carlito B; Miyamoto, Suzanne; Leiserowitz, Gary S

2009-06-01

Annotation of the human serum N-linked glycome is a formidable challenge but is necessary for disease marker discovery. A new theoretical glycan library was constructed and proposed to provide all possible glycan compositions in serum. It was developed based on established glycobiology and retrosynthetic state-transition networks. We find that at least 331 compositions are possible in the serum N-linked glycome. By pairing the theoretical glycan mass library with a high mass accuracy and high-resolution MS, human serum glycans were effectively profiled. Correct isotopic envelope deconvolution to monoisotopic masses and the high mass accuracy instruments drastically reduced the amount of false composition assignments. The high throughput capacity enabled by this library permitted the rapid glycan profiling of large control populations. With the use of the library, a human serum glycan mass profile was developed from 46 healthy individuals. This paper presents a theoretical N-linked glycan mass library that was used for accurate high-throughput human serum glycan profiling. Rapid methods for evaluating a patient's glycome are instrumental for studying glycan-based markers.

Electronic health record meets digital library: a new environment for achieving an old goal.

PubMed

Humphreys, B L

2000-01-01

Linking the electronic health record to the digital library is a Web-era reformulation of the long-standing informatics goal of seamless integration of automated clinical data and relevant knowledge-based information to support informed decisions. The spread of the Internet, the development of the World Wide Web, and converging format standards for electronic health data and digital publications make effective linking increasingly feasible. Some existing systems link electronic health data and knowledge-based information in limited settings or limited ways. Yet many challenging informatics research problems remain to be solved before flexible and seamless linking becomes a reality and before systems become capable of delivering the specific piece of information needed at the time and place a decision must be made. Connecting the electronic health record to the digital library also requires positive resolution of important policy issues, including health data privacy, government encouragement of high-speed communications, electronic intellectual property rights, and standards for health data and for digital libraries. Both the research problems and the policy issues should be important priorities for the field of medical informatics.

Electronic Health Record Meets Digital Library

PubMed Central

Humphreys, Betsy L.

2000-01-01

Linking the electronic health record to the digital library is a Web-era reformulation of the long-standing informatics goal of seamless integration of automated clinical data and relevant knowledge-based information to support informed decisions. The spread of the Internet, the development of the World Wide Web, and converging format standards for electronic health data and digital publications make effective linking increasingly feasible. Some existing systems link electronic health data and knowledge-based information in limited settings or limited ways. Yet many challenging informatics research problems remain to be solved before flexible and seamless linking becomes a reality and before systems become capable of delivering the specific piece of information needed at the time and place a decision must be made. Connecting the electronic health record to the digital library also requires positive resolution of important policy issues, including health data privacy, government envouragement of high-speed communications, electronic intellectual property rights, and standards for health data and for digital libraries. Both the research problems and the policy issues should be important priorities for the field of medical informatics. PMID:10984463

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

PubMed Central

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

2015-01-01

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

Overlapping community detection based on link graph using distance dynamics

NASA Astrophysics Data System (ADS)

Chen, Lei; Zhang, Jing; Cai, Li-Jun

2018-01-01

The distance dynamics model was recently proposed to detect the disjoint community of a complex network. To identify the overlapping structure of a network using the distance dynamics model, an overlapping community detection algorithm, called L-Attractor, is proposed in this paper. The process of L-Attractor mainly consists of three phases. In the first phase, L-Attractor transforms the original graph to a link graph (a new edge graph) to assure that one node has multiple distances. In the second phase, using the improved distance dynamics model, a dynamic interaction process is introduced to simulate the distance dynamics (shrink or stretch). Through the dynamic interaction process, all distances converge, and the disjoint community structure of the link graph naturally manifests itself. In the third phase, a recovery method is designed to convert the disjoint community structure of the link graph to the overlapping community structure of the original graph. Extensive experiments are conducted on the LFR benchmark networks as well as real-world networks. Based on the results, our algorithm demonstrates higher accuracy and quality than other state-of-the-art algorithms.

Discovering Link Communities in Complex Networks by an Integer Programming Model and a Genetic Algorithm

PubMed Central

Li, Zhenping; Zhang, Xiang-Sun; Wang, Rui-Sheng; Liu, Hongwei; Zhang, Shihua

2013-01-01

Identification of communities in complex networks is an important topic and issue in many fields such as sociology, biology, and computer science. Communities are often defined as groups of related nodes or links that correspond to functional subunits in the corresponding complex systems. While most conventional approaches have focused on discovering communities of nodes, some recent studies start partitioning links to find overlapping communities straightforwardly. In this paper, we propose a new quantity function for link community identification in complex networks. Based on this quantity function we formulate the link community partition problem into an integer programming model which allows us to partition a complex network into overlapping communities. We further propose a genetic algorithm for link community detection which can partition a network into overlapping communities without knowing the number of communities. We test our model and algorithm on both artificial networks and real-world networks. The results demonstrate that the model and algorithm are efficient in detecting overlapping community structure in complex networks. PMID:24386268

Link prediction measures considering different neighbors’ effects and application in social networks

NASA Astrophysics Data System (ADS)

