Science.gov

Sample records for impact information diffusion

  1. Optimal Network Modularity for Information Diffusion

    NASA Astrophysics Data System (ADS)

    Nematzadeh, Azadeh; Ferrara, Emilio; Flammini, Alessandro; Ahn, Yong-Yeol

    2014-08-01

    We investigate the impact of community structure on information diffusion with the linear threshold model. Our results demonstrate that modular structure may have counterintuitive effects on information diffusion when social reinforcement is present. We show that strong communities can facilitate global diffusion by enhancing local, intracommunity spreading. Using both analytic approaches and numerical simulations, we demonstrate the existence of an optimal network modularity, where global diffusion requires the minimal number of early adopters.

  2. Information filtering via preferential diffusion.

    PubMed

    Lü, Linyuan; Liu, Weiping

    2011-06-01

    Recommender systems have shown great potential in addressing the information overload problem, namely helping users in finding interesting and relevant objects within a huge information space. Some physical dynamics, including the heat conduction process and mass or energy diffusion on networks, have recently found applications in personalized recommendation. Most of the previous studies focus overwhelmingly on recommendation accuracy as the only important factor, while overlooking the significance of diversity and novelty that indeed provide the vitality of the system. In this paper, we propose a recommendation algorithm based on the preferential diffusion process on a user-object bipartite network. Numerical analyses on two benchmark data sets, MovieLens and Netflix, indicate that our method outperforms the state-of-the-art methods. Specifically, it can not only provide more accurate recommendations, but also generate more diverse and novel recommendations by accurately recommending unpopular objects.

  3. Information filtering via preferential diffusion

    NASA Astrophysics Data System (ADS)

    Lü, Linyuan; Liu, Weiping

    2011-06-01

    Recommender systems have shown great potential in addressing the information overload problem, namely helping users in finding interesting and relevant objects within a huge information space. Some physical dynamics, including the heat conduction process and mass or energy diffusion on networks, have recently found applications in personalized recommendation. Most of the previous studies focus overwhelmingly on recommendation accuracy as the only important factor, while overlooking the significance of diversity and novelty that indeed provide the vitality of the system. In this paper, we propose a recommendation algorithm based on the preferential diffusion process on a user-object bipartite network. Numerical analyses on two benchmark data sets, MovieLens and Netflix, indicate that our method outperforms the state-of-the-art methods. Specifically, it can not only provide more accurate recommendations, but also generate more diverse and novel recommendations by accurately recommending unpopular objects.

  4. Optimal multi-community network modularity for information diffusion

    NASA Astrophysics Data System (ADS)

    Wu, Jiaocan; Du, Ruping; Zheng, Yingying; Liu, Dong

    2016-02-01

    Studies demonstrate that community structure plays an important role in information spreading recently. In this paper, we investigate the impact of multi-community structure on information diffusion with linear threshold model. We utilize extended GN network that contains four communities and analyze dynamic behaviors of information that spreads on it. And we discover the optimal multi-community network modularity for information diffusion based on the social reinforcement. Results show that, within the appropriate range, multi-community structure will facilitate information diffusion instead of hindering it, which accords with the results derived from two-community network.

  5. Dynamics of information diffusion and its applications on complex networks

    NASA Astrophysics Data System (ADS)

    Zhang, Zi-Ke; Liu, Chuang; Zhan, Xiu-Xiu; Lu, Xin; Zhang, Chu-Xu; Zhang, Yi-Cheng

    2016-09-01

    The ongoing rapid expansion of the Word Wide Web (WWW) greatly increases the information of effective transmission from heterogeneous individuals to various systems. Extensive research for information diffusion is introduced by a broad range of communities including social and computer scientists, physicists, and interdisciplinary researchers. Despite substantial theoretical and empirical studies, unification and comparison of different theories and approaches are lacking, which impedes further advances. In this article, we review recent developments in information diffusion and discuss the major challenges. We compare and evaluate available models and algorithms to respectively investigate their physical roles and optimization designs. Potential impacts and future directions are discussed. We emphasize that information diffusion has great scientific depth and combines diverse research fields which makes it interesting for physicists as well as interdisciplinary researchers.

  6. Information Diffusion in Facebook-Like Social Networks Under Information Overload

    NASA Astrophysics Data System (ADS)

    Li, Pei; Xing, Kai; Wang, Dapeng; Zhang, Xin; Wang, Hui

    2013-07-01

    Research on social networks has received remarkable attention, since many people use social networks to broadcast information and stay connected with their friends. However, due to the information overload in social networks, it becomes increasingly difficult for users to find useful information. This paper takes Facebook-like social networks into account, and models the process of information diffusion under information overload. The term view scope is introduced to model the user information-processing capability under information overload, and the average number of times a message appears in view scopes after it is generated is proposed to characterize the information diffusion efficiency. Through theoretical analysis, we find that factors such as network structure and view scope number have no impact on the information diffusion efficiency, which is a surprising result. To verify the results, we conduct simulations and provide the simulation results, which are consistent with the theoretical analysis results perfectly.

  7. 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.

  8. Influence Function Learning in Information Diffusion Networks

    PubMed Central

    Du, Nan; Liang, Yingyu; Balcan, Maria-Florina; Song, Le

    2015-01-01

    Can we learn the influence of a set of people in a social network from cascades of information diffusion? This question is often addressed by a two-stage approach: first learn a diffusion model, and then calculate the influence based on the learned model. Thus, the success of this approach relies heavily on the correctness of the diffusion model which is hard to verify for real world data. In this paper, we exploit the insight that the influence functions in many diffusion models are coverage functions, and propose a novel parameterization of such functions using a convex combination of random basis functions. Moreover, we propose an efficient maximum likelihood based algorithm to learn such functions directly from cascade data, and hence bypass the need to specify a particular diffusion model in advance. We provide both theoretical and empirical analysis for our approach, showing that the proposed approach can provably learn the influence function with low sample complexity, be robust to the unknown diffusion models, and significantly outperform existing approaches in both synthetic and real world data. PMID:25973445

  9. Information diffusion in structured online social networks

    NASA Astrophysics Data System (ADS)

    Li, Pei; Zhang, Yini; Qiao, Fengcai; Wang, Hui

    2015-05-01

    Nowadays, due to the word-of-mouth effect, online social networks have been considered to be efficient approaches to conduct viral marketing, which makes it of great importance to understand the diffusion dynamics in online social networks. However, most research on diffusion dynamics in epidemiology and existing social networks cannot be applied directly to characterize online social networks. In this paper, we propose models to characterize the information diffusion in structured online social networks with push-based forwarding mechanism. We introduce the term user influence to characterize the average number of times that messages are browsed which is incurred by a given type user generating a message, and study the diffusion threshold, above which the user influence of generating a message will approach infinity. We conduct simulations and provide the simulation results, which are consistent with the theoretical analysis results perfectly. These results are of use in understanding the diffusion dynamics in online social networks and also critical for advertisers in viral marketing who want to estimate the user influence before posting an advertisement.

  10. SHIR competitive information diffusion model for online social media

    NASA Astrophysics Data System (ADS)

    Liu, Yun; Diao, Su-Meng; Zhu, Yi-Xiang; Liu, Qing

    2016-11-01

    In online social media, opinion divergences and differentiations generally exist as a result of individuals' extensive participation and personalization. In this paper, a Susceptible-Hesitated-Infected-Removed (SHIR) model is proposed to study the dynamics of competitive dual information diffusion. The proposed model extends the classical SIR model by adding hesitators as a neutralized state of dual information competition. It is both hesitators and stable spreaders that facilitate information dissemination. Researching on the impacts of diffusion parameters, it is found that the final density of stiflers increases monotonically as infection rate increases and removal rate decreases. And the advantage information with larger stable transition rate takes control of whole influence of dual information. The density of disadvantage information spreaders slightly grows with the increase of its stable transition rate, while whole spreaders of dual information and the relaxation time remain almost unchanged. Moreover, simulations imply that the final result of competition is closely related to the ratio of stable transition rates of dual information. If the stable transition rates of dual information are nearly the same, a slightly reduction of the smaller one brings out a significant disadvantage in its propagation coverage. Additionally, the relationship of the ratio of final stiflers versus the ratio of stable transition rates presents power characteristic.

  11. Fundamental Causes of Colorectal Cancer Mortality: The Implications of Informational Diffusion

    PubMed Central

    Wang, Andrew; Clouston, Sean AP; Rubin, Marcie S; Colen, Cynthia G; Link, Bruce G

    2012-01-01

    Context Colorectal cancer is a major cause of mortality in the United States, with 52,857 deaths estimated in 2012. To explore further the social inequalities in colorectal cancer mortality, we used fundamental cause theory to consider the role of societal diffusion of information and socioeconomic status. Methods We used the number of deaths from colorectal cancer in U.S. counties between 1968 and 2008. Through geographical mapping, we examined disparities in colorectal cancer mortality as a function of socioeconomic status and the rate of diffusion of information. In addition to providing year-specific trends in colorectal cancer mortality rates, we analyzed these data using negative binomial regression. Findings The impact of socioeconomic status (SES) on colorectal cancer mortality is substantial, and its protective impact increases over time. Equally important is the impact of informational diffusion on colorectal cancer mortality over time. However, while the impact of SES remains significant when concurrently considering the role of diffusion of information, the propensity for faster diffusion moderates its effect on colorectal cancer mortality. Conclusions The faster diffusion of information reduces both colorectal cancer mortality and inequalities in colorectal cancer mortality, although it was not sufficient to eliminate SES inequalities. These findings have important long-term implications for policymakers looking to reduce social inequalities in colorectal cancer mortality and other, related, preventable diseases. PMID:22985282

  12. Diffusion processes of fragmentary information on scale-free networks

    NASA Astrophysics Data System (ADS)

    Li, Xun; Cao, Lang

    2016-05-01

    Compartmental models of diffusion over contact networks have proven representative of real-life propagation phenomena among interacting individuals. However, there is a broad class of collective spreading mechanisms departing from compartmental representations, including those for diffusive objects capable of fragmentation and transmission unnecessarily as a whole. Here, we consider a continuous-state susceptible-infected-susceptible (SIS) model as an ideal limit-case of diffusion processes of fragmentary information on networks, where individuals possess fractions of the information content and update them by selectively exchanging messages with partners in the vicinity. Specifically, we incorporate local information, such as neighbors' node degrees and carried contents, into the individual partner choice, and examine the roles of a variety of such strategies in the information diffusion process, both qualitatively and quantitatively. Our method provides an effective and flexible route of modulating continuous-state diffusion dynamics on networks and has potential in a wide array of practical applications.

  13. Impacts of suppressing guide on information spreading

    NASA Astrophysics Data System (ADS)

    Xu, Jinghong; Zhang, Lin; Ma, Baojun; Wu, Ye

    2016-02-01

    It is quite common that guides are introduced to suppress the information spreading in modern society for different purposes. In this paper, an agent-based model is established to quantitatively analyze the impacts of suppressing guides on information spreading. We find that the spreading threshold depends on the attractiveness of the information and the topology of the social network with no suppressing guides at all. Usually, one would expect that the existence of suppressing guides in the spreading procedure may result in less diffusion of information within the overall network. However, we find that sometimes the opposite is true: the manipulating nodes of suppressing guides may lead to more extensive information spreading when there are audiences with the reversal mind. These results can provide valuable theoretical references to public opinion guidance on various information, e.g., rumor or news spreading.

  14. The electronic transfer of information and aerospace knowledge diffusion

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Bishop, Ann P.; Barclay, Rebecca O.; Kennedy, John M.

    1992-01-01

    Increasing reliance on and investment in information technology and electronic networking systems presupposes that computing and information technology will play a motor role in the diffusion of aerospace knowledge. Little is known, however, about actual information technology needs, uses, and problems within the aerospace knowledge diffusion process. The authors state that the potential contributions of information technology to increased productivity and competitiveness will be diminished unless empirically derived knowledge regarding the information-seeking behavior of the members of the social system - those who are producing, transferring, and using scientific and technical information - is incorporated into a new technology policy framework. Research into the use of information technology and electronic networks by U.S. aerospace engineers and scientists, collected as part of a research project designed to study aerospace knowledge diffusion, is presented in support of this assertion.

  15. Affinity based information diffusion model in social networks

    NASA Astrophysics Data System (ADS)

    Liu, Hongli; Xie, Yun; Hu, Haibo; Chen, Zhigao

    2014-12-01

    There is a widespread intuitive sense that people prefer participating in spreading the information in which they are interested. The affinity of people with information disseminated can affect the information propagation in social networks. In this paper, we propose an information diffusion model incorporating the mechanism of affinity of people with information which considers the fitness of affinity values of people with affinity threshold of the information. We find that the final size of information diffusion is affected by affinity threshold of the information, average degree of the network and the probability of people's losing their interest in the information. We also explore the effects of other factors on information spreading by numerical simulations and find that the probabilities of people's questioning and confirming the information can affect the propagation speed, but not the final scope.

  16. Impact of layering and microstructure on gas diffusion through snow

    NASA Astrophysics Data System (ADS)

    Whelsky, A. N.; Albert, M. R.

    2015-12-01

    Understanding relationships between snow structure and gas transport properties in seasonal snow is crucial for correctly quantifying gas fluxes through the snow. Wintertime soil respiration of CO2 has been estimated to significantly contribute to the carbon budget, but CO2 must first diffuse through the snowpack before being released to the atmosphere. The snowpack is not homogeneous; the structure varies both in space and in time, which can have profound impacts on the snow diffusivity. Former assessments of gas flux in seasonal snow apply empirical relations based on single, fixed conditions, which limits the accuracy of the assessment results. In this presentation we report on laboratory measurements through snow and firn samples that have various metamorphic properties. Diffusion coefficients determined from the measurements are used to investigate the impact of layering and inhomogeneous structure on diffusion rates on larger scales, through multidimensional numerical simulations.

  17. Correlation between information diffusion and opinion evolution on social media

    NASA Astrophysics Data System (ADS)

    Xiong, Fei; Liu, Yun; Zhang, Zhenjiang

    2014-12-01

    Information diffusion and opinion evolution are often treated as two independent processes. Opinion models assume the topic reaches each agent and agents initially have their own ideas. In fact, the processes of information diffusion and opinion evolution often intertwine with each other. Whether the influence between these two processes plays a role in the system state is unclear. In this paper, we collected more than one million real data from a well-known social platform, and analysed large-scale user diffusion behaviour and opinion formation. We found that user inter-event time follows a two-scaling power-law distribution with two different power exponents. Public opinion stabilizes quickly and evolves toward the direction of convergence, but the consensus state is prevented by a few opponents. We propose a three-state opinion model accompanied by information diffusion. Agents form and exchange their opinions during information diffusion. Conversely, agents' opinions also influence their diffusion actions. Simulations show that the model with a correlation of the two processes produces similar statistical characteristics as empirical results. A fast epidemic process drives individual opinions to converge more obviously. Unlike previous epidemic models, the number of infected agents does not always increase with the update rate, but has a peak with an intermediate value of the rate.

  18. Multi-source information diffusion in online social networks

    NASA Astrophysics Data System (ADS)

    Xiong, Fei; Liu, Yun; Zhang, Hai-Feng

    2015-07-01

    Individual spreading behavior in online social networks is closely related to user activity, tie strength, and other user and network features. The results concentrate on personal spreading decisions; however, whether these features promote the global information diffusion and increase the macroscopic density of infected agents, remains unclear to us. In this paper, we propose a multi-source diffusion model in which agents may create new messages and spread other agents’ messages. Agents receive many messages, and each time they select a certain message preferentially to spread in consideration of different features. Simulation results show the density of infected agents for different messages follows a power-law distribution in both scale-free and small-world networks. Selecting the largest author degree, author activity and tie strength preferentially can advance the overall diffusion process. Weak tie bias is the least effective feature for multiple information diffusion, but it helps to diffuse a single message. Unexpectedly, the bias of interest similarity does not have an apparent effect. Integrated with the influence on individual diffusion behavior, strong tie bias is a significant feature both for local and global diffusion.

  19. Fluid Registration of Diffusion Tensor Images Using Information Theory

    PubMed Central

    Chiang, Ming-Chang; Leow, Alex D.; Klunder, Andrea D.; Dutton, Rebecca A.; Barysheva, Marina; Rose, Stephen E.; McMahon, Katie L.; de Zubicaray, Greig I.; Toga, Arthur W.; Thompson, Paul M.

    2008-01-01

    We apply an information-theoretic cost metric, the symmetrized Kullback-Leibler (sKL) divergence, or J-divergence, to fluid registration of diffusion tensor images. The difference between diffusion tensors is quantified based on the sKL-divergence of their associated probability density functions (PDFs). Three-dimensional DTI data from 34 subjects were fluidly registered to an optimized target image. To allow large image deformations but preserve image topology, we regularized the flow with a large-deformation diffeomorphic mapping based on the kinematics of a Navier-Stokes fluid. A driving force was developed to minimize the J-divergence between the deforming source and target diffusion functions, while reorienting the flowing tensors to preserve fiber topography. In initial experiments, we showed that the sKL-divergence based on full diffusion PDFs is adaptable to higher-order diffusion models, such as high angular resolution diffusion imaging (HARDI). The sKL-divergence was sensitive to subtle differences between two diffusivity profiles, showing promise for nonlinear registration applications and multisubject statistical analysis of HARDI data. PMID:18390342

  20. Discovery of Information Diffusion Process in Social Networks

    NASA Astrophysics Data System (ADS)

    Kim, Kwanho; Jung, Jae-Yoon; Park, Jonghun

    Information diffusion analysis in social networks is of significance since it enables us to deeply understand dynamic social interactions among users. In this paper, we introduce approaches to discovering information diffusion process in social networks based on process mining. Process mining techniques are applied from three perspectives: social network analysis, process discovery and community recognition. We then present experimental results by using a real-life social network data. The proposed techniques are expected to employ as new analytical tools in online social networks such as blog and wikis for company marketers, politicians, news reporters and online writers.

  1. The impact of network characteristics on the diffusion of innovations

    NASA Astrophysics Data System (ADS)

    Peres, Renana

    2014-05-01

    This paper studies the influence of network topology on the speed and reach of new product diffusion. While previous research has focused on comparing network types, this paper explores explicitly the relationship between topology and measurements of diffusion effectiveness. We study simultaneously the effect of three network metrics: the average degree, the relative degree of social hubs (i.e., the ratio of the average degree of highly-connected individuals to the average degree of the entire population), and the clustering coefficient. A novel network-generation procedure based on random graphs with a planted partition is used to generate 160 networks with a wide range of values for these topological metrics. Using an agent-based model, we simulate diffusion on these networks and check the dependence of the net present value (NPV) of the number of adopters over time on the network metrics. We find that the average degree and the relative degree of social hubs have a positive influence on diffusion. This result emphasizes the importance of high network connectivity and strong hubs. The clustering coefficient has a negative impact on diffusion, a finding that contributes to the ongoing controversy on the benefits and disadvantages of transitivity. These results hold for both monopolistic and duopolistic markets, and were also tested on a sample of 12 real networks.

  2. Phase transitions for information diffusion in random clustered networks

    NASA Astrophysics Data System (ADS)

    Lim, Sungsu; Shin, Joongbo; Kwak, Namju; Jung, Kyomin

    2016-09-01

    We study the conditions for the phase transitions of information diffusion in complex networks. Using the random clustered network model, a generalisation of the Chung-Lu random network model incorporating clustering, we examine the effect of clustering under the Susceptible-Infected-Recovered (SIR) epidemic diffusion model with heterogeneous contact rates. For this purpose, we exploit the branching process to analyse information diffusion in random unclustered networks with arbitrary contact rates, and provide novel iterative algorithms for estimating the conditions and sizes of global cascades, respectively. Showing that a random clustered network can be mapped into a factor graph, which is a locally tree-like structure, we successfully extend our analysis to random clustered networks with heterogeneous contact rates. We then identify the conditions for phase transitions of information diffusion using our method. Interestingly, for various contact rates, we prove that random clustered networks with higher clustering coefficients have strictly lower phase transition points for any given degree sequence. Finally, we confirm our analytical results with numerical simulations of both synthetically-generated and real-world networks.

  3. Phase transitions for information diffusion in random clustered networks

    NASA Astrophysics Data System (ADS)

    Lim, Sungsu; Shin, Joongbo; Kwak, Namju; Jung, Kyomin

    2016-08-01

    We study the conditions for the phase transitions of information diffusion in complex networks. Using the random clustered network model, a generalisation of the Chung-Lu random network model incorporating clustering, we examine the effect of clustering under the Susceptible-Infected-Recovered (SIR) epidemic diffusion model with heterogeneous contact rates. For this purpose, we exploit the branching process to analyse information diffusion in random unclustered networks with arbitrary contact rates, and provide novel iterative algorithms for estimating the conditions and sizes of global cascades, respectively. Showing that a random clustered network can be mapped into a factor graph, which is a locally tree-like structure, we successfully extend our analysis to random clustered networks with heterogeneous contact rates. We then identify the conditions for phase transitions of information diffusion using our method. Interestingly, for various contact rates, we prove that random clustered networks with higher clustering coefficients have strictly lower phase transition points for any given degree sequence. Finally, we confirm our analytical results with numerical simulations of both synthetically-generated and real-world networks.

  4. Brain diffusivity pattern is individual-specific information.

    PubMed

    Takao, H; Hayashi, N; Ohtomo, K

    2015-08-20

    The human brain is composed of complex networks of 100 billion neurons that underlie its higher functions. The set of neural connections in the brain has recently attracted growing interest from the scientific community. It is important to identify individual differences in these neural connections to study the background of individual differences in brain function and performance. In the present study, we investigated whether the pattern of brain diffusion, reflecting neural connections, is discernibly different among individuals; i.e., whether brain diffusivity is personally identifiable information. Using diffusion tensor imaging data from 224 healthy subjects scanned twice at an interval of about 1year, we performed brain recognition by spatial normalization of fractional anisotropy maps, feature extraction based on Principal Component Analysis, and calculation of the Euclidean distances between image pairs projected into the subspace. Even with only 16 dimensions used for projection, the rank-one identification rate was 99.1%. The rank-one identification rate was 100% with ⩾32 dimensions used for projection. The genuine accept rates were 95.1% and 100% at a false accept rate of 0.001%, with 16 and ⩾32 dimensions used for projection, respectively. There were no large differences in the Euclidean distance among different combinations of scanners used or between image pairs with and without scanner upgrade. The results indicate that brain diffusivity can identify a specific individual; i.e., the pattern of brain diffusion is personally identifiable information. Individual differences in brain diffusivity will form the basis of individual differences in personality and brain function. PMID:26116520

  5. Maximizing Information Diffusion in the Cyber-physical Integrated Network.

    PubMed

    Lu, Hongliang; Lv, Shaohe; Jiao, Xianlong; Wang, Xiaodong; Liu, Juan

    2015-01-01

    Nowadays, our living environment has been embedded with smart objects, such as smart sensors, smart watches and smart phones. They make cyberspace and physical space integrated by their abundant abilities of sensing, communication and computation, forming a cyber-physical integrated network. In order to maximize information diffusion in such a network, a group of objects are selected as the forwarding points. To optimize the selection, a minimum connected dominating set (CDS) strategy is adopted. However, existing approaches focus on minimizing the size of the CDS, neglecting an important factor: the weight of links. In this paper, we propose a distributed maximizing the probability of information diffusion (DMPID) algorithm in the cyber-physical integrated network. Unlike previous approaches that only consider the size of CDS selection, DMPID also considers the information spread probability that depends on the weight of links. To weaken the effects of excessively-weighted links, we also present an optimization strategy that can properly balance the two factors. The results of extensive simulation show that DMPID can nearly double the information diffusion probability, while keeping a reasonable size of selection with low overhead in different distributed networks. PMID:26569254

  6. Maximizing Information Diffusion in the Cyber-physical Integrated Network.

    PubMed

    Lu, Hongliang; Lv, Shaohe; Jiao, Xianlong; Wang, Xiaodong; Liu, Juan

    2015-11-11

    Nowadays, our living environment has been embedded with smart objects, such as smart sensors, smart watches and smart phones. They make cyberspace and physical space integrated by their abundant abilities of sensing, communication and computation, forming a cyber-physical integrated network. In order to maximize information diffusion in such a network, a group of objects are selected as the forwarding points. To optimize the selection, a minimum connected dominating set (CDS) strategy is adopted. However, existing approaches focus on minimizing the size of the CDS, neglecting an important factor: the weight of links. In this paper, we propose a distributed maximizing the probability of information diffusion (DMPID) algorithm in the cyber-physical integrated network. Unlike previous approaches that only consider the size of CDS selection, DMPID also considers the information spread probability that depends on the weight of links. To weaken the effects of excessively-weighted links, we also present an optimization strategy that can properly balance the two factors. The results of extensive simulation show that DMPID can nearly double the information diffusion probability, while keeping a reasonable size of selection with low overhead in different distributed networks.

  7. Information Filtering via Heterogeneous Diffusion in Online Bipartite Networks

    PubMed Central

    Zhang, Fu-Guo; Zeng, An

    2015-01-01

    The rapid expansion of Internet brings us overwhelming online information, which is impossible for an individual to go through all of it. Therefore, recommender systems were created to help people dig through this abundance of information. In networks composed by users and objects, recommender algorithms based on diffusion have been proven to be one of the best performing methods. Previous works considered the diffusion process from user to object, and from object to user to be equivalent. We show in this work that it is not the case and we improve the quality of the recommendation by taking into account the asymmetrical nature of this process. We apply this idea to modify the state-of-the-art recommendation methods. The simulation results show that the new methods can outperform these existing methods in both recommendation accuracy and diversity. Finally, this modification is checked to be able to improve the recommendation in a realistic case. PMID:26125631

  8. Social Information Transmission in Animals: Lessons from Studies of Diffusion

    PubMed Central

    Duboscq, Julie; Romano, Valéria; MacIntosh, Andrew; Sueur, Cédric

    2016-01-01

    The capacity to use information provided by others to guide behavior is a widespread phenomenon in animal societies. A standard paradigm to test if and/or how animals use and transfer social information is through social diffusion experiments, by which researchers observe how information spreads within a group, sometimes by seeding new behavior in the population. In this article, we review the context, methodology and products of such social diffusion experiments. Our major focus is the transmission of information from an individual (or group thereof) to another, and the factors that can enhance or, more interestingly, inhibit it. We therefore also discuss reasons why social transmission sometimes does not occur despite being expected to. We span a full range of mechanisms and processes, from the nature of social information itself and the cognitive abilities of various species, to the idea of social competency and the constraints imposed by the social networks in which animals are embedded. We ultimately aim at a broad reflection on practical and theoretical issues arising when studying how social information spreads within animal groups. PMID:27540368

  9. Social Information Transmission in Animals: Lessons from Studies of Diffusion.

    PubMed

    Duboscq, Julie; Romano, Valéria; MacIntosh, Andrew; Sueur, Cédric

    2016-01-01

    The capacity to use information provided by others to guide behavior is a widespread phenomenon in animal societies. A standard paradigm to test if and/or how animals use and transfer social information is through social diffusion experiments, by which researchers observe how information spreads within a group, sometimes by seeding new behavior in the population. In this article, we review the context, methodology and products of such social diffusion experiments. Our major focus is the transmission of information from an individual (or group thereof) to another, and the factors that can enhance or, more interestingly, inhibit it. We therefore also discuss reasons why social transmission sometimes does not occur despite being expected to. We span a full range of mechanisms and processes, from the nature of social information itself and the cognitive abilities of various species, to the idea of social competency and the constraints imposed by the social networks in which animals are embedded. We ultimately aim at a broad reflection on practical and theoretical issues arising when studying how social information spreads within animal groups. PMID:27540368

  10. Split operator method for fluorescence diffuse optical tomography using anisotropic diffusion regularisation with prior anatomical information

    PubMed Central

    Correia, Teresa; Aguirre, Juan; Sisniega, Alejandro; Chamorro-Servent, Judit; Abascal, Juan; Vaquero, Juan J.; Desco, Manuel; Kolehmainen, Ville; Arridge, Simon

    2011-01-01

    Fluorescence diffuse optical tomography (fDOT) is an imaging modality that provides images of the fluorochrome distribution within the object of study. The image reconstruction problem is ill-posed and highly underdetermined and, therefore, regularisation techniques need to be used. In this paper we use a nonlinear anisotropic diffusion regularisation term that incorporates anatomical prior information. We introduce a split operator method that reduces the nonlinear inverse problem to two simpler problems, allowing fast and efficient solution of the fDOT problem. We tested our method using simulated, phantom and ex-vivo mouse data, and found that it provides reconstructions with better spatial localisation and size of fluorochrome inclusions than using the standard Tikhonov penalty term. PMID:22091447

  11. Impact Acceleration Model of Diffuse Traumatic Brain Injury.

    PubMed

    Hellewell, Sarah C; Ziebell, Jenna M; Lifshitz, Jonathan; Morganti-Kossmann, M Cristina

    2016-01-01

    The impact acceleration (I/A) model of traumatic brain injury (TBI) was developed to reliably induce diffuse traumatic axonal injury in rats in the absence of skull fractures and parenchymal focal lesions. This model replicates a pathophysiology that is commonly observed in humans with diffuse axonal injury (DAI) caused by acceleration-deceleration forces. Such injuries are typical consequences of motor vehicle accidents and falls, which do not necessarily require a direct impact to the closed skull. There are several desirable characteristics of the I/A model, including the extensive axonal injury produced in the absence of a focal contusion, the suitability for secondary insult modeling, and the adaptability for mild/moderate injury through alteration of height and/or weight. Furthermore, the trauma device is inexpensive and readily manufactured in any laboratory, and the induction of injury is rapid (~45 min per animal from weighing to post-injury recovery) allowing multiple animal experiments per day. In this chapter, we describe in detail the methodology and materials required to produce the rat model of I/A in the laboratory. We also review current adaptations to the model to alter injury severity, discuss frequent complications and technical issues encountered using this model, and provide recommendations to ensure technically sound injury induction. PMID:27604723

  12. Suppressing disease spreading by using information diffusion on multiplex networks

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Liu, Quan-Hui; Cai, Shi-Min; Tang, Ming; Braunstein, Lidia A.; Stanley, H. Eugene

    2016-07-01

    Although there is always an interplay between the dynamics of information diffusion and disease spreading, the empirical research on the systemic coevolution mechanisms connecting these two spreading dynamics is still lacking. Here we investigate the coevolution mechanisms and dynamics between information and disease spreading by utilizing real data and a proposed spreading model on multiplex network. Our empirical analysis finds asymmetrical interactions between the information and disease spreading dynamics. Our results obtained from both the theoretical framework and extensive stochastic numerical simulations suggest that an information outbreak can be triggered in a communication network by its own spreading dynamics or by a disease outbreak on a contact network, but that the disease threshold is not affected by information spreading. Our key finding is that there is an optimal information transmission rate that markedly suppresses the disease spreading. We find that the time evolution of the dynamics in the proposed model qualitatively agrees with the real-world spreading processes at the optimal information transmission rate.

  13. Suppressing disease spreading by using information diffusion on multiplex networks.

    PubMed

    Wang, Wei; Liu, Quan-Hui; Cai, Shi-Min; Tang, Ming; Braunstein, Lidia A; Stanley, H Eugene

    2016-01-01

    Although there is always an interplay between the dynamics of information diffusion and disease spreading, the empirical research on the systemic coevolution mechanisms connecting these two spreading dynamics is still lacking. Here we investigate the coevolution mechanisms and dynamics between information and disease spreading by utilizing real data and a proposed spreading model on multiplex network. Our empirical analysis finds asymmetrical interactions between the information and disease spreading dynamics. Our results obtained from both the theoretical framework and extensive stochastic numerical simulations suggest that an information outbreak can be triggered in a communication network by its own spreading dynamics or by a disease outbreak on a contact network, but that the disease threshold is not affected by information spreading. Our key finding is that there is an optimal information transmission rate that markedly suppresses the disease spreading. We find that the time evolution of the dynamics in the proposed model qualitatively agrees with the real-world spreading processes at the optimal information transmission rate. PMID:27380881

  14. Suppressing disease spreading by using information diffusion on multiplex networks

    PubMed Central

    Wang, Wei; Liu, Quan-Hui; Cai, Shi-Min; Tang, Ming; Braunstein, Lidia A.; Stanley, H. Eugene

    2016-01-01

    Although there is always an interplay between the dynamics of information diffusion and disease spreading, the empirical research on the systemic coevolution mechanisms connecting these two spreading dynamics is still lacking. Here we investigate the coevolution mechanisms and dynamics between information and disease spreading by utilizing real data and a proposed spreading model on multiplex network. Our empirical analysis finds asymmetrical interactions between the information and disease spreading dynamics. Our results obtained from both the theoretical framework and extensive stochastic numerical simulations suggest that an information outbreak can be triggered in a communication network by its own spreading dynamics or by a disease outbreak on a contact network, but that the disease threshold is not affected by information spreading. Our key finding is that there is an optimal information transmission rate that markedly suppresses the disease spreading. We find that the time evolution of the dynamics in the proposed model qualitatively agrees with the real-world spreading processes at the optimal information transmission rate. PMID:27380881

  15. Suppressing disease spreading by using information diffusion on multiplex networks.

    PubMed

    Wang, Wei; Liu, Quan-Hui; Cai, Shi-Min; Tang, Ming; Braunstein, Lidia A; Stanley, H Eugene

    2016-01-01

    Although there is always an interplay between the dynamics of information diffusion and disease spreading, the empirical research on the systemic coevolution mechanisms connecting these two spreading dynamics is still lacking. Here we investigate the coevolution mechanisms and dynamics between information and disease spreading by utilizing real data and a proposed spreading model on multiplex network. Our empirical analysis finds asymmetrical interactions between the information and disease spreading dynamics. Our results obtained from both the theoretical framework and extensive stochastic numerical simulations suggest that an information outbreak can be triggered in a communication network by its own spreading dynamics or by a disease outbreak on a contact network, but that the disease threshold is not affected by information spreading. Our key finding is that there is an optimal information transmission rate that markedly suppresses the disease spreading. We find that the time evolution of the dynamics in the proposed model qualitatively agrees with the real-world spreading processes at the optimal information transmission rate.

  16. Diffused holographic information storage and retrieval using photorefractive optical materials

    NASA Astrophysics Data System (ADS)

    McMillen, Deanna Kay

    Holography offers a tremendous opportunity for dense information storage, theoretically one bit per cubic wavelength of material volume, with rapid retrieval, of up to thousands of pages of information simultaneously. However, many factors prevent the theoretical storage limit from being reached, including dynamic range problems and imperfections in recording materials. This research explores new ways of moving closer to practical holographic information storage and retrieval by altering the recording materials, in this case, photorefractive crystals, and by increasing the current storage capacity while improving the information retrieved. As an experimental example of the techniques developed, the information retrieved is the correlation peak from an optical recognition architecture, but the materials and methods developed are applicable to many other holographic information storage systems. Optical correlators can potentially solve any signal or image recognition problem. Military surveillance, fingerprint identification for law enforcement or employee identification, and video games are but a few examples of applications. A major obstacle keeping optical correlators from being universally accepted is the lack of a high quality, thick (high capacity) holographic recording material that operates with red or infrared wavelengths which are available from inexpensive diode lasers. This research addresses the problems from two positions: find a better material for use with diode lasers, and reduce the requirements placed on the material while maintaining an efficient and effective system. This research found that the solutions are new dopants introduced into photorefractive lithium niobate to improve wavelength sensitivities and the use of a novel inexpensive diffuser that reduces the dynamic range and optical element quality requirements (which reduces the cost) while improving performance. A uniquely doped set of 12 lithium niobate crystals was specified and

  17. Mechanical vs. informational components of price impact

    NASA Astrophysics Data System (ADS)

    Doyne Farmer, J.; Zamani, N.

    2007-01-01

    We study the problem of what causes prices to change. It is well known that trading impacts prices — orders to buy drive the price up, and orders to sell drive it down. We introduce a means of decomposing the total impact of trading into two components, defining the mechanical impact of a trading order as the change in future prices in the absence of any future changes in decision making, and the informational impact as the remainder of the total impact once mechanical impact is removed. This decomposition is performed using order book data from the London Stock Exchange. The average mechanical impact of a market order decays to zero as a function of time, at an asymptotic rate that is consistent with a power law with an exponent of roughly 1.7. In contrast the average informational impact builds to approach a constant value. Initially the impact is entirely mechanical, and is about half as big as the asymptotic informational impact. The size of the informational impact is positively correlated to mechanical impact. For cases where the mechanical impact is zero for all times, we find that the informational impact is negative, i.e. buy market orders that have no mechanical impact at all generate strong negative price responses.

  18. Nitrogen diffusion in hafnia and the impact of nitridation on oxygen and hydrogen diffusion: A first-principles study

    SciTech Connect

    Sathiyanarayanan, Rajesh E-mail: rajesh.sathiyanarayanan@gmail.com; Pandey, R. K.; Murali, K. V. R. M.

    2015-01-21

    Using first-principles simulations, we have computed incorporation energies and diffusion barriers of ammonia, the nitrogen molecule and atomic nitrogen in monoclinic hafnia (m-HfO{sub 2}). Our calculations show that ammonia is likely to dissociate into an NH{sub 2} molecular unit, whereas the nitrogen molecule remains as a molecule either in the interstitial space or at an oxygen lattice site. The lowest energy pathway for the diffusion of atomic nitrogen interstitials consists of the hopping of the nitrogen interstitial between neighboring three-coordinated lattice oxygen atoms that share a single Hf atom, and the barrier for such hops is determined by a switching mechanism. The substitutional nitrogen atom shows a preference for diffusion through the doubly positive oxygen vacancy-mediated mechanism. Furthermore, we have investigated the impact of nitrogen atoms on the diffusion barriers of oxygen and hydrogen interstitials in m-HfO{sub 2}. Our results show that nitrogen incorporation has a significant impact on the barriers for oxygen and hydrogen diffusion: nitrogen atoms attract oxygen and hydrogen interstitials diffusing in the vicinity, thereby slowing down (reducing) their diffusion (diffusion length)

  19. NASA/DoD Aerospace Knowledge Diffusion Research Project. Paper 30: The electronic transfer of information and aerospace knowledge diffusion

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Bishop, Ann P.; Barclay, Rebecca O.; Kennedy, John M.

    1992-01-01

    Increasing reliance on and investment in information technology and electronic networking systems presupposes that computing and information technology will play a major role in the diffusion of aerospace knowledge. Little is known, however, about actual information technology needs, uses, and problems within the aerospace knowledge diffusion process. The authors state that the potential contributions of information technology to increased productivity and competitiveness will be diminished unless empirically derived knowledge regarding the information-seeking behavior of the members of the social system - those who are producing, transferring, and using scientific and technical information - is incorporated into a new technology policy framework. Research into the use of information technology and electronic networks by U.S. aerospace engineers and scientists, collected as part of a research project designed to study aerospace knowledge diffusion, is presented in support of this assertion.

  20. Modeling of Information Diffusion in Twitter-Like Social Networks under Information Overload

    PubMed Central

    Li, Wei

    2014-01-01

    Due to the existence of information overload in social networks, it becomes increasingly difficult for users to find useful information according to their interests. This paper takes Twitter-like social networks into account and proposes models to characterize the process of information diffusion under information overload. Users are classified into different types according to their in-degrees and out-degrees, and user behaviors are generalized into two categories: generating and forwarding. View scope is introduced to model the user information-processing capability under information overload, and the average number of times a message appears in view scopes after it is generated by a given type user is adopted to characterize the information diffusion efficiency, which is calculated theoretically. To verify the accuracy of theoretical analysis results, we conduct simulations and provide the simulation results, which are consistent with the theoretical analysis results perfectly. These results are of importance to understand the diffusion dynamics in social networks, and this analysis framework can be extended to consider more realistic situations. PMID:24795541

  1. A diffusive information preservation method for small Knudsen number flows

    NASA Astrophysics Data System (ADS)

    Fei, Fei; Fan, Jing

    2013-06-01

    The direct simulation Monte Carlo (DSMC) method is a powerful particle-based method for modeling gas flows. It works well for relatively large Knudsen (Kn) numbers, typically larger than 0.01, but quickly becomes computationally intensive as Kn decreases due to its time step and cell size limitations. An alternative approach was proposed to relax or remove these limitations, based on replacing pairwise collisions with a stochastic model corresponding to the Fokker-Planck equation [J. Comput. Phys., 229, 1077 (2010); J. Fluid Mech., 680, 574 (2011)]. Similar to the DSMC method, the downside of that approach suffers from computationally statistical noise. To solve the problem, a diffusion-based information preservation (D-IP) method has been developed. The main idea is to track the motion of a simulated molecule from the diffusive standpoint, and obtain the flow velocity and temperature through sampling and averaging the IP quantities. To validate the idea and the corresponding model, several benchmark problems with Kn ˜ 10-3-10-4 have been investigated. It is shown that the IP calculations are not only accurate, but also efficient because they make possible using a time step and cell size over an order of magnitude larger than the mean collision time and mean free path, respectively.

  2. A diffusive information preservation method for small Knudsen number flows

    SciTech Connect

    Fei, Fei; Fan, Jing

    2013-06-15

    The direct simulation Monte Carlo (DSMC) method is a powerful particle-based method for modeling gas flows. It works well for relatively large Knudsen (Kn) numbers, typically larger than 0.01, but quickly becomes computationally intensive as Kn decreases due to its time step and cell size limitations. An alternative approach was proposed to relax or remove these limitations, based on replacing pairwise collisions with a stochastic model corresponding to the Fokker–Planck equation [J. Comput. Phys., 229, 1077 (2010); J. Fluid Mech., 680, 574 (2011)]. Similar to the DSMC method, the downside of that approach suffers from computationally statistical noise. To solve the problem, a diffusion-based information preservation (D-IP) method has been developed. The main idea is to track the motion of a simulated molecule from the diffusive standpoint, and obtain the flow velocity and temperature through sampling and averaging the IP quantities. To validate the idea and the corresponding model, several benchmark problems with Kn ∼ 10{sup −3}–10{sup −4} have been investigated. It is shown that the IP calculations are not only accurate, but also efficient because they make possible using a time step and cell size over an order of magnitude larger than the mean collision time and mean free path, respectively.

  3. Information filtering by similarity-preferential diffusion processes

    NASA Astrophysics Data System (ADS)

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

    2014-03-01

    Recommender systems provide a promising way to address the information overload problem which is common in online systems. Based on past user preferences, a recommender system can find items that are likely to be relevant to a given user. Two classical physical processes, mass diffusion and heat conduction, have been used to design recommendation algorithms and a hybrid process based on them has been shown to provide accurate and diverse recommendation results. We modify both processes as well as their hybrid by introducing a parameter which can be used to enhance or suppress the weight of users who are most similar to the target user for whom the recommendation is done. Evaluation on two benchmark data sets demonstrates that both recommendation accuracy and diversity are improved for a wide range of parameter values. Threefold validation indicates that the achieved results are robust and the new recommendation methods are thus applicable in practice.

  4. Engaging farmers to inform future diffuse pollution policy in England

    NASA Astrophysics Data System (ADS)

    Vrain, Emilie; Lovett, Andrew; Nobel, Lister; Grant, Fiona; Blundell, Paul; Cleasby, Will

    2013-04-01

    Stakeholder knowledge and engagement is increasingly seen as a necessary ingredient for catchment management. Whilst many agricultural management options remain voluntary, the implementation of diffuse pollution mitigation measures will only be effective with the cooperation of stakeholders. Anthony et al. (2009) and Zhang et al. (2012) state the need for more information on the realistic farmer uptake of methods to enhance analyses of the potential for pollution mitigation. A study engaging farmers to understand current agricultural practices and their attitudes towards mitigation measures has formed part of the Demonstration Test Catchment (DTC) programme in England. Interviews with over seventy farmers were conducted during 2012 in three contrasting areas of the UK: the grassland dominated Eden catchment in the North West of England; the arable dominated Wensum catchment in East Anglia and the mixed farming of the Hampshire Avon catchment in southern England. Results from the farmer survey provide a baseline regarding current agricultural practices and give insight regarding attitudes to the adoption of other mitigation measures in the future. Opinions were obtained on eighty different measures taken from a recent guide to possible measures prepared for the UK government (Newell-Price et al., 2011). Analyses have been conducted examining how current use and attitudes towards future adoption of measures varies according to different characteristics of farm businesses. These findings will be of benefit to researchers, policy makers and farm advisers, particularly aiding decision making with respect to strategies for future implementation of programmes of measures. References. Anthony, S.G. et al., 2009. Quantitative assessment of scenarios for managing trade-off between the economic performance of agriculture and the environment and between different environmental media. Available at: http://randd.defra.gov.uk/Default

  5. The impact of hardpans and cemented layers on oxygen diffusivity in mining waste heaps: diffusion experiments and modelling studies.

    PubMed

    Kohfahl, Claus; Graupner, Torsten; Fetzer, Christian; Holzbecher, Ekkehard; Pekdeger, Asaf

    2011-08-01

    This study reports column tests and modelling results to assess the impact of hardpans and cemented layers on oxygen supply in mine waste sediments. The analysed sediment samples were obtained from a low-sulphide and low-carbonate polymetallic mine waste tailings impoundment located in the Freiberg mining district in Germany. The three samples were characterised by different degrees and types of cementation. After physical and mineralogical properties of the samples had been determined, breakthrough curves of oxygen were measured in column studies at different degrees of water saturation, and the diffusivities were assessed using a numerical modelling approach. Results demonstrate that cemented layers and hardpans in undisturbed sediments associated with fine-grained material operate as preferential pathways for diffusive gas transport during rewetting, leading to higher oxygen diffusivities compared to disturbed sediments. Under air-dry conditions, the disturbed samples show higher diffusivities than the undisturbed sample, indicating clogging of the porosity by precipitation of secondary minerals such as trivalent Fe oxyhydroxides acting as a barrier and thereby decreasing the diffusivity of the undisturbed sample. In contrast to sediments without cementation, diffusion experiments of sediments with cemented layers used in this study yield similar tortuosities in spite of their different grain size distributions, pointing to the important role of these heterogeneities for gas diffusion.

  6. Influence of topology in the evolution of coordination in complex networks under information diffusion constraints

    NASA Astrophysics Data System (ADS)

    Kasthurirathna, Dharshana; Piraveenan, Mahendra; Harré, Michael

    2014-01-01

    In this paper, we study the influence of the topological structure of social systems on the evolution of coordination in them. We simulate a coordination game ("Stag-hunt") on four well-known classes of complex networks commonly used to model social systems, namely scale-free, small-world, random and hierarchical-modular, as well as on the well-mixed model. Our particular focus is on understanding the impact of information diffusion on coordination, and how this impact varies according to the topology of the social system. We demonstrate that while time-lags and noise in the information about relative payoffs affect the emergence of coordination in all social systems, some topologies are markedly more resilient than others to these effects. We also show that, while non-coordination may be a better strategy in a society where people do not have information about the payoffs of others, coordination will quickly emerge as the better strategy when people get this information about others, even with noise and time lags. Societies with the so-called small-world structure are most conducive to the emergence of coordination, despite limitations in information propagation, while societies with scale-free topologies are most sensitive to noise and time-lags in information diffusion. Surprisingly, in all topologies, it is not the highest connected people (hubs), but the slightly less connected people (provincial hubs) who first adopt coordination. Our findings confirm that the evolution of coordination in social systems depends heavily on the underlying social network structure.

  7. The Impact of Diffuse Light on Terrestrial Carbon Uptake

    NASA Astrophysics Data System (ADS)

    Cheng, S. J.; Bohrer, G.; Steiner, A. L.; Nadelhoffer, K. J.; Fotis, A.

    2013-12-01

    Clouds and aerosols influence the strength of the terrestrial carbon sink by changing environmental conditions that control rates of photosynthesis and ecosystem gross primary productivity (GPP). Although clouds and aerosols can reduce GPP by lowering the amount of light entering ecosystems, they also create scattered, diffuse light that can penetrate deeper into plant canopies. This can potentially increase lower-canopy light absorption and photosynthesis, sometimes enough to compensate for any decreases in upper canopy photosynthesis under reduced light levels. To identify how strongly diffuse light influences ecosystem GPP, we analyze the relationship between diffuse light and GPP at Ameriflux sites with at least 3 years of diffuse photosynthetically active radiation (PAR) and GPP data. We also compare the effects of diffuse light across deciduous broadleaf forests, mixed forests, croplands, and grasslands. Preliminary results show a positive relationship between diffuse PAR and GPP, with the magnitude of the relationship dependent on zenith angle and vegetation type. The relationship remains positive for low zenith angles after taking into account the effect of direct light availability on GPP. Additionally, we use NASA Moderate Resolution Imaging Spectroradiometer (MODIS) data to analyze how the diffuse light effect on GPP changes under high cloud and aerosol optical depths. Quantifying the effects of diffuse light on GPP for different ecosystem types and determining how they change under different atmospheric conditions will expand our understanding of how changing cloud and aerosol conditions may alter local ecosystem carbon cycling and the magnitude of the terrestrial carbon sink.

  8. Impact of osmotic stress on protein diffusion in Lactococcus lactis.

    PubMed

    Mika, Jacek T; Schavemaker, Paul E; Krasnikov, Victor; Poolman, Bert

    2014-11-01

    We measured translational diffusion of proteins in the cytoplasm and plasma membrane of the Gram-positive bacterium Lactococcus lactis and probed the effect of osmotic upshift. For cells in standard growth medium the diffusion coefficients for cytosolic proteins (27 and 582 kDa) and 12-transmembrane helix membrane proteins are similar to those in Escherichia coli. The translational diffusion of GFP in L. lactis drops by two orders of magnitude when the medium osmolality is increased by ∼ 1.9 Osm, and the decrease in mobility is partly reversed in the presence of osmoprotectants. We find a large spread in diffusion coefficients over the full population of cells but a smaller spread if only sister cells are compared. While in general the diffusion coefficients we measure under normal osmotic conditions in L. lactis are similar to those reported in E. coli, the decrease in translational diffusion upon osmotic challenge in L. lactis is smaller than in E. coli. An even more striking difference is that in L. lactis the GFP diffusion coefficient drops much more rapidly with volume than in E. coli. We discuss these findings in the light of differences in turgor, cell volume, crowding and cytoplasmic structure of Gram-positive and Gram-negative bacteria.

  9. Sharing Health Information and Influencing Behavioral Intentions: The Role of Health Literacy, Information Overload, and the Internet in the Diffusion of Healthy Heart Information.

    PubMed

    Crook, Brittani; Stephens, Keri K; Pastorek, Angie E; Mackert, Michael; Donovan, Erin E

    2016-01-01

    Low health literacy remains an extremely common and problematic issue, given that individuals with lower health literacy are more likely to experience health challenges and negative health outcomes. In this study, we use the first three stages of the innovation-decision process found in the theory of diffusion of innovations (Rogers, 2003). We incorporate health literacy into a model explaining how perceived health knowledge, information sharing, attitudes, and behavior are related. Results show that health information sharing explains 33% of the variance in behavioral intentions, indicating that the communicative practice of sharing information can positively impact health outcomes. Further, individuals with high health literacy tend to share less information about heart health than those with lower health literacy. Findings also reveal that perceived heart-health knowledge operates differently than health literacy to predict health outcomes. PMID:25668744

  10. Sharing Health Information and Influencing Behavioral Intentions: The Role of Health Literacy, Information Overload, and the Internet in the Diffusion of Healthy Heart Information.

    PubMed

    Crook, Brittani; Stephens, Keri K; Pastorek, Angie E; Mackert, Michael; Donovan, Erin E

    2016-01-01

    Low health literacy remains an extremely common and problematic issue, given that individuals with lower health literacy are more likely to experience health challenges and negative health outcomes. In this study, we use the first three stages of the innovation-decision process found in the theory of diffusion of innovations (Rogers, 2003). We incorporate health literacy into a model explaining how perceived health knowledge, information sharing, attitudes, and behavior are related. Results show that health information sharing explains 33% of the variance in behavioral intentions, indicating that the communicative practice of sharing information can positively impact health outcomes. Further, individuals with high health literacy tend to share less information about heart health than those with lower health literacy. Findings also reveal that perceived heart-health knowledge operates differently than health literacy to predict health outcomes.

  11. Structural limitations of learning in a crowd: communication vulnerability and information diffusion in MOOCs.

    PubMed

    Gillani, Nabeel; Yasseri, Taha; Eynon, Rebecca; Hjorth, Isis

    2014-01-01

    Massive Open Online Courses (MOOCs) bring together a global crowd of thousands of learners for several weeks or months. In theory, the openness and scale of MOOCs can promote iterative dialogue that facilitates group cognition and knowledge construction. Using data from two successive instances of a popular business strategy MOOC, we filter observed communication patterns to arrive at the "significant" interaction networks between learners and use complex network analysis to explore the vulnerability and information diffusion potential of the discussion forums. We find that different discussion topics and pedagogical practices promote varying levels of 1) "significant" peer-to-peer engagement, 2) participant inclusiveness in dialogue, and ultimately, 3) modularity, which impacts information diffusion to prevent a truly "global" exchange of knowledge and learning. These results indicate the structural limitations of large-scale crowd-based learning and highlight the different ways that learners in MOOCs leverage, and learn within, social contexts. We conclude by exploring how these insights may inspire new developments in online education. PMID:25244925

  12. Structural limitations of learning in a crowd: communication vulnerability and information diffusion in MOOCs.

    PubMed

    Gillani, Nabeel; Yasseri, Taha; Eynon, Rebecca; Hjorth, Isis

    2014-09-23

    Massive Open Online Courses (MOOCs) bring together a global crowd of thousands of learners for several weeks or months. In theory, the openness and scale of MOOCs can promote iterative dialogue that facilitates group cognition and knowledge construction. Using data from two successive instances of a popular business strategy MOOC, we filter observed communication patterns to arrive at the "significant" interaction networks between learners and use complex network analysis to explore the vulnerability and information diffusion potential of the discussion forums. We find that different discussion topics and pedagogical practices promote varying levels of 1) "significant" peer-to-peer engagement, 2) participant inclusiveness in dialogue, and ultimately, 3) modularity, which impacts information diffusion to prevent a truly "global" exchange of knowledge and learning. These results indicate the structural limitations of large-scale crowd-based learning and highlight the different ways that learners in MOOCs leverage, and learn within, social contexts. We conclude by exploring how these insights may inspire new developments in online education.

  13. Structural limitations of learning in a crowd: communication vulnerability and information diffusion in MOOCs

    NASA Astrophysics Data System (ADS)

    Gillani, Nabeel; Yasseri, Taha; Eynon, Rebecca; Hjorth, Isis

    2014-09-01

    Massive Open Online Courses (MOOCs) bring together a global crowd of thousands of learners for several weeks or months. In theory, the openness and scale of MOOCs can promote iterative dialogue that facilitates group cognition and knowledge construction. Using data from two successive instances of a popular business strategy MOOC, we filter observed communication patterns to arrive at the ``significant'' interaction networks between learners and use complex network analysis to explore the vulnerability and information diffusion potential of the discussion forums. We find that different discussion topics and pedagogical practices promote varying levels of 1) ``significant'' peer-to-peer engagement, 2) participant inclusiveness in dialogue, and ultimately, 3) modularity, which impacts information diffusion to prevent a truly ``global'' exchange of knowledge and learning. These results indicate the structural limitations of large-scale crowd-based learning and highlight the different ways that learners in MOOCs leverage, and learn within, social contexts. We conclude by exploring how these insights may inspire new developments in online education.

  14. Cellular Automata with network incubation in information technology diffusion

    NASA Astrophysics Data System (ADS)

    Guseo, Renato; Guidolin, Mariangela

    2010-06-01

    Innovation diffusion of network goods determines direct network externalities that depress sales for long periods and delay full benefits. We model this effect through a multiplicative dynamic market potential driven by a latent individual threshold embedded in a special Cellular Automata representation. The corresponding mean field approximation of its aggregate version is a Riccati equation with a closed form solution. This allows the detection of a change-point time separating an incubation period from a subsequent take-off due to a collective threshold (critical mass). Weighted nonlinear least squares are the main inferential methodology. An application is analysed with reference to USA fax machine diffusion.

  15. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 19: Computer and information technology and aerospace knowledge diffusion

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Kennedy, John M.; Barclay, Rebecca O.; Bishop, Ann P.

    1992-01-01

    To remain a world leader in aerospace, the US must improve and maintain the professional competency of its engineers and scientists, increase the research and development (R&D) knowledge base, improve productivity, and maximize the integration of recent technological developments into the R&D process. How well these objectives are met, and at what cost, depends on a variety of factors, but largely on the ability of US aerospace engineers and scientists to acquire and process the results of federally funded R&D. The Federal Government's commitment to high speed computing and networking systems presupposes that computer and information technology will play a major role in the aerospace knowledge diffusion process. However, we know little about information technology needs, uses, and problems within the aerospace knowledge diffusion process. The use of computer and information technology by US aerospace engineers and scientists in academia, government, and industry is reported.

  16. How reliable is online diffusion of medical information targeting patients and families?

    PubMed Central

    Xavier-Elsas, Pedro; Bastos, Sandra Epifânio; Gaspar-Elsas, Maria Ignez C

    2015-01-01

    AIM: To determine whether online diffusion of the “Ten Warning Signs of Primary Immunodeficiency Diseases (PID)’’ adheres to accepted scientific standards. METHODS: We analyzed how reproducible is online diffusion of a unique instrument, the “Ten Warning Signs of PID”, created by the Jeffrey Modell Foundation (JMF), by Google-assisted searches among highly visited sites from professional, academic and scientific organizations; governmental agencies; and patient support/advocacy organizations. We examined the diffusion, consistency of use and adequate referencing of this instrument. Where applicable, variant versions of the instrument were examined for changes in factual content that would have practical impact on physicians or on patients and their families. RESULTS: Among the first 100 sites identified by Google search, 85 faithfully reproduced the JMF model, and correctly referenced to its source. By contrast, the other 15 also referenced the JMF source but presented one or more changes in content relative to their purported model and therefore represent uncontrolled variants, of unknown origin. Discrepancies identified in the latter included changes in factual content of the original JMF list (C), as well as removal (R) and introduction (I) of novel signs (Table 2), all made without reference to any scientific publications that might account for the drastic changes in factual content. Factual changes include changes in the number of infectious episodes considered necessary to raise suspicion of PID, as well as the inclusion of various medical conditions not mentioned in the original. Together, these changes will affect the way physicians use the instrument to consult or to inform patients, and the way patients and families think about the need for specialist consultation in view of a possible PID diagnosis. CONCLUSION: The retrieved adaptations and variants, which significantly depart from the original instrument, raise concerns about standards for

  17. Intracellular Signaling by Diffusion: Can Waves of Hydrogen Peroxide Transmit Intracellular Information in Plant Cells?

    PubMed Central

    Vestergaard, Christian Lyngby; Flyvbjerg, Henrik; Møller, Ian Max

    2012-01-01

    Amplitude- and frequency-modulated waves of Ca2+ ions transmit information inside cells. Reactive Oxygen Species (ROS), specifically hydrogen peroxide, have been proposed to have a similar role in plant cells. We consider the feasibility of such an intracellular communication system in view of the physical and biochemical conditions in plant cells. As model system, we use a H2O2 signal originating at the plasma membrane (PM) and spreading through the cytosol. We consider two maximally simple types of signals, isolated pulses and harmonic oscillations. First we consider the basic limits on such signals as regards signal origin, frequency, amplitude, and distance. Then we establish the impact of ROS-removing enzymes on the ability of H2O2 to transmit signals. Finally, we consider to what extent cytoplasmic streaming distorts signals. This modeling allows us to predict the conditions under which diffusion-mediated signaling is possible. We show that purely diffusive transmission of intracellular information by H2O2 over a distance of 1 μm (typical distance between organelles, which may function as relay stations) is possible at frequencies well above 1 Hz, which is the highest frequency observed experimentally. This allows both frequency and amplitude modulation of the signal. Signaling over a distance of 10 μm (typical distance between the PM and the nucleus) may be possible, but requires high signal amplitudes or, equivalently, a very low detection threshold. Furthermore, at this longer distance a high rate of enzymatic degradation is required to make signaling at frequencies above 0.1 Hz possible. In either case, cytoplasmic streaming does not seriously disturb signals. We conclude that although purely diffusion-mediated signaling without relaying stations is theoretically possible, it is unlikely to work in practice, since it requires a much faster enzymatic degradation and a much lower cellular background concentration of H2O2 than observed

  18. Aesthetical Information Impact of a Literary Text.

    ERIC Educational Resources Information Center

    Malik, M. F.

    The aim of this study was to explore the aesthetic impact of a literary text on the human mind and to extend the knowledge on how and when the information from a book enters the human brain, and if and when it starts to be processed and, possibly, memorized. Readers' responses to aesthetic texts were measured through a series of biometric…

  19. Seconds After Impact: Insights from Diffusion Between Lechatelierite and Host Glass in Tektites and Experiments

    NASA Astrophysics Data System (ADS)

    Macris, C. A.; Badro, J.; Asimow, P. D.; Eiler, J. M.; Stolper, E. D.

    2014-09-01

    This study exploits the presence of lechatelierites in tektites to extract information about their thermal histories by investigating chemical diffusion between molten silica inclusions and surrounding felsic melt in natural tektites and experiments.

  20. Impact of molecular diffusion on the CO2 distribution and the temperature in the mesosphere

    NASA Astrophysics Data System (ADS)

    Chabrillat, Simon; Kockarts, Gaston; Fonteyn, Dominique; Brasseur, Guy

    2002-08-01

    Modelling the energy budget in the mesosphere and lower thermosphere requires a precise evaluation of CO2 distribution in this region. This distribution is primarily determined by competition between vertical eddy diffusion and molecular diffusion. A simple algorithm is proposed to take into account both processes, at all altitudes. Using the SOCRATES bi-dimensional model of the middle atmosphere, we show that molecular diffusion has a direct impact on CO2 vertical distribution down to approximately 80 km altitude, i.e. well into the mesosphere and below the turbopause altitude. A sensitivity study with regard to different aeronomical processes shows that molecular diffusion has the deepest influence in the mesospheric polar night region. Our model shows that molecular diffusion of CO2 is responsible for a polar night mesopause 12 K warmer than if this process was neglected. Hence, dynamical models should take this process in account across the whole mesospheric altitude range.

  1. Astrocytic Gliotransmitter: Diffusion Dynamics and Induction of Information Processing on Tripartite Synapses

    NASA Astrophysics Data System (ADS)

    Li, Jia-Jia; Du, Meng-Meng; Wang, Rong; Lei, Jin-Zhi; Wu, Ying

    Astrocytes have important functions in the central nervous system (CNS) and are significant in our understanding of the neuronal network. Astrocytes modulate neuronal firings at both single cell level of tripartite synapses and the neuron-glial network level. Astrocytes release adenosine triphosphate (ATP) and glutamate into the neuron-glial network. These gliotransmitters diffuse over the network to form long distance signals to regulate neuron firings. In this paper, we study a neuron-glial network model that includes a diffusion of astrocytic ATP and glutamate to investigate how long distance diffusion of the gliotransmitters affects the information processing in a neuronal network. We find that gliotransmitters diffusion can compensate for the failure of information processing of interneuron network firings induced by defectively coupled synapses. Moreover, we find that calcium waves in astrocyte network and firings in interneuron network are both sensitive to the glutamate diffusion rate and feedback intensities of astrocytes on interneurons.

  2. Blogviz: mapping the dynamics of information diffusion in blogspace

    NASA Astrophysics Data System (ADS)

    Lima, Manuel S.

    2006-01-01

    Blogviz is a visualization model for mapping the transmission and internal structure of top links across the blogosphere. It explores the idea of meme propagation by assuming a parallel with the spreading of most cited URLs in daily weblog entries. The main goal of Blogviz is to unravel hidden patterns in the topics diffusion process. What's the life cycle of a topic? How does it start and how does it evolve through time? Are topics constrained to a specific community of users? Who are the most influential and innovative blogs in any topic? Are there any relationships amongst topic proliferators?

  3. Argon diffusion in Apollo 16 impact glass spherules: Implications for 40Ar/39Ar dating of lunar impact events

    NASA Astrophysics Data System (ADS)

    Gombosi, David J.; Baldwin, Suzanne L.; Watson, E. Bruce; Swindle, Timothy D.; Delano, John W.; Roberge, Wayne G.

    2015-01-01

    The 40Ar/39Ar technique applied to impact glass has been used to date both terrestrial and lunar impact events. The ability to utilize the 40Ar/39Ar technique rests on the assumption that impact glasses are closed to the loss of daughter product, 40Ar∗, after formation. Diffusion experiments were performed on three Apollo 16 lunar impact glasses and yielded activation energies for 39Ar of ∼17 to 20 kcal mol-1 and log10(D0/a2) values of -5.2 to -6.0 s-1. The resulting diffusion coefficients are interpreted as minimum values and the Apollo 16 glass is probably some of the least retentive of lunar glasses, as the degree of non-bridging oxygen is at one end of the range in lunar glasses. At temperatures below the glass transition temperature (i.e., ∼660 °C), the data can be explained by volume diffusion from a single diffusion domain. Modeling shows that Apollo 16 composition glass could lose significant quantities of radiogenic argon (40Ar∗) (∼90-100% over 20-40 Myr assuming a diffusion domain size (a) of 75 μm) due to diurnal temperature variations on the lunar surface, although 40Ar∗ loss is highly sensitive to exposure duration and effective diffusion domain size. Modeling shows that loss from transient thermal events (e.g., heating to ∼200 °C for 102 yr duration) can also cause partial resetting of apparent 40Ar/39Ar ages. In small (a = 75 μm) glasses a maximum of 50-60% of 40Ar∗ is lost over 4 Ga when buried to depths corresponding to temperatures of -15 °C. Results indicate that caution should be exercised in interpreting lunar impact glass 40Ar/39Ar ages, as the assumption of closed system behavior may have been violated, particularly in glasses with low fractions of non-bridging oxygen.

