Science.gov

Sample records for converging media environments

  1. Sweet! Generation "D" Takes on Media Convergence.

    ERIC Educational Resources Information Center

    Tarpenning, David; Schaub, Laura

    2002-01-01

    Notes that professional journalists continually emphasize the need for developing skills for all delivery systems. Proposes that students interested in journalism should learn about technology and develop projects without the guidance of a teacher or advisor. Describes students' experience with media convergence in a summer journalism workshop.…

  2. Uniform Convergence to Equilibrium for Granular Media

    NASA Astrophysics Data System (ADS)

    Bolley, François; Gentil, Ivan; Guillin, Arnaud

    2013-05-01

    We study the long time asymptotics of a nonlinear, nonlocal equation used in the modelling of granular media. We prove a uniform exponential convergence to equilibrium for degenerately convex and nonconvex interaction or confinement potentials, improving in particular results by J. A. Carrillo, R. J. McCann and C. Villani. The method is based on studying the dissipation of the Wasserstein distance between a solution and the steady state.

  3. Mass Media: The Invisible Environment.

    ERIC Educational Resources Information Center

    Glessing, Robert J.; White, William P.

    This anthology for students of media consists of essays and articles grouped under four topics: media forms, media content, media environments, and "the last word." Media forms deals with the nature of these kinds of media: electronic, print, film, music, and comics, graffiti, and clothing. Media content contains articles on the news, advertising,…

  4. Mass Media: The Invisible Environment.

    ERIC Educational Resources Information Center

    Glessing, Robert J.; White, William P.

    This anthology for students of media consists of essays and articles grouped under four topics: media forms, media content, media environments, and "the last word." Media forms deals with the nature of these kinds of media: electronic, print, film, music, and comics, graffiti, and clothing. Media content contains articles on the news, advertising,…

  5. Photoacoustic-guided convergence of light through optically diffusive media.

    PubMed

    Kong, Fanting; Silverman, Ronald H; Liu, Liping; Chitnis, Parag V; Lee, Kotik K; Chen, Y C

    2011-06-01

    We demonstrate that laser beams can be converged toward a light-absorbing target through optically diffusive media by using photoacoustic-guided interferometric focusing. The convergence of light is achieved by shaping the wavefront of the incident light with a deformable mirror to maximize the photoacoustic signal, which is proportional to the scattered light intensity at the light absorber.

  6. Photoacoustic-guided convergence of light through optically diffusive media

    PubMed Central

    Kong, Fanting; Silverman, Ronald H.; Liu, Liping; Chitnis, Parag V.; Lee, Kotik K.; Chen, Y. C.

    2012-01-01

    We demonstrate that laser beams can be converged toward a light-absorbing target through optically diffusive media by using photoacoustic-guided interferometric focusing. The convergence of light is achieved by shaping the wavefront of the incident light with a deformable mirror to maximize the photoacoustic signal, which is propor tional to the scattered light intensity at the light absorber. PMID:21633446

  7. Implication for Media Convergence on News Learning

    ERIC Educational Resources Information Center

    Gumus, Agah; Ozad, Bahire

    2011-01-01

    Over the last decade, comparisons of the effects of the traditional news media and the Internet have been made in relation to comprehension and remembering. This study aims at assessing the effects of single and compound presentational elements, and making predictions for the future. One of the two main aims of this study is to measure…

  8. Convergence.

    ERIC Educational Resources Information Center

    Hancock, Alan

    1984-01-01

    Characterizes the development over the past 30 years of the communication technologies employed in education by examining technological developments, structure of individual media, objectives and audiences of media systems, access to communications technologies, appropriateness of technology in new environments, social impact, and policy…

  9. Convergence.

    ERIC Educational Resources Information Center

    Hancock, Alan

    1984-01-01

    Characterizes the development over the past 30 years of the communication technologies employed in education by examining technological developments, structure of individual media, objectives and audiences of media systems, access to communications technologies, appropriateness of technology in new environments, social impact, and policy…

  10. Converged Social Media: Identity Management and Engagement on Facebook Mobile and Blogs

    ERIC Educational Resources Information Center

    Rambe, Patient

    2013-01-01

    There is scant evidence to demonstrate that researchers grasp the social dimensions of convergence, and particularly, the academic and social implications of converged media on students' lives. Despite a surge in student appropriation of social media-enabled mobile phones for exchanging educational resources and social practices, little is known…

  11. Converged Social Media: Identity Management and Engagement on Facebook Mobile and Blogs

    ERIC Educational Resources Information Center

    Rambe, Patient

    2013-01-01

    There is scant evidence to demonstrate that researchers grasp the social dimensions of convergence, and particularly, the academic and social implications of converged media on students' lives. Despite a surge in student appropriation of social media-enabled mobile phones for exchanging educational resources and social practices, little is known…

  12. Convergence and Divergence in Basque, Irish and Sami Media Language Policing

    ERIC Educational Resources Information Center

    Kelly-Holmes, Helen; Moriarty, Mairead; Pietikainen, Sari

    2009-01-01

    The language policies adopted, imposed, or rejected in minority language media highlight the complexities of multilingualism and its regulation or ordering in contemporary contexts. In this article, we discuss convergence and divergence in the language policing of three minority language media contexts, namely Basque, Irish and Sami. All of the…

  13. Convergence and Divergence in Basque, Irish and Sami Media Language Policing

    ERIC Educational Resources Information Center

    Kelly-Holmes, Helen; Moriarty, Mairead; Pietikainen, Sari

    2009-01-01

    The language policies adopted, imposed, or rejected in minority language media highlight the complexities of multilingualism and its regulation or ordering in contemporary contexts. In this article, we discuss convergence and divergence in the language policing of three minority language media contexts, namely Basque, Irish and Sami. All of the…

  14. Wave propagation in turbulent media: use of convergence acceleration methods.

    PubMed

    Baram, A; Tsadka, S; Azar, Z; Tur, M

    1988-06-01

    We propose the use of convergence acceleration methods for the evaluation of integral expressions of an oscillatory nature, often encountered in the study of optical wave propagation in the turbulent atmosphere. These techniques offer substantial savings in computation time with appreciable gain in accuracy. As an example, we apply the Levin u acceleration scheme to the problem of remote sensing of transversal wind profiles.

  15. Convergence

    NASA Astrophysics Data System (ADS)

    Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

    2005-09-01

    Call for Papers: Convergence The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and

  16. Effect of Convergent and Divergent Boundaries on Flow Resistance through Porous Media

    NASA Astrophysics Data System (ADS)

    Bhanu Prakasham Reddy, N.; Krishnaiah, S.; Ramakrishna Reddy, M.

    2015-12-01

    An experimental investigation on the effect of convergent and divergent streamlines on the total energy loss in the porous medium and the effect on linear parameter, a, and non-linear parameter, b, for different ratios of radii of the test section was studied in a convergent and divergent permeameter. This paper presents the results of applying dimensional analysis to obtain a relationship between friction factor (fd) and Reynolds number (Rd) for flow in porous media with convergent and divergent boundaries, using pore size of the media (d) as characteristic length. Using friction factor (fd) and Reynolds number (Rd) relationship, theoretical curves, are developed and verified with the help of existing experimental data. In the present case, Mc Corquodale data of size 1.66 cm was used as media and water as fluid, to develop curves relating friction factor (fd) and Reynolds number (Rd) for different ratios of radii of the test section of convergent permeameter and divergent permeameter with the same convergent and divergent angle of 0.328 rad.

  17. When Education, Media, and Technology Converge, What Do Latino/a Students Gain?

    ERIC Educational Resources Information Center

    Tanno, Dolores Valencia

    2003-01-01

    Research suggests that Latino students' success in college is closely linked to the interpersonal relationships they experience with faculty and staff. However, the convergence of technology, media, and education promises less rather than more of these types of interactions. Relevant research is reviewed on the growth of technology-based…

  18. When Education, Media, and Technology Converge, What Do Latino/a Students Gain?

    ERIC Educational Resources Information Center

    Tanno, Dolores Valencia

    2003-01-01

    Research suggests that Latino students' success in college is closely linked to the interpersonal relationships they experience with faculty and staff. However, the convergence of technology, media, and education promises less rather than more of these types of interactions. Relevant research is reviewed on the growth of technology-based…

  19. Convergence

    NASA Astrophysics Data System (ADS)

    Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

    2004-12-01

    Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and data, video and data, private-line and virtual private-line, fixed and mobile, and local and long-haul services. These

  20. Convergence

    NASA Astrophysics Data System (ADS)

    Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

    2005-08-01

    Call for Papers: Convergence The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and

  1. Convergence

    NASA Astrophysics Data System (ADS)

    Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

    2005-04-01

    Call for Papers: Convergence The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and

  2. Convergence

    NASA Astrophysics Data System (ADS)

    Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

    2005-06-01

    Call for Papers: Convergence The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and

  3. Convergence

    NASA Astrophysics Data System (ADS)

    Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

    2005-05-01

    Call for Papers: Convergence The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and

  4. Convergence

    NASA Astrophysics Data System (ADS)

    Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

    2005-02-01

    Call for Papers: Convergence Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and data, video and data, private-line and virtual private-line, fixed and mobile, and local and

  5. Convergence

    NASA Astrophysics Data System (ADS)

    Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

    2005-03-01

    Call for Papers: Convergence Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly within an evolved but backward-compatible SDH/SONET (synchronous digital hierarchy and synchronous optical network) multiplexing hierarchy. From this common underlying theme follow many specific instantiations. Examples include the convergence at the physical, logical, and operational levels of voice and data, video and data, private-line and virtual private-line, fixed and mobile, and local and

  6. Convergence

    NASA Astrophysics Data System (ADS)

    Darcie, Thomas E.; Doverspike, Robert; Zirngibl, Martin; Korotky, Steven K.

    2005-01-01

    Call for Papers: Convergence

    Guest Editors: Thomas E. Darcie, University of Victoria Robert Doverspike, AT&T Martin Zirngibl, Lucent Technologies

    Coordinating Associate Editor: Steven K. Korotky, Lucent Technologies

    The Journal of Optical Networking (JON) invites submissions to a special issue on Convergence. Convergence has become a popular theme in telecommunications, one that has broad implications across all segments of the industry. Continual evolution of technology and applications continues to erase lines between traditionally separate lines of business, with dramatic consequences for vendors, service providers, and consumers. Spectacular advances in all layers of optical networking-leading to abundant, dynamic, cost-effective, and reliable wide-area and local-area connections-have been essential drivers of this evolution. As services and networks continue to evolve towards some notion of convergence, the continued role of optical networks must be explored. One vision of convergence renders all information in a common packet (especially IP) format. This vision is driven by the proliferation of data services. For example, time-division multiplexed (TDM) voice becomes VoIP. Analog cable-television signals become MPEG bits streamed to digital set-top boxes. T1 or OC-N private lines migrate to Ethernet virtual private networks (VPNs). All these packets coexist peacefully within a single packet-routing methodology built on an optical transport layer that combines the flexibility and cost of data networks with telecom-grade reliability. While this vision is appealing in its simplicity and shared widely, specifics of implementation raise many challenges and differences of opinion. For example, many seek to expand the role of Ethernet in these transport networks, while massive efforts are underway to make traditional TDM networks more data friendly

  7. Solving radiative transfer problems in highly heterogeneous media via domain decomposition and convergence acceleration techniques.

    PubMed

    Previti, Alberto; Furfaro, Roberto; Picca, Paolo; Ganapol, Barry D; Mostacci, Domiziano

    2011-08-01

    This paper deals with finding accurate solutions for photon transport problems in highly heterogeneous media fastly, efficiently and with modest memory resources. We propose an extended version of the analytical discrete ordinates method, coupled with domain decomposition-derived algorithms and non-linear convergence acceleration techniques. Numerical performances are evaluated using a challenging case study available in the literature. A study of accuracy versus computational time and memory requirements is reported for transport calculations that are relevant for remote sensing applications.

  8. A convergent Born series for solving the inhomogeneous Helmholtz equation in arbitrarily large media

    NASA Astrophysics Data System (ADS)

    Osnabrugge, Gerwin; Leedumrongwatthanakun, Saroch; Vellekoop, Ivo M.

    2016-10-01

    We present a fast method for numerically solving the inhomogeneous Helmholtz equation. Our iterative method is based on the Born series, which we modified to achieve convergence for scattering media of arbitrary size and scattering strength. Compared to pseudospectral time-domain simulations, our modified Born approach is two orders of magnitude faster and nine orders of magnitude more accurate in benchmark tests in 1, 2, and 3-dimensional systems.

  9. Media Rich, Resource Poor: Practical Work in an Impractical Environment

    ERIC Educational Resources Information Center

    van der Vliet, Emma; Deacon, Andrew

    2004-01-01

    Film and media courses appear well placed to exploit technology convergence in exposing students both to practical skills and to theoretical concepts. For the University of Cape Town's (UCT) large film and media studies courses, it is impractical simply to use the technology of professionals as this would typically be too expensive to purchase and…

  10. Media Rich, Resource Poor: Practical Work in an Impractical Environment

    ERIC Educational Resources Information Center

    van der Vliet, Emma; Deacon, Andrew

    2004-01-01

    Film and media courses appear well placed to exploit technology convergence in exposing students both to practical skills and to theoretical concepts. For the University of Cape Town's (UCT) large film and media studies courses, it is impractical simply to use the technology of professionals as this would typically be too expensive to purchase and…

  11. a Diffusivity Model for Gas Diffusion in Dry Porous Media Composed of Converging-Diverging Capillaries

    NASA Astrophysics Data System (ADS)

    Wang, Shifang; Wu, Tao; Deng, Yongju; Zheng, Qiusha; Zheng, Qian

    2016-08-01

    Gas diffusion in dry porous media has been a hot topic in several areas of technology for many years. In this paper, a diffusivity model for gas diffusion in dry porous media is developed based on fractal theory and Fick’s law, which incorporates the effects of converging-diverging pores and tortuous characteristics of capillaries as well as Knudsen diffusion. The effective gas diffusivity model is expressed as a function of the fluctuation amplitude of the capillary cross-section size variations, the porosity, the pore area fractal dimension and the tortuosity fractal dimension. The results show that the relative diffusivity decreases with the increase of the fluctuation amplitude and increases with the increase of pore area fractal dimension. To verify the validity of the present model, the relative diffusivity from the proposed fractal model is compared with the existing experimental data as well as two available models of Bruggeman and Shou. Our proposed diffusivity model with pore converging-diverging effect included is in good agreement with reported experimental data.

  12. Hydrogenosomes: convergent adaptations of mitochondria to anaerobic environments.

    PubMed

    Hackstein, J H; Akhmanova, A; Voncken, F; van Hoek, A; van Alen, T; Boxma, B; Moon-van der Staay, S Y; van der Staay, G; Leunissen, J; Huynen, M; Rosenberg, J; Veenhuis, M

    2001-01-01

    Hydrogenosomes are membrane-bound organelles that compartmentalise the final steps of energy metabolism in a number of anaerobic eukaryotes. They produce hydrogen and ATP. Here we will review the data, which are relevant for the questions: how did the hydrogenosomes originate, and what was their ancestor? Notably, there is strong evidence that hydrogenosomes evolved several times as adaptations to anaerobic environments. Most likely, hydrogenosomes and mitochondria share a common ancestor, but an unequivocal proof for this hypothesis is difficult because hydrogenosomes lack an organelle genome - with one remarkable exception (Nyctotherus ovalis). In particular, the diversity of extant hydrogenosomes hampers a straightforward analysis of their origins. Nevertheless, it is conceivable to postulate that the common ancestor of mitochondria and hydrogenosomes was a facultative anaerobic organelle that participated in the early radiation of unicellular eukaryotes. Consequently, it is reasonable to assume that both, hydrogenosomes and mitochondria are evolutionary adaptations to anaerobic or aerobic environments, respectively.

  13. The challenge of the evolving media environment.

    PubMed

    Walsh, D A

    2000-08-01

    As media become more powerful and prominent, questions about their positive and negative effects on children and youth will increase. Although the body of quality research about media and youth is growing, there are some significant gaps. Three important areas for future research are identified: physiological research, differential effects research, and media education outcomes research.

  14. Media Environment as a Zone of Personal and Social Risk

    ERIC Educational Resources Information Center

    Medvedeva, Tatyana; Kazantseva, Galina; Karpukova, Albina; Serova, Olga; Sizova, Olga; Bikteeva, Lolita

    2016-01-01

    The paper considers elements of modern media environment taking more and more space in day-to-day life of people. The modern media environment enriched with various informational and technological resources, information transfer speed and availability of all kinds of content in unlimited quantities, requires careful examination--first of all,…

  15. School Library Media Centers: The Human Environment.

    ERIC Educational Resources Information Center

    Doll, Carol A.

    1992-01-01

    Review of the literature on aspects of human behavior relevant to library media center design discusses personal space, territoriality, privacy, variety, and color. Suggestions for media center design in the areas of color, carpeting, seating, private spaces, variety in spaces, ownership, and control are offered; and research needs are identified.…

  16. The Curtain Effect in a Multiple Convergence Zone Environment: Part 1. Implications for Ambient Noise.

    DTIC Science & Technology

    1991-01-24

    prepared under Project No. A20022, principal investigator P. Herstein . It contains the oral and written presentation, "The Curtain Effect in a Multiple...Convergence Zone Environment: Part 1 - Implications for Ambient Noise." The authors wish to express their graditude to Peter D. Herstein (Code 33A) for

  17. Convergence of the Bouguer-Beer law for radiation extinction in particulate media

    NASA Astrophysics Data System (ADS)

    Frankel, A.; Iaccarino, G.; Mani, A.

    2016-10-01

    Radiation transport in particulate media is a common physical phenomenon in natural and industrial processes. Developing predictive models of these processes requires a detailed model of the interaction between the radiation and the particles. Resolving the interaction between the radiation and the individual particles in a very large system is impractical, whereas continuum-based representations of the particle field lend themselves to efficient numerical techniques based on the solution of the radiative transfer equation. We investigate radiation transport through discrete and continuum-based representations of a particle field. Exact solutions for radiation extinction are developed using a Monte Carlo model in different particle distributions. The particle distributions are then projected onto a concentration field with varying grid sizes, and the Bouguer-Beer law is applied by marching across the grid. We show that the continuum-based solution approaches the Monte Carlo solution under grid refinement, but quickly diverges as the grid size approaches the particle diameter. This divergence is attributed to the homogenization error of an individual particle across a whole grid cell. We remark that the concentration energy spectrum of a point-particle field does not approach zero, and thus the concentration variance must also diverge under infinite grid refinement, meaning that no grid-converged solution of the radiation transport is possible.

  18. The convergence of gambling and digital media: implications for gambling in young people.

    PubMed

    King, Daniel; Delfabbro, Paul; Griffiths, Mark

    2010-06-01

    Adolescents' use of the Internet and other digital media for the purpose of gambling represents a serious concern in modern society. This paper overviews some of the available monetary and non-monetary forms of gambling within new digital and online media and monetary forms of games with gambling-like experiences. With reference to current psychological knowledge on the risk factors that promote adolescent gambling, it is suggested that new gambling technologies may: (a) make gambling more accessible and attractive to young people, (b) may promote factually incorrect information about gambling, (c) provide an easy escape from real world problems such as depression and social isolation, (d) create a gambling environment that easily facilitates peer pressures to gamble, (e) ease parental transmission of gambling attitudes and beliefs, and (f) make gambling more ubiquitous and socially acceptable. The unique risks of Internet gambling for young people are critically discussed, as well as the lack of restricted classification for video games and other media that feature interactive, non-monetary forms of gambling.

  19. Complex-plane generalization of scalar Levin transforms: A robust, rapidly convergent method to compute potentials and fields in multi-layered media

    NASA Astrophysics Data System (ADS)

    Sainath, Kamalesh; Teixeira, Fernando L.; Donderici, Burkay

    2014-07-01

    We propose the complex-plane generalization of a powerful algebraic sequence acceleration algorithm, the method of weighted averages (MWA), to guarantee exponential-cum-algebraic convergence of Fourier and Fourier-Hankel (F-H) integral transforms. This “complex-plane” MWA, effected via a linear-path detour in the complex plane, results in rapid, absolute convergence of field and potential solutions in multi-layered environments regardless of the source-observer geometry and anisotropy/loss of the media present. In this work, we first introduce a new integration path used to evaluate the field contribution arising from the radiation spectra. Subsequently, we (1) exhibit the foundational relations behind the complex-plane extension to a general Levin-type sequence convergence accelerator, (2) specialize this analysis to one member of the Levin transform family (the MWA), (3) address and circumvent restrictions, arising for two-dimensional integrals associated with wave dynamics problems, through minimal complex-plane detour restrictions and a novel partition of the integration domain, (4) develop and compare two formulations based on standard/real-axis MWA variants, and (5) present validation results and convergence characteristics for one of these two formulations.

  20. Complex-plane generalization of scalar Levin transforms: A robust, rapidly convergent method to compute potentials and fields in multi-layered media

    SciTech Connect

    Sainath, Kamalesh; Teixeira, Fernando L.; Donderici, Burkay

    2014-07-15

    We propose the complex-plane generalization of a powerful algebraic sequence acceleration algorithm, the method of weighted averages (MWA), to guarantee exponential-cum-algebraic convergence of Fourier and Fourier–Hankel (F–H) integral transforms. This “complex-plane” MWA, effected via a linear-path detour in the complex plane, results in rapid, absolute convergence of field and potential solutions in multi-layered environments regardless of the source-observer geometry and anisotropy/loss of the media present. In this work, we first introduce a new integration path used to evaluate the field contribution arising from the radiation spectra. Subsequently, we (1) exhibit the foundational relations behind the complex-plane extension to a general Levin-type sequence convergence accelerator, (2) specialize this analysis to one member of the Levin transform family (the MWA), (3) address and circumvent restrictions, arising for two-dimensional integrals associated with wave dynamics problems, through minimal complex-plane detour restrictions and a novel partition of the integration domain, (4) develop and compare two formulations based on standard/real-axis MWA variants, and (5) present validation results and convergence characteristics for one of these two formulations.

  1. Money Management in a Media Resources Environment.

    ERIC Educational Resources Information Center

    Kent, Alvin

    1983-01-01

    Director of Iowa State University's Media Resources Center argues that fiscal progress is the most reliable measure of functional progress or growth. How money is controlled to allow for allocation of funds and manipulation of service priorities is described as well as how service functions are managed. (MBR)

  2. Big data in the new media environment.

    PubMed

    O'Donnell, Matthew Brook; Falk, Emily B; Konrath, Sara

    2014-02-01

    Bentley et al. argue for the social scientific contextualization of "big data" by proposing a four-quadrant model. We suggest extensions of the east-west (i.e., socially motivated versus independently motivated) decision-making dimension in light of findings from social psychology and neuroscience. We outline a method that leverages linguistic tools to connect insights across fields that address the individuals underlying big-data media streams.

  3. Note-Taking and Memory in Different Media Environments

    ERIC Educational Resources Information Center

    Lin, Lin; Bigenho, Chris

    2011-01-01

    Through this study the authors investigated undergraduate students' memory recall in three media environments with three note-taking options, following an A x B design with nine experiments. The three environments included no-distraction, auditory-distraction, and auditory-visual-distraction; while the three note-taking options included…

  4. To converge or not to converge in environmental space: testing for similar environments between analogous succulent plants of North America and Africa

    PubMed Central

    Alvarado-Cárdenas, Leonardo O.; Martínez-Meyer, Enrique; Feria, Teresa P.; Eguiarte, Luis E.; Hernández, Héctor M.; Midgley, Guy; Olson, Mark E.

    2013-01-01

    Background and Aims Convergent evolution is invoked to explain similarity between unrelated organisms in similar environments, but most evaluations of convergence analyse similarity of organismal attributes rather than of the environment. This study focuses on the globular succulent plants of the Americas, the cacti, and their counterparts in Africa in the ice-plant, spurge and milkweed families. Though often held up as paragons of convergent morphological evolution, the environmental similarity of these plants has remained largely unexamined from a quantitative perspective. Methods Five hotspots (centres of high species diversity of globular succulents) were selected, two in Mexico and three in South Africa. Their environments were compared using niche modelling tools, randomization tests of niche similarity and multivariate analyses to test for environmental similarity. Key Results Although the sites selected have ‘similar’ but unrelated life forms, almost all our results highlighted more climate differences than similarities between the hotspots. Interprediction of niches within and between continents, a niche equivalence test, and MANOVA results showed significant differences. In contrast, a niche similarity test showed that the comparisons of Cuatrociénegas–Richtersveld, Huizache–Knersvlakte and Huizache–Richtersveld were similar. Conclusions Differences in rainfall and temperature regimes and the potential effect of edaphic factors may be involved in the differences between the hotspots. In addition, differences in structure, morphology and physiology of the globular succulents may coincide with some of the climatic dissimilarities; i.e. given convergence as the evolution of similar morphologies under similar conditions, then it may be that differing environments diagnose inconspicuous morphological differences. Moreover, although fine-scale differences between sites were found, a coarser perspective shows that these sites are clearly similar as

  5. Advancing cancer control research in an emerging news media environment.

    PubMed

    Smith, Katherine C; Niederdeppe, Jeff; Blake, Kelly D; Cappella, Joseph N

    2013-12-01

    Cancer is both highly feared and highly newsworthy, and there is a robust body of research documenting the content and effects of cancer news coverage on health behaviors and policy. Recent years have witnessed ongoing, transformative shifts in American journalism alongside rapid advances in communication technology and the public information environment. These changes create a pressing need to consider a new set of research questions, sampling strategies, measurement techniques, and theories of media effects to ensure continued relevance and adaptation of communication research to address critical cancer control concerns. This paper begins by briefly reviewing what we know about the role of cancer news in shaping cancer-related beliefs, attitudes, behaviors, and policies. We then outline challenges and opportunities, both theoretical and methodological, posed by the rapidly changing news media environment and the nature of audience engagement. We organize our discussion around three major shifts associated with the emerging news media environment as it relates to health communication: 1) speed and dynamism of news diffusion, 2) increased narrowcasting of media content for specialized audiences, and 3) broadened participation in shaping media content. In so doing, we articulate a set of questions for future theory and research, in an effort to catalyze innovative communication scholarship to improve cancer prevention and control.

  6. Flirting, Dating, and Breaking up within New Media Environments

    ERIC Educational Resources Information Center

    Meenagh, Joni

    2015-01-01

    Although romantic and sexual relationships are an important aspect of young people's lives, research on how young people negotiate their love/sex relationships is lacking. New media environments provide a new context within which young people negotiate their love/sex relationships; however, what is negotiated is often not all that different from…

  7. Flirting, Dating, and Breaking up within New Media Environments

    ERIC Educational Resources Information Center

    Meenagh, Joni

    2015-01-01

    Although romantic and sexual relationships are an important aspect of young people's lives, research on how young people negotiate their love/sex relationships is lacking. New media environments provide a new context within which young people negotiate their love/sex relationships; however, what is negotiated is often not all that different from…

  8. Planning Learning Environments for Library Media Programs: An Introduction.

    ERIC Educational Resources Information Center

    Klasing, Jane P.; Callison, Daniel

    1992-01-01

    Klasing discusses the inability of school library facilities to meet current challenges for the delivery of programs and information. Callison then provides an overview of this issue on planning learning environments for school media centers, which contains four articles covering space requirements, ergonomic design, legislation on equal access,…

  9. Reduction of Perceived Social Distance as an Explanation for Media's Influence on Personal Risk Perceptions: A Test of the Risk Convergence Model

    ERIC Educational Resources Information Center

    So, Jiyeon; Nabi, Robin

    2013-01-01

    The risk convergence model proposes reduction of perceived social distance to a mediated personality as a mechanism through which the mass media can influence audiences' personal risk perceptions. As an initial test of the model, this study examined whether 5 audience variables known to facilitate media effects on personal risk…

  10. Reduction of Perceived Social Distance as an Explanation for Media's Influence on Personal Risk Perceptions: A Test of the Risk Convergence Model

    ERIC Educational Resources Information Center

    So, Jiyeon; Nabi, Robin

    2013-01-01

    The risk convergence model proposes reduction of perceived social distance to a mediated personality as a mechanism through which the mass media can influence audiences' personal risk perceptions. As an initial test of the model, this study examined whether 5 audience variables known to facilitate media effects on personal risk…

  11. Convergent evolution of SWS2 opsin facilitates adaptive radiation of threespine stickleback into different light environments

    PubMed Central

    Taylor, John S.; Jones, Felicity C.; Di Palma, Federica; Kingsley, David M.; Reimchen, Thomas E.

    2017-01-01

    Repeated adaptation to a new environment often leads to convergent phenotypic changes whose underlying genetic mechanisms are rarely known. Here, we study adaptation of color vision in threespine stickleback during the repeated postglacial colonization of clearwater and blackwater lakes in the Haida Gwaii archipelago. We use whole genomes from 16 clearwater and 12 blackwater populations, and a selection experiment, in which stickleback were transplanted from a blackwater lake into an uninhabited clearwater pond and resampled after 19 y to test for selection on cone opsin genes. Patterns of haplotype homozygosity, genetic diversity, site frequency spectra, and allele-frequency change support a selective sweep centered on the adjacent blue- and red-light sensitive opsins SWS2 and LWS. The haplotype under selection carries seven amino acid changes in SWS2, including two changes known to cause a red-shift in light absorption, and is favored in blackwater lakes but disfavored in the clearwater habitat of the transplant population. Remarkably, the same red-shifting amino acid changes occurred after the duplication of SWS2 198 million years ago, in the ancestor of most spiny-rayed fish. Two distantly related fish species, bluefin killifish and black bream, express these old paralogs divergently in black- and clearwater habitats, while sticklebacks lost one paralog. Our study thus shows that convergent adaptation to the same environment can involve the same genetic changes on very different evolutionary time scales by reevolving lost mutations and reusing them repeatedly from standing genetic variation. PMID:28399148

  12. Convergent evolution of SWS2 opsin facilitates adaptive radiation of threespine stickleback into different light environments.

    PubMed

    Marques, David A; Taylor, John S; Jones, Felicity C; Di Palma, Federica; Kingsley, David M; Reimchen, Thomas E

    2017-04-01

    Repeated adaptation to a new environment often leads to convergent phenotypic changes whose underlying genetic mechanisms are rarely known. Here, we study adaptation of color vision in threespine stickleback during the repeated postglacial colonization of clearwater and blackwater lakes in the Haida Gwaii archipelago. We use whole genomes from 16 clearwater and 12 blackwater populations, and a selection experiment, in which stickleback were transplanted from a blackwater lake into an uninhabited clearwater pond and resampled after 19 y to test for selection on cone opsin genes. Patterns of haplotype homozygosity, genetic diversity, site frequency spectra, and allele-frequency change support a selective sweep centered on the adjacent blue- and red-light sensitive opsins SWS2 and LWS. The haplotype under selection carries seven amino acid changes in SWS2, including two changes known to cause a red-shift in light absorption, and is favored in blackwater lakes but disfavored in the clearwater habitat of the transplant population. Remarkably, the same red-shifting amino acid changes occurred after the duplication of SWS2 198 million years ago, in the ancestor of most spiny-rayed fish. Two distantly related fish species, bluefin killifish and black bream, express these old paralogs divergently in black- and clearwater habitats, while sticklebacks lost one paralog. Our study thus shows that convergent adaptation to the same environment can involve the same genetic changes on very different evolutionary time scales by reevolving lost mutations and reusing them repeatedly from standing genetic variation.

  13. The influence of the media environment on physical activity: looking for the big picture.

    PubMed

    Maibach, Edward

    2007-01-01

    The Influence of the Media Environment on Physical Activity: Looking for the Big Picture Media consumption is expected to continue to increase well into the future. With this in mind the author suggests opportunities to influence the media environment for the purposes of promoting physical activity. A research agenda focused on media consumption, media content, commercial considerations, promoting physical activity through the media, partnerships with industry, positioning, dissemination of proven methods, and environmental change is proposed.

  14. Maxwell equations in Fourier space: fast-converging formulation for diffraction by arbitrary shaped, periodic, anisotropic media.

    PubMed

    Popov, E; Nevière, M

    2001-11-01

    We establish the most general differential equations that are satisfied by the Fourier components of the electromagnetic field diffracted by an arbitrary periodic anisotropic medium. The equations are derived by use of the recently published fast-Fourier-factorization (FFF) method, which ensures fast convergence of the Fourier series of the field. The diffraction by classic isotropic gratings arises as a particular case of the derived equations; the case of anisotropic classic gratings was published elsewhere. The equations can be resolved either through classic differential theory or through the modal method for particular groove profiles. The new equations improve both methods in the same way. Crossed gratings, among which are grids and two-dimensional arbitrarily shaped periodic surfaces, appear as particular cases of the theory, as do three-dimensional photonic crystals. The method can be extended to nonperiodic media through the use of a Fourier transform.

  15. The General Environment Fit Scale: A Factor Analysis and Test of Convergent Construct Validity

    PubMed Central

    Beasley, Christopher; Jason, Leonard; Miller, Steven

    2014-01-01

    Person-environment fit (P-E fit) was initially espoused as an important construct in the field of community psychology; however, most of the theoretical and empirical development of the construct has been conducted by industrial/organizational (I/O) psychologists. In the current study, the GEFS—a P-E fit measure was developed from I/O and business management perspectives on fit—was administered to 246 attendees of an annual convention for residents and alumni of Oxford House (OH), a network of over 1400 mutual-help recovery homes. The authors conducted confirmatory factor and convergent construct validity analyses on the GEFS. The results suggested that the theoretical factor structure of the measure adequately fit the data, suggesting that the GEFS is a valid measure of P-E fit. OH resident fit with their recovery home was related to satisfaction, but not expected tenure. Exploratory analyses revealed that the sufficient supply of resident needs by the recovery home and similarity between residents and their housemates predicted satisfaction with the recovery home, but only similarity with housemates predicted how long residents intended to stay in the OHs. PMID:22071911

  16. Convergent life-history shifts: toxic environments result in big babies in two clades of poeciliids

    NASA Astrophysics Data System (ADS)

    Riesch, Rüdiger; Plath, Martin; García de León, Francisco J.; Schlupp, Ingo

    2010-02-01

    The majority of studies on ecological speciation in animals have investigated the divergence caused by biotic factors like divergent food sources or predatory regimes. Here, we examined a system where ecological speciation can clearly be ascribed to abiotic environmental gradients of naturally occurring toxic hydrogen sulfide (H2S). In southern Mexico, two genera of livebearing fishes (Poeciliidae: Poecilia and Gambusia) thrive in various watercourses with different concentrations of H2S. Previous studies have revealed pronounced genetic differentiation between different locally adapted populations in one species ( Poecilia mexicana), pointing towards incipient speciation. In the present study, we examined female reproductive life-history traits in two species pairs: Gambusia sexradiata (from a nonsulfidic and a sulfidic habitat) and Gambusia eurystoma (sulfide-endemic), as well as P. mexicana (nonsulfidic and sulfidic) and Poecilia sulphuraria (sulfide endemic). We found convergent divergence of life-history traits in response to sulfide; most prominently, extremophile poeciliids exhibit drastically increased offspring size coupled with reduced fecundity. Furthermore, within each genus, this trend increased with increasing sulfide concentrations and was most pronounced in the two endemic sulfur-adapted species. We discuss the adaptive significance of large offspring size in toxic environments and propose that divergent life-history evolution may promote further ecological divergence through isolation by adaptation.

  17. The general environment fit scale: a factor analysis and test of convergent construct validity.

    PubMed

    Beasley, Christopher R; Jason, Leonard A; Miller, Steven A

    2012-09-01

    Person-environment fit (P-E fit) was initially espoused as an important construct in the field of community psychology; however, most of the theoretical and empirical development of the construct has been conducted by the industrial/organizational (I/O) psychologists and business management fields. In the current study, the GEFS-a P-E fit measure that was developed from organizational perspectives on fit-was administered to 246 attendees of an annual convention for residents and alumni of Oxford House, a network of over 1,400 mutual-help addiction recovery homes. The authors conducted confirmatory factor and convergent construct validity analyses with the GEFS. The results suggested that the theoretical factor structure of the measure adequately fit the data and provided limited support for the measure's validity. Sufficient supply of resident needs by the Oxford House and similarity between residents and their housemates predicted satisfaction with the recovery home, but only perceived similarity to housemates predicted how long residents intended to stay in the Oxford Houses.

  18. Extreme environments as potential drivers of convergent evolution by exaptation: the Atacama Desert Coastal Range case

    PubMed Central

    Azua-Bustos, Armando; González-Silva, Carlos; Arenas-Fajardo, Cristián; Vicuña, Rafael

    2012-01-01

    We have recently discovered a variety of unrelated phototrophic microorganisms (two microalgae and one cyanobacteria) in specialized terrestrial habitats at The Coastal Range of the Atacama Desert. Interestingly, morphological and molecular evidence suggest that these three species are all recent colonists that came from aquatic habitats. The first case is Cyanidiales inhabiting coastal caves. Cyanidiales are microalgae that are commonly found in warm acid springs, but have also been recently discovered as cave flora in Italy. The case is Dunaliella biofilms colonizing spider webs in coastal caves; Dunaliella are microalgae typically found in hypersaline habitats. The third case is Chroococcidiopsis, a genus of Cyanobacteria commonly found in deserts around the world that has also been described in warm springs. Thus, we show that the traits found in the closest ancestors of the aforementioned species (which inhabited other unrelated extreme environments) seem to be now useful for the described species in their current subaerial habitats and may likely correspond to cases of exaptations. Altogether, the Coastal Range of the Atacama Desert may be considered as a place where key steps on the colonization of land by phototrophic organisms seem to be being repeated by convergent evolution of extant microalgae and Cyanobacteria. PMID:23267354

  19. Converging Indicators for Assessing Individual Differences in Adaptation to Extreme Environments: Preliminary Report

    NASA Technical Reports Server (NTRS)

    Cowings, Patricia S.; Toscano, William B.; DeRoshia, Charles W.; Taylor, Bruce; Hines, Seleimah; Bright, Andrew; Dodds, Anika

    2006-01-01

    This paper describes the development and validation of a new methodology for assessing the deleterious effects of spaceflight on crew health and performance. It is well known that microgravity results in various physiological alterations, e.g., headward fluid shifts which can impede physiological adaptation. Other factors that may affect crew operational efficiency include disruption of sleep-wake cycles, high workload, isolation, confinement, stress and fatigue. From an operational perspective, it is difficult to predict which individuals will be most or least affected in this unique environment given that most astronauts are first-time flyers. During future lunar and Mars missions space crews will include both men and women of multi-national origins, different professional backgrounds, and various states of physical condition. Therefore, new methods or technologies are needed to monitor and predict astronaut performance and health, and to evaluate the effects of various countermeasures on crew during long duration missions. This paper reviews several studies conducted in both laboratory and operational environments with men and women ranging in age between 18 to 50 years. The studies included the following: soldiers performing command and control functions during mobile operations in enclosed armored vehicles; subjects participating in laboratory tests of an anti-motion sickness medication; subjects exposed to chronic hypergravity aboard a centrifuge, and subject responses to 36-hours of sleep deprivation. Physiological measurements, performance metrics, and subjective self-reports were collected in each study. The results demonstrate that multivariate converging indicators provide a significantly more reliable method for assessing environmental effects on performance and health than any single indicator.

  20. Converging indicators for assessing individual differences in adaptation to extreme environments.

    PubMed

    Cowings, Patricia; Toscano, William; Deroshia, Charles; Taylor, Bruce; Hines, A'Liah; Bright, Andrew; Dodds, Anika

    2007-05-01

    It is well known that microgravity results in various physiological alterations, for example, head-ward fluid shifts which can impede physiological adaptation. Other factors that may affect crew operational efficiency include disruption of sleep-wake cycles, high workload, isolation, confinement, stress, and fatigue. From an operational perspective, it is difficult to predict which individuals will be most or least affected in this unique environment given that most astronauts are first-time flyers. During future lunar and Mars missions space crews will include both men and women of multi-national origins, different professional backgrounds, and various states of physical condition. Therefore, new methods or technologies are needed to monitor and predict astronaut performance and health, and to evaluate the effects of various countermeasures on crew during long-duration missions. Herein we describe the development and validation of a new methodology for assessing the deleterious effects of spaceflight on crew health and performance. We reviewed several studies conducted in both laboratory and operational environments with men and women ranging in age between 18 to 50 yr. The studies included the following: soldiers performing command and control functions during mobile operations in enclosed armored vehicles; subjects participating in laboratory tests of an anti-motion sickness medication; subjects exposed to chronic hypergravity aboard a centrifuge; and subject responses to 36-h of sleep deprivation. Physiological measurements, performance metrics, and subjective self-reports were collected in each study. The results demonstrate that multivariate converging indicators provide a significantly more reliable method for assessing environmental effects on performance and health than any single indicator.

  1. Fungal growth in culture media simulating an extreme environment.

    PubMed

    Alvarez-Pérez, Sergio; Blanco, José L; Alba, Patricia; García, Marta E

    2011-01-01

    There is an increasing interest in the study of microorganisms that inhabit extreme environments for reasons that vary from gaining insight into the origin of life to the searching of new biotechnological applications. In this work, we studied the tolerance of fungi isolated from the Aguas Agrias Stream (AAS; Tharsis, Huelva, Spain), an acidic metal-rich environment, to a culture medium prepared with water from this extreme ecosystem (AASW medium). The ability of some culture collection strains of moulds and yeasts to grow on AASW medium was also assessed. For moulds, a tolerance index was calculated by dividing the growth diameter of colonies on AASW medium by the diameter in the control medium, and their germinative potential was recorded. For yeasts and yeast-like fungi, the minimum inhibitory concentration of AASW was determined. In general, the fungi isolated from the AAS showed differences in their ability to germinate and grow on AASW medium. Collection strains of the genus Aspergillus could grow on AASW medium, but showed some differences in tolerance when compared to environmental isolates. Extremotolerant fungi can manifest differences in their tolerance to culture media that simulate the conditions of their natural habitat. The results of this work suggest that the ability of fungi to grow in acidic, metal-rich environments might be more widespread than previously thought, and highlight the importance of determining the factors that are responsible for tolerance to these extreme environments. Copyright © 2010 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

  2. Initiation of deep convection along boundary layer convergence lines in a semitropical environment

    SciTech Connect

    Fankhauser, J.C.; Crook, N.A.; Tuttle, J.; Miller, L.J.; Wade, C.G.

    1995-02-01

    The initiation of deep convection through forcing along boundary layer convergence lines is examined using observations from the Convection and Precipitation/Electrification (CaPE) Experiment conducted in east-central Florida during the summer of 1991. The study is concerned with the evolution and interaction of two converging air masses that were initially separated by an intervening boundary layer characterized by neutral stability and horizontal convective rolls. As anticipated, major thunderstorms erupt when the east coast breeze eventually collides with thunderstorm outflows from the west, but unexpected convection takes place prior to their merger along a well-defined confluence zone associated with a persistent quasi-stationary roll vortex signature. In this study, complementary interactions between roll vortex convergence lines and the sea-breeze front are not sufficient to trigger deep convection. However, organized convergence along the eastward-spreading thunderstorm outflows did interact periodically with roll vortex convergence maxima to initiate a new series of new storms. Results from two-dimensional numerical model simulations replicate many of the observed boundary layer features. Surface heating produces circulations similar to sea-breeze frontal zones that appear near the coastlines and progress steadily toward each other as the interior boundary layer deepens. Vertical velocity maxima develop over the associated convergence zones, but weaker periodic maxima also occur within the interior air mass at intervals similar to the spacing of observed horizontal roll vortices.

  3. Physical Volume Library deadlock avoidance in a striped media environment

    SciTech Connect

    Deutsch, J.K.; Gary, M.R.

    1995-03-01

    Most modern high performance storage systems store data in large repositories of removable media volumes. Management of the removable volumes is performed by a software module known as a Physical Volume Library (PVL). To meet performance and scalability requirements, a PVL may be asked to mount multiple removable media volumes for use by a single client for parallel data transfer. Mounting sets of volumes creates an environment in which it impossible for multiple client requests to deadlock while attempting to gain access to storage resources. Scenarios leading to deadlock in a PVL include multiple client requests that contend for the same cartridge(s), and client requests that vie for a limited set of drive resources. These deadlock scenarios are further complicated by the potential for out-of-order volumes to be mounted (for example, by Automatic Cartridge Loaders or human operators). This paper begins by introducing those PVL requirements Which create the possibility of deadlock. Next we examine traditional approaches to deadlock resolution and how they might be applied in a PVL. This leads to a design for a PVL which addresses deadlock scenarios. Following the design presentation is a discussion of possible design enhancements. We end with a case study of an actual implementation of the PVL design in the High Performance Storage System (HPSS).

  4. Convergence time and speed of multi-agent systems in noisy environments.

    PubMed

    Sun, Yongzheng; Li, Wang; Zhao, Donghua

    2012-12-01

    In this paper, the finite-time consensus problem of noise-perturbed multi-agent systems with fixed and switching undirected topologies is investigated. A continuous non-Lipschitz protocol for realizing stochastic consensus in a finite time is proposed. Based on the finite-time stability theory of stochastic differential equations, sufficient conditions are obtained to ensure finite-time stochastic consensus of multi-agent systems. An analytical upper bound for the convergence time is given. The effects of control parameters and noise intensity on convergence speed and time are also analyzed. Furthermore, numerical examples are provided to illustrate the effectiveness of the theoretical results.

  5. Convergence time and speed of multi-agent systems in noisy environments

    NASA Astrophysics Data System (ADS)

    Sun, Yongzheng; Li, Wang; Zhao, Donghua

    2012-12-01

    In this paper, the finite-time consensus problem of noise-perturbed multi-agent systems with fixed and switching undirected topologies is investigated. A continuous non-Lipschitz protocol for realizing stochastic consensus in a finite time is proposed. Based on the finite-time stability theory of stochastic differential equations, sufficient conditions are obtained to ensure finite-time stochastic consensus of multi-agent systems. An analytical upper bound for the convergence time is given. The effects of control parameters and noise intensity on convergence speed and time are also analyzed. Furthermore, numerical examples are provided to illustrate the effectiveness of the theoretical results.

  6. Cognition and the Media-ted Curriculum: Effects of Growing Up in an Electronic Environment.

    ERIC Educational Resources Information Center

    Chiarelott, Leigh

    1984-01-01

    Examines forms of media in today's electronic environment including television, microcomputers, video games, and music television, and considers these media forms and their effects on cognitive processing. Implications for teachers and instructional designers in achieving curricular balance between print and electronic media are discussed. (MBR)

  7. Trait convergence and plasticity among native and invasive species in resource-poor environments

    USDA-ARS?s Scientific Manuscript database

    Functional trait comparisons provide a framework with which to assess invasibility and invasion resistance. Recent research and meta-analyses have produced equivocal results, finding evidence for both trait convergence and trait divergence among coexisting dominant native and invasive species. Rese...

  8. The Convergence of Text and Graphics in an Online Learning Environment: A Case Study in Economics.

    ERIC Educational Resources Information Center

    Ingram, Deborah; Thompson, Eileen; Tcha, MoonJoong

    While much visually oriented teaching material that uses the new technologies is being developed, there is little understanding or research into the demands such material makes on students' information processing. This paper outlines an innovative approach to teaching complex economic models that incorporates the convergence of text and graphics…

  9. A Study of Learning and Motivation in a New Media Enriched Environment for Middle School Science

    ERIC Educational Resources Information Center

    Liu, Min; Horton, Lucas; Olmanson, Justin; Toprac, Paul

    2011-01-01

    This study examines middle school students' learning and motivation as they engaged in a new media enriched problem-based learning (PBL) environment for middle school science. Using a mixed-method design with both quantitative and qualitative data, we investigated the effect of a new media environment on sixth graders' science learning, their…

  10. Immersive Media Environments for Special Education: Developing Agency in Communication for Youth with Autism

    ERIC Educational Resources Information Center

    Tolentino, Lisa

    2013-01-01

    This dissertation describes the development of a state-of-the-art immersive media environment and its potential to motivate high school youth with autism to vocally express themselves. Due to the limited availability of media environments in public education settings, studies on the use of such systems in special education contexts are rare. A…

  11. Immersive Media Environments for Special Education: Developing Agency in Communication for Youth with Autism

    ERIC Educational Resources Information Center

    Tolentino, Lisa

    2013-01-01

    This dissertation describes the development of a state-of-the-art immersive media environment and its potential to motivate high school youth with autism to vocally express themselves. Due to the limited availability of media environments in public education settings, studies on the use of such systems in special education contexts are rare. A…

  12. A Study of Learning and Motivation in a New Media Enriched Environment for Middle School Science

    ERIC Educational Resources Information Center

    Liu, Min; Horton, Lucas; Olmanson, Justin; Toprac, Paul

    2011-01-01

    This study examines middle school students' learning and motivation as they engaged in a new media enriched problem-based learning (PBL) environment for middle school science. Using a mixed-method design with both quantitative and qualitative data, we investigated the effect of a new media environment on sixth graders' science learning, their…

  13. Convergent Evolution of Unique Morphological Adaptations to a Subterranean Environment in Cave Millipedes (Diplopoda)

    PubMed Central

    Golovatch, Sergei; Wesener, Thomas; Tian, Mingyi

    2017-01-01

    Animal life in caves has fascinated researchers and the public alike because of the unusual and sometimes bizarre morphological adaptations observed in numerous troglobitic species. Despite their worldwide diversity, the adaptations of cave millipedes (Diplopoda) to a troglobitic lifestyle have rarely been examined. In this study, morphological characters were analyzed in species belonging to four different orders (Glomerida, Polydesmida, Chordeumatida, and Spirostreptida) and six different families (Glomeridae, Paradoxosomatidae, Polydesmidae, Haplodesmidae, Megalotylidae, and Cambalopsidae) that represent the taxonomic diversity of class Diplopoda. We focused on the recently discovered millipede fauna of caves in southern China. Thirty different characters were used to compare cave troglobites and epigean species within the same genera. A character matrix was created to analyze convergent evolution of cave adaptations. Males and females were analyzed independently to examine sex differences in cave adaptations. While 10 characters only occurred in a few phylogenetic groups, 20 characters were scored for in all families. Of these, four characters were discovered to have evolved convergently in all troglobitic millipedes. The characters that represented potential morphological cave adaptations in troglobitic species were: (1) a longer body; (2) a lighter body color; (3) elongation of the femora; and (4) elongation of the tarsi of walking legs. Surprisingly, female, but not male, antennae were more elongated in troglobites than in epigean species. Our study clearly shows that morphological adaptations have evolved convergently in different, unrelated millipede orders and families, most likely as a direct adaptation to cave life. PMID:28178274

  14. Convergent Evolution of Unique Morphological Adaptations to a Subterranean Environment in Cave Millipedes (Diplopoda).

