Discovery of the largest orbweaving spider species: the evolution of gigantism in Nephila.

PubMed

Kuntner, Matjaz; Coddington, Jonathan A

2009-10-21

More than 41,000 spider species are known with about 400-500 added each year, but for some well-known groups, such as the giant golden orbweavers, Nephila, the last valid described species dates from the 19(th) century. Nephila are renowned for being the largest web-spinning spiders, making the largest orb webs, and are model organisms for the study of extreme sexual size dimorphism (SSD) and sexual biology. Here, we report on the discovery of a new, giant Nephila species from Africa and Madagascar, and review size evolution and SSD in Nephilidae. We formally describe N. komaci sp. nov., the largest web spinning species known, and place the species in phylogenetic context to reconstruct the evolution of mean size (via squared change parsimony). We then test female and male mean size correlation using phylogenetically independent contrasts, and simulate nephilid body size evolution using Monte Carlo statistics. Nephila females increased in size almost monotonically to establish a mostly African clade of true giants. In contrast, Nephila male size is effectively decoupled and hovers around values roughly one fifth of female size. Although N. komaci females are the largest Nephila yet discovered, the males are also large and thus their SSD is not exceptional.

Growth and structure of the World Wide Web: Towards realistic modeling

NASA Astrophysics Data System (ADS)

Tadić, Bosiljka

2002-08-01

We simulate evolution of the World Wide Web from the dynamic rules incorporating growth, bias attachment, and rewiring. We show that the emergent double-hierarchical structure with distinct distributions of out- and in-links is comparable with the observed empirical data when the control parameter (average graph flexibility β) is kept in the range β=3-4. We then explore the Web graph by simulating (a) Web crawling to determine size and depth of connected components, and (b) a random walker that discovers the structure of connected subgraphs with dominant attractor and promoter nodes. A random walker that adapts its move strategy to mimic local node linking preferences is shown to have a short access time to "important" nodes on the Web graph.

CF Metadata Conventions: Founding Principles, Governance, and Future Directions

NASA Astrophysics Data System (ADS)

Taylor, K. E.

2016-12-01

The CF Metadata Conventions define attributes that promote sharing of climate and forecasting data and facilitate automated processing by computers. The development, maintenance, and evolution of the conventions have mainly been provided by voluntary community contributions. Nevertheless, an organizational framework has been established, which relies on established rules and web-based discussion to ensure smooth (but relatively efficient) evolution of the standard to accommodate new types of data. The CF standard has been essential to the success of high-profile internationally-coordinated modeling activities (e.g, the Coupled Model Intercomparison Project). A summary of CF's founding principles and the prospects for its future evolution will be discussed.

Emergence of evolutionary cycles in size-structured food webs.

PubMed

Ritterskamp, Daniel; Bearup, Daniel; Blasius, Bernd

2016-11-07

The interplay of population dynamics and evolution within ecological communities has been of long-standing interest for ecologists and can give rise to evolutionary cycles, e.g. taxon cycles. Evolutionary cycling was intensely studied in small communities with asymmetric competition; the latter drives the evolutionary processes. Here we demonstrate that evolutionary cycling arises naturally in larger communities if trophic interactions are present, since these are intrinsically asymmetric. To investigate the evolutionary dynamics of a trophic community, we use an allometric food web model. We find that evolutionary cycles emerge naturally for a large parameter ranges. The origin of the evolutionary dynamics is an intrinsic asymmetry in the feeding kernel which creates an evolutionary ratchet, driving species towards larger bodysize. We reveal different kinds of cycles: single morph cycles, and coevolutionary and mixed cycling of complete food webs. The latter refers to the case where each trophic level can have different evolutionary dynamics. We discuss the generality of our findings and conclude that ongoing evolution in food webs may be more frequent than commonly believed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sensor Web Dynamic Measurement Techniques and Adaptive Observing Strategies

NASA Technical Reports Server (NTRS)

Talabac, Stephen J.

2004-01-01

Sensor Web observing systems may have the potential to significantly improve our ability to monitor, understand, and predict the evolution of rapidly evolving, transient, or variable environmental features and events. This improvement will come about by integrating novel data collection techniques, new or improved instruments, emerging communications technologies and protocols, sensor mark-up languages, and interoperable planning and scheduling systems. In contrast to today's observing systems, "event-driven" sensor webs will synthesize real- or near-real time measurements and information from other platforms and then react by reconfiguring the platforms and instruments to invoke new measurement modes and adaptive observation strategies. Similarly, "model-driven" sensor webs will utilize environmental prediction models to initiate targeted sensor measurements or to use a new observing strategy. The sensor web concept contrasts with today's data collection techniques and observing system operations concepts where independent measurements are made by remote sensing and in situ platforms that do not share, and therefore cannot act upon, potentially useful complementary sensor measurement data and platform state information. This presentation describes NASA's view of event-driven and model-driven Sensor Webs and highlights several research and development activities at the Goddard Space Flight Center.

Evidence for fast dynamo action in a chaotic web

NASA Technical Reports Server (NTRS)

Gilbert, A. D.; Childress, S.

1990-01-01

The evolution of a magnetic field in a chaotic web is studied. The model flow possessing the web is closely related to the nearly integrable ABC flow with A = B and C much less than 1. The magnetic diffusivity is taken to be zero and the field is followed using the Cauchy solution. It is found that the flow folds the magnetic field constructively, in the sense that the average magnetic field in a chaotic region grows exponentially in time. This is suggestive of fast dynamo action, although the effect of diffusion of the strong streamwise magnetic field remains to be assessed.

The role of capture spiral silk properties in the diversification of orb webs.

PubMed

Tarakanova, Anna; Buehler, Markus J

2012-12-07

Among a myriad of spider web geometries, the orb web presents a fascinating, exquisite example in architecture and evolution. Orb webs can be divided into two categories according to the capture silk used in construction: cribellate orb webs (composed of pseudoflagelliform silk) coated with dry cribellate threads and ecribellate orb webs (composed of flagelliform silk fibres) coated by adhesive glue droplets. Cribellate capture silk is generally stronger but less-extensible than viscid capture silk, and a body of phylogenic evidence suggests that cribellate capture silk is more closely related to the ancestral form of capture spiral silk. Here, we use a coarse-grained web model to investigate how the mechanical properties of spiral capture silk affect the behaviour of the whole web, illustrating that more elastic capture spiral silk yields a decrease in web system energy absorption, suggesting that the function of the capture spiral shifted from prey capture to other structural roles. Additionally, we observe that in webs with more extensible capture silk, the effect of thread strength on web performance is reduced, indicating that thread elasticity is a dominant driving factor in web diversification.

Transformation through Expeditionary Change Using Online Learning and Competence-Building Technologies

ERIC Educational Resources Information Center

Norris, Donald M.; Lefrere, Paul

2011-01-01

This paper presents a patterns-based model of the evolution of learning and competence-building technologies, grounded in examples of current practice. The model imagines five simple stages in how institutions use "expeditionary change" to innovate more nimbly. It builds upon three assertions. First, the pervasiveness of web-based…

Consistent Evolution of Software Artifacts and Non-Functional Models

DTIC Science & Technology

2014-11-14

induce bad software performance)? 15. SUBJECT TERMS EOARD, Nano particles, Photo-Acoustic Sensors, Model-Driven Engineering ( MDE ), Software Performance...Università degli Studi dell’Aquila, Via Vetoio, 67100 L’Aquila, Italy Email: vittorio.cortellessa@univaq.it Web : http: // www. di. univaq. it/ cortelle/ Phone...Model-Driven Engineering ( MDE ), Software Performance Engineering (SPE), Change Propagation, Performance Antipatterns. For sake of readability of the

Computation of direct and inverse mutations with the SEGM web server (Stochastic Evolution of Genetic Motifs): an application to splice sites of human genome introns.

PubMed

Benard, Emmanuel; Michel, Christian J

2009-08-01

We present here the SEGM web server (Stochastic Evolution of Genetic Motifs) in order to study the evolution of genetic motifs both in the direct evolutionary sense (past-present) and in the inverse evolutionary sense (present-past). The genetic motifs studied can be nucleotides, dinucleotides and trinucleotides. As an example of an application of SEGM and to understand its functionalities, we give an analysis of inverse mutations of splice sites of human genome introns. SEGM is freely accessible at http://lsiit-bioinfo.u-strasbg.fr:8080/webMathematica/SEGM/SEGM.html directly or by the web site http://dpt-info.u-strasbg.fr/~michel/. To our knowledge, this SEGM web server is to date the only computational biology software in this evolutionary approach.

Technology Review of Multi-Agent Systems and Tools

DTIC Science & Technology

2005-06-01

over a network, including the Internet. A web services architecture is the logical evolution of object-oriented analysis and design coupled with...the logical evolution of components geared towards the architecture, design, implementation, and deployment of e-business solutions. As in object...querying. The Web Services architecture describes the principles behind the next generation of e- business architectures, presenting a logical evolution

The role of capture spiral silk properties in the diversification of orb webs

PubMed Central

Tarakanova, Anna; Buehler, Markus J.

2012-01-01

Among a myriad of spider web geometries, the orb web presents a fascinating, exquisite example in architecture and evolution. Orb webs can be divided into two categories according to the capture silk used in construction: cribellate orb webs (composed of pseudoflagelliform silk) coated with dry cribellate threads and ecribellate orb webs (composed of flagelliform silk fibres) coated by adhesive glue droplets. Cribellate capture silk is generally stronger but less-extensible than viscid capture silk, and a body of phylogenic evidence suggests that cribellate capture silk is more closely related to the ancestral form of capture spiral silk. Here, we use a coarse-grained web model to investigate how the mechanical properties of spiral capture silk affect the behaviour of the whole web, illustrating that more elastic capture spiral silk yields a decrease in web system energy absorption, suggesting that the function of the capture spiral shifted from prey capture to other structural roles. Additionally, we observe that in webs with more extensible capture silk, the effect of thread strength on web performance is reduced, indicating that thread elasticity is a dominant driving factor in web diversification. PMID:22896566

Studying the co-evolution of protein families with the Mirrortree web server.

PubMed

Ochoa, David; Pazos, Florencio

2010-05-15

The Mirrortree server allows to graphically and interactively study the co-evolution of two protein families, and investigate their possible interactions and functional relationships in a taxonomic context. The server includes the possibility of starting from single sequences and hence it can be used by non-expert users. The web server is freely available at http://csbg.cnb.csic.es/mtserver. It was tested in the main web browsers. Adobe Flash Player is required at the client side to perform the interactive assessment of co-evolution. pazos@cnb.csic.es Supplementary data are available at Bioinformatics online.

Distinct spinning patterns gain differentiated loading tolerance of silk thread anchorages in spiders with different ecology.

PubMed

Wolff, Jonas O; van der Meijden, Arie; Herberstein, Marie E

2017-07-26

Building behaviour in animals extends biological functions beyond bodies. Many studies have emphasized the role of behavioural programmes, physiology and extrinsic factors for the structure and function of buildings. Structure attachments associated with animal constructions offer yet unrealized research opportunities. Spiders build a variety of one- to three-dimensional structures from silk fibres. The evolution of economic web shapes as a key for ecological success in spiders has been related to the emergence of high performance silks and thread coating glues. However, the role of thread anchorages has been widely neglected in those models. Here, we show that orb-web (Araneidae) and hunting spiders (Sparassidae) use different silk application patterns that determine the structure and robustness of the joint in silk thread anchorages. Silk anchorages of orb-web spiders show a greater robustness against different loading situations, whereas the silk anchorages of hunting spiders have their highest pull-off resistance when loaded parallel to the substrate along the direction of dragline spinning. This suggests that the behavioural 'printing' of silk into attachment discs along with spinneret morphology was a prerequisite for the evolution of extended silk use in a three-dimensional space. This highlights the ecological role of attachments in the evolution of animal architectures. © 2017 The Author(s).

New Perspectives: Wave Mechanical Interpretations of Dark Matter, Baryon and Dark Energy

NASA Astrophysics Data System (ADS)

Russell, Esra

We model the cosmic components: dark matter, dark energy and baryon distributions in the Cosmic Web by means of highly nonlinear Schrodinger type and reaction diffusion type wave mechanical descriptions. The construction of these wave mechanical models of the structure formation is achieved by introducing the Fisher information measure and its comparison with highly nonlinear term which has dynamical analogy to infamous quantum potential in the wave equations. Strikingly, the comparison of this nonlinear term and the Fisher information measure provides a dynamical distinction between lack of self-organization and self-organization in the dynamical evolution of the cosmic components. Mathematically equivalent to the standard cosmic fluid equations, these approaches make it possible to follow the evolution of the matter distribution even into the highly nonlinear regime by circumventing singularities. Also, numerical realizations of the emerging web-like patterns are presented from the nonlinear dynamics of the baryon component while dark energy component shows Gaussian type dynamics corresponding to soliton-like solutions.

Evolving EO-1 Sensor Web Testbed Capabilities in Pursuit of GEOSS

NASA Technical Reports Server (NTRS)

Mandi, Dan; Ly, Vuong; Frye, Stuart; Younis, Mohamed

2006-01-01

A viewgraph presentation to evolve sensor web capabilities in pursuit of capabilities to support Global Earth Observing System of Systems (GEOSS) is shown. The topics include: 1) Vision to Enable Sensor Webs with "Hot Spots"; 2) Vision Extended for Communication/Control Architecture for Missions to Mars; 3) Key Capabilities Implemented to Enable EO-1 Sensor Webs; 4) One of Three Experiments Conducted by UMBC Undergraduate Class 12-14-05 (1 - 3); 5) Closer Look at our Mini-Rovers and Simulated Mars Landscae at GSFC; 6) Beginning to Implement Experiments with Standards-Vision for Integrated Sensor Web Environment; 7) Goddard Mission Services Evolution Center (GMSEC); 8) GMSEC Component Catalog; 9) Core Flight System (CFS) and Extension for GMSEC for Flight SW; 10) Sensor Modeling Language; 11) Seamless Ground to Space Integrated Message Bus Demonstration (completed December 2005); 12) Other Experiments in Queue; 13) Acknowledgements; and 14) References.

Voids and the Cosmic Web: cosmic depression & spatial complexity

NASA Astrophysics Data System (ADS)

van de Weygaert, Rien

2016-10-01

Voids form a prominent aspect of the Megaparsec distribution of galaxies and matter. Not only do theyrepresent a key constituent of the Cosmic Web, they also are one of the cleanest probesand measures of global cosmological parameters. The shape and evolution of voids are highly sensitive tothe nature of dark energy, while their substructure and galaxy population provides a direct key to thenature of dark matter. Also, the pristine environment of void interiors is an important testing groundfor our understanding of environmental influences on galaxy formation and evolution. In this paper, we reviewthe key aspects of the structure and dynamics ofvoids, with a particular focus on the hierarchical evolution of the void population. We demonstratehow the rich structural pattern of the Cosmic Web is related to the complex evolution and buildupof voids.

Food web structure and the evolution of ecological communities

NASA Astrophysics Data System (ADS)

Quince, Christopher; Higgs, Paul G.; McKane, Alan J.

Simulations of the coevolution of many interacting species are performed using the Webworld model. The model has a realistic set of predator-prey equations that describe the population dynamics of the species for any structure of the food web. The equations account for competition between species for the same resources, and for the diet choice of predators between alternative prey according to an evolutionarily stable strategy. The set of species present undergoes long-term evolution d ue to speciation and extinction events. We summarize results obtained on the macro-evolutionary dynamics of speciations and extinctions, and on the statistical properties of the food webs that are generated by the model. Simulations begin from small numbers of species and build up to larger webs with relatively constant species number on average. The rate of origination and extinction of species are relatively high, but remain roughly balanced throughout the simulations. When a 'parent' species undergoes sp eciation, the 'child' species usually adds to the same trophic level as the parent. The chance of the child species surviving is significantly higher if the parent is on the second or third trophic level than if it is on the first level, most likely due to a wider choice of possible prey for species on higher levels. Addition of a new species sometimes causes extinction of existing species. The parent species has a high probability of extinction because it has strong competition with the new species. Non-pa rental competitors of the new species also have a significantly higher extinction probability than average, as do prey of the new species. Predators of the new species are less likely than average to become extinct.

The Evolution of Web Searching.

ERIC Educational Resources Information Center

Green, David

2000-01-01

Explores the interrelation between Web publishing and information retrieval technologies and lists new approaches to Web indexing and searching. Highlights include Web directories; search engines; portalisation; Internet service providers; browser providers; meta search engines; popularity based analysis; natural language searching; links-based…

WWW.cell Biology Education: Evolution Web Sites

ERIC Educational Resources Information Center

Liu, Dennis

2005-01-01

The debate over teaching evolution has once again reached a fever pitch in the United States. Earnest nineteenth-century clashes between scientific and religious worldviews have given way to the politically charged arguments of creation science and now intelligent design. The Web site of the National Center for Science Education (NCSE;…

The Convergent Evolution of a Chemistry Project: Using Laboratory Posters as a Platform for Web Page Construction.

ERIC Educational Resources Information Center

Rigeman, Sally

1998-01-01

Argues that evolution is a process that occurs within the curriculum as well as within the physical universe. Provides an example that involves student presentations. Discusses the transition from poster presentations to electronic presentations via the World Wide Web. (DDR)

Development of a Web-Based Periscope Simulator for Submarine Officer Training

DTIC Science & Technology

2014-09-01

31 2. The Evolution of Web-Based technology .........................................32...DEVELOPMENT ............................................................................65 A. TECHNOLOGY ...the possibility to deliver 3D simulations using the web browsers and web technology . The objective is to create an effective and efficient WBLE that

When parasites become prey: ecological and epidemiological significance of eating parasites

USGS Publications Warehouse

Johnson, Pieter T.J.; Dobson, Andrew P.; Lafferty, Kevin D.; Marcogliese, David J.; Memmott, Jane; Orlofske, Sarah A.; Poulin, Robert; Thieltges, David W.

2010-01-01

Recent efforts to include parasites in food webs have drawn attention to a previously ignored facet of foraging ecology: parasites commonly function as prey within ecosystems. Because of the high productivity of parasites, their unique nutritional composition and their pathogenicity in hosts, their consumption affects both food-web topology and disease risk in humans and wildlife. Here, we evaluate the ecological, evolutionary and epidemiological significance of feeding on parasites, including concomitant predation, grooming, predation on free-living stages and intraguild predation. Combining empirical data and theoretical models, we show that consumption of parasites is neither rare nor accidental, and that it can sharply affect parasite transmission and food web properties. Broader consideration of predation on parasites will enhance our understanding of disease control, food web structure and energy transfer, and the evolution of complex life cycles.

Lyα-emitting galaxies as a probe of reionization: large-scale bubble morphology and small-scale absorbers

NASA Astrophysics Data System (ADS)

Kakiichi, Koki; Dijkstra, Mark; Ciardi, Benedetta; Graziani, Luca

2016-12-01

The visibility of Lyα-emitting galaxies during the Epoch of Reionization is controlled by both diffuse H I patches in large-scale bubble morphology and small-scale absorbers. To investigate their impacts on Lyα transfer, we apply a novel combination of analytic modelling and cosmological hydrodynamical, radiative transfer simulations to three reionization models: (I) the `bubble' model, where only diffuse H I outside ionized bubbles is present; (II) the `web' model, where H I exists only in overdense self-shielded gas; and (III) the hybrid `web-bubble' model. The three models can explain the observed Lyα luminosity function equally well, but with very different H I fractions. This confirms a degeneracy between the ionization topology of the intergalactic medium (IGM) and the H I fraction inferred from Lyα surveys. We highlight the importance of the clustering of small-scale absorbers around galaxies. A combined analysis of the Lyα luminosity function and the Lyα fraction can break this degeneracy and provide constraints on the reionization history and its topology. Constraints can be improved by analysing the full MUV-dependent redshift evolution of the Lyα fraction of Lyman break galaxies. We find that the IGM-transmission probability distribution function is unimodal for bubble models and bimodal in web models. Comparing our models to observations, we infer that the neutral fraction at z ˜ 7 is likely to be of the order of tens of per cent when interpreted with bubble or web-bubble models, with a conservative lower limit ˜1 per cent when interpreted with web models.

Genome-wide analysis of signatures of selection in populations of African honey bees (Apis mellifera) using new web-based tools.

PubMed

Fuller, Zachary L; Niño, Elina L; Patch, Harland M; Bedoya-Reina, Oscar C; Baumgarten, Tracey; Muli, Elliud; Mumoki, Fiona; Ratan, Aakrosh; McGraw, John; Frazier, Maryann; Masiga, Daniel; Schuster, Stephen; Grozinger, Christina M; Miller, Webb

2015-07-10

With the development of inexpensive, high-throughput sequencing technologies, it has become feasible to examine questions related to population genetics and molecular evolution of non-model species in their ecological contexts on a genome-wide scale. Here, we employed a newly developed suite of integrated, web-based programs to examine population dynamics and signatures of selection across the genome using several well-established tests, including F ST, pN/pS, and McDonald-Kreitman. We applied these techniques to study populations of honey bees (Apis mellifera) in East Africa. In Kenya, there are several described A. mellifera subspecies, which are thought to be localized to distinct ecological regions. We performed whole genome sequencing of 11 worker honey bees from apiaries distributed throughout Kenya and identified 3.6 million putative single-nucleotide polymorphisms. The dense coverage allowed us to apply several computational procedures to study population structure and the evolutionary relationships among the populations, and to detect signs of adaptive evolution across the genome. While there is considerable gene flow among the sampled populations, there are clear distinctions between populations from the northern desert region and those from the temperate, savannah region. We identified several genes showing population genetic patterns consistent with positive selection within African bee populations, and between these populations and European A. mellifera or Asian Apis florea. These results lay the groundwork for future studies of adaptive ecological evolution in honey bees, and demonstrate the use of new, freely available web-based tools and workflows ( http://usegalaxy.org/r/kenyanbee ) that can be applied to any model system with genomic information.

The Effectiveness of an Online Curriculum on High School Students' Understanding of Biological Evolution

NASA Astrophysics Data System (ADS)

Marsteller, Robert B.; Bodzin, Alec M.

2015-12-01

An online curriculum about biological evolution was designed to promote increased student content knowledge and evidentiary reasoning. A feasibility study was conducted with 77 rural high school biology students who learned with the online biological evolution unit. Data sources included the Biological Evolution Assessment Measure (BEAM), an analysis of discussion forum posts, and a post-implementation perceptions and attitudes questionnaire. BEAM posttest scores were significantly higher than the pretest scores. However, the findings revealed that the students required additional support to develop evidentiary reasoning. Many students perceived that the Web-based curriculum would have been enhanced by increased immediate interaction and feedback. Students required greater scaffolding to support complex, process-oriented tasks. Implications for designing Web-based science instruction with curriculum materials to support students' acquisition of content knowledge and science process skills in a Web-based setting are discussed.

Autonomy and Sensor Webs: The Evolution of Mission Operations

NASA Technical Reports Server (NTRS)

Sherwood, Rob

2008-01-01

Demonstration of these sensor web capabilities will enable fast responding science campaigns that combine spaceborne, airborne, and ground assets. Sensor webs will also require new operations paradigms. These sensor webs will be operated directly by scientists using science goals to control their instruments. We will explore these new operations architectures through a study of existing sensor web prototypes.

Theory of invasion extinction dynamics in minimal food webs

NASA Astrophysics Data System (ADS)

Haerter, Jan O.; Mitarai, Namiko; Sneppen, Kim

2018-02-01

When food webs are exposed to species invasion, secondary extinction cascades may be set off. Although much work has gone into characterizing the structure of food webs, systematic predictions on their evolutionary dynamics are still scarce. Here we present a theoretical framework that predicts extinctions in terms of an alternating sequence of two basic processes: resource depletion by or competitive exclusion between consumers. We first propose a conceptual invasion extinction model (IEM) involving random fitness coefficients. We bolster this IEM by an analytical, recursive procedure for calculating idealized extinction cascades after any species addition and simulate the long-time evolution. Our procedure describes minimal food webs where each species interacts with only a single resource through the generalized Lotka-Volterra equations. For such food webs ex- tinction cascades are determined uniquely and the system always relaxes to a stable steady state. The dynamics and scale invariant species life time resemble the behavior of the IEM, and correctly predict an upper limit for trophic levels as observed in the field.

Theory of invasion extinction dynamics in minimal food webs.

PubMed

Haerter, Jan O; Mitarai, Namiko; Sneppen, Kim

2018-02-01

When food webs are exposed to species invasion, secondary extinction cascades may be set off. Although much work has gone into characterizing the structure of food webs, systematic predictions on their evolutionary dynamics are still scarce. Here we present a theoretical framework that predicts extinctions in terms of an alternating sequence of two basic processes: resource depletion by or competitive exclusion between consumers. We first propose a conceptual invasion extinction model (IEM) involving random fitness coefficients. We bolster this IEM by an analytical, recursive procedure for calculating idealized extinction cascades after any species addition and simulate the long-time evolution. Our procedure describes minimal food webs where each species interacts with only a single resource through the generalized Lotka-Volterra equations. For such food webs ex- tinction cascades are determined uniquely and the system always relaxes to a stable steady state. The dynamics and scale invariant species life time resemble the behavior of the IEM, and correctly predict an upper limit for trophic levels as observed in the field.

A Gateway for Phylogenetic Analysis Powered by Grid Computing Featuring GARLI 2.0

PubMed Central

Bazinet, Adam L.; Zwickl, Derrick J.; Cummings, Michael P.

2014-01-01

We introduce molecularevolution.org, a publicly available gateway for high-throughput, maximum-likelihood phylogenetic analysis powered by grid computing. The gateway features a garli 2.0 web service that enables a user to quickly and easily submit thousands of maximum likelihood tree searches or bootstrap searches that are executed in parallel on distributed computing resources. The garli web service allows one to easily specify partitioned substitution models using a graphical interface, and it performs sophisticated post-processing of phylogenetic results. Although the garli web service has been used by the research community for over three years, here we formally announce the availability of the service, describe its capabilities, highlight new features and recent improvements, and provide details about how the grid system efficiently delivers high-quality phylogenetic results. [garli, gateway, grid computing, maximum likelihood, molecular evolution portal, phylogenetics, web service.] PMID:24789072

Yonsei Evolutionary Population Synthesis (YEPS). II. Spectro-photometric Evolution of Helium-enhanced Stellar Populations

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

Chung, Chul; Yoon, Suk-Jin; Lee, Young-Wook, E-mail: chulchung@yonsei.ac.kr, E-mail: sjyoon0691@yonsei.ac.kr

The discovery of multiple stellar populations in Milky Way globular clusters (GCs) has stimulated various follow-up studies on helium-enhanced stellar populations. Here we present the evolutionary population synthesis models for the spectro-photometric evolution of simple stellar populations (SSPs) with varying initial helium abundance ( Y {sub ini}). We show that Y {sub ini} brings about dramatic changes in spectro-photometric properties of SSPs. Like the normal-helium SSPs, the integrated spectro-photometric evolution of helium-enhanced SSPs is also dependent on metallicity and age for a given Y {sub ini}. We discuss the implications and prospects for the helium-enhanced populations in relation to themore » second-generation populations found in the Milky Way GCs. All of the models are available at http://web.yonsei.ac.kr/cosmic/data/YEPS.htm.« less

Following the Social Media: Aspect Evolution of Online Discussion

NASA Astrophysics Data System (ADS)

Tang, Xuning; Yang, Christopher C.

Due to the advance of Internet and Web 2.0 technologies, it is easy to extract thousands of threads about a topic of interest from an online forum but it is nontrivial to capture the blueprint of different aspects (i.e., subtopic, or facet) associated with the topic. To better understand and analyze a forum discussion given topic, it is important to uncover the evolution relationships (temporal dependencies) between different topic aspects (i.e. how the discussion topic is evolving). Traditional Topic Detection and Tracking (TDT) techniques usually organize topics as a flat structure but it does not present the evolution relationships between topic aspects. In addition, the properties of short and sparse messages make the content-based TDT techniques difficult to perform well in identifying evolution relationships. The contributions in this paper are two-folded. We formally define a topic aspect evolution graph modeling framework and propose to utilize social network information, content similarity and temporal proximity to model evolution relationships between topic aspects. The experimental results showed that, by incorporating social network information, our technique significantly outperformed content-based technique in the task of extracting evolution relationships between topic aspects.

Augmenting Research, Education, and Outreach with Client-Side Web Programming.

PubMed

Abriata, Luciano A; Rodrigues, João P G L M; Salathé, Marcel; Patiny, Luc

2018-05-01

The evolution of computing and web technologies over the past decade has enabled the development of fully fledged scientific applications that run directly on web browsers. Powered by JavaScript, the lingua franca of web programming, these 'web apps' are starting to revolutionize and democratize scientific research, education, and outreach. Copyright © 2017 Elsevier Ltd. All rights reserved.

Geography and Similarity of Regional Cuisines in China

PubMed Central

Zhu, Yu-Xiao; Huang, Junming; Zhang, Zi-Ke; Zhang, Qian-Ming; Zhou, Tao; Ahn, Yong-Yeol

2013-01-01

Food occupies a central position in every culture and it is therefore of great interest to understand the evolution of food culture. The advent of the World Wide Web and online recipe repositories have begun to provide unprecedented opportunities for data-driven, quantitative study of food culture. Here we harness an online database documenting recipes from various Chinese regional cuisines and investigate the similarity of regional cuisines in terms of geography and climate. We find that geographical proximity, rather than climate proximity, is a crucial factor that determines the similarity of regional cuisines. We develop a model of regional cuisine evolution that provides helpful clues for understanding the evolution of cuisines and cultures. PMID:24260166

Geography and similarity of regional cuisines in China.

PubMed

Zhu, Yu-Xiao; Huang, Junming; Zhang, Zi-Ke; Zhang, Qian-Ming; Zhou, Tao; Ahn, Yong-Yeol

2013-01-01

Food occupies a central position in every culture and it is therefore of great interest to understand the evolution of food culture. The advent of the World Wide Web and online recipe repositories have begun to provide unprecedented opportunities for data-driven, quantitative study of food culture. Here we harness an online database documenting recipes from various Chinese regional cuisines and investigate the similarity of regional cuisines in terms of geography and climate. We find that geographical proximity, rather than climate proximity, is a crucial factor that determines the similarity of regional cuisines. We develop a model of regional cuisine evolution that provides helpful clues for understanding the evolution of cuisines and cultures.

Weaving Silos--A Leadership Challenge: A Cross-Functional Team Approach to Supporting Web-Based Student Services

ERIC Educational Resources Information Center

Kleemann, Gary L.

2005-01-01

The author reviews the evolution of Web services--from information sharing to transactional to relationship building--and the progression from first-generation to fourth-generation Web sites. (Contains 3 figures.)

Evolution of Mass and Velocity Field in the Cosmic Web: Comparison between Baryonic and Dark Matter

NASA Astrophysics Data System (ADS)

Zhu, Weishan; Feng, Long-Long

2017-03-01

We investigate the evolution of the cosmic web since z = 5 in grid-based cosmological hydrodynamical simulations, focusing on the mass and velocity fields of both baryonic and cold dark matter. The tidal tensor of density is used as the main method for web identification, with λ th = 0.2-1.2. The evolution trends in baryonic and dark matter are similar, although moderate differences are observed. Sheets appear early, and their large-scale pattern may have been set up by z = 3. In terms of mass, filaments supersede sheets as the primary collapsing structures from z ˜ 2-3. Tenuous filaments assembled with each other to form prominent ones at z < 2. In accordance with the construction of the frame of the sheets, the cosmic divergence velocity, v div, was already well-developed above 2-3 Mpc by z = 3. Afterwards, the curl velocity, v curl, grew dramatically along with the rising of filaments, becoming comparable to v div, for <2-3 Mpc at z = 0. The scaling of v curl can be described by the hierarchical turbulence model. The alignment between the vorticity and the eigenvectors of the shear tensor in the baryonic matter field resembles that in the dark matter field, and is even moderately stronger between {\\boldsymbol{ω }} and {{\\boldsymbol{e}}}1, and ω and {{\\boldsymbol{e}}}3. Compared with dark matter, there is slightly less baryonic matter found residing in filaments and clusters, and its vorticity developed more significantly below 2-3 Mpc. These differences may be underestimated because of the limited resolution and lack of star formation in our simulation. The impact of the change of dominant structures in overdense regions at z ˜ 2-3 on galaxy formation and evolution is shortly discussed.

Characteristic density contrasts in the evolution of superclusters. The case of A2142 supercluster

NASA Astrophysics Data System (ADS)

Gramann, Mirt; Einasto, Maret; Heinämäki, Pekka; Teerikorpi, Pekka; Saar, Enn; Nurmi, Pasi; Einasto, Jaan

2015-09-01

Context. The formation and evolution of the cosmic web in which galaxy superclusters are the largest relatively isolated objects is governed by a gravitational attraction of dark matter and antigravity of dark energy (cosmological constant). Aims: We study the characteristic density contrasts in the spherical collapse model for several epochs in the supercluster evolution and their dynamical state. Methods: We analysed the density contrasts for the turnaround, future collapse, and zero gravity in different ΛCDM models and applied them to study the dynamical state of the supercluster A2142 with an almost spherical main body, making it a suitable test object to apply a model that assumes sphericity. Results: We present characteristic density contrasts in the spherical collapse model for different cosmological parameters. The analysis of the supercluster A2142 shows that its high-density core has already started to collapse. The zero-gravity line outlines the outer region of the main body of the supercluster. In the course of future evolution, the supercluster may split into several collapsing systems. Conclusions: The various density contrasts presented in our study and applied to the supercluster A2142 offer a promising way to characterise the dynamical state and expected future evolution of galaxy superclusters.

Infusing Classrooms with Web 2.0 Technologies

ERIC Educational Resources Information Center

Velasco, Richard Carlos L.

2018-01-01

The evolution of digital technologies over the past couple of decades has contributed to a paradigm shift in education where the internet and web-based applications have become ubiquitous in primary and secondary classrooms (Glassman & Kang, 2011). With this shift came the digital phenomena known today as Web 2.0 technologies. Web 2.0…

Online Tools for Astronomy and Cosmochemistry

NASA Technical Reports Server (NTRS)

Meyer, B. S.

2005-01-01

Over the past year, the Webnucleo Group at Clemson University has been developing a web site with a number of interactive online tools for astronomy and cosmochemistry applications. The site uses SHP (Simplified Hypertext Preprocessor), which, because of its flexibility, allows us to embed almost any computer language into our web pages. For a description of SHP, please see http://www.joeldenny.com/ At our web site, an internet user may mine large and complex data sets, such as our stellar evolution models, and make graphs or tables of the results. The user may also run some of our detailed nuclear physics and astrophysics codes, such as our nuclear statistical equilibrium code, which is written in fortran and C. Again, the user may make graphs and tables and download the results.

Web building and silk properties functionally covary among species of wolf spider.

PubMed

Lacava, Mariángeles; Camargo, Arley; Garcia, Luis F; Benamú, Marco A; Santana, Martin; Fang, Jian; Wang, Xungai; Blamires, Sean J

2018-04-15

Although phylogenetic studies have shown covariation between the properties of spider major ampullate (MA) silk and web building, both spider webs and silks are highly plastic so we cannot be sure whether these traits functionally covary or just vary across environments that the spiders occupy. As MaSp2-like proteins provide MA silk with greater extensibility, their presence is considered necessary for spider webs to effectively capture prey. Wolf spiders (Lycosidae) are predominantly non-web building, but a select few species build webs. We accordingly collected MA silk from two web-building and six non-web-building species found in semirural ecosystems in Uruguay to test whether the presence of MaSp2-like proteins (indicated by amino acid composition, silk mechanical properties and silk nanostructures) was associated with web building across the group. The web-building and non-web-building species were from disparate subfamilies so we estimated a genetic phylogeny to perform appropriate comparisons. For all of the properties measured, we found differences between web-building and non-web-building species. A phylogenetic regression model confirmed that web building and not phylogenetic inertia influences silk properties. Our study definitively showed an ecological influence over spider silk properties. We expect that the presence of the MaSp2-like proteins and the subsequent nanostructures improves the mechanical performance of silks within the webs. Our study furthers our understanding of spider web and silk co-evolution and the ecological implications of spider silk properties. © 2018 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2018 European Society For Evolutionary Biology.

Climate Model Diagnostic Analyzer Web Service System

NASA Astrophysics Data System (ADS)

Lee, S.; Pan, L.; Zhai, C.; Tang, B.; Jiang, J. H.

2014-12-01

We have developed a cloud-enabled web-service system that empowers physics-based, multi-variable model performance evaluations and diagnoses through the comprehensive and synergistic use of multiple observational data, reanalysis data, and model outputs. We have developed a methodology to transform an existing science application code into a web service using a Python wrapper interface and Python web service frameworks. The web-service system, called Climate Model Diagnostic Analyzer (CMDA), currently supports (1) all the observational datasets from Obs4MIPs and a few ocean datasets from NOAA and Argo, which can serve as observation-based reference data for model evaluation, (2) many of CMIP5 model outputs covering a broad range of atmosphere, ocean, and land variables from the CMIP5 specific historical runs and AMIP runs, and (3) ECMWF reanalysis outputs for several environmental variables in order to supplement observational datasets. Analysis capabilities currently supported by CMDA are (1) the calculation of annual and seasonal means of physical variables, (2) the calculation of time evolution of the means in any specified geographical region, (3) the calculation of correlation between two variables, (4) the calculation of difference between two variables, and (5) the conditional sampling of one physical variable with respect to another variable. A web user interface is chosen for CMDA because it not only lowers the learning curve and removes the adoption barrier of the tool but also enables instantaneous use, avoiding the hassle of local software installation and environment incompatibility. CMDA will be used as an educational tool for the summer school organized by JPL's Center for Climate Science in 2014. In order to support 30+ simultaneous users during the school, we have deployed CMDA to the Amazon cloud environment. The cloud-enabled CMDA will provide each student with a virtual machine while the user interaction with the system will remain the same through web-browser interfaces. The summer school will serve as a valuable testbed for the tool development, preparing CMDA to serve its target community: Earth-science modeling and model-analysis community.

ProteomeVis: a web app for exploration of protein properties from structure to sequence evolution across organisms' proteomes.

PubMed

Razban, Rostam M; Gilson, Amy I; Durfee, Niamh; Strobelt, Hendrik; Dinkla, Kasper; Choi, Jeong-Mo; Pfister, Hanspeter; Shakhnovich, Eugene I

2018-05-08

Protein evolution spans time scales and its effects span the length of an organism. A web app named ProteomeVis is developed to provide a comprehensive view of protein evolution in the S. cerevisiae and E. coli proteomes. ProteomeVis interactively creates protein chain graphs, where edges between nodes represent structure and sequence similarities within user-defined ranges, to study the long time scale effects of protein structure evolution. The short time scale effects of protein sequence evolution are studied by sequence evolutionary rate (ER) correlation analyses with protein properties that span from the molecular to the organismal level. We demonstrate the utility and versatility of ProteomeVis by investigating the distribution of edges per node in organismal protein chain universe graphs (oPCUGs) and putative ER determinants. S. cerevisiae and E. coli oPCUGs are scale-free with scaling constants of 1.79 and 1.56, respectively. Both scaling constants can be explained by a previously reported theoretical model describing protein structure evolution (Dokholyan et al., 2002). Protein abundance most strongly correlates with ER among properties in ProteomeVis, with Spearman correlations of -0.49 (p-value<10-10) and -0.46 (p-value<10-10) for S. cerevisiae and E. coli, respectively. This result is consistent with previous reports that found protein expression to be the most important ER determinant (Zhang and Yang, 2015). ProteomeVis is freely accessible at http://proteomevis.chem.harvard.edu. Supplementary data are available at Bioinformatics. shakhnovich@chemistry.harvard.edu.

Prototyping a Web-of-Energy Architecture for Smart Integration of Sensor Networks in Smart Grids Domain.

PubMed

Caballero, Víctor; Vernet, David; Zaballos, Agustín; Corral, Guiomar

2018-01-30

Sensor networks and the Internet of Things have driven the evolution of traditional electric power distribution networks towards a new paradigm referred to as Smart Grid. However, the different elements that compose the Information and Communication Technologies (ICTs) layer of a Smart Grid are usually conceived as isolated systems that typically result in rigid hardware architectures which are hard to interoperate, manage, and to adapt to new situations. If the Smart Grid paradigm has to be presented as a solution to the demand for distributed and intelligent energy management system, it is necessary to deploy innovative IT infrastructures to support these smart functions. One of the main issues of Smart Grids is the heterogeneity of communication protocols used by the smart sensor devices that integrate them. The use of the concept of the Web of Things is proposed in this work to tackle this problem. More specifically, the implementation of a Smart Grid's Web of Things, coined as the Web of Energy is introduced. The purpose of this paper is to propose the usage of Web of Energy by means of the Actor Model paradigm to address the latent deployment and management limitations of Smart Grids. Smart Grid designers can use the Actor Model as a design model for an infrastructure that supports the intelligent functions demanded and is capable of grouping and converting the heterogeneity of traditional infrastructures into the homogeneity feature of the Web of Things. Conducted experimentations endorse the feasibility of this solution and encourage practitioners to point their efforts in this direction.

Prototyping a Web-of-Energy Architecture for Smart Integration of Sensor Networks in Smart Grids Domain

PubMed Central

Vernet, David; Corral, Guiomar

2018-01-01

Sensor networks and the Internet of Things have driven the evolution of traditional electric power distribution networks towards a new paradigm referred to as Smart Grid. However, the different elements that compose the Information and Communication Technologies (ICTs) layer of a Smart Grid are usually conceived as isolated systems that typically result in rigid hardware architectures which are hard to interoperate, manage, and to adapt to new situations. If the Smart Grid paradigm has to be presented as a solution to the demand for distributed and intelligent energy management system, it is necessary to deploy innovative IT infrastructures to support these smart functions. One of the main issues of Smart Grids is the heterogeneity of communication protocols used by the smart sensor devices that integrate them. The use of the concept of the Web of Things is proposed in this work to tackle this problem. More specifically, the implementation of a Smart Grid’s Web of Things, coined as the Web of Energy is introduced. The purpose of this paper is to propose the usage of Web of Energy by means of the Actor Model paradigm to address the latent deployment and management limitations of Smart Grids. Smart Grid designers can use the Actor Model as a design model for an infrastructure that supports the intelligent functions demanded and is capable of grouping and converting the heterogeneity of traditional infrastructures into the homogeneity feature of the Web of Things. Conducted experimentations endorse the feasibility of this solution and encourage practitioners to point their efforts in this direction. PMID:29385748

ProBiS tools (algorithm, database, and web servers) for predicting and modeling of biologically interesting proteins.

PubMed

Konc, Janez; Janežič, Dušanka

2017-09-01

ProBiS (Protein Binding Sites) Tools consist of algorithm, database, and web servers for prediction of binding sites and protein ligands based on the detection of structurally similar binding sites in the Protein Data Bank. In this article, we review the operations that ProBiS Tools perform, provide comments on the evolution of the tools, and give some implementation details. We review some of its applications to biologically interesting proteins. ProBiS Tools are freely available at http://probis.cmm.ki.si and http://probis.nih.gov. Copyright © 2017 Elsevier Ltd. All rights reserved.

Outreach/education interface for Cryosphere models using the Virtual Ice Sheet Laboratory

NASA Astrophysics Data System (ADS)

Larour, E. Y.; Halkides, D. J.; Romero, V.; Cheng, D. L.; Perez, G.

2014-12-01

In the past decade, great strides have been made in the development of models capable of projecting the future evolution of glaciers and the polar ice sheets in a changing climate. These models are now capable of replicating some of the trends apparent in satellite observations. However, because this field is just now maturing, very few efforts have been dedicated to adapting these capabilities to education. Technologies that have been used in outreach efforts in Atmospheric and Oceanic sciences still have not been extended to Cryospheric Science. We present a cutting-edge, technologically driven virtual laboratory, geared towards outreach and k-12 education, dedicated to the polar ice sheets on Antarctica and Greenland, and their role as major contributors to sea level rise in coming decades. VISL (Virtual Ice Sheet Laboratory) relies on state-of-the art Web GL rendering of polar ice sheets, Android/iPhone and web portability using Javascript, as well as C++ simulations (back-end) based on the Ice Sheet System Model, the NASA model for simulating the evolution of polar ice sheets. Using VISL, educators and students can have an immersive experience into the world of polar ice sheets, while at the same exercising the capabilities of a state-of-the-art climate model, all of it embedded into an education experience that follows the new STEM standards for education.This work was performed at the California Institute of Technology's Jet Propulsion Laboratory under a contract with the National Aeronautics and Space Administration's Cryosphere Science Program.

The Program Management Challenges of Web 2.0

DTIC Science & Technology

2010-06-01

identifying and keeping abreast of the newly emerging technologies; their fast pace of evolution or modification, changing domain focus areas, their varied...definitive experts. No one knows what the future holds for network-centric materiel development . We are in the early stages of the Information Age and...led to the development and evolution of online Web-based communities and services such as auction houses, knowledge portals, social networking sites

SIFTER search: a web server for accurate phylogeny-based protein function prediction

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

Sahraeian, Sayed M.; Luo, Kevin R.; Brenner, Steven E.

We are awash in proteins discovered through high-throughput sequencing projects. As only a minuscule fraction of these have been experimentally characterized, computational methods are widely used for automated annotation. Here, we introduce a user-friendly web interface for accurate protein function prediction using the SIFTER algorithm. SIFTER is a state-of-the-art sequence-based gene molecular function prediction algorithm that uses a statistical model of function evolution to incorporate annotations throughout the phylogenetic tree. Due to the resources needed by the SIFTER algorithm, running SIFTER locally is not trivial for most users, especially for large-scale problems. The SIFTER web server thus provides access tomore » precomputed predictions on 16 863 537 proteins from 232 403 species. Users can explore SIFTER predictions with queries for proteins, species, functions, and homologs of sequences not in the precomputed prediction set. Lastly, the SIFTER web server is accessible at http://sifter.berkeley.edu/ and the source code can be downloaded.« less

SIFTER search: a web server for accurate phylogeny-based protein function prediction

DOE PAGES

Sahraeian, Sayed M.; Luo, Kevin R.; Brenner, Steven E.

2015-05-15

We are awash in proteins discovered through high-throughput sequencing projects. As only a minuscule fraction of these have been experimentally characterized, computational methods are widely used for automated annotation. Here, we introduce a user-friendly web interface for accurate protein function prediction using the SIFTER algorithm. SIFTER is a state-of-the-art sequence-based gene molecular function prediction algorithm that uses a statistical model of function evolution to incorporate annotations throughout the phylogenetic tree. Due to the resources needed by the SIFTER algorithm, running SIFTER locally is not trivial for most users, especially for large-scale problems. The SIFTER web server thus provides access tomore » precomputed predictions on 16 863 537 proteins from 232 403 species. Users can explore SIFTER predictions with queries for proteins, species, functions, and homologs of sequences not in the precomputed prediction set. Lastly, the SIFTER web server is accessible at http://sifter.berkeley.edu/ and the source code can be downloaded.« less

Change and Anomaly Detection in Real-Time GPS Data

NASA Astrophysics Data System (ADS)

Granat, R.; Pierce, M.; Gao, X.; Bock, Y.

2008-12-01

The California Real-Time Network (CRTN) is currently generating real-time GPS position data at a rate of 1-2Hz at over 80 locations. The CRTN data presents the possibility of studying dynamical solid earth processes in a way that complements existing seismic networks. To realize this possibility we have developed a prototype system for detecting changes and anomalies in the real-time data. Through this system, we can can correlate changes in multiple stations in order to detect signals with geographical extent. Our approach involves developing a statistical model for each GPS station in the network, and then using those models to segment the time series into a number of discrete states described by the model. We use a hidden Markov model (HMM) to describe the behavior of each station; fitting the model to the data requires neither labeled training examples nor a priori information about the system. As such, HMMs are well suited to this problem domain, in which the data remains largely uncharacterized. There are two main components to our approach. The first is the model fitting algorithm, regularized deterministic annealing expectation- maximization (RDAEM), which provides robust, high-quality results. The second is a web service infrastructure that connects the data to the statistical modeling analysis and allows us to easily present the results of that analysis through a web portal interface. This web service approach facilitates the automatic updating of station models to keep pace with dynamical changes in the data. Our web portal interface is critical to the process of interpreting the data. A Google Maps interface allows users to visually interpret state changes not only on individual stations but across the entire network. Users can drill down from the map interface to inspect detailed results for individual stations, download the time series data, and inspect fitted models. Alternatively, users can use the web portal look at the evolution of changes on the network by moving backwards and forwards in time.

Understanding Evolution: An Evolution Website for Teachers

ERIC Educational Resources Information Center

Scotchmoor, Judy; Janulaw, Al

2005-01-01

While many states are facing challenges to the teaching of evolution in their science classrooms, the University of California Museum of Paleontology, working with the National Center for Science Education, has developed a useful web-based resource for science teachers of all grade- and experience-levels. Understanding Evolution (UE) was developed…

Evolutionary Biology Digital Dissection Project: Web-Based Laboratory Learning Opportunities for Students

ERIC Educational Resources Information Center

Fabian, Carole Ann

2004-01-01

A university in Buffalo introduced its students to evolution by providing them with information on evidence of evolution, mechanisms for evolution, principles of genetics, selection, adaptation, evolution and sociobiology. This method of teaching with technology enabled students to improve and expand their learning opportunities.

Expanding the Understanding of Evolution

ERIC Educational Resources Information Center

Musante, Susan

2011-01-01

Originally designed for K-12 teachers, the Understanding Evolution (UE) Web site ("www.understandingevolution.org") is a one-stop shop for all of a teacher's evolution education needs, with lesson plans, teaching tips, lists of common evolution misconceptions, and much more. However, during the past five years, the UE project team learned that…

Biodiversity and ecosystem functioning in evolving food webs.

PubMed

Allhoff, K T; Drossel, B

2016-05-19

We use computer simulations in order to study the interplay between biodiversity and ecosystem functioning (BEF) during both the formation and the ongoing evolution of large food webs. A species in our model is characterized by its own body mass, its preferred prey body mass and the width of its potential prey body mass spectrum. On an ecological time scale, population dynamics determines which species are viable and which ones go extinct. On an evolutionary time scale, new species emerge as modifications of existing ones. The network structure thus emerges and evolves in a self-organized manner. We analyse the relation between functional diversity and five community level measures of ecosystem functioning. These are the metabolic loss of the predator community, the total biomasses of the basal and the predator community, and the consumption rates on the basal community and within the predator community. Clear BEF relations are observed during the initial build-up of the networks, or when parameters are varied, causing bottom-up or top-down effects. However, ecosystem functioning measures fluctuate only very little during long-term evolution under constant environmental conditions, despite changes in functional diversity. This result supports the hypothesis that trophic cascades are weaker in more complex food webs. © 2016 The Author(s).

Web-based Interactive Landform Simulation Model - Grand Canyon

NASA Astrophysics Data System (ADS)

Luo, W.; Pelletier, J. D.; Duffin, K.; Ormand, C. J.; Hung, W.; Iverson, E. A.; Shernoff, D.; Zhai, X.; Chowdary, A.

2013-12-01

Earth science educators need interactive tools to engage and enable students to better understand how Earth systems work over geologic time scales. The evolution of landforms is ripe for interactive, inquiry-based learning exercises because landforms exist all around us. The Web-based Interactive Landform Simulation Model - Grand Canyon (WILSIM-GC, http://serc.carleton.edu/landform/) is a continuation and upgrade of the simple cellular automata (CA) rule-based model (WILSIM-CA, http://www.niu.edu/landform/) that can be accessed from anywhere with an Internet connection. Major improvements in WILSIM-GC include adopting a physically based model and the latest Java technology. The physically based model is incorporated to illustrate the fluvial processes involved in land-sculpting pertaining to the development and evolution of one of the most famous landforms on Earth: the Grand Canyon. It is hoped that this focus on a famous and specific landscape will attract greater student interest and provide opportunities for students to learn not only how different processes interact to form the landform we observe today, but also how models and data are used together to enhance our understanding of the processes involved. The latest development in Java technology (such as Java OpenGL for access to ubiquitous fast graphics hardware, Trusted Applet for file input and output, and multithreaded ability to take advantage of modern multi-core CPUs) are incorporated into building WILSIM-GC and active, standards-aligned curricula materials guided by educational psychology theory on science learning will be developed to accompany the model. This project is funded NSF-TUES program.

Working with WebQuests

ERIC Educational Resources Information Center

Raulston, Cassie; Moellinger, Donna

2007-01-01

With the evolution of technology, students can now take online classes that may not be offered in their home schools. While online courses are commonly found in many high schools, WebQuests are used more commonly in elementary schools. Through the exploration of WebQuests, students are able to integrate the Internet into classroom activities. The…

Pragmatic Computing - A Semiotic Perspective to Web Services

NASA Astrophysics Data System (ADS)

Liu, Kecheng

The web seems to have evolved from a syntactic web, a semantic web to a pragmatic web. This evolution conforms to the study of information and technology from the theory of semiotics. The pragmatics, concerning with the use of information in relation to the context and intended purposes, is extremely important in web service and applications. Much research in pragmatics has been carried out; but in the same time, attempts and solutions have led to some more questions. After reviewing the current work in pragmatic web, the paper presents a semiotic approach to website services, particularly on request decomposition and service aggregation.

Random drift versus selection in academic vocabulary: an evolutionary analysis of published keywords.

PubMed

Bentley, R Alexander

2008-08-27

The evolution of vocabulary in academic publishing is characterized via keyword frequencies recorded in the ISI Web of Science citations database. In four distinct case-studies, evolutionary analysis of keyword frequency change through time is compared to a model of random copying used as the null hypothesis, such that selection may be identified against it. The case studies from the physical sciences indicate greater selection in keyword choice than in the social sciences. Similar evolutionary analyses can be applied to a wide range of phenomena; wherever the popularity of multiple items through time has been recorded, as with web searches, or sales of popular music and books, for example.

Random Drift versus Selection in Academic Vocabulary: An Evolutionary Analysis of Published Keywords

PubMed Central

Bentley, R. Alexander

2008-01-01

The evolution of vocabulary in academic publishing is characterized via keyword frequencies recorded in the ISI Web of Science citations database. In four distinct case-studies, evolutionary analysis of keyword frequency change through time is compared to a model of random copying used as the null hypothesis, such that selection may be identified against it. The case studies from the physical sciences indicate greater selection in keyword choice than in the social sciences. Similar evolutionary analyses can be applied to a wide range of phenomena; wherever the popularity of multiple items through time has been recorded, as with web searches, or sales of popular music and books, for example. PMID:18728786

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

PubMed

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

2016-08-01

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

TMFoldWeb: a web server for predicting transmembrane protein fold class.

PubMed

Kozma, Dániel; Tusnády, Gábor E

2015-09-17

Here we present TMFoldWeb, the web server implementation of TMFoldRec, a transmembrane protein fold recognition algorithm. TMFoldRec uses statistical potentials and utilizes topology filtering and a gapless threading algorithm. It ranks template structures and selects the most likely candidates and estimates the reliability of the obtained lowest energy model. The statistical potential was developed in a maximum likelihood framework on a representative set of the PDBTM database. According to the benchmark test the performance of TMFoldRec is about 77 % in correctly predicting fold class for a given transmembrane protein sequence. An intuitive web interface has been developed for the recently published TMFoldRec algorithm. The query sequence goes through a pipeline of topology prediction and a systematic sequence to structure alignment (threading). Resulting templates are ordered by energy and reliability values and are colored according to their significance level. Besides the graphical interface, a programmatic access is available as well, via a direct interface for developers or for submitting genome-wide data sets. The TMFoldWeb web server is unique and currently the only web server that is able to predict the fold class of transmembrane proteins while assigning reliability scores for the prediction. This method is prepared for genome-wide analysis with its easy-to-use interface, informative result page and programmatic access. Considering the info-communication evolution in the last few years, the developed web server, as well as the molecule viewer, is responsive and fully compatible with the prevalent tablets and mobile devices.

Region Evolution eXplorer - A tool for discovering evolution trends in ontology regions.

PubMed

Christen, Victor; Hartung, Michael; Groß, Anika

2015-01-01

A large number of life science ontologies has been developed to support different application scenarios such as gene annotation or functional analysis. The continuous accumulation of new insights and knowledge affects specific portions in ontologies and thus leads to their adaptation. Therefore, it is valuable to study which ontology parts have been extensively modified or remained unchanged. Users can monitor the evolution of an ontology to improve its further development or apply the knowledge in their applications. Here we present REX (Region Evolution eXplorer) a web-based system for exploring the evolution of ontology parts (regions). REX provides an analysis platform for currently about 1,000 versions of 16 well-known life science ontologies. Interactive workflows allow an explorative analysis of changing ontology regions and can be used to study evolution trends for long-term periods. REX is a web application providing an interactive and user-friendly interface to identify (un)stable regions in large life science ontologies. It is available at http://www.izbi.de/rex.

Praedicere Possumus: An Italian web-based application for predictive microbiology to ensure food safety.

PubMed

Polese, Pierluigi; Torre, Manuela Del; Stecchini, Mara Lucia

2018-03-31

The use of predictive modelling tools, which mainly describe the response of microorganisms to a particular set of environmental conditions, may contribute to a better understanding of microbial behaviour in foods. In this paper, a tertiary model, in the form of a readily available and userfriendly web-based application Praedicere Possumus (PP) is presented with research examples from our laboratories. Through the PP application, users have access to different modules, which apply a set of published models considered reliable for determining the compliance of a food product with EU safety criteria and for optimising processing throughout the identification of critical control points. The application pivots around a growth/no-growth boundary model, coupled with a growth model, and includes thermal and non-thermal inactivation models. Integrated functionalities, such as the fractional contribution of each inhibitory factor to growth probability (f) and the time evolution of the growth probability (P t ), have also been included. The PP application is expected to assist food industry and food safety authorities in their common commitment towards the improvement of food safety.

Internet Librarian '98: Proceedings of the Internet Librarian Conference (2nd, Monterey, California, November 1-5, 1998).

ERIC Educational Resources Information Center

Nixon, Carol, Comp.; Dengler, M. Heide, Comp.; McHenry, Mare L., Comp.

This proceedings contains 56 papers, presentation summaries, and/or slide presentations pertaining to the Internet, World Wide Web, intranets, and library systems. Topics include: Web databases in medium sized libraries; Dow Jones Intranet Toolkit; the future of online; Web searching and Internet basics; digital archiving; evolution of the online…

A Framework for Synchronous Web-Based Professional Development: Measuring the Impact of Webinar Instruction

ERIC Educational Resources Information Center

Rich, Rachel L.

2011-01-01

Through the evolution and proliferation of the Internet, distance and online education have become more prevalent in modern society. Synchronous web-based professional development continues to gain popularity. Although online education has grown in popularity and breadth, there has been a lack of research about the impact of synchronous web-based…

Inside the Web: A Look at Digital Libraries and the Invisible/Deep Web

ERIC Educational Resources Information Center

Su, Mila C.

2009-01-01

The evolution of the Internet and the World Wide Web continually exceeds expectations with the "swift pace" of technological innovations. Information is added, and just as quickly becomes outdated at a rapid pace. Researchers have found that Digital materials can provide access to primary source materials and connect the researcher to institutions…

Seizing the Digital High Ground: Military Operations and Politics in the Social Media Era

DTIC Science & Technology

2015-04-13

divided on the relative threats and opportunities. Through the analysis of social media’s technological evolution, its impact on crowd behaviour , and... Through the analysis of social media’s technological evolution, its impact on crowd behaviour , and using case studies of the Arab Spring and Islamic... arguments and recommendations proposed. Web 2.0 is a term used to describe the way in which software developers and end-users utilize the World Wide Web as

Bayesian analysis of the dynamic cosmic web in the SDSS galaxy survey

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

Leclercq, Florent; Wandelt, Benjamin; Jasche, Jens, E-mail: florent.leclercq@polytechnique.org, E-mail: jasche@iap.fr, E-mail: wandelt@iap.fr

Recent application of the Bayesian algorithm \\textsc(borg) to the Sloan Digital Sky Survey (SDSS) main sample galaxies resulted in the physical inference of the formation history of the observed large-scale structure from its origin to the present epoch. In this work, we use these inferences as inputs for a detailed probabilistic cosmic web-type analysis. To do so, we generate a large set of data-constrained realizations of the large-scale structure using a fast, fully non-linear gravitational model. We then perform a dynamic classification of the cosmic web into four distinct components (voids, sheets, filaments, and clusters) on the basis of themore » tidal field. Our inference framework automatically and self-consistently propagates typical observational uncertainties to web-type classification. As a result, this study produces accurate cosmographic classification of large-scale structure elements in the SDSS volume. By also providing the history of these structure maps, the approach allows an analysis of the origin and growth of the early traces of the cosmic web present in the initial density field and of the evolution of global quantities such as the volume and mass filling fractions of different structures. For the problem of web-type classification, the results described in this work constitute the first connection between theory and observations at non-linear scales including a physical model of structure formation and the demonstrated capability of uncertainty quantification. A connection between cosmology and information theory using real data also naturally emerges from our probabilistic approach. Our results constitute quantitative chrono-cosmography of the complex web-like patterns underlying the observed galaxy distribution.« less

The angular momentum of cosmological coronae and the inside-out growth of spiral galaxies

NASA Astrophysics Data System (ADS)

Pezzulli, Gabriele; Fraternali, Filippo; Binney, James

2017-05-01

Massive and diffuse haloes of hot gas (coronae) are important intermediaries between cosmology and galaxy evolution, storing mass and angular momentum acquired from the cosmic web until eventual accretion on to star-forming discs. We introduce a method to reconstruct the rotation of a galactic corona, based on its angular momentum distribution (AMD). This allows us to investigate in what conditions the angular momentum acquired from tidal torques can be transferred to star-forming discs and explain observed galaxy-scale processes, such as inside-out growth and the build-up of abundance gradients. We find that a simple model of an isothermal corona with a temperature slightly smaller than virial and a cosmologically motivated AMD is in good agreement with galaxy evolution requirements, supporting hot-mode accretion as a viable driver for the evolution of spiral galaxies in a cosmological context. We predict moderately sub-centrifugal rotation close to the disc and slow rotation close to the virial radius. Motivated by the observation that the Milky Way has a relatively hot corona (T ≃ 2 × 106 K), we also explore models with a temperature larger than virial. To be able to drive inside-out growth, these models must be significantly affected by feedback, either mechanical (ejection of low angular momentum material) or thermal (heating of the central regions). However, the agreement with galaxy evolution constraints becomes, in these cases, only marginal, suggesting that our first and simpler model may apply to a larger fraction of galaxy evolution history.

Evolution of the cosmic web

NASA Astrophysics Data System (ADS)

Cautun, Marius; van de Weygaert, Rien; Jones, Bernard J. T.; Frenk, Carlos S.