  4. Effect of head impacts on diffusivity measures in a cohort of collegiate contact sport athletes

    PubMed Central

    Ford, James C.; Flashman, Laura A.; Maerlender, Arthur; Greenwald, Richard M.; Beckwith, Jonathan G.; Bolander, Richard P.; Tosteson, Tor D.; Turco, John H.; Raman, Rema; Jain, Sonia

    2014-01-01

    Objective: To determine whether exposure to repetitive head impacts over a single season affects white matter diffusion measures in collegiate contact sport athletes. Methods: A prospective cohort study at a Division I NCAA athletic program of 80 nonconcussed varsity football and ice hockey players who wore instrumented helmets that recorded the acceleration-time history of the head following impact, and 79 non–contact sport athletes. Assessment occurred preseason and shortly after the season with diffusion tensor imaging and neurocognitive measures. Results: There was a significant (p = 0.011) athlete-group difference for mean diffusivity (MD) in the corpus callosum. Postseason fractional anisotropy (FA) differed (p = 0.001) in the amygdala (0.238 vs 0.233). Measures of head impact exposure correlated with white matter diffusivity measures in several brain regions, including the corpus callosum, amygdala, cerebellar white matter, hippocampus, and thalamus. The magnitude of change in corpus callosum MD postseason was associated with poorer performance on a measure of verbal learning and memory. Conclusion: This study suggests a relationship between head impact exposure, white matter diffusion measures, and cognition over the course of a single season, even in the absence of diagnosed concussion, in a cohort of college athletes. Further work is needed to assess whether such effects are short term or persistent. PMID:24336143

  5. Learning Information Diffusion Model for Extracting Influential Nodes in a Social Network

    NASA Astrophysics Data System (ADS)

    Kimura, Masahiro; Saito, Kazumi; Nakano, Ryohei; Motoda, Hiroshi

    We address the problem of ranking influential nodes in complex social networks by estimating diffusion probabilities from observed information diffusion data using the popular independent cascade (IC) model. For this purpose we formulate the likelihood for information diffusion data which is a set of time sequence data of active nodes and propose an iterative method to search for the probabilities that maximizes this likelihood. We apply this to two real world social networks in the simplest setting where the probability is uniform for all the links, and show that when there is a reasonable amount of information diffusion data, the accuracy of the probability is outstandingly good, and the proposed method can predict the high ranked influential nodes much more accurately than the well studied conventional four heuristic methods.

  6. How multiple social networks affect user awareness: The information diffusion process in multiplex networks

    NASA Astrophysics Data System (ADS)

    Li, Weihua; Tang, Shaoting; Fang, Wenyi; Guo, Quantong; Zhang, Xiao; Zheng, Zhiming

    2015-10-01

    The information diffusion process in single complex networks has been extensively studied, especially for modeling the spreading activities in online social networks. However, individuals usually use multiple social networks at the same time, and can share the information they have learned from one social network to another. This phenomenon gives rise to a new diffusion process on multiplex networks with more than one network layer. In this paper we account for this multiplex network spreading by proposing a model of information diffusion in two-layer multiplex networks. We develop a theoretical framework using bond percolation and cascading failure to describe the intralayer and interlayer diffusion. This allows us to obtain analytical solutions for the fraction of informed individuals as a function of transmissibility T and the interlayer transmission rate θ . Simulation results show that interaction between layers can greatly enhance the information diffusion process. And explosive diffusion can occur even if the transmissibility of the focal layer is under the critical threshold, due to interlayer transmission.

  7. Assessment of diffuse transmission and reflection modes in near-infrared quantification, part 2: DIFFuse reflection information depth.

    PubMed

    Saeed, Muhanned; Probst, Leila; Betz, Gabriele

    2011-03-01

    Near-infrared spectroscopy offers tremendous advantages for pharmaceutical manufacturing as a fast and nondestructive method of quantitative and qualitative analysis. Content uniformity (end-product analytics) and process analytics are two important applications of the method. Diffuse reflection (DR) information depth (vertical sampling span) assessment is of equal importance in content prediction applications and to understand the effect of inhomogeneities in the sample. Three experiments were conducted: (a) 0.5 to 10.0 mm incremental thickness MCC tablets with constant porosity, (b) MCC/phenylbutazone (PBZ) double-layered (DL) tablets (PBZ layer 0%-100% in 0.5 mm steps), and (c) Comparison of placebo and 30% caffeine tablet cores with incremental film coating (film thickness of 0-0.35 mm). Incremental thickness and cluster analysis of DL tablets showed that DR information depth was <0.5 mm, whereas the data fitting from incremental coating showed that signal drop reached 50% at 0.05 to 0.07 mm, depending on the wavenumber and 90% signal drop (10% information content) can be seen between 0.20 and 0.25 mm without extrapolation. These results mean that DR mode for pharmaceutical tablets obtains spectral information from the very surface, and radiation is barely reflected back from beyond thin-film coatings, making it less useful than diffuse transmission mode for core content analysis, especially for thick-coated, multilayer, multicore, or highly inhomogeneous tablets.

  8. Subtle role of latency for information diffusion in online social networks

    NASA Astrophysics Data System (ADS)

    Xiong, Fei; Wang, Xi-Meng; Cheng, Jun-Jun

    2016-10-01

    Information diffusion in online social networks is induced by the event of forwarding information for users, and latency exists widely in user spreading behaviors. Little work has been done to reveal the effect of latency on the diffusion process. In this paper, we propose a propagation model in which nodes may suspend their spreading actions for a waiting period of stochastic length. These latent nodes may recover their activity again. Meanwhile, the mechanism of forwarding information is also introduced into the diffusion model. Mean-field analysis and numerical simulations indicate that our model has three nontrivial results. First, the spreading threshold does not correlate with latency in neither homogeneous nor heterogeneous networks, but depends on the spreading and refractory parameter. Furthermore, latency affects the diffusion process and changes the infection scale. A large or small latency parameter leads to a larger final diffusion extent, but the intrinsic dynamics is different. Large latency implies forwarding information rapidly, while small latency prevents nodes from dropping out of interactions. In addition, the betweenness is a better descriptor to identify influential nodes in the model with latency, compared with the coreness and degree. These results are helpful in understanding some collective phenomena of the diffusion process and taking measures to restrain a rumor in social networks. Project supported by the National Natural Science Foundation of China (Grant Nos. 61401015 and 61271308), the Fundamental Research Funds for the Central Universities, China (Grant No. 2014JBM018), and the Talent Fund of Beijing Jiaotong University, China (Grant No. 2015RC013).

  9. Epidemic model for information diffusion in web forums: experiments in marketing exchange and political dialog.

    PubMed

    Woo, Jiyoung; Chen, Hsinchun

    2016-01-01

    As social media has become more prevalent, its influence on business, politics, and society has become significant. Due to easy access and interaction between large numbers of users, information diffuses in an epidemic style on the web. Understanding the mechanisms of information diffusion through these new publication methods is important for political and marketing purposes. Among social media, web forums, where people in online communities disseminate and receive information, provide a good environment for examining information diffusion. In this paper, we model topic diffusion in web forums using the epidemiology model, the susceptible-infected-recovered (SIR) model, frequently used in previous research to analyze both disease outbreaks and knowledge diffusion. The model was evaluated on a large longitudinal dataset from the web forum of a major retail company and from a general political discussion forum. The fitting results showed that the SIR model is a plausible model to describe the diffusion process of a topic. This research shows that epidemic models can expand their application areas to topic discussion on the web, particularly social media such as web forums.

  10. Discovery of Super-Mediators of Information Diffusion in Social Networks

    NASA Astrophysics Data System (ADS)

    Saito, Kazumi; Kimura, Masahiro; Ohara, Kouzou; Motoda, Hiroshi

    We address the problem of discovering a different kind of influential nodes, which we call "super-mediator", i.e. those nodes which play an important role to pass the information to other nodes, and propose a method for discovering super-mediators from information diffusion samples without using a network structure. We divide the diffusion sequences in two groups (lower and upper), each assuming some probability distribution, find the best split by maximizing the likelihood, and rank the nodes in the upper sequences by the F-measure. We apply this measure to the information diffusion samples generated by two real networks, identify and rank the super-mediator nodes. We show that the high ranked super-mediators are also the high ranked influential nodes when the diffusion probability is large, i.e. the influential nodes also play a role of super-mediator for the other source nodes, and interestingly enough that when the high ranked super-mediators are different from the top ranked influential nodes, which is the case when the diffusion probability is small, those super-mediators become the high ranked influential nodes when the diffusion probability becomes larger. This finding will be useful to predict the influential nodes for the unexperienced spread of new information, e.g. spread of new acute contagion.

  11. Epidemic model for information diffusion in web forums: experiments in marketing exchange and political dialog.

    PubMed

    Woo, Jiyoung; Chen, Hsinchun

    2016-01-01

    As social media has become more prevalent, its influence on business, politics, and society has become significant. Due to easy access and interaction between large numbers of users, information diffuses in an epidemic style on the web. Understanding the mechanisms of information diffusion through these new publication methods is important for political and marketing purposes. Among social media, web forums, where people in online communities disseminate and receive information, provide a good environment for examining information diffusion. In this paper, we model topic diffusion in web forums using the epidemiology model, the susceptible-infected-recovered (SIR) model, frequently used in previous research to analyze both disease outbreaks and knowledge diffusion. The model was evaluated on a large longitudinal dataset from the web forum of a major retail company and from a general political discussion forum. The fitting results showed that the SIR model is a plausible model to describe the diffusion process of a topic. This research shows that epidemic models can expand their application areas to topic discussion on the web, particularly social media such as web forums. PMID:26839759

  12. Coupled information diffusion--pest dynamics models predict delayed benefits of farmer cooperation in pest management programs.

    PubMed

    Rebaudo, François; Dangles, Olivier

    2011-10-01

    Worldwide, the theory and practice of agricultural extension system have been dominated for almost half a century by Rogers' "diffusion of innovation theory". In particular, the success of integrated pest management (IPM) extension programs depends on the effectiveness of IPM information diffusion from trained farmers to other farmers, an important assumption which underpins funding from development organizations. Here we developed an innovative approach through an agent-based model (ABM) combining social (diffusion theory) and biological (pest population dynamics) models to study the role of cooperation among small-scale farmers to share IPM information for controlling an invasive pest. The model was implemented with field data, including learning processes and control efficiency, from large scale surveys in the Ecuadorian Andes. Our results predict that although cooperation had short-term costs for individual farmers, it paid in the long run as it decreased pest infestation at the community scale. However, the slow learning process placed restrictions on the knowledge that could be generated within farmer communities over time, giving rise to natural lags in IPM diffusion and applications. We further showed that if individuals learn from others about the benefits of early prevention of new pests, then educational effort may have a sustainable long-run impact. Consistent with models of information diffusion theory, our results demonstrate how an integrated approach combining ecological and social systems would help better predict the success of IPM programs. This approach has potential beyond pest management as it could be applied to any resource management program seeking to spread innovations across populations.

  13. Coupled information diffusion--pest dynamics models predict delayed benefits of farmer cooperation in pest management programs.

    PubMed

    Rebaudo, François; Dangles, Olivier

    2011-10-01

    Worldwide, the theory and practice of agricultural extension system have been dominated for almost half a century by Rogers' "diffusion of innovation theory". In particular, the success of integrated pest management (IPM) extension programs depends on the effectiveness of IPM information diffusion from trained farmers to other farmers, an important assumption which underpins funding from development organizations. Here we developed an innovative approach through an agent-based model (ABM) combining social (diffusion theory) and biological (pest population dynamics) models to study the role of cooperation among small-scale farmers to share IPM information for controlling an invasive pest. The model was implemented with field data, including learning processes and control efficiency, from large scale surveys in the Ecuadorian Andes. Our results predict that although cooperation had short-term costs for individual farmers, it paid in the long run as it decreased pest infestation at the community scale. However, the slow learning process placed restrictions on the knowledge that could be generated within farmer communities over time, giving rise to natural lags in IPM diffusion and applications. We further showed that if individuals learn from others about the benefits of early prevention of new pests, then educational effort may have a sustainable long-run impact. Consistent with models of information diffusion theory, our results demonstrate how an integrated approach combining ecological and social systems would help better predict the success of IPM programs. This approach has potential beyond pest management as it could be applied to any resource management program seeking to spread innovations across populations. PMID:22022258

  14. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 8: The role of the information intermediary in the diffusion of aerospace knowledge

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Kennedy, John M.; Barclay, Rebecca O.

    1990-01-01

    The United States aerospace industry is experiencing profound changes created by a combination of domestic actions and circumstances such as airline deregulation. Other changes result from external trends such as emerging foreign competition. These circumstances intensify the need to understand the production, transfer, and utilization of knowledge as a precursor to the rapid diffusion of technology. Presented here is a conceptual framework for understanding the diffusion of technology. A conceptual framework is given for understanding the diffusion of aerospace knowledge. The framework focuses on the information channels and members of the social system associated with the aerospace knowledge diffusion process, placing particular emphasis on aerospace librarians as information intermediaries.

  15. Axonal and glial microstructural information obtained with diffusion-weighted magnetic resonance spectroscopy at 7T

    PubMed Central

    Ronen, Itamar; Ercan, Ece; Webb, Andrew

    2013-01-01

    Diffusion-weighted magnetic resonance spectroscopy (DWS) offers unique access to compartment-specific microstructural information on tissue, and potentially sensitive detection of compartment-specific changes in disease. The specificity of DWS is, however, offset by its relative low sensitivity, intrinsic to all MRS-based methods, and further exacerbated by the signal loss due to the diffusion weighting and long echo times. In this work we first provide an experimental example for the type of compartment-specific information that can be obtained with DWS from a small volume of interest (VOI) in brain white matter. We then propose and discuss a strategy for the analysis of DWS data, which includes the use of models of diffusion in compartments with simple geometries. We conclude with a broader discussion of the potential role of DWS in the characterization of tissue microstructure and the complementarity of DWS with less-specific but more sensitive microstructural tools such as diffusion tensor imaging. PMID:23493316

  16. Diffusion of information about genetic risk within families.

    PubMed

    Ayme, Ségolène; Macquart-Moulin, Geneviève; Julian-Reynier, Claire; Chabal, Françoise; Giraud, Francis

    1993-01-01

    Recent developments in genetics are likely to exacerbate the ethical issues in clinical practice, especially with regard to privacy and disclosure of genetic information. To evaluate the behaviour of patients with respect to transmitting carrier information, we undertook a survey of 283 families with a balanced chromosomal rearrangement as a model. In these families, 1816 relatives were considered at risk and 806 of them were karyotyped (44.4%). The percentage of karyotypes performed is significantly related to the number of living children of the index couple, the reason for referral, the nature of the anomaly, the training of the counsellor and the age of the index case. This study shows the limits of the screening of at risk individuals within families, based on the willingness of the patients, and addresses practical and ethical issues around family disclosure in medical genetics.

  17. Diffusion of information about neurofibromatosis type 1 DNA testing.

    PubMed

    Hofman, K J

    1994-02-01

    There is little information available as to how individuals with genetic disorders receive information about the availability of DNA tests and what effect this has on their utilization. The purpose of this study was to survey centers where some individuals with neurofibromatosis type 1 (NF 1) are cared for, to establish how this type of information was disseminated. In 1990 announcement of the availability of testing for familial NF 1 was published in a newsletter of the National Neurofibromatosis Foundation (NNFF) and sent to individuals with NF 1 or NF 2 and their families, professionals, and NF centers in North America. Two years later these centers were surveyed to determine whether they had notified their patients of test availability. Of the 46 responding centers, 65% indicated they had attempted to notify their patients. The majority (80%) notified patients on an individual basis in clinic. The rest did so either on an individual basis in the clinic or by telephone or by letter or by a combination of these. Based on a survey response rate of 56% and approximately 1,000 enquiries received by the NNFF from families and physicians, it is concluded that 1) factors other than knowledge of test availability determined whether DNA testing for NF 1 was utilized; 2) some centers used testing more frequently than others; 100% of the referrals came from 40% of the centers, with 15% of referrals coming from a single center; 3) a significant percentage (35%) of NF centers did not inform their patients that DNA testing was available.

  18. Information diffusion, Facebook clusters, and the simplicial model of social aggregation: a computational simulation of simplicial diffusers for community health interventions.

    PubMed

    Kee, Kerk F; Sparks, Lisa; Struppa, Daniele C; Mannucci, Mirco A; Damiano, Alberto

    2016-01-01

    By integrating the simplicial model of social aggregation with existing research on opinion leadership and diffusion networks, this article introduces the constructs of simplicial diffusers (mathematically defined as nodes embedded in simplexes; a simplex is a socially bonded cluster) and simplicial diffusing sets (mathematically defined as minimal covers of a simplicial complex; a simplicial complex is a social aggregation in which socially bonded clusters are embedded) to propose a strategic approach for information diffusion of cancer screenings as a health intervention on Facebook for community cancer prevention and control. This approach is novel in its incorporation of interpersonally bonded clusters, culturally distinct subgroups, and different united social entities that coexist within a larger community into a computational simulation to select sets of simplicial diffusers with the highest degree of information diffusion for health intervention dissemination. The unique contributions of the article also include seven propositions and five algorithmic steps for computationally modeling the simplicial model with Facebook data.

  19. The impact of technology diffusion on treatment for prostate cancer

    PubMed Central

    Schroeck, Florian R.; Kaufman, Samuel R.; Jacobs, Bruce L.; Zhang, Yun; Weizer, Alon Z.; Montgomery, Jeffrey S.; Gilbert, Scott M.; Strope, Seth A.; Hollenbeck, Brent K.

    2014-01-01

    Background Use of local therapy for prostate cancer may increase because of the perceived advantages of new technologies such as intensity-modulated radiotherapy (IMRT) and robotic prostatectomy. Objective To examine the association of market-level technological capacity with receipt of local therapy. Design Retrospective cohort. Subjects Patients with localized prostate cancer who were diagnosed between 2003 and 2007 (n=59,043) from the Surveillance Epidemiology and End Results (SEER) – Medicare database. Measures We measured the capacity for delivering treatment with new technology as the number of providers offering robotic prostatectomy or IMRT per population in a market (hospital referral region). The association of this measure with receipt of prostatectomy, radiotherapy, or observation was examined with multinomial logistic regression. Results For each 1,000 patients diagnosed with prostate cancer, 174 underwent prostatectomy, 490 radiotherapy, and 336 were observed. Markets with high robotic prostatectomy capacity had higher use of prostatectomy (146 vs. 118 per 1,000 men, p=0.008) but a trend towards decreased use of radiotherapy (574 vs. 601 per 1,000 men, p=0.068), resulting in a stable rate of local therapy. High versus low IMRT capacity did not significantly impact use of prostatectomy (129 vs. 129 per 1,000 men, p=0.947) and radiotherapy (594 vs. 585 per 1,000 men, p=0.579). Conclusions Although there was a small shift from radiotherapy to prostatectomy in markets with high robotic prostatectomy capacity, increased capacity for both robotic prostatectomy and IMRT did not change the overall rate of local therapy. Our findings temper concerns that new technology spurs additional therapy of prostate cancer. PMID:24226306

  20. Impact of mechanical deformation on guest diffusion in zeolitic imidazolate frameworks.

    PubMed

    Zheng, Bin; Wang, Lian Li; Hui, Jia Chen; Du, Lifei; Du, Huiling; Zhu, Ming

    2016-03-14

    The effect of the mechanical deformation of metal-organic frameworks on guest diffusion was investigated by employing molecular dynamics simulations. Two basic deformation modes, uniaxial tensile and shear deformation, were considered. The computed shear modulus of the zeolitic imidazolate framework-8 (ZIF-8) model system was much lower than the Young's modulus, which is in agreement with the experimental results. The diffusion rate in ZIF-8 was calculated for two types of guest molecules: the nonpolar H2 and the quadrupolar CO2. Under tensile strain, the diffusion of both H2 and CO2 was found to be enhanced, whereas the diffusion rates did not change significantly under shear loading. The evolution of the internal structure of ZIF-8 was studied to determine its effect on guest diffusion. The organic-inorganic connection was identified as the source of the framework's flexibility, and therefore we focused on the N-Zn bond and the N-Zn-N angle. Under stretching deformation, the N-Zn bond is elongated and the N-Zn-N angle remains constant. Thus, the length of the C2-C2 long bond, determining the size of the 6-membered ring (6MR) gate, increases and the gate is opened, allowing for faster guest diffusion. Under shear deformation, the N-Zn bond length changes very little and the N-Zn-N angle is distorted. This results in the occurrence of three peaks in the C2-C2 bond length distribution. Although the 6MR gate is distorted, the variation of its average size is small, resulting in a very small effect on the guest diffusivity. In addition, we found that the fluctuation of the ZIF-8 cell can enhance the impact of the mechanical deformation of the host on guest diffusion.

  1. The Impact of Biofilms on the Process of Back Diffusion From a Contaminated Rock Matrix

    NASA Astrophysics Data System (ADS)

    Yungwirth, G. A.; Novakowski, K. S.; Ross, N.

    2005-12-01

    are based on a cylindrical coordinate system where one equation was developed for the rock and another for the biofilm. The solution was found using the Laplace Transform method. Preliminary results show substantial biofilm growth, confirming that the method of biofilm stimulation is viable. Preliminary analysis of data from the diffusion experiments shows the impact of biofilm presence on back diffusion to be profound.

  2. Long-range global warming impact of gaseous diffusion plant operation

    SciTech Connect

    Trowbridge, L.D.

    1992-09-01

    The DOE gaseous diffusion plant complex makes extensive use of CFC-114 as a primary coolant. As this material is on the Montreal Protocol list of materials scheduled for production curtailment, a substitute must be found. In addition to physical cooling properties, the gaseous diffusion application imposes the unique requirement of chemical inertness to fluorinating agents. This has narrowed the selection of a near-term substitute to two fully fluorinated material, FC-318 and FC-3110, which are likely to be strong, long-lived greenhouse gases. In this document, calculations are presented showing, for a number of plausible scenarios of diffusion plant operation and coolant replacement strategy, the future course of coolant use, greenhouse gas emissions (including coolant and power-related indirect CO{sub 2} emissions), and the consequent global temperature impacts of these scenarios.

  3. Spatial and Social Diffusion of Information and Influence: Models and Algorithms

    ERIC Educational Resources Information Center

    Doo, Myungcheol

    2012-01-01

    In this dissertation research, we argue that spatial alarms and activity-based social networks are two fundamentally new types of information and influence diffusion channels. Such new channels have the potential of enriching our professional experiences and our personal life quality in many unprecedented ways. First, we develop an activity driven…

  4. Whisper: Tracing the Spatiotemporal Process of Information Diffusion in Real Time.

    PubMed

    Cao, Nan; Lin, Yu-Ru; Sun, Xiaohua; Lazer, D; Liu, Shixia; Qu, Huamin

    2012-12-01

    When and where is an idea dispersed? Social media, like Twitter, has been increasingly used for exchanging information, opinions and emotions about events that are happening across the world. Here we propose a novel visualization design, "Whisper", for tracing the process of information diffusion in social media in real time. Our design highlights three major characteristics of diffusion processes in social media: the temporal trend, social-spatial extent, and community response of a topic of interest. Such social, spatiotemporal processes are conveyed based on a sunflower metaphor whose seeds are often dispersed far away. In Whisper, we summarize the collective responses of communities on a given topic based on how tweets were retweeted by groups of users, through representing the sentiments extracted from the tweets, and tracing the pathways of retweets on a spatial hierarchical layout. We use an efficient flux line-drawing algorithm to trace multiple pathways so the temporal and spatial patterns can be identified even for a bursty event. A focused diffusion series highlights key roles such as opinion leaders in the diffusion process. We demonstrate how our design facilitates the understanding of when and where a piece of information is dispersed and what are the social responses of the crowd, for large-scale events including political campaigns and natural disasters. Initial feedback from domain experts suggests promising use for today's information consumption and dispersion in the wild.

  5. Codimension-Two Bifurcation, Chaos and Control in a Discrete-Time Information Diffusion Model

    NASA Astrophysics Data System (ADS)

    Ren, Jingli; Yu, Liping

    2016-07-01

    In this paper, we present a discrete model to illustrate how two pieces of information interact with online social networks and investigate the dynamics of discrete-time information diffusion model in three types: reverse type, intervention type and mutualistic type. It is found that the model has orbits with period 2, 4, 6, 8, 12, 16, 20, 30, quasiperiodic orbit, and undergoes heteroclinic bifurcation near 1:2 point, a homoclinic structure near 1:3 resonance point and an invariant cycle bifurcated by period 4 orbit near 1:4 resonance point. Moreover, in order to regulate information diffusion process and information security, we give two control strategies, the hybrid control method and the feedback controller of polynomial functions, to control chaos, flip bifurcation, 1:2, 1:3 and 1:4 resonances, respectively, in the two-dimensional discrete system.

  6. Theoretical approach to characterize the non-Markovianity and diffusion through the influx of the information

    NASA Astrophysics Data System (ADS)

    Berrada, K.

    2016-08-01

    In this paper, we study the Fisher information for a quantum system consisting of two identical qubits, each of them locally interacting with a bosonic reservoir in the same environment for non-Markovian open, dissipative quantum system. Based on the influx of the information, we propose an information-theoretical approach for characterizing the time-dependent memory effect of environment and diffusion function under the effect of the physical parameters. More precisely, an interesting monotonic relation between the time derivative of quantum Fisher information (QFI) and diffusion function behavior is observed during the time evolution. The phenomenon is that the QFI, namely the precision of estimation, changes dramatically with the environment structure. The dependence of the physical parameters shows that the increasing in the temperature will damage the amount of the QFI with respect of the ratio between the reservoir cutoff frequency and the system oscillation frequency.

  7. Impact of network topology on cationic diffusion and hardness of borate glass surfaces

    NASA Astrophysics Data System (ADS)

    Smedskjaer, Morten M.; Mauro, John C.; Sen, Sabyasachi; Deubener, Joachim; Yue, Yuanzheng

    2010-10-01

    The connection between bulk glass properties and network topology is now well established. However, there has been little attention paid to the impact of network topology on the surface properties of glass. In this work, we report the impact of the network topology on both the transport properties (such as cationic inward diffusion) and the mechanical properties (such as hardness) of borate glasses with modified surfaces. We choose soda lime borate systems as the object of this study because of their interesting topological features, e.g., boron anomaly. An inward diffusion mechanism is employed to modify the glass surface compositions and hence the surface topology. We show that accurate quantitative predictions of the hardness of the modified surfaces can be made using topological constraint theory with temperature-dependent constraints. Experimental results reveal that Ca2+ diffusion is most intense in glasses with lowest BO4 fraction, whereas Na+ diffusion is only significant when nonbridging oxygens start to form. These phenomena are interpreted in terms of the atomic packing and the local electrostatic environments of the cations.

  8. Impact of diffuse light on isoprene and monoterpene emissions from a mixed temperate forest

    NASA Astrophysics Data System (ADS)

    Laffineur, Q.; Aubinet, M.; Schoon, N.; Amelynck, C.; Müller, J.-F.; Dewulf, J.; Steppe, K.; Heinesch, B.

    2013-08-01

    This study investigated the impact of diffuse light on canopy scale emission of isoprene and monoterpenes measured continuously above a mixed temperate forest, using the disjunct eddy-covariance by mass scanning technique with a proton transfer reaction-mass spectrometer (PTR-MS) instrument. To assess this impact, the relationship between emissions/radiation and emissions/gross primary production (GPP) under clear sky and cloudy conditions were analysed. Under cloudy conditions (high proportion of diffuse radiation), the isoprene and monoterpene fluxes were enhanced compared to clear sky conditions (low proportion of diffuse radiation) at equivalent temperature and above-canopy total radiation. The whole-canopy enzymatic activity of the metabolic isoprene production pathway, however, was suggested to be lower under cloudy conditions than under clear sky conditions at equivalent temperature. The mechanisms behind these observations are probably linked to the better penetration of diffuse radiation in the canopy. Shade leaves/needles receive more radiation in cloudy conditions than in clear sky conditions, thereby inducing the observed effects.

  9. Acid diffusion, standing waves, and information theory: a molecular-scale model of chemically amplified resist

    NASA Astrophysics Data System (ADS)

    Trefonas, Peter, III; Allen, Mary T.

    1992-06-01

    Shannon's information theory is adapted to analyze the photolithographic process, defining the mask pattern as the prior state. Definitions and constraints to the general theory are developed so that the information content at various stages of the lithographic process can be described. Its application is illustrated by exploring the information content within projected aerial images and resultant latent images. Next, a 3-dimensional molecular scale model of exposure, acid diffusion, and catalytic crosslinking in acid-hardened resists (AHR) is presented. In this model, initial positions of photogenerated acids are determined by probability functions generated from the aerial images and the local light intensity in the film. In order to simulate post-exposure baking processes, acids are diffused in a random walk manner, for which the catalytic chain length and the average distance between crosslinks can be set. Crosslink locations are defined in terms of the topologically minimized number required to link different chains. The size and location of polymer chains involved in a larger scale crosslinked network is established and related to polymer solubility. In this manner, the nature of the crosslinked latent image can be established. Good correlation with experimental data is found for the calculated percent insolubilization as a function of dose when the rms acid diffusion length is about 500 angstroms. Information analysis is applied in detail to the specific example of AHR chemistry. The information contained within the 3-D crosslinked latent image is explored as a function of exposure dose, catalytic chain length, average distance between crosslinks. Eopt (the exposure dose which optimizes the information contained within the latent image) was found to vary with catalytic chain length in a manner similar to that observed experimentally in a plot of E90 versus post-exposure bake time. Surprisingly, the information content of the crosslinked latent image remains

  10. Simultaneous registration of structural and diffusion weighed images using the full DTI information

    NASA Astrophysics Data System (ADS)

    Nadeau, Hélène; Chai, Yaqiong; Thompson, Paul; Leporé, Natasha

    2015-01-01

    Banks of high-quality, multimodal neurological images offer new possibilities for analyses based on brain registration. To take full advantage of these, current algorithms should be significantly enhanced. We present here a new brain registration method driven simultaneously by the structural intensity and the total diffusion information of MRI scans. Using the two modalities together allows for a better alignment of general and specific aspects of the anatomy. Furthermore, keeping the full diffusion tensor in the cost function, rather than only some of its scalar measures, will allow for a thorough statistical analysis once the Jacobian of the transformation is obtained.

  11. Modeling bee swarming behavior through diffusion adaptation with asymmetric information sharing

    NASA Astrophysics Data System (ADS)

    Li, Jinchao; Sayed, Ali H.

    2012-12-01

    Honeybees swarm when they move to a new site for their hive. During the process of swarming, their behavior can be analyzed by classifying them as informed bees or uninformed bees, where the informed bees have some information about the destination while the uninformed bees follow the informed bees. The swarm's movement can be viewed as a network of mobile nodes with asymmetric information exchange about their destination. In these networks, adaptive and mobile agents share information on the fly and adapt their estimates in response to local measurements and data shared with neighbors. Diffusion adaptation is used to model the adaptation process in the presence of asymmetric nodes and noisy data. The simulations indicate that the models are able to emulate the swarming behavior of bees under varied conditions such as a small number of informed bees, sharing of target location, sharing of target direction, and noisy measurements.

  12. Impact of Information Entropy on Teaching Effectiveness

    ERIC Educational Resources Information Center

    Wang, Zhi-guo

    2007-01-01

    Information entropy refers to the process in which information is sent out from the information source, transmitted through information channel and acquired by information sink, while the teaching process is the one of transmitting teaching information from teachers and teaching material to students. How to improve teaching effectiveness is…

  13. Impact of the Diffusion of Microtubule-Associated Protein EB1 on Kinesin Translocation in Vitro

    NASA Astrophysics Data System (ADS)

    Lopez, Benjamin; Valentine, Megan

    2014-03-01

    Using the slowly hydrolyzable GTP analog GMPCPP, we polymerize microtubules that recapitulate the end binding behavior of EB1 along their entire length, and investigate the impact of EB1 on kinesin translocation. Through direct observation of single molecules of EB1 fused to GFP, we find that EB1 diffuses along the microtubule lattice, and that the presence of taxol affects the rate of diffusion. To test whether EB1 presence and diffusion has an effect on kinesin-driven cargo transport, we observe quantum dot labeled kinesins walking on microtubules assembled with GMPCPP and taxol and coated with EB1. We find that the addition of EB1 significantly reduces kinesin speed compared to the no EB1 condition, but when microtubules stabilized by both taxol and GMPCPP are used, the speed reduction is nearly abolished. Our data suggest a new possible mechanism for the regulation of kinesin function by EB1 in which kinesin speed is directly modulated through the interference of EB1 diffusion. Our results also raise important questions about the effects of taxol on microtubule-MAP interactions.

  14. Maximizing Information Diffusion in the Cyber-physical Integrated Network †

    PubMed Central

    Lu, Hongliang; Lv, Shaohe; Jiao, Xianlong; Wang, Xiaodong; Liu, Juan

    2015-01-01

    Nowadays, our living environment has been embedded with smart objects, such as smart sensors, smart watches and smart phones. They make cyberspace and physical space integrated by their abundant abilities of sensing, communication and computation, forming a cyber-physical integrated network. In order to maximize information diffusion in such a network, a group of objects are selected as the forwarding points. To optimize the selection, a minimum connected dominating set (CDS) strategy is adopted. However, existing approaches focus on minimizing the size of the CDS, neglecting an important factor: the weight of links. In this paper, we propose a distributed maximizing the probability of information diffusion (DMPID) algorithm in the cyber-physical integrated network. Unlike previous approaches that only consider the size of CDS selection, DMPID also considers the information spread probability that depends on the weight of links. To weaken the effects of excessively-weighted links, we also present an optimization strategy that can properly balance the two factors. The results of extensive simulation show that DMPID can nearly double the information diffusion probability, while keeping a reasonable size of selection with low overhead in different distributed networks. PMID:26569254

  15. Impacts by point and diffuse micropollutant sources on the stream water quality at catchment scale

    NASA Astrophysics Data System (ADS)

    Petersen, M. F.; Eriksson, E.; Binning, P. J.; Bjerg, P. L.

    2012-04-01

    The water quality of surface waters is threatened by multiple anthropogenic pollutants and the large variety of pollutants challenges the monitoring and assessment of the water quality. The aim of this study was to characterize and quantify both point and diffuse sources of micropollutants impacting the water quality of a stream at catchment scale. Grindsted stream in western Jutland, Denmark was used as a study site. The stream passes both urban and agricultural areas and is impacted by severe groundwater contamination in Grindsted city. Along a 12 km reach of Grindsted stream, the potential pollution sources were identified including a pharmaceutical factory site with a contaminated old drainage ditch, two waste deposits, a wastewater treatment plant, overflow structures, fish farms, industrial discharges and diffuse agricultural and urban sources. Six water samples were collected along the stream and analyzed for general water quality parameters, inorganic constituents, pesticides, sulfonamides, chlorinated solvents, BTEXs, and paracetamol and ibuprofen. The latter two groups were not detected. The general water quality showed typical conditions for a stream in western Jutland. Minor impacts by releases of organic matter and nutrients were found after the fish farms and the waste water treatment plant. Nickel was found at concentrations 5.8 - 8.8 μg/l. Nine pesticides and metabolites of both agricultural and urban use were detected along the stream; among these were the two most frequently detected and some rarely detected pesticides in Danish water courses. The concentrations were generally consistent with other findings in Danish streams and in the range 0.01 - 0.09 μg/l; except for metribuzin-diketo that showed high concentrations up to 0.74 μg/l. The groundwater contamination at the pharmaceutical factory site, the drainage ditch and the waste deposits is similar in composition containing among others sulfonamides and chlorinated solvents (including vinyl

  16. [The differentiation between identity crisis and identity diffusion and its impact on treatment].

    PubMed

    Foelsch, Pamela A; Odom, Anna; Arena, Helen; Krischer, Maya K; Schmeck, Klaus; Schlüter-Müller, Susanne

    2010-01-01

    The differentiation between an identity crisis, a transient phenomenon that usually results (after resolution) in a well-integrated identity with flexible and adaptive functioning, and an identity diffusion that is viewed as a basis for subsequent personality pathology, has a major impact on the selection of a treatment method. A new treatment method (Adolescent Identity Treatment, AIT), a modification of Transference Focused Psychotherapy, was developed to treat adolescents with identity diffusion in order to improve their relationships with friends, parents, and teachers and to help them acquire positive self-esteem, clarify life goals and establish a stable identity. In a case study we describe the basic approaches of AIT in assessment and treatment.

  17. Image classification using multiscale information fusion based on saliency driven nonlinear diffusion filtering.

    PubMed

    Hu, Weiming; Hu, Ruiguang; Xie, Nianhua; Ling, Haibin; Maybank, Stephen

    2014-04-01

    In this paper, we propose saliency driven image multiscale nonlinear diffusion filtering. The resulting scale space in general preserves or even enhances semantically important structures such as edges, lines, or flow-like structures in the foreground, and inhibits and smoothes clutter in the background. The image is classified using multiscale information fusion based on the original image, the image at the final scale at which the diffusion process converges, and the image at a midscale. Our algorithm emphasizes the foreground features, which are important for image classification. The background image regions, whether considered as contexts of the foreground or noise to the foreground, can be globally handled by fusing information from different scales. Experimental tests of the effectiveness of the multiscale space for the image classification are conducted on the following publicly available datasets: 1) the PASCAL 2005 dataset; 2) the Oxford 102 flowers dataset; and 3) the Oxford 17 flowers dataset, with high classification rates. PMID:24569440

  18. DIFFUSE AND FOCAL CORTICOSPINAL TRACT DISEASE AND ITS IMPACT ON PATIENT DISABILITY IN MULTIPLE SCLEROSIS

    PubMed Central

    Tovar-Moll, Fernanda; Evangelou, Iordanis E.; Chiu, Annie W.; Auh, Sungyoung; Chen, Christina; Ehrmantraut, Mary; Ohayon, Joan M.; Richert, Nancy; Bagnato, Francesca

    2014-01-01

    Background and Purpose We investigated the impact of focal and diffuse corticospinal tracts damage on sensory-motor disability in multiple sclerosis (MS) patients. Methods Twenty-five MS patients underwent 3.0 Tesla (3T) magnetic resonance imaging with diffusion tensor imaging (DTI). The Expanded Disability Status Scale (EDSS) and the Timed 25-Foot Walk test (T25FW) quantified patient physical disability. Fractional anisotropy (FA) and mean diffusivity (MD) of the corticospinal tracts, whole brain and corticospinal tracts lesion volume were also computed. Spearman rank correlation analyses measured the associations between DTI-derived metrics and other measures of disease. Partial correlation analyses between DTI and disability measures were performed and corrected for lesion volumes as appropriate. Results Significant associations were seen between FA of the corticospinal tracts and EDSS (r =−0.500, p =0.0011), motor-EDSS (r = −0.519, p=0.008), and T25WF (r=−0.637, p =0.001) scores and MD of the corticospinal tracts and motor-EDSS (r=0.469, p=0.018) and T25WF (r=0.428, p=0.033) scores. When correcting for lesion volumes, only the association between FA of the corticospinal tracts and EDSS (p≤0.01, r≤ −0.516) or motor-EDSS score (p=0.03, r=−0.468,) persisted. Conclusions DTI at 3T shows that the impact of diffuse corticospinal tracts disease on sensory-motor disability is greatly mediated by focal lesions in MS. PMID:25318661

  19. The impact of gradient strength on in vivo diffusion MRI estimates of axon diameter.

    PubMed

    Huang, Susie Y; Nummenmaa, Aapo; Witzel, Thomas; Duval, Tanguy; Cohen-Adad, Julien; Wald, Lawrence L; McNab, Jennifer A

    2015-02-01

    Diffusion magnetic resonance imaging (MRI) methods for axon diameter mapping benefit from higher maximum gradient strengths than are currently available on commercial human scanners. Using a dedicated high-gradient 3T human MRI scanner with a maximum gradient strength of 300 mT/m, we systematically studied the effect of gradient strength on in vivo axon diameter and density estimates in the human corpus callosum. Pulsed gradient spin echo experiments were performed in a single scan session lasting approximately 2h on each of three human subjects. The data were then divided into subsets with maximum gradient strengths of 77, 145, 212, and 293 mT/m and diffusion times encompassing short (16 and 25 ms) and long (60 and 94 ms) diffusion time regimes. A three-compartment model of intra-axonal diffusion, extra-axonal diffusion, and free diffusion in cerebrospinal fluid was fitted to the data using a Markov chain Monte Carlo approach. For the acquisition parameters, model, and fitting routine used in our study, it was found that higher maximum gradient strengths decreased the mean axon diameter estimates by two to three fold and decreased the uncertainty in axon diameter estimates by more than half across the corpus callosum. The exclusive use of longer diffusion times resulted in axon diameter estimates that were up to two times larger than those obtained with shorter diffusion times. Axon diameter and density maps appeared less noisy and showed improved contrast between different regions of the corpus callosum with higher maximum gradient strength. Known differences in axon diameter and density between the genu, body, and splenium of the corpus callosum were preserved and became more reproducible at higher maximum gradient strengths. Our results suggest that an optimal q-space sampling scheme for estimating in vivo axon diameters should incorporate the highest possible gradient strength. The improvement in axon diameter and density estimates that we demonstrate from

  20. Replacement of chlorofluorocarbons at the DOE gaseous diffusion plants: An assessment of global impacts

    SciTech Connect

    Socolof, M.L.; McCold, L.N.; Saylor, R.E.

    1997-01-01

    Three gaseous diffusion plants (GDPs) for enriching uranium maintain a large inventory of chlorofluorocarbon-114 (CFC-114) as a coolant. To address the continued use of CFC-114, an ozone-depleting substance, the US Department of Energy (DOE) considered introducing perfluorocarbons (PFCs) by the end of 1995. These PFCs would not contribute to stratospheric ozone depletion but would be larger contributors to global warming than would CFC-114. The paper reports the results of an assessment of the global impacts of four alternatives for modifying GDP coolant system operations over a three-year period beginning in 1996. The overall contribution of GDP coolant releases to impacts on ozone depletion and global warming were quantified by parameters referred to as ozone-depletion impact and global-warming impact. The analysis showed that these parameters could be used as surrogates for predicting global impacts to all resources and could provide a framework for assessing environmental impacts of a permanent coolant replacement, eliminating the need for subsequent resource-specific analyses.

  1. An information diffusion model based on retweeting mechanism for online social media

    NASA Astrophysics Data System (ADS)

    Xiong, Fei; Liu, Yun; Zhang, Zhen-jiang; Zhu, Jiang; Zhang, Ying

    2012-06-01

    To characterize information propagation on online microblogs, we propose a diffusion model (SCIR) which contains four possible states: Susceptible, contacted, infected and refractory. Agents that read the information but have not decided to spread it, stay in the contacted state. They may become infected or refractory, and both the infected and refractory state are stable. Results show during the evolution process, more contacted agents appear in scale-free networks than in regular lattices. The degree based density of infected agents increases with the degree monotonously, but larger average network degree doesn't always mean less relaxation time.

  2. Replacement of chlorofluorocarbons (CFCs) at the DOE gaseous diffusion plants: An assessment of global impacts

    SciTech Connect

    Socolof, M.L.; Saylor, R.E.; McCold, L.N.

    1994-06-01

    The US Department of Energy (DOE) formerly operated two gaseous diffusion plants (GDPs) for enriching uranium and maintained a third shutdown GDP. These plants maintain a large inventory of dichlorotetrafluorethane (CFC-114), a cholorofluorocarbon (CFC), as a coolant. The paper evaluates the global impacts of four alternatives to modify GDP coolant system operations for a three-year period beginning in 1996. Interim modification of GDP coolant system operations has the potential to reduce stratospheric ozone depletion from GDP coolant releases while a permanent solution is studied.

  3. Positioning Education in the Information Society: The Transnational Diffusion of the Information and Communication Technology Curriculum

    ERIC Educational Resources Information Center

    Ham, Seung-Hwan; Cha, Yun-Kyung

    2009-01-01

    One of the most distinctive qualities that characterize present-day society is the social fact that people are shifting to the information age. In recent years, they have witnessed remarkable developments in information and communication technology (ICT), in which microelectronics, computers, and telecommunications have converged. Transnational…

  4. Impact of Information Technology in Academia

    ERIC Educational Resources Information Center

    Ranjan, Jayanthi

    2008-01-01

    Purpose--The purpose of this paper is to study the provisions of information technology IT for development of academic resources and examines the effect of IT in academic institutions for sharing information. Design/methodology/approach--The paper examines the role of IT in sharing information in academic institutions and explores the IT…

  5. Impact of the emulsification-diffusion method on the development of pharmaceutical nanoparticles.

    PubMed

    Quintanar-Guerrero, David; Zambrano-Zaragoza, María de la Luz; Gutierrez-Cortez, Elsa; Mendoza-Munoz, Nestor

    2012-12-01

    Nanotechnology is having a profound impact in many scientific fields and it has become one of the most important and exciting discipline. Like all technological advances, nanotechnology has its own scientific basis with a broad interdisciplinary effect. Perhaps, we are witnessing an exponential growth of nanotechnology, reflection of this is the important increase in the number of patents, scientific papers and specialized "nano" meetings and journals. The impact in the pharmaceutical area is related to the use of colloidal drug delivery systems as carriers for bioactive agents, in particular, the nanoparticle technology. The term nanoparticles designates solid submicronic particles formed of acceptable materials (e.g. polymers, lipids, etc.) containing an active substance. It includes both nanospheres (matricial systems) and nanocapsules (membrane systems). The knowledge of the nanoparticle preparation methods is a key issue for the formulator involved with drug-delivery research and development. In general, the methods based on preformed polymers, in particular biodegradable polymers, are preferred due to their easy implementation and lower potential toxicity. One of the most widely used methods to prepare polymeric nanoparticles is emulsification-diffusion. This method has been discussed in some reviews that compile research works but has a small number of patents. In this review, the emulsification-diffusion method is discussed from a technological point of view in order to show the operating conditions and formulation variables from data extracted of recent patents and experimental works. The main idea is to provide the reader with a general guide for formulators to make decisions about the usefulness of this method to develop specific nanoparticulate systems. The first part of this review provides an overview of the emulsification-diffusion method to prepare polymeric nanoparticles, while the second part evaluates the influence of preparative variables on the

  6. Environmental information system for visualizing environmental impact assessment information.

    PubMed

    Cserny, Angelika; Kovács, Zsófia; Domokos, Endre; Rédey, Akos

    2009-01-01

    The Institute of Environmental Engineering at the University of Pannonia has undertaken the challenge to develop an online environmental information system. This system is able to receive and process the collected environmental data via Internet. The authors have attached importance to the presentation of the data and have included other comprehensible information for laymen as well in order to work out visualisation techniques that are expressive and attract attention for environmental questions through the developed information system. The ways of visualizing physical and chemical parameters of surface water and the effects of motorway construction were examined.

  7. Impact of the Information Technology Profession.

    ERIC Educational Resources Information Center

    West, Thomas W.

    1991-01-01

    The 1990 winner of the ELITE Award for Exemplary Leadership and Information Technology Excellence in higher education offers his axioms for information resources management, covering authority/control, communications, project management, decision making, people management, strategic planning, change management, crisis management, and personal…

  8. Man-made black holes and Big Bangs: Diffusion and integration of scientific information into everyday thinking.

    PubMed

    Courvoisier, Nelly; Clémence, Alain; Green, Eva G T

    2013-04-01

    Drawing on Social Representations Theory, this study investigates focalisation and anchoring during the diffusion of information concerning the Large Hadron Collider (LHC), the particle accelerator at the European Organisation for Nuclear Research (CERN). We hypothesised that people focus on striking elements of the message, abandoning others, that the nature of the initial information affects diffusion of information, and that information is anchored in prior attitudes toward CERN and science. A serial reproduction experiment with two generations and four chains of reproduction diffusing controversial versus descriptive information about the LHC shows a reduction of information through generations, the persistence of terminology regarding the controversy and a decrease of other elements for participants exposed to polemical information. Concerning anchoring, positive attitudes toward CERN and science increase the use of expert terminology unrelated to the controversy. This research highlights the relevance of a social representational approach in the public understanding of science.

  9. Impacts of intense inward and outward ULF wave radial diffusion on the Van Allen belts

    NASA Astrophysics Data System (ADS)

    Mann, Ian; Ozeke, Louis; Rae, I. Jonathan; Murphy, Kyle

    2016-07-01

    During geomagnetic storms, the power in ultra-low frequency (ULF) waves can be orders of magnitude larger than that predicted by statistics determined from an entire solar cycle. This is especially true during the main phase and early recovery phase. These periods of enhanced storm-time ULF wave power can have significant impacts on the morphology and structure of the Van Allen belts. Either fast inward or outward radial diffusion can result, depending on the profiles of the electron phase space density and the outer boundary condition at the edge of the belts. Small changes in the time sequence of powerful ULF waves, and the time sequence of any magnetopause shadowing or the recovery of plamasheet sources relative to the ULF wave occurrence, have a remarkable impact on the resulting structure of the belts. The overall impact of the enhanced ULF wave power is profound, but the response can be very different depending on the available source flux in the plasmasheet. We review these impacts by examining ultra-relativistic electron dynamics during seemingly different storms during the Van Allen Probe era, including during the Baker et al. third radiation belt, and show the observed behaviour can be largely explained by differences in the time sequence of events described above.

  10. The Internet's Impact on Policy Evaluation: Information Compression and Credibility

    ERIC Educational Resources Information Center

    Bozeman, Barry

    2004-01-01

    As with all media, the Internet structures and frames information, rewarding some information search and decision behaviors while punishing others and, thereby, strongly influences evaluation research results and possibilities. Now that the Internet is for many evaluators the information medium of choice, the impacts of the medium on evaluation…

  11. Diffusion of Impact Innovations to University Professors. A Final Report to the Exxon Education Foundation.

    ERIC Educational Resources Information Center

    Rogers, Everett M.; And Others

    Using four IMPACT innovations as examples (EXPER SIM, Guided Design, TIPS, and Student-to-Student Counseling), this study attempts to define the nature of technological and social changes in university teaching. Data were gathered in three phases: (1) a questionnaire was mailed to individuals who requested information; (2) the adopters of…

  12. NASA/DoD Aerospace Knowledge Diffusion Research Project. XXIII - Information technology and aerospace knowledge diffusion: Exploring the intermediary-end user interface in a policy framework

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Barclay, Rebecca O.; Bishop, Ann P.; Kennedy, John M.

    1992-01-01

    Federal attempts to stimulate technological innovation have been unsuccessful because of the application of an inappropriate policy framework that lacks conceptual and empirical knowledge of the process of technological innovation and fails to acknowledge the relationship between knowledge production, transfer, and use as equally important components of the process of knowledge diffusion. This article argues that the potential contributions of high-speed computing and networking systems will be diminished unless empirically derived knowledge about the information-seeking behavior of members of the social system is incorporated into a new policy framework. Findings from the NASA/DoD Aerospace Knowledge Diffusion Research Project are presented in support of this assertion.

  13. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 23: Information technology and aerospace knowledge diffusion: Exploring the intermediary-end user interface in a policy framework

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Barclay, Rebecca O.; Bishop, Ann P.; Kennedy, John M.

    1992-01-01

    Federal attempts to stimulate technological innovation have been unsuccessful because of the application of an inappropriate policy framework that lacks conceptual and empirical knowledge of the process of technological innovation and fails to acknowledge the relationship between knowled reproduction, transfer, and use as equally important components of the process of knowledge diffusion. It is argued that the potential contributions of high-speed computing and networking systems will be diminished unless empirically derived knowledge about the information-seeking behavior of the members of the social system is incorporated into a new policy framework. Findings from the NASA/DoD Aerospace Knowledge Diffusion Research Project are presented in support of this assertion.

  14. Visualising Astronomy: Using Impact to Inform

    NASA Astrophysics Data System (ADS)

    Wyatt, R.

    2013-04-01

    Pop culture has visualised asteroids in a way that has made a far greater impact in the public domain than the outreach community can ever hope to achieve. Films such as Meteor (1979), Armageddon (1997) and Deep Impact (1997) may score poorly on scientific accuracy, but they have influenced our collective consciousness. (Perhaps in a fit of pre-millennial anxiety, the late 1990s saw a host of films featuring an asteroid or comet on a collision course with Earth1.) In addition to the destruction of Earth's cities, the Millennium Falcon dodging giant tumbling boulders in The Empire Strikes Back has probably influenced more people's mental image of an asteroid belt than any other single visual.

  15. Health information technology impact on productivity.

    PubMed

    Eastaugh, Steven R

    2012-01-01

    Managers work to achieve the greatest output for the least input effort, better balancing all factors of delivery to achieve the most with the smallest resource effort. Documentation of actual health information technology (HIT) cost savings has been elusive. Information technology and linear programming help to control hospital costs without harming service quality or staff morale. This study presents production function results from a study of hospital output during the period 2008-2011. The results suggest that productivity varies widely among the 58 hospitals as a function of staffing patterns, methods of organization, and the degree of reliance on information support systems. Financial incentives help to enhance productivity. Incentive pay for staff based on actual productivity gains is associated with improved productivity. HIT can enhance the marginal value product of nurses and staff, so that they concentrate their workday around patient care activities. The implementation of electronic health records (EHR) was associated with a 1.6 percent improvement in productivity.

  16. Impacts of Geospatial Information for Decision Making

    NASA Astrophysics Data System (ADS)

    Pearlman, F.; Coote, A.; Friedl, L.; Stewart, M.

    2012-12-01

    Geospatial information contributes to decisions by both societal and individual decision-makers. More effective use of this information is essential as issues are increasingly complex and consequences can be critical for future economic and social development. To address this, a workshop brought together analysts, communicators, officials, and researchers from academia, government, non-governmental organizations, and the private sector. A range of policy issues, management needs, and resource requirements were discussed and a wide array of analyses, geospatial data, methods of analysis, and metrics were presented for assessing and communicating the value of geospatial information. It is clear that there are many opportunities for integrating science and engineering disciplines with the social sciences for addressing societal issues that would benefit from using geospatial information and earth observations. However, these collaborations must have outcomes that can be easily communicated to decision makers. This generally requires either succinct quantitative statements of value based on rigorous models and/or user testimonials of actual applications that save real money. An outcome of the workshop is to pursue the development of a community of practice or society that encompasses a wide range of scientific, social, management, and communication disciplines and fosters collaboration across specialties, helping to build trust across social and science aspects. A resource base is also necessary. This presentation will address approaches for creating a shared knowledge database, containing a glossary of terms, reference materials and examples of case studies and the potential applications for benefit analyses.

  17. Role of propagation thresholds in sentiment-based model of opinion evolution with information diffusion

    NASA Astrophysics Data System (ADS)

    Si, Xia-Meng; Wang, Wen-Dong; Ma, Yan

    2016-06-01

    The degree of sentiment is the key factor for internet users in determining their propagating behaviors, i.e. whether participating in a discussion and whether withdrawing from a discussion. For this end, we introduce two sentiment-based propagation thresholds (i.e. infected threshold and refractory threshold) and propose an interacting model based on the Bayesian updating rules. Our model describe the phenomena that few internet users change their decisions and that someone has drop out of discussion about the topic when some others are just aware of it. Numerical simulations show that, large infected threshold restrains information diffusion but favors the lessening of extremism, while large refractory threshold facilitates decision interaction but promotes the extremism. Making netizens calm down and propagate information sanely can restrain the prevailing of extremism about rumors.

  18. Evaluating the Impact of a Special Library and Information Service

    ERIC Educational Resources Information Center

    Botha, Erika; Erasmus, Rene; van Deventer, Martie

    2009-01-01

    The mere fact that a library service is being used does not mean that the service makes a difference or has a positive impact on the user. This has significant implications for Special Library and Information Services (SL&IS) that have to constantly prove that they add value. Because of the difficulty of measuring impact effectively, the majority…

  19. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 48: Valuing information in an interactive environment

    NASA Technical Reports Server (NTRS)

    Brinberg, Herbert R.; Pinelli, Thomas E.; Barclay, Rebecca O.

    1995-01-01

    Consideration effort has been devoted over the past 30 years to developing methods and means of assessing the value of information. Two approaches - value in exchange and value in use - dominate; however, neither approach enjoys much practical application because validation schema for decision-making is missing. The approaches fail to measure objectively the real costs of acquiring information and the real benefits that information will yield. Moreover, these approaches collectively fail to provide economic justification to build and/or continue to support an information product or service. In addition, the impact of Cyberspace adds a new dimension to the problem. A new paradigm is required to make economic sense in this revolutionary information environment. In previous work, the authors explored the various approaches to measuring the value of information and concluded that, in large measure, these methods were unworkable concepts and constructs. Instead, they proposed several axioms for valuing information. Most particularly they concluded that the 'value of information cannot be measured in the absence of a specific task, objective, or goal.' This paper builds on those axioms and describes under which circumstances information can be measured in objective and actionable terms. This paper also proposes a methodology for undertaking such measures and validating the results.

  20. An appraisal of the impact of compositional and ripening parameters on CO2 diffusivity in semi-hard cheese.

    PubMed

    Acerbi, F; Guillard, V; Guillaume, C; Saubanere, M; Gontard, N

    2016-03-01

    This study focuses on CO2 diffusivity, which is one of the most important factors impacting eye growth in semi-hard cheese, but yet has scarcely been investigated in literature. The effect of compositional and ripening parameters on experimental CO2 diffusivity in semi-hard cheese was studied. CO2 diffusivity in semi-hard cheese showed a complex relationship with temperature in the range 4-25°C, represented by a quadratic curve with the highest diffusivity at 13°C. Salt was found to impact CO2 diffusivity, with a decrease of about 60% for 0-2.7% w/w salt addition, which may be ascribed to viscosity increase of the cheese matrix and "salting in" effect of protein. CO2 diffusivity was found to increase with moisture content from 39% to 42% w/w, then it decreased from 42% to 48% w/w. Inevitable changes in protein content of the three cheese variants may be responsible for the complex behaviour observed.

  1. Direct measurement of VOC diffusivities in tree tissues: impacts on tree-based phytoremediation and plant contamination.

    PubMed

    Baduru, Krishna K; Trapp, Stefan; Burken, Joel G

    2008-02-15

    Recent discoveries in the phytoremediation of volatile organic compounds (VOCs) show that vapor-phase transport into roots leads to VOC removal from the vadose zone and diffusion and volatilization out of plants is an important fate following uptake. Volatilization to the atmosphere constitutes one fundamental terminal fate processes for VOCs that have been translocated from contaminated soil or groundwater, and diffusion constitutes the mass transfer mechanism to the plant-atmosphere interface. Therefore, VOC diffusion through woody plant tissues, that is, xylem, has a direct impact on contaminant fate in numerous vegetation-VOC interactions, including the phytoremediation of soil vapors and dissolved aqueous-phase contaminants. The diffusion of VOCs through freshly excised tree tissue was directly measured for common groundwater contaminants, chlorinated compounds such as trichloroethylene, perchloroethene, and tetrachloroethane and aromatic hydrocarbons such as benzene, toluene, and methyl tert-butyl ether. All compounds tested are currently being treated at full scale with tree-based phytoremediation. Diffusivities were determined by modeling the diffusive transport data with a one-dimensional diffusive flux model, developed to mimic the experimental arrangement. Wood-water partition coefficients were also determined as needed for the model application. Diffusivities in xylem tissues were found to be inversely related to molecular weight, and values determined herein were compared to previous modeling on the basis of a tortuous diffusion path in woody tissues. The comparison validates the predictive model for the first time and allows prediction for other compounds on the basis of chemical molecular weight and specific plant properties such as water, lignin, and gas contents. This research provides new insight into phytoremediation efforts and into potential fruit contamination for fruit-bearing trees, specifically establishing diffusion rates from the

  2. Domestication and early agriculture in the Mediterranean Basin: Origins, diffusion, and impact.

    PubMed

    Zeder, Melinda A

    2008-08-19

    The past decade has witnessed a quantum leap in our understanding of the origins, diffusion, and impact of early agriculture in the Mediterranean Basin. In large measure these advances are attributable to new methods for documenting domestication in plants and animals. The initial steps toward plant and animal domestication in the Eastern Mediterranean can now be pushed back to the 12th millennium cal B.P. Evidence for herd management and crop cultivation appears at least 1,000 years earlier than the morphological changes traditionally used to document domestication. Different species seem to have been domesticated in different parts of the Fertile Crescent, with genetic analyses detecting multiple domestic lineages for each species. Recent evidence suggests that the expansion of domesticates and agricultural economies across the Mediterranean was accomplished by several waves of seafaring colonists who established coastal farming enclaves around the Mediterranean Basin. This process also involved the adoption of domesticates and domestic technologies by indigenous populations and the local domestication of some endemic species. Human environmental impacts are seen in the complete replacement of endemic island faunas by imported mainland fauna and in today's anthropogenic, but threatened, Mediterranean landscapes where sustainable agricultural practices have helped maintain high biodiversity since the Neolithic. PMID:18697943

  3. Domestication and early agriculture in the Mediterranean Basin: Origins, diffusion, and impact.

    PubMed

    Zeder, Melinda A

    2008-08-19

    The past decade has witnessed a quantum leap in our understanding of the origins, diffusion, and impact of early agriculture in the Mediterranean Basin. In large measure these advances are attributable to new methods for documenting domestication in plants and animals. The initial steps toward plant and animal domestication in the Eastern Mediterranean can now be pushed back to the 12th millennium cal B.P. Evidence for herd management and crop cultivation appears at least 1,000 years earlier than the morphological changes traditionally used to document domestication. Different species seem to have been domesticated in different parts of the Fertile Crescent, with genetic analyses detecting multiple domestic lineages for each species. Recent evidence suggests that the expansion of domesticates and agricultural economies across the Mediterranean was accomplished by several waves of seafaring colonists who established coastal farming enclaves around the Mediterranean Basin. This process also involved the adoption of domesticates and domestic technologies by indigenous populations and the local domestication of some endemic species. Human environmental impacts are seen in the complete replacement of endemic island faunas by imported mainland fauna and in today's anthropogenic, but threatened, Mediterranean landscapes where sustainable agricultural practices have helped maintain high biodiversity since the Neolithic.

  4. Domestication and early agriculture in the Mediterranean Basin: Origins, diffusion, and impact

    PubMed Central

    Zeder, Melinda A.

    2008-01-01

    The past decade has witnessed a quantum leap in our understanding of the origins, diffusion, and impact of early agriculture in the Mediterranean Basin. In large measure these advances are attributable to new methods for documenting domestication in plants and animals. The initial steps toward plant and animal domestication in the Eastern Mediterranean can now be pushed back to the 12th millennium cal B.P. Evidence for herd management and crop cultivation appears at least 1,000 years earlier than the morphological changes traditionally used to document domestication. Different species seem to have been domesticated in different parts of the Fertile Crescent, with genetic analyses detecting multiple domestic lineages for each species. Recent evidence suggests that the expansion of domesticates and agricultural economies across the Mediterranean was accomplished by several waves of seafaring colonists who established coastal farming enclaves around the Mediterranean Basin. This process also involved the adoption of domesticates and domestic technologies by indigenous populations and the local domestication of some endemic species. Human environmental impacts are seen in the complete replacement of endemic island faunas by imported mainland fauna and in today's anthropogenic, but threatened, Mediterranean landscapes where sustainable agricultural practices have helped maintain high biodiversity since the Neolithic. PMID:18697943

  5. Toward reliable retrieval of functional information of papillary dermis using spatially resolved diffuse reflectance spectroscopy

    PubMed Central

    Chen, Yu-Wen; Guo, Jun-Yen; Tzeng, Shih-Yu; Chou, Ting-Chun; Lin, Ming-Jen; Huang, Lynn Ling-Huei; Yang, Chao-Chun; Hsu, Chao-Kai; Tseng, Sheng-Hao

    2016-01-01

    Spatially resolved diffuse reflectance spectroscopy (SRDRS) has been employed to quantify tissue optical properties and its interrogation volume is majorly controlled by the source-to-detector separations (SDSs). To noninvasively quantify properties of dermis, a SRDRS setup that includes SDS shorter than 1 mm is required. It will be demonstrated in this study that Monte Carlo simulations employing the Henyey-Greenstein phase function cannot always precisely predict experimentally measured diffuse reflectance at such short SDSs, and we speculated this could be caused by the non-negligible backward light scattering at short SDSs that cannot be properly modeled by the Henyey-Greenstein phase function. To accurately recover the optical properties and functional information of dermis using SRDRS, we proposed the use of the modified two-layer (MTL) geometry. Monte Carlo simulations and phantom experiment results revealed that the MTL probing geometry was capable of faithfully recovering the optical properties of upper dermis. The capability of the MTL geometry in probing the upper dermis properties was further verified through a swine study, and it was found that the measurement results were reasonably linked to histological findings. Finally, the MTL probe was utilized to study psoriatic lesions. Our results showed that the MTL probe was sensitive to the physiological condition of tissue volumes within the papillary dermis and could be used in studying the physiology of psoriasis. PMID:26977361

  6. Impact of Changes in Diffuse Radiation on the Global Land Carbon Sink, 1901-2100

    NASA Astrophysics Data System (ADS)

    Mercado, L.; Bellouin, N.; Sitch, S.; Boucher, O.; Huntingford, C.; Wild, M.; Cox, P. M.