Luo, Peng; Wu, Chong; Li, Yongli

Link prediction measures have been attracted particular attention in the field of mathematical physics. In this paper, we consider the different effects of neighbors in link prediction and focus on four different situations: only consider the individual’s own effects; consider the effects of individual, neighbors and neighbors’ neighbors; consider the effects of individual, neighbors, neighbors’ neighbors, neighbors’ neighbors’ neighbors and neighbors’ neighbors’ neighbors’ neighbors; consider the whole network participants’ effects. Then, according to the four situations, we present our link prediction models which also take the effects of social characteristics into consideration. An artificial network is adopted to illustrate the parameter estimation based on logistic regression. Furthermore, we compare our methods with the some other link prediction methods (LPMs) to examine the validity of our proposed model in online social networks. The results show the superior of our proposed link prediction methods compared with others. In the application part, our models are applied to study the social network evolution and used to recommend friends and cooperators in social networks.

Optimal Link Removal for Epidemic Mitigation: A Two-Way Partitioning Approach

PubMed Central

Enns, Eva A.; Mounzer, Jeffrey J.; Brandeau, Margaret L.

2011-01-01

The structure of the contact network through which a disease spreads may influence the optimal use of resources for epidemic control. In this work, we explore how to minimize the spread of infection via quarantining with limited resources. In particular, we examine which links should be removed from the contact network, given a constraint on the number of removable links, such that the number of nodes which are no longer at risk for infection is maximized. We show how this problem can be posed as a non-convex quadratically constrained quadratic program (QCQP), and we use this formulation to derive a link removal algorithm. The performance of our QCQP-based algorithm is validated on small Erdős-Renyi and small-world random graphs, and then tested on larger, more realistic networks, including a real-world network of injection drug use. We show that our approach achieves near optimal performance and out-perform so ther intuitive link removal algorithms, such as removing links in order of edge centrality. PMID:22115862

Study of the second-order relativistic light deflection of the Sun using long-baseline fibre-linked interferometers: Laser-Interferometric Solar Relativity (LISOR) test

NASA Technical Reports Server (NTRS)

Ni, Wei-Tou; Shy, Jow-Tsong; Tseng, Shiao-Min; Shao, Michael

1992-01-01

A propasal to study the second order light deflection in the solar gravitational field is presented. It is proposed to use 1 to 2 W frequency stabilized lasers on two microspacecraft about 0.25 degree apart in the sky with apparent positions near the Sun, and observe the relative angle of two spacecraft using ground based fiber linked interferometers with 10 km baseline to determine the second order relativistic light deflection effects. The first two years of work would emphasize the establishment of a prototype stabilized laser system and fiber linked interferometer. The first year, a prototype fiber linked interferometer would be set up to study the phase noise produced by external perturbations to fiber links. The second year, a second interferometer would be set up. The cancellation of phase drift due to fiber links of both interferometers in the same environment would be investigated.

Leveraging Administrative Data for Program Evaluations: A Method for Linking Data Sets Without Unique Identifiers.

PubMed

Lorden, Andrea L; Radcliff, Tiffany A; Jiang, Luohua; Horel, Scott A; Smith, Matthew L; Lorig, Kate; Howell, Benjamin L; Whitelaw, Nancy; Ory, Marcia

2016-06-01

In community-based wellness programs, Social Security Numbers (SSNs) are rarely collected to encourage participation and protect participant privacy. One measure of program effectiveness includes changes in health care utilization. For the 65 and over population, health care utilization is captured in Medicare administrative claims data. Therefore, methods as described in this article for linking participant information to administrative data are useful for program evaluations where unique identifiers such as SSN are not available. Following fuzzy matching methodologies, participant information from the National Study of the Chronic Disease Self-Management Program was linked to Medicare administrative data. Linking variables included participant name, date of birth, gender, address, and ZIP code. Seventy-eight percent of participants were linked to their Medicare claims data. Linking program participant information to Medicare administrative data where unique identifiers are not available provides researchers with the ability to leverage claims data to better understand program effects. © The Author(s) 2014.

Cooperation and competition in business on example of Internet research of opto-electronic companies

NASA Astrophysics Data System (ADS)

Kaliczyńska, Małgorzata

2006-10-01

Based on findings from earlier studies which showed that links to academic web sites contain important information, the following study examines the practicability of using co-link data to describe cooperation and competition in optoelec-tronic business. The analysis was based on 32 companies and organizations which were found in an issue of a specialist magazine. For the purpose of the research three search engines - Google, Yahoo! and MSN Search were used. Assuming that a number of co-links to a pair of Web sites is a measure of the similarity between the two companies, the study aims at search for the sets of companies that would be similar to one another. The method applied is the MDS - multidimensional scaling that allows to present results of the analysis on a 2D map.