2014-07-01

The cosmic web is the largest scale manifestation of the anisotropic gravitational collapse of matter. It represents the transitional stage between linear and non-linear structures and contains easily accessible information about the early phases of structure formation processes. Here we investigate the characteristics and the time evolution of morphological components. Our analysis involves the application of the NEXUS Multiscale Morphology Filter technique, predominantly its NEXUS+ version, to high resolution and large volume cosmological simulations. We quantify the cosmic web components in terms of their mass and volume content, their density distribution and halo populations. We employ new analysis techniques to determine the spatial extent of filaments and sheets, like their total length and local width. This analysis identifies clusters and filaments as the most prominent components of the web. In contrast, while voids and sheets take most of the volume, they correspond to underdense environments and are devoid of group-sized and more massive haloes. At early times the cosmos is dominated by tenuous filaments and sheets, which, during subsequent evolution, merge together, such that the present-day web is dominated by fewer, but much more massive, structures. The analysis of the mass transport between environments clearly shows how matter flows from voids into walls, and then via filaments into cluster regions, which form the nodes of the cosmic web. We also study the properties of individual filamentary branches, to find long, almost straight, filaments extending to distances larger than 100 h-1 Mpc. These constitute the bridges between massive clusters, which seem to form along approximatively straight lines.

PIECE 2.0: an update for the plant gene structure comparison and evolution database

USDA-ARS?s Scientific Manuscript database

PIECE (Plant Intron Exon Comparision and Evolution) is a web-accessible database that houses intron and exon information of plant genes. PIECE serves as a resource for biologists interested in comparing intron-exon organization and provides valuable insights into the evolution of gene structure in ...

High-performance spider webs: integrating biomechanics, ecology and behaviour

PubMed Central

Harmer, Aaron M. T.; Blackledge, Todd A.; Madin, Joshua S.; Herberstein, Marie E.

2011-01-01

Spider silks exhibit remarkable properties, surpassing most natural and synthetic materials in both strength and toughness. Orb-web spider dragline silk is the focus of intense research by material scientists attempting to mimic these naturally produced fibres. However, biomechanical research on spider silks is often removed from the context of web ecology and spider foraging behaviour. Similarly, evolutionary and ecological research on spiders rarely considers the significance of silk properties. Here, we highlight the critical need to integrate biomechanical and ecological perspectives on spider silks to generate a better understanding of (i) how silk biomechanics and web architectures interacted to influence spider web evolution along different structural pathways, and (ii) how silks function in an ecological context, which may identify novel silk applications. An integrative, mechanistic approach to understanding silk and web function, as well as the selective pressures driving their evolution, will help uncover the potential impacts of environmental change and species invasions (of both spiders and prey) on spider success. Integrating these fields will also allow us to take advantage of the remarkable properties of spider silks, expanding the range of possible silk applications from single threads to two- and three-dimensional thread networks. PMID:21036911

Experimental Models to Study the Role of Microbes in Host-Parasite Interactions.

PubMed

Hahn, Megan A; Dheilly, Nolwenn M

2016-01-01

Until recently, parasitic infections have been primarily studied as interactions between the parasite and the host, leaving out crucial players: microbes. The recent realization that microbes play key roles in the biology of all living organisms is not only challenging our understanding of host-parasite evolution, but it also provides new clues to develop new therapies and remediation strategies. In this paper we provide a review of promising and advanced experimental organismal systems to examine the dynamic of host-parasite-microbe interactions. We address the benefits of developing new experimental models appropriate to this new research area and identify systems that offer the best promises considering the nature of the interactions among hosts, parasites, and microbes. Based on these systems, we identify key criteria for selecting experimental models to elucidate the fundamental principles of these complex webs of interactions. It appears that no model is ideal and that complementary studies should be performed on different systems in order to understand the driving roles of microbes in host and parasite evolution.

Earth surface modeling for education: How effective is it? Latest classroom tests with Web-based Interactive Landform Simulation Model - Grand Canyon (WILSIM-GC)

NASA Astrophysics Data System (ADS)

Luo, W.; Pelletier, J. D.; Smith, T.; Whalley, K.; Shelhamer, A.; Darling, A.; Ormand, C. J.; Duffin, K.; Hung, W. C.; Iverson, E. A. R.; Shernoff, D.; Zhai, X.; Chiang, J. L.; Lotter, N.

2016-12-01

The Web-based Interactive Landform Simulation Model - Grand Canyon (WILSIM-GC, http://serc.carleton.edu/landform/) is a simplified version of a physically-based model that simulates bedrock channel erosion, cliff retreat, and base level change. Students can observe the landform evolution in animation under different scenarios by changing parameter values. In addition, cross-sections and profiles at different time intervals can be displayed and saved for further quantitative analysis. Students were randomly assigned to a treatment group (using WILSIM-GC simulation) or a control group (using traditional paper-based material). Pre- and post-tests were administered to measure students' understanding of the concepts and processes related to Grand Canyon formation and evolution. Results from the ANOVA showed that for both groups there were statistically significant growth in scores from pre-test to post-test [F(1, 47) = 25.82, p < .001], but the growth in scores between the two groups was not statistically significant [F(1, 47) = 0.08, p =.774]. In semester 1, the WILSIM-GC group showed greater growth, while in semester 2, the paper-based group showed greater growth. Additionally, a significant time × group × gender × semester interaction effect was observed [F(1, 47) = 4.76, p =.034]. Here, in semester 1 female students were more strongly advantaged by the WILSIM-GC intervention than male students, while in semester 2, female students were less strongly advantaged than male students. The new results are consistent with our initial findings (Luo et al., 2016) and others reported in the literature, i.e., simulation approach is at least equally effective as traditional paper-based method in teaching students about landform evolution. Survey data indicate that students favor the simulation approach. Further study is needed to investigate the reasons for the difference by gender.

Climate Model Diagnostic Analyzer Web Service System

NASA Astrophysics Data System (ADS)

Lee, S.; Pan, L.; Zhai, C.; Tang, B.; Jiang, J. H.

2013-12-01

The latest Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report stressed the need for the comprehensive and innovative evaluation of climate models with newly available global observations. The traditional approach to climate model evaluation, which compares a single parameter at a time, identifies symptomatic model biases and errors but fails to diagnose the model problems. The model diagnosis process requires physics-based multi-variable comparisons that typically involve large-volume and heterogeneous datasets, making them both computationally- and data-intensive. To address these challenges, we are developing a parallel, distributed web-service system that enables the physics-based multi-variable model performance evaluations and diagnoses through the comprehensive and synergistic use of multiple observational data, reanalysis data, and model outputs. We have developed a methodology to transform an existing science application code into a web service using a Python wrapper interface and Python web service frameworks (i.e., Flask, Gunicorn, and Tornado). The web-service system, called Climate Model Diagnostic Analyzer (CMDA), currently supports (1) all the datasets from Obs4MIPs and a few ocean datasets from NOAA and Argo, which can serve as observation-based reference data for model evaluation and (2) many of CMIP5 model outputs covering a broad range of atmosphere, ocean, and land variables from the CMIP5 specific historical runs and AMIP runs. Analysis capabilities currently supported by CMDA are (1) the calculation of annual and seasonal means of physical variables, (2) the calculation of time evolution of the means in any specified geographical region, (3) the calculation of correlation between two variables, and (4) the calculation of difference between two variables. A web user interface is chosen for CMDA because it not only lowers the learning curve and removes the adoption barrier of the tool but also enables instantaneous use, avoiding the hassle of local software installation and environment incompatibility. CMDA is planned to be used as an educational tool for the summer school organized by JPL's Center for Climate Science in 2014. The requirements of the educational tool are defined with the interaction with the school organizers, and CMDA is customized to meet the requirements accordingly. The tool needs to be production quality for 30+ simultaneous users. The summer school will thus serve as a valuable testbed for the tool development, preparing CMDA to serve the Earth-science modeling and model-analysis community at the end of the project. This work was funded by the NASA Earth Science Program called Computational Modeling Algorithms and Cyberinfrastructure (CMAC).

Developing and sustaining a web-based library newsletter.

PubMed

Frisby, Anthony J; Kipnis, Daniel G; Mikita, Elizabeth G

2006-01-01

The JEFFLINE Forum, Scott Library's attempt to revive the traditional library newsletter by employing the technical advantages and increasing presence of the Web, debuted in October 1999. The fifth anniversary of the Forum was a good time to look back at its evolution and to examine some of the challenges inherent in developing and sustaining a library newsletter. By identifying the most successful strategies, and reflecting on the lessons learned along way, the authors hope to continue the evolution of the Forum and help to ensure the viability of the library newsletter.

Piece2.0: an update for the pant gene structure comparison and evolution database

USDA-ARS?s Scientific Manuscript database

PIECE (Plant Intron Exon Comparison and Evolution) is a web-accessible database that houses intron and exon information of plant genes. PIECE serves as a resource for biologists interested in comparing intron–exon organization and provides valuable insights into the evolution of gene structure in pl...

Evolution Kills: A Web Resource for Instructors of Evolutionary Biology

ERIC Educational Resources Information Center

Vondrasek, Joanna R.; Antonovics, Janis; Taylor, Douglas R.

2004-01-01

We have developed a laboratory course that demonstrates how evolution can be taught as a participatory, investigative science at the undergraduate college or advanced secondary high school level. The course emphasizes the applied importance of evolution to areas such as medicine and agriculture. Because many instructors face budgetary or other…

Increased Learning Observed in Redesigned Introductory Biology Course that Employed Web-enhanced, Interactive Pedagogy

PubMed Central

Lister, Bradford C.; Hanna, Michael H.; Roy, Harry

2007-01-01

Our Introduction to Biology course (BIOL 1010) changed in 2004 from a standard instructor-centered, lecture-homework-exam format to a student-centered format that used Web-enhanced, interactive pedagogy. To measure and compare conceptual learning gains in the traditional course in fall 2003 with a section of the interactive course in fall 2004, we created concept inventories for both evolution and ecology. Both classes were taught by the same instructor who had taught BIOL 1010 since 1976, and each had a similar student composition with comparable biological knowledge. A significant increase in learning gain was observed with the Web-enhanced, interactive pedagogy in evolution (traditional, 0.10; interactive, 0.19; p = 0.024) and ecology (traditional, −0.05; interactive, 0.14; p = 0.000009) when assessment was made unannounced and for no credit in the last week of classes. These results strengthen the case for augmenting or replacing instructor-centered teaching with Web-enhanced, interactive, student-centered teaching. When assessment was made using the final exam in the interactive course, for credit and after studying, significantly greater learning gains were made in evolution (95%, 0.37, p = 0.0001) and ecology (143%, 0.34, p = 0.000003) when compared with learning gains measured without credit or study in the last week of classes. PMID:17785407

The Evolution of WebCT in a Baccalaureate Nursing Program: An Alice in Wonderland Reflection

ERIC Educational Resources Information Center

Donato, Emily; Hudyma, Shirlene; Carter, Lorraine; Schroeder, Catherine

2010-01-01

The use of WebCT in the Laurentian University Bachelor of Science in Nursing program began in 2001 when faculty were eager to explore different modes of delivery for fourth-year courses. Since then, the use of WebCT within the baccalaureate program has increased substantively. This paper outlines the developmental growth of the use of this…

Monash Chemical Yields Project (Monχey) Element production in low- and intermediate-mass stars

NASA Astrophysics Data System (ADS)

Doherty, Carolyn; Lattanzio, John; Angelou, George; Campbell, Simon W.; Church, Ross; Constantino, Thomas; Cristallo, Sergio; Gil-Pons, Pilar; Karakas, Amanda; Lugaro, Maria; Stancliffe, Richard

The Monχey project will provide a large and homogeneous set of stellar yields for the low- and intermediate- mass stars and has applications particularly to galactic chemical evolution modelling. We describe our detailed grid of stellar evolutionary models and corresponding nucleosynthetic yields for stars of initial mass 0.8 M⊙ up to the limit for core collapse supernova (CC-SN) ~ 10 M⊙. Our study covers a broad range of metallicities, ranging from the first, primordial stars (Z = 0) to those of super-solar metallicity (Z = 0.04). The models are evolved from the zero-age main-sequence until the end of the asymptotic giant branch (AGB) and the nucleosynthesis calculations include all elements from H to Bi. A major innovation of our work is the first complete grid of heavy element nucleosynthetic predictions for primordial AGB stars as well as the inclusion of extra-mixing processes (in this case thermohaline) during the red giant branch. We provide a broad overview of our results with implications for galactic chemical evolution as well as highlight interesting results such as heavy element production in dredge-out events of super-AGB stars. We briefly introduce our forthcoming web-based database which provides the evolutionary tracks, structural properties, internal/surface nucleosynthetic compositions and stellar yields. Our web interface includes user- driven plotting capabilities with output available in a range of formats. Our nucleosynthetic results will be available for further use in post processing calculations for dust production yields.

An integrative top-down and bottom-up qualitative model construction framework for exploration of biochemical systems.

PubMed

Wu, Zujian; Pang, Wei; Coghill, George M

Computational modelling of biochemical systems based on top-down and bottom-up approaches has been well studied over the last decade. In this research, after illustrating how to generate atomic components by a set of given reactants and two user pre-defined component patterns, we propose an integrative top-down and bottom-up modelling approach for stepwise qualitative exploration of interactions among reactants in biochemical systems. Evolution strategy is applied to the top-down modelling approach to compose models, and simulated annealing is employed in the bottom-up modelling approach to explore potential interactions based on models constructed from the top-down modelling process. Both the top-down and bottom-up approaches support stepwise modular addition or subtraction for the model evolution. Experimental results indicate that our modelling approach is feasible to learn the relationships among biochemical reactants qualitatively. In addition, hidden reactants of the target biochemical system can be obtained by generating complex reactants in corresponding composed models. Moreover, qualitatively learned models with inferred reactants and alternative topologies can be used for further web-lab experimental investigations by biologists of interest, which may result in a better understanding of the system.

Evolution of the social network of scientific collaborations

NASA Astrophysics Data System (ADS)

Barabási, A. L.; Jeong, H.; Néda, Z.; Ravasz, E.; Schubert, A.; Vicsek, T.

2002-08-01

The co-authorship network of scientists represents a prototype of complex evolving networks. In addition, it offers one of the most extensive database to date on social networks. By mapping the electronic database containing all relevant journals in mathematics and neuro-science for an 8-year period (1991-98), we infer the dynamic and the structural mechanisms that govern the evolution and topology of this complex system. Three complementary approaches allow us to obtain a detailed characterization. First, empirical measurements allow us to uncover the topological measures that characterize the network at a given moment, as well as the time evolution of these quantities. The results indicate that the network is scale-free, and that the network evolution is governed by preferential attachment, affecting both internal and external links. However, in contrast with most model predictions the average degree increases in time, and the node separation decreases. Second, we propose a simple model that captures the network's time evolution. In some limits the model can be solved analytically, predicting a two-regime scaling in agreement with the measurements. Third, numerical simulations are used to uncover the behavior of quantities that could not be predicted analytically. The combined numerical and analytical results underline the important role internal links play in determining the observed scaling behavior and network topology. The results and methodologies developed in the context of the co-authorship network could be useful for a systematic study of other complex evolving networks as well, such as the world wide web, Internet, or other social networks.

The Zel'dovich approximation: key to understanding cosmic web complexity

NASA Astrophysics Data System (ADS)

Hidding, Johan; Shandarin, Sergei F.; van de Weygaert, Rien

2014-02-01

We describe how the dynamics of cosmic structure formation defines the intricate geometric structure of the spine of the cosmic web. The Zel'dovich approximation is used to model the backbone of the cosmic web in terms of its singularity structure. The description by Arnold et al. in terms of catastrophe theory forms the basis of our analysis. This two-dimensional analysis involves a profound assessment of the Lagrangian and Eulerian projections of the gravitationally evolving four-dimensional phase-space manifold. It involves the identification of the complete family of singularity classes, and the corresponding caustics that we see emerging as structure in Eulerian space evolves. In particular, as it is instrumental in outlining the spatial network of the cosmic web, we investigate the nature of spatial connections between these singularities. The major finding of our study is that all singularities are located on a set of lines in Lagrangian space. All dynamical processes related to the caustics are concentrated near these lines. We demonstrate and discuss extensively how all 2D singularities are to be found on these lines. When mapping this spatial pattern of lines to Eulerian space, we find a growing connectedness between initially disjoint lines, resulting in a percolating network. In other words, the lines form the blueprint for the global geometric evolution of the cosmic web.

Association of Small Computer Users in Education: Proceedings of the ASCUE Summer Conference (31st, North Myrtle Beach, South Carolina, June 7-11, 1998).

ERIC Educational Resources Information Center

Smith, Peter, Ed.

Topics addressed by the papers including in this proceedings include: multimedia in the classroom; World Wide Web site development; the evolution of academic library services; a Web-based literature course; development of a real-time intelligent network environment; serving grades over the Internet; e-mail over a Web browser; using technology to…

The GAENE--Generalized Acceptance of EvolutioN Evaluation: Development of a New Measure of Evolution Acceptance

ERIC Educational Resources Information Center

Smith, Mike U.; Snyder, Scott W.; Devereaux, Randolph S.

2016-01-01

The present study reports the development of a brief, quantitative, web-based, psychometrically sound measure--the Generalized Acceptance of EvolutioN Evaluation (GAENE, pronounced "gene") in a format that is useful in large and small groups, in research, and in classroom settings. The measure was designed to measure only evolution…

Reticulate evolution and the human past: an anthropological perspective.

PubMed

Winder, Isabelle C; Winder, Nick P

2014-01-01

The evidence is mounting that reticulate (web-like) evolution has shaped the biological histories of many macroscopic plants and animals, including non-human primates closely related to Homo sapiens, but the implications of this non-hierarchical evolution for anthropological enquiry are not yet fully understood. When they are understood, the result may be a paradigm shift in evolutionary anthropology. This paper reviews the evidence for reticulated evolution in the non-human primates and human lineage. Then it makes the case for extrapolating this sort of patterning to Homo sapiens and other hominins and explores the implications this would have for research design, method and understandings of evolution in anthropology. Reticulation was significant in human evolutionary history and continues to influence societies today. Anthropologists and human scientists-whether working on ancient or modern populations-thus need to consider the implications of non-hierarchic evolution, particularly where molecular clocks, mathematical models and simplifying assumptions about evolutionary processes are used. This is not just a problem for palaeoanthropology. The simple fact of different mating systems among modern human groups, for example, may demand that more attention is paid to the potential for complexity in human genetic and cultural histories.

FY09 Final Report for LDRD Project: Understanding Viral Quasispecies Evolution through Computation and Experiment

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

Zhou, C

2009-11-12

In FY09 they will (1) complete the implementation, verification, calibration, and sensitivity and scalability analysis of the in-cell virus replication model; (2) complete the design of the cell culture (cell-to-cell infection) model; (3) continue the research, design, and development of their bioinformatics tools: the Web-based structure-alignment-based sequence variability tool and the functional annotation of the genome database; (4) collaborate with the University of California at San Francisco on areas of common interest; and (5) submit journal articles that describe the in-cell model with simulations and the bioinformatics approaches to evaluation of genome variability and fitness.

An efficient scheme for automatic web pages categorization using the support vector machine

NASA Astrophysics Data System (ADS)

Bhalla, Vinod Kumar; Kumar, Neeraj

2016-07-01

In the past few years, with an evolution of the Internet and related technologies, the number of the Internet users grows exponentially. These users demand access to relevant web pages from the Internet within fraction of seconds. To achieve this goal, there is a requirement of an efficient categorization of web page contents. Manual categorization of these billions of web pages to achieve high accuracy is a challenging task. Most of the existing techniques reported in the literature are semi-automatic. Using these techniques, higher level of accuracy cannot be achieved. To achieve these goals, this paper proposes an automatic web pages categorization into the domain category. The proposed scheme is based on the identification of specific and relevant features of the web pages. In the proposed scheme, first extraction and evaluation of features are done followed by filtering the feature set for categorization of domain web pages. A feature extraction tool based on the HTML document object model of the web page is developed in the proposed scheme. Feature extraction and weight assignment are based on the collection of domain-specific keyword list developed by considering various domain pages. Moreover, the keyword list is reduced on the basis of ids of keywords in keyword list. Also, stemming of keywords and tag text is done to achieve a higher accuracy. An extensive feature set is generated to develop a robust classification technique. The proposed scheme was evaluated using a machine learning method in combination with feature extraction and statistical analysis using support vector machine kernel as the classification tool. The results obtained confirm the effectiveness of the proposed scheme in terms of its accuracy in different categories of web pages.

The SNAP Platform: Social Networking for Academic Purposes

ERIC Educational Resources Information Center

Kirkwood, Keith

2010-01-01

Purpose: This paper aims to introduce an enterprise-wide Web 2.0 learning support platform--SNAP, developed at Victoria University in Melbourne, Australia. Design/methodology/approach: Pointing to the evolution of the social web, the paper discusses the potential for the development of e-learning platforms that employ constructivist, connectivist,…

Spider Webs and Silks.

ERIC Educational Resources Information Center

Vollrath, Fritz

1992-01-01

Compares the attributes of the silk from spiders with those of the commercially harvested silk from silkworms. Discusses the evolution, design, and effectiveness of spider webs; the functional mechanics of the varieties of silk that can be produced by the same spider; and the composite, as well as molecular, structure of spider silk thread. (JJK)

Sloan Great Wall as a complex of superclusters with collapsing cores

NASA Astrophysics Data System (ADS)

Einasto, Maret; Lietzen, Heidi; Gramann, Mirt; Tempel, Elmo; Saar, Enn; Liivamägi, Lauri Juhan; Heinämäki, Pekka; Nurmi, Pasi; Einasto, Jaan

2016-10-01

Context. The formation and evolution of the cosmic web is governed by the gravitational attraction of dark matter and antigravity of dark energy (cosmological constant). In the cosmic web, galaxy superclusters or their high-density cores are the largest objects that may collapse at present or during the future evolution. Aims: We study the dynamical state and possible future evolution of galaxy superclusters from the Sloan Great Wall (SGW), the richest galaxy system in the nearby Universe. Methods: We calculated supercluster masses using dynamical masses of galaxy groups and stellar masses of galaxies. We employed normal mixture modelling to study the structure of rich SGW superclusters and search for components (cores) in superclusters. We analysed the radial mass distribution in the high-density cores of superclusters centred approximately at rich clusters and used the spherical collapse model to study their dynamical state. Results: The lower limit of the total mass of the SGW is approximately M = 2.5 × 1016 h-1 M⊙. Different mass estimators of superclusters agree well, the main uncertainties in masses of superclusters come from missing groups and clusters. We detected three high-density cores in the richest SGW supercluster (SCl 027) and two in the second richest supercluster (SCl 019). They have masses of 1.2 - 5.9 × 1015 h-1 M⊙ and sizes of up to ≈60 h-1 Mpc. The high-density cores of superclusters are very elongated, flattened perpendicularly to the line of sight. The comparison of the radial mass distribution in the high-density cores with the predictions of spherical collapse model suggests that their central regions with radii smaller than 8 h-1 Mpc and masses of up to M = 2 × 1015 h-1 M⊙ may be collapsing. Conclusions: The rich SGW superclusters with their high-density cores represent dynamically evolving environments for studies of the properties of galaxies and galaxy systems.

Philosophy and Sociology of Science Evolution and History

NASA Astrophysics Data System (ADS)

Rosen, Joe

The following sections are included: * Concrete Versus Abstract Theoretical Models * Introduction: concrete and abstract in kepler's contribution * Einstein's theory of gravitation and mach's principle * Unitary symmetry and the structure of hadrons * Conclusion * Dedication * Symmetry, Entropy and Complexity * Introduction * Symmetry Implies Abstraction and Loss of Information * Broken Symmetries - Imposed or Spontaneous * Symmetry, Order and Information * References * Cosmological Surrealism: More Than "Eternal Reality" Is Needed * Pythagoreanism in atomic, nuclear and particle physics * Introduction: Pythagoreanism as part of the Greek scientific world view — and the three questions I will tackle * Point 1: the impact of Gersonides and Crescas, two scientific anti-Aristotelian rebels * Point 2: Kepler's spheres to Bohr's orbits — Pythagoreanisms at last! * Point 3: Aristotle to Maupertuis, Emmy Noether, Schwinger * References * Paradigm Completion For Generalized Evolutionary Theory With Application To Epistemology * Evolution Fully Generalized * Entropy: Gravity as Model * Evolution and Entropy: Measures of Complexity * Extinctions and a Balanced Evolutionary Paradigm * The Evolution of Human Society - the Age of Information as example * High-Energy Physics and the World Wide Web * Twentieth Century Epistemology has Strong (de facto) Evolutionary Elements * The discoveries towards the beginning of the XXth Century * Summary and Conclusions * References * Evolutionary Epistemology and Invalidation * Introduction * Extinctions and A New Evolutionary Paradigm * Evolutionary Epistemology - Active Mutations * Evolutionary Epistemology: Invalidation as An Extinction * References

Color Addition and Subtraction Apps

NASA Astrophysics Data System (ADS)

Ruiz, Frances; Ruiz, Michael J.

2015-10-01

Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step in understanding mathematical representations of RGB color. Finally, color addition and subtraction are presented for the X11 colors from web design to illustrate yet another real-life application of color mixing.

High-resolution phylogenic microbial community profiling

USDA-ARS?s Scientific Manuscript database

PIECE (Plant Intron Exon Comparison and Evolution) is a web-accessible database that houses intron and exon information of plant genes. PIECE serves as a resource for biologists interested in comparing intron–exon organization and provides valuable insights into the evolution of gene structure in pl...

NAS operational evolution plan : a foundation for capacity enhancement 2001-2010

DOT National Transportation Integrated Search

2001-06-01

This series of World Wide Web slides focuses on the Operational Evolution Plan, which is a 10-year plan for aviation operational improvements to increase capacity and safety in the United States. This plan is unique in that it integrates all actions:...

Monash Chemical Yields Project (Monχey) - Element production in low- and intermediate-mass stars of metallicities Z = 0 to 0.04

NASA Astrophysics Data System (ADS)

Doherty, Carolyn Louise; Lattanzio, John; Angelou, George; Wattana Campbell, Simon; Church, Ross; Constantino, Thomas; Cristallo, Sergio; Gil-Pons, Pilar; Karakas, Amanda; Lugaro, Maria; Stancliffe, Richard James

2015-08-01

The Monχey project provides a large and homogeneous set of stellar yields for the low- and intermediate- mass stars and has applications particularly to galactic chemical evolution modelling.We present a detailed grid of stellar evolutionary models and corresponding nucleosynthetic yields for stars of initial mass 0.8 M⊙ up to the limit for core collapse supernova ≈ 10 M⊙. Our study covers a broad range of metallicities, ranging from the first, primordial stars (Z=0) to those of super-solar metallicity (Z=0.04). The models are evolved from the zero-age main-sequence until the end of the asymptotic giant branch (AGB) and the nucleosynthesis calculations include all elements from H to Bi.A major innovation of our work is the first complete grid of heavy element nucleosynthetic predictions for primordial AGB stars as well as the inclusion of extra-mixing processes (in this case thermohaline) during the red giant branch. We provide a broad overview of our results with implications for galactic chemical evolution as well as highlight interesting results such as heavy element production in dredge-out events of super-AGB stars.We briefly introduce our easy to use web-based database which provides the evolutionary tracks, structural properties, internal/surface nucleosynthetic compositions and stellar yields. Our web interface includes user- driven plotting capabilities with output available in a range of formats. Our nucleosynthetic results are available for further use in post processing calculations for dust production yields.

Content-Based Personalization Services Integrating Folksonomies

NASA Astrophysics Data System (ADS)

Musto, Cataldo; Narducci, Fedelucio; Lops, Pasquale; de Gemmis, Marco; Semeraro, Giovanni

Basic content-based personalization consists in matching up the attributes of a user profile, in which preferences and interests are stored, with the attributes of a content object. The Web 2.0 (r)evolution has changed the game for personalization, from ‘elitary’ Web 1.0, written by few and read by many, to web content generated by everyone (user-generated content - UGC), since the role of people has evolved from passive consumers of information to that of active contributors.

Ice Sheet System Model as Educational Entertainment

NASA Astrophysics Data System (ADS)

Perez, G.

2013-12-01

Understanding the importance of polar ice sheets and their role in the evolution of Sea Level Rise (SLR), as well as Climate Change, is of paramount importance for policy makers as well as the public and schools at large. For example, polar ice sheets and glaciers currently account for 1/3 of the SLR signal, a ratio that will increase in the near to long-term future, which has tremendous societal ramifications. Consequently, it is important to increase awareness about our changing planet. In our increasingly digital society, mobile and web applications are burgeoning venues for such outreach. The Ice Sheet System Model (ISSM) is a software that was developed at the Jet Propulsion Laboratory/CalTech/NASA, in collaboration with University of California Irvine (UCI), with the goal of better understanding the evolution of polar ice sheets. It is a state-of-the-art framework, which relies on higher-end cluster-computing to address some of the aforementioned challenges. In addition, it is a flexible framework that can be deployed on any hardware; in particular, on mobile platforms such as Android or iOS smart phones. Here, we look at how the ISSM development team managed to port their model to these platforms, what the implications are for improving how scientists disseminate their results, and how a broader audience may familiarize themselves with running complex climate models in simplified scenarios which are highly educational and entertaining in content. We also look at the future plans toward a web portal fully integrated with mobile technologies to deliver the best content to the public, and to provide educational plans/lessons that can be used in grades K-12 as well as collegiate under-graduate and graduate programs.

Higher Education on the Web.

ERIC Educational Resources Information Center

Lee, John

2001-01-01

The investment in information technology has doubled for colleges over the last 10 years, and the next big evolution, the development of Web-based learning, is well underway. Most colleges and universities have a strategic plan for distance education or are developing one. The effort is led by community colleges and private universities, both of…

OrthoVenn: a web server for genome wide comparison and annotation of orthologous clusters across multiple species

USDA-ARS?s Scientific Manuscript database

Genome wide analysis of orthologous clusters is an important component of comparative genomics studies. Identifying the overlap among orthologous clusters can enable us to elucidate the function and evolution of proteins across multiple species. Here, we report a web platform named OrthoVenn that i...

Signal conflict in spider webs driven by predators and prey

PubMed Central

Blackledge, T. A.

1998-01-01

Variation in the sensory physiologies of organisms can bias the receptions of signals, driving the direction of signal evolution. Sensory drive in the evolution of signals may be particularly important for organisms that confront trade-offs in signal design between the need for conspicuousness to allow effective transfer of information and the need for crypsis of the signal to unintended receivers. Several genera of orb-weaving spiders include conspicuous silk designs, stabilimenta, in the centre of their webs. Stabilimenta can be highly visible signals to predators, warning them of the presence of a noxious, sticky silk web. However, stabilimenta can also be used by prey as a signal in avoidance of webs, creating a trade-off in signal visibility. I argue that the derived spectral properties of stabilimentum silk have resulted in part from this conflict. The innate colour preferences of insects, their ability to learn colours, and the spectral properties of flowers all suggest that the reflectance spectra of stabilimenta renders them relatively cryptic to many insect prey, while maintaining their visibility to vertebrate predators.

Evolution of health web certification through the HONcode experience.

PubMed

Boyer, Célia; Baujard, Vincent; Geissbuhler, Antoine

2011-01-01

Today, the Web is a media with increasing pervasiveness around the world. Its use is constantly growing and the medical field is no exception. With this large amount of information, the problem is no longer about finding information but assessing the credibility of the publishers as well as the relevance and accuracy of the documents retrieved from the web. This problem is particularly relevant in the medical area which has a direct impact on the well-being of citizens and in the Web 2.0 context where information publishing is easier than ever. To address the quality of the medical Internet, the HONcode certification proposed by the Health On the Net Foundation (HON) is certainly the most successful initiative. The aims of this paper are to present certification activity through the HONcode experience and to show that certification is more complex than a simple code of conduct. Therefore, we first present the HONcode, its application and its current evolutions. Following that, we give some quantitative results and describe how the final user can access the certified information.

INTERSPIA: a web application for exploring the dynamics of protein-protein interactions among multiple species.

PubMed

Kwon, Daehong; Lee, Daehwan; Kim, Juyeon; Lee, Jongin; Sim, Mikang; Kim, Jaebum

2018-05-09

Proteins perform biological functions through cascading interactions with each other by forming protein complexes. As a result, interactions among proteins, called protein-protein interactions (PPIs) are not completely free from selection constraint during evolution. Therefore, the identification and analysis of PPI changes during evolution can give us new insight into the evolution of functions. Although many algorithms, databases and websites have been developed to help the study of PPIs, most of them are limited to visualize the structure and features of PPIs in a chosen single species with limited functions in the visualization perspective. This leads to difficulties in the identification of different patterns of PPIs in different species and their functional consequences. To resolve these issues, we developed a web application, called INTER-Species Protein Interaction Analysis (INTERSPIA). Given a set of proteins of user's interest, INTERSPIA first discovers additional proteins that are functionally associated with the input proteins and searches for different patterns of PPIs in multiple species through a server-side pipeline, and second visualizes the dynamics of PPIs in multiple species using an easy-to-use web interface. INTERSPIA is freely available at http://bioinfo.konkuk.ac.kr/INTERSPIA/.

Visualization on the Web of 20 Years of Crop Rotation and Wildlife Co-Evolutions

NASA Astrophysics Data System (ADS)

Plumejeaud-Perreau, Christine; Poitevin, Cyril; Bretagnolle, Vincent

2018-05-01

The accumulation of evidences of the effects of intensive agricultural practices against wildlife fauna and flora, and biodiversity in general, has been largely published in scientific papers (Tildman, 1999). However, data serving as sup-port to their conclusions are often kept hidden behind research institutions. This paper presents a data visualization sys-tem opened on the Web allowing citizens to get a comprehensive access to data issued from such kind of research institution, collected for more than 20 years. The Web Information System has been thought in order to ease the comparison of data issues from various databases describing the same object, the agricultural landscape, at different scales and through different observation devices. An interactive visualization is proposed in order to check co-evolution of fauna and flora together with agricultural practices. It mixes aerial orthoimagery produced since 1950 with vectorial data showing the evolutions of agricultural parcels with those of a few sentinel species such as the Montagu's harrier. This is made through a composition of maps, charts and time lines, and specific tools for comparison. A particular concern is given to the observation effort bias in order to show meaningful statistical aggregates.

Existence and significance of communities in the World Trade Web

NASA Astrophysics Data System (ADS)

Piccardi, Carlo; Tajoli, Lucia

2012-06-01

The World Trade Web (WTW), which models the international transactions among countries, is a fundamental tool for studying the economics of trade flows, their evolution over time, and their implications for a number of phenomena, including the propagation of economic shocks among countries. In this respect, the possible existence of communities is a key point, because it would imply that countries are organized in groups of preferential partners. In this paper, we use four approaches to analyze communities in the WTW between 1962 and 2008, based, respectively, on modularity optimization, cluster analysis, stability functions, and persistence probabilities. Overall, the four methods agree in finding no evidence of significant partitions. A few weak communities emerge from the analysis, but they do not represent secluded groups of countries, as intercommunity linkages are also strong, supporting the view of a truly globalized trading system.

Existence and significance of communities in the World Trade Web.

PubMed

Piccardi, Carlo; Tajoli, Lucia

2012-06-01

The World Trade Web (WTW), which models the international transactions among countries, is a fundamental tool for studying the economics of trade flows, their evolution over time, and their implications for a number of phenomena, including the propagation of economic shocks among countries. In this respect, the possible existence of communities is a key point, because it would imply that countries are organized in groups of preferential partners. In this paper, we use four approaches to analyze communities in the WTW between 1962 and 2008, based, respectively, on modularity optimization, cluster analysis, stability functions, and persistence probabilities. Overall, the four methods agree in finding no evidence of significant partitions. A few weak communities emerge from the analysis, but they do not represent secluded groups of countries, as intercommunity linkages are also strong, supporting the view of a truly globalized trading system.

Time-dependent extinction rate and species abundance in a tangled-nature model of biological evolution.

PubMed

Hall, Matt; Christensen, Kim; di Collobiano, Simone A; Jensen, Henrik Jeldtoft

2002-07-01

We present a model of evolutionary ecology consisting of a web of interacting individuals, a tangle-nature model. The reproduction rate of individuals characterized by their genome depends on the composition of the population in genotype space. Ecological features such as the taxonomy and the macroevolutionary mode of the dynamics are emergent properties. The macrodynamics exhibit intermittent two-mode switching with a gradually decreasing extinction rate. The generated ecologies become gradually better adapted as well as more complex in a collective sense. The form of the species abundance curve compares well with observed functional forms. The model's error threshold can be understood in terms of the characteristics of the two dynamical modes of the system.

Evolutionary Topology of a Currency Network in Asia

NASA Astrophysics Data System (ADS)

Feng, Xiaobing; Wang, Xiaofan

Although recently there are extensive research on currency network using minimum spanning trees approach, the knowledge about the actual evolution of a currency web in Asia is still limited. In the paper, we study the structural evolution of an Asian network using daily exchange rate data. It was found that the correlation between Asian currencies and US Dollar, the previous regional key currency has become weaker and the intra-Asia interactions have increased. This becomes more salient after the exchange rate reform of China. Different from the previous studies, we further reveal that it is the trade volume, national wealth gap and countries growth cycle that has contributed to the evolutionary topology of the minimum spanning tree. These findings provide a valuable platform for theoretical modeling and further analysis.

webMGR: an online tool for the multiple genome rearrangement problem.

PubMed

Lin, Chi Ho; Zhao, Hao; Lowcay, Sean Harry; Shahab, Atif; Bourque, Guillaume

2010-02-01

The algorithm MGR enables the reconstruction of rearrangement phylogenies based on gene or synteny block order in multiple genomes. Although MGR has been successfully applied to study the evolution of different sets of species, its utilization has been hampered by the prohibitive running time for some applications. In the current work, we have designed new heuristics that significantly speed up the tool without compromising its accuracy. Moreover, we have developed a web server (webMGR) that includes elaborate web output to facilitate navigation through the results. webMGR can be accessed via http://www.gis.a-star.edu.sg/~bourque. The source code of the improved standalone version of MGR is also freely available from the web site. Supplementary data are available at Bioinformatics online.

FPA Depot - Web Application

NASA Technical Reports Server (NTRS)

Avila, Edwin M. Martinez; Muniz, Ricardo; Szafran, Jamie; Dalton, Adam

2011-01-01

Lines of code (LOC) analysis is one of the methods used to measure programmer productivity and estimate schedules of programming projects. The Launch Control System (LCS) had previously used this method to estimate the amount of work and to plan development efforts. The disadvantage of using LOC as a measure of effort is that one can only measure 30% to 35% of the total effort of software projects involves coding [8]. In the application, instead of using the LOC we are using function point for a better estimation of hours in each software to develop. Because of these disadvantages, Jamie Szafran of the System Software Branch of Control And Data Systems (NE-C3) at Kennedy Space Canter developed a web application called Function Point Analysis (FPA) Depot. The objective of this web application is that the LCS software architecture team can use the data to more accurately estimate the effort required to implement customer requirements. This paper describes the evolution of the domain model used for function point analysis as project managers continually strive to generate more accurate estimates.

Bringing Control System User Interfaces to the Web

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

Chen, Xihui; Kasemir, Kay

With the evolution of web based technologies, especially HTML5 [1], it becomes possible to create web-based control system user interfaces (UI) that are cross-browser and cross-device compatible. This article describes two technologies that facilitate this goal. The first one is the WebOPI [2], which can seamlessly display CSS BOY [3] Operator Interfaces (OPI) in web browsers without modification to the original OPI file. The WebOPI leverages the powerful graphical editing capabilities of BOY and provides the convenience of re-using existing OPI files. On the other hand, it uses generic JavaScript and a generic communication mechanism between the web browser andmore » web server. It is not optimized for a control system, which results in unnecessary network traffic and resource usage. Our second technology is the WebSocket-based Process Data Access (WebPDA) [4]. It is a protocol that provides efficient control system data communication using WebSocket [5], so that users can create web-based control system UIs using standard web page technologies such as HTML, CSS and JavaScript. WebPDA is control system independent, potentially supporting any type of control system.« less

The Evolution of a National Distance Guidance Service: Trends and Challenges

ERIC Educational Resources Information Center

Watts, A. G.; Dent, Gareth

2008-01-01

Three trends in the evolution of the UK Learndirect advice service are identified: the partial migration from telephone to web-based services; the trend within the telephone service from information/advice-oriented interventions to more guidance-oriented interventions; and the move from a mainly learning-oriented service to a more career-oriented…

Designing a Resource Evolution Support System for Open Knowledge Communities

ERIC Educational Resources Information Center

Yang, Xianmin; Yu, Shengquan

2015-01-01

The continuous generation and evolution of digital learning resources is important for promoting open learning and meeting the personalized needs of learners. In the Web 2.0 era, open and collaborative authoring is becoming a popular method by which to create vast personalized learning resources in open knowledge communities (OKCs). However, the…

Web-based recruitment and survey methodology to capture followers of popular diets: the adhering to dietary approaches for personal taste (ADAPT) feasibility survey

USDA-ARS?s Scientific Manuscript database

Background: Although there is interest in popular diets such as vegan/vegetarian, Paleo, and other whole food diets, existing cohort studies lack specific data for these subgroups. With the evolution of new technologies, such as electronic data capture and web-based surveys, their application to nut...

Characteristics and evolution of the ecosystem of software tools supporting research in molecular biology.

PubMed

Pazos, Florencio; Chagoyen, Monica

2018-01-16

Daily work in molecular biology presently depends on a large number of computational tools. An in-depth, large-scale study of that 'ecosystem' of Web tools, its characteristics, interconnectivity, patterns of usage/citation, temporal evolution and rate of decay is crucial for understanding the forces that shape it and for informing initiatives aimed at its funding, long-term maintenance and improvement. In particular, the long-term maintenance of these tools is compromised because of their specific development model. Hundreds of published studies become irreproducible de facto, as the software tools used to conduct them become unavailable. In this study, we present a large-scale survey of >5400 publications describing Web servers within the two main bibliographic resources for disseminating new software developments in molecular biology. For all these servers, we studied their citation patterns, the subjects they address, their citation networks and the temporal evolution of these factors. We also analysed how these factors affect the availability of these servers (whether they are alive). Our results show that this ecosystem of tools is highly interconnected and adapts to the 'trendy' subjects in every moment. The servers present characteristic temporal patterns of citation/usage, and there is a worrying rate of server 'death', which is influenced by factors such as the server popularity and the institutions that hosts it. These results can inform initiatives aimed at the long-term maintenance of these resources. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Spinning Gland Transcriptomics from Two Main Clades of Spiders (Order: Araneae) - Insights on Their Molecular, Anatomical and Behavioral Evolution

PubMed Central

Prosdocimi, Francisco; Bittencourt, Daniela; da Silva, Felipe Rodrigues; Kirst, Matias; Motta, Paulo C.; Rech, Elibio L.

2011-01-01

Characterized by distinctive evolutionary adaptations, spiders provide a comprehensive system for evolutionary and developmental studies of anatomical organs, including silk and venom production. Here we performed cDNA sequencing using massively parallel sequencers (454 GS-FLX Titanium) to generate ∼80,000 reads from the spinning gland of Actinopus spp. (infraorder: Mygalomorphae) and Gasteracantha cancriformis (infraorder: Araneomorphae, Orbiculariae clade). Actinopus spp. retains primitive characteristics on web usage and presents a single undifferentiated spinning gland while the orbiculariae spiders have seven differentiated spinning glands and complex patterns of web usage. MIRA, Celera Assembler and CAP3 software were used to cluster NGS reads for each spider. CAP3 unigenes passed through a pipeline for automatic annotation, classification by biological function, and comparative transcriptomics. Genes related to spider silks were manually curated and analyzed. Although a single spidroin gene family was found in Actinopus spp., a vast repertoire of specialized spider silk proteins was encountered in orbiculariae. Astacin-like metalloproteases (meprin subfamily) were shown to be some of the most sampled unigenes and duplicated gene families in G. cancriformis since its evolutionary split from mygalomorphs. Our results confirm that the evolution of the molecular repertoire of silk proteins was accompanied by the (i) anatomical differentiation of spinning glands and (ii) behavioral complexification in the web usage. Finally, a phylogenetic tree was constructed to cluster most of the known spidroins in gene clades. This is the first large-scale, multi-organism transcriptome for spider spinning glands and a first step into a broad understanding of spider web systems biology and evolution. PMID:21738742

GEM System: automatic prototyping of cell-wide metabolic pathway models from genomes.

PubMed

Arakawa, Kazuharu; Yamada, Yohei; Shinoda, Kosaku; Nakayama, Yoichi; Tomita, Masaru

2006-03-23

Successful realization of a "systems biology" approach to analyzing cells is a grand challenge for our understanding of life. However, current modeling approaches to cell simulation are labor-intensive, manual affairs, and therefore constitute a major bottleneck in the evolution of computational cell biology. We developed the Genome-based Modeling (GEM) System for the purpose of automatically prototyping simulation models of cell-wide metabolic pathways from genome sequences and other public biological information. Models generated by the GEM System include an entire Escherichia coli metabolism model comprising 968 reactions of 1195 metabolites, achieving 100% coverage when compared with the KEGG database, 92.38% with the EcoCyc database, and 95.06% with iJR904 genome-scale model. The GEM System prototypes qualitative models to reduce the labor-intensive tasks required for systems biology research. Models of over 90 bacterial genomes are available at our web site.

Social Semantics for an Effective Enterprise

NASA Technical Reports Server (NTRS)

Berndt, Sarah; Doane, Mike

2012-01-01

An evolution of the Semantic Web, the Social Semantic Web (s2w), facilitates knowledge sharing with "useful information based on human contributions, which gets better as more people participate." The s2w reaches beyond the search box to move us from a collection of hyperlinked facts, to meaningful, real time context. When focused through the lens of Enterprise Search, the Social Semantic Web facilitates the fluid transition of meaningful business information from the source to the user. It is the confluence of human thought and computer processing structured with the iterative application of taxonomies, folksonomies, ontologies, and metadata schemas. The importance and nuances of human interaction are often deemphasized when focusing on automatic generation of semantic markup, which results in dissatisfied users and unrealized return on investment. Users consistently qualify the value of information sets through the act of selection, making them the de facto stakeholders of the Social Semantic Web. Employers are the ultimate beneficiaries of s2w utilization with a better informed, more decisive workforce; one not achieved with an IT miracle technology, but by improved human-computer interactions. Johnson Space Center Taxonomist Sarah Berndt and Mike Doane, principal owner of Term Management, LLC discuss the planning, development, and maintenance stages for components of a semantic system while emphasizing the necessity of a Social Semantic Web for the Enterprise. Identification of risks and variables associated with layering the successful implementation of a semantic system are also modeled.

Properties of galaxies reproduced by a hydrodynamic simulation

NASA Astrophysics Data System (ADS)

Vogelsberger, M.; Genel, S.; Springel, V.; Torrey, P.; Sijacki, D.; Xu, D.; Snyder, G.; Bird, S.; Nelson, D.; Hernquist, L.

2014-05-01

Previous simulations of the growth of cosmic structures have broadly reproduced the `cosmic web' of galaxies that we see in the Universe, but failed to create a mixed population of elliptical and spiral galaxies, because of numerical inaccuracies and incomplete physical models. Moreover, they were unable to track the small-scale evolution of gas and stars to the present epoch within a representative portion of the Universe. Here we report a simulation that starts 12 million years after the Big Bang, and traces 13 billion years of cosmic evolution with 12 billion resolution elements in a cube of 106.5 megaparsecs a side. It yields a reasonable population of ellipticals and spirals, reproduces the observed distribution of galaxies in clusters and characteristics of hydrogen on large scales, and at the same time matches the `metal' and hydrogen content of galaxies on small scales.

Integrating Engineering Data Systems for NASA Spaceflight Projects

NASA Technical Reports Server (NTRS)

Carvalho, Robert E.; Tollinger, Irene; Bell, David G.; Berrios, Daniel C.

2012-01-01

NASA has a large range of custom-built and commercial data systems to support spaceflight programs. Some of the systems are re-used by many programs and projects over time. Management and systems engineering processes require integration of data across many of these systems, a difficult problem given the widely diverse nature of system interfaces and data models. This paper describes an ongoing project to use a central data model with a web services architecture to support the integration and access of linked data across engineering functions for multiple NASA programs. The work involves the implementation of a web service-based middleware system called Data Aggregator to bring together data from a variety of systems to support space exploration. Data Aggregator includes a central data model registry for storing and managing links between the data in disparate systems. Initially developed for NASA's Constellation Program needs, Data Aggregator is currently being repurposed to support the International Space Station Program and new NASA projects with processes that involve significant aggregating and linking of data. This change in user needs led to development of a more streamlined data model registry for Data Aggregator in order to simplify adding new project application data as well as standardization of the Data Aggregator query syntax to facilitate cross-application querying by client applications. This paper documents the approach from a set of stand-alone engineering systems from which data are manually retrieved and integrated, to a web of engineering data systems from which the latest data are automatically retrieved and more quickly and accurately integrated. This paper includes the lessons learned through these efforts, including the design and development of a service-oriented architecture and the evolution of the data model registry approaches as the effort continues to evolve and adapt to support multiple NASA programs and priorities.

Development and evolution of The Knowledge Hub for Pathology and related electronic resources.

PubMed

Hardwick, David F; Sinard, John; Silva, Fred

2011-06-01

The Knowledge Hub for Pathology was created to provide authenticated and validated knowledge for United States and Canadian Academy of Pathology members and pathologists worldwide with access to the Web. Using the material presented at the annual meeting of the United States and Canadian Academy of Pathology with existing selection and review procedures ensured that these criteria were met without added costly procedures. Further submissions for courses and research papers are provided in electronic format and funded by universities and hospitals for their creation; thus, the principal costs borne by the United States and Canadian Academy of Pathology are Web site-posting costs. Use has escalated rapidly from 2 million hits in 2002 to 51 million in 2009 with use by 35,000 pathologists from now a total of 180 countries. This true "freemium" model is a successful process as are more traditional continuing professional development course structures such as Anatomic Pathology Electronic Case Series, a "premium" model for learning electronically also sponsored by the United States and Canadian Academy of Pathology. Copyright © 2011 Elsevier Inc. All rights reserved.

[SciELO: A cooperative project for the dissemination of science].

PubMed

Bojo Canales, C; Fraga Medín, C; Hernández Villegas, S; Primo Peña, E

2009-10-01

The article describes the SciELO (Scientific Electronic Library Online) model for the electronic publication and dissemination of scientific journals, its origin and evolution, methodology, components, services and potential, and its implantation in Spain. It consists of thirteen participant countries with eight certified web portals, with another 5 under development and another two thematic ones. In February 2009 Scielo.org had 611 magazines and 195,789 articles of which 46% were about health sciences. Spain became a project member in 1999 and launched the SciELO web portal in 2001, as well as 4 magazines. It currently has 39 titles in the field of Health Sciences; one of which is the Revista Española de Sanidad Penitenciaria, which joined the project in 2007 and which currently has 6 issues from 2007 and 2008 available. This makes it one of the most important open access initiatives existing. The report concludes by stating that the SciELO model contributes to the development of research and science by offering an effective and efficient method of promoting and increasing the dissemination of scientific publications in Latin America.

The Updated BaSTI Stellar Evolution Models and Isochrones. I. Solar-scaled Calculations

NASA Astrophysics Data System (ADS)

Hidalgo, Sebastian L.; Pietrinferni, Adriano; Cassisi, Santi; Salaris, Maurizio; Mucciarelli, Alessio; Savino, Alessandro; Aparicio, Antonio; Silva Aguirre, Victor; Verma, Kuldeep

2018-04-01

We present an updated release of the BaSTI (a Bag of Stellar Tracks and Isochrones) stellar model and isochrone library for a solar-scaled heavy element distribution. The main input physics that have been changed from the previous BaSTI release include the solar metal mixture, electron conduction opacities, a few nuclear reaction rates, bolometric corrections, and the treatment of the overshooting efficiency for shrinking convective cores. The new model calculations cover a mass range between 0.1 and 15 M ⊙, 22 initial chemical compositions between [Fe/H] = ‑3.20 and +0.45, with helium to metal enrichment ratio dY/dZ = 1.31. The isochrones cover an age range between 20 Myr and 14.5 Gyr, consistently take into account the pre-main-sequence phase, and have been translated to a large number of popular photometric systems. Asteroseismic properties of the theoretical models have also been calculated. We compare our isochrones with results from independent databases and with several sets of observations to test the accuracy of the calculations. All stellar evolution tracks, asteroseismic properties, and isochrones are made available through a dedicated web site.

Standards opportunities around data-bearing Web pages.

PubMed

Karger, David

2013-03-28

The evolving Web has seen ever-growing use of structured data, thanks to the way it enhances information authoring, querying, visualization and sharing. To date, however, most structured data authoring and management tools have been oriented towards programmers and Web developers. End users have been left behind, unable to leverage structured data for information management and communication as well as professionals. In this paper, I will argue that many of the benefits of structured data management can be provided to end users as well. I will describe an approach and tools that allow end users to define their own schemas (without knowing what a schema is), manage data and author (not program) interactive Web visualizations of that data using the Web tools with which they are already familiar, such as plain Web pages, blogs, wikis and WYSIWYG document editors. I will describe our experience deploying these tools and some lessons relevant to their future evolution.

Standards, Efficiency, and the Evolution of Web Design

ERIC Educational Resources Information Center

Mitchell, Erik

2010-01-01

The author recently created a presentation using HTML5 based on a tutorial put together by Marcin Wichary. The example presentation is part proof-of-concept, part instructional piece, and it is part of a larger site on HTML5 and how one can use it to create rich Web-based applications. The more he delved into HTML5, the more he found that it was…

Web Content Accessibility Guidelines 2.0: A Further Step towards Accessible Digital Information

ERIC Educational Resources Information Center

Ribera, Mireia; Porras, Merce; Boldu, Marc; Termens, Miquel; Sule, Andreu; Paris, Pilar

2009-01-01

Purpose: The purpose of this paper is to explain the changes in the Web Content Accessibility Guidelines (WCAG) 2.0 compared with WCAG 1.0 within the context of its historical development. Design/methodology/approach: In order to compare WCAG 2.0 with WCAG 1.0 a diachronic analysis of the evolution of these standards is done. Known authors and…

The New Challenges for E-learning: The Educational Semantic Web

ERIC Educational Resources Information Center

Aroyo, Lora; Dicheva, Darina

2004-01-01

The big question for many researchers in the area of educational systems now is what is the next step in the evolution of e-learning? Are we finally moving from a scattered intelligence to a coherent space of collaborative intelligence? How close we are to the vision of the Educational Semantic Web and what do we need to do in order to realize it?…

Embedding the Form Generator in a Content Management System

NASA Astrophysics Data System (ADS)

Delgado, A.; Wicenec, A.; Delmotte, N.; Tejero, A.

2008-08-01

Given the tremendous amount of data generated by ESO's telescopes and the rapid evolution of the World Wide Web, the ESO archive web interface needs to offer more flexible services and advanced functionalities to a growing community of users all over the world. To achieve this endeavour, a query form generator is being developed inside a Content Management System. We present here a progress report.

Realtime Data to Enable Earth-Observing Sensor Web Capabilities

NASA Astrophysics Data System (ADS)

Seablom, M. S.

2015-12-01

Over the past decade NASA's Earth Science Technology Office (ESTO) has invested in new technologies for information systems to enhance the Earth-observing capabilities of satellites, aircraft, and ground-based in situ observations. One focus area has been to create a common infrastructure for coordinated measurements from multiple vantage points which could be commanded either manually or through autonomous means, such as from a numerical model. This paradigm became known as the sensor web, formally defined to be "a coherent set of heterogeneous, loosely-coupled, distributed observing nodes interconnected by a communications fabric that can collectively behave as a single dynamically adaptive and reconfigurable observing system". This would allow for adaptive targeting of rapidly evolving, transient, or variable meteorological features to improve our ability to monitor, understand, and predict their evolution. It would also enable measurements earmarked at critical regions of the atmosphere that are highly sensitive to data analysis errors, thus offering the potential for significant improvements in the predictive skill of numerical weather forecasts. ESTO's investment strategy was twofold. Recognizing that implementation of an operational sensor web would not only involve technical cost and risk but also would require changes to the culture of how flight missions were designed and operated, ESTO funded the development of a mission-planning simulator that would quantitatively assess the added value of coordinated observations. The simulator was designed to provide the capability to perform low-cost engineering and design trade studies using synthetic data generated by observing system simulation experiments (OSSEs). The second part of the investment strategy was to invest in prototype applications that implemented key features of a sensor web, with the dual goals of developing a sensor web reference architecture as well as supporting useful science activities that would produce immediate benefit. We briefly discuss three of ESTO's sensor web projects that resulted from solicitations released in 2008 and 2011: the Earth System Sensor Web Simulator, the Earth Phenomena Observing System, and the Sensor Web 3G Namibia Flood Pilot.

Relation between halo spin and cosmic-web filaments at z ≃ 3

NASA Astrophysics Data System (ADS)

González, Roberto E.; Prieto, Joaquin; Padilla, Nelson; Jimenez, Raul

2017-02-01

We investigate the spin evolution of dark matter haloes and their dependence on the number of connected filaments from the cosmic web at high redshift (spin-filament relation hereafter). To this purpose, we have simulated 5000 haloes in the mass range 5 × 109 h-1 M⊙ to 5 × 1011 h-1 M⊙ at z = 3 in cosmological N-body simulations. We confirm the relation found by Prieto et al. (2015) where haloes with fewer filaments have larger spin. We also found that this relation is more significant for higher halo masses, and for haloes with a passive (no major mergers) assembly history. Another finding is that haloes with larger spin or with fewer filaments have their filaments more perpendicularly aligned with the spin vector. Our results point to a picture in which the initial spin of haloes is well described by tidal torque theory and then gets subsequently modified in a predictable way because of the topology of the cosmic web, which in turn is given by the currently favoured Lambda cold dark matter (LCDM) model. Our spin-filament relation is a prediction from LCDM that could be tested with observations.

Punctuated evolution of viscid silk in spider orb webs supported by mechanical behavior of wet cribellate silk

NASA Astrophysics Data System (ADS)

Piorkowski, Dakota; Blackledge, Todd A.

2017-08-01

The origin of viscid capture silk in orb webs, from cribellate silk-spinning ancestors, is a key innovation correlated with significant diversification of web-building spiders. Ancestral cribellate silk consists of dry nanofibrils surrounding a stiff, axial fiber that adheres to prey through van der Waals interactions, capillary forces, and physical entanglement. In contrast, viscid silk uses chemically adhesive aqueous glue coated onto a highly compliant and extensible flagelliform core silk. The extensibility of the flagelliform fiber accounts for half of the total work of adhesion for viscid silk and is enabled by water in the aqueous coating. Recent cDNA libraries revealed the expression of flagelliform silk proteins in cribellate orb-weaving spiders. We hypothesized that the presence of flagelliform proteins in cribellate silk could have allowed for a gradual shift in mechanical performance of cribellate axial silk, whose effect was masked by the dry nature of its adhesive. We measured supercontraction and mechanical performance of cribellate axial silk, in wet and dry states, for two species of cribellate orb web-weaving spiders to see if water enabled flagelliform silk-like performance. We found that compliance and extensibility of wet cribellate silk increased compared to dry state as expected. However, when compared to other silk types, the response to water was more similar to other web silks, like major and minor ampullate silk, than to viscid silk. These findings support the punctuated evolution of viscid silk mechanical performance.

Empirical analysis of web-based user-object bipartite networks

NASA Astrophysics Data System (ADS)

Shang, Ming-Sheng; Lü, Linyuan; Zhang, Yi-Cheng; Zhou, Tao

2010-05-01

Understanding the structure and evolution of web-based user-object networks is a significant task since they play a crucial role in e-commerce nowadays. This letter reports the empirical analysis on two large-scale web sites, audioscrobbler.com and del.icio.us, where users are connected with music groups and bookmarks, respectively. The degree distributions and degree-degree correlations for both users and objects are reported. We propose a new index, named collaborative similarity, to quantify the diversity of tastes based on the collaborative selection. Accordingly, the correlation between degree and selection diversity is investigated. We report some novel phenomena well characterizing the selection mechanism of web users and outline the relevance of these phenomena to the information recommendation problem.

Properties of galaxies reproduced by a hydrodynamic simulation.

PubMed

Vogelsberger, M; Genel, S; Springel, V; Torrey, P; Sijacki, D; Xu, D; Snyder, G; Bird, S; Nelson, D; Hernquist, L

2014-05-08

Previous simulations of the growth of cosmic structures have broadly reproduced the 'cosmic web' of galaxies that we see in the Universe, but failed to create a mixed population of elliptical and spiral galaxies, because of numerical inaccuracies and incomplete physical models. Moreover, they were unable to track the small-scale evolution of gas and stars to the present epoch within a representative portion of the Universe. Here we report a simulation that starts 12 million years after the Big Bang, and traces 13 billion years of cosmic evolution with 12 billion resolution elements in a cube of 106.5 megaparsecs a side. It yields a reasonable population of ellipticals and spirals, reproduces the observed distribution of galaxies in clusters and characteristics of hydrogen on large scales, and at the same time matches the 'metal' and hydrogen content of galaxies on small scales.

The bacterial composition within the Sarracenia purpurea model system: local scale differences and the relationship with the other members of the food web.

PubMed

Gray, Sarah M; Akob, Denise M; Green, Stefan J; Kostka, Joel E

2012-01-01

The leaves of the carnivorous pitcher plant, Sarracenia purpurea, contain a microscopic aquatic food web that is considered a model system in ecological research. The species identity of the intermediate and top trophic level of this food web, as well the detritivore midge, are highly similar across the native geographic range of S. purpurea and, in some cases, appear to have co-evolved with the plant. However, until recently, the identity, geographic variation, and diversity of the bacteria in the bottom trophic level of this food web have remained largely unknown. This study investigated bacterial community composition inside the leaves of S. purpurea to address: 1) variation in bacterial communities at the beginning of succession at the local scale in different areas of the plant's native geographic range (southern and mid-regional sites) and 2) the impacts of bacterial consumers and other members of the aquatic food web (i.e., insects) on bacterial community structure. Communities from six leaves (one leaf per plant) from New York and Florida study sites were analyzed using 16S ribosomal RNA gene cloning. Each pitcher within each site had a distinct community; however, there was more overlap in bacterial composition within each site than when communities were compared across sites. In contrast, the identity of protozoans and metazoans in this community were similar in species identity both within a site and between the two sites, but abundances differed. Our results indicate that, at least during the beginning of succession, there is no strong selection for bacterial taxa and that there is no core group of bacteria required by the plant to start the decomposition of trapped insects. Co-evolution between the plant and bacteria appears to not have occurred as it has for other members of this community.

The Bacterial Composition within the Sarracenia purpurea Model System: Local Scale Differences and the Relationship with the Other Members of the Food Web

PubMed Central

Gray, Sarah M.; Akob, Denise M.; Green, Stefan J.; Kostka, Joel E.