    2009-04-01

    Recent observational and theoretical studies have shown that changes in surface radiation that lead to increasing diffuse surface irradiance, enhance plant photosynthesis (Gu et al., 2003, Niyogi et al., 2004, Oliveira et al., 2007, Roderick et al., 2001). Solar radiation reaching the land surface has changed over the industrial era due to aerosols emitted from volcanoes and various anthropogenic sources (Kvalevag and Myhre, 2007). Such changes in total surface radiation are accompanied by changes in direct and diffuse surface solar radiation. Current global climate-carbon models do include the effects of changes in total surface radiation on the land biosphere but neglect the positive effects of increasing diffuse fraction on plant photosynthesis. In this study we estimate for the first time, the impact of variations in diffuse fraction on the land carbon sink using a global model (Mercado et al., 2007) modified to account for the effects of variations in both direct and diffuse radiation on canopy photosynthesis. We use meteorological forcing from the Climate Research Unit Data set. Additionally short wave and photosynthetic active radiation are reconstructed from the Hadley centre climate model, which accounts for the scattering and absorption of light by tropospheric and stratospheric aerosols and change in cloud properties due to indirect aerosol effects. References Gu L.H., Baldocchi D.D., Wofsy S.C., Munger J.W., Michalsky J.J., Urbanski S.P. & Boden T.A. (2003) Response of a deciduous forest to the Mount Pinatubo eruption: Enhanced photosynthesis. Science, 299, 2035-2038. M. M. Kvalevag and G. Myhre, J. Clim. 20, 4874 (2007). Mercado L.M., Huntingford C., Gash J.H.C., Cox P.M. & Jogireddy V. (2007) Improving the representation of radiation interception and photosynthesis for climate model applications. Tellus Series B-Chemical and Physical Meteorology, 59, 553-565. Niyogi D., Chang H.I., Saxena V.K., Holt T., Alapaty K., Booker F., Chen F., Davis K

  7. The Impact of Diffuse Ionized Gas on Emission-line Ratios and Gas Metallicity Measurements

    NASA Astrophysics Data System (ADS)

    Zhang, Kai; Yan, Renbin; MaNGA Team

    2016-01-01

    Diffuse Ionized Gas (DIG) is prevalent in star-forming galaxies. Using a sample of galaxies observed by MaNGA, we demonstrate how DIG in star-forming galaxies impact the measurements of emission line ratios, hence the gas-phase metallicity measurements and the interpretation of diagnostic diagrams. We demonstrate that emission line surface brightness (SB) is a reasonably good proxy to separate HII regions from regions dominated by diffuse ionized gas. For spatially-adjacent regions or regions at the same radius, many line ratios change systematically with emission line surface brightness, reflecting a gradual increase of dominance by DIG towards low SB. DIG could significantly bias the measurement of gas metallicity and metallicity gradient. Because DIG tend to have a higher temperature than HII regions, at fixed metallicity DIG displays lower [NII]/[OII] ratios. DIG also show lower [OIII]/[OII] ratios than HII regions, due to extended partially-ionized regions that enhance all low-ionization lines ([NII], [SII], [OII], [OI]). The contamination by DIG is responsible for a substantial portion of the scatter in metallicity measurements. At different surface brightness, line ratios and line ratio gradients can differ systematically. As DIG fraction could change with radius, it can affect the metallicity gradient measurements in systematic ways. The three commonly used strong-line metallicity indicators, R23, [NII]/[OII], O3N2, are all affected in different ways. To make robust metallicity gradient measurements, one has to properly isolate HII regions and correct for DIG contamination. In line ratio diagnostic diagrams, contamination by DIG moves HII regions towards composite or LINER-like regions.

  8. Critical behavior of a class of nonlinear stochastic models of diffusion of information

    NASA Astrophysics Data System (ADS)

    Sharma, C. L.; Pathria, R. K.; Karmeshu

    1982-12-01

    A theoretical analysis based on the concepts and techniques of statistical physics is carried out for two nonlinear models of diffusion of information-one in a closed population and the other in an open one. Owing to interpersonal contacts among the members of the population, the models exhibit a cooperative behavior when a certain parameter of the problem approaches a critical value. Mathematical similarities in the behavior of the two models, in the vicinity of the critical point, are so impelling that one is tempted to investigate the corresponding behavior of a generalized model, which can be done by carrying out a systematic system-size expansion of the master equation of the process and thereby deriving a nonlinear Fokker-Planck equation for the relevant probability distribution. This establishes a broader class of systems displaying identical behavior in the critical region and also elucidates the role played by fluctuations in bringing about the cooperative phenomenon.

  9. Impact of implanted phosphorus on the diffusivity of boron and its applicability to silicon solar cells

    SciTech Connect

    Schrof, Julian Müller, Ralph; Benick, Jan; Hermle, Martin; Reedy, Robert C.

    2015-07-28

    Boron diffusivity reduction in extrinsically doped silicon was investigated in the context of a process combination consisting of BBr{sub 3} furnace diffusion and preceding Phosphorus ion implantation. The implantation of Phosphorus leads to a substantial blocking of Boron during the subsequent Boron diffusion. First, the influences of ion implantation induced point defects as well as the initial P doping on B diffusivity were studied independently. Here, it was found that not the defects created during ion implantation but the P doping itself results in the observed B diffusion retardation. The influence of the initial P concentration was investigated in more detail by varying the P implantation dose. A secondary ion mass spectrometry (SIMS) analysis of the BSG layer after the B diffusion revealed that the B diffusion retardation is not due to potential P content in the BSG layer but rather caused by the n-type doping of the crystalline silicon itself. Based on the observations the B diffusion retardation was classified into three groups: (i) no reduction of B diffusivity, (ii) reduced B diffusivity, and (iii) blocking of the B diffusion. The retardation of B diffusion can well be explained by the phosphorus doping level resulting in a Fermi level shift and pairing of B and P ions, both reducing the B diffusivity. Besides these main influences, there are probably additional transient phenomena responsible for the blocking of boron. Those might be an interstitial transport mechanism caused by P diffusion that reduces interstitial concentration at the surface or the silicon/BSG interface shift due to oxidation during the BBr{sub 3} diffusion process. Lifetime measurements revealed that the residual (non-blocked) B leads to an increased dark saturation current density in the P doped region. Nevertheless, electrical quality is on a high level and was further increased by reducing the B dose as well as by removing the first few nanometers of the silicon surface after

  10. Impact of implanted phosphorus on the diffusivity of boron and its applicability to silicon solar cells

    NASA Astrophysics Data System (ADS)

    Schrof, Julian; Müller, Ralph; Reedy, Robert C.; Benick, Jan; Hermle, Martin

    2015-07-01

    Boron diffusivity reduction in extrinsically doped silicon was investigated in the context of a process combination consisting of BBr3 furnace diffusion and preceding Phosphorus ion implantation. The implantation of Phosphorus leads to a substantial blocking of Boron during the subsequent Boron diffusion. First, the influences of ion implantation induced point defects as well as the initial P doping on B diffusivity were studied independently. Here, it was found that not the defects created during ion implantation but the P doping itself results in the observed B diffusion retardation. The influence of the initial P concentration was investigated in more detail by varying the P implantation dose. A secondary ion mass spectrometry (SIMS) analysis of the BSG layer after the B diffusion revealed that the B diffusion retardation is not due to potential P content in the BSG layer but rather caused by the n-type doping of the crystalline silicon itself. Based on the observations the B diffusion retardation was classified into three groups: (i) no reduction of B diffusivity, (ii) reduced B diffusivity, and (iii) blocking of the B diffusion. The retardation of B diffusion can well be explained by the phosphorus doping level resulting in a Fermi level shift and pairing of B and P ions, both reducing the B diffusivity. Besides these main influences, there are probably additional transient phenomena responsible for the blocking of boron. Those might be an interstitial transport mechanism caused by P diffusion that reduces interstitial concentration at the surface or the silicon/BSG interface shift due to oxidation during the BBr3 diffusion process. Lifetime measurements revealed that the residual (non-blocked) B leads to an increased dark saturation current density in the P doped region. Nevertheless, electrical quality is on a high level and was further increased by reducing the B dose as well as by removing the first few nanometers of the silicon surface after the BBr3

  11. Enhancing a diffusion algorithm for 4D image segmentation using local information

    NASA Astrophysics Data System (ADS)

    Lösel, Philipp; Heuveline, Vincent

    2016-03-01

    Inspired by the diffusion of a particle, we present a novel approach for performing a semiautomatic segmentation of tomographic images in 3D, 4D or higher dimensions to meet the requirements of high-throughput measurements in a synchrotron X-ray microtomograph. Given a small number of 2D-slices with at least two manually labeled segments, one can either analytically determine the probability that an intelligently weighted random walk starting at one labeled pixel will be at a certain time at a specific position in the dataset or determine the probability approximately by performing several random walks. While the weights of a random walk take into account local information at the starting point, the random walk itself can be in any dimension. Starting a great number of random walks in each labeled pixel, a voxel in the dataset will be hit by several random walks over time. Hence, the image can be segmented by assigning each voxel to the label where the random walks most likely started from. Due to the high scalability of random walks, this approach is suitable for high throughput measurements. Additionally, we describe an interactively adjusted active contours slice by slice method considering local information, where we start with one manually labeled slice and move forward in any direction. This approach is superior with respect to accuracy towards the diffusion algorithm but inferior in the amount of tedious manual processing steps. The methods were applied on 3D and 4D datasets and evaluated by means of manually labeled images obtained in a realistic scenario with biologists.

  12. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 5: Aerospace librarians and technical information specialists as information intermediaries: A report of phase 2 activities of the NASA/DOD Aerospace Knowledge Diffusion Research Project

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Kennedy, John M.

    1990-01-01

    The objective of the NASA/DOD Aerospace Knowledge Diffusion Research Project is to provide descriptive and analytical data regarding the flow of scientific and technical information (STI) at the individual, organizational, national, and international levels, placing emphasis on the systems used to diffuse the results of federally funded aerospace STI. An overview of project assumptions, objectives, and design is presented and preliminary results of the phase 2 aerospace library survey are summarized. Phase 2 addressed aerospace knowledge transfer and use within the larger social system and focused on the flow of aerospace STI in government and industry and the role of the information intermediary in knowledge transfer.

  13. Characterising effects of impact velocity on brain and behaviour in a model of diffuse traumatic axonal injury.

    PubMed

    Yan, E B; Johnstone, V P A; Alwis, D S; Morganti-Kossmann, M-C; Rajan, R

    2013-09-17

    The velocity of impact between an object and the human head is a critical factor influencing brain injury outcomes but has not been explored in any detail in animal models. Here we provide a comprehensive overview of the interplay between impact velocity and injury severity in a well-established weight-drop impact acceleration (WDIA) model of diffuse brain injury in rodents. We modified the standard WDIA model to produce impact velocities of 5.4, 5.85 and 6.15 m/s while keeping constant the weight and the drop height. Gradations in impact velocity produced progressive degrees of injury severity measured behaviourally, electrophysiologically and anatomically, with the former two methods showing greater sensitivity to changes in impact velocity. There were impact velocity-dependent reductions in sensorimotor performance and in cortical depth-related depression of sensory cortex responses; however axonal injury (demonstrated by immunohistochemistry for β-amyloid precursor protein and neurofilament heavy-chain) was discernible only at the highest impact velocity. We conclude that the WDIA model is capable of producing graded axonal injury in a repeatable manner, and as such will prove useful in the study of the biomechanics, pathophysiology and potential treatment of diffuse axonal injury.

  14. Evaluation of mobility impacts of advanced information systems

    SciTech Connect

    Peeta, S.; Poonuru, K.; Sinha, K.

    2000-06-01

    Advanced technologies under the aegis of advanced traveler information systems and advanced traffic management systems are being employed to address the debilitating traffic congestion problem. Broadly identified under the label intelligent transportation systems (ITS), they focus on enhancing the efficiency of the existing roadway utilization. Though ITS has transitioned from the conceptual framework stage to the operational test phase that analyzes real-world feasibility, studies that systematically quantify the multidimensional real-world impacts of these technologies in terms of mobility, safety, and air quality, are lacking. This paper proposes a simulation-based framework to address the mobility impacts of these technologies through the provision of information to travelers. The information provision technologies are labeled as advanced information systems (AIS), and include pretrip information, en route information, variable message signs, and combinations thereof. The primary focus of the paper is to evaluate alternative AIS technologies using the heavily traveled Borman Expressway corridor in northwestern Indiana as a case study. Simulation results provide insights into the mobility impacts of AIS technologies, and contrast the effectiveness of alternative information provision sources and strategies.

  15. Impact of compression on gas transport in non-woven gas diffusion layers of high temperature polymer electrolyte fuel cells

    NASA Astrophysics Data System (ADS)

    Froning, Dieter; Yu, Junliang; Gaiselmann, Gerd; Reimer, Uwe; Manke, Ingo; Schmidt, Volker; Lehnert, Werner

    2016-06-01

    Gas transport in non-woven gas diffusion layers of a high-temperature polymer electrolyte fuel cell was calculated with the Lattice Boltzmann method. The underlying micro structure was taken from two sources. A real micro structure was analyzed in the synchrotron under the impact of a compression mask mimicking the channel/rib structure of a flow field. Furthermore a stochastic geometry model based on synchrotron X-ray tomography studies was applied. The effect of compression is included in the stochastic model. Gas transport in these micro structures was simulated and the impact of compression was analyzed. Fiber bundles overlaying the micro structure were identified which affect the homogeneity of the gas flow. There are significant deviations between the impact of compression on effective material properties for this type of gas diffusion layers and the Kozeny-Carman equation.

  16. The Performance of Direct Disk Diffusion for Community Acquired Bacteremia due to Gram-Negative Bacilli and Its Impact on Physician Treatment Decisions

    PubMed Central

    Daley, Peter; Comerford, Adam; Umali, Jurgienne; Penney, Carla

    2016-01-01

    Background. Direct disk diffusion susceptibility testing provides faster results than standard microtitre susceptibility. The direct result may impact patient outcome in sepsis if it is accurate and if physicians use the information to promptly and appropriately change antibiotic treatment. Objective. To compare the performance of direct disk diffusion with standard susceptibility and to consider physician decisions in response to these early results, for community acquired bacteremia with Gram-negative Bacilli. Methods. Retrospective observational study of all positive blood cultures with Gram-negative Bacilli, collected over one year. Physician antibiotic treatment decisions were assessed by an infectious diseases physician based on information available to the physician at the time of the decision. Results. 89 bottles growing Gram-negative Bacilli were included in the analysis. Direct disk diffusion agreement with standard susceptibility varied widely. In 47 cases (52.8%), the physician should have changed to a narrower spectrum but did not, in 18 cases (20.2%), the physician correctly narrowed from appropriate broad coverage, and in 8 cases (9.0%), the empiric therapy was correct. Discussion. Because inoculum is not standardized, direct susceptibility results do not agree with standard susceptibility results for all drugs. Physicians do not act on direct susceptibility results. Conclusion. Direct susceptibility should be discontinued in clinical microbiology laboratories. PMID:27366172

  17. The Performance of Direct Disk Diffusion for Community Acquired Bacteremia due to Gram-Negative Bacilli and Its Impact on Physician Treatment Decisions.

    PubMed

    Daley, Peter; Comerford, Adam; Umali, Jurgienne; Penney, Carla

    2016-01-01

    Background. Direct disk diffusion susceptibility testing provides faster results than standard microtitre susceptibility. The direct result may impact patient outcome in sepsis if it is accurate and if physicians use the information to promptly and appropriately change antibiotic treatment. Objective. To compare the performance of direct disk diffusion with standard susceptibility and to consider physician decisions in response to these early results, for community acquired bacteremia with Gram-negative Bacilli. Methods. Retrospective observational study of all positive blood cultures with Gram-negative Bacilli, collected over one year. Physician antibiotic treatment decisions were assessed by an infectious diseases physician based on information available to the physician at the time of the decision. Results. 89 bottles growing Gram-negative Bacilli were included in the analysis. Direct disk diffusion agreement with standard susceptibility varied widely. In 47 cases (52.8%), the physician should have changed to a narrower spectrum but did not, in 18 cases (20.2%), the physician correctly narrowed from appropriate broad coverage, and in 8 cases (9.0%), the empiric therapy was correct. Discussion. Because inoculum is not standardized, direct susceptibility results do not agree with standard susceptibility results for all drugs. Physicians do not act on direct susceptibility results. Conclusion. Direct susceptibility should be discontinued in clinical microbiology laboratories. PMID:27366172

  18. Prognostic impact of concurrent MYC and BCL6 rearrangements and expression in de novo diffuse large B-cell lymphoma

    PubMed Central

    Deng, Lijuan; Wang, Xiaoxiao; Manyam, Ganiraju C.; Visco, Carlo; Montes-Moreno, Santiago; Zhang, Li; Dybkær, Karen; Chiu, April; Orazi, Attilio; Zu, Youli; Bhagat, Govind; Richards, Kristy L.; Hsi, Eric D.; Choi, William W.L.; van Krieken, J. Han; Huh, Jooryung; Ponzoni, Maurilio; Ferreri, Andrés J.M.; Parsons, Ben M.; Møller, Michael B.; Piris, Miguel A.; Winter, Jane N.; Medeiros, L. Jeffrey; Hu, Shimin; Young, Ken H.

    2016-01-01

    Double-hit B-cell lymphoma is a common designation for a group of tumors characterized by concurrent translocations of MYC and BCL2, BCL6, or other genes. The prognosis of concurrent MYC and BCL6 translocations is not well known. In this study, we assessed rearrangements and expression of MYC, BCL2 and BCL6 in 898 patients with de novo diffuse large B-cell lymphoma treated with standard chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab). Neither BCL6 translocation alone (more frequent in activated B-cell like diffuse large B-cell lymphoma) nor in combination with MYC translocation (observed in 2.0% of diffuse large B-cell lymphoma) predicted poorer survival in diffuse large B-cell lymphoma patients. Diffuse large B-cell lymphoma patients with MYC/BCL6 co-expression did have significantly poorer survival, however, MYC/BCL6 co-expression had no effect on prognosis in the absence of MYC/BCL2 co-expression, and had no additive impact in MYC+/BCL2+ cases. The isolated MYC+/BCL6+/BCL2− subset, more frequent in germinal center B-cell like diffuse large B-cell lymphoma, had significantly better survival compared with the isolated MYC+/BCL2+/BCL6− subset (more frequent in activated B-cell like diffuse large B-cell lymphoma). In summary, diffuse large B-cell lymphoma patients with either MYC/BCL6 rearrangements or MYC/BCL6 co-expression did not always have poorer prognosis; MYC expression levels should be evaluated simultaneously; and double-hit B-cell lymphoma needs to be refined based on the specific genetic abnormalities present in these tumors. PMID:26573234

  19. Project IMPACT: A Computer Based Instructional Management Information System.

    ERIC Educational Resources Information Center

    Adams, Charles F.; And Others

    IMPACT is a computer-based information system designed to help school districts share materials and expertise and to implement state-mandated evaluation of student achievement. It is designed to meet local, regional, and state evaluation and reporting requirements. Based upon the diagnostic-prescriptive approach to instruction, it consists of: (1)…

  20. The Impact of New Informational Technology on Education in Wyoming.

    ERIC Educational Resources Information Center

    Dolly, John; And Others

    Educational changes in Wyoming that are linked to the emergence of new informational technologies are considered. Attention is directed to the following topics: assumptions for Wyoming educators as they plan to respond to the impact of technology on teacher education; the importance of educational goals and objectives; the national climate…

  1. Aging and the impact of irrelevant information on social judgments.

    PubMed

    Hess, Thomas M; Smith, Brian T

    2014-09-01

    We conducted 2 experiments to specifically examine whether older adults are more susceptible to the negative impact of irrelevant evaluative information when making social judgments. Young (ages 20-44), middle-aged (ages 45-63), and older (ages 65-85) adults were presented with descriptions of people consisting of positive and negative traits that varied in relevance to specific occupations. They were asked to either form a general impression based on these traits or to evaluate the person's fitness for the specified occupation. In both studies, evaluative content of the descriptions (i.e., the number of positive minus number of negative traits) was a significant predictor of subjective evaluations. Of prime importance, adults of all ages were similarly able to selectively process relevant versus irrelevant information when occupational fitness evaluations required them to focus on a subset of information in the descriptions. Participants also adjusted the specific types of information used in making judgments, with the relative importance of agentic traits and negative information being greater when making occupation evaluations than when forming impressions. The results suggest that age differences in the processing evaluative information are minimal, and that the availability of well-established knowledge structures can help older adults effectively control the impact of irrelevant evaluative information when making social inferences. PMID:25244474

  2. Aging and the impact of irrelevant information on social judgments.

    PubMed

    Hess, Thomas M; Smith, Brian T

    2014-09-01

    We conducted 2 experiments to specifically examine whether older adults are more susceptible to the negative impact of irrelevant evaluative information when making social judgments. Young (ages 20-44), middle-aged (ages 45-63), and older (ages 65-85) adults were presented with descriptions of people consisting of positive and negative traits that varied in relevance to specific occupations. They were asked to either form a general impression based on these traits or to evaluate the person's fitness for the specified occupation. In both studies, evaluative content of the descriptions (i.e., the number of positive minus number of negative traits) was a significant predictor of subjective evaluations. Of prime importance, adults of all ages were similarly able to selectively process relevant versus irrelevant information when occupational fitness evaluations required them to focus on a subset of information in the descriptions. Participants also adjusted the specific types of information used in making judgments, with the relative importance of agentic traits and negative information being greater when making occupation evaluations than when forming impressions. The results suggest that age differences in the processing evaluative information are minimal, and that the availability of well-established knowledge structures can help older adults effectively control the impact of irrelevant evaluative information when making social inferences.

  3. Aging and the Impact of Irrelevant Information on Social Judgments

    PubMed Central

    Hess, Thomas M.; Smith, Brian T.

    2014-01-01

    We conducted two experiments to specifically examine whether older adults are more susceptible to the negative impact of irrelevant evaluative information when making social judgments. Young (ages 20 – 44), middle-aged (ages 45 – 63), and older (ages 65 – 85) adults were presented with descriptions of people consisting of positive and negative traits that varied in relevance to specific occupations. They were asked to either form a general impression based on these traits or to evaluate the person’s fitness for the specified occupation. In both studies, evaluative content of the descriptions (i.e., the number of positive minus number of negative traits) was a significant predictor of subjective evaluations. Of prime importance, adults of all ages were similarly able to selectively process relevant versus irrelevant information when occupational fitness evaluations required them to focus on a subset of information in the descriptions. Participants also adjusted the specific types of information used in making judgments, with the relative importance of agentic traits and negative information being greater when making occupation evaluations than when forming impressions. The results suggest that age differences in the processing evaluative information are minimal, and that the availability of well-established knowledge structures can help older adults effectively control the impact of irrelevant evaluative information when making social inferences. PMID:25244474

  4. Beyond Economy: Impact of National Cultural Values on Nationwide Broadband Internet Diffusion

    ERIC Educational Resources Information Center

    Joo, Sung-Hee

    2010-01-01

    This study examines how the non-conventional factors of national cultural values and government involvement affect the diffusion of broadband Internet technologies in various nations around the world. An innovative element of the study was the examination of the influence patterns at different stages of diffusion, which was measured by the number…

  5. Evaluation of the impact of atmospheric ozone and aerosols on the horizontal global/diffuse UV Index at Livorno (Italy)

    NASA Astrophysics Data System (ADS)

    Scaglione, Daniele; Giulietti, Danilo; Morelli, Marco

    2016-08-01

    A study was conducted at Livorno (Italy) to evaluate the impact of atmospheric aerosols and ozone on the solar UV radiation and its diffuse component at ground in clear sky conditions. Solar UV radiation has been quantified in terms of UV Index (UVI), following the ISO 17166:1999/CIE S007/E-1998 international standard. UVI has been calculated by exploiting the libRadtran radiative transfer modelling software as a function of both the Aerosols Optical Depth (AOD) and the Total Ozone Column (TOC). In particular AOD and TOC values have been remotely sensed by the Ozone Monitoring Instrument (OMI) on board the NASA's EOS (Earth Observing System) satellites constellation. An experimental confirmation was also obtained by exploiting global UVI ground-based measurements from the 26/9/14 to 12/8/15 and diffuse UVI ground-based measurements from the 17/5/15 to 12/8/15. For every considered value of Solar Zenith Angle (SZA) and atmospheric condition, estimates and measurements confirm that the diffuse component contributes for more than 50% on the global UV radiation. Therefore an exposure of human skin also to diffuse solar UV radiation can be potentially harmful for health and need to be accurately monitored, e.g. by exploiting innovative applications such as a mobile app with a satellite-based UV dosimeter that has been developed. Global and diffuse UVI variations due to the atmosphere are primarily caused by the TOC variations (typically cyclic): the maximum TOC variation detected by OMI in the area under study leads to a corresponding variation in global and diffuse UVI of about 50%. Aerosols in the area concerned, mainly of maritime nature, have instead weaker effects causing a maximum variation of the global and diffuse UVI respectively of 9% and 35% with an SZA of 20° and respectively of 13% and 10% with an SZA of 60°.

  6. The impact of different vertical diffusion schemes in a three-dimensional oil spill model in the Bohai Sea

    NASA Astrophysics Data System (ADS)

    Li, Yan; Zhu, Jiang; Wang, Hui

    2013-11-01

    Vertical transport is critical to the movement of oil spills in seawater. Breaking waves play an important role by developing a well-defined mixing layer in the upper part of the water column. A three-dimensional (3-D) Lagrangian random walk oil spill model was used here to study the influence of sea surface waves on the vertical turbulence movement of oil particles. Three vertical diffusion schemes were utilized in the model to compare their impact on oil dispersion and transportation. The first scheme calculated the vertical eddy viscosity semi-empirically. In the second scheme, the vertical diffusion coefficient was obtained directly from an Eulerian hydrodynamic model (Princeton Ocean Model, POM2k) while considering wave-caused turbulence. The third scheme was formulated by solving the Langevin equation. The trajectories, percentages of oil particles intruding into water, and the vertical distribution structures of oil particles were analyzed for a series of numerical experiments with different wind magnitudes. The results showed that the different vertical diffusion schemes could generate different horizontal trajectories and spatial distributions of oil spills on the sea surface. The vertical diffusion schemes caused different water-intruding and resurfacing oil particle behaviors, leading to different horizontal transport of oil particles at the surface and subsurface of the ocean. The vertical diffusion schemes were also applied to a realistic oil spill simulation, and these results were compared to satellite observations. All three schemes yielded acceptable results, and those of the third scheme most closely simulated the observed data.

  7. Impact of Molecular Organization on Exciton Diffusion in Photosensitive Single-Crystal Halogenated Perylenediimides Charge Transfer Interfaces.

    PubMed

    Pinto, Rui M; Gouveia, Wilson; Maçôas, Ermelinda M S; Santos, Isabel C; Raja, Sebastian; Baleizão, Carlos; Alves, Helena

    2015-12-23

    The efficiency of organic photodetectors and optoelectronic devices is strongly limited by exciton diffusion, in particular for acceptor materials. Although mechanisms for exciton diffusion are well established, their correlation to molecular organization in real systems has received far less attention. In this report, organic single-crystals interfaces were probed with wavelength-dependent photocurrent spectroscopy and their crystal structure resolved using X-ray diffraction. All systems present a dynamic photoresponse, faster than 500 ms, up to 650 nm. A relationship between molecular organization and favorable exciton diffusion in substituted butyl-perylenediimides (PDIB) is established. This is demonstrated by a set of PDIBs with different intra- and interstack distances and short contacts and their impact on photoresponse. Given the short packing distances between PDIs cores along the same stacking direction (3.4-3.7 Å), and across parallel stacks (2.5 Å), singlet exciton in these PDIBs can follow both Förster and Dexter exciton diffusion, with the Dexter-type mechanism assuming special relevance for interstack exciton diffusion. Yet, the response is maximized in substituted PDIBs, where a 2D percolation network is formed through strong interstack contacts, allowing for PDIBs primary excitons to reach with great efficiency the splitting interface with crystalline rubrene. The importance of short contacts and molecular distances, which is often overlooked as a parameter to consider and optimize when choosing materials for excitonic devices, is emphasized. PMID:26599347

  8. Determination of partition and diffusion coefficients of formaldehyde in selected building materials and impact of relative humidity.

    PubMed

    Xu, Jing; Zhang, Jianshun S; Liu, Xiaoyu; Gao, Zhi

    2012-06-01

    The partition and effective diffusion coefficients of formaldehyde were measured for three materials (conventional gypsum wallboard, "green" gypsum wallboard, and "green" carpet) under three relative humidity (RH) conditions (20%, 50%, and 70% RH). The "green" materials contained recycled materials and were friendly to environment. A dynamic dual-chamber test method was used. Results showed that a higher relative humidity led to a larger effective diffusion coefficient for two kinds of wallboards and carpet. The carpet was also found to be very permeable resulting in an effective diffusion coefficient at the same order of magnitude with the formaldehyde diffusion coefficient in air. The partition coefficient (K(ma)) of formaldehyde in conventional wallboard was 1.52 times larger at 50% RH than at 20% RH, whereas it decreased slightly from 50% to 70% RH, presumably due to the combined effects of water solubility of formaldehyde and micro-pore blocking by condensed moisture at the high RH level. The partition coefficient of formaldehyde increased slightly with the increase of relative humidity in "green" wallboard and "green" carpet. At the same relative humidity level, the "green" wallboard had larger partition coefficient and effective diffusion coefficient than the conventional wallboard, presumably due to the micro-pore structure differences between the two materials. The data generated could be used to assess the sorption effects of formaldehyde on building materials and to evaluate its impact on the formaldehyde concentration in buildings.

  9. Effect of dissolved oxygen manipulation on diffusive emissions from NAPL-impacted low permeability soil layers.

    PubMed

    Clifton, Lisa M; Dahlen, Paul R; Johnson, Paul C

    2014-05-01

    Aquifer physical model experiments were performed to investigate if diffusive emissions from nonaqueous phase liquid (NAPL)-impacted low-permeability layers into groundwater moving through adjacent NAPL-free high-permeability layers can be reduced by creating an aerobic biotreatment zone at the interface between the two, and if over time that leads to reduced emissions after treatment ceases. Experiments were performed in two 1.2-m long × 1.2-m high × 5.4 cm wide stainless steel tanks; each with a high-permeability sand layer overlying a low-permeability crushed granite layer containing a NAPL mixture of indane and benzene. Each tank was water-saturated with horizontal flow primarily through the sand layer. The influent water was initially deoxygenated and the emissions and concentration distributions were allowed to reach near-steady conditions. The influent dissolved oxygen (DO) level was increased stepwise to 6.5-8.5 mg/L and 17-20 mg/L, and then decreased back to deoxygenated conditions. Each condition was maintained for at least 45 days. Relative to the near-steady benzene emission at the initial deoxygenated condition, the emission was reduced by about 70% when the DO was 6.5-8.5 mg/L, 90% when the DO was 17-20 mg/L, and ultimately 60% when returning to low DO conditions. While the reductions were substantial during treatment, longer-term reductions after 120 d of elevated DO treatment, relative to an untreated condition predicted by theory, were low: 29% and 6% in Tank 1 and Tank 2, respectively. Results show a 1-2 month lag between the end of DO delivery and rebound to the final near-steady emissions level. This observation has implications for post-treatment performance monitoring sampling at field sites. PMID:24716993

  10. Effect of dissolved oxygen manipulation on diffusive emissions from NAPL-impacted low permeability soil layers.

    PubMed

    Clifton, Lisa M; Dahlen, Paul R; Johnson, Paul C

    2014-05-01

    Aquifer physical model experiments were performed to investigate if diffusive emissions from nonaqueous phase liquid (NAPL)-impacted low-permeability layers into groundwater moving through adjacent NAPL-free high-permeability layers can be reduced by creating an aerobic biotreatment zone at the interface between the two, and if over time that leads to reduced emissions after treatment ceases. Experiments were performed in two 1.2-m long × 1.2-m high × 5.4 cm wide stainless steel tanks; each with a high-permeability sand layer overlying a low-permeability crushed granite layer containing a NAPL mixture of indane and benzene. Each tank was water-saturated with horizontal flow primarily through the sand layer. The influent water was initially deoxygenated and the emissions and concentration distributions were allowed to reach near-steady conditions. The influent dissolved oxygen (DO) level was increased stepwise to 6.5-8.5 mg/L and 17-20 mg/L, and then decreased back to deoxygenated conditions. Each condition was maintained for at least 45 days. Relative to the near-steady benzene emission at the initial deoxygenated condition, the emission was reduced by about 70% when the DO was 6.5-8.5 mg/L, 90% when the DO was 17-20 mg/L, and ultimately 60% when returning to low DO conditions. While the reductions were substantial during treatment, longer-term reductions after 120 d of elevated DO treatment, relative to an untreated condition predicted by theory, were low: 29% and 6% in Tank 1 and Tank 2, respectively. Results show a 1-2 month lag between the end of DO delivery and rebound to the final near-steady emissions level. This observation has implications for post-treatment performance monitoring sampling at field sites.

  11. Social impacts of technological diffusion: prenatal diagnosis and induced abortion in Brazil.

    PubMed

    Novaes, H M

    2000-01-01

    Scientific and technological development plays an essential part in shaping contemporary societies, and medicine and health care are considered to be particularly receptive to the incorporation of new concepts, techniques and products, producing impacts not only on the health problems for which they were originally intended, but also varied 'side-effects', less frequently recognised and studied. In this study the point of departure was the hypothesis that the intensive diffusion in Brazil of prenatal ultrasound would create new problems for individuals (pregnant women, their families and health professionals) and society in coping with foetal malformations, due to the existence of a very restrictive induced abortion legislation. The objective of the research was to study the social visibility of these problems, in the written mass media. The period under analysis went from 1991 to 1996. The four most important daily newspapers and two medical council journals were studied, with a criteria oriented selection of articles, and their macrotextual thematic analysis. The results indicate that the basic elements in the relationships between medical technology, prenatal diagnosis, foetal malformations and induced abortions stayed the same along the period - a restrictive Penal Code, the public recognition of the disseminated and usually tolerated practice of induced abortion, done in risky conditions for the majority of women, with very evident consequences on maternal health, a divided Congress, a divided 'public opinion', religious opposition and new scientific and technological practices in health care. Nevertheless, tension between these 'contradictory' factors increases, so much so, that new elements are introduced which make an accommodation possible, without implying in major changes of position. This is achieved through the development of new alliances between Science, the judiciary and obstetrical leaders, which benefit individual initiatives, instead of leading

  12. Identifying the main paths of information diffusion in online social networks

    NASA Astrophysics Data System (ADS)

    Zhu, Hengmin; Yin, Xicheng; Ma, Jing; Hu, Wei

    2016-06-01

    Recently, an increasing number of researches on relationship strength show that there are some socially active links in online social networks. Furthermore, it is likely that there exist main paths which play the most significant role in the process of information diffusion. Although much of previous work has focused on the pathway of a specific event, there are hardly any scholars that have extracted the main paths. To identify the main paths of online social networks, we proposed a method which measures the weights of links based on historical interaction records. The influence of node based on forwarding amount is quantified and top-ranked nodes are selected as the influential users. The path importance is evaluated by calculating the probability that a message would spread via this path. We applied our method to a real-world network and found interesting insights. Each influential user can access another one via a short main path and the distribution of main paths shows significant community effect.

  13. Quantitative spectroscopic diffuse optical tomography of the breast guided by imperfect a priori structural information

    NASA Astrophysics Data System (ADS)

    Boverman, Gregory; Miller, Eric L.; Li, Ang; Zhang, Quan; Chaves, Tina; Brooks, Dana H.; Boas, David A.

    2005-09-01

    Spectroscopic diffuse optical tomography (DOT) can directly image the concentrations of physiologically significant chromophores in the body. This information may be of importance in characterizing breast tumours and distinguishing them from benign structures. This paper studies the accuracy with which lesions can be characterized given a physiologically realistic situation in which the background architecture of the breast is heterogeneous yet highly structured. Specifically, in simulation studies, we assume that the breast is segmented into distinct glandular and adipose regions. Imaging with a high-resolution imaging modality, such as magnetic resonance imaging, in conjunction with a segmentation by a clinical expert, allows the glandular/adipose boundary to be determined. We then apply a two-step approach in which the background chromophore concentrations of each region are estimated in a nonlinear fashion, and a more localized lesion is subsequently estimated using a linear perturbational approach. In addition, we examine the consequences which errors in the breast segmentation have on estimating both the background and inhomogeneity chromophore concentrations.

  14. The diffusion of autism spectrum disorder in Costa Rica: Evidence of information spread or environmental effects?

    PubMed

    Schelly, David; Jiménez González, Patricia; Solís, Pedro J

    2015-09-01

    In the U.S., children with autism spectrum disorder (ASD) have been found to live in spatial clusters. Studies have suggested that the clustering is caused by social or environmental factors, but determining the cause of the clustering is difficult in the U.S. setting because of unmeasured variation in healthcare access and diagnostic practices. The present study explores the diffusion of ASD in a small setting in which the diagnosis is not widely publicised and there is no variation in healthcare access or diagnostic practices. Costa Rica provides universal healthcare and only has one diagnosing clinic for young children, and the diagnosis is relatively new and little known among clinicians and parents. In addition, the potential for mercury exposure from the source that has been associated with ASD is absent, and areas with high levels of air pollution are spatially concentrated. Focusing on all young children who underwent an ASD assessment from 2010 to 2013, we identify spatial clusters that suggest a mechanism that does not depend on information about ASD, healthcare access, diagnostic practices, or environmental toxicants. These findings provide details of the "contextual drivers" of the increasing worldwide prevalence of ASD. PMID:26318531

  15. Impact of water boundary layer diffusion on the nitrification rate of submerged biofilter elements from a recirculating aquaculture system.

    PubMed

    Prehn, Jonas; Waul, Christopher K; Pedersen, Lars-Flemming; Arvin, Erik

    2012-07-01

    Total ammonia nitrogen (TAN) removal by microbial nitrification is an essential process in recirculating aquaculture systems (RAS). In order to protect the aquatic environment and fish health, it is important to be able to predict the nitrification rates in RAS's. The aim of this study was to determine the impact of hydraulic film diffusion on the nitrification rate in a submerged biofilter. Using an experimental batch reactor setup with recirculation, active nitrifying biofilter units from a RAS were exposed to a range of hydraulic flow velocities. Corresponding nitrification rates were measured following ammonium chloride, NH₄Cl, spikes and the impact of hydraulic film diffusion was quantified. The nitrification performance of the tested biofilter could be significantly increased by increasing the hydraulic flow velocity in the filter. Area based first order nitrification rate constants ranged from 0.065 m d⁻¹ to 0.192 m d⁻¹ for flow velocities between 2.5 m h⁻¹ and 40 m h⁻¹ (18 °C). This study documents that hydraulic film diffusion may have a significant impact on the nitrification rate in fixed film biofilters with geometry and hydraulic flows corresponding to our experimental RAS biofilters. The results may thus have practical implications in relation to the design, operational strategy of RAS biofilters and how to optimize TAN removal in fixed film biofilter systems.

  16. Impacts of small-scale variability on the determination of bulk thermal diffusivity in snowpacks

    NASA Astrophysics Data System (ADS)

    Oldroyd, H. J.; Higgins, C. W.; Huwald, H.; Selker, J. S.; Parlange, M. B.

    2012-04-01

    Thermal diffusivity of snow is an important physical property associated with key hydrological phenomena such as snowmelt and heat and water vapor exchange with the atmosphere. These phenomena have broad implications in studies of climate and heat and water budgets on many scales. Furthermore, sub grid scale phenomena may enhance these heat and mass exchanges in the snow pack due to its porous nature. We hypothesize that the heat transfer effects of these small-scale variabilities may be seen as an increased bulk thermal diffusivity of the snow. Direct measurements of snow thermal diffusivity require coupled measurements of thermal conductivity and density, which are nonstationary due to snow metamorphism. Furthermore, thermal conductivity measurements are typically obtained with specialized heating probes or plates and snow density measurements require digging snow pits. Therefore, direct measurements are difficult to obtain with high enough temporal resolution such that direct comparisons with atmospheric conditions can be made. This study uses highly resolved temperature measurements from the Plaine Morte glacier in Switzerland as initial and boundary conditions to numerically solve the 1D heat equation and iteratively optimize for thermal diffusivity. The method uses flux boundary conditions to constrain thermal diffusivity such that spuriously high values in thermal diffusivity are eliminated. Additionally, a t-test ensuring statistical significance between solutions of varied thermal diffusivity results in further constraints on thermal diffusivity that eliminate spuriously low values. The results show that time resolved thermal diffusivity can be determined from easily implemented and inexpensive temperature measurements of seasonal snow with good agreement to widely used parameterizations based on snow density. This high time resolution further affords the ability to explore possible turbulence-induced enhancements to heat and mass transfer in the snow.

  17. Extracting Kinetic and Stationary Distribution Information from Short MD Trajectories via a Collection of Surrogate Diffusion Models

    PubMed Central

    Calderon, Christopher P.; Arora, Karunesh

    2009-01-01

    Low-dimensional stochastic models can summarize dynamical information and make long time predictions associated with observables of complex atomistic systems. Maximum likelihood based techniques for estimating low-dimensional surrogate diffusion models from relatively short time series are presented. It is found that a heterogeneous population of slowly evolving conformational degrees of freedom modulates the dynamics. This underlying heterogeneity results in a collection of estimated low-dimensional diffusion models. Numerical techniques for exploiting this finding to approximate skewed histograms associated with the simulation are presented. In addition, statistical tests are also used to assess the validity of the models and determine physically relevant sampling information, e.g. the maximum sampling frequency at which one can discretely sample from an atomistic time series and have a surrogate diffusion model pass goodness-of-fit tests. The information extracted from such analyses can possibly be used to assist umbrella sampling computations as well as help in approximating effective diffusion coefficients. The techniques are demonstrated on simulations of Adenylate Kinase. PMID:20046947

  18. Environmental impacts of modern agricultural technology diffusion in Bangladesh: an analysis of farmers' perceptions and their determinants.

    PubMed

    Rahman, Sanzidur

    2003-06-01

    Farmers' perception of the environmental impacts of modern agricultural technology diffusion and factors determining such awareness were examined using survey data from 21 villages in three agro-ecological regions of Bangladesh. Results reveal that farmers are well aware of the adverse environmental impacts of modern agricultural technology, although their awareness remains confined within visible impacts such as soil fertility, fish catches, and health effects. Their perception of intangible impacts such as, toxicity in water and soils is weak. Level and duration of modern agricultural technology adoption directly influence awareness of its adverse effects. Education and extension contacts also play an important role in raising awareness. Awareness is higher among farmers in developed regions, fertile locations and those with access to off-farm income sources. Promotion of education and strengthening extension services will boost farmers' environmental awareness. Infrastructure development and measures to replenish depleting soil fertility will also play a positive role in raising awareness.

  19. [Scientific information systems: tools for measures of biomedical research impact].

    PubMed

    Navarrete Cortés, José; Banqueri Ozáez, Jesús

    2008-12-01

    The present article provides an analysis and description of the use of scientific information systems as instruments to measure and monitor results and investigative activity in biomedicine. Based on the current situation concerning the use and implementation of these systems, we offer a detailed description of the actors of these systems and propose a functional architecture for this class of software. In addition, the instruments that these types of systems offer for the measurement of the impact of the results of research are described in depth, as these instruments can help in decision making. Finally, a selection of national and international scientific information systems are listed and reviewed. PMID:19631827

  20. Stochastic Simulation of Signal Transduction: Impact of the Cellular Architecture on Diffusion

    PubMed Central

    Klann, Michael T.; Lapin, Alexei; Reuss, Matthias

    2009-01-01

    Abstract The transduction of signals depends on the translocation of signaling molecules to specific targets. Undirected diffusion processes play a key role in the bridging of spaces between different cellular compartments. The diffusion of the molecules is, in turn, governed by the intracellular architecture. Molecular crowding and the cytoskeleton decrease macroscopic diffusion. This article shows the use of a stochastic simulation method to study the effects of the cytoskeleton structure on the mobility of macromolecules. Brownian dynamics and single particle tracking were used to simulate the diffusion process of individual molecules through a model cytoskeleton. The resulting average effective diffusion is in line with data obtained in the in vitro and in vivo experiments. It shows that the cytoskeleton structure strongly influences the diffusion of macromolecules. The simulation method used also allows the inclusion of reactions in order to model complete signaling pathways in their spatio-temporal dynamics, taking into account the effects of the cellular architecture. PMID:19527672

  1. Impacts of diffuse radiation on light use efficiency across terrestrial ecosystems based on Eddy covariance observation in China.

    PubMed

    Huang, Kun; Wang, Shaoqiang; Zhou, Lei; Wang, Huimin; Zhang, Junhui; Yan, Junhua; Zhao, Liang; Wang, Yanfen; Shi, Peili

    2014-01-01

    Ecosystem light use efficiency (LUE) is a key factor of production models for gross primary production (GPP) predictions. Previous studies revealed that ecosystem LUE could be significantly enhanced by an increase on diffuse radiation. Under large spatial heterogeneity and increasing annual diffuse radiation in China, eddy covariance flux data at 6 sites across different ecosystems from 2003 to 2007 were used to investigate the impacts of diffuse radiation indicated by the cloudiness index (CI) on ecosystem LUE in grassland and forest ecosystems. Our results showed that the ecosystem LUE at the six sites was significantly correlated with the cloudiness variation (0.24 ≤ R(2) ≤ 0.85), especially at the Changbaishan temperate forest ecosystem (R(2) = 0.85). Meanwhile, the CI values appeared more frequently between 0.8 and 1.0 in two subtropical forest ecosystems (Qianyanzhou and Dinghushan) and were much larger than those in temperate ecosystems. Besides, cloudiness thresholds which were favorable for enhancing ecosystem carbon sequestration existed at the three forest sites, respectively. Our research confirmed that the ecosystem LUE at the six sites in China was positively responsive to the diffuse radiation, and the cloudiness index could be used as an environmental regulator for LUE modeling in regional GPP prediction.

  2. Impacting university physics students through participation in informal science

    NASA Astrophysics Data System (ADS)

    Hinko, Kathleen; Finkelstein, Noah D.

    2013-01-01

    Informal education programs organized by university physics departments are a popular means of reaching out to communities and satisfying grant requirements. The outcomes of these programs are often described in terms of broader impacts on the community. Comparatively little attention, however, has been paid to the influence of such programs on those students facilitating the informal science programs. Through Partnerships for Informal Science Education in the Community (PISEC) at the University of Colorado Boulder, undergraduate and graduate physics students coach elementary and middle school children during an inquiry-based science afterschool program. As part of their participation in PISEC, university students complete preparation in pedagogy, communication and diversity, engage with children on a weekly basis and provide regular feedback about the program. We present findings that indicate these experiences improve the ability of university students to communicate in everyday language and positively influence their perspectives on teaching and learning.

  3. Impacts of regional mixing on the temperature structure of the equatorial Pacific Ocean. Part 1: Vertically uniform vertical diffusion

    NASA Astrophysics Data System (ADS)

    Furue, Ryo; Jia, Yanli; McCreary, Julian P.; Schneider, Niklas; Richards, Kelvin J.; Müller, Peter; Cornuelle, Bruce D.; Avellaneda, Nidia Martínez; Stammer, Detlef; Liu, Chuanyu; Köhl, Armin

    2015-07-01

    We investigate the sensitivity of numerical-model solutions to regional changes in vertical diffusion. Specifically, we vary the background diffusion coefficient, κb, within spatially distinct subregions of the tropical Pacific, assess the impacts of those changes, and diagnose the processes that account for them. Solutions respond to a diffusion anomaly, δκb, in three ways. Initially, there is a fast response (several months), due to the interaction of rapidly-propagating, barotropic and gravity waves with eddies and other mesoscale features. It is followed by a local response (roughly one year), the initial growth and spatial pattern of which can be explained by one-dimensional (vertical) diffusion. At this stage, temperature and salinity anomalies are generated that are either associated with a change in density ("dynamical" anomalies) or without one ("spiciness" anomalies). In a final adjustment stage, the dynamical and spiciness anomalies spread to remote regions by radiation of Rossby and Kelvin waves and by advection, respectively. In near-equilibrium solutions, dynamical anomalies are generally much larger in the latitude band of the forcing, but the impact of off-equatorial forcing by δκb on the equatorial temperature structure is still significant. Spiciness anomalies spread equatorward within the pycnocline, where they are carried to the equator as part of the subsurface branch of the Pacific Subtropical Cells, and spiciness also extends to the equator via western-boundary currents. Forcing near and at the equator generates strong dynamical anomalies, and sometimes additional spiciness anomalies, at pycnocline depths. The total response of the equatorial temperature structure to δκb in various regions depends on the strength and spatial pattern of the generation of each signal within the forcing region as well as on the processes of its spreading to the equator.

  4. Diffusion in Colocation Contact Networks: The Impact of Nodal Spatiotemporal Dynamics.

    PubMed

    Thomas, Bryce; Jurdak, Raja; Zhao, Kun; Atkinson, Ian

    2016-01-01

    Temporal contact networks are studied to understand dynamic spreading phenomena such as communicable diseases or information dissemination. To establish how spatiotemporal dynamics of nodes impact spreading potential in colocation contact networks, we propose "inducement-shuffling" null models which break one or more correlations between times, locations and nodes. By reconfiguring the time and/or location of each node's presence in the network, these models induce alternative sets of colocation events giving rise to contact networks with varying spreading potential. This enables second-order causal reasoning about how correlations in nodes' spatiotemporal preferences not only lead to a given contact network but ultimately influence the network's spreading potential. We find the correlation between nodes and times to be the greatest impediment to spreading, while the correlation between times and locations slightly catalyzes spreading. Under each of the presented null models we measure both the number of contacts and infection prevalence as a function of time, with the surprising finding that the two have no direct causality. PMID:27501240

  5. Diffusion in Colocation Contact Networks: The Impact of Nodal Spatiotemporal Dynamics

    PubMed Central

    Thomas, Bryce; Jurdak, Raja; Zhao, Kun; Atkinson, Ian

    2016-01-01

    Temporal contact networks are studied to understand dynamic spreading phenomena such as communicable diseases or information dissemination. To establish how spatiotemporal dynamics of nodes impact spreading potential in colocation contact networks, we propose “inducement-shuffling” null models which break one or more correlations between times, locations and nodes. By reconfiguring the time and/or location of each node’s presence in the network, these models induce alternative sets of colocation events giving rise to contact networks with varying spreading potential. This enables second-order causal reasoning about how correlations in nodes’ spatiotemporal preferences not only lead to a given contact network but ultimately influence the network’s spreading potential. We find the correlation between nodes and times to be the greatest impediment to spreading, while the correlation between times and locations slightly catalyzes spreading. Under each of the presented null models we measure both the number of contacts and infection prevalence as a function of time, with the surprising finding that the two have no direct causality. PMID:27501240

  6. Modeling the impacts of solar radiation partitioning into direct and diffuse fractions for the global water cycle

    NASA Astrophysics Data System (ADS)

    Oliveira, Paulo J. C.; Davin, Edouard L.; Seneviratne, Sonia I.

    2010-05-01

    Incident solar radiation at the Earth's surface affects plant photosynthesis and evapotranspiration, and consequently the global water budget. Observations from 1960-1990's across the Northern Hemisphere suggest that increased aerosol loadings from industrialization led not only to a decline in the intensity of solar radiation at the surface (global dimming), but also to a higher fraction of scattered light, which enhanced plant photosynthesis and the land carbon sink, with probable concurrent impacts on the water cycle. Thus, we used the NCAR Community Land Model (version 3.5) to perform global offline simulations and study the effects of the imposition of changes to radiation partitioning in diffuse and direct fractions on trends in evapotranspiration and runoff. We find that most modeled land surface variables respond to an increased-diffuse simulation where the relative fraction of radiation is changed globally at a high rate of increased diffuse as reported by some observation stations. Increased-diffuse partitioning causes a rise in total ET in all regions, an effect of opposite sign but smaller absolute value than that resulting from global dimming. Evapotranspiration rises by over 0.5 watt/m2 per decade in the tropics, due to increased shaded leaf stomatal conductance, with an opposite effect noted elsewhere due to lower ground evaporation. In the eastern U.S.A. and the Amazon basin, decadal trend anomalies in evapotranspiration for increased-diffuse radiation change reach 25-30% the absolute magnitude of those caused by dimming. Reductions to river runoff are modest nearly everywhere outside the Amazon. Understanding the mechanisms behind the interactions between solar radiation and the various land-surface components will help the development of climate models, improving predictions, in particular regarding changes in terrestrial hydrologic resources.

  7. Information to help reduce environmental impacts from freshwater oil spills

    SciTech Connect

    Fritz, D.E.; Steen, A.E.

    1995-12-31

    The American Petroleum Institute (API) has been working since 1990 to provide information to help the response community minimize the impact of spills to pared jointly with the US inland freshwater. Projects have included a manual, pre National Oceanic and Atmospheric Administration (NOAA), to give guidance on the cleanup techniques that will minimize environmental impacts on spills in freshwater habitats. Nearing completion are a literature review and annotated bibliography of the environmental and human health effects of oil spilled in freshwater habitats. The use of chemical treating agents for freshwater spill applications is being studied with input from other industry and government groups. A project has begun, with funding from API, the Louisiana Applied Oil Spill Research and Development Program, NOAA, the Marine Spill Response Corporation (MSRC), and the US Department of Energy, to evaluate in situ burning of oil spilled in marshes.

  8. Spatial Resolution, Grayscale, and Error Diffusion Trade-offs: Impact on Display System Design

    NASA Technical Reports Server (NTRS)

    Gille, Jennifer L. (Principal Investigator)

    1996-01-01

    We examine technology trade-offs related to grayscale resolution, spatial resolution, and error diffusion for tessellated display systems. We present new empirical results from our psychophysical study of these trade-offs and compare them to the predictions of a model of human vision.

  9. The impact of probe size on measurements of diffusion in active microrheology.

    PubMed

    Hoh, Nicholas J; Zia, Roseanna N

    2016-08-21

    We present a framework to elucidate the influence of polydispersity on flow-induced diffusion in active microrheology. A colloidal probe particle is driven through a suspension of hydrodynamically interacting background particles, where the probe may be larger or smaller than the bath particles. The thermodynamic size of the particles may be greater than their hydrodynamic size; the hydrodynamic sizes can be identical with thermodynamic sizes that differ, or vice versa, or a combination of both. The diffusive behavior is set entirely and dually by the proximity with which two particles can approach one another, and by the extent to which this minimum approach distance is occupied by the hydrodynamic size of the forced particle. We find that reducing the size of the probe reduces flow-induced diffusion when hydrodynamic interactions are weak but increases flow-induced diffusion when hydrodynamic interactions are strong-regardless of the strength of external forcing. This behavior owes its origins to a rich evolution of the dominance of hydrodynamic and entropic forces with changes in the relative hydrodynamic and thermodynamic sizes of the particles. PMID:27442485

  10. Impact of information and communication technology on child health.

    PubMed

    Woo, Eugenia Hc; White, Peter; Lai, Christopher Wk

    2016-06-01

    This article provides a general framework for understanding the use of information and communication technology in education and discusses the impact of computer usage on students' health and development. Potential beneficial and harmful effects of computer use by children are discussed. Early epidemiological and laboratory studies have indicated that children are at least of similar risk of developing musculoskeletal and vision problems as adults, and musculoskeletal and visual health problems developed in childhood are likely to persist into adulthood. This article, therefore, aims to provide a reflection on the deficits of existing policy and recommendations for child-specific guidelines in computer use. PMID:27333844

  11. Innovation Value of Information Technology: Impact of Information Technology--Intensity on Innovation Capability and Firm Performance

    ERIC Educational Resources Information Center

    Ramamani, Mahesh Kumar

    2010-01-01

    Though information technology adoptions have been always referred to as innovations in firms, much of the business value literature has concentrated on the tangible and immediately measurable impacts of information technology (IT) adoptions. This study aims to explore the impact of information technology investments on the innovativeness of a…

  12. NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 22: US academic librarians and technical information specialists as information intermediaries: Results of the phase 3 survey

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Barclay, Rebecca O.; Kennedy, John M.

    1994-01-01

    The U.S. government technical report is a primary means by which the results of federally funded research and development (R&D) are transferred to the U.S. aerospace industry. However, little is known about this information product in terms of its actual use, importance, and value in the transfer of federally funded R&D. To help establish a body of knowledge, the U.S. government technical report is being investigated as part of the NASA/DOD Aerospace Knowledge Diffusion Research Project. In this report, we summarize the literature on technical reports and provide a model that depicts the transfer of federally funded aerospace R&D via the U.S. government technical report. We present results from our investigation of aerospace knowledge diffusion vis-a-vis the U.S. government technical report, and present the results of research that investigated aerospace knowledge diffusion vis-a-vis U.S. academic librarians and technical information specialists as information intermediaries.

  13. NASA/DOD Aerospace Knowledge Diffusion Research Project. Report number 21: US aerospace industry librarians and technical information specialists as information intermediaries: Results of the phase 2 survey

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Barclay, Rebecca O.; Kennedy, John M.

    1994-01-01

    The U.S. government technical report is a primary means by which the results of federally funded research and development (R&D) are transferred to the U.S. aerospace industry. However, little is known about this information product in terms of its actual use, importance, and value in the transfer of federally funded R&D. To help establish a body of knowledge, the U.S. government technical report is being investigated as part of the NASA/DoD Aerospace Knowledge Diffusion Research Project. In this report, we summarize the literature on technical reports and provide a model that depicts the transfer of federally funded aerospace R&D via the U.S. government technical report. We present results from our investigation of aerospace knowledge diffusion vis-a-vis the U.S. government technical report, and present the results of research that investigated aerospace knowledge diffusion vis-a-vis U.S. aerospace industry librarians and technical information specialists as information intermediaries.

  14. Impact of Health Disclosure Laws on Health Information Exchanges

    PubMed Central

    Adjerid, Idris; Padman, Rema

    2011-01-01

    Health information exchanges (HIEs) are expected to facilitate data sharing between healthcare entities, thereby improving the efficiency and quality of care. Privacy concerns have been consistently cited as one of the primary challenges to HIE formation and success. Currently, it is unclear how privacy laws – in particular, legislation restricting the disclosure of health records – have shaped the development of HIEs. This preliminary study explores the landscape of state-level health privacy legislation and examines the impact of variations in such privacy and confidentiality laws on the progress of HIEs. We found that states with stronger privacy laws, limiting the disclosure of health information, had significantly more HIEs exchanging data and had fewer failed HIEs. We suggest that this counterintuitive finding may be explained by the more subtle benefits of such laws, such as increased confidence and trust of participants in an exchange. Other key contributors to this work are Alessandro Acquisti, Rahul Telang, and Julia Adler-Milstein PMID:22195054

  15. Spectral Resolution and Coverage Impact on Advanced Sounder Information Content

    NASA Technical Reports Server (NTRS)

    Larar, Allen M.; Liu, Xu; Zhou, Daniel K.; Smith, William L.

    2010-01-01

    Advanced satellite sensors are tasked with improving global measurements of the Earth s atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring capability, and environmental change detection. Achieving such measurement improvements requires instrument system advancements. This presentation focuses on the impact of spectral resolution and coverage changes on remote sensing system information content, with a specific emphasis on thermodynamic state and trace species variables obtainable from advanced atmospheric sounders such as the Infrared Atmospheric Sounding Interferometer (IASI) and Cross-track Infrared Sounder (CrIS) systems on the MetOp and NPP/NPOESS series of satellites. Key words: remote sensing, advanced sounders, information content, IASI, CrIS

  16. The impact of genetic information on policy and clinical practice.

    PubMed

    Abel, Elizabeth; Horner, Sharon D; Tyler, Diane; Innerarity, Sheryl A

    2005-02-01

    This article discusses genetics-related policy issues that have an impact on health care systems, health care providers, and their patients: privacy, mass screening, family screening, and knowledge dissemination. Access, cost, and ethical implications are important discussant points for each of these genetic-related policy issues. Embedded in the issue of privacy are concerns of insurability, confidentiality, and discrimination. The public health policy implications related to mass screening programs include efficacy of the screening tests, availability of primary and secondary interventions, access, costs, and program evaluation. Policy issues for family screening are similar to mass screening, with added concerns about privacy and availability of adequate resources, including health care providers and counselors trained in genetics. Knowledge dissemination is critical to maintaining currency of clinical information and applications of genetic technologies and treatments. As genetic information expands, the need for knowledge dissemination will increase. The importance of advanced practice nurses' involvement in these policy issues is discussed. PMID:16443953

  17. China Refrigerator Information Label: Specification Development and Potential Impact

    SciTech Connect

    Fridley, David; Fridley, David; Zheng, Nina; Zhou, Nan; Aden, Nathaniel; Lin, Jiang; Jianhong, Cheng; Sakamoto, Tomoyuki

    2008-02-01

    In the last five years, China's refrigerator market has grown rapidly, and now urban markets are showing signs of saturation, with ownership rates in urban households reaching 92%. Rural markets continue to grow from a much lower base. As a result of this growth, the Chinese government in 2006 decided to revise the refrigerator standards and its associated efficiency grades for the mandatory energy information label. In the Chinese standards process, the efficiency grades for the information label are tied to the minimum standards. Work on the minimum standards revision began in 2006 and continued through the first half of 2007, when the draft standard was completed under the direction of the China National Institute of Standardization (CNIS). Development of the information label grades required consideration of stakeholder input, continuity with the previous grade classification, ease of implementation, and potential impacts on the market. In this process, CLASP, with the support of METI/IEEJ, collaborated with CNIS to develop the efficiency grades, providing technical input to the process, comment and advice on particular technical issues, and evaluation of the results. After three months of effort and three drafts of the final grade specifications, this work was completed. In addition, in order to effectively evaluate the impact of the label on China's market, CLASP further provided assistance to CNIS to collect data on both the efficiency distribution and product volume distribution of refrigerators on the market. The new information label thresholds to be implemented in 2008 maintain the approach first adopted in 2005 of establishing efficiency levels relative to the minimum standard, but increased the related required efficiency levels by 20% over those established in 2003 and implemented in 2005. The focus of improvement was on the standard refrigerator/freezer (class 5), which constitutes the bulk of the Chinese market. Indeed, the new requirements to

  18. Impact of the atomic layer deposition precursors diffusion on solid-state carbon nanotube based supercapacitors performances

    NASA Astrophysics Data System (ADS)

    Fiorentino, Giuseppe; Vollebregt, Sten; Tichelaar, F. D.; Ishihara, Ryoichi; Sarro, Pasqualina M.

    2015-02-01

    A study on the impact of atomic layer deposition (ALD) precursors diffusion on the performance of solid-state miniaturized nanostructure capacitor array is presented. Three-dimensional nanostructured capacitor array based on double conformal coating of multiwalled carbon nanotubes (MWCNTs) bundles is realized using ALD to deposit Al2O3 as dielectric layer and TiN as high aspect-ratio conformal counter-electrode on 2 μm long MWCNT bundles. The devices have a small footprint (from 100 μm2 to 2500 μm2) and are realized using an IC wafer-scale manufacturing process with high reproducibility (≤0.3E-12F deviation). To evaluate the enhancement of the electrode surface, the measured capacitance values are compared to a lumped circuital model. The observed discrepancies are explained with a partial coating of the CNT, that determine a limited use of the available electrode surface area. To analyze the CNT coating effectiveness, the ALD precursors diffusions inside the CNT bundle is studied using a Knudsen diffusion mechanism.

  19. Critical Role of Dynamic Flexibility in Ge-Containing Zeolites: Impact on Diffusion.

    PubMed

    Gutiérrez-Sevillano, Juan José; Calero, Sofía; Hamad, Said; Grau-Crespo, Ricardo; Rey, Fernando; Valencia, Susana; Palomino, Miguel; Balestra, Salvador R G; Ruiz-Salvador, A Rabdel

    2016-07-11

    Incorporation of germanium in zeolites is well known to confer static flexibility to their framework, by stabilizing the formation of small rings. In this work, we show that the flexibility associated to Ge atoms in zeolites goes beyond this static effect, manifesting also a clear dynamic nature, in the sense that it leads to enhanced molecular diffusion. Our study combines experimental and theoretical methods providing evidence for this effect, which has not been described previously, as well as a rationalization for it, based on atomistic grounds. We have used both pure-silica and silico-germanate ITQ-29 (LTA topology) zeolites as a case study. Based on our simulations, we identify the flexibility associated to the pore breathing-like behavior induced by the Ge atoms, as the key factor leading to the enhanced diffusion observed experimentally in Ge-containing zeolites. PMID:27305363

  20. Impact of mesophyll diffusion on estimated global land CO2 fertilization

    DOE PAGES

    Sun, Ying; Gu, Lianhong; Dickinson, Robert E.; Norby, Richard J.; Pallardy, Stephen G.; Hoffman, Forrest M.

    2014-10-13

    In C3 plants, CO2 concentrations drop considerably along mesophyll diffusion pathways from substomatal cavities to chloroplasts where CO2 assimilation occurs. Global carbon cycle models have not explicitly represented this internal drawdown and so overestimate CO2 available for carboxylation and underestimate photosynthetic responsiveness to atmospheric CO2. An explicit consideration of mesophyll diffusion increases the modeled cumulative CO2 fertilization effect (CFE) for global gross primary production (GPP) from 915 PgC to 1057 PgC for the period of 1901 to 2010. This increase represents a 16% correction, large enough to explain the persistent overestimation of growth rates of historical atmospheric CO2 by Earthmore » System Models. Without this correction, the CFE for global GPP is underestimated by 0.05 PgC yr-1ppm-1. This finding implies that the contemporary terrestrial biosphere is more CO2-limited than previously thought.« less

  1. Impact of nonlocal boundary-layer diffusion scheme on forecasts over Indian region

    NASA Astrophysics Data System (ADS)

    Sanjay, J.; Mukhopadhyay, P.; Singh, S. S.

    The results of incorporating a nonlocal boundary-layer diffusion scheme in a forecast model over Indian region are discussed. The simple formulation of atmospheric boundary layer height in the nonlocal diffusion scheme is examined in detail to understand how far the model simulated boundary layer height is realistic. Analyses of the temporal and spatial variability of the boundary height for three cases representing premonsoon, active monsoon and post monsoon conditions over Indian region show that it is comparable with the observational evidence. Further, for a case of active monsoon condition over Indian region, comparison of precipitation forecasts with the nonlocal scheme and the control local boundary-layer scheme clearly indicated that the model run with the nonlocal scheme is significantly more accurate in forecasting the intense precipitation locations.