Multicast backup reprovisioning problem for Hamiltonian cycle-based protection on WDM networks

NASA Astrophysics Data System (ADS)

Din, Der-Rong; Huang, Jen-Shen

2014-03-01

As networks grow in size and complexity, the chance and the impact of failures increase dramatically. The pre-allocated backup resources cannot provide 100% protection guarantee when continuous failures occur in a network. In this paper, the multicast backup re-provisioning problem (MBRP) for Hamiltonian cycle (HC)-based protection on WDM networks for the link-failure case is studied. We focus on how to recover the protecting capabilities of Hamiltonian cycle against the subsequent link-failures on WDM networks for multicast transmissions, after recovering the multicast trees affected by the previous link-failure. Since this problem is a hard problem, an algorithm, which consists of several heuristics and a genetic algorithm (GA), is proposed to solve it. The simulation results of the proposed method are also given. Experimental results indicate that the proposed algorithm can solve this problem efficiently.

Hospital-acquired listeriosis linked to a persistently contaminated milkshake machine.

PubMed

Mazengia, E; Kawakami, V; Rietberg, K; Kay, M; Wyman, P; Skilton, C; Aberra, A; Boonyaratanakornkit, J; Limaye, A P; Pergam, S A; Whimbey, E; Olsen-Scribner, R J; Duchin, J S

2017-04-01

One case of hospital-acquired listeriosis was linked to milkshakes produced in a commercial-grade shake freezer machine. This machine was found to be contaminated with a strain of Listeria monocytogenes epidemiologically and molecularly linked to a contaminated pasteurized, dairy-based ice cream product at the same hospital a year earlier, despite repeated cleaning and sanitizing. Healthcare facilities should be aware of the potential for prolonged Listeria contamination of food service equipment. In addition, healthcare providers should consider counselling persons who have an increased risk for Listeria infections regarding foods that have caused Listeria infections. The prevalence of persistent Listeria contamination of commercial-grade milkshake machines in healthcare facilities and the risk associated with serving dairy-based ice cream products to hospitalized patients at increased risk for invasive L. monocytogenes infections should be further evaluated.

A Wireless Implantable Switched-Capacitor Based Optogenetic Stimulating System

PubMed Central

Lee, Hyung-Min; Kwon, Ki-Yong; Li, Wen

2015-01-01

This paper presents a power-efficient implantable optogenetic interface using a wireless switched-capacitor based stimulating (SCS) system. The SCS efficiently charges storage capacitors directly from an inductive link and periodically discharges them into an array of micro-LEDs, providing high instantaneous power without affecting wireless link and system supply voltage. A custom-designed computer interface in LabVIEW environment wirelessly controls stimulation parameters through the inductive link, and an optrode array enables simultaneous neural recording along with optical stimulation. The 4-channel SCS system prototype has been implemented in a 0.35-μm CMOS process and combined with the optrode array. In vivo experiments involving light-induced local field potentials verified the efficacy of the SCS system. An implantable version of the SCS system with flexible hermetic sealing is under development for chronic experiments. PMID:25570099

The Electron Microscopy Outreach Program: A Web-based resource for research and education.

PubMed

Sosinsky, G E; Baker, T S; Hand, G; Ellisman, M H

1999-01-01

We have developed a centralized World Wide Web (WWW)-based environment that serves as a resource of software tools and expertise for biological electron microscopy. A major focus is molecular electron microscopy, but the site also includes information and links on structural biology at all levels of resolution. This site serves to help integrate or link structural biology techniques in accordance with user needs. The WWW site, called the Electron Microscopy (EM) Outreach Program (URL: http://emoutreach.sdsc.edu), provides scientists with computational and educational tools for their research and edification. In particular, we have set up a centralized resource containing course notes, references, and links to image analysis and three-dimensional reconstruction software for investigators wanting to learn about EM techniques either within or outside of their fields of expertise. Copyright 1999 Academic Press.

In search of new lead compounds for trypanosomiasis drug design: A protein structure-based linked-fragment approach

NASA Astrophysics Data System (ADS)

Verlinde, Christophe L. M. J.; Rudenko, Gabrielle; Hol, Wim G. J.

1992-04-01

A modular method for pursuing structure-based inhibitor design in the framework of a design cycle is presented. The approach entails four stages: (1) a design pathway is defined in the three-dimensional structure of a target protein; (2) this pathway is divided into subregions; (3) complementary building blocks, also called fragments, are designed in each subregion; complementarity is defined in terms of shape, hydrophobicity, hydrogen bond properties and electrostatics; and (4) fragments from different subregions are linked into potential lead compounds. Stages (3) and (4) are qualitatively guided by force-field calculations. In addition, the designed fragments serve as entries for retrieving existing compounds from chemical databases. This linked-fragment approach has been applied in the design of potentially selective inhibitors of triosephosphate isomerase from Trypanosoma brucei, the causative agent of sleeping sickness.

A knowledge-based system with learning for computer communication network design

NASA Technical Reports Server (NTRS)

Pierre, Samuel; Hoang, Hai Hoc; Tropper-Hausen, Evelyne

1990-01-01

Computer communication network design is well-known as complex and hard. For that reason, the most effective methods used to solve it are heuristic. Weaknesses of these techniques are listed and a new approach based on artificial intelligence for solving this problem is presented. This approach is particularly recommended for large packet switched communication networks, in the sense that it permits a high degree of reliability and offers a very flexible environment dealing with many relevant design parameters such as link cost, link capacity, and message delay.