2012-01-01

The leaves of the carnivorous pitcher plant, Sarracenia purpurea, contain a microscopic aquatic food web that is considered a model system in ecological research. The species identity of the intermediate and top trophic level of this food web, as well the detritivore midge, are highly similar across the native geographic range of S. purpurea and, in some cases, appear to have co-evolved with the plant. However, until recently, the identity, geographic variation, and diversity of the bacteria in the bottom trophic level of this food web have remained largely unknown. This study investigated bacterial community composition inside the leaves of S. purpurea to address: 1) variation in bacterial communities at the beginning of succession at the local scale in different areas of the plant’s native geographic range (southern and mid-regional sites) and 2) the impacts of bacterial consumers and other members of the aquatic food web (i.e., insects) on bacterial community structure. Communities from six leaves (one leaf per plant) from New York and Florida study sites were analyzed using 16S ribosomal RNA gene cloning. Each pitcher within each site had a distinct community; however, there was more overlap in bacterial composition within each site than when communities were compared across sites. In contrast, the identity of protozoans and metazoans in this community were similar in species identity both within a site and between the two sites, but abundances differed. Our results indicate that, at least during the beginning of succession, there is no strong selection for bacterial taxa and that there is no core group of bacteria required by the plant to start the decomposition of trapped insects. Co-evolution between the plant and bacteria appears to not have occurred as it has for other members of this community. PMID:23227224

The cosmic web in CosmoGrid void regions

NASA Astrophysics Data System (ADS)

Rieder, Steven; van de Weygaert, Rien; Cautun, Marius; Beygu, Burcu; Portegies Zwart, Simon

2016-10-01

We study the formation and evolution of the cosmic web, using the high-resolution CosmoGrid ΛCDM simulation. In particular, we investigate the evolution of the large-scale structure around void halo groups, and compare this to observations of the VGS-31 galaxy group, which consists of three interacting galaxies inside a large void. The structure around such haloes shows a great deal of tenuous structure, with most of such systems being embedded in intra-void filaments and walls. We use the Nexus+} algorithm to detect walls and filaments in CosmoGrid, and find them to be present and detectable at every scale. The void regions embed tenuous walls, which in turn embed tenuous filaments. We hypothesize that the void galaxy group of VGS-31 formed in such an environment.

Spider phylogenomics: untangling the Spider Tree of Life.

PubMed

Garrison, Nicole L; Rodriguez, Juanita; Agnarsson, Ingi; Coddington, Jonathan A; Griswold, Charles E; Hamilton, Christopher A; Hedin, Marshal; Kocot, Kevin M; Ledford, Joel M; Bond, Jason E

2016-01-01

Spiders (Order Araneae) are massively abundant generalist arthropod predators that are found in nearly every ecosystem on the planet and have persisted for over 380 million years. Spiders have long served as evolutionary models for studying complex mating and web spinning behaviors, key innovation and adaptive radiation hypotheses, and have been inspiration for important theories like sexual selection by female choice. Unfortunately, past major attempts to reconstruct spider phylogeny typically employing the "usual suspect" genes have been unable to produce a well-supported phylogenetic framework for the entire order. To further resolve spider evolutionary relationships we have assembled a transcriptome-based data set comprising 70 ingroup spider taxa. Using maximum likelihood and shortcut coalescence-based approaches, we analyze eight data sets, the largest of which contains 3,398 gene regions and 696,652 amino acid sites forming the largest phylogenomic analysis of spider relationships produced to date. Contrary to long held beliefs that the orb web is the crowning achievement of spider evolution, ancestral state reconstructions of web type support a phylogenetically ancient origin of the orb web, and diversification analyses show that the mostly ground-dwelling, web-less RTA clade diversified faster than orb weavers. Consistent with molecular dating estimates we report herein, this may reflect a major increase in biomass of non-flying insects during the Cretaceous Terrestrial Revolution 125-90 million years ago favoring diversification of spiders that feed on cursorial rather than flying prey. Our results also have major implications for our understanding of spider systematics. Phylogenomic analyses corroborate several well-accepted high level groupings: Opisthothele, Mygalomorphae, Atypoidina, Avicularoidea, Theraphosoidina, Araneomorphae, Entelegynae, Araneoidea, the RTA clade, Dionycha and the Lycosoidea. Alternatively, our results challenge the monophyly of Eresoidea, Orbiculariae, and Deinopoidea. The composition of the major paleocribellate and neocribellate clades, the basal divisions of Araneomorphae, appear to be falsified. Traditional Haplogynae is in need of revision, as our findings appear to support the newly conceived concept of Synspermiata. The sister pairing of filistatids with hypochilids implies that some peculiar features of each family may in fact be synapomorphic for the pair. Leptonetids now are seen as a possible sister group to the Entelegynae, illustrating possible intermediates in the evolution of the more complex entelegyne genitalic condition, spinning organs and respiratory organs.

Spider phylogenomics: untangling the Spider Tree of Life

PubMed Central

Garrison, Nicole L.; Rodriguez, Juanita; Agnarsson, Ingi; Coddington, Jonathan A.; Griswold, Charles E.; Hamilton, Christopher A.; Hedin, Marshal; Kocot, Kevin M.; Ledford, Joel M.

2016-01-01

Spiders (Order Araneae) are massively abundant generalist arthropod predators that are found in nearly every ecosystem on the planet and have persisted for over 380 million years. Spiders have long served as evolutionary models for studying complex mating and web spinning behaviors, key innovation and adaptive radiation hypotheses, and have been inspiration for important theories like sexual selection by female choice. Unfortunately, past major attempts to reconstruct spider phylogeny typically employing the “usual suspect” genes have been unable to produce a well-supported phylogenetic framework for the entire order. To further resolve spider evolutionary relationships we have assembled a transcriptome-based data set comprising 70 ingroup spider taxa. Using maximum likelihood and shortcut coalescence-based approaches, we analyze eight data sets, the largest of which contains 3,398 gene regions and 696,652 amino acid sites forming the largest phylogenomic analysis of spider relationships produced to date. Contrary to long held beliefs that the orb web is the crowning achievement of spider evolution, ancestral state reconstructions of web type support a phylogenetically ancient origin of the orb web, and diversification analyses show that the mostly ground-dwelling, web-less RTA clade diversified faster than orb weavers. Consistent with molecular dating estimates we report herein, this may reflect a major increase in biomass of non-flying insects during the Cretaceous Terrestrial Revolution 125–90 million years ago favoring diversification of spiders that feed on cursorial rather than flying prey. Our results also have major implications for our understanding of spider systematics. Phylogenomic analyses corroborate several well-accepted high level groupings: Opisthothele, Mygalomorphae, Atypoidina, Avicularoidea, Theraphosoidina, Araneomorphae, Entelegynae, Araneoidea, the RTA clade, Dionycha and the Lycosoidea. Alternatively, our results challenge the monophyly of Eresoidea, Orbiculariae, and Deinopoidea. The composition of the major paleocribellate and neocribellate clades, the basal divisions of Araneomorphae, appear to be falsified. Traditional Haplogynae is in need of revision, as our findings appear to support the newly conceived concept of Synspermiata. The sister pairing of filistatids with hypochilids implies that some peculiar features of each family may in fact be synapomorphic for the pair. Leptonetids now are seen as a possible sister group to the Entelegynae, illustrating possible intermediates in the evolution of the more complex entelegyne genitalic condition, spinning organs and respiratory organs. PMID:26925338

Bioavailability of Mercury to Riverine Food Webs as a Function of Flood-Event Inundation of Channel Boundary Sediments

NASA Astrophysics Data System (ADS)

Singer, M. B.; Pellachini, C.; Blum, J. D.; Marvin-DiPasquale, M. C.; Donovan, P. M.

2013-12-01

Bioavailability of sediment-adsorbed contaminants to food webs in river corridors is typically controlled by biological, chemical, and physical factors, but understanding of their respective influences is limited due to a dearth of landscape-scale investigations of these biogeochemical links. Studies that account for the dynamics and interactions of hydrology and sediment transport in affecting the reactivity of sediment-adsorbed heavy metals such as mercury (Hg) are particularly lacking. Sequences of flood events generate complex inundation histories with banks, terraces, and floodplains that have the potential to alter local redox conditions and thereby affect the oxidation of elemental Hg0 to inorganic Hg(II), and the microbial conversion of Hg(II) to methylmercury (MeHg), potentially increasing the risk of Hg uptake into aquatic food webs. However, the probability distributions of saturation/inundation frequency and duration are typically unknown for channel boundaries along sediment transport pathways, and landscape-scale characterizations of Hg reactivity are rare along contaminated rivers. This research provides the first links between the dynamics of physical processes and biochemical processing and uptake into food webs in fluvial systems beset by large-scale mining contamination. Here we present new research on Hg-contaminated legacy terraces and banks along the Yuba River anthropogenic fan, produced by 19th C. hydraulic gold mining in Northern California. To assess the changes in Hg(II) availability for methylation and MeHg bioavailability into the food web, we combine numerical modeling of streamflow with geochemical assays of total Hg and Hg reactivity to identify hot spots of toxicity within the river corridor as a function of cycles of wetting/drying. We employ a 3D hydraulic model to route historical streamflow hydrographs from major flood events through the Yuba and Feather Rivers into the Central Valley to assess the frequency and duration of saturation/inundation of channel boundary sediments. We compare these spatiotemporal modeling results to sediment total Hg and stannous chloride ';reducible' Hg(II) concentrations (the latter as a proxy for Hg(II) availability for methylation) along this ~70 km swath of river corridor. Finally, we evaluate these potential hot spots of Hg toxicity against MeHg concentrations in local aquatic biota at several trophic levels. The research will provide the basis for new models describing the evolution of toxic substances in river corridors and may prove helpful in explaining the contribution of Hg to food webs of the San Francisco Bay-Delta as an enduring legacy of California's 19th C. Gold Rush.

Co-Evolution of User and Organizational Interfaces: A Longitudinal Case Study of WWW Dissemination of National Statistics.

ERIC Educational Resources Information Center

Marchionini, Gary

2002-01-01

Describes how user interfaces for the Bureau of Labor Statistics (BLS) web site evolved over a 5-year period along with the larger organizational interface and how this co-evolution has influenced the institution. Interviews with BLS staff and transaction log analysis are the foci of this study, as well as user information-seeking studies and user…

The Fast Debris Evolution Model

NASA Astrophysics Data System (ADS)

Lewis, Hugh G.; Swinerd, Graham; Newland, Rebecca; Saunders, Arrun

The ‘Particles-in-a-box' (PIB) model introduced by Talent (1992) removed the need for computerintensive Monte Carlo simulation to predict the gross characteristics of an evolving debris environment. The PIB model was described using a differential equation that allows the stability of the low Earth orbit (LEO) environment to be tested by a straightforward analysis of the equation's coefficients. As part of an ongoing research effort to investigate more efficient approaches to evolutionary modelling and to develop a suite of educational tools, a new PIB model has been developed. The model, entitled Fast Debris Evolution (FaDE), employs a first-order differential equation to describe the rate at which new objects (˜ 10 cm) are added and removed from the environment. Whilst Talent (1992) based the collision theory for the PIB approach on collisions between gas particles and adopted specific values for the parameters of the model from a number of references, the form and coefficients of the FaDE model equations can be inferred from the outputs of future projections produced by high-fidelity models, such as the DAMAGE model. The FaDE model has been implemented as a client-side, web-based service using Javascript embedded within a HTML document. Due to the simple nature of the algorithm, FaDE can deliver the results of future projections immediately in a graphical format, with complete user-control over key simulation parameters. Historical and future projections for the ˜ 10 cm low Earth orbit (LEO) debris environment under a variety of different scenarios are possible, including business as usual, no future launches, post-mission disposal and remediation. A selection of results is presented with comparisons with predictions made using the DAMAGE environment model. The results demonstrate that the FaDE model is able to capture comparable time-series of collisions and number of objects as predicted by DAMAGE in several scenarios. Further, and perhaps more importantly, its speed and flexibility allows the user to explore and understand the evolution of the space debris environment.

Functional genetic divergence in high CO2 adapted Emiliania huxleyi populations.

PubMed

Lohbeck, Kai T; Riebesell, Ulf; Collins, Sinéad; Reusch, Thorsten B H

2013-07-01

Predicting the impacts of environmental change on marine organisms, food webs, and biogeochemical cycles presently relies almost exclusively on short-term physiological studies, while the possibility of adaptive evolution is often ignored. Here, we assess adaptive evolution in the coccolithophore Emiliania huxleyi, a well-established model species in biological oceanography, in response to ocean acidification. We previously demonstrated that this globally important marine phytoplankton species adapts within 500 generations to elevated CO2 . After 750 and 1000 generations, no further fitness increase occurred, and we observed phenotypic convergence between replicate populations. We then exposed adapted populations to two novel environments to investigate whether or not the underlying basis for high CO2 -adaptation involves functional genetic divergence, assuming that different novel mutations become apparent via divergent pleiotropic effects. The novel environment "high light" did not reveal such genetic divergence whereas growth in a low-salinity environment revealed strong pleiotropic effects in high CO2 adapted populations, indicating divergent genetic bases for adaptation to high CO2 . This suggests that pleiotropy plays an important role in adaptation of natural E. huxleyi populations to ocean acidification. Our study highlights the potential mutual benefits for oceanography and evolutionary biology of using ecologically important marine phytoplankton for microbial evolution experiments. © 2012 The Author(s). Evolution © 2012 The Society for the Study of Evolution.

WebTag: Web browsing into sensor tags over NFC.

PubMed

Echevarria, Juan Jose; Ruiz-de-Garibay, Jonathan; Legarda, Jon; Alvarez, Maite; Ayerbe, Ana; Vazquez, Juan Ignacio

2012-01-01

Information and Communication Technologies (ICTs) continue to overcome many of the challenges related to wireless sensor monitoring, such as for example the design of smarter embedded processors, the improvement of the network architectures, the development of efficient communication protocols or the maximization of the life cycle autonomy. This work tries to improve the communication link of the data transmission in wireless sensor monitoring. The upstream communication link is usually based on standard IP technologies, but the downstream side is always masked with the proprietary protocols used for the wireless link (like ZigBee, Bluetooth, RFID, etc.). This work presents a novel solution (WebTag) for a direct IP based access to a sensor tag over the Near Field Communication (NFC) technology for secure applications. WebTag allows a direct web access to the sensor tag by means of a standard web browser, it reads the sensor data, configures the sampling rate and implements IP based security policies. It is, definitely, a new step towards the evolution of the Internet of Things paradigm.

WebTag: Web Browsing into Sensor Tags over NFC

PubMed Central

Echevarria, Juan Jose; Ruiz-de-Garibay, Jonathan; Legarda, Jon; Álvarez, Maite; Ayerbe, Ana; Vazquez, Juan Ignacio

2012-01-01

Information and Communication Technologies (ICTs) continue to overcome many of the challenges related to wireless sensor monitoring, such as for example the design of smarter embedded processors, the improvement of the network architectures, the development of efficient communication protocols or the maximization of the life cycle autonomy. This work tries to improve the communication link of the data transmission in wireless sensor monitoring. The upstream communication link is usually based on standard IP technologies, but the downstream side is always masked with the proprietary protocols used for the wireless link (like ZigBee, Bluetooth, RFID, etc.). This work presents a novel solution (WebTag) for a direct IP based access to a sensor tag over the Near Field Communication (NFC) technology for secure applications. WebTag allows a direct web access to the sensor tag by means of a standard web browser, it reads the sensor data, configures the sampling rate and implements IP based security policies. It is, definitely, a new step towards the evolution of the Internet of Things paradigm. PMID:23012511

SynechoNET: integrated protein-protein interaction database of a model cyanobacterium Synechocystis sp. PCC 6803.

PubMed

Kim, Woo-Yeon; Kang, Sungsoo; Kim, Byoung-Chul; Oh, Jeehyun; Cho, Seongwoong; Bhak, Jong; Choi, Jong-Soon

2008-01-01

Cyanobacteria are model organisms for studying photosynthesis, carbon and nitrogen assimilation, evolution of plant plastids, and adaptability to environmental stresses. Despite many studies on cyanobacteria, there is no web-based database of their regulatory and signaling protein-protein interaction networks to date. We report a database and website SynechoNET that provides predicted protein-protein interactions. SynechoNET shows cyanobacterial domain-domain interactions as well as their protein-level interactions using the model cyanobacterium, Synechocystis sp. PCC 6803. It predicts the protein-protein interactions using public interaction databases that contain mutually complementary and redundant data. Furthermore, SynechoNET provides information on transmembrane topology, signal peptide, and domain structure in order to support the analysis of regulatory membrane proteins. Such biological information can be queried and visualized in user-friendly web interfaces that include the interactive network viewer and search pages by keyword and functional category. SynechoNET is an integrated protein-protein interaction database designed to analyze regulatory membrane proteins in cyanobacteria. It provides a platform for biologists to extend the genomic data of cyanobacteria by predicting interaction partners, membrane association, and membrane topology of Synechocystis proteins. SynechoNET is freely available at http://synechocystis.org/ or directly at http://bioportal.kobic.kr/SynechoNET/.

Prediction system of the 1-AU arrival times of CME-associated interplanetary shocks using three-dimensional simulations

NASA Astrophysics Data System (ADS)

den, Mitsue; Amo, Hiroyoshi; Sugihara, Kohta; Takei, Toshifumi; Ogawa, Tomoya; Tanaka, Takashi; Watari, Shinichi

We describe prediction system of the 1-AU arrival times of interplanetary shock waves associated with coromal mass ejections (CMEs). The system is based on modeling of the shock propagation using a three-dimensional adaptive mesh refinement (AMR) code. Once a CME is observed by LASCO/SOHO, firstly ambient solar wind is obtained by numerical simulation, which reproduces the solar wind parameters at that time observed by ACE spacecraft. Then we input the expansion speed and occurrence position data of that CME as initial condtions for an CME model, and 3D simulation of the CME and the shock propagation is perfomed until the shock wave passes the 1-AU. Input the parameters, execution of simulation and output of the result are available on Web, so a person who is not familiar with operation of computer or simulations or is not a researcher can use this system to predict the shock passage time. Simulated CME and shock evolution is visuallized at the same time with simulation and snap shots appear on the web automatically, so that user can follow the propagation. This system is expected to be useful for forecasters of space weather. We will describe the system and simulation model in detail.

Web Services Provide Access to SCEC Scientific Research Application Software

NASA Astrophysics Data System (ADS)

Gupta, N.; Gupta, V.; Okaya, D.; Kamb, L.; Maechling, P.

2003-12-01

Web services offer scientific communities a new paradigm for sharing research codes and communicating results. While there are formal technical definitions of what constitutes a web service, for a user community such as the Southern California Earthquake Center (SCEC), we may conceptually consider a web service to be functionality provided on-demand by an application which is run on a remote computer located elsewhere on the Internet. The value of a web service is that it can (1) run a scientific code without the user needing to install and learn the intricacies of running the code; (2) provide the technical framework which allows a user's computer to talk to the remote computer which performs the service; (3) provide the computational resources to run the code; and (4) bundle several analysis steps and provide the end results in digital or (post-processed) graphical form. Within an NSF-sponsored ITR project coordinated by SCEC, we are constructing web services using architectural protocols and programming languages (e.g., Java). However, because the SCEC community has a rich pool of scientific research software (written in traditional languages such as C and FORTRAN), we also emphasize making existing scientific codes available by constructing web service frameworks which wrap around and directly run these codes. In doing so we attempt to broaden community usage of these codes. Web service wrapping of a scientific code can be done using a "web servlet" construction or by using a SOAP/WSDL-based framework. This latter approach is widely adopted in IT circles although it is subject to rapid evolution. Our wrapping framework attempts to "honor" the original codes with as little modification as is possible. For versatility we identify three methods of user access: (A) a web-based GUI (written in HTML and/or Java applets); (B) a Linux/OSX/UNIX command line "initiator" utility (shell-scriptable); and (C) direct access from within any Java application (and with the correct API interface from within C++ and/or C/Fortran). This poster presentation will provide descriptions of the following selected web services and their origin as scientific application codes: 3D community velocity models for Southern California, geocoordinate conversions (latitude/longitude to UTM), execution of GMT graphical scripts, data format conversions (Gocad to Matlab format), and implementation of Seismic Hazard Analysis application programs that calculate hazard curve and hazard map data sets.

A cricket Gene Index: a genomic resource for studying neurobiology, speciation, and molecular evolution

PubMed Central

Danley, Patrick D; Mullen, Sean P; Liu, Fenglong; Nene, Vishvanath; Quackenbush, John; Shaw, Kerry L

2007-01-01

Background As the developmental costs of genomic tools decline, genomic approaches to non-model systems are becoming more feasible. Many of these systems may lack advanced genetic tools but are extremely valuable models in other biological fields. Here we report the development of expressed sequence tags (EST's) in an orthopteroid insect, a model for the study of neurobiology, speciation, and evolution. Results We report the sequencing of 14,502 EST's from clones derived from a nerve cord cDNA library, and the subsequent construction of a Gene Index from these sequences, from the Hawaiian trigonidiine cricket Laupala kohalensis. The Gene Index contains 8607 unique sequences comprised of 2575 tentative consensus (TC) sequences and 6032 singletons. For each of the unique sequences, an attempt was made to assign a provisional annotation and to categorize its function using a Gene Ontology-based classification through a sequence-based comparison to known proteins. In addition, a set of unique 70 base pair oligomers that can be used for DNA microarrays was developed. All Gene Index information is posted at the DFCI Gene Indices web page Conclusion Orthopterans are models used to understand the neurophysiological basis of complex motor patterns such as flight and stridulation. The sequences presented in the cricket Gene Index will provide neurophysiologists with many genetic tools that have been largely absent in this field. The cricket Gene Index is one of only two gene indices to be developed in an evolutionary model system. Species within the genus Laupala have speciated recently, rapidly, and extensively. Therefore, the genes identified in the cricket Gene Index can be used to study the genomics of speciation. Furthermore, this gene index represents a significant EST resources for basal insects. As such, this resource is a valuable comparative tool for the understanding of invertebrate molecular evolution. The sequences presented here will provide much needed genomic resources for three distinct but overlapping fields of inquiry: neurobiology, speciation, and molecular evolution. PMID:17459168

Web-Based Learning - Yes We Can!

NASA Astrophysics Data System (ADS)

Schroeder, Ulrik

Web-based Learning has become a matter of fact at universities. We are now at the edge of new developments with Web 2.0 applications and social software is radically changing the way of how we communicate and share in social networks. Can we expect an analogous revolution for university education 2.0? I will give some arguments that I rather expect an incremental evolution than a radical change. First, I take a look at current eLearning implementations and organizational frameworks and give an example from RWTH Aachen University. Against the background of cognitive theories the utilization of Web 2.0 applications are promising to strengthen 21st century learning. But methods and tools must be adapted to the context of institutional learning as well as the formal regulations must be adjusted vice versa.

WEB-BASED MODELING OF A FERTILIZER SOLUTION SPILL IN THE OHIO RIVER

EPA Science Inventory

Environmental computer models are usually desktop models. Some web-enabled models are beginning to appear where the user can use a browser to run the models on a central web server. Several issues arise when a desktop model is transferred to a web architecture. This paper discuss...

Representing Human Expertise by the OWL Web Ontology Language to Support Knowledge Engineering in Decision Support Systems.

PubMed

Ramzan, Asia; Wang, Hai; Buckingham, Christopher

2014-01-01

Clinical decision support systems (CDSSs) often base their knowledge and advice on human expertise. Knowledge representation needs to be in a format that can be easily understood by human users as well as supporting ongoing knowledge engineering, including evolution and consistency of knowledge. This paper reports on the development of an ontology specification for managing knowledge engineering in a CDSS for assessing and managing risks associated with mental-health problems. The Galatean Risk and Safety Tool, GRiST, represents mental-health expertise in the form of a psychological model of classification. The hierarchical structure was directly represented in the machine using an XML document. Functionality of the model and knowledge management were controlled using attributes in the XML nodes, with an accompanying paper manual for specifying how end-user tools should behave when interfacing with the XML. This paper explains the advantages of using the web-ontology language, OWL, as the specification, details some of the issues and problems encountered in translating the psychological model to OWL, and shows how OWL benefits knowledge engineering. The conclusions are that OWL can have an important role in managing complex knowledge domains for systems based on human expertise without impeding the end-users' understanding of the knowledge base. The generic classification model underpinning GRiST makes it applicable to many decision domains and the accompanying OWL specification facilitates its implementation.

A molecular phylogeny of nephilid spiders: evolutionary history of a model lineage.

PubMed

Kuntner, Matjaž; Arnedo, Miquel A; Trontelj, Peter; Lokovšek, Tjaša; Agnarsson, Ingi

2013-12-01

The pantropical orb web spider family Nephilidae is known for the most extreme sexual size dimorphism among terrestrial animals. Numerous studies have made Nephilidae, particularly Nephila, a model lineage in evolutionary research. However, a poorly understood phylogeny of this lineage, relying only on morphology, has prevented thorough evolutionary syntheses of nephilid biology. We here use three nuclear and five mitochondrial genes for 28 out of 40 nephilid species to provide a more robust nephilid phylogeny and infer clade ages in a fossil-calibrated Bayesian framework. We complement the molecular analyses with total evidence analysis including morphology. All analyses find strong support for nephilid monophyly and exclusivity and the monophyly of the genera Herennia and Clitaetra. The inferred phylogenetic structure within Nephilidae is novel and conflicts with morphological phylogeny and traditional taxonomy. Nephilengys species fall into two clades, one with Australasian species (true Nephilengys) as sister to Herennia, and another with Afrotropical species (Nephilingis Kuntner new genus) as sister to a clade containing Clitaetra plus most currently described Nephila. Surprisingly, Nephila is also diphyletic, with true Nephila containing N. pilipes+N. constricta, and the second clade with all other species sister to Clitaetra; this "Nephila" clade is further split into an Australasian clade that also contains the South American N. sexpunctata and the Eurasian N. clavata, and an African clade that also contains the Panamerican N. clavipes. An approximately unbiased test constraining the monophyly of Nephilengys, Nephila, and Nephilinae (Nephila, Nephilengys, Herennia), respectively, rejected Nephilengys monophyly, but not that of Nephila and Nephilinae. Further data are therefore necessary to robustly test these two new, but inconclusive findings, and also to further test the precise placement of Nephilidae within the Araneoidea. For divergence date estimation we set the minimum bound for the stems of Nephilidae at 40 Ma and of Nephila at 16 Ma to accommodate Palaeonephila from Baltic amber and Dominican Nephila species, respectively. We also calibrated and dated the phylogeny under three different interpretations of the enigmatic 165 Ma fossil Nephila jurassica, which we suspected based on morphology to be misplaced. We found that by treating N. jurassica as stem Nephila or nephilid the inferred clade ages were vastly older, and the mitochondrial substitution rates much slower than expected from other empirical spider data. This suggests that N. jurassica is not a Nephila nor a nephilid, but possibly a stem orbicularian. The estimated nephilid ancestral age (40-60 Ma) rejects a Gondwanan origin of the family as most of the southern continents were already split at that time. The origin of the family is equally likely to be African, Asian, or Australasian, with a global biogeographic history dominated by dispersal events. A reinterpretation of web architecture evolution suggests that a partially arboricolous, asymmetric orb web with a retreat, as exemplified by both groups of "Nephilengys", is plesiomorphic in Nephilidae, that this architecture was modified into specialized arboricolous webs in Herennia and independently in Clitaetra, and that the web became aerial, gigantic, and golden independently in both "Nephila" groups. The new topology questions previously hypothesized gradual evolution of female size from small to large, and rather suggests a more mosaic evolutionary pattern with independent female size increases from medium to giant in both "Nephila" clades, and two reversals back to medium and small; combined with male size evolution, this pattern will help detect gross evolutionary events leading to extreme sexual size dimorphism, and its morphological and behavioral correlates. Copyright © 2013 Elsevier Inc. All rights reserved.

A Smart Modeling Framework for Integrating BMI-enabled Models as Web Services

NASA Astrophysics Data System (ADS)

Jiang, P.; Elag, M.; Kumar, P.; Peckham, S. D.; Liu, R.; Marini, L.; Hsu, L.

2015-12-01

Serviced-oriented computing provides an opportunity to couple web service models using semantic web technology. Through this approach, models that are exposed as web services can be conserved in their own local environment, thus making it easy for modelers to maintain and update the models. In integrated modeling, the serviced-oriented loose-coupling approach requires (1) a set of models as web services, (2) the model metadata describing the external features of a model (e.g., variable name, unit, computational grid, etc.) and (3) a model integration framework. We present the architecture of coupling web service models that are self-describing by utilizing a smart modeling framework. We expose models that are encapsulated with CSDMS (Community Surface Dynamics Modeling System) Basic Model Interfaces (BMI) as web services. The BMI-enabled models are self-describing by uncovering models' metadata through BMI functions. After a BMI-enabled model is serviced, a client can initialize, execute and retrieve the meta-information of the model by calling its BMI functions over the web. Furthermore, a revised version of EMELI (Peckham, 2015), an Experimental Modeling Environment for Linking and Interoperability, is chosen as the framework for coupling BMI-enabled web service models. EMELI allows users to combine a set of component models into a complex model by standardizing model interface using BMI as well as providing a set of utilities smoothing the integration process (e.g., temporal interpolation). We modify the original EMELI so that the revised modeling framework is able to initialize, execute and find the dependencies of the BMI-enabled web service models. By using the revised EMELI, an example will be presented on integrating a set of topoflow model components that are BMI-enabled and exposed as web services. Reference: Peckham, S.D. (2014) EMELI 1.0: An experimental smart modeling framework for automatic coupling of self-describing models, Proceedings of HIC 2014, 11th International Conf. on Hydroinformatics, New York, NY.

Information architecture for a planetary 'exploration web'

NASA Technical Reports Server (NTRS)

Lamarra, N.; McVittie, T.

2002-01-01

'Web services' is a common way of deploying distributed applications whose software components and data sources may be in different locations, formats, languages, etc. Although such collaboration is not utilized significantly in planetary exploration, we believe there is significant benefit in developing an architecture in which missions could leverage each others capabilities. We believe that an incremental deployment of such an architecture could significantly contribute to the evolution of increasingly capable, efficient, and even autonomous remote exploration.

Chronic Mycobacterium infection of first dorsal web space after accidental Bacilli Calmette-Guérin injection in a health worker: case report.

PubMed

Vigler, Mordechai; Mulett, Hanan; Hausman, Michael R

2008-11-01

We present a case of inoculation of the first dorsal web space by a nurse practitioner who accidentally stuck herself while preparing Bacilli Calmette-Guérin vaccine for treatment of bladder tumor. We report the evolution and management of this resistant chronic Mycobacterium infection that ultimately required use of a vacuum wound management system followed by a microvascular free tissue transfer.

ComplexContact: a web server for inter-protein contact prediction using deep learning.

PubMed

Zeng, Hong; Wang, Sheng; Zhou, Tianming; Zhao, Feifeng; Li, Xiufeng; Wu, Qing; Xu, Jinbo

2018-05-22

ComplexContact (http://raptorx2.uchicago.edu/ComplexContact/) is a web server for sequence-based interfacial residue-residue contact prediction of a putative protein complex. Interfacial residue-residue contacts are critical for understanding how proteins form complex and interact at residue level. When receiving a pair of protein sequences, ComplexContact first searches for their sequence homologs and builds two paired multiple sequence alignments (MSA), then it applies co-evolution analysis and a CASP-winning deep learning (DL) method to predict interfacial contacts from paired MSAs and visualizes the prediction as an image. The DL method was originally developed for intra-protein contact prediction and performed the best in CASP12. Our large-scale experimental test further shows that ComplexContact greatly outperforms pure co-evolution methods for inter-protein contact prediction, regardless of the species.

Conceptual Modeling in the Time of the Revolution: Part II

NASA Astrophysics Data System (ADS)

Mylopoulos, John

Conceptual Modeling was a marginal research topic at the very fringes of Computer Science in the 60s and 70s, when the discipline was dominated by topics focusing on programs, systems and hardware architectures. Over the years, however, the field has moved to centre stage and has come to claim a central role both in Computer Science research and practice in diverse areas, such as Software Engineering, Databases, Information Systems, the Semantic Web, Business Process Management, Service-Oriented Computing, Multi-Agent Systems, Knowledge Management, and more. The transformation was greatly aided by the adoption of standards in modeling languages (e.g., UML), and model-based methodologies (e.g., Model-Driven Architectures) by the Object Management Group (OMG) and other standards organizations. We briefly review the history of the field over the past 40 years, focusing on the evolution of key ideas. We then note some open challenges and report on-going research, covering topics such as the representation of variability in conceptual models, capturing model intentions, and models of laws.

Morphology controlled synthesis of 2-D Ni-Ni3S2 and Ni3S2 nanostructures on Ni foam towards oxygen evolution reaction

NASA Astrophysics Data System (ADS)

Chaudhari, Nitin Kaduba; Oh, Aram; Sa, Young Jin; Jin, Haneul; Baik, Hionsuck; Kim, Sang Gu; Lee, Suk Joong; Joo, Sang Hoon; Lee, Kwangyeol

2017-03-01

Catalysts for oxygen evolution reactions (OER) are at the heart of key renewable energy technologies, and development of non-precious metal catalysts with high activity and stability remain a great challenge in this field. Among various material candidates, metal sulfides are receiving increasing attention. While morphology-dependent catalytic performances are well established in noble metal-based catalysts, relatively little is known for the morphology‒catalytic performance relationship in metal sulfide catalysts. In this study, uniform spider web-like Ni nanosheets-Ni3S2 and honeycomb-like Ni3S2 structures are deposited on nickel foam (Ni3S2/NF) by a facile one-step hydrothermal synthetic route. When used as an oxygen evolution electrode, the spider web-like Ni-Ni3S2/NF with the large exposed surface area shown excellent catalytic activity and stability with an overpotential of 310 mV to achieve at 10 mA/cm2 and a Tafel slope of 63 mV/dec in alkaline media, which is superior to the honeycomb-like structure without Ni nanosheet. The low Tafel slope of the spider web-like Ni-Ni3S2/NF represents one of the best OER kinetics among nickel sulfide-based OER catalysts. The results point to the fact that performance of the metal sulfide electrocatalysts might be fine-tuned and optimized with morphological controls.

Modelling Size Structured Food Webs Using a Modified Niche Model with Two Predator Traits

PubMed Central

Klecka, Jan

2014-01-01

The structure of food webs is frequently described using phenomenological stochastic models. A prominent example, the niche model, was found to produce artificial food webs resembling real food webs according to a range of summary statistics. However, the size structure of food webs generated by the niche model and real food webs has not yet been rigorously compared. To fill this void, I use a body mass based version of the niche model and compare prey-predator body mass allometry and predator-prey body mass ratios predicted by the model to empirical data. The results show that the model predicts weaker size structure than observed in many real food webs. I introduce a modified version of the niche model which allows to control the strength of size-dependence of predator-prey links. In this model, optimal prey body mass depends allometrically on predator body mass and on a second trait, such as foraging mode. These empirically motivated extensions of the model allow to represent size structure of real food webs realistically and can be used to generate artificial food webs varying in several aspects of size structure in a controlled way. Hence, by explicitly including the role of species traits, this model provides new opportunities for simulating the consequences of size structure for food web dynamics and stability. PMID:25119999

The (De-)evolution of Evolution Games: A Content Analysis of the Representation of Evolution Through Natural Selection in Digital Games

NASA Astrophysics Data System (ADS)

Leith, Alex P.; Ratan, Rabindra A.; Wohn, Donghee Yvette

2016-08-01

Given the diversity and complexity of education game mechanisms and topics, this article contributes to a theoretical understanding of how game mechanisms "map" to educational topics through inquiry-based learning. Namely, the article examines the presence of evolution through natural selection (ENS) in digital games. ENS is a fundamentally important and widely misunderstood theory. This analysis of ENS portrayal in digital games provides insight into the use of games in teaching ENS. Systematic database search results were coded for the three principles of ENS: phenotypic variation, differential fitness, and fitness heritability. Though thousands of games use the term evolution, few presented elements of evolution, and even fewer contained all principles of ENS. Games developed to specifically teach evolution were difficult to find through Web searches. These overall deficiencies in ENS games reflect the inherent incompatibility between game control elements and the automatic process of ENS.

THE STELLAR SPHEROID, THE DISK, AND THE DYNAMICS OF THE COSMIC WEB

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

Domínguez-Tenreiro, R.; Obreja, A.; Brook, C. B.

Models of the advanced stages of gravitational instability predict that baryons that form the stellar populations of current galaxies at z = 0 displayed a web-like structure at high z, as part of the cosmic web (CW). We explore details of these predictions using cosmological hydrodynamical simulations. When the stellar populations of the spheroid and disk components of simulated late-type galaxies are traced back separately to high zs we found CW-like structures where spheroid progenitors are more evolved than disk progenitors. The distinction between the corresponding stellar populations, as driven by their specific angular momentum content j, can be explainedmore » in terms of the CW evolution, extended to two processes occurring at lower z. First, the spheroid progenitors strongly lose j at collapse, which contrasts with the insignificant j loss of the disk progenitors. The second is related to the lack of alignment, at assembly, between the spheroid-to-be material and the already settled proto-disk, in contrast to the alignment of disk-to-be material, in some cases resulting from circumgalactic, disk-induced gravitational torques. The different final outcomes of these low-z processes have their origins in the different initial conditions driven by the CW dynamics.« less

New in protein structure and function annotation: hotspots, single nucleotide polymorphisms and the 'Deep Web'.

PubMed

Bromberg, Yana; Yachdav, Guy; Ofran, Yanay; Schneider, Reinhard; Rost, Burkhard

2009-05-01

The rapidly increasing quantity of protein sequence data continues to widen the gap between available sequences and annotations. Comparative modeling suggests some aspects of the 3D structures of approximately half of all known proteins; homology- and network-based inferences annotate some aspect of function for a similar fraction of the proteome. For most known protein sequences, however, there is detailed knowledge about neither their function nor their structure. Comprehensive efforts towards the expert curation of sequence annotations have failed to meet the demand of the rapidly increasing number of available sequences. Only the automated prediction of protein function in the absence of homology can close the gap between available sequences and annotations in the foreseeable future. This review focuses on two novel methods for automated annotation, and briefly presents an outlook on how modern web software may revolutionize the field of protein sequence annotation. First, predictions of protein binding sites and functional hotspots, and the evolution of these into the most successful type of prediction of protein function from sequence will be discussed. Second, a new tool, comprehensive in silico mutagenesis, which contributes important novel predictions of function and at the same time prepares for the onset of the next sequencing revolution, will be described. While these two new sub-fields of protein prediction represent the breakthroughs that have been achieved methodologically, it will then be argued that a different development might further change the way biomedical researchers benefit from annotations: modern web software can connect the worldwide web in any browser with the 'Deep Web' (ie, proprietary data resources). The availability of this direct connection, and the resulting access to a wealth of data, may impact drug discovery and development more than any existing method that contributes to protein annotation.

A Query Integrator and Manager for the Query Web

PubMed Central

Brinkley, James F.; Detwiler, Landon T.

2012-01-01

We introduce two concepts: the Query Web as a layer of interconnected queries over the document web and the semantic web, and a Query Web Integrator and Manager (QI) that enables the Query Web to evolve. QI permits users to write, save and reuse queries over any web accessible source, including other queries saved in other installations of QI. The saved queries may be in any language (e.g. SPARQL, XQuery); the only condition for interconnection is that the queries return their results in some form of XML. This condition allows queries to chain off each other, and to be written in whatever language is appropriate for the task. We illustrate the potential use of QI for several biomedical use cases, including ontology view generation using a combination of graph-based and logical approaches, value set generation for clinical data management, image annotation using terminology obtained from an ontology web service, ontology-driven brain imaging data integration, small-scale clinical data integration, and wider-scale clinical data integration. Such use cases illustrate the current range of applications of QI and lead us to speculate about the potential evolution from smaller groups of interconnected queries into a larger query network that layers over the document and semantic web. The resulting Query Web could greatly aid researchers and others who now have to manually navigate through multiple information sources in order to answer specific questions. PMID:22531831

Trends in the Evolution of the Public Web, 1998-2002; The Fedora Project: An Open-source Digital Object Repository Management System; State of the Dublin Core Metadata Initiative, April 2003; Preservation Metadata; How Many People Search the ERIC Database Each Day?

ERIC Educational Resources Information Center

O'Neill, Edward T.; Lavoie, Brian F.; Bennett, Rick; Staples, Thornton; Wayland, Ross; Payette, Sandra; Dekkers, Makx; Weibel, Stuart; Searle, Sam; Thompson, Dave; Rudner, Lawrence M.

2003-01-01

Includes five articles that examine key trends in the development of the public Web: size and growth, internationalization, and metadata usage; Flexible Extensible Digital Object and Repository Architecture (Fedora) for use in digital libraries; developments in the Dublin Core Metadata Initiative (DCMI); the National Library of New Zealand Te Puna…

Integrating hydrologic modeling web services with online data sharing to prepare, store, and execute models in hydrology

NASA Astrophysics Data System (ADS)

Gan, T.; Tarboton, D. G.; Dash, P. K.; Gichamo, T.; Horsburgh, J. S.

2017-12-01

Web based apps, web services and online data and model sharing technology are becoming increasingly available to support research. This promises benefits in terms of collaboration, platform independence, transparency and reproducibility of modeling workflows and results. However, challenges still exist in real application of these capabilities and the programming skills researchers need to use them. In this research we combined hydrologic modeling web services with an online data and model sharing system to develop functionality to support reproducible hydrologic modeling work. We used HydroDS, a system that provides web services for input data preparation and execution of a snowmelt model, and HydroShare, a hydrologic information system that supports the sharing of hydrologic data, model and analysis tools. To make the web services easy to use, we developed a HydroShare app (based on the Tethys platform) to serve as a browser based user interface for HydroDS. In this integration, HydroDS receives web requests from the HydroShare app to process the data and execute the model. HydroShare supports storage and sharing of the results generated by HydroDS web services. The snowmelt modeling example served as a use case to test and evaluate this approach. We show that, after the integration, users can prepare model inputs or execute the model through the web user interface of the HydroShare app without writing program code. The model input/output files and metadata describing the model instance are stored and shared in HydroShare. These files include a Python script that is automatically generated by the HydroShare app to document and reproduce the model input preparation workflow. Once stored in HydroShare, inputs and results can be shared with other users, or published so that other users can directly discover, repeat or modify the modeling work. This approach provides a collaborative environment that integrates hydrologic web services with a data and model sharing system to enable model development and execution. The entire system comprised of the HydroShare app, HydroShare and HydroDS web services is open source and contributes to capability for web based modeling research.

RNAmutants: a web server to explore the mutational landscape of RNA secondary structures

PubMed Central

Waldispühl, Jerome; Devadas, Srinivas; Berger, Bonnie; Clote, Peter

2009-01-01

The history and mechanism of molecular evolution in DNA have been greatly elucidated by contributions from genetics, probability theory and bioinformatics—indeed, mathematical developments such as Kimura's neutral theory, Kingman's coalescent theory and efficient software such as BLAST, ClustalW, Phylip, etc., provide the foundation for modern population genetics. In contrast to DNA, the function of most noncoding RNA depends on tertiary structure, experimentally known to be largely determined by secondary structure, for which dynamic programming can efficiently compute the minimum free energy secondary structure. For this reason, understanding the effect of pointwise mutations in RNA secondary structure could reveal fundamental properties of structural RNA molecules and improve our understanding of molecular evolution of RNA. The web server RNAmutants provides several efficient tools to compute the ensemble of low-energy secondary structures for all k-mutants of a given RNA sequence, where k is bounded by a user-specified upper bound. As we have previously shown, these tools can be used to predict putative deleterious mutations and to analyze regulatory sequences from the hepatitis C and human immunodeficiency genomes. Web server is available at http://bioinformatics.bc.edu/clotelab/RNAmutants/, and downloadable binaries at http://rnamutants.csail.mit.edu/. PMID:19531740

Rational analyses of information foraging on the web.

PubMed

Pirolli, Peter

2005-05-06

This article describes rational analyses and cognitive models of Web users developed within information foraging theory. This is done by following the rational analysis methodology of (a) characterizing the problems posed by the environment, (b) developing rational analyses of behavioral solutions to those problems, and (c) developing cognitive models that approach the realization of those solutions. Navigation choice is modeled as a random utility model that uses spreading activation mechanisms that link proximal cues (information scent) that occur in Web browsers to internal user goals. Web-site leaving is modeled as an ongoing assessment by the Web user of the expected benefits of continuing at a Web site as opposed to going elsewhere. These cost-benefit assessments are also based on spreading activation models of information scent. Evaluations include a computational model of Web user behavior called Scent-Based Navigation and Information Foraging in the ACT Architecture, and the Law of Surfing, which characterizes the empirical distribution of the length of paths of visitors at a Web site. 2005 Lawrence Erlbaum Associates, Inc.

Evolution of branched regulatory genetic pathways: directional selection on pleiotropic loci accelerates developmental system drift.

PubMed

Johnson, Norman A; Porter, Adam H

2007-01-01

Developmental systems are regulated by a web of interacting loci. One common and useful approach in studying the evolution of development is to focus on classes of interacting elements within these systems. Here, we use individual-based simulations to study the evolution of traits controlled by branched developmental pathways involving three loci, where one locus regulates two different traits. We examined the system under a variety of selective regimes. In the case where one branch was under stabilizing selection and the other under directional selection, we observed "developmental system drift": the trait under stabilizing selection showed little phenotypic change even though the loci underlying that trait showed considerable evolutionary divergence. This occurs because the pleiotropic locus responds to directional selection and compensatory mutants are then favored in the pathway under stabilizing selection. Though developmental system drift may be caused by other mechanisms, it seems likely that it is accelerated by the same underlying genetic mechanism as that producing the Dobzhansky-Muller incompatibilities that lead to speciation in both linear and branched pathways. We also discuss predictions of our model for developmental system drift and how different selective regimes affect probabilities of speciation in the branched pathway system.

BioPortal: enhanced functionality via new Web services from the National Center for Biomedical Ontology to access and use ontologies in software applications.

PubMed

Whetzel, Patricia L; Noy, Natalya F; Shah, Nigam H; Alexander, Paul R; Nyulas, Csongor; Tudorache, Tania; Musen, Mark A

2011-07-01

The National Center for Biomedical Ontology (NCBO) is one of the National Centers for Biomedical Computing funded under the NIH Roadmap Initiative. Contributing to the national computing infrastructure, NCBO has developed BioPortal, a web portal that provides access to a library of biomedical ontologies and terminologies (http://bioportal.bioontology.org) via the NCBO Web services. BioPortal enables community participation in the evaluation and evolution of ontology content by providing features to add mappings between terms, to add comments linked to specific ontology terms and to provide ontology reviews. The NCBO Web services (http://www.bioontology.org/wiki/index.php/NCBO_REST_services) enable this functionality and provide a uniform mechanism to access ontologies from a variety of knowledge representation formats, such as Web Ontology Language (OWL) and Open Biological and Biomedical Ontologies (OBO) format. The Web services provide multi-layered access to the ontology content, from getting all terms in an ontology to retrieving metadata about a term. Users can easily incorporate the NCBO Web services into software applications to generate semantically aware applications and to facilitate structured data collection.

Reviews Toy: Air swimmers Book: Their Arrows will Darken the Sun: The Evolution and Science of Ballistics Book: Physics Experiments for your Bag Book: Quantum Physics for Poets Equipment: SEP colour wheel kit Equipment: SEP colour mixing kit Software: USB DrDAQ App: iHandy Level Equipment: Photonics Explorer kit Web Watch

NASA Astrophysics Data System (ADS)

2012-01-01

WE RECOMMEND Air swimmers Helium balloon swims like a fish Their Arrows will Darken the Sun: The Evolution and Science of Ballistics Ballistics book hits the spot Physics Experiments for your Bag Handy experiments for your lessons Quantum Physics for Poets Book shows the economic importance of physics SEP colour wheel kit Wheels investigate colour theory SEP colour mixing kit Cheap colour mixing kit uses red, green and blue LEDs iHandy Level iPhone app superbly measures angles Photonics Explorer kit Free optics kit given to schools WORTH A LOOK DrDAQ DrDAQ software gets an upgrade WEB WATCH Websites show range of physics

Color polymorphic lures target different visual channels in prey.

PubMed

White, Thomas E; Kemp, Darrell J

2016-06-01

Selection for signal efficacy in variable environments may favor color polymorphism, but little is known about this possibility outside of sexual systems. Here we used the color polymorphic orb-web spider Gasteracantha fornicata, whose yellow- or white-banded dorsal signal attracts dipteran prey, to test the hypothesis that morphs may be tuned to optimize either chromatic or achromatic conspicuousness in their visually noisy forest environments. We used data from extensive observations of naturally existing spiders and precise assessments of visual environments to model signal conspicuousness according to dipteran vision. Modeling supported a distinct bias in the chromatic (yellow morph) or achromatic (white morph) contrast presented by spiders at the times when they caught prey, as opposed to all other times at which they may be viewed. Hence, yellow spiders were most successful when their signal produced maximum color contrast against viewing backgrounds, whereas white spiders were most successful when they presented relatively greatest luminance contrast. Further modeling across a hypothetical range of lure variation confirmed that yellow versus white signals should, respectively, enhance chromatic versus achromatic conspicuousness to flies, in G. fornicata's visual environments. These findings suggest that color polymorphism may be adaptively maintained by selection for conspicuousness within different visual channels in receivers. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Web Instruction with the LBO Model.

ERIC Educational Resources Information Center

Agarwal, Rajshree; Day, A. Edward

2000-01-01

Presents a Web site that utilizes the Learning-by-Objective (LBO) model that integrates Internet tools for knowledge transmission, communication, and assessment of learning. Explains that the LBO model has been used in creating micro and macroeconomic course Web sites with WebCT software. (CMK)

FloorspaceJS - A New, Open Source, Web-Based Geometry Editor for Building Energy Modeling (BEM): Preprint

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

Macumber, Daniel L; Horowitz, Scott G; Schott, Marjorie

Across most industries, desktop applications are being rapidly migrated to web applications for a variety of reasons. Web applications are inherently cross platform, mobile, and easier to distribute than desktop applications. Fueling this trend are a wide range of free, open source libraries and frameworks that make it incredibly easy to develop powerful web applications. The building energy modeling community is just beginning to pick up on these larger trends, with a small but growing number of building energy modeling applications starting on or moving to the web. This paper presents a new, open source, web based geometry editor formore » Building Energy Modeling (BEM). The editor is written completely in JavaScript and runs in a modern web browser. The editor works on a custom JSON file format and is designed to be integrated into a variety of web and desktop applications. The web based editor is available to use as a standalone web application at: https://nrel.github.io/openstudio-geometry-editor/. An example integration is demonstrated with the OpenStudio desktop application. Finally, the editor can be easily integrated with a wide range of possible building energy modeling web applications.« less

Duplication and concerted evolution of MiSp-encoding genes underlie the material properties of minor ampullate silks of cobweb weaving spiders.

PubMed

Vienneau-Hathaway, Jannelle M; Brassfield, Elizabeth R; Lane, Amanda Kelly; Collin, Matthew A; Correa-Garhwal, Sandra M; Clarke, Thomas H; Schwager, Evelyn E; Garb, Jessica E; Hayashi, Cheryl Y; Ayoub, Nadia A

2017-03-14

Orb-web weaving spiders and their relatives use multiple types of task-specific silks. The majority of spider silk studies have focused on the ultra-tough dragline silk synthesized in major ampullate glands, but other silk types have impressive material properties. For instance, minor ampullate silks of orb-web weaving spiders are as tough as draglines, due to their higher extensibility despite lower strength. Differences in material properties between silk types result from differences in their component proteins, particularly members of the spidroin (spider fibroin) gene family. However, the extent to which variation in material properties within a single silk type can be explained by variation in spidroin sequences is unknown. Here, we compare the minor ampullate spidroins (MiSp) of orb-weavers and cobweb weavers. Orb-web weavers use minor ampullate silk to form the auxiliary spiral of the orb-web while cobweb weavers use it to wrap prey, suggesting that selection pressures on minor ampullate spidroins (MiSp) may differ between the two groups. We report complete or nearly complete MiSp sequences from five cobweb weaving spider species and measure material properties of minor ampullate silks in a subset of these species. We also compare MiSp sequences and silk properties of our cobweb weavers to published data for orb-web weavers. We demonstrate that all our cobweb weavers possess multiple MiSp loci and that one locus is more highly expressed in at least two species. We also find that the proportion of β-spiral-forming amino acid motifs in MiSp positively correlates with minor ampullate silk extensibility across orb-web and cobweb weavers. MiSp sequences vary dramatically within and among spider species, and have likely been subject to multiple rounds of gene duplication and concerted evolution, which have contributed to the diverse material properties of minor ampullate silks. Our sequences also provide templates for recombinant silk proteins with tailored properties.

The visualCMAT: A web-server to select and interpret correlated mutations/co-evolving residues in protein families.

PubMed

Suplatov, Dmitry; Sharapova, Yana; Timonina, Daria; Kopylov, Kirill; Švedas, Vytas

2018-04-01

The visualCMAT web-server was designed to assist experimental research in the fields of protein/enzyme biochemistry, protein engineering, and drug discovery by providing an intuitive and easy-to-use interface to the analysis of correlated mutations/co-evolving residues. Sequence and structural information describing homologous proteins are used to predict correlated substitutions by the Mutual information-based CMAT approach, classify them into spatially close co-evolving pairs, which either form a direct physical contact or interact with the same ligand (e.g. a substrate or a crystallographic water molecule), and long-range correlations, annotate and rank binding sites on the protein surface by the presence of statistically significant co-evolving positions. The results of the visualCMAT are organized for a convenient visual analysis and can be downloaded to a local computer as a content-rich all-in-one PyMol session file with multiple layers of annotation corresponding to bioinformatic, statistical and structural analyses of the predicted co-evolution, or further studied online using the built-in interactive analysis tools. The online interactivity is implemented in HTML5 and therefore neither plugins nor Java are required. The visualCMAT web-server is integrated with the Mustguseal web-server capable of constructing large structure-guided sequence alignments of protein families and superfamilies using all available information about their structures and sequences in public databases. The visualCMAT web-server can be used to understand the relationship between structure and function in proteins, implemented at selecting hotspots and compensatory mutations for rational design and directed evolution experiments to produce novel enzymes with improved properties, and employed at studying the mechanism of selective ligand's binding and allosteric communication between topologically independent sites in protein structures. The web-server is freely available at https://biokinet.belozersky.msu.ru/visualcmat and there are no login requirements.

Demonstration of the Web-based Interspecies Correlation Estimation (Web-ICE) modeling application

EPA Science Inventory

The Web-based Interspecies Correlation Estimation (Web-ICE) modeling application is available to the risk assessment community through a user-friendly internet platform (http://epa.gov/ceampubl/fchain/webice/). ICE models are log-linear least square regressions that predict acute...

Criteria for representing circular arc and sine wave spar webs by non-curved elements

NASA Technical Reports Server (NTRS)

Jenkins, J. M.

1979-01-01

The basic problem of how to simply represent a curved web of a spar in a finite element structural model was addressed. The ratio of flat web to curved web axial deformations and longitudinal rotations were calculated using NASTRAN models. Multiplying factors were developed from these calculations for various web thicknesses. These multiplying factors can be applied directly to the area and moment of inertia inputs of the finite element model. This allows the thermal stress relieving configurations of sine wave and circular arc webs to be simply accounted for in finite element structural models.

Research infrastructure support to address ecosystem dynamics

NASA Astrophysics Data System (ADS)

Los, Wouter

2014-05-01

Predicting the evolution of ecosystems to climate change or human pressures is a challenge. Even understanding past or current processes is complicated as a result of the many interactions and feedbacks that occur within and between components of the system. This talk will present an example of current research on changes in landscape evolution, hydrology, soil biogeochemical processes, zoological food webs, and plant community succession, and how these affect feedbacks to components of the systems, including the climate system. Multiple observations, experiments, and simulations provide a wealth of data, but not necessarily understanding. Model development on the coupled processes on different spatial and temporal scales is sensitive for variations in data and of parameter change. Fast high performance computing may help to visualize the effect of these changes and the potential stability (and reliability) of the models. This may than allow for iteration between data production and models towards stable models reducing uncertainty and improving the prediction of change. The role of research infrastructures becomes crucial is overcoming barriers for such research. Environmental infrastructures are covering physical site facilities, dedicated instrumentation and e-infrastructure. The LifeWatch infrastructure for biodiversity and ecosystem research will provide services for data integration, analysis and modeling. But it has to cooperate intensively with the other kinds of infrastructures in order to support the iteration between data production and model computation. The cooperation in the ENVRI project (Common operations of environmental research infrastructures) is one of the initiatives to foster such multidisciplinary research.

Utilization of two web-based continuing education courses evaluated by Markov chain model.

PubMed

Tian, Hao; Lin, Jin-Mann S; Reeves, William C

2012-01-01

To evaluate the web structure of two web-based continuing education courses, identify problems and assess the effects of web site modifications. Markov chain models were built from 2008 web usage data to evaluate the courses' web structure and navigation patterns. The web site was then modified to resolve identified design issues and the improvement in user activity over the subsequent 12 months was quantitatively evaluated. Web navigation paths were collected between 2008 and 2010. The probability of navigating from one web page to another was analyzed. The continuing education courses' sequential structure design was clearly reflected in the resulting actual web usage models, and none of the skip transitions provided was heavily used. The web navigation patterns of the two different continuing education courses were similar. Two possible design flaws were identified and fixed in only one of the two courses. Over the following 12 months, the drop-out rate in the modified course significantly decreased from 41% to 35%, but remained unchanged in the unmodified course. The web improvement effects were further verified via a second-order Markov chain model. The results imply that differences in web content have less impact than web structure design on how learners navigate through continuing education courses. Evaluation of user navigation can help identify web design flaws and guide modifications. This study showed that Markov chain models provide a valuable tool to evaluate web-based education courses. Both the results and techniques in this study would be very useful for public health education and research specialists.

Utilization of two web-based continuing education courses evaluated by Markov chain model

PubMed Central

Lin, Jin-Mann S; Reeves, William C

2011-01-01

Objectives To evaluate the web structure of two web-based continuing education courses, identify problems and assess the effects of web site modifications. Design Markov chain models were built from 2008 web usage data to evaluate the courses' web structure and navigation patterns. The web site was then modified to resolve identified design issues and the improvement in user activity over the subsequent 12 months was quantitatively evaluated. Measurements Web navigation paths were collected between 2008 and 2010. The probability of navigating from one web page to another was analyzed. Results The continuing education courses' sequential structure design was clearly reflected in the resulting actual web usage models, and none of the skip transitions provided was heavily used. The web navigation patterns of the two different continuing education courses were similar. Two possible design flaws were identified and fixed in only one of the two courses. Over the following 12 months, the drop-out rate in the modified course significantly decreased from 41% to 35%, but remained unchanged in the unmodified course. The web improvement effects were further verified via a second-order Markov chain model. Conclusions The results imply that differences in web content have less impact than web structure design on how learners navigate through continuing education courses. Evaluation of user navigation can help identify web design flaws and guide modifications. This study showed that Markov chain models provide a valuable tool to evaluate web-based education courses. Both the results and techniques in this study would be very useful for public health education and research specialists. PMID:21976027

PUMa - modelling the groundwater flow in Baltic Sedimentary Basin

NASA Astrophysics Data System (ADS)

Kalvane, G.; Marnica, A.; Bethers, U.

2012-04-01

In 2009-2012 at University of Latvia and Latvia University of Agriculture project "Establishment of interdisciplinary scientist group and modelling system for groundwater research" is implemented financed by the European Social Fund. The aim of the project is to develop groundwater research in Latvia by establishing interdisciplinary research group and modelling system covering groundwater flow in the Baltic Sedimentary Basin. Researchers from fields like geology, chemistry, mathematical modelling, physics and environmental engineering are involved in the project. The modelling system is used as a platform for addressing scientific problems such as: (1) large-scale groundwater flow in Baltic Sedimentary Basin and impact of human activities on it; (2) the evolution of groundwater flow since the last glaciation and subglacial groundwater recharge; (3) the effects of climate changes on shallow groundwater and interaction of hydrographical network and groundwater; (4) new programming approaches for groundwater modelling. Within the frame of the project most accessible geological information such as description of geological wells, geological maps and results of seismic profiling in Latvia as well as Estonia and Lithuania are collected and integrated into modelling system. For example data form more then 40 thousands wells are directly used to automatically generate the geological structure of the model. Additionally a groundwater sampling campaign is undertaken. Contents of CFC, stabile isotopes of O and H and radiocarbon are the most significant parameters of groundwater that are established in unprecedented scale for Latvia. The most important modelling results will be published in web as a data set. Project number: 2009/0212/1DP/1.1.1.2.0/09/APIA/VIAA/060. Project web-site: www.puma.lu.lv

The Great Silk Alternative: Multiple Co-Evolution of Web Loss and Sticky Hairs in Spiders

PubMed Central

Wolff, Jonas O.; Nentwig, Wolfgang; Gorb, Stanislav N.

2013-01-01

Spiders are the most important terrestrial predators among arthropods. Their ecological success is reflected by a high biodiversity and the conquest of nearly every terrestrial habitat. Spiders are closely associated with silk, a material, often seen to be responsible for their great ecological success and gaining high attention in life sciences. However, it is often overlooked that more than half of all Recent spider species have abandoned web building or never developed such an adaptation. These species must have found other, more economic solutions for prey capture and retention, compensating the higher energy costs of increased locomotion activity. Here we show that hairy adhesive pads (scopulae) are closely associated with the convergent evolution of a vagrant life style, resulting in highly diversified lineages of at least, equal importance as the derived web building taxa. Previous studies often highlighted the idea that scopulae have the primary function of assisting locomotion, neglecting the fact that only the distal most pads (claw tufts) are suitable for those purposes. The former observations, that scopulae are used in prey capture, are largely overlooked. Our results suggest the scopulae evolved as a substitute for silk in controlling prey and that the claw tufts are, in most cases, a secondary development. Evolutionary trends towards specialized claw tufts and their composition from a low number of enlarged setae to a dense array of slender ones, as well as the secondary loss of those pads are discussed further. Hypotheses about the origin of the adhesive setae and their diversification throughout evolution are provided. PMID:23650526

Imprints of the large-scale structure on AGN formation and evolution

NASA Astrophysics Data System (ADS)

Porqueres, Natàlia; Jasche, Jens; Enßlin, Torsten A.; Lavaux, Guilhem

2018-04-01

Black hole masses are found to correlate with several global properties of their host galaxies, suggesting that black holes and galaxies have an intertwined evolution and that active galactic nuclei (AGN) have a significant impact on galaxy evolution. Since the large-scale environment can also affect AGN, this work studies how their formation and properties depend on the environment. We have used a reconstructed three-dimensional high-resolution density field obtained from a Bayesian large-scale structure reconstruction method applied to the 2M++ galaxy sample. A web-type classification relying on the shear tensor is used to identify different structures on the cosmic web, defining voids, sheets, filaments, and clusters. We confirm that the environmental density affects the AGN formation and their properties. We found that the AGN abundance is equivalent to the galaxy abundance, indicating that active and inactive galaxies reside in similar dark matter halos. However, occurrence rates are different for each spectral type and accretion rate. These differences are consistent with the AGN evolutionary sequence suggested by previous authors, Seyferts and Transition objects transforming into low-ionization nuclear emission line regions (LINERs), the weaker counterpart of Seyferts. We conclude that AGN properties depend on the environmental density more than on the web-type. More powerful starbursts and younger stellar populations are found in high densities, where interactions and mergers are more likely. AGN hosts show smaller masses in clusters for Seyferts and Transition objects, which might be due to gas stripping. In voids, the AGN population is dominated by the most massive galaxy hosts.