  2. Impact of Mesophyll Diffusion on Estimated Global Land CO2 Fertilization

    NASA Astrophysics Data System (ADS)

    Sun, Y.; Gu, L.; Dickinson, R. E.

    2014-12-01

    In C3 plants, CO2 concentrations drop considerably along mesophyll diffusion pathways from substomatal cavities to chloroplasts where CO2 assimilation occurs. Global carbon cycle models have not explicitly represented this internal drawdown and so overestimate CO2 available for carboxylation and underestimate photosynthetic responsiveness to atmospheric CO2. An explicit consideration of mesophyll diffusion increases the modeled cumulative CO2 fertilization effect (CFE) for global gross primary production (GPP) from 915 PgC to 1057 PgC for the period of 1901 to 2010. This increase represents a 16% correction large enough to explain the persistent overestimation of growth rates of historical atmospheric CO2 by Earth System Models. Without this correction, the CFE for global GPP is underestimated by 0.05 PgC yr-1ppm-1. This finding implies that the contemporary terrestrial biosphere is more CO2-limited than previously thought.

  3. Atomic diffusion on vicinal surfaces: step roughening impact on step permeability

    NASA Astrophysics Data System (ADS)

    Ranguelov, B.; Michailov, M.

    2014-12-01

    The problem of mass transport in material science for systems with reduced dimensionality holds special academic and technological attention since the fine diffusion control of adatoms could initiate exotic nanoscale patterning at epitaxial interfaces. The present study brings out important details of the atomic diffusion mechanisms on vicinal surfaces, accounting for the subtle competition between an external field imposed on the migrating adatoms and the roughening of the steps bordering the atomic terraces. The computational model reveals a temperature gap for breakdown of step permeability in the vicinity of the step roughening transition and sheds light on recently observed experimental results for atomic step dynamics on Si surfaces. The present study also demonstrates the extended capability of atomistic models in computer simulations to unravel simultaneous effects, to distinguish between them, and finally to assess their specific contribution to experimentally observed complex physical phenomena.

  4. Impact of mesophyll diffusion on estimated global land CO2 fertilization.

    PubMed

    Sun, Ying; Gu, Lianhong; Dickinson, Robert E; Norby, Richard J; Pallardy, Stephen G; Hoffman, Forrest M

    2014-11-01

    In C3 plants, CO2 concentrations drop considerably along mesophyll diffusion pathways from substomatal cavities to chloroplasts where CO2 assimilation occurs. Global carbon cycle models have not explicitly represented this internal drawdown and therefore overestimate CO2 available for carboxylation and underestimate photosynthetic responsiveness to atmospheric CO2. An explicit consideration of mesophyll diffusion increases the modeled cumulative CO2 fertilization effect (CFE) for global gross primary production (GPP) from 915 to 1,057 PgC for the period of 1901-2010. This increase represents a 16% correction, which is large enough to explain the persistent overestimation of growth rates of historical atmospheric CO2 by Earth system models. Without this correction, the CFE for global GPP is underestimated by 0.05 PgC/y/ppm. This finding implies that the contemporary terrestrial biosphere is more CO2 limited than previously thought.

  5. Impact of homogeneous strain on uranium vacancy diffusion in uranium dioxide

    NASA Astrophysics Data System (ADS)

    Goyal, Anuj; Phillpot, Simon R.; Subramanian, Gopinath; Andersson, David A.; Stanek, Chris R.; Uberuaga, Blas P.

    2015-03-01

    We present a detailed mechanism of, and the effect of homogeneous strains on, the migration of uranium vacancies in UO2. Vacancy migration pathways and barriers are identified using density functional theory and the effect of uniform strain fields are accounted for using the dipole tensor approach. We report complex migration pathways and noncubic symmetry associated with the uranium vacancy in UO2 and show that these complexities need to be carefully accounted for to predict the correct diffusion behavior of uranium vacancies. We show that under homogeneous strain fields, only the dipole tensor of the saddle with respect to the minimum is required to correctly predict the change in the energy barrier between the strained and the unstrained case. Diffusivities are computed using kinetic Monte Carlo simulations for both neutral and fully charged state of uranium single and divacancies. We calculate the effect of strain on migration barriers in the temperature range 800-1800 K for both vacancy types. Homogeneous strains as small as 2 % have a considerable effect on diffusivity of both single and divacancies of uranium, with the effect of strain being more pronounced for single vacancies than divacancies. In contrast, the response of a given defect to strain is less sensitive to changes in the charge state of the defect. Further, strain leads to anisotropies in the mobility of the vacancy and the degree of anisotropy is very sensitive to the nature of the applied strain field for strain of equal magnitude. Our results suggest that the influence of strain on vacancy diffusivity will be significantly greater when single vacancies dominate the defect structure, such as sintering, while the effects will be much less substantial under irradiation conditions where divacancies dominate.

  6. Impact of multi-component diffusion in turbulent combustion using direct numerical simulations

    DOE PAGES

    Bruno, Claudio; Sankaran, Vaidyanathan; Kolla, Hemanth; Chen, Jacqueline H.

    2015-08-28

    This study presents the results of DNS of a partially premixed turbulent syngas/air flame at atmospheric pressure. The objective was to assess the importance and possible effects of molecular transport on flame behavior and structure. To this purpose DNS were performed at with two proprietary DNS codes and with three different molecular diffusion transport models: fully multi-component, mixture averaged, and imposing the Lewis number of all species to be unity.

  7. Impact of homogeneous strain on uranium vacancy diffusion in uranium dioxide

    DOE PAGES

    Goyal, Anuj; Phillpot, Simon R.; Subramanian, Gopinath; Andersson, David A.; Stanek, Chris R.; Uberuaga, Blas P.

    2015-03-03

    We present a detailed mechanism of, and the effect of homogeneous strains on, the migration of uranium vacancies in UO2. Vacancy migration pathways and barriers are identified using density functional theory and the effect of uniform strain fields are accounted for using the dipole tensor approach. We report complex migration pathways and noncubic symmetry associated with the uranium vacancy in UO2 and show that these complexities need to be carefully accounted for to predict the correct diffusion behavior of uranium vacancies. We show that under homogeneous strain fields, only the dipole tensor of the saddle with respect to the minimummore » is required to correctly predict the change in the energy barrier between the strained and the unstrained case. Diffusivities are computed using kinetic Monte Carlo simulations for both neutral and fully charged state of uranium single and divacancies. We calculate the effect of strain on migration barriers in the temperature range 800–1800 K for both vacancy types. Homogeneous strains as small as 2% have a considerable effect on diffusivity of both single and divacancies of uranium, with the effect of strain being more pronounced for single vacancies than divacancies. In contrast, the response of a given defect to strain is less sensitive to changes in the charge state of the defect. Further, strain leads to anisotropies in the mobility of the vacancy and the degree of anisotropy is very sensitive to the nature of the applied strain field for strain of equal magnitude. Our results indicate that the influence of strain on vacancy diffusivity will be significantly greater when single vacancies dominate the defect structure, such as sintering, while the effects will be much less substantial under irradiation conditions where divacancies dominate.« less

  8. Impact of homogeneous strain on uranium vacancy diffusion in uranium dioxide

    SciTech Connect

    Goyal, Anuj; Phillpot, Simon R.; Subramanian, Gopinath; Andersson, David A.; Stanek, Chris R.; Uberuaga, Blas P.

    2015-03-03

    We present a detailed mechanism of, and the effect of homogeneous strains on, the migration of uranium vacancies in UO2. Vacancy migration pathways and barriers are identified using density functional theory and the effect of uniform strain fields are accounted for using the dipole tensor approach. We report complex migration pathways and noncubic symmetry associated with the uranium vacancy in UO2 and show that these complexities need to be carefully accounted for to predict the correct diffusion behavior of uranium vacancies. We show that under homogeneous strain fields, only the dipole tensor of the saddle with respect to the minimum is required to correctly predict the change in the energy barrier between the strained and the unstrained case. Diffusivities are computed using kinetic Monte Carlo simulations for both neutral and fully charged state of uranium single and divacancies. We calculate the effect of strain on migration barriers in the temperature range 800–1800 K for both vacancy types. Homogeneous strains as small as 2% have a considerable effect on diffusivity of both single and divacancies of uranium, with the effect of strain being more pronounced for single vacancies than divacancies. In contrast, the response of a given defect to strain is less sensitive to changes in the charge state of the defect. Further, strain leads to anisotropies in the mobility of the vacancy and the degree of anisotropy is very sensitive to the nature of the applied strain field for strain of equal magnitude. Our results indicate that the influence of strain on vacancy diffusivity will be significantly greater when single vacancies dominate the defect structure, such as sintering, while the effects will be much less substantial under irradiation conditions where divacancies dominate.

  9. Impacts of diffusive transport on carbonate mineral formation from magnesium silicate-CO2-water reactions.

    PubMed

    Giammar, Daniel E; Wang, Fei; Guo, Bin; Surface, J Andrew; Peters, Catherine A; Conradi, Mark S; Hayes, Sophia E

    2014-12-16

    Reactions of CO2 with magnesium silicate minerals to precipitate magnesium carbonates can result in stable carbon sequestration. This process can be employed in ex situ reactors or during geologic carbon sequestration in magnesium-rich formations. The reaction of aqueous CO2 with the magnesium silicate mineral forsterite was studied in systems with transport controlled by diffusion. The approach integrated bench-scale experiments, an in situ spectroscopic technique, and reactive transport modeling. Experiments were performed using a tube packed with forsterite and open at one end to a CO2-rich solution. The location and amounts of carbonate minerals that formed were determined by postexperiment characterization of the solids. Complementing this ex situ characterization, (13)C NMR spectroscopy tracked the inorganic carbon transport and speciation in situ. The data were compared with the output of reactive transport simulations that accounted for diffusive transport processes, aqueous speciation, and the forsterite dissolution rate. All three approaches found that the onset of magnesium carbonate precipitation was spatially localized about 1 cm from the opening of the forsterite bed. Magnesite was the dominant reaction product. Geochemical gradients that developed in the diffusion-limited zones led to locally supersaturated conditions at specific locations even while the volume-averaged properties of the system remained undersaturated.

  10. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 12: The diffusion of federally funded aerospace research and development (R/D) and the information seeking behavior of US aerospace engineers and scientists

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Kennedy, John M.; Barclay, Rebecca O.

    1991-01-01

    In this paper, the diffusion of federally funded aerospace R&D is explored from the perspective of the information-seeking behavior of U.S. aerospace engineers and scientists. The following three assumptions frame this exploration: (1) knowledge production, transfer, and utilization are equally important components of the aerospace R&D process; (2) the diffusion of knowledge resulting from federally funded aerospace R&D is indispensable for the U.S. to remain a world leader in aerospace; and (3) U.S. government technical reports, produced by NASA and DOD, play an important, but as yet undefined, role in the diffusion of federally funded aerospace R&D. A conceptual model for federally funded aerospace knowledge diffusion, one that emphasizes U.S. goverment technical reports, is presented. Data regarding three research questions concerning the information-seeking behavior of U.S. aerospace engineers and scientists are also presented.

  11. Impact of Measurement System Characteristics on Advanced Sounder Information Content

    NASA Technical Reports Server (NTRS)

    Larar, Allen M.; Liu, Xu; Zhou, Daniel K.

    2011-01-01

    Advanced satellite sensors are tasked with improving global observations of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring capability, and environmental change detection. Achieving such an improvement in geophysical information inferred from these observations requires optimal usage of data from current systems as well as instrument system enhancements for future sensors. This presentation addresses results of tradeoff studies evaluating the impact of spectral resolution, spectral coverage, instrument noise, and a priori knowledge on remote sensing system information content, with a specific emphasis on thermodynamic state and trace species information obtainable from advanced atmospheric sounders. Particular attention will be devoted toward information achievable from the Atmospheric InfraRed Sounder (AIRS) on the NASA EOS Aqua satellite in orbit since 2002, the Infrared Atmospheric Sounding Interferometer (IASI) aboard MetOp-A since 2006, and the Cross-track Infrared Sounder (CrIS) instrument to fly aboard the NPP and JPSS series of satellites expected to begin in late 2011. While all of these systems cover nearly the same infrared spectral extent, they have very different number of channels, instrument line shapes, coverage continuity, and instrument noise. AIRS is a grating spectrometer having 2378 discrete spectral channels ranging from about 0.4 to 2.2/cm resolution; IASI is a Michelson interferometer with 8461 uniformly-spaced spectral channels of 0.5/cm (apodized) resolution; and CrIS is a Michelson interferometer having 1305 spectral channels of 0.625, 1.250, and 2.50/cm (unapodized) spectral resolution, respectively, over its three continuous but non-overlapping bands. Results of tradeoff studies showing information content sensitivity to assumed measurement system characteristics will be presented.

  12. Impact of Repeated Exposures on Information Spreading in Social Networks.

    PubMed

    Zhou, Cangqi; Zhao, Qianchuan; Lu, Wenbo

    2015-01-01

    Clustered structure of social networks provides the chances of repeated exposures to carriers with similar information. It is commonly believed that the impact of repeated exposures on the spreading of information is nontrivial. Does this effect increase the probability that an individual forwards a message in social networks? If so, to what extent does this effect influence people's decisions on whether or not to spread information? Based on a large-scale microblogging data set, which logs the message spreading processes and users' forwarding activities, we conduct a data-driven analysis to explore the answer to the above questions. The results show that an overwhelming majority of message samples are more probable to be forwarded under repeated exposures, compared to those under only a single exposure. For those message samples that cover various topics, we observe a relatively fixed, topic-independent multiplier of the willingness of spreading when repeated exposures occur, regardless of the differences in network structure. We believe that this finding reflects average people's intrinsic psychological gain under repeated stimuli. Hence, it makes sense that the gain is associated with personal response behavior, rather than network structure. Moreover, we find that the gain is robust against the change of message popularity. This finding supports that there exists a relatively fixed gain brought by repeated exposures. Based on the above findings, we propose a parsimonious model to predict the saturated numbers of forwarding activities of messages. Our work could contribute to better understandings of behavioral psychology and social media analytics. PMID:26465749

  13. Impact of Repeated Exposures on Information Spreading in Social Networks.

    PubMed

    Zhou, Cangqi; Zhao, Qianchuan; Lu, Wenbo

    2015-01-01

    Clustered structure of social networks provides the chances of repeated exposures to carriers with similar information. It is commonly believed that the impact of repeated exposures on the spreading of information is nontrivial. Does this effect increase the probability that an individual forwards a message in social networks? If so, to what extent does this effect influence people's decisions on whether or not to spread information? Based on a large-scale microblogging data set, which logs the message spreading processes and users' forwarding activities, we conduct a data-driven analysis to explore the answer to the above questions. The results show that an overwhelming majority of message samples are more probable to be forwarded under repeated exposures, compared to those under only a single exposure. For those message samples that cover various topics, we observe a relatively fixed, topic-independent multiplier of the willingness of spreading when repeated exposures occur, regardless of the differences in network structure. We believe that this finding reflects average people's intrinsic psychological gain under repeated stimuli. Hence, it makes sense that the gain is associated with personal response behavior, rather than network structure. Moreover, we find that the gain is robust against the change of message popularity. This finding supports that there exists a relatively fixed gain brought by repeated exposures. Based on the above findings, we propose a parsimonious model to predict the saturated numbers of forwarding activities of messages. Our work could contribute to better understandings of behavioral psychology and social media analytics.

  14. Prognostic impact of the 2016 WHO classification of diffuse gliomas in the French POLA cohort.

    PubMed

    Tabouret, Emeline; Nguyen, Anh Tuan; Dehais, Caroline; Carpentier, Catherine; Ducray, François; Idbaih, Ahmed; Mokhtari, Karima; Jouvet, Anne; Uro-Coste, Emmanuelle; Colin, Carole; Chinot, Olivier; Loiseau, Hugues; Moyal, Elisabeth; Maurage, Claude-Alain; Polivka, Marc; Lechapt-Zalcman, Emmanuèle; Desenclos, Christine; Meyronet, David; Delattre, Jean-Yves; Figarella-Branger, Dominique

    2016-10-01

    The new WHO classification of diffuse gliomas has been refined and now includes the 1p/19q codeletion, IDH1/2 mutation, and histone H3-K27M mutation. Our objective was to assess the prognostic value of the updated 2016 WHO classification in the French POLA cohort. All cases of high-grade oligodendroglial tumors sent for central pathological review and included into the French nationwide POLA cohort were reclassified according to the updated 4th WHO classification. In total, 1041 patients were included, with a median age at diagnosis of 50.4 years (range 17.1-84.4). Based on the new histomolecular classification, diagnoses included anaplastic oligodendroglioma IDH mutant and 1p/19q-codeleted (32.5 %), anaplastic astrocytoma IDH mutant (IDH (mut)) (11.0 %), anaplastic astrocytoma IDH wild type (IDH (wt)) (5.3 %), glioblastoma IDH (mut) (17.1 %), and glioblastoma IDH (wt) (33.2 %). Ten patients presented with a diffuse midline tumor, H3 K27M mutant. The new WHO classification was prognostic for progression-free survival (PFS) and overall survival (OS) (p < 0.001). We did not find prognosis differences between grades III and IV for IDH (mut) 1p/19q intact and IDH (wt) gliomas in univariate and multivariate analyses. Among anaplastic astrocytoma IDH (wt), cases with chromosome arm 7p gain and 10q loss (55 %) had shorter PFS than the others (p = 0.027). In conclusion, the new WHO histomolecular classification of diffuse gliomas presented with high prognostic value. Grading was not discriminant between grade III and IV high-grade gliomas.

  15. Prognostic impact of the 2016 WHO classification of diffuse gliomas in the French POLA cohort.

    PubMed

    Tabouret, Emeline; Nguyen, Anh Tuan; Dehais, Caroline; Carpentier, Catherine; Ducray, François; Idbaih, Ahmed; Mokhtari, Karima; Jouvet, Anne; Uro-Coste, Emmanuelle; Colin, Carole; Chinot, Olivier; Loiseau, Hugues; Moyal, Elisabeth; Maurage, Claude-Alain; Polivka, Marc; Lechapt-Zalcman, Emmanuèle; Desenclos, Christine; Meyronet, David; Delattre, Jean-Yves; Figarella-Branger, Dominique

    2016-10-01

    The new WHO classification of diffuse gliomas has been refined and now includes the 1p/19q codeletion, IDH1/2 mutation, and histone H3-K27M mutation. Our objective was to assess the prognostic value of the updated 2016 WHO classification in the French POLA cohort. All cases of high-grade oligodendroglial tumors sent for central pathological review and included into the French nationwide POLA cohort were reclassified according to the updated 4th WHO classification. In total, 1041 patients were included, with a median age at diagnosis of 50.4 years (range 17.1-84.4). Based on the new histomolecular classification, diagnoses included anaplastic oligodendroglioma IDH mutant and 1p/19q-codeleted (32.5 %), anaplastic astrocytoma IDH mutant (IDH (mut)) (11.0 %), anaplastic astrocytoma IDH wild type (IDH (wt)) (5.3 %), glioblastoma IDH (mut) (17.1 %), and glioblastoma IDH (wt) (33.2 %). Ten patients presented with a diffuse midline tumor, H3 K27M mutant. The new WHO classification was prognostic for progression-free survival (PFS) and overall survival (OS) (p < 0.001). We did not find prognosis differences between grades III and IV for IDH (mut) 1p/19q intact and IDH (wt) gliomas in univariate and multivariate analyses. Among anaplastic astrocytoma IDH (wt), cases with chromosome arm 7p gain and 10q loss (55 %) had shorter PFS than the others (p = 0.027). In conclusion, the new WHO histomolecular classification of diffuse gliomas presented with high prognostic value. Grading was not discriminant between grade III and IV high-grade gliomas. PMID:27573687

  16. R&D Advancement, Technology Diffusion, and Impact on Evaluation of Public R&D

    SciTech Connect

    Moore, M. C.; Arent, D. J.; Norland, D.

    2005-01-01

    In a 2001 report titled "Research at DOE: Was It Worth It?", a National Research Council (NRC) committee defined a set of simplifying rules to estimate the net economic benefits from technologies supported by the Department of Energy (DOE). This NREL paper evaluates the efficacy of the NRC rules compared to published literature on acceleration of technology introduction into markets, technology diffusion, and infrastructure change. It also offers considerations for revisions of the rules that call for the use of technology and sector-specific data, advanced forecasting techniques, and sensitivity analysis to test the robustness of the methodology.

  17. 40Ar/39Ar impact ages and time-temperature argon diffusion history of the Bunburra Rockhole anomalous basaltic achondrite

    NASA Astrophysics Data System (ADS)

    Jourdan, Fred; Benedix, Gretchen; Eroglu, Ela.; Bland, Phil. A.; Bouvier, Audrey.

    2014-09-01

    The Bunburra Rockhole meteorite is a brecciated anomalous basaltic achondrite containing coarse-, medium- and fine-grained lithologies. Petrographic observations constrain the limited shock pressure to between ca. 10 GPa and 20 GPa. In this study, we carried out nine 40Ar/39Ar step-heating experiments on distinct single-grain fragments extracted from the coarse and fine lithologies. We obtained six plateau ages and three mini-plateau ages. These ages fall into two internally concordant populations with mean ages of 3640 ± 21 Ma (n = 7; P = 0.53) and 3544 ± 26 Ma (n = 2; P = 0.54), respectively. Based on these results, additional 40Ar/39Ar data of fusion crust fragments, argon diffusion modelling, and petrographic observations, we conclude that the principal components of the Bunburra Rockhole basaltic achondrite are from a melt rock formed at ∼3.64 Ga by a medium to large impact event. The data imply that this impact generated high enough energy to completely melt the basaltic target rock and reset the Ar systematics, but only partially reset the Pb-Pb age. We also conclude that a complete 40Ar∗ resetting of pyroxene and plagioclase at this time could not have been achieved at solid-state conditions. Comparison with a terrestrial analog (Lonar crater) shows that the time-temperature conditions required to melt basaltic target rocks upon impact are relatively easy to achieve. Ar data also suggest that a second medium-size impact event occurred on a neighbouring part of the same target rock at ∼3.54 Ga. Concordant low-temperature step ages of the nine aliquots suggest that, at ∼3.42 Ga, a third smaller impact excavated parts of the ∼3.64 Ga and ∼3.54 Ga melt rocks and brought the fragments together. The lack of significant impact activity after 3.5 Ga, as recorded by the Bunburra Rockhole suggests that (1) either the meteorite was ejected in a small secondary parent body where it resided untouched by large impacts, or (2) it was covered by a porous heat

  18. Impact of mesophyll diffusion on estimated global land CO2 fertilization

    SciTech Connect

    Sun, Ying; Gu, Lianhong; Dickinson, Robert E.; Norby, Richard J.; Pallardy, Stephen G.; Hoffman, Forrest M.

    2014-10-13

    In C3 plants, CO2 concentrations drop considerably along mesophyll diffusion pathways from substomatal cavities to chloroplasts where CO2 assimilation occurs. Global carbon cycle models have not explicitly represented this internal drawdown and so overestimate CO2 available for carboxylation and underestimate photosynthetic responsiveness to atmospheric CO2. An explicit consideration of mesophyll diffusion increases the modeled cumulative CO2 fertilization effect (CFE) for global gross primary production (GPP) from 915 PgC to 1057 PgC for the period of 1901 to 2010. This increase represents a 16% correction, large enough to explain the persistent overestimation of growth rates of historical atmospheric CO2 by Earth System Models. Without this correction, the CFE for global GPP is underestimated by 0.05 PgC yr-1ppm-1. This finding implies that the contemporary terrestrial biosphere is more CO2-limited than previously thought.

  19. Information geometric analysis of phase transitions in complex patterns: the case of the Gray-Scott reaction–diffusion model

    NASA Astrophysics Data System (ADS)

    Har-Shemesh, Omri; Quax, Rick; Hoekstra, Alfons G.; Sloot, Peter M. A.

    2016-04-01

    The Fisher–Rao metric from information geometry is related to phase transition phenomena in classical statistical mechanics. Several studies propose to extend the use of information geometry to study more general phase transitions in complex systems. However, it is unclear whether the Fisher–Rao metric does indeed detect these more general transitions, especially in the absence of a statistical model. In this paper we study the transitions between patterns in the Gray-Scott reaction–diffusion model using Fisher information. We describe the system by a probability density function that represents the size distribution of blobs in the patterns and compute its Fisher information with respect to changing the two rate parameters of the underlying model. We estimate the distribution non-parametrically so that we do not assume any statistical model. The resulting Fisher map can be interpreted as a phase-map of the different patterns. Lines with high Fisher information can be considered as boundaries between regions of parameter space where patterns with similar characteristics appear. These lines of high Fisher information can be interpreted as phase transitions between complex patterns.

  20. Wear resistance of diffusion coatings on the working parts of impact-rebound crushers

    SciTech Connect

    Nedzel'skii, M.D.; Katkov, Y.K.

    1984-01-01

    Impact-rebound crushers used in the chemical industry suffer intensive wear of the crusher blades when crushing materials like quartz sand, corundum, and diabase. A special impact-rebound crushers has been made for testing the wear resistance of hardened prototype blades, andi it is described in detail in this paper. Tests were done to determine the most effective methods of surface hardening for the replaceable inserts made of readily available steel and it is found that the carbonitriding of steel gives a hardened layer to increase the wear resistance of the crusher body and rotor surfaces.

  1. The diffusion of maize to the southwestern United States and its impact

    PubMed Central

    Merrill, William L.; Hard, Robert J.; Mabry, Jonathan B.; Fritz, Gayle J.; Adams, Karen R.; Roney, John R.; MacWilliams, A. C.

    2009-01-01

    Our understanding of the initial period of agriculture in the southwestern United States has been transformed by recent discoveries that establish the presence of maize there by 2100 cal. B.C. (calibrated calendrical years before the Christian era) and document the processes by which it was integrated into local foraging economies. Here we review archaeological, paleoecological, linguistic, and genetic data to evaluate the hypothesis that Proto-Uto-Aztecan (PUA) farmers migrating from a homeland in Mesoamerica introduced maize agriculture to the region. We conclude that this hypothesis is untenable and that the available data indicate instead a Great Basin homeland for the PUA, the breakup of this speech community into northern and southern divisions ≈6900 cal. B.C. and the dispersal of maize agriculture from Mesoamerica to the US Southwest via group-to-group diffusion across a Southern Uto-Aztecan linguistic continuum. PMID:19995985

  2. Impact of Repeated Exposures on Information Spreading in Social Networks

    PubMed Central

    Zhou, Cangqi; Zhao, Qianchuan; Lu, Wenbo

    2015-01-01

    Clustered structure of social networks provides the chances of repeated exposures to carriers with similar information. It is commonly believed that the impact of repeated exposures on the spreading of information is nontrivial. Does this effect increase the probability that an individual forwards a message in social networks? If so, to what extent does this effect influence people’s decisions on whether or not to spread information? Based on a large-scale microblogging data set, which logs the message spreading processes and users’ forwarding activities, we conduct a data-driven analysis to explore the answer to the above questions. The results show that an overwhelming majority of message samples are more probable to be forwarded under repeated exposures, compared to those under only a single exposure. For those message samples that cover various topics, we observe a relatively fixed, topic-independent multiplier of the willingness of spreading when repeated exposures occur, regardless of the differences in network structure. We believe that this finding reflects average people’s intrinsic psychological gain under repeated stimuli. Hence, it makes sense that the gain is associated with personal response behavior, rather than network structure. Moreover, we find that the gain is robust against the change of message popularity. This finding supports that there exists a relatively fixed gain brought by repeated exposures. Based on the above findings, we propose a parsimonious model to predict the saturated numbers of forwarding activities of messages. Our work could contribute to better understandings of behavioral psychology and social media analytics. PMID:26465749

  3. Final environmental impact assessment of the Paducah Gaseous Diffusion Plant site, Paducah, Kentucky

    SciTech Connect

    Not Available

    1982-08-01

    This document considers: the need for uranium enrichment facilities; site location; plant description; and describes the power generating facilities in light of its existing environment. The impacts from continuing operations are compared with alternatives of shutdown, relocation, and alternative power systems. (PSB)

  4. The impact of depression on Veterans with PTSD and traumatic brain injury: a diffusion tensor imaging study.

    PubMed

    Isaac, Linda; Main, Keith L; Soman, Salil; Gotlib, Ian H; Furst, Ansgar J; Kinoshita, Lisa M; Fairchild, J Kaci; Yesavage, Jerome A; Ashford, J Wesson; Bayley, Peter J; Adamson, Maheen M

    2015-02-01

    A significant proportion of military personnel deployed in support of Operation Enduring Freedom and Operation Iraqi Freedom were exposed to war-zone events associated with traumatic brain injury (TBI), depression (DEP) and posttraumatic stress disorder (PTSD). The co-occurrence of TBI, PTSD and DEP in returning Veterans has recently increased research and clinical interest. This study tested the hypothesis that white matter abnormalities are further impacted by depression. Of particular relevance is the uncinate fasciculus (UF), which is a key fronto-temporal tract involved in mood regulation, and the cingulum; a tract that connects to the hippocampus involved in memory integration. Diffusion tensor imaging (DTI) was performed on 25 patients with a combination of PTSD, TBI and DEP and 20 patients with PTSD and TBI (no DEP). Microstructural changes of white matter were found in the cingulum and UF. Fractional anisotropy (FA) was lower in Veterans with DEP compared to those without DEP.

  5. Diffusion in liquid metal systems. [information on electrical resistivity and thermal conductivity

    NASA Technical Reports Server (NTRS)

    Ukanwa, A. O.

    1975-01-01

    Physical properties of twenty liquid metals are reported; some of the data on such liquid metal properties as density, electrical resistivity, thermal conductivity, and heat capacity are summarized in graphical form. Data on laboratory handling and safety procedure are summarized for each metal; heat-transfer-correlations for liquid metals under various conditions of laminar and turbulent flow are included. Where sufficient data were available, temperature equations of properties were obtained by the method of least-squares fit. All values of properties given are valid in the given liquid phase ranges only. Additional tabular data on some 40 metals are reported in the appendix. Included is a brief description of experiments that were performed to investigate diffusion in liquid indium-gallium systems.

  6. Information processing and intracellular 'neural' (protein) networks: considerations regarding the diffusion-based hypothesis of Bray.

    PubMed

    Agutter, P S; Wheatley, D N

    1997-03-01

    The possibility that the disposition of subsets of proteins within the cell can retain memory traces and may act therefore in a computationial role has been advanced and more recently refined by Bray (Nature (1995) 376, 307-312). The proposition is not without its merits but inevitably has a number of associated difficulties, some of which are discussed in this article. These relate to the nature of the computational units envisaged (analog vs digital), their limitations in the number of stable patterns they can accommodate, the reliance on diffusion at the molecular level as the 'governing principle', and the complication of the turnover of proteins through degradative mechanisms. These issues suggest that certain modifications of the original model are required.

  7. Microstructural parameter estimation in vivo using diffusion MRI and structured prior information

    PubMed Central

    Nagy, Zoltan; Weiskopf, Nikolaus; Alexander, Daniel C.; Clark, Chris A.

    2015-01-01

    Purpose Diffusion MRI has recently been used with detailed models to probe tissue microstructure. Much of this work has been performed ex vivo with powerful scanner hardware, to gain sensitivity to parameters such as axon radius. By contrast, performing microstructure imaging on clinical scanners is extremely challenging. Methods We use an optimized dual spin‐echo diffusion protocol, and a Bayesian fitting approach, to obtain reproducible contrast (histogram overlap of up to 92%) in estimated maps of axon radius index in healthy adults at a modest, widely‐available gradient strength (35 mT m −1). A key innovation is the use of influential priors. Results We demonstrate that our priors can improve precision in axon radius estimates—a 7‐fold reduction in voxelwise coefficient of variation in vivo—without significant bias. Our results may reflect true axon radius differences between white matter regions, but this interpretation should be treated with caution due to the complexity of the tissue relative to our model. Conclusions Some sensitivity to relatively large axons (3–15 μm) may be available at clinical field and gradient strengths. Future applications at higher gradient strength will benefit from the favorable eddy current properties of the dual spin‐echo sequence, and greater precision available with suitable priors. Magn Reson Med, 2015. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Magn Reson Med 75:1787–1796, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance. PMID:25994918

  8. Social relevance: toward understanding the impact of the individual in an information cascade

    NASA Astrophysics Data System (ADS)

    Hall, Robert T.; White, Joshua S.; Fields, Jeremy

    2016-05-01

    Information Cascades (IC) through a social network occur due to the decision of users to disseminate content. We define this decision process as User Diffusion (UD). IC models typically describe an information cascade by treating a user as a node within a social graph, where a node's reception of an idea is represented by some activation state. The probability of activation then becomes a function of a node's connectedness to other activated nodes as well as, potentially, the history of activation attempts. We enrich this Coarse-Grained User Diffusion (CGUD) model by applying actor type logics to the nodes of the graph. The resulting Fine-Grained User Diffusion (FGUD) model utilizes prior research in actor typing to generate a predictive model regarding the future influence a user will have on an Information Cascade. Furthermore, we introduce a measure of Information Resonance that is used to aid in predictions regarding user behavior.

  9. The effect of the diffusion time and pulse gradient duration ratio on the diffraction pattern and the structural information estimated from q-space diffusion MR: Experiments and simulations

    NASA Astrophysics Data System (ADS)

    Bar-Shir, Amnon; Avram, Liat; Özarslan, Evren; Basser, Peter J.; Cohen, Yoram

    2008-10-01

    q-Space diffusion MRI (QSI) provides a means of obtaining microstructural information about porous materials and neuronal tissues from diffusion data. However, the accuracy of this structural information depends on experimental parameters used to collect the MR data. q-Space diffusion MR performed on clinical scanners is generally collected with relatively long diffusion gradient pulses, in which the gradient pulse duration, δ, is comparable to the diffusion time, Δ. In this study, we used phantoms, consisting of ensembles of microtubes, and mathematical models to assess the effect of the ratio of the diffusion time and the duration of the diffusion pulse gradient, i.e., Δ/ δ, on the MR signal attenuation vs. q, and on the measured structural information extracted therefrom. We found that for Δ/ δ ˜ 1, the diffraction pattern obtained from q-space MR data are shallower than when the short gradient pulse (SGP) approximation is satisfied. For long δ the estimated compartment size is, as expected, smaller than the real size. Interestingly, for Δ/ δ ˜ 1 the diffraction peaks are shifted to even higher q-values, even when δ is kept constant, giving the impression that the restricted compartments are even smaller than they are. When phantoms composed of microtubes of different diameters are used, it is more difficult to estimate the diameter distribution in this regime. Excellent agreement is found between the experimental results and simulations that explicitly account for the use of long duration gradient pulses. Using such experimental data and this mathematical framework, one can estimate the true compartment dimensions when long and finite gradient pulses are used even when Δ/ δ ˜ 1.

  10. European information on climate change impacts, vulnerability and adaptation

    NASA Astrophysics Data System (ADS)

    Jol, A.; Isoard, S.

    2010-09-01

    development in 2010 and is likely to manage the system after 2011. The European Commission in its Communication in 2009 on disaster risk prevention also calls for improving and better sharing of data on disasters, disaster risk mapping and disaster risk management, in the context of the EU civil protection mechanism. Such information might also be linked to the planned EU Clearinghouse on climate change adaptation. The activities of EEA on climate change impacts, vulnerability and adaptation (including disaster risk reduction) include indicators of the impacts of climate change; a regularly updated overview of national assessments and adaptation plans on the EEA web site and specific focused reports, e.g. on adaptation to the challenges of changing water resources in the Alps (2009) and on analysis of past trends in natural disasters (due in 2010) and regular expert meetings and workshops with EEA member countries. The ECAC presentation will include the latest developments in the EU Clearinghouse on adaptation and progress in relevant EEA activities.

  11. Impact of one-layer assumption on diffuse reflectance spectroscopy of skin

    NASA Astrophysics Data System (ADS)

    Hennessy, Ricky; Markey, Mia K.; Tunnell, James W.

    2015-02-01

    Diffuse reflectance spectroscopy (DRS) can be used to noninvasively measure skin properties. To extract skin properties from DRS spectra, you need a model that relates the reflectance to the tissue properties. Most models are based on the assumption that skin is homogenous. In reality, skin is composed of multiple layers, and the homogeneity assumption can lead to errors. In this study, we analyze the errors caused by the homogeneity assumption. This is accomplished by creating realistic skin spectra using a computational model, then extracting properties from those spectra using a one-layer model. The extracted parameters are then compared to the parameters used to create the modeled spectra. We used a wavelength range of 400 to 750 nm and a source detector separation of 250 μm. Our results show that use of a one-layer skin model causes underestimation of hemoglobin concentration [Hb] and melanin concentration [mel]. Additionally, the magnitude of the error is dependent on epidermal thickness. The one-layer assumption also causes [Hb] and [mel] to be correlated. Oxygen saturation is overestimated when it is below 50% and underestimated when it is above 50%. We also found that the vessel radius factor used to account for pigment packaging is correlated with epidermal thickness.

  12. Impact of one-layer assumption on diffuse reflectance spectroscopy of skin.

    PubMed

    Hennessy, Ricky; Markey, Mia K; Tunnell, James W

    2015-02-01

    Diffuse reflectance spectroscopy (DRS) can be used to noninvasively measure skin properties. To extract skin properties from DRS spectra, you need a model that relates the reflectance to the tissue properties. Most models are based on the assumption that skin is homogenous. In reality, skin is composed of multiple layers, and the homogeneity assumption can lead to errors. In this study, we analyze the errors caused by the homogeneity assumption. This is accomplished by creating realistic skin spectra using a computational model, then extracting properties from those spectra using a one-layer model. The extracted parameters are then compared to the parameters used to create the modeled spectra. We used a wavelength range of 400 to 750 nm and a source detector separation of 250 μm. Our results show that use of a one-layer skin model causes underestimation of hemoglobin concentration [Hb] and melanin concentration [mel]. Additionally, the magnitude of the error is dependent on epidermal thickness. The one-layer assumption also causes [Hb] and [mel] to be correlated. Oxygen saturation is overestimated when it is below 50% and underestimated when it is above 50%. We also found that the vessel radius factor used to account for pigment packaging is correlated with epidermal thickness. PMID:25649627

  13. Impact of one-layer assumption on diffuse reflectance spectroscopy of skin

    PubMed Central

    Hennessy, Ricky; Markey, Mia K.; Tunnell, James W.

    2015-01-01

    Abstract. Diffuse reflectance spectroscopy (DRS) can be used to noninvasively measure skin properties. To extract skin properties from DRS spectra, you need a model that relates the reflectance to the tissue properties. Most models are based on the assumption that skin is homogenous. In reality, skin is composed of multiple layers, and the homogeneity assumption can lead to errors. In this study, we analyze the errors caused by the homogeneity assumption. This is accomplished by creating realistic skin spectra using a computational model, then extracting properties from those spectra using a one-layer model. The extracted parameters are then compared to the parameters used to create the modeled spectra. We used a wavelength range of 400 to 750 nm and a source detector separation of 250  μm. Our results show that use of a one-layer skin model causes underestimation of hemoglobin concentration [Hb] and melanin concentration [mel]. Additionally, the magnitude of the error is dependent on epidermal thickness. The one-layer assumption also causes [Hb] and [mel] to be correlated. Oxygen saturation is overestimated when it is below 50% and underestimated when it is above 50%. We also found that the vessel radius factor used to account for pigment packaging is correlated with epidermal thickness. PMID:25649627

  14. Diffuse gamma-ray constraints on dark matter revisited I: the impact of subhalos

    SciTech Connect

    Blanchet, Steve; Lavalle, Julien E-mail: lavalle@in2p3.fr

    2012-11-01

    We make a detailed analysis of the indirect diffuse gamma-ray signals from dark matter annihilation in the Galaxy. We include the prompt emission, as well as the emission from inverse Compton scattering whenever the annihilation products contain light leptons. We consider both the contribution from the smooth dark matter halo and that from substructures. The main parameters for the latter are the mass function index and the minimal subhalo mass. We use recent results from N-body simulations to set the most reasonable range of parameters, and find that the signal can be boosted by a factor ranging from 2 to 15 towards the Galactic poles, slightly more towards the Galactic anticenter, with an important dependence on the subhalo mass index. This uncertainty is however much less than that of the extragalactic signal studied in the literature. We derive upper bounds on the dark matter annihilation cross section using the isotropic gamma-ray emission measured by Fermi-LAT, for two directions in the sky, the Galactic anticenter and the Galactic pole(s). The former represents the lowest irreducible signal from dark matter annihilation, and the latter is robust as the astrophysical background, dominated by the hadronic contribution, is rather well established in that direction. Finally, we show how the knowledge of the minimal subhalo mass, which formally depends on the dark matter particle interactions with normal matter, can be used to derive the mass function index.

  15. Synoptic monitoring as an approach to discriminating between point and diffuse source contributions to zinc loads in mining impacted catchments.

    PubMed

    Banks, V J; Palumbo-Roe, B

    2010-09-01

    One of the global legacies of industrialisation is the environmental impacts of historic mineral exploitation. Recent national initiatives to manage the impacts on ground and surface waters have driven the need to develop better techniques for assessing understanding of the catchment-scale distribution and characterisation of the relative contribution of point and diffuse contaminant sources. The benefits of a detailed, multidisciplinary investigation are highlighted through a case study focused on the Rookhope Burn, a tributary of the River Wear, which falls within a significantly mine impacted area of the North Pennines Orefield, UK. Zinc (Zn) has been identified as the contaminant of concern within this catchment, which is judged by the Environment Agency to be at risk of failing to achieve good water quality status in the context of the Water Framework Directive. The results of synoptic flow monitoring and sampling for chemical determinations of major and trace elements have been used to calculate mass balances of instream and inflow chemical loads in the Rookhope Burn. Despite a dominant impact on the water quality from a mine outburst (especially Zn [1.45 to 2.42 mg/l], Fe [2.18 to 3.97 mg/l], Mn [3.69 to 6.77 mg/l], F [3.99 to 4.80 mg/l] and SO(4) [178 to 299 mg/l]), mass balance calculations combined with geological mapping have facilitated the identification of significant, previously unknown, subsurface contributions of Zn contaminated groundwater (with Zn concentrations in excess of 0.4 to 0.9 mg/l and 0.18 to 0.36 mg/l) to the Burn. The subsurface contributions exhibit spatial correspondence to mine workings with associated mineral veins and adits, or to points of suspected karst groundwater resurgence. These findings reiterate the challenges posed in decision making with respect to remediation, in this case in the context of the management of significant subsurface contributions.

  16. 78 FR 2379 - Agency Information Collection Activities; Comment Request; Impact Evaluation of Math Professional...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-11

    ... Agency Information Collection Activities; Comment Request; Impact Evaluation of Math Professional... of Collection: Impact Evaluation of Math Professional Development. OMB Control Number: 1850-NEW. Type..., and teachers for a study of math professional development. The study will provide...

  17. Integrative analysis of diffusion-weighted MRI and genomic data to inform treatment of glioblastoma.

    PubMed

    Jajamovich, Guido H; Valiathan, Chandni R; Cristescu, Razvan; Somayajula, Sangeetha

    2016-09-01

    Gene expression profiling from glioblastoma (GBM) patients enables characterization of cancer into subtypes that can be predictive of response to therapy. An integrative analysis of imaging and gene expression data can potentially be used to obtain novel biomarkers that are closely associated with the genetic subtype and gene signatures and thus provide a noninvasive approach to stratify GBM patients. In this retrospective study, we analyzed the expression of 12,042 genes for 558 patients from The Cancer Genome Atlas (TCGA). Among these patients, 50 patients had magnetic resonance imaging (MRI) studies including diffusion weighted (DW) MRI in The Cancer Imaging Archive (TCIA). We identified the contrast enhancing region of the tumors using the pre- and post-contrast T1-weighted MRI images and computed the apparent diffusion coefficient (ADC) histograms from the DW-MRI images. Using the gene expression data, we classified patients into four molecular subtypes, determined the number and composition of genes modules using the gap statistic, and computed gene signature scores. We used logistic regression to find significant predictors of GBM subtypes. We compared the predictors for different subtypes using Mann-Whitney U tests. We assessed detection power using area under the receiver operating characteristic (ROC) analysis. We computed Spearman correlations to determine the associations between ADC and each of the gene signatures. We performed gene enrichment analysis using Ingenuity Pathway Analysis (IPA). We adjusted all p values using the Benjamini and Hochberg method. The mean ADC was a significant predictor for the neural subtype. Neural tumors had a significantly lower mean ADC compared to non-neural tumors ([Formula: see text]), with mean ADC of [Formula: see text] and [Formula: see text] for neural and non-neural tumors, respectively. Mean ADC showed an area under the ROC of 0.75 for detecting neural tumors. We found eight gene modules in the GBM cohort. The

  18. Impact of Information based Classification on Network Epidemics

    NASA Astrophysics Data System (ADS)

    Mishra, Bimal Kumar; Haldar, Kaushik; Sinha, Durgesh Nandini

    2016-06-01

    Formulating mathematical models for accurate approximation of malicious propagation in a network is a difficult process because of our inherent lack of understanding of several underlying physical processes that intrinsically characterize the broader picture. The aim of this paper is to understand the impact of available information in the control of malicious network epidemics. A 1-n-n-1 type differential epidemic model is proposed, where the differentiality allows a symptom based classification. This is the first such attempt to add such a classification into the existing epidemic framework. The model is incorporated into a five class system called the DifEpGoss architecture. Analysis reveals an epidemic threshold, based on which the long-term behavior of the system is analyzed. In this work three real network datasets with 22002, 22469 and 22607 undirected edges respectively, are used. The datasets show that classification based prevention given in the model can have a good role in containing network epidemics. Further simulation based experiments are used with a three category classification of attack and defense strengths, which allows us to consider 27 different possibilities. These experiments further corroborate the utility of the proposed model. The paper concludes with several interesting results.

  19. Impact of Information based Classification on Network Epidemics

    PubMed Central

    Mishra, Bimal Kumar; Haldar, Kaushik; Sinha, Durgesh Nandini

    2016-01-01

    Formulating mathematical models for accurate approximation of malicious propagation in a network is a difficult process because of our inherent lack of understanding of several underlying physical processes that intrinsically characterize the broader picture. The aim of this paper is to understand the impact of available information in the control of malicious network epidemics. A 1-n-n-1 type differential epidemic model is proposed, where the differentiality allows a symptom based classification. This is the first such attempt to add such a classification into the existing epidemic framework. The model is incorporated into a five class system called the DifEpGoss architecture. Analysis reveals an epidemic threshold, based on which the long-term behavior of the system is analyzed. In this work three real network datasets with 22002, 22469 and 22607 undirected edges respectively, are used. The datasets show that classification based prevention given in the model can have a good role in containing network epidemics. Further simulation based experiments are used with a three category classification of attack and defense strengths, which allows us to consider 27 different possibilities. These experiments further corroborate the utility of the proposed model. The paper concludes with several interesting results. PMID:27329348

  20. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 5: Aerospace librarians and technical information specialists as information intermediaries: A report of phase 2 activities of the NASA/DOD Aerospace Knowledge Diffusion Research Project

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Kennedy, John M.

    1990-01-01

    The flow of U.S. government-funded and foreign scientific and technical information (STI) through libraries and related facilities to users in government and industry is examined, summarizing preliminary results of Phase 2 of the NASA/DOD Aerospace Knowledge Diffusion Research Project (NAKDRP). The design and objectives of NAKDRP are reviewed; the NAKDRP model of STI transfer among producers, STI intermediaries, surrogates (technical report repositories or clearinghouses), and users is explained and illustrated with diagrams; and particular attention is given to the organization and operation of aerospace libraries. In a survey of North American libraries it was found that 25-30 percent of libraries regularly receive technical reports from ESA and the UK; the corresponding figures for Germany and for France, Sweden, and Japan are 18 and 5 percent, respectively. Also included is a series of bar graphs showing the librarians' assessments of the quality and use of NASA Technical Reports.

  1. Impacts of the climate change on runoff and diffuse phosphorus load to Lake Balaton (Hungary).

    PubMed

    Kovács, A; Clement, A

    2009-01-01

    The paper outlines a multi-component assessment of the impacts of the climate change on runoff and total phosphorus loads to the large shallow Lake Balaton in Hungary. Present hydrological cycle of the lake catchment has been examined using the rainfall-runoff model WetSpa. Particular phosphorus concentration in runoff was estimated on the basis of the simulated streamflow using an empirical power equation. Dissolved phosphorus concentrations were determined as a function of landuse and soil type of the corresponding sub-catchment. The model was calibrated and validated against daily observations manually at monitoring sites of sixteen inflowing streams around the lake. Runoff stemming from shoreline urban developments was calculated by the urban runoff simulation model SWMM. Phosphorus concentrations in urban runoff were calculated by an empirical relationship derived from field measurements. The model was henceforward run for climate change scenario analysis. Present weather data were modified by the climate change scenarios imported from the results of the CLIME project. The results indicate that the impact of the climate change on runoff and phosphorus load appears in the change of the distribution within a time period rather than in the total volume. However, due to the high uncertainties in climate models, the presented calculations are possible assumptions rather than established statements. PMID:19213995

  2. Replacement of chlorofluorocarbons (CFCs) at the DOE Gaseous Diffusion Plants: An assessment of global impacts

    SciTech Connect

    Socolof, M.L.; Saylor, R.E.; McCold, L.N.

    1994-12-31

    The US Department of Energy (DOE) operates two uranium enrichment plants. Together, the two plants maintain an inventory of approximately 14 million pounds of a chlorofluorocarbon (CFC), dichlorote-trafluoroethane (CFC-114) as a coolant. Annual operational CFC-114 losses total over 500,000 pounds. In February, 1992, President Bush announced that the US would terminate manufacture and importation of Class 1 ozone depleting substances (including CFC-114) by the end of 1995. To comply with this requirement DOE has considered introducing a replacement coolant by the end of 1995. Two perfluorocarbons (PFCs) - namely, octofluoro-cyclobutane and decafluorobutane - are presently the only known coolants that could meet safety requirements. They would not contribute to stratospheric ozone depletion but contribute to global warming. The paper describes an analysis of the potential global impacts of the proposed replacement of CFC-114 with a PFC. A problem with analyses of global warming and ozone depletion impacts is that even large sources of compounds that contribute to these effects contribute only very small fractions of the total effect. The authors take the position that significant effects to global warming and ozone depletion have already occurred, and that any additional contribution to these effects are contributions to cumulatively significant adverse effects on the environment. The paper describes four alternatives and the extent to which each would contribute to global warming and ozone depletion.

  3. Assessment of climate change impacts on diffuse nutrient and pesticide fluxes at the watershed scale

    NASA Astrophysics Data System (ADS)

    Arabi, M.; Records, R.; Ahmadi, M.

    2012-12-01

    The study aims to assess the potential impacts of the changing climate on pollutant fluxes including sediment, phosphorus, nitrogen, and atrazine at the watershed scale over the 21st century. Specific objectives are (i) to understand changes in climatic conditions under a comprehensive set of 112 climate projections consistent with Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (IPCC-SRES) emission pathways and models; (ii) to fully enumerate and synthesize hydrologic and water quality responses to projected climate scenarios; and (iii) to investigate changes in dissolved and particulate water quality constituents. These objectives were investigated in a predominantly agricultural watershed in the Midwestern United States. The hydrologic model Soil and Water Assessment Tool (SWAT) was utilized to represent processes governing hydrology and water quality within the watershed. The SWAT model was driven with a suite of 112 distinct dynamically downscaled climate projections representing IPCC-SERES low, moderate, and high greenhouse gas emission pathways. Statistical downscaling procedures were used to derive daily climatic values for meteorological stations in the study area from grid-based dynamically downscaled monthly predictions. Predicted changes in hydroclimatic, nutrient, and pesticide fluxes under the 112 distinct simulations were then analyzed by emission pathway ensemble and characterized over early-, mid-, and late-century assessment periods (2015-2034, 2045-2064, and 2080-2099). Clear warming trends were apparent for temperature, while increases in precipitation were insignificant. Stream discharge, sediment yield, and total nutrient yields did not differ significantly between assessment periods, although atrazine yields were predicted to be slightly greater by late-century. However, the proportion of dissolved to total nutrients increased, with nitrate and soluble phosphorus yields increasing significantly between early

  4. Impact of Taylor-Aris diffusivity on analyte and system zone dispersion in CZE assessed by computer simulation and experimental validation.

    PubMed

    Caslavska, Jitka; Mosher, Richard A; Thormann, Wolfgang

    2015-07-01

    Application of pressure-driven laminar flow has an impact on zone and boundary dispersion in open tubular CE. The GENTRANS dynamic simulator for electrophoresis was extended with Taylor-Aris diffusivity which accounts for dispersion due to the parabolic flow profile associated with pressure-driven flow. Effective diffusivity of analyte and system zones as functions of the capillary diameter and the amount of flow in comparison to molecular diffusion alone were studied for configurations with concomitant action of imposed hydrodynamic flow and electroosmosis. For selected examples under realistic experimental conditions, simulation data are compared with those monitored experimentally using modular CE setups featuring both capacitively coupled contactless conductivity and UV absorbance detection along a 50 μm id fused-silica capillary of 90 cm total length. The data presented indicate that inclusion of flow profile based Taylor-Aris diffusivity provides realistic simulation data for analyte and system peaks, particularly those monitored in CE with conductivity detection. PMID:25820794

  5. A geographic information system screening tool to tackle diffuse pollution through the use of sustainable drainage systems.

    PubMed

    Todorovic, Zorica; Breton, Neil P

    2014-01-01

    Sustainable drainage systems (SUDS) offer many benefits that traditional solutions do not. Traditional approaches are unable to offer a solution to problems of flood management and water quality. Holistic consideration of the wide range of benefits from SUDS can result in advantages such as improved flood resilience and water quality enhancement through consideration of diffuse pollution sources. Using a geographical information system (GIS) approach, diffuse pollutant sources and opportunities for SUDS are easily identified. Consideration of potential SUDS locations results in source, site and regional controls, leading to improved water quality (to meet Water Framework Directive targets). The paper will discuss two different applications of the tool, the first of which is where the pollutant of interest is known. In this case the outputs of the tool highlight and isolate the areas contributing the pollutants and suggest the adequate SUDS measures to meet the required criteria. The second application is where the tool identifies likely pollutants at a receiving location, and SUDS measures are proposed to reduce pollution with assessed efficiencies.

  6. Enzymatically structured emulsions in simulated gastrointestinal environment: impact on interfacial proteolysis and diffusion in intestinal mucus.

    PubMed

    Macierzanka, Adam; Böttger, Franziska; Rigby, Neil M; Lille, Martina; Poutanen, Kaisa; Mills, E N Clare; Mackie, Alan R

    2012-12-18

    Fundamental knowledge of physicochemical interactions in the gastrointestinal environment is required in order to support rational designing of protein-stabilized colloidal food and pharmaceutical delivery systems with controlled behavior. In this paper, we report on the colloidal behavior of emulsions stabilized with the milk protein sodium caseinate (Na-Cas), and exposed to conditions simulating the human upper gastrointestinal tract. In particular, we looked at how the kinetics of proteolysis was affected by adsorption to an oil-water interface in emulsion and whether the proteolysis and the emulsion stability could be manipulated by enzymatic structuring of the interface. After cross-linking with the enzyme transglutaminase, the protein was digested with use of an in vitro model of gastro-duodenal proteolysis in the presence or absence of physiologically relevant surfactants (phosphatidylcholine, PC; bile salts, BS). Significant differences were found between the rates of digestion of Na-Cas cross-linked in emulsion (adsorbed protein) and in solution. In emulsion, the digestion of a population of polypeptides of M(r) ca. 50-100 kDa was significantly retarded through the gastric digestion. The persistent interfacial polypeptides maintained the original emulsion droplet size and prevented the system from phase separating. Rapid pepsinolysis of adsorbed, non-cross-linked Na-Cas and its displacement by PC led to emulsion destabilization. These results suggest that structuring of emulsions by enzymatic cross-linking of the interfacial protein may affect the phase behavior of emulsion in the stomach and the gastric digestion rate in vivo. Measurements of ζ-potential revealed that BS displaced the remaining protein from the oil droplets during the simulated duodenal phase of digestion. Diffusion of the postdigestion emulsion droplets through ex vivo porcine intestinal mucus was only significant in the presence of BS due to the high negative charge these

  7. Real-Time Diffusion of Information on Twitter and the Financial Markets.

    PubMed

    Tafti, Ali; Zotti, Ryan; Jank, Wolfgang

    2016-01-01

    Do spikes in Twitter chatter about a firm precede unusual stock market trading activity for that firm? If so, Twitter activity may provide useful information about impending financial market activity in real-time. We study the real-time relationship between chatter on Twitter and the stock trading volume of 96 firms listed on the Nasdaq 100, during 193 days of trading in the period from May 21, 2012 to September 18, 2013. We identify observations featuring firm-specific spikes in Twitter activity, and randomly assign each observation to a ten-minute increment matching on the firm and a number of repeating time indicators. We examine the extent that unusual levels of chatter on Twitter about a firm portend an oncoming surge of trading of its stock within the hour, over and above what would normally be expected for the stock for that time of day and day of week. We also compare the findings from our explanatory model to the predictive power of Tweets. Although we find a compelling and potentially informative real-time relationship between Twitter activity and trading volume, our forecasting exercise highlights how difficult it can be to make use of this information for monetary gain.

  8. Real-Time Diffusion of Information on Twitter and the Financial Markets.

    PubMed

    Tafti, Ali; Zotti, Ryan; Jank, Wolfgang

    2016-01-01

    Do spikes in Twitter chatter about a firm precede unusual stock market trading activity for that firm? If so, Twitter activity may provide useful information about impending financial market activity in real-time. We study the real-time relationship between chatter on Twitter and the stock trading volume of 96 firms listed on the Nasdaq 100, during 193 days of trading in the period from May 21, 2012 to September 18, 2013. We identify observations featuring firm-specific spikes in Twitter activity, and randomly assign each observation to a ten-minute increment matching on the firm and a number of repeating time indicators. We examine the extent that unusual levels of chatter on Twitter about a firm portend an oncoming surge of trading of its stock within the hour, over and above what would normally be expected for the stock for that time of day and day of week. We also compare the findings from our explanatory model to the predictive power of Tweets. Although we find a compelling and potentially informative real-time relationship between Twitter activity and trading volume, our forecasting exercise highlights how difficult it can be to make use of this information for monetary gain. PMID:27504639

  9. Real-Time Diffusion of Information on Twitter and the Financial Markets

    PubMed Central

    Tafti, Ali; Zotti, Ryan; Jank, Wolfgang

    2016-01-01

    Do spikes in Twitter chatter about a firm precede unusual stock market trading activity for that firm? If so, Twitter activity may provide useful information about impending financial market activity in real-time. We study the real-time relationship between chatter on Twitter and the stock trading volume of 96 firms listed on the Nasdaq 100, during 193 days of trading in the period from May 21, 2012 to September 18, 2013. We identify observations featuring firm-specific spikes in Twitter activity, and randomly assign each observation to a ten-minute increment matching on the firm and a number of repeating time indicators. We examine the extent that unusual levels of chatter on Twitter about a firm portend an oncoming surge of trading of its stock within the hour, over and above what would normally be expected for the stock for that time of day and day of week. We also compare the findings from our explanatory model to the predictive power of Tweets. Although we find a compelling and potentially informative real-time relationship between Twitter activity and trading volume, our forecasting exercise highlights how difficult it can be to make use of this information for monetary gain. PMID:27504639

  10. 75 FR 55305 - Proposed Information Collection; Comment Request; Social Impacts of the Implementation of a Catch...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-10

    ... include loss of employment opportunities and shoreside infrastructure, and disruption to social networks... National Oceanic and Atmospheric Administration Proposed Information Collection; Comment Request; Social... is for new information collection. Social Impact Assessment (SIA) is required in fisheries under...

  11. Where Are We on the Diffusion Curve? Trends and Drivers of Primary Care Physicians’ Use of Health Information Technology

    PubMed Central

    Audet, Anne-Marie; Squires, David; Doty, Michelle M

    2014-01-01

    Objective To describe trends in primary care physicians’ use of health information technology (HIT) between 2009 and 2012, examine practice characteristics associated with greater HIT capacity in 2012, and explore factors such as delivery system and payment reforms that may affect adoption and functionality. Data We used data from the 2012 and 2009 Commonwealth Fund International Health Policy Surveys of Primary Care Physicians. The data were collected in both years by postal mail between March and July among a nationally representative sample of primary care physicians in the United States. Study Design We compared primary care physicians’ HIT capacity in 2009 and 2012. We employed multivariable logistic regression to analyze whether participating in an integrated delivery system, sharing resources and support with other practices, and being eligible for financial incentives were associated with greater HIT capacity in 2012. Principal Findings Primary care physicians’ HIT capacity has significantly expanded since 2009, although solo practices continue to lag. Practices that are part of an integrated delivery system or share resources with other practices have higher rates of electronic medical record (EMR) adoption, multifunctional HIT, electronic information exchange, and electronic access for patients. Receiving or being eligible for financial incentives is associated with greater adoption of EMRs and information exchange. Conclusions Federal efforts to increase adoption have coincided with a rapid increase in HIT capacity. Delivery system and payment reforms and federally funded extension programs could offer promising pathways for further diffusion. PMID:24358958

  12. Reconstruction algorithm for diffuse optical tomography using x-ray CT anatomical information and application to bioluminescence tomography

    NASA Astrophysics Data System (ADS)

    Naser, Mohamed A.; Pekar, Julius; Patterson, Michael S.

    2011-02-01

    An algorithm to solve the diffuse optical tomography (DOT) problem is described which uses the anatomical information from x-ray CT images. These provide a priori information about the distribution of the optical properties hence reducing the number of variables and permitting a unique solution to the ill-posed problem. The light fluence rate at the boundary is written as a Taylor series expansion around an initial guess corresponding to an optically homogenous object. The second order approximation is considered and the derivatives are calculated by direct methods. These are used in an iterative algorithm to reconstruct the tissue optical properties. The reconstructed optical properties are then used for bioluminescence tomography where a minimization problem is formed based on the L1 norm objective function which uses normalized values for the light fluence rates and the corresponding Green's functions. Then an iterative minimization solution shrinks the permissible regions where the sources are allowed by selecting points with higher probability to contribute to the source distribution. Throughout this process the permissible region shrinks from the entire object to just a few points. The optimum reconstructed bioluminescence distributions are chosen to be the results of the iteration corresponding to the permissible region where the objective function has its global minimum. This provides efficient BLT reconstruction algorithms without the need for a priori information about the bioluminescence sources.

  13. Impact of diffuse nitrate pollution sources on groundwater quality--some examples from Czechoslovakia.

    PubMed Central

    Benes, V; Pĕkný, V; Skorepa, J; Vrba, J

    1989-01-01

    In several regions of Czechoslovakia with intensive agricultural production, the correlation between the amount of nitrogen fertilizer applied and the nitrate content in groundwater has been recognized. Nitrate pollution of groundwater is considered to be the most serious source of nonpoint pollution in Czechoslovakia. A program of research into the effects of farming activities on groundwater quality in Czechoslovakia is under way on experimental fields (20 to 30 hectares) and, simultaneously, in regions in which shallow, vulnerable aquifers occur. The importance of the soil organic matter's stability for maintaining the groundwater quality is emphasized. Research based on nitrogen and organic carbon balance has shown that the restoration of a soil-groundwater system is a complicated process that usually requires changes in the extent and intensity of agricultural activities and consistent attention to the effects produced by natural conditions. Regional investigation of the impact of farming on shallow aquifers in the fluvial deposits of the Elbe River in Bohemia has proved the hydrochemical instability and vertical hydrochemical heterogeneity of these aquifers. The WASTEN deterministic model was used for modeling the transport and transformation of various types of inorganic fertilizers. The input data is based on laboratory and field measurements. Special topics are the verification of model calculations and the time and spatial variability of input data with respect to the unsaturated zone. The research results are being used for making regional and national agro-groundwater managerial schemes more precise, as well as for decision-making. PMID:2559844

  14. Impact of diffuse nitrate pollution sources on groundwater quality--some examples from Czechoslovakia.

    PubMed

    Benes, V; Pĕkný, V; Skorepa, J; Vrba, J

    1989-11-01

    In several regions of Czechoslovakia with intensive agricultural production, the correlation between the amount of nitrogen fertilizer applied and the nitrate content in groundwater has been recognized. Nitrate pollution of groundwater is considered to be the most serious source of nonpoint pollution in Czechoslovakia. A program of research into the effects of farming activities on groundwater quality in Czechoslovakia is under way on experimental fields (20 to 30 hectares) and, simultaneously, in regions in which shallow, vulnerable aquifers occur. The importance of the soil organic matter's stability for maintaining the groundwater quality is emphasized. Research based on nitrogen and organic carbon balance has shown that the restoration of a soil-groundwater system is a complicated process that usually requires changes in the extent and intensity of agricultural activities and consistent attention to the effects produced by natural conditions. Regional investigation of the impact of farming on shallow aquifers in the fluvial deposits of the Elbe River in Bohemia has proved the hydrochemical instability and vertical hydrochemical heterogeneity of these aquifers. The WASTEN deterministic model was used for modeling the transport and transformation of various types of inorganic fertilizers. The input data is based on laboratory and field measurements. Special topics are the verification of model calculations and the time and spatial variability of input data with respect to the unsaturated zone. The research results are being used for making regional and national agro-groundwater managerial schemes more precise, as well as for decision-making.