    PubMed

    Liu, Weixin; Golovatch, Sergei; Wesener, Thomas; Tian, Mingyi

    2017-01-01

    Animal life in caves has fascinated researchers and the public alike because of the unusual and sometimes bizarre morphological adaptations observed in numerous troglobitic species. Despite their worldwide diversity, the adaptations of cave millipedes (Diplopoda) to a troglobitic lifestyle have rarely been examined. In this study, morphological characters were analyzed in species belonging to four different orders (Glomerida, Polydesmida, Chordeumatida, and Spirostreptida) and six different families (Glomeridae, Paradoxosomatidae, Polydesmidae, Haplodesmidae, Megalotylidae, and Cambalopsidae) that represent the taxonomic diversity of class Diplopoda. We focused on the recently discovered millipede fauna of caves in southern China. Thirty different characters were used to compare cave troglobites and epigean species within the same genera. A character matrix was created to analyze convergent evolution of cave adaptations. Males and females were analyzed independently to examine sex differences in cave adaptations. While 10 characters only occurred in a few phylogenetic groups, 20 characters were scored for in all families. Of these, four characters were discovered to have evolved convergently in all troglobitic millipedes. The characters that represented potential morphological cave adaptations in troglobitic species were: (1) a longer body; (2) a lighter body color; (3) elongation of the femora; and (4) elongation of the tarsi of walking legs. Surprisingly, female, but not male, antennae were more elongated in troglobites than in epigean species. Our study clearly shows that morphological adaptations have evolved convergently in different, unrelated millipede orders and families, most likely as a direct adaptation to cave life.

  15. Social Media: Valuable Tools in Today’s Operational Environment

    DTIC Science & Technology

    2011-05-04

    Lee Odden, ―Best and Worst Practices Social Media Marketing ,‖ Top Rank® Online Market Blog, entry posted 12 February 2009, http://www.toprankblog.com...to what Lee Odden described as a best practice for social media marketing in the civilian sector. 28 Equally important, commanders must dedicate the...1001 (accessed 30 March 2011). Odden, Lee. ―Best and Worst Practices Social Media Marketing .‖ Top Rank® Online Market Blog, entry posted 12

  16. Social Media and the New Academic Environment: Pedagogical Challenges

    ERIC Educational Resources Information Center

    Patrut, Bogdan; Patrut, Monica; Cmeciu, Camelia

    2013-01-01

    As web applications play a vital role in our society, social media has emerged as an important tool in the creation and exchange of user-generated content and social interaction. The benefits of these services have entered in the educational areas to become new means by which scholars communicate, collaborate and teach. Social Media and the New…

  17. Social Media and the New Academic Environment: Pedagogical Challenges

    ERIC Educational Resources Information Center

    Patrut, Bogdan; Patrut, Monica; Cmeciu, Camelia

    2013-01-01

    As web applications play a vital role in our society, social media has emerged as an important tool in the creation and exchange of user-generated content and social interaction. The benefits of these services have entered in the educational areas to become new means by which scholars communicate, collaborate and teach. Social Media and the New…

  18. The Media Environment: Mass Communications in American Society.

    ERIC Educational Resources Information Center

    Stanley, Robert H.; Steinberg, Charles S.

    The purpose of this book is to provide the reader with an informational frame of reference that will permit the formation of critical judgments concerning America's mass media institutions. The book covers the broad spectrum of the communications media in terms of their impact on American society. Such topics are discussed as social aspects of…

  19. The Convergence of Gaming Practices with Other Media Forms: What Potential for Learning? A Review of the Literature

    ERIC Educational Resources Information Center

    de Freitas, Sara; Griffiths, Mark

    2008-01-01

    Nowhere in the current digital technology landscape is the process of "blurring the lines between media" more apparent than with the uses and applications of gaming practices and technologies. Here the overlaps between new media and media interfaces are becoming significant as games technologies and practices are becoming more pervasive as…

  20. The Convergence of Gaming Practices with Other Media Forms: What Potential for Learning? A Review of the Literature

    ERIC Educational Resources Information Center

    de Freitas, Sara; Griffiths, Mark

    2008-01-01

    Nowhere in the current digital technology landscape is the process of "blurring the lines between media" more apparent than with the uses and applications of gaming practices and technologies. Here the overlaps between new media and media interfaces are becoming significant as games technologies and practices are becoming more pervasive as…

  1. Changing the home nutrition environment: effects of a nutrition and media literacy pilot intervention.

    PubMed

    Evans, Alexandra E; Dave, Jayna; Tanner, Andrea; Duhe, Sonya; Condrasky, Margaret; Wilson, Dawn; Griffin, Sarah; Palmer, Meredith; Evans, Martin

    2006-01-01

    The specific aim for this pilot study was to evaluate the effectiveness of a nutrition and media literacy intervention targeting elementary students and their parents. The purpose of the intervention was to increase child fruit and vegetables (FV) consumption and change the home nutrition environment (measured with FV availability and accessibility and parental social support). During the intervention, students learned about nutrition, the role media plays in shaping values concerning nutrition, and developed a media campaign for their parents. A quasi-experimental research design was used to evaluate the effectiveness of the intervention. The media intervention was effective in changing the home environment.

  2. Genetic convergence in the adaptation of dogs and humans to the high-altitude environment of the tibetan plateau.

    PubMed

    Wang, Guo-Dong; Fan, Ruo-Xi; Zhai, Weiwei; Liu, Fei; Wang, Lu; Zhong, Li; Wu, Hong; Yang, He-Chuan; Wu, Shi-Fang; Zhu, Chun-Ling; Li, Yan; Gao, Yun; Ge, Ri-Li; Wu, Chung-I; Zhang, Ya-Ping

    2014-08-01

    The high-altitude hypoxic environment represents one of the most extreme challenges for mammals. Previous studies of humans on the Tibetan plateau and in the Andes Mountains have identified statistical signatures of selection in different sets of loci. Here, we first measured the hemoglobin levels in village dogs from Tibet and those from Chinese lowlands. We found that the hemoglobin levels are very similar between the two groups, suggesting that Tibetan dogs might share similar adaptive strategies as the Tibetan people. Through a whole-genome sequencing approach, we have identified EPAS1 and HBB as candidate genes for the hypoxic adaptation on the Tibetan plateau. The population genetic analysis shows a significant convergence between humans and dogs in Tibet. The similarities in the sets of loci that exhibit putative signatures of selection and the hemoglobin levels between humans and dogs of the same environment, but not between human populations in different regions, suggests an extraordinary landscape of convergent evolution between human beings and their best friend on the Tibetan plateau.

  3. Genetic Convergence in the Adaptation of Dogs and Humans to the High-Altitude Environment of the Tibetan Plateau

    PubMed Central

    Wang, Guo-Dong; Fan, Ruo-Xi; Zhai, Weiwei; Liu, Fei; Wang, Lu; Zhong, Li; Wu, Hong; Yang, He-Chuan; Wu, Shi-Fang; Zhu, Chun-Ling; Li, Yan; Gao, Yun; Ge, Ri-Li; Wu, Chung-I; Zhang, Ya-Ping

    2014-01-01

    The high-altitude hypoxic environment represents one of the most extreme challenges for mammals. Previous studies of humans on the Tibetan plateau and in the Andes Mountains have identified statistical signatures of selection in different sets of loci. Here, we first measured the hemoglobin levels in village dogs from Tibet and those from Chinese lowlands. We found that the hemoglobin levels are very similar between the two groups, suggesting that Tibetan dogs might share similar adaptive strategies as the Tibetan people. Through a whole-genome sequencing approach, we have identified EPAS1 and HBB as candidate genes for the hypoxic adaptation on the Tibetan plateau. The population genetic analysis shows a significant convergence between humans and dogs in Tibet. The similarities in the sets of loci that exhibit putative signatures of selection and the hemoglobin levels between humans and dogs of the same environment, but not between human populations in different regions, suggests an extraordinary landscape of convergent evolution between human beings and their best friend on the Tibetan plateau. PMID:25091388

  4. Toward faster OPC convergence: advanced analysis for OPC iterations and simulation environment

    NASA Astrophysics Data System (ADS)

    Bahnas, Mohamed; Al-Imam, Mohamed; Tawfik, Tamer

    2008-10-01

    Achieving faster Turn-Around-Time (TAT) is one of the most attractive objectives for the silicon wafer manufacturers despite the technology node they are processing. This is valid for all the active technology nodes from 130nm till the cutting edge technologies. There have been several approaches adopted to cut down the OPC simulation runtime without sacrificing the OPC output quality, among them is using stronger CPU power and Hardware acceleration which is a good usage for the advancing powerful processing technology. Another favorable approach for cutting down the runtime is to look deeper inside the used OPC algorithm and the implemented OPC recipe. The OPC algorithm includes the convergence iterations and simulation sites distribution, and the OPC recipe is in definition how to smartly tune the OPC knobs to efficiently use the implemented algorithm. Many previous works were exposed to monitoring the OPC convergence through iterations and analyze the size of the shift per iteration, similarly several works tried to calculate the amount of simulation capacity needed for all these iterations and how to optimize it for less amount. The scope of the work presented here is an attempt to decrease the number of optical simulations by reducing the number of control points per site and without affecting OPC accuracy. The concept is proved by many simulation results and analysis. Implementing this flow illustrated the achievable simulation runtime reduction which is reflected in faster TAT. For its application, it is not just runtime optimization, additionally it puts some more intelligence in the sparse OPC engine by eliminating the headache of specifying the optimum simulation site length.

  5. Composing Focus: Shaping Temporal, Social, Media, Social Media, and Attentional Environments

    ERIC Educational Resources Information Center

    Fife, Jane

    2017-01-01

    Writers must learn to control factors that influence the ability to focus, especially in what some call a culture of distraction. In our efforts to promote metacognition and flexible writing processes, writing teachers need to engage students in study and discussion of factors in our temporal, social, media, social media, and attentional…

  6. Gaining Media Attention in the Changing Media Environment: A Case Study.

    ERIC Educational Resources Information Center

    Hardenbergh, Margot

    The media's use of videotaped 1992 New Year's greetings to President George Bush (taped by several people in front of a life size image of the president from his college days) raises questions of the media's diversity, ethics, and agenda setting. A New Haven television station reported on the activity as one of many taking place that night. Ten…

  7. Generating news media interest in tobacco control; challenges in an advanced policy environment.

    PubMed

    MacKenzie, Ross; Chapman, Simon

    2012-08-01

    To determine the efficacy of using media releases for tobacco control advocacy in Australia's advanced policy environment. Between February and August 2010, news releases that summarised either newly published but unpublicized research findings, or local developments in tobacco control, were sent to NSW media outlets. Reports arising from the releases were tracked using commercial services Media Monitors and Factiva, as well as Google and Google News. Other tobacco control related news items during the same period were also tracked and recorded. Twenty-one news releases generated 93 news items across all news media, with a quarter of these related to a story of porcine haemoglobin in cigarette filters. By comparison, 'live' policy issues (especially plain packaging and a significant tobacco tax increase) covered in this period attracted 1,033 news stories in the Australian media. Press releases describing recently published, but underpublicized research were issued in weeks where no major competing tobacco control news occurred. Results of this project indicate that in environments with advanced tobacco policy, media opportunities related to tobacco control advocacy are limited, as many objectives have been achieved. The media can still play a key advocacy role in such environments, and advocates need to be particularly vigilant for opportunities that do arise. The paper also highlights the increasingly important role of internet-based media, including opportunities presented by social media for tobacco control.

  8. Detecting Rumors Through Modeling Information Propagation Networks in a Social Media Environment.

    PubMed

    Liu, Yang; Xu, Songhua; Tourassi, Georgia

    2015-01-01

    In the midst of today's pervasive influence of social media content and activities, information credibility has increasingly become a major issue. Accordingly, identifying false information, e.g. rumors circulated in social media environments, attracts expanding research attention and growing interests. Many previous studies have exploited user-independent features for rumor detection. These prior investigations uniformly treat all users relevant to the propagation of a social media message as instances of a generic entity. Such a modeling approach usually adopts a homogeneous network to represent all users, the practice of which ignores the variety across an entire user population in a social media environment. Recognizing this limitation of modeling methodologies, this study explores user-specific features in a social media environment for rumor detection. The new approach hypothesizes that whether a user tends to spread a rumor is dependent upon specific attributes of the user in addition to content characteristics of the message itself. Under this hypothesis, information propagation patterns of rumors versus those of credible messages in a social media environment are systematically differentiable. To explore and exploit this hypothesis, we develop a new information propagation model based on a heterogeneous user representation for rumor recognition. The new approach is capable of differentiating rumors from credible messages through observing distinctions in their respective propagation patterns in social media. Experimental results show that the new information propagation model based on heterogeneous user representation can effectively distinguish rumors from credible social media content.

  9. The Influence of Social Media on Collaborative Learning in a Cohort Environment

    ERIC Educational Resources Information Center

    Wandera, Silas; James-Waldon, Natasha; Bromley, Debbi; Henry, Zandra

    2016-01-01

    This paper provides an overview of the impact that social media has on the development of collaborative learning within a cohort environment in a doctoral program. The researchers surveyed doctoral students in an education program to determine how social media use has influenced the doctoral students. The study looked at the following areas: a)…

  10. The Influence of Social Media on Collaborative Learning in a Cohort Environment

    ERIC Educational Resources Information Center

    Wandera, Silas; James-Waldon, Natasha; Bromley, Debbi; Henry, Zandra

    2016-01-01

    This paper provides an overview of the impact that social media has on the development of collaborative learning within a cohort environment in a doctoral program. The researchers surveyed doctoral students in an education program to determine how social media use has influenced the doctoral students. The study looked at the following areas: a)…

  11. Detecting Rumors Through Modeling Information Propagation Networks in a Social Media Environment

    PubMed Central

    Liu, Yang; Xu, Songhua; Tourassi, Georgia

    2015-01-01

    In the midst of today's pervasive influence of social media content and activities, information credibility has increasingly become a major issue. Accordingly, identifying false information, e.g. rumors circulated in social media environments, attracts expanding research attention and growing interests. Many previous studies have exploited user-independent features for rumor detection. These prior investigations uniformly treat all users relevant to the propagation of a social media message as instances of a generic entity. Such a modeling approach usually adopts a homogeneous network to represent all users, the practice of which ignores the variety across an entire user population in a social media environment. Recognizing this limitation of modeling methodologies, this study explores user-specific features in a social media environment for rumor detection. The new approach hypothesizes that whether a user tends to spread a rumor is dependent upon specific attributes of the user in addition to content characteristics of the message itself. Under this hypothesis, information propagation patterns of rumors versus those of credible messages in a social media environment are systematically differentiable. To explore and exploit this hypothesis, we develop a new information propagation model based on a heterogeneous user representation for rumor recognition. The new approach is capable of differentiating rumors from credible messages through observing distinctions in their respective propagation patterns in social media. Experimental results show that the new information propagation model based on heterogeneous user representation can effectively distinguish rumors from credible social media content. PMID:26623445

  12. Genetic algorithm optimization for focusing through turbid media in noisy environments.

    PubMed

    Conkey, Donald B; Brown, Albert N; Caravaca-Aguirre, Antonio M; Piestun, Rafael

    2012-02-27

    We introduce genetic algorithms (GA) for wavefront control to focus light through highly scattering media. We theoretically and experimentally compare GAs to existing phase control algorithms and show that GAs are particularly advantageous in low signal-to-noise environments.

  13. Children and Their Changing Media Environment: A European Comparative Study.

    ERIC Educational Resources Information Center

    Livingstone, Sonia, Ed.; Bovill, Moira, Ed.

    Integrating broadcasting, video, computing, games, and the Internet, the domestic television screen is being transformed into the site of a multimedia culture. To address questions about the meaning and uses of such new media, this volume brings together work by researchers in 12 countries--Belgium, Denmark, Finland, France, Germany, the United…

  14. Segmenting Broadcast News Audiences in the New Media Environment.

    ERIC Educational Resources Information Center

    Wicks, Robert H.

    1989-01-01

    Examines the "benefit segmentation model," a marketing strategy for local news media which is capable of sorting consumers into discrete segments interested in similar salient product attributes or benefits. Concludes that benefit segmentation may provide a means by which news programmers may respond to their audience. (RS)

  15. Introduction of Mobile Media into Formal Classroom Learning Environments

    ERIC Educational Resources Information Center

    Laskin, Alexander V.; Avena, Joseph

    2015-01-01

    Among all the technological changes in the society, smartphones have become one of the most adopted innovations. Yet, in the classroom a common response to phones in students' hands is to ban them! This study uses Social Construction of Technology theory to investigate whether mobile media can have a place in the classroom. Using in-depth…

  16. Children and Their Changing Media Environment: A European Comparative Study.

    ERIC Educational Resources Information Center

    Livingstone, Sonia, Ed.; Bovill, Moira, Ed.

    Integrating broadcasting, video, computing, games, and the Internet, the domestic television screen is being transformed into the site of a multimedia culture. To address questions about the meaning and uses of such new media, this volume brings together work by researchers in 12 countries--Belgium, Denmark, Finland, France, Germany, the United…

  17. Introduction of Mobile Media into Formal Classroom Learning Environments

    ERIC Educational Resources Information Center

    Laskin, Alexander V.; Avena, Joseph

    2015-01-01

    Among all the technological changes in the society, smartphones have become one of the most adopted innovations. Yet, in the classroom a common response to phones in students' hands is to ban them! This study uses Social Construction of Technology theory to investigate whether mobile media can have a place in the classroom. Using in-depth…

  18. The convergence of neomillennial learning styles and a multi-user virtual environment

    NASA Astrophysics Data System (ADS)

    Dieterle, Edward Robert, II

    Learning styles influenced and cultivated by immersive technologies have spawned a new area of research, "neomillennial" learning styles (NLS). The present study utilizes a quantitative approach, including principal components analysis and multiple regression/correlation analysis, to investigate NLS. Evidence supporting the arguments laid out in this study derives from a sample of 574 middle grades students from urban, suburban, and rural school settings in North America that participated in the River City Project (RCP) in academic year 2006-07. Central to RCP is an immersive simulation for teaching inquiry-based science and 21st century skills, where success is measured across five dimensions: (a) collaboration, (b) science content understanding, (c) self-efficacy in science, (d) self-efficacy in scientific inquiry, and (e) thoughtfulness of inquiry. Besides taking part in RCP, participating students completed an instrument that generates a profile of their NLS. The resulting profile includes measures of students' fluency in multiple media; the extent to which they prefer learning based on collectively seeking, sieving, and synthesizing experiences; and their tendency toward expression through webs of representations. This study revealed that, on average, a student who prefers: (1) engaging tasks that require creative strategies and seeing and doing things in new ways, while avoiding tasks that involve details, is well suited for learning disease transmission and the scientific method in RCP; (2) distributing attention across multiple tasks that have been prioritized will further his or her belief in their ability to do science by participating via RCP whereas the same conditions may undercut a student who avoids distributing attention across multiple tasks that have been prioritized; (3) to read books, magazines, and newspapers by choice and who score high on measures of their general connectedness with the media is well suited for increasing his or her belief in

  19. The Virtual Collaboration Environment: New Media for Crisis Response

    DTIC Science & Technology

    2011-05-01

    Edinburgh a.tate@ed.ac.uk Jeffrey Hansberger US Army Research Laboratory jeff.hansberger@us.army.mil ABSTRACT This paper concerns the use of new media...the US Joint Forces Command (USJFCOM) and the US Army Research Laboratory’s Human Research and Engineering Directorate (ARL HRED) launched a project...5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) US Army Research Laboratory,Adelphi

  20. Social Media Influencing C2 in Underdeveloped and Degraded Operational Environments

    DTIC Science & Technology

    2013-06-01

    18th ICCRTS: “C2 in Underdeveloped, Degraded and Denied Operational Environments” Paper ID: 103 Social Media Influencing C2 in Underdeveloped...of emergencies and crises is rapidly changing the C2 operational environment for responses to natural disasters, terrorist threats and social ...when information is scarce, social media have been elected by citizens as valuable instruments for identifying and locating victims, for assisting

  1. Engaging Learners through Interactive Media: Findings and Implications from a Technology Enhanced Problem-Based Learning Environment

    ERIC Educational Resources Information Center

    Horton, Lucas; Liu, Min; Olmanson, Justin; Toprac, Paul

    2011-01-01

    In this paper we explore students' engagement in a new media enhanced problem-based learning (PBL) environment and investigate the characteristics of these environments that facilitate learning. We investigated both student experiences using a new media enhanced PBL environment and the specific elements students found most supportive of their…

  2. The PACA Project: Convergence of Scientific Research, Social Media and Citizen Science in the Era of Astronomical Big Data

    NASA Astrophysics Data System (ADS)

    Yanamandra-Fisher, Padma A.

    2015-08-01

    The Pro-Am Collaborative Astronomy (PACA) project promotes and supports the professional-amateur astronomer collaboration in scientific research via social media and has been implemented in several comet observing campaigns. In 2014, two comet observing campaigns involving pro-am collaborations were initiated: (1) C/2013 A1 (C/SidingSpring) and (2) 67P/Churyumov-Gerasimenko (CG), target for ESA/Rosetta mission. The evolving need for individual customized observing campaigns has been incorporated into the evolution of The PACA Project that currently is focused on comets: from supporting observing campaigns of current comets, legacy data, historical comets; interconnected with social media and a set of shareable documents addressing observational strategies; consistent standards for data; data access, use, and storage, to align with the needs of professional observers in the era of astronmical big data. The empowerment of amateur astronomers vis-à-vis their partnerships with the professional scientists creates a new demographic of data scientists, enabling citizen science of the integrated data from both the professional and amateur communities.While PACA identifies a consistent collaborative approach to pro-am collaborations, given the volume of data generated for each campaign, new ways of rapid data analysis, mining access and storage are needed. Several interesting results emerged from the synergistic inclusion of both social media and amateur astronomers. The PACA Project is expanding to include pro-am collaborations on other solar system objects; allow for immersive outreach and include various types of astronomical communities, ranging from individuals, to astronmical societies and telescopic networks. Enabling citizen science research in the era of astronomical big data is a challenge which requires innovative approaches and integration of professional and amateur astronomers with data scientists and some examples of recent projects will be highlighted.

  3. Guaranteeing QoS of media-based applications in virtualized environment

    NASA Astrophysics Data System (ADS)

    Zhou, Like; Wu, Song; Shi, Xuanhua; Jin, Hai; Zhou, Jiangfu

    2013-12-01

    With the rapid development of web technology and smart phone, multimedia contents spread all over the Internet. The prevalence of virtualization technology enables multimedia service providers to run media servers in virtualized servers or rented virtual machines (VMs) in a cloud environment. Although server consolidation using virtualization can substantially increase the efficient use of server resources, it introduces resources competition among VMs running different applications. Recently, hypervisors do not make any Quality of Service (QoS) guarantee for media-based applications if they are consolidated with other network-intensive applications, which leads to significant performance degradation. For example, Xen only offers a static method to allocate network bandwidth. In this paper, we find that the performance of media-based applications running in VMs degrades seriously when they are consolidated with other VMs running network-intensive applications and argues that dynamic network bandwidth allocation is essential to guarantee the QoS of media-based applications. Then, we present a dynamic network bandwidth allocation system in virtualized environment, which allocates network bandwidth dynamically and effectively, and does not interrupt running services in VMs. The experiments show that our system can not only guarantee the QoS of media-based applications well but also maximize the system's the overall performance while ensuring the QoS of media-based applications.

  4. A multi-gene phylogeny of Cephalopoda supports convergent morphological evolution in association with multiple habitat shifts in the marine environment

    PubMed Central

    2012-01-01

    Background The marine environment is comprised of numerous divergent organisms living under similar selective pressures, often resulting in the evolution of convergent structures such as the fusiform body shape of pelagic squids, fishes, and some marine mammals. However, little is known about the frequency of, and circumstances leading to, convergent evolution in the open ocean. Here, we present a comparative study of the molluscan class Cephalopoda, a marine group known to occupy habitats from the intertidal to the deep sea. Several lineages bear features that may coincide with a benthic or pelagic existence, making this a valuable group for testing hypotheses of correlated evolution. To test for convergence and correlation, we generate the most taxonomically comprehensive multi-gene phylogeny of cephalopods to date. We then create a character matrix of habitat type and morphological characters, which we use to infer ancestral character states and test for correlation between habitat and morphology. Results Our study utilizes a taxonomically well-sampled phylogeny to show convergent evolution in all six morphological characters we analyzed. Three of these characters also correlate with habitat. The presence of an autogenic photophore (those relying upon autonomous enzymatic light reactions) is correlated with a pelagic habitat, while the cornea and accessory nidamental gland correlate with a benthic lifestyle. Here, we present the first statistical tests for correlation between convergent traits and habitat in cephalopods to better understand the evolutionary history of characters that are adaptive in benthic or pelagic environments, respectively. Discussion Our study supports the hypothesis that habitat has influenced convergent evolution in the marine environment: benthic organisms tend to exhibit similar characteristics that confer protection from invasion by other benthic taxa, while pelagic organisms possess features that facilitate crypsis and communication

  5. A multi-gene phylogeny of Cephalopoda supports convergent morphological evolution in association with multiple habitat shifts in the marine environment.

    PubMed

    Lindgren, Annie R; Pankey, Molly S; Hochberg, Frederick G; Oakley, Todd H

    2012-07-28

    The marine environment is comprised of numerous divergent organisms living under similar selective pressures, often resulting in the evolution of convergent structures such as the fusiform body shape of pelagic squids, fishes, and some marine mammals. However, little is known about the frequency of, and circumstances leading to, convergent evolution in the open ocean. Here, we present a comparative study of the molluscan class Cephalopoda, a marine group known to occupy habitats from the intertidal to the deep sea. Several lineages bear features that may coincide with a benthic or pelagic existence, making this a valuable group for testing hypotheses of correlated evolution. To test for convergence and correlation, we generate the most taxonomically comprehensive multi-gene phylogeny of cephalopods to date. We then create a character matrix of habitat type and morphological characters, which we use to infer ancestral character states and test for correlation between habitat and morphology. Our study utilizes a taxonomically well-sampled phylogeny to show convergent evolution in all six morphological characters we analyzed. Three of these characters also correlate with habitat. The presence of an autogenic photophore (those relying upon autonomous enzymatic light reactions) is correlated with a pelagic habitat, while the cornea and accessory nidamental gland correlate with a benthic lifestyle. Here, we present the first statistical tests for correlation between convergent traits and habitat in cephalopods to better understand the evolutionary history of characters that are adaptive in benthic or pelagic environments, respectively. Our study supports the hypothesis that habitat has influenced convergent evolution in the marine environment: benthic organisms tend to exhibit similar characteristics that confer protection from invasion by other benthic taxa, while pelagic organisms possess features that facilitate crypsis and communication in an environment lacking

  6. Engagement in social media environments for individuals with who use augmentative and alternative communication.

    PubMed

    Caron, Jessica

    2016-10-14

    Communicative interactions, despite the mode (e.g., face-to-face, online) rely on the communication skills of each individual participating. Some individuals have significant speech and language impairments and require the use of augmentative and alternative communication (AAC) (i.e., signs, speech generating devices) to maximize their communication participation across a variety of on and offline contexts. Use of social media has brought about changes to communication environments, contributing new contexts for engagement. To provide a framework for considering application of engagement theory for interventions around social media use by individuals who use AAC. The author has applied examples from qualitative social media and AAC research to a framework of engagement. No formal data collection was used. Social media use has become a conventional form of communication. Yet recognition of the value of social media (and other electronic modalities) for individuals who use AAC has not been fully translated into practice. The examples used illustrated how the proposed framework can assist in clinical practice and future research directions. Engagement, including the proposed framework for considerations of social media engagement activities, can provide a systematic way to approach social media use for individuals who use AAC.

  7. Use of static and dynamic media to simulate environments: a meta-analysis.

    PubMed

    Stamps, Arthur E

    2010-10-01

    This article is a review of studies on how strongly responses from static media (such as color slides) and dynamic media (such as virtual reality models) compared to onsite evaluations or to each other. Eighty-four empirical findings were found. 6,323 participants and 967 environments were included in the review. The overall correlation of subjective responses obtained either onsite or by viewing static color simulations was r = .86. The overall correlation of subjective responses obtained either onsite or by viewing dynamic simulations was r = .83. The overall correlation of subjective responses obtained either from static or dynamic media was r = .82. It is suggested that both types of simulation generate statistically equivalent results and so a choice of simulation media should be based on efficacy rather than concerns about validity.

  8. Mass Media Campaigns in a Hostile Environment: Advertising as Anti-Health Education.

    ERIC Educational Resources Information Center

    Wallack, Lawrence M.

    1983-01-01

    Charges that mass media campaigns have not been effective in dealing with such public health problems as drinking, smoking, and drugs. Reasons for this lack of effectiveness are discussed in terms of a hostile environment of antihealth advertising. Three conditions for success (monopolization, canalization, and supplementation) are discussed. (JAC)

  9. Media, Tourism, Environment, and Cultural Issues in Australia: A Case Study of a Study Abroad Program

    ERIC Educational Resources Information Center

    Freedman, Eric

    2010-01-01

    A multidisciplinary study abroad program developed by a U.S. journalism school and cosponsored by a college of agriculture and natural resources interweaves the themes of mass media, tourism, environment, and cultural issues in Australia. This article traces the development and evolution of the faculty-led program and discusses its curriculum,…

  10. Instructional Designers' Media Selection Practices for Distributed Problem-Based Learning Environments

    ERIC Educational Resources Information Center

    Fells, Stephanie

    2012-01-01

    The design of online or distributed problem-based learning (dPBL) is a nascent, complex design problem. Instructional designers are challenged to effectively unite the constructivist principles of problem-based learning (PBL) with appropriate media in order to create quality dPBL environments. While computer-mediated communication (CMC) tools and…

  11. Media, Tourism, Environment, and Cultural Issues in Australia: A Case Study of a Study Abroad Program

    ERIC Educational Resources Information Center

    Freedman, Eric

    2010-01-01

    A multidisciplinary study abroad program developed by a U.S. journalism school and cosponsored by a college of agriculture and natural resources interweaves the themes of mass media, tourism, environment, and cultural issues in Australia. This article traces the development and evolution of the faculty-led program and discusses its curriculum,…

  12. Parent and child screen-viewing time and home media environment.

    PubMed

    Jago, Russell; Stamatakis, Emmanuel; Gama, Augusta; Carvalhal, Isabel Mourão; Nogueira, Helena; Rosado, Vítor; Padez, Cristina

    2012-08-01

    Screen-viewing time has been associated with adverse health outcomes. Data on the predictors of youth screen-viewing time is predominately from older children in North America. Parental and home media environment factors that are associated with screen-viewing time could be targeted in interventions. Examine if parental screen-viewing time and electronic media (access to game equipment, TVs, PCs, and laptops) environment factors were associated with Portuguese children's screen-viewing time and if associations differed by child age (<7 vs ≥7 years); gender; or type of screen viewing. Data are reported for 2965 families with children aged 3-10 years. Data were collected in 2009-2010 and analyzed in 2011. Outcomes were child spending ≥2 hours watching TV and ≥1 hour per day playing with combined other media. Exposures were mothers and fathers watching ≥2 hours of TV and electronic media variables. Parental TV-viewing time was strongly associated with child weekday and weekend TV-viewing time across all four gender and age subgroups. Maternal TV-viewing time was a stronger predictor of child TV-viewing time than paternal TV-viewing time. There was very limited evidence that parental TV-viewing time was associated with combined other media time among boys or girls. Access to electronic game equipment increased the likelihood that children spent >1 hour using combined other media on weekdays and weekend days. Parental TV-viewing time was associated with Portuguese children's TV-viewing time. The numbers of TVs in the household and electronic games equipment access were also associated with TV- and combined other media-viewing/usage time. Copyright © 2012 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

  13. Stochastic Porous Media Equations and Self-Organized Criticality: Convergence to the Critical State in all Dimensions

    NASA Astrophysics Data System (ADS)

    Barbu, Viorel; Röckner, Michael

    2012-04-01

    If X = X( t, ξ) is the solution to the stochastic porous media equation in {{O}subset {R}^d, 1le dle 3,} modelling the self-organized criticality (Barbu et al. in Commun Math Phys 285:901-923, 2009) and X c is the critical state, then it is proved that {int^{infty}_0m({O}{setminus}{O}^t_0)dt<{infty},{P}-a.s.} and {lim_{tto{infty}} int_{O}|X(t)-X_c|dξ=ell<{infty}, {P}-a.s.} Here, m is the Lebesgue measure and {{O}^t_c} is the critical region {\\{ξin{O}; X(t,ξ)=X_c(ξ)\\}} and X c ( ξ) ≤ X(0, ξ) a.e. {ξin{O}}. If the stochastic Gaussian perturbation has only finitely many modes (but is still function-valued), {lim_{t to {infty}} int_K|X(t)-X_c|dξ=0} exponentially fast for all compact {Ksubset{O}} with probability one, if the noise is sufficiently strong. We also recover that in the deterministic case ℓ = 0.

  14. Convergence Among Multiple Methods of Measuring Positivity and Negativity in the Family Environment: Relation to Depression inMothers and Their Children

    PubMed Central

    Park, Irene J. Kim; Garber, Judy; Ciesla, Jeffrey A.; Ellis, Bruce J.

    2010-01-01

    The present study addressed the following questions: (a) To what extent do different methods of measuring the family environment converge onto a single latent construct? (b) How are the constructs of positive and of negative family environment related? (c) Do the associations among various methods of measuring the family environment differ as a function of children's gender or of risk? and (d) How are the latent constructs of family environment related to depression in mothers and their children? Participants were 240 children (mean age = 11.86 years, SD = 0.57) and their mothers, who varied with regard to their history of depression. Family environment was measured with self-report questionnaires completed separately by mothers and by children, observations of mother–child interactions, and a 5-min speech sample of each mother talking about her child. Confirmatory factor analyses revealed that different methods for assessment of the family environment converged and that the constructs of positive and of negative family environments were significantly related to each other and to depression in both mothers and their children. These findings may help inform future intervention efforts by highlighting specific parenting dimensions that are strongly associated with maternal and with child depression. PMID:18266539

  15. Convergence Insufficiency

    MedlinePlus

    ... report of improvement in symptoms. What is the method of treatment for convergence insufficiency? Convergence insufficiency can ... be brought in to the office visit. Which method of treatment will be used for an individual ...

  16. The Convergence Years

    ERIC Educational Resources Information Center

    Kolodzy, Janet; Grant, August E.; DeMars, Tony R.; Wilkinson, Jeffrey S.

    2014-01-01

    The emergence of the Internet, social media, and digital technologies in the twenty-first century accelerated an evolution in journalism and communication that fit under the broad term of convergence. That evolution changed the relationship between news producers and consumers. It broke down the geographical boundaries in defining our communities,…

  17. The Convergence Years

    ERIC Educational Resources Information Center

    Kolodzy, Janet; Grant, August E.; DeMars, Tony R.; Wilkinson, Jeffrey S.

    2014-01-01

    The emergence of the Internet, social media, and digital technologies in the twenty-first century accelerated an evolution in journalism and communication that fit under the broad term of convergence. That evolution changed the relationship between news producers and consumers. It broke down the geographical boundaries in defining our communities,…

  18. Selection and Transmission Processes for Information in the Emerging Media Environment: Psychological Motives and Message Characteristics.

    PubMed

    Cappella, Joseph N; Kim, Hyun Suk; Albarracín, Dolores

    2015-07-01

    The emerging media environment introduced fundamental changes in the quality and format of information available to the public, which can now flexibly seek, alter, and disseminate the information they receive. Therefore, the two processes of information selection and information retransmission are crucial for understanding the reach of any information available in the online information environment. From this starting point, we examine the common psychological motives driving information selection and transmission of attitude-relevant information: Defense and accuracy motives adding a focus on interpersonal motives. We also review message factors that can activate psychological motives leading to selection of retransmission of information, such as the desire for novelty and emotional stimulation. We speculate about the directions for the next generation of research necessary to understand exposure as a core outcome in media effects research and theory.

  19. Selection and Transmission Processes for Information in the Emerging Media Environment: Psychological Motives and Message Characteristics

    PubMed Central

    Cappella, Joseph N.; Kim, Hyun Suk; Albarracín, Dolores

    2014-01-01

    The emerging media environment introduced fundamental changes in the quality and format of information available to the public, which can now flexibly seek, alter, and disseminate the information they receive. Therefore, the two processes of information selection and information retransmission are crucial for understanding the reach of any information available in the online information environment. From this starting point, we examine the common psychological motives driving information selection and transmission of attitude-relevant information: Defense and accuracy motives adding a focus on interpersonal motives. We also review message factors that can activate psychological motives leading to selection of retransmission of information, such as the desire for novelty and emotional stimulation. We speculate about the directions for the next generation of research necessary to understand exposure as a core outcome in media effects research and theory. PMID:26190944

  20. Convergence, adaptation, and constraint.

    PubMed

    Losos, Jonathan B

    2011-07-01

    Convergent evolution of similar phenotypic features in similar environmental contexts has long been taken as evidence of adaptation. Nonetheless, recent conceptual and empirical developments in many fields have led to a proliferation of ideas about the relationship between convergence and adaptation. Despite criticism from some systematically minded biologists, I reaffirm that convergence in taxa occupying similar selective environments often is the result of natural selection. However, convergent evolution of a trait in a particular environment can occur for reasons other than selection on that trait in that environment, and species can respond to similar selective pressures by evolving nonconvergent adaptations. For these reasons, studies of convergence should be coupled with other methods-such as direct measurements of selection or investigations of the functional correlates of trait evolution-to test hypotheses of adaptation. The independent acquisition of similar phenotypes by the same genetic or developmental pathway has been suggested as evidence of constraints on adaptation, a view widely repeated as genomic studies have documented phenotypic convergence resulting from change in the same genes, sometimes even by the same mutation. Contrary to some claims, convergence by changes in the same genes is not necessarily evidence of constraint, but rather suggests hypotheses that can test the relative roles of constraint and selection in directing phenotypic evolution. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  1. Neuronal connectivity as a convergent target of gene-environment interactions that confer risk for Autism Spectrum Disorders

    PubMed Central

    Stamou, Marianna; Streifel, Karin M.; Goines, Paula E.; Lein, Pamela J.

    2013-01-01

    Evidence implicates environmental factors in the pathogenesis of Autism Spectrum Disorders (ASD). However, the identity of specific environmental chemicals that influence ASD risk, severity or treatment outcome remains elusive. The impact of any given environmental exposure likely varies across a population according to individual genetic substrates, and this increases the difficulty of identifying clear associations between exposure and ASD diagnoses. Heritable genetic vulnerabilities may amplify adverse effects triggered by environmental exposures if genetic and environmental factors converge to dysregulate the same signaling systems at critical times of development. Thus, one strategy for identifying environmental risk factors for ASD is to screen for environmental factors that modulate the same signaling pathways as ASD susceptibility genes. Recent advances in defining the molecular and cellular pathology of ASD point to altered patterns of neuronal connectivity in the developing brain as the neurobiological basis of these disorders. Studies of syndromic ASD and rare highly penetrant mutations or CNVs in ASD suggest that ASD risk genes converge on several major signaling pathways linked to altered neuronal connectivity in the developing brain. This review briefly summarizes the evidence implicating dysfunctional signaling via Ca2+-dependent mechanisms, extracellular signal-regulated kinases (ERK)/phosphatidylinositol-3-kinases (PI3K) and neuroligin-neurexin-SHANK as convergent molecular mechanisms in ASD, and then discusses examples of environmental chemicals for which there is emerging evidence of their potential to interfere with normal neuronal connectivity via perturbation of these signaling pathways. PMID:23269408

  2. From ABCs to DVDs: Profiles of Infants' Home Media Environments in the First Two Years of Life

    ERIC Educational Resources Information Center

    Mol, Suzanne E.; Neuman, Susan B.; Strouse, Gabrielle A.

    2014-01-01

    The very definition of print exposure has evolved in recent years as has the production of new media for infants and toddlers. Recognising that parents now have a confluence of media to select from, our study was designed to provide a richer understanding of home-literacy environments among 100 infants. Three profiles of families' home media…

  3. From ABCs to DVDs: Profiles of Infants' Home Media Environments in the First Two Years of Life

    ERIC Educational Resources Information Center

    Mol, Suzanne E.; Neuman, Susan B.; Strouse, Gabrielle A.

    2014-01-01

    The very definition of print exposure has evolved in recent years as has the production of new media for infants and toddlers. Recognising that parents now have a confluence of media to select from, our study was designed to provide a richer understanding of home-literacy environments among 100 infants. Three profiles of families' home media…

  4. Using social media to facilitate knowledge transfer in complex engineering environments: a primer for educators

    NASA Astrophysics Data System (ADS)

    Murphy, Glen; Salomone, Sonia

    2013-03-01

    While highly cohesive groups are potentially advantageous they are also often correlated with the emergence of knowledge and information silos based around those same functional or occupational clusters. Consequently, an essential challenge for engineering organisations wishing to overcome informational silos is to implement mechanisms that facilitate, encourage and sustain interactions between otherwise disconnected groups. This paper acts as a primer for those seeking to gain an understanding of the design, functionality and utility of a suite of software tools generically termed social media technologies in the context of optimising the management of tacit engineering knowledge. Underpinned by knowledge management theory and using detailed case examples, this paper explores how social media technologies achieve such goals, allowing for the transfer of knowledge by tapping into the tacit and explicit knowledge of disparate groups in complex engineering environments.

  5. The remote, the mouse, and the no. 2 pencil: the household media environment and academic achievement among third grade students.

    PubMed

    Borzekowski, Dina L G; Robinson, Thomas N

    2005-07-01

    Media can influence aspects of a child's physical, social, and cognitive development; however, the associations between a child's household media environment, media use, and academic achievement have yet to be determined. To examine relationships among a child's household media environment, media use, and academic achievement. During a single academic year, data were collected through classroom surveys and telephone interviews from an ethnically diverse sample of third grade students and their parents from 6 northern California public elementary schools. The majority of our analyses derive from spring 2000 data, including academic achievement assessed through the mathematics, reading, and language arts sections of the Stanford Achievement Test. We fit linear regression models to determine the associations between variations in household media and performance on the standardized tests, adjusting for demographic and media use variables. The household media environment is significantly associated with students' performance on the standardized tests. It was found that having a bedroom television set was significantly and negatively associated with students' test scores, while home computer access and use were positively associated with the scores. Regression models significantly predicted up to 24% of the variation in the scores. Absence of a bedroom television combined with access to a home computer was consistently associated with the highest standardized test scores. This study adds to the growing literature reporting that having a bedroom television set may be detrimental to young elementary school children. It also suggests that having and using a home computer may be associated with better academic achievement.

  6. Dealing with dissonance: responding to an incongruent test result in a new media environment.

    PubMed

    Vraga, Emily K

    2011-11-01

    In a new media environment replete with opportunities to test and express political identity, this study examines how people respond when confronted with a political test result that contradicts their partisan affiliation. An incongruent test result should produce motivated processing, but only when individuals do not dismiss the incongruent result will they experience dissonance and alter their social identification. Using a series of experiments, the results of this study supported these hypotheses. Implications of these findings for political psychology and message response are discussed.

  7. Tweeting nano: how public discourses about nanotechnology develop in social media environments

    NASA Astrophysics Data System (ADS)

    Runge, Kristin K.; Yeo, Sara K.; Cacciatore, Michael; Scheufele, Dietram A.; Brossard, Dominique; Xenos, Michael; Anderson, Ashley; Choi, Doo-hun; Kim, Jiyoun; Li, Nan; Liang, Xuan; Stubbings, Maria; Su, Leona Yi-Fan

    2013-01-01

    The growing popularity of social media as a channel for distributing and debating scientific information raises questions about the types of discourse that surround emerging technologies, such as nanotechnology, in online environments, as well as the different forms of information that audiences encounter when they use these online tools of information sharing. This study maps the landscape surrounding social media traffic about nanotechnology. Specifically, we use computational linguistic software to analyze a census of all English-language nanotechnology-related tweets expressing opinions posted on Twitter between September 1, 2010 and August 31, 2011. Results show that 55 % of tweets expressed certainty and 45 % expressed uncertainty. Twenty-seven percent of tweets expressed optimistic outlooks, 32 % expressed neutral outlooks and 41 % expressed pessimistic outlooks. Tweets were mapped by U.S. state, and our data show that tweets are more likely to originate from states with a federally funded National Nanotechnology Initiative center or network. The trend toward certainty in opinion coupled with the distinct geographic origins of much of the social media traffic on Twitter for nanotechnology-related opinion has significant implications for understanding how key online influencers are debating and positioning the issue of nanotechnology for lay and policy audiences.

  8. Convergence in relationships between leaf traits, spectra and age across diverse canopy environments and two contrasting tropical forests.

    PubMed

    Wu, Jin; Chavana-Bryant, Cecilia; Prohaska, Neill; Serbin, Shawn P; Guan, Kaiyu; Albert, Loren P; Yang, Xi; van Leeuwen, Willem J D; Garnello, Anthony John; Martins, Giordane; Malhi, Yadvinder; Gerard, France; Oliviera, Raimundo Cosme; Saleska, Scott R

    2017-05-01

    Leaf age structures the phenology and development of plants, as well as the evolution of leaf traits over life histories. However, a general method for efficiently estimating leaf age across forests and canopy environments is lacking. Here, we explored the potential for a statistical model, previously developed for Peruvian sunlit leaves, to consistently predict leaf ages from leaf reflectance spectra across two contrasting forests in Peru and Brazil and across diverse canopy environments. The model performed well for independent Brazilian sunlit and shade canopy leaves (R(2)  = 0.75-0.78), suggesting that canopy leaves (and their associated spectra) follow constrained developmental trajectories even in contrasting forests. The model did not perform as well for mid-canopy and understory leaves (R(2)  = 0.27-0.29), because leaves in different environments have distinct traits and trait developmental trajectories. When we accounted for distinct environment-trait linkages - either by explicitly including traits and environments in the model, or, even better, by re-parameterizing the spectra-only model to implicitly capture distinct trait-trajectories in different environments - we achieved a more general model that well-predicted leaf age across forests and environments (R(2)  = 0.79). Fundamental rules, linked to leaf environments, constrain the development of leaf traits and allow for general prediction of leaf age from spectra across species, sites and canopy environments.

  9. Diffusion Dominant Solute Transport Modelling in Fractured Media Under Deep Geological Environment - 12211

    SciTech Connect

    Kwong, S.; Jivkov, A.P.

    2012-07-01

    Deep geologic disposal of high activity and long-lived radioactive waste is gaining increasing support in many countries, where suitable low permeability geological formation in combination with engineered barriers are used to provide long term waste contaminant and minimise the impacts to the environment and risk to the biosphere. This modelling study examines the solute transport in fractured media under low flow velocities that are relevant to a deep geological environment. In particular, reactive solute transport through fractured media is studied using a 2-D model, that considers advection and diffusion, to explore the coupled effects of kinetic and equilibrium chemical processes. The effects of water velocity in the fracture, matrix porosity and diffusion on solute transport are investigated and discussed. Some illustrative modelled results are presented to demonstrate the use of the model to examine the effects of media degradation on solute transport, under the influences of hydrogeological (diffusion dominant) and microbially mediated chemical processes. The challenges facing the prediction of long term degradation such as cracks evolution, interaction and coalescence are highlighted. The potential of a novel microstructure informed modelling approach to account for these effects is discussed, particularly with respect to investigating multiple phenomena impact on material performance. The GRM code is used to examine the effects of media degradation for a geological waste disposal package, under the combined hydrogeological (diffusion dominant) and chemical effects in low groundwater flow conditions that are typical of deep geological disposal systems. An illustrative reactive transport modelling application demonstrates the use of the code to examine the interplay of kinetic controlled biogeochemical reactive processes with advective and diffusive transport, under the influence of media degradation. The initial model results are encouraging which show the

  10. Media Literacy, Social Networking, and the Web 2.0 Environment for the K-12 Educator. Minding the Media: Critical Issues for Learning and Teaching. Volume 4

    ERIC Educational Resources Information Center

    de Abreu, Belinha S.

    2011-01-01

    This book, a resource for educators, uses the theme of media literacy as a lens through which to view and discuss social networking and Web 2.0 environments. There is ongoing and positive research on the participatory culture created by youth who are heavily involved in the new digital technologies, yet schools tend to avoid these mediums for fear…

  11. Media Literacy, Social Networking, and the Web 2.0 Environment for the K-12 Educator. Minding the Media: Critical Issues for Learning and Teaching. Volume 4

    ERIC Educational Resources Information Center

    de Abreu, Belinha S.