[Matematical modeling of antibiotic resistance: perspectives from a meta-analysys].

PubMed

Fresnadillo-Martínez, M J; García-Sánchez, E; García-Merino, E; Martín-Del-Rey, A; Rodríguez-Encinas, A; Rodríguez-Sánchez, G; García-Sánchez, J E

2012-09-01

The antibiotic resistance is one of the greatest challenges of the international health community. The study of antibiotic resistance must be a multidisciplinary task and, in this sense, the main goal of this work is to analyze the role that Mathematical Modeling can play in this scenario. A qualitative and cuantitative analysis of the works published in the scientific literature is done by means of a search in the most important databases: MEDLINE, SCOPUS and ISI Web of Science. Consequently, there are few papers related to our topic but the existing works have been published in high-quality and impact international journals. Moreover, we can state that mathematical models are a very important and useful tool to analyze and study both the treatments protocols for resistance prevention and the assesment of control strategies in hospital environtment, or the prediction of the evolution of diseases due to resistant strains.

Two classes of bipartite networks: nested biological and social systems.

PubMed

Burgos, Enrique; Ceva, Horacio; Hernández, Laura; Perazzo, R P J; Devoto, Mariano; Medan, Diego

2008-10-01

Bipartite graphs have received some attention in the study of social networks and of biological mutualistic systems. A generalization of a previous model is presented, that evolves the topology of the graph in order to optimally account for a given contact preference rule between the two guilds of the network. As a result, social and biological graphs are classified as belonging to two clearly different classes. Projected graphs, linking the agents of only one guild, are obtained from the original bipartite graph. The corresponding evolution of its statistical properties is also studied. An example of a biological mutualistic network is analyzed in detail, and it is found that the model provides a very good fitting of all the main statistical features. The model also provides a proper qualitative description of the same features observed in social webs, suggesting the possible reasons underlying the difference in the organization of these two kinds of bipartite networks.

The fast debris evolution model

NASA Astrophysics Data System (ADS)

Lewis, H. G.; Swinerd, G. G.; Newland, R. J.; Saunders, A.

2009-09-01

The 'particles-in-a-box' (PIB) model introduced by Talent [Talent, D.L. Analytic model for orbital debris environmental management. J. Spacecraft Rocket, 29 (4), 508-513, 1992.] removed the need for computer-intensive Monte Carlo simulation to predict the gross characteristics of an evolving debris environment. The PIB model was described using a differential equation that allows the stability of the low Earth orbit (LEO) environment to be tested by a straightforward analysis of the equation's coefficients. As part of an ongoing research effort to investigate more efficient approaches to evolutionary modelling and to develop a suite of educational tools, a new PIB model has been developed. The model, entitled Fast Debris Evolution (FADE), employs a first-order differential equation to describe the rate at which new objects ⩾10 cm are added and removed from the environment. Whilst Talent [Talent, D.L. Analytic model for orbital debris environmental management. J. Spacecraft Rocket, 29 (4), 508-513, 1992.] based the collision theory for the PIB approach on collisions between gas particles and adopted specific values for the parameters of the model from a number of references, the form and coefficients of the FADE model equations can be inferred from the outputs of future projections produced by high-fidelity models, such as the DAMAGE model. The FADE model has been implemented as a client-side, web-based service using JavaScript embedded within a HTML document. Due to the simple nature of the algorithm, FADE can deliver the results of future projections immediately in a graphical format, with complete user-control over key simulation parameters. Historical and future projections for the ⩾10 cm LEO debris environment under a variety of different scenarios are possible, including business as usual, no future launches, post-mission disposal and remediation. A selection of results is presented with comparisons with predictions made using the DAMAGE environment model. The results demonstrate that the FADE model is able to capture comparable time-series of collisions and number of objects as predicted by DAMAGE in several scenarios. Further, and perhaps more importantly, its speed and flexibility allows the user to explore and understand the evolution of the space debris environment.

The Evolution of Ecological Systems.

ERIC Educational Resources Information Center

May, Robert M.

1978-01-01

Discusses the coevaluation of species within ecosystems. This process gives rise to interesting patterns in the total number of species found in a given area, in their relative abundances, and in the overall structure of the local food web. (Author/MA)

[WebSurvCa: web-based estimation of death and survival probabilities in a cohort].

PubMed

Clèries, Ramon; Ameijide, Alberto; Buxó, Maria; Vilardell, Mireia; Martínez, José Miguel; Alarcón, Francisco; Cordero, David; Díez-Villanueva, Ana; Yasui, Yutaka; Marcos-Gragera, Rafael; Vilardell, Maria Loreto; Carulla, Marià; Galceran, Jaume; Izquierdo, Ángel; Moreno, Víctor; Borràs, Josep M

2018-01-19

Relative survival has been used as a measure of the temporal evolution of the excess risk of death of a cohort of patients diagnosed with cancer, taking into account the mortality of a reference population. Once the excess risk of death has been estimated, three probabilities can be computed at time T: 1) the crude probability of death associated with the cause of initial diagnosis (disease under study), 2) the crude probability of death associated with other causes, and 3) the probability of absolute survival in the cohort at time T. This paper presents the WebSurvCa application (https://shiny.snpstats.net/WebSurvCa/), whereby hospital-based and population-based cancer registries and registries of other diseases can estimate such probabilities in their cohorts by selecting the mortality of the relevant region (reference population). Copyright © 2017 SESPAS. Publicado por Elsevier España, S.L.U. All rights reserved.

A Quantitative Cost Effectiveness Model for Web-Supported Academic Instruction

ERIC Educational Resources Information Center

Cohen, Anat; Nachmias, Rafi

2006-01-01

This paper describes a quantitative cost effectiveness model for Web-supported academic instruction. The model was designed for Web-supported instruction (rather than distance learning only) characterizing most of the traditional higher education institutions. It is based on empirical data (Web logs) of students' and instructors' usage…

Smart caching based on mobile agent of power WebGIS platform.

PubMed

Wang, Xiaohui; Wu, Kehe; Chen, Fei

2013-01-01

Power information construction is developing towards intensive, platform, distributed direction with the expansion of power grid and improvement of information technology. In order to meet the trend, power WebGIS was designed and developed. In this paper, we first discuss the architecture and functionality of power WebGIS, and then we study caching technology in detail, which contains dynamic display cache model, caching structure based on mobile agent, and cache data model. We have designed experiments of different data capacity to contrast performance between WebGIS with the proposed caching model and traditional WebGIS. The experimental results showed that, with the same hardware environment, the response time of WebGIS with and without caching model increased as data capacity growing, while the larger the data was, the higher the performance of WebGIS with proposed caching model improved.

The use of advanced web-based survey design in Delphi research.

PubMed

Helms, Christopher; Gardner, Anne; McInnes, Elizabeth

2017-12-01

A discussion of the application of metadata, paradata and embedded data in web-based survey research, using two completed Delphi surveys as examples. Metadata, paradata and embedded data use in web-based Delphi surveys has not been described in the literature. The rapid evolution and widespread use of online survey methods imply that paper-based Delphi methods will likely become obsolete. Commercially available web-based survey tools offer a convenient and affordable means of conducting Delphi research. Researchers and ethics committees may be unaware of the benefits and risks of using metadata in web-based surveys. Discussion paper. Two web-based, three-round Delphi surveys were conducted sequentially between August 2014 - January 2015 and April - May 2016. Their aims were to validate the Australian nurse practitioner metaspecialties and their respective clinical practice standards. Our discussion paper is supported by researcher experience and data obtained from conducting both web-based Delphi surveys. Researchers and ethics committees should consider the benefits and risks of metadata use in web-based survey methods. Web-based Delphi research using paradata and embedded data may introduce efficiencies that improve individual participant survey experiences and reduce attrition across iterations. Use of embedded data allows the efficient conduct of multiple simultaneous Delphi surveys across a shorter timeframe than traditional survey methods. The use of metadata, paradata and embedded data appears to improve response rates, identify bias and give possible explanation for apparent outlier responses, providing an efficient method of conducting web-based Delphi surveys. © 2017 John Wiley & Sons Ltd.

A community effort to construct a gravity database for the United States and an associated Web portal

USGS Publications Warehouse

Keller, Gordon R.; Hildenbrand, T.G.; Kucks, R.; Webring, M.; Briesacher, A.; Rujawitz, K.; Hittleman, A.M.; Roman, D.R.; Winester, D.; Aldouri, R.; Seeley, J.; Rasillo, J.; Torres, R.; Hinze, W. J.; Gates, A.; Kreinovich, V.; Salayandia, L.

2006-01-01

Potential field data (gravity and magnetic measurements) are both useful and costeffective tools for many geologic investigations. Significant amounts of these data are traditionally in the public domain. A new magnetic database for North America was released in 2002, and as a result, a cooperative effort between government agencies, industry, and universities to compile an upgraded digital gravity anomaly database, grid, and map for the conterminous United States was initiated and is the subject of this paper. This database is being crafted into a data system that is accessible through a Web portal. This data system features the database, software tools, and convenient access. The Web portal will enhance the quality and quantity of data contributed to the gravity database that will be a shared community resource. The system's totally digital nature ensures that it will be flexible so that it can grow and evolve as new data, processing procedures, and modeling and visualization tools become available. Another goal of this Web-based data system is facilitation of the efforts of researchers and students who wish to collect data from regions currently not represented adequately in the database. The primary goal of upgrading the United States gravity database and this data system is to provide more reliable data that support societal and scientific investigations of national importance. An additional motivation is the international intent to compile an enhanced North American gravity database, which is critical to understanding regional geologic features, the tectonic evolution of the continent, and other issues that cross national boundaries. ?? 2006 Geological Society of America. All rights reserved.

On the topology of the world exchange arrangements web

NASA Astrophysics Data System (ADS)

Li, Xiang; Jin, Yu Ying; Chen, Guanrong

2004-11-01

Exchange arrangements among different countries over the world are foundations of the world economy, which generally stand behind the daily economic evolution. As the first study of the world exchange arrangements web (WEAW), we built a bipartite network with countries as one type of nodes and currencies as the other, and found it to have a prominent scale-free feature with a power-law degree distribution. In a further empirical study of the currency section of the WEAW, we calculated the clustering coefficients, average nearest-neighbors degree, and average shortest distance. As an essential economic network, the WEAW is found to be a correlated disassortative network with a hierarchical structure, possessing a more prominent scale-free feature than the world trade web (WTW).

A generalized 3D framework for visualization of planetary data.

NASA Astrophysics Data System (ADS)

Larsen, K. W.; De Wolfe, A. W.; Putnam, B.; Lindholm, D. M.; Nguyen, D.

2016-12-01

As the volume and variety of data returned from planetary exploration missions continues to expand, new tools and technologies are needed to explore the data and answer questions about the formation and evolution of the solar system. We have developed a 3D visualization framework that enables the exploration of planetary data from multiple instruments on the MAVEN mission to Mars. This framework not only provides the opportunity for cross-instrument visualization, but is extended to include model data as well, helping to bridge the gap between theory and observation. This is made possible through the use of new web technologies, namely LATIS, a data server that can stream data and spacecraft ephemerides to a web browser, and Cesium, a Javascript library for 3D globes. The common visualization framework we have developed is flexible and modular so that it can easily be adapted for additional missions. In addition to demonstrating the combined data and modeling capabilities of the system for the MAVEN mission, we will display the first ever near real-time `QuickLook', interactive, 4D data visualization for the Magnetospheric Multiscale Mission (MMS). In this application, data from all four spacecraft can be manipulated and visualized as soon as the data is ingested into the MMS Science Data Center, less than one day after collection.

A topological framework for interactive queries on 3D models in the Web.

PubMed

Figueiredo, Mauro; Rodrigues, José I; Silvestre, Ivo; Veiga-Pires, Cristina

2014-01-01

Several technologies exist to create 3D content for the web. With X3D, WebGL, and X3DOM, it is possible to visualize and interact with 3D models in a web browser. Frequently, three-dimensional objects are stored using the X3D file format for the web. However, there is no explicit topological information, which makes it difficult to design fast algorithms for applications that require adjacency and incidence data. This paper presents a new open source toolkit TopTri (Topological model for Triangle meshes) for Web3D servers that builds the topological model for triangular meshes of manifold or nonmanifold models. Web3D client applications using this toolkit make queries to the web server to get adjacent and incidence information of vertices, edges, and faces. This paper shows the application of the topological information to get minimal local points and iso-lines in a 3D mesh in a web browser. As an application, we present also the interactive identification of stalactites in a cave chamber in a 3D web browser. Several tests show that even for large triangular meshes with millions of triangles, the adjacency and incidence information is returned in real time making the presented toolkit appropriate for interactive Web3D applications.

A Topological Framework for Interactive Queries on 3D Models in the Web

PubMed Central

Figueiredo, Mauro; Rodrigues, José I.; Silvestre, Ivo; Veiga-Pires, Cristina

2014-01-01

Several technologies exist to create 3D content for the web. With X3D, WebGL, and X3DOM, it is possible to visualize and interact with 3D models in a web browser. Frequently, three-dimensional objects are stored using the X3D file format for the web. However, there is no explicit topological information, which makes it difficult to design fast algorithms for applications that require adjacency and incidence data. This paper presents a new open source toolkit TopTri (Topological model for Triangle meshes) for Web3D servers that builds the topological model for triangular meshes of manifold or nonmanifold models. Web3D client applications using this toolkit make queries to the web server to get adjacent and incidence information of vertices, edges, and faces. This paper shows the application of the topological information to get minimal local points and iso-lines in a 3D mesh in a web browser. As an application, we present also the interactive identification of stalactites in a cave chamber in a 3D web browser. Several tests show that even for large triangular meshes with millions of triangles, the adjacency and incidence information is returned in real time making the presented toolkit appropriate for interactive Web3D applications. PMID:24977236

Topology and evolution of technology innovation networks

NASA Astrophysics Data System (ADS)

Valverde, Sergi; Solé, Ricard V.; Bedau, Mark A.; Packard, Norman

2007-11-01

The web of relations linking technological innovation can be fairly described in terms of patent citations. The resulting patent citation network provides a picture of the large-scale organization of innovations and its time evolution. Here we study the patterns of change of patents registered by the U.S. Patent and Trademark Office. We show that the scaling behavior exhibited by this network is consistent with a preferential attachment mechanism together with a Weibull-shaped aging term. Such an attachment kernel is shared by scientific citation networks, thus indicating a universal type of mechanism linking ideas and designs and their evolution. The implications for evolutionary theory of innovation are discussed.

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

PubMed

Woo, Jiyoung; Chen, Hsinchun

2016-01-01

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

Real-time GIS data model and sensor web service platform for environmental data management.

PubMed

Gong, Jianya; Geng, Jing; Chen, Zeqiang

2015-01-09

Effective environmental data management is meaningful for human health. In the past, environmental data management involved developing a specific environmental data management system, but this method often lacks real-time data retrieving and sharing/interoperating capability. With the development of information technology, a Geospatial Service Web method is proposed that can be employed for environmental data management. The purpose of this study is to determine a method to realize environmental data management under the Geospatial Service Web framework. A real-time GIS (Geographic Information System) data model and a Sensor Web service platform to realize environmental data management under the Geospatial Service Web framework are proposed in this study. The real-time GIS data model manages real-time data. The Sensor Web service platform is applied to support the realization of the real-time GIS data model based on the Sensor Web technologies. To support the realization of the proposed real-time GIS data model, a Sensor Web service platform is implemented. Real-time environmental data, such as meteorological data, air quality data, soil moisture data, soil temperature data, and landslide data, are managed in the Sensor Web service platform. In addition, two use cases of real-time air quality monitoring and real-time soil moisture monitoring based on the real-time GIS data model in the Sensor Web service platform are realized and demonstrated. The total time efficiency of the two experiments is 3.7 s and 9.2 s. The experimental results show that the method integrating real-time GIS data model and Sensor Web Service Platform is an effective way to manage environmental data under the Geospatial Service Web framework.

Evolution of and projections for automated composite material placement equipment in the aerospace industry

NASA Astrophysics Data System (ADS)

McCarville, Douglas A.

2009-12-01

As the commercial aircraft industry attempts to improve airplane fuel efficiency by shifting from aluminum to composites (reinforced plastics), there is a concern that composite processing equipment is not mature enough to meet increasing demand and that delivery delays and loss of high tech jobs could result. The research questions focused on the evolution of composite placement machines, improvement of machine functionality by equipment vendors, and the probability of new inventions helping to avoid production shortfalls. An extensive review of the literature found no studies that addressed these issues. Since the early twentieth century, exploratory case study of pivotal technological advances has been an accepted means of performing historic analysis and furthering understanding of rapidly changing marketplaces and industries. This qualitative case study investigated evolution of automated placement equipment by (a) codifying and mapping patent data (e.g., claims and functionality descriptions), (b) triangulating archival data (i.e., trade literature, vender Web sites, and scholarly texts), and (c) interviewing expert witnesses. An industry-level sensitivity model developed by the author showed that expanding the vendor base and increasing the number of performance enhancing inventions will most likely allow the industry to make the transition from aluminum to composites without schedule delays. This study will promote social change by (a) advancing individual and community knowledge (e.g., teaching modules for students, practitioners, and professional society members) and (b) providing an empirical model that will help in the understanding and projection of next generation composite processing equipment demand and productivity output.

Smart Caching Based on Mobile Agent of Power WebGIS Platform

PubMed Central

Wang, Xiaohui; Wu, Kehe; Chen, Fei

2013-01-01

Power information construction is developing towards intensive, platform, distributed direction with the expansion of power grid and improvement of information technology. In order to meet the trend, power WebGIS was designed and developed. In this paper, we first discuss the architecture and functionality of power WebGIS, and then we study caching technology in detail, which contains dynamic display cache model, caching structure based on mobile agent, and cache data model. We have designed experiments of different data capacity to contrast performance between WebGIS with the proposed caching model and traditional WebGIS. The experimental results showed that, with the same hardware environment, the response time of WebGIS with and without caching model increased as data capacity growing, while the larger the data was, the higher the performance of WebGIS with proposed caching model improved. PMID:24288504

A Web-Based Modelling Platform for Interactive Exploration of Regional Responses to Global Change

NASA Astrophysics Data System (ADS)

Holman, I.

2014-12-01

Climate change adaptation is a complex human-environmental problem that is framed by the uncertainty in impacts and the adaptation choices available, but is also bounded by real-world constraints such as future resource availability and environmental and institutional capacities. Educating the next generation of informed decision-makers that will be able to make knowledgeable responses to global climate change impacts requires them to have access to information that is credible, accurate, easy to understand, and appropriate. However, available resources are too often produced by inaccessible models for scenario simulations chosen by researchers hindering exploration and enquiry. This paper describes the interactive exploratory web-based CLIMSAVE Integrated Assessment (IA) Platform (www.climsave.eu/iap) that aims to democratise climate change impacts, adaptation and vulnerability modelling. The regional version of the Platform contain linked simulation models (of the urban, agriculture, forestry, water and biodiversity sectors), probabilistic climate scenarios and socio-economic scenarios, that enable users to select their inputs (climate and socioeconomic), rapidly run the models using their input variable settings and view their chosen outputs. The interface of the CLIMSAVE IA Platform is designed to facilitate a two-way iterative process of dialogue and exploration of "what if's" to enable a wide range of users to improve their understanding surrounding impacts, adaptation responses and vulnerability of natural resources and ecosystem services under uncertain futures. This paper will describe the evolution of the Platform and demonstrate how using its holistic framework (multi sector / ecosystem service; cross-sectoral, climate and socio-economic change) will help to assist learning around the challenging concepts of responding to global change.

Web-video-mining-supported workflow modeling for laparoscopic surgeries.

PubMed

Liu, Rui; Zhang, Xiaoli; Zhang, Hao

2016-11-01

As quality assurance is of strong concern in advanced surgeries, intelligent surgical systems are expected to have knowledge such as the knowledge of the surgical workflow model (SWM) to support their intuitive cooperation with surgeons. For generating a robust and reliable SWM, a large amount of training data is required. However, training data collected by physically recording surgery operations is often limited and data collection is time-consuming and labor-intensive, severely influencing knowledge scalability of the surgical systems. The objective of this research is to solve the knowledge scalability problem in surgical workflow modeling with a low cost and labor efficient way. A novel web-video-mining-supported surgical workflow modeling (webSWM) method is developed. A novel video quality analysis method based on topic analysis and sentiment analysis techniques is developed to select high-quality videos from abundant and noisy web videos. A statistical learning method is then used to build the workflow model based on the selected videos. To test the effectiveness of the webSWM method, 250 web videos were mined to generate a surgical workflow for the robotic cholecystectomy surgery. The generated workflow was evaluated by 4 web-retrieved videos and 4 operation-room-recorded videos, respectively. The evaluation results (video selection consistency n-index ≥0.60; surgical workflow matching degree ≥0.84) proved the effectiveness of the webSWM method in generating robust and reliable SWM knowledge by mining web videos. With the webSWM method, abundant web videos were selected and a reliable SWM was modeled in a short time with low labor cost. Satisfied performances in mining web videos and learning surgery-related knowledge show that the webSWM method is promising in scaling knowledge for intelligent surgical systems. Copyright © 2016 Elsevier B.V. All rights reserved.

Advancing data reuse in phyloinformatics using an ontology-driven Semantic Web approach.

PubMed

Panahiazar, Maryam; Sheth, Amit P; Ranabahu, Ajith; Vos, Rutger A; Leebens-Mack, Jim

2013-01-01

Phylogenetic analyses can resolve historical relationships among genes, organisms or higher taxa. Understanding such relationships can elucidate a wide range of biological phenomena, including, for example, the importance of gene and genome duplications in the evolution of gene function, the role of adaptation as a driver of diversification, or the evolutionary consequences of biogeographic shifts. Phyloinformaticists are developing data standards, databases and communication protocols (e.g. Application Programming Interfaces, APIs) to extend the accessibility of gene trees, species trees, and the metadata necessary to interpret these trees, thus enabling researchers across the life sciences to reuse phylogenetic knowledge. Specifically, Semantic Web technologies are being developed to make phylogenetic knowledge interpretable by web agents, thereby enabling intelligently automated, high-throughput reuse of results generated by phylogenetic research. This manuscript describes an ontology-driven, semantic problem-solving environment for phylogenetic analyses and introduces artefacts that can promote phyloinformatic efforts to promote accessibility of trees and underlying metadata. PhylOnt is an extensible ontology with concepts describing tree types and tree building methodologies including estimation methods, models and programs. In addition we present the PhylAnt platform for annotating scientific articles and NeXML files with PhylOnt concepts. The novelty of this work is the annotation of NeXML files and phylogenetic related documents with PhylOnt Ontology. This approach advances data reuse in phyloinformatics.

a Geodatabase for Multisource Data Applied to Cultural Heritage: the Case Study of Villa Revedin Bolasco

NASA Astrophysics Data System (ADS)

Guarnieri, A.; Masiero, A.; Piragnolo, M.; Pirotti, F.; Vettore, A.

2016-06-01

In this paper we present the results of the development of a Web-based archiving and documenting system aimed to the management of multisource and multitemporal data related to cultural heritage. As case study we selected the building complex of Villa Revedin Bolasco in Castefranco Veneto (Treviso, Italy) and its park. Buildings and park were built in XIX century after several restorations of the original XIV century area. The data management system relies on a geodatabase framework, in which different kinds of datasets were stored. More specifically, the geodatabase elements consist of historical information, documents, descriptions of artistic characteristics of the building and the park, in the form of text and images. In addition, we used also floorplans, sections and views of the outer facades of the building extracted by a TLS-based 3D model of the whole Villa. In order to manage and explore these rich dataset, we developed a geodatabase using PostgreSQL and PostGIS as spatial plugin. The Web-GIS platform, based on HTML5 and PHP programming languages, implements the NASA Web World Wind virtual globe, a 3D virtual globe we used to enable the navigation and interactive exploration of the park. Furthermore, through a specific timeline function, the user can explore the historical evolution of the building complex.

SensorWeb Evolution Using the Earth Observing One (EO-1) Satellite as a Test Platform

NASA Technical Reports Server (NTRS)

Mandl, Daniel; Frye, Stuart; Cappelaere, Pat; Ly, Vuong; Handy, Matthew; Chien, Steve; Grossman, Robert; Tran, Daniel

2012-01-01

The Earth Observing One (EO-1) satellite was launched in November 2000 as a one year technology demonstration mission for a variety of space technologies. After the first year, in addition to collecting science data from its instruments, the EO-1 mission has been used as a testbed for a variety of technologies which provide various automation capabilities and which have been used as a pathfinder for the creation of SensorWebs. A SensorWeb is the integration of variety of space, airborne and ground sensors into a loosely coupled collaborative sensor system that automatically provides useful data products. Typically, a SensorWeb is comprised of heterogeneous sensors tied together with a messaging architecture and web services. This paper provides an overview of the various technologies that were tested and eventually folded into normal operations. As these technologies were folded in, the nature of operations transformed. The SensorWeb software enables easy connectivity for collaboration with sensors, but the side benefit is that it improved the EO-1 operational efficiency. This paper presents the various phases of EO-1 operation over the past 12 years and also presents operational efficiency gains demonstrated by some metrics.

Adding a Visualization Feature to Web Search Engines: It’s Time

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

Wong, Pak C.

Since the first world wide web (WWW) search engine quietly entered our lives in 1994, the “information need” behind web searching has rapidly grown into a multi-billion dollar business that dominates the internet landscape, drives e-commerce traffic, propels global economy, and affects the lives of the whole human race. Today’s search engines are faster, smarter, and more powerful than those released just a few years ago. With the vast investment pouring into research and development by leading web technology providers and the intense emotion behind corporate slogans such as “win the web” or “take back the web,” I can’t helpmore » but ask why are we still using the very same “text-only” interface that was used 13 years ago to browse our search engine results pages (SERPs)? Why has the SERP interface technology lagged so far behind in the web evolution when the corresponding search technology has advanced so rapidly? In this article I explore some current SERP interface issues, suggest a simple but practical visual-based interface design approach, and argue why a visual approach can be a strong candidate for tomorrow’s SERP interface.« less

IsoWeb: A Bayesian Isotope Mixing Model for Diet Analysis of the Whole Food Web

PubMed Central

Kadoya, Taku; Osada, Yutaka; Takimoto, Gaku

2012-01-01

Quantitative description of food webs provides fundamental information for the understanding of population, community, and ecosystem dynamics. Recently, stable isotope mixing models have been widely used to quantify dietary proportions of different food resources to a focal consumer. Here we propose a novel mixing model (IsoWeb) that estimates diet proportions of all consumers in a food web based on stable isotope information. IsoWeb requires a topological description of a food web, and stable isotope signatures of all consumers and resources in the web. A merit of IsoWeb is that it takes into account variation in trophic enrichment factors among different consumer-resource links. Sensitivity analysis using realistic hypothetical food webs suggests that IsoWeb is applicable to a wide variety of food webs differing in the number of species, connectance, sample size, and data variability. Sensitivity analysis based on real topological webs showed that IsoWeb can allow for a certain level of topological uncertainty in target food webs, including erroneously assuming false links, omission of existent links and species, and trophic aggregation into trophospecies. Moreover, using an illustrative application to a real food web, we demonstrated that IsoWeb can compare the plausibility of different candidate topologies for a focal web. These results suggest that IsoWeb provides a powerful tool to analyze food-web structure from stable isotope data. We provide R and BUGS codes to aid efficient applications of IsoWeb. PMID:22848427

Food web topology and parasites in the pelagic zone of a subarctic lake

USGS Publications Warehouse

Amundsen, Per-Arne; Lafferty, K.D.; Knudsen, R.; Primicerio, R.; Klemetsen, A.; Kuris, A.M.

2009-01-01

Parasites permeate trophic webs with their often complex life cycles, but few studies have included parasitism in food web analyses. Here we provide a highly resolved food web from the pelagic zone of a subarctic lake and explore how the incorporation of parasites alters the topology of the web. 2. Parasites used hosts at all trophic levels and increased both food-chain lengths and the total number of trophic levels. Their inclusion in the network analyses more than doubled the number of links and resulted in an increase in important food-web characteristics such as linkage density and connectance. 3. More than half of the parasite taxa were trophically transmitted, exploiting hosts at multiple trophic levels and thus increasing the degree of omnivory in the trophic web. 4. For trophically transmitted parasites, the number of parasite-host links exhibited a positive correlation with the linkage density of the host species, whereas no such relationship was seen for nontrophically transmitted parasites. Our findings suggest that the linkage density of free-living species affects their exposure to trophically transmitted parasites, which may be more likely to adopt highly connected species as hosts during the evolution of complex life cycles. 5. The study supports a prominent role for parasites in ecological networks and demonstrates that their incorporation may substantially alter considerations of food-web structure and functioning. ?? 2009 British Ecological Society.

Modelling food-web mediated effects of hydrological variability and environmental flows.

PubMed

Robson, Barbara J; Lester, Rebecca E; Baldwin, Darren S; Bond, Nicholas R; Drouart, Romain; Rolls, Robert J; Ryder, Darren S; Thompson, Ross M

2017-11-01

Environmental flows are designed to enhance aquatic ecosystems through a variety of mechanisms; however, to date most attention has been paid to the effects on habitat quality and life-history triggers, especially for fish and vegetation. The effects of environmental flows on food webs have so far received little attention, despite food-web thinking being fundamental to understanding of river ecosystems. Understanding environmental flows in a food-web context can help scientists and policy-makers better understand and manage outcomes of flow alteration and restoration. In this paper, we consider mechanisms by which flow variability can influence and alter food webs, and place these within a conceptual and numerical modelling framework. We also review the strengths and weaknesses of various approaches to modelling the effects of hydrological management on food webs. Although classic bioenergetic models such as Ecopath with Ecosim capture many of the key features required, other approaches, such as biogeochemical ecosystem modelling, end-to-end modelling, population dynamic models, individual-based models, graph theory models, and stock assessment models are also relevant. In many cases, a combination of approaches will be useful. We identify current challenges and new directions in modelling food-web responses to hydrological variability and environmental flow management. These include better integration of food-web and hydraulic models, taking physiologically-based approaches to food quality effects, and better representation of variations in space and time that may create ecosystem control points. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Food-web models predict species abundances in response to habitat change.

PubMed

Gotelli, Nicholas J; Ellison, Aaron M

2006-10-01

Plant and animal population sizes inevitably change following habitat loss, but the mechanisms underlying these changes are poorly understood. We experimentally altered habitat volume and eliminated top trophic levels of the food web of invertebrates that inhabit rain-filled leaves of the carnivorous pitcher plant Sarracenia purpurea. Path models that incorporated food-web structure better predicted population sizes of food-web constituents than did simple keystone species models, models that included only autecological responses to habitat volume, or models including both food-web structure and habitat volume. These results provide the first experimental confirmation that trophic structure can determine species abundances in the face of habitat loss.

Adopt-a-Dino

ERIC Educational Resources Information Center

Clary, Renee; Wandersee, James

2011-01-01

This article discusses a creative visualization project to motivate and engage students. Students depict a dinosaur in its ecosystem and include all three elements of the environment: air, land, and water. Students explore scientific content in evolution, natural selection, food webs, ecosystems and geologic time. (Contains 6 figures.)

What is Justice for Juveniles?

ERIC Educational Resources Information Center

Rothwell, Jennifer Truran

1997-01-01

Provides background information and related learning activities for three areas of inquiry involving youth and violence: (1) "Evolution of the Juvenile Justice System"; (2) "The Literature of Crime and Poverty"; (3) "Youth Crime and Public Policy." Includes a list of six recommended Web sites. (MJP)

Customer Decision Making in Web Services with an Integrated P6 Model

NASA Astrophysics Data System (ADS)

Sun, Zhaohao; Sun, Junqing; Meredith, Grant

Customer decision making (CDM) is an indispensable factor for web services. This article examines CDM in web services with a novel P6 model, which consists of the 6 Ps: privacy, perception, propensity, preference, personalization and promised experience. This model integrates the existing 6 P elements of marketing mix as the system environment of CDM in web services. The new integrated P6 model deals with the inner world of the customer and incorporates what the customer think during the DM process. The proposed approach will facilitate the research and development of web services and decision support systems.

Information-Flow-Based Access Control for Web Browsers

NASA Astrophysics Data System (ADS)

Yoshihama, Sachiko; Tateishi, Takaaki; Tabuchi, Naoshi; Matsumoto, Tsutomu

The emergence of Web 2.0 technologies such as Ajax and Mashup has revealed the weakness of the same-origin policy[1], the current de facto standard for the Web browser security model. We propose a new browser security model to allow fine-grained access control in the client-side Web applications for secure mashup and user-generated contents. We propose a browser security model that is based on information-flow-based access control (IBAC) to overcome the dynamic nature of the client-side Web applications and to accurately determine the privilege of scripts in the event-driven programming model.

A continuum membrane model for small deformations of a spider orb-web

NASA Astrophysics Data System (ADS)

Morassi, Antonino; Soler, Alejandro; Zaera, Ramón

2017-09-01

In this paper we propose a continuum membrane model for the infinitesimal deformation of a spider web. The model is derived in the simple context of axially-symmetric webs formed by radial threads connected with circumferential threads belonging to concentric circles. Under suitable assumption on the tensile pre-stress acting in the referential configuration, the out-of-plane static equilibrium and the free transverse and in-plane vibration of a supported circular orb-web are studied in detail. The accuracy of the model in describing a discrete spider web is numerically investigated.

Vibration Propagation in Spider Webs

NASA Astrophysics Data System (ADS)

Hatton, Ross; Otto, Andrew; Elias, Damian

Due to their poor eyesight, spiders rely on web vibrations for situational awareness. Web-borne vibrations are used to determine the location of prey, predators, and potential mates. The influence of web geometry and composition on web vibrations is important for understanding spider's behavior and ecology. Past studies on web vibrations have experimentally measured the frequency response of web geometries by removing threads from existing webs. The full influence of web structure and tension distribution on vibration transmission; however, has not been addressed in prior work. We have constructed physical artificial webs and computer models to better understand the effect of web structure on vibration transmission. These models provide insight into the propagation of vibrations through the webs, the frequency response of the bare web, and the influence of the spider's mass and stiffness on the vibration transmission patterns. Funded by NSF-1504428.

Development of Web-Based Learning Environment Model to Enhance Cognitive Skills for Undergraduate Students in the Field of Electrical Engineering

ERIC Educational Resources Information Center

Lakonpol, Thongmee; Ruangsuwan, Chaiyot; Terdtoon, Pradit

2015-01-01

This research aimed to develop a web-based learning environment model for enhancing cognitive skills of undergraduate students in the field of electrical engineering. The research is divided into 4 phases: 1) investigating the current status and requirements of web-based learning environment models. 2) developing a web-based learning environment…

The Development of Web-Based Collaborative Training Model for Enhancing Human Performances on ICT for Students in Banditpattanasilpa Institute

ERIC Educational Resources Information Center

Pumipuntu, Natawut; Kidrakarn, Pachoen; Chetakarn, Somchock

2015-01-01

This research aimed to develop the model of Web-based Collaborative (WBC) Training model for enhancing human performances on ICT for students in Banditpattanasilpa Institute. The research is divided into three phases: 1) investigating students and teachers' training needs on ICT web-based contents and performance, 2) developing a web-based…

Evolution, Nucleosynthesis, and Yields of AGB Stars at Different Metallicities. III. Intermediate-mass Models, Revised Low-mass Models, and the ph-FRUITY Interface

NASA Astrophysics Data System (ADS)

Cristallo, S.; Straniero, O.; Piersanti, L.; Gobrecht, D.

2015-08-01

We present a new set of models for intermediate-mass asymptotic giant branch (AGB) stars (4.0, 5.0, and 6.0 M⊙) at different metallicities (-2.15 ≤ [Fe/H] ≤ +0.15). This set integrates the existing models for low-mass AGB stars (1.3 ≤ M/M⊙ ≤ 3.0) already included in the FRUITY database. We describe the physical and chemical evolution of the computed models from the main sequence up to the end of the AGB phase. Due to less efficient third dredge up episodes, models with large core masses show modest surface enhancements. This effect is due to the fact that the interpulse phases are short and, therefore, thermal pulses (TPs) are weak. Moreover, the high temperature at the base of the convective envelope prevents it from deeply penetrating the underlying radiative layers. Depending on the initial stellar mass, the heavy element nucleosynthesis is dominated by different neutron sources. In particular, the s-process distributions of the more massive models are dominated by the 22Ne(α,n)25Mg reaction, which is efficiently activated during TPs. At low metallicities, our models undergo hot bottom burning and hot third dredge up. We compare our theoretical final core masses to available white dwarf observations. Moreover, we quantify the influence intermediate-mass models have on the carbon star luminosity function. Finally, we present the upgrade of the FRUITY web interface, which now also includes the physical quantities of the TP-AGB phase for all of the models included in the database (ph-FRUITY).

Reminiscing about 15 years of interoperability efforts

DOE PAGES

Van de Sompel, Herbert; Nelson, Michael L.

2015-11-01

Over the past fifteen years, our perspective on tackling information interoperability problems for web-based scholarship has evolved significantly. In this opinion piece, we look back at three efforts that we have been involved in that aptly illustrate this evolution: OAI-PMH, OAI-ORE, and Memento. Understanding that no interoperability specification is neutral, we attempt to characterize the perspectives and technical toolkits that provided the basis for these endeavors. With that regard, we consider repository-centric and web-centric interoperability perspectives, and the use of a Linked Data or a REST/HATEAOS technology stack, respectively. In addition, we lament the lack of interoperability across nodes thatmore » play a role in web-based scholarship, but end on a constructive note with some ideas regarding a possible path forward.« less

CSTminer: a web tool for the identification of coding and noncoding conserved sequence tags through cross-species genome comparison

PubMed Central

Castrignanò, Tiziana; Canali, Alessandro; Grillo, Giorgio; Liuni, Sabino; Mignone, Flavio; Pesole, Graziano

2004-01-01

The identification and characterization of genome tracts that are highly conserved across species during evolution may contribute significantly to the functional annotation of whole-genome sequences. Indeed, such sequences are likely to correspond to known or unknown coding exons or regulatory motifs. Here, we present a web server implementing a previously developed algorithm that, by comparing user-submitted genome sequences, is able to identify statistically significant conserved blocks and assess their coding or noncoding nature through the measure of a coding potential score. The web tool, available at http://www.caspur.it/CSTminer/, is dynamically interconnected with the Ensembl genome resources and produces a graphical output showing a map of detected conserved sequences and annotated gene features. PMID:15215464

A Two-Tiered Model for Analyzing Library Web Site Usage Statistics, Part 1: Web Server Logs.

ERIC Educational Resources Information Center

Cohen, Laura B.

2003-01-01

Proposes a two-tiered model for analyzing web site usage statistics for academic libraries: one tier for library administrators that analyzes measures indicating library use, and a second tier for web site managers that analyzes measures aiding in server maintenance and site design. Discusses the technology of web site usage statistics, and…

DPTEdb, an integrative database of transposable elements in dioecious plants.

PubMed

Li, Shu-Fen; Zhang, Guo-Jun; Zhang, Xue-Jin; Yuan, Jin-Hong; Deng, Chuan-Liang; Gu, Lian-Feng; Gao, Wu-Jun

2016-01-01

Dioecious plants usually harbor 'young' sex chromosomes, providing an opportunity to study the early stages of sex chromosome evolution. Transposable elements (TEs) are mobile DNA elements frequently found in plants and are suggested to play important roles in plant sex chromosome evolution. The genomes of several dioecious plants have been sequenced, offering an opportunity to annotate and mine the TE data. However, comprehensive and unified annotation of TEs in these dioecious plants is still lacking. In this study, we constructed a dioecious plant transposable element database (DPTEdb). DPTEdb is a specific, comprehensive and unified relational database and web interface. We used a combination of de novo, structure-based and homology-based approaches to identify TEs from the genome assemblies of previously published data, as well as our own. The database currently integrates eight dioecious plant species and a total of 31 340 TEs along with classification information. DPTEdb provides user-friendly web interfaces to browse, search and download the TE sequences in the database. Users can also use tools, including BLAST, GetORF, HMMER, Cut sequence and JBrowse, to analyze TE data. Given the role of TEs in plant sex chromosome evolution, the database will contribute to the investigation of TEs in structural, functional and evolutionary dynamics of the genome of dioecious plants. In addition, the database will supplement the research of sex diversification and sex chromosome evolution of dioecious plants.Database URL: http://genedenovoweb.ticp.net:81/DPTEdb/index.php. © The Author(s) 2016. Published by Oxford University Press.

Food-Web Models Predict Species Abundances in Response to Habitat Change

PubMed Central

Gotelli, Nicholas J; Ellison, Aaron M

2006-01-01

Plant and animal population sizes inevitably change following habitat loss, but the mechanisms underlying these changes are poorly understood. We experimentally altered habitat volume and eliminated top trophic levels of the food web of invertebrates that inhabit rain-filled leaves of the carnivorous pitcher plant Sarracenia purpurea. Path models that incorporated food-web structure better predicted population sizes of food-web constituents than did simple keystone species models, models that included only autecological responses to habitat volume, or models including both food-web structure and habitat volume. These results provide the first experimental confirmation that trophic structure can determine species abundances in the face of habitat loss. PMID:17002518

A tutorial of diverse genome analysis tools found in the CoGe web-platform using Plasmodium spp. as a model

PubMed Central

Castillo, Andreina I; Nelson, Andrew D L; Haug-Baltzell, Asher K; Lyons, Eric

2018-01-01

Abstract Integrated platforms for storage, management, analysis and sharing of large quantities of omics data have become fundamental to comparative genomics. CoGe (https://genomevolution.org/coge/) is an online platform designed to manage and study genomic data, enabling both data- and hypothesis-driven comparative genomics. CoGe’s tools and resources can be used to organize and analyse both publicly available and private genomic data from any species. Here, we demonstrate the capabilities of CoGe through three example workflows using 17 Plasmodium genomes as a model. Plasmodium genomes present unique challenges for comparative genomics due to their rapidly evolving and highly variable genomic AT/GC content. These example workflows are intended to serve as templates to help guide researchers who would like to use CoGe to examine diverse aspects of genome evolution. In the first workflow, trends in genome composition and amino acid usage are explored. In the second, changes in genome structure and the distribution of synonymous (Ks) and non-synonymous (Kn) substitution values are evaluated across species with different levels of evolutionary relatedness. In the third workflow, microsyntenic analyses of multigene families’ genomic organization are conducted using two Plasmodium-specific gene families—serine repeat antigen, and cytoadherence-linked asexual gene—as models. In general, these example workflows show how to achieve quick, reproducible and shareable results using the CoGe platform. We were able to replicate previously published results, as well as leverage CoGe’s tools and resources to gain additional insight into various aspects of Plasmodium genome evolution. Our results highlight the usefulness of the CoGe platform, particularly in understanding complex features of genome evolution. Database URL: https://genomevolution.org/coge/

Rapid contemporary evolution and clonal food web dynamics

PubMed Central

Jones, Laura E.; Becks, Lutz; Ellner, Stephen P.; Hairston, Nelson G.; Yoshida, Takehito; Fussmann, Gregor F.

2009-01-01

Character evolution that affects ecological community interactions often occurs contemporaneously with temporal changes in population size, potentially altering the very nature of those dynamics. Such eco-evolutionary processes may be most readily explored in systems with short generations and simple genetics. Asexual and cyclically parthenogenetic organisms such as microalgae, cladocerans and rotifers, which frequently dominate freshwater plankton communities, meet these requirements. Multiple clonal lines can coexist within each species over extended periods, until either fixation occurs or a sexual phase reshuffles the genetic material. When clones differ in traits affecting interspecific interactions, within-species clonal dynamics can have major effects on the population dynamics. We first consider a simple predator–prey system with two prey genotypes, parametrized with data from a well-studied experimental system, and explore how the extent of differences in defence against predation within the prey population determine dynamic stability versus instability of the system. We then explore how increased potential for evolution affects the community dynamics in a more general community model with multiple predator and multiple prey genotypes. These examples illustrate how microevolutionary ‘details’ that enhance or limit the potential for heritable phenotypic change can have significant effects on contemporaneous community-level dynamics and the persistence and coexistence of species. PMID:19414472

Conceptual Web Users' Actions Prediction for Ontology-Based Browsing Recommendations

NASA Astrophysics Data System (ADS)

Robal, Tarmo; Kalja, Ahto

The Internet consists of thousands of web sites with different kinds of structures. However, users are browsing the web according to their informational expectations towards the web site searched, having an implicit conceptual model of the domain in their minds. Nevertheless, people tend to repeat themselves and have partially shared conceptual views while surfing the web, finding some areas of web sites more interesting than others. Herein, we take advantage of the latter and provide a model and a study on predicting users' actions based on the web ontology concepts and their relations.

Optimal web investment in sub-optimal foraging conditions.

PubMed

Harmer, Aaron M T; Kokko, Hanna; Herberstein, Marie E; Madin, Joshua S

2012-01-01

Orb web spiders sit at the centre of their approximately circular webs when waiting for prey and so face many of the same challenges as central-place foragers. Prey value decreases with distance from the hub as a function of prey escape time. The further from the hub that prey are intercepted, the longer it takes a spider to reach them and the greater chance they have of escaping. Several species of orb web spiders build vertically elongated ladder-like orb webs against tree trunks, rather than circular orb webs in the open. As ladder web spiders invest disproportionately more web area further from the hub, it is expected they will experience reduced prey gain per unit area of web investment compared to spiders that build circular webs. We developed a model to investigate how building webs in the space-limited microhabitat on tree trunks influences the optimal size, shape and net prey gain of arboricolous ladder webs. The model suggests that as horizontal space becomes more limited, optimal web shape becomes more elongated, and optimal web area decreases. This change in web geometry results in decreased net prey gain compared to webs built without space constraints. However, when space is limited, spiders can achieve higher net prey gain compared to building typical circular webs in the same limited space. Our model shows how spiders optimise web investment in sub-optimal conditions and can be used to understand foraging investment trade-offs in other central-place foragers faced with constrained foraging arenas.

Optimal web investment in sub-optimal foraging conditions

NASA Astrophysics Data System (ADS)

Harmer, Aaron M. T.; Kokko, Hanna; Herberstein, Marie E.; Madin, Joshua S.

2012-01-01

Orb web spiders sit at the centre of their approximately circular webs when waiting for prey and so face many of the same challenges as central-place foragers. Prey value decreases with distance from the hub as a function of prey escape time. The further from the hub that prey are intercepted, the longer it takes a spider to reach them and the greater chance they have of escaping. Several species of orb web spiders build vertically elongated ladder-like orb webs against tree trunks, rather than circular orb webs in the open. As ladder web spiders invest disproportionately more web area further from the hub, it is expected they will experience reduced prey gain per unit area of web investment compared to spiders that build circular webs. We developed a model to investigate how building webs in the space-limited microhabitat on tree trunks influences the optimal size, shape and net prey gain of arboricolous ladder webs. The model suggests that as horizontal space becomes more limited, optimal web shape becomes more elongated, and optimal web area decreases. This change in web geometry results in decreased net prey gain compared to webs built without space constraints. However, when space is limited, spiders can achieve higher net prey gain compared to building typical circular webs in the same limited space. Our model shows how spiders optimise web investment in sub-optimal conditions and can be used to understand foraging investment trade-offs in other central-place foragers faced with constrained foraging arenas.

Blood Mercury Levels of Zebra Finches Are Heritable: Implications for the Evolution of Mercury Resistance

PubMed Central

Buck, Kenton A.; Varian-Ramos, Claire W.; Cristol, Daniel A.; Swaddle, John P.

2016-01-01

Mercury is a ubiquitous metal contaminant that negatively impacts reproduction of wildlife and has many other sub-lethal effects. Songbirds are sensitive bioindicators of mercury toxicity and may suffer population declines as a result of mercury pollution. Current predictions of mercury accumulation and biomagnification often overlook possible genetic variation in mercury uptake and elimination within species and the potential for evolution in affected populations. We conducted a study of dietary mercury exposure in a model songbird species, maintaining a breeding population of zebra finches (Taeniopygia guttata) on standardized diets ranging from 0.0–2.4 μg/g methylmercury. We applied a quantitative genetics approach to examine patterns of variation and heritability of mercury accumulation within dietary treatments using a method of mixed effects modeling known as the 'animal model'. Significant variation in blood mercury accumulation existed within each treatment for birds exposed at the same dietary level; moreover, this variation was highly repeatable for individuals. We observed substantial genetic variation in blood mercury accumulation for birds exposed at intermediate dietary concentrations. Taken together, this is evidence that genetic variation for factors affecting blood mercury accumulation could be acted on by selection. If similar heritability for mercury accumulation exists in wild populations, selection could result in genetic differentiation for populations in contaminated locations, with possible consequences for mercury biomagnification in food webs. PMID:27668745

An evolution-based DNA-binding residue predictor using a dynamic query-driven learning scheme.

PubMed

Chai, H; Zhang, J; Yang, G; Ma, Z

2016-11-15

DNA-binding proteins play a pivotal role in various biological activities. Identification of DNA-binding residues (DBRs) is of great importance for understanding the mechanism of gene regulations and chromatin remodeling. Most traditional computational methods usually construct their predictors on static non-redundant datasets. They excluded many homologous DNA-binding proteins so as to guarantee the generalization capability of their models. However, those ignored samples may potentially provide useful clues when studying protein-DNA interactions, which have not obtained enough attention. In view of this, we propose a novel method, namely DQPred-DBR, to fill the gap of DBR predictions. First, a large-scale extensible sample pool was compiled. Second, evolution-based features in the form of a relative position specific score matrix and covariant evolutionary conservation descriptors were used to encode the feature space. Third, a dynamic query-driven learning scheme was designed to make more use of proteins with known structure and functions. In comparison with a traditional static model, the introduction of dynamic models could obviously improve the prediction performance. Experimental results from the benchmark and independent datasets proved that our DQPred-DBR had promising generalization capability. It was capable of producing decent predictions and outperforms many state-of-the-art methods. For the convenience of academic use, our proposed method was also implemented as a web server at .

Food-web complexity emerging from ecological dynamics on adaptive networks.

PubMed

Garcia-Domingo, Josep L; Saldaña, Joan

2007-08-21

Food webs are complex networks describing trophic interactions in ecological communities. Since Robert May's seminal work on random structured food webs, the complexity-stability debate is a central issue in ecology: does network complexity increase or decrease food-web persistence? A multi-species predator-prey model incorporating adaptive predation shows that the action of ecological dynamics on the topology of a food web (whose initial configuration is generated either by the cascade model or by the niche model) render, when a significant fraction of adaptive predators is present, similar hyperbolic complexity-persistence relationships as those observed in empirical food webs. It is also shown that the apparent positive relation between complexity and persistence in food webs generated under the cascade model, which has been pointed out in previous papers, disappears when the final connection is used instead of the initial one to explain species persistence.

Hidden Markov models for evolution and comparative genomics analysis.

PubMed

Bykova, Nadezda A; Favorov, Alexander V; Mironov, Andrey A

2013-01-01

The problem of reconstruction of ancestral states given a phylogeny and data from extant species arises in a wide range of biological studies. The continuous-time Markov model for the discrete states evolution is generally used for the reconstruction of ancestral states. We modify this model to account for a case when the states of the extant species are uncertain. This situation appears, for example, if the states for extant species are predicted by some program and thus are known only with some level of reliability; it is common for bioinformatics field. The main idea is formulation of the problem as a hidden Markov model on a tree (tree HMM, tHMM), where the basic continuous-time Markov model is expanded with the introduction of emission probabilities of observed data (e.g. prediction scores) for each underlying discrete state. Our tHMM decoding algorithm allows us to predict states at the ancestral nodes as well as to refine states at the leaves on the basis of quantitative comparative genomics. The test on the simulated data shows that the tHMM approach applied to the continuous variable reflecting the probabilities of the states (i.e. prediction score) appears to be more accurate then the reconstruction from the discrete states assignment defined by the best score threshold. We provide examples of applying our model to the evolutionary analysis of N-terminal signal peptides and transcription factor binding sites in bacteria. The program is freely available at http://bioinf.fbb.msu.ru/~nadya/tHMM and via web-service at http://bioinf.fbb.msu.ru/treehmmweb.

Evolution, Nucleosynthesis, and Yields of Low-mass Asymptotic Giant Branch Stars at Different Metallicities. II. The FRUITY Database

NASA Astrophysics Data System (ADS)

Cristallo, S.; Piersanti, L.; Straniero, O.; Gallino, R.; Domínguez, I.; Abia, C.; Di Rico, G.; Quintini, M.; Bisterzo, S.

2011-12-01

By using updated stellar low-mass stars models, we systematically investigate the nucleosynthesis processes occurring in asymptotic giant branch (AGB) stars. In this paper, we present a database dedicated to the nucleosynthesis of AGB stars: FRANEC Repository of Updated Isotopic Tables & Yields (FRUITY). An interactive Web-based interface allows users to freely download the full (from H to Bi) isotopic composition, as it changes after each third dredge-up (TDU) episode and the stellar yields the models produce. A first set of AGB models, having masses in the range 1.5 <=M/M ⊙ <= 3.0 and metallicities 1 × 10-3 <= Z <= 2 × 10-2, is discussed. For each model, a detailed description of the physical and the chemical evolution is provided. In particular, we illustrate the details of the s-process and we evaluate the theoretical uncertainties due to the parameterization adopted to model convection and mass loss. The resulting nucleosynthesis scenario is checked by comparing the theoretical [hs/ls] and [Pb/hs] ratios to those obtained from the available abundance analysis of s-enhanced stars. On the average, the variation with the metallicity of these spectroscopic indexes is well reproduced by theoretical models, although the predicted spread at a given metallicity is substantially smaller than the observed one. Possible explanations for such a difference are briefly discussed. An independent check of the TDU efficiency is provided by the C-stars luminosity function. Consequently, theoretical C-stars luminosity functions for the Galactic disk and the Magellanic Clouds have been derived. We generally find good agreement with observations.

Component, Context, and Manufacturing Model Library (C2M2L)

DTIC Science & Technology

2012-11-01

123 5.1 MML Population and Web Service Interface...104 Table 41. Relevant Questions with Associated Web Services...the models, and implementing web services that provide semantically aware programmatic access to the models, including implementing the MS&T

An open source web interface for linking models to infrastructure system databases

NASA Astrophysics Data System (ADS)

Knox, S.; Mohamed, K.; Harou, J. J.; Rheinheimer, D. E.; Medellin-Azuara, J.; Meier, P.; Tilmant, A.; Rosenberg, D. E.

2016-12-01

Models of networked engineered resource systems such as water or energy systems are often built collaboratively with developers from different domains working at different locations. These models can be linked to large scale real world databases, and they are constantly being improved and extended. As the development and application of these models becomes more sophisticated, and the computing power required for simulations and/or optimisations increases, so has the need for online services and tools which enable the efficient development and deployment of these models. Hydra Platform is an open source, web-based data management system, which allows modellers of network-based models to remotely store network topology and associated data in a generalised manner, allowing it to serve multiple disciplines. Hydra Platform uses a web API using JSON to allow external programs (referred to as `Apps') to interact with its stored networks and perform actions such as importing data, running models, or exporting the networks to different formats. Hydra Platform supports multiple users accessing the same network and has a suite of functions for managing users and data. We present ongoing development in Hydra Platform, the Hydra Web User Interface, through which users can collaboratively manage network data and models in a web browser. The web interface allows multiple users to graphically access, edit and share their networks, run apps and view results. Through apps, which are located on the server, the web interface can give users access to external data sources and models without the need to install or configure any software. This also ensures model results can be reproduced by removing platform or version dependence. Managing data and deploying models via the web interface provides a way for multiple modellers to collaboratively manage data, deploy and monitor model runs and analyse results.

Opinion formation driven by PageRank node influence on directed networks

NASA Astrophysics Data System (ADS)

Eom, Young-Ho; Shepelyansky, Dima L.

2015-10-01

We study a two states opinion formation model driven by PageRank node influence and report an extensive numerical study on how PageRank affects collective opinion formations in large-scale empirical directed networks. In our model the opinion of a node can be updated by the sum of its neighbor nodes' opinions weighted by the node influence of the neighbor nodes at each step. We consider PageRank probability and its sublinear power as node influence measures and investigate evolution of opinion under various conditions. First, we observe that all networks reach steady state opinion after a certain relaxation time. This time scale is decreasing with the heterogeneity of node influence in the networks. Second, we find that our model shows consensus and non-consensus behavior in steady state depending on types of networks: Web graph, citation network of physics articles, and LiveJournal social network show non-consensus behavior while Wikipedia article network shows consensus behavior. Third, we find that a more heterogeneous influence distribution leads to a more uniform opinion state in the cases of Web graph, Wikipedia, and Livejournal. However, the opposite behavior is observed in the citation network. Finally we identify that a small number of influential nodes can impose their own opinion on significant fraction of other nodes in all considered networks. Our study shows that the effects of heterogeneity of node influence on opinion formation can be significant and suggests further investigations on the interplay between node influence and collective opinion in networks.

Saint: a lightweight integration environment for model annotation.

PubMed

Lister, Allyson L; Pocock, Matthew; Taschuk, Morgan; Wipat, Anil

2009-11-15

Saint is a web application which provides a lightweight annotation integration environment for quantitative biological models. The system enables modellers to rapidly mark up models with biological information derived from a range of data sources. Saint is freely available for use on the web at http://www.cisban.ac.uk/saint. The web application is implemented in Google Web Toolkit and Tomcat, with all major browsers supported. The Java source code is freely available for download at http://saint-annotate.sourceforge.net. The Saint web server requires an installation of libSBML and has been tested on Linux (32-bit Ubuntu 8.10 and 9.04).

WebQuests for Reflection and Conceptual Change: Variations on a Popular Model for Guided Inquiry.

ERIC Educational Resources Information Center

Young, David L.; Wilson, Brent G.

WebQuests have become a popular form of guided inquiry using Web resources. The goal of WebQuests is to help students think and reason at higher levels,and use information to solve problems. This paper presents modifications to the WebQuest model drawing on primarily on schema theory. It is believed that these changes will further enhance student…

The inverse niche model for food webs with parasites

USGS Publications Warehouse

Warren, Christopher P.; Pascual, Mercedes; Lafferty, Kevin D.; Kuris, Armand M.

2010-01-01

Although parasites represent an important component of ecosystems, few field and theoretical studies have addressed the structure of parasites in food webs. We evaluate the structure of parasitic links in an extensive salt marsh food web, with a new model distinguishing parasitic links from non-parasitic links among free-living species. The proposed model is an extension of the niche model for food web structure, motivated by the potential role of size (and related metabolic rates) in structuring food webs. The proposed extension captures several properties observed in the data, including patterns of clustering and nestedness, better than does a random model. By relaxing specific assumptions, we demonstrate that two essential elements of the proposed model are the similarity of a parasite's hosts and the increasing degree of parasite specialization, along a one-dimensional niche axis. Thus, inverting one of the basic rules of the original model, the one determining consumers' generality appears critical. Our results support the role of size as one of the organizing principles underlying niche space and food web topology. They also strengthen the evidence for the non-random structure of parasitic links in food webs and open the door to addressing questions concerning the consequences and origins of this structure.

Bacterial adaptation to sublethal antibiotic gradients can change the ecological properties of multitrophic microbial communities

PubMed Central

Friman, Ville-Petri; Guzman, Laura Melissa; Reuman, Daniel C.; Bell, Thomas

2015-01-01

Antibiotics leak constantly into environments due to widespread use in agriculture and human therapy. Although sublethal concentrations are well known to select for antibiotic-resistant bacteria, little is known about how bacterial evolution cascades through food webs, having indirect effect on species not directly affected by antibiotics (e.g. via population dynamics or pleiotropic effects). Here, we used an experimental evolution approach to test how temporal patterns of antibiotic stress, as well as migration within metapopulations, affect the evolution and ecology of microcosms containing one prey bacterium, one phage and two protist predators. We found that environmental variability, autocorrelation and migration had only subtle effects for population and evolutionary dynamics. However, unexpectedly, bacteria evolved greatest fitness increases to both antibiotics and enemies when the sublethal levels of antibiotics were highest, indicating positive pleiotropy. Crucially, bacterial adaptation cascaded through the food web leading to reduced predator-to-prey abundance ratio, lowered predator community diversity and increased instability of populations. Our results show that the presence of natural enemies can modify and even reverse the effects of antibiotics on bacteria, and that antibiotic selection can change the ecological properties of multitrophic microbial communities by having indirect effects on species not directly affected by antibiotics. PMID:25833854

Bacterial adaptation to sublethal antibiotic gradients can change the ecological properties of multitrophic microbial communities.

PubMed

Friman, Ville-Petri; Guzman, Laura Melissa; Reuman, Daniel C; Bell, Thomas

2015-05-07

Antibiotics leak constantly into environments due to widespread use in agriculture and human therapy. Although sublethal concentrations are well known to select for antibiotic-resistant bacteria, little is known about how bacterial evolution cascades through food webs, having indirect effect on species not directly affected by antibiotics (e.g. via population dynamics or pleiotropic effects). Here, we used an experimental evolution approach to test how temporal patterns of antibiotic stress, as well as migration within metapopulations, affect the evolution and ecology of microcosms containing one prey bacterium, one phage and two protist predators. We found that environmental variability, autocorrelation and migration had only subtle effects for population and evolutionary dynamics. However, unexpectedly, bacteria evolved greatest fitness increases to both antibiotics and enemies when the sublethal levels of antibiotics were highest, indicating positive pleiotropy. Crucially, bacterial adaptation cascaded through the food web leading to reduced predator-to-prey abundance ratio, lowered predator community diversity and increased instability of populations. Our results show that the presence of natural enemies can modify and even reverse the effects of antibiotics on bacteria, and that antibiotic selection can change the ecological properties of multitrophic microbial communities by having indirect effects on species not directly affected by antibiotics. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Designing a Pedagogical Model for Web Engineering Education: An Evolutionary Perspective

ERIC Educational Resources Information Center

Hadjerrouit, Said

2005-01-01

In contrast to software engineering, which relies on relatively well established development approaches, there is a lack of a proven methodology that guides Web engineers in building reliable and effective Web-based systems. Currently, Web engineering lacks process models, architectures, suitable techniques and methods, quality assurance, and a…

Web-based Interspecies Correlation Estimation (Web-ICE) for Acute Toxicity: User Manual Version 3.1

EPA Science Inventory

Predictive toxicological models are integral to ecological risk assessment because data for most species are limited. Web-based Interspecies Correlation Estimation (Web-ICE) models are least square regressions that predict acute toxicity (LC50/LD50) of a chemical to a species, ge...