  15. Diffusion of personal health information services: self-determining and empowering practices for Manitoba Inuit.

    PubMed

    Clark, Wayne Voisey

    2014-01-01

    This article highlights findings from research conducted with the Manitoba Urban Inuit Association with regard to culturally safe practices for communicating personal health information services related to a provincial integrated electronic health record. By applying a "two-eyed seeing research approach," which incorporates traditional and Western scientific perspectives, the author describes Inuit cultural considerations when communicating electronic health concepts with a vision of advancing toward program evaluation opportunities. The research is supported by two Inuit-driven focus groups, interviews with three jurisdictional representatives of electronic health program delivery agencies and one interview with an Inuk elder.

  16. Diffusion of personal health information services: self-determining and empowering practices for Manitoba Inuit.

    PubMed

    Clark, Wayne Voisey

    2014-01-01

    This article highlights findings from research conducted with the Manitoba Urban Inuit Association with regard to culturally safe practices for communicating personal health information services related to a provincial integrated electronic health record. By applying a "two-eyed seeing research approach," which incorporates traditional and Western scientific perspectives, the author describes Inuit cultural considerations when communicating electronic health concepts with a vision of advancing toward program evaluation opportunities. The research is supported by two Inuit-driven focus groups, interviews with three jurisdictional representatives of electronic health program delivery agencies and one interview with an Inuk elder. PMID:24844716

  17. Some Probable Technological Trends and Their Impact on an Information Network System. LINCS Project Document Series.

    ERIC Educational Resources Information Center

    Ebersole, Joseph L.

    Improvements in the technology associated with the information sciences will have their primary potential impact on the distribution of costs, information flow level, information availability, and use among information channels. This improvement implied not only a capability to perform a given function, but a lower cost. For example, the trend…

  18. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 57; US Scientific and Technical Information Policy

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Barclay, Rebecca O.; Kennedy, John M.

    1996-01-01

    In fiscal year 1994, the United States government spent about $68 billion for science and technology. Although there is general agreement among policy makers that the results of this expenditure can be used to enhance technological innovation and improve economic competitiveness, there is no coherent scientific and technical information (STI) policy. The absence of a cohesive policy and STI policy framework means that the transfer and utilization of STI goes uncoordinated. This chapter examines the U.S. government's role in funding science and technology, reviews Federal STI activities and involvement in the transfer and use of STI resulting from federally-funded science and technology, presents issues surrounding the use of federally-funded STI, and offers recommendations for improving the transfer and use of STI.

  19. The Fortune Cookie: Socio-Political Impact of Information Technology.

    ERIC Educational Resources Information Center

    Gell, Marilyn K.

    1981-01-01

    Presents an historical perspective and analysis of information policy issues, including the relationship between public and private sectors, information and productivity, and the role of government. Ten references are cited. (FM)

  20. A Potential Value of Familiarity and Experience: Can Informal Fieldwork Have a Lasting Impact upon Literacy?

    ERIC Educational Resources Information Center

    Scott, Graham W.; Boyd, Margaret

    2014-01-01

    This paper demonstrates that an informal field trip can have a lasting impact upon aspects of learning in a primary school context. Specifically, we consider the longer term impact of an informal trip to a rocky shore upon scores achieved in literacy assessments taking place five months after a relevant five months after a fieldwork. Pupils…

  1. Privatization of Public Information: Its Impact on Libraries.

    ERIC Educational Resources Information Center

    Shill, Harold B.

    1991-01-01

    Explores the ideas and policies behind the movement toward privatization, and traces the history of information privatization during the Reagan administration. A discussion of privatization of government information focuses on attempts to privatize NTIS (National Technical Information Service), and differences between print and electronic…

  2. Informed RESTORE: A method for robust estimation of diffusion tensor from low redundancy datasets in the presence of physiological noise artifacts.

    PubMed

    Chang, Lin-Ching; Walker, Lindsay; Pierpaoli, Carlo

    2012-11-01

    Physiological noise artifacts, especially those originating from cardiac pulsation and subject motion, are common in clinical Diffusion tensor-MRI acquisitions. Previous works show that signal perturbations produced by artifacts can be severe and neglecting to account for their contribution can result in erroneous diffusion tensor values. The Robust Estimation of Tensors by Outlier Rejection (RESTORE) method has been shown to be an effective strategy for improving tensor estimation on a voxel-by-voxel basis in the presence of artifactual data points in diffusion-weighted images. In this article, we address potential instabilities that may arise when using RESTORE and propose practical constraints to improve its usability. Moreover, we introduce a method, called informed RESTORE designed to remove physiological noise artifacts in datasets acquired with low redundancy (less than 30-40 diffusion-weighted image volumes)--a condition in which the original RESTORE algorithm may converge to an incorrect solution. This new method is based on the notion that physiological noise is more likely to result in signal dropouts than signal increases. Results from both Monte Carlo simulation and clinical diffusion data indicate that informed RESTORE performs very well in removing physiological noise artifacts for low redundancy diffusion-weighted image datasets.

  3. Diffusion-Weighted MRI for Nodal Staging of Head and Neck Squamous Cell Carcinoma: Impact on Radiotherapy Planning

    SciTech Connect

    Dirix, Piet; Vandecaveye, Vincent; De Keyzer, Frederik; Op de beeck, Katya; Poorten, Vincent Vander; Delaere, Pierre; Verbeken, Eric; Hermans, Robert; Nuyts, Sandra

    2010-03-01

    Purpose: To evaluate the use of diffusion-weighted magnetic resonance imaging (DW-MRI) for nodal staging and its impact on radiotherapy (RT) planning. Methods and Materials: Twenty-two patients with locally advanced head and neck squamous cell carcinoma underwent contrast-enhanced computed tomography (CT), as well as MRI (with routine and DW sequences) prior to neck dissection. After topographic correlation, lymph nodes were evaluated microscopically with prekeratin immunostaining. Pathology results were correlated with imaging findings and an RT planning study was performed for these surgically treated patients. One set of target volumes was based on conventional imaging only, and another set was based on the corresponding DW-MRI images. A third reference set was contoured based solely on pathology results. Results: A sensitivity of 89% and a specificity of 97% per lymph node were found for DW-MRI. Nodal staging agreement between imaging and pathology was significantly stronger for DW-MRI (kappa = 0.97; 95% confidence interval [CI], 0.84-1.00) than for conventional imaging (kappa = 0.56; 95% CI, 0.16-0.96; p = 0.019, by McNemar's test). For both imaging modalities, the absolute differences between RT volumes and those obtained by pathology were calculated. Using an exact paired Wilcoxon test, the observed difference was significantly larger for conventional imaging than for DW-MRI for nodal gross tumor volume (p = 0.0013), as well as for nodal clinical target volume (p = 0.0415) delineation. Conclusions: These results suggest that DW-MRI is superior to conventional imaging for preradiotherapy nodal staging of head and neck squamous cell carcinoma, and provides a potential impact on organsparing and tumor control.

  4. Anthropogenic impact on diffuse trace metal accumulation in river sediments from agricultural reclamation areas with geochemical and isotopic approaches.

    PubMed

    Jiao, Wei; Ouyang, Wei; Hao, Fanghua; Lin, Chunye

    2015-12-01

    A better understanding of anthropogenic impact can help assess the diffuse trace metal accumulation in the agricultural environment. In this study, both river sediments and background soils were collected from a case study area in Northeast China and analyzed for total concentrations of six trace metals, four major elements and three lead isotopes. Results showed that Pb, Cd, Cu, Zn, Cr and Ni have accumulated in the river sediments after about 40 years of agricultural development, with average concentrations 1.23-1.71 times higher than local soil background values. Among them Ni, Cr and Cu were of special concern and they may pose adverse biological effects. By calculating enrichment factor (EF), it was found that the trace metal accumulation was still mainly ascribed to natural weathering processes, but anthropogenic contribution could represent up to 40.09% of total sediment content. For Pb, geochemical and isotopic approaches gave very similar anthropogenic contributions. Principal component analysis (PCA) further suggested that the anthropogenic Pb, Cu, Cr and Ni inputs were mostly related to the regional atmospheric deposition of industrial emissions and gasoline combustion, which had a strong affinity for iron oxides in the sediments. Concerning Cd, however, it mainly originated from local fertilizer applications and was controlled by sediment carbonates.

  5. Time-resolved diffuse optical tomographic imaging for the provision of both anatomical and functional information about biological tissue

    NASA Astrophysics Data System (ADS)

    Zhao, Huijuan; Gao, Feng; Tanikawa, Yukari; Homma, Kazuhiro; Yamada, Yukio

    2005-04-01

    We present in vivo images of near-infrared (NIR) diffuse optical tomography (DOT) of human lower legs and forearm to validate the dual functions of a time-resolved (TR) NIR DOT in clinical diagnosis, i.e., to provide anatomical and functional information simultaneously. The NIR DOT system is composed of time-correlated single-photon-counting channels, and the image reconstruction algorithm is based on the modified generalized pulsed spectral technique, which effectively incorporates the TR data with reasonable computation time. The reconstructed scattering images of both the lower legs and the forearm revealed their anatomies, in which the bones were clearly distinguished from the muscles. In the absorption images, some of the blood vessels were observable. In the functional imaging, a subject was requested to do handgripping exercise to stimulate physiological changes in the forearm tissue. The images of oxyhemoglobin, deoxyhemoglobin, and total hemoglobin concentration changes in the forearm were obtained from the differential images of the absorption at three wavelengths between the exercise and the rest states, which were reconstructed with a differential imaging scheme. These images showed increases in both blood volume and oxyhemoglobin concentration in the arteries and simultaneously showed hypoxia in the corresponding muscles. All the results have demonstrated the capability of TR NIR DOT by reconstruction of the absolute images of the scattering and the absorption with a high spatial resolution that finally provided both the anatomical and functional information inside bulky biological tissues.

  6. Untangling a crystal storm through time: how do 500 diffusion stopwatches inform our view of Eyjafjallajökull 2010?

    NASA Astrophysics Data System (ADS)

    Pankhurst, M. J.; Morgan, D. J.; Thordarson, T.; Loughlin, S.

    2014-12-01

    A new database of 500+ olivine crystal timescales from samples that encompass the duration of the 2010 Fimmvörðuháls-Eyjafjallajökull eruption is presented. We also integrate new petrologic, thermometric and barometric data to read a 4D narrative of the magmatic processes within this volcanic plumbing system preceding­­- and during- eruption. Using this perspective we can identify and semi-quantify magmatic componentry, detect new magmatic inputs, and 'watch' those crystal chemical populations age. We find that major crystal-liquid disequilibrium events occurred up to several years preceding the eruptions, and inputs fed the plumbing system during the eruption window (days - hours). We place timeframes upon processes including magma-mixing, mush remobilization and erosion, and final-ascent quenching and eruption. Fe-Mg binary diffusion in olivine modelling conducted upon this scale was made possible using new advances -also presented here- in both the gathering and processing of raw data, and extraction of timescale information. We demonstrate that this streamlined workflow can now produce statistically robust timescale data within an integrated petrologic and geochemical context that may be resolved alongside independent geophysical and other remote sensing data into a common dimension - time. Transposing petrologic information (record of past process) and geophysical observation (phenomenological in the present) into a common language is designed to produce new understanding of both active and palaeo- volcanic systems, the implications of which we discuss here using our case study as an example.

  7. Derivation of particulate directional information from analysis of elliptical impact craters on LDEF

    NASA Technical Reports Server (NTRS)

    Newman, P. J.; Mackay, N.; Deshpande, S. P.; Green, S. F.; Mcdonnell, J. A. M.

    1993-01-01

    The Long Duration Exposure Facility provided a gravity gradient stabilized platform which allowed limited directional information to be derived from particle impact experiments. The morphology of impact craters on semi-infinite materials contains information which may be used to determine the direction of impact much more accurately. We demonstrate the applicability of this technique and present preliminary results of measurements from LDEF and modelling of interplanetary dust and space debris.

  8. Simulations of Diffusive Pb-, Ti- and REE-loss in Terrestrial and Lunar Zircon and Apatite as a Function of Impact Heating During Impact Bombardments

    NASA Astrophysics Data System (ADS)

    Abramov, O.; Mojzsis, S. J.

    2009-12-01

    Ultra-high spatial resolution ion microprobe depth-profiles of pre-3.9 Ga terrestrial zircons from the Jack Hills (Western Australia) have the potential to record a sharply elevated impactor flux to the inner planets at ca. 3.95 Ga termed the Late Heavy Bombardment (LHB). A putative signature of this is in the form of ~3.95 Ga, 2 to 4 μm mantles over the (oldest) igneous zircon cores (up to 4.3 Ga). These minute mantles show Pb-loss (up to 90% discordance) over narrow domains that could be the result of impact heating. Pre-3.9 Ga lunar zircon grains have not yet been depth-profiled, but it is evident from published spot analyses that grain cores preserve original igneous ages albeit with no clear super-imposition of later thermal events. However, the U-Pb systematics of apatites in the same lunar rocks were reset ca. 3.95 Ga. The motivation of this study is to explain the high degree of Pb (and other cation) loss over very short distances (<6 μm) in terrestrial zircons at ~3.9 Ga, the complete resetting of U-Pb isotope systematics of lunar apatites at approximately the same time, and to make predictions in preparation for depth-profile work on lunar samples. To accomplish these goals, we used existing models that simulate the thermal consequences of LHB, as well as established equations for cation diffusion in zircon and apatite. The main thermal model consists of (i) a stochastic cratering model which populates the surface with craters within constraints derived from the lunar cratering record, the size/frequency distribution of the asteroid belt, and dynamical models; (ii) analytical expressions that calculate a temperature field for each model crater; and (iii) three-dimensional thermal models of lunar and terrestrial lithospheres, where craters are allowed to cool by conduction in the subsurface and radiation at the surface. In addition, a high-resolution near-surface model was used to account for additional thermal pulses due to global deposition of hot

  9. Mapping Physician Twitter Networks: Describing How They Work as a First Step in Understanding Connectivity, Information Flow, and Message Diffusion

    PubMed Central

    2014-01-01

    Background Twitter is becoming an important tool in medicine, but there is little information on Twitter metrics. In order to recommend best practices for information dissemination and diffusion, it is important to first study and analyze the networks. Objective This study describes the characteristics of four medical networks, analyzes their theoretical dissemination potential, their actual dissemination, and the propagation and distribution of tweets. Methods Open Twitter data was used to characterize four networks: the American Medical Association (AMA), the American Academy of Family Physicians (AAFP), the American Academy of Pediatrics (AAP), and the American College of Physicians (ACP). Data were collected between July 2012 and September 2012. Visualization was used to understand the follower overlap between the groups. Actual flow of the tweets for each group was assessed. Tweets were examined using Topsy, a Twitter data aggregator. Results The theoretical information dissemination potential for the groups is large. A collective community is emerging, where large percentages of individuals are following more than one of the groups. The overlap across groups is small, indicating a limited amount of community cohesion and cross-fertilization. The AMA followers’ network is not as active as the other networks. The AMA posted the largest number of tweets while the AAP posted the fewest. The number of retweets for each organization was low indicating dissemination that is far below its potential. Conclusions To increase the dissemination potential, medical groups should develop a more cohesive community of shared followers. Tweet content must be engaging to provide a hook for retweeting and reaching potential audience. Next steps call for content analysis, assessment of the behavior and actions of the messengers and the recipients, and a larger-scale study that considers other medical groups using Twitter. PMID:24733146

  10. The Impact of Social Media on Informal Learning in Museums

    ERIC Educational Resources Information Center

    Russo, Angelina; Watkins, Jerry; Groundwater-Smith, Susan

    2009-01-01

    This paper posits that social networking can take a central role in learning in informal environments such as museums, libraries and galleries. It argues that social media offers young people agency previously unavailable in informal learning environments in order to explore complex responses to and participation with cultural content. The paper…

  11. Impacting Student Perceptions about Careers in Information Systems

    ERIC Educational Resources Information Center

    Walstrom, Kent A.; Schambach, Thomas P.

    2012-01-01

    A shortage of graduates prepared to fill the available jobs in Information Systems remains. Previous studies have verified the shortage and attempted to explain why students do not major in Information Technology related fields. Since prior studies identified lack of awareness regarding the discipline as a major reason in ignoring the major, the…

  12. The Impact of Information on Death Penalty Support, Revisited

    ERIC Educational Resources Information Center

    Lambert, Eric G.; Camp, Scott D.; Clarke, Alan; Jiang, Shanhe

    2011-01-01

    In 1972, former Supreme Court Justice Marshall postulated that the public was uninformed about the death penalty and information would change their support for it. There is some indication that information about the death penalty may change people's level of support. This study re-examines data used by Lambert and Clarke (2001). Using multivariate…

  13. Societal Impact of Improved Environment and Geospatial Information

    NASA Astrophysics Data System (ADS)

    Pearlman, J.; Andrzejewska, M.; Stonor, T.

    2013-12-01

    Geospatial projects are often dogged by the inability to establish a strong quantitative value proposition and are unable to sustain the attention of senior decision makers. In a tough economic climate, it is particularly important that any project that requires a significant investment can show a clear Return on Investment (ROI). In the case of commerce, benefit can be quantified through increase in sales/profit or reduction of risk. In the case of societal impact, quantification is more challenging. At the Geospatial World Forum (GWF) 2013 in Rotterdam, a number of case studies were presented on social impacts which used differing approaches to impact assessment. Some of the cases discussed projects with community issues and explained alternative means of conflict resolution. However, a comparison of the different case studies was not made at the GWF meeting. This presentation will take the next step and address the commonalities and differences in the approaches.

  14. Additional information for impact response of the restart safety rods

    SciTech Connect

    Yau, W.W.F.

    1991-10-14

    WSRC-RP-91-677 studied the structural response of the safety rods under the conditions of brake failure and accidental release. It was concluded that the maximum impact loading to the safety rod is 6020 pounds based on conservative considerations that energy dissipation attributable to fluid resistance and reactor superstructure flexibility. The staffers of the Defense Nuclear Facility Safety Board reviewed the results and inquired about the extent of conservatism. By request of the RESTART team, I reassessed the impact force due to these conservative assumptions. This memorandum reports these assessments.

  15. Disentangling diffusion information of individual components in a mixture with a 3D COMPACT-IDOSY NMR experiment.

    PubMed

    Shukla, Matsyendranath; Dorai, Kavita

    2012-05-01

    A new 3D diffusion-ordered heteronuclear NMR experiment COMPACT-IDOSY (cross-polarization optimized multisite polarized accelerated time internally encoded diffusion ordered spectroscopy) has been designed and experimentally implemented on a mixture of flavonoids rutin and quercetin. The pulse sequence uses a cross-polarization mixing period and diffusion encoding gradients internally incorporated into the coherence transfer interval of a long-range heteronuclear correlation experiment. Substantial reduction in experimental time, good sensitivity and excellent resolution of signal overlap lead to the accurate determination of translational diffusion coefficients of individual components in the mixture.

  16. Pre-Service Teachers' Perspectives of the Diffusion of Information and Communications Technologies (ICTs) and the Effect of Case-Based Discussions (CBDs)

    ERIC Educational Resources Information Center

    Sahin, Sami

    2012-01-01

    This study investigates pre-service teachers' perspectives of the diffusion of information and communication technologies (ICTs) in elementary education and the effect of case-based discussions (CBDs). The sample consisted of 170 first-year pre-service teachers from elementary teacher education programs of the largest teacher education college in…

  17. 78 FR 77442 - Agency Information Collection Activities; Comment Request; The Impact of Professional Development...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-23

    ... information collection requirements and provide the requested data in the desired format. ED is soliciting... Agency Information Collection Activities; Comment Request; The Impact of Professional Development in... Reduction Act of 1995 (44 U.S.C. chapter 3501 et seq.), ED is proposing a new information collection....

  18. The Impact of Variability of Item Parameter Estimators on Test Information Function

    ERIC Educational Resources Information Center

    Zhang, Jinming

    2012-01-01

    The impact of uncertainty about item parameters on test information functions is investigated. The information function of a test is one of the most important tools in item response theory (IRT). Inaccuracy in the estimation of test information can have substantial consequences on data analyses based on IRT. In this article, the major part (called…

  19. ASM Journals Eliminate Impact Factor Information from Journal Websites.

    PubMed

    Casadevall, Arturo; Bertuzzi, Stefano; Buchmeier, Michael J; Davis, Roger J; Drake, Harold; Fang, Ferric C; Gilbert, Jack; Goldman, Barbara M; Imperiale, Michael J; Matsumura, Philip; McAdam, Alexander J; Pasetti, Marcela F; Sandri-Goldin, Rozanne M; Silhavy, Thomas; Rice, Louis; Young, Jo-Anne H; Shenk, Thomas

    2016-01-01

    Many scientists attempt to publish their work in a journal with the highest possible journal impact factor (IF). Despite widespread condemnation of the use of journal IFs to assess the significance of published work, these numbers continue to be widely misused in publication, hiring, funding, and promotion decisions (1, 2). PMID:27408939

  20. Federal Environmental Impact Statements as an Important Source of Information.

    ERIC Educational Resources Information Center

    Orr, Patricia S.

    1995-01-01

    Examines the background and characteristics of environmental impact statements (EIS), and discusses the sources that provide bibliographic control for EISs. Explores the usefulness of EISs, outlines their legislative basis, describes the EIS process and format, and identifies sources that facilitate access to them. (Author/DGM)

  1. Assessing the socioeconomic impact and value of open geospatial information

    USGS Publications Warehouse

    Pearlman, Francoise; Pearlman, Jay; Bernknopf, Richard; Coote, Andrew; Craglia, Massimo; Friedl, Lawrence; Gallo, Jason; Hertzfeld, Henry; Jolly, Claire; Macauley, Molly; Shapiro, Carl; Smart, Alan

    2016-01-01

    The workshop included 68 participants coming from international organizations, the U.S. public and private sectors, nongovernmental organizations, and academia. Participants included policy makers and analysts, financial analysts, economists, information scientists, geospatial practitioners, and other discipline experts.

  2. Designing-and Redesigning-Information Services for Maximum Impact.

    ERIC Educational Resources Information Center

    Jones, Rebecca; Dysart, Jane

    2002-01-01

    Discusses innovative information services, including new services and the redesign of existing services. Describes the development process, including assessing the market and developing a marketing plan; and explains the implementation process, including monitoring client satisfaction and quality control. (LRW)

  3. Assessing the socioeconomic impact and value of open geospatial information

    USGS Publications Warehouse

    Pearlman, Francoise; Pearlman, Jay; Bernknopf, Richard; Coote, Andrew; Craglia, Massimo; Friedl, Lawrence; Gallo, Jason; Hertzfeld, Henry; Jolly, Claire; Macauley, Molly; Shapiro, Carl; Smart, Alan

    2016-03-10

    The workshop included 68 participants coming from international organizations, the U.S. public and private sectors, nongovernmental organizations, and academia. Participants included policy makers and analysts, financial analysts, economists, information scientists, geospatial practitioners, and other discipline experts.

  4. Impacts of regional mixing on the temperature structure of the equatorial Pacific Ocean. Part 2: Depth-dependent vertical diffusion

    NASA Astrophysics Data System (ADS)

    Jia, Yanli; Furue, Ryo; McCreary, Julian P.

    2015-07-01

    In this study, we use an ocean model to explore how vertical mixing influences temperature in the eastern equatorial Pacific Ocean. Our approach is to change the background diffusion coefficient from a constant value κb to κb + δκ(z) in various subregions of the tropical Pacific, and then to determine the resulting temperature changes in the near-equilibrium response. In a companion paper (Furue et al., 2015), we consider the impacts of depth-independent κb anomalies. Here, we examine the impacts of depth-dependent anomalies that are confined above, or centered on, the mid-depth of the pycnocline. During the first year of adjustment, solutions develop a local temperature response that results largely from the one-dimensional balance δTt =(δκTz)z = δκzTz + δκTzz, with a similar equation for salinity. At this stage, δκ generates temperature and salinity anomalies that are either associated with a density change (dynamical anomalies) or without one (spiciness anomalies). Subsequently, dynamical and spiciness anomalies spread to remote regions by wave radiation and advection, respectively. For positive δκ anomalies confined above the mid-pycnocline, δκzTz tends to produce positive temperature anomalies, which spread to the equator dynamically (by wave radiation) and are still apparent in near-equilibrium solutions. For δκ anomalies confined within the pycnocline (with monopole, dipole, and tripole profiles), the response is dominated by δκzTz, owing to δκ having a smaller vertical scale than T and to the depth range where δκ is large not overlapping well with that where ∣Tzz∣ is; the resulting temperature anomalies tend to shift the pycnocline vertically (dipole profile) or to alter its thickness (monopole and tripole profiles). Positive anomalies from all subregions contribute to an increase of near-surface(upper 50 m) temperature in the eastern equatorial Pacific, the amplitude and location of the warming depending on the depth range of

  5. Impact of Informal Science Education on Children's Attitudes About Science

    NASA Astrophysics Data System (ADS)

    Wulf, Rosemary; Mayhew, Laurel M.; Finkelstein, Noah D.

    2010-10-01

    The JILA Physics Frontier Center Partnerships for Informal Science Education in the Community (PISEC) provides informal afterschool inquiry-based science teaching opportunities for university participants with children typically underrepresented in science. We focus on the potential for this program to help increase children's interest in science, mathematics, and engineering and their understanding of the nature of science by validating the Children's Attitude Survey, which is based on the Colorado Learning Attitudes about Science Survey [1] and designed to measure shifts in children's attitudes about science and the nature of science. We present pre- and post-semester results for several semesters of the PISEC program, and demonstrate that, unlike most introductory physics courses in college, our after-school informal science programs support and promote positive attitudes about science.

  6. Hybrid Diffusion Imaging

    PubMed Central

    Wu, Yu-Chien; Alexander, Andrew L.

    2007-01-01

    Diffusion measurements in the human central nervous system are complex to characterize and a broad spectrum of methods have been proposed. In this study, a comprehensive diffusion encoding and analysis approach, Hybrid Diffusion Imaging (HYDI), is described. The HYDI encoding scheme is composed of multiple concentric “shells” of constant diffusion-weighting, which may be used to characterize the signal behavior with low, moderate and high diffusion-weighting. HYDI facilitates the application of multiple data-analyses strategies including diffusion tensor imaging (DTI), multi-exponential diffusion measurements, diffusion spectrum imaging (DSI) and q-ball imaging (QBI). These different analysis strategies may provide complementary information. DTI measures (mean diffusivity and fractional anisotropy) may be estimated from either data in the inner shells or the entire HYDI data. Fast and slow diffusivities were estimated using a nonlinear least-squares bi-exponential fit on geometric means of the HYDI shells. DSI measurements from the entire HYDI data yield empirical model-independent diffusion information and are well-suited for characterizing tissue regions with complex diffusion behavior. DSI measurements were characterized using the zero displacement probability and the mean squared displacement. The outermost HYDI shell was analyzed using QBI analysis to estimate the orientation distribution function (ODF), which is useful for characterizing the directions of multiple fiber groups within a voxel. In this study, a HYDI encoding scheme with 102 diffusion-weighted measurements was obtained over most of the human cerebrum in under 30 minutes. PMID:17481920

  7. What impact might mitigation of diffuse nitrate pollution have on river water quality in a rural catchment?

    PubMed

    Hutchins, Michael G

    2012-10-30

    Observations of river flow, river quality and solar radiation were collated to assess the degree to which light and nutrients may be limiting phytoplankton growth at seven sites in the River Ouse catchment in NE England under average conditions. Hydraulic information derived from river network model applications was then used to determine where river water has sufficient residence time above the tidal limit to facilitate bloom development. A nitrate model (NALTRACES) was developed to estimate the impact of land management change on mean river nitrate concentrations. Applications of this model showed that although agricultural activity contributes substantially to nitrate loads in the Ouse it is likely to have little impact on phytoplankton growth, which could still occur extensively in its absence given favourable sunny and dry conditions. As an example of a means of controlling light availability, establishing full riparian tree cover would appear to be a considerably more effective management scenario than suppressing inputs to the river of nitrate or phosphorus. Any actions should be prioritised in headwater areas such as the upper reaches of the Swale and Ure tributaries. These conclusions are in broad agreement with those arising from more detailed simulations at daily resolution using the QUESTOR river quality model. The combination of simple modelling approaches applied here allows an initial identification of suitable spatially-targeted options for mitigating against phytoplankton blooms which can be applied more widely at a regional or national level. PMID:22659646

  8. What impact might mitigation of diffuse nitrate pollution have on river water quality in a rural catchment?

    PubMed

    Hutchins, Michael G

    2012-10-30

    Observations of river flow, river quality and solar radiation were collated to assess the degree to which light and nutrients may be limiting phytoplankton growth at seven sites in the River Ouse catchment in NE England under average conditions. Hydraulic information derived from river network model applications was then used to determine where river water has sufficient residence time above the tidal limit to facilitate bloom development. A nitrate model (NALTRACES) was developed to estimate the impact of land management change on mean river nitrate concentrations. Applications of this model showed that although agricultural activity contributes substantially to nitrate loads in the Ouse it is likely to have little impact on phytoplankton growth, which could still occur extensively in its absence given favourable sunny and dry conditions. As an example of a means of controlling light availability, establishing full riparian tree cover would appear to be a considerably more effective management scenario than suppressing inputs to the river of nitrate or phosphorus. Any actions should be prioritised in headwater areas such as the upper reaches of the Swale and Ure tributaries. These conclusions are in broad agreement with those arising from more detailed simulations at daily resolution using the QUESTOR river quality model. The combination of simple modelling approaches applied here allows an initial identification of suitable spatially-targeted options for mitigating against phytoplankton blooms which can be applied more widely at a regional or national level.

  9. Information Assurance Alignment: A Study of Performance Impacts

    ERIC Educational Resources Information Center

    Ghezal, Said

    2011-01-01

    The positive effect on performance of the alignment between a business strategy and its different functional strategies has a wide support in the literature. As an emerging functional area, information assurance has come to play a strategic role by providing all departments and functions across an organization with a reliable, safe, and efficient…

  10. Impact of Information Technology Governance Structures on Strategic Alignment

    ERIC Educational Resources Information Center

    Gordon, Fitzroy R.

    2013-01-01

    This dissertation is a study of the relationship between Information Technology (IT) strategic alignment and IT governance structure within the organization. This dissertation replicates Asante (2010) among a different population where the prior results continue to hold, the non-experimental approach explored two research questions but include two…

  11. The Development and Impact of a Global Information System.

    ERIC Educational Resources Information Center

    Kranch, Douglas A.

    1989-01-01

    Predicts that, over the next several decades, technological advancements in large scale database construction and maintenance, high speed digital transmission networks, and highly precise intelligent searchware will result in a worldwide information system. A projected model illustrates pricing and retrieval rate changes that may be expected over…

  12. The Information Machines; Their Impact on Men and the Media.

    ERIC Educational Resources Information Center

    Bagdikian, Ben H.

    "Today we are on the threshold of a change in human communications which is more powerful and perhaps more significant than all past changes in the technology of information. The way men deal with each other and with the distant world is about to be transformed by a combination of the computer, innovations in the transmission of signals, and new…

  13. The Impact of New Information Technology on Bureaucratic Organizational Culture

    ERIC Educational Resources Information Center

    Givens, Mark A.

    2011-01-01

    Virtual work environments (VWEs) have been used in the private sector for more than a decade, but the United States Marine Corps (USMC), as a whole, has not yet taken advantage of associated benefits. The USMC construct parallels the bureaucratic organizational culture and uses an antiquated information technology (IT) infrastructure. During an…

  14. Impact of Anaphoric Resolution in Information Retrieval. Final Report.

    ERIC Educational Resources Information Center

    Katzer, Jeffrey; And Others

    This project examines anaphora (the linguistic device of abbreviated subsequent reference to a concept) in information retrieval (IR) systems in order to develop procedures to recognize anaphors in text and distinguish between anaphoric and non-anaphoric uses of a given term, estimate the number of anaphors appearing in bibliographic records, and…

  15. Hanford site solid waste management environmental impact statement technical information document [SEC 1 THRU 4

    SciTech Connect

    FRITZ, L.L.

    2003-04-01

    This Technical Information Document (TID) provides engineering data to support DOE/EIS-0286, ''Hanford Site Solid (Radioactive and Hazardous) Waste Program Environmental Impact Statement,'' including assumptions and waste volumes calculation data.

  16. Impact of information and communications technologies on residental customer energy services

    SciTech Connect

    Goldman, C.; Kempton, W.; Eide, A.; Iyer, M.

    1996-10-01

    This study analyzes the potential impact of information and communications technologies on utility delivery of residential customer energy services. Many utilities are conducting trials which test energy-related and non-energy services using advanced communications systems.

  17. The Impact of Buoyancy and Flame Structure on Soot, Radiation and NOx Emissions from a Turbulent Diffusion Flame

    NASA Technical Reports Server (NTRS)

    Kennedy, I. M.; Kollman, W.; VanderWal, R. L.

    1999-01-01

    It is hypothesized that the spatial structure of a turbulent diffusion flame plays an important role in determining the emissions of radiative energy, soot and NO, from a combustor. This structure, manifested in the two point statistics, is influenced by buoyancy. Radiation, soot and NOx emissions are the cumulative result of processes that occur throughout a flame. For example, radiation fluxes along a line of sight can be found from summing up the contributions from sources in individual pockets of hot soot that emit, and from sinks in cold soot that absorb. Soot and NOx are both the results of slow chemistry and are not equilibrium products. The time that is available for production and burnout is crucial in determining the eventual emissions of these pollutants. Turbulence models generally rely on a single point closure of the appropriate time averaged equations. Hence, spatial information is lost and needs to be modeled using solution variables such as turbulence kinetic energy and dissipation rate, often with the assumption of isotropy. However, buoyancy can affect the physical structure of turbulent flames and can change the spatial extent of soot bearing regions. Theoretical comparisons with models are best done in the limit of infinite Froude number because the inclusion of buoyancy in flow models introduces significant uncertainties. Hence, LII measurements of soot, measurements of radiation fluxes from soot, Particle Imaging Velocimetry (PIV) of the flow field and measurements of post flame NOX will be carried out on the NASA Lewis 2.2 sec drop tower and eventually on the parabolic flight aircraft. The drop rig will be a modified version of a unit that has been successfully used at Lewis in the past.

  18. The impact of concomitant diffuse idiopathic skeletal hyperostosis on the achievement of minimal disease activity in subjects with psoriatic arthritis.

    PubMed

    Pappone, Nicola; Di Minno, Matteo Nicola Dario; Iervolino, Salvatore; Lupoli, Roberta; Mader, Reuven; Zincarelli, Carmela; Peluso, Rosario

    2015-12-01

    Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by ossification of different entheses. Psoriatic arthritis (PsA) is a seronegative spondyloarthritis associated with psoriasis. Given the possible overlap of the two diseases, we assessed whether DISH presence may affect PsA clinical outcomes. Also, predictors of DISH presence in the cohort were investigated. Consecutive PsA patients from two Italian Rheumatology Research Units were enrolled. Subjects were splitted into two groups, according to the current treatment (TNF-α blockers or traditional DMARDs). All patients underwent a rheumatologic examination, blood sample collections and spine radiographs. Information about traditional vascular risk factors was recorded. In each patient, the presence of minimal disease activity was evaluated and the presence of DISH was established according to the Resnick and Niwayama criteria. Among the 80 enrolled subjects (57.5 % men, mean age 56.5 ± 11.1 years), the overall prevalence of DISH was 30.0 %. Patients with DISH were older, with higher BMI and waist circumference. DISH subjects showed worsen BASMI, HAQ and ESR. In a multivariate regression model, BASMI was a significant predictor of DISH presence (OR 3.027, 95 % CI 1.449-6.325, p = 0.003). The prevalence of MDA was lower in DISH patients than in no-DISH (16.7 vs 41.1 %, p = 0.041), and the presence of DISH was a predictor of not achieving MDA (OR 3.485, 95 % CI 1.051-11.550, p = 0.041). PsA subjects with DISH showed worsen indices of spine mobility and articular function and lower prevalence of minimal disease activity than no-DISH patients.

  19. Mechanisms of Innovation Diffusion under Information Abundance and Information Scarcity--On the Contribution of Social Networks in Group vs. Individual Extension Approaches in Semi-Arid Kenya

    ERIC Educational Resources Information Center

    Darr, Dietrich; Pretzsch, Jurgen

    2008-01-01

    Purpose: The objective of this paper is to assess the effectiveness of innovation diffusion under group-oriented and individual-oriented extension. Current theoretical notions of innovation diffusion in social networks shall be briefly reviewed, and the concepts of "search" and "innovation" vis-a-vis "transfer" and "imitation" mechanisms (Hansen,…

  20. Determination of partition and diffusion coefficient of formaldehyde in selected building materials and impact of relative humidity

    EPA Science Inventory

    The partition and effective diffusion coefficients of formaldehyde were measured for three materials (conventional gypsum wallboard, "green" gypsum wallboard, and "green" carpet) under three relative humidity (RH) conditions (20%, 50% and 70% RH). A dynamic dual-chamber test meth...

  1. Determination of partition and diffusion coefficients of formaldehyde in selected building materials and impact of relative humidity (journal)

    EPA Science Inventory

    The partition and effective diffusion coefficients of formaldehyde were measured for three materials (conventional gypsum wallboard, "green" gypsum wallboard, and "green" carpet) under three relative humidity (RH) conditions (20%, 50% and 70% RH). A dynamic dual-chamber test meth...

  2. 76 FR 68219 - Agency Information Collection Activities; Submission for OMB Review; Comment Request; Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ...; Impact Evaluation of the YouthBuild Program ACTION: Notice. SUMMARY: The Department of Labor (DOL) is submitting the Employment and Training Administration (ETA) sponsored proposal for a new information collection titled, ``Impact Evaluation of the YouthBuild Program,'' to the Office of Management and...

  3. Information and the War against Terrorism, Part III: New Information-Related Laws and the Impact on Civil Liberties.

    ERIC Educational Resources Information Center

    Strickland, Lee S.

    2002-01-01

    Reviews provisions of information-related laws in light of the September 11th attacks and their impact on civil liberties. Highlights include the USA Patriot Act of 2001; law enforcement and the ECPA (Electronic Communications Privacy Act); intelligence and the FISA (Foreign Intelligence Surveillance Act of 1978); implications for information…

  4. National Integrated Drought Information System (NIDIS), United State Drought Portal (USDP): A Window on Drought Information, Impacts and Implications

    NASA Astrophysics Data System (ADS)

    Owen, T.; Svoboda, M.; Pulwarty, R.

    2007-12-01

    The NIDIS Act of 2006 calls for an interagency approach to improve drought monitoring, forecasting and early warning. Led by NOAA, NIDIS focuses on the consolidation of physical, hydrological and socio-economic impacts data; integrated observing networks; development of a suite of drought decision support and simulation tools; and interactive delivery of standardized products through an internet portal. The vision for NIDIS is a dynamic and accessible drought risk information system that informs user decisions in preparing for and mitigating of the effects of drought. In support of this vision, the U.S. Drought Portal (USDP) will be a national resource for data, models, risk information and impacts of drought, with responsibility for integrating, archiving, and disseminating data via the internet. A portal environment, defined as a "site on the World Wide Web that typically provides personalized capabilities for their visitors," is critical, as it allows selected drought information from multiple authorities to be consolidated and interrogated, while simultaneously using metadata references to identify emerging information from the drought community. The USDP will provide reliable information on drought conditions at county, regional and national scales and serve as the primary point of entry for drought-related queries (through the already secured drought.gov URL) for a variety of user groups. Such questions include: -Where are drought conditions now and where might they develop? -Does this drought event look like other events in the past? -Will the drought continue? -How is the drought affecting me? -How can I plan for and manage the impacts of drought? The USDP will be comprised of information tailored for various user communities. The portal will work by combining NIDIS-related data and information with tools necessary to exchange and integrate data on various space and time scales, and among various formats. These portal data will incorporate a spectrum of

  5. Geobase Information System Impacts on Space Image Formats

    NASA Technical Reports Server (NTRS)

    Simonett, D. S. (Editor); Smith, T. R. (Editor); Tobler, W. (Editor); Marks, D. G. (Editor); Frew, J. E. (Editor); Dozier, J. C. (Editor)

    1978-01-01

    As Geobase Information Systems increase in number, size and complexity, the format compatability of satellite remote sensing data becomes increasingly more important. Because of the vast and continually increasing quantity of data available from remote sensing systems the utility of these data is increasingly dependent on the degree to which their formats facilitate, or hinder, their incorporation into Geobase Information Systems. To merge satellite data into a geobase system requires that they both have a compatible geographic referencing system. Greater acceptance of satellite data by the user community will be facilitated if the data are in a form which most readily corresponds to existing geobase data structures. The conference addressed a number of specific topics and made recommendations.

  6. Reassembling the Information Technology Innovation Process: An Actor Network Theory Method for Managing the Initiation, Production, and Diffusion of Innovations

    NASA Astrophysics Data System (ADS)

    Zendejas, Gerardo; Chiasson, Mike

    This paper will propose and explore a method to enhance focal actors' abilities to enroll and control the many social and technical components interacting during the initiation, production, and diffusion of innovations. The reassembling and stabilizing of such components is the challenging goal of the focal actors involved in these processes. To address this possibility, a healthcare project involving the initiation, production, and diffusion of an IT-based innovation will be influenced by the researcher, using concepts from actor network theory (ANT), within an action research methodology (ARM). The experiences using this method, and the nature of enrolment and translation during its use, will highlight if and how ANT can provide a problem-solving method to help assemble the social and technical actants involved in the diffusion of an innovation. Finally, the paper will discuss the challenges and benefits of implementing such methods to attain widespread diffusion.

  7. Indian aspects of drug information resources and impact of drug information centre on community

    PubMed Central

    Chauhan, Nitesh; Moin, Sabeeya; Pandey, Anushree; Mittal, Ashu; Bajaj, Umakant

    2013-01-01

    Drug information centre refer to facility specially set aside for, and specializing in the provision of drug information and related issues. The purpose of drug information center is to provide authentic individualized, accurate, relevant and unbiased drug information to the consumers and healthcare professionals regarding medication related inquiries to the nation for health care and drug safety aspects by answering their call regarding the all critical problems on drug information, their uses and their side effects. Apart from that the center also provides in-depth, impartial source of crucial drug information to meet the needs of the practicing physicians, pharmacists and other health care professionals to safeguard the health, financial and legal interests of the patient and to broaden the pharmacist role visible in the society and community. The service should include collecting, reviewing, evaluating, indexing and distributing information on drugs to health workers. Drug and poisons information centers are best established within major teaching hospitals. This allows access to clinical experience, libraries, research facilities and educational activities. Information present in the current paper will not only enlighten the role of drug information center but also focused on the rational use of drug. PMID:23833748

  8. The Impact of Internet Health Information on Patient Compliance: A Research Model and an Empirical Study

    PubMed Central

    Hassanein, Khaled; Yuan, Yufei

    2015-01-01

    Background Patients have been increasingly seeking and using Internet health information to become more active in managing their own health in a partnership with their physicians. This trend has both positive and negative effects on the interactions between patients and their physicians. Therefore, it is important to understand the impact that the increasing use of Internet health information has on the patient-physician relationship and patients’ compliance with their treatment regimens. Objective This study examines the impact of patients’ use of Internet health information on various elements that characterize the interactions between a patient and her/his physician through a theoretical model based on principal-agent theory and the information asymmetry perspective. Methods A survey-based study consisting of 225 participants was used to validate a model through various statistical techniques. A full assessment of the measurement model and structural model was completed in addition to relevant post hoc analyses. Results This research revealed that both patient-physician concordance and perceived information asymmetry have significant effects on patient compliance, with patient-physician concordance exhibiting a considerably stronger relationship. Additionally, both physician quality and Internet health information quality have significant effects on patient-physician concordance, with physician quality exhibiting a much stronger relationship. Finally, only physician quality was found to have a significant impact on perceived information asymmetry, whereas Internet health information quality had no impact on perceived information asymmetry. Conclusions Overall, this study found that physicians can relax regarding their fears concerning patient use of Internet health information because physician quality has the greatest impact on patients and their physician coming to an agreement on their medical situation and recommended treatment regimen as well as

  9. The impact of star physicians on diffusion of a medical technology: the case of laparoscopic gastric bypass surgery.

    PubMed

    Shinn, Laura

    2014-01-01

    Using data on all bariatric surgeries performed in the state of Pennsylvania from 1995 through 2007, this article uses logistic and OLS regressions to measure the effect of star physicians and star hospitals on the diffusion of an innovation in bariatric surgery called laparoscopic gastric bypass surgery (LGBS). This article tests for effects at both the hospital and physician level. Compared to hospitals with no star physicians (11 percent adoption rate), those with star physicians on staff show a much higher adoption rate (89 percent). Compared to hospitals that are not classified as star hospitals (13 percent diffusion rate), hospitals with star status show a much higher diffusion rate (87 percent from first quarter 2000 to fourth quarter 2001); being a star hospital raises the likelihood of that hospital diffusing LCBS from 13 percent to 87 percent. At the physician level, the empirical results indicate that star physicians exert positive asymmetric influence on the adoption and utilization rates of nonstars at the same hospital. Stars are those who: (1) graduated from a Top 30 medical school, (2) completed residency at a Top 30 hospital, or (3) are included in a Castle Connolly Top Doctors publication. The results of this article support earlier work on the role of key individuals in technology diffusion. It extends research on medical technology diffusion by testing a new data set for a chronic disease treatment. JEL classifications: D2, I10, I11, L2, O33. D2 production and organizations; L2 firm objectives, organization and behavior; I10 health general; I11 Analysis of health care markets; O33 technological change: choices and consequences; diffusion processes.

  10. Nanoparticle diffusion within intestinal mucus: Three-dimensional response analysis dissecting the impact of particle surface charge, size and heterogeneity across polyelectrolyte, pegylated and viral particles.

    PubMed

    Abdulkarim, Muthanna; Agulló, Nuria; Cattoz, Beatrice; Griffiths, Peter; Bernkop-Schnürch, Andreas; Borros, Salvador Gómez; Gumbleton, Mark

    2015-11-01

    Multiple particle tracking (MPT) methodology was used to dissect the impact of nanoparticle surface charge and size upon particle diffusion through freshly harvested porcine jejunum mucus. The mucus was characterised rheologically and by atomic force microscopy. To vary nanoparticle surface charge we used a series of self-assembly polyelectrolyte particles composed of varying ratios of the negatively charged polyacrylic acid polymer and the positively charged chitosan polymer. This series included a neutral or near-neutral particle to correspond to highly charged but near-neutral viral particles that appear to effectively permeate mucus. In order to negate the confounding issue of self-aggregation of such neutral synthetic particles a sonication step effectively reduced particle size (to less than 340 nm) for a sufficient period to conduct the tracking experiments. Across the polyelectrolyte particles a broad and meaningful relationship was observed between particle diffusion in mucus (×1000 difference between slowest and fastest particle types), particle size (104-373 nm) and particle surface charge (-29 mV to +19.5 mV), where the beneficial characteristic promoting diffusion was a neutral or near-neutral charge. The diffusion of the neutral polyelectrolyte particle (0.02887 cm S(-1)×10(-9)) compared favourably with that of a highly diffusive PEGylated-PLGA particle (0.03182 cm(2) S(-1)×10(-9)), despite the size of the latter (54 nm diameter) accommodating a reduced steric hindrance with the mucin network. Heterogeneity of particle diffusion within a given particle type revealed the most diffusive 10% sub-population for the neutral polyelectrolyte formulation (5.809 cm(2) S(-1)×10(-9)) to be faster than that of the most diffusive 10% sub-populations obtained either for the PEGylated-PLGA particle (4.061 cm(2) S(-1)×10(-9)) or for a capsid adenovirus particle (1.922 cm(2) S(-1)×10(-9)). While this study has used a simple self-assembly polyelectrolyte system

  11. Artificial Intelligence and Expert Systems Research and Their Possible Impact on Information Science.

    ERIC Educational Resources Information Center

    Borko, Harold

    1985-01-01

    Defines artificial intelligence (AI) and expert systems; describes library applications utilizing AI to automate creation of document representations, request formulations, and design and modify search strategies for information retrieval systems; discusses expert system development for information services; and reviews impact of these…

  12. College Students' Health Information Activities on Facebook: Investigating the Impacts of Health Topic Sensitivity, Information Sources, and Demographics.

    PubMed

    Syn, Sue Yeon; Kim, Sung Un

    2016-07-01

    College students tend to lack access to health information. Because social networking sites (SNSs) are popularly adopted by college students, SNSs are considered to be good media channels for college students to obtain health-related information. This study examines the factors that influence college students' health information-seeking and -sharing activities on Facebook. An online survey was distributed to college students between the ages of 18 and 29 to determine intentions pertaining to health information activities according to the factors identified for the study. The factors included both contextual factors (such as health topic sensitivity and health information sources) as well as user factors (such as demographics). Our findings showed that college students are willing to read and post health-related information on Facebook when the health topic is not sensitive. In addition, there are clear differences in preferences between professional sources and personal sources as health information sources. It was found that most user factors, except gender, have no influence on health information activities. The impacts of SNS contexts, awareness of information sources, types of interlocutors, and privacy concerns are further discussed.

  13. College Students' Health Information Activities on Facebook: Investigating the Impacts of Health Topic Sensitivity, Information Sources, and Demographics.

    PubMed

    Syn, Sue Yeon; Kim, Sung Un

    2016-07-01

    College students tend to lack access to health information. Because social networking sites (SNSs) are popularly adopted by college students, SNSs are considered to be good media channels for college students to obtain health-related information. This study examines the factors that influence college students' health information-seeking and -sharing activities on Facebook. An online survey was distributed to college students between the ages of 18 and 29 to determine intentions pertaining to health information activities according to the factors identified for the study. The factors included both contextual factors (such as health topic sensitivity and health information sources) as well as user factors (such as demographics). Our findings showed that college students are willing to read and post health-related information on Facebook when the health topic is not sensitive. In addition, there are clear differences in preferences between professional sources and personal sources as health information sources. It was found that most user factors, except gender, have no influence on health information activities. The impacts of SNS contexts, awareness of information sources, types of interlocutors, and privacy concerns are further discussed. PMID:27220029

  14. The Impact of Information Richness on Information Security Awareness Training Effectiveness

    ERIC Educational Resources Information Center

    Shaw, R. S.; Chen, Charlie C.; Harris, Albert L.; Huang, Hui-Jou

    2009-01-01

    In recent years, rapid progress in the use of the internet has resulted in huge losses in many organizations due to lax security. As a result, information security awareness is becoming an important issue to anyone using the Internet. To reduce losses, organizations have made information security awareness a top priority. The three main barriers…

  15. Impact of structural defect density on gettering of transition metal impurities during phosphorus emitter diffusion in multi-crystalline silicon solar cell processing

    NASA Astrophysics Data System (ADS)

    Park, Yongkook; Lu, Jinggang; Park, Jin-Hong; Rozgonyi, George

    2015-07-01

    The impact of structural defect density on gettering of transition metal impurities during phosphorous emitter diffusion has been investigated using a pair of multi-crystalline silicon (mc-Si) wafers. Chromium (Cr) impurities incorporated during growth were identified by deep level transient spectroscopy (DLTS) and used to evaluate the gettering efficiency. The Cr impurity concentration in the low defect density region of mc-Si wafers was reduced from ~3.5 × 1013 cm-3 to ~1.7 × 1012 cm-3 after phosphorous diffusion gettering (PDG), while for the high defect density region, there is no appreciable variation in the Cr concentration which only changed from ~3.0 to ~2.2 × 1012 cm-3 following PDG. It was concluded that the gettering process is not effective for highly defective regions of mc-Si wafers due to the ineffective impurity release from structural defects during the PDG process. [Figure not available: see fulltext.

  16. Impacts of long-line aquaculture of Pacific oysters (Crassostrea gigas) on sulfate reduction and diffusive nutrient flux in the coastal sediments of Jinhae-Tongyeong, Korea.

    PubMed

    Hyun, Jung-Ho; Kim, Sung-Han; Mok, Jin-Sook; Lee, Jae Seong; An, Sung-Uk; Lee, Won-Chan; Jung, Rae-Hong

    2013-09-15

    We investigated the environmental impacts of long-line aquaculture of Pacific oysters (Crassostrea gigas) on sediment geochemistry and carbon oxidation by sulfate reduction and diffusive benthic nutrient flux in a coastal ecosystem in Korea. Inventories of the NH4(+) and HPO4(2-) at the farm site were 7.7-11.5 and 1.8-8.0 times higher, respectively, than those at a reference site. Sulfate reduction rates (SRRs) at the oyster farm were 2.4-5.2 times higher than SRRs at the reference site. The SRRs at the farm site were responsible for 48-99% (average 70%) of the total C oxidation in the sediment. The diffusive benthic fluxes of NH4(+) and HPO4(2-) at the oyster farm were comparable to 30-164% and 19-58%, respectively, of the N and P demands for primary production, and were responsible for the enhanced benthic microalgal biomass on the surface sediment.

  17. Information Literacy in a Digital Era: Understanding the Impact of Mobile Information for Undergraduate Nursing Students.

    PubMed

    Doyle, Glynda J; Furlong, Karen E; Secco, Loretta

    2016-01-01

    Recent entry-to-practice nursing informatics competencies for Registered Nurses in Canada mean nurse educators need educational strategies to promote student competency within the rapidly evolving informatics field. A collaborative research team from three Canadian nursing programs completed a mixed method survey to describe how nursing students used mobile nursing information support and the extent of this support for learning. The Mobile Information Support Evaluation Tool (MISET) assessed Usefulness/Helpfulness, Information Literacy Support, and Use of Evidence-Based Sources. The quantitative and qualitative data were analyzed to describe students' perspectives and the ways they used mobile resources in learning situations. Findings suggest nursing students mainly accessed mobile resources to support clinical learning, and specifically for task-oriented information such as drug medication or patient conditions/diagnoses. Researchers recommend a paradigm shift whereby educators emphasize information literacy in a way that supports evidence-based quality care.

  18. Information Literacy in a Digital Era: Understanding the Impact of Mobile Information for Undergraduate Nursing Students.

    PubMed

    Doyle, Glynda J; Furlong, Karen E; Secco, Loretta

    2016-01-01

    Recent entry-to-practice nursing informatics competencies for Registered Nurses in Canada mean nurse educators need educational strategies to promote student competency within the rapidly evolving informatics field. A collaborative research team from three Canadian nursing programs completed a mixed method survey to describe how nursing students used mobile nursing information support and the extent of this support for learning. The Mobile Information Support Evaluation Tool (MISET) assessed Usefulness/Helpfulness, Information Literacy Support, and Use of Evidence-Based Sources. The quantitative and qualitative data were analyzed to describe students' perspectives and the ways they used mobile resources in learning situations. Findings suggest nursing students mainly accessed mobile resources to support clinical learning, and specifically for task-oriented information such as drug medication or patient conditions/diagnoses. Researchers recommend a paradigm shift whereby educators emphasize information literacy in a way that supports evidence-based quality care. PMID:27332210

  19. Gyrokinetic study of the impact of the electron to ion heating ratio on the turbulent diffusion of highly charged impurities

    SciTech Connect

    Angioni, C.

    2015-10-15

    A gyrokinetic study based on numerical and analytical calculations is presented, which computes the dependence of the turbulent diffusion of highly charged impurities on the ratio of the electron to the ion heat flux of the plasma. Nonlinear simulations show that the size of the turbulent diffusion of heavy impurities can vary by one order of magnitude with fixed total heat flux and is an extremely sensitive function of the electron to ion heat flux ratio. Numerical linear calculations are found to reproduce the nonlinear results. Thereby, a quasi-linear analytical approach is used to explain the origin of this dependence.

  20. Impact of weak excitatory synapses on chaotic transients in a diffusively coupled Morris-Lecar neuronal network

    SciTech Connect

    Lafranceschina, Jacopo Wackerbauer, Renate

    2015-01-15

    Spatiotemporal chaos collapses to either a rest state or a propagating pulse solution in a ring network of diffusively coupled, excitable Morris-Lecar neurons. Weak excitatory synapses can increase the Lyapunov exponent, expedite the collapse, and promote the collapse to the rest state rather than the pulse state. A single traveling pulse solution may no longer be asymptotic for certain combinations of network topology and (weak) coupling strengths, and initiate spatiotemporal chaos. Multiple pulses can cause chaos initiation due to diffusive and synaptic pulse-pulse interaction. In the presence of chaos initiation, intermittent spatiotemporal chaos exists until typically a collapse to the rest state.

  1. Designing a Software for Flood Risk Assessment Based on Multi Criteria Desicion Analysis and Information Diffusion Methods

    NASA Astrophysics Data System (ADS)

    Musaoglu, N.; Saral, A.; Seker, D. Z.

    2012-12-01

    Flooding is one of the major natural disasters not only in Turkey but also in all over the world and it causes serious damage and harm. It is estimated that of the total economic loss caused by all kinds of disasters, 40% was due to floods. In July 1995, the Ayamama Creek in Istanbul was flooded, the insurance sector received around 1,200 claims notices during that period, insurance companies had to pay a total of $40 million for claims. In 2009, the same creek was flooded again and killed 31 people over two days and insurance firms paid for damages around cost €150 million for claims. To solve these kinds of problems modern tools such as GIS and Remote Sensing should be utilized. In this study, a software was designed for the flood risk analysis with Analytic Hierarchy Process (AHP) and Information Diffusion( InfoDif) methods.In the developed sofware, five evaluation criterias were taken into account, which were slope, aspect, elevation, geology and land use which were extracted from the satellite sensor data. The Digital Elevation Model (DEM) of the Ayamama River Basin was acquired from the SPOT 5 satellite image with 2.5 meter spatial resolution. Slope and aspect values of the study basin were extracted from this DEM. The land use of the Ayamama Creek was obtained by performing object-oriented nearest neighbor classification method by image segmentation on SPOT 5 image dated 2010. All produced data were used as an input for the part of Multi Criteria Desicion Analysis (MCDA) method of this software. Criterias and their each sub criteras were weighted and flood vulnerability was determined with MCDA-AHP. Also, daily flood data was collected from Florya Meteorological Station, between 1975 to 2009 years and the daily flood peak discharge was calculated with the method of Soil Conservation Service-Curve Number (SCS-CN) and were used as an input in the software for the part of InfoDif.Obtained results were verified using ground truth data and it has been clearly

  2. Impact of the solute exclusion on the bed longitudinal diffusion coefficient and particle intra-tortuosity determined by ISEC.

    PubMed

    Wernert, Véronique; Bouchet, Renaud; Denoyel, Renaud

    2014-01-17

    The effective diffusion coefficient of non retained toluene and polystyrenes compounds was measured by the peak parking method for two columns packed with mesoporous silica. Different models used to predict the effective diffusion are compared. These models include the conventional Knox time-averaged model and some effective medium theory models such as Maxwell, Landauer, Garnett or Torquato models. In all these models the effective intraparticle diffusion coefficient is needed. It is derived here, in non-adsorbing conditions, from internal porosity, hindrance factor, which can be estimated with the Renkin correlation, and internal tortuosity, which can be considered as either constant or calculated by the Weissberg equation τ=1-plnɛ, where ɛ is the accessible particle porosity and p a parameter characteristic of the topology. The experimental effective diffusion coefficients of toluene and polystyrenes were found to be in good agreement with the values predicted by the Maxwell, or Torquato models, provided the internal tortuosity is calculated by using the Weissberg equation. PMID:24380650

  3. Reduction of noise in diffusion tensor images using anisotropic smoothing.

    PubMed

    Ding, Zhaohua; Gore, John C; Anderson, Adam W

    2005-02-01

    To improve the accuracy of tissue structural and architectural characterization with diffusion tensor imaging, a novel smoothing technique is developed for reducing noise in diffusion tensor images. The technique extends the traditional anisotropic diffusion filtering method by allowing isotropic smoothing within homogeneous regions and anisotropic smoothing along structure boundaries. This is particularly useful for smoothing diffusion tensor images in which direction information contained in the tensor needs to be restored following noise corruption and preserved around tissue boundaries. The effectiveness of this technique is quantitatively studied with experiments on simulated and human in vivo diffusion tensor data. Illustrative results demonstrate that the anisotropic smoothing technique developed can significantly reduce the impact of noise on the direction as well as anisotropy measures of the diffusion tensor images.

  4. Leveraging Informal Leadership in Higher Education Institutions: A Case of Diffusion of Emerging Technologies in a Southern Context

    ERIC Educational Resources Information Center

    Ng'ambi, Dick; Bozalek, Vivienne

    2013-01-01

    In the last decade, emerging technologies and transformative practices have diffused into higher education social systems in ways that formal leadership styles are increasingly stretched to both keep abreast of and to manage. While many scholars have argued for the importance of the role of leadership styles in shaping the strategic direction of…

  5. The influence of incomplete or unavailable information on environmental impact assessment in the USA

    SciTech Connect

    Atkinson, Samuel F. . E-mail: atkinson@unt.edu; Canter, Larry W. . E-mail: envimptr@aol.com; Ravan, Melanie D. . E-mail: melanie.raven@navy.mil

    2006-07-15

    One of the more common activities of environmental scientists in the United States is the preparation of environmental assessments or environmental impact statements in response to the mandates of the National Environmental Policy Act. The central thesis of this paper revolves around a frequent dilemma those scientists face: how to proceed with the environmental impact analysis when information on potential impacts is incomplete or unavailable. The paper examines how the 'hard look' standard that U.S. courts have imposed upon agencies considering proposed actions came about. Further, U.S. courts have said agencies cannot make arbitrary and capricious decisions when deciding to build a project, implement a plan, issue a permit or other give other approvals, and this paper discusses how the courts have defined what arbitrary and capricious decision are, especially when decisions are made when information about impacts is incomplete or unavailable. The paper examines why agencies win or lose lawsuits filed against the environmental assessments or environmental impact statements they write, focusing on those cases that have occurred after the Supreme Court ruled on the issue in 1989. The paper suggests recommendations to environmental scientists faced with incomplete or unavailable information when preparing an environmental assessment or environmental impact statement in the U.S.

  6. NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 34: How early career-stage US aerospace engineers and scientists produce and use information

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Barclay, Rebecca O.; Kennedy, John M.

    1995-01-01

    The U.S. government technical report is a primary means by which the results of federally funded research and development (R&D) are transferred to the U.S. aerospace industry. However, little is known about this information product in terms of its actual use, importance, and value in the transfer of federally funded R&D. To help establish a body of knowledge, the U.S. government technical report is being investigated as part of the NASA/DOD Aerospace Knowledge Diffusion Research Project. In this report, we summarize the literature on technical reports and provide a model that depicts the transfer of federally funded aerospace R&D via the U.S. government technical report. We present results from our investigation of aerospace knowledge diffusion vis-a-vis the U.S. government technical report, and present the results of research that investigated aerospace knowledge diffusion vis-a-vis the production and use of information by U.S. aerospace engineers and scientists who had changed their American Institute of Aeronautics and Astronautics (AIAA) membership from student to professional in the past five years.

  7. Local boundary reflections in lattice Boltzmann schemes: Spurious boundary layers and their impact on the velocity, diffusion and dispersion

    NASA Astrophysics Data System (ADS)

    Ginzburg, Irina; Roux, Laetitia; Silva, Goncalo

    2015-10-01

    This work demonstrates that in advection-diffusion Lattice Boltzmann schemes, the local mass-conserving boundary rules, such as bounce-back and local specular reflection, may modify the transport coefficients predicted by the Chapman-Enskog expansion when they enforce to zero not only the normal, but also the tangential boundary flux. In order to accommodate it to the bulk solution, the system develops a Knudsen-layer correction to the non-equilibrium part of the population solution. Two principal secondary effects-(i) decrease in the diffusion coefficient, and (ii) retardation of the average advection velocity, obtained in a closed analytical form, are proportional, respectively, to freely assigned diagonal weights for equilibrium mass and velocity terms. In addition, due to their transverse velocity gradients, the boundary layers affect the longitudinal diffusion coefficient similarly to Taylor dispersion, as they grow as the square of the Péclet number. These numerical artifacts can be eliminated or reduced by a proper space distribution of the free-tunable collision eigenvalue in two-relaxation-time schemes.

  8. Radon emanation of building material -- Impact of back diffusion and difference between one-dimensional and three-dimensional tests

    SciTech Connect

    Chao, C.Y.H. ); Tung, T.C.W. . Dept. of Building Services Engineering)

    1999-06-01

    Small-scale chamber experiments were conducted to investigate the radon emanation rates of commonly used building materials such as bare concrete, granite, red brick, and sand brick. It has been found that back diffusion caused by the accumulation of radon in the indoor environment has significant influence on the radon emanation rate. The radon emanation rate can be expressed as the summation of an initial emanation rate and the product of a specific back diffusion coefficient and the indoor radon level. In some occasions the radon emanation rate can be significantly lower than its initial value. A database was developed summarizing results from 26 samples. The influence of relative humidity on the radon emanation characteristics has also been discussed. Separate tests were done by coating the four sides of the building material with silicone gel to simulate a one-dimensional radon diffusion geometry. The results show that a factor has to be included when the three-dimensional test results are used to describe one-dimensional geometry, such as radon emanation from building wall surfaces.

  9. Impact and user satisfaction of a clinical information portal embedded in an electronic health record.

    PubMed

    Tannery, Nancy H; Epstein, Barbara A; Wessel, Charles B; Yarger, Frances; LaDue, John; Klem, Mary Lou

    2011-01-01

    In 2008, a clinical information tool was developed and embedded in the electronic health record system of an academic medical center. In 2009, the initial information tool, Clinical-e, was superseded by a portal called Clinical Focus, with a single search box enabling a federated search of selected online information resources. To measure the usefulness and impact of Clinical Focus, a survey was used to gather feedback about users' experience with this clinical resource. The survey determined what type of clinicians were using this tool and assessed user satisfaction and perceived impact on patient care decision making. Initial survey results suggest the majority of respondents found Clinical Focus easy to navigate, the content easy to read, and the retrieved information relevant and complete. The majority would recommend Clinical Focus to their colleagues. Results indicate that this tool is a promising area for future development.