    2011-01-01

    This book, a resource for educators, uses the theme of media literacy as a lens through which to view and discuss social networking and Web 2.0 environments. There is ongoing and positive research on the participatory culture created by youth who are heavily involved in the new digital technologies, yet schools tend to avoid these mediums for fear…

  12. Media Choice for Intra-School Communication: The Role of Environment, User, and Medium

    ERIC Educational Resources Information Center

    Caspi, Avner; Blau, Ina

    2011-01-01

    The influence of media richness, media attentional load, social influence and users' prior experience with media on selection of media to transmit different messages to peers within an educational organization was tested. Media were discriminated by all potential variables. Support was found for the role of prior experience and social influence in…

  13. Media Choice for Intra-School Communication: The Role of Environment, User, and Medium

    ERIC Educational Resources Information Center

    Caspi, Avner; Blau, Ina

    2011-01-01

    The influence of media richness, media attentional load, social influence and users' prior experience with media on selection of media to transmit different messages to peers within an educational organization was tested. Media were discriminated by all potential variables. Support was found for the role of prior experience and social influence in…

  14. Social media indicators of the food environment and state health outcomes.

    PubMed

    Nguyen, Q C; Meng, H; Li, D; Kath, S; McCullough, M; Paul, D; Kanokvimankul, P; Nguyen, T X; Li, F

    2017-07-01

    Contextual factors can influence health through exposures to health-promoting and risk-inducing factors. The aim of this study was to (1) build, from geotagged Twitter and Yelp data, a national food environment database and (2) to test associations between state food environment indicators and health outcomes. This is a cross-sectional study based upon secondary analyses of publicly available data. Using Twitter's Streaming Application Programming Interface (API), we collected and processed 4,041,521 food-related, geotagged tweets between April 2015 and March 2016. Using Yelp's Search API, we collected data on 505,554 unique food-related businesses. In linear regression models, we examined associations between food environment characteristics and state-level health outcomes, controlling for state-level differences in age, percent non-Hispanic white, and median household income. A one standard deviation increase in caloric density of food tweets was related to higher all-cause mortality (+46.50 per 100,000), diabetes (+0.75%), obesity (+1.78%), high cholesterol (+1.40%), and fair/poor self-rated health (2.01%). More burger Yelp listings were related to higher prevalence of diabetes (+0.55%), obesity (1.35%), and fair/poor self-rated health (1.12%). More alcohol tweets and Yelp bars and pub listings were related to higher state-level binge drinking and heavy drinking, but lower mortality and lower percent reporting fair/poor self-rated health. Supplemental analyses with county-level social media indicators and county health outcomes resulted in finding similar but slightly attenuated associations compared to those found at the state level. Social media can be utilized to create indicators of the food environment that are associated with area-level mortality, health behaviors, and chronic conditions. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  15. Convergence in relationships between leaf traits, spectra and age across diverse canopy environments and two contrasting tropical forests

    DOE PAGES

    Wu, Jin; Chavana-Bryant, Cecilia; Prohaska, Neill; ...

    2016-07-06

    Leaf age structures the phenology and development of plants, as well as the evolution of leaf traits over life histories. Furthermore, a general method for efficiently estimating leaf age across forests and canopy environments is lacking.

  16. Application of social media in the environment and health professional community

    PubMed Central

    2012-01-01

    The purpose of the EU FP6 funded coordination action HENVINET was to create a permanent network of environment and health professionals. The main outcome is a networking portal (http://www.henvinet.eu), based on the concepts of social media to support communication between professional stakeholders in the environment and health fields. Its aim is to enable sharing of relevant information in an innovative and interactive manner to eventually support policy making. A social networking tool is not necessarily a typical platform for communication in the professional context, or between scientists and decision-makers. The aim of this paper is to look upon the use of social media in relevant professional communities in the light of the HENVINET experience, and to reflect on the acceptance and usefulness of such a new approach. The portal was designed over the course of HENVINET through intensive interactions by a multi-disciplinary group, involving environmental as well as health scientists, but with only limited access to decision-makers’ opinions. After the social networking portal was launched, a recruitment campaign was run during the last six months of the project, taking every opportunity to present the portal and to get feedback from users. This feedback was used to improve the functionalities of the tool. Additionally, a feedback session was organized at the final event of the project, attended by over 50 professionals, about half of whom participated from the beginning in the entire HENVINET project. We have also compared the HENVINET portal with similar tools employed by other related communities, and made a literature-based survey on the use of social media for scientific communication. At the end of the project, the portal had more than 300 members with registered professional profile, over 10 topics and 15 discussion groups. The HENVINET consortium members were the most active group of users. The quality of the portal content was considered more important

  17. Application of social media in the environment and health professional community.

    PubMed

    Grossberndt, Sonja; van den Hazel, Peter; Bartonova, Alena

    2012-06-28

    The purpose of the EU FP6 funded coordination action HENVINET was to create a permanent network of environment and health professionals. The main outcome is a networking portal (http://www.henvinet.eu), based on the concepts of social media to support communication between professional stakeholders in the environment and health fields. Its aim is to enable sharing of relevant information in an innovative and interactive manner to eventually support policy making. A social networking tool is not necessarily a typical platform for communication in the professional context, or between scientists and decision-makers. The aim of this paper is to look upon the use of social media in relevant professional communities in the light of the HENVINET experience, and to reflect on the acceptance and usefulness of such a new approach. The portal was designed over the course of HENVINET through intensive interactions by a multi-disciplinary group, involving environmental as well as health scientists, but with only limited access to decision-makers' opinions. After the social networking portal was launched, a recruitment campaign was run during the last six months of the project, taking every opportunity to present the portal and to get feedback from users. This feedback was used to improve the functionalities of the tool. Additionally, a feedback session was organized at the final event of the project, attended by over 50 professionals, about half of whom participated from the beginning in the entire HENVINET project. We have also compared the HENVINET portal with similar tools employed by other related communities, and made a literature-based survey on the use of social media for scientific communication. At the end of the project, the portal had more than 300 members with registered professional profile, over 10 topics and 15 discussion groups. The HENVINET consortium members were the most active group of users. The quality of the portal content was considered more important

  18. Convergence of folding free energy landscapes via application of enhanced sampling methods in a distributed computing environment.

    PubMed

    Huang, Xuhui; Bowman, Gregory R; Pande, Vijay S

    2008-05-28

    We have implemented the serial replica exchange method (SREM) and simulated tempering (ST) enhanced sampling algorithms in a global distributed computing environment. Here we examine the helix-coil transition of a 21 residue alpha-helical peptide in explicit solvent. For ST, we demonstrate the efficacy of a new method for determining initial weights allowing the system to perform a random walk in temperature space based on short trial simulations. These weights are updated throughout the production simulation by an adaptive weighting method. We give a detailed comparison of SREM, ST, as well as standard MD and find that SREM and ST give equivalent results in reasonable agreement with experimental data. In addition, we find that both enhanced sampling methods are much more efficient than standard MD simulations. The melting temperature of the Fs peptide with the AMBER99phi potential was calculated to be about 310 K, which is in reasonable agreement with the experimental value of 334 K. We also discuss other temperature dependent properties of the helix-coil transition. Although ST has certain advantages over SREM, both SREM and ST are shown to be powerful methods via distributed computing and will be applied extensively in future studies of complex bimolecular systems.

  19. Personal Learning Environments, Social Media, and Self-Regulated Learning: A Natural Formula for Connecting Formal and Informal Learning

    ERIC Educational Resources Information Center

    Dabbagh, Nada; Kitsantas, Anastasia

    2012-01-01

    A Personal Learning Environment or PLE is a potentially promising pedagogical approach for both integrating formal and informal learning using social media and supporting student self-regulated learning in higher education contexts. The purpose of this paper is to (a) review research that support this claim, (b) conceptualize the connection…

  20. Personal Learning Environments, Social Media, and Self-Regulated Learning: A Natural Formula for Connecting Formal and Informal Learning

    ERIC Educational Resources Information Center

    Dabbagh, Nada; Kitsantas, Anastasia

    2012-01-01

    A Personal Learning Environment or PLE is a potentially promising pedagogical approach for both integrating formal and informal learning using social media and supporting student self-regulated learning in higher education contexts. The purpose of this paper is to (a) review research that support this claim, (b) conceptualize the connection…

  1. Convergent chaos

    NASA Astrophysics Data System (ADS)

    Pradas, Marc; Pumir, Alain; Huber, Greg; Wilkinson, Michael

    2017-07-01

    Chaos is widely understood as being a consequence of sensitive dependence upon initial conditions. This is the result of an instability in phase space, which separates trajectories exponentially. Here, we demonstrate that this criterion should be refined. Despite their overall intrinsic instability, trajectories may be very strongly convergent in phase space over extremely long periods, as revealed by our investigation of a simple chaotic system (a realistic model for small bodies in a turbulent flow). We establish that this strong convergence is a multi-facetted phenomenon, in which the clustering is intense, widespread and balanced by lacunarity of other regions. Power laws, indicative of scale-free features, characterize the distribution of particles in the system. We use large-deviation and extreme-value statistics to explain the effect. Our results show that the interpretation of the ‘butterfly effect’ needs to be carefully qualified. We argue that the combination of mixing and clustering processes makes our specific model relevant to understanding the evolution of simple organisms. Lastly, this notion of convergent chaos, which implies the existence of conditions for which uncertainties are unexpectedly small, may also be relevant to the valuation of insurance and futures contracts.

  2. Childhood family psychosocial environment and carotid intima media thickness: the CARDIA study.

    PubMed

    Loucks, Eric B; Taylor, Shelley E; Polak, Joseph F; Wilhelm, Aude; Kalra, Preety; Matthews, Karen A

    2014-03-01

    Little is known about whether the childhood family psychosocial environment (characterized by cold, unaffectionate interactions, conflict, aggression, neglect and/or low nurturance) affects coronary heart disease (CHD) risk. Objectives were to evaluate associations of childhood family psychosocial environment with carotid intima media thickness (IMT), a subclinical measure of atherosclerosis. The study population included 2659 CARDIA study participants, aged 37-52 years. Childhood family psychosocial environment was measured using a risky family questionnaire via self-report. Carotid IMT was calculated using the average of 20 measurements of mean common carotid, bulb and internal carotid IMT, assessed using high-resolution B-mode ultrasound images. Utilizing linear regression analyses adjusted for age, a 1-unit (range 0-21) increase in risky family score was associated with 0.0036 (95% CI: 0.0006,0.0066 mm) and 0.0020 (95% CI: 0.0002,0.0038) mm increase in mean IMT in white males and females, respectively. Formal mediation analyses and covariate adjustments suggested childhood socioeconomic position and smoking may be important mechanisms in white males and females, as well as education and depressive symptomatology in white males. No associations were found in black participants. Formal statistical tests for interaction between risky family score and sex, and between risky family score and race/ethnicity, demonstrated borderline evidence of interactions for both sex (p = 0.12) and race/ethnicity (p = 0.14) with risky family score for associations with mean IMT. In conclusion, childhood family psychosocial environment was positively associated with IMT in white participants, with little evidence of association in black participants. Mechanisms in white participants may include potential negative impacts of socioeconomic constraints on parenting quality, potentially influencing offspring's cardiovascular risk factors (e.g. smoking), socioeconomic position (e

  3. The Media Environment of the '90s: A Period of Danger for Newspaper Journalism?

    ERIC Educational Resources Information Center

    McManus, John

    The news media of the 1990s will probably not use videotext systems or three-dimensional holograms to replace the newspaper. Instead, simpler combinations of news media that mimic the characteristics of print may replace advertising in newspapers, causing them to downgrade journalism or increase subscription cost, thereby decreasing circulation…

  4. Japanese Communication Research: The Emphasis on Macro Theories of Media in an "Information-Based" Environment.

    ERIC Educational Resources Information Center

    Cooper, Roger

    1997-01-01

    Most mass media research in Japan focuses on the influence of mass communication on society as a whole; these "macro" theories typically employ traditional social science techniques. Reasons for this situation are examined, as well as how media researchers outside of Japan might learn from the Japanese perspectives about the role and…

  5. Media Use and Child Sleep: The Impact of Content, Timing, and Environment

    PubMed Central

    Liekweg, Kimberly; Christakis, Dimitri A.

    2011-01-01

    BACKGROUND: Media use has been shown to negatively affect a child's sleep, especially in the context of evening use or with a television in the child's bedroom. However, little is known about how content choices and adult co-use affect this relationship. OBJECTIVE: To describe the impact of media content, timing, and use behaviors on child sleep. METHODS: These data were collected in the baseline survey and media diary of a randomized controlled trial on media use in children aged 3 to 5 years. Sleep measures were derived from the Children's Sleep Habits Questionnaire. Media diaries captured time, content title, and co-use of television, video-game, and computer usage; titles were coded for ratings, violence, scariness, and pacing. Nested linear regression models were built to examine the impact of timing, content, and co-use on the sleep problem score. RESULTS: On average, children consumed 72.9 minutes of media screen time daily, with 14.1 minutes occurring after 7:00 pm. Eighteen percent of parents reported at least 1 sleep problem; children with a bedroom television consumed more media and were more likely to have a sleep problem. In regression models, each additional hour of evening media use was associated with a significant increase in the sleep problem score (0.743 [95% confidence interval: 0.373–1.114]), as was daytime use with violent content (0.398 [95% confidence interval: 0.121–0.676]). There was a trend toward greater impact of daytime violent use in the context of a bedroom television (P = .098) and in low-income children (P = .07). CONCLUSIONS: Violent content and evening media use were associated with increased sleep problems. However, no such effects were observed with nonviolent daytime media use. PMID:21708803

  6. Media use and child sleep: the impact of content, timing, and environment.

    PubMed

    Garrison, Michelle M; Liekweg, Kimberly; Christakis, Dimitri A

    2011-07-01

    Media use has been shown to negatively affect a child's sleep, especially in the context of evening use or with a television in the child's bedroom. However, little is known about how content choices and adult co-use affect this relationship. To describe the impact of media content, timing, and use behaviors on child sleep. These data were collected in the baseline survey and media diary of a randomized controlled trial on media use in children aged 3 to 5 years. Sleep measures were derived from the Children's Sleep Habits Questionnaire. Media diaries captured time, content title, and co-use of television, video-game, and computer usage; titles were coded for ratings, violence, scariness, and pacing. Nested linear regression models were built to examine the impact of timing, content, and co-use on the sleep problem score. On average, children consumed 72.9 minutes of media screen time daily, with 14.1 minutes occurring after 7:00 pm. Eighteen percent of parents reported at least 1 sleep problem; children with a bedroom television consumed more media and were more likely to have a sleep problem. In regression models, each additional hour of evening media use was associated with a significant increase in the sleep problem score (0.743 [95% confidence interval: 0.373-1.114]), as was daytime use with violent content (0.398 [95% confidence interval: 0.121-0.676]). There was a trend toward greater impact of daytime violent use in the context of a bedroom television (P=.098) and in low-income children (P=.07). Violent content and evening media use were associated with increased sleep problems. However, no such effects were observed with nonviolent daytime media use. Copyright © 2011 by the American Academy of Pediatrics.

  7. Do convergent developmental mechanisms underlie convergent phenotypes?

    NASA Technical Reports Server (NTRS)

    Wray, Gregory A.

    2002-01-01

    Convergence is a pervasive evolutionary process, affecting many aspects of phenotype and even genotype. Relatively little is known about convergence in developmental processes, however, nor about the degree to which convergence in development underlies convergence in anatomy. A switch in the ecology of sea urchins from feeding to nonfeeding larvae illustrates how convergence in development can be associated with convergence in anatomy. Comparisons to more distantly related taxa, however, suggest that this association may be limited to relatively close phylogenetic comparisons. Similarities in gene expression during development provide another window into the association between convergence in developmental processes and convergence in anatomy. Several well-studied transcription factors exhibit likely cases of convergent gene expression in distantly related animal phyla. Convergence in regulatory gene expression domains is probably more common than generally acknowledged, and can arise for several different reasons. Copyright 2002 S. Karger AG, Basel.

  8. Do convergent developmental mechanisms underlie convergent phenotypes?

    NASA Technical Reports Server (NTRS)

    Wray, Gregory A.

    2002-01-01

    Convergence is a pervasive evolutionary process, affecting many aspects of phenotype and even genotype. Relatively little is known about convergence in developmental processes, however, nor about the degree to which convergence in development underlies convergence in anatomy. A switch in the ecology of sea urchins from feeding to nonfeeding larvae illustrates how convergence in development can be associated with convergence in anatomy. Comparisons to more distantly related taxa, however, suggest that this association may be limited to relatively close phylogenetic comparisons. Similarities in gene expression during development provide another window into the association between convergence in developmental processes and convergence in anatomy. Several well-studied transcription factors exhibit likely cases of convergent gene expression in distantly related animal phyla. Convergence in regulatory gene expression domains is probably more common than generally acknowledged, and can arise for several different reasons. Copyright 2002 S. Karger AG, Basel.

  9. Social Media in the Dental School Environment, Part A: Benefits, Challenges, and Recommendations for Use.

    PubMed

    Spallek, Heiko; Turner, Sharon P; Donate-Bartfield, Evelyn; Chambers, David; McAndrew, Maureen; Zarkowski, Pamela; Karimbux, Nadeem

    2015-10-01

    Social media consist of powerful tools that impact not only communication but relationships among people, thus posing an inherent challenge to the traditional standards of who we are as dental educators and what we can expect of each other. This article examines how the world of social media has changed dental education. Its goal is to outline the complex issues that social media use presents for academic dental institutions and to examine these issues from personal, professional, and legal perspectives. After providing an update on social media, the article considers the advantages and risks associated with the use of social media at the interpersonal, professional, and institutional levels. Policies and legal issues of which academic dental institutions need to be aware from a compliance perspective are examined, along with considerations and resources needed to develop effective social media policies. The challenge facing dental educators is how to capitalize on the benefits that social media offer, while minimizing risks and complying with the various forms of legal constraint.

  10. From Augmentation Media to Meme Media.

    ERIC Educational Resources Information Center

    Tanaka, Yuzuru

    Computers as meta media are now evolving from augmentation media vehicles to meme media vehicles. While an augmentation media system provides a seamlessly integrated environment of various tools and documents, meme media system provides further functions to edit and distribute tools and documents. Documents and tools on meme media can easily…

  11. Converging Interests

    ERIC Educational Resources Information Center

    Nance, Molly

    2009-01-01

    When the first Earth Day was celebrated in 1970, millions of Americans--many of whom were college and university students--participated in an effort that sought to improve the quality of the environment and conserve natural resources. Since then, environmental studies programs have popped up throughout the nation, creating jobs for ecologists,…

  12. Converging Interests

    ERIC Educational Resources Information Center

    Nance, Molly

    2009-01-01

    When the first Earth Day was celebrated in 1970, millions of Americans--many of whom were college and university students--participated in an effort that sought to improve the quality of the environment and conserve natural resources. Since then, environmental studies programs have popped up throughout the nation, creating jobs for ecologists,…

  13. Volume serving and media management in a networked, distributed client/server environment

    NASA Technical Reports Server (NTRS)

    Herring, Ralph H.; Tefend, Linda L.

    1993-01-01

    The E-Systems Modular Automated Storage System (EMASS) is a family of hierarchical mass storage systems providing complete storage/'file space' management. The EMASS volume server provides the flexibility to work with different clients (file servers), different platforms, and different archives with a 'mix and match' capability. The EMASS design considers all file management programs as clients of the volume server system. System storage capacities are tailored to customer needs ranging from small data centers to large central libraries serving multiple users simultaneously. All EMASS hardware is commercial off the shelf (COTS), selected to provide the performance and reliability needed in current and future mass storage solutions. All interfaces use standard commercial protocols and networks suitable to service multiple hosts. EMASS is designed to efficiently store and retrieve in excess of 10,000 terabytes of data. Current clients include CRAY's YMP Model E based Data Migration Facility (DMF), IBM's RS/6000 based Unitree, and CONVEX based EMASS File Server software. The VolSer software provides the capability to accept client or graphical user interface (GUI) commands from the operator's console and translate them to the commands needed to control any configured archive. The VolSer system offers advanced features to enhance media handling and particularly media mounting such as: automated media migration, preferred media placement, drive load leveling, registered MediaClass groupings, and drive pooling.

  14. What Drives Students' Loyalty-Formation in Social Media Learning within a Personal Learning Environment Approach? The Moderating Role of Need for Cognition

    ERIC Educational Resources Information Center

    Arquero, José L.; del Barrio-García, Salvador; Romero-Frías, Esteban

    2017-01-01

    Our study analyzes an educational experience based on the integrated use of social media within a higher education course under a personal learning environment approach and investigates the factors that determine students' loyalty to social media learning. We examined the moderating role of need for cognition (NFC) in students' formation of…

  15. Middle School Students Are Co-Researchers of Their Media Environment: An Integrated Project

    ERIC Educational Resources Information Center

    Bernt, Phyllis W.; Turner, Sandra V.; Bernt, Joseph P.

    2005-01-01

    Collaborating with three university researchers, three seventh-grade teachers and their students worked on one component of a three-year NSF-funded research project examining the media messages about information technology and careers that middle school students receive from television, popular magazines, books, videotapes, movies, and Web sites.…

  16. Social Media in the Classroom: A Simple yet Complex Hybrid Environment for Students

    ERIC Educational Resources Information Center

    Casey, Gail

    2013-01-01

    This article reports on part of the author's PhD action research study. It examines the complexity of features that social media and Web 2.0 offer when combined with face-to-face teaching and learning. Action research was used to help redesign the learning programs of XXX's thirteen Middle Years classes over an eighteen month period. These…

  17. Social Media in the Dental School Environment, Part B: Curricular Considerations.

    PubMed

    Spallek, Heiko; Turner, Sharon P; Donate-Bartfield, Evelyn; Chambers, David; McAndrew, Maureen; Zarkowski, Pamela; Karimbux, Nadeem

    2015-10-01

    The goal of this article is to describe the broad curricular constructs surrounding teaching and learning about social media in dental education. This analysis takes into account timing, development, and assessment of the knowledge, skills, attitudes, and behaviors needed to effectively use social media tools as a contemporary dentist. Three developmental stages in a student's path to becoming a competent professional are described: from undergraduate to dental student, from the classroom and preclinical simulation laboratory to the clinical setting, and from dental student to licensed practitioner. Considerations for developing the dental curriculum and suggestions for effective instruction at each stage are offered. In all three stages in the future dentist's evolution, faculty members need to educate students about appropriate professional uses of social media. Faculty members should provide instruction on the beneficial aspects of this communication medium and help students recognize the potential pitfalls associated with its use. The authors provide guidelines for customizing instruction to complement each stage of development, recognizing that careful timing is not only important for optimal learning but can prevent inappropriate use of social media as students are introduced to novel situations.

  18. Learning Science in Virtual Reality Multimedia Environments: Role of Methods and Media.

    ERIC Educational Resources Information Center

    Moreno, Roxana; Mayer, Richard E.

    2002-01-01

    College students learned about botany through an agent-based multimedia game. Students received either spoken or identical on-screen text explanations. Results reveal that students scored higher on retention, transfer, and program ratings in narration conditions than in text conditions. The media--desktop displays or headmounted displays--did not…

  19. Social Media in the Classroom: A Simple yet Complex Hybrid Environment for Students

    ERIC Educational Resources Information Center

    Casey, Gail

    2013-01-01

    This article reports on part of the author's PhD action research study. It examines the complexity of features that social media and Web 2.0 offer when combined with face-to-face teaching and learning. Action research was used to help redesign the learning programs of XXX's thirteen Middle Years classes over an eighteen month period. These…

  20. An Analysis of Electronic Media to Prepare Children for Safe and Ethical Practices in Digital Environments

    ERIC Educational Resources Information Center

    Berson, Ilene R.; Berson, Michael J.; Desai, Shreya; Falls, Donald; Fenaughty, John

    2008-01-01

    A range of electronic resources, including video-based instruction, are used to promote cybersafety to young people at school. This evaluation analyzed seven distinct programs that use electronic media in Internet safety initiatives in schools. The findings highlight emerging evidence on successful approaches to engage children in assessing risky…

  1. Mass Media and the Environment: Volume One, San Francisco and Monterey Bay Water Resources.

    ERIC Educational Resources Information Center

    Sachs, David Peter; Rubin, David Mark

    In an interdisciplinary project graduate students from several fields--including medicine and communication--conducted an assessment and critique of media performance in the are of environmental problems. The project had no direct faculty supervision--the first such student project funded by the National Science Foundation. This volume presents an…

  2. Learning Science in Virtual Reality Multimedia Environments: Role of Methods and Media.

    ERIC Educational Resources Information Center

    Moreno, Roxana; Mayer, Richard E.

    2002-01-01

    College students learned about botany through an agent-based multimedia game. Students received either spoken or identical on-screen text explanations. Results reveal that students scored higher on retention, transfer, and program ratings in narration conditions than in text conditions. The media--desktop displays or headmounted displays--did not…

  3. An Analysis of Electronic Media to Prepare Children for Safe and Ethical Practices in Digital Environments

    ERIC Educational Resources Information Center

    Berson, Ilene R.; Berson, Michael J.; Desai, Shreya; Falls, Donald; Fenaughty, John

    2008-01-01

    A range of electronic resources, including video-based instruction, are used to promote cybersafety to young people at school. This evaluation analyzed seven distinct programs that use electronic media in Internet safety initiatives in schools. The findings highlight emerging evidence on successful approaches to engage children in assessing risky…

  4. Gas in Scattering Media Absorption Spectroscopy -- Laser Spectroscopy in Unconventional Environments

    NASA Astrophysics Data System (ADS)

    Svanberg, Sune

    2010-02-01

    An overview of the new field of Gas in Scattering Media Absorption Spectroscopy (GASMAS) is presented. The GASMAS technique combines narrow-band diode-laser spectroscopy with optical propagation in diffuse media. Whereas solids and liquids have broad absorption features, free gas in pores and cavities in the material is characterized by sharp spectral signatures. These are typically 10,000 times sharper than those of the host material. Many applications in materials science, food packaging, pharmaceutics and medicine have been demonstrated. Molecular oxygen and water vapor have been studied around 760 and 935 nm, respectively. Liquid water, an important constituent in many natural materials, such as tissue, has a low absorption at such wavelengths, allowing propagation. Polystyrene foam, wood, fruits, food-stuffs, pharmaceutical tablets, and human sinus cavities have been studied, demonstrating new possibilities for characterization and diagnostics. Transport of gas in porous media can readily be studied by first immersing the material in, e.g., pure nitrogen gas, and then observing the rate at which normal air, containing oxygen, reinvades the material. The conductance of the human sinus connective passages can be measured in this way by flushing the nasal cavity with nitrogen, while breathing normally through the mouth. A clinical study comprising 40 patients has been concluded.

  5. A Delphi Study: Expert Recommendations on Employing Instructional Media in Collaborative Online Learning Environments

    ERIC Educational Resources Information Center

    Ortiz-Arteaga, Carmen A.

    2013-01-01

    Instructional designers must design and develop online learning environments that present the content in a way that learners will find important and useful. Faculty and novice designers are being tasked to design and develop online learning environments without having the necessary knowledge or experience in instructional design in order to select…

  6. A Delphi Study: Expert Recommendations on Employing Instructional Media in Collaborative Online Learning Environments

    ERIC Educational Resources Information Center

    Ortiz-Arteaga, Carmen A.

    2013-01-01

    Instructional designers must design and develop online learning environments that present the content in a way that learners will find important and useful. Faculty and novice designers are being tasked to design and develop online learning environments without having the necessary knowledge or experience in instructional design in order to select…

  7. [Digital media as laypeople's source of information about the environment and health].

    PubMed

    Sassenberg, Kai

    2017-06-01

    Over the last two decades, the Internet has become the primary source of information. Thanks to the Internet, laypeople have access to information from the health and the environmental sector, which was for a long time available only to experts (e. g. scientific publications, statistics). Information on the Internet varies in quality, as generally anybody can publish online, without any quality control. At the same time, Internet use comes with specific situational characteristics. Given that the amount of information is nearly unlimited and that this information is easily available via search engines, users are not restricted to one or just a few texts, but can choose between multiple sources depending on their motivation and interest. Together with the heterogeneity of the sources, this provides the basis for a strong impact of motivation on the process and the outcomes of information acquisition online. Based on empirical research in the domain of Internet searching in the health sector, the current article discusses the impact of the use of digital media in the context of environmental medicine. Research has led to four conclusions: (1) Users are not sufficiently sensitive to the quality of information. (2) Information supporting their own opinion is preferably processed. (3) Users who feel threatened focus on positive information. (4) Vigilant users focus on negative information, which might result in cyberchrondria. The implications of these effects for the use of digital media in the sector of environmental medicine are discussed.

  8. Evaluation of volcanic pumice stone as media in fixed bed sequence batch reactor for atrazine removal from aquatic environments.

    PubMed

    Derakhshan, Zahra; Ehrampoush, Mohammad Hassan; Mahvi, Amir Hossein; Faramarzian, Mohammad; Mokhtari, Mehdi; Mazloomi, Seyed Mohammad

    2016-12-01

    Atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) is a component of S-triazine. Its characteristics make it a pollutant of ecosystems and a probable human carcinogen. The present study evaluated volcanic pumice stone as a suitable media for biological growth and biofilm development in a fixed-bed sequencing batch reactor (FBSBR) for atrazine removal from aquatic environments. The FBSBR was fed with synthetic wastewater containing sucrose and atrazine at four hydraulic retention times to assess biodegradation of atrazine by a microbial consortium for removal from aquatic environments. The maximum efficiency for atrazine and soluble chemical oxygen demand removal were 97.9% and 98.9%, respectively. The results of this research showed that the Stover-Kincannon model was a very good fit (R(2) > 99%) for loading atrazine onto the FBSBR. Increasing the initial concentration of atrazine increased the removal efficiency. There was no significant inhibition of the mixed aerobic microbial consortia by the atrazine. Atrazine degradation depended on its initial concentration in the wastewater and the amount of atrazine in the influent. Although this system shows good potential for atrazine removal from aqueous environments, that remaining in the effluent does not yet meet international standards. Further research is required to make this system effective for removal of atrazine from the environment.

  9. U.S. News Media Coverage of Pharmaceutical Pollution in the Aquatic Environment: A Content Analysis of the Problems and Solutions Presented by Actors.

    PubMed

    Blair, Benjamin; Zimny-Schmitt, Daniel; Rudd, Murray A

    2017-08-01

    Pharmaceutical pollution in the aquatic environment is an issue of concern that has attracted attention by the news media. Understanding the factors that contribute to media framing of pharmaceutical pollution may lead to a better understanding of the management and governance of this issue, including why these pollutants are generally unregulated at this time. This study conducted a content analysis of 405 newspaper articles (81 had substantive information on the topic) from 2007 to 2014, using the search terms "water" and "pharmaceuticals" in the Chicago Tribune, Denver Post, Los Angeles Times, New York Daily News, New York Times, USA Today, Wall Street Journal, and Washington Post. We sought to analyze the factors that contributed to the news media presentation of pharmaceutical pollution in the United States, including the presentation of the risks/safety and solutions by various actors. We found that the primary issues in the news media were uncertainty regarding public health and harm to the environment. The primary solutions recommended within the news media were implementing additional water treatment technologies, taking unused pharmaceuticals to predetermined sites for disposal (take-back programs), and trash disposal of unused pharmaceuticals. Water utilities and scientists presented improved water treatment technology, government actors presented take-back programs, and pharmaceutical representatives, while sparsely involved in the news media, presented trash disposal as their primary solutions. To advance the understanding of the management of pharmaceutical pollution, this article offers further insight into the debate and potential solutions within the news media presentation of this complex scientific topic.

  10. U.S. News Media Coverage of Pharmaceutical Pollution in the Aquatic Environment: A Content Analysis of the Problems and Solutions Presented by Actors

    NASA Astrophysics Data System (ADS)

    Blair, Benjamin; Zimny-Schmitt, Daniel; Rudd, Murray A.

    2017-08-01

    Pharmaceutical pollution in the aquatic environment is an issue of concern that has attracted attention by the news media. Understanding the factors that contribute to media framing of pharmaceutical pollution may lead to a better understanding of the management and governance of this issue, including why these pollutants are generally unregulated at this time. This study conducted a content analysis of 405 newspaper articles (81 had substantive information on the topic) from 2007 to 2014, using the search terms "water" and "pharmaceuticals" in the Chicago Tribune, Denver Post, Los Angeles Times, New York Daily News, New York Times, USA Today, Wall Street Journal, and Washington Post. We sought to analyze the factors that contributed to the news media presentation of pharmaceutical pollution in the United States, including the presentation of the risks/safety and solutions by various actors. We found that the primary issues in the news media were uncertainty regarding public health and harm to the environment. The primary solutions recommended within the news media were implementing additional water treatment technologies, taking unused pharmaceuticals to predetermined sites for disposal (take-back programs), and trash disposal of unused pharmaceuticals. Water utilities and scientists presented improved water treatment technology, government actors presented take-back programs, and pharmaceutical representatives, while sparsely involved in the news media, presented trash disposal as their primary solutions. To advance the understanding of the management of pharmaceutical pollution, this article offers further insight into the debate and potential solutions within the news media presentation of this complex scientific topic.

  11. Constructing Media Artifacts in a Social Constructivist Environment to Enhance Students' Environmental Awareness and Activism

    NASA Astrophysics Data System (ADS)

    Karahan, Engin; Roehrig, Gillian

    2015-02-01

    Current science education reforms and policy documents highlight the importance of environmental awareness and perceived need for activism. As "environmental problems are socially constructed in terms of their conceptualized effects on individuals, groups, other living things and systems research based on constructivist principles provides not only a coherent framework in which to theorize about learning, but also a context for understanding socially constructed issues" (Palmer and Suggate in Res Pap Educ 19(2), 2004, p. 208). This research study investigated the impacts of the learning processes structured based on the theories of constructionism and social constructivism on students' environmental awareness and perceived need for activism. Students constructed multimedia artifacts expressing their knowledge, attitudes, awareness, and activism about environmental issues through a constructionist design process. In addition, a social networking site was designed and used to promote social interaction among students. Twenty-two high school environmental science students participated in this study. A convergent mixed methods design was implemented to allow for the triangulation of methods by directly comparing and contrasting quantitative results with qualitative findings for corroboration and validation purposes. Using a mixed method approach, quantitative findings are supported with qualitative data (student video projects, writing prompts, blog entries, video projects of the students, observational field notes, and reflective journals) including spontaneous responses in both synchronous and asynchronous conversations on the social network to provide a better understanding of the change in students' environmental awareness and perceived need for activism. The findings of the study indicated that students' environmental awareness and perceived need for activism were improved at different scales (personal, community, global) throughout the constructionist and social

  12. Home Musical Environment of Children in Singapore: On Globalization, Technology, and Media

    ERIC Educational Resources Information Center

    Lum, Chee-Hoo

    2008-01-01

    The home musical environments of a class of 28 first-grade children in Singapore were examined in this ethnographic study. Technology was an integral part of the soundscape in the home. The musical repertoire gathered was closely associated with electronic and pop-influenced music, approaching the styles favored by teens and adults. Particular…

  13. Human-Computer Interaction (HCI) in Educational Environments: Implications of Understanding Computers as Media.

    ERIC Educational Resources Information Center

    Berg, Gary A.

    2000-01-01

    Reviews literature in the field of human-computer interaction (HCI) as it applies to educational environments. Topics include the origin of HCI; human factors; usability; computer interface design; goals, operations, methods, and selection (GOMS) models; command language versus direct manipulation; hypertext; visual perception; interface…

  14. USE OF TECHNICAL MEDIA FOR SIMULATING ENVIRONMENTS TO PROVIDE INDIVIDUALIZED INSTRUCTION.

    ERIC Educational Resources Information Center

    WING, RICHARD L.

    AN ESTIMATE WAS OBTAINED OF THE EFFECTIVENESS WITH WHICH THE SIMULATED ENVIRONMENT MODE CAN BE USED TO TEACH CERTAIN UNITS IN EIGHT DIFFERENT SUBJECT AREAS--ART, BIOLOGY, CHEMISTRY, ELECTRONICS, ELEMENTARY PHYSICS, FRENCH, MUSIC, AND ECONOMICS. THE SPECIFIC MODE USED WAS A SPECIAL CASE OF SIMULATION IN WHICH THE USEFUL FEATURES OF VARIOUS LEARNING…

  15. Home Musical Environment of Children in Singapore: On Globalization, Technology, and Media

    ERIC Educational Resources Information Center

    Lum, Chee-Hoo

    2008-01-01

    The home musical environments of a class of 28 first-grade children in Singapore were examined in this ethnographic study. Technology was an integral part of the soundscape in the home. The musical repertoire gathered was closely associated with electronic and pop-influenced music, approaching the styles favored by teens and adults. Particular…

  16. Individual, social, and physical environment factors associated with electronic media use among children: sedentary behavior at home.

    PubMed

    Granich, Joanna; Rosenberg, Michael; Knuiman, Matthew W; Timperio, Anna

    2011-07-01

    Individual, home social and physical environment correlates of electronic media (EM) use among children were examined and pattern of differences on school and weekend days. Youth (n = 298) aged 11 to 12 years self-reported time spent using EM (TV, video/DVD, computer use, and electronic games) on a typical school and a weekend day, each dichotomized at the median to indicate heavy and light EM users. Anthropometric measurements were taken. Logistic regression examined correlates of EM use. In total, 87% of participants exceeded electronic media use recommendations of ≤ 2 hrs/day. Watching TV during breakfast (OR = 3.17) and after school (OR = 2.07), watching TV with mother (OR = 1.96), no rule(s) limiting time for computer game usage (OR = 2.30), having multiple (OR = 2.99) EM devices in the bedroom and BMI (OR = 1.15) were associated with higher odds of being heavy EM user on a school day. Boys (OR = 2.35) and participants who usually watched TV at midday (OR = 2.91) and late at night (OR = 2.04) had higher odds of being a heavy EM user on the weekend. Efforts to modify children's EM use should focus on a mix of intervention strategies that address patterns and reinforcement of TV viewing, household rules limiting screen time, and the presence of EM devices in the child's bedroom.

  17. Staying Relevant in a Crowded Media Environment: Telling Stories about Ever Changing Forests

    NASA Astrophysics Data System (ADS)

    Perry, C. H.; Oswalt, C.; Stanton, S.

    2016-12-01

    The USDA Forest Service's Forest Inventory and Analysis program faces a serious challenge: how do we communicate information about the status and trends of the nation's forest resource to a public whose appetite for reading is declining rapidly? Our data, reports, and analyses are highly regarded; states demand our data be loaded into FIADB ever more quickly, and the time from the last plot to a published report is shrinking. At the same time, the average person spends only 25 minutes per day with print media. The Forest Service seeks to address the challenge by releasing reports as PDFs and e-books, but there are exciting opportunities to increase reader engagement with our content. Here, we discuss our evolving strategy for integrating traditional data delivery tools with cutting edge technology like ArcGIS Online and free JavaScript libraries to create visually compelling, interactive and information-rich experiences for an increasingly diverse set of target audiences. You can try these tools yourself by checking out our Engagement Portfolio.

  18. Changing learning with new interactive and media-rich instruction environments: virtual labs case study report.

    PubMed

    Huang, Camillan

    2003-01-01

    Technology has created a new dimension for visual teaching and learning with web-delivered interactive media. The Virtual Labs Project has embraced this technology with instructional design and evaluation methodologies behind the simPHYSIO suite of simulation-based, online interactive teaching modules in physiology for the Stanford students. In addition, simPHYSIO provides the convenience of anytime web-access and a modular structure that allows for personalization and customization of the learning material. This innovative tool provides a solid delivery and pedagogical backbone that can be applied to developing an interactive simulation-based training tool for the use and management of the Picture Archiving and Communication System (PACS) image information system. The disparity in the knowledge between health and IT professionals can be bridged by providing convenient modular teaching tools to fill the gaps in knowledge. An innovative teaching method in the whole PACS is deemed necessary for its successful implementation and operation since it has become widely distributed with many interfaces, components, and customizations. This paper will discuss the techniques for developing an interactive-based teaching tool, a case study of its implementation, and a perspective for applying this approach to an online PACS training tool.

  19. A network-based distributed, media-rich computing and information environment

    SciTech Connect

    Phillips, R.L.

    1995-12-31

    Sunrise is a Los Alamos National Laboratory (LANL) project started in October 1993. It is intended to be a prototype National Information Infrastructure development project. A main focus of Sunrise is to tie together enabling technologies (networking, object-oriented distributed computing, graphical interfaces, security, multi-media technologies, and data-mining technologies) with several specific applications. A diverse set of application areas was chosen to ensure that the solutions developed in the project are as generic as possible. Some of the application areas are materials modeling, medical records and image analysis, transportation simulations, and K-12 education. This paper provides a description of Sunrise and a view of the architecture and objectives of this evolving project. The primary objectives of Sunrise are three-fold: (1) To develop common information-enabling tools for advanced scientific research and its applications to industry; (2) To enhance the capabilities of important research programs at the Laboratory; (3) To define a new way of collaboration between computer science and industrially-relevant research.

  20. Gender on the brain: a case study of science communication in the new media environment.

    PubMed

    O'Connor, Cliodhna; Joffe, Helene

    2014-01-01

    Neuroscience research on sex difference is currently a controversial field, frequently accused of purveying a 'neurosexism' that functions to naturalise gender inequalities. However, there has been little empirical investigation of how information about neurobiological sex difference is interpreted within wider society. This paper presents a case study that tracks the journey of one high-profile study of neurobiological sex differences from its scientific publication through various layers of the public domain. A content analysis was performed to ascertain how the study was represented in five domains of communication: the original scientific article, a press release, the traditional news media, online reader comments and blog entries. Analysis suggested that scientific research on sex difference offers an opportunity to rehearse abiding cultural understandings of gender. In both scientific and popular contexts, traditional gender stereotypes were projected onto the novel scientific information, which was harnessed to demonstrate the factual truth and normative legitimacy of these beliefs. Though strains of misogyny were evident within the readers' comments, most discussion of the study took pains to portray the sexes' unique abilities as equal and 'complementary'. However, this content often resembled a form of benevolent sexism, in which praise of women's social-emotional skills compensated for their relegation from more esteemed trait-domains, such as rationality and productivity. The paper suggests that embedding these stereotype patterns in neuroscience may intensify their rhetorical potency by lending them the epistemic authority of science. It argues that the neuroscience of sex difference does not merely reflect, but can actively shape the gender norms of contemporary society.

  1. Gender on the Brain: A Case Study of Science Communication in the New Media Environment

    PubMed Central

    O’Connor, Cliodhna; Joffe, Helene

    2014-01-01

    Neuroscience research on sex difference is currently a controversial field, frequently accused of purveying a ‘neurosexism’ that functions to naturalise gender inequalities. However, there has been little empirical investigation of how information about neurobiological sex difference is interpreted within wider society. This paper presents a case study that tracks the journey of one high-profile study of neurobiological sex differences from its scientific publication through various layers of the public domain. A content analysis was performed to ascertain how the study was represented in five domains of communication: the original scientific article, a press release, the traditional news media, online reader comments and blog entries. Analysis suggested that scientific research on sex difference offers an opportunity to rehearse abiding cultural understandings of gender. In both scientific and popular contexts, traditional gender stereotypes were projected onto the novel scientific information, which was harnessed to demonstrate the factual truth and normative legitimacy of these beliefs. Though strains of misogyny were evident within the readers’ comments, most discussion of the study took pains to portray the sexes’ unique abilities as equal and ‘complementary’. However, this content often resembled a form of benevolent sexism, in which praise of women’s social-emotional skills compensated for their relegation from more esteemed trait-domains, such as rationality and productivity. The paper suggests that embedding these stereotype patterns in neuroscience may intensify their rhetorical potency by lending them the epistemic authority of science. It argues that the neuroscience of sex difference does not merely reflect, but can actively shape the gender norms of contemporary society. PMID:25354280

  2. After Convergence: YouTube and Remix Culture

    NASA Astrophysics Data System (ADS)

    Fagerjord, Anders

    The term “convergence” has been used to describe the media developments following digitalization. In this article, Fagerjord argues that while convergence was a suitable term to describe the first developments, it is no longer fitting. Convergence levelled out the differences between media, allowing for the developments we now see, and for which Fagerjord proposes the term “remix”. Using YouTube as an example, he outlines how genre developments may be seen as remixes of earlier genres, how remixing has become a widespread creative practice, and how online media also remix power relations between media owners and their audience.

  3. Home media server content management

    NASA Astrophysics Data System (ADS)

    Tokmakoff, Andrew A.; van Vliet, Harry

    2001-07-01

    With the advent of set-top boxes, the convergence of TV (broadcasting) and PC (Internet) is set to enter the home environment. Currently, a great deal of activity is occurring in developing standards (TV-Anytime Forum) and devices (TiVo) for local storage on Home Media Servers (HMS). These devices lie at the heart of convergence of the triad: communications/networks - content/media - computing/software. Besides massive storage capacity and being a communications 'gateway', the home media server is characterised by the ability to handle metadata and software that provides an easy to use on-screen interface and intelligent search/content handling facilities. In this paper, we describe a research prototype HMS that is being developed within the GigaCE project at the Telematica Instituut . Our prototype demonstrates advanced search and retrieval (video browsing), adaptive user profiling and an innovative 3D component of the Electronic Program Guide (EPG) which represents online presence. We discuss the use of MPEG-7 for representing metadata, the use of MPEG-21 working draft standards for content identification, description and rights expression, and the use of HMS peer-to-peer content distribution approaches. Finally, we outline explorative user behaviour experiments that aim to investigate the effectiveness of the prototype HMS during development.

  4. Bacterial Colonies in Solid Media and Foods: A Review on Their Growth and Interactions with the Micro-Environment

    PubMed Central

    Jeanson, Sophie; Floury, Juliane; Gagnaire, Valérie; Lortal, Sylvie; Thierry, Anne

    2015-01-01

    Bacteria, either indigenous or added, are immobilized in solid foods where they grow as colonies. Since the 80's, relatively few research groups have explored the implications of bacteria growing as colonies and mostly focused on pathogens in large colonies on agar/gelatine media. It is only recently that high resolution imaging techniques and biophysical characterization techniques increased the understanding of the growth of bacterial colonies, for different sizes of colonies, at the microscopic level and even down to the molecular level. This review covers the studies on bacterial colony growth in agar or gelatine media mimicking the food environment and in model cheese. The following conclusions have been brought to light. Firstly, under unfavorable conditions, mimicking food conditions, the immobilization of bacteria always constrains their growth in comparison with planktonic growth and increases the sensibility of bacteria to environmental stresses. Secondly, the spatial distribution describes both the distance between colonies and the size of the colonies as a function of the initial level of population. By studying the literature, we concluded that there systematically exists a threshold that distinguishes micro-colonies (radius < 100–200 μm) from macro-colonies (radius >200 μm). Micro-colonies growth resembles planktonic growth and no pH microgradients could be observed. Macro-colonies growth is slower than planktonic growth and pH microgradients could be observed in and around them due to diffusion limitations which occur around, but also inside the macro-colonies. Diffusion limitations of milk proteins have been demonstrated in a model cheese around and in the bacterial colonies. In conclusion, the impact of immobilization is predominant for macro-colonies in comparison with micro-colonies. However, the interaction between the colonies and the food matrix itself remains to be further investigated at the microscopic scale. PMID:26648910

  5. Bacterial Colonies in Solid Media and Foods: A Review on Their Growth and Interactions with the Micro-Environment.

    PubMed

    Jeanson, Sophie; Floury, Juliane; Gagnaire, Valérie; Lortal, Sylvie; Thierry, Anne

    2015-01-01

    Bacteria, either indigenous or added, are immobilized in solid foods where they grow as colonies. Since the 80's, relatively few research groups have explored the implications of bacteria growing as colonies and mostly focused on pathogens in large colonies on agar/gelatine media. It is only recently that high resolution imaging techniques and biophysical characterization techniques increased the understanding of the growth of bacterial colonies, for different sizes of colonies, at the microscopic level and even down to the molecular level. This review covers the studies on bacterial colony growth in agar or gelatine media mimicking the food environment and in model cheese. The following conclusions have been brought to light. Firstly, under unfavorable conditions, mimicking food conditions, the immobilization of bacteria always constrains their growth in comparison with planktonic growth and increases the sensibility of bacteria to environmental stresses. Secondly, the spatial distribution describes both the distance between colonies and the size of the colonies as a function of the initial level of population. By studying the literature, we concluded that there systematically exists a threshold that distinguishes micro-colonies (radius < 100-200 μm) from macro-colonies (radius >200 μm). Micro-colonies growth resembles planktonic growth and no pH microgradients could be observed. Macro-colonies growth is slower than planktonic growth and pH microgradients could be observed in and around them due to diffusion limitations which occur around, but also inside the macro-colonies. Diffusion limitations of milk proteins have been demonstrated in a model cheese around and in the bacterial colonies. In conclusion, the impact of immobilization is predominant for macro-colonies in comparison with micro-colonies. However, the interaction between the colonies and the food matrix itself remains to be further investigated at the microscopic scale.

  6. A comparison of sampling media for environmental viable fungi collected in a hospital environment.

    PubMed

    Wu, P C; Su, H J; Ho, H M

    2000-03-01

    Quantitative evaluation of fungal exposure is often conducted by analysis of the composition of microbes in air samples and calculation of the concentrations afterward. The collecting medium that favors the growth for most saprophytic fungi is considered to be the ideal choice in most circumstances. Currently, the culture medium most frequently adopted in environmental sampling for airborne fungi is MEA (malt extract agar) recommended by the ACGIH for its suitability for most fungal growth. DG18 (dichloran glycerol-18), developed in 1980, is suggested for growth at lower water activity (a(w)=0.95) specifically and is not as commonly used in general studies. This investigation collected airborne viable fungi using a single stage/N6 Andersen impactor with MEA and DG18 agar plates attached simultaneously to the same set of samplers. The sampling locations were at 17 sites within a central air-conditioned hospital. After incubation and morphological identification, concentrations of airborne fungi and bacteria were expressed as CFU/m(3) (colony forming units/m(3)). There are 405 DG18 plates and 378 plates available for statistical analysis. Results show that the airborne fungal concentrations, shown by geometric mean (GM), are higher from the DG18 plates than from the MEA plates. The total fungal concentrations is 68.6 vs 12.94 CFU/m(3), and for Aspergillus spp., the concentration is 1.58 vs 0.72 CFU/m(3); for Penicillium spp., 3.37 vs 0.71; and for yeast, 5.09 vs 0.49 CFU/m(3). In addition, the number of different genera present is greater on the DG18 plates than on the MEA plates, on average, 2.85 types vs 1.72. This study suggests that in a hospital environment with 24-h, central air conditioning, DG18 plates appear to be more effective in collecting more fungal colonies in terms of both quantity and types of genera. Such a finding is presumed to be attributed to the characteristic of DG18 in slowing colony growth so that the dominating genus will not over occupy

  7. Glycoprotein and protein markers for strain differentiation and growth environment or media attribution

    SciTech Connect

    Wunschel, David S.; Fox, Alvin; Wahl, Karen L.