WEB-BASED INTERSPECIES CORRELATION ESTIMATION (WEB-ICE) FOR ACUTE TOXICITY: USER MANUAL V2

EPA Science Inventory

Predictive toxicological models are integral to environmental risk Assessment where data for most species are limited. Web-based Interspecies Correlation Estimation (Web-ICE) models are least square regressions that predict acute toxicity (LC50/LD50) of a chemical to a species, ...

Integrating natural language processing and web GIS for interactive knowledge domain visualization

NASA Astrophysics Data System (ADS)

Du, Fangming

Recent years have seen a powerful shift towards data-rich environments throughout society. This has extended to a change in how the artifacts and products of scientific knowledge production can be analyzed and understood. Bottom-up approaches are on the rise that combine access to huge amounts of academic publications with advanced computer graphics and data processing tools, including natural language processing. Knowledge domain visualization is one of those multi-technology approaches, with its aim of turning domain-specific human knowledge into highly visual representations in order to better understand the structure and evolution of domain knowledge. For example, network visualizations built from co-author relations contained in academic publications can provide insight on how scholars collaborate with each other in one or multiple domains, and visualizations built from the text content of articles can help us understand the topical structure of knowledge domains. These knowledge domain visualizations need to support interactive viewing and exploration by users. Such spatialization efforts are increasingly looking to geography and GIS as a source of metaphors and practical technology solutions, even when non-georeferenced information is managed, analyzed, and visualized. When it comes to deploying spatialized representations online, web mapping and web GIS can provide practical technology solutions for interactive viewing of knowledge domain visualizations, from panning and zooming to the overlay of additional information. This thesis presents a novel combination of advanced natural language processing - in the form of topic modeling - with dimensionality reduction through self-organizing maps and the deployment of web mapping/GIS technology towards intuitive, GIS-like, exploration of a knowledge domain visualization. A complete workflow is proposed and implemented that processes any corpus of input text documents into a map form and leverages a web application framework to let users explore knowledge domain maps interactively. This workflow is implemented and demonstrated for a data set of more than 66,000 conference abstracts.

The SAMCO Web-platform for resilience assessment in mountainous valleys impacted by landslide risks.

NASA Astrophysics Data System (ADS)

Grandjean, Gilles; Thomas, Loic; Bernardie, Severine

2016-04-01

The ANR-SAMCO project aims to develop a proactive resilience framework enhancing the overall resilience of societies on the impacts of mountain risks. The project aims to elaborate methodological tools to characterize and measure ecosystem and societal resilience from an operative perspective on three mountain representative case studies. To achieve this objective, the methodology is split in several points: (1) the definition of the potential impacts of global environmental changes (climate system, ecosystem e.g. land use, socio-economic system) on landslide hazards, (2) the analysis of these consequences in terms of vulnerability (e.g. changes in the location and characteristics of the impacted areas and level of their perturbation) and (3) the implementation of a methodology for quantitatively investigating and mapping indicators of mountain slope vulnerability exposed to several hazard types, and the development of a GIS-based demonstration platform available on the web. The strength and originality of the SAMCO project lies in the combination of different techniques, methodologies and models (multi-hazard assessment, risk evolution in time, vulnerability functional analysis, and governance strategies) that are implemented in a user-oriented web-platform, currently in development. We present the first results of this development task, architecture and functions of the web-tools, the case studies database showing the multi-hazard maps and the stakes at risks. Risk assessment over several area of interest in Alpine or Pyrenean valleys are still in progress, but the first analyses are presented for current and future periods for which climate change and land-use (economical, geographical and social aspects) scenarios are taken into account. This tool, dedicated to stakeholders, should be finally used to evaluate resilience of mountainous regions since multiple scenarios can be tested and compared.

A web based Radiation Oncology Dose Manager with a rich User Interface developed using AJAX, ruby, dynamic XHTML and the new Yahoo/EXT User Interface Library.

PubMed

Vali, Faisal; Hong, Robert

2007-10-11

With the evolution of AJAX, ruby on rails, advanced dynamic XHTML technologies and the advent of powerful user interface libraries for javascript (EXT, Yahoo User Interface Library), developers now have the ability to provide truly rich interfaces within web browsers, with reasonable effort and without third-party plugins. We designed and developed an example of such a solution. The User Interface allows radiation oncology practices to intuitively manage different dose fractionation schemes by helping estimate total dose to irradiated organs.

Development of a multichemical food web model: application to PBDEs in Lake Ellasjoen, Bear Island, Norway.

PubMed

Gandhi, Nilima; Bhavsar, Satyendra P; Gewurtz, Sarah B; Diamond, Miriam L; Evenset, Anita; Christensen, Guttorm N; Gregor, Dennis

2006-08-01

A multichemical food web model has been developed to estimate the biomagnification of interconverting chemicals in aquatic food webs. We extended a fugacity-based food web model for single chemicals to account for reversible and irreversible biotransformation among a parent chemical and transformation products, by simultaneously solving mass balance equations of the chemicals using a matrix solution. The model can be applied to any number of chemicals and organisms or taxonomic groups in a food web. The model was illustratively applied to four PBDE congeners, BDE-47, -99, -100, and -153, in the food web of Lake Ellasjøen, Bear Island, Norway. In Ellasjøen arctic char (Salvelinus alpinus), the multichemical model estimated PBDE biotransformation from higher to lower brominated congeners and improved the correspondence between estimated and measured concentrations in comparison to estimates from the single-chemical food web model. The underestimation of BDE-47, even after considering bioformation due to biotransformation of the otherthree congeners, suggests its formation from additional biotransformation pathways not considered in this application. The model estimates approximate values for congener-specific biotransformation half-lives of 5.7,0.8,1.14, and 0.45 years for BDE-47, -99, -100, and -153, respectively, in large arctic char (S. alpinus) of Lake Ellasjøen.

Creating and Nurturing Distributed Asynchronous Learning Environments.

ERIC Educational Resources Information Center

Kochtanek, Thomas R.; Hein, Karen K.

2000-01-01

Describes the evolution of a university course from a face-to-face experience to a Web-based asynchronous learning environment. Topics include cognition and learning; distance learning and distributed learning; student learning communities and the traditional classroom; the future as it relates to education and technology; collaborative student…

Evolution of a Common Controller

DTIC Science & Technology

2012-04-01

focused on distribution but with the same design concepts used in MOCU. Remote Operator Control Services (ROCS) will use an HTML5 enabled browser to...provide the presentation layer. HTML5 and WebGL provide most of the capability provided within MOCU 3 but in a standardized format. Data is

Demarcating Advanced Learning Approaches from Methodological and Technological Perspectives

ERIC Educational Resources Information Center

Horvath, Imre; Peck, David; Verlinden, Jouke

2009-01-01

In the field of design and engineering education, the fast and expansive evolution of information and communication technologies is steadily converting traditional learning approaches into more advanced ones. Facilitated by Broadband (high bandwidth) personal computers, distance learning has developed into web-hosted electronic learning. The…

A web-based portfolio model as the students' final assignment: Dealing with the development of higher education trend

NASA Astrophysics Data System (ADS)

Utanto, Yuli; Widhanarto, Ghanis Putra; Maretta, Yoris Adi

2017-03-01

This study aims to develop a web-based portfolio model. The model developed in this study could reveal the effectiveness of the new model in experiments conducted at research respondents in the department of curriculum and educational technology FIP Unnes. In particular, the further research objectives to be achieved through this development of research, namely: (1) Describing the process of implementing a portfolio in a web-based model; (2) Assessing the effectiveness of web-based portfolio model for the final task, especially in Web-Based Learning courses. This type of research is the development of research Borg and Gall (2008: 589) says "educational research and development (R & D) is a process used to develop and validate educational production". The series of research and development carried out starting with exploration and conceptual studies, followed by testing and evaluation, and also implementation. For the data analysis, the technique used is simple descriptive analysis, analysis of learning completeness, which then followed by prerequisite test for normality and homogeneity to do T - test. Based on the data analysis, it was concluded that: (1) a web-based portfolio model can be applied to learning process in higher education; (2) The effectiveness of web-based portfolio model with field data from the respondents of large group trial participants (field trial), the number of respondents who reached mastery learning (a score of 60 and above) were 24 people (92.3%) in which it indicates that the web-based portfolio model is effective. The conclusion of this study is that a web-based portfolio model is effective. The implications of the research development of this model, the next researcher is expected to be able to use the guideline of the development model based on the research that has already been conducted to be developed on other subjects.

A general explanation on the correlation of dark matter halo spin with the large-scale environment

NASA Astrophysics Data System (ADS)

Wang, Peng; Kang, Xi

2017-06-01

Both simulations and observations have found that the spin of halo/galaxy is correlated with the large-scale environment, and particularly the spin of halo flips in filament. A consistent picture of halo spin evolution in different environments is still lacked. Using N-body simulation, we find that halo spin with its environment evolves continuously from sheet to cluster, and the flip of halo spin happens both in filament and nodes. The flip in filament can be explained by halo formation time and migrating time when its environment changes from sheet to filament. For low-mass haloes, they form first in sheets and migrate into filaments later, so their mass and spin growth inside filament are lower, and the original spin is still parallel to filament. For high-mass haloes, they migrate into filaments first, and most of their mass and spin growth are obtained in filaments, so the resulted spin is perpendicular to filament. Our results well explain the overall evolution of cosmic web in the cold dark matter model and can be tested using high-redshift data. The scenario can also be tested against alternative models of dark matter, such as warm/hot dark matter, where the structure formation will proceed in a different way.

Sharing on Web 3d Models of Ancient Theatres. a Methodological Workflow

NASA Astrophysics Data System (ADS)

Scianna, A.; La Guardia, M.; Scaduto, M. L.

2016-06-01

In the last few years, the need to share on the Web the knowledge of Cultural Heritage (CH) through navigable 3D models has increased. This need requires the availability of Web-based virtual reality systems and 3D WEBGIS. In order to make the information available to all stakeholders, these instruments should be powerful and at the same time very user-friendly. However, research and experiments carried out so far show that a standardized methodology doesn't exist. All this is due both to complexity and dimensions of geometric models to be published, on the one hand, and to excessive costs of hardware and software tools, on the other. In light of this background, the paper describes a methodological approach for creating 3D models of CH, freely exportable on the Web, based on HTML5 and free and open source software. HTML5, supporting the WebGL standard, allows the exploration of 3D spatial models using most used Web browsers like Chrome, Firefox, Safari, Internet Explorer. The methodological workflow here described has been tested for the construction of a multimedia geo-spatial platform developed for three-dimensional exploration and documentation of the ancient theatres of Segesta and of Carthage, and the surrounding landscapes. The experimental application has allowed us to explore the potential and limitations of sharing on the Web of 3D CH models based on WebGL standard. Sharing capabilities could be extended defining suitable geospatial Web-services based on capabilities of HTML5 and WebGL technology.

A Framework for Sharing and Integrating Remote Sensing and GIS Models Based on Web Service

PubMed Central

Chen, Zeqiang; Lin, Hui; Chen, Min; Liu, Deer; Bao, Ying; Ding, Yulin

2014-01-01

Sharing and integrating Remote Sensing (RS) and Geographic Information System/Science (GIS) models are critical for developing practical application systems. Facilitating model sharing and model integration is a problem for model publishers and model users, respectively. To address this problem, a framework based on a Web service for sharing and integrating RS and GIS models is proposed in this paper. The fundamental idea of the framework is to publish heterogeneous RS and GIS models into standard Web services for sharing and interoperation and then to integrate the RS and GIS models using Web services. For the former, a “black box” and a visual method are employed to facilitate the publishing of the models as Web services. For the latter, model integration based on the geospatial workflow and semantic supported marching method is introduced. Under this framework, model sharing and integration is applied for developing the Pearl River Delta water environment monitoring system. The results show that the framework can facilitate model sharing and model integration for model publishers and model users. PMID:24901016

A framework for sharing and integrating remote sensing and GIS models based on Web service.

PubMed

Chen, Zeqiang; Lin, Hui; Chen, Min; Liu, Deer; Bao, Ying; Ding, Yulin

2014-01-01

Sharing and integrating Remote Sensing (RS) and Geographic Information System/Science (GIS) models are critical for developing practical application systems. Facilitating model sharing and model integration is a problem for model publishers and model users, respectively. To address this problem, a framework based on a Web service for sharing and integrating RS and GIS models is proposed in this paper. The fundamental idea of the framework is to publish heterogeneous RS and GIS models into standard Web services for sharing and interoperation and then to integrate the RS and GIS models using Web services. For the former, a "black box" and a visual method are employed to facilitate the publishing of the models as Web services. For the latter, model integration based on the geospatial workflow and semantic supported marching method is introduced. Under this framework, model sharing and integration is applied for developing the Pearl River Delta water environment monitoring system. The results show that the framework can facilitate model sharing and model integration for model publishers and model users.

Evolution of community structure in the world trade web

NASA Astrophysics Data System (ADS)

Tzekina, I.; Danthi, K.; Rockmore, D. N.

2008-06-01

In this note we study the bilateral merchandise trade flows between 186 countries over the 1948 2005 period using data from the International Monetary Fund. We use the network visualization package Pajek to identify network structure and behavior across thresholds and over time. In particular, we focus on the evolution of trade “islands” in a world trade network in which countries are linked with directed edges weighted according to the fraction of total dollars sent from one country to another. We find mixed evidence for globalization.

Optimizing Crawler4j using MapReduce Programming Model

NASA Astrophysics Data System (ADS)

Siddesh, G. M.; Suresh, Kavya; Madhuri, K. Y.; Nijagal, Madhushree; Rakshitha, B. R.; Srinivasa, K. G.

2017-06-01

World wide web is a decentralized system that consists of a repository of information on the basis of web pages. These web pages act as a source of information or data in the present analytics world. Web crawlers are used for extracting useful information from web pages for different purposes. Firstly, it is used in web search engines where the web pages are indexed to form a corpus of information and allows the users to query on the web pages. Secondly, it is used for web archiving where the web pages are stored for later analysis phases. Thirdly, it can be used for web mining where the web pages are monitored for copyright purposes. The amount of information processed by the web crawler needs to be improved by using the capabilities of modern parallel processing technologies. In order to solve the problem of parallelism and the throughput of crawling this work proposes to optimize the Crawler4j using the Hadoop MapReduce programming model by parallelizing the processing of large input data. Crawler4j is a web crawler that retrieves useful information about the pages that it visits. The crawler Crawler4j coupled with data and computational parallelism of Hadoop MapReduce programming model improves the throughput and accuracy of web crawling. The experimental results demonstrate that the proposed solution achieves significant improvements with respect to performance and throughput. Hence the proposed approach intends to carve out a new methodology towards optimizing web crawling by achieving significant performance gain.

From global action against malaria to local issues: state of the art and perspectives of web platforms dealing with malaria information.

PubMed

Briand, Dominique; Roux, Emmanuel; Desconnets, Jean Christophe; Gervet, Carmen; Barcellos, Christovam

2018-03-21

Since prehistory to present times and despite a rough combat against it, malaria remains a concern for human beings. While evolutions of science and technology through times allowed for some infectious diseases eradication in the 20th century, malaria resists. This review aims at assessing how Internet and web technologies are used in fighting malaria. Precisely, how do malaria fighting actors profit from these developments, how do they deal with ensuing phenomena, such as the increase of data volume, and did these technologies bring new opportunities for fighting malaria? Eleven web platforms linked to spatio-temporal malaria information are reviewed, focusing on data, metadata, web services and categories of users. Though the web platforms are highly heterogeneous the review reveals that the latest advances in web technologies are underused. Information are rarely updated dynamically, metadata catalogues are absent, web services are more and more used, but rarely standardized, and websites are mainly dedicated to scientific communities, essentially researchers. Improvement of systems interoperability, through standardization, is an opportunity to be seized in order to allow real time information exchange and online multisource data analysis. To facilitate multidisciplinary/multiscale studies, the web of linked data and the semantic web innovations can be used in order to formalize the different view points of actors involved in the combat against malaria. By doing so, new malaria fighting strategies could take place, to tackle the bottlenecks listed in the United Nation Millennium Development Goals reports, but also specific issues highlighted by the World Health Organization such as malaria elimination in international borders.

Rapid thermal adaptation in a marine diatom reveals constraints and tradeoffs.

PubMed

O'Donnell, Daniel R; Hamman, Carolyn R; Johnson, Evan C; Kremer, Colin T; Klausmeier, Christopher A; Litchman, Elena

2018-06-25

Rapid evolution in response to environmental change will likely be a driving force determining the distribution of species across the biosphere in coming decades. This is especially true of microorganisms, many of which may evolve in step with warming, including phytoplankton, the diverse photosynthetic microbes forming the foundation of most aquatic food webs. Here we tested the capacity of a globally important, model marine diatom Thalassiosira pseudonana, for rapid evolution in response to temperature. Selection at 16 and 31°C for 350 generations led to significant divergence in several temperature response traits, demonstrating local adaptation and the existence of tradeoffs associated with adaptation to different temperatures. In contrast, competitive ability for nitrogen (commonly limiting in marine systems), measured after 450 generations of temperature selection, did not diverge in a systematic way between temperatures. This study shows how rapid thermal adaptation affects key temperature and nutrient traits and, thus, a population's long-term physiological, ecological, and biogeographic response to climate change. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Statistical physics of language dynamics

NASA Astrophysics Data System (ADS)

Loreto, Vittorio; Baronchelli, Andrea; Mukherjee, Animesh; Puglisi, Andrea; Tria, Francesca

2011-04-01

Language dynamics is a rapidly growing field that focuses on all processes related to the emergence, evolution, change and extinction of languages. Recently, the study of self-organization and evolution of language and meaning has led to the idea that a community of language users can be seen as a complex dynamical system, which collectively solves the problem of developing a shared communication framework through the back-and-forth signaling between individuals. We shall review some of the progress made in the past few years and highlight potential future directions of research in this area. In particular, the emergence of a common lexicon and of a shared set of linguistic categories will be discussed, as examples corresponding to the early stages of a language. The extent to which synthetic modeling is nowadays contributing to the ongoing debate in cognitive science will be pointed out. In addition, the burst of growth of the web is providing new experimental frameworks. It makes available a huge amount of resources, both as novel tools and data to be analyzed, allowing quantitative and large-scale analysis of the processes underlying the emergence of a collective information and language dynamics.

Sensing Cell-Culture Assays with Low-Cost Circuitry.

PubMed

Pérez, Pablo; Huertas, Gloria; Maldonado-Jacobi, Andrés; Martín, María; Serrano, Juan A; Olmo, Alberto; Daza, Paula; Yúfera, Alberto

2018-06-11

An alternative approach for cell-culture end-point protocols is proposed herein. This new technique is suitable for real-time remote sensing. It is based on Electrical Cell-substrate Impedance Spectroscopy (ECIS) and employs the Oscillation-Based Test (OBT) method. Simple and straightforward circuit blocks form the basis of the proposed measurement system. Oscillation parameters - frequency and amplitude - constitute the outcome, directly correlated with the culture status. A user can remotely track the evolution of cell cultures in real time over the complete experiment through a web tool continuously displaying the acquired data. Experiments carried out with commercial electrodes and a well-established cell line (AA8) are described, obtaining the cell number in real time from growth assays. The electrodes have been electrically characterized along the design flow in order to predict the system performance and the sensitivity curves. Curves for 1-week cell growth are reported. The obtained experimental results validate the proposed OBT for cell-culture characterization. Furthermore, the proposed electrode model provides a good approximation for the cell number and the time evolution of the studied cultures.

Satisfiers and Dissatisfiers: A Two-Factor Model for Website Design and Evaluation.

ERIC Educational Resources Information Center

Zhang, Ping; von Dran, Gisela M.

2000-01-01

Investigates Web site design factors and their impact from a theoretical perspective. Presents a two-factor model that can guide Web site design and evaluation. According to the model, there are two types of design factors: hygiene and motivator. Results showed that the two-factor model provides a means for Web-user interface studies. Provides…

Lateral cascade of indirect effects in food webs with different types of adaptive behavior.

PubMed

Kamran-Disfani, Ahmad R; Golubski, Antonio J

2013-12-21

It is widely recognized that indirect effects due to adaptive behaviors can have important effects on food webs. One consequence may be to change how readily perturbations propagate through the web, because species' behaviors as well as densities may respond to perturbations. It is not well understood which types of behavior are more likely to facilitate versus inhibit propagation of disturbances through a food web, or how this might be affected by the shape of a food web or the patterns of interaction strengths within it. We model two simple, laterally expanded food webs (one with three trophic levels and one with four), and compare how various adaptive behaviors affect the potential for a newly introduced predator to change the equilibrium densities of distant species. Patterns of changes in response to the introduction were qualitatively similar across most models, as were the ways in which patterns of direct interaction strengths affected those responses. Depending on both the web structure and the specific adaptive behavior, the potential for density changes to propagate through the web could be either increased or diminished relative to the no-behavior model. Two behaviors allowed density changes to propagate through a four-level web that precluded such propagation in the no-behavior model, and each of these two behaviors led to qualitatively different patterns of density changes. In the one model (diet choice) in which density changes were able to propagate in both web structures, patterns of density changes differed qualitatively between webs. Some of our results flowed from the fact that behaviors did not interact directly in the systems we considered, so that indirect effects on distant species had to be at least partly density-mediated. Our models highlight this as an inherent limitation of considering in isolation behaviors that are strictly foraging-related or strictly defense-related, making a case for the value of simultaneously considering multiple interacting types of behavior in the same model. Copyright © 2013 Elsevier Ltd. All rights reserved.

Validation of a model for the cast-film process

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

Chambon, F.; Ohlsson, S.; Silagy, D.

1996-12-31

We have developed a model of the cast-film process and compared theoretical predictions against experiments on a pilot line. Three polyethylenes with a markedly different level of melt elasticity were used in this evaluation; namely, a high pressure low density polyethylene, LDPE, and two linear low density polyethylenes, LLDPE-1 and LLDPE-2. The final film dimensions of the LDPE were found to be in good agreement with 1-D viscoelastic stationary predictions. Flow field visualization experiments indicate, however, a 2-D velocity field in the airgap between the extrusion die and the chill roll. Taking this observation into account, evolutions of the freemore » surface of the web along the airgap were recorded with LLDPE-2, our least elastic melt. An excellent agreement is found between these measurements and predictions of neck-in and edge bead with 2-D Newtonian stationary simulations. The time-dependent solution, which is based on a linear stability analysis, allows to identify a zone of draw resonance within the working space of the process, defined by the draw ratio, the Deborah number, and the web aspect ratio. It is predicted that increasing this latter parameter stabilizes the process until an optimum value is reached. Experiments with LLDPE-1 are shown to validate this unique theoretical result, thus allowing to increase the draw ratio by about 75%.« less

Phylogenomics resolves a spider backbone phylogeny and rejects a prevailing paradigm for orb web evolution.

PubMed

Bond, Jason E; Garrison, Nicole L; Hamilton, Chris A; Godwin, Rebecca L; Hedin, Marshal; Agnarsson, Ingi

2014-08-04

Spiders represent an ancient predatory lineage known for their extraordinary biomaterials, including venoms and silks. These adaptations make spiders key arthropod predators in most terrestrial ecosystems. Despite ecological, biomedical, and biomaterial importance, relationships among major spider lineages remain unresolved or poorly supported. Current working hypotheses for a spider "backbone" phylogeny are largely based on morphological evidence, as most molecular markers currently employed are generally inadequate for resolving deeper-level relationships. We present here a phylogenomic analysis of spiders including taxa representing all major spider lineages. Our robust phylogenetic hypothesis recovers some fundamental and uncontroversial spider clades, but rejects the prevailing paradigm of a monophyletic Orbiculariae, the most diverse lineage, containing orb-weaving spiders. Based on our results, the orb web either evolved much earlier than previously hypothesized and is ancestral for a majority of spiders or else it has multiple independent origins, as hypothesized by precladistic authors. Cribellate deinopoid orb weavers that use mechanically adhesive silk are more closely related to a diverse clade of mostly webless spiders than to the araneoid orb-weaving spiders that use adhesive droplet silks. The fundamental shift in our understanding of spider phylogeny proposed here has broad implications for interpreting the evolution of spiders, their remarkable biomaterials, and a key extended phenotype--the spider web. Copyright © 2014 Elsevier Ltd. All rights reserved.

Zebra: a web server for bioinformatic analysis of diverse protein families.

PubMed

Suplatov, Dmitry; Kirilin, Evgeny; Takhaveev, Vakil; Svedas, Vytas

2014-01-01

During evolution of proteins from a common ancestor, one functional property can be preserved while others can vary leading to functional diversity. A systematic study of the corresponding adaptive mutations provides a key to one of the most challenging problems of modern structural biology - understanding the impact of amino acid substitutions on protein function. The subfamily-specific positions (SSPs) are conserved within functional subfamilies but are different between them and, therefore, seem to be responsible for functional diversity in protein superfamilies. Consequently, a corresponding method to perform the bioinformatic analysis of sequence and structural data has to be implemented in the common laboratory practice to study the structure-function relationship in proteins and develop novel protein engineering strategies. This paper describes Zebra web server - a powerful remote platform that implements a novel bioinformatic analysis algorithm to study diverse protein families. It is the first application that provides specificity determinants at different levels of functional classification, therefore addressing complex functional diversity of large superfamilies. Statistical analysis is implemented to automatically select a set of highly significant SSPs to be used as hotspots for directed evolution or rational design experiments and analyzed studying the structure-function relationship. Zebra results are provided in two ways - (1) as a single all-in-one parsable text file and (2) as PyMol sessions with structural representation of SSPs. Zebra web server is available at http://biokinet.belozersky.msu.ru/zebra .

Internet College Recruiting and Marketing: Web Promotion, Techniques and Law.

ERIC Educational Resources Information Center

Mentz, George; Whiteside, Richard

2003-01-01

After using online recruiting techniques, researching Internet marketing, and consulting companies regarding search engine ranking, the authors made many observations about the evolution of the Internet as a tool for educating students and targeting enrollment for new admission. Article presents recommendations for using Internet to promote online…

Overcoming Learning Time and Space Constraints through Technological Tool

ERIC Educational Resources Information Center

Zarei, Nafiseh; Hussin, Supyan; Rashid, Taufik

2015-01-01

Today the use of technological tools has become an evolution in language learning and language acquisition. Many instructors and lecturers believe that integrating Web-based learning tools into language courses allows pupils to become active learners during learning process. This study investigates how the Learning Management Blog (LMB) overcomes…

QoS Adaptation in Multimedia Multicast Conference Applications for E-Learning Services

ERIC Educational Resources Information Center

Deusdado, Sérgio; Carvalho, Paulo

2006-01-01

The evolution of the World Wide Web service has incorporated new distributed multimedia conference applications, powering a new generation of e-learning development and allowing improved interactivity and prohuman relations. Groupware applications are increasingly representative in the Internet home applications market, however, the Quality of…

Darwinian Liberal Education

ERIC Educational Resources Information Center

Arnhart, Larry

2006-01-01

Be it metaphysics, theology, or some other unifying framework, humans have long sought to determine "first principles" underlying knowledge. Larry Arnhart continues in this vein, positing a Darwinian web of genetic, cultural, and cognitive evolution to explain our social behavior in terms of human nature as governed by biology. He leaves it to us…

A Functional Data Model Realized: LaTiS Deployments

NASA Astrophysics Data System (ADS)

Baltzer, T.; Lindholm, D. M.; Wilson, A.; Putnam, B.; Christofferson, R.; Flores, N.; Roughton, S.

2016-12-01

At prior AGU annual meetings, members of the University of Colorado Laboratory for Atmospheric and Space Physics (LASP) Web Team have described work being done on a functional data model and the software framework called LaTis, that implements it. This presentation describes the evolution of LaTiS and presents several instances of LaTiS in operation today that demonstrate its various capabilities. With LaTiS, serving a new dataset can be a simple as adding a small descriptor file. From providing access to spacecraft telemetry data in a variety of forms for the LASP missions operation group, to providing access to scientific data for the MMS and MAVEN science teams, to server-side functionality such as fusing satellite visible and infrared data along with forecast model data into a Geotiff image for situational awareness purposes, LaTiS has demonstrated itself as a highly flexible, standards-based framework that provides easy data access, dynamic reformatting, and customizable server side functionality.

GeoGML - a Mark-up Language for 4-dimensional geomorphic objects and processes

NASA Astrophysics Data System (ADS)

Löwner, M.-O.

2009-04-01

We developed an use-oriented GML3 based data model that enables researchers to share 4-dimensional information about landforms and their process related interaction. Using the Unified Modelling Language it is implemented as a GML3-based application schema available on the Internet. As the science of the land's surface Geomorphology investigates landforms, their change, and the processes causing this change. The main problem of comparing research results in geomorphology is that the objects under investigation are composed of 3-dimensional geometries that change in time due to processes of material fluxes, e. g. soil erosion or mass movements. They have internal properties, e. g. soil texture or bulk density, that determine the effectiveness of these processes but are under change as well. Worldwide geographical data can be shared over the Internet using Web Feature Services. The precondition is the development of a semantic model or ontology based on international standards like GML3 as an implementation of the ISO 109107 and others. Here we present a GML3-based Mark-up Language or application schema for geomorphic purposes that fulfils the following requirements: First, an object-oriented view of landforms with a true 3-dimensional geometric data format was established. Second, the internal structure and attributes of landforms can be stored. Third, the interaction of processes and landforms is represented. Fourth, the change of all these mentioned attributes over time was considered. The presented application schema is available on the Internet and therefore a first step to enable researchers to share information using an OGC's Web feature service. In this vein comparing modelling results of landscape evolution with results of other scientist's observations is possible. Compared to prevalent data concepts the model presented makes it possible to store information about landforms, their geometry and the characteristics in more detail. It allows to represent the 3D-geometry, the set of material properties and the genesis of a landform by associating processes to a geoobject. Thus, time slices of a geomorphic system can be represented as well as scenarios of landscape modelling. Commercial GI-software is not adapted to the needs of the science of geomorphology. Therefore the development of an application model i. e. a formal description of semantics is imperative to partake in technologies like Web Feature Services supporting interoperable data transfer.

A physical map of Brassica oleracea shows complexity of chromosomal changes following recursive paleopolyploidizations

PubMed Central

2011-01-01

Background Evolution of the Brassica species has been recursively affected by polyploidy events, and comparison to their relative, Arabidopsis thaliana, provides means to explore their genomic complexity. Results A genome-wide physical map of a rapid-cycling strain of B. oleracea was constructed by integrating high-information-content fingerprinting (HICF) of Bacterial Artificial Chromosome (BAC) clones with hybridization to sequence-tagged probes. Using 2907 contigs of two or more BACs, we performed several lines of comparative genomic analysis. Interspecific DNA synteny is much better preserved in euchromatin than heterochromatin, showing the qualitative difference in evolution of these respective genomic domains. About 67% of contigs can be aligned to the Arabidopsis genome, with 96.5% corresponding to euchromatic regions, and 3.5% (shown to contain repetitive sequences) to pericentromeric regions. Overgo probe hybridization data showed that contigs aligned to Arabidopsis euchromatin contain ~80% of low-copy-number genes, while genes with high copy number are much more frequently associated with pericentromeric regions. We identified 39 interchromosomal breakpoints during the diversification of B. oleracea and Arabidopsis thaliana, a relatively high level of genomic change since their divergence. Comparison of the B. oleracea physical map with Arabidopsis and other available eudicot genomes showed appreciable 'shadowing' produced by more ancient polyploidies, resulting in a web of relatedness among contigs which increased genomic complexity. Conclusions A high-resolution genetically-anchored physical map sheds light on Brassica genome organization and advances positional cloning of specific genes, and may help to validate genome sequence assembly and alignment to chromosomes. All the physical mapping data is freely shared at a WebFPC site (http://lulu.pgml.uga.edu/fpc/WebAGCoL/brassica/WebFPC/; Temporarily password-protected: account: pgml; password: 123qwe123. PMID:21955929

20th century human pressures drive reductions in deepwater oxygen leading to losses of benthic methane-based food webs

NASA Astrophysics Data System (ADS)

Belle, Simon; Millet, Laurent; Verneaux, Valérie; Lami, Andrea; David, Etienne; Murgia, Laurie; Parent, Claire; Musazzi, Simona; Gauthier, Emilie; Bichet, Vincent; Magny, Michel

2016-04-01

Freshwater lakes play a key role in the global carbon cycle as sinks (organic carbon sequestration) and sources (greenhouse gas emissions). Understanding the carbon cycle response to environmental changes is becoming a crucial challenge in the context of global warming and the preponderance of human pressures. We reconstructed the long-term (1500 years) evolution of trophic functioning of the benthic food web, based on methanotrophic ancient DNA and chironomid isotope analyses). In addition, human land use is also reconstructed in three different lakes (eastern France, Jura Mountains). Our findings confirm that the benthic food web can be highly dependent on methane-derived carbon (up to 50% of the chironomid biomass) and reveal that the activation of this process can correspond to a natural functioning or be a consequence of anthropic perturbation. The studied lakes also showed a similar temporal evolution over the last century with the disappearance of the profundal aquatic insects (Chironomidae, Diptera), considered as keystone for the whole lake food web (e.g., coupling benthic-pelagic), inducing a potential collapse in the transfer of methane to top consumers. This functional state, also called the dead zone expansion, was caused by the change in human land-use occurring at the beginning of the 20th century. The strong modification of agro-pastoral practices (e.g., fertilization practices, intensive grazing, and sewage effluent) modified the influx of nutrients (by diffuse and/or point-source inputs) and induced a significant increase in the trophic status and organic matter sedimentation to reach unprecedented values. Further studies should be planned to assess dead zone expansion and, according to the regime shift theory, to provide environmental tipping points for sustainable resource management.

WebGLORE: a web service for Grid LOgistic REgression.

PubMed

Jiang, Wenchao; Li, Pinghao; Wang, Shuang; Wu, Yuan; Xue, Meng; Ohno-Machado, Lucila; Jiang, Xiaoqian

2013-12-15

WebGLORE is a free web service that enables privacy-preserving construction of a global logistic regression model from distributed datasets that are sensitive. It only transfers aggregated local statistics (from participants) through Hypertext Transfer Protocol Secure to a trusted server, where the global model is synthesized. WebGLORE seamlessly integrates AJAX, JAVA Applet/Servlet and PHP technologies to provide an easy-to-use web service for biomedical researchers to break down policy barriers during information exchange. http://dbmi-engine.ucsd.edu/webglore3/. WebGLORE can be used under the terms of GNU general public license as published by the Free Software Foundation.

Empirical Examination of the Adoption of WebCT Using TAM

ERIC Educational Resources Information Center

Ngai, E. W. T.; Poon, J. K. L.; Chan, Y. H. C.

2007-01-01

Web Course Tools (WebCT) have enhanced the ability and motivation of institutes of higher education to support e-learning. In this study, we extended the Technology Acceptance Model to include technical support as a precursor and then investigated the role of the extended model in user acceptance of WebCT. Responses from 836 university students…

Web 2.0 chronic disease self-management for older adults: a systematic review.

PubMed

Stellefson, Michael; Chaney, Beth; Barry, Adam E; Chavarria, Enmanuel; Tennant, Bethany; Walsh-Childers, Kim; Sriram, P S; Zagora, Justin

2013-02-14

Participatory Web 2.0 interventions promote collaboration to support chronic disease self-management. Growth in Web 2.0 interventions has led to the emergence of e-patient communication tools that enable older adults to (1) locate and share disease management information and (2) receive interactive healthcare advice. The evolution of older e-patients contributing to Web 2.0 health and medical forums has led to greater opportunities for achieving better chronic disease outcomes. To date, there are no review articles investigating the planning, implementation, and evaluation of Web 2.0 chronic disease self-management interventions for older adults. To review the planning, implementation, and overall effectiveness of Web 2.0 self-management interventions for older adults (mean age ≥ 50) with one or more chronic disease(s). A systematic literature search was conducted using six popular health science databases. The RE-AIM (Reach, Efficacy, Adoption, Implementation and Maintenance) model was used to organize findings and compute a study quality score (SQS) for 15 reviewed articles. Most interventions were adopted for delivery by multidisciplinary healthcare teams and tested among small samples of white females with diabetes. Studies indicated that Web 2.0 participants felt greater self-efficacy for managing their disease(s) and benefitted from communicating with health care providers and/or website moderators to receive feedback and social support. Participants noted asynchronous communication tools (eg, email, discussion boards) and progress tracking features (eg, graphical displays of uploaded personal data) as being particularly useful for self-management support. Despite high attrition being noted as problematic, this review suggests that greater Web 2.0 engagement may be associated with improvements in health behaviors (eg, physical activity) and health status (eg, HRQoL). However, few studies indicated statistically significant improvements in medication adherence, biological outcomes, or health care utilization. Mean SQS scores were notably low (mean=63%, SD 18%). Studies were judged to be weakest on the Maintenance dimension of RE-AIM; 13 reviewed studies (87%) did not describe any measures taken to sustain Web 2.0 effects past designated study time periods. Detailed process and impact evaluation frameworks were also missing in almost half (n=7) of the reviewed interventions. There is need for a greater understanding of the costs and benefits associated with using patient-centered Web 2.0 technologies for chronic disease self-management. More research is needed to determine whether the long-term effectiveness of these programs is sustainable among larger, more diverse samples of chronically ill patients. The effective translation of new knowledge, social technologies, and engagement techniques will likely result in novel approaches for empowering, engaging, and educating older adults with chronic disease.

Web 2.0 Chronic Disease Self-Management for Older Adults: A Systematic Review

PubMed Central

Chaney, Beth; Barry, Adam E; Chavarria, Enmanuel; Tennant, Bethany; Walsh-Childers, Kim; Sriram, P.S; Zagora, Justin

2013-01-01

Background Participatory Web 2.0 interventions promote collaboration to support chronic disease self-management. Growth in Web 2.0 interventions has led to the emergence of e-patient communication tools that enable older adults to (1) locate and share disease management information and (2) receive interactive healthcare advice. The evolution of older e-patients contributing to Web 2.0 health and medical forums has led to greater opportunities for achieving better chronic disease outcomes. To date, there are no review articles investigating the planning, implementation, and evaluation of Web 2.0 chronic disease self-management interventions for older adults. Objective To review the planning, implementation, and overall effectiveness of Web 2.0 self-management interventions for older adults (mean age ≥ 50) with one or more chronic disease(s). Methods A systematic literature search was conducted using six popular health science databases. The RE-AIM (Reach, Efficacy, Adoption, Implementation and Maintenance) model was used to organize findings and compute a study quality score (SQS) for 15 reviewed articles. Results Most interventions were adopted for delivery by multidisciplinary healthcare teams and tested among small samples of white females with diabetes. Studies indicated that Web 2.0 participants felt greater self-efficacy for managing their disease(s) and benefitted from communicating with health care providers and/or website moderators to receive feedback and social support. Participants noted asynchronous communication tools (eg, email, discussion boards) and progress tracking features (eg, graphical displays of uploaded personal data) as being particularly useful for self-management support. Despite high attrition being noted as problematic, this review suggests that greater Web 2.0 engagement may be associated with improvements in health behaviors (eg, physical activity) and health status (eg, HRQoL). However, few studies indicated statistically significant improvements in medication adherence, biological outcomes, or health care utilization. Mean SQS scores were notably low (mean=63%, SD 18%). Studies were judged to be weakest on the Maintenance dimension of RE-AIM; 13 reviewed studies (87%) did not describe any measures taken to sustain Web 2.0 effects past designated study time periods. Detailed process and impact evaluation frameworks were also missing in almost half (n=7) of the reviewed interventions. Conclusions There is need for a greater understanding of the costs and benefits associated with using patient-centered Web 2.0 technologies for chronic disease self-management. More research is needed to determine whether the long-term effectiveness of these programs is sustainable among larger, more diverse samples of chronically ill patients. The effective translation of new knowledge, social technologies, and engagement techniques will likely result in novel approaches for empowering, engaging, and educating older adults with chronic disease. PMID:23410671

Dependence of GAMA galaxy halo masses on the cosmic web environment from 100 deg2 of KiDS weak lensing data

NASA Astrophysics Data System (ADS)

Brouwer, Margot M.; Cacciato, Marcello; Dvornik, Andrej; Eardley, Lizzie; Heymans, Catherine; Hoekstra, Henk; Kuijken, Konrad; McNaught-Roberts, Tamsyn; Sifón, Cristóbal; Viola, Massimo; Alpaslan, Mehmet; Bilicki, Maciej; Bland-Hawthorn, Joss; Brough, Sarah; Choi, Ami; Driver, Simon P.; Erben, Thomas; Grado, Aniello; Hildebrandt, Hendrik; Holwerda, Benne W.; Hopkins, Andrew M.; de Jong, Jelte T. A.; Liske, Jochen; McFarland, John; Nakajima, Reiko; Napolitano, Nicola R.; Norberg, Peder; Peacock, John A.; Radovich, Mario; Robotham, Aaron S. G.; Schneider, Peter; Sikkema, Gert; van Uitert, Edo; Verdoes Kleijn, Gijs; Valentijn, Edwin A.

2016-11-01

Galaxies and their dark matter haloes are part of a complex network of mass structures, collectively called the cosmic web. Using the tidal tensor prescription these structures can be classified into four cosmic environments: voids, sheets, filaments and knots. As the cosmic web may influence the formation and evolution of dark matter haloes and the galaxies they host, we aim to study the effect of these cosmic environments on the average mass of galactic haloes. To this end we measure the galaxy-galaxy lensing profile of 91 195 galaxies, within 0.039 < z < 0.263, from the spectroscopic Galaxy And Mass Assembly survey, using {˜ }100 ° ^2 of overlapping data from the Kilo-Degree Survey. In each of the four cosmic environments we model the contributions from group centrals, satellites and neighbouring groups to the stacked galaxy-galaxy lensing profiles. After correcting the lens samples for differences in the stellar mass distribution, we find no dependence of the average halo mass of central galaxies on their cosmic environment. We do find a significant increase in the average contribution of neighbouring groups to the lensing profile in increasingly dense cosmic environments. We show, however, that the observed effect can be entirely attributed to the galaxy density at much smaller scales (within 4 h-1 Mpc), which is correlated with the density of the cosmic environments. Within our current uncertainties we find no direct dependence of galaxy halo mass on their cosmic environment.

Assessing ecosystem effects of reservoir operations using food web-energy transfer and water quality models

USGS Publications Warehouse

Saito, L.; Johnson, B.M.; Bartholow, J.; Hanna, R.B.

2001-01-01

We investigated the effects on the reservoir food web of a new temperature control device (TCD) on the dam at Shasta Lake, California. We followed a linked modeling approach that used a specialized reservoir water quality model to forecast operation-induced changes in phytoplankton production. A food web–energy transfer model was also applied to propagate predicted changes in phytoplankton up through the food web to the predators and sport fishes of interest. The food web–energy transfer model employed a 10% trophic transfer efficiency through a food web that was mapped using carbon and nitrogen stable isotope analysis. Stable isotope analysis provided an efficient and comprehensive means of estimating the structure of the reservoir's food web with minimal sampling and background data. We used an optimization procedure to estimate the diet proportions of all food web components simultaneously from their isotopic signatures. Some consumers were estimated to be much more sensitive than others to perturbations to phytoplankton supply. The linked modeling approach demonstrated that interdisciplinary efforts enhance the value of information obtained from studies of managed ecosystems. The approach exploited the strengths of engineering and ecological modeling methods to address concerns that neither of the models could have addressed alone: (a) the water quality model could not have addressed quantitatively the possible impacts to fish, and (b) the food web model could not have examined how phytoplankton availability might change due to reservoir operations.

SBMLmod: a Python-based web application and web service for efficient data integration and model simulation.

PubMed

Schäuble, Sascha; Stavrum, Anne-Kristin; Bockwoldt, Mathias; Puntervoll, Pål; Heiland, Ines

2017-06-24

Systems Biology Markup Language (SBML) is the standard model representation and description language in systems biology. Enriching and analysing systems biology models by integrating the multitude of available data, increases the predictive power of these models. This may be a daunting task, which commonly requires bioinformatic competence and scripting. We present SBMLmod, a Python-based web application and service, that automates integration of high throughput data into SBML models. Subsequent steady state analysis is readily accessible via the web service COPASIWS. We illustrate the utility of SBMLmod by integrating gene expression data from different healthy tissues as well as from a cancer dataset into a previously published model of mammalian tryptophan metabolism. SBMLmod is a user-friendly platform for model modification and simulation. The web application is available at http://sbmlmod.uit.no , whereas the WSDL definition file for the web service is accessible via http://sbmlmod.uit.no/SBMLmod.wsdl . Furthermore, the entire package can be downloaded from https://github.com/MolecularBioinformatics/sbml-mod-ws . We envision that SBMLmod will make automated model modification and simulation available to a broader research community.

A resource oriented webs service for environmental modeling

NASA Astrophysics Data System (ADS)

Ferencik, Ioan

2013-04-01

Environmental modeling is a largely adopted practice in the study of natural phenomena. Environmental models can be difficult to build and use and thus sharing them within the community is an important aspect. The most common approach to share a model is to expose it as a web service. In practice the interaction with this web service is cumbersome due to lack of standardized contract and the complexity of the model being exposed. In this work we investigate the use of a resource oriented approach in exposing environmental models as web services. We view a model as a layered resource build atop the object concept from Object Oriented Programming, augmented with persistence capabilities provided by an embedded object database to keep track of its state and implementing the four basic principles of resource oriented architectures: addressability, statelessness, representation and uniform interface. For implementation we use exclusively open source software: Django framework, dyBase object oriented database and Python programming language. We developed a generic framework of resources structured into a hierarchy of types and consequently extended this typology with recurses specific to the domain of environmental modeling. To test our web service we used cURL, a robust command-line based web client.

Specification and Verification of Web Applications in Rewriting Logic

NASA Astrophysics Data System (ADS)

Alpuente, María; Ballis, Demis; Romero, Daniel

This paper presents a Rewriting Logic framework that formalizes the interactions between Web servers and Web browsers through a communicating protocol abstracting HTTP. The proposed framework includes a scripting language that is powerful enough to model the dynamics of complex Web applications by encompassing the main features of the most popular Web scripting languages (e.g. PHP, ASP, Java Servlets). We also provide a detailed characterization of browser actions (e.g. forward/backward navigation, page refresh, and new window/tab openings) via rewrite rules, and show how our models can be naturally model-checked by using the Linear Temporal Logic of Rewriting (LTLR), which is a Linear Temporal Logic specifically designed for model-checking rewrite theories. Our formalization is particularly suitable for verification purposes, since it allows one to perform in-depth analyses of many subtle aspects related to Web interaction. Finally, the framework has been completely implemented in Maude, and we report on some successful experiments that we conducted by using the Maude LTLR model-checker.

Importance of the spatial data and the sensor web in the ubiquitous computing area

NASA Astrophysics Data System (ADS)

Akçit, Nuhcan; Tomur, Emrah; Karslıoǧlu, Mahmut O.

2014-08-01

Spatial data has become a critical issue in recent years. In the past years, nearly more than three quarters of databases, were related directly or indirectly to locations referring to physical features, which constitute the relevant aspects. Spatial data is necessary to identify or calculate the relationships between spatial objects when using spatial operators in programs or portals. Originally, calculations were conducted using Geographic Information System (GIS) programs on local computers. Subsequently, through the Internet, they formed a geospatial web, which is integrated into a discoverable collection of geographically related web standards and key features, and constitutes a global network of geospatial data that employs the World Wide Web to process textual data. In addition, the geospatial web is used to gather spatial data producers, resources, and users. Standards also constitute a critical dimension in further globalizing the idea of the geospatial web. The sensor web is an example of the real time service that the geospatial web can provide. Sensors around the world collect numerous types of data. The sensor web is a type of sensor network that is used for visualizing, calculating, and analyzing collected sensor data. Today, people use smart devices and systems more frequently because of the evolution of technology and have more than one mobile device. The considerable number of sensors and different types of data that are positioned around the world have driven the production of interoperable and platform-independent sensor web portals. The focus of such production has been on further developing the idea of an interoperable and interdependent sensor web of all devices that share and collect information. The other pivotal idea consists of encouraging people to use and send data voluntarily for numerous purposes with the some level of credibility. The principal goal is to connect mobile and non-mobile device in the sensor web platform together to operate for serving and collecting information from people.

The importance of nature's invisible fabric: food web structure mediates modeled responses to river restoration

NASA Astrophysics Data System (ADS)

Bellmore, R.; Benjamin, J.; Newsom, M.; Bountry, J.; Dombroski, D.

2016-12-01

Restoration is frequently aimed at the recovery of target species, but also influences the larger food web in which these species participate. Effects of restoration on this broader network of organisms can influence target species both directly and indirectly via changes in energy flow through food webs. To help incorporate these complexities into river restoration planning we constructed a food web model that links river food web dynamics to in-stream physical habitat and riparian vegetation conditions. We present an application of this model to the Methow River, Washington (USA), a location of on-going restoration aimed at recovering salmon. Three restoration strategies were simulated: riparian vegetation restoration, nutrient augmentation via salmon carcass addition, and floodplain reconnection. To explore how food web structure mediates responses to these actions, we modified the food web by adding populations of invasive aquatic snails and nonnative fish. Simulations suggest that floodplain reconnection may be a better strategy than carcass addition and vegetation planting for improving conditions for salmon in this river segment. However, modeled responses were strongly sensitive to changes in the structure of the food web. The addition of invasive snails and nonnative fishes modified pathways of energy through the food web, which negated restoration improvements. This finding illustrates that forecasting responses to restoration may require accounting for the structure of food webs, and that changes in this structure—as might be expected with the spread of invasive species—could compromise restoration outcomes. By elucidating the direct and indirect pathways by which restoration affects target species, dynamic food web models can improve restoration planning by fostering a deeper understanding of system connectedness and dynamics.

Using Web-Based Knowledge Extraction Techniques to Support Cultural Modeling

NASA Astrophysics Data System (ADS)

Smart, Paul R.; Sieck, Winston R.; Shadbolt, Nigel R.

The World Wide Web is a potentially valuable source of information about the cognitive characteristics of cultural groups. However, attempts to use the Web in the context of cultural modeling activities are hampered by the large-scale nature of the Web and the current dominance of natural language formats. In this paper, we outline an approach to support the exploitation of the Web for cultural modeling activities. The approach begins with the development of qualitative cultural models (which describe the beliefs, concepts and values of cultural groups), and these models are subsequently used to develop an ontology-based information extraction capability. Our approach represents an attempt to combine conventional approaches to information extraction with epidemiological perspectives of culture and network-based approaches to cultural analysis. The approach can be used, we suggest, to support the development of models providing a better understanding of the cognitive characteristics of particular cultural groups.

Quantitative analysis of bloggers' collective behavior powered by emotions

NASA Astrophysics Data System (ADS)

Mitrović, Marija; Paltoglou, Georgios; Tadić, Bosiljka

2011-02-01

Large-scale data resulting from users' online interactions provide the ultimate source of information to study emergent social phenomena on the Web. From individual actions of users to observable collective behaviors, different mechanisms involving emotions expressed in the posted text play a role. Here we combine approaches of statistical physics with machine-learning methods of text analysis to study the emergence of emotional behavior among Web users. Mapping the high-resolution data from digg.com onto bipartite networks of users and their comments onto posted stories, we identify user communities centered around certain popular posts and determine emotional contents of the related comments by the emotion classifier developed for this type of text. Applied over different time periods, this framework reveals strong correlations between the excess of negative emotions and the evolution of communities. We observe avalanches of emotional comments exhibiting significant self-organized critical behavior and temporal correlations. To explore the robustness of these critical states, we design a network-automaton model on realistic network connections and several control parameters, which can be inferred from the dataset. Dissemination of emotions by a small fraction of very active users appears to critically tune the collective states.

The i5k Workspace@NAL—enabling genomic data access, visualization and curation of arthropod genomes

PubMed Central

Poelchau, Monica; Childers, Christopher; Moore, Gary; Tsavatapalli, Vijaya; Evans, Jay; Lee, Chien-Yueh; Lin, Han; Lin, Jun-Wei; Hackett, Kevin

2015-01-01

The 5000 arthropod genomes initiative (i5k) has tasked itself with coordinating the sequencing of 5000 insect or related arthropod genomes. The resulting influx of data, mostly from small research groups or communities with little bioinformatics experience, will require visualization, dissemination and curation, preferably from a centralized platform. The National Agricultural Library (NAL) has implemented the i5k Workspace@NAL (http://i5k.nal.usda.gov/) to help meet the i5k initiative's genome hosting needs. Any i5k member is encouraged to contact the i5k Workspace with their genome project details. Once submitted, new content will be accessible via organism pages, genome browsers and BLAST search engines, which are implemented via the open-source Tripal framework, a web interface for the underlying Chado database schema. We also implement the Web Apollo software for groups that choose to curate gene models. New content will add to the existing body of 35 arthropod species, which include species relevant for many aspects of arthropod genomic research, including agriculture, invasion biology, systematics, ecology and evolution, and developmental research. PMID:25332403

Compliant threads maximize spider silk connection strength and toughness

PubMed Central

Meyer, Avery; Pugno, Nicola M.; Cranford, Steven W.

2014-01-01

Millions of years of evolution have adapted spider webs to achieve a range of functionalities, including the well-known capture of prey, with efficient use of material. One feature that has escaped extensive investigation is the silk-on-silk connection joints within spider webs, particularly from a structural mechanics perspective. We report a joint theoretical and computational analysis of an idealized silk-on-silk fibre junction. By modifying the theory of multiple peeling, we quantitatively compare the performance of the system while systematically increasing the rigidity of the anchor thread, by both scaling the stress–strain response and the introduction of an applied pre-strain. The results of our study indicate that compliance is a virtue—the more extensible the anchorage, the tougher and stronger the connection becomes. In consideration of the theoretical model, in comparison with rigid substrates, a compliant anchorage enormously increases the effective adhesion strength (work required to detach), independent of the adhered thread itself, attributed to a nonlinear alignment between thread and anchor (contact peeling angle). The results can direct novel engineering design principles to achieve possible load transfer from compliant fibre-to-fibre anchorages, be they silk-on-silk or another, as-yet undeveloped, system. PMID:25008083

[OISO, automatic treatment of patients management in oncogenetics].

PubMed

Guien, Céline; Fabre, Aurélie; Lagarde, Arnaud; Salgado, David; Gensollen-Thiriez, Catherine; Zattara, Hélène; Beroud, Christophe; Olschwang, Sylviane

Oncogenetics is a long-term process, which requires a close relation between patients and medical teams, good familial links allowing lifetime follow-up. Numerous documents are exchanged in between the medical team, which has to frequently interact. We present here a new tool that has been conceived specifically for this management. The tool has been developed according to a model-view-controler approach with the relational system PostgreSQL 9.3. The web site used PHP 5.3, HTML5 and CSS3 languages, completed with JavaScript and jQuery-AJAX functions and two additional modules, FPDF and PHPMailer. The tool allows multiple interactions, clinical data management, mailing and emailing, follow-up plannings. Requests are able to follow all patients and planning automatically, to send information to a large number of patients or physicians, and to report activity. The tool has been designed for oncogenetics and adapted to its different aspects. The CNIL delivered an authorization for use. Secured web access allows the management at a regional level. Its simple concept makes it evolutive according to the constant updates of genetic and clinical management of patients. Copyright © 2017 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

Enriching the trustworthiness of health-related web pages.

PubMed

Gaudinat, Arnaud; Cruchet, Sarah; Boyer, Celia; Chrawdhry, Pravir

2011-06-01

We present an experimental mechanism for enriching web content with quality metadata. This mechanism is based on a simple and well-known initiative in the field of the health-related web, the HONcode. The Resource Description Framework (RDF) format and the Dublin Core Metadata Element Set were used to formalize these metadata. The model of trust proposed is based on a quality model for health-related web pages that has been tested in practice over a period of thirteen years. Our model has been explored in the context of a project to develop a research tool that automatically detects the occurrence of quality criteria in health-related web pages.

Advancing the Implementation of Hydrologic Models as Web-based Applications

NASA Astrophysics Data System (ADS)

Dahal, P.; Tarboton, D. G.; Castronova, A. M.

2017-12-01

Advanced computer simulations are required to understand hydrologic phenomenon such as rainfall-runoff response, groundwater hydrology, snow hydrology, etc. Building a hydrologic model instance to simulate a watershed requires investment in data (diverse geospatial datasets such as terrain, soil) and computer resources, typically demands a wide skill set from the analyst, and the workflow involved is often difficult to reproduce. This work introduces a web-based prototype infrastructure in the form of a web application that provides researchers with easy to use access to complete hydrological modeling functionality. This includes creating the necessary geospatial and forcing data, preparing input files for a model by applying complex data preprocessing, running the model for a user defined watershed, and saving the results to a web repository. The open source Tethys Platform was used to develop the web app front-end Graphical User Interface (GUI). We used HydroDS, a webservice that provides data preparation processing capability to support backend computations used by the app. Results are saved in HydroShare, a hydrologic information system that supports the sharing of hydrologic data, model and analysis tools. The TOPographic Kinematic APproximation and Integration (TOPKAPI) model served as the example for which we developed a complete hydrologic modeling service to demonstrate the approach. The final product is a complete modeling system accessible through the web to create input files, and run the TOPKAPI hydrologic model for a watershed of interest. We are investigating similar functionality for the preparation of input to Regional Hydro-Ecological Simulation System (RHESSys). Key Words: hydrologic modeling, web services, hydrologic information system, HydroShare, HydroDS, Tethys Platform

Autonomous Mission Operations for Sensor Webs

NASA Astrophysics Data System (ADS)

Underbrink, A.; Witt, K.; Stanley, J.; Mandl, D.

2008-12-01

We present interim results of a 2005 ROSES AIST project entitled, "Using Intelligent Agents to Form a Sensor Web for Autonomous Mission Operations", or SWAMO. The goal of the SWAMO project is to shift the control of spacecraft missions from a ground-based, centrally controlled architecture to a collaborative, distributed set of intelligent agents. The network of intelligent agents intends to reduce management requirements by utilizing model-based system prediction and autonomic model/agent collaboration. SWAMO agents are distributed throughout the Sensor Web environment, which may include multiple spacecraft, aircraft, ground systems, and ocean systems, as well as manned operations centers. The agents monitor and manage sensor platforms, Earth sensing systems, and Earth sensing models and processes. The SWAMO agents form a Sensor Web of agents via peer-to-peer coordination. Some of the intelligent agents are mobile and able to traverse between on-orbit and ground-based systems. Other agents in the network are responsible for encapsulating system models to perform prediction of future behavior of the modeled subsystems and components to which they are assigned. The software agents use semantic web technologies to enable improved information sharing among the operational entities of the Sensor Web. The semantics include ontological conceptualizations of the Sensor Web environment, plus conceptualizations of the SWAMO agents themselves. By conceptualizations of the agents, we mean knowledge of their state, operational capabilities, current operational capacities, Web Service search and discovery results, agent collaboration rules, etc. The need for ontological conceptualizations over the agents is to enable autonomous and autonomic operations of the Sensor Web. The SWAMO ontology enables automated decision making and responses to the dynamic Sensor Web environment and to end user science requests. The current ontology is compatible with Open Geospatial Consortium (OGC) Sensor Web Enablement (SWE) Sensor Model Language (SensorML) concepts and structures. The agents are currently deployed on the U.S. Naval Academy MidSTAR-1 satellite and are actively managing the power subsystem on-orbit without the need for human intervention.

The paradox of enrichment in an adaptive world

PubMed Central

Mougi, Akihiko; Nishimura, Kinya

2008-01-01

Paradoxically, enrichment can destabilize a predator–prey food web. While adaptive dynamics can greatly influence the stability of interaction systems, few theoretical studies have examined the effect of the adaptive dynamics of interaction-related traits on the possibility of resolution of the paradox of enrichment. We consider the evolution of attack and defence traits of a predator and two prey species in a one predator–two prey system in which the predator practises optimal diet use. The results showed that optimal foraging alone cannot eliminate a pattern of destabilization with enrichment, but trait evolution of the predator or prey can change the pattern to one of stabilization, implying a possible resolution of the paradox of enrichment. Furthermore, trait evolution in all species can broaden the parameter range of stabilization. Importantly, rapid evolution can stabilize this system, but weaken its stability in the face of enrichment. PMID:18700201

Hybrid evolutionary computing model for mobile agents of wireless Internet multimedia

NASA Astrophysics Data System (ADS)

Hortos, William S.

2001-03-01

The ecosystem is used as an evolutionary paradigm of natural laws for the distributed information retrieval via mobile agents to allow the computational load to be added to server nodes of wireless networks, while reducing the traffic on communication links. Based on the Food Web model, a set of computational rules of natural balance form the outer stage to control the evolution of mobile agents providing multimedia services with a wireless Internet protocol WIP. The evolutionary model shows how mobile agents should behave with the WIP, in particular, how mobile agents can cooperate, compete and learn from each other, based on an underlying competition for radio network resources to establish the wireless connections to support the quality of service QoS of user requests. Mobile agents are also allowed to clone themselves, propagate and communicate with other agents. A two-layer model is proposed for agent evolution: the outer layer is based on the law of natural balancing, the inner layer is based on a discrete version of a Kohonen self-organizing feature map SOFM to distribute network resources to meet QoS requirements. The former is embedded in the higher OSI layers of the WIP, while the latter is used in the resource management procedures of Layer 2 and 3 of the protocol. Algorithms for the distributed computation of mobile agent evolutionary behavior are developed by adding a learning state to the agent evolution state diagram. When an agent is in an indeterminate state, it can communicate to other agents. Computing models can be replicated from other agents. Then the agents transitions to the mutating state to wait for a new information-retrieval goal. When a wireless terminal or station lacks a network resource, an agent in the suspending state can change its policy to submit to the environment before it transitions to the searching state. The agents learn the facts of agent state information entered into an external database. In the cloning process, two agents on a host station sharing a common goal can be merged or married to compose a new agent. Application of the two-layer set of algorithms for mobile agent evolution, performed in a distributed processing environment, is made to the QoS management functions of the IP multimedia IM sub-network of the third generation 3G Wideband Code-division Multiple Access W-CDMA wireless network.

eSciMart: Web Platform for Scientific Software Marketplace

NASA Astrophysics Data System (ADS)

Kryukov, A. P.; Demichev, A. P.