  10. Impact and user satisfaction of a clinical information portal embedded in an electronic health record.

    PubMed

    Tannery, Nancy H; Epstein, Barbara A; Wessel, Charles B; Yarger, Frances; LaDue, John; Klem, Mary Lou

    2011-01-01

    In 2008, a clinical information tool was developed and embedded in the electronic health record system of an academic medical center. In 2009, the initial information tool, Clinical-e, was superseded by a portal called Clinical Focus, with a single search box enabling a federated search of selected online information resources. To measure the usefulness and impact of Clinical Focus, a survey was used to gather feedback about users' experience with this clinical resource. The survey determined what type of clinicians were using this tool and assessed user satisfaction and perceived impact on patient care decision making. Initial survey results suggest the majority of respondents found Clinical Focus easy to navigate, the content easy to read, and the retrieved information relevant and complete. The majority would recommend Clinical Focus to their colleagues. Results indicate that this tool is a promising area for future development. PMID:22016670

  11. Impact and User Satisfaction of a Clinical Information Portal Embedded in an Electronic Health Record

    PubMed Central

    Tannery, Nancy H; Epstein, Barbara A; Wessel, Charles B; Yarger, Frances; LaDue, John; Klem, Mary Lou

    2011-01-01

    In 2008, a clinical information tool was developed and embedded in the electronic health record system of an academic medical center. In 2009, the initial information tool, Clinical-e, was superseded by a portal called Clinical Focus, with a single search box enabling a federated search of selected online information resources. To measure the usefulness and impact of Clinical Focus, a survey was used to gather feedback about users' experience with this clinical resource. The survey determined what type of clinicians were using this tool and assessed user satisfaction and perceived impact on patient care decision making. Initial survey results suggest the majority of respondents found Clinical Focus easy to navigate, the content easy to read, and the retrieved information relevant and complete. The majority would recommend Clinical Focus to their colleagues. Results indicate that this tool is a promising area for future development. PMID:22016670

  12. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 13: The information-seeking habits and practices of engineers

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.

    1991-01-01

    It is argued that only by maximizing the research and development process can the United States maintain and possibly capture its international competitive edge. Key to this goal is the provision of information services and products which meet the information needs of engineers. Evidence exists which indicates that traditional information services and products may, in fact, not be meeting the information needs of engineers. The primary reason for this deficiency is three fold. First, the specific information needs of engineers are neither well known nor well understood. Second, what is known about the information seeking habits and practices of engineers has not been applied to existing engineering information services. Third, the information professionals continue to over-emphasize technology instead of concentrating on the quality of the information itself and the ability of the information to meet the needs of the user.

  13. Impact of the information age on residency training: communication, access to public information, and clinical care.

    PubMed

    Hilty, Donald M; Belitsky, Richard; Cohen, Mitchell B; Cabaniss, Deborah L; Dickstein, Leah J; Bernstein, Carol A; Kaplan, Allan S; Scheiber, Stephen C; Crisp-Han, Holly D; Wrzosek, Marika I; Silberman, Edward K

    2015-02-01

    Access to technology in practice helps physicians manage information, communicate, and research topics; however, those in training receive almost no formal preparation for integrating web-based technologies into practice. One reason for this is that many faculty-aside from junior faculty or those in recent generations-did not grow up using Internet communication, may use it minimally, if at all, in their own practices, and may know little about its forms and varieties. This report presents a case to illustrate how these disparities may play out in the supervisory situation and makes suggestions about helping supervisors integrate technology-awareness into their teaching. PMID:25124878

  14. Impact of the information age on residency training: communication, access to public information, and clinical care.

    PubMed

    Hilty, Donald M; Belitsky, Richard; Cohen, Mitchell B; Cabaniss, Deborah L; Dickstein, Leah J; Bernstein, Carol A; Kaplan, Allan S; Scheiber, Stephen C; Crisp-Han, Holly D; Wrzosek, Marika I; Silberman, Edward K

    2015-02-01

    Access to technology in practice helps physicians manage information, communicate, and research topics; however, those in training receive almost no formal preparation for integrating web-based technologies into practice. One reason for this is that many faculty-aside from junior faculty or those in recent generations-did not grow up using Internet communication, may use it minimally, if at all, in their own practices, and may know little about its forms and varieties. This report presents a case to illustrate how these disparities may play out in the supervisory situation and makes suggestions about helping supervisors integrate technology-awareness into their teaching.

  15. Impact of information cost and switching of trading strategies in an artificial stock market

    NASA Astrophysics Data System (ADS)

    Liu, Yi-Fang; Zhang, Wei; Xu, Chao; Vitting Andersen, Jørgen; Xu, Hai-Chuan

    2014-08-01

    This paper studies the switching of trading strategies and its effect on the market volatility in a continuous double auction market. We describe the behavior when some uninformed agents, who we call switchers, decide whether or not to pay for information before they trade. By paying for the information they behave as informed traders. First we verify that our model is able to reproduce some of the stylized facts in real financial markets. Next we consider the relationship between switching and the market volatility under different structures of investors. We find that there exists a positive relationship between the market volatility and the percentage of switchers. We therefore conclude that the switchers are a destabilizing factor in the market. However, for a given fixed percentage of switchers, the proportion of switchers that decide to buy information at a given moment of time is negatively related to the current market volatility. In other words, if more agents pay for information to know the fundamental value at some time, the market volatility will be lower. This is because the market price is closer to the fundamental value due to information diffusion between switchers.

  16. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 20: Engineers as information processors: A survey of US aerospace engineering faculty and students

    NASA Technical Reports Server (NTRS)

    Holland, Maurita Peterson; Pinelli, Thomas E.; Barclay, Rebecca O.; Kennedy, John M.

    1991-01-01

    U.S. aerospace engineering faculty and students were surveyed as part of the NASA/DoD Aerospace Knowledge Research Project. Faculty and students were viewed as information processors within a conceptual framework of information seeking behavior. Questionnaires were received from 275 faculty members and 640 students, which were used to determine: (1) use and importance of information sources; (2) use of specific print sources and electronic data bases; (3) use of information technology; and (4) the influence of instruction on the use of information sources and the products of faculty and students. Little evidence was found to support the belief that instruction in library or engineering information use has significant impact either on broadening the frequency or range of information products and sources used by U.S. aerospace engineering students.

  17. Measurement and Modeling of Water-Vapor Diffusion in Elastomers with Impact in Humidity and Vacuum Measurements

    NASA Astrophysics Data System (ADS)

    Šetina, Janez; Sefa, Makfir; Erjavec, Bojan; Hudoklin, Domen

    2013-03-01

    The dynamics of water-vapor dissolution in Viton O-rings is measured with a gravimetric method using a precise mass comparator. A sample gasket was degassed in high vacuum for a sufficiently long period to remove more than 99 % of the dissolved water vapor. After that, it was exposed to the ambient atmosphere with a controlled temperature, and relative humidity and water-vapor uptake curves were measured gravimetrically with a precise balance. The dynamics of a water-vapor release into vacuum from another sample that was previously saturated with water vapor at room temperature was determined. The sample was placed in a vacuum outgassing rate measurement apparatus. The time dependence of the evolved water vapor was calculated by integrating the measured outgassing rate. The physical process of water absorption can be described by the diffusion equation. The geometry of the samples required solving the diffusion equation in cylindrical coordinates. This was done numerically using a finite-difference method. As a result of the modeling, room temperature values of the diffusion constant D, the solubility s, and the permeability K = D× s of water vapor in the sample material (Viton A-401C) were obtained. For sample 1, we obtained D = 8.0 × 10 ^{-8} cm2 {\\cdot } s^{-1} and s = 6.5 × 10^{-7} g {\\cdot } cm^-3 Pa^{-1}, while for sample 2, D = 3.0 × 10^{-7} cm2 s^{-1} and s = 3.5 × 10^{-7} g {\\cdot } cm^{-3} {\\cdot } Pa^{-1}.

  18. 76 FR 5192 - BOEMRE Information Collection Activity: 1010-0170-Coastal Impact Assistance Program (CIAP...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-28

    ...: 1010-0170--Coastal Impact Assistance Program (CIAP), Extension of a Collection; Comment Request AGENCY... extension of an information collection (1010- 0170). SUMMARY: To comply with the Paperwork Reduction Act of..., Virginia 20170-4817. Please reference ICR 1010-0170 in your comment and include your name and...

  19. The Impact of School Buildings on Learning. Information Capsule. Volume 1204

    ERIC Educational Resources Information Center

    Blazer, Christie

    2012-01-01

    This Information Capsule examines the impact of deteriorating school buildings on students and teachers. Research indicates that students attending schools that are in poor physical condition score lower on achievement tests than students in newer, functional buildings. Studies suggest that several specific factors contribute to lower levels of…

  20. The Impact of an Informal Science Program on Students' Science Knowledge and Interest

    ERIC Educational Resources Information Center

    Zandstra, Anne Maria

    2012-01-01

    In this sequential explanatory mixed methods study, quantitative and qualitative data were used to measure the impact of an informal science program on eleventh grade students' science knowledge and interest. The local GEAR UP project has been working for six years with a cohort of students who were in eleventh and twelfth grade during the…

  1. The Impact of Informal Mentoring among Latino Males as It Relates to Pursuing Postsecondary Education

    ERIC Educational Resources Information Center

    Ayon, Maria Concepcion

    2013-01-01

    Purpose: The purpose of this study was to understand the lived experiences of Latino males who engaged in an informal mentoring relationship and the impact of these relationships as it related to their pursuit of a postsecondary education. Methodology: The researcher conducted a qualitative approach to the study. The subjects in the present study…

  2. Impacting Information Literacy Learning in First-Year Seminars: A Rubric-Based Evaluation

    ERIC Educational Resources Information Center

    Lowe, M. Sara; Booth, Char; Stone, Sean; Tagge, Natalie

    2015-01-01

    The authors conducted a rubric assessment of information literacy (IL) skills in research papers across five undergraduate first-year seminar programs to explore the question "What impact does librarian intervention in first-year courses have on IL performance in student work?" Statistical results indicate that students in courses with…

  3. Impacts of an Information Commons on an Academic Library's Service Points

    ERIC Educational Resources Information Center

    Gohlke, Mary Jo; Ray, Kathlin

    2003-01-01

    The impacts of technology upon traditional library resources are sometimes unexpected. The library at California's University of the Pacific discovered that usage of print materials was dwindling, even though the addition of a 50-station "Information Commons" had bolstered overall library use. At first it was anticipated that the circulation desk…

  4. High Database Prices and Their Impact on Information Access: Is There a Solution?

    ERIC Educational Resources Information Center

    Nelson, Michael L.

    1987-01-01

    Recent trends in the pricing of online database systems are described and their impact on searcher behavior and satisfaction is discussed. A design is proposed for a major research project that would use data gathered by the Information Market Indicators to assess the feasibility of a price-based solution. (CLB)

  5. A Longitudinal Study of Information Technology Impact on Business Faculty in Distance Education

    ERIC Educational Resources Information Center

    Zhao, Jensen, J.; Alexander, Melody W.; Perrreault, Heidi; Waldman, Lila

    2007-01-01

    This longitudinal study compared business faculty's use of information technology in distance education as well as their perception of the technology's impact on their productivity and technology preferences between 2000 and 2006. Data were collected from 81 professors in 2000 and 140 professors in 2006 at AACSB-accredited business colleges across…

  6. The Impact of Trade Liberalization and Information Technology on India's Manufacturing Sector

    ERIC Educational Resources Information Center

    Sharma, Shruti

    2013-01-01

    This dissertation is an investigation into how trade liberalization and the adoption of information technology have impacted labour and productivity in India's manufacturing sector respectively. The second chapter analyses the relationship between India's liberalization of tariffs on imported intermediate inputs (henceforth input tariff…

  7. Impact of Internet on Schools of Library and Information Science in Thailand.

    ERIC Educational Resources Information Center

    Manmart, Lampang

    This paper looks at how the Internet has impacted library and information science (LIS) schools in Thailand, focusing on how it has been used and changes in the teaching/learning process, curriculum, and programs. Data were collected by questionnaires sent to 146 academic staff in 16 LIS schools, interviews with 16 heads of LIS schools, and…

  8. 18 CFR 33.4 - Additional information requirements for applications involving vertical competitive impacts.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Additional information requirements for applications involving vertical competitive impacts. 33.4 Section 33.4 Conservation of Power... FEDERAL POWER ACT APPLICATIONS UNDER FEDERAL POWER ACT SECTION 203 § 33.4 Additional...

  9. 18 CFR 33.4 - Additional information requirements for applications involving vertical competitive impacts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Additional information requirements for applications involving vertical competitive impacts. 33.4 Section 33.4 Conservation of Power... FEDERAL POWER ACT APPLICATIONS UNDER FEDERAL POWER ACT SECTION 203 § 33.4 Additional...

  10. 78 FR 57135 - Agency Information Collection Activities; Comment Request; Impact Aid Program Application for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-17

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF EDUCATION Agency Information Collection Activities; Comment Request; Impact Aid Program Application for Section... response to this notice should be submitted electronically through the Federal eRulemaking Portal at...

  11. Digital Avionics Information System (DAIS): Impact of DAIS Concept on Life Cycle Cost. Final Report.

    ERIC Educational Resources Information Center

    Goclowski, John C.; And Others

    Designed to identify and quantify the potential impacts of the Digital Avionics Information System (DAIS) on weapon system personnel requirements and life cycle cost (LCC), this study postulated a typical close-air-support (CAS) mission avionics suite to serve as a basis for comparing present day and DAIS configuration specifications. The purpose…

  12. Impact of Using Information Technology in Central University Libraries in India: Results of a Survey

    ERIC Educational Resources Information Center

    Peyala, Venkataramana

    2011-01-01

    Purpose: The purpose of this article is to present the results of a research study conducted to assess the perceptions and opinions of 100 staff working in libraries on the impact of using IT on library housekeeping operations and information services, in eight central university libraries in India. Design/methodology/approach: Data gathering…

  13. "Finding Useful Questions: On Bayesian Diagnosticity, Probability, Impact, and Information Gain": Correction to Nelson (2005)

    ERIC Educational Resources Information Center

    Nelson, Jonathan D.

    2007-01-01

    Reports an error in "Finding Useful Questions: On Bayesian Diagnosticity, Probability, Impact, and Information Gain" by Jonathan D. Nelson (Psychological Review, 2005[Oct], Vol 112[4], 979-999). In Table 13, the data should indicate that 7% of females had short hair and 93% of females had long hair. The calculations and discussion in the article…

  14. Climate Change Education: Quantitatively Assessing the Impact of a Botanical Garden as an Informal Learning Environment

    ERIC Educational Resources Information Center

    Sellmann, Daniela; Bogner, Franz X.

    2013-01-01

    Although informal learning environments have been studied extensively, ours is one of the first studies to quantitatively assess the impact of learning in botanical gardens on students' cognitive achievement. We observed a group of 10th graders participating in a one-day educational intervention on climate change implemented in a botanical…

  15. Professors Are People Too: The Impact of Informal Evaluations of Professors on Students and Professors

    ERIC Educational Resources Information Center

    Kowai-Bell, Neneh; Guadagno, Rosanna E.; Little, Tannah E.; Ballew, Jamie L.

    2012-01-01

    There are websites where individuals anonymously provide informal reviews of professors. What impact do such sites have on student and professor motivational factors? Research suggests that undergraduate students are affected (e.g. Edwards et al. in "J Comput Mediat Commun" 14:368-392, 2009; Kowai-Bell et al. in "Comput Hum Behav" 27(5):1862-1867,…

  16. Factors that Impact Software Project Success in Offshore Information Technology (IT) Companies

    ERIC Educational Resources Information Center

    Edara, Venkatarao

    2011-01-01

    Information technology (IT) projects are unsuccessful at a rate of 65% to 75% per year, in spite of employing the latest technologies and training employees. Although many studies have been conducted on project successes in U.S. companies, there is a lack of research studying the impact of various factors on software project success in offshore IT…

  17. A Study of the Impact of Representations in Information Retrieval Systems. Annual Technical Report.

    ERIC Educational Resources Information Center

    Katzer, Jeffrey; And Others

    This study conducted to determine representation impact on information items retrieval in terms of precision and recall performance and overlap used the INSPEC "Computers and Control Abstracts" loaded on DIATOM, an online retrieval system based on DIALOG, as the database to be searched. Sixty-nine users provided 84 queries which were searched for…

  18. NASA/DoD Aerospace Knowledge Diffusion Research Project. Paper 31: The information-seeking behavior of engineers

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Bishop, Ann P.; Barclay, Rebecca O.; Kennedy, John M.

    1993-01-01

    Engineers are an extraordinarily diverse group of professionals, but an attribute common to all engineers is their use of information. Engineering can be conceptualized as an information processing system that must deal with work-related uncertainty through patterns of technical communications. Throughout the process, data, information, and tacit knowledge are being acquired, produced, transferred, and utilized. While acknowledging that other models exist, we have chosen to view the information-seeking behavior of engineers within a conceptual framework of the engineer as an information processor. This article uses the chosen framework to discuss information-seeking behavior of engineers, reviewing selected literature and empirical studies from library and information science, management, communications, and sociology. The article concludes by proposing a research agenda designed to extend our current, limited knowledge of the way engineers process information.

  19. Li diffusion in zircon

    NASA Astrophysics Data System (ADS)

    Cherniak, D. J.; Watson, E. B.

    2010-09-01

    Diffusion of Li under anhydrous conditions at 1 atm and under fluid-present elevated pressure (1.0-1.2 GPa) conditions has been measured in natural zircon. The source of diffusant for 1-atm experiments was ground natural spodumene, which was sealed under vacuum in silica glass capsules with polished slabs of zircon. An experiment using a Dy-bearing source was also conducted to evaluate possible rate-limiting effects on Li diffusion of slow-diffusing REE+3 that might provide charge balance. Diffusion experiments performed in the presence of H2O-CO2 fluid were run in a piston-cylinder apparatus, using a source consisting of a powdered mixture of spodumene, quartz and zircon with oxalic acid added to produce H2O-CO2 fluid. Nuclear reaction analysis (NRA) with the resonant nuclear reaction 7Li(p,γ)8Be was used to measure diffusion profiles for the experiments. The following Arrhenius parameters were obtained for Li diffusion normal to the c-axis over the temperature range 703-1.151°C at 1 atm for experiments run with the spodumene source: D_{text{Li}} = 7.17 × 10^{ - 7} { exp }( - 275 ± 11 {text{kJmol}}^{ - 1} /{text{RT}}){text{m}}2 {text{s}}^{ - 1}. Diffusivities are similar for transport parallel to the c-axis, indicating little anisotropy for Li diffusion in zircon. Similar Li diffusivities were also found for experiments run under fluid-present conditions and for the experiment run with the Dy-bearing source. Li diffusion is considerably faster than diffusion of other cations in zircon, with a smaller activation energy for diffusion. Although Li diffusion in zircon is comparatively rapid, zircons will be moderately retentive of Li signatures at mid-crustal metamorphic temperatures, but they are unlikely to retain this information for geologically significant times under high-grade metamorphism.

  20. Developing Broader Impacts Activities through Informal STEM Education Collaborations and Strategies

    NASA Astrophysics Data System (ADS)

    Bell, James

    2015-03-01

    With the National Science Foundation and other funding agencies' renewed emphasis on broader impacts merit criterion in proposals, investigators and directors of education, outreach and engagement are challenged to identify, plan and implement innovative and transformative activities that engage a variety of audiences in the broader impacts of scientific research. These activities are also often required to have an evaluation plan for assessing the effectiveness of the strategies employed to achieve learning goals or other intended impacts. One approach to developing such plans is to partner with an informal science education institution, program, project or individual to create exhibits, media or programming that will convey the scientific concepts and processes involved in research and engage students and public audiences in appreciation for, and understanding of same. A growing body of evidence -based knowledge about what works for whom and under what conditions in fostering science learning and literacy in informal settings, as well as an expanding network of informal science, technology, engineering and math (STEM) education professionals provide researchers, graduate students and staff resources to tap into as they consider their broader impacts directions. Web infrastructure like the informalscience.org website and others offer aggregated, vetted, and searchable examples of successful partnerships and strategies, as well as access to a community of colleagues working at the nexus of scientific research and informal education for further exploration. Through heightened awareness, stronger connectivity and a growing repository of knowledge, projects like the Center for Advancement of Informal Science Education (CAISE) hope to support and disseminate the results of efforts that are enhancing the quality and visibility of broader impacts activities in whatever form they take.

  1. Electronic Structure and Ferromagnetism Modulation in Cu/Cu2O Interface: Impact of Interfacial Cu Vacancy and Its Diffusion

    PubMed Central

    Li, Hao-Bo; Wang, Weichao; Xie, Xinjian; Cheng, Yahui; Zhang, Zhaofu; Dong, Hong; Zheng, Rongkun; Wang, Wei-Hua; Lu, Feng; Liu, Hui

    2015-01-01

    Cu/Cu2O composite structures have been discovered to show sizable ferromagnetism (FM) with the potential applications in spintronic devices. To date, there is no consensus on the FM origin in Cu/Cu2O systems. Here, first principles calculations are performed on the interface structure to explore the microscopic mechanism of the FM. It is found that only the Cu vacancy (VCu) adjacent to the outermost Cu2O layer induces a considerable magnetic moment, mostly contributed by 2p orbitals of the nearest-neighbor oxygen atom (ONN) with two dangling bonds and 3d orbitals of the Cu atoms bonding with the ONN. Meanwhile, the charge transfer from Cu to Cu2O creates higher density of states at the Fermi level and subsequently leads to the spontaneous FM. Furthermore, the FM could be modulated by the amount of interfacial VCu, governed by the interfacial Cu diffusion with a moderate energy barrier (~1.2 eV). These findings provide insights into the FM mechanism and tuning the FM via interfacial cation diffusion in the Cu/Cu2O contact. PMID:26478505

  2. Influence of Drought on Mesophyll Resistance to CO2 Diffusion and its Impact on Water-Use Efficiency in Trees

    NASA Astrophysics Data System (ADS)

    Guo, J.; Beverly, D.; Cook, C.; Ewers, B. E.; Williams, D. G.

    2015-12-01

    The resistance to CO2 diffusion inside leaves (mesophyll resistance; rm) during photosynthesis is often comparable in magnitude to stomatal diffusion resistance, and varies among species and across environmental conditions. Consequently, photosynthesis is strongly limited by rm at low internal CO2 partial pressures, such that its variation may determine patterns of leaf water-use efficiency (WUE). Reduction in stomatal conductance with drought typically increases WUE, but also decreases photosynthesis. In theory, the decrease in photosynthesis could be countered by reduction in rm while maintaining high WUE. It is still uncertain how drought-related changes in rm affect short- and long-term WUE strategies of different tree species. We conducted field observations of instantaneous WUE and 13C discrimination in two dominant conifer species (Pinus contorta and Picea engelmannii) in SE Wyoming over the seasonal dry-down period in the summer of 2015. rm was examined by on-line 13C discrimination using isotope laser spectroscopy. Controlled environment studies on three conifer species (P. contorta, P. engelmannii, and Abies lasiocarpa) and one angiosperm (Populus tremuloides) are in progress. We hypothesize that the plasticity of rm in response to drought accounts for significant adjustments in photosynthetic capacity and WUE. Needle leaf conifers are known to have relatively high rm, and we expect them to show greater improvements in photosynthesis and WUE when rm is decreased compared to angiosperm tree species.

  3. Graphene chemical vapor deposition at very low pressure: The impact of substrate surface self-diffusion in domain shape

    SciTech Connect

    Cunha, T. H. R.; Ek-Weis, J.; Lacerda, R. G.; Ferlauto, A. S.

    2014-08-18

    The initial stages of graphene chemical vapor deposition at very low pressures (<10{sup −5 }Torr) were investigated. The growth of large graphene domains (∼up to 100 μm) at very high rates (up to 3 μm{sup 2} s{sup −1}) has been achieved in a cold-wall reactor using a liquid carbon precursor. For high temperature growth (>900 °C), graphene grain shape and symmetry were found to depend on the underlying symmetry of the Cu crystal, whereas for lower temperatures (<900 °C), mostly rounded grains are observed. The temperature dependence of graphene nucleation density was determined, displaying two thermally activated regimes, with activation energy values of 6 ± 1 eV for temperatures ranging from 900 °C to 960 °C and 9 ± 1 eV for temperatures above 960 °C. The comparison of such dependence with the temperature dependence of Cu surface self-diffusion suggests that graphene growth at high temperatures and low pressures is strongly influenced by copper surface rearrangement. We propose a model that incorporates Cu surface self-diffusion as an essential process to explain the orientation correlation between graphene and Cu crystals, and which can clarify the difference generally observed between graphene domain shapes in atmospheric-pressure and low-pressure chemical vapor deposition.

  4. A two-layered diffusion model traces the dynamics of information processing in the valuation-and-choice circuit of decision making.

    PubMed

    Piu, Pietro; Fargnoli, Francesco; Innocenti, Alessandro; Rufa, Alessandra

    2014-01-01

    A circuit of evaluation and selection of the alternatives is considered a reliable model in neurobiology. The prominent contributions of the literature to this topic are reported. In this study, valuation and choice of a decisional process during Two-Alternative Forced-Choice (TAFC) task are represented as a two-layered network of computational cells, where information accrual and processing progress in nonlinear diffusion dynamics. The evolution of the response-to-stimulus map is thus modeled by two linked diffusive modules (2LDM) representing the neuronal populations involved in the valuation-and-decision circuit of decision making. Diffusion models are naturally appropriate for describing accumulation of evidence over the time. This allows the computation of the response times (RTs) in valuation and choice, under the hypothesis of ex-Wald distribution. A nonlinear transfer function integrates the activities of the two layers. The input-output map based on the infomax principle makes the 2LDM consistent with the reinforcement learning approach. Results from simulated likelihood time series indicate that 2LDM may account for the activity-dependent modulatory component of effective connectivity between the neuronal populations. Rhythmic fluctuations of the estimate gain functions in the delta-beta bands also support the compatibility of 2LDM with the neurobiology of DM.

  5. A Two-Layered Diffusion Model Traces the Dynamics of Information Processing in the Valuation-and-Choice Circuit of Decision Making

    PubMed Central

    2014-01-01

    A circuit of evaluation and selection of the alternatives is considered a reliable model in neurobiology. The prominent contributions of the literature to this topic are reported. In this study, valuation and choice of a decisional process during Two-Alternative Forced-Choice (TAFC) task are represented as a two-layered network of computational cells, where information accrual and processing progress in nonlinear diffusion dynamics. The evolution of the response-to-stimulus map is thus modeled by two linked diffusive modules (2LDM) representing the neuronal populations involved in the valuation-and-decision circuit of decision making. Diffusion models are naturally appropriate for describing accumulation of evidence over the time. This allows the computation of the response times (RTs) in valuation and choice, under the hypothesis of ex-Wald distribution. A nonlinear transfer function integrates the activities of the two layers. The input-output map based on the infomax principle makes the 2LDM consistent with the reinforcement learning approach. Results from simulated likelihood time series indicate that 2LDM may account for the activity-dependent modulatory component of effective connectivity between the neuronal populations. Rhythmic fluctuations of the estimate gain functions in the delta-beta bands also support the compatibility of 2LDM with the neurobiology of DM. PMID:25254039

  6. Exploring the Impact of Information Seeking Behaviors of Online Health Consumers in the Arab World.

    PubMed

    Bahkali, Salwa; Almaiman, Reem; El-Awad, Mamoun; Almohanna, Huda; Al-Surimi, Khaled; Househ, Mowafa

    2016-01-01

    In the Arab world, increasing numbers of people are seeking online health related information for diagnoses, medicine, fitness, pharmaceutical drugs, and smoking cessation programs, among others. Studies exploring the impact of social media channels on health seeking behavior among Arabic users are limited. This study has two goals: (1) describe the prevalence of online health information-seeking behavior in the Arab world, and (2) study the impacts of social media based platforms in helping promote healthy living in the Arab world. In order to gather primary data, a web-based cross-sectional survey with a total of 7013 self-administered questionnaires was sent via SMS messages (n=1278), to Twitter followers of an Arab women's health social media account (n=3630 followers), and WhatsApp messages (n=2105) to participants above 16 years of age representing different socioeconomic groups and within the Arabic speaking world. The findings of this study show high interest among the participants (84.9%) in seeking online health information. Furthermore, reporting online information had an impact on participant health behaviors. Social media can play an important role in strengthening the health care system to provide valuable information, educational programs and interventions to promote healthy life styles among the Arabic people. PMID:27350525

  7. Exploring the Impact of Information Seeking Behaviors of Online Health Consumers in the Arab World.

    PubMed

    Bahkali, Salwa; Almaiman, Reem; El-Awad, Mamoun; Almohanna, Huda; Al-Surimi, Khaled; Househ, Mowafa

    2016-01-01

    In the Arab world, increasing numbers of people are seeking online health related information for diagnoses, medicine, fitness, pharmaceutical drugs, and smoking cessation programs, among others. Studies exploring the impact of social media channels on health seeking behavior among Arabic users are limited. This study has two goals: (1) describe the prevalence of online health information-seeking behavior in the Arab world, and (2) study the impacts of social media based platforms in helping promote healthy living in the Arab world. In order to gather primary data, a web-based cross-sectional survey with a total of 7013 self-administered questionnaires was sent via SMS messages (n=1278), to Twitter followers of an Arab women's health social media account (n=3630 followers), and WhatsApp messages (n=2105) to participants above 16 years of age representing different socioeconomic groups and within the Arabic speaking world. The findings of this study show high interest among the participants (84.9%) in seeking online health information. Furthermore, reporting online information had an impact on participant health behaviors. Social media can play an important role in strengthening the health care system to provide valuable information, educational programs and interventions to promote healthy life styles among the Arabic people.

  8. Limited information estimation of the diffusion-based item response theory model for responses and response times.

    PubMed

    Ranger, Jochen; Kuhn, Jörg-Tobias; Szardenings, Carsten

    2016-05-01

    Psychological tests are usually analysed with item response models. Recently, some alternative measurement models have been proposed that were derived from cognitive process models developed in experimental psychology. These models consider the responses but also the response times of the test takers. Two such models are the Q-diffusion model and the D-diffusion model. Both models can be calibrated with the diffIRT package of the R statistical environment via marginal maximum likelihood (MML) estimation. In this manuscript, an alternative approach to model calibration is proposed. The approach is based on weighted least squares estimation and parallels the standard estimation approach in structural equation modelling. Estimates are determined by minimizing the discrepancy between the observed and the implied covariance matrix. The estimator is simple to implement, consistent, and asymptotically normally distributed. Least squares estimation also provides a test of model fit by comparing the observed and implied covariance matrix. The estimator and the test of model fit are evaluated in a simulation study. Although parameter recovery is good, the estimator is less efficient than the MML estimator.

  9. Lunar water migration in the interval between large impacts: Heterogeneous delivery to Permanently Shadowed Regions, fractionation, and diffusive barriers

    NASA Astrophysics Data System (ADS)

    Moores, John E.

    2016-01-01

    The migration of water molecules across the lunar surface from sources sufficiently small, so as to not generate a transient collisional atmosphere, was examined using a Monte Carlo simulation. Previous work using similar models is extended by examining a realistic distribution of large south polar Permanently Shadowed Regions (PSRs) to examine the heterogeneities observed in their water content—frost in Haworth and the nearby lowlands, but not in neighboring Shoemaker, and anomalously high hydrogen abundances from neutron data—and to determine how the pattern of water delivery can be distinguished from that predicted for transient collisional atmospheres. While the Haworth lowlands were seen to accumulate 3.9 times as much water as Shoemaker, the additional water delivered to Haworth crater was only 47% greater than Shoemaker, possibly due to shielding by Faustini and the lowlands. This relatively small difference is likely inadequate to explain the difference in frosting. More broadly, latitudinal trends in delivery dominate over meridional trends. Despite the heterogeneity in water delivery, fractionation effects from ballistic migration were small for the PSRs with equal D/H ratios seen in all PSRs within confidence limits. Finally, a diffusive barrier was observed starting at approximately 15° from each pole that hampers the poleward progress of equatorial particles. This barrier is the result of a reduction in the migration diffusivity from 1.0 × 107 m2 s-1 near the equator to 5.5 × 105 m2 s-1 within 10° of the pole and finally to 6.8 × 103 m2 s-1 within 4° of the pole.

  10. Diffuse neutrino intensity from the inner jets of active galactic nuclei: Impacts of external photon fields and the blazar sequence

    NASA Astrophysics Data System (ADS)

    Murase, Kohta; Inoue, Yoshiyuki; Dermer, Charles D.

    2014-07-01

    We study high-energy neutrino production in inner jets of radio-loud active galactic nuclei (AGN), taking into account effects of external photon fields and the blazar sequence. We show that the resulting diffuse neutrino intensity is dominated by quasar-hosted blazars, in particular, flat spectrum radio quasars, and that PeV-EeV neutrino production due to photohadronic interactions with broadline and dust radiation is unavoidable if the AGN inner jets are ultrahigh-energy cosmic-ray (UHECR) sources. Their neutrino spectrum has a cutoff feature around PeV energies since target photons are due to Lyα emission. Because of infrared photons provided by the dust torus, neutrino spectra above PeV energies are too hard to be consistent with the IceCube data unless the proton spectral index is steeper than 2.5, or the maximum proton energy is ≲100 PeV. Thus, the simple model has difficulty in explaining the IceCube data. For the cumulative neutrino intensity from blazars to exceed ˜10-8 GeV cm-2 s-1 sr-1, their local cosmic-ray energy generation rate would be ˜10-100 times larger than the local UHECR emissivity but is comparable to the averaged γ-ray blazar emissivity. Interestingly, future detectors such as the Askaryan Radio Array can detect ˜0.1-1 EeV neutrinos even in more conservative cases, allowing us to indirectly test the hypothesis that UHECRs are produced in the inner jets. We find that the diffuse neutrino intensity from radio-loud AGN is dominated by blazars with γ-ray luminosity of ≳1048 erg s-1, and the arrival directions of their ˜1-100 PeV neutrinos correlate with the luminous blazars detected by Fermi.

  11. Impact of informal networks on opinion dynamics in hierarchically formal organization

    NASA Astrophysics Data System (ADS)

    Song, Xiao; Shi, Wen; Ma, Yaofei; Yang, Chen

    2015-10-01

    Traditional opinion dynamics model focused mainly on the conditions under which a group of agents would reach a consensus. Conclusion has been gained that continuous opinion dynamics are subject to the constraint that convergent opinion adjustment only proceeds when opinion difference is below a given tolerance. This conclusion is useful but neglected the fact that an organization often consists of overlapped networks including formally hierarchical network and small-world/scale-free informal networks. To study the impact of different types of informal networks on converging speed or the number of opinion clusters, four typical types of informal networks (small-world, scale-free, tree and fully connected) are modeled and proposed as complements to formal communications. Experiments to compare formal network and hybrid networks are then carried out. It is observed that opinion dynamics with supplemented communications of informal networks can benefit convergence speed and reduce opinion clusters. More importantly, it is revealed that three key factors of informal networks affect their impact on formal network. These factors of informal network in descending orders are: agents' tolerances, scale and number of links.

  12. Indicators and protocols for monitoring impacts of formal and informal trails in protected areas

    USGS Publications Warehouse

    Marion, Jeffrey L.; Leung, Yu-Fai

    2011-01-01

    Trails are a common recreation infrastructure in protected areas and their conditions affect the quality of natural resources and visitor experiences. Various trail impact indicators and assessment protocols have been developed in support of monitoring programs, which are often used for management decision-making or as part of visitor capacity management frameworks. This paper reviews common indicators and assessment protocols for three types of trails, surfaced formal trails, unsurfaced formal trails, and informal (visitor-created) trails. Monitoring methods and selected data from three U.S. National Park Service units are presented to illustrate some common trail impact indicators and assessment options.

  13. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 26: The relationship between technology policy and scientific and technical information within the US and Japanese aerospace industries

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Barclay, Rebecca O.; Kennedy, John M.

    1993-01-01

    Government technology policy has nurtured the growth of the aerospace industry which is vital to both the U.S. and Japanese economies. Japanese technology policy differs significantly from U.S. technology policy, however, particularly with respect to the production, transfer, and use of scientific and technical information (STI). In this paper, we discuss the unique position of the aerospace industry in the U.S. and Japan, U.S. and Japanese aerospace policy, and the role of STI in the process of aerospace innovation. The information-seeking behaviors of U.S. and Japanese aerospace engineers and scientists are compared. The authors advocate the development of innovation-adoption technology and STI policy goals for U.S. aerospace and the inclusion of an aerospace knowledge diffusion transfer system with an 'active' component for scanning and acquiring foreign aerospace technology and STI.

  14. Diffusion MRI

    NASA Astrophysics Data System (ADS)

    Fukuyama, Hidenao

    Recent advances of magnetic resonance imaging have been described, especially stressed on the diffusion sequences. We have recently applied the diffusion sequence to functional brain imaging, and found the appropriate results. In addition to the neurosciences fields, diffusion weighted images have improved the accuracies of clinical diagnosis depending upon magnetic resonance images in stroke as well as inflammations.

  15. Approaches to patient health information exchange and their impact on emergency medicine.

    PubMed

    Shapiro, Jason S; Kannry, Joseph; Lipton, Mark; Goldberg, Eric; Conocenti, Paul; Stuard, Susan; Wyatt, Brian M; Kuperman, Gilad

    2006-10-01

    Regional health information organizations and electronic health information exchange may have an important impact on the practice of emergency medicine in the United States. Regional health information organizations are local or regional information-sharing networks that enable electronic data interchange among stakeholders in a given geographic area. These stakeholders may include hospitals, skilled nursing facilities, clinics, private physicians' offices, pharmacies, laboratories, radiology facilities, health departments, payers, and possibly the patients themselves. Regional health information organizations are being formed across the country to improve the safety and efficiency of clinical care; improve public health efforts, biosurveillance, and disaster management response; and potentially create large databases of deidentified aggregate data for research. Because of the unique need for rapid access to information and the acuity of the clinical environment, few areas of the health care delivery system stand to change and benefit more from health information exchange than our nation's emergency departments. This article will explain the motivation for the development of regional health information organizations, identify some of the important issues in their formation, and discuss how their development might affect the practice of emergency medicine. PMID:16997679

  16. Approaches to patient health information exchange and their impact on emergency medicine.

    PubMed

    Shapiro, Jason S; Kannry, Joseph; Lipton, Mark; Goldberg, Eric; Conocenti, Paul; Stuard, Susan; Wyatt, Brian M; Kuperman, Gilad

    2006-10-01

    Regional health information organizations and electronic health information exchange may have an important impact on the practice of emergency medicine in the United States. Regional health information organizations are local or regional information-sharing networks that enable electronic data interchange among stakeholders in a given geographic area. These stakeholders may include hospitals, skilled nursing facilities, clinics, private physicians' offices, pharmacies, laboratories, radiology facilities, health departments, payers, and possibly the patients themselves. Regional health information organizations are being formed across the country to improve the safety and efficiency of clinical care; improve public health efforts, biosurveillance, and disaster management response; and potentially create large databases of deidentified aggregate data for research. Because of the unique need for rapid access to information and the acuity of the clinical environment, few areas of the health care delivery system stand to change and benefit more from health information exchange than our nation's emergency departments. This article will explain the motivation for the development of regional health information organizations, identify some of the important issues in their formation, and discuss how their development might affect the practice of emergency medicine.

  17. 25 CFR 292.18 - What information must an application contain on detrimental impacts to the surrounding community?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... detrimental impacts to the surrounding community? 292.18 Section 292.18 Indians BUREAU OF INDIAN AFFAIRS... application contain on detrimental impacts to the surrounding community? To satisfy the requirements of § 292.16(f), an application must contain the following information on detrimental impacts of the...

  18. Assessing the impact of changes in landuse and management practices on the diffuse pollution and retention of nitrate in a riparian floodplain.

    PubMed

    Krause, Stefan; Jacobs, Joerg; Voss, Anja; Bronstert, Axel; Zehe, Erwin

    2008-01-15

    In many European lowland rivers and riparian floodplains diffuse nutrient pollution is causing a major risk for the surface waters and groundwater to not achieve a good status as demanded by the European Water Framework Directive. In order to delimit the impact of diffuse nutrient pollution substantial and often controversial changes in landuse and management are under discussion. In this study we investigate the impact of two complex scenarios considering changes in landuse and land management practices on the nitrate loads of a typical lowland stream and the riparian groundwater in the North German Plains. Therefore the impacts of both scenarios on the nitrate dynamics, the attenuation efficiency and the nitrate exchange between groundwater and surface water were investigated for a 998.1 km(2) riparian floodplain of the Lower and Central Havel River and compared with the current conditions. Both scenarios target a substantial improvement of the ecological conditions and the water quality in the research area but promote different typical riparian landscape functions and consider a different grade of economical and legal feasibility of the proposed measures. Scenario 1 focuses on the optimisation of conservation measures for all natural resources of the riparian floodplain, scenario 2 considers measures in order to restore a good status of the water bodies mainly. The IWAN model was setup for the simulation of water balance and nitrate dynamics of the floodplain for a perennial simulation period of the current landuse and management conditions and of the scenario assumptions. The proposed landuse and management changes result in reduced rates of nitrate leaching from the root zone into the riparian groundwater (85% for scenario 1, 43% for scenario 2). The net contributions of nitrate from the floodplain can be reduced substantially for both scenarios. In case of scenario 2 a decrease by 70% can be obtained. For scenario 1 the nitrate exfiltration rates to the

  19. Assessing the impact of changes in landuse and management practices on the diffuse pollution and retention of nitrate in a riparian floodplain.

    PubMed

    Krause, Stefan; Jacobs, Joerg; Voss, Anja; Bronstert, Axel; Zehe, Erwin

    2008-01-15

    In many European lowland rivers and riparian floodplains diffuse nutrient pollution is causing a major risk for the surface waters and groundwater to not achieve a good status as demanded by the European Water Framework Directive. In order to delimit the impact of diffuse nutrient pollution substantial and often controversial changes in landuse and management are under discussion. In this study we investigate the impact of two complex scenarios considering changes in landuse and land management practices on the nitrate loads of a typical lowland stream and the riparian groundwater in the North German Plains. Therefore the impacts of both scenarios on the nitrate dynamics, the attenuation efficiency and the nitrate exchange between groundwater and surface water were investigated for a 998.1 km(2) riparian floodplain of the Lower and Central Havel River and compared with the current conditions. Both scenarios target a substantial improvement of the ecological conditions and the water quality in the research area but promote different typical riparian landscape functions and consider a different grade of economical and legal feasibility of the proposed measures. Scenario 1 focuses on the optimisation of conservation measures for all natural resources of the riparian floodplain, scenario 2 considers measures in order to restore a good status of the water bodies mainly. The IWAN model was setup for the simulation of water balance and nitrate dynamics of the floodplain for a perennial simulation period of the current landuse and management conditions and of the scenario assumptions. The proposed landuse and management changes result in reduced rates of nitrate leaching from the root zone into the riparian groundwater (85% for scenario 1, 43% for scenario 2). The net contributions of nitrate from the floodplain can be reduced substantially for both scenarios. In case of scenario 2 a decrease by 70% can be obtained. For scenario 1 the nitrate exfiltration rates to the

  20. Impact of user influence on information multi-step communication in a micro-blog

    NASA Astrophysics Data System (ADS)

    Wu, Yue; Hu, Yong; He, Xiao-Hai; Deng, Ken

    2014-06-01

    User influence is generally considered as one of the most critical factors that affect information cascading spreading. Based on this common assumption, this paper proposes a theoretical model to examine user influence on the information multi-step communication in a micro-blog. The multi-steps of information communication are divided into first-step and non-first-step, and user influence is classified into five dimensions. Actual data from the Sina micro-blog is collected to construct the model by means of an approach based on structural equations that uses the Partial Least Squares (PLS) technique. Our experimental results indicate that the dimensions of the number of fans and their authority significantly impact the information of first-step communication. Leader rank has a positive impact on both first-step and non-first-step communication. Moreover, global centrality and weight of friends are positively related to the information non-first-step communication, but authority is found to have much less relation to it.

  1. The Impact of Alpha-Syntrophin Deletion on the Changes in Tissue Structure and Extracellular Diffusion Associated with Cell Swelling under Physiological and Pathological Conditions

    PubMed Central

    Dmytrenko, Lesia; Cicanic, Michal; Anderova, Miroslava; Vorisek, Ivan; Ottersen, Ole Petter; Sykova, Eva; Vargova, Lydia

    2013-01-01

    Aquaporin-4 (AQP4) is the primary cellular water channel in the brain and is abundantly expressed by astrocytes along the blood-brain barrier and brain-cerebrospinal fluid interfaces. Water transport via AQP4 contributes to the activity-dependent volume changes of the extracellular space (ECS), which affect extracellular solute concentrations and neuronal excitability. AQP4 is anchored by α-syntrophin (α-syn), the deletion of which leads to reduced AQP4 levels in perivascular and subpial membranes. We used the real-time iontophoretic method and/or diffusion-weighted magnetic resonance imaging to clarify the impact of α-syn deletion on astrocyte morphology and changes in extracellular diffusion associated with cell swelling in vitro and in vivo. In mice lacking α-syn, we found higher resting values of the apparent diffusion coefficient of water (ADCW) and the extracellular volume fraction (α). No significant differences in tortuosity (λ) or non-specific uptake (k′), were found between α-syn-negative (α-syn −/−) and α-syn-positive (α-syn +/+) mice. The deletion of α-syn resulted in a significantly smaller relative decrease in α observed during elevated K+ (10 mM) and severe hypotonic stress (−100 mOsmol/l), but not during mild hypotonic stress (−50 mOsmol/l). After the induction of terminal ischemia/anoxia, the final values of ADCW as well as of the ECS volume fraction α indicate milder cell swelling in α-syn −/− in comparison with α-syn +/+ mice. Shortly after terminal ischemia/anoxia induction, the onset of a steep rise in the extracellular potassium concentration and an increase in λ was faster in α-syn −/− mice, but the final values did not differ between α-syn −/− and α-syn +/+ mice. This study reveals that water transport through AQP4 channels enhances and accelerates astrocyte swelling. The substantially altered ECS diffusion parameters will likely affect the movement of neuroactive substances and/or trophic factors

  2. TIME Impact - a new user-friendly tuberculosis (TB) model to inform TB policy decisions.

    PubMed

    Houben, R M G J; Lalli, M; Sumner, T; Hamilton, M; Pedrazzoli, D; Bonsu, F; Hippner, P; Pillay, Y; Kimerling, M; Ahmedov, S; Pretorius, C; White, R G

    2016-01-01

    Tuberculosis (TB) is the leading cause of death from infectious disease worldwide, predominantly affecting low- and middle-income countries (LMICs), where resources are limited. As such, countries need to be able to choose the most efficient interventions for their respective setting. Mathematical models can be valuable tools to inform rational policy decisions and improve resource allocation, but are often unavailable or inaccessible for LMICs, particularly in TB. We developed TIME Impact, a user-friendly TB model that enables local capacity building and strengthens country-specific policy discussions to inform support funding applications at the (sub-)national level (e.g. Ministry of Finance) or to international donors (e.g. the Global Fund to Fight AIDS, Tuberculosis and Malaria).TIME Impact is an epidemiological transmission model nested in TIME, a set of TB modelling tools available for free download within the widely-used Spectrum software. The TIME Impact model reflects key aspects of the natural history of TB, with additional structure for HIV/ART, drug resistance, treatment history and age. TIME Impact enables national TB programmes (NTPs) and other TB policymakers to better understand their own TB epidemic, plan their response, apply for funding and evaluate the implementation of the response.The explicit aim of TIME Impact's user-friendly interface is to enable training of local and international TB experts towards independent use. During application of TIME Impact, close involvement of the NTPs and other local partners also builds critical understanding of the modelling methods, assumptions and limitations inherent to modelling. This is essential to generate broad country-level ownership of the modelling data inputs and results. In turn, it stimulates discussions and a review of the current evidence and assumptions, strengthening the decision-making process in general.TIME Impact has been effectively applied in a variety of settings. In South Africa, it

  3. TIME Impact - a new user-friendly tuberculosis (TB) model to inform TB policy decisions.

    PubMed

    Houben, R M G J; Lalli, M; Sumner, T; Hamilton, M; Pedrazzoli, D; Bonsu, F; Hippner, P; Pillay, Y; Kimerling, M; Ahmedov, S; Pretorius, C; White, R G

    2016-03-24

    Tuberculosis (TB) is the leading cause of death from infectious disease worldwide, predominantly affecting low- and middle-income countries (LMICs), where resources are limited. As such, countries need to be able to choose the most efficient interventions for their respective setting. Mathematical models can be valuable tools to inform rational policy decisions and improve resource allocation, but are often unavailable or inaccessible for LMICs, particularly in TB. We developed TIME Impact, a user-friendly TB model that enables local capacity building and strengthens country-specific policy discussions to inform support funding applications at the (sub-)national level (e.g. Ministry of Finance) or to international donors (e.g. the Global Fund to Fight AIDS, Tuberculosis and Malaria).TIME Impact is an epidemiological transmission model nested in TIME, a set of TB modelling tools available for free download within the widely-used Spectrum software. The TIME Impact model reflects key aspects of the natural history of TB, with additional structure for HIV/ART, drug resistance, treatment history and age. TIME Impact enables national TB programmes (NTPs) and other TB policymakers to better understand their own TB epidemic, plan their response, apply for funding and evaluate the implementation of the response.The explicit aim of TIME Impact's user-friendly interface is to enable training of local and international TB experts towards independent use. During application of TIME Impact, close involvement of the NTPs and other local partners also builds critical understanding of the modelling methods, assumptions and limitations inherent to modelling. This is essential to generate broad country-level ownership of the modelling data inputs and results. In turn, it stimulates discussions and a review of the current evidence and assumptions, strengthening the decision-making process in general.TIME Impact has been effectively applied in a variety of settings. In South Africa, it

  4. The Role of Public Policy in Enhancing the Design and Diffusion of Information Systems and Technology for Human Benefit

    NASA Astrophysics Data System (ADS)

    Venable, John; Newman, Peter; Letch, Nick; Ash, Sue

    Technologies for human benefit, such as information systems and information technology, have a key role to play in the realization of quality of life for all citizenry by modern societies. New forms of IS and IT can be developed and used creatively to improve education, health, social equity, environmental conditions, social and environ mental sustainability, government and not-for-profit services, participation in govern ment, and enjoyment of life in general.

  5. Meteoroid stream impacts on the Moon: information of duration of the seismograms

    NASA Astrophysics Data System (ADS)

    Khavroshkin, O. B.; Tsyplakov, V. V.

    2001-11-01

    The seismograms of meteoroid stream impacts on the Moon have brought important information about inside structure of the Moon any years ago. This work is a new attempt of using records of "Apollo" seismic network for receiving further information about dynamic processes on the Moon. The Nakamura Catalogue is employed for research of these problems. We have built up some histograms from seismic data of Catalogue. The duration of impact τimp in minutes was a general parameter for our analysis. Preliminary conclusions of processing histograms is as follows: the increase of energy of impact from 1 imp/day to 3 imp/day moves a maximum of histograms to shorter duration, this is especially evident in the case of 4 - 8 impacts per day; every histogram contains significant peaks which are 58 - 56; 40; 38; 25; 19 - 20; 16 minutes, but 6; 10; 13 minute peaks exist only for 4 - 8 imp/day histogram. We expect that physical models for explaining these peaks might be discussed at the meeting.

  6. Impact of rock heterogeneity in matrix diffusion process : a single fracture case at the Äspö granitic site (Sweden)

    NASA Astrophysics Data System (ADS)

    Grenier, C.; Fourno, A.; Mouche, E.; Benabderrahmane, H.

    2003-04-01

    Within the framework of nuclear spent fuel storage, special concern is put on experimentation and modelling work to improve the modelling capacities for the transfers of radionuclides within natural fractured media. Several aspects make it a challenging task, among which the heterogeneity of the system, the scarcity of the available information, the strong contrasts in the parameter values between mobile and immobile zones. One of the key retention process is related with diffusion in immobile zones within the fractured medium (fractions of the plume are temporally retained from the main flow paths by diffusion processes into these zones). The importance of this mechanism increases with the contact time of the plume with these zones. This means that for a post closure situation matrix diffusion plays the larger role. We provide here with results obtained within the SKB Task Force (Task6) in relation with the single fracture tracer experiments (TRUE1 Project - feature A at Äspö site in Sweden). The purpose of this task, involving several other modelling teams, is to provide a bridge between detailed SC (Site Characterization) models operating at experimental time scale and more simple PA (Performance Assessment) models operating at large time scales. A good level of realism is obtained in the definition of the task by relying on the very extensive and valuable Äspö site data base. We conducted the study with different representations of the system (involving deterministic and stochastic approaches). Our simulation code is Cast3M with a mixed and hybrid finite element scheme. We show here our main conclusions concerning the role played by different matrix zones (fracture coating, fracture infilling, altered and non altered rock ), the ability to identify the heterogeneous matrix zone properties from tracer tests or independent measurements, the type of zones accessed by the plume as a function of the time scale of the test, the homogenisation of transport

  7. Cosmology with matter diffusion

    SciTech Connect

    Calogero, Simone; Velten, Hermano E-mail: velten@cce.ufes.br

    2013-11-01

    We construct a viable cosmological model based on velocity diffusion of matter particles. In order to ensure the conservation of the total energy-momentum tensor in the presence of diffusion, we include a cosmological scalar field φ which we identify with the dark energy component of the universe. The model is characterized by only one new degree of freedom, the diffusion parameter σ. The standard ΛCDM model can be recovered by setting σ = 0. If diffusion takes place (σ > 0) the dynamics of the matter and of the dark energy fields are coupled. We argue that the existence of a diffusion mechanism in the universe may serve as a theoretical motivation for interacting models. We constrain the background dynamics of the diffusion model with Supernovae, H(z) and BAO data. We also perform a perturbative analysis of this model in order to understand structure formation in the universe. We calculate the impact of diffusion both on the CMB spectrum, with particular attention to the integrated Sachs-Wolfe signal, and on the matter power spectrum P(k). The latter analysis places strong constraints on the magnitude of the diffusion mechanism but does not rule out the model.

  8. Word Diffusion and Climate Science

    PubMed Central

    Bentley, R. Alexander; Garnett, Philip; O'Brien, Michael J.; Brock, William A.

    2012-01-01

    As public and political debates often demonstrate, a substantial disjoint can exist between the findings of science and the impact it has on the public. Using climate-change science as a case example, we reconsider the role of scientists in the information-dissemination process, our hypothesis being that important keywords used in climate science follow “boom and bust” fashion cycles in public usage. Representing this public usage through extraordinary new data on word frequencies in books published up to the year 2008, we show that a classic two-parameter social-diffusion model closely fits the comings and goings of many keywords over generational or longer time scales. We suggest that the fashions of word usage contributes an empirical, possibly regular, correlate to the impact of climate science on society. PMID:23144839

  9. Soliciting Feedback from Resource Managers to Inform Response to Extreme Event Impact

    NASA Astrophysics Data System (ADS)

    Bedsworth, L. W.

    2014-12-01

    To date, extreme events have been defined by scientists through a top-down approach, relying on observations for current extremes and climate model projections based on future scenarios for their expected changes. These abstract definitions of extreme events are based on a corresponding characterization of what is "normal" and perhaps the choice of a threshold (e.g., a percentile of a historical distribution for a given climate variable), beyond which would represent an extreme event. However, there are not necessarily direct connections between these definitions and what is considered "extreme" in terms of impacts that challenge resource management. Several researchers have suggested that extreme event definitions would also be informed by input from on-the-ground resource managers who are familiar with the systems being impacted, the climate conditions that pose risks to those systems, and their resilience and adaptive capacity. This research will present preliminary survey work designed to solicit input from air and water quality managers in terms of what is considered an extreme event, how these events have been weathered in the past, and planned for in the future. The survey is based on literature review, interviews with air and water quality managers in California, and outreach to the scientific community. This work is the first step of a multistage research effort to link input from resource managers with scientific information to better inform air and water quality management and impacts of extreme events under a changing climate.

  10. Developing services for climate impact and adaptation baseline information and methodologies for the Andes

    NASA Astrophysics Data System (ADS)

    Huggel, C.

    2012-04-01

    Impacts of climate change are observed and projected across a range of ecosystems and economic sectors, and mountain regions thereby rank among the hotspots of climate change. The Andes are considered particularly vulnerable to climate change, not only due to fragile ecosystems but also due to the high vulnerability of the population. Natural resources such as water systems play a critical role and are observed and projected to be seriously affected. Adaptation to climate change impacts is therefore crucial to contain the negative effects on the population. Adaptation projects require information on the climate and affected socio-environmental systems. There is, however, generally a lack of methodological guidelines how to generate the necessary scientific information and how to communicate to implementing governmental and non-governmental institutions. This is particularly important in view of the international funds for adaptation such as the Green Climate Fund established and set into process at the UNFCCC Conferences of the Parties in Cancun 2010 and Durban 2011. To facilitate this process international and regional organizations (World Bank and Andean Community) and a consortium of research institutions have joined forces to develop and define comprehensive methodologies for baseline and climate change impact assessments for the Andes, with an application potential to other mountain regions (AndesPlus project). Considered are the climatological baseline of a region, and the assessment of trends based on ground meteorological stations, reanalysis data, and satellite information. A challenge is the scarcity of climate information in the Andes, and the complex climatology of the mountain terrain. A climate data platform has been developed for the southern Peruvian Andes and is a key element for climate data service and exchange. Water resources are among the key livelihood components for the Andean population, and local and national economy, in particular for

  11. Environmental impact assessment of the proposed Information Technology Park at Perungudi.

    PubMed

    Sharmilaa, G

    2007-10-01

    Environmental impact assessment studies of the proposed Information Technology Park at Perungudi have been carried out. The study involved assessing the existing environmental quality of the proposed site, and predicting impacts and preparing an environmental management plan. Data on the existing quality of water, soil, land use pattern, air, noise and socio-economic details of the proposed project were assessed. The impacts due to the proposed activity were identified and evaluated using the Network Impact Methodology. The water requirement was found to be 3,63,400 L/day. The total wastewater likely to be generated was found to be 2,90,720 L/day. The wastewater will be treated in a sewage treatment plant. The generation of solid waste was assessed to about 500 kg/day. Increase in traffic level was found out by traffic survey. The socio-economic environment will have a positive impact from the proposed project. An Environmental Management Plan was prepared which includes the mitigation measures for improving the eco-profile of the study area.

  12. Characterization of the olfactory impact around a wastewater treatment plant: optimization and validation of a hydrogen sulfide determination procedure based on passive diffusion sampling.

    PubMed

    Colomer, Fernando Llavador; Espinós-Morató, Héctor; Iglesias, Enrique Mantilla; Pérez, Tatiana Gómez; Campos-Candel, Andreu; Lozano, Caterina Coll

    2012-08-01

    A monitoring program based on an indirect method was conducted to assess the approximation of the olfactory impact in several wastewater treatment plants (in the present work, only one is shown). The method uses H2S passive sampling using Palmes-type diffusion tubes impregnated with silver nitrate and fluorometric analysis employing fluorescein mercuric acetate. The analytical procedure was validated in the exposure chamber. Exposure periods ofat least 4 days are recommended. The quantification limit of the procedure is 0.61 ppb for a 5-day sampling, which allows the H2S immission (ground concentration) level to be measured within its low odor threshold, from 0.5 to 300 ppb. Experimental results suggest an exposure time greater than 4 days, while recovery efficiency of the procedure, 93.0+/-1.8%, seems not to depend on the amount of H2S collected by the samplers within their application range. The repeatability, expressed as relative standard deviation, is lower than 7%, which is within the limits normally accepted for this type of sampler. Statistical comparison showed that this procedure and the reference method provide analogous accuracy. The proposed procedure was applied in two experimental campaigns, one intensive and the other extensive, and concentrations within the H2S low odor threshold were quantified at each sampling point. From these results, it can be concluded that the procedure shows good potential for monitoring the olfactory impact around facilities where H2S emissions are dominant. PMID:22916433

  13. The impact of residency match information disseminated by a third-party website.

    PubMed

    Kutikov, Alexander; Morgan, Todd M; Resnick, Matthew J

    2009-01-01

    Over the past 10 years, a dramatic shift has occurred toward web-based applications and information dissemination both for medical students applying to residency programs and for current housestaff seeking specialty-specific information. This shift has been witnessed in urology with adoption of the Internet-based Electronic Residency Application Service for residency application submission. Currently, most residency programs devote significant attention to developing and maintaining an attractive web page, as studies have suggested departmental websites may impact applicants' decisions regarding residency preference lists.(1,2) Recently, some third-party websites have been established to provide information to medical students and residents in a variety of specialties. No studies are available that evaluate the impact of these external websites on residency decision making. In 2003, a website under the domain name www.UrologyMatch.com was created by 2 coauthors (A.K. and T.M.M.) with the purpose of assisting medical students through the American Urological Association (AUA) match process. Additionally, by providing a discussion forum for students, residents, and faculty, it sought to aid with the dissemination of information between urology programs and applicants. The website has been gradually expanded to provide educational content for urology trainees at a wide range of levels. Components of the website include an introduction to the field of urology, a detailed description of the match process, an "expert advice" section from urologic leaders, a library of relevant Internet links, a digital surgical atlas, and program-specific questionnaire responses provided by residency directors and department chairs. A discussion board providing an uncensored forum for visitors is integrated into the website to aid with the dissemination of information between and among urology programs, residents, and applicants. The high usage of this site has suggested that external

  14. Key Factors that Influence the Diffusion and Infusion of Information and Communication Technologies in Kenyan Higher Education

    ERIC Educational Resources Information Center

    Macharia, Jimmy K. N.; Pelser, Theunis G.

    2014-01-01

    Previous studies have shown that in the higher education sector, information and communication technology (ICT) provides the impetus for change from the traditional concepts of teaching and learning, as well as prime motivation behind the change in scholarly and professional activities. This underscores the importance of ICT in higher education in…

  15. [Impact of the Internet on communication flow of scientific health information].

    PubMed

    Castro, Regina C Figueiredo

    2006-08-01

    Communication flow of scientific information has been restructured with the development of new technologies and the Internet and their impact on social relations worldwide. The production of scientific knowledge has also been influenced by these cultural, social and economic changes and has contributed to new patterns of scientific communication. The objective of the study was to present the traditional scientific communication model and its evolution to electronic scientific communication stimulated by the use of electronic media and Internet and networking. While the traditional model is based on printed publications, the new one focuses on electronic publishing and open unlimited access to published literature. The challenges faced are in using all the potential of electronic media for improving traditional communication flow of scientific information and defining policies to support the new model of scientific communication to ensure quality, preservation and dissemination of information as a common good.

  16. Impact of information about obesity genomics on the stigmatization of overweight individuals: an experimental study.

    PubMed

    Lippa, Natalie C; Sanderson, Saskia C

    2012-12-01

    Advances in genomic technologies are rapidly leading to new understandings of the roles that genetic variations play in obesity. Increasing public dissemination of information regarding the role of genetics in obesity could have beneficial, harmful, or neutral effects on the stigmatization of obese individuals. This study used an online survey and experimental design to examine the impact of genetic versus non-genetic information on obesity stigma among self-perceived non-overweight individuals. Participants (n = 396) were randomly assigned to read either genetic, non-genetic (environment), or gene-environment interaction obesity causal information. A total of 48% of participants were female; mean age was 42.7 years (range = 18-86 years); 75% were white; 45.2% had an annual household income of less than $40,000; mean BMI was 23.4 kg/m(2). Obesity stigma was measured using the Fat Phobia Scale - short form (FPS-S). After reading the experimental information, participants in the genetic and gene-environment conditions were more likely to believe that genetics increase obesity risk than participants in the non-genetic condition (both P < 0.05), but did not differ on obesity stigma. Obesity stigma was higher among whites and Asians than Hispanics and African Americans (P = 0.029), and associated with low self-esteem (P = 0.036). Obesity stigma was also negatively associated with holding 'germ or virus' (P = 0.033) and 'overwork' (P = 0.016) causal beliefs about obesity, and positively associated with 'diet or eating habits' (P = 0.001) and 'lack of exercise' (P = 0.004) causal beliefs. Dissemination of brief information about the role of genetics in obesity may have neither a beneficial nor a harmful impact on obesity stigmatization compared with non-genetic information among self-perceived non-overweight individuals. PMID:22673191

  17. Media and Memory: The Impact of Presentation Style on Middle Aged and Older Adults' Recall of Health Information

    ERIC Educational Resources Information Center

    Wilson, Elizabeth Anne Hamann

    2009-01-01

    Educational tools such as printed pamphlets and videos can enhance patients' understanding and memory of health-related information, but in order for such materials to be effective, designers of such tools should take care to understand the impact of variables such as the medium in which information is displayed, the type of information to be…

  18. The Impact of Converging Information Technologies. Proceedings of the CAUSE National Conference (Monterey, California, December 9-12, 1986).

    ERIC Educational Resources Information Center

    CAUSE, Boulder, CO.

    Proceedings of a 1986 CAUSE conference on the impact of converging information technologies are presented. Topics of conference papers include: policy issues in higher education, planning and information technology, people issues in information technology, telecommunications/networking, special environments, microcomputer issues and applications,…

  19. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 33: Technical communications practices and the use of information technologies as reported by Dutch and US aerospace engineers

    NASA Technical Reports Server (NTRS)

    Barclay, Rebecca O.; Pinelli, Thomas E.; Tan, Axel S. T.; Kennedy, John M.