    2012-01-01

    Recent experience with Bacillus spore characterization has demonstrated that protein markers can provide potentially vital identifying and bioforensic information. The masses of constitutively expressed proteins and their peptide fragments can be used to identify bacterial isolates. Protein marker mass variation information reflects the underlying amino acid sequence variation to provide complementary information to genetic sequence analysis. Protein markers (identified by mass or sequence) that are conserved or variable can be readily selected. In contrast, genetic primers, as used in PCR, target conserved genetic regions. Furthermore, protein markers are relatively stable compared to nucleic acids and may remain in samples for longer periods of time. This is important to consider when the source, age and condition of samples may vary in a forensic investigation. Examples of constitutively expressed proteins that have been extensively characterized include the exosporium BclA and BclB proteins and small acid soluble proteins (SASPs). Finally, gene expression (usually assessed at the mRNA level) can vary in response to different environmental conditions. As a result, the profile of protein markers of the organism also reflects the culture environment. Mass spectrometric tools can be used to access the same information on culture-related protein expression variation. However, unlike genetic methods, with proteomic methodology there is the potential to define exactly which medium was employed for organism growth. This potential could provide additional clues for forensic attribution

  8. Geosciences in an Immersive Fulldome Environment: Developing Science and Communication Skills by Creating Digital Media

    NASA Astrophysics Data System (ADS)

    Alley, K. E.; Crawford, A.; Eakin, J.

    2011-12-01

    The Ho Tung Visualization Laboratory and Planetarium at Colgate University provides an opportunity for students of diverse backgrounds to learn scientific concepts and communication techniques through the creation of fulldome digital animations. Students give presentations to classes, school groups, and the public in the planetarium setting, and enhance learning by creating digital content appropriate to these audiences. The immersive environment is well-suited for showing large-scale geologic processes that may not be easily seen in the field. Geoscience projects include fly-bys of the Hudson River Valley, Cascade Mountain Range, Grand Canyon, and Basin and Range province, animation of the advance of the Laurentide Ice Sheet, evolution of continental positions since the late Precambrian, and comparisons of volcanic eruption styles. In order to create a digital animation, students must have a detailed understanding of the subject matter as well as all aspects of presentation, ranging from intended audience to relevant production technologies. This encourages students to explore material at a depth beyond conventional learning methods while integrating the skills necessary to effectively communicate scientific concepts to varied audiences. Based on these explorations, it appears beneficial to promote scientific visualization creation as a tool in itself to help students develop both scientific knowledge and communication skills.

  9. Responses of polar organic compounds to different ionic environments in aqueous media are interrelated.

    PubMed

    Ferreira, L A; Chervenak, A; Placko, S; Kestranek, A; Madeira, P P; Zaslavsky, B Y

    2014-11-14

    Solubilities of 17 polar organic compounds in aqueous solutions of Na2SO4, NaCl, NaClO4, and NaSCN at the salt concentrations of up to 1.0-2.0 M were determined and the Setschenow constant, ksalt, values were estimated. It was found that NaClO4 may display both salting-in and salting-out effects depending on the particular compound structure. The Setschenow constant values for all the polar compounds examined in different salt solutions are found to be interrelated. Similar relationships were observed for partition coefficients of nonionic organic compounds in aqueous polyethylene glycol-sodium sulfate two-phase systems in the presence of different salt additives reported previously [Ferreira et al., J. Chromatogr. A, 2011, 1218, 5031], and for the effects of different salts on optical rotation of amino acids reported by Rossi et al. [J. Phys. Chem. B, 2007, 111, 10510]. In order to explain the observed relationships it is suggested that all the effects observed originate as responses of the compounds to the presence of a given ionic environment and its interaction with the compounds by forming direct or solvent-separated ionic pairs. The response is compound-specific and its strength is determined by the compound structure and the type (and concentration) of ions inducing the response.

  10. When New Media Meet the Strong Web of Connected Learning Environments: A New Vision of Progressive Education in the Digital Age

    ERIC Educational Resources Information Center

    Nam, Chaebong

    2013-01-01

    This paper shows how the legacy of Jane Addams' socialized education can live on in today's progressive education, especially in the digital age. Discussion is drawn from a case study of an anti-underage drinking campaign conducted by urban youth of color in an afterschool program. The media ecology environment in the campaign--the integrated…

  11. The Home Literacy Environment: Exploring How Media and Parent-Child Interactions Are Associated with Children's Language Production

    ERIC Educational Resources Information Center

    Liebeskind, Kara G.; Piotrowski, Jessica T.; Lapierre, Matthew A.; Linebarger, Deborah L.

    2014-01-01

    Children who start school with strong language skills initiate a trajectory of academic success, while children with weaker skills are likely to struggle. Research has demonstrated that media and parent-child interactions, both characteristics of the home literacy environment, influence children's language skills. Using a national sample of…

  12. When New Media Meet the Strong Web of Connected Learning Environments: A New Vision of Progressive Education in the Digital Age

    ERIC Educational Resources Information Center

    Nam, Chaebong

    2013-01-01

    This paper shows how the legacy of Jane Addams' socialized education can live on in today's progressive education, especially in the digital age. Discussion is drawn from a case study of an anti-underage drinking campaign conducted by urban youth of color in an afterschool program. The media ecology environment in the campaign--the integrated…

  13. New Media, Evolving Multimodal Literacy Practices and the Potential Impact of Increased Use of the Visual Mode in the Urban Environment on Young Children's Learning

    ERIC Educational Resources Information Center

    Yamada-Rice, Dylan

    2011-01-01

    This article looks at the way in which the changing visual environment affects education at two levels: in communication patterns and research methodologies. The research considers differences in the variance and quantity of types of visual media and their relationship to the written mode in the urban landscapes of Tokyo and London, using…

  14. The Home Literacy Environment: Exploring How Media and Parent-Child Interactions Are Associated with Children's Language Production

    ERIC Educational Resources Information Center

    Liebeskind, Kara G.; Piotrowski, Jessica T.; Lapierre, Matthew A.; Linebarger, Deborah L.

    2014-01-01

    Children who start school with strong language skills initiate a trajectory of academic success, while children with weaker skills are likely to struggle. Research has demonstrated that media and parent-child interactions, both characteristics of the home literacy environment, influence children's language skills. Using a national sample of…

  15. Independent molecular basis of convergent highland adaptation in maize

    USDA-ARS?s Scientific Manuscript database

    Convergent evolution is the independent evolution of similar traits in different species or lineages of the same species; this often is a result of adaptation to similar environments, a process referred to as convergent adaptation. We investigate here the molecular basis of convergent adaptation in ...

  16. Geochemical characteristics of aluminum depleted and undepleted komatiites and HREE-enriched low-Ti tholeiites, western Abitibi greenstone belt: A heterogeneous mantle plume-convergent margin environment

    NASA Astrophysics Data System (ADS)

    Fan, J.; Kerrich, R.

    1997-11-01

    -depleted komatiites in the Abitibi belt. They have absolute concentrations and ratios of most moderately and highly compatible elements comparable to N- MORB (Zr ˜79 vs. 74, Y ˜30 vs. 28, and Zr/Y = 2.4-2.9 vs. 2.6 ), but are relatively less depleted in highly incompatible elements and lack positive Nb or P anomalies. Type II basalts are relatively aluminous (Al 2O 3 ˜ 16 wt%), with high Al 2O 3/TiO 2 (24-28) ratios. They are characterized by low Th, Nb, and LREE contents at eight to ten times chondrite, with slightly convex-up LREE patterns ( La/Smn = 0.86-0.99 ), but strongly fractionated and enriched HREEs, Y, and Sc, where Gd/Ybn = 0.50-0.55 and consistently positive Zr(Hf)/MREEs anomalies. These basalts are tentatively interpreted as low-Ti tholeiites formed in a convergent margin setting with second stage melting, induced by fluids and melts enriched in incompatible elements and Zr(Hf) relative to MREEs, of a mantle source depleted during first stage melting. They are analogous to the Phanerozoic low-Ti tholeiite - boninite association. Accordingly the Tisdale volcanic sequence records a plume-convergent margin interaction. New analyses of Al-undepleted komatiites from the classical locality at Pyke Hill in Munro Township confirm the presence of small positive anomalies of P, Zr, and Hf, with Zr/Hf ratios generally < 36. These signatures are similar in spinifex and cumulate zones signifying that they are unlikely to have resulted from alteration. The data were generated by INAA and ICP-MS using both HFHNO 3 dissolution and Na 2O 2 sinter. The lack of LREE enrichment with negative Nb, Ta, P, and Ti anomalies in any of the Tisdale or Munro komatiites confirms an intraoceanic setting for the volcanic stage of the Western Abitibi greenstone belt.

  17. Re-Examination of Mixed Media Communication: The Impact of Voice, Data Link, and Mixed Air Traffic Control Environments on the Flight Deck

    NASA Technical Reports Server (NTRS)

    Dunbar, Melisa; McGann, Alison; Mackintosh, Margaret-Anne; Lozito, Sandra; Ashford, Rose (Technical Monitor)

    2001-01-01

    A simulation in the B747-400 was conducted at NASA Ames Research Center that compared how crews handled voice and data link air traffic control (ATC) messages in a single medium versus a mixed voice and data link ATC environment The interval between ATC messages was also varied to examine the influence of time pressure in voice, data link, and mixed ATC environments. For messages sent via voice, transaction times were lengthened in the mixed media environment for closely spaced messages. The type of environment did not affect data link times. However, messages times were lengthened in both single and mixed-modality environments under time pressure. Closely spaced messages also increased the number of requests for clarification for voice messages in the mixed environment and review menu use for data link messages. Results indicated that when time pressure is introduced, the mix of voice and data link does not necessarily capitalize on the advantages of both media. These findings emphasize the need to develop procedures for managing communication in mixed voice and data link environments.

  18. Media Violence and Children.

    ERIC Educational Resources Information Center

    Groebel, Jo

    1998-01-01

    Presents the results of the UNESCO global study on media violence and children which was conducted between 1996 and 1997. Highlights include the role of the media, media heroes as role models, media violence and aggression, differences by gender, rural versus urban environments, the pervasiveness of television, and recommendations. (Author/LRW)

  19. Gene environment interaction in periphery and brain converge to modulate behavioral outcomes: Insights from the SP1 transient early in life interference rat model

    PubMed Central

    Asor, Eyal; Ben-Shachar, Dorit

    2016-01-01

    It is generally assumed that behavior results from an interaction between susceptible genes and environmental stimuli during critical life stages. The present article reviews the main theoretical and practical concepts in the research of gene environment interaction, emphasizing the need for models simulating real life complexity. We review a novel approach to study gene environment interaction in which a brief post-natal interference with the expression of multiple genes, by hindering the activity of the ubiquitous transcription factor specificity protein 1 (Sp1) is followed by later-in-life exposure of rats to stress. Finally, this review discusses the role of peripheral processes in behavioral responses, with the Sp1 model as one example demonstrating how specific behavioral patterns are linked to modulations in both peripheral and central physiological processes. We suggest that models, which take into account the tripartite reciprocal interaction between the central nervous system, peripheral systems and environmental stimuli will advance our understanding of the complexity of behavior. PMID:27679768

  20. Media Presentation Mode, English Listening Comprehension and Cognitive Load in Ubiquitous Learning Environments: Modality Effect or Redundancy Effect?

    ERIC Educational Resources Information Center

    Chang, Chi-Cheng; Lei, Hao; Tseng, Ju-Shih

    2011-01-01

    Although ubiquitous learning enhances students' access to learning materials, it is crucial to find out which media presentation modes produce the best results for English listening comprehension. The present study examined the effect of media presentation mode (sound and text versus sound) on English listening comprehension and cognitive load.…

  1. The Media Environments and Television-Viewing Diets of Infants and Toddlers: Findings from a National Survey of Parents

    ERIC Educational Resources Information Center

    Vaala, Sarah E.; Bleakley, Amy; Jordan, Amy B.

    2013-01-01

    High rates of infant and toddler screen media use coupled with research indicating no benefit to this viewing have led the American Academy of Pediatrics (AAP) to advise against any screen media use with children less than 2 years old and less than 2 hours per day of entertainment programming for children 2 years and older (AAP, 2011). Our survey…

  2. Media Presentation Mode, English Listening Comprehension and Cognitive Load in Ubiquitous Learning Environments: Modality Effect or Redundancy Effect?

    ERIC Educational Resources Information Center

    Chang, Chi-Cheng; Lei, Hao; Tseng, Ju-Shih

    2011-01-01

    Although ubiquitous learning enhances students' access to learning materials, it is crucial to find out which media presentation modes produce the best results for English listening comprehension. The present study examined the effect of media presentation mode (sound and text versus sound) on English listening comprehension and cognitive load.…

  3. The Media Environments and Television-Viewing Diets of Infants and Toddlers: Findings from a National Survey of Parents

    ERIC Educational Resources Information Center

    Vaala, Sarah E.; Bleakley, Amy; Jordan, Amy B.

    2013-01-01

    High rates of infant and toddler screen media use coupled with research indicating no benefit to this viewing have led the American Academy of Pediatrics (AAP) to advise against any screen media use with children less than 2 years old and less than 2 hours per day of entertainment programming for children 2 years and older (AAP, 2011). Our survey…

  4. Crossroads on the Information Highway: Convergence and Diversity in Communications Technologies.

    ERIC Educational Resources Information Center

    Institute for Information Studies, Falls Church, VA.

    The convergence of the telecommunications, computer, and cable television industries is beginning to take place. Each of the seven articles in this volume provides a perspective on either the forces that are influencing the convergence of media or on the impact that this convergence is having on the rest of the world. They address the issues of…

  5. Crossroads on the Information Highway: Convergence and Diversity in Communications Technologies.

    ERIC Educational Resources Information Center

    Institute for Information Studies, Falls Church, VA.

    The convergence of the telecommunications, computer, and cable television industries is beginning to take place. Each of the seven articles in this volume provides a perspective on either the forces that are influencing the convergence of media or on the impact that this convergence is having on the rest of the world. They address the issues of…

  6. Comparison of biorelevant simulated media mimicking the intestinal environment to assess the solubility profiles of poorly soluble drugs.

    PubMed

    Prasad, Dev; Gu, Chong-Hui; Kuldipkumar, Anuj

    2016-01-01

    During the discovery stage in lead identification/optimization, compounds are characterized for their solubilities in biorelevant media and these data are often used to model the in vivo behavior of the compounds and predict the fraction absorbed. These media are selected to closely approximate the composition of human intestinal fluid. Owing to the complexity and variability in human intestinal fluid composition, it is essential that the chosen simulated media mimic the in vivo condition as closely as possible. Several recipes have been developed and are routinely used in assessing the solubilities of compounds. It is necessary to revisit these recipes and modify them as the understanding of the human GI tract increases. In the present work, we have evaluated the solubilities of six model compounds in several media and have proposed slight modifications to the currently used recipes based on our own data and that reported in the literature.

  7. Nonaccommodative convergence excess.

    PubMed

    von Noorden, G K; Avilla, C W

    1986-01-15

    Nonaccommodative convergence excess is a condition in which a patient has orthotropia or a small-angle esophoria or esotropia at distance and a large-angle esotropia at near, not significantly reduced by the addition of spherical plus lenses. The AC/A ratio, determined with the gradient method, is normal or subnormal. Tonic convergence is suspected of causing the convergence excess in these patients. Nonaccommodative convergence excess must be distinguished from esotropia with a high AC/A ratio and from hypoaccommodative esotropia. In 24 patients treated with recession of both medial recti muscles with and without posterior fixation or by posterior fixation alone, the mean correction of esotropia was 7.4 prism diopters at distance and 17 prism diopters at near.

  8. Evaluation of culture media for detecting airborne Salmonella enteritidis collected with an electrostatic sampling device from the environment of experimentally infected laying hens.

    PubMed

    Gast, R K; Mitchell, B W; Holt, P S

    2004-07-01

    Detection of Salmonella enteritidis in the environment of commercial laying hens is critical for reducing the production of contaminated eggs by infected flocks. In the present study, an inexpensive and portable electrostatic air sampling device was used to collect S. enteritidis in rooms containing experimentally infected laying hens. After hens were orally inoculated with a phage type 13a S. enteritidis strain and housed in individual cages, air samples were collected 3 times each week with electrostatic devices onto plates of 6 types of culture media (brilliant green agar, modified lysine iron agar, modified semisolid Rappaport-Vassiliadis agar, Rambach agar, XLD agar, and XLT4 agar). Air sampling plates were incubated at 37 degrees C, examined visually for presumptive identification of typical S. enteritidis colonies and then subjected to confirmatory enrichment culturing. Air samples (collected using all 6 culture media) were positive for S. enteritidis for 3 wk postinoculation. Because visual determination of the presence or absence of typical S. enteritidis colonies on air sampling plates was not consistently confirmed by enrichment culturing, the postenrichment results were used for comparing sampling strategies. The frequency of positive air sampling results using brilliant green agar (66.7% overall) was significantly greater than was obtained using most other media. A combination of several plating media (brilliant green agar, modified lysine iron agar, and XLT4 agar) allowed detection of airborne S. enteritidis at an overall frequency of 83.3% over the 3 wk of sampling. When used with appropriate culture media, electrostatic collection of airborne S. enteritidis can provide a sensitive alternative to traditional methods for detecting this pathogen in the environment of laying flocks.

  9. Convergence of estuarine channels

    NASA Astrophysics Data System (ADS)

    Dronkers, Job

    2017-07-01

    Tide-dominated coastal plain estuaries have typically up-estuary convergent tidal channels. Analysis of estuarine characteristics indicates a dependence of the convergence length on relative tidal amplitude, relative intertidal area and river flow velocity. In order to explain these relationships we investigate a condition for continuity of net sediment transport throughout the estuary, corresponding to morphodynamic equilibrium. We show, by using an analytical solution of the tidal equations, that this condition is equivalent to a condition on the convergence length. This condition is evaluated for 21 estuaries in different regions of the world. It appears that the convergence length determined in this way can explain observed convergence lengths for the considered set of estuaries. The dependence of the convergence length on different estuarine characteristics is analysed by solving the fully coupled hydro-morphodynamic equations. We show that this dependence limits the range of variation of the tidal velocity amplitude. The analysis provides insight in the morphological response of estuaries to human interventions. The condition can easily be evaluated to yield an estimate of this response.

  10. Why Use the Online Environment with Face-to-Face Students? Insights from Early Adopters.

    ERIC Educational Resources Information Center

    Bunker, Alison; Vardi, Iris

    This study illustrates the convergence of two teaching and learning media, face-to-face and online, as reflective lecturers seek to address the limitations of a single medium. Innovative university lecturers at a large Western Australia university were interviewed about their use of online environments with face-to-face students. The interview…

  11. Media Culture 2020: Collaborative Teaching and Blended Learning Using Social Media and Cloud-Based Technologies

    ERIC Educational Resources Information Center

    Vickers, Richard; Field, James; Melakoski, Cai

    2015-01-01

    In 2013 five universities from across Europe undertook an innovative project "Media Culture 2020", combining skills and forces to develop new practices that would face the challenge of the convergence of digital media, taking full advantage of social media and cloud-based technologies. The aim of the Media Culture 2020 project was to…

  12. Convergent evolution of the genomes of marine mammals

    PubMed Central

    Foote, Andrew D.; Liu, Yue; Thomas, Gregg W.C.; Vinař, Tomáš; Alföldi, Jessica; Deng, Jixin; Dugan, Shannon; van Elk, Cornelis E.; Hunter, Margaret E.; Joshi, Vandita; Khan, Ziad; Kovar, Christie; Lee, Sandra L.; Lindblad-Toh, Kerstin; Mancia, Annalaura; Nielsen, Rasmus; Qin, Xiang; Qu, Jiaxin; Raney, Brian J.; Vijay, Nagarjun; Wolf, Jochen B. W.; Hahn, Matthew W.; Muzny, Donna M.; Worley, Kim C.; Gilbert, M. Thomas P.; Gibbs, Richard A.

    2015-01-01

    Marine mammals from different mammalian orders share several phenotypic traits adapted to the aquatic environment and are therefore a classic example of convergent evolution. To investigate convergent evolution at the genomic level, we sequenced and de novo assembled the genomes of three species of marine mammals (the killer whale, walrus and manatee) from three mammalian orders that share independently evolved phenotypic adaptations to a marine existence. Our comparative genomic analyses found that convergent amino acid substitutions were widespread throughout the genome, and that a subset were in genes evolving under positive selection and putatively associated with a marine phenotype. However, we found higher levels of convergent amino acid substitutions in a control set of terrestrial sister taxa to the marine mammals. Our results suggest that while convergent molecular evolution is relatively common, adaptive molecular convergence linked to phenotypic convergence is comparatively rare. PMID:25621460

  13. Convergent evolution of the genomes of marine mammals

    USGS Publications Warehouse

    Foote, Andrew D.; Liu, Yue; Thomas, Gregg W.C.; Vinař, Tomáš; Alföldi, Jessica; Deng, Jixin; Dugan, Shannon; van Elk, Cornelis E.; Hunter, Margaret; Joshi, Vandita; Khan, Ziad; Kovar, Christie; Lee, Sandra L.; Lindblad-Toh, Kerstin; Mancia, Annalaura; Nielsen, Rasmus; Qin, Xiang; Qu, Jiaxin; Raney, Brian J.; Vijay, Nagarjun; Wolf, Jochen B. W.; Hahn, Matthew W.; Muzny, Donna M.; Worley, Kim C.; Gilbert, M. Thomas P.; Gibbs, Richard A.

    2015-01-01

    Marine mammals from different mammalian orders share several phenotypic traits adapted to the aquatic environment and therefore represent a classic example of convergent evolution. To investigate convergent evolution at the genomic level, we sequenced and performed de novo assembly of the genomes of three species of marine mammals (the killer whale, walrus and manatee) from three mammalian orders that share independently evolved phenotypic adaptations to a marine existence. Our comparative genomic analyses found that convergent amino acid substitutions were widespread throughout the genome and that a subset of these substitutions were in genes evolving under positive selection and putatively associated with a marine phenotype. However, we found higher levels of convergent amino acid substitutions in a control set of terrestrial sister taxa to the marine mammals. Our results suggest that, whereas convergent molecular evolution is relatively common, adaptive molecular convergence linked to phenotypic convergence is comparatively rare.

  14. Collaborative Instructional Strategies to Enhance Knowledge Convergence

    ERIC Educational Resources Information Center

    Draper, Darryl C.

    2015-01-01

    To promote knowledge convergence through collaborative learning activities in groups, this qualitative case study involved a layered approach for the design and delivery of a highly collaborative learning environment incorporating various instructional technologies grounded in learning theory. In a graduate-level instructional technology course,…

  15. Collaborative Instructional Strategies to Enhance Knowledge Convergence

    ERIC Educational Resources Information Center

    Draper, Darryl C.

    2015-01-01

    To promote knowledge convergence through collaborative learning activities in groups, this qualitative case study involved a layered approach for the design and delivery of a highly collaborative learning environment incorporating various instructional technologies grounded in learning theory. In a graduate-level instructional technology course,…

  16. Convergence of Arnoldi method

    SciTech Connect

    Nevanlinna, O.

    1994-12-31

    This note summarizes some results on (a monitored version of) the Arnoldi method in Hilbert spaces. The interest in working in infinite dimensional spaces comes partly from the fact that only then can one have meaningful asymptotical statements (which hopefully give some light to the convergence of Arnoldi in large dimensional problems with iteration indices far less than the dimension).

  17. Converging or Diverging Lens?

    ERIC Educational Resources Information Center

    Branca, Mario

    2013-01-01

    Why does a lens magnify? Why does it shrink objects? Why does this happen? The activities that we propose here are useful in helping us to understand how lenses work, and they show that the same lens can have different magnification capabilities. A converging lens can also act as a diverging lens. (Contains 4 figures.)

  18. Converging or Diverging Lens?

    ERIC Educational Resources Information Center

    Branca, Mario

    2013-01-01

    Why does a lens magnify? Why does it shrink objects? Why does this happen? The activities that we propose here are useful in helping us to understand how lenses work, and they show that the same lens can have different magnification capabilities. A converging lens can also act as a diverging lens. (Contains 4 figures.)

  19. A hierarchical view of convergent evolution in microbial eukaryotes.

    PubMed

    Leander, Brian S

    2008-01-01

    Distinguishing convergent evolution from other causes of similarity in organisms is necessary for reconstructing phylogenetic relationships, inferring patterns of character evolution, and investigating the forces of natural selection. In contrast to animals and land plants, the pervasiveness and adaptive significance of convergent evolution in microbes has yet to be systematically explored or articulated. Convergent evolution in microbial eukaryotes, for instance, often involves very distantly related lineages with relatively limited repertoires of morphological features. These large phylogenetic distances weaken the role of ancestral developmental programs on the subsequent evolution of morphological characters, making convergent evolution between very distantly related lineages fundamentally different from convergent evolution between closely related lineages. This suggests that examples of convergence at different levels in the phylogenetic hierarchy offer different clues about the causes and processes of macroevolutionary diversification. Accordingly (and despite opinions to the contrary), I recognize three broad and overlapping categories of phenotypic convergence-"parallel", "proximate" and "ultimate"-that represent either (1) subcellular analogues, (2) subcellular analogues to multicellular systems (and vice versa), or (3) multicellular analogues. Microbial eukaryotes living in planktonic environments, interstitial environments, and the intestinal environments of metazoan hosts provide compelling examples of ultimate convergence. After describing selected examples in microbial eukaryotes, I suggest some future directions needed to more fully understand the hierarchical structure of convergent evolution and the overall history of life.

  20. Twin Convergence Zones

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's QuikSCAT satellite has confirmed a 30-year old largely unproven theory that there are two areas near the equator where the winds converge year after year and drive ocean circulation south of the equator. By analyzing winds, QuikSCAT has found a year-round southern and northern Intertropical Convergence Zone. This find is important to climate modelers and weather forecasters because it provides more detail on how the oceans and atmosphere interact near the equator. The Intertropical Convergence Zone (ITCZ) is the region that circles the Earth near the equator, where the trade winds of both the Northern and Southern Hemispheres come together. North of the equator, strong sun and warm water of the equator heats the air in the ITCZ, drawing air in from north and south and causing the air to rise. As the air rises it cools, releasing the accumulated moisture in an almost perpetual series of thunderstorms. Satellite data, however, has confirmed that there is an ITCZ north of the equator and a parallel ITCZ south of the equator. Variation in the location of the ITCZ is important to people around the world because it affects the north-south atmospheric circulation, which redistributes energy. It drastically affects rainfall in many equatorial nations, resulting in the wet and dry seasons of the tropics rather than the cold and warm seasons of higher latitudes. Longer term changes in the ITCZ can result in severe droughts or flooding in nearby areas. 'The double ITCZ is usually only identified in the Pacific and Atlantic Oceans on a limited and seasonal basis,' said Timothy Liu, of NASA's Jet Propulsion Laboratory and California Institute of Technology, Pasadena, Calif., and lead researcher on the project. In the eastern Pacific Ocean, the southern ITCZ is usually seen springtime. In the western Atlantic Ocean, the southern ITCZ was recently clearly identified only in the summertime. However, QuikSCAT's wind data has seen the southern ITCZ in all seasons across the

  1. Twin Convergence Zones

    NASA Technical Reports Server (NTRS)

    2002-01-01

    NASA's QuikSCAT satellite has confirmed a 30-year old largely unproven theory that there are two areas near the equator where the winds converge year after year and drive ocean circulation south of the equator. By analyzing winds, QuikSCAT has found a year-round southern and northern Intertropical Convergence Zone. This find is important to climate modelers and weather forecasters because it provides more detail on how the oceans and atmosphere interact near the equator. The Intertropical Convergence Zone (ITCZ) is the region that circles the Earth near the equator, where the trade winds of both the Northern and Southern Hemispheres come together. North of the equator, strong sun and warm water of the equator heats the air in the ITCZ, drawing air in from north and south and causing the air to rise. As the air rises it cools, releasing the accumulated moisture in an almost perpetual series of thunderstorms. Satellite data, however, has confirmed that there is an ITCZ north of the equator and a parallel ITCZ south of the equator. Variation in the location of the ITCZ is important to people around the world because it affects the north-south atmospheric circulation, which redistributes energy. It drastically affects rainfall in many equatorial nations, resulting in the wet and dry seasons of the tropics rather than the cold and warm seasons of higher latitudes. Longer term changes in the ITCZ can result in severe droughts or flooding in nearby areas. 'The double ITCZ is usually only identified in the Pacific and Atlantic Oceans on a limited and seasonal basis,' said Timothy Liu, of NASA's Jet Propulsion Laboratory and California Institute of Technology, Pasadena, Calif., and lead researcher on the project. In the eastern Pacific Ocean, the southern ITCZ is usually seen springtime. In the western Atlantic Ocean, the southern ITCZ was recently clearly identified only in the summertime. However, QuikSCAT's wind data has seen the southern ITCZ in all seasons across the

  2. Cosmic Convergence: Art and Science

    NASA Astrophysics Data System (ADS)

    Mayo, Elizabeth A.; Zisholtz, E.; Hilton, H.

    2010-01-01

    The I.P. Stanback Museum and Planetarium is a major educational and teaching resource for South Carolina State University, K-12 schools, other universities and the community of Orangeburg and well beyond. The concept of creating a museum with a planetarium on the campus of SC State was ahead of its time. Today scholars are writing about the unity of creative disciplines. Through its integration of the arts, humanities and sciences, the Stanback, the only art museum with a planetarium at any of the Historically Black Colleges and Universities and one of the few in the nation, stands in the forefront of modern thinking. Cosmic Convergence: Art and Science, opening at the I.P. Stanback Museum and Planetarium in February 2010, will feature the works of Mildred Thompson (1936-2003), a prominent African American artist who worked in the media of painting, drawing, print making, sculpture, and photography. Thompson’s artwork shows the strong influences of her interest in physics, astronomy, and metaphysics as well as music and spiritualism. “My work in the visual arts is, and has always been, a continuous search for understanding. It is an expression of purpose and reflects a personal interpretation of the Universe.” Cosmic Convergence will explore the meeting of Art and Science through Mildred Thompson's work and the scientific basis of that work. The paintings and sculptures of the exhibit will be combined with astronomical images showing both the reality and interpretation of the surrounding Universe. Support for this work was provided by the NSF PAARE program to South Carolina State University under award AST-0750814.

  3. Bioprecipitation of Calcium Carbonate Crystals by Bacteria Isolated from Saline Environments Grown in Culture Media Amended with Seawater and Real Brine

    PubMed Central

    Silva-Castro, G. A.; Uad, I.; Gonzalez-Martinez, A.; Rivadeneyra, A.; Gonzalez-Lopez, J.; Rivadeneyra, M. A.

    2015-01-01

    The precipitation of calcium carbonate and calcium sulphate by isolated bacteria from seawater and real brine obtained in a desalination plant growth in culture media containing seawater and brine as mineral sources has been studied. However, only bioprecipitation was detected when the bacteria were grown in media with added organic matter. Biomineralization process started rapidly, crystal formation taking place in the beginning a few days after inoculation of media; roughly 90% of total cultivated bacteria showed. Six major colonies with carbonate precipitation capacity dominated bacterial community structure cultivated in heterotrophic platable bacteria medium. Taxonomic identification of these six strains through partial 16S rRNA gene sequences showed their affiliation with Gram-positive Bacillus and Virgibacillus genera. These strains were able to form calcium carbonate minerals, which precipitated as calcite and aragonite crystals and showed bacterial fingerprints or bacteria calcification. Also, carbonic anhydrase activity was observed in three of these isolated bacteria. The results of this research suggest that microbiota isolated from sea water and brine is capable of precipitation of carbonate biominerals, which can occur in situ with mediation of organic matter concentrations. Moreover, calcium carbonate precipitation ability of this microbiota could be of importance in bioremediation of CO2 and calcium in certain environments. PMID:26273646

  4. Bioprecipitation of Calcium Carbonate Crystals by Bacteria Isolated from Saline Environments Grown in Culture Media Amended with Seawater and Real Brine.

    PubMed

    Silva-Castro, G A; Uad, I; Gonzalez-Martinez, A; Rivadeneyra, A; Gonzalez-Lopez, J; Rivadeneyra, M A

    2015-01-01

    The precipitation of calcium carbonate and calcium sulphate by isolated bacteria from seawater and real brine obtained in a desalination plant growth in culture media containing seawater and brine as mineral sources has been studied. However, only bioprecipitation was detected when the bacteria were grown in media with added organic matter. Biomineralization process started rapidly, crystal formation taking place in the beginning a few days after inoculation of media; roughly 90% of total cultivated bacteria showed. Six major colonies with carbonate precipitation capacity dominated bacterial community structure cultivated in heterotrophic platable bacteria medium. Taxonomic identification of these six strains through partial 16S rRNA gene sequences showed their affiliation with Gram-positive Bacillus and Virgibacillus genera. These strains were able to form calcium carbonate minerals, which precipitated as calcite and aragonite crystals and showed bacterial fingerprints or bacteria calcification. Also, carbonic anhydrase activity was observed in three of these isolated bacteria. The results of this research suggest that microbiota isolated from sea water and brine is capable of precipitation of carbonate biominerals, which can occur in situ with mediation of organic matter concentrations. Moreover, calcium carbonate precipitation ability of this microbiota could be of importance in bioremediation of CO2 and calcium in certain environments.

  5. Astronomical Ice: The Effects of Treating Ice as a Porous Media on the Dynamics and Evolution of Extraterrestrial Ice-Ocean Environments

    NASA Astrophysics Data System (ADS)

    Buffo, J.; Schmidt, B. E.

    2015-12-01

    With the prevalence of water and ice rich environments in the solar system, and likely the universe, becoming more apparent, understanding the evolutionary dynamics and physical processes of such locales is of great importance. Piqued interest arises from the understanding that the persistence of all known life depends on the presence of liquid water. As in situ investigation is currently infeasible, accurate numerical modeling is the best technique to demystify these environments. We will discuss an evolving model of ice-ocean interaction aimed at realistically describing the behavior of the ice-ocean interface by treating basal ice as a porous media, and its possible implications on the formation of astrobiological niches. Treating ice as a porous media drastically affects the thermodynamic properties it exhibits. Thus inclusion of this phenomenon is critical in accurately representing the dynamics and evolution of all ice-ocean environments. This model utilizes equations that describe the dynamics of sea ice when it is treated as a porous media (Hunke et. al. 2011), coupled with a basal melt and accretion model (Holland and Jenkins 1999). Combined, these two models produce the most accurate description of the processes occurring at the base of terrestrial sea ice and ice shelves, capable of resolving variations within the ice due to environmental pressures. While these models were designed for application to terrestrial environments, the physics occurring at any ice-water interface is identical, and these models can be used to represent the evolution of a variety of icy astronomical bodies. As terrestrial ice shelves provide a close analog to planetary ice-ocean environments, we truth test the models validity against observations of ice shelves. We apply this model to the ice-ocean interface of the icy Galilean moon Europa. We include profiles of temperature, salinity, solid fraction, and Darcy velocity, as well as temporally and spatially varying melt and

  6. From Gutenberg to Gates: Media Matters

    ERIC Educational Resources Information Center

    Considine, David M.

    2009-01-01

    Media consolidation and convergence have increasingly changed the way individuals as both consumers and citizens access, process, and communicate information at the local, national, and global levels. Media industries and institutions influence public perception and occupy our time at work and at home more and more. Media literacy has become…

  7. Media Literacy Education at the University Level

    ERIC Educational Resources Information Center

    Schmidt, Hans

    2012-01-01

    In recent years, the media literacy education movement has developed to help individuals of all ages acquire the competencies necessary to fully participate in the modern world of media convergence. Yet media literacy education is not practiced uniformly at all educational levels. This study used a survey to compare the extent to which students…

  8. Growth media simulating ileal and colonic environments affect the intracellular proteome and carbon fluxes of enterohemorrhagic Escherichia coli O157:H7 strain EDL933.

    PubMed

    Polzin, Sabrina; Huber, Claudia; Eylert, Eva; Elsenhans, Ines; Eisenreich, Wolfgang; Schmidt, Herbert

    2013-06-01

    In this study, the intracellular proteome of Escherichia coli O157:H7 strain EDL933 was analyzed by two-dimensional gel electrophoresis and matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF) spectrometry after growth in simulated ileal environment media (SIEM) and simulated colonic environment media (SCEM) under aerobic and microaerobic conditions. Differentially expressed intracellular proteins were identified and allocated to functional protein groups. Moreover, metabolic fluxes were analyzed by isotopologue profiling with [U-(13)C(6)]glucose as a tracer. The results of this study show that EDL933 responds with differential expression of a complex network of proteins and metabolic pathways, reflecting the high metabolic adaptability of the strain. Growth in SIEM and SCEM is obviously facilitated by the upregulation of nucleotide biosynthesis pathway proteins and could be impaired by exposition to 50 µM 6-mercaptopurine under aerobic conditions. Notably, various stress and virulence factors, including Shiga toxin, were expressed without having contact with a human host.

  9. Ecomorphological convergence of cave communities.

    PubMed

    Trontelj, Peter; Blejec, Andrej; Fišer, Cene

    2012-12-01

    Extreme selective environments are commonly believed to funnel evolution toward a few predictable outcomes. Caves are well-known extreme environments with characteristically adapted faunas that are similar in appearance, physiology, and behavior all over the world, even if not closely related. Morphological diversity between closely related cave species has been explained by difference in time since colonization and different ecological influence from the surface. Here, we tested a more classical hypothesis: morphological diversity is niche-based, and different morphologies reflect properties of microhabitats within caves. We analyzed seven communities with altogether 30 species of the subterranean amphipod (crustacean) genus Niphargus using multivariate morphometrics, multinomial logit models cross-validation, and phylogenetic reconstruction. Species clustered into four distinct ecomorph classes-small pore, cave stream, cave lake, and lake giants-associated with specific cave microhabitats and of multiple independent phylogenetic origins. Traits commonly regarded as adaptations to caves, such as antenna length, were shown to be related to microhabitat parameters, such as flow velocity. These results demonstrate that under the selection pressure of extreme environment, the ecomorphological structure of communities can converge. Thus, morphological diversity does not result from adaptive response to temporal and ecological gradients, but from fine-level niche partitioning. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  10. Knowledge Convergence and Collaborative Learning

    ERIC Educational Resources Information Center

    Jeong, Heisawn; Chi, Michelene T. H.

    2007-01-01

    This paper operationalized the notion of knowledge convergence and assessed quantitatively how much knowledge convergence occurred during collaborative learning. Knowledge convergence was defined as an increase in common knowledge where common knowledge referred to the knowledge that all collaborating partners had. Twenty pairs of college students…

  11. Knowledge Convergence and Collaborative Learning

    ERIC Educational Resources Information Center

    Jeong, Heisawn; Chi, Michelene T. H.

    2007-01-01

    This paper operationalized the notion of knowledge convergence and assessed quantitatively how much knowledge convergence occurred during collaborative learning. Knowledge convergence was defined as an increase in common knowledge where common knowledge referred to the knowledge that all collaborating partners had. Twenty pairs of college students…

  12. Priming Sexual and Romantic Representations in Two Media Environments: Sex Encourages and Romance Discourages Sexual Permissiveness … Sometimes.

    PubMed

    Dillman Carpentier, Francesca R

    2016-06-29

    Two experiments (Ns = 314, 447) were used to evaluate the effectiveness of sexual cues in temporarily increasing young adults' self-reported sexual permissiveness, as well as the effects of romantic cues in temporarily decreasing permissiveness. Participants were exposed to sexual or romantic cues embedded as a theme-defining component of an online game (Study 1) or in advertisements peripheral to the online game (Study 2). Sexual and romantic conditions were compared against a control condition. As hypothesized, participants in the romantic conditions rated themselves lower in sexual permissiveness, compared to participants in the sexual and control conditions, particularly when participants positively evaluated the online game experience. Findings suggest that exposure to entertaining media depictions of two people, as a committed couple, expressing love, as well as lust, for each other might deter young adults from considering engagement in casual sexual encounters indicative of "hookup culture."

  13. Convergent Flows: Humanities Scholars and Their Interactions with Electronic Texts

    ERIC Educational Resources Information Center

    Sukovic, Suzana

    2008-01-01

    This article reports research findings related to converging formats, media, practices, and ideas in the process of academics' interaction with electronic texts during a research project. The findings are part of the results of a study that explored interactions of scholars in literary and historical studies with electronic texts as primary…

  14. Convergent Flows: Humanities Scholars and Their Interactions with Electronic Texts

    ERIC Educational Resources Information Center

    Sukovic, Suzana

    2008-01-01

    This article reports research findings related to converging formats, media, practices, and ideas in the process of academics' interaction with electronic texts during a research project. The findings are part of the results of a study that explored interactions of scholars in literary and historical studies with electronic texts as primary…

  15. The Influence of Media Violence on Youth.

    PubMed

    Anderson, Craig A; Berkowitz, Leonard; Donnerstein, Edward; Huesmann, L Rowell; Johnson, James D; Linz, Daniel; Malamuth, Neil M; Wartella, Ellen

    2003-12-01

    Research on violent television and films, video games, and music reveals unequivocal evidence that media violence increases the likelihood of aggressive and violent behavior in both immediate and long-term contexts. The effects appear larger for milder than for more severe forms of aggression, but the effects on severe forms of violence are also substantial (r = .13 to .32) when compared with effects of other violence risk factors or medical effects deemed important by the medical community (e.g., effect of aspirin on heart attacks). The research base is large; diverse in methods, samples, and media genres; and consistent in overall findings. The evidence is clearest within the most extensively researched domain, television and film violence. The growing body of video-game research yields essentially the same conclusions. Short-term exposure increases the likelihood of physically and verbally aggressive behavior, aggressive thoughts, and aggressive emotions. Recent large-scale longitudinal studies provide converging evidence linking frequent exposure to violent media in childhood with aggression later in life, including physical assaults and spouse abuse. Because extremely violent criminal behaviors (e.g., forcible rape, aggravated assault, homicide) are rare, new longitudinal studies with larger samples are needed to estimate accurately how much habitual childhood exposure to media violence increases the risk for extreme violence. Well-supported theory delineates why and when exposure to media violence increases aggression and violence. Media violence produces short-term increases by priming existing aggressive scripts and cognitions, increasing physiological arousal, and triggering an automatic tendency to imitate observed behaviors. Media violence produces long-term effects via several types of learning processes leading to the acquisition of lasting (and automatically accessible) aggressive scripts, interpretational schemas, and aggression-supporting beliefs

  16. Situated Cognition and Learning Environments: Implications for Teachers On- and Offline in the New Digital Media Age

    ERIC Educational Resources Information Center

    Gomez, Kimberley; Lee, Ung-Sang

    2015-01-01

    John Seely Brown suggested that learning environments should be spaces in which all work is public, is subject to iterative critique by instructors and peers, and in which social interaction is primary. In such spaces, students and teachers engage in a situated cognition approach to teaching and learning where "cognitive accomplishments rely…

  17. MEDIA ADVISORY: EPA Region 10 Administrator McLerran speaks at Alaska Forum on the Environment today in Anchorage

    EPA Pesticide Factsheets

    (Anchorage - February 8, 2016) Today, U.S. EPA Region 10 Administrator Dennis McLerran will give a keynote address opening the 2016 Alaska Forum on the Environment, in Anchorage, focusing on EPA's work in rural Alaska and ongoing federal commitments highli

  18. "Get Some Secured Credit Cards Homey": Hip Hop Discourse, Financial Literacy and the Design of Digital Media Learning Environments

    ERIC Educational Resources Information Center

    Devane, Ben

    2009-01-01

    In the midst of the worst economic crisis since the Great Depression, there exists a deficit of compelling financial education curricula in urban schools that serve financially vulnerable working-class students. Part of a design-based research investigation aimed at creating culturally-relevant financial literacy learning environments, this study…

  19. Situated Cognition and Learning Environments: Implications for Teachers On- and Offline in the New Digital Media Age

    ERIC Educational Resources Information Center

    Gomez, Kimberley; Lee, Ung-Sang

    2015-01-01

    John Seely Brown suggested that learning environments should be spaces in which all work is public, is subject to iterative critique by instructors and peers, and in which social interaction is primary. In such spaces, students and teachers engage in a situated cognition approach to teaching and learning where "cognitive accomplishments rely…

  20. Influence of biofilms on the movement of colloids in porous media. Implications for colloid facilitated transport in subsurface environments.

    PubMed

    Leon Morales, Carlos Felipe; Strathmann, Martin; Flemming, Hans-Curt

    2007-05-01

    Colloid transport through porous media can be influenced by the presence of biofilms. Sterile and non-sterile sand columns were investigated using Laponite RD as model colloid and a highly mucoid strain of Pseudomonas aeruginosa as model biofilm former. Laponite RD was marked specifically by fluorescent complexes with rhodamine 6G. Breakthrough curves (BTCs) were used as parameters for determination of colloid transport characteristics. In the sterile columns, the colloid was mobile (collision efficiencies from 0.05 to 0.08) both after the presence of Na(+) and Ca(2+) ions followed by deionised water influent. In the biofilm-grown column, the same treatment did not result in colloid retention in the case of Na(+) exposure, but in altered or enhanced colloid transport. In the case of Ca(2+) ions exposure, colloid retention increased with biofilm age. After 3 weeks, almost complete retention was observed. Similar observations were made in columns packed with material from slow sand filtration units. These data reveal the complex interactions between biofilms, cations and colloid transport. Changes in the electrolyte composition of water percolating the subsurface can frequently occur and will result in different colloid transport characteristics with regard to the dominating species of ions and the relative abundance of microbial biofilms. This has to be considered when modelling colloid transport through the subsurface.

  1. Human health risks from TNT, RDX, and HMX in environmental media and consideration of the US Regulatory Environment

    SciTech Connect

    Daniels, J.I.; Knezovich, J.P.

    1994-12-01

    Although the most economical method for disposing of unwanted energetic high explosives [HEs; e.g., 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-triazine (RDX, also known as Cyclonite), and octahydro-1,3,5,7-tetrazocine (HMX, also known as Octogen)] involves open burning and open or underground detonation [OB/O(U)D]; federal, state, and even local government agencies in the United States (U.S.) are implementing stricter environmental regulations that eventually may prevent such activities. These stricter regulations will promote alternative technologies that are designed to be environmentally benign. However, past HE-waste disposal practices at manufacturing and fabrication facilities in the U.S. have included uncontrolled OB/O(U)D, as well as direct surface discharge of HE-contaminated waste water, resulting in contaminated environmental media (e.g., ground water, soil, and perhaps even edible vegetation) near residential areas. Using TNT, RDX, and HMX as examples, this paper describes how risk-based standards for HEs can be derived that account for potential multimedia exposures (associated with contaminated air, water, food, and soil) by individuals near a contaminated site, and used to (1) protect public health and safety; (2)prevent limited resources from being dedicated to unnecessary cleanup activities; and (3) identify the most cost-effective, practical, and environmentally benign technologies suitable for integrating with the handling of the large quantity of high explosives scheduled for demilitarization.

  2. Educational Multi-media in a Networked Society.

    ERIC Educational Resources Information Center

    Bates, A. W.

    Multimedia is developing fast due to the convergence of different media (text, data. graphics, video, audio) into a common digital platform, and due to the convergence of telecommunications, television, and computing. Parallel to these technical convergencies is another set of developments in work and leisure that is opening up new markets for…

  3. Electronic media time and sedentary behaviors in children: Findings from the Built Environment and Active Play Study in the Washington DC area.

    PubMed

    Roberts, Jennifer D; Rodkey, Lindsey; Ray, Rashawn; Knight, Brandon; Saelens, Brian E

    2017-06-01

    An objective of the Built Environment and Active Play (BEAP) Study was to examine whether home built environment, bedroom electronic presence, parental rules and demographics predicted children's sedentary behavior (SB). In 2014, BEAP Study questionnaires were mailed to 2000 parents of children (7-12 years) within the Washington DC area. SB-Duration (hours/day) and SB-Frequency (days/week) were assessed by two questions with multiple subparts relating to SB activity type (e.g. car riding) and SB companionship (e.g. friends). Built environment, bedroom electronic presence, parental rules and demographic data were obtained through questionnaire items and ordered logistic regression models were used to examine whether these variables were associated with SB. Study sample included 144 children (female (50%); average age (9.7 years); White (56.3%); Black/African-American (23.7%); Asian-Americans (10.4%)). Nearly 40% of the sample reported daily solitary SB with car riding being the most frequently reported type of SB. Children living on streets without a dead-end/cul-de-sac exhibited a higher odds in SB-Duration using electric media [2.61 (CI: 1.31, 5.18)] and having no television in a child's bedroom was associated with a lower odds in SB-Frequency [0.048 (CI: 0.006, 0.393)] and SB-Duration [0.085 (CI: 0.018, 0.395)]. Non-Hispanic/Latino children were also found to have higher odds in solitary SB-Frequency when parental rules of electronic use were modeled [8.56 (CI: 1.11, 66.01)]. Based on results from this cross-sectional study, home neighborhood built environment, bedroom electronic presence and absence of parental rules can significantly predict children's SB.