2016-10-01

In this paper we suggest a design of a web marketplace where users of scientific application software and databases, presented in the form of web services, as well as their providers will have presence simultaneously. The model, which will be the basis for the web marketplace is close to the customer-to-customer (C2C) model, which has been successfully used, for example, on the auction sites such as eBay (ebay.com). Unlike the classical model of C2C the suggested marketplace focuses on application software in the form of web services, and standardization of API through which application software will be integrated into the web marketplace. A prototype of such a platform, entitled eSciMart, is currently being developed at SINP MSU.

WebGLORE: a Web service for Grid LOgistic REgression

PubMed Central

Jiang, Wenchao; Li, Pinghao; Wang, Shuang; Wu, Yuan; Xue, Meng; Ohno-Machado, Lucila; Jiang, Xiaoqian

2013-01-01

WebGLORE is a free web service that enables privacy-preserving construction of a global logistic regression model from distributed datasets that are sensitive. It only transfers aggregated local statistics (from participants) through Hypertext Transfer Protocol Secure to a trusted server, where the global model is synthesized. WebGLORE seamlessly integrates AJAX, JAVA Applet/Servlet and PHP technologies to provide an easy-to-use web service for biomedical researchers to break down policy barriers during information exchange. Availability and implementation: http://dbmi-engine.ucsd.edu/webglore3/. WebGLORE can be used under the terms of GNU general public license as published by the Free Software Foundation. Contact: x1jiang@ucsd.edu PMID:24072732

Parasites in food webs: the ultimate missing links

PubMed Central

Lafferty, Kevin D; Allesina, Stefano; Arim, Matias; Briggs, Cherie J; De Leo, Giulio; Dobson, Andrew P; Dunne, Jennifer A; Johnson, Pieter T J; Kuris, Armand M; Marcogliese, David J; Martinez, Neo D; Memmott, Jane; Marquet, Pablo A; McLaughlin, John P; Mordecai, Erin A; Pascual, Mercedes; Poulin, Robert; Thieltges, David W

2008-01-01

Parasitism is the most common consumer strategy among organisms, yet only recently has there been a call for the inclusion of infectious disease agents in food webs. The value of this effort hinges on whether parasites affect food-web properties. Increasing evidence suggests that parasites have the potential to uniquely alter food-web topology in terms of chain length, connectance and robustness. In addition, parasites might affect food-web stability, interaction strength and energy flow. Food-web structure also affects infectious disease dynamics because parasites depend on the ecological networks in which they live. Empirically, incorporating parasites into food webs is straightforward. We may start with existing food webs and add parasites as nodes, or we may try to build food webs around systems for which we already have a good understanding of infectious processes. In the future, perhaps researchers will add parasites while they construct food webs. Less clear is how food-web theory can accommodate parasites. This is a deep and central problem in theoretical biology and applied mathematics. For instance, is representing parasites with complex life cycles as a single node equivalent to representing other species with ontogenetic niche shifts as a single node? Can parasitism fit into fundamental frameworks such as the niche model? Can we integrate infectious disease models into the emerging field of dynamic food-web modelling? Future progress will benefit from interdisciplinary collaborations between ecologists and infectious disease biologists. PMID:18462196

Parasites in food webs: the ultimate missing links.

PubMed

Lafferty, Kevin D; Allesina, Stefano; Arim, Matias; Briggs, Cherie J; De Leo, Giulio; Dobson, Andrew P; Dunne, Jennifer A; Johnson, Pieter T J; Kuris, Armand M; Marcogliese, David J; Martinez, Neo D; Memmott, Jane; Marquet, Pablo A; McLaughlin, John P; Mordecai, Erin A; Pascual, Mercedes; Poulin, Robert; Thieltges, David W

2008-06-01

Parasitism is the most common consumer strategy among organisms, yet only recently has there been a call for the inclusion of infectious disease agents in food webs. The value of this effort hinges on whether parasites affect food-web properties. Increasing evidence suggests that parasites have the potential to uniquely alter food-web topology in terms of chain length, connectance and robustness. In addition, parasites might affect food-web stability, interaction strength and energy flow. Food-web structure also affects infectious disease dynamics because parasites depend on the ecological networks in which they live. Empirically, incorporating parasites into food webs is straightforward. We may start with existing food webs and add parasites as nodes, or we may try to build food webs around systems for which we already have a good understanding of infectious processes. In the future, perhaps researchers will add parasites while they construct food webs. Less clear is how food-web theory can accommodate parasites. This is a deep and central problem in theoretical biology and applied mathematics. For instance, is representing parasites with complex life cycles as a single node equivalent to representing other species with ontogenetic niche shifts as a single node? Can parasitism fit into fundamental frameworks such as the niche model? Can we integrate infectious disease models into the emerging field of dynamic food-web modelling? Future progress will benefit from interdisciplinary collaborations between ecologists and infectious disease biologists.

Parasites in food webs: the ultimate missing links

USGS Publications Warehouse

Lafferty, Kevin D.; Allesina, Stefano; Arim, Matias; Briggs, Cherie J.; De Leo, Giulio A.; Dobson, Andrew P.; Dunne, Jennifer A.; Johnson, Pieter T.J.; Kuris, Armand M.; Marcogliese, David J.; Martinez, Neo D.; Memmott, Jane; Marquet, Pablo A.; McLaughlin, John P.; Mordecai, Eerin A.; Pascual, Mercedes; Poulin, Robert; Thieltges, David W.

2008-01-01

Parasitism is the most common consumer strategy among organisms, yet only recently has there been a call for the inclusion of infectious disease agents in food webs. The value of this effort hinges on whether parasites affect food-web properties. Increasing evidence suggests that parasites have the potential to uniquely alter food-web topology in terms of chain length, connectance and robustness. In addition, parasites might affect food-web stability, interaction strength and energy flow. Food-web structure also affects infectious disease dynamics because parasites depend on the ecological networks in which they live. Empirically, incorporating parasites into food webs is straightforward. We may start with existing food webs and add parasites as nodes, or we may try to build food webs around systems for which we already have a good understanding of infectious processes. In the future, perhaps researchers will add parasites while they construct food webs. Less clear is how food-web theory can accommodate parasites. This is a deep and central problem in theoretical biology and applied mathematics. For instance, is representing parasites with complex life cycles as a single node equivalent to representing other species with ontogenetic niche shifts as a single node? Can parasitism fit into fundamental frameworks such as the niche model? Can we integrate infectious disease models into the emerging field of dynamic food-web modelling? Future progress will benefit from interdisciplinary collaborations between ecologists and infectious disease biologists.

Uncovering changes in spider orb-web topology owing to aerodynamic effects

PubMed Central

Zaera, Ramón; Soler, Alejandro; Teus, Jaime

2014-01-01

An orb-weaving spider's likelihood of survival is influenced by its ability to retain prey with minimum damage to its web and at the lowest manufacturing cost. This set of requirements has forced the spider silk to evolve towards extreme strength and ductility to a degree that is rare among materials. Previous studies reveal that the performance of the web upon impact may not be based on the mechanical properties of silk alone, aerodynamic drag could play a role in the dissipation of the prey's energy. Here, we present a thorough analysis of the effect of the aerodynamic drag on wind load and prey impact. The hypothesis considered by previous authors for the evaluation of the drag force per unit length of thread has been revisited according to well-established principles of fluid mechanics, highlighting the functional dependence on thread diameter that was formerly ignored. Theoretical analysis and finite-element simulations permitted us to identify air drag as a relevant factor in reducing deterioration of the orb web, and to reveal how the spider can take greater—and not negligible—advantage of drag dissipation. The study shows the beneficial air drag effects of building smaller and less dense webs under wind load, and larger and denser webs under prey impact loads. In essence, it points out why the aerodynamics need to be considered as an additional driving force in the evolution of silk threads and orb webs. PMID:24966235

BIRI: a new approach for automatically discovering and indexing available public bioinformatics resources from the literature.

PubMed

de la Calle, Guillermo; García-Remesal, Miguel; Chiesa, Stefano; de la Iglesia, Diana; Maojo, Victor

2009-10-07

The rapid evolution of Internet technologies and the collaborative approaches that dominate the field have stimulated the development of numerous bioinformatics resources. To address this new framework, several initiatives have tried to organize these services and resources. In this paper, we present the BioInformatics Resource Inventory (BIRI), a new approach for automatically discovering and indexing available public bioinformatics resources using information extracted from the scientific literature. The index generated can be automatically updated by adding additional manuscripts describing new resources. We have developed web services and applications to test and validate our approach. It has not been designed to replace current indexes but to extend their capabilities with richer functionalities. We developed a web service to provide a set of high-level query primitives to access the index. The web service can be used by third-party web services or web-based applications. To test the web service, we created a pilot web application to access a preliminary knowledge base of resources. We tested our tool using an initial set of 400 abstracts. Almost 90% of the resources described in the abstracts were correctly classified. More than 500 descriptions of functionalities were extracted. These experiments suggest the feasibility of our approach for automatically discovering and indexing current and future bioinformatics resources. Given the domain-independent characteristics of this tool, it is currently being applied by the authors in other areas, such as medical nanoinformatics. BIRI is available at http://edelman.dia.fi.upm.es/biri/.

Uncovering changes in spider orb-web topology owing to aerodynamic effects.

PubMed

Zaera, Ramón; Soler, Alejandro; Teus, Jaime

2014-09-06

An orb-weaving spider's likelihood of survival is influenced by its ability to retain prey with minimum damage to its web and at the lowest manufacturing cost. This set of requirements has forced the spider silk to evolve towards extreme strength and ductility to a degree that is rare among materials. Previous studies reveal that the performance of the web upon impact may not be based on the mechanical properties of silk alone, aerodynamic drag could play a role in the dissipation of the prey's energy. Here, we present a thorough analysis of the effect of the aerodynamic drag on wind load and prey impact. The hypothesis considered by previous authors for the evaluation of the drag force per unit length of thread has been revisited according to well-established principles of fluid mechanics, highlighting the functional dependence on thread diameter that was formerly ignored. Theoretical analysis and finite-element simulations permitted us to identify air drag as a relevant factor in reducing deterioration of the orb web, and to reveal how the spider can take greater-and not negligible-advantage of drag dissipation. The study shows the beneficial air drag effects of building smaller and less dense webs under wind load, and larger and denser webs under prey impact loads. In essence, it points out why the aerodynamics need to be considered as an additional driving force in the evolution of silk threads and orb webs. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Designing Effective Online Instruction: A Handbook for Web-Based Courses

ERIC Educational Resources Information Center

Koontz, Franklin R.; Li, Hongqin; Compora, Daniel P.

2006-01-01

The designing of online courses requires a radical change in the way the instruction is designed and presented to the student. To date, however, there are no research-based models, using a systems approach, that are available to design Web-based instruction. This book introduces the ASSIST-ME Model, an instructional design model for Web-based…

Applying Constructivist and Objectivist Learning Theories in the Design of a Web-based Course: Implications for Practice.

ERIC Educational Resources Information Center

Moallem, Mahnaz

2001-01-01

Provides an overview of the process of designing and developing a Web-based course using instructional design principles and models, including constructivist and objectivist theories. Explains the process of implementing an instructional design model in designing a Web-based undergraduate course and evaluates the model based on course evaluations.…

Typologies of Cohabitation: Implications for Clinical Practice and Research

ERIC Educational Resources Information Center

Gold, Joshua M.

2012-01-01

This article will explore the current evolution in the practice of cohabitation. The intent of this literature- and web-based article is to acquaint counselors with three typologies of cohabitation. These categories can be utilized in the development of psychoeducational and remedial interventions and in the identification of areas of future…

The ChemViz Project: Using a Supercomputer To Illustrate Abstract Concepts in Chemistry.

ERIC Educational Resources Information Center

Beckwith, E. Kenneth; Nelson, Christopher

1998-01-01

Describes the Chemistry Visualization (ChemViz) Project, a Web venture maintained by the University of Illinois National Center for Supercomputing Applications (NCSA) that enables high school students to use computational chemistry as a technique for understanding abstract concepts. Discusses the evolution of computational chemistry and provides a…

Using the Internet in Rural Special Education: Accessing Resources.

ERIC Educational Resources Information Center

Bull, Kay S.; Kimball, Sarah L.

This paper provides basic information on searching the Internet and describes sites of interest in the area of rural special education. The first section traces the evolution of the Internet through various phases--ARPANET, NSFNET, CERNET, and the beginnings of the World Wide Web--and describes various protocols (methods and tools) developed to…

Hypercat: A Database for Extragalactic Astronomy

NASA Astrophysics Data System (ADS)

Prugniel, Ph.; Maubon, G.

The Hypercat Database is developed at Observatoire de Lyon and is distributed on the WEB(www-obs.univ-lyon1.fr/hypercat) through different mirrors in Europe. The goal of Hypercat is to gather data necessary for studying the evolution of galaxies (dynamics and stellar contains) and particularly for providing a z = 0 reference for these studies.

Computers and Teaching: Evolution of a Cyberclass.

ERIC Educational Resources Information Center

Young, Jerome

1998-01-01

Addresses the role of technology in higher education outlining the various steps in creating a cyberclass: (1) provide access to Web sites on general research; (2) create a class listserv and a FTP site for students to upload coursework; (3) provide access to the syllabus electronically; and (4) teach an entire course online. (CMK)

"The Evolution of e-Learning in the Context of 3D Virtual Worlds"

ERIC Educational Resources Information Center

Kotsilieris, Theodore; Dimopoulou, Nikoletta

2013-01-01

Information and Communication Technologies (ICT) offer new approaches towards knowledge acquisition and collaboration through distance learning processes. Web-based Learning Management Systems (LMS) have transformed the way that education is conducted nowadays. At the same time, the adoption of Virtual Worlds in the educational process is of great…

A Web-Based Monitoring System for Multidisciplinary Design Projects

NASA Technical Reports Server (NTRS)

Rogers, James L.; Salas, Andrea O.; Weston, Robert P.

1998-01-01

In today's competitive environment, both industry and government agencies are under pressure to reduce the time and cost of multidisciplinary design projects. New tools have been introduced to assist in this process by facilitating the integration of and communication among diverse disciplinary codes. One such tool, a framework for multidisciplinary computational environments, is defined as a hardware and software architecture that enables integration, execution, and communication among diverse disciplinary processes. An examination of current frameworks reveals weaknesses in various areas, such as sequencing, displaying, monitoring, and controlling the design process. The objective of this research is to explore how Web technology, integrated with an existing framework, can improve these areas of weakness. This paper describes a Web-based system that optimizes and controls the execution sequence of design processes; and monitors the project status and results. The three-stage evolution of the system with increasingly complex problems demonstrates the feasibility of this approach.

Health 2.0 and Implications for Nursing Education

PubMed Central

Nelson, Ramona

2012-01-01

Over the last 20 years the evolution of web browsers providing easy access to the Internet has initiated a revolution in access to healthcare related information for both healthcare providers and patients. This access has changed both the process used to deliver education and the content of the nursing education curriculum worldwide. Our amazing ability to access information around the world is referred as to Web 1.0. Web 2.0 moves beyond access to a world where users are interactively creating information. With the advent of Health 2.0 we are confronting a second revolution that is challenging all aspects of healthcare including all aspects of nursing. This paper explores the concept of Health 2.0, discusses a conceptual framework approach for integrating Health 2.0 content into the nursing curriculum, outlines examples of key concepts required in today’s nursing curriculum and identifies selected issues arising from the impact of Health 2.0. PMID:24199108

A Prototype Land Information Sensor Web: Design, Implementation and Implication for the SMAP Mission

NASA Astrophysics Data System (ADS)

Su, H.; Houser, P.; Tian, Y.; Geiger, J. K.; Kumar, S. V.; Gates, L.

2009-12-01

Land Surface Model (LSM) predictions are regular in time and space, but these predictions are influenced by errors in model structure, input variables, parameters and inadequate treatment of sub-grid scale spatial variability. Consequently, LSM predictions are significantly improved through observation constraints made in a data assimilation framework. Several multi-sensor satellites are currently operating which provide multiple global observations of the land surface, and its related near-atmospheric properties. However, these observations are not optimal for addressing current and future land surface environmental problems. To meet future earth system science challenges, NASA will develop constellations of smart satellites in sensor web configurations which provide timely on-demand data and analysis to users, and can be reconfigured based on the changing needs of science and available technology. A sensor web is more than a collection of satellite sensors. That means a sensor web is a system composed of multiple platforms interconnected by a communication network for the purpose of performing specific observations and processing data required to support specific science goals. Sensor webs can eclipse the value of disparate sensor components by reducing response time and increasing scientific value, especially when the two-way interaction between the model and the sensor web is enabled. The study of a prototype Land Information Sensor Web (LISW) is sponsored by NASA, trying to integrate the Land Information System (LIS) in a sensor web framework which allows for optimal 2-way information flow that enhances land surface modeling using sensor web observations, and in turn allows sensor web reconfiguration to minimize overall system uncertainty. This prototype is based on a simulated interactive sensor web, which is then used to exercise and optimize the sensor web modeling interfaces. The Land Information Sensor Web Service-Oriented Architecture (LISW-SOA) has been developed and it is the very first sensor web framework developed especially for the land surface studies. Synthetic experiments based on the LISW-SOA and the virtual sensor web provide a controlled environment in which to examine the end-to-end performance of the prototype, the impact of various sensor web design trade-offs and the eventual value of sensor webs for a particular prediction or decision support. In this paper, the design, implementation of the LISW-SOA and the implication for the Soil Moisture Active and Passive (SMAP) mission is presented. Particular attention is focused on examining the relationship between the economic investment on a sensor web (space and air borne, ground based) and the accuracy of the model predicted soil moisture, which can be achieved by using such sensor observations. The Study of Virtual Land Information Sensor Web (LISW) is expected to provide some necessary a priori knowledge for designing and deploying the next generation Global Earth Observing System of systems (GEOSS).

EdiPy: a resource to simulate the evolution of plant mitochondrial genes under the RNA editing.

PubMed

Picardi, Ernesto; Quagliariello, Carla

2006-02-01

EdiPy is an online resource appropriately designed to simulate the evolution of plant mitochondrial genes in a biologically realistic fashion. EdiPy takes into account the presence of sites subjected to RNA editing and provides multiple artificial alignments corresponding to both genomic and cDNA sequences. Each artificial data set can successively be submitted to main and widespread evolutionary and phylogenetic software packages such as PAUP, Phyml, PAML and Phylip. As an online bioinformatic resource, EdiPy is available at the following web page: http://biologia.unical.it/py_script/index.html.

Flow Webs: Mechanism and Architecture for the Implementation of Sensor Webs

NASA Astrophysics Data System (ADS)

Gorlick, M. M.; Peng, G. S.; Gasster, S. D.; McAtee, M. D.

2006-12-01

The sensor web is a distributed, federated infrastructure much like its predecessors, the internet and the world wide web. It will be a federation of many sensor webs, large and small, under many distinct spans of control, that loosely cooperates and share information for many purposes. Realistically, it will grow piecemeal as distinct, individual systems are developed and deployed, some expressly built for a sensor web while many others were created for other purposes. Therefore, the architecture of the sensor web is of fundamental import and architectural strictures that inhibit innovation, experimentation, sharing or scaling may prove fatal. Drawing upon the architectural lessons of the world wide web, we offer a novel system architecture, the flow web, that elevates flows, sequences of messages over a domain of interest and constrained in both time and space, to a position of primacy as a dynamic, real-time, medium of information exchange for computational services. The flow web captures; in a single, uniform architectural style; the conflicting demands of the sensor web including dynamic adaptations to changing conditions, ease of experimentation, rapid recovery from the failures of sensors and models, automated command and control, incremental development and deployment, and integration at multiple levels—in many cases, at different times. Our conception of sensor webs—dynamic amalgamations of sensor webs each constructed within a flow web infrastructure—holds substantial promise for earth science missions in general, and of weather, air quality, and disaster management in particular. Flow webs, are by philosophy, design and implementation a dynamic infrastructure that permits massive adaptation in real-time. Flows may be attached to and detached from services at will, even while information is in transit through the flow. This concept, flow mobility, permits dynamic integration of earth science products and modeling resources in response to real-time demands. Flows are the connective tissue of flow webs—massive computational engines organized as directed graphs whose nodes are semi-autonomous components and whose edges are flows. The individual components of a flow web may themselves be encapsulated flow webs. In other words, a flow web subgraph may be presented to a yet larger flow web as a single, seamless component. Flow webs, at all levels, may be edited and modified while still executing. Within a flow web individual components may be added, removed, started, paused, halted, reparameterized, or inspected. The topology of a flow web may be changed at will. Thus, flow webs exhibit an extraordinary degree of adaptivity and robustness as they are explicitly designed to be modified on the fly, an attribute well suited for dynamic model interactions in sensor webs. We describe our concept for a sensor web, implemented as a flow web, in the context of a wildfire disaster management system for the southern California region. Comprehensive wildfire management requires cooperation among multiple agencies. Flow webs allow agencies to share resources in exactly the manner they choose. We will explain how to employ flow webs and agents to integrate satellite remote sensing data, models, in-situ sensors, UAVs and other resources into a sensor web that interconnects organizations and their disaster management tools in a manner that simultaneously preserves their independence and builds upon the individual strengths of agency-specific models and data sources.

A verification strategy for web services composition using enhanced stacked automata model.

PubMed

Nagamouttou, Danapaquiame; Egambaram, Ilavarasan; Krishnan, Muthumanickam; Narasingam, Poonkuzhali

2015-01-01

Currently, Service-Oriented Architecture (SOA) is becoming the most popular software architecture of contemporary enterprise applications, and one crucial technique of its implementation is web services. Individual service offered by some service providers may symbolize limited business functionality; however, by composing individual services from different service providers, a composite service describing the intact business process of an enterprise can be made. Many new standards have been defined to decipher web service composition problem namely Business Process Execution Language (BPEL). BPEL provides an initial work for forming an Extended Markup Language (XML) specification language for defining and implementing business practice workflows for web services. The problems with most realistic approaches to service composition are the verification of composed web services. It has to depend on formal verification method to ensure the correctness of composed services. A few research works has been carried out in the literature survey for verification of web services for deterministic system. Moreover the existing models did not address the verification properties like dead transition, deadlock, reachability and safetyness. In this paper, a new model to verify the composed web services using Enhanced Stacked Automata Model (ESAM) has been proposed. The correctness properties of the non-deterministic system have been evaluated based on the properties like dead transition, deadlock, safetyness, liveness and reachability. Initially web services are composed using Business Process Execution Language for Web Service (BPEL4WS) and it is converted into ESAM (combination of Muller Automata (MA) and Push Down Automata (PDA)) and it is transformed into Promela language, an input language for Simple ProMeLa Interpreter (SPIN) tool. The model is verified using SPIN tool and the results revealed better recital in terms of finding dead transition and deadlock in contrast to the existing models.

Cosmic Web of Galaxies in the COMOS Field

NASA Astrophysics Data System (ADS)

Darvish, Behnam; Martin, Christopher D.; Mobasher, Bahram; Scoville, Nicholas; Sobral, David; COSMOS science Team

2017-01-01

We use a mass complete sample of galaxies with accurate photometric redshifts in the COSMOS field to estimate the density field and to extract the components of the cosmic web. The comic web extraction algorithm relies on the signs and the ratio of eigenvalues of the Hessian matrix and is enable to integrate the density field into clusters, filaments and the field. We show that at z < 0.8, the median star-formation rate in the cosmic web gradually declines from the field to clusters and this decline is especially sharp for satellite galaxies (~1 dex vs. ~0.4 dex for centrals). However, at z > 0.8, the trend flattens out. For star-forming galaxies only, the median star-formation rate declines by ~ 0.3-0.4 dex from the field to clusters for both satellites and centrals, only at z < 0.5. We argue that for satellite galaxies, the main role of the cosmic web environment is to control their star-forming/quiescent fraction, whereas for centrals, it is mainly to control their overall star-formation rate. Given these, we suggest that most satellite galaxies experience a rapid quenching mechanism as they fall from the field into clusters through the channel of filaments, whereas for central galaxies, it is mostly due to a slow quenching process. Our preliminary results highlight the importance of the large-scale cosmic web on the evolution of galaxies.

[Using web 2.0 technologies and social media for the nephrologist].

PubMed

Santoro, Eugenio; Quintaliani, Giuseppe

2013-01-01

New media tools such as web 2.0 are increasingly being used in the medical field. RSS feeds, podcasts, blogs, wikis, online social networks and social media have all been proposed as innovative tools for the education and updating of clinicians, nurses, other health workers and medical students because of their ease of access and widespread use. Nephrology is one of the medical fields where these technologies have been successfully applied. Medical journals such as the American Journal Kidney Diseases and the Journal of the American Society of Nephrology, and medical societies such as the American Society of Nephrology, are all using these new and powerful communication tools. In addition, blogs and social networks have been developed to allow physicians to distribute, share and comment medical material concerning issues related to nephrology and kidney disease, including images, videos, slides, scientific abstracts and clinical trials updates. This review provides background information on the evolution of both web 2.0 and the social media and describes some of the most interesting applications of web 2.0 and its correlated tools in the field of nephrology.

CartograTree: connecting tree genomes, phenotypes and environment.

PubMed

Vasquez-Gross, Hans A; Yu, John J; Figueroa, Ben; Gessler, Damian D G; Neale, David B; Wegrzyn, Jill L

2013-05-01

Today, researchers spend a tremendous amount of time gathering, formatting, filtering and visualizing data collected from disparate sources. Under the umbrella of forest tree biology, we seek to provide a platform and leverage modern technologies to connect biotic and abiotic data. Our goal is to provide an integrated web-based workspace that connects environmental, genomic and phenotypic data via geo-referenced coordinates. Here, we connect the genomic query web-based workspace, DiversiTree and a novel geographical interface called CartograTree to data housed on the TreeGenes database. To accomplish this goal, we implemented Simple Semantic Web Architecture and Protocol to enable the primary genomics database, TreeGenes, to communicate with semantic web services regardless of platform or back-end technologies. The novelty of CartograTree lies in the interactive workspace that allows for geographical visualization and engagement of high performance computing (HPC) resources. The application provides a unique tool set to facilitate research on the ecology, physiology and evolution of forest tree species. CartograTree can be accessed at: http://dendrome.ucdavis.edu/cartogratree. © 2013 Blackwell Publishing Ltd.

A User-centered Model for Web Site Design

PubMed Central

Kinzie, Mable B.; Cohn, Wendy F.; Julian, Marti F.; Knaus, William A.

2002-01-01

As the Internet continues to grow as a delivery medium for health information, the design of effective Web sites becomes increasingly important. In this paper, the authors provide an overview of one effective model for Web site design, a user-centered process that includes techniques for needs assessment, goal/task analysis, user interface design, and rapid prototyping. They detail how this approach was employed to design a family health history Web site, Health Heritage . This Web site helps patients record and maintain their family health histories in a secure, confidential manner. It also supports primary care physicians through analysis of health histories, identification of potential risks, and provision of health care recommendations. Visual examples of the design process are provided to show how the use of this model resulted in an easy-to-use Web site that is likely to meet user needs. The model is effective across diverse content arenas and is appropriate for applications in varied media. PMID:12087113

Marketing for a Web-Based Master's Degree Program in Light of Marketing Mix Model

ERIC Educational Resources Information Center

Pan, Cheng-Chang

2012-01-01

The marketing mix model was applied with a focus on Web media to re-strategize a Web-based Master's program in a southern state university in U.S. The program's existing marketing strategy was examined using the four components of the model: product, price, place, and promotion, in hopes to repackage the program (product) to prospective students…

A Generic Evaluation Model for Semantic Web Services

NASA Astrophysics Data System (ADS)

Shafiq, Omair

Semantic Web Services research has gained momentum over the last few Years and by now several realizations exist. They are being used in a number of industrial use-cases. Soon software developers will be expected to use this infrastructure to build their B2B applications requiring dynamic integration. However, there is still a lack of guidelines for the evaluation of tools developed to realize Semantic Web Services and applications built on top of them. In normal software engineering practice such guidelines can already be found for traditional component-based systems. Also some efforts are being made to build performance models for servicebased systems. Drawing on these related efforts in component-oriented and servicebased systems, we identified the need for a generic evaluation model for Semantic Web Services applicable to any realization. The generic evaluation model will help users and customers to orient their systems and solutions towards using Semantic Web Services. In this chapter, we have presented the requirements for the generic evaluation model for Semantic Web Services and further discussed the initial steps that we took to sketch such a model. Finally, we discuss related activities for evaluating semantic technologies.

Food web conceptual model

USGS Publications Warehouse

Hartman, Rosemary; Brown, Larry R.; Hobbs, Jim

2017-01-01

This chapter describes a general model of food webs within tidal wetlands and represents how physical features of the wetland affect the structure and function of the food web. This conceptual model focuses on how the food web provides support for (or may reduce support for) threatened fish species. This model is part of a suite of conceptual models designed to guide monitoring of restoration sites throughout the San Francisco Estuary (SFE), but particularly within the Sacramento-San Joaquin Delta (Delta) and Suisun Marsh. The conceptual models have been developed based on the Delta Regional Ecosystem Restoration Implementation Plan (DRERIP) models, and are designed to aid in the identification and evaluation of monitoring metrics for tidal wetland restoration projects. Many tidal restoration sites in the Delta are being constructed to comply with environmental regulatory requirements associated with the operation of the Central Valley Project and State Water Project. These include the Biological Opinions for Delta Smelt (Hypomesus transpacificus) and salmonids (U.S. Fish and Wildlife Service 2008; National Marine Fisheries Service 2009), and the Incidental Take Permit for Longfin Smelt (Spirinchus thaleichthyes) (California Department of Fish and Wildlife 2009). These regulatory requirements are based on the hypothesis that the decline of listed fish species is due in part to a decline in productivity of the food web (phytoplankton and zooplankton in particular) or alterations in the food web such that production is consumed by other species in the Estuary (Sommer et al. 2007; Baxter et al. 2010; Brown et al. 2016a). Intertidal wetlands and shallow subtidal habitat can be highly productive, so restoring areas of tidal wetlands may result in a net increase in productivity that will provide food web support for these fish species. However, other factors such as invasive bivalves that reduce phytoplankton and zooplankton biomass and invasive predatory fishes that may compete with or prey upon listed fishes can limit the utility of tidal wetlands for food web support (Lucas and Thompson 2012; Herbold et al. 2014). This model utilizes information from the previous DRERIP models for Delta food webs (Durand 2008) and tidal wetlands (Kneib et al. 2008), an updated DRERIP model (Durand 2015), and the State of BayDelta Science 2016 review of recent Delta food web literature (Brown et al. 2016a).

Complications of stent placement in patients with esophageal cancer: A systematic review and network meta-analysis

PubMed Central

Doosti-Irani, Amin; Mansournia, Mohammad Ali; Rahimi-Foroushani, Abbas; Haddad, Peiman

2017-01-01

Background Palliative treatments and stents are necessary for relieving dysphagia in patients with esophageal cancer. The aim of this study was to simultaneously compare available treatments in terms of complications. Methods Web of Science, Medline, Scopus, Cochrane Library and Embase were searched. Statistical heterogeneity was assessed using the Chi2 test and was quantified by I2. The results of this study were summarized in terms of Risk Ratio (RR). The random effects model was used to report the results. The rank probability for each treatment was calculated using the p-score. Results Out of 17855 references, 24 RCTs reported complications including treatment related death (TRD), bleeding, stent migration, aspiration, severe pain and fistula formation. In the ranking of treatments, thermal ablative therapy (p-score = 0.82), covered Evolution® stent (p-score = 0.70), brachytherapy (p-score = 0.72) and antireflux stent (p-score = 0.74) were better treatments in the network of TRD. Thermal ablative therapy (p-score = 0.86), the conventional stent (p-score = 0.62), covered Evolution® stent (p-score = 0.96) and brachytherapy (p-score = 0.82) were better treatments in the network of bleeding complications. Covered Evolution® (p-score = 0.78), uncovered (p-score = 0.88) and irradiation stents (p-score = 0.65) were better treatments in network of stent migration complications. In the network of severe pain, Conventional self-expandable nitinol alloy covered stent (p-score = 0.73), polyflex (p-score = 0.79), latex prosthesis (p-score = 0.96) and brachytherapy (p-score = 0.65) were better treatments. Conclusion According to our results, thermal ablative therapy, covered Evolution® stents, brachytherapy, and antireflux stents are associated with a lower risk of TRD. Moreover, thermal ablative therapy, conventional, covered Evolution® and brachytherapy had lower risks of bleeding. Overall, fewer complications were associated with covered Evolution® stent and brachytherapy. PMID:28968416

Service-oriented model-encapsulation strategy for sharing and integrating heterogeneous geo-analysis models in an open web environment

NASA Astrophysics Data System (ADS)

Yue, Songshan; Chen, Min; Wen, Yongning; Lu, Guonian

2016-04-01

Earth environment is extremely complicated and constantly changing; thus, it is widely accepted that the use of a single geo-analysis model cannot accurately represent all details when solving complex geo-problems. Over several years of research, numerous geo-analysis models have been developed. However, a collaborative barrier between model providers and model users still exists. The development of cloud computing has provided a new and promising approach for sharing and integrating geo-analysis models across an open web environment. To share and integrate these heterogeneous models, encapsulation studies should be conducted that are aimed at shielding original execution differences to create services which can be reused in the web environment. Although some model service standards (such as Web Processing Service (WPS) and Geo Processing Workflow (GPW)) have been designed and developed to help researchers construct model services, various problems regarding model encapsulation remain. (1) The descriptions of geo-analysis models are complicated and typically require rich-text descriptions and case-study illustrations, which are difficult to fully represent within a single web request (such as the GetCapabilities and DescribeProcess operations in the WPS standard). (2) Although Web Service technologies can be used to publish model services, model users who want to use a geo-analysis model and copy the model service into another computer still encounter problems (e.g., they cannot access the model deployment dependencies information). This study presents a strategy for encapsulating geo-analysis models to reduce problems encountered when sharing models between model providers and model users and supports the tasks with different web service standards (e.g., the WPS standard). A description method for heterogeneous geo-analysis models is studied. Based on the model description information, the methods for encapsulating the model-execution program to model services and for describing model-service deployment information are also included in the proposed strategy. Hence, the model-description interface, model-execution interface and model-deployment interface are studied to help model providers and model users more easily share, reuse and integrate geo-analysis models in an open web environment. Finally, a prototype system is established, and the WPS standard is employed as an example to verify the capability and practicability of the model-encapsulation strategy. The results show that it is more convenient for modellers to share and integrate heterogeneous geo-analysis models in cloud computing platforms.

Predictive power of food web models based on body size decreases with trophic complexity.

PubMed

Jonsson, Tomas; Kaartinen, Riikka; Jonsson, Mattias; Bommarco, Riccardo

2018-05-01

Food web models parameterised using body size show promise to predict trophic interaction strengths (IS) and abundance dynamics. However, this remains to be rigorously tested in food webs beyond simple trophic modules, where indirect and intraguild interactions could be important and driven by traits other than body size. We systematically varied predator body size, guild composition and richness in microcosm insect webs and compared experimental outcomes with predictions of IS from models with allometrically scaled parameters. Body size was a strong predictor of IS in simple modules (r 2  = 0.92), but with increasing complexity the predictive power decreased, with model IS being consistently overestimated. We quantify the strength of observed trophic interaction modifications, partition this into density-mediated vs. behaviour-mediated indirect effects and show that model shortcomings in predicting IS is related to the size of behaviour-mediated effects. Our findings encourage development of dynamical food web models explicitly including and exploring indirect mechanisms. © 2018 John Wiley & Sons Ltd/CNRS.

Modeling Traffic on the Web Graph

NASA Astrophysics Data System (ADS)

Meiss, Mark R.; Gonçalves, Bruno; Ramasco, José J.; Flammini, Alessandro; Menczer, Filippo

Analysis of aggregate and individual Web requests shows that PageRank is a poor predictor of traffic. We use empirical data to characterize properties of Web traffic not reproduced by Markovian models, including both aggregate statistics such as page and link traffic, and individual statistics such as entropy and session size. As no current model reconciles all of these observations, we present an agent-based model that explains them through realistic browsing behaviors: (1) revisiting bookmarked pages; (2) backtracking; and (3) seeking out novel pages of topical interest. The resulting model can reproduce the behaviors we observe in empirical data, especially heterogeneous session lengths, reconciling the narrowly focused browsing patterns of individual users with the extreme variance in aggregate traffic measurements. We can thereby identify a few salient features that are necessary and sufficient to interpret Web traffic data. Beyond the descriptive and explanatory power of our model, these results may lead to improvements in Web applications such as search and crawling.

Web malware spread modelling and optimal control strategies

NASA Astrophysics Data System (ADS)

Liu, Wanping; Zhong, Shouming

2017-02-01

The popularity of the Web improves the growth of web threats. Formulating mathematical models for accurate prediction of malicious propagation over networks is of great importance. The aim of this paper is to understand the propagation mechanisms of web malware and the impact of human intervention on the spread of malicious hyperlinks. Considering the characteristics of web malware, a new differential epidemic model which extends the traditional SIR model by adding another delitescent compartment is proposed to address the spreading behavior of malicious links over networks. The spreading threshold of the model system is calculated, and the dynamics of the model is theoretically analyzed. Moreover, the optimal control theory is employed to study malware immunization strategies, aiming to keep the total economic loss of security investment and infection loss as low as possible. The existence and uniqueness of the results concerning the optimality system are confirmed. Finally, numerical simulations show that the spread of malware links can be controlled effectively with proper control strategy of specific parameter choice.

Web malware spread modelling and optimal control strategies.

PubMed

Liu, Wanping; Zhong, Shouming

2017-02-10

The popularity of the Web improves the growth of web threats. Formulating mathematical models for accurate prediction of malicious propagation over networks is of great importance. The aim of this paper is to understand the propagation mechanisms of web malware and the impact of human intervention on the spread of malicious hyperlinks. Considering the characteristics of web malware, a new differential epidemic model which extends the traditional SIR model by adding another delitescent compartment is proposed to address the spreading behavior of malicious links over networks. The spreading threshold of the model system is calculated, and the dynamics of the model is theoretically analyzed. Moreover, the optimal control theory is employed to study malware immunization strategies, aiming to keep the total economic loss of security investment and infection loss as low as possible. The existence and uniqueness of the results concerning the optimality system are confirmed. Finally, numerical simulations show that the spread of malware links can be controlled effectively with proper control strategy of specific parameter choice.

Web malware spread modelling and optimal control strategies

PubMed Central

Liu, Wanping; Zhong, Shouming

2017-01-01

The popularity of the Web improves the growth of web threats. Formulating mathematical models for accurate prediction of malicious propagation over networks is of great importance. The aim of this paper is to understand the propagation mechanisms of web malware and the impact of human intervention on the spread of malicious hyperlinks. Considering the characteristics of web malware, a new differential epidemic model which extends the traditional SIR model by adding another delitescent compartment is proposed to address the spreading behavior of malicious links over networks. The spreading threshold of the model system is calculated, and the dynamics of the model is theoretically analyzed. Moreover, the optimal control theory is employed to study malware immunization strategies, aiming to keep the total economic loss of security investment and infection loss as low as possible. The existence and uniqueness of the results concerning the optimality system are confirmed. Finally, numerical simulations show that the spread of malware links can be controlled effectively with proper control strategy of specific parameter choice. PMID:28186203

Incorporating food web dynamics into ecological restoration: A modeling approach for river ecosystems

USGS Publications Warehouse

Bellmore, J. Ryan; Benjamin, Joseph R.; Newsom, Michael; Bountry, Jennifer A.; Dombroski, Daniel

2017-01-01

Restoration is frequently aimed at the recovery of target species, but also influences the larger food web in which these species participate. Effects of restoration on this broader network of organisms can influence target species both directly and indirectly via changes in energy flow through food webs. To help incorporate these complexities into river restoration planning we constructed a model that links river food web dynamics to in-stream physical habitat and riparian vegetation conditions. We present an application of the model to the Methow River, Washington (USA), a location of on-going restoration aimed at recovering salmon. Three restoration strategies were simulated: riparian vegetation restoration, nutrient augmentation via salmon carcass addition, and side-channel reconnection. We also added populations of nonnative aquatic snails and fish to the modeled food web to explore how changes in food web structure mediate responses to restoration. Simulations suggest that side-channel reconnection may be a better strategy than carcass addition and vegetation planting for improving conditions for salmon in this river segment. However, modeled responses were strongly sensitive to changes in the structure of the food web. The addition of nonnative snails and fish modified pathways of energy through the food web, which negated restoration improvements. This finding illustrates that forecasting responses to restoration may require accounting for the structure of food webs, and that changes in this structure—as might be expected with the spread of invasive species—could compromise restoration outcomes. Unlike habitat-based approaches to restoration assessment that focus on the direct effects of physical habitat conditions on single species of interest, our approach dynamically links the success of target organisms to the success of competitors, predators, and prey. By elucidating the direct and indirect pathways by which restoration affects target species, dynamic food web models can improve restoration planning by fostering a deeper understanding of system connectedness and dynamics.

Java 3D Interactive Visualization for Astrophysics

NASA Astrophysics Data System (ADS)

Chae, K.; Edirisinghe, D.; Lingerfelt, E. J.; Guidry, M. W.

2003-05-01

We are developing a series of interactive 3D visualization tools that employ the Java 3D API. We have applied this approach initially to a simple 3-dimensional galaxy collision model (restricted 3-body approximation), with quite satisfactory results. Running either as an applet under Web browser control, or as a Java standalone application, this program permits real-time zooming, panning, and 3-dimensional rotation of the galaxy collision simulation under user mouse and keyboard control. We shall also discuss applications of this technology to 3-dimensional visualization for other problems of astrophysical interest such as neutron star mergers and the time evolution of element/energy production networks in X-ray bursts. *Managed by UT-Battelle, LLC, for the U.S. Department of Energy under contract DE-AC05-00OR22725.

The impact of web services at the IRIS DMC

NASA Astrophysics Data System (ADS)

Weekly, R. T.; Trabant, C. M.; Ahern, T. K.; Stults, M.; Suleiman, Y. Y.; Van Fossen, M.; Weertman, B.

2015-12-01

The IRIS Data Management Center (DMC) has served the seismological community for nearly 25 years. In that time we have offered data and information from our archive using a variety of mechanisms ranging from email-based to desktop applications to web applications and web services. Of these, web services have quickly become the primary method for data extraction at the DMC. In 2011, the first full year of operation, web services accounted for over 40% of the data shipped from the DMC. In 2014, over ~450 TB of data was delivered directly to users through web services, representing nearly 70% of all shipments from the DMC that year. In addition to handling requests directly from users, the DMC switched all data extraction methods to use web services in 2014. On average the DMC now handles between 10 and 20 million requests per day submitted to web service interfaces. The rapid adoption of web services is attributed to the many advantages they bring. For users, they provide on-demand data using an interface technology, HTTP, that is widely supported in nearly every computing environment and language. These characteristics, combined with human-readable documentation and existing tools make integration of data access into existing workflows relatively easy. For the DMC, the web services provide an abstraction layer to internal repositories allowing for concentrated optimization of extraction workflow and easier evolution of those repositories. Lending further support to DMC's push in this direction, the core web services for station metadata, timeseries data and event parameters were adopted as standards by the International Federation of Digital Seismograph Networks (FDSN). We expect to continue enhancing existing services and building new capabilities for this platform. For example, the DMC has created a federation system and tools allowing researchers to discover and collect seismic data from data centers running the FDSN-standardized services. A future capability will leverage the DMC's MUSTANG project to select data based on data quality measurements. Within five years, the DMC's web services have proven to be a robust and flexible platform that enables continued growth for the DMC. We expect continued enhancements and adoption of web services.

Environmental Models as a Service: Enabling Interoperability ...

EPA Pesticide Factsheets

Achieving interoperability in environmental modeling has evolved as software technology has progressed. The recent rise of cloud computing and proliferation of web services initiated a new stage for creating interoperable systems. Scientific programmers increasingly take advantage of streamlined deployment processes and affordable cloud access to move algorithms and data to the web for discoverability and consumption. In these deployments, environmental models can become available to end users through RESTful web services and consistent application program interfaces (APIs) that consume, manipulate, and store modeling data. RESTful modeling APIs also promote discoverability and guide usability through self-documentation. Embracing the RESTful paradigm allows models to be accessible via a web standard, and the resulting endpoints are platform- and implementation-agnostic while simultaneously presenting significant computational capabilities for spatial and temporal scaling. RESTful APIs present data in a simple verb-noun web request interface: the verb dictates how a resource is consumed using HTTP methods (e.g., GET, POST, and PUT) and the noun represents the URL reference of the resource on which the verb will act. The RESTful API can self-document in both the HTTP response and an interactive web page using the Open API standard. This lets models function as an interoperable service that promotes sharing, documentation, and discoverability. Here, we discuss the

A Web-based Visualization System for Three Dimensional Geological Model using Open GIS

NASA Astrophysics Data System (ADS)

Nemoto, T.; Masumoto, S.; Nonogaki, S.

2017-12-01

A three dimensional geological model is an important information in various fields such as environmental assessment, urban planning, resource development, waste management and disaster mitigation. In this study, we have developed a web-based visualization system for 3D geological model using free and open source software. The system has been successfully implemented by integrating web mapping engine MapServer and geographic information system GRASS. MapServer plays a role of mapping horizontal cross sections of 3D geological model and a topographic map. GRASS provides the core components for management, analysis and image processing of the geological model. Online access to GRASS functions has been enabled using PyWPS that is an implementation of WPS (Web Processing Service) Open Geospatial Consortium (OGC) standard. The system has two main functions. Two dimensional visualization function allows users to generate horizontal and vertical cross sections of 3D geological model. These images are delivered via WMS (Web Map Service) and WPS OGC standards. Horizontal cross sections are overlaid on the topographic map. A vertical cross section is generated by clicking a start point and an end point on the map. Three dimensional visualization function allows users to visualize geological boundary surfaces and a panel diagram. The user can visualize them from various angles by mouse operation. WebGL is utilized for 3D visualization. WebGL is a web technology that brings hardware-accelerated 3D graphics to the browser without installing additional software. The geological boundary surfaces can be downloaded to incorporate the geologic structure in a design on CAD and model for various simulations. This study was supported by JSPS KAKENHI Grant Number JP16K00158.

Analyzing depression tendency of web posts using an event-driven depression tendency warning model.

PubMed

Tung, Chiaming; Lu, Wenhsiang

2016-01-01

The Internet has become a platform to express individual moods/feelings of daily life, where authors share their thoughts in web blogs, micro-blogs, forums, bulletin board systems or other media. In this work, we investigate text-mining technology to analyze and predict the depression tendency of web posts. In this paper, we defined depression factors, which include negative events, negative emotions, symptoms, and negative thoughts from web posts. We proposed an enhanced event extraction (E3) method to automatically extract negative event terms. In addition, we also proposed an event-driven depression tendency warning (EDDTW) model to predict the depression tendency of web bloggers or post authors by analyzing their posted articles. We compare the performance among the proposed EDDTW model, negative emotion evaluation (NEE) model, and the diagnostic and statistical manual of mental disorders-based depression tendency evaluation method. The EDDTW model obtains the best recall rate and F-measure at 0.668 and 0.624, respectively, while the diagnostic and statistical manual of mental disorders-based method achieves the best precision rate of 0.666. The main reason is that our enhanced event extraction method can increase recall rate by enlarging the negative event lexicon at the expense of precision. Our EDDTW model can also be used to track the change or trend of depression tendency for each post author. The depression tendency trend can help doctors to diagnose and even track depression of web post authors more efficiently. This paper presents an E3 method to automatically extract negative event terms in web posts. We also proposed a new EDDTW model to predict the depression tendency of web posts and possibly help bloggers or post authors to early detect major depressive disorder. Copyright © 2015 Elsevier B.V. All rights reserved.

Model My Watershed and BiG CZ Data Portal: Interactive geospatial analysis and hydrological modeling web applications that leverage the Amazon cloud for scientists, resource managers and students

NASA Astrophysics Data System (ADS)

Aufdenkampe, A. K.; Mayorga, E.; Tarboton, D. G.; Sazib, N. S.; Horsburgh, J. S.; Cheetham, R.

2016-12-01

The Model My Watershed Web app (http://wikiwatershed.org/model/) was designed to enable citizens, conservation practitioners, municipal decision-makers, educators, and students to interactively select any area of interest anywhere in the continental USA to: (1) analyze real land use and soil data for that area; (2) model stormwater runoff and water-quality outcomes; and (3) compare how different conservation or development scenarios could modify runoff and water quality. The BiG CZ Data Portal is a web application for scientists for intuitive, high-performance map-based discovery, visualization, access and publication of diverse earth and environmental science data via a map-based interface that simultaneously performs geospatial analysis of selected GIS and satellite raster data for a selected area of interest. The two web applications share a common codebase (https://github.com/WikiWatershed and https://github.com/big-cz), high performance geospatial analysis engine (http://geotrellis.io/ and https://github.com/geotrellis) and deployment on the Amazon Web Services (AWS) cloud cyberinfrastructure. Users can use "on-the-fly" rapid watershed delineation over the national elevation model to select their watershed or catchment of interest. The two web applications also share the goal of enabling the scientists, resource managers and students alike to share data, analyses and model results. We will present these functioning web applications and their potential to substantially lower the bar for studying and understanding our water resources. We will also present work in progress, including a prototype system for enabling citizen-scientists to register open-source sensor stations (http://envirodiy.org/mayfly/) to stream data into these systems, so that they can be reshared using Water One Flow web services.

Trophic dilution of cyclic volatile methylsiloxanes (cVMS) in the pelagic marine food web of Tokyo Bay, Japan.

PubMed

Powell, David E; Suganuma, Noriyuki; Kobayashi, Keiji; Nakamura, Tsutomu; Ninomiya, Kouzo; Matsumura, Kozaburo; Omura, Naoki; Ushioka, Satoshi

2017-02-01

Bioaccumulation and trophic transfer of cyclic volatile methylsiloxanes (cVMS), specifically octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6), were evaluated in the pelagic marine food web of Tokyo Bay, Japan. Polychlorinated biphenyl (PCB) congeners that are "legacy" chemicals known to bioaccumulate in aquatic organisms and biomagnify across aquatic food webs were used as a benchmark chemical (CB-180) to calibrate the sampled food web and as a reference chemical (CB-153) to validate the results. Trophic magnification factors (TMFs) were calculated from slopes of ordinary least-squares (OLS) regression models and slopes of bootstrap regression models, which were used as robust alternatives to the OLS models. Various regression models were developed that incorporated benchmarking to control bias associated with experimental design, food web dynamics, and trophic level structure. There was no evidence from any of the regression models to suggest biomagnification of cVMS in Tokyo Bay. Rather, the regression models indicated that trophic dilution of cVMS, not trophic magnification, occurred across the sampled food web. Comparison of results for Tokyo Bay to results from other studies indicated that bioaccumulation of cVMS was not related to type of food web (pelagic vs demersal), environment (marine vs freshwater), species composition, or location. Rather, results suggested that differences between study areas was likely related to food web dynamics and variable conditions of exposure resulting from non-uniform patterns of organism movement across spatial concentration gradients. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

An Analysis of Web Image Queries for Search.

ERIC Educational Resources Information Center

Pu, Hsiao-Tieh

2003-01-01

Examines the differences between Web image and textual queries, and attempts to develop an analytic model to investigate their implications for Web image retrieval systems. Provides results that give insight into Web image searching behavior and suggests implications for improvement of current Web image search engines. (AEF)

Tethys: A Platform for Water Resources Modeling and Decision Support Apps

NASA Astrophysics Data System (ADS)

Nelson, J.; Swain, N. R.

2015-12-01

The interactive nature of web applications or "web apps" makes it an excellent medium for conveying complex scientific concepts to lay audiences and creating decision support tools that harness cutting edge modeling techniques. However, the technical expertise required to develop web apps represents a barrier for would-be developers. This barrier can be characterized by the following hurdles that developers must overcome: (1) identify, select, and install software that meet the spatial and computational capabilities commonly required for water resources modeling; (2) orchestrate the use of multiple free and open source (FOSS) projects and navigate their differing application programming interfaces; (3) learn the multi-language programming skills required for modern web development; and (4) develop a web-secure and fully featured web portal to host the app. Tethys Platform has been developed to lower the technical barrier and minimize the initial development investment that prohibits many scientists and engineers from making use of the web app medium. It includes (1) a suite of FOSS that address the unique data and computational needs common to water resources web app development, (2) a Python software development kit that streamlines development, and (3) a customizable web portal that is used to deploy the completed web apps. Tethys synthesizes several software projects including PostGIS, 52°North WPS, GeoServer, Google Maps™, OpenLayers, and Highcharts. It has been used to develop a broad array of web apps for water resources modeling and decision support for several projects including CI-WATER, HydroShare, and the National Flood Interoperability Experiment. The presentation will include live demos of some of the apps that have been developed using Tethys to demonstrate its capabilities.

Distributed run of a one-dimensional model in a regional application using SOAP-based web services

NASA Astrophysics Data System (ADS)

Smiatek, Gerhard

This article describes the setup of a distributed computing system in Perl. It facilitates the parallel run of a one-dimensional environmental model on a number of simple network PC hosts. The system uses Simple Object Access Protocol (SOAP) driven web services offering the model run on remote hosts and a multi-thread environment distributing the work and accessing the web services. Its application is demonstrated in a regional run of a process-oriented biogenic emission model for the area of Germany. Within a network consisting of up to seven web services implemented on Linux and MS-Windows hosts, a performance increase of approximately 400% has been reached compared to a model run on the fastest single host.

The Virtual Learning Commons (VLC): Enabling Co-Innovation Across Disciplines

NASA Astrophysics Data System (ADS)

Pennington, D. D.; Gandara, A.; Del Rio, N.

2014-12-01

A key challenge for scientists addressing grand-challenge problems is identifying, understanding, and integrating potentially relevant methods, models and tools that that are rapidly evolving in the informatics community. Such tools are essential for effectively integrating data and models in complex research projects, yet it is often difficult to know what tools are available and it is not easy to understand or evaluate how they might be used in a given research context. The goal of the National Science Foundation-funded Virtual Learning Commons (VLC) is to improve awareness and understanding of emerging methodologies and technologies, facilitate individual and group evaluation of these, and trace the impact of innovations within and across teams, disciplines, and communities. The VLC is a Web-based social bookmarking site designed specifically to support knowledge exchange in research communities. It is founded on well-developed models of technology adoption, diffusion of innovation, and experiential learning. The VLC makes use of Web 2.0 (Social Web) and Web 3.0 (Semantic Web) approaches. Semantic Web approaches enable discovery of potentially relevant methods, models, and tools, while Social Web approaches enable collaborative learning about their function. The VLC is under development and the first release is expected Fall 2014.

Optics of spider "sticky" orb webs

NASA Astrophysics Data System (ADS)

Kane, Deb M.; Staib, Gregory R.; Naidoo, Nishen; Little, Douglas J.; Herberstein, Marie E.

2011-04-01

Spider orb webs are known to produce colour displays in nature, both in reflection and transmission of sunlight, under certain illumination conditions. The cause of these colours has been the subject of speculation since the time of Newton. It has also been the topic of observational interpretation and some experiment which has proposed diffraction by the fine silks, scattering from rough/structured surfaces and thin film effects as the primary causes. We report systematic studies carried out using the silks of Australian orb web weaving spiders. Studies of both white light and laser light scattering/propagation by natural spider silks have definitively determined the primary cause of the colour displays is rainbows that can be understood by the application of geometric optics combined with new knowledge of the optical properties of the spider web strands, silks, and proteins as optical materials. Additionally, a range of microscopies (optical, AFM, optical surface profiling) show the silks to be optically flat. Overall, spider silks emerge as fascinating optical materials with high dispersion, high birefringence and the potential for future research to show they have high nonlinear optical coefficients. Their importance as a bioinspiration in optics is only just beginning to be realised. Their special optical properties have been achieved by ~136 million years of evolution driven by the need for the web to evade detection by insect prey.

An Ontology of Quality Initiatives and a Model for Decentralized, Collaborative Quality Management on the (Semantic) World Wide Web

PubMed Central

2001-01-01

This editorial provides a model of how quality initiatives concerned with health information on the World Wide Web may in the future interact with each other. This vision fits into the evolving "Semantic Web" architecture - ie, the prospective that the World Wide Web may evolve from a mess of unstructured, human-readable information sources into a global knowledge base with an additional layer providing richer and more meaningful relationships between resources. One first prerequisite for forming such a "Semantic Web" or "web of trust" among the players active in quality management of health information is that these initiatives make statements about themselves and about each other in a machine-processable language. I present a concrete model on how this collaboration could look, and provide some recommendations on what the role of the World Health Organization (WHO) and other policy makers in this framework could be. PMID:11772549

An ontology of quality initiatives and a model for decentralized, collaborative quality management on the (semantic) World-Wide-Web.

PubMed

Eysenbach, G

2001-01-01

This editorial provides a model of how quality initiatives concerned with health information on the World Wide Web may in the future interact with each other. This vision fits into the evolving "Semantic Web" architecture - ie, the prospective that the World Wide Web may evolve from a mess of unstructured, human-readable information sources into a global knowledge base with an additional layer providing richer and more meaningful relationships between resources. One first prerequisite for forming such a "Semantic Web" or "web of trust" among the players active in quality management of health information is that these initiatives make statements about themselves and about each other in a machine-processable language. I present a concrete model on how this collaboration could look, and provide some recommendations on what the role of the World Health Organization (WHO) and other policy makers in this framework could be.

Evaluation of physical activity web sites for use of behavior change theories.

PubMed

Doshi, Amol; Patrick, Kevin; Sallis, James F; Calfas, Karen

2003-01-01

Physical activity (PA) Web sites were assessed for their use of behavior change theories, including constructs of the health belief model, Transtheoretical Model, social cognitive theory, and the theory of reasoned action and planned behavior. An evaluation template for assessing PA Web sites was developed, and content validity and interrater reliability were demonstrated. Two independent raters evaluated 24 PA Web sites. Web sites varied widely in application of theory-based constructs, ranging from 5 to 48 on a 100-point scale. The most common intervention strategies were general information, social support, and realistic goal areas. Coverage of theory-based strategies was low, varying from 26% for social cognitive theory to 39% for health belief model. Overall, PA Web sites provided little assessment, feedback, or individually tailored assistance for users. They were unable to substantially tailor the on-line experience for users at different stages of change or different demographic characteristics.

Marketing Opportunities in the Digital World.

ERIC Educational Resources Information Center

Kiani, G. Reza

1998-01-01

Addresses the opportunities offered by the Web to marketers. Considers the Web as a two-way communication model in which four different communication states can take place. Suggests the necessity of new concepts and models for marketers to manage their Web sites, and presents opportunities supporting the marketers' objectives in the new…

The World-Wide Web and Mosaic: An Overview for Librarians.

ERIC Educational Resources Information Center

Morgan, Eric Lease

1994-01-01

Provides an overview of the Internet's World-Wide Web (Web), a hypertext system. Highlights include the client/server model; Uniform Resource Locator; examples of software; Web servers versus Gopher servers; HyperText Markup Language (HTML); converting files; Common Gateway Interface; organizing Web information; and the role of librarians in…

Dynamic Web Pages: Performance Impact on Web Servers.

ERIC Educational Resources Information Center

Kothari, Bhupesh; Claypool, Mark

2001-01-01

Discussion of Web servers and requests for dynamic pages focuses on experimentally measuring and analyzing the performance of the three dynamic Web page generation technologies: CGI, FastCGI, and Servlets. Develops a multivariate linear regression model and predicts Web server performance under some typical dynamic requests. (Author/LRW)

Web tools for predictive toxicology model building.

PubMed

Jeliazkova, Nina

2012-07-01

The development and use of web tools in chemistry has accumulated more than 15 years of history already. Powered by the advances in the Internet technologies, the current generation of web systems are starting to expand into areas, traditional for desktop applications. The web platforms integrate data storage, cheminformatics and data analysis tools. The ease of use and the collaborative potential of the web is compelling, despite the challenges. The topic of this review is a set of recently published web tools that facilitate predictive toxicology model building. The focus is on software platforms, offering web access to chemical structure-based methods, although some of the frameworks could also provide bioinformatics or hybrid data analysis functionalities. A number of historical and current developments are cited. In order to provide comparable assessment, the following characteristics are considered: support for workflows, descriptor calculations, visualization, modeling algorithms, data management and data sharing capabilities, availability of GUI or programmatic access and implementation details. The success of the Web is largely due to its highly decentralized, yet sufficiently interoperable model for information access. The expected future convergence between cheminformatics and bioinformatics databases provides new challenges toward management and analysis of large data sets. The web tools in predictive toxicology will likely continue to evolve toward the right mix of flexibility, performance, scalability, interoperability, sets of unique features offered, friendly user interfaces, programmatic access for advanced users, platform independence, results reproducibility, curation and crowdsourcing utilities, collaborative sharing and secure access.

Web Mining for Web Image Retrieval.

ERIC Educational Resources Information Center

Chen, Zheng; Wenyin, Liu; Zhang, Feng; Li, Mingjing; Zhang, Hongjiang

2001-01-01

Presents a prototype system for image retrieval from the Internet using Web mining. Discusses the architecture of the Web image retrieval prototype; document space modeling; user log mining; and image retrieval experiments to evaluate the proposed system. (AEF)

What do patients know about their low back pain? An analysis of the quality of information available on the Internet.

PubMed

Galbusera, Fabio; Brayda-Bruno, Marco; Freutel, Maren; Seitz, Andreas; Steiner, Malte; Wehrle, Esther; Wilke, Hans-Joachim

2012-01-01

Previous surveys showed a poor quality of the web sites providing health information about low back pain. However, the rapid and continuous evolution of the Internet content may question the current validity of those investigations. The present study is aimed to quantitatively assess the quality of the Internet information about low back pain retrieved with the most commonly employed search engines. An Internet search with the keywords "low back pain" has been performed with Google, Yahoo!® and Bing™ in the English language. The top 30 hits obtained with each search engine were evaluated by five independent raters and averaged following criteria derived from previous works. All search results were categorized as declaring compliant to a quality standard for health information (e.g. HONCode) or not and based on the web site type (Institutional, Free informative, Commercial, News, Social Network, Unknown). The quality of the hits retrieved by the three search engines was extremely similar. The web sites had a clear purpose, were easy to navigate, and mostly lacked in validity and quality of the provided links. The conformity to a quality standard was correlated with a marked greater quality of the web sites in all respects. Institutional web sites had the best validity and ease of use. Free informative web sites had good quality but a markedly lower validity compared to Institutional websites. Commercial web sites provided more biased information. News web sites were well designed and easy to use, but lacked in validity. The average quality of the hits retrieved by the most commonly employed search engines could be defined as satisfactory and favorably comparable with previous investigations. Awareness of the user about checking the quality of the information remains of concern.

BioModels.net Web Services, a free and integrated toolkit for computational modelling software.