    1993-01-01

    As part of Phase 4 of the NASA/DOD Aerospace Knowledge Diffusion Research Project, two studies were conducted that investigated the technical communications practices of Dutch and U.S. aerospace engineers and scientists. A self-administered questionnaire was distributed to aerospace engineers and scientists at the National Aerospace Laboratory (The Netherlands), and NASA ARC (U.S.), and NASA LaRC (U.S.). This paper presents responses of the Dutch and U.S. participants to selected questions concerning four of the seven project objectives: determining the importance of technical communications to aerospace engineering professionals, investigating the production of technical communications, examining the use and importance of computer and information technology, and exploring the use of electronic networks.

  20. Diffuse CO2 Emanations from a Deep Magmatic Source-Multiphase Dynamics, Soil Impacts, and Lessons for Sequestration Monitoring

    NASA Astrophysics Data System (ADS)

    Stonestrom, D. A.; Werner, C. A.; Schulz, M. S.; Howle, J. F.; Farrar, C. D.; Smith, T. R.; Rogie, J. D.

    2011-12-01

    Naturally occurring emissions of nearly pure CO2 at Mammoth Mountain, California, have been suggested as an analog of possible leakage from large-scale carbon capture and sequestration operations. Impacts of sustained elevated levels (>20%) of soil CO2 are greater than the observable forest dieback. Repeated soil-transect studies six and 22 years after onset of CO2 emissions demonstrate substantial degradation of base-cation status in the area of active emission. Detailed time series of soil-gas pressures, CO2 concentrations and fluxes, water contents, and snow-cover dynamics show large short-term (minutes-to-days) variability and switching between quasi-stable states, suggesting countercurrent gas and liquid movement within a shared fracture-pore network. Single fluid phase (Darcian-Fickian) approaches are inadequate to explain the gross features of the measured time series; engineering equations developed for two-fluid-phase flow reactors are more likely to apply. Micrometeorological data show that atmospheric forcing affects total CO2 fluxes. Data presented here show that interactions among the atmospheric boundary layer, water in all its forms (snowpack, percolating soil moisture, groundwater), and upward moving CO2 must be taken into account so that changes in surface CO2 concentrations and fluxes due to hydrologic perturbations can be differentiated from those due to changes in sources at depth.

  1. NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 13: Source selection and information use by US aerospace engineers and scientists: Results of a telephone survey

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Glassman, Nanci A.

    1992-01-01

    A telephone survey of U.S. aerospace engineers and scientists belonging to the Society of Automotive Engineers (SAE) was conducted between December 4, 1991 and January 5, 1992. The survey was undertaken to (1) validate the telephone survey as an appropriate technique for collecting data from U.S. aerospace engineers and scientists; (2) collect information about how the results of NASA/DoD aerospace research are used in the R&D process; (3) identify those selection criteria which affect the use of federally-funded aerospace R&D; and (4) obtain information that could be used to develop a self-administered mail questionnaire for use with the same population. The average rating of importance of U.S. government technical reports was 2.5 (on a 4-point scale); The mean/median number of times U.S. government technical reports were used per 6 months was 8/2. Factors scoring highest for U.S. government technical reports were technical accuracy (2.9), reliable data and technical information (2.8), and contains comprehensive data and information (2.7) on a 4-point system. The factors scoring highest for influencing the use of U.S. government technical reports were relevance (3.1), technical accuracy (3.06), and reliable data/information (3.02). Ease of use, familiarity, technical accuracy, and relevance correlated with use of U.S. government technical reports. Survey demographics, survey questionnaire, and the NASA/DoD Aerospace Knowledge Diffusion Research Project publications list are included.

  2. Impact of FDA Actions, DTCA, and Public Information on the Market for Pain Medication.

    PubMed

    Bradford, W David; Kleit, Andrew N

    2015-07-01

    Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most important classes of prescription drugs used by primary care physicians to manage pain. The NSAID class of products has a somewhat controversial history, around which a complex regulatory and informational environment has developed. This history includes a boxed warning mandated by the Food and Drug Administration (FDA) for all NSAIDs in 2005. We investigate the impact that various information shocks have had on the use of prescription medications for pain in primary care in the USA. We accomplish this by extracting data on nearly 600,000 patients from a unique nationwide electronic medical record database and estimate the probability of any active prescription for the four types of pain medications as a function of FDA actions, advertising, media coverage, and patient characteristics. We find that even after accounting for multiple sources of information, the FDA label changes and boxed warnings had a significant effect on pain medication prescribing. The boxed warning did not have the same impact on the use of all NSAID inhibitors. We find that the boxed warning reduced the use of NSAID COX-2 inhibitor use, which was the focus of much of the press attention. In contrast, however, the warning actually increased the use of non-COX-2 NSAID inhibitors. Thus, the efficacy of the FDA's black box warning is clearly mixed. PMID:25059655

  3. Information seeking and social support in online health communities: impact on patients' perceived empathy

    PubMed Central

    2011-01-01

    Objective Many healthcare organizations (HCOs) including Kaiser Permanente, Johns Hopkins, Cleveland Medical Center, and MD Anderson Cancer Center, provide access to online health communities as part of their overall patient support services. The key objective in establishing and running these online health communities is to offer empathic support to patients. Patients' perceived empathy is considered to be critical in patient recovery, specifically, by enhancing patient's compliance with treatment protocols and the pace of healing. Most online health communities are characterized by two main functions: informational support and social support. This study examines the relative impact of these two distinct functions—that is, as an information seeking forum and as a social support forum—on patients' perceived empathy in online health communities. Design This study tests the impact of two variables that reflect the above functions of online health communities—information seeking effectiveness and perceived social support—on perceived empathy. The model also incorporates the potential moderating effect of homophily on these relationships. Measurements A web-based survey was used to collect data from members of the online health communities provided by three major healthcare centers. A regression technique was used to analyze the data to test the hypotheses. Results The study finds that it is the information seeking effectiveness rather than the social support which affects patient's perceived empathy in online health communities run by HCOs. The results indicate that HCOs that provide online health communities for their patients need to focus more on developing tools that will make information seeking more effective and efficient. PMID:21486888

  4. Impact of Electronic Health Record Systems on Information Integrity: Quality and Safety Implications

    PubMed Central

    Bowman, Sue

    2013-01-01

    While the adoption of electronic health record (EHR) systems promises a number of substantial benefits, including better care and decreased healthcare costs, serious unintended consequences from the implementation of these systems have emerged. Poor EHR system design and improper use can cause EHR-related errors that jeopardize the integrity of the information in the EHR, leading to errors that endanger patient safety or decrease the quality of care. These unintended consequences also may increase fraud and abuse and can have serious legal implications. This literature review examines the impact of unintended consequences of the use of EHR systems on the quality of care and proposed solutions to address EHR-related errors. This analysis of the literature on EHR risks is intended to serve as an impetus for further research on the prevalence of these risks, their impact on quality and safety of patient care, and strategies for reducing them. PMID:24159271

  5. Dynamics of the full information minority game due to the agent's impact

    NASA Astrophysics Data System (ADS)

    Son, Woo-Sik; Park, Young-Jai

    2013-02-01

    We propose the full information minority game (FIMG) in which agents perfectly recognize their impact on the market. For reflecting the impact of agents, we introduce an actual total action and an actual payoff which depend on the agent's strategies. Unlike the perpetual fluctuating dynamics of the standard minority game, the dynamics of the FIMG settles into one of four steady states after a transient time. We classify steady states of the FIMG and analyze their characteristics. In most cases, the total payoff is maximized, and the total action settles into a periodic state. For measuring the degree of cooperation on the FIMG, we calculate a fraction of total payoff maximization and a mean relaxation time for the dynamics to settle into a steady state whose total payoff is maximized.

  6. The perceived impact of interprofessional information sharing on young people about their sexual healthcare.

    PubMed

    Hyde, Abbey; Fullerton, Deirdre; Lohan, Maria; McKeown, Caroline; Dunne, Laura; Macdonald, Geraldine; Howlin, Frances; Healy, Maria

    2016-07-01

    This article presents the results from an analysis of data from service providers and young adults who were formerly in state care about how information about the sexual health of young people in state care is managed. In particular, the analysis focuses on the perceived impact of information sharing between professionals on young people. Twenty-two service providers from a range of professions including social work, nursing and psychology, and 19 young people aged 18-22 years who were formerly in state care participated in the study. A qualitative approach was employed in which participants were interviewed in depth and data were analysed using modified analytical induction (Bogdan & Biklen, 2007). Findings suggest that within the care system in which service provider participants worked it was standard practice that sensitive information about a young person's sexual health would be shared across team members, even where there appeared to be no child protection issues. However, the accounts of the young people indicated that they experienced the sharing of information in this way as an invasion of their privacy. An unintended outcome of a high level of information sharing within teams is that the privacy of the young person in care is compromised in a way that is not likely to arise in the case of young people who are not in care. This may deter young people from availing themselves of the sexual health services.

  7. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 9: Information intermediaries and the transfer of aerospace Scientific and Technical Information (STI): A report from the field

    NASA Technical Reports Server (NTRS)

    Eveland, J. D.; Pinelli, Thomas E.

    1991-01-01

    From the NASA/DOD survey data, there can be no way of inferring what strategy for knowledge transfer is best; indeed, given the fact that the respondents were all presumably well qualified professionals, the data tend to call into serious question the idea that any one model might meet the needs of more than a distinct minority of possible users. The evidence to date appears to reinforce the concept that different information environments take many different shapes, and interact with each other and with formal data transmission sources in many different and equally valuable ways. Any overall strategy for improving the effectiveness and efficiency of scientific and technical information sharing must take this divergence into account, and work toward the creation of systems that reinforce true interactive knowledge utilization rather than simply disseminating data.

  8. Revisiting the impact of mobile phone screen size on user comprehension of health information.

    PubMed

    Alghamdi, Ebtisam; Yunus, Faisel; Househ, Mowafa

    2014-01-01

    Abstract goes here. This is completion of the research and update of the previous work that was published in 2013[1]. The paper describes our recent experimental study of the impact of mobile screen size on the user comprehension of health information and application structures. An experiment was conducted to measure the impact of screen size on user comprehension and retention. Participants were given the same simple scenario, which consisted of searching from different menus, navigating and reading some contents. They were timed and tracked for correctness. Also, a follow-up survey was given to each participant that consisted of a rating scale to assess usability features, comprehension and retention abilities of the participants based on different mobile screen sizes. Results showed that there was a significant difference between mobile phone screen size and the time taken to read the contents, which was at its highest on small screens (p-value=0.02). Also, reading characters was hardest on a small screen (p-value=0.003). In addition, there was a significant difference between the three screen sizes regarding the organization of the application's information, showing that the smaller the screen size, the more organized the information. On the other hand, there was no significant impact of screen size on user comprehension, retention scores, number of errors or effective task completion but it was generally better if a large screen size was used. This study concludes that the screen size is not the main concern in comprehension of the contents or application structure. However, reading speed improves with the larger screen size and positively influences the task completion and understanding of the application elements.

  9. Data fusion for adaptive control in manufacturing: Impact on engineering information models

    SciTech Connect

    Bray, O.H.

    1997-01-01

    Data fusion is the integration and analysis of data from multiple sensors to develop a more accurate understanding of a situation and determine how to respond to it. Although data fusion can be applied in many situations, this paper focuses on its application to manufacturing and how it changes some of the more traditional, less adaptive information models that support the design and manufacturing functions. The paper consists of four parts: Section 1 defines data fusion and explains its impact on manufacturing. Section 2 describes an information system architecture and explains the natural language-based information modeling methodology used by this research project. Section 3 identifies the major design and manufacturing functions, reviews the information models required to support them, and then shows how these models must be extended to support data fusion. Section 4 discusses the future directions of this work. This report is one of three produced by an FY93 LDRD project, Information Integration for Data Fusion. The project confirmed: (1) that the natural language-based information modeling methodology could be used effectively in data fusion areas, and (2) that commonalities could be found that would allow synergy across various data fusion areas, such as defense, manufacturing, and health care. The project found five common objects that are the basis for all of the data fusion areas examined: targets, behaviors, environments, signatures, and sensors. Many of these objects and the specific facts related to them were common across several models and could easily be reused. In some cases, even the terminology remained the same. This commonality is important with the growing use of multisensor data fusion. Data fusion is much more difficult if each type of sensor uses its own objects and models rather than building on a common set. Information model integration at the conceptual level is much easier than at the implementation level.

  10. Impact of information technology on productivity and efficiency in Iranian manufacturing industries

    NASA Astrophysics Data System (ADS)

    Abri, Amir Gholam; Mahmoudzadeh, Mahmoud

    2015-12-01

    The aim of this paper is to assess the impact of information technology (IT) on the productivity and efficiency of manufacturing industries in Iran. So, the data will be collected from 23 Iranian manufacturing industries during "2002-2006" and the methods such as DEA and panel data used to study the subject. Results obtained by the above two methods represent that IT has a positive and statistically significant effect on the productivity of manufacturing industries. It will be more in high IT-intensive industries than the other industries. But, there is no significant difference between the growth of labor productivity in IT-producing and IT-using industries.

  11. A Synthetic Method for Atmospheric Diffusion Simulation and Environmental Impact Assessment of Accidental Pollution in the Chemical Industry in a WEBGIS Context

    PubMed Central

    Ni, Haochen; Rui, Yikang; Wang, Jiechen; Cheng, Liang

    2014-01-01

    The chemical industry poses a potential security risk to factory personnel and neighboring residents. In order to mitigate prospective damage, a synthetic method must be developed for an emergency response. With the development of environmental numeric simulation models, model integration methods, and modern information technology, many Decision Support Systems (DSSs) have been established. However, existing systems still have limitations, in terms of synthetic simulation and network interoperation. In order to resolve these limitations, the matured simulation model for chemical accidents was integrated into the WEB Geographic Information System (WEBGIS) platform. The complete workflow of the emergency response, including raw data (meteorology information, and accident information) management, numeric simulation of different kinds of accidents, environmental impact assessments, and representation of the simulation results were achieved. This allowed comprehensive and real-time simulation of acute accidents in the chemical industry. The main contribution of this paper is that an organizational mechanism of the model set, based on the accident type and pollutant substance; a scheduling mechanism for the parallel processing of multi-accident-type, multi-accident-substance, and multi-simulation-model; and finally a presentation method for scalar and vector data on the web browser on the integration of a WEB Geographic Information System (WEBGIS) platform. The outcomes demonstrated that this method could provide effective support for deciding emergency responses of acute chemical accidents. PMID:25198686

  12. A synthetic method for atmospheric diffusion simulation and environmental impact assessment of accidental pollution in the chemical industry in a WEBGIS context.

    PubMed

    Ni, Haochen; Rui, Yikang; Wang, Jiechen; Cheng, Liang

    2014-09-01

    The chemical industry poses a potential security risk to factory personnel and neighboring residents. In order to mitigate prospective damage, a synthetic method must be developed for an emergency response. With the development of environmental numeric simulation models, model integration methods, and modern information technology, many Decision Support Systems (DSSs) have been established. However, existing systems still have limitations, in terms of synthetic simulation and network interoperation. In order to resolve these limitations, the matured simulation model for chemical accidents was integrated into the WEB Geographic Information System (WEBGIS) platform. The complete workflow of the emergency response, including raw data (meteorology information, and accident information) management, numeric simulation of different kinds of accidents, environmental impact assessments, and representation of the simulation results were achieved. This allowed comprehensive and real-time simulation of acute accidents in the chemical industry. The main contribution of this paper is that an organizational mechanism of the model set, based on the accident type and pollutant substance; a scheduling mechanism for the parallel processing of multi-accident-type, multi-accident-substance, and multi-simulation-model; and finally a presentation method for scalar and vector data on the web browser on the integration of a WEB Geographic Information System (WEBGIS) platform. The outcomes demonstrated that this method could provide effective support for deciding emergency responses of acute chemical accidents. PMID:25198686

  13. A synthetic method for atmospheric diffusion simulation and environmental impact assessment of accidental pollution in the chemical industry in a WEBGIS context.

    PubMed

    Ni, Haochen; Rui, Yikang; Wang, Jiechen; Cheng, Liang

    2014-09-05

    The chemical industry poses a potential security risk to factory personnel and neighboring residents. In order to mitigate prospective damage, a synthetic method must be developed for an emergency response. With the development of environmental numeric simulation models, model integration methods, and modern information technology, many Decision Support Systems (DSSs) have been established. However, existing systems still have limitations, in terms of synthetic simulation and network interoperation. In order to resolve these limitations, the matured simulation model for chemical accidents was integrated into the WEB Geographic Information System (WEBGIS) platform. The complete workflow of the emergency response, including raw data (meteorology information, and accident information) management, numeric simulation of different kinds of accidents, environmental impact assessments, and representation of the simulation results were achieved. This allowed comprehensive and real-time simulation of acute accidents in the chemical industry. The main contribution of this paper is that an organizational mechanism of the model set, based on the accident type and pollutant substance; a scheduling mechanism for the parallel processing of multi-accident-type, multi-accident-substance, and multi-simulation-model; and finally a presentation method for scalar and vector data on the web browser on the integration of a WEB Geographic Information System (WEBGIS) platform. The outcomes demonstrated that this method could provide effective support for deciding emergency responses of acute chemical accidents.

  14. Coherence and interference in diffuse noise: on the information and statistics associated with spatial wave correlations in directional noise fields.

    PubMed

    Walker, S C

    2012-03-01

    Broadband noise correlation methods for the passive extraction of information about the propagation of waves between distant sensor locations have received considerable attention in the literature. For the case of an isotropic ambient field distribution, there is a well-defined relationship between the expectation value of the wave coherence over the sensors and point-to-point wave propagation. Experimental applications, however, must contend with ambient field anisotropy as well as the performance limitations associated with stochastic fluctuations. This paper explores the influence of ambient field directionality on both (1) the connection between the measured wave coherence and sensor-to-sensor propagation and on (2) the rate at which measurements stochastically converge to the expectation value of the underlying wave coherence. Due to diffraction, the relationship between the measured wave coherence and sensor-to-sensor propagation is shown to be robust to even highly directional ambient field features. While the fluctuations of a stochastic system are generally known to depend on bandwidth and measurement duration, the rate of stochastic convergence depends additionally on the cross-spectral power density (coherent power) relative to the power-spectral density (total incident power). Practical experimental implications of these results are discussed.

  15. Highlighting the impact of aging on type I collagen: label-free investigation using confocal reflectance microscopy and diffuse reflectance spectroscopy in 3D matrix model.

    PubMed

    Guilbert, Marie; Roig, Blandine; Terryn, Christine; Garnotel, Roselyne; Jeannesson, Pierre; Sockalingum, Ganesh D; Manfait, Michel; Perraut, François; Dinten, Jean-Marc; Koenig, Anne; Piot, Olivier

    2016-02-23

    During aging, alterations of extracellular matrix proteins contribute to various pathological phenotypes. Among these alterations, type I collagen cross-linking and associated glycation products accumulation over time detrimentally affects its physico-chemical properties, leading to alterations of tissue biomechanical stability. Here, different-age collagen 3D matrices using non-destructive and label-free biophotonic techniques were analysed to highlight the impact of collagen I aging on 3D constructs, at macroscopic and microscopic levels. Matrices were prepared with collagens extracted from tail tendons of rats (newborns, young and old adults) to be within the physiological aging process. The data of diffuse reflectance spectroscopy reveal that aging leads to an inhibition of fibril assembly and a resulting decrease of gel density. Investigations by confocal reflectance microscopy highlight poor-fibrillar structures in oldest collagen networks most likely related to the glycation products accumulation. Complementarily, an infrared analysis brings out marked spectral variations in the Amide I profile, specific of the peptidic bond conformation and for carbohydrates vibrations as function of collagen-age. Interestingly, we also highlight an unexpected behavior for newborn collagen, exhibiting poorly-organized networks and microscopic features close to the oldest collagen. These results demonstrate that changes in collagen optical properties are relevant for investigating the incidence of aging in 3D matrix models.

  16. Highlighting the impact of aging on type I collagen: label-free investigation using confocal reflectance microscopy and diffuse reflectance spectroscopy in 3D matrix model

    PubMed Central

    Terryn, Christine; Garnotel, Roselyne; Jeannesson, Pierre; Sockalingum, Ganesh D.; Manfait, Michel; Perraut, François; Dinten, Jean-Marc; Koenig, Anne; Piot, Olivier

    2016-01-01

    During aging, alterations of extracellular matrix proteins contribute to various pathological phenotypes. Among these alterations, type I collagen cross-linking and associated glycation products accumulation over time detrimentally affects its physico-chemical properties, leading to alterations of tissue biomechanical stability. Here, different-age collagen 3D matrices using non-destructive and label-free biophotonic techniques were analysed to highlight the impact of collagen I aging on 3D constructs, at macroscopic and microscopic levels. Matrices were prepared with collagens extracted from tail tendons of rats (newborns, young and old adults) to be within the physiological aging process. The data of diffuse reflectance spectroscopy reveal that aging leads to an inhibition of fibril assembly and a resulting decrease of gel density. Investigations by confocal reflectance microscopy highlight poor-fibrillar structures in oldest collagen networks most likely related to the glycation products accumulation. Complementarily, an infrared analysis brings out marked spectral variations in the Amide I profile, specific of the peptidic bond conformation and for carbohydrates vibrations as function of collagen-age. Interestingly, we also highlight an unexpected behavior for newborn collagen, exhibiting poorly-organized networks and microscopic features close to the oldest collagen. These results demonstrate that changes in collagen optical properties are relevant for investigating the incidence of aging in 3D matrix models. PMID:26885896

  17. Vaneless diffusers

    NASA Astrophysics Data System (ADS)

    Senoo, Y.

    The influence of vaneless diffusers on flow in centrifugal compressors, particularly on surge, is discussed. A vaneless diffuser can demonstrate stable operation in a wide flow range only if it is installed with a backward leaning blade impeller. The circumferential distortion of flow in the impeller disappears quickly in the vaneless diffuser. The axial distortion of flow at the diffuser inlet does not decay easily. In large specific speed compressors, flow out of the impeller is distorted axially. Pressure recovery of diffusers at distorted inlet flow is considerably improved by half guide vanes. The best height of the vanes is a little 1/2 diffuser width. In small specific speed compressors, flow out of the impeller is not much distorted and pressure recovery can be predicted with one-dimensional flow analysis. Wall friction loss is significant in narrow diffusers. The large pressure drop at a small flow rate can cause the positive gradient of the pressure-flow rate characteristic curve, which may cause surging.

  18. Online Health Information Impacts Patients’ Decisions to Seek Emergency Department Care

    PubMed Central

    Pourmand, Ali; Sikka, Neal

    2011-01-01

    Objective: To investigate the impact of online health information (OHI) and patients’ decisions to seek emergency department (ED) care. Methods: We conducted a survey of a convenience sample of 489 ambulatory patients at an academic ED between February and September 2006. The primary measure was the prevalence of Internet use, and the secondary outcome was the impact of OHI on patients’ decision to seek ED care. Results: The study group comprised 175 (38%) males. Mean age was 33 years old; 222 (45.4%) patients were white, 189 (38.7%) patients were African American, and 33 (6.7%) were Hispanic. 92.6% had Internet access, and 94.5% used email; 58.7% reported that OHI was easy to locate, while 49.7% felt that it was also easy to understand. Of the subjects who had Internet access, 15.1% (1.6, 95% CI 1.3–2.0) stated that they had changed their decision to seek care in the ED. Conclusion: This study suggests that Internet access in an urban adult ED population may mirror reported Internet use among American adults. Many ED patients report that they are able to access and understand online health information, as well as use it to make decisions about seeking emergency care. PMID:21691522

  19. Spatial Mapping of Translational Diffusion Coefficients Using Diffusion Tensor Imaging: A Mathematical Description

    PubMed Central

    SHETTY, ANIL N.; CHIANG, SHARON; MALETIC-SAVATIC, MIRJANA; KASPRIAN, GREGOR; VANNUCCI, MARINA; LEE, WESLEY

    2016-01-01

    In this article, we discuss the theoretical background for diffusion weighted imaging and diffusion tensor imaging. Molecular diffusion is a random process involving thermal Brownian motion. In biological tissues, the underlying microstructures restrict the diffusion of water molecules, making diffusion directionally dependent. Water diffusion in tissue is mathematically characterized by the diffusion tensor, the elements of which contain information about the magnitude and direction of diffusion and is a function of the coordinate system. Thus, it is possible to generate contrast in tissue based primarily on diffusion effects. Expressing diffusion in terms of the measured diffusion coefficient (eigenvalue) in any one direction can lead to errors. Nowhere is this more evident than in white matter, due to the preferential orientation of myelin fibers. The directional dependency is removed by diagonalization of the diffusion tensor, which then yields a set of three eigenvalues and eigenvectors, representing the magnitude and direction of the three orthogonal axes of the diffusion ellipsoid, respectively. For example, the eigenvalue corresponding to the eigenvector along the long axis of the fiber corresponds qualitatively to diffusion with least restriction. Determination of the principal values of the diffusion tensor and various anisotropic indices provides structural information. We review the use of diffusion measurements using the modified Stejskal–Tanner diffusion equation. The anisotropy is analyzed by decomposing the diffusion tensor based on symmetrical properties describing the geometry of diffusion tensor. We further describe diffusion tensor properties in visualizing fiber tract organization of the human brain. PMID:27441031

  20. Diffuse radiation

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A diffuse celestial radiation which is isotropic at least on a course scale were measured from the soft X-ray region to about 150 MeV, at which energy the intensity falls below that of the galactic emission for most galactic latitudes. The spectral shape, the intensity, and the established degree of isotropy of this diffuse radiation already place severe constraints on the possible explanations for this radiation. Among the extragalactic theories, the more promising explanations of the isotropic diffuse emission appear to be radiation from exceptional galaxies from matter antimatter annihilation at the boundaries of superclusters of galaxies of matter and antimatter in baryon symmetric big bang models. Other possible sources for extragalactic diffuse gamma radiation are discussed and include normal galaxies, clusters of galaxies, primordial cosmic rays interacting with intergalactic matter, primordial black holes, and cosmic ray leakage from galaxies.

  1. Diffusion barriers

    NASA Technical Reports Server (NTRS)

    Nicolet, M. A.

    1983-01-01

    The choice of the metallic film for the contact to a semiconductor device is discussed. One way to try to stabilize a contact is by interposing a thin film of a material that has low diffusivity for the atoms in question. This thin film application is known as a diffusion barrier. Three types of barriers can be distinguished. The stuffed barrier derives its low atomic diffusivity to impurities that concentrate along the extended defects of a polycrystalline layer. Sacrificial barriers exploit the fact that some (elemental) thin films react in a laterally uniform and reproducible fashion. Sacrificial barriers have the advantage that the point of their failure is predictable. Passive barriers are those most closely approximating an ideal barrier. The most-studied case is that of sputtered TiN films. Stuffed barriers may be viewed as passive barriers whose low diffusivity material extends along the defects of the polycrystalline host.

  2. NASA/DOD Aerospace Knowledge Diffusion Research Project. Paper 42: An analysis of the transfer of Scientific and Technical Information (STI) in the US aerospace industry

    NASA Technical Reports Server (NTRS)

    Kennedy, John M.; Pinelli, Thomas E.; Hecht, Laura F.; Barclay, Rebecca O.

    1994-01-01

    The U.S. aerospace industry has a long history of federal support for research related to its needs. Since the establishment of the National Advisory Committee for Aeronautics (NACA) in 1915, the federal government has provided continuous research support related to flight and aircraft design. This research has contributed to the international preeminence of the U.S. aerospace industry. In this paper, we present a sociological analysis of aerospace engineers and scientists and how their attitudes and behaviors impact the flow of scientific and technical information (STI). We use a constructivist framework to explain the spotty dissemination of federally funded aerospace research. Our research is aimed towards providing federal policymakers with a clearer understanding of how and when federally funded aerospace research is used. This understanding will help policymakers design improved information transfer systems that will aid the competitiveness of the U.S. aerospace industry.

  3. Impact of Psychiatric Information on Potential Jurors in Evaluating High-Functioning Autism Spectrum Disorder (hfASD)

    ERIC Educational Resources Information Center

    Berryessa, Colleen M.; Milner, Lauren C.; Garrison, Nanibaa' A.; Cho, Mildred K.

    2015-01-01

    During a trial involving an offender with a mental disorder, jurors are often required to evaluate information on the disorder and its characteristics. This evaluation relies on how jurors understand and synthesize psychiatric and other evidence on the disorder and this information's impact on the case, an offender's culpability, and the rendered…

  4. Data-Informed Decision Making on High-Impact Strategies: Developing and Validating an Instrument for Principals

    ERIC Educational Resources Information Center

    Shen, Jianping; Cooley, Van E.; Ma, Xin; Reeves, Patricia L.; Burt, Walter L.; Rainey, J. Mark; Yuan, Wenhui

    2012-01-01

    In this study, the authors connect 3 streams of literature to develop an instrument for measuring the degree to which principals engage in data-informed decision making on high-impact strategies that are empirically associated with higher student achievement. The 3 literature streams are (a) the importance of data-informed decision making, (b) the…

  5. Dementia Risk and Financial Decision Making by Older Households: The Impact of Information

    PubMed Central

    Hsu, Joanne W.; Willis, Robert

    2014-01-01

    The knowledge and reasoning ability needed to manage one’s finances is a form of human capital. Alzheimer’s disease and other dementias cause progressive declines in cognition that lead to a complete loss of functional capacities. In this paper we analyze the impact of information about cognitive decline on the choice of household financial decision-maker. Using longitudinal data on older married couples in a novel application of survival analysis, we find that as the financial decision maker’s cognition declines, the management of finances is eventually turned over to his cognitively intact spouse, often well after difficulties handling money have already emerged. However, a memory disease diagnosis increases the hazard of switching the financial respondent by over 200 percent for couples who control their retirement accounts, like 401(k) accounts, relative to those who passively receive retirement income. This finding is consistent with a model of the value of information: households with the most to gain financially from preparation are most responsive to information about cognitive decline. PMID:25525476

  6. Potential impact of advanced clinical information technology on cancer care in 2015.

    PubMed

    Sittig, Dean F

    2006-08-01

    New clinical information technologies now sporadically available will soon be in routine clinical use, bringing many changes to all phases of the cancer care continuum. For example, new technologies such as: (1) The next generation Internet; (2) Real-time clinical decision support systems; (3) Off-line, population-based systems; (4) Large, integrated, individual patient-level phenotypic and genotypic databases with intelligent data mining capabilities; (5) Wireless, invasive and non-invasive physiologic monitoring devices; (6) Natural Language Processing (NLP) systems; and (7) Mathematical models of complex biological systems all have the potential to impact significantly the provision of cancer care throughout its continuum. While new information management and communication techniques and technologies will reduce many of the inefficiencies and inaccuracies of our present systems, there will be an equal, and potentially far more dangerous, set of unintended consequences. Informatics investigators, cancer specialists, and health system administrators must focus on the study of what is working and what is not, as well as, on development and testing of the new clinical information management and communication technologies, if we are to be ready for the future. PMID:16783609

  7. Potential impact of advanced clinical information technology on healthcare in 2015.

    PubMed

    Sittig, Dean F

    2004-01-01

    Clinical information technologies now sporadically available will soon be in routine clinical use, bringing many changes to healthcare. For example, 1) The next generation Internet; 2) Real-time clinical decision support systems; 3) Off-line, population-based systems; 4) Large, integrated, individual patient-level phenotypic and genotypic databases with intelligent data mining capabilities; 5) Wireless, invasive and non-invasive physiologic monitoring devices; 6) Natural Language Processing (NLP) systems; and 7) Mathematical models of complex biological systems have the potential to impact significantly the future healthcare delivery system. While new information management and communication techniques and technologies will reduce many of the inefficiencies and inaccuracies of our present systems, there will be an equal, and potentially far more dangerous, set of unintended consequences. Informatics investigators and health system administrators must focus on the study of what is working and what is not, as well as, on development and testing of the new clinical information management and communication technologies, if we are to be ready for the future. PMID:15361041

  8. Impact of informal regulation of pollution on water quality in rivers in India.

    PubMed

    Goldar, Bishwanath; Banerjee, Nandini

    2004-11-01

    In this paper an attempt is made to assess the impact of informal regulation of water pollution on water quality in Indian rivers. For this purpose, an econometric analysis of determinants of water quality in Indian rivers is carried out using water quality (water class) data for 106 monitoring points on 10 important rivers for five years, 1995-1999. To explain variations in water quality, an Ordered Probit model is estimated, in which poll percentage in parliamentary elections, a proxy for the intensity of informal regulation, is taken as one of the main explanatory variables. Rainfall, industrialization, irrigation intensity and fertilizer use are some of the other explanatory variables used in the model to control for the influence of these factors. As expected, river water quality is found to be positively related with rainfall, and negatively related with industrialization, irrigation intensity and fertilizer use. A significant positive relationship is found between poll percentage and water quality, and also between the rate of increase in literacy level in a district and the water quality in rivers flowing through the district. These results point to a significant favorable effect of informal regulation of pollution on water quality in rivers in India. PMID:15380317

  9. Impact of informal regulation of pollution on water quality in rivers in India.

    PubMed

    Goldar, Bishwanath; Banerjee, Nandini

    2004-11-01

    In this paper an attempt is made to assess the impact of informal regulation of water pollution on water quality in Indian rivers. For this purpose, an econometric analysis of determinants of water quality in Indian rivers is carried out using water quality (water class) data for 106 monitoring points on 10 important rivers for five years, 1995-1999. To explain variations in water quality, an Ordered Probit model is estimated, in which poll percentage in parliamentary elections, a proxy for the intensity of informal regulation, is taken as one of the main explanatory variables. Rainfall, industrialization, irrigation intensity and fertilizer use are some of the other explanatory variables used in the model to control for the influence of these factors. As expected, river water quality is found to be positively related with rainfall, and negatively related with industrialization, irrigation intensity and fertilizer use. A significant positive relationship is found between poll percentage and water quality, and also between the rate of increase in literacy level in a district and the water quality in rivers flowing through the district. These results point to a significant favorable effect of informal regulation of pollution on water quality in rivers in India.

  10. The impact of eLearning on health professional educators’ attitudes to information and communication technology

    PubMed Central

    Neville, Victoria; Lam, Mary; Gordon, Christopher J

    2015-01-01

    Background The use of information and communication technology (ICT) in health professional education is increasing rapidly. Health professional educators need to be responsive to health professionals’ information and communication technological needs; however, there is a paucity of information about educators’ attitudes to, and capabilities with, ICT. Methods Fifty-two health professional educators, enrolled in health professional education postgraduate studies, participated in an online subject with specific eLearning components requiring the use of ICT. They completed a pre- and postquestionnaire pertaining to ICT attitudes, confidence, and usage. Results Participants reported significant increases in overall ICT confidence during the subject despite it being high at baseline (mean: 7.0 out of 10; P=0.02). Even with increased ICT confidence, there were decreases in the participants’ sense of ICT control when related to health professional education (P=0.002); whereas, the amount of time participants engaged with ICT devices was negatively correlated with the sense of ICT control (P=0.002). The effect of age and health discipline on ICT attitudes and confidence was not significant (P>0.05). Conclusion This study reports that health professional educators have perceptual deficits toward ICT. The impact of eLearning increased confidence in ICT but caused a reduction in participants’ sense of control of ICT. Health professional educators require more ICT training and support to facilitate better ICT integration in health professional education settings. PMID:25678796

  11. The Impact of Electronic Media on Research and Education. Role of Libraries in Information Service

    NASA Astrophysics Data System (ADS)

    Evstigneeva, Galina; Wegner, Bernd

    The paper gives a short survey how electronic media have changed the working conditions at research institutions, universities and higher schools, which new possibilities in research and education emerge from this, and which problems will have to be solved with respect to this in the future. We shall concentrate our attention on the role of the libraries as information brokers in such an environment. In this context archiving of electronic documents, software and access systems will be addressed as one of the challenging future tasks of libraries. Each of these themes may serve as a subject for a seminar on its own. Hence the paper only can highlight some of these features referring to more detailed work elsewhere. At the beginning the main classes of electronic offers providing infrastructure for research and education are introduced. The role of editors, publishers, software producers and web managers is shortly discussed. Information gateways and information brokers are important for the distribution of these offers. The impact of electronic media on research and education is described by representative examples of different types. Some final conclusions deal with the problems to be solved in the future when electronic media will occupy the central place in the daily work of professionals, researchers and teachers.

  12. Hydrological externalities and livelihoods impacts: Informed communities for better resource management

    NASA Astrophysics Data System (ADS)

    Reddy, V. Ratna

    2012-01-01

    SummaryHydrological knowledge or information has mostly remained in the domain of scientific community. The communities that interact with the hydrological aspects such as groundwater and surface water on a day to day basis are hardly aware of the information that could critically influence their livelihoods. From the perspective of the communities' information pertaining to groundwater aquifer characters, potential to provide the water resource, surface groundwater interactions in varying geo-hydrological conditions are important. The 'public good' nature of the resources and their linkages with ecological systems gives rise to externalities that could be pervasive. In a number of countries, especially the developing countries, groundwater is the single largest source of drinking as well as irrigation water. In the absence of scientific information with the communities, extraction of groundwater resources for productive purposes has become a risky venture leading to adverse impacts on livelihoods. The externalities associated with over exploitation of groundwater resources and the resulting widespread well failure is identified as one of the main reasons for pushing farmers into debt trap and one of the reasons for farmer suicides in India. The negative externalities are increasingly becoming severe in the context of climate variability. This paper attempts to highlight the importance of hydrological information to the user communities from a socioeconomic perspective using a newly developed framework 'REDUCE' based on theories of effective communication. It shows, based on the evidence, how farming communities are getting affected in the absence of the basic hydrological information across socioeconomic groups. It is argued, using relevant information that the negative externalities could be mitigated to a large extent with proper dissemination of information among the communities and capacitating them to measure and use the information on their own. In order to

  13. Impacts of Informal Caregiver Availability on Long-term Care Expenditures in OECD Countries

    PubMed Central

    Yoo, Byung-Kwang; Bhattacharya, Jay; McDonald, Kathryn M; Garber, Alan M

    2004-01-01

    Objective To quantify the effects of informal caregiver availability and public funding on formal long-term care (LTC) expenditures in developed countries. Data Source/Study Setting Secondary data were acquired for 15 Organization for Economic Cooperation and Development (OECD) countries from 1970 to 2000. Study Design Secondary data analysis, applying fixed- and random-effects models to time-series cross-sectional data. Outcome variables are inpatient or home heath LTC expenditures. Key explanatory variables are measures of the availability of informal caregivers, generosity in public funding for formal LTC, and the proportion of the elderly population in the total population. Data Collection/Extraction Method Aggregated macro data were obtained from OECD Health Data, United Nations Demographic Yearbooks, and U.S. Census Bureau International Data Base. Principal Findings Most of the 15 OECD countries experienced growth in LTC expenditures over the study period. The availability of a spouse caregiver, measured by male-to-female ratio among the elderly, is associated with a $28,840 (1995 U.S. dollars) annual reduction in formal LTC expenditure per additional elderly male. Availability of an adult child caregiver, measured by female labor force participation and full-time/part-time status shift, is associated with a reduction of $310 to $3,830 in LTC expenditures. These impacts on LTC expenditure vary across countries and across time within a country. Conclusions The availability of an informal caregiver, particularly a spouse caregiver, is among the most important factors explaining variation in LTC expenditure growth. Long-term care policies should take into account behavioral responses: decreased public funding in LTC may lead working women to leave the labor force to provide more informal care. PMID:15544640

  14. Health information technology implementation - impacts and policy considerations: a comparison between Israel and Portugal.

    PubMed

    Catan, Gabriel; Espanha, Rita; Mendes, Rita Veloso; Toren, Orly; Chinitz, David

    2015-01-01

    The use of Information and Communications Technology (ICT) in health systems is increasing worldwide. While it is assumed that ICT holds great potential to make health services more efficient and grant patients more empowerment, research on these trends is at an early stage. Building on a study of the impact of ICT on physicians and patients in Israel, a Short Term Scientific Mission (STSM) sponsored by COST Net in conjunction with CIES/ISCTE IUL (Portugal) facilitated a comparison of ICT in health in Israel and Portugal. The comparison focused on patient empowerment, physician behavior and the role of government in implementing ICT. The research in both countries was qualitative in nature. In-depth interviews with the Ministry of Health (MOH), the private sector, patients associations, health plans and researchers were used to collect data. Purposeful sampling was used to select respondents, and secondary sources were used for triangulation. The findings indicate that respondents in both countries feel that patient empowerment has indeed been furthered by introduction of ICT. Regarding physicians, in both countries ICT is seen as providing more information that can be used in medical decision making. Increased access of patients to web-based medical information can strengthen the role of patients in decision making and improve the physician-patient relationship, but also shift the latter in ways that may require adjustments in physician orientation. Physician uptake of ICT in both countries involves overcoming certain barriers, such as resistance to change. At the national level, important differences were found between the two countries. While in Israel, ICT was promoted and adopted by the meso level of the health system, in particular the health plans and government intervention can be found in a later stage, in Portugal the government was the main developer and national strategies were built from the beginning. These two approaches present different advantages

  15. Health information technology implementation - impacts and policy considerations: a comparison between Israel and Portugal.

    PubMed

    Catan, Gabriel; Espanha, Rita; Mendes, Rita Veloso; Toren, Orly; Chinitz, David

    2015-01-01

    The use of Information and Communications Technology (ICT) in health systems is increasing worldwide. While it is assumed that ICT holds great potential to make health services more efficient and grant patients more empowerment, research on these trends is at an early stage. Building on a study of the impact of ICT on physicians and patients in Israel, a Short Term Scientific Mission (STSM) sponsored by COST Net in conjunction with CIES/ISCTE IUL (Portugal) facilitated a comparison of ICT in health in Israel and Portugal. The comparison focused on patient empowerment, physician behavior and the role of government in implementing ICT. The research in both countries was qualitative in nature. In-depth interviews with the Ministry of Health (MOH), the private sector, patients associations, health plans and researchers were used to collect data. Purposeful sampling was used to select respondents, and secondary sources were used for triangulation. The findings indicate that respondents in both countries feel that patient empowerment has indeed been furthered by introduction of ICT. Regarding physicians, in both countries ICT is seen as providing more information that can be used in medical decision making. Increased access of patients to web-based medical information can strengthen the role of patients in decision making and improve the physician-patient relationship, but also shift the latter in ways that may require adjustments in physician orientation. Physician uptake of ICT in both countries involves overcoming certain barriers, such as resistance to change. At the national level, important differences were found between the two countries. While in Israel, ICT was promoted and adopted by the meso level of the health system, in particular the health plans and government intervention can be found in a later stage, in Portugal the government was the main developer and national strategies were built from the beginning. These two approaches present different advantages

  16. Analysis of health impact inputs to the US Department of Energy's risk information system

    SciTech Connect

    Droppo, J.G. Jr.; Buck, J.W.; Strenge, D.L.; Siegel, M.R.

    1990-08-01

    The US Department of Energy (DOE) is in the process of completing a survey of environmental problems, referred to as the Environmental Survey, at their facilities across the country. The DOE Risk Information System (RIS) is being used to prioritize these environmental problems identified in the Environmental Survey's findings. This report contains a discussion of site-specific public health risk parameters and the rationale for their inclusion in the RIS. These parameters are based on computed potential impacts obtained with the Multimedia Environmental Pollutant Assessment System (MEPAS). MEPAS is a computer-based methodology for evaluating the potential exposures resulting from multimedia environmental transport of hazardous materials. This report has three related objectives: document the role of MEPAS in the RIS framework, report the results of the analysis of alternative risk parameters that led to the current RIS risk parameters, and describe analysis of uncertainties in the risk-related parameters. 20 refs., 17 figs., 10 tabs.

  17. Evaluation of information technology impact on effective internal control in the University system

    NASA Astrophysics Data System (ADS)

    Sanusi Fasilat, A.; Hassan, Haslinda

    2015-12-01

    Information Technology (IT) plays a key role in internal control system in various organizations in terms of maintaining records and other internal services. Internal control system is defined as an efficient control procedures set up by firm to safeguard resources and to assure the reliability and accuracy of both financial and non-financial records in line with applicable governance and procedure to acquire the established goal and objectives. This paper focuses on the impact of IT on internal control system in the Nigerian universities. Data are collected from three different universities via questionnaire. Descriptive statistics is used to analyze the data; Chi-square is performed to test the hypothesis. The results of the hypothesis showed that IT has a positive relationship with the effective internal control activities in the University system. It is concluded that the adoption of IT will significantly improve the effectiveness of the internal control system operations in the University in terms of quality service delivery.

  18. Evaluation of information technology impact on effective internal control in the University system

    SciTech Connect

    Sanusi Fasilat, A. Hassan, Haslinda

    2015-12-11

    Information Technology (IT) plays a key role in internal control system in various organizations in terms of maintaining records and other internal services. Internal control system is defined as an efficient control procedures set up by firm to safeguard resources and to assure the reliability and accuracy of both financial and non-financial records in line with applicable governance and procedure to acquire the established goal and objectives. This paper focuses on the impact of IT on internal control system in the Nigerian universities. Data are collected from three different universities via questionnaire. Descriptive statistics is used to analyze the data; Chi-square is performed to test the hypothesis. The results of the hypothesis showed that IT has a positive relationship with the effective internal control activities in the University system. It is concluded that the adoption of IT will significantly improve the effectiveness of the internal control system operations in the University in terms of quality service delivery.

  19. The impact of negative emotions on self-concept abstraction depends on accessible information processing styles.

    PubMed

    Isbell, Linda M; Rovenpor, Daniel R; Lair, Elicia C

    2016-10-01

    Research suggests that anger promotes global, abstract processing whereas sadness and fear promote local, concrete processing (see Schwarz & Clore, 2007 for a review). Contrary to a large and influential body of work suggesting that specific affective experiences are tethered to specific cognitive outcomes, the affect-as-cognitive-feedback account maintains that affective experiences confer positive or negative value on currently dominant processing styles, and thus can lead to either global or local processing (Huntsinger, Isbell, & Clore, 2014). The current work extends this theoretical perspective by investigating the impact of discrete negative emotions on the self-concept. By experimentally manipulating information processing styles and discrete negative emotions that vary in appraisals of certainty, we demonstrate that the impact of discrete negative emotions on the spontaneous self-concept depends on accessible processing styles. When global processing was accessible, individuals in angry (negative, high certainty) states generated more abstract statements about themselves than individuals in either sad (Experiment 1) or fearful (Experiment 2; negative, low certainty) states. When local processing was made accessible, however, the opposite pattern emerged, whereby individuals in angry states generated fewer abstract statements than individuals in sad or fearful states. Together these studies provide new insights into the mechanisms through which discrete emotions influence cognition. In contrast to theories assuming a dedicated link between emotions and processing styles, these results suggest that discrete emotions provide feedback about accessible ways of thinking, and are consistent with recent evidence suggesting that the impact of affect on cognition is highly context-dependent. (PsycINFO Database Record PMID:27685154

  20. Impact of visiting an Onsite Casino information centre on perceptions about randomness and gambling behaviours.

    PubMed

    Boutin, Claude; Tremblay, Nicole; Ladouceur, Robert

    2009-09-01

    At the beginning of 2000, some educational initiatives in the field of responsible gambling resulted in the implementation of Onsite Casino Information Centres (OCICs). However, no study has yet empirically evaluated the impact of visiting an OCIC. This paper includes two studies evaluating the OCIC Au Centre du Hasard, located in Montreal, Quebec. The goal of the first study was to identify the profile of the visitors and to assess their appreciation. After a visit, 336 patrons accepted to complete a pen and paper questionnaire. The goal of the second study was to evaluate the impact of a visit on the perceptions about randomness and the gambling behaviours of the visitors. For this study, 67 visitors were evaluated before, after, and 3 months following a visit and their results were compared to a control group. Data showed that most visitors were seniors, occasional slot machine gamblers, and in control of their gambling activities. The majority of guests greatly appreciated their visit. A visit to Au Centre du Hasard seemed to modify the misconceptions towards the notion of randomness but not the gambling behaviours. These gains were maintained at 3-month follow-up. Results with respect to other prevention programs are discussed, and future research avenues are suggested.

  1. Text de-identification for privacy protection: a study of its impact on clinical text information content.

    PubMed

    Meystre, Stéphane M; Ferrández, Óscar; Friedlin, F Jeffrey; South, Brett R; Shen, Shuying; Samore, Matthew H

    2014-08-01

    As more and more electronic clinical information is becoming easier to access for secondary uses such as clinical research, approaches that enable faster and more collaborative research while protecting patient privacy and confidentiality are becoming more important. Clinical text de-identification offers such advantages but is typically a tedious manual process. Automated Natural Language Processing (NLP) methods can alleviate this process, but their impact on subsequent uses of the automatically de-identified clinical narratives has only barely been investigated. In the context of a larger project to develop and investigate automated text de-identification for Veterans Health Administration (VHA) clinical notes, we studied the impact of automated text de-identification on clinical information in a stepwise manner. Our approach started with a high-level assessment of clinical notes informativeness and formatting, and ended with a detailed study of the overlap of select clinical information types and Protected Health Information (PHI). To investigate the informativeness (i.e., document type information, select clinical data types, and interpretation or conclusion) of VHA clinical notes, we used five different existing text de-identification systems. The informativeness was only minimally altered by these systems while formatting was only modified by one system. To examine the impact of de-identification on clinical information extraction, we compared counts of SNOMED-CT concepts found by an open source information extraction application in the original (i.e., not de-identified) version of a corpus of VHA clinical notes, and in the same corpus after de-identification. Only about 1.2-3% less SNOMED-CT concepts were found in de-identified versions of our corpus, and many of these concepts were PHI that was erroneously identified as clinical information. To study this impact in more details and assess how generalizable our findings were, we examined the overlap between

  2. Impact of Information and Communication Technology on Information Seeking Behavior of Users in Astronomy and Astrophysics Centers of India: A Survey

    NASA Astrophysics Data System (ADS)

    Sahu, H. K.; Singh, S. N.

    2010-10-01

    This study is based on a survey designed to determine the Information Seeking Behavior (ISB) of Astronomy and Astrophysics users in India. The main objective of the study is to determine the sources consulted and the general pattern of the information-gathering system of users and the impact of Information and Communication Technology (ICT) on the Astronomy and Astrophysics user's Information Seeking Behavior. It examines various Information and Communication Technology-based resources and methods of access and use. A descriptive sample stratified method has been used and data was collected using a questionnaire as the main tool. The response rate was 72%. Descriptive statistics were also employed and data have been presented in tables and graphs. The study is supported by earlier studies. It shows that Astronomy and Astrophysics users have developed a unique Information Seeking Behavior to carry out their education and research. The vast majority of respondents reported that more information is available from a variety of e-resources. Consequently, they are able to devote more time to seek out relevant information in the current Information and Communication Technology scenario. The study also indicates that respondents use a variety of information resources including e-resources for teaching and research. Books and online databases such as the NASA Astrophysics Data System (ADS) were considered more important as formal sources of information. E-mail and face-to-face communications are used extensively by users as informal sources of information. It also reveals that despite the presence of electronic sources, Astronomy and Astrophysics users are still using printed materials. This study should to help to improve various Information and Communication Technology-based services. It also suggests that GOI should adopt Information and Communication Technology-based Information Centers and Libraries services and recommends a network-based model for Astronomy and

  3. Configurational diffusion of coal macromolecules

    SciTech Connect

    Guin, J.A.; Curtis, C.W.; Tarrer, A.R.

    1991-01-01

    It has been reported that the most predominant constituents of coal extract are the polycyclic aromatic hydrocarbons. Yet the experimental values of diffusivity in ethyl acetate for the most of these materials were not available in the literature. Thus, the diffusion coefficients of some of these materials were measured to increase an understanding of the diffusional behavior of coal macromolecules. In an earlier quarterly report, the authors reported the diffusion coefficients of some model coal molecules determined using their diffusion cell with polycarbonate membranes. Subsequently, they have found that these polycarbonate membranes are semi-permeable to some of the model compounds, so that the measured diffusion flux was greater than that through the pores alone. This extra solute flux could result in over estimation of the diffusion coefficients, therefore, they have now re-measured these diffusivities using polyester, rather than polycarbonate, membranes. The polyester material is not permeable to the solute molecules, except through the open pore area. Thus the only diffusion flux is that through the pores, resulting in correct diffusion coefficients as reported herein. The detailed results are presented in the body of this report. Finally in the last section the authors discuss a slight departure in methodology of some of their earlier planned work. This change will have a positive beneficial impact on the results and speed-up the collection of configurational diffusion data in actual tortuous porous media. 12 refs., 3 figs., 4 tabs.

  4. Information Communication Technology and Politics: A Synthesized Analysis of the Impacts of Information Technology on Voter Participation in Kenya

    ERIC Educational Resources Information Center

    Tsuma, Clive Katiba

    2011-01-01

    The availability of political information throughout society made possible by the evolution of contemporary information communication technology has precipitated conflicting debate regarding the effects of technology use on real life political participation. Proponents of technology argue that the use of new information technology stimulates…

  5. The Impact of Group Size and Proportion of Shared Information on the Exchange and Integration of Information in Groups.

    ERIC Educational Resources Information Center

    Cruz, Michael G.; Boster, Franklin J.; Rodriguez, Jose I.

    1997-01-01

    Seeks conditions that improve group performance on "hidden profiles." Finds that, among undergraduate student groups, group information sharing and decision-making effectiveness were higher in small groups with a low percentage of shared information, and lower when groups either were large or shared a high percentage of information. Notes that…

  6. Integration of Acoustical Information in the Perception of Impacted Sound Sources: The Role of Information Accuracy and Exploitability

    ERIC Educational Resources Information Center

    Giordano, Bruno L.; Rocchesso, Davide; McAdams, Stephen

    2010-01-01

    Sound sources are perceived by integrating information from multiple acoustical features. The factors influencing the integration of information are largely unknown. We measured how the perceptual weighting of different features varies with the accuracy of information and with a listener's ability to exploit it. Participants judged the hardness of…

  7. [Perinatal Information System. Incorporation latency and impact on perinatal clinical registry].

    PubMed

    Simini, F; Fernández, A; Sosa, C; Díaz Rossello, J L

    2001-10-01

    The Perinatal Information System (SIP) is a clinical record, local management and quality assurance software standard in Latin America and the Caribbean. The time to implement SIP in a Maternity Hospital is evaluated as well as the effect of statistics on perinatal health indicators in subsequent years. In the sample of 20 Maternity Hospitals (5 Countries, 40% Private and 60% Public) 85% had a reliable information system by the third year of use of SIP. 15% of hospitals still had problems at that time that were already clear during the second year, a time corrective measures can still be taken. The evaluation of the impact of yearly reports shows that 58% of recommendations were fulfilled, specially those regarding the complete filling-in of clinical records (62%) and to a lesser extent variables that reflect clinical practices and organization of services (52%). The conclusion is that Maternity Hospitals in Latin America and the Caribbean have the capacity to adopt a complex tool of computerized clinical records for quality assurance of perinatal care and monitoring of health indicators.

  8. Delivering health information statewide via the Internet in a collaborative environment: impact on individual member institutions.

    PubMed Central

    McCray, J C

    1999-01-01

    The Arizona Health Information Network (AZHIN) is a statewide member-driven organization committed to improving access to information for health sciences students and practitioners. Members include several hospitals and hospital systems, an academic health sciences center, and other diverse health care organizations. AZHIN offers its members unlimited Web access to ten well-known health sciences databases. This paper explores the impact that AZHIN has had on its member institutions. A survey asked members to reflect on AZHIN and its possible effects on the visibility of the librarian within the institution, relative dollars spent on AZHIN and range of resources available, Internet connectivity within their institution, access to AZHIN and other Internet resources, teaching, and benefits of collaboration. Results indicated that AZHIN members have access to a wider range of resources than they would otherwise. There are financial savings for some. Internet connectivity and AZHIN membership can provide the librarian with a broadened role and increased visibility. The availability of MEDLINE and other AZHIN resources encouraged some institutions to install Internet connectivity more quickly. Teaching library users has increased. Overall, AZHIN members recognized many benefits of their collaboration. PMID:10427425

  9. [Perinatal Information System. Incorporation latency and impact on perinatal clinical registry].

    PubMed

    Simini, F; Fernández, A; Sosa, C; Díaz Rossello, J L

    2001-10-01

    The Perinatal Information System (SIP) is a clinical record, local management and quality assurance software standard in Latin America and the Caribbean. The time to implement SIP in a Maternity Hospital is evaluated as well as the effect of statistics on perinatal health indicators in subsequent years. In the sample of 20 Maternity Hospitals (5 Countries, 40% Private and 60% Public) 85% had a reliable information system by the third year of use of SIP. 15% of hospitals still had problems at that time that were already clear during the second year, a time corrective measures can still be taken. The evaluation of the impact of yearly reports shows that 58% of recommendations were fulfilled, specially those regarding the complete filling-in of clinical records (62%) and to a lesser extent variables that reflect clinical practices and organization of services (52%). The conclusion is that Maternity Hospitals in Latin America and the Caribbean have the capacity to adopt a complex tool of computerized clinical records for quality assurance of perinatal care and monitoring of health indicators. PMID:11816526

  10. Delivering health information statewide via the Internet in a collaborative environment: impact on individual member institutions.

    PubMed

    McCray, J C

    1999-07-01

    The Arizona Health Information Network (AZHIN) is a statewide member-driven organization committed to improving access to information for health sciences students and practitioners. Members include several hospitals and hospital systems, an academic health sciences center, and other diverse health care organizations. AZHIN offers its members unlimited Web access to ten well-known health sciences databases. This paper explores the impact that AZHIN has had on its member institutions. A survey asked members to reflect on AZHIN and its possible effects on the visibility of the librarian within the institution, relative dollars spent on AZHIN and range of resources available, Internet connectivity within their institution, access to AZHIN and other Internet resources, teaching, and benefits of collaboration. Results indicated that AZHIN members have access to a wider range of resources than they would otherwise. There are financial savings for some. Internet connectivity and AZHIN membership can provide the librarian with a broadened role and increased visibility. The availability of MEDLINE and other AZHIN resources encouraged some institutions to install Internet connectivity more quickly. Teaching library users has increased. Overall, AZHIN members recognized many benefits of their collaboration. PMID:10427425

  11. The impact of epistemological beliefs and cognitive ability on recall and critical evaluation of scientific information.

    PubMed

    Feinkohl, Insa; Flemming, Danny; Cress, Ulrike; Kimmerle, Joachim

    2016-05-01

    Scientific research findings are frequently picked up by the mainstream media, but it is largely unclear which factors have an impact on laypeople's processing of the presented scientific information. In this study, we investigated the influence of cognitive and metacognitive inter-individual differences on recall and on critical evaluation of new scientific information that was presented in a journalistic article. Sixty-three participants (80 % female; mean age 24.1 ± 3.3 years) read a newspaper article reporting research findings on a recently developed and yet unproven treatment for depression. We found that more sophisticated, domain-specific epistemological beliefs and a higher cognitive ability were independently associated with better recall of content from the article. Additionally, participants with more sophisticated epistemological beliefs displayed a more critical evaluation of the article. Cognitive ability was unrelated to critical evaluation and to epistemological beliefs. There were also no interaction effects of cognitive ability and epistemological beliefs on recall or on critical evaluation. Based on our preliminary findings and previous evidence of epistemological beliefs as a modifiable feature, we discuss this inter-individual characteristic as a potential target for the promotion of better understanding of scientific topics by the general public.

  12. Equal impact of diffusion and DNA binding rates on the potential spatial distribution of nuclear factor κB transcription factor inside the nucleus.

    PubMed

    Sycheva, A M; Kel, A; Nikolaev, E N; Moshkovskii, S A

    2014-06-01

    There are two physical processes that influence the spatial distribution of transcription factor molecules entering the nucleus of a eukaryotic cell, the binding to genomic DNA and the diffusion throughout the nuclear volume. Comparison of the DNA-protein association rate constant and the protein diffusion constant may determine which one is the limiting factor. If the process is diffusion-limited, transcription factor molecules are captured by DNA before their even distribution in the nuclear volume. Otherwise, if the reaction rate is limiting, these molecules diffuse evenly and then find their binding sites. Using well-studied human NF-κB dimer as an example, we calculated its diffusion constant using the Debye-Smoluchowski equation. The value of diffusion constant was about 10(-15) cm(3)/s, and it was comparable to the NF-κB association rate constant for DNA binding known from previous studies. Thus, both diffusion and DNA binding play an equally important role in NF-κB spatial distribution. The importance of genome 3D-structure in gene expression regulation and possible dependence of gene expression on the local concentration of open chromatin can be hypothesized from our theoretical estimate.

  13. Information beyond the forum: Motivations, strategies, and impacts of citizen participants seeking information during a consensus conference.

    PubMed

    Anderson, Ashley A; Delborne, Jason; Kleinman, Daniel Lee

    2013-11-01

    During traditional consensus conferences, organizers control the formal information available to participants-by compiling structured background materials and recruiting expert panelists. Less formally, however, participants are encouraged to bring their own experiences into the deliberations, and in doing so, they often seek outside information. We explore this heretofore understudied phenomenon of information seeking during a deliberative event: the U.S. National Citizens' Technology Forum (2008), which addressed the convergence of nanotechnology, biotechnology, information technology, and cognitive science on the potential development of human-enhancement technologies. Through interviews with participants and observation of in-person and online deliberations, we identify outside information-seeking strategies and motivations. Our study demonstrates that conceptualizing models of deliberation as standalone settings of communication exchange ignores the reality of the complex information environment from which deliberative participants draw when making sense of technical issues. Future citizen deliberations must incorporate outside information seeking in the design of the exercises. PMID:23825244

  14. Information beyond the forum: Motivations, strategies, and impacts of citizen participants seeking information during a consensus conference.

    PubMed

    Anderson, Ashley A; Delborne, Jason; Kleinman, Daniel Lee

    2013-11-01

    During traditional consensus conferences, organizers control the formal information available to participants-by compiling structured background materials and recruiting expert panelists. Less formally, however, participants are encouraged to bring their own experiences into the deliberations, and in doing so, they often seek outside information. We explore this heretofore understudied phenomenon of information seeking during a deliberative event: the U.S. National Citizens' Technology Forum (2008), which addressed the convergence of nanotechnology, biotechnology, information technology, and cognitive science on the potential development of human-enhancement technologies. Through interviews with participants and observation of in-person and online deliberations, we identify outside information-seeking strategies and motivations. Our study demonstrates that conceptualizing models of deliberation as standalone settings of communication exchange ignores the reality of the complex information environment from which deliberative participants draw when making sense of technical issues. Future citizen deliberations must incorporate outside information seeking in the design of the exercises.

  15. Informing Water Resource Decisionmaking Through Assessments of Global Change Impacts on Aquatic Ecosystem Services

    NASA Astrophysics Data System (ADS)

    Rogers, C. E.; Julius, S. H.

    2001-05-01

    The combined forces of land use change, climate change and variability, and UV radiation are altering aquatic ecosystems (e.g., streams, rivers, lakes, wetlands, estuaries, coral reefs). Changes in aquatic ecosystems are mediated by changes in temperature, hydrology, water quality/pollutant loading, sea level rise, storm surges, UV radiation and riparian habitat. The importance of these changes for water resource management is evident, but decisionmakers often have difficulty obtaining information that is timely, relevant and useful. EPA's Global Change Research Program is applying the concept of ecosystem services (conditions and processes through which ecosystems sustain and fulfill human life) to selected watersheds to help local decisionmakers evaluate how global changes could affect their water resources. We are developing a framework that will help identify a priori the types of services most likely to be affected, and methods for measuring, modeling, or estimating impacts on ecosystem services at specific sites. These methods involve using climate and land use change scenarios to drive linked hydrologic and ecological models. Our presentation will focus on how scientific information is being developed and communicated among stakeholders to inform decisions in three areas: San Pedro River Basin, San Francisco Bay & Basin, and watersheds near Washington, DC. These case studies represent different climate regimes (arid southwest, west coast Mediterranean type, subtropical zone of the east coast), different potential changes in climate (change in timing of seasonal floods and greater evaporation, change from winter snow to winter rain yielding decreased spring & summer streamflow, increased intensity of precipitation events), different land use pressures (agricultural and urban), and different spatial scales (1 to 43,000 sq. mi.). These case studies cover different sets of aquatic ecosystems and emphasize different ecosystem services. In addition, we will

  16. Attitude of Ayurveda doctors toward the impact of health information technology

    PubMed Central

    Sinha, Rajesh Kumar; Shetty, Soumya R.

    2015-01-01

    Background: Health information technology (HIT) equips healthcare professionals with the required information and tools for making quality decisions in patient care, but it is always advisable to assess their attitude before its actual implementation. Objectives: To assess the attitude of Ayurvedic doctors toward the impact of HIT. Materials and Methods: A cross-sectional survey was carried out among 140 doctors of an Ayurvedic center of Southern India. A validated questionnaire consisting of 18 questions based on a 5-point Likert scale was administered to the participants after receiving their due consent. Results: About 75–80% of the respondents concurred that the HIT application, such as electronic health record, has the potentials to reduce the duplication of documentation work, is easy and has an instant processing and real-time access to patient information. They also felt the need of such application to report the patient data to local and national health institutions. A total of 85% of them mentioned that these applications can make the collection and accessibility of patient data much easier compared with paper-based records, whereas 87.4% of them claimed telemedicine as a platform for multidisciplinary collaborative research and patient care. Conclusion: Even though most of the respondents agreed about the role of HIT in improving the quality of health care, there were many who held no opinion about HIT, including privacy and security of patient data. The need of proper awareness and training program is identified to make them aware about the HIT and its application in patient care, education and research. PMID:26166998

  17. Optimal marking of threatened species to balance benefits of information with impacts of marking.

    PubMed

    McCarthy, Michael A; Parris, Kirsten M

    2008-12-01

    Marking animals so that they are uniquely identifiable provides information that may assist conservation efforts. Nevertheless, some methods used to mark animals can be harmful. We used mathematical methods to assess the trade-off between the impact of marking threatened species and the value of the information gained. We considered the case where 2 management strategies, each aiming to improve a species' survival rate, are implemented in an experimental phase. The results of the experiment were applied in a postexperimental management phase. We expressed the expected number of survivors in both phases mathematically, accounting for any mortality caused by the experiment, and determined the proportion of animals to mark to maximize this number. The optimal number of animals to mark increased with the number of individuals available for the experiment and with the number of individuals to be managed in the future. The optimal solution was to mark only 25% of the animals when there were 1000 individuals available for the experiment, the results were used to manage 2000 individuals, and marking caused mortality of 1%. Fewer animals were marked when there were fewer animals in either phase or when marking caused higher mortality. In the case of the Helmeted Honeyeater (Lichenostomus melanops cassidix), the optimal proportion to mark was <1 if the mortality rate was >0.15%-1%, with the threshold depending on the number of animals in the experimental and postexperimental phases. The trade-off between gaining more information about a species and possibly harming individuals of that species by marking them is difficult to assess subjectively. We show how to determine objectively the optimal proportion of animals to mark to enhance the management of threatened species.