  4. Homology, convergence and parallelism.

    PubMed

    Ghiselin, Michael T

    2016-01-05

    Homology is a relation of correspondence between parts of parts of larger wholes. It is used when tracking objects of interest through space and time and in the context of explanatory historical narratives. Homologues can be traced through a genealogical nexus back to a common ancestral precursor. Homology being a transitive relation, homologues remain homologous however much they may come to differ. Analogy is a relationship of correspondence between parts of members of classes having no relationship of common ancestry. Although homology is often treated as an alternative to convergence, the latter is not a kind of correspondence: rather, it is one of a class of processes that also includes divergence and parallelism. These often give rise to misleading appearances (homoplasies). Parallelism can be particularly hard to detect, especially when not accompanied by divergences in some parts of the body. © 2015 The Author(s).

  5. Grand network convergence.

    PubMed

    Bader, Joel S

    2011-06-17

    A report of the Systems Biology: Networks meeting, Cold Spring Harbor, USA, 22-26 March 2011.The success of the human genome project has provided a model for an analogous interactome project to map how proteins, genes, metabolites and other regulatory components interact to transform a biochemical soup into a living system. These maps promise to serve as a framework for models that predict how a biological system responds to a perturbation or an input, which is relevant to gene mutations and therapeutic treatment in human disease, and as a framework for designing new systems in synthetic biology.Three major themes arose during the 2011 meeting: technological drivers and data generation, algorithmic advances, and convergence on biological applications with context-sensitive networks.

  6. Homology, convergence and parallelism

    PubMed Central

    Ghiselin, Michael T.

    2016-01-01

    Homology is a relation of correspondence between parts of parts of larger wholes. It is used when tracking objects of interest through space and time and in the context of explanatory historical narratives. Homologues can be traced through a genealogical nexus back to a common ancestral precursor. Homology being a transitive relation, homologues remain homologous however much they may come to differ. Analogy is a relationship of correspondence between parts of members of classes having no relationship of common ancestry. Although homology is often treated as an alternative to convergence, the latter is not a kind of correspondence: rather, it is one of a class of processes that also includes divergence and parallelism. These often give rise to misleading appearances (homoplasies). Parallelism can be particularly hard to detect, especially when not accompanied by divergences in some parts of the body. PMID:26598721

  7. Convergent evolution in plant specialized metabolism.

    PubMed

    Pichersky, Eran; Lewinsohn, Efraim

    2011-01-01

    Plants synthesize a multitude of compounds that contribute to adaptation to their ecological niches. Such compounds serve as attractants of other living organisms beneficial to the plants or as defense against other biotic as well as abiotic agents. Selection for increased fitness, a never-ending process, has resulted in each plant lineage synthesizing a distinct set of specialized metabolites appropriate for its environment. The total number of specialized metabolites found in the plant kingdom far exceeds the capacity of any one plant genome to encode the necessary enzymes, and just as a plant lineage acquires the ability to make new specialized compounds during evolution, it also loses the ability to make others. Although the ability of plants to make novel, specialized metabolites continues to evolve, there are also many examples in which different plants have independently evolved the ability to make compounds already present in other plant lineages or to make different compounds that fulfill the same role-both are examples of convergent evolution. Here, we discuss many examples of convergent evolution in specialized metabolism. There are many genetic and biochemical mechanisms that can give rise to convergent evolution, and we conclude that, overall, convergent evolution in plant specialized metabolism is surprisingly common.

  8. Series that Converge Absolutely but Don't Converge

    ERIC Educational Resources Information Center

    Kantrowitz, Robert; Schramm, Michael

    2012-01-01

    If a series of real numbers converges absolutely, then it converges. The usual proof requires completeness in the form of the Cauchy criterion. Failing completeness, the result is false. We provide examples of rational series that illustrate this point. The Cantor set appears in connection with one of the examples.

  9. Series that Converge Absolutely but Don't Converge

    ERIC Educational Resources Information Center

    Kantrowitz, Robert; Schramm, Michael

    2012-01-01

    If a series of real numbers converges absolutely, then it converges. The usual proof requires completeness in the form of the Cauchy criterion. Failing completeness, the result is false. We provide examples of rational series that illustrate this point. The Cantor set appears in connection with one of the examples.

  10. Multivalent calix[4]arene-based fluorescent sensor for detecting silver ions in aqueous media and physiological environment.

    PubMed

    Lotfi, Behzad; Tarlani, Aliakbar; Akbari-Moghaddam, Peyman; Mirza-Aghayan, Maryam; Peyghan, Ali Ahmadi; Muzart, Jacques; Zadmard, Reza

    2017-04-15

    A new derivative of dipodal 1,3-calix[4]arene-based chemosensor (R), which was containing several binding sites have been synthesized and characterized by NMR, IR and LC-MS spectroscopic methods. The selectivity of Rhas been investigated in aqueous methanol, resulting in fluorescence shift and selective recognition of Ag(+) among 20 various alkali, alkaline earth and transition metal ions. Microstructural features of R and its complex with Ag(+)have been investigated by Atomic Force Microscopy (AFM). AFM images can clearly differentiate R from its complex of Ag(+). Moreover; the complicated binding mode of metal-ligand complex has been explored by UV-Vis, LC-MS, FIR, Fluorescence titration, Job's plot method and theoretical approaches. Density functional theory (DFT) method at B3LYP/LANL2DZ level of theory was employed for computational studies. Theoretical calculations revealed that selectivity and specificity of R toward Ag(+) could be attributed to structural conformation of 1,3-alternate-calix[4]arene scaffold and molecular electrostatic potential of its surface. Furthermore; the competitive experiments were carried out to test sensor's ability for practical uses. Finally, the efficiency of R in matrix of physiological cations was examined and showed gradual emission enhancement which makes R an ideal candidate for monitoring of Ag(+) in physiological environment.

  11. Digital Media and Learning

    ERIC Educational Resources Information Center

    John D. and Catherine T. MacArthur Foundation, 2012

    2012-01-01

    MacArthur launched the digital media and learning initiative in 2006 to explore how digital media are changing the way young people learn, socialize, communicate, and play. Since 2006, the Foundation has awarded grants totaling more than $100 million for research, development of innovative new technologies, new learning environments for youth,…

  12. Convergent ablator performance measurements

    SciTech Connect

    Hicks, D. G.; Spears, B. K.; Braun, D. G.; Sorce, C. M.; Celliers, P. M.; Collins, G. W.; Landen, O. L.; Olson, R. E.

    2010-10-15

    The velocity and remaining ablator mass of an imploding capsule are critical metrics for assessing the progress toward ignition of an inertially confined fusion experiment. These and other convergent ablator performance parameters have been measured using a single streaked x-ray radiograph. Traditional Abel inversion of such a radiograph is ill-posed since backlighter intensity profiles and x-ray attenuation by the ablated plasma are unknown. To address this we have developed a regularization technique which allows the ablator density profile {rho}(r) and effective backlighter profile I{sub 0}(y) at each time step to be uniquely determined subject to the constraints that {rho}(r) is localized in radius space and I{sub 0}(y) is delocalized in object space. Moments of {rho}(r) then provide the time-resolved areal density, mass, and average radius (and thus velocity) of the remaining ablator material. These results are combined in the spherical rocket model to determine the ablation pressure and mass ablation rate during the implosion. The technique has been validated on simulated radiographs of implosions at the National Ignition Facility [Miller et al., Nucl. Fusion 44, 228 (2004)] and implemented on experiments at the OMEGA laser facility [Boehly et al., Opt. Commun. 133, 495 (1997)].

  13. The Intertropical Convergence Zone

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Intertropical Convergence Zone, or ITCZ, is the region that circles the Earth, near the equator, where the trade winds of the Northern and Southern Hemispheres come together. The intense sun and warm water of the equator heats the air in the ITCZ, raising its humidity and causing it to rise. As the air rises it cools, releasing the accumulated moisture in an almost perpetual series of thunderstorms. Variation in the location of the ITCZ drastically affects rainfall in many equatorial nations, resulting in the wet and dry seasons of the tropics rather than the cold and warm seasons of higher latitudes. Longer term changes in the ITCZ can result in severe droughts or flooding in nearby areas. This image is a combination of cloud data from NOAA's newest Geostationary Operational Environmental Satellite (GOES-11) and color land cover classification data. The ITCZ is the band of bright white clouds that cuts across the center of the image. For more GOES images, visit the GOES Project Science site. Image Courtesy GOES Project Science Office

  14. The Intertropical Convergence Zone

    NASA Technical Reports Server (NTRS)

    2002-01-01

    The Intertropical Convergence Zone, or ITCZ, is the region that circles the Earth, near the equator, where the trade winds of the Northern and Southern Hemispheres come together. The intense sun and warm water of the equator heats the air in the ITCZ, raising its humidity and causing it to rise. As the air rises it cools, releasing the accumulated moisture in an almost perpetual series of thunderstorms. Variation in the location of the ITCZ drastically affects rainfall in many equatorial nations, resulting in the wet and dry seasons of the tropics rather than the cold and warm seasons of higher latitudes. Longer term changes in the ITCZ can result in severe droughts or flooding in nearby areas. This image is a combination of cloud data from NOAA's newest Geostationary Operational Environmental Satellite (GOES-11) and color land cover classification data. The ITCZ is the band of bright white clouds that cuts across the center of the image. For more GOES images, visit the GOES Project Science site. Image Courtesy GOES Project Science Office

  15. Some Observations on Grid Convergence

    NASA Technical Reports Server (NTRS)

    Salas, manuel D.

    2006-01-01

    It is claimed that current practices in grid convergence studies, particularly in the field of external aerodynamics, are flawed. The necessary conditions to properly establish grid convergence are presented. A theoretical model and a numerical example are used to demonstrate these ideas.

  16. Literacy, Play and Globalization: Converging Imaginaries in Children's Critical and Cultural Performances. Routledge Research in Education

    ERIC Educational Resources Information Center

    Medina, Carmen L.; Wohlwend, Karen E.

    2014-01-01

    This book takes on current perspectives on children's relationships to literacy, media, childhood, markets and transtionalism in converging global worlds. It introduces the idea of multi-sited imaginaries to explain how children's media and literacy performances shape and are shaped by shared visions of communities that we collectively imagine,…

  17. Literacy, Play and Globalization: Converging Imaginaries in Children's Critical and Cultural Performances. Routledge Research in Education

    ERIC Educational Resources Information Center

    Medina, Carmen L.; Wohlwend, Karen E.

    2014-01-01

    This book takes on current perspectives on children's relationships to literacy, media, childhood, markets and transtionalism in converging global worlds. It introduces the idea of multi-sited imaginaries to explain how children's media and literacy performances shape and are shaped by shared visions of communities that we collectively imagine,…

  18. Giant lobelias exemplify convergent evolution.

    PubMed

    Givnish, Thomas J

    2010-01-14

    Giant lobeliads on tropical mountains in East Africa and Hawaii have highly unusual, giant-rosette growth forms that appear to be convergent on each other and on those of several independently evolved groups of Asteraceae and other families. A recent phylogenetic analysis by Antonelli, based on sequencing the widest selection of lobeliads to date, raises doubts about this paradigmatic example of convergent evolution. Here I address the kinds of evidence needed to test for convergent evolution and argue that the analysis by Antonelli fails on four points. Antonelli's analysis makes several important contributions to our understanding of lobeliad evolution and geographic spread, but his claim regarding convergence appears to be invalid. Giant lobeliads in Hawaii and Africa represent paradigmatic examples of convergent evolution.

  19. Convergence and the multidimensional niche.

    PubMed

    Harmon, Luke J; Kolbe, Jason J; Cheverud, James M; Losos, Jonathan B

    2005-02-01

    Convergent evolution has played an important role in the development of the ecological niche concept. We investigated patterns of convergent and divergent evolution of Caribbean Anolis lizards. These lizards diversified independently on each of the islands of the Greater Antilles, producing the same set of habitat specialists on each island. Using a phylogenetic comparative framework, we examined patterns of morphological convergence in five functionally distinct sets of morphological characters: body size, body shape, head shape, lamella number, and sexual size dimorphism. We find evidence for convergence among members of the habitat specialist types for each of these five datasets. Furthermore, the patterns of convergence differ among at least four of the five datasets; habitat specialists that are similar for one set of characters are often greatly different for another. This suggests that the habitat specialist niches into which these anoles have evolved are multidimensional, involving several distinct and independent aspects of morphology.

  20. Giant lobelias exemplify convergent evolution

    PubMed Central

    2010-01-01

    Giant lobeliads on tropical mountains in East Africa and Hawaii have highly unusual, giant-rosette growth forms that appear to be convergent on each other and on those of several independently evolved groups of Asteraceae and other families. A recent phylogenetic analysis by Antonelli, based on sequencing the widest selection of lobeliads to date, raises doubts about this paradigmatic example of convergent evolution. Here I address the kinds of evidence needed to test for convergent evolution and argue that the analysis by Antonelli fails on four points. Antonelli's analysis makes several important contributions to our understanding of lobeliad evolution and geographic spread, but his claim regarding convergence appears to be invalid. Giant lobeliads in Hawaii and Africa represent paradigmatic examples of convergent evolution. PMID:20074322

  1. Convergence of temperate and tropical stream fish assemblages

    EPA Science Inventory

    The hypothesis of convergence takes the deterministic view that community (or assemblage) structure can be predicted from the environment, and that the environment is expected to drive evolution in a predictable direction. Here we present results of a comparative study of freshwa...

  2. Convergence of temperate and tropical stream fish assemblages

    EPA Science Inventory

    The hypothesis of convergence takes the deterministic view that community (or assemblage) structure can be predicted from the environment, and that the environment is expected to drive evolution in a predictable direction. Here we present results of a comparative study of freshwa...

  3. Sounding of Groundwater Through Conductive Media in Mars Analog Environments Using Transient Electromagnetics and Low Frequency GPR.

    NASA Astrophysics Data System (ADS)

    Jernsletten, J. A.; Heggy, E.

    2004-05-01

    INTRODUCTION: This study compares the use of (diffusive) Transient Electromagnetics (TEM) for sounding of subsurface water in conductive Mars analog environments to the use of (propagative) Ground-Penetrating Radar (GPR) for the same purpose. We show data from three field studies: 1) Radar sounding data (GPR) from the Nubian aquifer, Bahria Oasis, Egypt; 2) Diffusive sounding data (TEM) from Pima County, Arizona; and 3) Shallower sounding data using the Fast-Turnoff TEM method from Peña de Hierro in the Rio Tinto area, Spain. The latter is data from work conducted under the auspices of the Mars Analog Research and Technology Experiment (MARTE). POTENTIAL OF TEM: A TEM survey was carried out in Pima County, Arizona, in January 2003. Data was collected using 100 m Tx loops, a ferrite-cored magnetic coil Rx antenna, and a sounding frequency of 16 Hz. The dataset has ~500 m depth of investigation, shows a ~120 m depth to the water table (confirmed by several USGS test wells in the area), and a conductive (~20-40 Ω m) clay-rich soil above the water table. The Rio Tinto Fast-Turnoff TEM data was collected using 40 m Tx loops, 10 m Rx loops, and a 32 Hz sounding frequency. Note ~200 m depth of investigation and a conductive high at ~80 m depth (interpreted as water table). Data was also collected using 20 m Tx loops (10 m Rx loops) in other parts of the area. Note ~50 m depth of investigation and a conductive high at ~15 m depth (interpreted as subsurface water flow under mine tailings matching surface flows seen coming out from under the tailings, and shown on maps). Both of these interpretations were roughly confirmed by preliminary results from the MARTE ground truth drilling campaign carried out in September and October 2003. POTENTIAL OF GPR: A GPR experiment was carried out in February 2003 in the Bahria Oasis in the western Egyptian desert, using a 2 MHz monostatic GPR, mapping the Nubian Aquifer at depths of 100-900 m, beneath a thick layer of homogenous marine

  4. Library Media Specialists: Doing the News!

    ERIC Educational Resources Information Center

    Barron, Daniel D.

    2003-01-01

    Discusses Newspapers in Education (NIE) Week and how it can relate to school library media specialists. Highlights include the convergence of news media, including news on the Web; ERIC (Educational Resources Information Center) resources, including lesson plans; relevant books; Web sites; and Web journalism. (LRW)

  5. Library Media Specialists: Doing the News!

    ERIC Educational Resources Information Center

    Barron, Daniel D.

    2003-01-01

    Discusses Newspapers in Education (NIE) Week and how it can relate to school library media specialists. Highlights include the convergence of news media, including news on the Web; ERIC (Educational Resources Information Center) resources, including lesson plans; relevant books; Web sites; and Web journalism. (LRW)

  6. The Convergence of Intelligences

    NASA Astrophysics Data System (ADS)

    Diederich, Joachim

    Minsky (1985) argued an extraterrestrial intelligence may be similar to ours despite very different origins. ``Problem- solving'' offers evolutionary advantages and individuals who are part of a technical civilisation should have this capacity. On earth, the principles of problem-solving are the same for humans, some primates and machines based on Artificial Intelligence (AI) techniques. Intelligent systems use ``goals'' and ``sub-goals'' for problem-solving, with memories and representations of ``objects'' and ``sub-objects'' as well as knowledge of relations such as ``cause'' or ``difference.'' Some of these objects are generic and cannot easily be divided into parts. We must, therefore, assume that these objects and relations are universal, and a general property of intelligence. Minsky's arguments from 1985 are extended here. The last decade has seen the development of a general learning theory (``computational learning theory'' (CLT) or ``statistical learning theory'') which equally applies to humans, animals and machines. It is argued that basic learning laws will also apply to an evolved alien intelligence, and this includes limitations of what can be learned efficiently. An example from CLT is that the general learning problem for neural networks is intractable, i.e. it cannot be solved efficiently for all instances (it is ``NP-complete''). It is the objective of this paper to show that evolved intelligences will be constrained by general learning laws and will use task-decomposition for problem-solving. Since learning and problem-solving are core features of intelligence, it can be said that intelligences converge despite very different origins.

  7. [Media for 21st century--towards human communication media].

    PubMed

    Harashima, H

    2000-05-01

    Today, with the approach of the 21st century, attention is focused on multi-media communications combining computer, visual and audio technologies. This article discusses the communication media target and the technological problems constituting the nucleus of multi-media. The communication media is becoming an environment from which no one can escape. Since the media has such a great power, what is needed now is not to predict the future technologies, but to estimate the future world and take to responsibility for future environments.

  8. CVD Prevention Through Policy: a Review of Mass Media, Food/Menu Labeling, Taxation/Subsidies, Built Environment, School Procurement, Worksite Wellness, and Marketing Standards to Improve Diet.

    PubMed

    Afshin, Ashkan; Penalvo, Jose; Del Gobbo, Liana; Kashaf, Michael; Micha, Renata; Morrish, Kurtis; Pearson-Stuttard, Jonathan; Rehm, Colin; Shangguan, Siyi; Smith, Jessica D; Mozaffarian, Dariush

    2015-11-01

    Poor diet is the leading cause of cardiovascular disease in the USA and globally. Evidence-based policies are crucial to improve diet and population health. We reviewed the effectiveness for a range of policy levers to alter diet and diet-related risk factors. We identified evidence to support benefits of focused mass media campaigns (especially for fruits, vegetables, salt), food pricing strategies (both subsidies and taxation, with stronger effects at lower income levels), school procurement policies (for increasing healthful or reducing unhealthful choices), and worksite wellness programs (especially when comprehensive and multicomponent). Evidence was inconclusive for food and menu labeling (for consumer or industry behavior) and changes in local built environment (e.g., availability or accessibility of supermarkets, fast food outlets). We found little empiric evidence evaluating marketing restrictions, although broad principles and large resources spent on marketing suggest utility. Widespread implementation and evaluation of evidence-based policy strategies, with further research on other strategies with mixed/limited evidence, are essential "population medicine" to reduce health and economic burdens and inequities of diet-related illness worldwide.

  9. Entertainment-education in a media-saturated environment: examining the impact of single and multiple exposures to breast cancer storylines on two popular medical dramas.

    PubMed

    Hether, Heather J; Huang, Grace C; Beck, Vicki; Murphy, Sheila T; Valente, Thomas W

    2008-12-01

    In the United States, entertainment-education (E-E) initiatives in primetime television that provide public health information are at risk for diminished impact due to the media-saturated environment in which they must compete. One strategy to overcome this limitation is to use multiple primetime TV shows to reinforce similar health messages in multiple storylines. The current study explores such an approach by evaluating the impact of two separate breast cancer genetics storylines featured on two different TV programs as the result of outreach to writers and producers. These storylines aired within approximately 3 weeks of each other on the popular medical dramas, ER (NBC) and Grey's Anatomy (ABC), and included information about the BRCA1 breast cancer gene mutation and the risks it poses to women who test positive for it. The evaluation used data collected from a panel sample of 599 female survey respondents at three points in time. Results show that while the individual storylines had a modest impact on viewers' knowledge, attitudes, and behaviors related to breast cancer, combined exposure seemed to be most effective at changing outcomes. Implications of our findings for future E-E interventions and evaluations are discussed.

  10. Why does continental convergence stop

    SciTech Connect

    Hynes, A.

    1985-01-01

    Convergence between India and Asia slowed at 45 Ma when they collided, but continues today. This requires that substantial proportions of the Indian and/or Asian lithospheric mantle are still being subducted. The resulting slab-pull is probably comparable with that from complete lithospheric slabs and may promote continued continental convergence even after collision. Since descending lithospheric slabs are present at all collision zones at the time of collision such continued convergence may be general after continental collisions. It may cease only when there is a major (global) plate reorganization which results in new forces on the convergent continents that may counteract the slab-pull. These inferences may be tested on the late Paleozoic collision between Gondwanaland and Laurasia. This is generally considered to have been complete by mid-Permian time (250 Ma). However, this may be only the time of docking of Gondwanaland with North America, not that of the cessation of convergence. Paleomagnetic polar-wander paths for the Gondwanide continents exhibit consistently greater latitudinal shifts from 250 Ma to 200 Ma than those of Laurasia when corrected for post-Triassic drift, suggesting that convergence continued through late Permian well into the Triassic. It may have been accommodated by crustal thickening under what is now the US Coastal Plain, or by strike-slip faulting. Convergence may have ceased only when Pangea began to fragment again, in which case the cause for its cessation may be related to the cause of continental fragmentation.

  11. The Impact of Mass Media.

    ERIC Educational Resources Information Center

    Aldrich, Pearl G.

    In order to bring the student's contemporary environment into the classroom for study and to avoid topicality, this book provides general principles by which to evaluate current media offerings, outlines the patterns from which media materials are cut for public consumption, and focuses the student's attention on the mass media themselves. Each of…

  12. The Impact of Mass Media.

    ERIC Educational Resources Information Center

    Aldrich, Pearl G.

    In order to bring the student's contemporary environment into the classroom for study and to avoid topicality, this book provides general principles by which to evaluate current media offerings, outlines the patterns from which media materials are cut for public consumption, and focuses the student's attention on the mass media themselves. Each of…

  13. Convergence insufficiency and vision therapy.

    PubMed

    McGregor, Mary Lou

    2014-06-01

    There is no standard meaning of the term "vision therapy", and for this reason it is often a controversial topic between some members of the ophthalmic and optometric community. Most pediatric ophthalmologists avoid using the term because it is nonspecific. Convergence Insufficiency (CI) is a binocular visual problem that causes problems and symptoms with near fixation. There is consensus among eye care professionals that convergence therapy is effective in treating CI. Convergence therapy is not effective in treating learning disabilities, but can sometimes relieve symptoms that might be a barrier to reading. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Unstable resonators with excited converging wave

    SciTech Connect

    Hodgson, N. ); Weber, H. )

    1990-04-01

    This paper reports the properties of unstable resonators with an additional mirror inside or outside the resonator investigated, both experimentally and theoretically. The additional mirror excites the converging wave, and by this, output coupling is decreased without affecting beam quality. Experiments were performed with a pulsed Nd:YAG system. The theoretical model was based on the coupled Kirchhoff integrals and solved numerically. Agreement between theory and experiments indicates that this kind of resonator provides high focusability and maximum extraction efficiency simultaneously, even with low-gain media. This enables one to apply unstable resonators to solid-state lasers with low small-signal gain, like alexandrite or CW-pumped Nd:YAG.

  15. Media Clips

    ERIC Educational Resources Information Center

    Vennebush, G. Patrick

    2004-01-01

    Media Clips aims to offer readers contemporary, authentic applications of quantitative reasoning based on print or electronic media. Clips may be in text or graphic format, and clip sources may be either print or electronic media.

  16. Data Convergence - An Australian Perspective

    NASA Astrophysics Data System (ADS)

    Allen, S. S.; Howell, B.

    2012-12-01

    Coupled numerical physical, biogeochemical and sediment models are increasingly being used as integrators to help understand the cumulative or far field effects of change in the coastal environment. This reliance on modeling has forced observations to be delivered as data streams ingestible by modeling frameworks. This has made it easier to create near real-time or forecasting models than to try to recreate the past, and has lead in turn to the conversion of historical data into data streams to allow them to be ingested by the same frameworks. The model and observation frameworks under development within Australia's Commonwealth and Industrial Research Organisation (CSIRO) are now feeding into the Australian Ocean Data Network's (AODN's) MARine Virtual Laboratory (MARVL) . The sensor, or data stream, brokering solution is centred around the "message" and all data flowing through the gateway is wrapped as a message. Messages consist of a topic and a data object and their routing through the gateway to pre-processors and listeners is determined by the topic. The Sensor Message Gateway (SMG) method is allowing data from different sensors measuring the same thing but with different temporal resolutions, units or spatial coverage to be ingested or visualized seamlessly. At the same time the model output as a virtual sensor is being explored, this again being enabled by the SMG. It is only for two way communications with sensor that rigorous adherence to standards is needed, by accepting existing data in less than ideal formats, but exposing them though the SMG we can move a step closer to the Internet Of Things by creating an Internet of Industries where each vested interest can continue with business as usual, contribute to data convergence and adopt more open standards when investment seems appropriate to that sector or business.Architecture Overview

  17. Optimality Functions and Lopsided Convergence

    DTIC Science & Technology

    2015-03-16

    Royset and E.Y. Pee . Rate of convergence analysis of discretization and smoothing algorithms for semi-infinite minimax problems. Journal of Optimization Theory and Applications, 155(3):855– 882, 2012. 17

  18. Spaces of Ideal Convergent Sequences

    PubMed Central

    Mursaleen, M.; Sharma, Sunil K.

    2014-01-01

    In the present paper, we introduce some sequence spaces using ideal convergence and Musielak-Orlicz function ℳ = (Mk). We also examine some topological properties of the resulting sequence spaces. PMID:24592143

  19. Reliability enhancement of Navier-Stokes codes through convergence acceleration

    NASA Technical Reports Server (NTRS)

    Merkle, Charles L.; Dulikravich, George S.

    1995-01-01

    Methods for enhancing the reliability of Navier-Stokes computer codes through improving convergence characteristics are presented. The improving of these characteristics decreases the likelihood of code unreliability and user interventions in a design environment. The problem referred to as a 'stiffness' in the governing equations for propulsion-related flowfields is investigated, particularly in regard to common sources of equation stiffness that lead to convergence degradation of CFD algorithms. Von Neumann stability theory is employed as a tool to study the convergence difficulties involved. Based on the stability results, improved algorithms are devised to ensure efficient convergence in different situations. A number of test cases are considered to confirm a correlation between stability theory and numerical convergence. The examples of turbulent and reacting flow are presented, and a generalized form of the preconditioning matrix is derived to handle these problems, i.e., the problems involving additional differential equations for describing the transport of turbulent kinetic energy, dissipation rate and chemical species. Algorithms for unsteady computations are considered. The extension of the preconditioning techniques and algorithms derived for Navier-Stokes computations to three-dimensional flow problems is discussed. New methods to accelerate the convergence of iterative schemes for the numerical integration of systems of partial differential equtions are developed, with a special emphasis on the acceleration of convergence on highly clustered grids.

  20. Convergence palsy secondary to amoxicillin.

    PubMed

    Pérez-Roca, F; Alfaro Juárez, A; Sánchez Merino, C; Navarro Mingorance, A

    2016-12-01

    We present the case of an 11-year-old boy with acute diplopia in near vision secondary to transient convergence palsy, possibly in relation to amoxicillin. Convergence palsy is an uncommon eye disorder. The causes are reviewed, and amoxicilin is identified as presumptive etiologic agent. This is the first case reported. Copyright © 2016 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Intercontinental community convergence of ecology and morphology in desert lizards.

    PubMed

    Melville, Jane; Harmon, Luke J; Losos, Jonathan B

    2006-03-07

    Evolutionary ecologists have long debated the extent to which communities in similar environments but different geographic regions exhibit convergence. On the one hand, if species' adaptations and community structure are determined by environmental features, convergence would be expected. However, if historical contingencies have long-lasting effects convergence would be unlikely. Most studies to date have emphasized the differences between communities in similar environments and little quantitative evidence for convergence exists. The application of comparative phylogenetic methods to ecological studies provides an opportunity to further investigate hypotheses of convergence. We compared the evolutionary patterns of structural ecology and morphology of 42 species of iguanian lizards from deserts of Australia and North America. Using a comparative approach, we found that evolutionary convergence of ecology and morphology occurs both in overall, community-wide patterns and in terms of pairs of highly similar intercontinental pairs of species. This result indicates that in these desert lizards, deterministic adaptive evolution shapes community patterns and overrides the historical contingencies unique to particular lineages.

  2. Intercontinental community convergence of ecology and morphology in desert lizards

    PubMed Central

    Melville, Jane; Harmon, Luke J; Losos, Jonathan B

    2005-01-01

    Evolutionary ecologists have long debated the extent to which communities in similar environments but different geographic regions exhibit convergence. On the one hand, if species' adaptations and community structure are determined by environmental features, convergence would be expected. However, if historical contingencies have long-lasting effects convergence would be unlikely. Most studies to date have emphasized the differences between communities in similar environments and little quantitative evidence for convergence exists. The application of comparative phylogenetic methods to ecological studies provides an opportunity to further investigate hypotheses of convergence. We compared the evolutionary patterns of structural ecology and morphology of 42 species of iguanian lizards from deserts of Australia and North America. Using a comparative approach, we found that evolutionary convergence of ecology and morphology occurs both in overall, community-wide patterns and in terms of pairs of highly similar intercontinental pairs of species. This result indicates that in these desert lizards, deterministic adaptive evolution shapes community patterns and overrides the historical contingencies unique to particular lineages. PMID:16537126

  3. Single-scattering parabolic equation solutions for elastic media propagation, including Rayleigh waves.

    PubMed

    Metzler, Adam M; Siegmann, William L; Collins, Michael D

    2012-02-01

    The parabolic equation method with a single-scattering correction allows for accurate modeling of range-dependent environments in elastic layered media. For problems with large contrasts, accuracy and efficiency are gained by subdividing vertical interfaces into a series of two or more single-scattering problems. This approach generates several computational parameters, such as the number of interface slices, an iteration convergence parameter τ, and the number of iterations n for convergence. Using a narrow-angle approximation, the choices of n=1 and τ=2 give accurate solutions. Analogous results from the narrow-angle approximation extend to environments with larger variations when slices are used as needed at vertical interfaces. The approach is applied to a generic ocean waveguide that includes the generation of a Rayleigh interface wave. Results are presented in both frequency and time domains.

  4. Understanding the Use and Impact of Social Media Features on the Educational Experiences of Higher-Education Students in Blended and Distance-Learning Environments

    ERIC Educational Resources Information Center

    Scialdone, Michael John

    2014-01-01

    Students are increasingly expecting social media to be a component of their educational experiences both outside and inside of the classroom. The phenomenon of interest in this dissertation is understanding how the educational experiences of students are affected when social media are incorporated into online and blended course activities.…

  5. Engagement with Novel Virtual Environments: The Role of Perceived Novelty and Flow in the Development of the Deficient Self-Regulation of Internet Use and Media Habits

    ERIC Educational Resources Information Center

    Tokunaga, Robert Shota

    2013-01-01

    This article extends theory on the deficient self-regulation (DSR) of Internet use and media habits by integrating predictors relevant to technology use. It introduces novelty perceptions of a technology and flow as conditions that increase the likelihood of experiencing DSR and media habits. An experiment, with between- and within-subjects…

  6. Understanding the Use and Impact of Social Media Features on the Educational Experiences of Higher-Education Students in Blended and Distance-Learning Environments

    ERIC Educational Resources Information Center

    Scialdone, Michael John

    2014-01-01

    Students are increasingly expecting social media to be a component of their educational experiences both outside and inside of the classroom. The phenomenon of interest in this dissertation is understanding how the educational experiences of students are affected when social media are incorporated into online and blended course activities.…

  7. Media Competency.

    ERIC Educational Resources Information Center

    Curtis, Ron

    The need to teach media competency in the schools in a systematic way has been largely unrecognized. The Media Now course of study provides an example of the type of instruction needed to teach the knowledge and skills necessary for informed media consumption and skilled media production. The course, which has been thoroughly tested and validated…

  8. The Effects of Increasing the Number of Taxa on Inferences of Molecular Convergence

    PubMed Central

    Hahn, Matthew W.; Hahn, Yoonsoo

    2017-01-01

    Convergent evolution provides insight into the link between phenotype and genotype. Recently, large-scale comparative studies of convergent evolution have become possible, but researchers are still trying to determine the best way to design these types of analyses. One aspect of molecular convergence studies that has not yet been investigated is how taxonomic sample size affects inferences of molecular convergence. Here we show that increased sample size decreases the amount of inferred molecular convergence associated with the three convergent transitions to a marine environment in mammals. The sampling of more taxa—both with and without the convergent phenotype—reveals that alleles associated only with marine mammals in small datasets are actually more widespread, or are not shared by all marine species. The sampling of more taxa also allows finer resolution of ancestral substitutions, revealing that they are not in fact on lineages leading to solely marine species. We revisit a previous study on marine mammals and find that only 7 of the reported 43 genes with convergent substitutions still show signs of convergence with a larger number of background species. However, four of those seven genes also showed signs of positive selection in the original analysis and may still be good candidates for adaptive convergence. Though our study is framed around the convergence of marine mammals, we expect our conclusions on taxonomic sampling are generalizable to any study of molecular convergence. PMID:28057728

  9. The camera convergence problem revisited

    NASA Astrophysics Data System (ADS)

    Allison, Robert S.

    2004-05-01

    Convergence of the real or virtual stereoscopic cameras is an important operation in stereoscopic display systems. For example, convergence can shift the range of portrayed depth to improve visual comfort; can adjust the disparity of targets to bring them nearer to the screen and reduce accommodation-vergence conflict; or can bring objects of interest into the binocular field-of-view. Although camera convergence is acknowledged as a useful function, there has been considerable debate over the transformation required. It is well known that rotational camera convergence or 'toe-in' distorts the images in the two cameras producing patterns of horizontal and vertical disparities that can cause problems with fusion of the stereoscopic imagery. Behaviorally, similar retinal vertical disparity patterns are known to correlate with viewing distance and strongly affect perception of stereoscopic shape and depth. There has been little analysis of the implications of recent findings on vertical disparity processing for the design of stereoscopic camera and display systems. We ask how such distortions caused by camera convergence affect the ability to fuse and perceive stereoscopic images.

  10. NONSURGICAL TREATMENT OF CONVERGENT STRABISMUS

    PubMed Central

    Tour, Robert L.

    1959-01-01

    It is generally agreed that surgical treatment of convergent strabismus should be withheld until all other less traumatic approaches have proved ineffectual. There are four categories of nonsurgical treatment. One is psychiatric. Too often psychiatric problems in the causation of convergent strabismus are either overlooked or unrecognized. Another is the proper employment of optical devices. For example, spectacle lenses to eliminate the need for excessive accommodation with its associated convergence excess, and the employment of prisms in the lenses to permit the two eyes to see as a unit even though they may not be properly anatomically oriented. Another kind of treatment is orthoptics, the use of exercises and rather complex optical equipment in a laboratory to train the patient in coordination between the two eyes. Treatment with drugs is based on the fact that certain drugs reduce the effort necessary for accommodation (much as eye-glasses do) and therefore lessen the stimulus toward convergence which may possibly tend toward the development of convergent strabismus. PMID:13662849

  11. Rainfall Morphology in Semi-Tropical Convergence Zones

    NASA Technical Reports Server (NTRS)

    Shepherd, J. Marshall; Ferrier, Brad S.; Ray, Peter S.

    2000-01-01

    Central Florida is the ideal test laboratory for studying convergence zone-induced convection. The region regularly experiences sea breeze fronts and rainfall-induced outflow boundaries. The focus of this study is the common yet poorly-studied convergence zone established by the interaction of the sea breeze front and an outflow boundary. Previous studies have investigated mechanisms primarily affecting storm initiation by such convergence zones. Few have focused on rainfall morphology yet these storms contribute a significant amount precipitation to the annual rainfall budget. Low-level convergence and mid-tropospheric moisture have both been shown to correlate with rainfall amounts in Florida. Using 2D and 3D numerical simulations, the roles of low-level convergence and mid-tropospheric moisture in rainfall evolution are examined. The results indicate that time-averaged, vertical moisture flux (VMF) at the sea breeze front/outflow convergence zone is directly and linearly proportional to initial condensation rates. This proportionality establishes a similar relationship between VMF and initial rainfall. Vertical moisture flux, which encompasses depth and magnitude of convergence, is better correlated to initial rainfall production than surface moisture convergence. This extends early observational studies which linked rainfall in Florida to surface moisture convergence. The amount and distribution of mid-tropospheric moisture determines how rainfall associated with secondary cells develop. Rainfall amount and efficiency varied significantly over an observable range of relative humidities in the 850- 500 mb layer even though rainfall evolution was similar during the initial or "first-cell" period. Rainfall variability was attributed to drier mid-tropospheric environments inhibiting secondary cell development through entrainment effects. Observationally, 850-500 mb moisture structure exhibits wider variability than lower level moisture, which is virtually always

  12. Media education.

    PubMed

    Strasburger, Victor C

    2010-11-01

    The American Academy of Pediatrics recognizes that exposure to mass media (eg, television, movies, video and computer games, the Internet, music lyrics and videos, newspapers, magazines, books, advertising) presents health risks for children and adolescents but can provide benefits as well. Media education has the potential to reduce the harmful effects of media and accentuate the positive effects. By understanding and supporting media education, pediatricians can play an important role in reducing harmful effects of media on children and adolescents.

  13. From SuperGoo to Scratch: Exploring Creative Digital Media Production in Informal Learning

    ERIC Educational Resources Information Center

    Peppler, Kylie A.; Kafai, Yasmin B.

    2007-01-01

    Based on work in media studies, new literacy studies, applied linguistics, the arts and empirical research on the experiences of urban youths' informal media arts practices, we articulate a new vision for media education in the digital age that encompasses new genres, convergence, media mixes and participation. We first outline the history of how…

  14. From SuperGoo to Scratch: Exploring Creative Digital Media Production in Informal Learning

    ERIC Educational Resources Information Center

    Peppler, Kylie A.; Kafai, Yasmin B.

    2007-01-01

    Based on work in media studies, new literacy studies, applied linguistics, the arts and empirical research on the experiences of urban youths' informal media arts practices, we articulate a new vision for media education in the digital age that encompasses new genres, convergence, media mixes and participation. We first outline the history of how…

  15. The potentials of virtual environments in the education and training of people with learning disabilities.

    PubMed

    Cromby, J J; Standen, P J; Brown, D J

    1996-12-01

    The expansion of 'care in the community' has highlighted the need for more effective educational and training media for people with learning disabilities, and this paper suggests that virtual environments (VEs) may help to meet this need. Firstly, key terms (virtual environment, cyberspace and artificial reality) are defined. Secondly, aspects of developmental and cognitive psychological theories and principles of computer-assisted learning are presented that suggest that VEs might be an especially valuable educational media for people with learning disabilities. Thirdly, the existing literature in this field is reviewed. Fourthly, ethical issues associated with the use of VE, both generally and specifically by people with learning disabilities are discussed. Fifth, possible future developments of VEs, both in education and through their convergence with technologies of miniaturization, are suggested. It is concluded that VEs are an effective, affordable, accessible and safe training and educational media for people with learning disabilities, although further research will be required to realise their full potentials.

  16. Convergent and Divergent Validity of the Learning Transfer System Inventory

    ERIC Educational Resources Information Center

    Holton, Elwood F., III; Bates, Reid A.; Bookter, Annette I.; Yamkovenko, V. Bogdan

    2007-01-01

    The Learning Transfer System Inventory (LTSI) was developed to identify a select set of factors with the potential to substantially enhance or inhibit transfer of learning to the work environment. It has undergone a variety of validation studies, including construct, criterion, and crosscultural studies. However, the convergent and divergent…

  17. Interactive Patterns and Conceptual Convergence during Student Collaborations in Science

    ERIC Educational Resources Information Center

    Oliveira, Alandeom W.; Sadler, Troy D.

    2008-01-01

    This study examines cognitive and social processes in group interactions that shape collaborative learning in science classrooms. Three small groups of students were observed while working collaboratively on explaining the burning of a candle under a jar. The learning environment served as a context for examination of conceptual convergence, a…

  18. Interactive Patterns and Conceptual Convergence during Student Collaborations in Science

    ERIC Educational Resources Information Center

    Oliveira, Alandeom W.; Sadler, Troy D.

    2008-01-01

    This study examines cognitive and social processes in group interactions that shape collaborative learning in science classrooms. Three small groups of students were observed while working collaboratively on explaining the burning of a candle under a jar. The learning environment served as a context for examination of conceptual convergence, a…

  19. Convergence methods on time scales

    NASA Astrophysics Data System (ADS)

    Turan, Ceylan; Duman, Oktay

    2013-10-01

    In this paper, we introduce the concepts of lacunary statistical convergence and strongly lacunary Cesàro summability of delta measurable functions on time scales and obtain some inclusion results between them. We also display some examples containing discrete and continuous cases.

  20. Convergence of a Catalan Series

    ERIC Educational Resources Information Center

    Koshy, Thomas; Gao, Zhenguang

    2012-01-01

    This article studies the convergence of the infinite series of the reciprocals of the Catalan numbers. We extract the sum of the series as well as some related ones, illustrating the power of the calculus in the study of the Catalan numbers.

  1. Media, Gadgets.

    ERIC Educational Resources Information Center

    Journal of Chemical Education, 1981

    1981-01-01

    Summarizes papers presented at the Sixth Biennial Conference on Chemical Education describing new media and gadgets, particularly models, computers, and other media. A bibliography of 15 presented papers on these topics is attached. (CS)

  2. Converging shocks in elastic-plastic solids.

    PubMed

    Ortega, A López; Lombardini, M; Hill, D J

    2011-11-01

    We present an approximate description of the behavior of an elastic-plastic material processed by a cylindrically or spherically symmetric converging shock, following Whitham's shock dynamics theory. Originally applied with success to various gas dynamics problems, this theory is presently derived for solid media, in both elastic and plastic regimes. The exact solutions of the shock dynamics equations obtained reproduce well the results obtained by high-resolution numerical simulations. The examined constitutive laws share a compressible neo-Hookean structure for the internal energy e=e(s)(I(1))+e(h)(ρ,ς), where e(s) accounts for shear through the first invariant of the Cauchy-Green tensor, and e(h) represents the hydrostatic contribution as a function of the density ρ and entropy ς. In the strong-shock limit, reached as the shock approaches the axis or origin r=0, we show that compression effects are dominant over shear deformations. For an isothermal constitutive law, i.e., e(h)=e(h)(ρ), with a power-law dependence e(h) is proportional to ρ(α), shock dynamics predicts that for a converging shock located at r=R(t) at time t, the Mach number increases as M is proportional to [log(1/R)](α), independently of the space index s, where s=2 in cylindrical geometry and 3 in spherical geometry. An alternative isothermal constitutive law with p(ρ) of the arctanh type, which enforces a finite density in the strong-shock limit, leads to M is proportional to R(-(s-1)) for strong shocks. A nonisothermal constitutive law, whose hydrostatic part e(h) is that of an ideal gas, is also tested, recovering the strong-shock limit M is proportional to R(-(s-1)/n(γ)) originally derived by Whitham for perfect gases, where γ is inherently related to the maximum compression ratio that the material can reach, (γ+1)/(γ-1). From these strong-shock limits, we also estimate analytically the density, radial velocity, pressure, and sound speed immediately behind the shock. While the

  3. Converging shocks in elastic-plastic solids

    NASA Astrophysics Data System (ADS)

    López Ortega, A.; Lombardini, M.; Hill, D. J.

    2011-11-01

    We present an approximate description of the behavior of an elastic-plastic material processed by a cylindrically or spherically symmetric converging shock, following Whitham's shock dynamics theory. Originally applied with success to various gas dynamics problems, this theory is presently derived for solid media, in both elastic and plastic regimes. The exact solutions of the shock dynamics equations obtained reproduce well the results obtained by high-resolution numerical simulations. The examined constitutive laws share a compressible neo-Hookean structure for the internal energy e=es(I1)+eh(ρ,ς), where es accounts for shear through the first invariant of the Cauchy-Green tensor, and eh represents the hydrostatic contribution as a function of the density ρ and entropy ς. In the strong-shock limit, reached as the shock approaches the axis or origin r=0, we show that compression effects are dominant over shear deformations. For an isothermal constitutive law, i.e., eh=eh(ρ), with a power-law dependence eh∝ρα, shock dynamics predicts that for a converging shock located at r=R(t) at time t, the Mach number increases as M∝[log(1/R)]α, independently of the space index s, where s=2 in cylindrical geometry and 3 in spherical geometry. An alternative isothermal constitutive law with p(ρ) of the arctanh type, which enforces a finite density in the strong-shock limit, leads to M∝R-(s-1) for strong shocks. A nonisothermal constitutive law, whose hydrostatic part eh is that of an ideal gas, is also tested, recovering the strong-shock limit M∝R-(s-1)/n(γ) originally derived by Whitham for perfect gases, where γ is inherently related to the maximum compression ratio that the material can reach, (γ+1)/(γ-1). From these strong-shock limits, we also estimate analytically the density, radial velocity, pressure, and sound speed immediately behind the shock. While the hydrostatic part of the energy essentially commands the strong-shock behavior, the shear

  4. Media violence.

    PubMed

    Strasburger, V C

    1999-01-01

    For decades, media violence has been viewed as largely a Western problem. New studies indicate that Indian children have increasing access to the media and that media violence will subject them to the same problems as Western children: imitation, desensitization, fear, and inappropriate attitudes about violence and aggression. Solutions exist but will have to be implemented within the next decade to protect Indian children and adolescents from the harmful effects of media violence.

  5. Media Interaction.

    ERIC Educational Resources Information Center

    Nordlund, Jan-Erik

    1978-01-01

    Defines and operationalizes the concept of media interaction, which implies that the audience member experiences "interaction" with, and in many cases identifies with, persons in the media content. Presents a model of media interaction and the results of surveys conducted to explore hypotheses derived form the model. (JMF)

  6. New Media.

    ERIC Educational Resources Information Center

    Downtown Business Quarterly, 1998

    1998-01-01

    This theme issue explores lower Manhattan's burgeoning "New Media" industry, a growing source of jobs in lower Manhattan. The first article, "New Media Manpower Issues" (Rodney Alexander), addresses manpower, training, and workforce demands faced by new media companies in New York City. The second article, "Case Study:…

  7. Media Panel.

    ERIC Educational Resources Information Center

    Marklund, Inger, Ed.; Hanse, Mona-Britt, Ed.

    1984-01-01

    The Swedish Media Panel is a research program about children and young persons and their use of mass media. The aim of the ten-year (1975-1985) project is to explain how media habits originate, how they change as children grow older, what factors on the part of children themselves and in their surroundings may be connected with a certain use of…

  8. Delivering risk information in a dynamic information environment: Framing and authoritative voice in Centers for Disease Control (CDC) and primetime broadcast news media communications during the 2014 Ebola outbreak.

    PubMed

    Kott, Anne; Limaye, Rupali J

    2016-11-01

    During a disease outbreak, media serve as primary transmitters of information from public health agencies to the public, and have been shown to influence both behavior and perception of risk. Differences in news frequency, framing and information source can impact the public's interpretation of risk messages and subsequent attitudes and behaviors about a particular threat. The media's framing of an outbreak is important, as it may affect both perception of risk and the ability to process important health information. To understand how risk communication by the Centers for Disease Control and Prevention (CDC) during the 2014 Ebola outbreak was framed and delivered and to what extent primetime broadcast news media mirrored CDC's framing and authoritative voice, 209 CDC communications and primetime broadcast transcripts issued between July 24 and December 29, 2014 were analyzed and coded by thematic frame and authoritative voice. Dominant frame and voice were determined for each month and for overall period of analysis. Medical frame was dominant in CDC (60%), Anderson Cooper 360 (49%), The Rachel Maddow Show (47%) and All In with Chris Hayes (47%). The human interest frame was dominant in The Kelly File (45%), while The O'Reilly Factor coverage was equally split between sociopolitical and medical frames (28%, respectively). Primetime news media also changed dominant frames over time. Dominant authoritative voice in CDC communications was that of CDC officials, while primetime news dominantly featured local and federal (non-CDC) government officials and academic/medical experts. Differences in framing and delivery could have led the public to interpret risk in a different way than intended by CDC. Overall, public health agencies should consider adapting risk communication strategies to account for a dynamic news environment and the media's agenda. Options include adapting communications to short-form styles and embracing the concept of storytelling. Copyright © 2016

  9. Converging beam optical Fourier transforms

    NASA Astrophysics Data System (ADS)

    Puang-ngern, Srisuda; Almeida, Silverio P.

    1985-08-01

    The classical, most often used, system for performing the optical Fourier transform is by using parallel coherent beam illumination. Lenses used in this method can become quite costly. In this paper we present results obtained using converging beam illumination which is suitable for many applications and is less expensive than the parallel beam method. The input objects for which the Fourier transforms were made are transparencies of snowflakes.

  10. Adaptive sampling in convergent beams.

    PubMed

    Espinosa, Julián; Mas, David; Pérez, Jorge; Illueca, Carlos

    2008-09-01

    Numerical calculation of convergent Fresnel patterns through fast Fourier transform usually requires a large number of samples to fulfill the Nyquist sampling condition around the focus. From polynomial decomposition of the wavefront it is possible to determine which polynomial orders are the main contributors to the number of samples. This information can be used to properly modify the initial wavefront and relax the Nyquist condition thus giving a more efficient numerical algorithm.