PubMed

Li, Chen; Courtot, Mélanie; Le Novère, Nicolas; Laibe, Camille

2010-05-01

Exchanging and sharing scientific results are essential for researchers in the field of computational modelling. BioModels.net defines agreed-upon standards for model curation. A fundamental one, MIRIAM (Minimum Information Requested in the Annotation of Models), standardises the annotation and curation process of quantitative models in biology. To support this standard, MIRIAM Resources maintains a set of standard data types for annotating models, and provides services for manipulating these annotations. Furthermore, BioModels.net creates controlled vocabularies, such as SBO (Systems Biology Ontology) which strictly indexes, defines and links terms used in Systems Biology. Finally, BioModels Database provides a free, centralised, publicly accessible database for storing, searching and retrieving curated and annotated computational models. Each resource provides a web interface to submit, search, retrieve and display its data. In addition, the BioModels.net team provides a set of Web Services which allows the community to programmatically access the resources. A user is then able to perform remote queries, such as retrieving a model and resolving all its MIRIAM Annotations, as well as getting the details about the associated SBO terms. These web services use established standards. Communications rely on SOAP (Simple Object Access Protocol) messages and the available queries are described in a WSDL (Web Services Description Language) file. Several libraries are provided in order to simplify the development of client software. BioModels.net Web Services make one step further for the researchers to simulate and understand the entirety of a biological system, by allowing them to retrieve biological models in their own tool, combine queries in workflows and efficiently analyse models.

Objectively Optimized Observation Direction System Providing Situational Awareness for a Sensor Web

NASA Astrophysics Data System (ADS)

Aulov, O.; Lary, D. J.

2010-12-01

There is great utility in having a flexible and automated objective observation direction system for the decadal survey missions and beyond. Such a system allows us to optimize the observations made by suite of sensors to address specific goals from long term monitoring to rapid response. We have developed such a prototype using a network of communicating software elements to control a heterogeneous network of sensor systems, which can have multiple modes and flexible viewing geometries. Our system makes sensor systems intelligent and situationally aware. Together they form a sensor web of multiple sensors working together and capable of automated target selection, i.e. the sensors “know” where they are, what they are able to observe, what targets and with what priorities they should observe. This system is implemented in three components. The first component is a Sensor Web simulator. The Sensor Web simulator describes the capabilities and locations of each sensor as a function of time, whether they are orbital, sub-orbital, or ground based. The simulator has been implemented using AGIs Satellite Tool Kit (STK). STK makes it easy to analyze and visualize optimal solutions for complex space scenarios, and perform complex analysis of land, sea, air, space assets, and shares results in one integrated solution. The second component is target scheduler that was implemented with STK Scheduler. STK Scheduler is powered by a scheduling engine that finds better solutions in a shorter amount of time than traditional heuristic algorithms. The global search algorithm within this engine is based on neural network technology that is capable of finding solutions to larger and more complex problems and maximizing the value of limited resources. The third component is a modeling and data assimilation system. It provides situational awareness by supplying the time evolution of uncertainty and information content metrics that are used to tell us what we need to observe and the priority we should give to the observations. A prototype of this component was implemented with AutoChem. AutoChem is NASA release software constituting an automatic code generation, symbolic differentiator, analysis, documentation, and web site creation tool for atmospheric chemical modeling and data assimilation. Its model is explicit and uses an adaptive time-step, error monitoring time integration scheme for stiff systems of equations. AutoChem was the first model to ever have the facility to perform 4D-Var data assimilation and Kalman filter. The project developed a control system with three main accomplishments. First, fully multivariate observational and theoretical information with associated uncertainties was combined using a full Kalman filter data assimilation system. Second, an optimal distribution of the computations and of data queries was achieved by utilizing high performance computers/load balancing and a set of automatically mirrored databases. Third, inter-instrument bias correction was performed using machine learning. The PI for this project was Dr. David Lary of the UMBC Joint Center for Earth Systems Technology at NASA/Goddard Space Flight Center.

Debating Whether Dinosaurs Should Be "Cloned" from Ancient DNA To Promote Cooperative Learning in an Introductory Evolution Course.

ERIC Educational Resources Information Center

Soja, Constance M.; Huerta, Deborah

2001-01-01

Describes an interactive internet exercise that enables students to engage in cooperative library and web research on a controversial topic in science, specifically the cloning of extinct lifeforms. Creates a dynamic learning environment in a large introductory geology course and demonstrates the importance of scientific literacy. (Author/SAH)

The Emergence and Evolution of School Psychology Literature: A Scientometric Analysis from 1907 through 2014

ERIC Educational Resources Information Center

Liu, Shuyan; Oakland, Thomas

2016-01-01

The objective of this current study is to identify the growth and development of scholarly literature that specifically references the term "school psychology" in the Science Citation Index from 1907 through 2014. Documents from Web of Science were accessed and analyzed through the use of scientometric analyses, including HistCite and…

Creating Interactive Web-Based Environments to Scaffold Creative Reasoning and Meaningful Learning: From Physics to Products

ERIC Educational Resources Information Center

Jou, Min; Chuang, Chien-Pen; Wu, Yu-Shiang

2010-01-01

With the evolution of the surrounding world market, engineers have to propose innovations in products and processes. Industrial innovation frequently results from an improved understanding of basic physics. In this paper, an approach to accelerate inventive preliminary design is presented. This method combines the main advantages of CBR (Case…

Location, evolution and importance of Cephalcia spp. (Hym: Pamphiliidae) populations in Polish Carpathian Mountains

Treesearch

Marcin Jachym

2003-01-01

The web-spinning sawflies (Cephalcia Panz.) are members of the Symphyta that are of economic significance, and which constitutes an integral part of the spruce forest environment. Spruce, which is the dominant component of Western Carpathian forest stands, is the only known host plant for all the species of Cephalcia...

The State of the Art in Library Discovery 2010

ERIC Educational Resources Information Center

Breeding, Marshall

2010-01-01

Resource discovery tops the charts as the foremost issue within the realm of library automation. As a new year commences, the author sees a more pressing need to accelerate the pace with which libraries deliver content and services in ways that users will find compelling, relevant, and convenient. The evolution of the web advances relentlessly,…

Exploring Writing Individually and Collaboratively Using Google Docs in EFL Contexts

ERIC Educational Resources Information Center

Alsubaie, Jawaher; Ashuraidah, Ali

2017-01-01

Online teaching and learning became popular with the evolution of the World Wide Web now days. Implementing online learning tools within EFL contexts will help better address the multitude of teaching and learning styles. Difficulty in academic writing can be considered one of the common problems that students face in and outside their classrooms.…

Ontology-Based Organizational Memory for e-Learning

ERIC Educational Resources Information Center

Abel, Marie-Helene; Benayache, Ahcene; Lenne, Dominique; Moulin, Claude; Barry, Catherine; Chaput, Brigitte

2004-01-01

E-learning leads to evolutions in the way of designing a course. Diffused through the web, the course content cannot be the direct transcription of a face to face course content. A course can be seen as an organization in which different actors are involved. These actors produce documents, information and knowledge that they often share. We…

Reprint of: Technology and the Evolution of Clinical Methods for Stuttering

ERIC Educational Resources Information Center

Packman, Ann; Meredith, Grant

2011-01-01

The World Wide Web (WWW) was 20 years old last year. Enormous amounts of information about stuttering are now available to anyone who can access the Internet. Compared to 20 years ago, people who stutter and their families can now make more informed choices about speech-language interventions, from a distance. Blogs and chat rooms provide…

First Steps Towards a University Social Network on Personal Learning Environments

ERIC Educational Resources Information Center

Marín-Diaz, Veronica; Vázquez Martínez, Ana Isabel; McMullin, Karen Josephine

2014-01-01

The evolution of the media and the Internet in education today is an unquestionable reality. At the university level, the use of Web 2.0 tools has become increasingly visible in the new resources that professors have been incorporating both into the classroom and into their research, reinforcing the methodological renewal that the implementation…

Of woods and webs: possible alternatives to the tree of life for studying genomic fluidity in E. coli.

PubMed

Beauregard-Racine, Julie; Bicep, Cédric; Schliep, Klaus; Lopez, Philippe; Lapointe, François-Joseph; Bapteste, Eric

2011-07-20

We introduce several forest-based and network-based methods for exploring microbial evolution, and apply them to the study of thousands of genes from 30 strains of E. coli. This case study illustrates how additional analyses could offer fast heuristic alternatives to standard tree of life (TOL) approaches. We use gene networks to identify genes with atypical modes of evolution, and genome networks to characterize the evolution of genetic partnerships between E. coli and mobile genetic elements. We develop a novel polychromatic quartet method to capture patterns of recombination within E. coli, to update the clanistic toolkit, and to search for the impact of lateral gene transfer and of pathogenicity on gene evolution in two large forests of trees bearing E. coli. We unravel high rates of lateral gene transfer involving E. coli (about 40% of the trees under study), and show that both core genes and shell genes of E. coli are affected by non-tree-like evolutionary processes. We show that pathogenic lifestyle impacted the structure of 30% of the gene trees, and that pathogenic strains are more likely to transfer genes with one another than with non-pathogenic strains. In addition, we propose five groups of genes as candidate mobile modules of pathogenicity. We also present strong evidence for recent lateral gene transfer between E. coli and mobile genetic elements. Depending on which evolutionary questions biologists want to address (i.e. the identification of modules, genetic partnerships, recombination, lateral gene transfer, or genes with atypical evolutionary modes, etc.), forest-based and network-based methods are preferable to the reconstruction of a single tree, because they provide insights and produce hypotheses about the dynamics of genome evolution, rather than the relative branching order of species and lineages. Such a methodological pluralism - the use of woods and webs - is to be encouraged to analyse the evolutionary processes at play in microbial evolution.This manuscript was reviewed by: Ford Doolittle, Tal Pupko, Richard Burian, James McInerney, Didier Raoult, and Yan Boucher.

Comparison of PubMed, Scopus, Web of Science, and Google Scholar: strengths and weaknesses.

PubMed

Falagas, Matthew E; Pitsouni, Eleni I; Malietzis, George A; Pappas, Georgios

2008-02-01

The evolution of the electronic age has led to the development of numerous medical databases on the World Wide Web, offering search facilities on a particular subject and the ability to perform citation analysis. We compared the content coverage and practical utility of PubMed, Scopus, Web of Science, and Google Scholar. The official Web pages of the databases were used to extract information on the range of journals covered, search facilities and restrictions, and update frequency. We used the example of a keyword search to evaluate the usefulness of these databases in biomedical information retrieval and a specific published article to evaluate their utility in performing citation analysis. All databases were practical in use and offered numerous search facilities. PubMed and Google Scholar are accessed for free. The keyword search with PubMed offers optimal update frequency and includes online early articles; other databases can rate articles by number of citations, as an index of importance. For citation analysis, Scopus offers about 20% more coverage than Web of Science, whereas Google Scholar offers results of inconsistent accuracy. PubMed remains an optimal tool in biomedical electronic research. Scopus covers a wider journal range, of help both in keyword searching and citation analysis, but it is currently limited to recent articles (published after 1995) compared with Web of Science. Google Scholar, as for the Web in general, can help in the retrieval of even the most obscure information but its use is marred by inadequate, less often updated, citation information.

Tabizi Pythons and Clendro Hawks: Using Imaginary Animals to Achieve Real Knowledge about Ecosystems

ERIC Educational Resources Information Center

Rockow, Michael

2007-01-01

The author describes how he used to teach a unit on food webs and ecosystems using actual food webs as models. However, the models used by the author tend to be either too simplistic or too complicated for his students. A few years ago, he solved these problems by making up his own food web, complete with invented plants and animals. The model has…

The Ecological Model Web Concept: A Consultative Infrastructure for Decision Makers and Researchers

NASA Astrophysics Data System (ADS)

Geller, G.; Nativi, S.

2011-12-01

Rapid climate and socioeconomic changes may be outrunning society's ability to understand, predict, and respond to change effectively. Decision makers want better information about what these changes will be and how various resources will be affected, while researchers want better understanding of the components and processes of ecological systems, how they interact, and how they respond to change. Although there are many excellent models in ecology and related disciplines, there is only limited coordination among them, and accessible, openly shared models or model systems that can be consulted to gain insight on important ecological questions or assist with decision-making are rare. A "consultative infrastructure" that increased access to and sharing of models and model outputs would benefit decision makers, researchers, as well as modelers. Of course, envisioning such an ambitious system is much easier than building it, but several complementary approaches exist that could contribute. The one discussed here is called the Model Web. This is a concept for an open-ended system of interoperable computer models and databases based on making models and their outputs available as services ("model as a service"). Initially, it might consist of a core of several models from which it could grow gradually as new models or databases were added. However, a model web would not be a monolithic, rigidly planned and built system--instead, like the World Wide Web, it would grow largely organically, with limited central control, within a framework of broad goals and data exchange standards. One difference from the WWW is that a model web is much harder to create, and has more pitfalls, and thus is a long term vision. However, technology, science, observations, and models have advanced enough so that parts of an ecological model web can be built and utilized now, forming a framework for gradual growth as well as a broadly accessible infrastructure. Ultimately, the value of a model web lies in the increase in access to and sharing of both models and model outputs. By lowering access barriers to models and their outputs there is less reinvention, more efficient use of resources, greater interaction among researchers and across disciplines, as well as other benefits. The growth of such a system of models fits well with the concept and architecture of the Global Earth Observing System of Systems (GEOSS) as well as the Semantic Web. And, while framed here in the context of ecological forecasting, the same concept can be applied to any discipline utilizing models.

Herschel and the Molecular Universe

NASA Technical Reports Server (NTRS)

Tielens, A. G. G. M.; Helmich, F. P.

2006-01-01

Over the next decade, space-based missions will open up the universe to high spatial and spectral resolution studies at infrared and submillimeter wavelengths. This will allow us to study, in much greater detail, the composition and the origin and evolution of molecules in space. Moreover, molecular transitions in these spectral ranges provide a sensitive probe of the dynamics and the physical and chemical conditions in a wide range of objects at scales ranging from budding planetary systems to galactic and extragalactic sizes. Hence, these missions provide us with the tools to study key astrophysical and astrochemical processes involved in the formation and evolution of planets, stars, and galaxies. These new missions can be expected to lead to the detection of many thousands of new spectral features. Identification, analysis and interpretation of these features in terms of the physical and chemical characteristics of the astronomical sources will require detailed astronomical modeling tools supported by laboratory measurements and theoretical studies of chemical reactions and collisional excitation rates on species of astrophysical relevance. These data will have to be made easily accessible to the scientific community through web-based data archives. In this paper, we will review the Herschel mission and its expected impact on our understanding of the molecular universe.

WMT: The CSDMS Web Modeling Tool

NASA Astrophysics Data System (ADS)

Piper, M.; Hutton, E. W. H.; Overeem, I.; Syvitski, J. P.

2015-12-01

The Community Surface Dynamics Modeling System (CSDMS) has a mission to enable model use and development for research in earth surface processes. CSDMS strives to expand the use of quantitative modeling techniques, promotes best practices in coding, and advocates for the use of open-source software. To streamline and standardize access to models, CSDMS has developed the Web Modeling Tool (WMT), a RESTful web application with a client-side graphical interface and a server-side database and API that allows users to build coupled surface dynamics models in a web browser on a personal computer or a mobile device, and run them in a high-performance computing (HPC) environment. With WMT, users can: Design a model from a set of components Edit component parameters Save models to a web-accessible server Share saved models with the community Submit runs to an HPC system Download simulation results The WMT client is an Ajax application written in Java with GWT, which allows developers to employ object-oriented design principles and development tools such as Ant, Eclipse and JUnit. For deployment on the web, the GWT compiler translates Java code to optimized and obfuscated JavaScript. The WMT client is supported on Firefox, Chrome, Safari, and Internet Explorer. The WMT server, written in Python and SQLite, is a layered system, with each layer exposing a web service API: wmt-db: database of component, model, and simulation metadata and output wmt-api: configure and connect components wmt-exe: launch simulations on remote execution servers The database server provides, as JSON-encoded messages, the metadata for users to couple model components, including descriptions of component exchange items, uses and provides ports, and input parameters. Execution servers are network-accessible computational resources, ranging from HPC systems to desktop computers, containing the CSDMS software stack for running a simulation. Once a simulation completes, its output, in NetCDF, is packaged and uploaded to a data server where it is stored and from which a user can download it as a single compressed archive file.

Enabling Real-time Water Decision Support Services Using Model as a Service

NASA Astrophysics Data System (ADS)

Zhao, T.; Minsker, B. S.; Lee, J. S.; Salas, F. R.; Maidment, D. R.; David, C. H.

2014-12-01

Through application of computational methods and an integrated information system, data and river modeling services can help researchers and decision makers more rapidly understand river conditions under alternative scenarios. To enable this capability, workflows (i.e., analysis and model steps) are created and published as Web services delivered through an internet browser, including model inputs, a published workflow service, and visualized outputs. The RAPID model, which is a river routing model developed at University of Texas Austin for parallel computation of river discharge, has been implemented as a workflow and published as a Web application. This allows non-technical users to remotely execute the model and visualize results as a service through a simple Web interface. The model service and Web application has been prototyped in the San Antonio and Guadalupe River Basin in Texas, with input from university and agency partners. In the future, optimization model workflows will be developed to link with the RAPID model workflow to provide real-time water allocation decision support services.

A Relationship-Building Model for the Web Retail Marketplace.

ERIC Educational Resources Information Center

Wang, Fang; Head, Milena; Archer, Norm

2000-01-01

Discusses the effects of the Web on marketing practices. Introduces the concept and theory of relationship marketing. The relationship network concept, which typically is only applied to the business-to-business market, is discussed within the business-to-consumer market, and a new relationship-building model for the Web marketplace is proposed.…

The Path to Graduation: A Model Interactive Web Site Design Supporting Doctoral Students

ERIC Educational Resources Information Center

Simmons-Johnson, Nicole

2012-01-01

Objective. This 2-phase mixed method study assessed 2nd-year doctoral students' and dissertation students' perceptions of the current Graduate School of Education dissertation support Web site, with implications for designing a model dissertation support Web site. Methods. Phase 1 collected quantitative and qualitative data through an…

Can You Build It? Using Manipulatives to Assess Student Understanding of Food-Web Concepts

ERIC Educational Resources Information Center

Grumbine, Richard

2012-01-01

This article outlines an exercise that assesses student knowledge of food-web and energy-flow concepts. Students work in teams and use manipulatives to build food-web models based on criteria assigned by the instructor. The models are then peer reviewed according to guidelines supplied by the instructor.

IMPORTANCE OF TEMPERATURE IN MODELLING PCB BIOACCUMULATION IN THE LAKE MICHIGAN FOOD WEB

EPA Science Inventory

In most food web models, the exposure temperature of a food web is typically defined using a single spatial compartment. This essentially assumes that the predator and prey are exposed to the same temperature. However, in a large water body such as Lake Michigan, due to the spati...

Modeling Rich Interactions for Web Search Intent Inference, Ranking and Evaluation

ERIC Educational Resources Information Center

Guo, Qi

2012-01-01

Billions of people interact with Web search engines daily and their interactions provide valuable clues about their interests and preferences. While modeling search behavior, such as queries and clicks on results, has been found to be effective for various Web search applications, the effectiveness of the existing approaches are limited by…

Perspectives for Electronic Books in the World Wide Web Age.

ERIC Educational Resources Information Center

Bry, Francois; Kraus, Michael

2002-01-01

Discusses the rapid growth of the World Wide Web and the lack of use of electronic books and suggests that specialized contents and device independence can make Web-based books compete with print. Topics include enhancing the hypertext model of XML; client-side adaptation, including browsers and navigation; and semantic modeling. (Author/LRW)

Computational model of cerebral blood flow redistribution during cortical spreading depression

NASA Astrophysics Data System (ADS)

Verisokin, Andrey Y.; Verveyko, Darya V.; Postnov, Dmitry E.

2016-04-01

In recent decades modelling studies on cortical spreading depression (CSD) and migraine waves successfully contributed to formation of modern view on these fundamental phenomena of brain physiology. However, due to the extreme complexity of object under study (brain cortex) and the diversity of involved physiological pathways, the development of new mathematical models of CSD is still a very relevant and challenging research problem. In our study we follow the functional modelling approach aimed to map the action of known physiological pathways to the specific nonlinear mechanisms that govern formation and evolution of CSD wave patterns. Specifically, we address the role of cerebral blood flow (CBF) redistribution that is caused by excessive neuronal activity by means of neurovascular coupling and mediates a spatial pattern of oxygen and glucose delivery. This in turn changes the local metabolic status of neural tissue. To build the model we simplify the web of known cell-to-cell interactions within a neurovascular unit by selecting the most relevant ones, such as local neuron-induced elevation of extracellular potassium concentration and biphasic response of arteriole radius. We propose the lumped description of distance-dependent hemodynamic coupling that fits the most recent experimental findings.

Silicon web process development

NASA Technical Reports Server (NTRS)

Duncan, C. S.; Seidensticker, R. G.; Mchugh, J. P.; Blais, P. D.; Davis, J. R., Jr.

1977-01-01

Thirty-five (35) furnace runs were carried out during this quarter, of which 25 produced a total of 120 web crystals. The two main thermal models for the dendritic growth process were completed and are being used to assist the design of the thermal geometry of the web growth apparatus. The first model, a finite element representation of the susceptor and crucible, was refined to give greater precision and resolution in the critical central region of the melt. The second thermal model, which describes the dissipation of the latent heat to generate thickness-velocity data, was completed. Dendritic web samples were fabricated into solar cells using a standard configuration and a standard process for a N(+) -P-P(+) configuration. The detailed engineering design was completed for a new dendritic web growth facility of greater width capability than previous facilities.

[Nursing on the Web: the creation and validation process of a web site on coronary artery disease].

PubMed

Marques, Isaac Rosa; Marin, Heimar de Fátima

2002-01-01

The World Wide Web is an important health information research source. A challenge for the Brazilian Nursing Informatics area is to use its potential to promote health education. This paper aims to present a developing and validating model used in an educational Web site, named CardioSite, which subject is Coronary Heart Disease. In its creation it was adopted a method with phases of conceptual modeling, development, implementation, and evaluation. In the evaluation phase, the validation was performed through an online informatics and health experts panel. The results demonstrated that information was reliable and valid. Considering that national official systems are not available to that approach, this model demonstrated effectiveness in assessing the quality of the Web site content.

Food-web complexity, meta-community complexity and community stability.

PubMed

Mougi, A; Kondoh, M

2016-04-13

What allows interacting, diverse species to coexist in nature has been a central question in ecology, ever since the theoretical prediction that a complex community should be inherently unstable. Although the role of spatiality in species coexistence has been recognized, its application to more complex systems has been less explored. Here, using a meta-community model of food web, we show that meta-community complexity, measured by the number of local food webs and their connectedness, elicits a self-regulating, negative-feedback mechanism and thus stabilizes food-web dynamics. Moreover, the presence of meta-community complexity can give rise to a positive food-web complexity-stability effect. Spatiality may play a more important role in stabilizing dynamics of complex, real food webs than expected from ecological theory based on the models of simpler food webs.

Realising the Uncertainty Enabled Model Web

NASA Astrophysics Data System (ADS)

Cornford, D.; Bastin, L.; Pebesma, E. J.; Williams, M.; Stasch, C.; Jones, R.; Gerharz, L.

2012-12-01

The FP7 funded UncertWeb project aims to create the "uncertainty enabled model web". The central concept here is that geospatial models and data resources are exposed via standard web service interfaces, such as the Open Geospatial Consortium (OGC) suite of encodings and interface standards, allowing the creation of complex workflows combining both data and models. The focus of UncertWeb is on the issue of managing uncertainty in such workflows, and providing the standards, architecture, tools and software support necessary to realise the "uncertainty enabled model web". In this paper we summarise the developments in the first two years of UncertWeb, illustrating several key points with examples taken from the use case requirements that motivate the project. Firstly we address the issue of encoding specifications. We explain the usage of UncertML 2.0, a flexible encoding for representing uncertainty based on a probabilistic approach. This is designed to be used within existing standards such as Observations and Measurements (O&M) and data quality elements of ISO19115 / 19139 (geographic information metadata and encoding specifications) as well as more broadly outside the OGC domain. We show profiles of O&M that have been developed within UncertWeb and how UncertML 2.0 is used within these. We also show encodings based on NetCDF and discuss possible future directions for encodings in JSON. We then discuss the issues of workflow construction, considering discovery of resources (both data and models). We discuss why a brokering approach to service composition is necessary in a world where the web service interfaces remain relatively heterogeneous, including many non-OGC approaches, in particular the more mainstream SOAP and WSDL approaches. We discuss the trade-offs between delegating uncertainty management functions to the service interfaces themselves and integrating the functions in the workflow management system. We describe two utility services to address conversion between uncertainty types, and between the spatial / temporal support of service inputs / outputs. Finally we describe the tools being generated within the UncertWeb project, considering three main aspects: i) Elicitation of uncertainties on model inputs. We are developing tools to enable domain experts to provide judgements about input uncertainties from UncertWeb model components (e.g. parameters in meteorological models) which allow panels of experts to engage in the process and reach a consensus view on the current knowledge / beliefs about that parameter or variable. We are developing systems for continuous and categorical variables as well as stationary spatial fields. ii) Visualisation of the resulting uncertain outputs from the end of the workflow, but also at intermediate steps. At this point we have prototype implementations driven by the requirements from the use cases that motivate UncertWeb. iii) Sensitivity and uncertainty analysis on model outputs. Here we show the design of the overall system we are developing, including the deployment of an emulator framework to allow computationally efficient approaches. We conclude with a summary of the open issues and remaining challenges we are facing in UncertWeb, and provide a brief overview of how we plan to tackle these.

NASA's Earth Observing System Data and Information System - Many Mechanisms for On-Going Evolution

NASA Astrophysics Data System (ADS)

Ramapriyan, H. K.

2012-12-01

NASA's Earth Observing System Data and Information System has been serving a broad user community since August 1994. As a long-lived multi-mission system serving multiple scientific disciplines and a diverse user community, EOSDIS has been evolving continuously. It has had and continues to have many forms of community input to help with this evolution. Early in its history, it had inputs from the EOSDIS Advisory Panel, benefited from the reviews by various external committees and evolved into the present distributed architecture with discipline-based Distributed Active Archive Centers (DAACs), Science Investigator-led Processing Systems and a cross-DAAC search and data access capability. EOSDIS evolution has been helped by advances in computer technology, moving from an initially planned supercomputing environment to SGI workstations to Linux Clusters for computation and from near-line archives of robotic silos with tape cassettes to RAID-disk-based on-line archives for storage. The network capacities have increased steadily over the years making delivery of data on media almost obsolete. The advances in information systems technologies have been having an even greater impact on the evolution of EOSDIS. In the early days, the advent of the World Wide Web came as a game-changer in the operation of EOSDIS. The metadata model developed for the EOSDIS Core System for representing metadata from EOS standard data products has had an influence on the Federal Geographic Data Committee's metadata content standard and the ISO metadata standards. The influence works both ways. As ISO 19115 metadata standard has developed in recent years, EOSDIS is reviewing its metadata to ensure compliance with the standard. Improvements have been made in the cross-DAAC search and access of data using the centralized metadata clearing house (EOS Clearing House - ECHO) and the client Reverb. Given the diversity of the Earth science disciplines served by the DAACs, the DAACs have developed a number of software tools tailored to their respective user communities. Web services play an important part in improved access to data products including some basic analysis and visualization capabilities. A coherent view into all capabilities available from EOSDIS is evolving through the "Coherent Web" effort. Data are being made available in near real-time for scientific research as well as time-critical applications. On-going community inputs for infusion for maintaining vitality of EOSDIS come from technology developments by NASA-sponsored community data system programs - Advancing Collaborative Connections for Earth System Science (ACCESS), Making Earth System Data Records for Use in Research Environments (MEaSUREs) and Applied Information System Technology (AIST), as well as participation in Earth Science Data System Working Groups, the Earth Science Information Partners Federation and other interagency/international activities. An important source of community needs is the annual American Customer Satisfaction Index survey of EOSDIS users. Some of the key areas in which improvements are required and incremental progress is being made are: ease of discovery and access; cross-organizational interoperability; data inter-use; ease of collaboration; ease of citation of datasets; preservation of provenance and context and making them conveniently available to users.

Biodiversity maintenance in food webs with regulatory environmental feedbacks.

PubMed

Bagdassarian, Carey K; Dunham, Amy E; Brown, Christopher G; Rauscher, Daniel

2007-04-21

Although the food web is one of the most fundamental and oldest concepts in ecology, elucidating the strategies and structures by which natural communities of species persist remains a challenge to empirical and theoretical ecologists. We show that simple regulatory feedbacks between autotrophs and their environment when embedded within complex and realistic food-web models enhance biodiversity. The food webs are generated through the niche-model algorithm and coupled with predator-prey dynamics, with and without environmental feedbacks at the autotroph level. With high probability and especially at lower, more realistic connectance levels, regulatory environmental feedbacks result in fewer species extinctions, that is, in increased species persistence. These same feedback couplings, however, also sensitize food webs to environmental stresses leading to abrupt collapses in biodiversity with increased forcing. Feedback interactions between species and their material environments anchor food-web persistence, adding another dimension to biodiversity conservation. We suggest that the regulatory features of two natural systems, deep-sea tubeworms with their microbial consortia and a soil ecosystem manifesting adaptive homeostatic changes, can be embedded within niche-model food-web dynamics.

Ajax Architecture Implementation Techniques

NASA Astrophysics Data System (ADS)

Hussaini, Syed Asadullah; Tabassum, S. Nasira; Baig, Tabassum, M. Khader

2012-03-01

Today's rich Web applications use a mix of Java Script and asynchronous communication with the application server. This mechanism is also known as Ajax: Asynchronous JavaScript and XML. The intent of Ajax is to exchange small pieces of data between the browser and the application server, and in doing so, use partial page refresh instead of reloading the entire Web page. AJAX (Asynchronous JavaScript and XML) is a powerful Web development model for browser-based Web applications. Technologies that form the AJAX model, such as XML, JavaScript, HTTP, and XHTML, are individually widely used and well known. However, AJAX combines these technologies to let Web pages retrieve small amounts of data from the server without having to reload the entire page. This capability makes Web pages more interactive and lets them behave like local applications. Web 2.0 enabled by the Ajax architecture has given rise to a new level of user interactivity through web browsers. Many new and extremely popular Web applications have been introduced such as Google Maps, Google Docs, Flickr, and so on. Ajax Toolkits such as Dojo allow web developers to build Web 2.0 applications quickly and with little effort.

XML — an opportunity for data standards in the geosciences

NASA Astrophysics Data System (ADS)

Houlding, Simon W.

2001-08-01

Extensible markup language (XML) is a recently introduced meta-language standard on the Web. It provides the rules for development of metadata (markup) standards for information transfer in specific fields. XML allows development of markup languages that describe what information is rather than how it should be presented. This allows computer applications to process the information in intelligent ways. In contrast hypertext markup language (HTML), which fuelled the initial growth of the Web, is a metadata standard concerned exclusively with presentation of information. Besides its potential for revolutionizing Web activities, XML provides an opportunity for development of meaningful data standards in specific application fields. The rapid endorsement of XML by science, industry and e-commerce has already spawned new metadata standards in such fields as mathematics, chemistry, astronomy, multi-media and Web micro-payments. Development of XML-based data standards in the geosciences would significantly reduce the effort currently wasted on manipulating and reformatting data between different computer platforms and applications and would ensure compatibility with the new generation of Web browsers. This paper explores the evolution, benefits and status of XML and related standards in the more general context of Web activities and uses this as a platform for discussion of its potential for development of data standards in the geosciences. Some of the advantages of XML are illustrated by a simple, browser-compatible demonstration of XML functionality applied to a borehole log dataset. The XML dataset and the associated stylesheet and schema declarations are available for FTP download.

Experience versus talent shapes the structure of the Web.

PubMed

Kong, Joseph S; Sarshar, Nima; Roychowdhury, Vwani P

2008-09-16

We use sequential large-scale crawl data to empirically investigate and validate the dynamics that underlie the evolution of the structure of the web. We find that the overall structure of the web is defined by an intricate interplay between experience or entitlement of the pages (as measured by the number of inbound hyperlinks a page already has), inherent talent or fitness of the pages (as measured by the likelihood that someone visiting the page would give a hyperlink to it), and the continual high rates of birth and death of pages on the web. We find that the web is conservative in judging talent and the overall fitness distribution is exponential, showing low variability. The small variance in talent, however, is enough to lead to experience distributions with high variance: The preferential attachment mechanism amplifies these small biases and leads to heavy-tailed power-law (PL) inbound degree distributions over all pages, as well as over pages that are of the same age. The balancing act between experience and talent on the web allows newly introduced pages with novel and interesting content to grow quickly and surpass older pages. In this regard, it is much like what we observe in high-mobility and meritocratic societies: People with entitlement continue to have access to the best resources, but there is just enough screening for fitness that allows for talented winners to emerge and join the ranks of the leaders. Finally, we show that the fitness estimates have potential practical applications in ranking query results.

Designing Crop Simulation Web Service with Service Oriented Architecture Principle

NASA Astrophysics Data System (ADS)

Chinnachodteeranun, R.; Hung, N. D.; Honda, K.

2015-12-01

Crop simulation models are efficient tools for simulating crop growth processes and yield. Running crop models requires data from various sources as well as time-consuming data processing, such as data quality checking and data formatting, before those data can be inputted to the model. It makes the use of crop modeling limited only to crop modelers. We aim to make running crop models convenient for various users so that the utilization of crop models will be expanded, which will directly improve agricultural applications. As the first step, we had developed a prototype that runs DSSAT on Web called as Tomorrow's Rice (v. 1). It predicts rice yields based on a planting date, rice's variety and soil characteristics using DSSAT crop model. A user only needs to select a planting location on the Web GUI then the system queried historical weather data from available sources and expected yield is returned. Currently, we are working on weather data connection via Sensor Observation Service (SOS) interface defined by Open Geospatial Consortium (OGC). Weather data can be automatically connected to a weather generator for generating weather scenarios for running the crop model. In order to expand these services further, we are designing a web service framework consisting of layers of web services to support compositions and executions for running crop simulations. This framework allows a third party application to call and cascade each service as it needs for data preparation and running DSSAT model using a dynamic web service mechanism. The framework has a module to manage data format conversion, which means users do not need to spend their time curating the data inputs. Dynamic linking of data sources and services are implemented using the Service Component Architecture (SCA). This agriculture web service platform demonstrates interoperability of weather data using SOS interface, convenient connections between weather data sources and weather generator, and connecting various services for running crop models for decision support.

[Construction and Application of Innovative Education Technology Strategies in Nursing].

PubMed

Chao, Li-Fen; Huang, Hsiang-Ping; Ni, Lee-Fen; Tsai, Chia-Lan; Huang, Tsuey-Yuan

2017-12-01

The evolution of information and communication technologies has deeply impacted education reform, promoted the development of digital-learning models, and stimulated the development of diverse nursing education strategies in order to better fulfill needs and expand in new directions. The present paper introduces the intelligent-learning resources that are available for basic medical science education, problem-based learning, nursing scenario-based learning, objective structured clinical examinations, and other similar activities in the Department of Nursing at Chang Gung University of Science and Technology. The program is offered in two parts: specialized classroom facilities and cloud computing / mobile-learning. The latter includes high-fidelity simulation classrooms, online e-books, and virtual interactive simulation and augmented reality mobile-learning materials, which are provided through multimedia technology development, learning management systems, web-certificated examinations, and automated teaching and learning feedback mechanisms. It is expected that the teaching experiences that are shared in this article may be used as a reference for applying professional wisdom teaching models into nursing education.

Buying best value health care: Evolution of purchasing among Australian private health insurers

PubMed Central

Willcox, Sharon

2005-01-01

Since 1995 Australian health insurers have been able to purchase health services pro-actively through negotiating contracts with hospitals, but little is known about their experience of purchasing. This paper examines the current status of purchasing through interviews with senior managers representing all Australian private health insurers. Many of the traditional tools used to generate competition and enhance efficiency (such as selective contracting and co-payments) have had limited use due to public and political opposition. Adoption of bundled case payment models using diagnosis related groups (DRGs) has been slow. Insurers cite multiple reasons including poor understanding of private hospital costs, unfamiliarity with DRGs, resistance from the medical profession and concerns about premature discharge. Innovation in payment models has been limited, although some insurers are considering introduction of volume-outcome purchasing and pay for performance incentives. Private health insurers also face a complex web of regulation, some of which appears to impede moves towards more efficient purchasing. PMID:15801982

Shape priors for segmentation of the cervix region within uterine cervix images

NASA Astrophysics Data System (ADS)

Lotenberg, Shelly; Gordon, Shiri; Greenspan, Hayit

2008-03-01

The work focuses on a unique medical repository of digital Uterine Cervix images ("Cervigrams") collected by the National Cancer Institute (NCI), National Institute of Health, in longitudinal multi-year studies. NCI together with the National Library of Medicine is developing a unique web-based database of the digitized cervix images to study the evolution of lesions related to cervical cancer. Tools are needed for the automated analysis of the cervigram content to support the cancer research. In recent works, a multi-stage automated system for segmenting and labeling regions of medical and anatomical interest within the cervigrams was developed. The current paper concentrates on incorporating prior-shape information in the cervix region segmentation task. In accordance with the fact that human experts mark the cervix region as circular or elliptical, two shape models (and corresponding methods) are suggested. The shape models are embedded within an active contour framework that relies on image features. Experiments indicate that incorporation of the prior shape information augments previous results.

Foraging mode affects the evolution of egg size in generalist predators embedded in complex food webs.

PubMed

Verdeny-Vilalta, O; Fox, C W; Wise, D H; Moya-Laraño, J

2015-06-01

Ecological networks incorporate myriad biotic interactions that determine the selection pressures experienced by the embedded populations. We argue that within food webs, the negative scaling of abundance with body mass and foraging theory predict that the selective advantages of larger egg size should be smaller for sit-and-wait than active-hunting generalist predators, leading to the evolution of a difference in egg size between them. Because body mass usually scales negatively with predator abundance and constrains predation rate, slightly increasing egg mass should simultaneously allow offspring to feed on more prey and escape from more predators. However, the benefits of larger offspring would be relatively smaller for sit-and-wait predators because (i) due to their lower mobility, encounters with other predators are less common, and (ii) they usually employ a set of alternative hunting strategies that help to subdue relatively larger prey. On the other hand, for active predators, which need to confront prey as they find them, body-size differences may be more important in subduing prey. This difference in benefits should lead to the evolution of larger egg sizes in active-hunting relative to sit-and-wait predators. This prediction was confirmed by a phylogenetically controlled analysis of 268 spider species, supporting the view that the structure of ecological networks may serve to predict relevant selective pressures acting on key life history traits. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Formalized landscape models for surveying and modelling tasks

NASA Astrophysics Data System (ADS)

Löwner, Marc-Oliver

2010-05-01

We present a formalization of main geomorphic landscape models, mainly the concept of slopes, to clarify the needs and potentials of surveying technologies and modelling approaches. Using the Unified Modelling Language (UML) it is implemented as a exchangeable Geography Markup Language (GML3) -based application schema and therefore supports shared measurement campaigns. Today, knowledge in Geomorphology is given synoptically in textbooks in a more or less lyrical way. This knowledge is hard to implement for the use of modelling algorithms or data storage and sharing questions. On the other hand physical based numerical modelling and high resolution surveying technologies enable us to investigate case scenarios within small scales. Bringing together such approaches and organizing our data in an appropriate way will need the formalization of the concepts and knowledge that is archived in the science of geomorphology. The main problem of comparing research results in geomorphology but is that the objects under investigation are composed of 3-dimensional geometries that change in time due to processes of material fluxes, e. g. soil erosion or mass movements. They have internal properties, e. g. soil texture or bulk density, that determine the effectiveness of these processes but are under change as well. The presented application schema is available on the Internet and therefore a first step to enable researchers to share information using an OGC's Web feature service. In this vein comparing modelling results of landscape evolution with results of other scientist's observations is possible. Compared to prevalent data concepts the model presented makes it possible to store information about landforms, their geometry and the characteristics in more detail. It allows to represent the 3D-geometry, the set of material properties and the genesis of a landform by associating processes to a geoobject. Thus, time slices of a geomorphic system can be represented as well as scenarios of landscape modelling. Commercial GI-software is not adapted to the needs of the science of geomorphology. Therefore the development of an application model i. e. a formal description of semantics is imperative to partake in technologies like Web Feature Services supporting interoperable data transfer.

Low cost silicon solar array project large area silicon sheet task: Silicon web process development

NASA Technical Reports Server (NTRS)

Duncan, C. S.; Seidensticker, R. G.; Mchugh, J. P.; Blais, P. D.; Davis, J. R., Jr.

1977-01-01

Growth configurations were developed which produced crystals having low residual stress levels. The properties of a 106 mm diameter round crucible were evaluated and it was found that this design had greatly enhanced temperature fluctuations arising from convection in the melt. Thermal modeling efforts were directed to developing finite element models of the 106 mm round crucible and an elongated susceptor/crucible configuration. Also, the thermal model for the heat loss modes from the dendritic web was examined for guidance in reducing the thermal stress in the web. An economic analysis was prepared to evaluate the silicon web process in relation to price goals.

Strong regularities in world wide web surfing

PubMed

Huberman; Pirolli; Pitkow; Lukose

1998-04-03

One of the most common modes of accessing information in the World Wide Web is surfing from one document to another along hyperlinks. Several large empirical studies have revealed common patterns of surfing behavior. A model that assumes that users make a sequence of decisions to proceed to another page, continuing as long as the value of the current page exceeds some threshold, yields the probability distribution for the number of pages that a user visits within a given Web site. This model was verified by comparing its predictions with detailed measurements of surfing patterns. The model also explains the observed Zipf-like distributions in page hits observed at Web sites.

Astrobiology and Microbial Diversity Websites at MBL

NASA Astrophysics Data System (ADS)

Bahr, M.; Bordenstein, S. R.

2006-12-01

The NASA Astrobiology Institute (NAI) mission is to study the origin, evolution and future of life in the Universe. The MBL Astrobiology team explores the evolution and interaction of genomes of diverse organisms that play significant roles in environmental biology over evolutionary time scales. Communication about our research includes the personal contact of teacher workshops, and the development of web-based resources. Microbial Life Educational Resources (MLER) provides an expanding internet resource about the ecology, diversity and evolution for students, K-12 teachers, university faculty, and the general public. MLER includes websites, PowerPoint presentations, teaching activities, data sets, and other useful materials for creating or enhancing courses related to astrobiology. Our second site, micro*scope (http://microscope.mbl.edu), has images of microbes, classification schemes, descriptions of organisms, talks and other educational resources to improve awareness of the biodiversity of our microbial partners.

Functional Effects of Parasites on Food Web Properties during the Spring Diatom Bloom in Lake Pavin: A Linear Inverse Modeling Analysis

PubMed Central

Niquil, Nathalie; Jobard, Marlène; Saint-Béat, Blanche; Sime-Ngando, Télesphore

2011-01-01

This study is the first assessment of the quantitative impact of parasitic chytrids on a planktonic food web. We used a carbon-based food web model of Lake Pavin (Massif Central, France) to investigate the effects of chytrids during the spring diatom bloom by developing models with and without chytrids. Linear inverse modelling procedures were employed to estimate undetermined flows in the lake. The Monte Carlo Markov chain linear inverse modelling procedure provided estimates of the ranges of model-derived fluxes. Model results support recent theories on the probable impact of parasites on food web function. In the lake, during spring, when ‘inedible’ algae (unexploited by planktonic herbivores) were the dominant primary producers, the epidemic growth of chytrids significantly reduced the sedimentation loss of algal carbon to the detritus pool through the production of grazer-exploitable zoospores. We also review some theories about the potential influence of parasites on ecological network properties and argue that parasitism contributes to longer carbon path lengths, higher levels of activity and specialization, and lower recycling. Considering the “structural asymmetry” hypothesis as a stabilizing pattern, chytrids should contribute to the stability of aquatic food webs. PMID:21887240

Functional ecology of aquatic phagotrophic protists - Concepts, limitations, and perspectives.

PubMed

Weisse, Thomas; Anderson, Ruth; Arndt, Hartmut; Calbet, Albert; Hansen, Per Juel; Montagnes, David J S

2016-08-01

Functional ecology is a subdiscipline that aims to enable a mechanistic understanding of patterns and processes from the organismic to the ecosystem level. This paper addresses some main aspects of the process-oriented current knowledge on phagotrophic, i.e. heterotrophic and mixotrophic, protists in aquatic food webs. This is not an exhaustive review; rather, we focus on conceptual issues, in particular on the numerical and functional response of these organisms. We discuss the evolution of concepts and define parameters to evaluate predator-prey dynamics ranging from Lotka-Volterra to the Independent Response Model. Since protists have extremely versatile feeding modes, we explore if there are systematic differences related to their taxonomic affiliation and life strategies. We differentiate between intrinsic factors (nutritional history, acclimatisation) and extrinsic factors (temperature, food, turbulence) affecting feeding, growth, and survival of protist populations. We briefly consider intraspecific variability of some key parameters and constraints inherent in laboratory microcosm experiments. We then upscale the significance of phagotrophic protists in food webs to the ocean level. Finally, we discuss limitations of the mechanistic understanding of protist functional ecology resulting from principal unpredictability of nonlinear dynamics. We conclude by defining open questions and identifying perspectives for future research on functional ecology of aquatic phagotrophic protists. Copyright © 2016 The Authors. Published by Elsevier GmbH.. All rights reserved.

A Web Tool for Research in Nonlinear Optics

NASA Astrophysics Data System (ADS)

Prikhod'ko, Nikolay V.; Abramovsky, Viktor A.; Abramovskaya, Natalia V.; Demichev, Andrey P.; Kryukov, Alexandr P.; Polyakov, Stanislav P.

2016-02-01

This paper presents a project of developing the web platform called WebNLO for computer modeling of nonlinear optics phenomena. We discuss a general scheme of the platform and a model for interaction between the platform modules. The platform is built as a set of interacting RESTful web services (SaaS approach). Users can interact with the platform through a web browser or command line interface. Such a resource has no analogues in the field of nonlinear optics and will be created for the first time therefore allowing researchers to access high-performance computing resources that will significantly reduce the cost of the research and development process.

An Integrative Model of "Information Visibility" and "Information Seeking" on the Web

ERIC Educational Resources Information Center

Mansourian, Yazdan; Ford, Nigel; Webber, Sheila; Madden, Andrew

2008-01-01

Purpose: This paper aims to encapsulate the main procedure and key findings of a qualitative research on end-users' interactions with web-based search tools in order to demonstrate how the concept of "information visibility" emerged and how an integrative model of information visibility and information seeking on the web was constructed.…

Integrating DXplain into a clinical information system using the World Wide Web.

PubMed

Elhanan, G; Socratous, S A; Cimino, J J

1996-01-01

The World Wide Web(WWW) offers a cross-platform environment and standard protocols that enable integration of various applications available on the Internet. The authors use the Web to facilitate interaction between their Web-based Clinical Information System and a decision-support system-DXplain, at the Massachusetts General Hospital-using local architecture and Common Gateway Interface programs. The current application translates patients laboratory test results into DXplain's terms to generate diagnostic hypotheses. Two different access methods are utilized for this model; Hypertext Transfer Protocol (HTTP) and TCP/IP function calls. While clinical aspects cannot be evaluated as yet, the model demonstrates the potential of Web-based applications for interaction and integration and how local architecture, with a controlled vocabulary server, can further facilitate such integration. This model serves to demonstrate some of the limitations of the current WWW technology and identifies issues such as control over Web resources and their utilization and liability issues as possible obstacles for further integration.

Using a web-based application to define the accuracy of diagnostic tests when the gold standard is imperfect.

PubMed

Lim, Cherry; Wannapinij, Prapass; White, Lisa; Day, Nicholas P J; Cooper, Ben S; Peacock, Sharon J; Limmathurotsakul, Direk

2013-01-01

Estimates of the sensitivity and specificity for new diagnostic tests based on evaluation against a known gold standard are imprecise when the accuracy of the gold standard is imperfect. Bayesian latent class models (LCMs) can be helpful under these circumstances, but the necessary analysis requires expertise in computational programming. Here, we describe open-access web-based applications that allow non-experts to apply Bayesian LCMs to their own data sets via a user-friendly interface. Applications for Bayesian LCMs were constructed on a web server using R and WinBUGS programs. The models provided (http://mice.tropmedres.ac) include two Bayesian LCMs: the two-tests in two-population model (Hui and Walter model) and the three-tests in one-population model (Walter and Irwig model). Both models are available with simplified and advanced interfaces. In the former, all settings for Bayesian statistics are fixed as defaults. Users input their data set into a table provided on the webpage. Disease prevalence and accuracy of diagnostic tests are then estimated using the Bayesian LCM, and provided on the web page within a few minutes. With the advanced interfaces, experienced researchers can modify all settings in the models as needed. These settings include correlation among diagnostic test results and prior distributions for all unknown parameters. The web pages provide worked examples with both models using the original data sets presented by Hui and Walter in 1980, and by Walter and Irwig in 1988. We also illustrate the utility of the advanced interface using the Walter and Irwig model on a data set from a recent melioidosis study. The results obtained from the web-based applications were comparable to those published previously. The newly developed web-based applications are open-access and provide an important new resource for researchers worldwide to evaluate new diagnostic tests.

Program Director as Webmaster? Analysis of 131 Anesthesiology Department Web Sites and Program Director Web Site Involvement and Opinion Survey.

PubMed

Daneshpayeh, Negin; Lee, Howard; Berger, Jeffrey

2013-01-01

The last formal review of academic anesthesiology department Web sites (ADWs) for content was conducted in 2009. ADWs have been rated as very important by medical students in researching residency training programs; however, the rapid evolution of sites require that descriptive statistics must be more current to be considered reliable. We set out to provide an updated overview of ADW content and to better understand residency program directors' (PD) role and comfort with ADWs. Two independent reviewers (ND and HL) analyzed all 131 Accreditation Council for Graduate Medical Education (ACGME) accredited ADWs. A binary system (Yes/No) was used to determine which features were present. Reviewer reliability was confirmed with inter-rater reliability and percentage agreement calculation. Additionally, a blinded electronic survey (Survey Monkey, Portland, OR) was sent to anesthesiology residency PDs via electronic mail investigating the audiences for ADWs, the frequency of updates and the degree of PD involvement. 13% of anesthesiology departments still lack a Web site with a homepage with links to the residency program and educational offerings (18% in 2009). Only half (55%) of Web sites contain information for medical students, including clerkship information. Furthermore, programs rarely contain up-to-date calendars (13%), accreditation cycle lengths (11%), accreditation dates (7%) or board pass rates (6%). The PD survey, completed by 42 of 131 PDs, noted a correlation (r = 0.36) between the number of years as PD and the frequency of Web site updates - less experienced PDs appear to update their sites more frequently (p = 0.03). Although 86% of PDs regarded a Web site as "very" important in recruitment, only 9% felt "very" comfortable with the skills required to advertise and market a Web site. Despite the overall increase in ADW content since 2009, privacy concerns, limited resources and time constraints may prevent PDs from providing the most up-to-date Web sites for applicants and other interested audiences. PDs are aware of value of Web sites for recruitment, are typically involved in determining ADW content, but few feel very comfortable marketing a training program on the Web.

Applying the Technology Acceptance Model and flow theory to Cyworld user behavior: implication of the Web2.0 user acceptance.

PubMed

Shin, Dong-Hee; Kim, Won-Yong; Kim, Won-Young

2008-06-01

This study explores attitudinal and behavioral patterns when using Cyworld by adopting an expanded Technology Acceptance Model (TAM). A model for Cyworld acceptance is used to examine how various factors modified from the TAM influence acceptance and its antecedents. This model is examined through an empirical study involving Cyworld users using structural equation modeling techniques. The model shows reasonably good measurement properties and the constructs are validated. The results not only confirm the model but also reveal general factors applicable to Web2.0. A set of constructs in the model can be the Web2.0-specific factors, playing as enhancing factor to attitudes and intention.

3DNOW: Image-Based 3d Reconstruction and Modeling via Web

NASA Astrophysics Data System (ADS)

Tefera, Y.; Poiesi, F.; Morabito, D.; Remondino, F.; Nocerino, E.; Chippendale, P.

2018-05-01

This paper presents a web-based 3D imaging pipeline, namely 3Dnow, that can be used by anyone without the need of installing additional software other than a browser. By uploading a set of images through the web interface, 3Dnow can generate sparse and dense point clouds as well as mesh models. 3D reconstructed models can be downloaded with standard formats or previewed directly on the web browser through an embedded visualisation interface. In addition to reconstructing objects, 3Dnow offers the possibility to evaluate and georeference point clouds. Reconstruction statistics, such as minimum, maximum and average intersection angles, point redundancy and density can also be accessed. The paper describes all features available in the web service and provides an analysis of the computational performance using servers with different GPU configurations.

Physical heterogeneity and aquatic community function in river networks: A case study from the Kanawha River Basin, USA

NASA Astrophysics Data System (ADS)

Thoms, M. C.; Delong, M. D.; Flotemersch, J. E.; Collins, S. E.

2017-08-01

The geomorphological character of a river network provides the template upon which evolution acts to create unique biological communities. Deciphering commonly observed patterns and processes within riverine landscapes resulting from the interplay between physical and biological components is a central tenet for the interdisciplinary field of river science. Relationships between the physical heterogeneity and food web character of functional process zones (FPZs) - large tracts of river with a similar geomorphic character -in the Kanawha River (West Virginia, USA) are examined in this study. Food web character was measured as food chain length (FCL), which reflects ecological community structure and ecosystem function. Our results show that the same basal resources were present throughout the Kanawha River but that their assimilation into the aquatic food web by primary consumers differed between FPZs. Differences in the trophic position of higher consumers (fish) were also recorded between FPZs. Overall, the morphological heterogeneity and heterogeneity of the river bed sediment of FPZs were significantly correlated with FCL. Specifically, FCL increases with greater FPZ physical heterogeneity. The result of this study does not support the current paradigm that ecosystem size is the primary determinant of food web character in river ecosystems.

Evolution mediates the effects of apex predation on aquatic food webs

PubMed Central

Urban, Mark C.

2013-01-01

Ecological and evolutionary mechanisms are increasingly thought to shape local community dynamics. Here, I evaluate if the local adaptation of a meso-predator to an apex predator alters local food webs. The marbled salamander (Ambystoma opacum) is an apex predator that consumes both the spotted salamander (Ambystoma maculatum) and shared zooplankton prey. Common garden experiments reveal that spotted salamander populations which co-occur with marbled salamanders forage more intensely than those that face other predator species. These foraging differences, in turn, alter the diversity, abundance and composition of zooplankton communities in common garden experiments and natural ponds. Locally adapted spotted salamanders exacerbate prey biomass declines associated with apex predation, but dampen the top-down effects of apex predation on prey diversity. Countergradient selection on foraging explains why locally adapted spotted salamanders exacerbate prey biomass declines. The two salamander species prefer different prey species, which explains why adapted spotted salamanders buffer changes in prey composition owing to apex predation. Results suggest that local adaptation can strongly mediate effects from apex predation on local food webs. Community ecologists might often need to consider the evolutionary history of populations to understand local diversity patterns, food web dynamics, resource gradients and their responses to disturbance. PMID:23720548

Evolution mediates the effects of apex predation on aquatic food webs.

PubMed

Urban, Mark C

2013-07-22

Ecological and evolutionary mechanisms are increasingly thought to shape local community dynamics. Here, I evaluate if the local adaptation of a meso-predator to an apex predator alters local food webs. The marbled salamander (Ambystoma opacum) is an apex predator that consumes both the spotted salamander (Ambystoma maculatum) and shared zooplankton prey. Common garden experiments reveal that spotted salamander populations which co-occur with marbled salamanders forage more intensely than those that face other predator species. These foraging differences, in turn, alter the diversity, abundance and composition of zooplankton communities in common garden experiments and natural ponds. Locally adapted spotted salamanders exacerbate prey biomass declines associated with apex predation, but dampen the top-down effects of apex predation on prey diversity. Countergradient selection on foraging explains why locally adapted spotted salamanders exacerbate prey biomass declines. The two salamander species prefer different prey species, which explains why adapted spotted salamanders buffer changes in prey composition owing to apex predation. Results suggest that local adaptation can strongly mediate effects from apex predation on local food webs. Community ecologists might often need to consider the evolutionary history of populations to understand local diversity patterns, food web dynamics, resource gradients and their responses to disturbance.

Quality evaluation on an e-learning system in continuing professional education of nurses.

PubMed

Lin, I-Chun; Chien, Yu-Mei; Chang, I-Chiu

2006-01-01

Maintaining high quality in Web-based learning is a powerful means of increasing the overall efficiency and effectiveness of distance learning. Many studies have evaluated Web-based learning but seldom evaluate from the information systems (IS) perspective. This study applied the famous IS Success model in measuring the quality of a Web-based learning system using a Web-based questionnaire for data collection. One hundred and fifty four nurses participated in the survey. Based on confirmatory factor analysis, the variables of the research model fit for measuring the quality of a Web-based learning system. As Web-based education continues to grow worldwide, the results of this study may assist the system adopter (hospital executives), the learner (nurses), and the system designers in making reasonable and informed judgments with regard to the quality of Web-based learning system in continuing professional education.

Comparing cosmic web classifiers using information theory

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

Leclercq, Florent; Lavaux, Guilhem; Wandelt, Benjamin

We introduce a decision scheme for optimally choosing a classifier, which segments the cosmic web into different structure types (voids, sheets, filaments, and clusters). Our framework, based on information theory, accounts for the design aims of different classes of possible applications: (i) parameter inference, (ii) model selection, and (iii) prediction of new observations. As an illustration, we use cosmographic maps of web-types in the Sloan Digital Sky Survey to assess the relative performance of the classifiers T-WEB, DIVA and ORIGAMI for: (i) analyzing the morphology of the cosmic web, (ii) discriminating dark energy models, and (iii) predicting galaxy colors. Ourmore » study substantiates a data-supported connection between cosmic web analysis and information theory, and paves the path towards principled design of analysis procedures for the next generation of galaxy surveys. We have made the cosmic web maps, galaxy catalog, and analysis scripts used in this work publicly available.« less

Bridging Social and Semantic Computing - Design and Evaluation of User Interfaces for Hybrid Systems

ERIC Educational Resources Information Center

Bostandjiev, Svetlin Alex I.

2012-01-01

The evolution of the Web brought new interesting problems to computer scientists that we loosely classify in the fields of social and semantic computing. Social computing is related to two major paradigms: computations carried out by a large amount of people in a collective intelligence fashion (i.e. wikis), and performing computations on social…

Conversational Scholarship in Cyberspace: The Evolution and Activities of H-Net, the Online Network for the Humanities.

ERIC Educational Resources Information Center

Turnbull, Paul

1996-01-01

The origins and current use of H-Net, an online humanities network on the World Wide Web, are examined. H-Net currently sponsors 73 electronic discussion lists that reach subscribers in 68 countries. Discussion groups have not met expectations for scholarly exchange, possibly because of plagiarism and copyright concerns. New ventures include book…

Fostering the Public Voice: Blogging as a Pedagogical Practice in Ministerial Education

ERIC Educational Resources Information Center

Zsupan-Jerome, Daniella

2014-01-01

In the evolution of the World Wide Web toward a more participatory experience, the blog is one opportunity with intriguing educational potential. Among its educational benefits, the blog can offer a platform for exercising the public voice, but does so in a way that is simultaneously private and public, giving the author a safe distance through…

The Evolution of an Undergraduate Service Course--How To Cope with Success of an Age of Dinosaurs Class.

ERIC Educational Resources Information Center

Montgomery, Homer

2003-01-01

Discusses how to address the issue of a course becoming too popular. Uses as an example the Age of Dinosaurs course at the University of Texas at Dallas. Describes some issues that can arise such as classroom overflow, overwhelmed labs, cheating, testing methods, and asynchronous instruction. Recommends looking to web-based course management…

The Internet and the Evolution of Library Research: The Perspective of One Longitudinal Study

ERIC Educational Resources Information Center

Jaeger, Paul T.; Thompson, Kim M.; Lazar, Jonathan

2012-01-01

The impacts of the Internet on library services and information usage since the advent of the World Wide Web have been significant, changing patron expectations for libraries, the ways in which libraries can reach patrons, the amount of information available, the job requirements of librarians, and the roles that libraries can play in their…

Women in the Academy: Female Leadership in STEM Education and the Evolution of a Mentoring Web

ERIC Educational Resources Information Center

Gorman, Susan T.; Durmowicz, Meredith C.; Roskes, Ellen M.; Slattery, Susan P.

2010-01-01

Women continue to be underrepresented in science, technology, engineering, and mathematics (STEM) fields and in STEM leadership positions. According to the most recent data available from the National Science Foundation, in academia only 31% of full-time STEM faculty and 27% of STEM deans and department heads are women. By comparison at Stevenson…

Topographic signatures of deep-seated landslides and a general landscape evolution model

NASA Astrophysics Data System (ADS)

Booth, A. M.; Roering, J. J.; Rempel, A. W.

2012-12-01

A fundamental goal of studying earth surface processes is to disentangle the complex web of interactions among baselevel, climate, and rock properties that generate characteristic landforms. Mechanistic geomorphic transport laws can quantitatively address this goal, but no widely accepted law for landslides exists. Here, we propose a transport law for deep-seated landslides and demonstrate its utility using a two-dimensional numerical landscape evolution model informed by study areas in the Waipaoa catchment, New Zealand and the Eel River catchment, California. We define a non-dimensional landslide number, which is the ratio of uplift to landslide flow time scales, that predicts three distinct landscape types. The first is dominated by stochastic landsliding, whereby discrete landslide events episodically erode material at rates far exceeding the long term uplift rate. The second is characterized by steady landsliding, in which the landslide flux at any location remains constant through time and is largest at the steepest locations in the catchment. The third is not significantly affected by landsliding. In both the "stochastic landsliding" and "steady landsliding" regimes, increases in the non-dimensional landslide number systematically reduce catchment relief and widen valley spacing, producing long, quasi-planar, low angle hillslopes despite high uplift rates. The stochastic landsliding regime best captures the frequent observation that deep-seated landslides produce a large sediment flux from a small aerial extent while being active only a fraction of the time. We suggest that this model is adaptable to a wide range of geologic settings and may be useful for interpreting climate-driven changes in landslide behavior.

Topographic signatures and a general transport law for deep-seated landslides in a landscape evolution model

NASA Astrophysics Data System (ADS)

Booth, Adam M.; Roering, Josh J.; Rempel, Alan W.