  18. Optimal marking of threatened species to balance benefits of information with impacts of marking.

    PubMed

    McCarthy, Michael A; Parris, Kirsten M

    2008-12-01

    Marking animals so that they are uniquely identifiable provides information that may assist conservation efforts. Nevertheless, some methods used to mark animals can be harmful. We used mathematical methods to assess the trade-off between the impact of marking threatened species and the value of the information gained. We considered the case where 2 management strategies, each aiming to improve a species' survival rate, are implemented in an experimental phase. The results of the experiment were applied in a postexperimental management phase. We expressed the expected number of survivors in both phases mathematically, accounting for any mortality caused by the experiment, and determined the proportion of animals to mark to maximize this number. The optimal number of animals to mark increased with the number of individuals available for the experiment and with the number of individuals to be managed in the future. The optimal solution was to mark only 25% of the animals when there were 1000 individuals available for the experiment, the results were used to manage 2000 individuals, and marking caused mortality of 1%. Fewer animals were marked when there were fewer animals in either phase or when marking caused higher mortality. In the case of the Helmeted Honeyeater (Lichenostomus melanops cassidix), the optimal proportion to mark was <1 if the mortality rate was >0.15%-1%, with the threshold depending on the number of animals in the experimental and postexperimental phases. The trade-off between gaining more information about a species and possibly harming individuals of that species by marking them is difficult to assess subjectively. We show how to determine objectively the optimal proportion of animals to mark to enhance the management of threatened species. PMID:18680498

  19. Demonstrating Diffusion

    ERIC Educational Resources Information Center

    Foy, Barry G.

    1977-01-01

    Two demonstrations are described. Materials and instructions for demonstrating movement of molecules into cytoplasm using agar blocks, phenolphthalein, and sodium hydroxide are given. A simple method for demonstrating that the rate of diffusion of a gas is inversely proportional to its molecular weight is also presented. (AJ)

  20. Relativistic diffusion

    NASA Astrophysics Data System (ADS)

    Haba, Z.

    2009-02-01

    We discuss relativistic diffusion in proper time in the approach of Schay (Ph.D. thesis, Princeton University, Princeton, NJ, 1961) and Dudley [Ark. Mat. 6, 241 (1965)]. We derive (Langevin) stochastic differential equations in various coordinates. We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form. We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution. We discuss drag terms leading to an equilibrium distribution. The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Jüttner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed.

  1. Defusing Diffusion

    ERIC Educational Resources Information Center

    Dou, Remy; Hogan, DaNel; Kossover, Mark; Spuck, Timothy; Young, Sarah

    2013-01-01

    Diffusion has often been taught in science courses as one of the primary ways by which molecules travel, particularly within organisms. For years, classroom teachers have used the same common demonstrations to illustrate this concept (e.g., placing drops of food coloring in a beaker of water). Most of the time, the main contributor to the motion…

  2. Relativistic diffusion.

    PubMed

    Haba, Z

    2009-02-01

    We discuss relativistic diffusion in proper time in the approach of Schay (Ph.D. thesis, Princeton University, Princeton, NJ, 1961) and Dudley [Ark. Mat. 6, 241 (1965)]. We derive (Langevin) stochastic differential equations in various coordinates. We show that in some coordinates the stochastic differential equations become linear. We obtain momentum probability distribution in an explicit form. We discuss a relativistic particle diffusing in an external electromagnetic field. We solve the Langevin equations in the case of parallel electric and magnetic fields. We derive a kinetic equation for the evolution of the probability distribution. We discuss drag terms leading to an equilibrium distribution. The relativistic analog of the Ornstein-Uhlenbeck process is not unique. We show that if the drag comes from a diffusion approximation to the master equation then its form is strongly restricted. The drag leading to the Tsallis equilibrium distribution satisfies this restriction whereas the one of the Jüttner distribution does not. We show that any function of the relativistic energy can be the equilibrium distribution for a particle in a static electric field. A preliminary study of the time evolution with friction is presented. It is shown that the problem is equivalent to quantum mechanics of a particle moving on a hyperboloid with a potential determined by the drag. A relation to diffusions appearing in heavy ion collisions is briefly discussed.

  3. Sucrose diffusion in aqueous solution.

    PubMed

    Price, Hannah C; Mattsson, Johan; Murray, Benjamin J

    2016-07-28

    The diffusion of sugar in aqueous solution is important both in nature and in technological applications, yet measurements of diffusion coefficients at low water content are scarce. We report directly measured sucrose diffusion coefficients in aqueous solution. Our technique utilises a Raman isotope tracer method to monitor the diffusion of non-deuterated and deuterated sucrose across a boundary between the two aqueous solutions. At a water activity of 0.4 (equivalent to 90 wt% sucrose) at room temperature, the diffusion coefficient of sucrose was determined to be approximately four orders of magnitude smaller than that of water in the same material. Using literature viscosity data, we show that, although inappropriate for the prediction of water diffusion, the Stokes-Einstein equation works well for predicting sucrose diffusion under the conditions studied. As well as providing information of importance to the fundamental understanding of diffusion in binary solutions, these data have technological, pharmaceutical and medical implications, for example in cryopreservation. Moreover, in the atmosphere, slow organic diffusion may have important implications for aerosol growth, chemistry and evaporation, where processes may be limited by the inability of a molecule to diffuse between the bulk and the surface of a particle. PMID:27364512

  4. Sucrose diffusion in aqueous solution

    PubMed Central

    Murray, Benjamin J.

    2016-01-01

    The diffusion of sugar in aqueous solution is important both in nature and in technological applications, yet measurements of diffusion coefficients at low water content are scarce. We report directly measured sucrose diffusion coefficients in aqueous solution. Our technique utilises a Raman isotope tracer method to monitor the diffusion of non-deuterated and deuterated sucrose across a boundary between the two aqueous solutions. At a water activity of 0.4 (equivalent to 90 wt% sucrose) at room temperature, the diffusion coefficient of sucrose was determined to be approximately four orders of magnitude smaller than that of water in the same material. Using literature viscosity data, we show that, although inappropriate for the prediction of water diffusion, the Stokes–Einstein equation works well for predicting sucrose diffusion under the conditions studied. As well as providing information of importance to the fundamental understanding of diffusion in binary solutions, these data have technological, pharmaceutical and medical implications, for example in cryopreservation. Moreover, in the atmosphere, slow organic diffusion may have important implications for aerosol growth, chemistry and evaporation, where processes may be limited by the inability of a molecule to diffuse between the bulk and the surface of a particle. PMID:27364512

  5. Diffusion in silicon isotope heterostructures

    SciTech Connect

    Silvestri, Hughes Howland

    2004-05-14

    The simultaneous diffusion of Si and the dopants B, P, and As has been studied by the use of a multilayer structure of isotopically enriched Si. This structure, consisting of 5 pairs of 120 nm thick natural Si and {sup 28}Si enriched layers, enables the observation of {sup 30}Si self-diffusion from the natural layers into the {sup 28}Si enriched layers, as well as dopant diffusion from an implanted source in an amorphous Si cap layer, via Secondary Ion Mass Spectrometry (SIMS). The dopant diffusion created regions of the multilayer structure that were extrinsic at the diffusion temperatures. In these regions, the Fermi level shift due to the extrinsic condition altered the concentration and charge state of the native defects involved in the diffusion process, which affected the dopant and self-diffusion. The simultaneously recorded diffusion profiles enabled the modeling of the coupled dopant and self-diffusion. From the modeling of the simultaneous diffusion, the dopant diffusion mechanisms, the native defect charge states, and the self- and dopant diffusion coefficients can be determined. This information is necessary to enhance the physical modeling of dopant diffusion in Si. It is of particular interest to the modeling of future electronic Si devices, where the nanometer-scale features have created the need for precise physical models of atomic diffusion in Si. The modeling of the experimental profiles of simultaneous diffusion of B and Si under p-type extrinsic conditions revealed that both species are mediated by neutral and singly, positively charged Si self-interstitials. The diffusion of As and Si under extrinsic n-type conditions yielded a model consisting of the interstitialcy and vacancy mechanisms of diffusion via singly negatively charged self-interstitials and neutral vacancies. The simultaneous diffusion of P and Si has been modeled on the basis of neutral and singly negatively charged self-interstitials and neutral and singly positively charged P

  6. The Production of Information for Genred Activity Spaces: Informational Motives and Consequences of the Environmental Impact Statement

    ERIC Educational Resources Information Center

    Bazerman, Charles; Little, Joseph; Chavkin, Teri

    2003-01-01

    Genres, although aligning people to joint activity and joint attention, shape the substantive material or information represented within the bounded space of the text. Each genre creates a space that prompts the production of particular kinds of information to populate that space. The National Environmental Policy Act of 1969 that mandated the…

  7. Portsmouth Gaseous Diffusion Plant Environmental report for 1990

    SciTech Connect

    Counce-Brown, D.

    1991-09-01

    This calendar year 1990 annual report on environmental surveillance of the US Department of Energy's (DOE's) Portsmouth Gaseous Diffusion Plant (PORTS) and its environs consists of two parts: the summary, discussion, and conclusions (Part 1) and the data presentation (Part 2). The objectives of this report are as follows: report 1990 monitoring data for the installation and its environs that may have been affected by operations on the plant site, provide reasonably detailed information about the plant site and plant operations, provide detailed information on input and assumptions used in all calculations, provide trend analyses (when appropriate) to indicate increases and decreases in environmental impact, and provide general information on plant quality assurance.

  8. The impact of electronic health record (EHR) interoperability on immunization information system (IIS) data quality

    PubMed Central

    Woinarowicz, Mary; Howell, Molly

    2016-01-01

    Objectives: To evaluate the impact of electronic health record (EHR) interoperability on the quality of immunization data in the North Dakota Immunization Information System (NDIIS). Methods: NDIIS doses administered data was evaluated for completeness of the patient and dose-level core data elements for records that belong to interoperable and non-interoperable providers. Data was compared at three months prior to electronic health record (EHR) interoperability enhancement to data at three, six, nine and twelve months post-enhancement following the interoperability go live date. Doses administered per month and by age group, timeliness of vaccine entry and the number of duplicate clients added to the NDIIS was also compared, in addition to, immunization rates for children 19 – 35 months of age and adolescents 11 – 18 years of age. Results: Doses administered by both interoperable and non-interoperable providers remained fairly consistent from pre-enhancement through twelve months post-enhancement. Comparing immunization rates for infants and adolescents, interoperable providers had higher rates both pre- and post-enhancement than non-interoperable providers for all vaccines and vaccine series assessed. The overall percentage of doses entered into the NDIIS within one month of administration varied slightly between interoperable and non-interoperable providers; however, there were significant changes between the percentage of doses entered within one day and within one week with the percentage entered within one day increasing and within one week decreasing with interoperability. The number of duplicate client records created by interoperable providers increased from 94 duplicates pre-enhancement to 10,552 at twelve months post-enhancement, while the duplicates from non-interoperable providers only increased from 300 to 637 over the same period. Of the 40 core data elements in the NDIIS, there was some difference in completeness between the interoperable versus

  9. The utilization of research-based information: Moving beyond communicating assessments of (climate) impacts

    NASA Astrophysics Data System (ADS)

    Pulwarty, R.; Cohen, S. J.

    2006-12-01

    Societal impacts of changing environments include primary or direct effects (increased soil moisture, loss of life, crop and building damage etc.), secondary or indirect effects (displacement, illness) and, higher order or systemic effects (debt, loss of livelihood). Vulnerability to such events is constructed from: (1) the timing, magnitude, spatial extent, and duration of the physical hazard i.e. risk of occurrence; (2) exposure in regions of risk e.g. population, property; and, (3) factors that pre-condition the degree of impact and the capacity to respond and recover. The call for better articulated decision support and services components is rising on par with more traditional axes of assessments i.e. characterizing the integrated physical system and its social and environmental impacts. The expectation is that increasing the rate at which policy makers and resource managers acquire knowledge about environment-society interactions will result in improvements in the quality of public and private decisions (a decidedly idealized view). Much recent work has shown that this expectation is most difficult to meet when decision stakes are high, uncertainty is great, technologies are new, experience is limited, and there are unequal distributions of burdens and benefits. We review generalized frames of reference on the use of climate information identified in independent studies undertaken by the authors in different river basins of North America. As shown in these (and other) studies, researchers, policy-makers and practitioners (public and private) operate on different time-lines, use different languages, and most importantly respond to different problem definitions and accountability incentives. The process of communication is increasingly recognized to be complex, transactional, and heavily dependent on the potential user's pre-existing knowledge, beliefs and experiences. We outline differing approaches to risk communication and their associated assumptions

  10. The impact of electronic health record (EHR) interoperability on immunization information system (IIS) data quality.

    PubMed

    Woinarowicz, Mary; Howell, Molly

    2016-01-01

    Objectives: To evaluate the impact of electronic health record (EHR) interoperability on the quality of immunization data in the North Dakota Immunization Information System (NDIIS). Methods: NDIIS doses administered data was evaluated for completeness of the patient and dose-level core data elements for records that belong to interoperable and non-interoperable providers. Data was compared at three months prior to electronic health record (EHR) interoperability enhancement to data at three, six, nine and twelve months post-enhancement following the interoperability go live date. Doses administered per month and by age group, timeliness of vaccine entry and the number of duplicate clients added to the NDIIS was also compared, in addition to, immunization rates for children 19 - 35 months of age and adolescents 11 - 18 years of age. Results: Doses administered by both interoperable and non-interoperable providers remained fairly consistent from pre-enhancement through twelve months post-enhancement. Comparing immunization rates for infants and adolescents, interoperable providers had higher rates both pre- and post-enhancement than non-interoperable providers for all vaccines and vaccine series assessed. The overall percentage of doses entered into the NDIIS within one month of administration varied slightly between interoperable and non-interoperable providers; however, there were significant changes between the percentage of doses entered within one day and within one week with the percentage entered within one day increasing and within one week decreasing with interoperability. The number of duplicate client records created by interoperable providers increased from 94 duplicates pre-enhancement to 10,552 at twelve months post-enhancement, while the duplicates from non-interoperable providers only increased from 300 to 637 over the same period. Of the 40 core data elements in the NDIIS, there was some difference in completeness between the interoperable versus non

  11. The impact of product information and trials on demand for smokeless tobacco and cigarettes: Evidence from experimental auctions

    PubMed Central

    Rousu, Matthew C.; O'Connor, Richard; Thrasher, James F; June, Kristie; Bansal-Travers, Maansi; Pitcavage, James

    2014-01-01

    Introduction Epidemiological and toxicological evidence suggests lower risk of smokeless tobacco (ST) products compared to cigarettes. Less is known, however, about consumer perceptions and use of novel forms of ST, including snus and dissolvable tobacco. Methods In this study, we conducted in-person experimental auctions in Buffalo, NY, Columbia, SC, and Selinsgrove, PA with 571 smokers to test the impact of information and product trials on smokers’ preferences. Auctions were conducted between November 2010-November 2011. Results We found no evidence of an impact of product trials on demand in our auctions. Anti-ST information increased demand for cigarettes when presented alone, but when presented with Pro-ST information it decreased demand for cigarettes. It did not decrease demand for ST products. Anti-smoking information increased demand for ST products, but did not affect cigarette demand. Conclusions These findings suggest that credible and effective communications about tobacco harm reduction should reinforce the negative effects of smoking. PMID:24321456

  12. Beyond the Classroom: The Impact of Informal STEM Experiences on Student Attitudes and Interest

    NASA Astrophysics Data System (ADS)

    Scinski, Lidia

    A lack of social capital can be a critical factor impeding underrepresented minority (URM) students from obtaining the mathematical and scientific background required to achieve educational and career success in STEM fields. In this study, the effects of generating and utilizing social capital within an informal STEM outreach summer camp are examined as resources in strengthening the academic pipeline for Hispanic students towards careers in STEM. Empirical studies have shown that economically disadvantaged and minority students experience larger learning losses during "unschooled" periods of time than their middle-class and White counterparts. The "faucet theory" explains how the achievement gap widens during unschooled periods of time when the resource faucet is turned off and families of students from disadvantaged backgrounds are unable to make up for these resources. Consequently, minority and students of disadvantaged backgrounds are quickly shortcircuited in taking advantage of opportunities to pursue careers in STEM fields. To address the research questions, this study employed a qualitative research design, specifically an instrumental case study design using mixed methods within a bounded program. The methods included multiple measures to collect and analyze data from focus group interviews, electronic documents, observations, and survey administrations. The sample population included forty-nine Hispanic 7th and 8th grade students from middle schools in San Diego County. Results of the study demonstrated that the informal STEM outreach summer camp positively impacted Hispanic students and increased interest and attitudes toward STEM choices. STEM programs offered during out-of-school time need to be relationship based to support young students' social and emotional development (Goldstein, Lee, & Chung, 2010). The resource faucet continued to flow during the summer for iQUEST science camp participants because they were able to tap into social capital in

  13. Analysis of Information, Impact and Control of HIV amongst Dental Professionals of Central India

    PubMed Central

    Agarwal, Jatin; Shrivastava, Asha; Shrivastava, Sudha

    2015-01-01

    Background Dental health care providers may be exposed to a variety of microorganisms via blood, oral or respiratory secretions. Though the risk of transmission of Human Immunodeficiency Virus (HIV) in dental settings is low, the consequences of being infected are life threatening. Therefore, high standards in infection control and waste management are required in controlling occupational contagion and cross infection. Aim To obtain comprehensive information about the HIV related information, its impact on the health care provider’s attitude towards treating patients living with HIV/AIDS (PLWHA), infection control & waste disposal practices among dental professionals of Malwa region of Madhya Pradesh; situated in Central India. Materials and Methods A cross-sectional survey was conducted among 320 private dental practitioners. Data was collected using a pretested, self administered 40 item questionnaire and statistically analysed. Results The response rate was 81.25%. Over all 50.76% dentists were graded as having good knowledge of HIV. Unfortunately, their willingness to treat these patients remained low. In all 39.23% dentist were willing to render care to PLWHA. Junior dentists expressed less hesitation with regard to acceptance of risk patients than other dentists. Over 65% of the respondents reported adherence to universal precautions. The most alarming observation was that dentists were not following safe waste management practices. Conclusion Dental professionals continue to indicate a reluctance to treat patients with HIV/AIDS or those in high- risk groups. The results suggest need to have a comprehensive motivational program and implementing ways to ensure access and availability of safe dental care for PLWHA. The desire to get training on how to handle PLWHA illustrates that receptiveness to change exists. PMID:26393211

  14. The Impact of Scientific Information on Ecosystem Management: Making Sense of the Contextual Gap Between Information Providers and Decision Makers

    NASA Astrophysics Data System (ADS)

    van Wyk, Ernita; Roux, Dirk J.; Drackner, Mikael; McCool, Stephen F.

    2008-05-01

    Scientific information is not always effectively incorporated into decision-making processes. This phenomenon seems to hold even when the information is aligned with an articulated need, is generated according to sound scientific procedures, and is packaged with end-user preferences in mind. We propose that contextual or cultural differences contribute significantly to the misalignment in communication between those who generate information and those who seek information for improved management of natural resources. The solution is to cultivate shared understanding, which in turn relies on acknowledgment and sharing of diverse values and attitudes. This constitutes a difficult challenge in a culturally diverse environment. Whereas cultural diversity represents wealth in experiences, knowledge and perspectives it can constrain the potential to develop the shared understandings necessary for effective integration of new information. This article illustrates how a lack of shared understanding among participants engaged in a resource-management process can produce and perpetuate divergent views of the world, to the extent that information and knowledge flows are ineffective and scientific information, even when requested, cannot be used effectively. Four themes were distilled from interviews with management and scientific staff of a natural resource-management agency in South Africa. The themes are used to illustrate how divergent views embedded in different cultures can discourage alignment of effort toward a common purpose. The article then presents a sense-making framework to illustrate the potential for developing shared understandings in a culturally diverse world.

  15. The impact of scientific information on ecosystem management: making sense of the contextual gap between information providers and decision makers.

    PubMed

    van Wyk, Ernita; Roux, Dirk J; Drackner, Mikael; McCool, Stephen F

    2008-05-01

    Scientific information is not always effectively incorporated into decision-making processes. This phenomenon seems to hold even when the information is aligned with an articulated need, is generated according to sound scientific procedures, and is packaged with end-user preferences in mind. We propose that contextual or cultural differences contribute significantly to the misalignment in communication between those who generate information and those who seek information for improved management of natural resources. The solution is to cultivate shared understanding, which in turn relies on acknowledgment and sharing of diverse values and attitudes. This constitutes a difficult challenge in a culturally diverse environment. Whereas cultural diversity represents wealth in experiences, knowledge and perspectives it can constrain the potential to develop the shared understandings necessary for effective integration of new information. This article illustrates how a lack of shared understanding among participants engaged in a resource-management process can produce and perpetuate divergent views of the world, to the extent that information and knowledge flows are ineffective and scientific information, even when requested, cannot be used effectively. Four themes were distilled from interviews with management and scientific staff of a natural resource-management agency in South Africa. The themes are used to illustrate how divergent views embedded in different cultures can discourage alignment of effort toward a common purpose. The article then presents a sense-making framework to illustrate the potential for developing shared understandings in a culturally diverse world.

  16. Exploring the 3D geometry of the diffusion kurtosis tensor--impact on the development of robust tractography procedures and novel biomarkers.

    PubMed

    Neto Henriques, Rafael; Correia, Marta Morgado; Nunes, Rita Gouveia; Ferreira, Hugo Alexandre

    2015-05-01

    Diffusion kurtosis imaging (DKI) is a diffusion-weighted technique which overcomes limitations of the commonly used diffusion tensor imaging approach. This technique models non-Gaussian behaviour of water diffusion by the diffusion kurtosis tensor (KT), which can be used to provide indices of tissue heterogeneity and a better characterisation of the spatial architecture of tissue microstructure. In this study, the geometry of the KT is elucidated using synthetic data generated from multi-compartmental models, where diffusion heterogeneity between intra- and extra-cellular media is taken into account, as well as the sensitivity of the results to each model parameter and to synthetic noise. Furthermore, based on the assumption that the maxima of the KT are distributed perpendicularly to the direction of well-aligned fibres, a novel algorithm for estimating fibre direction directly from the KT is proposed and compared to the fibre directions extracted from DKI-based orientation distribution function (ODF) estimates previously proposed in the literature. Synthetic data results showed that, for fibres crossing at high intersection angles, direction estimates extracted directly from the KT have smaller errors than the DKI-based ODF estimation approaches (DKI-ODF). Nevertheless, the proposed method showed smaller angular resolution and lower stability to changes of the simulation parameters. On real data, tractography performed on these KT fibre estimates suggests a higher sensitivity than the DKI-based ODF in resolving lateral corpus callosum fibres reaching the pre-central cortex when diffusion acquisition is performed with five b-values. Using faster acquisition schemes, KT-based tractography did not show improved performance over the DKI-ODF procedures. Nevertheless, it is shown that direct KT fibre estimates are more adequate for computing a generalised version of radial kurtosis maps. PMID:25676915

  17. Diffusion bonding

    DOEpatents

    Anderson, Robert C.

    1976-06-22

    1. A method for joining beryllium to beryllium by diffusion bonding, comprising the steps of coating at least one surface portion of at least two beryllium pieces with nickel, positioning a coated surface portion in a contiguous relationship with an other surface portion, subjecting the contiguously disposed surface portions to an environment having an atmosphere at a pressure lower than ambient pressure, applying a force upon the beryllium pieces for causing the contiguous surface portions to abut against each other, heating the contiguous surface portions to a maximum temperature less than the melting temperature of the beryllium, substantially uniformly decreasing the applied force while increasing the temperature after attaining a temperature substantially above room temperature, and maintaining a portion of the applied force at a temperature corresponding to about maximum temperature for a duration sufficient to effect the diffusion bond between the contiguous surface portions.

  18. Impact of fluoxetine on the human brain in multiple sclerosis as quantified by proton magnetic resonance spectroscopy and diffusion tensor imaging.

    PubMed

    Sijens, Paul E; Mostert, Jop P; Irwan, Roy; Potze, Jan Hendrik; Oudkerk, Matthijs; De Keyser, Jacques

    2008-12-30

    The antidepressant fluoxetine stimulates astrocytic glycogenolysis, which serves as an energy source for axons. In multiple sclerosis patients fluoxetine administration may improve energy supply in neuron cells and thus inhibit axonal degeneration. In a preliminary pilot study, 15 patients with multiple sclerosis (MS) were examined by diffusion tensor imaging (DTI) and (1)H magnetic resonance spectroscopy (MRS) in order to quantify the brain tissue diffusion properties (fractional anisotropy, apparent diffusion coefficient) and metabolite levels (choline, creatine and N-acetylaspartate) in cortical gray matter brain tissue, in normal appearing white matter and in white matter lesions. After oral administration of fluoxetine (20 mg/day) for 1 week, the DTI and MRS measurements were repeated and after treatment with a higher dose (40 mg/day) during the next week, a third series of DTI/MRS examinations was performed in order to assess any changes in diffusion properties and metabolism. One trend was observed in gray matter tissue, a decrease of choline measured at weeks 1 and 2 (significant in a subgroup of 11 relapsing remitting/secondary progressive MS patients). In white matter lesions, the apparent diffusion coefficient was increased at week 1 and N-acetylaspartate was increased at week 2 (both significant). These preliminary results provide evidence of a neuroprotective effect of fluoxetine in MS by the observed partial normalization of the structure-related MRS parameter N-acetylaspartate in white matter lesions.

  19. Final Environmental Assessment and Finding of No Significant Impact: The Implementation of the Authorized Limits Process for Waste Acceptance at the C-746-U Landfill Paducah Gaseous Diffusion Plant Paducah, Kentucky

    SciTech Connect

    N /A

    2002-08-06

    The US Department of Energy (DOE) has completed an environmental assessment (DOE/EA-1414) for the proposed implementation of the authorized limits process for waste acceptance at the C-746-U Landfill at the Paducah Gaseous Diffusion Plant (PGDP) in Paducah, Kentucky. Based on the results of the impact analysis reported in the EA, which is incorporated herein by this reference, DOE has determined that the proposed action is not a major Federal action that would significantly affect the quality of the human environment within the context of the ''National Environmental Policy Act of 1969'' (NEPA). Therefore preparation of an environmental impact statement is not necessary, and DOE is issuing this Finding of No Significant Impact (FONSI).

  20. A Study of the Institutional Factors Influencing the External Impacts of Student Assessment Information. AIR 2000 Annual Forum Paper.

    ERIC Educational Resources Information Center

    Peterson, Marvin W.; Vaughan, Derek S.

    This study examined the external impacts and monitoring patterns of student assessment information on institutions, based on institutional type and control in seven areas: student applications or acceptance rates, allocation or share of state funding, evaluations from regional accrediting agency, private fund-raising results, success on grant…

  1. Information Technology (IT) Strategic Alignment: A Correlational Study between the Impact of IT Governance Structures and IT Strategic Alignment

    ERIC Educational Resources Information Center

    Asante, Keith K.

    2010-01-01

    This dissertation explored the extent to which Information Technology (IT) strategic alignment are impacted by IT governance structures. The study discusses several strategic alignment and IT governance literature that presents a gap in the literature domain. Subsequent studies researched issues surrounding why organizations are not able to align…

  2. The Impact of Teachers' Age, Gender and Experience on the Use of Information and Communication Technology in EFL Teaching

    ERIC Educational Resources Information Center

    Mahdi, Hassan Saleh; Al-Dera, Abdullah Sa'ad

    2013-01-01

    The integration of information and communication technology (ICT) into language teaching and learning depends on many factors. Some of these factors are associated with teachers. Teachers play a crucial role in the integration of ICT. This study investigates the impact of teacher's age, experience, and gender on the integration of ICT into…

  3. 33 CFR Appendix C to Part 273 - Information Requirements for Aquatic Plant Control Program Environmental Impact Statements

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Aquatic Plant Control Program Environmental Impact Statements C Appendix C to Part 273 Navigation and.... 273, App. C Appendix C to Part 273—Information Requirements for Aquatic Plant Control Program... specifically as possible. c. Severity of infestation. Discuss the degree and importance of the pest problem....

  4. 33 CFR Appendix C to Part 273 - Information Requirements for Aquatic Plant Control Program Environmental Impact Statements

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Aquatic Plant Control Program Environmental Impact Statements C Appendix C to Part 273 Navigation and.... 273, App. C Appendix C to Part 273—Information Requirements for Aquatic Plant Control Program... specifically as possible. c. Severity of infestation. Discuss the degree and importance of the pest problem....

  5. The Impact of Learner Characteristics on Information Utilization Strategies, Cognitive Load Experienced, and Performance in Hypermedia Learning

    ERIC Educational Resources Information Center

    Scheiter, Katharina; Gerjets, Peter; Vollmann, Brigitte; Catrambone, Richard

    2009-01-01

    Against the background of an adaptation of Cognitive Load Theory to learner-controlled settings we investigated the impact of learner characteristics on information utilization strategies, cognitive load, and learning outcomes in a hypermedia environment. Based on the data of 79 students, five clusters of students were identified according to…

  6. Digital Avionics Information System (DAIS): Impact of DAIS Concept on Life Cycle Cost--Supplement. Final Report.

    ERIC Educational Resources Information Center

    Goclowski, John C.; And Others

    This supplement to a technical report providing the results of a preliminary investigation of the potential impact of the Digital Avionics Information System (DAIS) concept on system support personnel requirements and life cycle cost (LCC) includes: (1) additional details of the cost comparison of a hypothetical application of a conceptual…

  7. Museums, Zoos, and Gardens: How Formal-Informal Partnerships Can Impact Urban Students' Performance. Working Paper #04-13

    ERIC Educational Resources Information Center

    Weinstein, Meryle; Whitesell, Emilyn Ruble; Schwartz, Amy Ellen

    2013-01-01

    In this paper we provide the first rigorous evidence of the impact of a partnership between public middle schools and informal science institutions (ISIs), such as museums and zoos, on student outcomes. This study focuses on Urban Advantage (UA), a program in New York City (NYC) that explicitly draws upon the expertise and resources of the city's…

  8. 25 CFR 292.18 - What information must an application contain on detrimental impacts to the surrounding community?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... community; (d) Anticipated costs of impacts to the surrounding community and identification of sources of revenue to mitigate them; (e) Anticipated cost, if any, to the surrounding community of treatment programs... cultural connection to the land; and (g) Any other information that may provide a basis for a...

  9. The Impact of Emerging Technologies on Reference Service and Bibliographic Instruction. Contributions in Librarianship and Information Science, Number 87.

    ERIC Educational Resources Information Center

    Pitkin, Gary M., Ed.

    Librarians need to be aware of the technologies involved with change and the ways in which technologies will impact the total organization and its provision of services. The library school curriculum must be restructured in order to prepare future librarians for the reality of technological change and help them become able to manage information in…

  10. Can Cross-Listing Mitigate the Impact of an Information Security Breach Announcement on a Firm's Values?

    NASA Astrophysics Data System (ADS)

    Chen, Yong; Dong, Feng; Chen, Hong; Xu, Li

    2016-08-01

    The increase in globalization in the markets has driven firms to adopt online technologies and to cross-list their stocks. Recent studies have consistently found that the announcements of information security breaches (ISBs) are negatively associated with the market values of the announcing firms during the days surrounding the breach announcements. Given the improvement in firms’ information environments and the better protection for investors generated by cross-listing, does cross-listing help firms to reduce the negative impacts caused by their announcements of ISBs? This paper conducts an event study of 120 publicly traded firms (among which 25 cross-list and 95 do not), in order to explore the answer. The results indicate that the impact of ISB announcements on a firm's stock prices shows no difference between cross-listing firms and non-cross-listing firms. Cross-listing does not mitigate the impact of ISBs announcement on a firm's market value.

  11. Rethinking the role and impact of health information technology: informatics as an interventional discipline.

    PubMed

    Payne, Philip R O; Lussier, Yves; Foraker, Randi E; Embi, Peter J

    2016-01-01

    Recent advances in the adoption and use of health information technology (HIT) have had a dramatic impact on the practice of medicine. In many environments, this has led to the ability to achieve new efficiencies and levels of safety. In others, the impact has been less positive, and is associated with both: 1) workflow and user experience dissatisfaction; and 2) perceptions of missed opportunities relative to the use of computational tools to enable data-driven and precise clinical decision making. Simultaneously, the "pipeline" through which new diagnostic tools and therapeutic agents are being developed and brought to the point-of-care or population health is challenged in terms of both cost and timeliness. Given the confluence of these trends, it can be argued that now is the time to consider new ways in which HIT can be used to deliver health and wellness interventions comparable to traditional approaches (e.g., drugs, devices, diagnostics, and behavioral modifications). Doing so could serve to fulfill the promise of what has been recently promoted as "precision medicine" in a rapid and cost-effective manner. However, it will also require the health and life sciences community to embrace new modes of using HIT, wherein the use of technology becomes a primary intervention as opposed to enabler of more conventional approaches, a model that we refer to in this commentary as "interventional informatics". Such a paradigm requires attention to critical issues, including: 1) the nature of the relationships between HIT vendors and healthcare innovators; 2) the formation and function of multidisciplinary teams consisting of technologists, informaticians, and clinical or scientific subject matter experts; and 3) the optimal design and execution of clinical studies that focus on HIT as the intervention of interest. Ultimately, the goal of an "interventional informatics" approach can and should be to substantially improve human health and wellness through the use of data

  12. Rethinking the role and impact of health information technology: informatics as an interventional discipline.

    PubMed

    Payne, Philip R O; Lussier, Yves; Foraker, Randi E; Embi, Peter J

    2016-03-29

    Recent advances in the adoption and use of health information technology (HIT) have had a dramatic impact on the practice of medicine. In many environments, this has led to the ability to achieve new efficiencies and levels of safety. In others, the impact has been less positive, and is associated with both: 1) workflow and user experience dissatisfaction; and 2) perceptions of missed opportunities relative to the use of computational tools to enable data-driven and precise clinical decision making. Simultaneously, the "pipeline" through which new diagnostic tools and therapeutic agents are being developed and brought to the point-of-care or population health is challenged in terms of both cost and timeliness. Given the confluence of these trends, it can be argued that now is the time to consider new ways in which HIT can be used to deliver health and wellness interventions comparable to traditional approaches (e.g., drugs, devices, diagnostics, and behavioral modifications). Doing so could serve to fulfill the promise of what has been recently promoted as "precision medicine" in a rapid and cost-effective manner. However, it will also require the health and life sciences community to embrace new modes of using HIT, wherein the use of technology becomes a primary intervention as opposed to enabler of more conventional approaches, a model that we refer to in this commentary as "interventional informatics". Such a paradigm requires attention to critical issues, including: 1) the nature of the relationships between HIT vendors and healthcare innovators; 2) the formation and function of multidisciplinary teams consisting of technologists, informaticians, and clinical or scientific subject matter experts; and 3) the optimal design and execution of clinical studies that focus on HIT as the intervention of interest. Ultimately, the goal of an "interventional informatics" approach can and should be to substantially improve human health and wellness through the use of data

  13. A Quantitative Study into the Information Technology Project Portfolio Practice: The Impact on Information Technology Project Deliverables

    ERIC Educational Resources Information Center

    Yu, Wei

    2013-01-01

    This dissertation applied the quantitative approach to the data gathered from online survey questionnaires regarding the three objects: Information Technology (IT) Portfolio Management, IT-Business Alignment, and IT Project Deliverables. By studying this data, this dissertation uncovered the underlying relationships that exist between the…

  14. Sarbanes-Oxley Act and Acquisition Trends: Information Technology Managers' Perceptions of the Impact on Information Technology Outsourcing

    ERIC Educational Resources Information Center

    Bui-Le, Linda Thanhthuy

    2010-01-01

    This research study provides a platform for extending the body of knowledge associated with the sourcing of Information Technology (IT) in the legal environment determined by the Sarbanes-Oxley Act. This analysis of IT sourcing was conducted via consideration of legal and situational factors which may influence an IT manager's decision to…

  15. Differences in the impacts of formal and informal recreational trails on urban forest loss and tree structure.

    PubMed

    Ballantyne, Mark; Pickering, Catherine Marina

    2015-08-15

    Recreational trails are one of the most common types of infrastructure used for nature-based activities such as hiking and mountain biking worldwide. Depending on their design, location, construction, maintenance and use, these trails differ in their environmental impacts. There are few studies, however, comparing the impacts of different trail types including between formal management-created trails and informal visitor-created trails. Although both types of trails can be found in remote natural areas, dense networks of them often occur in forests close to cities where they experience intense visitor use. To assess the relative impacts of different recreational trails in urban forests, we compared the condition of the trail surface, loss of forest strata and changes in tree structure caused by seven types of trails (total network 46.1 km) traversing 17 remnants of an endangered urban forest in Australia. After mapping and classifying all trails, we assessed their impact on the forest condition at 125 sites (15 sites per trail type, plus 15 control sites within undisturbed forest). On the trail sites, the condition of the trail surface, distance from the trail edge to four forest strata (litter, understory, midstorey and tree cover) and structure of the tree-line were assessed. Informal trails generally had poorer surface conditions and were poorly-designed and located. Per site, formal and informal trails resulted in similar loss of forest strata, with wider trails resulting in greater loss of forest. Because there were more informal trails, however, they accounted for the greatest cumulative forest loss. Structural impacts varied, with the widest informal trails and all formal hardened trails resulting in similar reductions in canopy cover and tree density but an increase in saplings. These structural impacts are likely a function of the unregulated and intense use of large informal trails, and disturbance from the construction and maintenance of formal trails

  16. Differences in the impacts of formal and informal recreational trails on urban forest loss and tree structure.

    PubMed

    Ballantyne, Mark; Pickering, Catherine Marina

    2015-08-15

    Recreational trails are one of the most common types of infrastructure used for nature-based activities such as hiking and mountain biking worldwide. Depending on their design, location, construction, maintenance and use, these trails differ in their environmental impacts. There are few studies, however, comparing the impacts of different trail types including between formal management-created trails and informal visitor-created trails. Although both types of trails can be found in remote natural areas, dense networks of them often occur in forests close to cities where they experience intense visitor use. To assess the relative impacts of different recreational trails in urban forests, we compared the condition of the trail surface, loss of forest strata and changes in tree structure caused by seven types of trails (total network 46.1 km) traversing 17 remnants of an endangered urban forest in Australia. After mapping and classifying all trails, we assessed their impact on the forest condition at 125 sites (15 sites per trail type, plus 15 control sites within undisturbed forest). On the trail sites, the condition of the trail surface, distance from the trail edge to four forest strata (litter, understory, midstorey and tree cover) and structure of the tree-line were assessed. Informal trails generally had poorer surface conditions and were poorly-designed and located. Per site, formal and informal trails resulted in similar loss of forest strata, with wider trails resulting in greater loss of forest. Because there were more informal trails, however, they accounted for the greatest cumulative forest loss. Structural impacts varied, with the widest informal trails and all formal hardened trails resulting in similar reductions in canopy cover and tree density but an increase in saplings. These structural impacts are likely a function of the unregulated and intense use of large informal trails, and disturbance from the construction and maintenance of formal trails

  17. Reconstructing missing information on precipitation datasets: impact of tails on adopted statistical distributions.

    NASA Astrophysics Data System (ADS)

    Pedretti, Daniele; Beckie, Roger Daniel

    2014-05-01

    Missing data in hydrological time-series databases are ubiquitous in practical applications, yet it is of fundamental importance to make educated decisions in problems involving exhaustive time-series knowledge. This includes precipitation datasets, since recording or human failures can produce gaps in these time series. For some applications, directly involving the ratio between precipitation and some other quantity, lack of complete information can result in poor understanding of basic physical and chemical dynamics involving precipitated water. For instance, the ratio between precipitation (recharge) and outflow rates at a discharge point of an aquifer (e.g. rivers, pumping wells, lysimeters) can be used to obtain aquifer parameters and thus to constrain model-based predictions. We tested a suite of methodologies to reconstruct missing information in rainfall datasets. The goal was to obtain a suitable and versatile method to reduce the errors given by the lack of data in specific time windows. Our analyses included both a classical chronologically-pairing approach between rainfall stations and a probability-based approached, which accounted for the probability of exceedence of rain depths measured at two or multiple stations. Our analyses proved that it is not clear a priori which method delivers the best methodology. Rather, this selection should be based considering the specific statistical properties of the rainfall dataset. In this presentation, our emphasis is to discuss the effects of a few typical parametric distributions used to model the behavior of rainfall. Specifically, we analyzed the role of distributional "tails", which have an important control on the occurrence of extreme rainfall events. The latter strongly affect several hydrological applications, including recharge-discharge relationships. The heavy-tailed distributions we considered were parametric Log-Normal, Generalized Pareto, Generalized Extreme and Gamma distributions. The methods were

  18. DIFFUSION PUMP

    DOEpatents

    Levenson, L.

    1963-09-01

    A high-vacuum diffusion pump is described, featuring a novel housing geometry for enhancing pumping speed. An upright, cylindrical lower housing portion is surmounted by a concentric, upright, cylindrical upper housing portion of substantially larger diameter; an uppermost nozzle, disposed concentrically within the upper portion, is adapted to eject downwardly a conical sheet of liquid outwardly to impinge upon the uppermost extremity of the interior wall of the lower portion. Preferably this nozzle is mounted upon a pedestal rising coaxially from within the lower portion and projecting up into said upper portion. (AEC)

  19. The Impact of Cognitive Training on Cerebral White Matter in Community-Dwelling Elderly: One-Year Prospective Longitudinal Diffusion Tensor Imaging Study

    PubMed Central

    Cao, Xinyi; Yao, Ye; Li, Ting; Cheng, Yan; Feng, Wei; Shen, Yuan; Li, Qingwei; Jiang, Lijuan; Wu, Wenyuan; Wang, Jijun; Sheng, Jianhua; Feng, Jianfeng; Li, Chunbo

    2016-01-01

    It has been shown that cognitive training (CogTr) is effective and recuperative for older adults, and can be used to fight against cognitive decline. In this study, we investigated whether behavioural gains from CogTr would extend to white matter (WM) microstructure, and whether training-induced changes in WM integrity would be associated with improvements in cognitive function, using diffusion tensor imaging (DTI). 48 healthy community elderly were either assigned to multi-domain or single-domain CogTr groups to receive 24 sessions over 12 weeks, or to a control group. DTI was performed at both baseline and 12-month follow-up. Positive effects of multi-domain CogTr on long-term changes in DTI indices were found in posterior parietal WM. Participants in the multi-domain group showed a trend of long-term decrease in axial diffusivity (AD) without significant change in fractional anisotropy (FA), mean diffusivity (MD) or radial diffusivity (RD), while those in the control group displayed a significant FA decrease, and an increase in MD and RD. In addition, significant relationships between an improvement in processing speed and changes in RD, MD and AD were found in the multi-domain group. These findings support the hypothesis that plasticity of WM can be modified by CogTr, even in late adulthood. PMID:27628682

  20. The Impact of Cognitive Training on Cerebral White Matter in Community-Dwelling Elderly: One-Year Prospective Longitudinal Diffusion Tensor Imaging Study.

    PubMed

    Cao, Xinyi; Yao, Ye; Li, Ting; Cheng, Yan; Feng, Wei; Shen, Yuan; Li, Qingwei; Jiang, Lijuan; Wu, Wenyuan; Wang, Jijun; Sheng, Jianhua; Feng, Jianfeng; Li, Chunbo

    2016-01-01

    It has been shown that cognitive training (CogTr) is effective and recuperative for older adults, and can be used to fight against cognitive decline. In this study, we investigated whether behavioural gains from CogTr would extend to white matter (WM) microstructure, and whether training-induced changes in WM integrity would be associated with improvements in cognitive function, using diffusion tensor imaging (DTI). 48 healthy community elderly were either assigned to multi-domain or single-domain CogTr groups to receive 24 sessions over 12 weeks, or to a control group. DTI was performed at both baseline and 12-month follow-up. Positive effects of multi-domain CogTr on long-term changes in DTI indices were found in posterior parietal WM. Participants in the multi-domain group showed a trend of long-term decrease in axial diffusivity (AD) without significant change in fractional anisotropy (FA), mean diffusivity (MD) or radial diffusivity (RD), while those in the control group displayed a significant FA decrease, and an increase in MD and RD. In addition, significant relationships between an improvement in processing speed and changes in RD, MD and AD were found in the multi-domain group. These findings support the hypothesis that plasticity of WM can be modified by CogTr, even in late adulthood. PMID:27628682

  1. A Cross-Case Study of the Impact of Organizational Change through the Diffusion of the Classrooms for the Future Initiative

    ERIC Educational Resources Information Center

    Slamecka, Brian Jeffrey

    2011-01-01

    In 2006, Governor Edward Rendell announced a three-year, $200 million Classrooms for the Future program to provide technology and technology support to schools across the Commonwealth of Pennsylvania, beginning in the 2006-2007 school year. The purpose of this research study is to examine the change process of the diffusion of technology within…

  2. Supplemental Information For: Asymmetric Distribution of Lunar Impact Basins Caused by Variations in Target Properties

    NASA Technical Reports Server (NTRS)

    Miljkovic, Katarina; Wieczorek, Mark; Collins, Gareth S.; Laneuville, Matthieu; Neumann, Gregory A.; Melosh, H. Jay; Solomon, Sean C.; Phillips, Roger J.; Smith, David E.; Zuber, Maria T.

    2014-01-01

    Maps of crustal thickness derived from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission revealed more large impact basins on the nearside hemisphere of the Moon than on its farside. The enrichment in heat-producing elements and prolonged volcanic activity on the lunar nearside hemisphere indicate that the temperature of the nearside crust and uppermantle was hotter than that of the farside at the time of basin formation. Using the iSALE-2D hydrocode to model impact basin formation, we found that impacts on the hotter nearside would have formed basins up to two times larger than similar impacts on the cooler farside hemisphere. The size distribution of lunar impact basins is thus not representative of the earliest inner Solar system impact bombardment

  3. Protected Areas' Impacts on Brazilian Amazon Deforestation: Examining Conservation-Development Interactions to Inform Planning.

    PubMed

    Pfaff, Alexander; Robalino, Juan; Herrera, Diego; Sandoval, Catalina

    2015-01-01

    Protected areas are the leading forest conservation policy for species and ecoservices goals and they may feature in climate policy if countries with tropical forest rely on familiar tools. For Brazil's Legal Amazon, we estimate the average impact of protection upon deforestation and show how protected areas' forest impacts vary significantly with development pressure. We use matching, i.e., comparisons that are apples-to-apples in observed land characteristics, to address the fact that protected areas (PAs) tend to be located on lands facing less pressure. Correcting for that location bias lowers our estimates of PAs' forest impacts by roughly half. Further, it reveals significant variation in PA impacts along development-related dimensions: for example, the PAs that are closer to roads and the PAs closer to cities have higher impact. Planners have multiple conservation and development goals, and are constrained by cost, yet still conservation planning should reflect what our results imply about future impacts of PAs.

  4. Protected Areas’ Impacts on Brazilian Amazon Deforestation: Examining Conservation – Development Interactions to Inform Planning

    PubMed Central

    Pfaff, Alexander; Robalino, Juan; Herrera, Diego; Sandoval, Catalina

    2015-01-01

    Protected areas are the leading forest conservation policy for species and ecoservices goals and they may feature in climate policy if countries with tropical forest rely on familiar tools. For Brazil's Legal Amazon, we estimate the average impact of protection upon deforestation and show how protected areas’ forest impacts vary significantly with development pressure. We use matching, i.e., comparisons that are apples-to-apples in observed land characteristics, to address the fact that protected areas (PAs) tend to be located on lands facing less pressure. Correcting for that location bias lowers our estimates of PAs’ forest impacts by roughly half. Further, it reveals significant variation in PA impacts along development-related dimensions: for example, the PAs that are closer to roads and the PAs closer to cities have higher impact. Planners have multiple conservation and development goals, and are constrained by cost, yet still conservation planning should reflect what our results imply about future impacts of PAs. PMID:26225922

  5. 77 FR 46748 - Notice of Proposed Information Collection Requests; Institute of Education Sciences; Impact...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-06

    ... Teacher and Leader Evaluation Systems SUMMARY: This study provides important implementation and impact... of Teacher and Leader Evaluation Systems. OMB Control Number: 1850-0890. Type of Review:...

  6. Differential Impact of Relative Dose-Intensity Reductions in Diffuse Large B-Cell Lymphoma Treated with R-CHOP21 or R-CHOP14

    PubMed Central

    Bautista-Gili, Antonia Maria; Garcia, Francesc; Martinez-Serra, Jordi; Sanchez, Blanca; Martorell, Clara; Gines, Jordi; Garcia, Lucia; Gimeno, Eva; Ferraro, Mariana; Del Campo, Raquel; Bargay, Joan; Perez, Albert; Vercher, Javier; Scaff, Miguel; Pacheco, Ana; Ballester, Carmen; Garcia, Florencia; Ramos, Rafael; Salar, Antonio; Besalduch, Joan

    2015-01-01

    DLBCL is an aggressive lymphoma treated with R-CHOP. Recently, attempts have been made to improve the outcome by increasing both dose-density and intensity but there have been no benefits in terms of survival. When treating malignancies RDI is important to consider but there is little published information on DLBCL. The purpose of this study was to analyze the differential prognostic impact of RDI in two cohorts of DLBCL patients treated with R-CHOP21 or R-CHOP14. From January 2001 to August 2013 we included DLBCL patients homogenously treated with R-CHOP21 or R-CHOP14, with or without radiotherapy, at University Hospital Son Espases, Hospital Son Llatzer of Palma and Hospital del Mar of Barcelona (N = 157). In order to avoid selection bias the patients were retrospectively identified from the Pathology Department and Pharmacy registries. Median follow-up was 68 months. There was no difference in the response or survival between the two cohorts. In the R-CHOP21 group, both a reduction higher than 15% in RDI (RR 7.41) and R-IPI (RR 2.99) were independently associated with OS. However, a reduction higher than 15% in RDI (RR 4.41) was only noted for PFS. In the R-CHOP14 group, NCCN-IPI (RR 7.09) and B-symptoms (RR 5.37) for OS; AA stage III-IV (RR 6.26) and bulky disease (RR 4.05) for PFS. There was a trend towards a higher rate of RDI reduction observed in the R-CHOP14 group but it only made an impact in the R-CHOP21 group. We conclude that R-CHOP21 and R-CHOP14 are equivalent regimens in terms of response and survival, but only if RDI reductions are avoided. For patients receiving R-CHOP21 we recommend using clinical and support measures in order to avoid RDI reductions. PMID:25909361

  7. Information Needs of Cancer Patients and Perception of Impact of the Disease, of Self-Efficacy, and Locus of Control.

    PubMed

    Keinki, C; Seilacher, E; Ebel, M; Ruetters, D; Kessler, I; Stellamanns, J; Rudolph, I; Huebner, J

    2016-09-01

    The aim of our study was to investigate the relationship between information needs and cancer patients' perceptions of the impact of the disease, self-efficacy, and locus of control. Using a standardized questionnaire, we obtained data from patients who attended a series of lectures. The questionnaire included questions on their information needs, sources of information, satisfaction with information, and short questionnaires on self-efficacy, perception of the disease, and locus of control of reinforcement. Data was obtained from 185 patients. Our results showed that the sources of information that were most often used were physicians (84 %), print media (68 %), and the Internet (59 %); online fora (7.5 %), non-medical practitioners (9.7 %), and telephone-based counseling (8.6 %) were only used by a minority. Patients with a high perception of their own control over the disease more often used any source of information available to them and were more often interested in acquiring additional information. Higher self-efficacy was significantly associated with the need for information on all topics. Patients with a higher external locus of control significantly more often used sources of information and had significantly more need for additional information. By contrast, there were no associations with an internal locus of control. Neither external nor internal locus of control showed any associations with satisfaction with information. Information needs seem to be higher in patients with a high external locus of control and low self-efficacy. Physicians, other professionals, and institutions that provide information may take these relationships into consideration for tailoring their services to patients.

  8. Hydrogen diffusion in Zircon

    NASA Astrophysics Data System (ADS)

    Ingrin, Jannick; Zhang, Peipei

    2016-04-01

    Hydrogen mobility in gem quality zircon single crystals from Madagascar was investigated through H-D exchange experiments. Thin slices were annealed in a horizontal furnace flushed with a gas mixture of Ar/D2(10%) under ambient pressure between 900 ° C to 1150 ° C. FTIR analyses were performed on oriented slices before and after each annealing run. H diffusion along [100] and [010] follow the same diffusion law D = D0exp[-E /RT], with log D0 = 2.24 ± 1.57 (in m2/s) and E = 374 ± 39 kJ/mol. H diffusion along [001] follows a slightly more rapid diffusion law, with log D0 = 1.11 ± 0.22 (in m2/s) and E = 334 ± 49 kJ/mol. H diffusion in zircon has much higher activation energy and slower diffusivity than other NAMs below 1150 ° C even iron-poor garnets which are known to be among the slowest (Blanchard and Ingrin, 2004; Kurka et al. 2005). During H-D exchange zircon incorporates also deuterium. This hydration reaction involves uranium reduction as it is shown from the exchange of U5+ and U4+ characteristic bands in the near infrared region during annealing. It is the first time that a hydration reaction U5+ + OH‑ = U4+ + O2‑ + 1/2H2, is experimentally reported. The kinetics of deuterium incorporation is slightly slower than hydrogen diffusion, suggesting that the reaction is limited by hydrogen mobility. Hydrogen isotopic memory of zircon is higher than other NAMs. Zircons will be moderately retentive of H signatures at mid-crustal metamorphic temperatures. At 500 ° C, a zircon with a radius of 300 μm would retain its H isotopic signature over more than a million years. However, a zircon is unable to retain this information for geologically significant times under high-grade metamorphism unless the grain size is large enough. Refrences Blanchard, M. and Ingrin, J. (2004) Hydrogen diffusion in Dora Maira pyrope. Physics and Chemistry of Minerals, 31, 593-605. Kurka, A., Blanchard, M. and Ingrin, J. (2005) Kinetics of hydrogen extraction and deuteration in

  9. Hydrogen diffusion in Zircon

    NASA Astrophysics Data System (ADS)

    Ingrin, Jannick; Zhang, Peipei

    2016-04-01

    Hydrogen mobility in gem quality zircon single crystals from Madagascar was investigated through H-D exchange experiments. Thin slices were annealed in a horizontal furnace flushed with a gas mixture of Ar/D2(10%) under ambient pressure between 900 ° C to 1150 ° C. FTIR analyses were performed on oriented slices before and after each annealing run. H diffusion along [100] and [010] follow the same diffusion law D = D0exp[-E /RT], with log D0 = 2.24 ± 1.57 (in m2/s) and E = 374 ± 39 kJ/mol. H diffusion along [001] follows a slightly more rapid diffusion law, with log D0 = 1.11 ± 0.22 (in m2/s) and E = 334 ± 49 kJ/mol. H diffusion in zircon has much higher activation energy and slower diffusivity than other NAMs below 1150 ° C even iron-poor garnets which are known to be among the slowest (Blanchard and Ingrin, 2004; Kurka et al. 2005). During H-D exchange zircon incorporates also deuterium. This hydration reaction involves uranium reduction as it is shown from the exchange of U5+ and U4+ characteristic bands in the near infrared region during annealing. It is the first time that a hydration reaction U5+ + OH- = U4+ + O2- + 1/2H2, is experimentally reported. The kinetics of deuterium incorporation is slightly slower than hydrogen diffusion, suggesting that the reaction is limited by hydrogen mobility. Hydrogen isotopic memory of zircon is higher than other NAMs. Zircons will be moderately retentive of H signatures at mid-crustal metamorphic temperatures. At 500 ° C, a zircon with a radius of 300 μm would retain its H isotopic signature over more than a million years. However, a zircon is unable to retain this information for geologically significant times under high-grade metamorphism unless the grain size is large enough. Refrences Blanchard, M. and Ingrin, J. (2004) Hydrogen diffusion in Dora Maira pyrope. Physics and Chemistry of Minerals, 31, 593-605. Kurka, A., Blanchard, M. and Ingrin, J. (2005) Kinetics of hydrogen extraction and deuteration in

  10. Combining Land Use Information and Small Stream Sampling with PCR-Based Methods for Better Characterization of Diffuse Sources of Human Fecal Pollution

    EPA Science Inventory

    Diffuse sources of human fecal pollution allow for the direct discharge of waste into receiving waters with minimal or no treatment. Traditional culture-based methods are commonly used to characterize fecal pollution in ambient waters, however these methods do not discern between...

  11. Frequency and impact of informant replacement in Alzheimer’s disease research

    PubMed Central

    Grill, Joshua D.; Zhou, Yan; Karlawish, Jason; Elashoff, David

    2014-01-01

    Informants serve an essential role in Alzheimer’s disease (AD) research. Were an informant to be replaced during a longitudinal study, this could have negative implications. We used data from the National Alzheimer’s Coordinating Center Uniform Data Set to examine the frequency of informant replacement among AD dementia participants, whether patient and informant characteristics were associated with replacement, and how replacement affected research outcome measures. Informant replacement was common (15.5%) and typically occurred after the first or the second research visit. Adult child (24%) and other (38%) informants were more frequently replaced than spouse informants (10%). Older spouse informant age and younger adult child informant age were associated with replacement. The between-visit change in Functional Assessment Questionnaire (FAQ) scores was greater in patients who replaced informants than in those with stable informants. Clinical Dementia Rating-Sum of Boxes, FAQ, and Neuropsychiatric Inventory scores showed greater variability in between-visit change in patients who replaced informants compared to those with stable informants. These findings suggest that informant replacement is relatively common, may have implications to study analyses, and warrant further examination in the setting of clinical trials. PMID:25551863

  12. NASA/DOD Aerospace Knowledge Diffusion Research Project. Report number 20: The use of selected information products and services by US aerospace engineers and scientists: Results of two surveys

    NASA Technical Reports Server (NTRS)

    Pinelli, Thomas E.; Barclay, Rebecca O.; Kennedy, John M.

    1994-01-01

    The U.S. government technical report is a primary means by which the results of federally funded research and development (R&D) are transferred to the U.S. aerospace industry. However, little is known about this information product in terms of its actual use, importance, and value in the transfer of federally, funded R&D. To help establish a body of knowledge, the U.S. government technical report is being investigated as part of the NASA/DoD Aerospace Knowledge Diffusion Research Project. In this report, we summarize the literature on technical reports and provide a model that depicts the transfer of federally funded aerospace R&D via the U.S. government technical report. We present results from two surveys of our investigation of aerospace knowledge diffusion vis-a-vis the U.S. government technical report and close with a brief overview of on-going research into aerospace knowledge diffusion focusing on the role of the industry-affiliated information intermediary.

  13. The impact of information on medical thinking and health care policy.

    PubMed

    Shani, M

    2000-09-01

    The information revolution has, till now, concentrated on the collection, storage, transfer, and analysis of data, with emphasis on the technology and not on the information itself. Information in health care is conductive to two major changes. One aspect is the conversion of clinical medicine from an art, based on clinical intuition to a more scientific profession based on clinical guidelines and evidence based medicine. The second aspect relates to health care policy based on better information.

  14. The impact of prior knowledge from participant instructions in a mock crime P300 Concealed Information Test.

    PubMed

    Winograd, Michael R; Rosenfeld, J Peter

    2014-12-01

    In P300-Concealed Information Tests used with mock crime scenarios, the amount of detail revealed to a participant prior to the commission of the mock crime can have a serious impact on a study's validity. We predicted that exposure to crime details through instructions would bias detection rates toward enhanced sensitivity. In a 2 × 2 factorial design, participants were either informed (through mock crime instructions) or naïve as to the identity of a to-be-stolen item, and then either committed (guilty) or did not commit (innocent) the crime. Results showed that prior knowledge of the stolen item was sufficient to cause 69% of innocent-informed participants to be incorrectly classified as guilty. Further, we found a trend toward enhanced detection rate for guilty-informed participants over guilty-naïve participants. Results suggest that revealing details to participants through instructions biases detection rates in the P300-CIT toward enhanced sensitivity.

  15. The impact of prior knowledge from participant instructions in a mock crime P300 Concealed Information Test.

    PubMed

    Winograd, Michael R; Rosenfeld, J Peter

    2014-12-01

    In P300-Concealed Information Tests used with mock crime scenarios, the amount of detail revealed to a participant prior to the commission of the mock crime can have a serious impact on a study's validity. We predicted that exposure to crime details through instructions would bias detection rates toward enhanced sensitivity. In a 2 × 2 factorial design, participants were either informed (through mock crime instructions) or naïve as to the identity of a to-be-stolen item, and then either committed (guilty) or did not commit (innocent) the crime. Results showed that prior knowledge of the stolen item was sufficient to cause 69% of innocent-informed participants to be incorrectly classified as guilty. Further, we found a trend toward enhanced detection rate for guilty-informed participants over guilty-naïve participants. Results suggest that revealing details to participants through instructions biases detection rates in the P300-CIT toward enhanced sensitivity. PMID:25128283

  16. On the ECCD current density profile with particle diffusion in eITBs and its impact on the q-profile

    SciTech Connect

    Asp, E.; Sauter, O.; Coda, S.; Fable, E.; Goodman, T. P.; Turri, G.; Udintsev, V. S.; Zucca, C.

    2006-11-30

    The Fokker-Planck code CQL3D has been used to investigate the effect of radial particle diffusion on ECCD current density profiles in the TCV tokamak. For two discharges with electron internal transport barriers (eITB), the jcd and the resulting q-profile have been calculated and reconstructed. The studied eITBs are of two kinds: fully sustained non-inductive eITB with off-axis co-current ECCD, or with a large Ohmic current and on-axis counter ECCD. It is shown that different diffusion profiles do modify the ECCD current density profiles, but that the resulting q-profiles are less influenced due to the resulting necessary self-consistent inductive current contribution.

  17. The Impact of National Culture on Informal Learning in the Workplace

    ERIC Educational Resources Information Center

    Kim, Sehoon; McLean, Gary N.

    2014-01-01

    The purpose of this article was to identify how differing cultural factors affect informal learning in the workplace. We have introduced concepts and reviewed studies on informal learning and national culture based on an extensive literature review on the factors influencing informal learning, particularly based on five Hofstede's dimensions…

  18. Greek Academic Librarians' Perceptions of the Impact of Google on Their Role as Information Providers

    ERIC Educational Resources Information Center

    Garoufallou, Emmanouel; Balatsoukas, Panos; Siatri, Rania; Zafeiriou, Georgia; Asderi, S.; Ekizoglou; P.

    2008-01-01

    The increased popularity of Google search engine in the daily routine in one's workplace and in the academic information seeking process is undeniable. "Googling" challenges the traditional skills of librarians as information providers and the role of library and information service provision in the digital era. This paper reports on the…

  19. The Impact of Causality on Information-Theoretic Source and Channel Coding Problems

    ERIC Educational Resources Information Center

    Palaiyanur, Harikrishna R.

    2011-01-01

    This thesis studies several problems in information theory where the notion of causality comes into play. Causality in information theory refers to the timing of when information is available to parties in a coding system. The first part of the thesis studies the error exponent (or reliability function) for several communication problems over…

  20. Information retrieval system: impacts of water-level changes on uses of federal storage reservoirs of the Columbia River.

    SciTech Connect

    Fickeisen, D.H.; Cowley, P.J.; Neitzel, D.A.; Simmons, M.A.

    1982-09-01

    A project undertaken to provide the Bonneville Power Administration (BPA) with information needed to conduct environmental assessments and meet requirements of the National Environmental Policy Act (NEPA) and the Pacific Northwest Electric Power Planning and Conservation Act (Regional Act) is described. Access to information on environmental effects would help BPA fulfill its responsibilities to coordinate power generation on the Columbia River system, protect uses of the river system (e.g., irrigation, recreation, navigation), and enhance fish and wildlife production. Staff members at BPA identified the need to compile and index information resources that would help answer environmental impact questions. A computer retrieval system that would provide ready access to the information was envisioned. This project was supported by BPA to provide an initial step toward a compilation of environmental impact information. Scientists at Pacific Northwest Laboratory (PNL) identified, gathered, and evaluated information related to environmental effects of water level on uses of five study reservoirs and developed and implemented and environmental data retrieval system, which provides for automated storage and retrieval of annotated citations to published and unpublished information. The data retrieval system is operating on BPA's computer facility and includes the reservoir water-level environmental data. This project was divided into several tasks, some of which were conducted simultaneously to meet project deadlines. The tasks were to identify uses of the five study reservoirs, compile and evaluate reservoir information, develop a data entry and retrieval system, identify and analyze research needs, and document the data retrieval system and train users. Additional details of the project are described in several appendixes.