  11. Information Provenance in Social Media

    NASA Astrophysics Data System (ADS)

    Barbier, Geoffrey; Liu, Huan

    Information appearing in social media provides a challenge for determining the provenance of the information. However, the same characteristics that make the social media environment challenging provide unique and untapped opportunities for solving the information provenance problem for social media. Current approaches for tracking provenance information do not scale for social media and consequently there is a gap in provenance methodologies and technologies providing exciting research opportunities for computer scientists and sociologists. This paper introduces a theoretical approach aimed guiding future efforts to realize a provenance capability for social media that is not available today. The guiding vision is the use of social media information itself to realize a useful amount provenance data for information in social media.

  12. Sliding mode control method having terminal convergence in finite time

    NASA Technical Reports Server (NTRS)

    Venkataraman, Subramanian T. (Inventor); Gulati, Sandeep (Inventor)

    1994-01-01

    An object of this invention is to provide robust nonlinear controllers for robotic operations in unstructured environments based upon a new class of closed loop sliding control methods, sometimes denoted terminal sliders, where the new class will enforce closed-loop control convergence to equilibrium in finite time. Improved performance results from the elimination of high frequency control switching previously employed for robustness to parametric uncertainties. Improved performance also results from the dependence of terminal slider stability upon the rate of change of uncertainties over the sliding surface rather than the magnitude of the uncertainty itself for robust control. Terminal sliding mode control also yields improved convergence where convergence time is finite and is to be controlled. A further object is to apply terminal sliders to robot manipulator control and benchmark performance with the traditional computed torque control method and provide for design of control parameters.

  13. Open questions in the ethics of convergence.

    PubMed

    Khushf, George

    2007-01-01

    After historically situating NBIC Convergence in the context of earlier bioethical debate on genetics, ten questions are raised in areas related to the ethics of Convergence, indicating where future research is needed.

  14. Converging shocks for DSD modelling

    NASA Astrophysics Data System (ADS)

    Matignon, Christophe

    2013-06-01

    Modelling of pyrotechnic systems requires both, a good understanding and precise prediction capabilities of the dynamics of detonation. When using insensitive high explosives IHE (such as TATB-based explosives) the interaction of the detonation front with the confinement can lead to very different detonation velocities. One of the most popular engineering tools used to model this behaviour is the Detonation Shock Dynamics (DSD). In the DSD assumption, the detonation front propagates at a normal shock velocity (Dn) which depends only on its local curvature (κ). For divergent detonations, the DSD limit is very well established both experimentally and theoretically and one can easily propose a model (which obeys the 1D quasi-steady weakly curved detonation theory) to reproduce this behavior. We propose to extend the DSD theory to slightly convergent detonation fronts and to validate it against experimental data. Two series of experiments were carried out. The first series was designed to collect precise information regarding converging detonation. Usually, in such configurations, the detonation is non steady, making precise and simultaneous measurements of velocity and curvature difficult to achieve. The originality of the proposed setup is to drive a self similar convergent detonation at constant speed in an IHE rod by an external explosive tube of greater detonation velocity (allowing an accurate recording of both velocity and curvature). A wide range EOS/reaction rate model (inspired from previous works of Wescott et al.) was then calibrated to reproduce both the strong shock initiation and the newly extended (Dn- κ) law. This model can be used to perform either direct numerical simulation (DNS) on fine resolved mesh grid, or its reduced PZR model (DSD based) on a much coarser grid. This model was then successfully validated against the second series of experiments involving a detonation propagating around an obstacle and exhibiting a non steady converging front

  15. Independent Molecular Basis of Convergent Highland Adaptation in Maize

    PubMed Central

    Takuno, Shohei; Ralph, Peter; Swarts, Kelly; Elshire, Rob J.; Glaubitz, Jeffrey C.; Buckler, Edward S.; Hufford, Matthew B.; Ross-Ibarra, Jeffrey

    2015-01-01

    Convergent evolution is the independent evolution of similar traits in different species or lineages of the same species; this often is a result of adaptation to similar environments, a process referred to as convergent adaptation. We investigate here the molecular basis of convergent adaptation in maize to highland climates in Mesoamerica and South America, using genome-wide SNP data. Taking advantage of archaeological data on the arrival of maize to the highlands, we infer demographic models for both populations, identifying evidence of a strong bottleneck and rapid expansion in South America. We use these models to then identify loci showing an excess of differentiation as a means of identifying putative targets of natural selection and compare our results to expectations from recently developed theory on convergent adaptation. Consistent with predictions across a wide parameter space, we see limited evidence for convergent evolution at the nucleotide level in spite of strong similarities in overall phenotypes. Instead, we show that selection appears to have predominantly acted on standing genetic variation and that introgression from wild teosinte populations appears to have played a role in highland adaptation in Mexican maize. PMID:26078279

  16. Independent Molecular Basis of Convergent Highland Adaptation in Maize.

    PubMed

    Takuno, Shohei; Ralph, Peter; Swarts, Kelly; Elshire, Rob J; Glaubitz, Jeffrey C; Buckler, Edward S; Hufford, Matthew B; Ross-Ibarra, Jeffrey

    2015-08-01

    Convergent evolution is the independent evolution of similar traits in different species or lineages of the same species; this often is a result of adaptation to similar environments, a process referred to as convergent adaptation. We investigate here the molecular basis of convergent adaptation in maize to highland climates in Mesoamerica and South America, using genome-wide SNP data. Taking advantage of archaeological data on the arrival of maize to the highlands, we infer demographic models for both populations, identifying evidence of a strong bottleneck and rapid expansion in South America. We use these models to then identify loci showing an excess of differentiation as a means of identifying putative targets of natural selection and compare our results to expectations from recently developed theory on convergent adaptation. Consistent with predictions across a wide parameter space, we see limited evidence for convergent evolution at the nucleotide level in spite of strong similarities in overall phenotypes. Instead, we show that selection appears to have predominantly acted on standing genetic variation and that introgression from wild teosinte populations appears to have played a role in highland adaptation in Mexican maize.

  17. Convergence of m-bonacci 'golden ratios'

    NASA Astrophysics Data System (ADS)

    Ahrens, K.; Brown, D. A.; Kramer, A.

    2014-05-01

    This paper proves that the ratios of consecutive terms of the m-bonacci sequence converge to a limit φm < 2 and, as m → ∞, these φm converge to 2. Further, it is shown that the generating functions for the m-bonacci sequences converge pointwise to the geometric series.

  18. Convergence analysis of combinations of different methods

    SciTech Connect

    Kang, Y.

    1994-12-31

    This paper provides a convergence analysis for combinations of different numerical methods for solving systems of differential equations. The author proves that combinations of two convergent linear multistep methods or Runge-Kutta methods produce a new convergent method of which the order is equal to the smaller order of the two original methods.

  19. "Nanoselves": NBIC and the Culture of Convergence

    ERIC Educational Resources Information Center

    Venkatesan, Priya

    2010-01-01

    The subject of this essay is NBIC convergence (nanotechnology, biotechnology, information technology and cognitive science convergence). NBIC convergence is a recurring trope that is dominated by the paradigm of integration of the sciences. It is largely influenced by the considerations of social and economic impact, and it assumes positivism in…

  20. "Nanoselves": NBIC and the Culture of Convergence

    ERIC Educational Resources Information Center

    Venkatesan, Priya

    2010-01-01

    The subject of this essay is NBIC convergence (nanotechnology, biotechnology, information technology and cognitive science convergence). NBIC convergence is a recurring trope that is dominated by the paradigm of integration of the sciences. It is largely influenced by the considerations of social and economic impact, and it assumes positivism in…

  1. Libraries/Media Centers.

    ERIC Educational Resources Information Center

    American School & University, 2003

    2003-01-01

    Presents K-12 and college libraries/media centers considered outstanding in a competition, which judged the most outstanding learning environments at educational institutions nationwide. Jurors spent two days reviewing projects, highlighting concepts and ideas that made them exceptional. For each citation, the article offers information on the…

  2. Re-Purposing of Content and Digital Delivery Convergence: Implications for Interface Design.

    ERIC Educational Resources Information Center

    Milekic, Slavko

    With the introduction of the digital medium, an abundance of content previously obtainable through other media became available in digital form. Digital delivery implied the necessity for some kind of content modification dictated by the specific characteristics of the digital medium. The situation is further complicated by the convergence of…

  3. Predictors of media multitasking in Chinese adolescents.

    PubMed

    Yang, Xiaohui; Zhu, Liqi

    2016-12-01

    We examined predictors of media multitasking in Chinese adolescents from 3 contexts: characteristics of the media user, types of media use and family media contexts. Three hundred and twenty adolescents, 11-18 years of age, completed questionnaires to measure media use, impulsivity, sensation seeking, time management disposition and family media environment. The results showed that media multitasking was positively correlated with age and total media use time. Participants with high levels of impulsivity and sensation seeking reported more multitasking behaviour. Multitasking was negatively correlated with time management. Children from media-oriented families often engage in more multitasking. What's more, social networking sites use and music use can mediate the effect of individual and family factors on media multitasking.

  4. Corporate Schooling Meets Corporate Media: Standards, Testing, and Technophilia

    ERIC Educational Resources Information Center

    Saltman, Kenneth J.

    2016-01-01

    Educational publishing corporations and media corporations in the United States have been converging, especially through the promotion of standardization, testing, and for-profit educational technologies. Media and technology companies--including News Corp, Apple, and Microsoft--have significantly expanded their presence in public schools to sell…

  5. Corporate Schooling Meets Corporate Media: Standards, Testing, and Technophilia

    ERIC Educational Resources Information Center

    Saltman, Kenneth J.

    2016-01-01

    Educational publishing corporations and media corporations in the United States have been converging, especially through the promotion of standardization, testing, and for-profit educational technologies. Media and technology companies--including News Corp, Apple, and Microsoft--have significantly expanded their presence in public schools to sell…

  6. Convergent evolution across the Australian continent: ecotype diversification drives morphological convergence in two distantly related clades of Australian frogs.

    PubMed

    Vidal-García, M; Keogh, J S

    2015-12-01

    Animals from different clades but subject to similar environments often evolve similar body shapes and physiological adaptations due to convergent evolution, but this has been rarely tested at the transcontinental level and across entire classes of animal. Australia's biome diversity, isolation and aridification history provide excellent opportunities for comparative analyses on broad-scale macroevolutionary patterns. We collected morphological and environmental data on eighty-four (98%) Australian hylid frog species and categorized them into ecotypes. Using a phylogenetic framework, we tested the hypothesis that frogs from the same ecotype display similar body shape patterns: (i) across all the Australian hylids, and (ii) through comparison with a similar previous study on 127 (97%) Australian myobatrachid species. Body size and shape variation did not follow a strong phylogenetic pattern and was not tightly correlated with environment, but there was a stronger association between morphotype and ecotype. Both arboreal and aquatic frogs had long limbs, whereas limbs of fossorial species were shorter. Other terrestrial species were convergent on the more typical frog body shape. We quantified the strength of morphological convergence at two levels: (i) between fossorial myobatrachid and hylid frogs, and (ii) in each ecomorph within the hylids. We found strong convergence within ecotypes, especially in fossorial species. Ecotypes were also reflected in physiological adaptations: both arboreal and cocooned fossorial frogs tend to have higher rates of evaporative water loss. Our results illustrate how adaptation to different ecological niches plays a crucial role in morphological evolution, boosting phenotypic diversity within a clade. Despite phylogenetic conservatism, morphological adaptation to repeatedly emerging new environments can erase the signature of ancestral morphotypes, resulting in phenotypic diversification and convergence both within and between diverse

  7. Curating Media Learning: Towards a Porous Expertise

    ERIC Educational Resources Information Center

    McDougall, Julian; Potter, John

    2015-01-01

    This article combines research results from a range of projects with two consistent themes. Firstly, we explore the potential for curation to offer a productive metaphor for the convergence of digital media learning across and between home/lifeworld and formal educational/system-world spaces--or between the public and private spheres. Secondly, we…

  8. Curating Media Learning: Towards a Porous Expertise

    ERIC Educational Resources Information Center

    McDougall, Julian; Potter, John

    2015-01-01

    This article combines research results from a range of projects with two consistent themes. Firstly, we explore the potential for curation to offer a productive metaphor for the convergence of digital media learning across and between home/lifeworld and formal educational/system-world spaces--or between the public and private spheres. Secondly, we…

  9. Laser control of molecular excitations in stochastic dissipative media.

    PubMed

    Tremblay, Jean Christophe

    2011-05-07

    In the present work, ideas for controlling photochemical reactions in dissipative environments using shaped laser pulses are presented. New time-local control algorithms for the stochastic Schrödinger equation are introduced and compared to their reduced density matrix analog. The numerical schemes rely on time-dependent targets for guiding the reaction along a preferred path. The methods are tested on the vibrational control of adsorbates at metallic surfaces and on the ultrafast electron dynamics in a strong dissipative medium. The selective excitation of the specific states is achieved with improved yield when using the new algorithms. Both methods exhibit similar convergence behavior and results compare well with those obtained using local optimal control for the reduced density matrix. The favorable scaling of the methods allows to tackle larger systems and to control photochemical reactions in dissipative media of molecules with many more degrees of freedom.

  10. Laser control of molecular excitations in stochastic dissipative media

    NASA Astrophysics Data System (ADS)

    Tremblay, Jean Christophe

    2011-05-01

    In the present work, ideas for controlling photochemical reactions in dissipative environments using shaped laser pulses are presented. New time-local control algorithms for the stochastic Schrödinger equation are introduced and compared to their reduced density matrix analog. The numerical schemes rely on time-dependent targets for guiding the reaction along a preferred path. The methods are tested on the vibrational control of adsorbates at metallic surfaces and on the ultrafast electron dynamics in a strong dissipative medium. The selective excitation of the specific states is achieved with improved yield when using the new algorithms. Both methods exhibit similar convergence behavior and results compare well with those obtained using local optimal control for the reduced density matrix. The favorable scaling of the methods allows to tackle larger systems and to control photochemical reactions in dissipative media of molecules with many more degrees of freedom.

  11. Ocular Convergence Deficits in Schizophrenia

    PubMed Central

    Bolding, Mark S.; Lahti, Adrienne C.; Gawne, Timothy J.; Hopkins, Kristine B.; Gurler, Demet; Gamlin, Paul D.

    2012-01-01

    Individuals with schizophrenia (SZ) have been reported to exhibit a higher prevalence of convergence insufficiency (CI) than the “normal” adult population. The purpose of this study was to determine if individuals with SZ exhibit clinical signs of CI and to determine if the Convergence Insufficiency Symptom Survey (CISS) is an effective instrument for identifying CI in this population. Twenty participants with SZ and 20 healthy controls (HC) completed the study. The prevalence of CI (15%) in the SZ group was slightly higher than reported norms, but the difference was not significant. The SZ group had significantly higher scores on the CISS than the HC group, but the CISS scores did not correlate with clinical measures of CI in individuals with SZ. The only exception was that SZ patients had a significantly reduced fusional reserve as determined by Sheard’s criteria. Further study is needed to determine why individuals with SZ reported symptoms associated with CI even though clinical measures did not support this diagnosis. PMID:23087652

  12. Earned Media

    ERIC Educational Resources Information Center

    Sunshine, Alice

    2011-01-01

    "Earned media" is exactly what one thinks it is. The people who do the necessary work to earn coverage of their issue or battle are the ones who will get their story out to the public. Earning media coverage involves giving careful attention to the mechanics of reaching out to news outlets. Most people can learn the mechanics through…

  13. Mixed Media

    ERIC Educational Resources Information Center

    Peterson, Erin

    2010-01-01

    While institutions do not often have a hook as compelling as an eagerly awaited movie, great content is critical for media relations success--and coupling it with the right distribution channel can ensure the story finds the right audience. Even better, retooling it for several media platforms can extend the life and reach of a story. The changes…

  14. Earned Media

    ERIC Educational Resources Information Center

    Sunshine, Alice

    2011-01-01

    "Earned media" is exactly what one thinks it is. The people who do the necessary work to earn coverage of their issue or battle are the ones who will get their story out to the public. Earning media coverage involves giving careful attention to the mechanics of reaching out to news outlets. Most people can learn the mechanics through…

  15. Mixed Media

    ERIC Educational Resources Information Center

    Peterson, Erin

    2010-01-01

    While institutions do not often have a hook as compelling as an eagerly awaited movie, great content is critical for media relations success--and coupling it with the right distribution channel can ensure the story finds the right audience. Even better, retooling it for several media platforms can extend the life and reach of a story. The changes…

  16. Media Effects: Theory and Research.

    PubMed

    Valkenburg, Patti M; Peter, Jochen; Walther, Joseph B

    2016-01-01

    This review analyzes trends and commonalities among prominent theories of media effects. On the basis of exemplary meta-analyses of media effects and bibliometric studies of well-cited theories, we identify and discuss five features of media effects theories as well as their empirical support. Each of these features specifies the conditions under which media may produce effects on certain types of individuals. Our review ends with a discussion of media effects in newer media environments. This includes theories of computer-mediated communication, the development of which appears to share a similar pattern of reformulation from unidirectional, receiver-oriented views, to theories that recognize the transactional nature of communication. We conclude by outlining challenges and promising avenues for future research.

  17. Convergent Validity of the PUTS

    PubMed Central

    Brandt, Valerie Cathérine; Beck, Christian; Sajin, Valeria; Anders, Silke; Münchau, Alexander

    2016-01-01

    Premonitory urges are a cardinal feature in Gilles de la Tourette syndrome. Severity of premonitory urges can be assessed with the “Premonitory Urge for Tic Disorders Scale” (PUTS). However, convergent validity of the measure has been difficult to assess due to the lack of other urge measures. We investigated the relationship between average real-time urge intensity assessed by an in-house developed real-time urge monitor (RUM), measuring urge intensity continuously for 5 min on a visual analog scale, and general urge intensity assessed by the PUTS in 22 adult Tourette patients (mean age 29.8 ± 10.3 SD, 19 males). Additionally, underlying factors of premonitory urges assessed by the PUTS were investigated in the adult sample using factor analysis and were replicated in 40 children and adolescents diagnosed with Tourette syndrome (mean age 12.05 ± 2.83 SD, 31 males). Cronbach’s α for the PUTS 10 was acceptable (α = 0.79) in the adult sample. Convergent validity between average real-time urge intensity scores (as assessed with the RUM) and the 10-item version of the PUTS (r = 0.64) and the 9-item version of the PUTS (r = 0.66) was good. A factor analysis including the 10 items of the PUTS and average real-time urge intensity scores revealed three factors. One factor included the average real-time urge intensity score and appeared to measure urge intensity, whereas the other two factors can be assumed to reflect the (sensory) quality of urges and subjective control, respectively. The factor structure of the 10 PUTS items alone was replicated in a sample of children and adolescents. The results indicate that convergent validity between the PUTS and the real-time urge assessment monitor is good. Furthermore, the results suggest that the PUTS might assess more than one dimension of urges, and it may be worthwhile developing different subscales of the PUTS assessing premonitory urges in terms of intensity and quality, as well as

  18. Media Publics and Media Trust.

    ERIC Educational Resources Information Center

    Gaziano, Cecilie; McGrath, Kristin

    To gain a perspective on the kinds of people who find newspapers and television to be high or low in credibility, a two-phase study combined demographic and other characteristics, media behavior, and attitudes toward the media. The first phase involved a series of focused group discussions, while the second was a national, representative sampling…

  19. Media violence.

    PubMed

    Cantor, J

    2000-08-01

    Research on the effects of media violence is not well understood by the general public. Despite this fact, there is an overwhelming consensus in the scientific literature about the unhealthy effects of media violence. Meta-analyses show that media-violence viewing consistently is associated with higher levels of antisocial behavior, ranging from the trivial (imitative violence directed against toys) to the serious (criminal violence), with many consequential outcomes in between (acceptance of violence as a solution to problems, increased feelings of hostility, and the apparent delivery of painful stimulation to another person). Desensitization is another well-documented effect of viewing violence, which is observable in reduced arousal and emotional disturbance while witnessing violence, the reduced tendency to intervene in a fight, and less sympathy for the victims of violence. Although there is evidence that youth who are already violent are more likely to seek out violent entertainment, there is strong evidence that the relationship between violence viewing and antisocial behavior is bidirectional. There is growing evidence that media violence also engenders intense fear in children which often lasts days, months, and even years. The media's potential role in solutions to these problems is only beginning to be explored, in investigations examining the uses and effects of movie ratings, television ratings, and the V-chip, and the effects of media literacy programs and public education efforts. Future research should explore important individual differences in responses to media violence and effective ways to intervene in the negative effects.

  20. Particles Acceleration in Converged Shocks

    NASA Astrophysics Data System (ADS)

    Wang, Xin

    2016-07-01

    Observations show that there is a proton spectral ``break" with E_{break} at 1-10MeV in some large CME-driven shocks. However, the understanding of this energy spectral ``break" from the diffusive shock acceleration theory still remains uncertain. Although previous numerical methods can hardly predict this ``break" from current theoretical models due to high computational expense, the present paper focuses on simulating this energy spectrum in converged two shocks by Monte Carlo numerical method. Considering the Dec 13 2006 CME-driven shock interaction with an Earth bow shock, we examine whether the energy spectral ``break" could occur on an interaction between two shocks. As result, we indeed obtain the maximum proton energy up to 10MeV, and we further find a proton spectral ``break" appears distinctly at the energy ˜5MeV.

  1. Estimator reduction and convergence of adaptive BEM.

    PubMed

    Aurada, Markus; Ferraz-Leite, Samuel; Praetorius, Dirk

    2012-06-01

    A posteriori error estimation and related adaptive mesh-refining algorithms have themselves proven to be powerful tools in nowadays scientific computing. Contrary to adaptive finite element methods, convergence of adaptive boundary element schemes is, however, widely open. We propose a relaxed notion of convergence of adaptive boundary element schemes. Instead of asking for convergence of the error to zero, we only aim to prove estimator convergence in the sense that the adaptive algorithm drives the underlying error estimator to zero. We observe that certain error estimators satisfy an estimator reduction property which is sufficient for estimator convergence. The elementary analysis is only based on Dörfler marking and inverse estimates, but not on reliability and efficiency of the error estimator at hand. In particular, our approach gives a first mathematical justification for the proposed steering of anisotropic mesh-refinements, which is mandatory for optimal convergence behavior in 3D boundary element computations.

  2. Comprehensive Proteomic and Metabolomic Signatures of Nontypeable Haemophilus influenzae-Induced Acute Otitis Media Reveal Bacterial Aerobic Respiration in an Immunosuppressed Environment.

    PubMed

    Harrison, Alistair; Dubois, Laura G; St John-Williams, Lisa; Moseley, M Arthur; Hardison, Rachael L; Heimlich, Derek R; Stoddard, Alexander; Kerschner, Joseph E; Justice, Sheryl S; Thompson, J Will; Mason, Kevin M

    2016-03-01

    A thorough understanding of the molecular details of the interactions between bacteria and host are critical to ultimately prevent disease. Recent technological advances allow simultaneous analysis of host and bacterial protein and metabolic profiles from a single small tissue sample to provide insight into pathogenesis. We used the chinchilla model of human otitis media to determine, for the first time, the most expansive delineation of global changes in protein and metabolite profiles during an experimentally induced disease. After 48 h of infection with nontypeable Haemophilus influenzae, middle ear tissue lysates were analyzed by high-resolution quantitative two-dimensional liquid chromatography-tandem mass spectrometry. Dynamic changes in 105 chinchilla proteins and 66 metabolites define the early proteomic and metabolomic signature of otitis media. Our studies indicate that establishment of disease coincides with actin morphogenesis, suppression of inflammatory mediators, and bacterial aerobic respiration. We validated the observed increase in the actin-remodeling complex, Arp2/3, and experimentally showed a role for Arp2/3 in nontypeable Haemophilus influenzae invasion. Direct inhibition of actin branch morphology altered bacterial invasion into host epithelial cells, and is supportive of our efforts to use the information gathered to modify outcomes of disease. The twenty-eight nontypeable Haemophilus influenzae proteins identified participate in carbohydrate and amino acid metabolism, redox homeostasis, and include cell wall-associated metabolic proteins. Quantitative characterization of the molecular signatures of infection will redefine our understanding of host response driven developmental changes during pathogenesis. These data represent the first comprehensive study of host protein and metabolite profiles in vivo in response to infection and show the feasibility of extensive characterization of host protein profiles during disease. Identification of

  3. Comprehensive Proteomic and Metabolomic Signatures of Nontypeable Haemophilus influenzae-Induced Acute Otitis Media Reveal Bacterial Aerobic Respiration in an Immunosuppressed Environment*

    PubMed Central

    Harrison, Alistair; Dubois, Laura G.; St. John-Williams, Lisa; Moseley, M. Arthur; Hardison, Rachael L.; Heimlich, Derek R.; Stoddard, Alexander; Kerschner, Joseph E.; Justice, Sheryl S.; Thompson, J. Will; Mason, Kevin M.

    2016-01-01

    A thorough understanding of the molecular details of the interactions between bacteria and host are critical to ultimately prevent disease. Recent technological advances allow simultaneous analysis of host and bacterial protein and metabolic profiles from a single small tissue sample to provide insight into pathogenesis. We used the chinchilla model of human otitis media to determine, for the first time, the most expansive delineation of global changes in protein and metabolite profiles during an experimentally induced disease. After 48 h of infection with nontypeable Haemophilus influenzae, middle ear tissue lysates were analyzed by high-resolution quantitative two-dimensional liquid chromatography-tandem mass spectrometry. Dynamic changes in 105 chinchilla proteins and 66 metabolites define the early proteomic and metabolomic signature of otitis media. Our studies indicate that establishment of disease coincides with actin morphogenesis, suppression of inflammatory mediators, and bacterial aerobic respiration. We validated the observed increase in the actin-remodeling complex, Arp2/3, and experimentally showed a role for Arp2/3 in nontypeable Haemophilus influenzae invasion. Direct inhibition of actin branch morphology altered bacterial invasion into host epithelial cells, and is supportive of our efforts to use the information gathered to modify outcomes of disease. The twenty-eight nontypeable Haemophilus influenzae proteins identified participate in carbohydrate and amino acid metabolism, redox homeostasis, and include cell wall-associated metabolic proteins. Quantitative characterization of the molecular signatures of infection will redefine our understanding of host response driven developmental changes during pathogenesis. These data represent the first comprehensive study of host protein and metabolite profiles in vivo in response to infection and show the feasibility of extensive characterization of host protein profiles during disease. Identification of

  4. Convergence of broad-scale migration strategies in terrestrial birds

    PubMed Central

    La Sorte, Frank A.; Fink, Daniel; Hochachka, Wesley M.; Kelling, Steve

    2016-01-01

    Migration is a common strategy used by birds that breed in seasonal environments. Selection for greater migration efficiency is likely to be stronger for terrestrial species whose migration strategies require non-stop transoceanic crossings. If multiple species use the same transoceanic flyway, then we expect the migration strategies of these species to converge geographically towards the most optimal solution. We test this by examining population-level migration trajectories within the Western Hemisphere for 118 migratory species using occurrence information from eBird. Geographical convergence of migration strategies was evident within specific terrestrial regions where geomorphological features such as mountains or isthmuses constrained overland migration. Convergence was also evident for transoceanic migrants that crossed the Gulf of Mexico or Atlantic Ocean. Here, annual population-level movements were characterized by clockwise looped trajectories, which resulted in faster but more circuitous journeys in the spring and more direct journeys in the autumn. These findings suggest that the unique constraints and requirements associated with transoceanic migration have promoted the spatial convergence of migration strategies. The combination of seasonal atmospheric and environmental conditions that has facilitated the use of similar broad-scale migration strategies may be especially prone to disruption under climate and land-use change. PMID:26791618

  5. Convergence of broad-scale migration strategies in terrestrial birds.

    PubMed

    La Sorte, Frank A; Fink, Daniel; Hochachka, Wesley M; Kelling, Steve

    2016-01-27

    Migration is a common strategy used by birds that breed in seasonal environments. Selection for greater migration efficiency is likely to be stronger for terrestrial species whose migration strategies require non-stop transoceanic crossings. If multiple species use the same transoceanic flyway, then we expect the migration strategies of these species to converge geographically towards the most optimal solution. We test this by examining population-level migration trajectories within the Western Hemisphere for 118 migratory species using occurrence information from eBird. Geographical convergence of migration strategies was evident within specific terrestrial regions where geomorphological features such as mountains or isthmuses constrained overland migration. Convergence was also evident for transoceanic migrants that crossed the Gulf of Mexico or Atlantic Ocean. Here, annual population-level movements were characterized by clockwise looped trajectories, which resulted in faster but more circuitous journeys in the spring and more direct journeys in the autumn. These findings suggest that the unique constraints and requirements associated with transoceanic migration have promoted the spatial convergence of migration strategies. The combination of seasonal atmospheric and environmental conditions that has facilitated the use of similar broad-scale migration strategies may be especially prone to disruption under climate and land-use change.

  6. Convergent evolution of 'creepers' in the Hawaiian honeycreeper radiation.

    PubMed

    Reding, Dawn M; Foster, Jeffrey T; James, Helen F; Pratt, H Douglas; Fleischer, Robert C

    2009-04-23

    Natural selection plays a fundamental role in the ecological theory of adaptive radiation. A prediction of this theory is the convergent evolution of traits in lineages experiencing similar environments. The Hawaiian honeycreepers are a spectacular example of adaptive radiation and may demonstrate convergence, but uncertainty about phylogenetic relationships within the group has made it difficult to assess such evolutionary patterns. We examine the phylogenetic relationships of the Hawaii creeper (Oreomystis mana), a bird that in a suite of morphological, ecological and behavioural traits closely resembles the Kauai creeper (Oreomystis bairdi), but whose mitochondrial DNA (mtDNA) and osteology suggest a relationship with the amakihis (Hemignathus in part) and akepas (Loxops). We analysed nuclear DNA sequence data from 11 relevant honeycreeper taxa and one outgroup to test whether the character contradiction results from historical hybridization and mtDNA introgression, or convergent evolution. We found no evidence of past hybridization, a phenomenon that remains undocumented in Hawaiian honeycreepers, and confirmed mtDNA and osteological evidence that the Hawaii creeper is most closely related to the amakihis and akepas. Thus, the morphological, ecological and behavioural similarities between the evolutionarily distant Hawaii and Kauai creepers represent an extreme example of convergent evolution and demonstrate how natural selection can lead to repeatable evolutionary outcomes.

  7. Convergence Analysis of LMS based Adaptive filter

    NASA Astrophysics Data System (ADS)

    Rai, Amrita; Kohli, Amit Kumar

    2010-11-01

    A standard algorithm for LMS-filter simulation, tested with several convergence criteria is presented in this paper. We analyze the steady-state mean square error (MSE) convergence of the LMS algorithm when random functions are used as reference inputs. In this paper, we make a more precise analysis using the deterministic nature of the reference inputs and their time-variant correlation matrix. Simulations performed under MATLAB show remarkable differences between convergence criteria with various value of the step size.

  8. Systematically Accelerated Convergence of Path Integrals

    SciTech Connect

    Bogojevic, A.; Balaz, A.; Belic, A.

    2005-05-13

    We present a new analytical method that systematically improves the convergence of path integrals of a generic N-fold discretized theory. Using it we calculate the effective actions S{sup (p)} for p{<=}9, which lead to the same continuum amplitudes as the starting action, but that converge to that continuum limit as 1/N{sup p}. We checked this derived speedup in convergence by performing Monte Carlo simulations on several different models.

  9. Media violence.

    PubMed

    Willis, E; Strasburger, V C

    1998-04-01

    American media are the most violent in the world, and American society is now paying a high price in terms of real life violence. Research has confirmed that mass media violence contributes to aggressive behavior, fear, and desensitization of violence. Television, movies, music videos, computer/video games are pervasive media and represent important influences on children and adolescents. Portraying rewards and punishments and showing the consequences of violence are probably the two most essential contextual factors for viewers as they interpret the meaning of what they are viewing on television. Public health efforts have emphasized public education, media literacy campaign for children and parents, and an increased use of technology to prevent access to certain harmful medial materials.

  10. Testing hypotheses of convergence with multivariate data: morphological and functional convergence among herbivorous lizards.

    PubMed

    Stayton, C Tristan

    2006-04-01

    Despite its importance to evolutionary theory, convergence remains an understudied phenomenon and is usually investigated using qualitative data. This paper advances a new, multidimensional view of convergence. Three patterns indicative of convergence are discussed, and techniques to discover and test convergent patterns in a quantitative framework are developed. These concepts and methods are applied to a dataset of digitized coordinates on 1554 lizard skulls and 1292 lower jaws to test hypotheses of convergence among herbivorous lizards. Encompassing seven independent acquisitions of herbivory, this lizard sample provides an ideal natural experiment for exploring ideas of convergence among different systems (here, morphological and functional). Three related questions are addressed: (1) Do herbivorous lizards show evidence of convergence in skull and lower jaw morphology? (2) What, if any, is the morphospace pattern associated with this convergence? (3) Is it possible to predict the direction of convergence using functional models? Relative warp analysis and permutation tests reveal that the skulls and lower jaws of herbivorous lizards do show evidence of convergence. Herbivore skulls deviate from their carnivorous or omnivorous sister groups toward the same area of morphospace. Without a phylogenetic perspective, this pattern would not be recognizable. Lower jaws of herbivores are not convergent in morphology but are convergent in function: herbivores deviate away from their carnivorous sister groups toward higher values of mechanical advantage. These results illustrate the desirability of quantitative methods, informed by phylogenetic information, in the study of convergence.

  11. The Impact of Environmental Variation on Demographic Convergence of Leslie Matrix Population Models: An Assessment Using Lyapunov Characteristic Exponents

    PubMed

    Grant; Benton

    1996-08-01

    In a constant environment, the rate of convergence of a density-independent Leslie matrix model to stable age distribution is determined by the damping ratio (the ratio of the absolute magnitudes of the first and second eigenvalues of the projection matrix). In a stochastic environment, the difference between the first two Lyapunov exponents is known to be analogous to the logarithm of the damping ratio, but there has been no systematic investigation of the consequences of enviromnental variation on convergence rates. In this study, the Lyapunov spectrum has been calculated for a wide variety of density-independent projection matrices subject to random variations in vital rates. This allows the impact of these random variations on convergence rates to be assessed. For rapidly convergent life histories, stochastic variation leads to a decrease in convergence rate. For life histories which are slow to converge, stochastic variation speeds up convergence. These effects are, however, relatively minor, and the value of the damping ratio for the mean matrix is a good predictor of the damping ratio in a stochastic environment. Consequently, when only an approximate indication of convergence rates is needed, the damping ratio for the mean projection matrix gives a very good guide. Detailed calculations of the Lyapunov spectrum would only be necessary to make comparisons between similar life histories or if very precise information on convergence rates were needed.

  12. PHYSALIS: a new method for particle flow simulation. Part III: convergence analysis of two-dimensional flows

    NASA Astrophysics Data System (ADS)

    Huang, Huaxiong; Takagi, Shu

    2003-08-01

    In this paper, we study the convergence property of PHYSALIS when it is applied to incompressible particle flows in two-dimensional space. PHYSALIS is a recently proposed iterative method which computes the solution without imposing the boundary conditions on the particle surfaces directly. Instead, a consistency equation based on the local (near particle) representation of the solution is used as the boundary conditions. One of the important issues needs to be addressed is the convergence properties of the iterative procedure. In this paper, we present the convergence analysis using Laplace and biharmonic equations as two model problems. It is shown that convergence of the method can be achieved but the rate of convergence depends on the relative locations of the cages. The results are directly related to potential and Stokes flows. However, they are also relevant to Navier-Stokes flows, heat conduction in composite media, and other problems.

  13. Lack of convergence in aquatic Anolis lizards.

    PubMed

    Leal, Manuel; Knox, Alison K; Losos, Jonathan B

    2002-04-01

    Why convergent evolution occurs among some species occupying similar habitats but not among others is a question that has received surprisingly little attention. Caribbean Anolis lizards, known for their extensive convergent evolution among islands in the Greater Antilles, are an appropriate group with which to address this question. Despite the well-documented pattern of between-island convergence, some Greater Antillean anoles are not obviously part of the convergence syndrome. One example involves aquatic anoles--species that are found near to and readily enter streams-which have evolved independently twice in the Caribbean and also twice on mainland Central America. Despite being found in similar habitats, no previous study has investigated whether aquatic anoles represent yet another case of morphological convergence. We tested this hypothesis by collecting morphological data for seven aquatic anole species and 29 species from the six convergent types of Greater Antillean habitat specialists. We failed to find evidence for morphological convergence: the two Caribbean aquatic species are greatly dissimilar to each other and to the Central American species, which, however, may be convergent upon each other. We suggest two possible reasons for this lack of convergence in an otherwise highly convergent system: either there is more than one habitat type occupied by anoles in the proximity of water, or there is more than one way to adapt to a single aquatic habitat. We estimate that almost all of the 113 species of Greater Antillean anoles occupy habitats that are also used by distantly related species, but only 15% of these species are not morphologically similar to their distantly related ecological counterparts. Comparative data from other taxa would help enlighten the question of why the extent of convergence is so great in some lineages and not in others.

  14. Evolutionary convergence in experimental Pseudomonas populations.

    PubMed

    Lind, Peter A; Farr, Andrew D; Rainey, Paul B

    2017-03-01

    Model microbial systems provide opportunity to understand the genetic bases of ecological traits, their evolution, regulation and fitness contributions. Experimental populations of Pseudomonas fluorescens rapidly diverge in spatially structured microcosms producing a range of surface-colonising forms. Despite divergent molecular routes, wrinkly spreader (WS) niche specialist types overproduce a cellulosic polymer allowing mat formation at the air-liquid interface and access to oxygen. Given the range of ways by which cells can form mats, such phenotypic parallelism is unexpected. We deleted the cellulose-encoding genes from the ancestral genotype and asked whether this mutant could converge on an alternate phenotypic solution. Two new traits were discovered. The first involved an exopolysaccharide encoded by pgaABCD that functions as cell-cell glue similar to cellulose. The second involved an activator of an amidase (nlpD) that when defective causes cell chaining. Both types form mats, but were less fit in competition with cellulose-based WS types. Surprisingly, diguanylate cyclases linked to cellulose overexpression underpinned evolution of poly-beta-1,6-N-acetyl-d-glucosamine (PGA)-based mats. This prompted genetic analyses of the relationships between the diguanylate cyclases WspR, AwsR and MwsR, and both cellulose and PGA. Our results suggest that c-di-GMP regulatory networks may have been shaped by evolution to accommodate loss and gain of exopolysaccharide modules facilitating adaptation to new environments.

  15. Bat echolocation calls: adaptation and convergent evolution

    PubMed Central

    Jones, Gareth; Holderied, Marc W

    2007-01-01

    Bat echolocation calls provide remarkable examples of ‘good design’ through evolution by natural selection. Theory developed from acoustics and sonar engineering permits a strong predictive basis for understanding echolocation performance. Call features, such as frequency, bandwidth, duration and pulse interval are all related to ecological niche. Recent technological breakthroughs have aided our understanding of adaptive aspects of call design in free-living bats. Stereo videogrammetry, laser scanning of habitat features and acoustic flight path tracking permit reconstruction of the flight paths of echolocating bats relative to obstacles and prey in nature. These methods show that echolocation calls are among the most intense airborne vocalizations produced by animals. Acoustic tracking has clarified how and why bats vary call structure in relation to flight speed. Bats using broadband echolocation calls adjust call design in a range-dependent manner so that nearby obstacles are localized accurately. Recent phylogenetic analyses based on gene sequences show that particular types of echolocation signals have evolved independently in several lineages of bats. Call design is often influenced more by perceptual challenges imposed by the environment than by phylogeny, and provides excellent examples of convergent evolution. Now that whole genome sequences of bats are imminent, understanding the functional genomics of echolocation will become a major challenge. PMID:17251105

  16. The geography of morphological convergence in the radiations of Pacific Sebastes rockfishes.

    PubMed

    Ingram, Travis; Kai, Yoshiaki

    2014-11-01

    The evolution of convergent phenotypes in lineages subject to similar selective pressures is a common feature of adaptive radiation. In geographically replicated radiations, repeated convergence occurs between clades occupying distinct regions or islands. Alternatively, a clade may repeatedly reach the same adaptive peaks in broadscale sympatry, resulting in extensive convergence within a region. Rockfish (Sebastes sp.) have radiated in both the northeast and northwest Pacific, allowing tests of the extent and geographic pattern of convergence in a marine environment. We used a suite of phylogenetically informed methods to test for morphological convergence in rockfish. We examined patterns of faunal similarity using nearest neighbor distances in morphospace and the frequency of morphologically similar yet distantly related species pairs. The extent of convergence both between regions and within the northeast Pacific exceeds the expectation under a Brownian motion null model, although constraints on trait space could account for the similarity. We then used a recently developed method (SURFACE) to identify adaptive peak shifts in Sebastes evolutionary history. We found that the majority of convergent peak shifts occur within the northeast Pacific rather than between regions and that the signal of peak shifts is strongest for traits related to trophic morphology. Pacific rockfish thus demonstrate a tendency toward morphological convergence within one of the two broad geographic regions in which they have diversified.

  17. A Collaborative Media Production Project on Human Rights: Bridging Everyday and Media Education

    ERIC Educational Resources Information Center

    Haydari, Nazan; Kara, Mustafa

    2015-01-01

    Given the importance of media institutions and universities as spaces of knowledge productions, development of "critical media pedagogy" becomes crucial for the establishment of a responsible and ethical media environment. Drawing from the collaborative project of The First Step into Human Rights: I do not do it!--A Short Film Project on…

  18. A Collaborative Media Production Project on Human Rights: Bridging Everyday and Media Education

    ERIC Educational Resources Information Center

    Haydari, Nazan; Kara, Mustafa

    2015-01-01

    Given the importance of media institutions and universities as spaces of knowledge productions, development of "critical media pedagogy" becomes crucial for the establishment of a responsible and ethical media environment. Drawing from the collaborative project of The First Step into Human Rights: I do not do it!--A Short Film Project on…

  19. Hepatitis C Virus Antigenic Convergence

    PubMed Central

    Campo, David S.; Dimitrova, Zoya; Yokosawa, Jonny; Hoang, Duc; Perez, Nestor O.; Ramachandran, Sumathi; Khudyakov, Yury

    2012-01-01

    Vaccine development against hepatitis C virus (HCV) is hindered by poor understanding of factors defining cross-immunoreactivity among heterogeneous epitopes. Using synthetic peptides and mouse immunization as a model, we conducted a quantitative analysis of cross-immunoreactivity among variants of the HCV hypervariable region 1 (HVR1). Analysis of 26,883 immunological reactions among pairs of peptides showed that the distribution of cross-immunoreactivity among HVR1 variants was skewed, with antibodies against a few variants reacting with all tested peptides. The HVR1 cross-immunoreactivity was accurately modeled based on amino acid sequence alone. The tested peptides were mapped in the HVR1 sequence space, which was visualized as a network of 11,319 sequences. The HVR1 variants with a greater network centrality showed a broader cross-immunoreactivity. The entire sequence space is explored by each HCV genotype and subtype. These findings indicate that HVR1 antigenic diversity is extensively convergent and effectively limited, suggesting significant implications for vaccine development. PMID:22355779

  20. Convergence of a Linear Recursive Sequence

    ERIC Educational Resources Information Center

    Tay, E. G.; Toh, T. L.; Dong, F. M.; Lee, T. Y.

    2004-01-01

    A necessary and sufficient condition is found for a linear recursive sequence to be convergent, no matter what initial values are given. Its limit is also obtained when the sequence is convergent. Methods from various areas of mathematics are used to obtain the results.

  1. New concurrent iterative methods with monotonic convergence

    SciTech Connect

    Yao, Qingchuan

    1996-12-31

    This paper proposes the new concurrent iterative methods without using any derivatives for finding all zeros of polynomials simultaneously. The new methods are of monotonic convergence for both simple and multiple real-zeros of polynomials and are quadratically convergent. The corresponding accelerated concurrent iterative methods are obtained too. The new methods are good candidates for the application in solving symmetric eigenproblems.

  2. Selective Grammatical Convergence: Learning from Desirable Speakers

    ERIC Educational Resources Information Center

    Lev-Ari, Shiri

    2016-01-01

    Models of language learning often assume that we learn from all the input we receive. This assumption is particularly strong in the domain of short-term and long-term grammatical convergence, where researchers argue that grammatical convergence is mostly an automatic process insulated from social factors. This article shows that the degree to…

  3. Numerical simulation of converging shock waves

    NASA Astrophysics Data System (ADS)

    Yee, Seokjune; Abe, Kanji

    We can achieve the high pressure and high temperature state of gas if the shock wave converges stably. In order to check the stability of the converging shock wave, we introduce two kinds of perturbed initial conditions. The Euler equations of conservation form are integrated by using explicit Non-Muscl TVD finite difference scheme.

  4. Selective Grammatical Convergence: Learning from Desirable Speakers

    ERIC Educational Resources Information Center

    Lev-Ari, Shiri

    2016-01-01

    Models of language learning often assume that we learn from all the input we receive. This assumption is particularly strong in the domain of short-term and long-term grammatical convergence, where researchers argue that grammatical convergence is mostly an automatic process insulated from social factors. This article shows that the degree to…

  5. Convergence of a Linear Recursive Sequence

    ERIC Educational Resources Information Center

    Tay, E. G.; Toh, T. L.; Dong, F. M.; Lee, T. Y.

    2004-01-01

    A necessary and sufficient condition is found for a linear recursive sequence to be convergent, no matter what initial values are given. Its limit is also obtained when the sequence is convergent. Methods from various areas of mathematics are used to obtain the results.

  6. Non-diffractive beam in random media

    NASA Astrophysics Data System (ADS)

    Shiina, Tatsuo

    2017-09-01

    Beam propagation has been given important attention in a variety of applications in medicine, remote sensing and information science. Especially, the beam propagation in highly scattering media, which is called random media, is important. In general, the multiple scattering gets rid of beam characteristics, e.g., intensity distribution, phase front, and polarization. In this study, self-converging effect of annular beam was applied in random media. Diluted milk was used as random media, and the transmitted light was detected with a narrow view angle of 5.5mrad. The collimated annular beam of a few tens millimeters takes a few hundred meters to transform its beam shape into the non-diffractive beam in free space, while this transformation was shorten only to 20 cm in random media, that is, the collimated annular beam caused its transformation at only 20 cm in random media. The transformed beam kept its optical characteristics of ;non-diffractive beam;. Such transformation of the annular beam needs the appropriate condition of random media. Media concentration and propagation distance control the generation of the center peak intensity of the transformed beam. This study indicates the generation of the non-diffractive beam in random media and reveals its appropriate condition.

  7. Measuring phonetic convergence in speech production

    PubMed Central

    Pardo, Jennifer S.

    2013-01-01

    Phonetic convergence is defined as an increase in the similarity of acoustic-phonetic form between talkers. Previous research has demonstrated phonetic convergence both when a talker listens passively to speech and while talkers engage in social interaction. Much of this research has focused on a diverse array of acoustic-phonetic attributes, with fewer studies incorporating perceptual measures of phonetic convergence. The current paper reviews research on phonetic convergence in both non-interactive and conversational settings, and attempts to consolidate the diverse array of findings by proposing a paradigm that models perceptual and acoustic measures together. By modeling acoustic measures as predictors of perceived phonetic convergence, this paradigm has the potential to reconcile some of the diverse and inconsistent findings currently reported in the literature. PMID:23986738

  8. Degradation of Iodinated Contrast Media in Aquatic Environment by Means of UV, UV/TiO2 Process, and by Activated Sludge.

    PubMed

    Borowska, Ewa; Felis, Ewa; Żabczyński, Sebastian

    Iodinated contrast media (ICM), which are used for radiological visualization of human tissue and cardiovascular system, are poorly biodegradable; hence, new methods of their removal are sought. In this study, the effectiveness of selected X-ray ICM removal by means of UV and UV/TiO2 pretreatment processes from synthetic hospital wastewater was demonstrated. The following compounds were investigated: iodipamide, iohexol, and diatrizoate. The experiments were as follows: (i) estimated susceptibility of the ICM to decay by UV radiation in different aquatic matrices, (ii) determined an optimal retention time of hospital wastewater in the UV reactor, (iii) determined optimum TiO2 concentration to improve the effectiveness of the UV pretreatment, and (iv) investigated removal of ICM by combination of the photochemical and biological treatment methods. The quantum yields of selected ICM decay in deionized water (pH = 7.0) were established as 0.006, 0.004, and 0.029 for iohexol, diatrizoate, and iodipamide, respectively. Furthermore, the experiments revealed that diatrizoate and iohexol removal in the UV/TiO2 process is more efficient than in UV process alone. For diatrizoate, the removal efficiency equaled to 40 and 30 %, respectively, and for iohexol, the efficiency was 38 and 27 %, respectively. No significant increase in iodipamide removal in UV and UV/TiO2 processes was observed (29 and 28 %, respectively). However, highest removal efficiency was demonstrated in synthetic hospital wastewater with the combined photochemical and biological treatment method. The removal of diatrizoate and iohexol increased to at least 90 %, and for iodipamide, to at least 50 %.