2013-06-01

A fundamental goal of studying earth surface processes is to disentangle the complex web of interactions among baselevel, tectonics, climate, and rock properties that generate characteristic landforms. Mechanistic geomorphic transport laws can quantitatively address this goal, but no widely accepted law for landslides exists. Here we propose a transport law for deep-seated landslides in weathered bedrock and demonstrate its utility using a two-dimensional numerical landscape evolution model informed by study areas in the Waipaoa catchment, New Zealand, and the Eel River catchment, California. We define a non-dimensional landslide number, which is the ratio of the horizontal landslide flux to the vertical tectonic flux, that characterizes three distinct landscape types. One is dominated by stochastic landsliding, whereby discrete landslide events episodically erode material at rates exceeding the long-term uplift rate. Another is characterized by steady landsliding, in which the landslide flux at any location remains constant through time and is greatest at the steepest locations in the catchment. The third is not significantly affected by landsliding. In both the "stochastic landsliding" and "steady landsliding" regimes, increases in the non-dimensional landslide number systematically reduce catchment relief and widen valley spacing, producing long, low angle hillslopes despite high uplift rates. The stochastic landsliding regime captures the frequent observation that deep-seated landslides produce large sediment fluxes from small areal extents while being active only a fraction of the time. We suggest that this model is adaptable to a wide range of geologic settings and is useful for interpreting climate-driven changes in landslide behavior.

The Evolving Role of Information Technology in Haemovigilance Systems

PubMed Central

Condeço, Jorge; Escoval, Maria Antónia; Faber, Jean-Claude

2018-01-01

This work provides an overview and appraisal of the general evolution of IS/IT in haemovigilance, from which lessons can be learned for its future strategic management. An electronic survey was conducted among the members of the International Haemovigilance Network to compile information on the mechanisms implemented to gather, process, validate, and store these data, to monitor haemovigilance activity, and to produce analytical reports. Survey responses were analysed by means of descriptive statistics, and comments/observations were considered in the final discussion. The answers received from 23 haemovigilance organizations show a direct relationship between the number of collected notifications (i.e., communication of adverse effects and events) and the technical specifications of the haemovigilance system in use. Notably, IT is used in the notification reception of 17 of these systems, out of which 8 systems are exclusively based on Web solutions. Most assessments of the evolution of IS/IT tend to focus on the scalability and flexibility of data gathering and reporting, considering the ever-changing requirements of haemovigilance. Data validation is poorly implemented, and data reporting has not reached its full potential. Web-based solutions are seen as the most intuitive and flexible for a system-user interaction. PMID:29707185

A Connection Model between the Positioning Mechanism and Ultrasonic Measurement System via a Web Browser to Assess Acoustic Target Strength

NASA Astrophysics Data System (ADS)

Ishii, Ken; Imaizumi, Tomohito; Abe, Koki; Takao, Yoshimi; Tamura, Shuko

This paper details a network-controlled measurement system for use in fisheries engineering. The target strength (TS) of fish is important in order to convert acoustic integration values obtained during acoustic surveys into estimates of fish abundance. The target strength pattern is measured with the combination of the rotation system for the aspect of the sample and the echo data acquisition system using the underwater supersonic wave. The user interface of the network architecture is designed for collaborative use with researchers in other organizations. The flexible network architecture is based on the web direct-access model for the rotation mechanism. The user interface is available for monitoring and controlling via a web browser that is installed in any terminal PC (personal computer). Previously the combination of two applications was performed not by a web browser but by the exclusive interface program. So a connection model is proposed between two applications by indirect communication via the DCOM (Distributed Component Object Model) server and added in the web direct-access model. A prompt report system in the TS measurement system and a positioning and measurement system using an electric flatcar via a web browser are developed. By a secure network architecture, DCOM communications via both Intranet and LAN are successfully certificated.

Technical note: Harmonizing met-ocean model data via standard web services within small research groups

NASA Astrophysics Data System (ADS)

Signell, R. P.; Camossi, E.

2015-11-01

Work over the last decade has resulted in standardized web-services and tools that can significantly improve the efficiency and effectiveness of working with meteorological and ocean model data. While many operational modelling centres have enabled query and access to data via common web services, most small research groups have not. The penetration of this approach into the research community, where IT resources are limited, can be dramatically improved by: (1) making it simple for providers to enable web service access to existing output files; (2) using technology that is free, and that is easy to deploy and configure; and (3) providing tools to communicate with web services that work in existing research environments. We present a simple, local brokering approach that lets modelers continue producing custom data, but virtually aggregates and standardizes the data using NetCDF Markup Language. The THREDDS Data Server is used for data delivery, pycsw for data search, NCTOOLBOX (Matlab®1) and Iris (Python) for data access, and Ocean Geospatial Consortium Web Map Service for data preview. We illustrate the effectiveness of this approach with two use cases involving small research modelling groups at NATO and USGS.1 Mention of trade names or commercial products does not constitute endorsement or recommendation for use by the US Government.

Verifying Food Web Bioaccumulation Models by Tracking Fish Exposure and Contaminant Uptake

DTIC Science & Technology

2012-03-01

Arnot, J. A. and F. A. P. C. Gobas (2004). "A Food Web Bioaccumulation Model for Organic Chemicals in Aquatic Ecosystems." Environmental Toxicology...site in Eagle Harbor, Washington." Aquatic Toxicology 88: 277-288. Myers, M. S., L. L. Johnson, et al. (2003). "Establishing the Causal Relationship...P. Connolly, et al. (1992). "An Equilibrium Model of Organic Chemical Accumulation in Aquatic Food Webs with Sediment Interaction." Environmental

Using Sensor Web Processes and Protocols to Assimilate Satellite Data into a Forecast Model

NASA Technical Reports Server (NTRS)

Goodman, H. Michael; Conover, Helen; Zavodsky, Bradley; Maskey, Manil; Jedlovec, Gary; Regner, Kathryn; Li, Xiang; Lu, Jessica; Botts, Mike; Berthiau, Gregoire

2008-01-01

The goal of the Sensor Management Applied Research Technologies (SMART) On-Demand Modeling project is to develop and demonstrate the readiness of the Open Geospatial Consortium (OGC) Sensor Web Enablement (SWE) capabilities to integrate both space-based Earth observations and forecast model output into new data acquisition and assimilation strategies. The project is developing sensor web-enabled processing plans to assimilate Atmospheric Infrared Sounding (AIRS) satellite temperature and moisture retrievals into a regional Weather Research and Forecast (WRF) model over the southeastern United States.

Parmodel: a web server for automated comparative modeling of proteins.

PubMed

Uchôa, Hugo Brandão; Jorge, Guilherme Eberhart; Freitas Da Silveira, Nelson José; Camera, João Carlos; Canduri, Fernanda; De Azevedo, Walter Filgueira

2004-12-24

Parmodel is a web server for automated comparative modeling and evaluation of protein structures. The aim of this tool is to help inexperienced users to perform modeling, assessment, visualization, and optimization of protein models as well as crystallographers to evaluate structures solved experimentally. It is subdivided in four modules: Parmodel Modeling, Parmodel Assessment, Parmodel Visualization, and Parmodel Optimization. The main module is the Parmodel Modeling that allows the building of several models for a same protein in a reduced time, through the distribution of modeling processes on a Beowulf cluster. Parmodel automates and integrates the main softwares used in comparative modeling as MODELLER, Whatcheck, Procheck, Raster3D, Molscript, and Gromacs. This web server is freely accessible at .

The features of the Cosmic Web unveiled by the flip-flop field

NASA Astrophysics Data System (ADS)

Shandarin, Sergei F.; Medvedev, Mikhail V.

2017-07-01

Currently the dark matter environment is widely accepted as a framework for understanding of the observed structure in the universe. N-body simulations are indispensable for the analysis of the formation and evolution of the dark matter web. Two primary fields - density and velocity fields - are used in most of studies. Dark matter provides two additional fields that are unique for collisionless media only. They are the multistream field in Eulerian space and flip-flop field in Lagrangian space. The flip-flop field represents the number of sign reversals of an elementary volume of each collisionless fluid element. This field can be estimated by counting the sign reversals of the Jacobian at each particle at every time step of the simulation. The Jacobian is evaluated by numerical differentiation of the Lagrangian submanifold, I.e. the three-dimensional dark matter sheet in the six-dimensional space formed by three Lagrangian and three Eulerian coordinates. We present the results of the statistical study of the evolution of the flip-flop field from z = 50 to the present time z = 0. A number of statistical characteristics show that the pattern of the flip-flop field remains remarkably stable from z ≈ 30 to the present time. As a result the flip-flop field evaluated at z = 0 stores a wealth of information about the dynamical history of the dark matter web. In particular one of the most intriguing properties of the flip-flop is a unique capability to preserve the information about the merging history of haloes.

A web system of virtual morphometric globes for Mars and the Moon

NASA Astrophysics Data System (ADS)

Florinsky, I. V.; Garov, A. S.; Karachevtseva, I. P.

2018-09-01

We developed a web system of virtual morphometric globes for Mars and the Moon. As the initial data, we used 15-arc-minutes gridded global digital elevation models (DEMs) extracted from the Mars Orbiter Laser Altimeter (MOLA) and the Lunar Orbiter Laser Altimeter (LOLA) gridded archives. We derived global digital models of sixteen morphometric variables including horizontal, vertical, minimal, and maximal curvatures, as well as catchment area and topographic index. The morphometric models were integrated into the web system developed as a distributed application consisting of a client front-end and a server back-end. The following main functions are implemented in the system: (1) selection of a morphometric variable; (2) two-dimensional visualization of a calculated global morphometric model; (3) 3D visualization of a calculated global morphometric model on the sphere surface; (4) change of a globe scale; and (5) globe rotation by an arbitrary angle. Free, real-time web access to the system is provided. The web system of virtual morphometric globes can be used for geological and geomorphological studies of Mars and the Moon at the global, continental, and regional scales.

Combining Domain-driven Design and Mashups for Service Development

NASA Astrophysics Data System (ADS)

Iglesias, Carlos A.; Fernández-Villamor, José Ignacio; Del Pozo, David; Garulli, Luca; García, Boni

This chapter presents the Romulus project approach to Service Development using Java-based web technologies. Romulus aims at improving productivity of service development by providing a tool-supported model to conceive Java-based web applications. This model follows a Domain Driven Design approach, which states that the primary focus of software projects should be the core domain and domain logic. Romulus proposes a tool-supported model, Roma Metaframework, that provides an abstraction layer on top of existing web frameworks and automates the application generation from the domain model. This metaframework follows an object centric approach, and complements Domain Driven Design by identifying the most common cross-cutting concerns (security, service, view, ...) of web applications. The metaframework uses annotations for enriching the domain model with these cross-cutting concerns, so-called aspects. In addition, the chapter presents the usage of mashup technology in the metaframework for service composition, using the web mashup editor MyCocktail. This approach is applied to a scenario of the Mobile Phone Service Portability case study for the development of a new service.

Service-based analysis of biological pathways

PubMed Central

Zheng, George; Bouguettaya, Athman

2009-01-01

Background Computer-based pathway discovery is concerned with two important objectives: pathway identification and analysis. Conventional mining and modeling approaches aimed at pathway discovery are often effective at achieving either objective, but not both. Such limitations can be effectively tackled leveraging a Web service-based modeling and mining approach. Results Inspired by molecular recognitions and drug discovery processes, we developed a Web service mining tool, named PathExplorer, to discover potentially interesting biological pathways linking service models of biological processes. The tool uses an innovative approach to identify useful pathways based on graph-based hints and service-based simulation verifying user's hypotheses. Conclusion Web service modeling of biological processes allows the easy access and invocation of these processes on the Web. Web service mining techniques described in this paper enable the discovery of biological pathways linking these process service models. Algorithms presented in this paper for automatically highlighting interesting subgraph within an identified pathway network enable the user to formulate hypothesis, which can be tested out using our simulation algorithm that are also described in this paper. PMID:19796403

ExPASy: SIB bioinformatics resource portal.

PubMed

Artimo, Panu; Jonnalagedda, Manohar; Arnold, Konstantin; Baratin, Delphine; Csardi, Gabor; de Castro, Edouard; Duvaud, Séverine; Flegel, Volker; Fortier, Arnaud; Gasteiger, Elisabeth; Grosdidier, Aurélien; Hernandez, Céline; Ioannidis, Vassilios; Kuznetsov, Dmitry; Liechti, Robin; Moretti, Sébastien; Mostaguir, Khaled; Redaschi, Nicole; Rossier, Grégoire; Xenarios, Ioannis; Stockinger, Heinz

2012-07-01

ExPASy (http://www.expasy.org) has worldwide reputation as one of the main bioinformatics resources for proteomics. It has now evolved, becoming an extensible and integrative portal accessing many scientific resources, databases and software tools in different areas of life sciences. Scientists can henceforth access seamlessly a wide range of resources in many different domains, such as proteomics, genomics, phylogeny/evolution, systems biology, population genetics, transcriptomics, etc. The individual resources (databases, web-based and downloadable software tools) are hosted in a 'decentralized' way by different groups of the SIB Swiss Institute of Bioinformatics and partner institutions. Specifically, a single web portal provides a common entry point to a wide range of resources developed and operated by different SIB groups and external institutions. The portal features a search function across 'selected' resources. Additionally, the availability and usage of resources are monitored. The portal is aimed for both expert users and people who are not familiar with a specific domain in life sciences. The new web interface provides, in particular, visual guidance for newcomers to ExPASy.

Quicker, slicker, and better? An evaluation of a web-based human resource management system

NASA Astrophysics Data System (ADS)

Gibb, Stephen; McBride, Andrew

2001-10-01

This paper reviews the design and development of a web based Human Resource Management (HRM) system which has as its foundation a 'capability profiler' tool for analysing individual or team roles in organisations. This provides a foundation for managing a set of integrated activities in recruitment and selection, performance and career management, and training and development for individuals, teams, and whole organisations. The challenges of representing and processing information about the human side of organisation encountered in the design and implementation of such systems are evident. There is a combination of legal, practical, technical and philosophical issues to be faced in the processes of defining roles, selecting staff, monitoring and managing the performance of employees in the design and implementation of such systems. The strengths and weaknesses of web based systems in this context are evaluated. This evaluation highlights both the potential, given the evolution of broader Enterprise Resource Planning (ERP) systems and strategies in manufacturing, and concerns about the migration of HRM processes to such systems.

Web Services for Astronomical Databases: Connecting AIPS++ to the Virtual Observatory

NASA Astrophysics Data System (ADS)

Douthit, M. C.

2002-12-01

In the year 2010, the NRAO will be operating four of the world's most powerful radio telescopes: GBT, EVLA, VLBA, and ALMA (with international partnership). Multi-Terabyte data sets will quickly accumulate with a rate of twenty-five to fifty Megabytes of data per second generated by ALMA and EVLA each. It will be imperative for scientists to possess software capable of automated data reduction, image synthesis, and archiving. With the evolution of AIPS++ and the recently developed concepts of the image pipeline, the participation of the NRAO in the virtual observatories of the future is now on the horizon giving birth to the need for fast archive access and web service development in AIPS++. When the software package began over 10 years ago, it was not designed for data transfer via the web. In response to the demands of the NVO, we have designed and implemented an application layer that will allow our system to communicate with others. Sponsored by the NRAO and California State University, San Marcos.

Large-area sheet task: Advanced dendritic-web-growth development

NASA Technical Reports Server (NTRS)

Duncan, C. S.; Seidensticker, R. G.; Mchugh, J. P.; Schruben, J.

1983-01-01

Thermally generated stresses in the growing web crystal were reduced. These stresses, which if too high cause the ribbon to degenerate, were reduced by a factor of three, resulting in the demonstrated growth of high-quality web crystals to widths of 5.4 cm. This progress was brought about chiefly by the application of thermal models to the development of low-stress growth configurations. A new temperature model was developed which can analyze the thermal effects of much more complex lid and top shield configurations than was possible with the old lumped shield model. Growth experiments which supplied input data such as actual shield temperature and melt levels were used to verify the modeling results. Desirable modifications in the melt level-sensing circuitry were made in the new experimental web growth furnace, and this furnace has been used to carry out growth experiments under steady-state conditions. New growth configurations were tested in long growth runs at Westinghouse AESD which produced wider, lower stress and higher quality web crystals than designs previously used.

Critical design elements of e-health applications for users with severe mental illness: singular focus, simple architecture, prominent contents, explicit navigation, and inclusive hyperlinks.

PubMed

Rotondi, Armando J; Eack, Shaun M; Hanusa, Barbara H; Spring, Michael B; Haas, Gretchen L

2015-03-01

E-health applications are becoming integral components of general medical care delivery models and emerging for mental health care. Few exist for treatment of those with severe mental illness (SMI). In part, this is due to a lack of models to design such technologies for persons with cognitive impairments and lower technology experience. This study evaluated the effectiveness of an e-health design model for persons with SMI termed the Flat Explicit Design Model (FEDM). Persons with schizophrenia (n = 38) performed tasks to evaluate the effectiveness of 5 Web site designs: 4 were prominent public Web sites, and 1 was designed according to the FEDM. Linear mixed-effects regression models were used to examine differences in usability between the Web sites. Omnibus tests of between-site differences were conducted, followed by post hoc pairwise comparisons of means to examine specific Web site differences when omnibus tests reached statistical significance. The Web site designed using the FEDM required less time to find information, had a higher success rate, and was rated easier to use and less frustrating than the other Web sites. The home page design of one of the other Web sites provided the best indication to users about a Web site's contents. The results are consistent with and were used to expand the FEDM. The FEDM provides evidence-based guidelines to design e-health applications for person with SMI, including: minimize an application's layers or hierarchy, use explicit text, employ navigational memory aids, group hyperlinks in 1 area, and minimize the number of disparate subjects an application addresses. © The Author 2013. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Using Hi-FAME (High Feedback-Assessment-Multimedia-Environment) Instructional Model in WBI: A Case Study for Biology Teacher Education.

ERIC Educational Resources Information Center

Wang, Tzu-Hua; Wang, Wei-Lung; Wang, Kuo-Hua; Huang, Shih-Chieh

The study attempted to adapt two web tools, FFS system (Frontpage Feedback System) and WATA system (Web-based Assessment and Test Analysis System), to construct a Hi-FAME (High Feedback-Assessment-Multimedia-Environment) Model in WBI (Web-based Instruction) to facilitate pre-service teacher training. Participants were 30 junior pre-service…

Orientation of cosmic web filaments with respect to the underlying velocity field

NASA Astrophysics Data System (ADS)

Tempel, E.; Libeskind, N. I.; Hoffman, Y.; Liivamägi, L. J.; Tamm, A.

2014-01-01

The large-scale structure of the Universe is characterized by a web-like structure made of voids, sheets, filaments and knots. The structure of this so-called cosmic web is dictated by the local velocity shear tensor. In particular, the local direction of a filament should be strongly aligned with hat{e}_3, the eigenvector associated with the smallest eigenvalue of the tensor. That conjecture is tested here on the basis of a cosmological simulation. The cosmic web delineated by the halo distribution is probed by a marked point process with interactions (the Bisous model), detecting filaments directly from the halo distribution (P-web). The detected P-web filaments are found to be strongly aligned with the local hat{e}_3: the alignment is within 30° for ˜80 per cent of the elements. This indicates that large-scale filaments defined purely from the distribution of haloes carry more than just morphological information, although the Bisous model does not make any prior assumption on the underlying shear tensor. The P-web filaments are also compared to the structure revealed from the velocity shear tensor itself (V-web). In the densest regions, the P- and V-web filaments overlap well (90 per cent), whereas in lower density regions, the P-web filaments preferentially mark sheets in the V-web.

An Approach to Comprehensive and Sustainable Solar Wind Model Validation

NASA Astrophysics Data System (ADS)

Rastaetter, L.; MacNeice, P. J.; Mays, M. L.; Boblitt, J. M.; Wiegand, C.

2017-12-01

The number of models of the corona and inner heliosphere and of their updates and upgrades grows steadily, as does the number and character of the model inputs. Maintaining up to date validation of these models, in the face of this constant model evolution, is a necessary but very labor intensive activity. In the last year alone, both NASA's LWS program and the CCMC's ongoing support of model forecasting activities at NOAA SWPC have sought model validation reports on the quality of all aspects of the community's coronal and heliospheric models, including both ambient and CME related wind solutions at L1. In this presentation I will give a brief review of the community's previous model validation results of L1 wind representation. I will discuss the semi-automated web based system we are constructing at the CCMC to present comparative visualizations of all interesting aspects of the solutions from competing models.This system is designed to be easily queried to provide the essential comprehensive inputs to repeat andupdate previous validation studies and support extensions to them. I will illustrate this by demonstrating how the system is being used to support the CCMC/LWS Model Assessment Forum teams focused on the ambient and time dependent corona and solar wind, including CME arrival time and IMF Bz.I will also discuss plans to extend the system to include results from the Forum teams addressing SEP model validation.

Publishing and Editing of Semantically-Enabled Scientific Metadata Across Multiple Web Platforms: Challenges and Experiences

NASA Astrophysics Data System (ADS)

Patton, E. W.; West, P.; Greer, R.; Jin, B.

2011-12-01

Following on work presented at the 2010 AGU Fall Meeting, we present a number of real-world collections of semantically-enabled scientific metadata ingested into the Tetherless World RDF2HTML system as structured data and presented and edited using that system. Two separate datasets from two different domains (oceanography and solar sciences) are made available using existing web standards and services, e.g. encoded using ontologies represented with the Web Ontology Language (OWL) and stored in a SPARQL endpoint for querying. These datasets are deployed for use in three different web environments, i.e. Drupal, MediaWiki, and a custom web portal written in Java, to highlight the cross-platform nature of the data presentation. Stylesheets used to transform concepts in each domain as well as shared terms into HTML will be presented to show the power of using common ontologies to publish data and support reuse of existing terminologies. In addition, a single domain dataset is shared between two separate portal instances to demonstrate the ability for this system to offer distributed access and modification of content across the Internet. Lastly, we will highlight challenges that arose in the software engineering process, outline the design choices we made in solving those issues, and discuss how future improvements to this and other systems will enable the evolution of distributed, decentralized collaborations for scientific data sharing across multiple research groups.

WebDISCO: a web service for distributed cox model learning without patient-level data sharing.

PubMed

Lu, Chia-Lun; Wang, Shuang; Ji, Zhanglong; Wu, Yuan; Xiong, Li; Jiang, Xiaoqian; Ohno-Machado, Lucila

2015-11-01

The Cox proportional hazards model is a widely used method for analyzing survival data. To achieve sufficient statistical power in a survival analysis, it usually requires a large amount of data. Data sharing across institutions could be a potential workaround for providing this added power. The authors develop a web service for distributed Cox model learning (WebDISCO), which focuses on the proof-of-concept and algorithm development for federated survival analysis. The sensitive patient-level data can be processed locally and only the less-sensitive intermediate statistics are exchanged to build a global Cox model. Mathematical derivation shows that the proposed distributed algorithm is identical to the centralized Cox model. The authors evaluated the proposed framework at the University of California, San Diego (UCSD), Emory, and Duke. The experimental results show that both distributed and centralized models result in near-identical model coefficients with differences in the range [Formula: see text] to [Formula: see text]. The results confirm the mathematical derivation and show that the implementation of the distributed model can achieve the same results as the centralized implementation. The proposed method serves as a proof of concept, in which a publicly available dataset was used to evaluate the performance. The authors do not intend to suggest that this method can resolve policy and engineering issues related to the federated use of institutional data, but they should serve as evidence of the technical feasibility of the proposed approach.Conclusions WebDISCO (Web-based Distributed Cox Regression Model; https://webdisco.ucsd-dbmi.org:8443/cox/) provides a proof-of-concept web service that implements a distributed algorithm to conduct distributed survival analysis without sharing patient level data. © The Author 2015. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

CelOWS: an ontology based framework for the provision of semantic web services related to biological models.

PubMed

Matos, Ely Edison; Campos, Fernanda; Braga, Regina; Palazzi, Daniele

2010-02-01

The amount of information generated by biological research has lead to an intensive use of models. Mathematical and computational modeling needs accurate description to share, reuse and simulate models as formulated by original authors. In this paper, we introduce the Cell Component Ontology (CelO), expressed in OWL-DL. This ontology captures both the structure of a cell model and the properties of functional components. We use this ontology in a Web project (CelOWS) to describe, query and compose CellML models, using semantic web services. It aims to improve reuse and composition of existent components and allow semantic validation of new models.

Cosmic Web of Galaxies in the COSMOS Field: Public Catalog and Different Quenching for Centrals and Satellites

NASA Astrophysics Data System (ADS)

Darvish, Behnam; Mobasher, Bahram; Martin, D. Christopher; Sobral, David; Scoville, Nick; Stroe, Andra; Hemmati, Shoubaneh; Kartaltepe, Jeyhan

2017-03-01

We use a mass complete (log(M/{M}⊙ ) ≥slant 9.6) sample of galaxies with accurate photometric redshifts in the COSMOS field to construct the density field and the cosmic web to z = 1.2. The comic web extraction relies on the density field Hessian matrix and breaks the density field into clusters, filaments, and the field. We provide the density field and cosmic web measures to the community. We show that at z ≲ 0.8, the median star formation rate (SFR) in the cosmic web gradually declines from the field to clusters and this decline is especially sharp for satellites (˜1 dex versus ˜0.5 dex for centrals). However, at z ≳ 0.8, the trend flattens out for the overall galaxy population and satellites. For star-forming (SF) galaxies only, the median SFR is constant at z ≳ 0.5 but declines by ˜0.3-0.4 dex from the field to clusters for satellites and centrals at z ≲ 0.5. We argue that for satellites, the main role of the cosmic web environment is to control their SF fraction, whereas for centrals, it is mainly to control their overall SFR at z ≲ 0.5 and to set their fraction at z ≳ 0.5. We suggest that most satellites experience a rapid quenching mechanism as they fall from the field into clusters through filaments, whereas centrals mostly undergo a slow environmental quenching at z ≲ 0.5 and a fast mechanism at higher redshifts. Our preliminary results highlight the importance of the large-scale cosmic web on galaxy evolution.

Visual aspects of perception of multimedia messages on the web through the "eye tracker" method.

PubMed

Svilicić, Niksa

2010-09-01

Since the dawn of civilisation visual communication played a role in everyday life. In the early times there were simply shaped drawings of animals, pictograms explaining hunting tactics or strategies of attacking the enemies. Through evolution visual expression becomes an important component of communication process on several levels, from the existential and economic level to the artistic level. However, there was always a question of the level of user reception of such visual information in the medium transmitting the information. Does physical positioning of information in the medium contribute to the efficiency of the message? Do the same rules of content positioning apply for traditional (offline) and online media (Internet)? Rapid development of information technology and Internet in almost all segments of contemporary life calls for defining the rules of designing and positioning multimedia online contents on web sites. Recent research indicates beyond doubt that the physical positioning of an online content on a web site significantly determines the quality of user's perception of such content. By employing the "Eye tracking" method it is possible to objectively analyse the level of user perception of a multimedia content on a web site. What is the first thing observed by the user after opening the web site and how does he/she visually search the online content? By which methods can this be investigated subjectively and objectively? How can the survey results be used to improve the creation of web sites and to optimise the positioning of relevant contents on the site? The answers to these questions will significantly improve the presentation of multimedia interactive contents on the Web.

A food web modeling analysis of a Midwestern, USA eutrophic lake dominated by non-native Common Carp and Zebra Mussels

USGS Publications Warehouse

Colvin, Michael E.; Pierce, Clay; Stewart, Timothy W.

2015-01-01

Food web modeling is recognized as fundamental to understanding the complexities of aquatic systems. Ecopath is the most common mass-balance model used to represent food webs and quantify trophic interactions among groups. We constructed annual Ecopath models for four consecutive years during the first half-decade of a zebra mussel invasion in shallow, eutrophic Clear Lake, Iowa, USA, to evaluate changes in relative biomass and total system consumption among food web groups, evaluate food web impacts of non-native common carp and zebra mussels on food web groups, and to interpret food web impacts in light of on-going lake restoration. Total living biomass increased each year of the study; the majority of the increase due to a doubling in planktonic blue green algae, but several other taxa also increased including a more than two-order of magnitude increase in zebra mussels. Common carp accounted for the largest percentage of total fish biomass throughout the study even with on-going harvest. Chironomids, common carp, and zebra mussels were the top-three ranking consumer groups. Non-native common carp and zebra mussels accounted for an average of 42% of the total system consumption. Despite the relatively high biomass densities of common carp and zebra mussel, food web impacts was minimal due to excessive benthic and primary production in this eutrophic system. Consumption occurring via benthic pathways dominated system consumption in Clear Lake throughout our study, supporting the argument that benthic food webs are significant in shallow, eutrophic lake ecosystems and must be considered if ecosystem-level understanding is to be obtained.

Extinction risk and structure of a food web model

NASA Astrophysics Data System (ADS)

Pękalski, Andrzej; Szwabiński, Janusz; Bena, Ioana; Droz, Michel

2008-03-01

We investigate in detail the model of a trophic web proposed by Amaral and Meyer [Phys. Rev. Lett. 82, 652 (1999)]. We focus on small-size systems that are relevant for real biological food webs and for which the fluctuations play an important role. We show, using Monte Carlo simulations, that such webs can be nonviable, leading to extinction of all species in small and/or weakly coupled systems. Estimations of the extinction times and survival chances are also given. We show that before the extinction the fraction of highly connected species (“omnivores”) is increasing. Viable food webs exhibit a pyramidal structure, where the density of occupied niches is higher at lower trophic levels, and moreover the occupations of adjacent levels are closely correlated. We also demonstrate that the distribution of the lengths of food chains has an exponential character and changes weakly with the parameters of the model. On the contrary, the distribution of avalanche sizes of the extinct species depends strongly on the connectedness of the web. For rather loosely connected systems, we recover the power-law type of behavior with the same exponent as found in earlier studies, while for densely connected webs the distribution is not of a power-law type.

Using ant-behavior-based simulation model AntWeb to improve website organization

NASA Astrophysics Data System (ADS)

Li, Weigang; Pinheiro Dib, Marcos V.; Teles, Wesley M.; Morais de Andrade, Vlaudemir; Alves de Melo, Alba C. M.; Cariolano, Judas T.

2002-03-01

Some web usage mining algorithms showed the potential application to find the difference among the organizations expected by visitors to the website. However, there are still no efficient method and criterion for a web administrator to measure the performance of the modification. In this paper, we developed an AntWeb, a model inspired by ants' behavior to simulate the sequence of visiting the website, in order to measure the efficient of the web structure. We implemented a web usage mining algorithm using backtrack to the intranet website of the Politec Informatic Ltd., Brazil. We defined throughput (the number of visitors to reach their target pages per time unit relates to the total number of visitors) as an index to measure the website's performance. We also used the link in a web page to represent the effect of visitors' pheromone trails. For every modification in the website organization, for example, putting a link from the expected location to the target object, the simulation reported the value of throughput as a quick answer about this modification. The experiment showed the stability of our simulation model, and a positive modification to the intranet website of the Politec.

Knowledge Evolution in Distributed Geoscience Datasets and the Role of Semantic Technologies

NASA Astrophysics Data System (ADS)

Ma, X.

2014-12-01

Knowledge evolves in geoscience, and the evolution is reflected in datasets. In a context with distributed data sources, the evolution of knowledge may cause considerable challenges to data management and re-use. For example, a short news published in 2009 (Mascarelli, 2009) revealed the geoscience community's concern that the International Commission on Stratigraphy's change to the definition of Quaternary may bring heavy reworking of geologic maps. Now we are in the era of the World Wide Web, and geoscience knowledge is increasingly modeled and encoded in the form of ontologies and vocabularies by using semantic technologies. Accordingly, knowledge evolution leads to a consequence called ontology dynamics. Flouris et al. (2008) summarized 10 topics of general ontology changes/dynamics such as: ontology mapping, morphism, evolution, debugging and versioning, etc. Ontology dynamics makes impacts at several stages of a data life cycle and causes challenges, such as: the request for reworking of the extant data in a data center, semantic mismatch among data sources, differentiated understanding of a same piece of dataset between data providers and data users, as well as error propagation in cross-discipline data discovery and re-use (Ma et al., 2014). This presentation will analyze the best practices in the geoscience community so far and summarize a few recommendations to reduce the negative impacts of ontology dynamics in a data life cycle, including: communities of practice and collaboration on ontology and vocabulary building, link data records to standardized terms, and methods for (semi-)automatic reworking of datasets using semantic technologies. References: Flouris, G., Manakanatas, D., Kondylakis, H., Plexousakis, D., Antoniou, G., 2008. Ontology change: classification and survey. The Knowledge Engineering Review 23 (2), 117-152. Ma, X., Fox, P., Rozell, E., West, P., Zednik, S., 2014. Ontology dynamics in a data life cycle: Challenges and recommendations from a Geoscience Perspective. Journal of Earth Science 25 (2), 407-412. Mascarelli, A.L., 2009. Quaternary geologists win timescale vote. Nature 459, 624.

Content and Workflow Management for Library Websites: Case Studies

ERIC Educational Resources Information Center

Yu, Holly, Ed.

2005-01-01

Using database-driven web pages or web content management (WCM) systems to manage increasingly diverse web content and to streamline workflows is a commonly practiced solution recognized in libraries today. However, limited library web content management models and funding constraints prevent many libraries from purchasing commercially available…

A Design Analysis Model for Developing World Wide Web Sites.

ERIC Educational Resources Information Center

Ma, Yan

2002-01-01

Examines the relationship between and among designers, text, and users of the Galter Health Sciences Library Web site at Northwestern University by applying reader-response criticism. Highlights include Web site design; comparison of designers' intentions with the actual organization of knowledge on the Web site; and compares designer's intentions…

The web of Penelope. Regulating women's night work: an unfinished job?

PubMed

Riva, Michele A; Scordo, Francesco; Turato, Massimo; Messina, Giovanni; Cesana, Giancarlo

2015-12-01

Even though unhealthy consequences of night work for women have been evidenced by international scientific literature only in recent years, they were well acknowledged from ancient times. This essay traces the historical evolution of women's health conditions at work, focusing specifically on nocturnal work. Using the legendary web of Penelope of ancient Greek myths as a metaphor, the paper analyses the early limitations of night-work for women in pre-industrial era and the development of a modern international legislation on this issue, aimed at protecting women's health at the beginning of the twentieth century. The reform of national legislations in a gender-neutral manner has recently abolished gender disparities in night-work, but it seems it also reduced women's protection at work.

Analysis of web-related threats in ten years of logs from a scientific portal

NASA Astrophysics Data System (ADS)

Santos, Rafael D. C.; Grégio, André R. A.; Raddick, Jordan; Vattki, Vamsi; Szalay, Alex

2012-06-01

SkyServer is an Internet portal to data from the Sloan Digital Sky Survey, the largest online archive of astronomy data in the world. provides free access to hundreds of millions of celestial objects for science, education and outreach purposes. Logs of accesses to SkyServer comprise around 930 million hits, 140 million web services accesses and 170 million SQL submitted queries, collected over the past 10 years. These logs also contain indications of compromise attempts on the servers. In this paper, we show some threats that were detected in ten years of stored logs, and compare them with known threats in those years. Also, we present an analysis of the evolution of those threats over these years.

The Prolate Dark Matter Halo of the Andromeda Galaxy

NASA Astrophysics Data System (ADS)

Hayashi, Kohei; Chiba, Masashi

2014-07-01

We present new limits on the global shape of the dark matter halo in the Andromeda galaxy using and generalizing non-spherical mass models developed by Hayashi & Chiba and compare our results with theoretical predictions of cold dark matter (CDM) models. This is motivated by the fact that CDM models predict non-spherical virialized dark halos, which reflect the process of mass assembly in the galactic scale. Applying our models to the latest kinematic data of globular clusters and dwarf spheroidal galaxies in the Andromeda halo, we find that the most plausible cases for Andromeda yield a prolate shape for its dark halo, irrespective of assumed density profiles. We also find that this prolate dark halo in Andromeda is consistent with theoretical predictions in which the satellites are distributed anisotropically and preferentially located along major axes of their host halos. It is a reflection of the intimate connection between galactic dark matter halos and the cosmic web. Therefore, our result is profound in understanding internal dynamics of halo tracers in Andromeda, such as orbital evolutions of tidal stellar streams, which play important roles in extracting the abundance of CDM subhalos through their dynamical effects on stream structures.

The Checkerboard Model of the Nucleus

NASA Astrophysics Data System (ADS)

Lach, Theodore

2015-04-01

The Checker Board Model (CBM) of the nucleus and the associated extended standard model predicts that nature has 5 generations of quarks not 3 and that Nucleus is 2 dimensional. The CBM theory began with an insight into the structure of the He nucleus around the year 1989. Details of how this theory evolved which took many years, and is found on my web site (http://checkerboard.dnsalias.net) or in the following references One independent check of this model is that the wavelength of the ``up'' quark orbiting inside the proton at 84.8123% the speed of light (around the ``dn'' quark in the center of the proton) turns out to be exactly one de Broglie wavelength something determined after the mass and speed of the up quark were determined by other means. This theory explains the mass of the proton and neutron and their magnetic moments and this along with the beautiful symmetric 2D structure of the He nucleus led to the evolution of this theory. When this theory was first presented at Argonne in 1996, it was the first time that anyone had predicted the quarks orbited inside the proton at relativistic speeds and it was met with skepticism.

The prolate dark matter halo of the Andromeda galaxy

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

Hayashi, Kohei; Chiba, Masashi, E-mail: k.hayasi@astr.tohoku.ac.jp, E-mail: chiba@astr.tohoku.ac.jp

We present new limits on the global shape of the dark matter halo in the Andromeda galaxy using and generalizing non-spherical mass models developed by Hayashi and Chiba and compare our results with theoretical predictions of cold dark matter (CDM) models. This is motivated by the fact that CDM models predict non-spherical virialized dark halos, which reflect the process of mass assembly in the galactic scale. Applying our models to the latest kinematic data of globular clusters and dwarf spheroidal galaxies in the Andromeda halo, we find that the most plausible cases for Andromeda yield a prolate shape for itsmore » dark halo, irrespective of assumed density profiles. We also find that this prolate dark halo in Andromeda is consistent with theoretical predictions in which the satellites are distributed anisotropically and preferentially located along major axes of their host halos. It is a reflection of the intimate connection between galactic dark matter halos and the cosmic web. Therefore, our result is profound in understanding internal dynamics of halo tracers in Andromeda, such as orbital evolutions of tidal stellar streams, which play important roles in extracting the abundance of CDM subhalos through their dynamical effects on stream structures.« less

Allocation of DSST in the New implementation of Tastrodyweb Tools Web-site

NASA Astrophysics Data System (ADS)

San Juan, J. F.; Lara, M.; López, R.; López, L. M.; Weeden, B.; Cefola, P. J.

2012-09-01

The Draper Semianalytic Satellite Theory (DSST) is a semianalytic orbit propagator, which was carried out on Fortran to run from a command line interface. The construction of DSST began at the Computer Sciences Corporation and continued at the Draper Laboratory in the late 1970's and early 1980's. There are two versions of this application. One of them can be found as an option within the Goddard Trajectory Determination System (GTDS), whereas the other is available as a Standalone Orbit Propagator Package. Both versions are constantly evolving and updating. This constant evolution and updating allows DSST to take into account a wide variety of perturbation forces, which can be selected by means of a non-trivial options system at run time, and makes DSST a useful tool for performing short-term high accuracy orbit determination as well as long-term evolution. DSST has been included as part of an open source project for Space Situational Awareness and space object catalog work. On the last IAC 2011 a first step was taken in this sense and DSST was included on the tastrody Web-Site prototype [3, 4], which provided DSST with a friendly web interface, thus simplifying its use for both expert and non-expert users. However, this prototype has evolved into a stable platform based on the Drupal open source content management system (http://drupal.org Drupal), which simplifies the integration of our own application server. Drupal is supported by a large group of developers and users. Furthermore, a significant number of web-sites have been created using Drupal. In this work we present the integration of DSST in the new web-site, the new facilities provide by this platform to create the research community based on DSST and the comparison tests between the GTDS DSST, DSST Standalone and DSST Web version. These tests will be available in order to facilitate the user with better understanding of DSST. REFERENCES [1] J. G. Neelon, P. J. Cefola, and R. J. Proulx, Current Development of the Draper Semianalytical Satellite Theory Standalone Orbit Propagator Package", AAS Pre-print 97-731, presented at the AAS/AIAA Astrodynamics Conference, Sun Valley, ID, August 1997. [2] P. J. Cefola, D. Phillion, and K. S. Kim, Improving Access to the Semi-Analytical Satellite Theory, AAS 09-341, presented at the AAS/AIAA Astrodynamic Specialist Conference, Pittsburgh, PA, August 2009. [3] P. J. Cefola, B. Weeden and C. Levit, Open Source Software Suite for Space Situational Awareness and Space Object Catalog Work, 4th International Conference on Astrodynamics Tools Techniques, Madrid, Spain, 3-6 May 2010. [4] J. F. San Juan, R. López and I. Pérez, Nonlinear Dynamics Web Tools, 4th International Conference on Astrodynamics Tools Techniques, Madrid, Spain, 3-6 May 2010. [5] J. F. San Juan, M. Lara, R. López. L. M. López, B. Weeden and P. J. Cefola, Using the DSST Semi-Analytical Orbit. Propagator Package via the NondyWebTools/. AstrodyWebTools. Proceedings of 62nd International Astronautical Congress, Cape Town, SA., 2011.

FragFit: a web-application for interactive modeling of protein segments into cryo-EM density maps.

PubMed

Tiemann, Johanna K S; Rose, Alexander S; Ismer, Jochen; Darvish, Mitra D; Hilal, Tarek; Spahn, Christian M T; Hildebrand, Peter W

2018-05-21

Cryo-electron microscopy (cryo-EM) is a standard method to determine the three-dimensional structures of molecular complexes. However, easy to use tools for modeling of protein segments into cryo-EM maps are sparse. Here, we present the FragFit web-application, a web server for interactive modeling of segments of up to 35 amino acids length into cryo-EM density maps. The fragments are provided by a regularly updated database containing at the moment about 1 billion entries extracted from PDB structures and can be readily integrated into a protein structure. Fragments are selected based on geometric criteria, sequence similarity and fit into a given cryo-EM density map. Web-based molecular visualization with the NGL Viewer allows interactive selection of fragments. The FragFit web-application, accessible at http://proteinformatics.de/FragFit, is free and open to all users, without any login requirements.

Flows of dioxins and furans in coastal food webs: inverse modeling, sensitivity analysis, and applications of linear system theory.

PubMed

Saloranta, Tuomo M; Andersen, Tom; Naes, Kristoffer

2006-01-01

Rate constant bioaccumulation models are applied to simulate the flow of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the coastal marine food web of Frierfjorden, a contaminated fjord in southern Norway. We apply two different ways to parameterize the rate constants in the model, global sensitivity analysis of the models using Extended Fourier Amplitude Sensitivity Test (Extended FAST) method, as well as results from general linear system theory, in order to obtain a more thorough insight to the system's behavior and to the flow pathways of the PCDD/Fs. We calibrate our models against observed body concentrations of PCDD/Fs in the food web of Frierfjorden. Differences between the predictions from the two models (using the same forcing and parameter values) are of the same magnitude as their individual deviations from observations, and the models can be said to perform about equally well in our case. Sensitivity analysis indicates that the success or failure of the models in predicting the PCDD/F concentrations in the food web organisms highly depends on the adequate estimation of the truly dissolved concentrations in water and sediment pore water. We discuss the pros and cons of such models in understanding and estimating the present and future concentrations and bioaccumulation of persistent organic pollutants in aquatic food webs.

A web GIS based integrated flood assessment modeling tool for coastal urban watersheds

NASA Astrophysics Data System (ADS)

Kulkarni, A. T.; Mohanty, J.; Eldho, T. I.; Rao, E. P.; Mohan, B. K.

2014-03-01

Urban flooding has become an increasingly important issue in many parts of the world. In this study, an integrated flood assessment model (IFAM) is presented for the coastal urban flood simulation. A web based GIS framework has been adopted to organize the spatial datasets for the study area considered and to run the model within this framework. The integrated flood model consists of a mass balance based 1-D overland flow model, 1-D finite element based channel flow model based on diffusion wave approximation and a quasi 2-D raster flood inundation model based on the continuity equation. The model code is written in MATLAB and the application is integrated within a web GIS server product viz: Web Gram Server™ (WGS), developed at IIT Bombay, using Java, JSP and JQuery technologies. Its user interface is developed using open layers and the attribute data are stored in MySQL open source DBMS. The model is integrated within WGS and is called via Java script. The application has been demonstrated for two coastal urban watersheds of Navi Mumbai, India. Simulated flood extents for extreme rainfall event of 26 July, 2005 in the two urban watersheds of Navi Mumbai city are presented and discussed. The study demonstrates the effectiveness of the flood simulation tool in a web GIS environment to facilitate data access and visualization of GIS datasets and simulation results.

Some Programs Should Not Run on Laptops - Providing Programmatic Access to Applications Via Web Services

NASA Astrophysics Data System (ADS)

Gupta, V.; Gupta, N.; Gupta, S.; Field, E.; Maechling, P.

2003-12-01

Modern laptop computers, and personal computers, can provide capabilities that are, in many ways, comparable to workstations or departmental servers. However, this doesn't mean we should run all computations on our local computers. We have identified several situations in which it preferable to implement our seismological application programs in a distributed, server-based, computing model. In this model, application programs on the user's laptop, or local computer, invoke programs that run on an organizational server, and the results are returned to the invoking system. Situations in which a server-based architecture may be preferred include: (a) a program is written in a language, or written for an operating environment, that is unsupported on the local computer, (b) software libraries or utilities required to execute a program are not available on the users computer, (c) a computational program is physically too large, or computationally too expensive, to run on a users computer, (d) a user community wants to enforce a consistent method of performing a computation by standardizing on a single implementation of a program, and (e) the computational program may require current information, that is not available to all client computers. Until recently, distributed, server-based, computational capabilities were implemented using client/server architectures. In these architectures, client programs were often written in the same language, and they executed in the same computing environment, as the servers. Recently, a new distributed computational model, called Web Services, has been developed. Web Services are based on Internet standards such as XML, SOAP, WDSL, and UDDI. Web Services offer the promise of platform, and language, independent distributed computing. To investigate this new computational model, and to provide useful services to the SCEC Community, we have implemented several computational and utility programs using a Web Service architecture. We have hosted these Web Services as a part of the SCEC Community Modeling Environment (SCEC/CME) ITR Project (http://www.scec.org/cme). We have implemented Web Services for several of the reasons sited previously. For example, we implemented a FORTRAN-based Earthquake Rupture Forecast (ERF) as a Web Service for use by client computers that don't support a FORTRAN runtime environment. We implemented a Generic Mapping Tool (GMT) Web Service for use by systems that don't have local access to GMT. We implemented a Hazard Map Calculator Web Service to execute Hazard calculations that are too computationally intensive to run on a local system. We implemented a Coordinate Conversion Web Service to enforce a standard and consistent method for converting between UTM and Lat/Lon. Our experience developing these services indicates both strengths and weakness in current Web Service technology. Client programs that utilize Web Services typically need network access, a significant disadvantage at times. Programs with simple input and output parameters were the easiest to implement as Web Services, while programs with complex parameter-types required a significant amount of additional development. We also noted that Web services are very data-oriented, and adapting object-oriented software into the Web Service model proved problematic. Also, the Web Service approach of converting data types into XML format for network transmission has significant inefficiencies for some data sets.

Food webs for parasitologists: a review.

PubMed

Sukhdeo, Michael V K

2010-04-01

This review examines the historical origins of food web theory and explores the reasons why parasites have traditionally been left out of food web studies. Current paradigms may still be an impediment because, despite several attempts, it remains virtually impossible to retrofit parasites into food web theory in any satisfactory manner. It seems clear that parasitologists must return to first principles to solve how best to incorporate parasites into ecological food webs, and a first step in changing paradigms will be to include parasites in the classic ecological patterns that inform food web theory. The limitations of current food web models are discussed with respect to their logistic exclusion of parasites, and the traditional matrix approach in food web studies is critically examined. The well-known energetic perspective on ecosystem organization is presented as a viable alternative to the matrix approach because it provides an intellectually powerful theoretical paradigm for generating testable hypotheses on true food web structure. This review proposes that to make significant contributions to the food web debate, parasitologists must work from the standpoint of natural history to elucidate patterns of biomass, species abundance, and interaction strengths in real food webs, and these will provide the basis for more realistic models that incorporate parasite dynamics into the overall functional dynamics of the whole web. A general conclusion is that only by quantifying the effects of parasites in terms of energy flows (or biomass) will we be able to correctly place parasites into food webs.

Dynamic selection mechanism for quality of service aware web services

NASA Astrophysics Data System (ADS)

D'Mello, Demian Antony; Ananthanarayana, V. S.

2010-02-01

A web service is an interface of the software component that can be accessed by standard Internet protocols. The web service technology enables an application to application communication and interoperability. The increasing number of web service providers throughout the globe have produced numerous web services providing the same or similar functionality. This necessitates the use of tools and techniques to search the suitable services available over the Web. UDDI (universal description, discovery and integration) is the first initiative to find the suitable web services based on the requester's functional demands. However, the requester's requirements may also include non-functional aspects like quality of service (QoS). In this paper, the authors define a QoS model for QoS aware and business driven web service publishing and selection. The authors propose a QoS requirement format for the requesters, to specify their complex demands on QoS for the web service selection. The authors define a tree structure called quality constraint tree (QCT) to represent the requester's variety of requirements on QoS properties having varied preferences. The paper proposes a QoS broker based architecture for web service selection, which facilitates the requesters to specify their QoS requirements to select qualitatively optimal web service. A web service selection algorithm is presented, which ranks the functionally similar web services based on the degree of satisfaction of the requester's QoS requirements and preferences. The paper defines web service provider qualities to distinguish qualitatively competitive web services. The paper also presents the modelling and selection mechanism for the requester's alternative constraints defined on the QoS. The authors implement the QoS broker based system to prove the correctness of the proposed web service selection mechanism.

Large-area sheet task advanced dendritic web growth development

NASA Technical Reports Server (NTRS)

Duncan, C. S.; Seidensticker, R. G.; Mchugh, J. P.; Hopkins, R. H.; Meier, D. L.; Schruben, J.

1982-01-01

Thermal models were developed that accurately predict the thermally generated stresses in the web crystal which, if too high, cause the crystal to degenerate. The application of the modeling results to the design of low-stress experimental growth configurations will allow the growth of wider web crystals at higher growth velocities. A new experimental web growth machine was constructed. This facility includes all the features necessary for carrying out growth experiments under steady thermal conditions. Programmed growth initiation was developed to give reproducible crystal starts. Width control permits the growth of long ribbons at constant width. Melt level is controlled to 0.1 mm or better. Thus, the capability exists to grow long web crystals of constant width and thickness with little operator intervention, and web growth experiments can now be performed with growth variables controlled to a degree not previously possible.

Rumor spreading model with consideration of forgetting mechanism: A case of online blogging LiveJournal

NASA Astrophysics Data System (ADS)

Zhao, Laijun; Wang, Qin; Cheng, Jingjing; Chen, Yucheng; Wang, Jiajia; Huang, Wei

2011-07-01

Rumor is an important form of social interaction, and its spreading has a significant impact on people’s lives. In the age of Web, people are using electronic media more frequently than ever before, and blog has become one of the main online social interactions. Therefore, it is essential to learn the evolution mechanism of rumor spreading on homogeneous network in consideration of the forgetting mechanism of spreaders. Here we study a rumor spreading model on an online social blogging platform called LiveJournal. In comparison with the Susceptible-Infected-Removed (SIR) model, we provide a more detailed and realistic description of rumor spreading process with combination of forgetting mechanism and the SIR model of epidemics. A mathematical model has been presented and numerical solutions of the model were used to analyze the impact factors of rumor spreading, such as the average degree, forgetting rate and stifling rate. Our results show that there exist a threshold of the average degree of LiveJournal and above which the influence of rumor reaches saturation. Forgetting mechanism and stifling rate exert great influence on rumor spreading on online social network. The analysis results can guide people’s behaviors in view of the theoretical and practical aspects.

Diagnosing Students' Mental Models via the Web-Based Mental Models Diagnosis System

ERIC Educational Resources Information Center

Wang, Tzu-Hua; Chiu, Mei-Hung; Lin, Jing-Wen; Chou, Chin-Cheng

2013-01-01

Mental models play an important role in science education research. To extend the effectiveness of conceptual change research and to improve mental model identi?cation and diagnosis, the authors developed and tested the Web-Based Mental Models Diagnosis (WMMD) system. In this article, they describe their WMMD system, which goes beyond the…

The iMeteo is a web-based weather visualization tool

NASA Astrophysics Data System (ADS)

Tuni San-Martín, Max; San-Martín, Daniel; Cofiño, Antonio S.

2010-05-01

iMeteo is a web-based weather visualization tool. Designed with an extensible J2EE architecture, it is capable of displaying information from heterogeneous data sources such as gridded data from numerical models (in NetCDF format) or databases of local predictions. All this information is presented in a user-friendly way, being able to choose the specific tool to display data (maps, graphs, information tables) and customize it to desired locations. *Modular Display System* Visualization of the data is achieved through a set of mini tools called widgets. A user can add them at will and arrange them around the screen easily with a drag and drop movement. They can be of various types and each can be configured separately, forming a really powerful and configurable system. The "Map" is the most complex widget, since it can show several variables simultaneously (either gridded or point-based) through a layered display. Other useful widgets are the the "Histogram", which generates a graph with the frequency characteristics of a variable and the "Timeline" which shows the time evolution of a variable at a given location in an interactive way. *Customization and security* Following the trends in web development, the user can easily customize the way data is displayed. Due to programming in client side with technologies like AJAX, the interaction with the application is similar to the desktop ones because there are rapid respone times. If a user is registered then he could also save his settings in the database, allowing access from any system with Internet access with his particular setup. There is particular emphasis on application security. The administrator can define a set of user profiles, which may have associated restrictions on access to certain data sources, geographic areas or time intervals.

Experience versus talent shapes the structure of the Web

PubMed Central

Kong, Joseph S.; Sarshar, Nima; Roychowdhury, Vwani P.

2008-01-01

We use sequential large-scale crawl data to empirically investigate and validate the dynamics that underlie the evolution of the structure of the web. We find that the overall structure of the web is defined by an intricate interplay between experience or entitlement of the pages (as measured by the number of inbound hyperlinks a page already has), inherent talent or fitness of the pages (as measured by the likelihood that someone visiting the page would give a hyperlink to it), and the continual high rates of birth and death of pages on the web. We find that the web is conservative in judging talent and the overall fitness distribution is exponential, showing low variability. The small variance in talent, however, is enough to lead to experience distributions with high variance: The preferential attachment mechanism amplifies these small biases and leads to heavy-tailed power-law (PL) inbound degree distributions over all pages, as well as over pages that are of the same age. The balancing act between experience and talent on the web allows newly introduced pages with novel and interesting content to grow quickly and surpass older pages. In this regard, it is much like what we observe in high-mobility and meritocratic societies: People with entitlement continue to have access to the best resources, but there is just enough screening for fitness that allows for talented winners to emerge and join the ranks of the leaders. Finally, we show that the fitness estimates have potential practical applications in ranking query results. PMID:18779560

Evolution of ESA's SSA Conjunction Prediction Service

NASA Astrophysics Data System (ADS)

Escobar, D.; Sancho, A. Tirado, J.; Agueda, A.; Martin, L.; Luque, F.; Fletcher, E.; Navarro, V.

2013-08-01

This paper presents the recent evolution of ESA's SSA Conjunction Prediction Service (CPS) as a result of an on-going activity in the Space Surveillance and Tracking (SST) Segment of ESA's Space Situational Awareness (SSA) Programme. The CPS is one of a number of precursor services being developed as part of the SST segment. It has been implemented as a service to provide external users with web-based access to conjunction information and designed with a service-oriented architecture. The paper encompasses the following topics: service functionality enhancements, integration with a live objects catalogue, all vs. all analyses supporting an operational concept based on low and high fidelity screenings, and finally conjunction detection and probability algorithms.

Assessing uncertain human exposure to ambient air pollution using environmental models in the Web

NASA Astrophysics Data System (ADS)

Gerharz, L. E.; Pebesma, E.; Denby, B.

2012-04-01

Ambient air quality can have significant impact on human health by causing respiratory and cardio-vascular diseases. Thereby, the pollutant concentration a person is exposed to can differ considerably between individuals depending on their daily routine and movement patterns. Using a straight forward approach this exposure can be estimated by integration of individual space-time paths and spatio-temporally resolved ambient air quality data. To allow a realistic exposure assessment, it is furthermore important to consider uncertainties due to input and model errors. In this work, we present a generic, web-based approach for estimating individual exposure by integration of uncertain position and air quality information implemented as a web service. Following the Model Web initiative envisioning an infrastructure for deploying, executing and chaining environmental models as services, existing models and data sources for e.g. air quality, can be used to assess exposure. Therefore, the service needs to deal with different formats, resolutions and uncertainty representations provided by model or data services. Potential mismatch can be accounted for by transformation of uncertainties and (dis-)aggregation of data under consideration of changes in the uncertainties using components developed in the UncertWeb project. In UncertWeb, the Model Web vision is extended to an Uncertainty-enabled Model Web, where services can process and communicate uncertainties in the data and models. The propagation of uncertainty to the exposure results is quantified using Monte Carlo simulation by combining different realisations of positions and ambient concentrations. Two case studies were used to evaluate the developed exposure assessment service. In a first study, GPS tracks with a positional uncertainty of a few meters, collected in the urban area of Münster, Germany were used to assess exposure to PM10 (particulate matter smaller 10 µm). Air quality data was provided by an uncertainty-enabled air quality model system which provided realisations of concentrations per hour on a 250 m x 250 m resolved grid over Münster. The second case study uses modelled human trajectories in Rotterdam, The Netherlands. The trajectories were provided as realisations in 15 min resolution per 4 digit postal code from an activity model. Air quality estimates were provided for different pollutants as ensembles by a coupled meteorology and air quality model system on a 1 km x 1 km grid with hourly resolution. Both case studies show the successful application of the service to different resolutions and uncertainty representations.

Examining the Relationship between Teachers' Attitudes and Motivation toward Web-Based Professional Development: A Structural Equation Modeling Approach

ERIC Educational Resources Information Center

Chien, Hui-Min; Kao, Chia-Pin; Yeh, I-Jan; Lin, Kuen-Yi

2012-01-01

This study was conducted to investigate elementary school teachers' attitudes and motivation toward web-based professional development. The relationship between teachers' attitudes and motivation was explored using the AWPD (Attitudes toward Web-based Professional Development) and MWPD (Motivation toward Web-based Professional Development)…

A Risk-Analysis Approach to Implementing Web-Based Assessment

ERIC Educational Resources Information Center

Ricketts, Chris; Zakrzewski, Stan

2005-01-01

Computer-Based Assessment is a risky business. This paper proposes the use of a model for web-based assessment systems that identifies pedagogic, operational, technical (non web-based), web-based and financial risks. The strategies and procedures for risk elimination or reduction arise from risk analysis and management and are the means by which…

Graph Structure in Three National Academic Webs: Power Laws with Anomalies.

ERIC Educational Resources Information Center

Thelwall, Mike; Wilkinson, David

2003-01-01

Explains how the Web can be modeled as a mathematical graph and analyzes the graph structures of three national university publicly indexable Web sites from Australia, New Zealand, and the United Kingdom. Topics include commercial search engines and academic Web link research; method-analysis environment and data sets; and power laws. (LRW)

Authoring Educational Courseware Using OXYGEN.

ERIC Educational Resources Information Center

Ip, Albert

Engaging learners on the World Wide Web is more than sending Web pages to the user. However, for many course delivery software programs, the smallest unit of delivery is a Web page. How content experts can create engaging Web pages has largely been ignored or taken for granted. This paper reports on an authoring model for creating pedagogically…

The Adoption and Diffusion of Web Technologies into Mainstream Teaching.

ERIC Educational Resources Information Center

Hansen, Steve; Salter, Graeme

2001-01-01

Discusses various adoption and diffusion frameworks and methodologies to enhance the use of Web technologies by teaching staff. Explains the use of adopter-based models for product development; discusses the innovation-decision process; and describes PlatformWeb, a Web information system that was developed to help integrate a universities'…

Library Web Site Administration: A Strategic Planning Model For the Smaller Academic Library

ERIC Educational Resources Information Center

Ryan, Susan M.

2003-01-01

Strategic planning provides a useful structure for creating and implementing library web sites. The planned integration of a library's web site into its mission and objectives ensures that the library's community of users will consider the web site one of the most important information tools the library offers.

Growing and navigating the small world Web by local content

PubMed Central

Menczer, Filippo

2002-01-01

Can we model the scale-free distribution of Web hypertext degree under realistic assumptions about the behavior of page authors? Can a Web crawler efficiently locate an unknown relevant page? These questions are receiving much attention due to their potential impact for understanding the structure of the Web and for building better search engines. Here I investigate the connection between the linkage and content topology of Web pages. The relationship between a text-induced distance metric and a link-based neighborhood probability distribution displays a phase transition between a region where linkage is not determined by content and one where linkage decays according to a power law. This relationship is used to propose a Web growth model that is shown to accurately predict the distribution of Web page degree, based on textual content and assuming only local knowledge of degree for existing pages. A qualitatively similar phase transition is found between linkage and semantic distance, with an exponential decay tail. Both relationships suggest that efficient paths can be discovered by decentralized Web navigation algorithms based on textual and/or categorical cues. PMID:12381792

Growing and navigating the small world Web by local content

NASA Astrophysics Data System (ADS)

Menczer, Filippo

2002-10-01

Can we model the scale-free distribution of Web hypertext degree under realistic assumptions about the behavior of page authors? Can a Web crawler efficiently locate an unknown relevant page? These questions are receiving much attention due to their potential impact for understanding the structure of the Web and for building better search engines. Here I investigate the connection between the linkage and content topology of Web pages. The relationship between a text-induced distance metric and a link-based neighborhood probability distribution displays a phase transition between a region where linkage is not determined by content and one where linkage decays according to a power law. This relationship is used to propose a Web growth model that is shown to accurately predict the distribution of Web page degree, based on textual content and assuming only local knowledge of degree for existing pages. A qualitatively similar phase transition is found between linkage and semantic distance, with an exponential decay tail. Both relationships suggest that efficient paths can be discovered by decentralized Web navigation algorithms based on textual and/or categorical cues.

Growing and navigating the small world Web by local content.

PubMed

Menczer, Filippo

2002-10-29

Can we model the scale-free distribution of Web hypertext degree under realistic assumptions about the behavior of page authors? Can a Web crawler efficiently locate an unknown relevant page? These questions are receiving much attention due to their potential impact for understanding the structure of the Web and for building better search engines. Here I investigate the connection between the linkage and content topology of Web pages. The relationship between a text-induced distance metric and a link-based neighborhood probability distribution displays a phase transition between a region where linkage is not determined by content and one where linkage decays according to a power law. This relationship is used to propose a Web growth model that is shown to accurately predict the distribution of Web page degree, based on textual content and assuming only local knowledge of degree for existing pages. A qualitatively similar phase transition is found between linkage and semantic distance, with an exponential decay tail. Both relationships suggest that efficient paths can be discovered by decentralized Web navigation algorithms based on textual and/or categorical cues.