  9. Dynamic Convergent Evolution Drives the Passage Adaptation across 48 Years' History of H3N2 Influenza Evolution.

    PubMed

    Chen, Hui; Deng, Qiang; Ng, Sock Hoon; Lee, Raphael Tze Chuen; Maurer-Stroh, Sebastian; Zhai, Weiwei

    2016-12-01

    Influenza viruses are often propagated in a diverse set of culturing media and additional substitutions known as passage adaptation can cause extra evolution in the target strain, leading to ineffective vaccines. Using 25,482 H3N2 HA1 sequences curated from Global Initiative on Sharing All Influenza Data and National Center for Biotechnology Information databases, we found that passage adaptation is a very dynamic process that changes over time and evolves in a seesaw like pattern. After crossing the species boundary from bird to human in 1968, the influenza H3N2 virus evolves to be better adapted to the human environment and passaging them in embryonated eggs (i.e., an avian environment) leads to increasingly stronger positive selection. On the contrary, passage adaptation to the mammalian cell lines changes from positive selection to negative selection. Using two statistical tests, we identified 19 codon positions around the receptor binding domain strongly contributing to passage adaptation in the embryonated egg. These sites show strong convergent evolution and overlap extensively with positively selected sites identified in humans, suggesting that passage adaptation can confound many of the earlier studies on influenza evolution. Interestingly, passage adaptation in recent years seems to target a few codon positions in antigenic surface epitopes, which makes it difficult to produce antigenically unaltered vaccines using embryonic eggs. Our study outlines another interesting scenario whereby both convergent and adaptive evolution are working in synchrony driving viral adaptation. Future studies from sequence analysis to vaccine production need to take careful consideration of passage adaptation. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Kaiser Permanente's Convergent Medical Terminology.

    PubMed

    Dolin, Robert H; Mattison, John E; Cohn, Simon; Campbell, Keith E; Wiesenthal, Andrew M; Hochhalter, Brad; LaBerge, Diane; Barsoum, Rita; Shalaby, James; Abilla, Alan; Clements, Robert J; Correia, Carol M; Esteva, Diane; Fedack, John M; Goldberg, Bruce J; Gopalarao, Sridhar; Hafeza, Eza; Hendler, Peter; Hernandez, Enrique; Kamangar, Ron; Kahn, Rafique A; Kurtovich, Georgina; Lazzareschi, Gerry; Lee, Moon H; Lee, Tracy; Levy, David; Lukoff, Jonathan Y; Lundberg, Cyndie; Madden, Michael P; Ngo, Trongtu L; Nguyen, Ben T; Patel, Nikhilkumar P; Resneck, Jim; Ross, David E; Schwarz, Kathleen M; Selhorst, Charles C; Snyder, Aaron; Umarji, Mohamed I; Vilner, Max; Zer-Chen, Roy; Zingo, Chris

    2004-01-01

    This paper describes Kaiser Permanente's (KP) enterprise-wide medical terminology solution, referred to as our Convergent Medical Terminology (CMT). Initially developed to serve the needs of a regional electronic health record, CMT has evolved into a core KP asset, serving as the common terminology across all applications. CMT serves as the definitive source of concept definitions for the organization, provides a consistent structure and access method to all codes used by the organization, and is KP's language of interoperability, with cross-mappings to regional ancillary systems and administrative billing codes. The core of CMT is comprised of SNOMED CT, laboratory LOINC, and First DataBank drug terminology. These are integrated into a single poly-hierarchically structured knowledge base. Cross map sets provide bi-directional translations between CMT and ancillary applications and administrative billing codes. Context sets provide subsets of CMT for use in specific contexts. Our experience with CMT has lead us to conclude that a successful terminology solution requires that: (1) usability considerations are an organizational priority; (2) "interface" terminology is differentiated from "reference" terminology; (3) it be easy for clinicians to find the concepts they need; (4) the immediate value of coded data be apparent to clinician user; (5) there be a well defined approach to terminology extensions. Over the past several years, there has been substantial progress made in the domain coverage and standardization of medical terminology. KP has learned to exploit that terminology in ways that are clinician-acceptable and that provide powerful options for data analysis and reporting.

  11. Media Training

    ScienceCinema

    None

    2016-07-12

    With the LHC starting up soon, the world's media are again turning their attention to CERN. We're all likely to be called upon to explain what is happening at CERN to media, friends and neighbours. The seminar will be given by BBC television news journalists Liz Pike and Nadia Marchant, and will deal with the kind of questions we're likely to be confronted with through the restart period. The training is open for everybody. Make sure you arrive early enough to get a seat - there are only 200 seats in the Globe. The session will also be webcast: http://webcast.cern.ch/

  12. Media Training

    SciTech Connect

    2009-12-11

    With the LHC starting up soon, the world's media are again turning their attention to CERN. We're all likely to be called upon to explain what is happening at CERN to media, friends and neighbours. The seminar will be given by BBC television news journalists Liz Pike and Nadia Marchant, and will deal with the kind of questions we're likely to be confronted with through the restart period. The training is open for everybody. Make sure you arrive early enough to get a seat - there are only 200 seats in the Globe. The session will also be webcast: http://webcast.cern.ch/

  13. The effects of media on sleep.

    PubMed

    Van den Bulck, Jan

    2010-12-01

    The media are an important part of young people's lives, but television, computer games, Internet use, cellular phone use, and even book reading threaten healthy sleep. Adults do not fully comprehend the ways in which young people use various media. Media use is a type of behavior that may displace sleep time or shorten it. Media content may lead to overexcitement or cause recurring nightmares. The cellular telephone is a particular threat. Parents may also use media excessively, establishing an unhealthy environment that may lead to sleep dysfunction in children and adolescents. Therefore, anticipatory guidance for healthy behavioral changes should be focused on the family.

  14. Canonical forms of unconditionally convergent multipliers☆

    PubMed Central

    Stoeva, D.T.; Balazs, P.

    2013-01-01

    Multipliers are operators that combine (frame-like) analysis, a multiplication with a fixed sequence, called the symbol, and synthesis. They are very interesting mathematical objects that also have a lot of applications for example in acoustical signal processing. It is known that bounded symbols and Bessel sequences guarantee unconditional convergence. In this paper we investigate necessary and equivalent conditions for the unconditional convergence of multipliers. In particular, we show that, under mild conditions, unconditionally convergent multipliers can be transformed by shifting weights between symbol and sequence, into multipliers with symbol (1) and Bessel sequences (called multipliers in canonical form). PMID:23564973

  15. Canonical forms of unconditionally convergent multipliers.

    PubMed

    Stoeva, D T; Balazs, P

    2013-03-01

    Multipliers are operators that combine (frame-like) analysis, a multiplication with a fixed sequence, called the symbol, and synthesis. They are very interesting mathematical objects that also have a lot of applications for example in acoustical signal processing. It is known that bounded symbols and Bessel sequences guarantee unconditional convergence. In this paper we investigate necessary and equivalent conditions for the unconditional convergence of multipliers. In particular, we show that, under mild conditions, unconditionally convergent multipliers can be transformed by shifting weights between symbol and sequence, into multipliers with symbol (1) and Bessel sequences (called multipliers in canonical form).

  16. On the Local Convergence of Pattern Search

    NASA Technical Reports Server (NTRS)

    Dolan, Elizabeth D.; Lewis, Robert Michael; Torczon, Virginia; Bushnell, Dennis M. (Technical Monitor)

    2000-01-01

    We examine the local convergence properties of pattern search methods, complementing the previously established global convergence properties for this class of algorithms. We show that the step-length control parameter which appears in the definition of pattern search algorithms provides a reliable asymptotic measure of first-order stationarity. This gives an analytical justification for a traditional stopping criterion for pattern search methods. Using this measure of first-order stationarity, we analyze the behavior of pattern search in the neighborhood of an isolated local minimizer. We show that a recognizable subsequence converges r-linearly to the minimizer.

  17. Communication Technologies and the Classroom Teaching Environment

    ERIC Educational Resources Information Center

    Matijevic, Milan; Radovanovic, Diana

    2007-01-01

    The authors consider the present and future of new media and the classroom environment of pupils in primary education. Some experts are inclined to see the future of the classroom teaching environment solely through the perspective of new media, primarily computers and the Internet. The authors agree that these media are essential for modern…

  18. Media Matters

    ERIC Educational Resources Information Center

    Cooper, Kenneth J.; Pyrillis, Rita; Rosario, Ruben; Stuart, Reginald; Zinngrabe, Elaine

    2007-01-01

    This article presents five vignettes, written by veteran journalists, that focus on the current and future state of journalism. Despite almost daily reports of media consolidation and newspaper layoffs, the journalists sound a cautionary but optimistic tone about the industry. They weigh in on everything from the threats to diversity to the future…

  19. Media Matters

    ERIC Educational Resources Information Center

    Cooper, Kenneth J.; Pyrillis, Rita; Rosario, Ruben; Stuart, Reginald; Zinngrabe, Elaine

    2007-01-01

    This article presents five vignettes, written by veteran journalists, that focus on the current and future state of journalism. Despite almost daily reports of media consolidation and newspaper layoffs, the journalists sound a cautionary but optimistic tone about the industry. They weigh in on everything from the threats to diversity to the future…

  20. Streaming Media

    ERIC Educational Resources Information Center

    Pulley, John

    2009-01-01

    At a time when the evolutionary pace of new media resembles the real-time mutation of certain microorganisms, the age-old question of how best to connect with constituents can seem impossibly complex--even for an elite institution plugged into the motherboard of Silicon Valley. Identifying the most effective vehicle for reaching a particular…

  1. Streaming Media

    ERIC Educational Resources Information Center

    Pulley, John

    2009-01-01

    At a time when the evolutionary pace of new media resembles the real-time mutation of certain microorganisms, the age-old question of how best to connect with constituents can seem impossibly complex--even for an elite institution plugged into the motherboard of Silicon Valley. Identifying the most effective vehicle for reaching a particular…

  2. Normal vector method for convergence improvement using the RCWA for crossed gratings.

    PubMed

    Schuster, Thomas; Ruoff, Johannes; Kerwien, Norbert; Rafler, Stephan; Osten, Wolfgang

    2007-09-01

    The rigorous coupled wave analysis (RCWA) is a widely used method for simulating diffraction from periodic structures. Since its recognized formulation by Moharam [J. Opt. Soc. Am. A12, 1068 and 1077 (1995)], there still has been a discussion about convergence problems. Those problems are more or less solved for the diffraction from line gratings, but there remain different concurrent proposals about the convergence improvement for crossed gratings. We propose to combine Popov and Nevière's formulation of the differential method [Light Propagation in Periodic Media (Dekker, 2003) and J. Opt. Soc. Am. A18, 2886 (2001)] with the classical RCWA. With a suitable choice of a normal vector field we obtain a better convergence than for the formulations that are known from the literature.

  3. Neuroscience and nanotechnologies in Japan--beyond the hope and hype of converging technologies.

    PubMed

    Mushiaki, Shigeru

    2011-01-01

    Nanotechnologies are often said to be "converging" with other technologies like biotechnology, information technology, and cognitive science. And so-called "NBIC convergence" is thought to enable "enhancement" of human performance. First, I classify various kinds of enhancement. Second, I focus on the "cybernetic enhancement," to which nanotechnologies are supposed to contribute, and analyze the connection and integration of humans with machines, which could lead to the cyborgization of human beings. Third, I examine the portrayal of robot/cyborg technology in Japanese popular media, point out the tendency to empathy or ensoulment concerning robots/cyborgs, and raise the question of "ethical issues of ethical enhancement." Fourth, I compare nanotechnologies with neurotechnology and criticize the hype of "converging technologies."

  4. [Chronic otitis mediaChronic Otitis Media].

    PubMed

    Kohles, N; Schulz, T; Eßer, D

    2015-11-01

    There are 2 different kinds of chronic otitis media: Otitis media chronica mesotympanalis and otitis media chronica epitympanalis (cholesteatoma). The incidence of chronic otitis media as reported in literature differs in a wide range. The incidence rates vary between 0.45 and 46%. Both, otitis media chronica mesotympanalis and cholesteatoma, lead to eardrum perforation due to lengthy and recurring inflammations. Furthermore, chronic otitis media is characterized by frequently recurring otorrhea and conductive hearing loss.

  5. Borrowed alleles and convergence in serpentine adaptation

    PubMed Central

    Arnold, Brian J.; Lahner, Brett; DaCosta, Jeffrey M.; Weisman, Caroline M.; Hollister, Jesse D.; Salt, David E.; Bomblies, Kirsten; Yant, Levi

    2016-01-01

    Serpentine barrens represent extreme hazards for plant colonists. These sites are characterized by high porosity leading to drought, lack of essential mineral nutrients, and phytotoxic levels of metals. Nevertheless, nature forged populations adapted to these challenges. Here, we use a population-based evolutionary genomic approach coupled with elemental profiling to assess how autotetraploid Arabidopsis arenosa adapted to a multichallenge serpentine habitat in the Austrian Alps. We first demonstrate that serpentine-adapted plants exhibit dramatically altered elemental accumulation levels in common conditions, and then resequence 24 autotetraploid individuals from three populations to perform a genome scan. We find evidence for highly localized selective sweeps that point to a polygenic, multitrait basis for serpentine adaptation. Comparing our results to a previous study of independent serpentine colonizations in the closely related diploid Arabidopsis lyrata in the United Kingdom and United States, we find the highest levels of differentiation in 11 of the same loci, providing candidate alleles for mediating convergent evolution. This overlap between independent colonizations in different species suggests that a limited number of evolutionary strategies are suited to overcome the multiple challenges of serpentine adaptation. Interestingly, we detect footprints of selection in A. arenosa in the context of substantial gene flow from nearby off-serpentine populations of A. arenosa, as well as from A. lyrata. In several cases, quantitative tests of introgression indicate that some alleles exhibiting strong selective sweep signatures appear to have been introgressed from A. lyrata. This finding suggests that migrant alleles may have facilitated adaptation of A. arenosa to this multihazard environment. PMID:27357660

  6. Media, audience, and policy perspectives in health broadcasting.

    PubMed

    Sharada, P V; Venkataramana, C; Nirupama, K R

    2001-01-01

    Effective coordination between service delivery systems and communication networks is essential for the success of development programs. This becomes particularly crucial when the number of agencies involved is large and they are not working under 1 authority. Information needs of the community are another major concern. This article attempts to assess the extent of convergence between electronic media, government policy, and the targeted audience on the coverage of health topics. The Indian state of Andhra Pradesh was chosen as the field. The study adopts a mix of both quantitative and qualitative techniques. The findings reveal limited convergence, indicating the need for more effective reflection of the policy guidelines into media programs.

  7. New convergence estimates for multigrid algorithms

    SciTech Connect

    Bramble, J.H.; Pasciak, J.E.

    1987-10-01

    In this paper, new convergence estimates are proved for both symmetric and nonsymmetric multigrid algorithms applied to symmetric positive definite problems. Our theory relates the convergence of multigrid algorithms to a ''regularity and approximation'' parameter ..cap alpha.. epsilon (0, 1) and the number of relaxations m. We show that for the symmetric and nonsymmetric ..nu.. cycles, the multigrid iteration converges for any positive m at a rate which deteriorates no worse than 1-cj/sup -(1-//sup ..cap alpha..//sup )///sup ..cap alpha../, where j is the number of grid levels. We then define a generalized ..nu.. cycle algorithm which involves exponentially increasing (for example, doubling) the number of smoothings on successively coarser grids. We show that the resulting symmetric and nonsymmetric multigrid iterations converge for any ..cap alpha.. with rates that are independent of the mesh size. The theory is presented in an abstract setting which can be applied to finite element multigrid and finite difference multigrid methods.

  8. Morphological and molecular convergences in mammalian phylogenetics.

    PubMed

    Zou, Zhengting; Zhang, Jianzhi

    2016-09-02

    Phylogenetic trees reconstructed from molecular sequences are often considered more reliable than those reconstructed from morphological characters, in part because convergent evolution, which confounds phylogenetic reconstruction, is believed to be rarer for molecular sequences than for morphologies. However, neither the validity of this belief nor its underlying cause is known. Here comparing thousands of characters of each type that have been used for inferring the phylogeny of mammals, we find that on average morphological characters indeed experience much more convergences than amino acid sites, but this disparity is explained by fewer states per character rather than an intrinsically higher susceptibility to convergence for morphologies than sequences. We show by computer simulation and actual data analysis that a simple method for identifying and removing convergence-prone characters improves phylogenetic accuracy, potentially enabling, when necessary, the inclusion of morphologies and hence fossils for reliable tree inference.

  9. On Convergent Probability of a Random Walk

    ERIC Educational Resources Information Center

    Lee, Y.-F.; Ching, W.-K.

    2006-01-01

    This note introduces an interesting random walk on a straight path with cards of random numbers. The method of recurrent relations is used to obtain the convergent probability of the random walk with different initial positions.

  10. Topics in global convergence of density estimates

    NASA Technical Reports Server (NTRS)

    Devroye, L.

    1982-01-01

    The problem of estimating a density f on R sup d from a sample Xz(1),...,X(n) of independent identically distributed random vectors is critically examined, and some recent results in the field are reviewed. The following statements are qualified: (1) For any sequence of density estimates f(n), any arbitrary slow rate of convergence to 0 is possible for E(integral/f(n)-fl); (2) In theoretical comparisons of density estimates, integral/f(n)-f/ should be used and not integral/f(n)-f/sup p, p 1; and (3) For most reasonable nonparametric density estimates, either there is convergence of integral/f(n)-f/ (and then the convergence is in the strongest possible sense for all f), or there is no convergence (even in the weakest possible sense for a single f). There is no intermediate situation.

  11. Cultivate technology convergence for product innovation.

    PubMed

    Wilkinson, J Malcolm

    2006-04-01

    Technologies from diverse scientific disciplines are being combined to drive innovation in medical devices. How technology convergence and innovation could be further stimulated is explored here using developments in imaging and point-of-care devices as examples.

  12. Convergence results for elliptic quasivariational inequalities

    NASA Astrophysics Data System (ADS)

    Sofonea, Mircea; Benraouda, Ahlem

    2017-02-01

    In this paper, we state and prove various convergence results for a general class of elliptic quasivariational inequalities with constraints. Thus, we prove the convergence of the solution of a class of penalized problems to the solution of the original inequality, as the penalty parameter converges to zero. We also prove a continuous dependence result of the solution with respect the convex set of constraints. Then, we consider a mathematical model which describes the equilibrium of an elastic rod attached to a nonlinear spring. We derive the variational formulation of the model which is in a form of an elliptic quasivariational inequality for the displacement field. We prove the unique weak solvability of the model, and then we state and prove two convergence results and provide their corresponding mechanical interpretation.

  13. Convergence of Attitudes among College Students

    ERIC Educational Resources Information Center

    Whatley, Alice E.; Appel, Victor H.

    1973-01-01

    Attempts to determine whether the intersex convergence phenomenon could be applicable to the measured attitudes of collegiate samples. Both sexes seemed to be moving toward a more liberal view on issues related to marriage and the family. (Author)

  14. Morphological and molecular convergences in mammalian phylogenetics

    PubMed Central

    Zou, Zhengting; Zhang, Jianzhi

    2016-01-01

    Phylogenetic trees reconstructed from molecular sequences are often considered more reliable than those reconstructed from morphological characters, in part because convergent evolution, which confounds phylogenetic reconstruction, is believed to be rarer for molecular sequences than for morphologies. However, neither the validity of this belief nor its underlying cause is known. Here comparing thousands of characters of each type that have been used for inferring the phylogeny of mammals, we find that on average morphological characters indeed experience much more convergences than amino acid sites, but this disparity is explained by fewer states per character rather than an intrinsically higher susceptibility to convergence for morphologies than sequences. We show by computer simulation and actual data analysis that a simple method for identifying and removing convergence-prone characters improves phylogenetic accuracy, potentially enabling, when necessary, the inclusion of morphologies and hence fossils for reliable tree inference. PMID:27585543

  15. On Convergent Probability of a Random Walk

    ERIC Educational Resources Information Center

    Lee, Y.-F.; Ching, W.-K.

    2006-01-01

    This note introduces an interesting random walk on a straight path with cards of random numbers. The method of recurrent relations is used to obtain the convergent probability of the random walk with different initial positions.

  16. Convergent Evolution of Health Information Management and Health Informatics

    PubMed Central

    Gibson, C. J.; Abrams, K.

    2015-01-01

    Summary Clearly defined boundaries are disappearing among the activities, sources, and uses of health care data and information managed by health information management (HIM) and health informatics (HI) professionals. Definitions of the professional domains and scopes of practice for HIM and HI are converging with the proliferation of information and communication technologies in health care settings. Convergence is changing both the roles that HIM and HI professionals serve in their organizations as well as the competencies necessary for training future professionals. Many of these changes suggest a blurring of roles and responsibilities with increasingly overlapping curricula, job descriptions, and research agendas. Blurred lines in a highly competitive market create confusion for students and employers. In this essay, we provide some perspective on the changing landscape and suggest a course for the future. First we review the evolving definitions of HIM and HI. We next compare the current domains and competencies, review the characteristics as well as the education and credentialing of both disciplines, and examine areas of convergence. Given the current state, we suggest a path forward to strengthen the contributions HIM and HI professionals and educators make to the evolving health care environment. PMID:25848421

  17. Genome-Wide Convergence during Evolution of Mangroves from Woody Plants.

    PubMed

    Xu, Shaohua; He, Ziwen; Guo, Zixiao; Zhang, Zhang; Wyckoff, Gerald J; Greenberg, Anthony; Wu, Chung-I; Shi, Suhua

    2017-04-01

    When living organisms independently invade a new environment, the evolution of similar phenotypic traits is often observed. An interesting but contentious issue is whether the underlying molecular biology also converges in the new habitat. Independent invasions of tropical intertidal zones by woody plants, collectively referred to as mangrove trees, represent some dramatic examples. The high salinity, hypoxia, and other stressors in the new habitat might have affected both genomic features and protein structures. Here, we developed a new method for detecting convergence at conservative Sites (CCS) and applied it to the genomic sequences of mangroves. In simulations, the CCS method drastically reduces random convergence at rapidly evolving sites as well as falsely inferred convergence caused by the misinferences of the ancestral character. In mangrove genomes, we estimated ∼400 genes that have experienced convergence over the background level of convergence in the nonmangrove relatives. The convergent genes are enriched in pathways related to stress response and embryo development, which could be important for mangroves' adaptation to the new habitat.

  18. Otitis media with effusion

    MedlinePlus

    OME; Secretory otitis media; Serous otitis media; Silent otitis media; Silent ear infection; Glue ear ... Kerschner JE, Preciado D. Otitis media. In: Kliegman RM, Stanton BF, ... Textbook of Pediatrics . 20th ed. Philadelphia, PA: Elsevier; ...

  19. On Media Education

    ERIC Educational Resources Information Center

    Fedorov, Alexander

    2008-01-01

    This monograph analyzes the theory and practice of media education and media literacy. The book also includes the list of Russian media education literature and addresses of websites of the associations for media education.

  20. International Convergence on Geoscience Cyberinfrastructure

    NASA Astrophysics Data System (ADS)

    Allison, M. L.; Atkinson, R.; Arctur, D. K.; Cox, S.; Jackson, I.; Nativi, S.; Wyborn, L. A.

    2012-04-01

    There is growing international consensus on addressing the challenges to cyber(e)-infrastructure for the geosciences. These challenges include: Creating common standards and protocols; Engaging the vast number of distributed data resources; Establishing practices for recognition of and respect for intellectual property; Developing simple data and resource discovery and access systems; Building mechanisms to encourage development of web service tools and workflows for data analysis; Brokering the diverse disciplinary service buses; Creating sustainable business models for maintenance and evolution of information resources; Integrating the data management life-cycle into the practice of science. Efforts around the world are converging towards de facto creation of an integrated global digital data network for the geosciences based on common standards and protocols for data discovery and access, and a shared vision of distributed, web-based, open source interoperable data access and integration. Commonalities include use of Open Geospatial Consortium (OGC) and ISO specifications and standardized data interchange mechanisms. For multidisciplinarity, mediation, adaptation, and profiling services have been successfully introduced to leverage the geosciences standards which are commonly used by the different geoscience communities -introducing a brokering approach which extends the basic SOA archetype. Principal challenges are less technical than cultural, social, and organizational. Before we can make data interoperable, we must make people interoperable. These challenges are being met by increased coordination of development activities (technical, organizational, social) among leaders and practitioners in national and international efforts across the geosciences to foster commonalities across disparate networks. In doing so, we will 1) leverage and share resources, and developments, 2) facilitate and enhance emerging technical and structural advances, 3) promote

  1. [Convergence in health: dream or reality?].

    PubMed

    Comín Novella, D

    1997-01-01

    In the last fifty years the distance between the poorest and the richest countries, measured in income per capita, has augmented. Keeping in mind the absence of economic convergence, this paper use the life expectancy data compiled by the World Bank for 125 countries to examine whether their health levels have converged in the period 1960-1992. In order to answer this question we apply the concepts of beta and sigma convergence and the evolution of the distribution developed in the economic literature. The most relevant results that arise from the analysis are that 1) there is convergence in the health levels in the world during the period 1960-89, 2) the existence of convergence is not sensible to the measure used but it is to the variable used to proxy the health level, 3) the speed of convergence fell down from the eighties, and 4) the African countries reduced the distance from their health level to the levels of the rest of the world but, within Africa, the differences increased along 1960-92. These evidences suggest a nonlinear relation between health and income per capita.

  2. Auto convergence for stereoscopic 3D cameras

    NASA Astrophysics Data System (ADS)

    Zhang, Buyue; Kothandaraman, Sreenivas; Batur, Aziz Umit

    2012-03-01

    Viewing comfort is an important concern for 3-D capable consumer electronics such as 3-D cameras and TVs. Consumer generated content is typically viewed at a close distance which makes the vergence-accommodation conflict particularly pronounced, causing discomfort and eye fatigue. In this paper, we present a Stereo Auto Convergence (SAC) algorithm for consumer 3-D cameras that reduces the vergence-accommodation conflict on the 3-D display by adjusting the depth of the scene automatically. Our algorithm processes stereo video in realtime and shifts each stereo frame horizontally by an appropriate amount to converge on the chosen object in that frame. The algorithm starts by estimating disparities between the left and right image pairs using correlations of the vertical projections of the image data. The estimated disparities are then analyzed by the algorithm to select a point of convergence. The current and target disparities of the chosen convergence point determines how much horizontal shift is needed. A disparity safety check is then performed to determine whether or not the maximum and minimum disparity limits would be exceeded after auto convergence. If the limits would be exceeded, further adjustments are made to satisfy the safety limits. Finally, desired convergence is achieved by shifting the left and the right frames accordingly. Our algorithm runs real-time at 30 fps on a TI OMAP4 processor. It is tested using an OMAP4 embedded prototype stereo 3-D camera. It significantly improves 3-D viewing comfort.

  3. Effect of genetic convergence on phylogenetic inference.

    PubMed

    Christin, Pascal-Antoine; Besnard, Guillaume; Edwards, Erika J; Salamin, Nicolas

    2012-03-01

    Phylogenetic reconstructions are a major component of many studies in evolutionary biology, but their accuracy can be reduced under certain conditions. Recent studies showed that the convergent evolution of some phenotypes resulted from recurrent amino acid substitutions in genes belonging to distant lineages. It has been suggested that these convergent substitutions could bias phylogenetic reconstruction toward grouping convergent phenotypes together, but such an effect has never been appropriately tested. We used computer simulations to determine the effect of convergent substitutions on the accuracy of phylogenetic inference. We show that, in some realistic conditions, even a relatively small proportion of convergent codons can strongly bias phylogenetic reconstruction, especially when amino acid sequences are used as characters. The strength of this bias does not depend on the reconstruction method but varies as a function of how much divergence had occurred among the lineages prior to any episodes of convergent substitutions. While the occurrence of this bias is difficult to predict, the risk of spurious groupings is strongly decreased by considering only 3rd codon positions, which are less subject to selection, as long as saturation problems are not present. Therefore, we recommend that, whenever possible, topologies obtained with amino acid sequences and 3rd codon positions be compared to identify potential phylogenetic biases and avoid evolutionarily misleading conclusions. Copyright © 2011 Elsevier Inc. All rights reserved.

  4. Convergent evolution of marine mammals is associated with distinct substitutions in common genes.

    PubMed

    Zhou, Xuming; Seim, Inge; Gladyshev, Vadim N

    2015-11-09

    Phenotypic convergence is thought to be driven by parallel substitutions coupled with natural selection at the sequence level. Multiple independent evolutionary transitions of mammals to an aquatic environment offer an opportunity to test this thesis. Here, whole genome alignment of coding sequences identified widespread parallel amino acid substitutions in marine mammals; however, the majority of these changes were not unique to these animals. Conversely, we report that candidate aquatic adaptation genes, identified by signatures of likelihood convergence and/or elevated ratio of nonsynonymous to synonymous nucleotide substitution rate, are characterized by very few parallel substitutions and exhibit distinct sequence changes in each group. Moreover, no significant positive correlation was found between likelihood convergence and positive selection in all three marine lineages. These results suggest that convergence in protein coding genes associated with aquatic lifestyle is mainly characterized by independent substitutions and relaxed negative selection.

  5. Genetic architecture underlying convergent evolution of egg-laying behavior in a seed-feeding beetle.

    PubMed

    Fox, Charles W; Wagner, James D; Cline, Sara; Thomas, Frances Ann; Messina, Frank J

    2009-05-01

    Independent populations subjected to similar environments often exhibit convergent evolution. An unresolved question is the frequency with which such convergence reflects parallel genetic mechanisms. We examined the convergent evolution of egg-laying behavior in the seed-feeding beetle Callosobruchus maculatus. Females avoid ovipositing on seeds bearing conspecific eggs, but the degree of host discrimination varies among geographic populations. In a previous experiment, replicate lines switched from a small host to a large one evolved reduced discrimination after 40 generations. We used line crosses to determine the genetic architecture underlying this rapid response. The most parsimonious genetic models included dominance and/or epistasis for all crosses. The genetic architecture underlying reduced discrimination in two lines was not significantly different from the architecture underlying differences between geographic populations, but the architecture underlying the divergence of a third line differed from all others. We conclude that convergence of this complex trait may in some cases involve parallel genetic mechanisms.

  6. Convergent evolution of marine mammals is associated with distinct substitutions in common genes

    PubMed Central

    Zhou, Xuming; Seim, Inge; Gladyshev, Vadim N.

    2015-01-01

    Phenotypic convergence is thought to be driven by parallel substitutions coupled with natural selection at the sequence level. Multiple independent evolutionary transitions of mammals to an aquatic environment offer an opportunity to test this thesis. Here, whole genome alignment of coding sequences identified widespread parallel amino acid substitutions in marine mammals; however, the majority of these changes were not unique to these animals. Conversely, we report that candidate aquatic adaptation genes, identified by signatures of likelihood convergence and/or elevated ratio of nonsynonymous to synonymous nucleotide substitution rate, are characterized by very few parallel substitutions and exhibit distinct sequence changes in each group. Moreover, no significant positive correlation was found between likelihood convergence and positive selection in all three marine lineages. These results suggest that convergence in protein coding genes associated with aquatic lifestyle is mainly characterized by independent substitutions and relaxed negative selection. PMID:26549748

  7. Otitis Media

    PubMed Central

    Bain, John

    1992-01-01

    Otitis media remains one of the least understood conditions seen by a family physician. More attention to follow up instead of widespread use of antibiotics and decongestant mixtures could improve family practice care of children with middle ear disorders. Greater selection in resorting to surgical management would be helpful. Unnecessary interference is unlikely to be of long-term benefit to either children or their families. ImagesFigures 1-3Figures 4-5 PMID:21221314

  8. Media Education Initiatives by Media Organizations: The Uses of Media Literacy in Hong Kong Media

    ERIC Educational Resources Information Center

    Chu, Donna; Lee, Alice Y. L.

    2014-01-01

    As more media organizations have engaged in media education, this paper investigates the goals and practices of these activities. This article coins media education initiatives by media organizations with the term "media-organization media literac"y (MOML). Four MOML projects in Hong Kong were selected for examination. Built on critical…

  9. Media Education Initiatives by Media Organizations: The Uses of Media Literacy in Hong Kong Media

    ERIC Educational Resources Information Center

    Chu, Donna; Lee, Alice Y. L.

    2014-01-01

    As more media organizations have engaged in media education, this paper investigates the goals and practices of these activities. This article coins media education initiatives by media organizations with the term "media-organization media literac"y (MOML). Four MOML projects in Hong Kong were selected for examination. Built on critical…

  10. Media matters.

    PubMed

    Martinez, L M

    1995-01-01

    The impact of the mass media on woman's status was addressed at two 1995 conferences: the Fourth World Conference on Women, held in Beijing, China, and the Congress of the World Association for Christian Communication, held in Puebla, Mexico. The globalization process facilitated by the mass media has served to increase the power of patriarchy, with no advantages to the cause of women's rights. Coverage of popular movements has been suppressed out of deference to male-controlled governments. Coverage of the Beijing Conference highlighted celebrities and personal stories, to the exclusion of the economic and political issues under debate. Television has commodified women, reinforcing their oppression. On the other hand, the alternative media, which tend to be decentralized, democratic, low-cost, and low in technology, are presenting women as subjects rather than objects and deconstructing gender stereotypes. Of concern, however, is the tendency of computer technology to widen the gap between social classes and developed and developing countries. Women must use information networks to disseminate information on women's rights and strengthen the links between women throughout the world.

  11. Porous media

    SciTech Connect

    Bullien, F.A.L. . Dept. of Chemical Engineering)

    1992-01-01

    The unique property of a porous medium, the one that distinguishes it from other solid bodies on the one hand and from simple conduits on the other, is its complicated pore structure. Fluid flow, diffusion, and electrical conduction in porous media take place within extremely complicated microscopic boundaries that in the past made a rigorous solution of the equations of change in the capillary network practically impossible. The past state of affairs is one of the reasons why some of the brilliant and successful practitioners in the field of flow through porous media have tried, as much as possible, to stick with the continuum approach in which no attention is paid to pores or pore structure. Another reason is that the continuum approach is often adequate for the phenomenological description of macroscopic transport processes in porous media. This book has been written with the primary purpose of presenting in an organized manner the most pertinent information available on the role of pore structure and then putting it to use in the interpretation of experimental data and the results of model calculations.

  12. Beethoven: architecture for media telephony

    NASA Astrophysics Data System (ADS)

    Keskinarkaus, Anja; Ohtonen, Timo; Sauvola, Jaakko J.

    1999-11-01

    This paper presents a new architecture and techniques for media-based telephony over wireless/wireline IP networks, called `Beethoven'. The platform supports complex media transport and mobile conferencing for multi-user environments having a non-uniform access. New techniques are presented to provide advanced multimedia call management over different media types and their presentation. The routing and distribution of the media is rendered over the standards based protocol. Our approach offers a generic, distributed and object-oriented solution having interfaces, where signal processing and unified messaging algorithms are embedded as instances of core classes. The platform services are divided into `basic communication', `conferencing' and `media session'. The basic communication form platform core services and supports access from scalable user interface to network end-points. Conferencing services take care of media filter adaptation, conversion, error resiliency, multi-party connection and event signaling, while the media session services offer resources for application-level communication between the terminals. The platform allows flexible attachment of any number of plug-in modules, and thus we use it as a test bench for multiparty/multi-point conferencing and as an evaluation bench for signal coding algorithms. In tests, our architecture showed the ability to easily be scaled from simple voice terminal to complex multi-user conference sharing virtual data.

  13. Possibilities for global governance of converging technologies

    NASA Astrophysics Data System (ADS)

    Roco, Mihail C.

    2008-01-01

    The convergence of nanotechnology, modern biology, the digital revolution and cognitive sciences will bring about tremendous improvements in transformative tools, generate new products and services, enable opportunities to meet and enhance human potential and social achievements, and in time reshape societal relationships. This paper focuses on the progress made in governance of such converging, emerging technologies and suggests possibilities for a global approach. Specifically, this paper suggests creating a multidisciplinary forum or a consultative coordinating group with members from various countries to address globally governance of converging, emerging technologies. The proposed framework for governance of converging technologies calls for four key functions: supporting the transformative impact of the new technologies; advancing responsible development that includes health, safety and ethical concerns; encouraging national and global partnerships; and establishing commitments to long-term planning and investments centered on human development. Principles of good governance guiding these functions include participation of all those who are forging or affected by the new technologies, transparency of governance strategies, responsibility of each participating stakeholder, and effective strategic planning. Introduction and management of converging technologies must be done with respect for immediate concerns, such as privacy, access to medical advancements, and potential human health effects. At the same time, introduction and management should also be done with respect for longer-term concerns, such as preserving human integrity, dignity and welfare. The suggested governance functions apply to four levels of governance: (a) adapting existing regulations and organizations; (b) establishing new programs, regulations and organizations specifically to handle converging technologies; (c) building capacity for addressing these issues into national policies and

  14. Convergence of gut microbiomes in myrmecophagous mammals.

    PubMed

    Delsuc, Frédéric; Metcalf, Jessica L; Wegener Parfrey, Laura; Song, Se Jin; González, Antonio; Knight, Rob

    2014-03-01

    Mammals have diversified into many dietary niches. Specialized myrmecophagous (ant- and termite-eating) placental mammals represent a textbook example of evolutionary convergence driven by extreme diet specialization. Armadillos, anteaters, aardvarks, pangolins and aardwolves thus provide a model system for understanding the potential role of gut microbiota in the convergent adaptation to myrmecophagy. Here, we expand upon previous mammalian gut microbiome studies by using high-throughput barcoded Illumina sequencing of the 16S rRNA gene to characterize the composition of gut microbiota in 15 species representing all placental myrmecophagous lineages and their close relatives from zoo- and field-collected samples. We confirm that both diet and phylogeny drive the evolution of mammalian gut microbiota, with cases of convergence in global composition, but also examples of phylogenetic inertia. Our results reveal specialized placental myrmecophages as a spectacular case of large-scale convergence in gut microbiome composition. Indeed, neighbour-net networks and beta-diversity plots based on UniFrac distances show significant clustering of myrmecophagous species (anteaters, aardvarks and aardwolves), even though they belong to phylogenetically distant lineages representing different orders. The aardwolf, which diverged from carnivorous hyenas only in the last 10 million years, experienced a convergent shift in the composition of its gut microbiome to become more similar to other myrmecophages. These results confirm diet adaptation to be a major driving factor of convergence in gut microbiome composition over evolutionary timescales. This study sets the scene for future metagenomic studies aiming at evaluating potential convergence in functional gene content in the microbiomes of specialized mammalian myrmecophages. © 2013 John Wiley & Sons Ltd.

  15. Incorporating Social Media in the Classroom

    ERIC Educational Resources Information Center

    McMeans, April

    2015-01-01

    Incorporating social media into the classroom will provide a positive, upbeat learning environment that students are engaged in on a regular basis. In doing this, educators will be ensuring discussion, collaboration, critical thinking, and creativity amongst their students. Social media is a knowledgeable topic for our students, and it is an…

  16. Toward Global Content Analysis and Media Criticism.

    ERIC Educational Resources Information Center

    Nordenstreng, Kaarle

    1995-01-01

    Presents the background, rationale, and implementation prospects for an international system of monitoring media coverage of global problems such as peace and war, human rights, and the environment. Outlines the monitoring project carried out in January 1995 concerning the representation and portrayal of women in news media. (SR)

  17. Colloid transport in dual-permeability media

    USDA-ARS?s Scientific Manuscript database

    It has been widely reported that colloids can travel faster and over longer distances in natural structured porous media than in uniform structureless media used in laboratory studies. The presence of preferential pathways for colloids in the subsurface environment is of concern because of the incre...

  18. Screen Media and Young Children: Who Benefits?

    ERIC Educational Resources Information Center

    Cardany, Audrey Berger

    2010-01-01

    Since the airing of "Sesame Street" in 1985, television produced for children has expanded to more television shows and educational media that includes videos, DVDs, and computer products. Viewing screen media is pervasive in the environments of young children, and companies are designing products for our youngest viewers--infants and toddlers.…

  19. Toward Global Content Analysis and Media Criticism.

    ERIC Educational Resources Information Center

    Nordenstreng, Kaarle

    1995-01-01

    Presents the background, rationale, and implementation prospects for an international system of monitoring media coverage of global problems such as peace and war, human rights, and the environment. Outlines the monitoring project carried out in January 1995 concerning the representation and portrayal of women in news media. (SR)

  20. Incorporating Social Media in the Classroom

    ERIC Educational Resources Information Center

    McMeans, April

    2015-01-01

    Incorporating social media into the classroom will provide a positive, upbeat learning environment that students are engaged in on a regular basis. In doing this, educators will be ensuring discussion, collaboration, critical thinking, and creativity amongst their students. Social media is a knowledgeable topic for our students, and it is an…

  1. Screen Media and Young Children: Who Benefits?

    ERIC Educational Resources Information Center

    Cardany, Audrey Berger

    2010-01-01

    Since the airing of "Sesame Street" in 1985, television produced for children has expanded to more television shows and educational media that includes videos, DVDs, and computer products. Viewing screen media is pervasive in the environments of young children, and companies are designing products for our youngest viewers--infants and toddlers.…

  2. Grid Convergence for Turbulent Flows(Invited)

    NASA Technical Reports Server (NTRS)

    Diskin, Boris; Thomas, James L.; Rumsey, Christopher L.; Schwoppe, Axel

    2015-01-01

    A detailed grid convergence study has been conducted to establish accurate reference solutions corresponding to the one-equation linear eddy-viscosity Spalart-Allmaras turbulence model for two dimensional turbulent flows around the NACA 0012 airfoil and a flat plate. The study involved three widely used codes, CFL3D (NASA), FUN3D (NASA), and TAU (DLR), and families of uniformly refined structured grids that differ in the grid density patterns. Solutions computed by different codes on different grid families appear to converge to the same continuous limit, but exhibit different convergence characteristics. The grid resolution in the vicinity of geometric singularities, such as a sharp trailing edge, is found to be the major factor affecting accuracy and convergence of discrete solutions, more prominent than differences in discretization schemes and/or grid elements. The results reported for these relatively simple turbulent flows demonstrate that CFL3D, FUN3D, and TAU solutions are very accurate on the finest grids used in the study, but even those grids are not sufficient to conclusively establish an asymptotic convergence order.

  3. Formation of polarity convergences underlying shoot outgrowths

    PubMed Central

    Abley, Katie; Sauret-Güeto, Susanna; Marée, Athanasius FM; Coen, Enrico

    2016-01-01

    The development of outgrowths from plant shoots depends on formation of epidermal sites of cell polarity convergence with high intracellular auxin at their centre. A parsimonious model for generation of convergence sites is that cell polarity for the auxin transporter PIN1 orients up auxin gradients, as this spontaneously generates convergent alignments. Here we test predictions of this and other models for the patterns of auxin biosynthesis and import. Live imaging of outgrowths from kanadi1 kanadi2 Arabidopsis mutant leaves shows that they arise by formation of PIN1 convergence sites within a proximodistal polarity field. PIN1 polarities are oriented away from regions of high auxin biosynthesis enzyme expression, and towards regions of high auxin importer expression. Both expression patterns are required for normal outgrowth emergence, and may form part of a common module underlying shoot outgrowths. These findings are more consistent with models that spontaneously generate tandem rather than convergent alignments. DOI: http://dx.doi.org/10.7554/eLife.18165.001 PMID:27478985

  4. Experimental and numerical analysis of convergent nozzlex

    NASA Astrophysics Data System (ADS)

    Srinivas, G.; Rakham, Bhupal

    2017-05-01

    In this paper the main focus was given to convergent nozzle where both the experimental and numerical calculations were carried out with the support of standardized literature. In the recent years the field of air breathing and non-air breathing engine developments significantly increase its performance. To enhance the performance of both the type of engines the nozzle is the one of the component which will play a vital role, especially selecting the type of nozzle depends upon the vehicle speed requirement and aerodynamic behavior at most important in the field of propulsion. The convergent nozzle flow experimental analysis done using scaled apparatus and the similar setup was arranged artificially in the ANSYS software for doing the flow analysis across the convergent nozzle. The consistent calculation analysis are done based on the public literature survey to validate the experimental and numerical simulation results of convergent nozzle. Using these two experimental and numerical simulation approaches the best fit results will bring up to meet the design requirements. However the comparison also made to meet the reliability of the work on design criteria of convergent nozzle which can entrench in the field of propulsion applications.

  5. Numerical Convergence In Smoothed Particle Hydrodynamics

    NASA Astrophysics Data System (ADS)

    Zhu, Qirong; Hernquist, Lars; Li, Yuexing

    2015-02-01

    We study the convergence properties of smoothed particle hydrodynamics (SPH) using numerical tests and simple analytic considerations. Our analysis shows that formal numerical convergence is possible in SPH only in the joint limit N → ∞, h → 0, and Nnb → ∞, where N is the total number of particles, h is the smoothing length, and Nnb is the number of neighbor particles within the smoothing volume used to compute smoothed estimates. Previous work has generally assumed that the conditions N → ∞ and h → 0 are sufficient to achieve convergence, while holding Nnb fixed. We demonstrate that if Nnb is held fixed as the resolution is increased, there will be a residual source of error that does not vanish as N → ∞ and h → 0. Formal numerical convergence in SPH is possible only if Nnb is increased systematically as the resolution is improved. Using analytic arguments, we derive an optimal compromise scaling for Nnb by requiring that this source of error balance that present in the smoothing procedure. For typical choices of the smoothing kernel, we find Nnb vpropN 0.5. This means that if SPH is to be used as a numerically convergent method, the required computational cost does not scale with particle number as O(N), but rather as O(N 1 + δ), where δ ≈ 0.5, with a weak dependence on the form of the smoothing kernel.

  6. Uplift of Zagros Mountains slows plate convergence

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2013-05-01

    Research has indicated that mountain ranges can slow down the convergence between two tectonic plates on timescales as short as a few million years, as the growing mountains provide enough tectonic force to impact plate motions. Focusing on the convergence of the Arabian and Eurasian plates at the Zagros mountain range, which runs across Iran and Iraq, Austermann and Iaffaldano reconstructed the relative motion of the plates using published paleomagnetic data covering the past 13 million years, as well as current geodetic measurements. They show that the convergence of the two plates has decreased by about 30% over the past 5 million years. Looking at the geological record to infer past topography and using a computer model of the mantle-lithosphere system, the authors examined whether the recent uplift across the Zagros Mountains could have caused the observed slowdown. They also considered several other geological events that might have influenced the convergence rate, but the authors were able to rule those out as dominant controls. The authors conclude that the uplift across the Zagros Mountains in the past 5 million years did indeed play a key role in slowing down the convergence between the Eurasian and Arabian plates. (Tectonics, doi:10.1002/tect.20027, 2013)

  7. Global Eco-Communication: Assessing the Communication and Information Environment.

    ERIC Educational Resources Information Center

    Rush, Ramona R.

    It is no longer "new" news that the "new" media, separately or in convergence with the traditional mass media, are often reinforcing old ways and traditional patterns. Concentration of ownership; under- or misappropriate employment patterns for certain groups and classes of people; and inadequate, inappropriate, and inaccurate…

  8. Convergence Estimates for Multidisciplinary Analysis and Optimization

    NASA Technical Reports Server (NTRS)

    Arian, Eyal

    1997-01-01

    A quantitative analysis of coupling between systems of equations is introduced. This analysis is then applied to problems in multidisciplinary analysis, sensitivity, and optimization. For the sensitivity and optimization problems both multidisciplinary and single discipline feasibility schemes are considered. In all these cases a "convergence factor" is estimated in terms of the Jacobians and Hessians of the system, thus it can also be approximated by existing disciplinary analysis and optimization codes. The convergence factor is identified with the measure for the "coupling" between the disciplines in the system. Applications to algorithm development are discussed. Demonstration of the convergence estimates and numerical results are given for a system composed of two non-linear algebraic equations, and for a system composed of two PDEs modeling aeroelasticity.

  9. Convergence studies in meshfree peridynamic simulations

    SciTech Connect

    Seleson, Pablo; Littlewood, David J.

    2016-04-15

    Meshfree methods are commonly applied to discretize peridynamic models, particularly in numerical simulations of engineering problems. Such methods discretize peridynamic bodies using a set of nodes with characteristic volume, leading to particle-based descriptions of systems. In this article, we perform convergence studies of static peridynamic problems. We show that commonly used meshfree methods in peridynamics suffer from accuracy and convergence issues, due to a rough approximation of the contribution to the internal force density of nodes near the boundary of the neighborhood of a given node. We propose two methods to improve meshfree peridynamic simulations. The first method uses accurate computations of volumes of intersections between neighbor cells and the neighborhood of a given node, referred to as partial volumes. The second method employs smooth influence functions with a finite support within peridynamic kernels. Numerical results demonstrate great improvements in accuracy and convergence of peridynamic numerical solutions, when using the proposed methods.

  10. Convergence Properties of KKR Green Function Methods

    NASA Astrophysics Data System (ADS)

    Moghadam, N. Y.; Stocks, G. M.; Zhang, X.-G.; Nicholson, D. M. C.; Shelton, W. A.; Wang, Yang; Faulkner, J. S.

    1998-03-01

    Most multiple scattering theory (MST) electronic structure methods (e.g. KKR, KKR-CPA, impurity Greens function, O[N] LSMS method(Yang Wang et al. Phys. Rev. Letters 75), 2867,(1995)) make use of a expression for the single particle Green function that is based on a single center expansion(J. S. Faulkner and G. M. Stocks, Phys. Rev. B 21),3222, (1980). Because the electronic structure is rapidly convergent in angular momentum, l, the multiple scattering equations are typically truncated at l_max <= 4. Using the LSMS method as illustrative we show that the Green function and, therefore, the cell densities of states and charge density converge more slowly requiring l_max ~ 8 arrow 12 even for muffin-tin potentails. We discuss the consequences of this for previous MST based work, and show that this slow convergence can be trivially accommodated within the LSMS method.

  11. Convergence studies in meshfree peridynamic simulations

    SciTech Connect

    Seleson, Pablo; Littlewood, David J.

    2016-04-15

    Meshfree methods are commonly applied to discretize peridynamic models, particularly in numerical simulations of engineering problems. Such methods discretize peridynamic bodies using a set of nodes with characteristic volume, leading to particle-based descriptions of systems. In this article, we perform convergence studies of static peridynamic problems. We show that commonly used meshfree methods in peridynamics suffer from accuracy and convergence issues, due to a rough approximation of the contribution to the internal force density of nodes near the boundary of the neighborhood of a given node. We propose two methods to improve meshfree peridynamic simulations. The first method uses accurate computations of volumes of intersections between neighbor cells and the neighborhood of a given node, referred to as partial volumes. The second method employs smooth influence functions with a finite support within peridynamic kernels. Numerical results demonstrate great improvements in accuracy and convergence of peridynamic numerical solutions, when using the proposed methods.

  12. Theoretical convergence guarantees for cooperative coevolutionary algorithms.

    PubMed

    Panait, Liviu

    2010-01-01

    Cooperative coevolutionary algorithms have the potential to significantly speed up the search process by dividing the space into parts that can each be conquered separately. However, recent research presented theoretical and empirical arguments that these algorithms tend to converge to suboptimal solutions in the search space, and are thus not fit for optimization tasks. This paper details an extended formal model for cooperative coevolutionary algorithms, and uses it to explore possible reasons these algorithms converge to optimal or suboptimal solutions. We demonstrate that, under specific conditions, this theoretical model will converge to the globally optimal solution. The proofs provide the underlying theoretical foundation for a better application of cooperative coevolutionary algorithms. We demonstrate the practical advantages of applying ideas from this theoretical work to a simple problem domain.

  13. On phonetic convergence during conversational interaction.

    PubMed

    Pardo, Jennifer S

    2006-04-01

    Following research that found imitation in single-word shadowing, this study examines the degree to which interacting talkers increase similarity in phonetic repertoire during conversational interaction. Between-talker repetitions of the same lexical items produced in a conversational task were examined for phonetic convergence by asking a separate set of listeners to detect similarity in pronunciation across items in a perceptual task. In general, a listener judged a repeated item spoken by one talker in the task to be more similar to a sample production spoken by the talker's partner than corresponding pre- and postinteraction utterances. Both the role of a participant in the task and the sex of the pair of talkers affected the degree of convergence. These results suggest that talkers in conversational settings are susceptible to phonetic convergence, which can mark nonlinguistic functions in social discourse and can form the basis for phenomena such as accent change and dialect formation.

  14. Convergence studies in meshfree peridynamic simulations

    DOE PAGES

    Seleson, Pablo; Littlewood, David J.

    2016-04-15

    Meshfree methods are commonly applied to discretize peridynamic models, particularly in numerical simulations of engineering problems. Such methods discretize peridynamic bodies using a set of nodes with characteristic volume, leading to particle-based descriptions of systems. In this article, we perform convergence studies of static peridynamic problems. We show that commonly used meshfree methods in peridynamics suffer from accuracy and convergence issues, due to a rough approximation of the contribution to the internal force density of nodes near the boundary of the neighborhood of a given node. We propose two methods to improve meshfree peridynamic simulations. The first method uses accuratemore » computations of volumes of intersections between neighbor cells and the neighborhood of a given node, referred to as partial volumes. The second method employs smooth influence functions with a finite support within peridynamic kernels. Numerical results demonstrate great improvements in accuracy and convergence of peridynamic numerical solutions, when using the proposed methods.« less

  15. Mnemonic convergence in the human hippocampus

    PubMed Central

    Backus, Alexander R.; Bosch, Sander E.; Ekman, Matthias; Grabovetsky, Alejandro Vicente; Doeller, Christian F.

    2016-01-01

    The ability to form associations between a multitude of events is the hallmark of episodic memory. Computational models have espoused the importance of the hippocampus as convergence zone, binding different aspects of an episode into a coherent representation, by integrating information from multiple brain regions. However, evidence for this long-held hypothesis is limited, since previous work has largely focused on representational and network properties of the hippocampus in isolation. Here we identify the hippocampus as mnemonic convergence zone, using a combination of multivariate pattern and graph-theoretical network analyses of functional magnetic resonance imaging data from humans performing an associative memory task. We observe overlap of conjunctive coding and hub-like network attributes in the hippocampus. These results provide evidence for mnemonic convergence in the hippocampus, underlying the integration of distributed information into episodic memory representations. PMID:27325442

  16. Science and technology convergence: with emphasis for nanotechnology-inspired convergence

    NASA Astrophysics Data System (ADS)

    Bainbridge, William S.; Roco, Mihail C.

    2016-07-01

    Convergence offers a new universe of discovery, innovation, and application opportunities through specific theories, principles, and methods to be implemented in research, education, production, and other societal activities. Using a holistic approach with shared goals, convergence seeks to transcend existing human limitations to achieve improved conditions for work, learning, aging, physical, and cognitive wellness. This paper outlines ten key theories that offer complementary perspectives on this complex dynamic. Principles and methods are proposed to facilitate and enhance science and technology convergence. Several convergence success stories in the first part of the 21st century—including nanotechnology and other emerging technologies—are discussed in parallel with case studies focused on the future. The formulation of relevant theories, principles, and methods aims at establishing the convergence science.

  17. Instructional Media

    ERIC Educational Resources Information Center

    Pulliam, William E., Ed.; Rich, Lynne O'Brien, Ed.

    1978-01-01

    Presents six social studies teaching materials comprised of filmstrips with accompanying cassettes and teacher's guides. Content and activities focus on life in the universe, ocean rights, the environment, foreign cultures, social problems, and listening and research skills. (AV)

  18. Use and Rationale of Media Types in Performance-Centered Design.

    ERIC Educational Resources Information Center

    Schubert, Dave

    2002-01-01

    Focuses on the convergent rationale and use of media within performance centered design and how that can affect user performance using real-time electronic performance support system appliance design. Discusses the more effective time-based, interactive, and synchronized media types that have become viable with technological advancements.…

  19. Unconditionally convergent nonlinear solver for hyperbolic conservation laws with S-shaped flux functions

    SciTech Connect

    Jenny, Patrick Tchelepi, Hamdi A.; Lee, Seong H.

    2009-11-01

    This paper addresses the convergence properties of implicit numerical solution algorithms for nonlinear hyperbolic transport problems. It is shown that the Newton-Raphson (NR) method converges for any time step size, if the flux function is convex, concave, or linear, which is, in general, the case for CFD problems. In some problems, e.g., multiphase flow in porous media, the nonlinear flux function is S-shaped (not uniformly convex or concave); as a result, a standard NR iteration can diverge for large time steps, even if an implicit discretization scheme is used to solve the nonlinear system of equations. In practice, when such convergence difficulties are encountered, the current time step is cut, previous iterations are discarded, a smaller time step size is tried, and the NR process is repeated. The criteria for time step cutting and selection are usually based on heuristics that limit the allowable change in the solution over a time step and/or NR iteration. Here, we propose a simple modification to the NR iteration scheme for conservation laws with S-shaped flux functions that converges for any time step size. The new scheme allows one to choose the time step size based on accuracy consideration only without worrying about the convergence behavior of the nonlinear solver. The proposed method can be implemented in an existing simulator, e.g., for CO{sub 2} sequestration or reservoir flow modeling, quite easily. The numerical analysis is confirmed with simulation studies using various test cases of nonlinear multiphase transport in porous media. The analysis and numerical experiments demonstrate that the modified scheme allows for the use of arbitrarily large time steps for this class of problems.

  20. Deterministic convergence in iterative phase shifting

    SciTech Connect

    Luna, Esteban; Salas, Luis; Sohn, Erika; Ruiz, Elfego; Nunez, Juan M.; Herrera, Joel

    2009-03-10

    Previous implementations of the iterative phase shifting method, in which the phase of a test object is computed from measurements using a phase shifting interferometer with unknown positions of the reference, do not provide an accurate way of knowing when convergence has been attained. We present a new approach to this method that allows us to deterministically identify convergence. The method is tested with a home-built Fizeau interferometer that measures optical surfaces polished to {lambda}/100 using the Hydra tool. The intrinsic quality of the measurements is better than 0.5 nm. Other possible applications for this technique include fringe projection or any problem where phase shifting is involved.

  1. Experience and convergence in spiritual direction.

    PubMed

    Evans, Jean

    2015-02-01

    The practice of spiritual direction concerns the human experience of God. As praxis, spiritual direction has a long tradition in Western Christianity. It is a process rooted in spirituality with theology as its foundation. This paper explores the convergences between aspects of philosophy (contemplative awareness), psychology (Rogerian client-centered approach) and phenomenology. There are significant points of convergence between phenomenology and spiritual direction: first, in Ignatius of Loyola's phenomenological approach to his religious experience; second, in the appropriation by spiritual directors of concepts of epochē and empathy; third, in the process of "unpacking" religious experience within a spiritual direction interview.

  2. Antibiotics from microbes: converging to kill.

    PubMed

    Fischbach, Michael A

    2009-10-01

    As genetically encoded small molecules, antibiotics are phenotypes that have resulted from mutation and natural selection. Advances in genetics, biochemistry, and bioinformatics have connected hundreds of antibiotics to the gene clusters that encode them, allowing these molecules to be analyzed using the tools of evolutionary biology. This review surveys examples of convergent evolution from microbially produced antibiotics, including the convergence of distinct gene clusters on similar phenotypes and the merger of distinct gene clusters into a single functional unit. Examining antibiotics through an evolutionary lens highlights the versatility of biosynthetic pathways, reveals lessons for combating antibiotic resistance, and provides an entry point for studying the natural roles of these natural products.

  3. On Iλ -statistical convergence of weight g

    NASA Astrophysics Data System (ADS)

    Savas, Ekrem

    2016-08-01

    In this paper, following a very recent and new approach of [M. Balcerzak, P. Das, M. Filipczak, and J. Swaczyna, Acta Math. Hungar. 147, 97-115 (2015)], we further generalize the recently introduced summability method of [E. Savas, and P. Das, Appl. Math. Lett. 24, 826-830 (2011)] and introduce the new notion namely, Iλ -statistical convergence of weight g, where g : ℕ → [0, ∞) is a function satisfying g(n) → ∞ and g(n) ↛ 0 as n → ∞. We mainly investigate certain properties of this convergence.

  4. Cultivation in the Newer Media Environment.

    ERIC Educational Resources Information Center

    Perse, Elizabeth M.; And Others

    1994-01-01

    Tests the impact of cable, VCRs, and remote control devices on fear of crime and interpersonal mistrust. Finds that interpersonal mistrust was linked to greater exposure to cable's broadcast-type channels, but fear of crime and mistrust were negatively related to increased exposure to specialized cable channels. Finds fear of crime linked…

  5. Cultivation in the Newer Media Environment.

    ERIC Educational Resources Information Center

    Perse, Elizabeth M.; And Others

    Researchers who study television's cultivation effects believe that heavy television viewing exposes people to consistent messages that lead them to be more fearful and mistrustful of others. The widespread adoption and use of new television technologies, such as cable, VCR, and remote control devices (RCD), however, have the potential to alter…

  6. Educational Media and Technology: The State of the Profession.

    ERIC Educational Resources Information Center

    Gustafson, Kent L.

    1996-01-01

    Discussion of the field of educational media and technology focuses on external forces in society that will shape its destiny. Highlights include demographic and cultural changes; family structure; globalization; changing nature of the workplace; technological developments including digitization, communication, technical convergence, and…

  7. Measuring News Media Literacy

    ERIC Educational Resources Information Center

    Maksl, Adam; Ashley, Seth; Craft, Stephanie

    2015-01-01

    News media literacy refers to the knowledge and motivations needed to identify and engage with journalism. This study measured levels of news media literacy among 500 teenagers using a new scale measure based on Potter's model of media literacy and adapted to news media specifically. The adapted model posits that news media literate individuals…

  8. Measuring News Media Literacy

    ERIC Educational Resources Information Center

    Maksl, Adam; Ashley, Seth; Craft, Stephanie

    2015-01-01

    News media literacy refers to the knowledge and motivations needed to identify and engage with journalism. This study measured levels of news media literacy among 500 teenagers using a new scale measure based on Potter's model of media literacy and adapted to news media specifically. The adapted model posits that news media literate individuals…

  9. Adolescents and media literacy.

    PubMed

    McCannon, Robert

    2005-06-01

    In the face of media industry consolidation, fewer people control media content which makes it harder for parents and citizens to know the research about media-related issues, such as video game violence, nutrition, and sexual risk-taking. Media literacy offers a popular and potentially successful way to counter the misinformation that is spread by Big Media public relations.

  10. Geographic Media Literacy

    ERIC Educational Resources Information Center

    Lukinbeal, Chris

    2014-01-01

    While the use of media permeates geographic research and pedagogic practice, the underlying literacies that link geography and media remain uncharted. This article argues that geographic media literacy incorporates visual literacy, information technology literacy, information literacy, and media literacy. Geographic media literacy is the ability…

  11. Geographic Media Literacy

    ERIC Educational Resources Information Center

    Lukinbeal, Chris

    2014-01-01

    While the use of media permeates geographic research and pedagogic practice, the underlying literacies that link geography and media remain uncharted. This article argues that geographic media literacy incorporates visual literacy, information technology literacy, information literacy, and media literacy. Geographic media literacy is the ability…

  12. The Mass Media Book.

    ERIC Educational Resources Information Center

    Holmgren, Rod, Ed.; Norton, William, Ed.

    This anthology consists of two major sections, "The News Media" and "The Entertainment Media." Both feature essays by critics, working professionals, and professional observers of the media. One aim of the anthology is to show the pervasive effect of the media on us. The section on news media comments on such topics as credibility gap, Vice…

  13. The Mass Media Book.

    ERIC Educational Resources Information Center

    Holmgren, Rod, Ed.; Norton, William, Ed.

    This anthology consists of two major sections, "The News Media" and "The Entertainment Media." Both feature essays by critics, working professionals, and professional observers of the media. One aim of the anthology is to show the pervasive effect of the media on us. The section on news media comments on such topics as credibility gap, Vice…

  14. Potential Interrelationships Between Library and Other Mass Media Systems.

    ERIC Educational Resources Information Center

    Parker, Edwin B.

    The function of libraries is to make it easy for the people in their community to obtain information from other people or environments that may be distant is space, time or imagination. To perform this function libraries require communication media. Storage media are essential, but duplication and transmission media can improve the service of…

  15. Predictors of orbital convergence in primates: a test of the snake detection hypothesis of primate evolution.

    PubMed

    Wheeler, Brandon C; Bradley, Brenda J; Kamilar, Jason M

    2011-09-01

    Traditional explanations for the evolution of high orbital convergence and stereoscopic vision in primates have focused on how stereopsis might have aided early primates in foraging or locomoting in an arboreal environment. It has recently been suggested that predation risk by constricting snakes was the selective force that favored the evolution of orbital convergence in early primates, and that later exposure to venomous snakes favored further degrees of convergence in anthropoid primates. Our study tests this snake detection hypothesis (SDH) by examining whether orbital convergence among extant primates is indeed associated with the shared evolutionary history with snakes or the risk that snakes pose for a given species. We predicted that orbital convergence would be higher in species that: 1) have a longer history of sympatry with venomous snakes, 2) are likely to encounter snakes more frequently, 3) are less able to detect or deter snakes due to group size effects, and 4) are more likely to be preyed upon by snakes. Results based on phylogenetically independent contrasts do not support the SDH. Orbital convergence shows no relationship to the shared history with venomous snakes, likelihood of encountering snakes, or group size. Moreover, those species less likely to be targeted as prey by snakes show significantly higher values of orbital convergence. Although an improved ability to detect camouflaged snakes, along with other cryptic stimuli, is likely a consequence of increased orbital convergence, this was unlikely to have been the primary selective force favoring the evolution of stereoscopic vision in primates. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Another Perspective: A Response to "Toward Convergence"

    ERIC Educational Resources Information Center

    Regelski, Thomas A.

    2013-01-01

    This response by Thomas A. Regelski was solicited to complement the lead article in this issue, "Toward Convergence: Adapting Music Education to Contemporary Society and Participatory Culture" by Evan S. Tobias. The author notes that many interesting and vital questions and alternatives that are often studiously ignored, overlooked, or taken for…

  17. [Conservative and surgical treatment of convergence excess].

    PubMed

    Ehrt, O

    2016-07-01

    Convergence excess is a common finding especially in pediatric strabismus. A detailed diagnostic approach has to start after full correction of any hyperopia measured in cycloplegia. It includes measurements of manifest and latent deviation at near and distance fixation, near deviation after relaxation of accommodation with addition of +3 dpt, assessment of binocular function with and without +3 dpt as well as the accommodation range. This diagnostic approach is important for the classification into three types of convergence excess, which require different therapeutic approaches: 1) hypo-accommodative convergence excess is treated with permanent bifocal glasses, 2) norm-accommodative patients should be treated with bifocals which can be weaned over years, especially in patients with good stereopsis and 3) non-accommodative convergence excess and patients with large distance deviations need a surgical approach. The most effective operations include those which reduce the muscle torque, e. g. bimedial Faden operations or Y‑splitting of the medial rectus muscles.

  18. Convergence of some asynchronous nonlinear multisplitting methods

    NASA Astrophysics Data System (ADS)

    Szyld, Daniel B.; Xu, Jian-Jun

    2000-09-01

    Frommer's nonlinear multisplitting methods for solving nonlinear systems of equations are extended to the asynchronous setting. Block methods are extended to include overlap as well. Several specific cases are discussed. Sufficient conditions to guarantee their local convergence are given. A numerical example is presented illustrating the performance of the new approach.

  19. Convergence of coupled cluster perturbation theory

    NASA Astrophysics Data System (ADS)

    Eriksen, Janus J.; Kristensen, Kasper; Matthews, Devin A.; Jørgensen, Poul; Olsen, Jeppe

    2016-12-01

    The convergence of a recently proposed coupled cluster (CC) family of perturbation series [J. J. Eriksen et al., J. Chem. Phys. 140, 064108 (2014)], in which the energetic difference between two CC models—a low-level parent and a high-level target model—is expanded in orders of the Møller-Plesset (MP) fluctuation potential, is investigated for four prototypical closed-shell systems (Ne, singlet CH2, distorted HF, and F-) in standard and augmented basis sets. In these investigations, energy corrections of the various series have been calculated to high orders and their convergence radii have been determined by probing for possible front- and back-door intruder states, the existence of which would make the series divergent. In summary, we conclude how it is primarily the choice of the target state, and not the choice of the parent state, which ultimately governs the convergence behavior of a given series. For example, restricting the target state to, say, triple or quadruple excitations might remove intruders present in series which target the full configuration interaction limit, such as the standard MP series. Furthermore, we find that whereas a CC perturbation series might converge within standard correlation consistent basis sets, it may start to diverge whenever these become augmented by diffuse functions, similar to the MP case. However, unlike for the MP case, such potential divergences are not found to invalidate the practical use of the low-order corrections of the CC perturbation series.

  20. The Convergence Coefficient across Political Systems

    PubMed Central

    Schofield, Norman

    2013-01-01

    Formal work on the electoral model often suggests that parties or candidates should locate themselves at the electoral mean. Recent research has found no evidence of such convergence. In order to explain nonconvergence, the stochastic electoral model is extended by including estimates of electoral valence. We introduce the notion of a convergence coefficient, c. It has been shown that high values of c imply that there is a significant centrifugal tendency acting on parties. We used electoral surveys to construct a stochastic valence model of the the elections in various countries. We find that the convergence coefficient varies across elections in a country, across countries with similar regimes, and across political regimes. In some countries, the centripetal tendency leads parties to converge to the electoral mean. In others the centrifugal tendency dominates and some parties locate far from the electoral mean. In particular, for countries with proportional electoral systems, namely, Israel, Turkey, and Poland, the centrifugal tendency is very high. In the majoritarian polities of the United States and Great Britain, the centrifugal tendency is very low. In anocracies, the autocrat imposes limitations on how far from the origin the opposition parties can move. PMID:24385886

  1. Professionalization in Universities and European Convergence

    ERIC Educational Resources Information Center

    Vivas, Amparo Jimenez; Hevia, David Menendez Alvarez

    2009-01-01

    The constant assessment of the quality of higher education within the framework of European convergence is a challenge for all those universities that wish their degrees and diplomas to reflect a unified Europe. As is the case in any assessment, change and review process, the quest to improve quality implies measuring achievement of the objectives…

  2. Professionalization in Universities and European Convergence

    ERIC Educational Resources Information Center

    Vivas, Amparo Jimenez; Hevia, David Menendez Alvarez

    2009-01-01

    The constant assessment of the quality of higher education within the framework of European convergence is a challenge for all those universities that wish their degrees and diplomas to reflect a unified Europe. As is the case in any assessment, change and review process, the quest to improve quality implies measuring achievement of the objectives…

  3. Culture and Social Psychology: Converging Perspectives

    ERIC Educational Resources Information Center

    Dimaggio, Paul; Markus, Hazel Rose

    2010-01-01

    Views of culture in psychology and sociology have converged markedly in the past two decades. Both have rejected what Adams and Markus (2004) refer to as the "entity" conception of culture--the view that culture is coherent, stable, and located in the heads of collectivities' members--in favor of more supple and dynamic constructs. Culture, in…

  4. Bandlimited image extrapolation with faster convergence.

    PubMed

    Cahana, D; Stark, H

    1981-08-15

    The Gerchberg-Papoulis (GP) algorithm has been widely discussed in the literature in connection with band-limited or space-limited image extrapolation. Despite its seemingly superior noise-resistant properties over earlier superresolution schemes, the GP algorithm generally exhibits very slow convergence thereby making the choice of starting point critical. We discuss how additional a priori information, such as the low-pass projection of the image (LPI), can be incorporated in the algorithm to decrease the initial error between the starting point of the recursion and the true signal. We also investigate how convergence rates might be improved by (1) using the LPI in each iteration to achieve a double per cycle correction, and (2) applying adaptive thresholding. Somewhat surprisingly, it was found that using the LPI had only a minor effect on the rate of convergence. On the other hand, when combined with adaptive thresholding the use of the LPI both significantly reduced the starting point error and improved the rate of convergence.

  5. Phonological Convergence in a Contracting Language Variety

    ERIC Educational Resources Information Center

    Bullock, Barbara E.; Gerfen, Chip

    2004-01-01

    Most work investigating the role of convergence in situations of language attrition has focused on the morpho-syntactic restructuring of the dying language variety. A central concern of such research has been untangling the factors driving the restructuring with an eye towards establishing whether the changes observed are best viewed as externally…

  6. Culture and Social Psychology: Converging Perspectives

    ERIC Educational Resources Information Center

    Dimaggio, Paul; Markus, Hazel Rose

    2010-01-01

    Views of culture in psychology and sociology have converged markedly in the past two decades. Both have rejected what Adams and Markus (2004) refer to as the "entity" conception of culture--the view that culture is coherent, stable, and located in the heads of collectivities' members--in favor of more supple and dynamic constructs. Culture, in…

  7. Converging Oceaniac Internal Waves, Somalia, Africa

    NASA Image and Video Library

    1988-10-03

    The arculate fronts of these apparently converging internal waves off the northeast coast of Somalia (11.5N, 51.5E) probably were produced by interaction with two parallel submarine canyons off the Horn of Africa. Internal waves are packets of tidally generated waves traveling within the ocean at varying depths and are not detectable by any surface disturbance.

  8. The convergence coefficient across political systems.

    PubMed

    Gallego, Maria; Schofield, Norman

    2013-01-01

    Formal work on the electoral model often suggests that parties or candidates should locate themselves at the electoral mean. Recent research has found no evidence of such convergence. In order to explain nonconvergence, the stochastic electoral model is extended by including estimates of electoral valence. We introduce the notion of a convergence coefficient, c. It has been shown that high values of c imply that there is a significant centrifugal tendency acting on parties. We used electoral surveys to construct a stochastic valence model of the the elections in various countries. We find that the convergence coefficient varies across elections in a country, across countries with similar regimes, and across political regimes. In some countries, the centripetal tendency leads parties to converge to the electoral mean. In others the centrifugal tendency dominates and some parties locate far from the electoral mean. In particular, for countries with proportional electoral systems, namely, Israel, Turkey, and Poland, the centrifugal tendency is very high. In the majoritarian polities of the United States and Great Britain, the centrifugal tendency is very low. In anocracies, the autocrat imposes limitations on how far from the origin the opposition parties can move.

  9. Governance Challenges of Technological Systems Convergence

    ERIC Educational Resources Information Center

    Whitman, Jim

    2006-01-01

    The convergence of several technological systems (especially nanotechnology, biotechnology, information technology, and robotics) has now been adopted as a strategic goal by several countries, most notably the United States and those of the European Union. The anticipated benefits and related fears of competitive disadvantage have brought together…

  10. World health inequality: convergence, divergence, and development.

    PubMed

    Clark, Rob

    2011-02-01

    Recent studies characterize the last half of the twentieth century as an era of cross-national health convergence, with some attributing welfare gains in the developing world to economic growth. In this study, I examine the extent to which welfare outcomes have actually converged and the extent to which economic development is responsible for the observed trends. Drawing from estimates covering 195 nations during the 1955-2005 period, I find that life expectancy averages converged during this time, but that infant mortality rates continuously diverged. I develop a narrative that implicates economic development in these contrasting trends, suggesting that health outcomes follow a "welfare Kuznets curve." Among poor countries, economic development improves life expectancy more than it reduces infant mortality, whereas the situation is reversed among wealthier nations. In this way, development has contributed to both convergence in life expectancy and divergence in infant mortality. Drawing from 674 observations across 163 countries during the 1980-2005 period, I find that the positive effect of GDP PC on life expectancy attenuates at higher levels of development, while the negative effect of GDP PC on infant mortality grows stronger. Copyright © 2010 Elsevier Ltd. All rights reserved.

  11. Convergence behavior of a new DSMC algorithm.

    SciTech Connect

    Gallis, Michail A.; Rader, Daniel John; Torczynski, John Robert; Bird, Graeme A.

    2008-10-01

    The convergence rate of a new direct simulation Monte Carlo (DSMC) method, termed 'sophisticated DSMC', is investigated for one-dimensional Fourier flow. An argon-like hard-sphere gas at 273.15K and 266.644Pa is confined between two parallel, fully accommodating walls 1mm apart that have unequal temperatures. The simulations are performed using a one-dimensional implementation of the sophisticated DSMC algorithm. In harmony with previous work, the primary convergence metric studied is the ratio of the DSMC-calculated thermal conductivity to its corresponding infinite-approximation Chapman-Enskog theoretical value. As discretization errors are reduced, the sophisticated DSMC algorithm is shown to approach the theoretical values to high precision. The convergence behavior of sophisticated DSMC is compared to that of original DSMC. The convergence of the new algorithm in a three-dimensional implementation is also characterized. Implementations using transient adaptive sub-cells and virtual sub-cells are compared. The new algorithm is shown to significantly reduce the computational resources required for a DSMC simulation to achieve a particular level of accuracy, thus improving the efficiency of the method by a factor of 2.

  12. Converging Oceaniac Internal Waves, Somalia, Africa

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The arculate fronts of these apparently converging internal waves off the northeast coast of Somalia (11.5N, 51.5E) probably were produced by interaction with two parallel submarine canyons off the Horn of Africa. Internal waves are packets of tidally generated waves traveling within the ocean at varying depths and are not detectable by any surface disturbance.

  13. Environmental professionals and the mass media

    SciTech Connect

    Schoenfeld, C.

    1983-01-01

    Environmental professionals frequently attempt to use the mass media as vehicles for public information and education campaigns; the mass media, on the other hand, frequently engage in ''the use of subject matter and literary treatment calculated to arouse excited interest and emotional response.'' It is not then surprising that environmental professionals and others have given the media mixed reviews in terms of media performance in constructing the environment as a social problem. Yet it is difficult to see how pervasive public pro-environmental reportage by the mass media. The continuing challenge to environmental professional-media relations is one of facilitating a sober consideration of ways that will help enhance environmental quality and energy conservation without jeopardizing other human needs. 61 references.

  14. Kids & Media @ the New Millennium: A Kaiser Family Foundation Report [with] Appendices. A Comprehensive National Analysis of Children's Media Use.

    ERIC Educational Resources Information Center

    Roberts, Donald F.

    This report presents details of a study which gathered information about all kinds of media behaviors from a nationally representative sample of American youth--the study asked: In this modern media environment, how much time do American children devote to each of the different media? According to the report. The data for the study came from two…

  15. Media advocacy: a strategy for empowering people and communities.

    PubMed

    Wallack, L

    1994-01-01

    Media advocacy is a new strategy that is emerging in the public health community. It has been particularly visible in communities of color. Media advocacy is defined as the strategic use of mass media to advance public policy initiatives. Media advocacy is rooted in community advocacy and has as its goal the promotion of healthy public policies. It can be differentiated from traditional mass media strategies in a number of ways. Media advocacy shifts the focus from the personal to the social, from the individual to the political, from the behavior or practice to the policy or environment. While traditional media approaches try to fill the "knowledge gap," media advocacy addresses the "power gap." Improvements in health status are believed to come about primarily from gaining more power over the policy environment rather than simply gaining more knowledge about health behaviors.

  16. NUMERICAL CONVERGENCE IN SMOOTHED PARTICLE HYDRODYNAMICS

    SciTech Connect

    Zhu, Qirong; Li, Yuexing; Hernquist, Lars

    2015-02-10

    We study the convergence properties of smoothed particle hydrodynamics (SPH) using numerical tests and simple analytic considerations. Our analysis shows that formal numerical convergence is possible in SPH only in the joint limit N → ∞, h → 0, and N{sub nb} → ∞, where N is the total number of particles, h is the smoothing length, and N{sub nb} is the number of neighbor particles within the smoothing volume used to compute smoothed estimates. Previous work has generally assumed that the conditions N → ∞ and h → 0 are sufficient to achieve convergence, while holding N{sub nb} fixed. We demonstrate that if N{sub nb} is held fixed as the resolution is increased, there will be a residual source of error that does not vanish as N → ∞ and h → 0. Formal numerical convergence in SPH is possible only if N{sub nb} is increased systematically as the resolution is improved. Using analytic arguments, we derive an optimal compromise scaling for N{sub nb} by requiring that this source of error balance that present in the smoothing procedure. For typical choices of the smoothing kernel, we find N{sub nb} ∝N {sup 0.5}. This means that if SPH is to be used as a numerically convergent method, the required computational cost does not scale with particle number as O(N), but rather as O(N {sup 1} {sup +} {sup δ}), where δ ≈ 0.5, with a weak dependence on the form of the smoothing kernel.

  17. Multidimensional Convergence in Future 5G Networks

    NASA Astrophysics Data System (ADS)

    Ruffini, Marco

    2017-02-01

    Future 5G services are characterised by unprecedented need for high rate, ubiquitous availability, ultra-low latency and high reliability. The fragmented network view that is widespread in current networks will not stand the challenge posed by next generations of users. A new vision is required, and this paper provides an insight on how network convergence and application-centric approaches will play a leading role towards enabling the 5G vision. The paper, after expressing the view on the need for an end-to-end approach to network design, brings the reader into a journey on the expected 5G network requirements and outlines some of the work currently carried out by main standardisation bodies. It then proposes the use of the concept of network convergence for providing the overall architectural framework to bring together all the different technologies within a unifying and coherent network ecosystem. The novel interpretation of multi-dimensional convergence we introduce leads us to the exploration of aspects of node consolidation and converged network architectures, delving into details of optical-wireless integration and future convergence of optical data centre and access-metro networks. We then discuss how ownership models enabling network sharing will be instrumental in realising the 5G vision. The paper concludes with final remarks on the role SDN will play in 5G and on the need for new business models that reflect the application-centric view of the network. Finally, we provide some insight on growing research areas in 5G networking.

  18. Convergent Evolution During Local Adaptation to Patchy Landscapes

    PubMed Central

    2015-01-01

    Species often encounter, and adapt to, many patches of similar environmental conditions across their range. Such adaptation can occur through convergent evolution if different alleles arise in different patches, or through the spread of shared alleles by migration acting to synchronize adaptation across the species. The tension between the two reflects the constraint imposed on evolution by the underlying genetic architecture versus how effectively selection and geographic isolation act to inhibit the geographic spread of locally adapted alleles. This paper studies the balance between these two routes to adaptation in a model of continuous environments with patchy selection pressures. We address the following questions: How long does it take for a novel allele to appear in a patch where it is locally adapted through mutation? Or, through migration from another, already adapted patch? Which is more likely to occur, as a function of distance between the patches? What population genetic signal is left by the spread of migrant alleles? To answer these questions we examine the family structure underlying migration–selection equilibrium surrounding an already adapted patch, treating those rare families that reach new patches as spatial branching processes. A main result is that patches further apart than a critical distance will likely evolve independent locally adapted alleles; this distance is proportional to the spatial scale of selection (σ/sm, where σ is the dispersal distance and s m is the selective disadvantage of these alleles between patches), and depends linearly on log(s m/μ), where μ is the mutation rate. This provides a way to understand the role of geographic separation between patches in promoting convergent adaptation and the genomic signals it leaves behind. We illustrate these ideas using the convergent evolution of cryptic coloration in the rock pocket mouse, Chaetodipus intermedius, as an empirical example. PMID:26571125

  19. Undesirable Effects of Media on Children: Why Limitation is Necessary?

    PubMed

    Karaagac, Aysu Turkmen

    2015-06-01

    Pervasive media environment is a social problem shared by most of the countries around the world. Several studies have been performed to highlight the undesired effects of media on children. Some of these studies have focused on the time spent by children watching television, playing with computers or using mobile media devices while some others have tried to explain the associations between the obesity, postural abnormalities or psychological problems of children, and their media use. This article discusses the recent approaches to curb influence of media on children, and the importance of family media literacy education programs with particular relevance to developing countries.

  20. Methane Production by Methanogens in Perchlorate-supplemented Media

    NASA Astrophysics Data System (ADS)

    Howe, K. L.; Gavin, P.; Goodhart, T.; Kral, T. A.

    2009-03-01

    Perchlorates, found on the martian surface, create a harsh environment. Methanogens are familiar with harsh environments and their growth was tested in perchlorate salt media. All four species of methanogens produced methane at all concentrations of each salt tested.

  1. A Social Media Practicum: An Action-Learning Approach to Social Media Marketing and Analytics

    ERIC Educational Resources Information Center

    Atwong, Catherine T.

    2015-01-01

    To prepare students for the rapidly evolving field of digital marketing, which requires more and more technical skills every year, a social media practicum creates a learning environment in which students can apply marketing principles and become ready for collaborative work in social media marketing and analytics. Using student newspapers as…

  2. A Social Media Practicum: An Action-Learning Approach to Social Media Marketing and Analytics

    ERIC Educational Resources Information Center

    Atwong, Catherine T.

    2015-01-01

    To prepare students for the rapidly evolving field of digital marketing, which requires more and more technical skills every year, a social media practicum creates a learning environment in which students can apply marketing principles and become ready for collaborative work in social media marketing and analytics. Using student newspapers as…

  3. Convergence, Consilience, and the Evolution of Temperate Deciduous Forests.

    PubMed

    Edwards, Erika J; Chatelet, David S; Chen, Bo-Chang; Ong, Jin Yao; Tagane, Shuichiro; Kanemitsu, Hironobu; Tagawa, Kazuki; Teramoto, Kentaro; Park, Brian; Chung, Kuo-Fang; Hu, Jer-Ming; Yahara, Tetsukazu; Donoghue, Michael J

    2017-08-01

    The deciduous habit of northern temperate trees and shrubs provides one of the most obvious examples of convergent evolution, but how did it evolve? Hypotheses based on the fossil record posit that deciduousness evolved first in response to drought or darkness and preadapted certain lineages as cold climates spread. An alternative is that evergreens first established in freezing environments and later evolved the deciduous habit. We monitored phenological patterns of 20 species of Viburnum spanning tropical, lucidophyllous (subtropical montane and warm temperate), and cool temperate Asian forests. In lucidophyllous forests, all viburnums were evergreen plants that exhibited coordinated leaf flushes with the onset of the rainy season but varied greatly in the timing of leaf senescence. In contrast, deciduous species exhibited tight coordination of both flushing and senescence, and we found a perfect correlation between the deciduous habit and prolonged annual freezing. In contrast to previous stepwise hypotheses, a consilience of independent lines of evidence supports a lockstep model in which deciduousness evolved in situ, in parallel, and concurrent with a gradual cooling climate. A pervasive selective force combined with the elevated evolutionary accessibility of a particular response may explain the massive convergence of adaptive strategies that characterizes the world's biomes.

  4. American Academy of Pediatrics. Media violence. Committee on Public Education.

    PubMed

    2001-11-01

    The American Academy of Pediatrics recognizes exposure to violence in media, including television, movies, music, and video games, as a significant risk to the health of children and adolescents. Extensive research evidence indicates that media violence can contribute to aggressive behavior, desensitization to violence, nightmares, and fear of being harmed. Pediatricians should assess their patients' level of media exposure and intervene on media-related health risks. Pediatricians and other child health care providers can advocate for a safer media environment for children by encouraging media literacy, more thoughtful and proactive use of media by children and their parents, more responsible portrayal of violence by media producers, and more useful and effective media ratings.

  5. On domains of convergence in optimization problems

    NASA Technical Reports Server (NTRS)

    Diaz, Alejandro R.; Shaw, Steven S.; Pan, Jian

    1990-01-01

    Numerical optimization algorithms require the knowledge of an initial set of design variables. Starting from an initial design x(sup 0), improved solutions are obtained by updating the design iteratively in a way prescribed by the particular algorithm used. If the algorithm is successful, convergence is achieved to a local optimal solution. Let A denote the iterative procedure that characterizes a typical optimization algorithm, applied to the problem: Find x belonging to R(sup n) that maximizes f(x) subject to x belonging to Omega contained in R(sup n). We are interested in problems with several local maxima (x(sub j))(sup *), j=1, ..., m, in the feasible design space Omega. In general, convergence of the algorithm A to a specific solution (x(sub j))(sup *) is determined by the choice of initial design x(sup 0). The domain of convergence D(sub j) of A associated with a local maximum (x(sub j))(sup *) is a subset of initial designs x(sup 0) in Omega such that the sequence (x(sup k)), k=0,1,2,... defined by x(sup k+1) = A(x(sup k)), k=0,1,... converges to (x(sub j))(sup *). The set D(sub j) is also called the basin of attraction of (x(sub j))(sup *). Cayley first proposed the problem of finding the basin of attraction for Newton's method in 1897. It has been shown that the basin of attraction for Newton's method exhibits chaotic behavior in problems with polynomial objective. This implies that there may be regions in the feasible design space where arbitrarily close starting points will converge to different local optimal solutions. Furthermore, the boundaries of the domains of convergence may have a very complex, even fractal structure. In this paper we show that even simple structural optimization problems solved using standard gradient based (first order) algorithms exhibit similar features.

  6. Convergence characteristics of the multiple input, multiple output LMS algorithm

    NASA Technical Reports Server (NTRS)

    Snyder, Scott D.; Hansen, Colin H.; Clark, Robert L.

    1992-01-01

    The convergence characteristics of the multiple input, multiple output LMS algorithm, as applied to active noise and vibration control systems, are examined. The mean square error during the convergence process, as well as the final converged value, are examined analytically and in computer simulation. It is shown that the ratio of number of error sensors to number of control sources has a significant influence upon both the converging and converged value of the mean square error. Other active control system variables, such as the inherent time delays and structural/acoustic transfer functions, are also shown to have a significant influence upon the convergence process.

  7. Convergence characteristics of the multiple input, multiple output LMS algorithm

    NASA Technical Reports Server (NTRS)

    Snyder, Scott D.; Hansen, Colin H.; Clark, Robert L.

    1992-01-01

    The convergence characteristics of the multiple input, multiple output LMS algorithm, as applied to active noise and vibration control systems, are examined. The mean square error during the convergence process, as well as the final converged value, are examined analytically and in computer simulation. It is shown that the ratio of number of error sensors to number of control sources has a significant influence upon both the converging and converged value of the mean square error. Other active control system variables, such as the inherent time delays and structural/acoustic transfer functions, are also shown to have a significant influence upon the convergence process.

  8. METAL MEDIA FILTERS, AG-1 SECTION FI

    SciTech Connect

    Adamson, D.

    2012-05-23

    One application of metal media filters is in various nuclear air cleaning processes including applications for protecting workers, the public and the environment from hazardous and radioactive particles. To support this application the development of the ASME AG-1 FI Standard on Metal Media has been under way for more than ten years. Development of the proposed section has required resolving several difficult issues associated with operating conditions (media velocity, pressure drop, etc.), qualification testing, and quality acceptance testing. Performance characteristics of metal media are dramatically different than the glass fiber media with respect to parameters like differential pressures, operating temperatures, media strength, etc. These differences make existing data for a glass fiber media inadequate for qualifying a metal media filter for AG-1. In the past much work has been conducted on metal media filters at facilities such as Lawrence Livermore National Laboratory (LLNL) and Savannah River National Laboratory (SRNL) to qualify the media as High Efficiency Particulate Air (HEPA) Filters. Particle retention testing has been conducted at Oak Ridge Filter Test Facility and at Air Techniques International (ATI) to prove that the metal media meets or exceeds the 99.97% particle retention required for a HEPA Filter. Even with his testing, data was lacking to complete an AG-1 FI Standard on metal media. With funding secured by Mississippi State University (MSU) from National Nuclear Security Administration (NNSA), a research test stand is being designed and fabricated at MSU's Institute for Clean Energy Technology (ICET) Facility to obtain qualification data on metal media. This in turn will support required data needed for the FI Standard. The paper will discuss in detail how the test stand at MSU will obtain the necessary data to complete the FI Standard.

  9. A Waterfall Design Strategy for Using Social Media for Instruction

    ERIC Educational Resources Information Center

    Ahern, Terence C.

    2016-01-01

    Using social media can create a rich learning environment that crosses all content areas. The key to creating this environment is for instructors and designers to match appropriate social media software with the intended learning outcome. This article describes an instructional design strategy that helps educators create learning activities that…

  10. A Waterfall Design Strategy for Using Social Media for Instruction

    ERIC Educational Resources Information Center

    Ahern, Terence C.

    2016-01-01

    Using social media can create a rich learning environment that crosses all content areas. The key to creating this environment is for instructors and designers to match appropriate social media software with the intended learning outcome. This article describes an instructional design strategy that helps educators create learning activities that…

  11. Requirements for Instrument Approaches to Converging Runways,

    DTIC Science & Technology

    1981-09-01

    PERSPECTIVE 2-1 2.1 Definition 2-1 2.2 Types of Converging Runways 2-1 2.2.1 Intersecting Approach Streams 2-3 2.2.2 Intersecting Runways 2-3 2.2.3...Therefore, a methodology to define and characterize ’e converging approaches is presented in this chapter. 2.1 Definition If two runways are not parallel...c nter of ARC, the positive X-direction is paralel to IA, and the positive Y-direction is parallel to TC,i C-1 *z / ,i// \\2D 2B0 C-2 FIUE w 4Z a!w wV

  12. Stability of spherical converging shock wave

    SciTech Connect

    Murakami, M.; Sanz, J.; Iwamoto, Y.

    2015-07-15

    Based on Guderley's self-similar solution, stability of spherical converging shock wave is studied. A rigorous linear perturbation theory is developed, in which the growth rate of perturbation is given as a function of the spherical harmonic number ℓ and the specific heats ratio γ. Numerical calculation reveals the existence of a γ-dependent cut-off mode number ℓ{sub c}, such that all the eigenmode perturbations for ℓ > ℓ{sub c} are smeared out as the shock wave converges at the center. The analysis is applied to partially spherical geometries to give significant implication for different ignition schemes of inertial confinement fusion. Two-dimensional hydrodynamic simulations are performed to verify the theory.

  13. The genetic causes of convergent evolution.

    PubMed

    Stern, David L

    2013-11-01

    The evolution of phenotypic similarities between species, known as convergence, illustrates that populations can respond predictably to ecological challenges. Convergence often results from similar genetic changes, which can emerge in two ways: the evolution of similar or identical mutations in independent lineages, which is termed parallel evolution; and the evolution in independent lineages of alleles that are shared among populations, which I call collateral genetic evolution. Evidence for parallel and collateral evolution has been found in many taxa, and an emerging hypothesis is that they result from the fact that mutations in some genetic targets minimize pleiotropic effects while simultaneously maximizing adaptation. If this proves correct, then the molecular changes underlying adaptation might be more predictable than has been appreciated previously.

  14. Antibiotics From Microbes: Converging To Kill

    PubMed Central

    Fischbach, Michael A.

    2011-01-01

    Summary As genetically encoded small molecules, antibiotics are phenotypes that have resulted from mutation and natural selection. Advances in genetics, biochemistry, and bioinformatics have connected hundreds of antibiotics to the gene clusters that encode them, allowing these molecules to be analyzed using the tools of evolutionary biology. This review surveys examples of convergent evolution from microbially produced antibiotics, including the convergence of distinct gene clusters on similar phenotypes and the merger of distinct gene clusters into a single functional unit. Examining antibiotics through an evolutionary lens highlights the versatility of biosynthetic pathways, reveals lessons for combating antibiotic resistance, and provides an entry point for studying the natural roles of these natural products. PMID:19695947

  15. A Numerical, Literal, and Converged Perturbation Algorithm

    NASA Astrophysics Data System (ADS)

    Wiesel, William E.

    2017-09-01

    The KAM theorem and von Ziepel's method are applied to a perturbed harmonic oscillator, and it is noted that the KAM methodology does not allow for necessary frequency or angle corrections, while von Ziepel does. The KAM methodology can be carried out with purely numerical methods, since its generating function does not contain momentum dependence. The KAM iteration is extended to allow for frequency and angle changes, and in the process apparently can be successfully applied to degenerate systems normally ruled out by the classical KAM theorem. Convergence is observed to be geometric, not exponential, but it does proceed smoothly to machine precision. The algorithm produces a converged perturbation solution by numerical methods, while still retaining literal variable dependence, at least in the vicinity of a given trajectory.

  16. Non-surgical interventions for convergence insufficiency

    PubMed Central

    Scheiman, Mitchell; Gwiazda, Jane; Li, Tianjing

    2014-01-01

    Background Convergence insufficiency is a common eye muscle co-ordination problem in which the eyes have a strong tendency to drift outward (exophoria) when reading or doing close work. Symptoms may include eye strain, headaches, double vision, print moving on the page, frequent loss of place when reading, inability to concentrate, and short attention span. Objectives To systematically assess and synthesize evidence from randomized controlled trials (RCTs) on the effectiveness of non-surgical interventions for convergence insufficiency. Search strategy We searched The Cochrane Library, MEDLINE, EMBASE, Science Citation Index, the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov (www.clinicaltrials.gov) on 7 October 2010. We manually searched reference lists and optometric journals. Selection criteria We included RCTs examining any form of non-surgical intervention against placebo, no treatment, sham treatment, or each other. Data collection and analysis Two authors independently assessed eligibility, risk of bias, and extracted data. We performed meta-analyses when appropriate. Main results We included six trials (three in children, three in adults) with a total of 475 participants. We graded four trials at low risk of bias. Evidence from one trial (graded at low risk of bias) suggests that base-in prism reading glasses was no more effective than placebo reading glasses in improving clinical signs or symptoms in children. Evidence from one trial (graded at high risk of bias) suggests that base-in prism glasses using a progressive addition lens design was more effective than progressive addition lens alone in decreasing symptoms in adults. At three weeks of therapy, the mean difference in Convergence Insufficiency Symptoms Survey (CISS) score was −10.24 points (95% confidence interval (CI) −15.45 to −5.03). Evidence from two trials (graded at low risk of bias) suggests that outpatient (or office-based as used in the

  17. [Orthoptic treatment efficiency in convergence insufficiency treatment].

    PubMed

    Dragomir, M; Truş, L; Chirilă, D; Stîngu, C

    2001-01-01

    We studied a group of 162 patients(89 females, 73 males), with ages between 15-30 years, who complained of blurred vision at near work. 98 patients(60.4%) were diagnosed with convergence insufficiency (C.I.), the rest of 64 patients(39.6%) had: low refractive errors, heterophoria and intermittent heterotropia. Patients with convergence insufficiency were divided in 3 groups: group 1(34 patients--34.6%) were treated with orthoptic exercises and near point exercises at home, group 2 (34 patients--34.6%) were treated with only near point exercises at home and control group 3 (30 patients--30.8%) without treatment. The result of the treatment of C.I. was good at 25 patients(73.5%) of group 1, at 8 patients(23.5%) of group 2 while in group 3 at only one patient the symptoms disappeared.

  18. On the convergence of validity interval analysis.

    PubMed

    Maire, F

    2000-01-01

    Validity interval analysis (VIA) is a generic tool for analyzing the input-output behavior of feedforward neural networks. VIA is a rule extraction technique that relies on a rule refinement algorithm. The rules are of the form R(i)-->R(0) which reads if the input of the neural network is in the region R(i), then its output is in the region R(0), where regions are axis parallel hypercubes. VIA conjectures, then refines and checks rules for inconsistency. This process can be computationally expensive, and the rule refinement phase becomes critical. Hence, the importance of knowing the complexity of these rule refinement algorithms. In this paper, we show that the rule refinement part of VIA always converges in one run for single-weight-layer networks, and has an exponential average rate of convergence for multilayer networks. We also discuss some variations of the standard VIA formulae.

  19. Broadband converging plano-concave lens.

    PubMed

    Yang, Rui; Lei, Zhenya; Chen, Lei; Zhang, Jiawei; Wang, Zhaoxu; Xie, Yongjun

    2013-07-01

    A plano-concave lens with source-tailored geometric profile and transformational gradient index is proposed for broadband illumination. Such a design, capable of focusing and collimating the electromagnetic fields, fulfils the functionality of a converging lens and can also achieve a steerable beam and multiple beams efficiently. Nonresonant synthesis with a perforated dielectric plate and dielectric rod arrays is demonstrated for the lensing realization, promising a wide operating frequency band in the practical implementation.

  20. Convergent designs for electrogenesis and electroreception.

    PubMed

    Hopkins, C D

    1995-12-01

    New- and old-world tropical electric fish lack a common electrical ancestor, suggesting that the mechanisms of signal generation and recognition evolved independently in the two groups. Recent research on convergent designs for electrogenesis and electroreception has focused on the structure of electric organs, the neural circuitry controlling the pacemaker driving the electric organ, and the neural circuitry underlying time coding of electric waveforms.